December 13, 2024
Carbon Nanofibers as Supporting Substrate for Growth of Polyaniline Nanorods on Fe2O3 Nanoneedles toward Electrochemical Energy Storage
Yuanhang Gu - ,
Junjie Ding - ,
Guang Hu - ,
Feng You - ,
Shaoyun Chen *- ,
Huabo Huang *- , and
Chenglong Hu *
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Iron-oxide (Fe2O3) nanoneedles were first in situ grown on the surface of carbon nanofibers (CNFs) using hydrothermal and N2 annealing process, and then polyaniline (PANI) was coated on the Fe2O3 nanoneedles to form network-like nanorods through dilute solution polymerization. The PANI/Fe2O3/CNFs binder-free electrode exhibited a high specific capacitance of 603 F/g at 1 A/g with good rate capability. (The capacitance loss was about 48.3% when the current density increased from 1.0 to 5.0 A/g.) It was caused by the fact that the PANI/Fe2O3/CNFs with a well-connected structure could provide a continuous electron transport path and improve the conductivity of the entire electrode. The solid-state hybrid PANI/Fe2O3/CNFs∥PANI/Fe2O3/CNFs symmetric device also achieved a high energy density of 29.85 Wh/kg at a power density of 500 W/kg. This universal compatible synthetic method for the PANI/Fe2O3/CNFs electrode could extend to other supercapacitor electrode systems, making it easy to fabricate various ternary electrodes for supercapacitors.
Production and Characterization of Silk Fibroin–Aloe vera Hydrogel: A Study on Extraction, Hydrogel Properties, and Release Mechanism
Camila Lopes Rodrigues - ,
Bruno Thorihara Tomoda - ,
Juliane Viganó - ,
Anna Rafaela Cavalcante Braga - ,
Mariana Agostini de Moraes - , and
Priscilla Carvalho Veggi *
This publication is Open Access under the license indicated. Learn More
This work investigated the production and characterization of a silk fibroin (SF) hydrogel incorporated with an Aloe vera (AV) extract. Four extraction methods, ultrasound-assisted extraction with bath and probe, stirring, and Soxhlet, were tested, while the hydrogel was produced by a one-step freeze–thaw method. Besides the extraction yield, the antioxidant capacity of the extracts was accessed, which allowed to select the extract obtained by ultrasound-assisted extraction to be incorporated into the hydrogels. Hydrogels were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Rheological assay, swelling behavior, and water uptake capacity were measured. The SF–AV hydrogel was submitted to release test, and the data were mathematically modeled. The hydrogels exhibited malleability, insolubility in water, interconnected pores, and thermal and physical stability. The SF–AV hydrogel released 37% extract over 330 min, with diffusion controlled by the Fickian mechanism. These promising results make the SF–AV hydrogel an attractive choice for wound dressing and other biomaterial-related applications.
Production of Cellulose Nanoparticles from Cashew Apple Bagasse by Sequential Enzymatic Hydrolysis with an Ultrasonic Process and Its Application in Biofilm Packaging
Layanne Guedes Silva de Araújo - ,
Tigressa Helena Soares Rodrigues - ,
Erick Rafael Dias Rates - ,
Luciana Magalhães Rebelo Alencar - ,
Morsyleide de Freitas Rosa - , and
Maria Valderez Ponte Rocha *
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Cellulose nanostructures obtained from lignocellulosic biomass via enzymatic processes may offer advantages in terms of material properties and processing sustainability. Thus, in this study, cellulose nanoparticles with a spherical morphology were produced through the enzymatic hydrolysis of cashew apple bagasse (CAB). CAB was previously subjected to alkaline and acid-alkali pretreatment, and the pretreated solids were labeled as CAB-PTA and CAB-PT-HA, respectively. The enzymatic hydrolysis was carried out using two different enzymatic loadings (7.5 and 12 FPU/gcellulose) of the Trichoderma reesei cellulase complex, and the formation of nanostructures occurred only at 7.5 FPU/gcellulose. The results indicated the production of nanocellulose using only CAB-PT-HA as the precursor, obtaining nanosphere structures with a yield of 65.1 ± 2.9% and a diameter range of 57.26–220.66 nm. The nanocellulose showed good thermal and colloidal stability and was subsequently used for biofilm production. Biofilms were prepared using different percentages of nanocellulose (5 and 7% w/v), and they showed a greater water retention capacity and higher biodegradability compared to the control film, indicating potential for application in food packaging and cosmetic masks. Thus, it highlights the potential for developing new biodegradable plastics incorporated with nanocellulose obtained from CAB through a more sustainable process.
December 12, 2024
Greener Synthesis of Poly(LIM-co-DVB-co-AMPS): A Sustainable Approach to Methylene Blue Removal
Aslı Erdem Yayayürük - ,
Nevin Çankaya - , and
Onur Yayayürük *
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A novel environmentally friendly adsorbent, poly(limonene-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propanesulfonic acid, LIM-co-DVB-co-AMPS), was synthesized and applied for the adsorption of methylene blue from aqueous solutions in this study. The structure, morphology, and thermal stability of the green adsorbent were determined by the FTIR, SEM, TGA/DTA/DTG, and BET techniques, ζ potential, and elemental analysis. The efficiency of the adsorption process was improved with respect to several experimental conditions, viz., adsorbent dose, pH, and contact time. The adsorption process was found to fit very well with the Langmuir isotherm and the pseudo-second-order model. Benefiting from the higher number of surface sites, porous structure, and good surface area, poly(LIM-co-DVB-co-AMPS) particles exhibited a superior adsorption performance for MB with a Langmuir adsorption capacity of 98 mg g–1. The selectivity of the sorbent does not depend on the coexisting ions, and the sorbent is applicable in complex matrixes in the presence of these ions. The elution process was employed using ethanol within a 1.0 M hydrochloric acid (HCl) medium, leading to a remarkable usability exceeding 90% even after five consecutive adsorption/desorption cycles. Spike recovery experiments conducted using real water samples substantiate the practical applicability of the adsorbent. The high efficiency, utilization of cost-effective materials, and ease of fabrication, coupled with their selective nature and lower environmental impact through sorbent reuse, collectively confer superior advantages. These distinctive features render the environmentally benign adsorbent highly applicable for promising applications in the removal of methylene blue from aqueous solutions.
Optimization of Green Extraction Techniques for Polyphenolics in Pinus brutia Bark Extract and Steam Gasification of the Remaining Fraction to Obtain Hydrogen-Rich Syngas and Activated Carbon
Ece Yildiz-Ozturk *- ,
Pelin Secim-Karakaya - ,
Fikret Muge Alptekin - , and
Melih Soner Celiktas *
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Utilization of renewable resources has become imperative, and considerable efforts have been devoted to tackling diverse global sustainability challenges, which contribute to the circular economy. The focus of this work was to optimize the extraction of polyphenolic compounds in Pinus brutia bark using microwave-assisted (MAE) and ultrasonically assisted (UAE) extractions and evaluate the biological efficacies of the extracts. Additionally, the residue of the extracted pine bark was subjected to steam gasification to produce hydrogen-rich syngas and activated carbon. The optimum process parameters for MAE were determined as 70 °C, 10 min, and 900 W, and 987.32 mg gallic acid equivalent (GAE), 23.7 mg quercetin/g extract, and 86.2% antioxidant activity were obtained. The optimum process parameters for UAE were determined as 70 °C, 20 min, and 50% power, and 811.84 mg gallic acid equivalent (GAE), 30.1 mg quercetin/g extract, and 90.8% antioxidant efficiency were obtained. The extracts obtained under optimized conditions were assessed for the bioactive phenolic compounds taxifolin, (−)-catechin, (−)-epicatechin, and (−)-epicatechin gallate by ultra performance liquid chromatography (UPLC). Especially in MAE (ethanol), taxifolin content was notable (34.0 mg/g extract), followed by UAE (ethanol) (23.5 mg/g extract). Compared to MAE (ethanol) and UAE (ethanol) with regards to catechin content, 1.05 mg/g extract and 0.81 mg/g extract were obtained, respectively. Catalytic and noncatalytic steam gasification of pine bark residue yielded 57.3 and 60.8 mol % H2, respectively. In addition, excellent tar reduction was achieved through utilizing a 10% boron-modified CaO alkali catalyst, and the obtained activated carbon exhibited 1358.32 m2/g Brunauer–Emmett–Teller (BET) surface area and 1.05 cm3/g total pore volume, which has potential use as an adsorbent for removing heavy metals and electrode material for supercapacitor application.
Maleation of Biodegradable Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by Reactive Extrusion: Effect of Initiator Concentration and a Chain Extender on Grafting Percentage and Thermal and Rheological Properties
Debarshi Nath - ,
Ehsan Pesaranhajiabbas - ,
Fatemeh Jahangiri - ,
Aarsha Surendren - ,
Akhilesh Kumar Pal - ,
Arturo Rodriguez-Uribe - ,
Manjusri Misra *- , and
Amar K. Mohanty *
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Recently, there has been immense interest in using biodegradable polymers to replace petro-derived polymers. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), which is gaining popularity due to its biodegradability, is used in developing blends and composites for a variety of applications. To enhance the miscibility between different components of a material with PHBV, functionalization of the PHBV chain can be done. In this study, grafting of maleic anhydride (MA) onto PHBV was performed using organic peroxide also, called Luperox [2,5-dimethyl-2,5-di(tert-butylperoxy)hexane], as an initiator. The effects of different initiator and MA concentrations on the grafting percentage, gel content, rheology, and thermal properties were evaluated. Additionally, a chain extender (Joncryl ADR 4468) was added during the grafting process to prevent chain scission of PHBV during processing and to promote long-chain branching. Higher initiator concentrations played a significant role in increasing the grafting percentage. Adding the chain extender further enhanced the grafting percentage of the compatibilizers. Compatibilizers with chain extenders increased the grafting percentage by up to 91% compared with their counterparts without chain extenders. Differential scanning calorimetry analysis demonstrated that the melting temperature of the compatibilizers decreased by up to 8 °C with increasing initiator concentration. Furthermore, the thermal stability of maleic anhydride grafted PHBV (MA-g-PHBV) reduced at higher initiator content, likely attributed to the formation of low-molecular-weight species during processing. The maleated PHBV with a chain extender exhibited improved thermal stability, with an increase of up to 6 °C, attributed to an increase in molecular weight because of the chain extender. This can be corroborated by the rheological studies, which showed higher viscosity, particularly for MA-g-PHBV with chain extender. Therefore, this is the first ever scientific study to improve and analyze the grafting percentage of MA-g-PHBV using a combination of chain extender and varying initiator concentrations. This maleated PHBV with a higher grafting percentage will then facilitate the development of composites and blends with improved performance, even at low MA-g-PHBV concentrations.
Comprehensive Review of CO2 Adsorption on Shale Formations: Exploring Widely Adopted Isothermal Models and Calculation Techniques
Zaheer Hussain Zardari *- ,
Dzeti Farhah Mohshim - ,
Mohammad Sarmadivaleh - ,
Muhammad Aslam Md Yusof - , and
Adnan Aftab
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The continuous use of fossil fuels has a huge impact on climate change because they release CO2, which is a major greenhouse gas that causes 70–75% of global warming. Shale reserves could be used to store CO2 to lower greenhouse gas emissions. This could happen mostly through adsorbed gas, which can make up about 85% of all shale gas. It is important to fully understand the CO2 adsorption processes in shale, especially when using isothermal models, to get accurate estimates of storage capacity and predictions of how shale will behave. This work examines the application of several isothermal models, including Langmuir, Freundlich, Brunauer–Emmett–Teller, Dubinin–Radushkevich, Dubinin–Astakhov, Sips, Toth, and Ono-Kondo lattice models, to explore the adsorption of CO2 on shale formations. The aim of this research work is to assess the efficiency of these models in forecasting CO2 adsorption in different shale samples with specific mineral compositions, total organic content (TOC), surface areas, and pore geometry at 298 K and up to 2 MPa. This review provides a state-of-the-art knowledge on the constraints of existing models and proposes adaptations, such as integrating density-dependent correction factors and hybrid modeling techniques, to enhance precision during numerical simulation work. Furthermore, the possible incorporation of molecular dynamic (MD) simulations with experimental data is suggested to improve the understanding of the CO2 adsorption in the geological rock at the molecular scale. The results emphasize the need for future studies to concentrate on the improvement of models and empirical validation to more accurately forecast the storage behavior of CO2 in shale formations at resevoir conditions.
Sugar Cane (Saccharum officinarum L.) Waste Synthesized Si,N,S-Carbon Quantum Dots as High-Performance Corrosion Inhibitors for Mild Steel in Hydrochloric Acid
Rayani da Silva Nunes - ,
Victor Magno Paiva *- ,
Sanair Massafra de Oliveira - ,
Clara Muniz da Silva de Almeida - ,
Mariane Silva de Oliveira - ,
Joyce Rodrigues de Araujo - ,
Bráulio Soares Archanjo - ,
Natasha Midori Suguihiro - , and
Eliane D’Elia *
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This work reports the obtention of Si,N,S-CQDs from sugar cane bagasse and their inhibitory action on the mild steel corrosion in 1 mol L–1 HCl solution. The CQDs were successfully obtained and characterized by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, Dynamic light scattering, Raman, and UV–vis techniques, also showing endogenous self-doping. The anti-corrosive activity of CQDs was investigated by gravimetric tests, potentiodynamic polarization curves, electrochemical impedance measurements, atomic force microscopy, and scanning electron microscopy. The electrochemical results show that the CQDs present a predominant inhibitory action on the cathodic process, presenting inhibition efficiency of 82, 89, 91, and 94% for 15, 25, 50, and 100 ppm, respectively. Gravimetric tests varying temperature demonstrate that the inhibitor functions through physical adsorption and remains effective for up to 72 h, exhibiting corrosion efficiency of 80.2, 93.2, 96.3, and 97.8% at 15, 25, 50, and 100 ppm concentrations, respectively, after 72 h of immersion. Dynamic light scattering and zeta potential measurements indicate that agglomerations of CQDs play a crucial role in inhibiting corrosion. These results show an excellent alternative for using sugar cane bagasse to produce CQDs and its application as a corrosion inhibitor, valuing agricultural waste and simultaneously solving industry problems.
Two-Step Esterification Process of Palm Fatty Acid Distillate Using Soaking Coupled with Ultrasound: Process Optimization and Reusable Solid Acid Catalysts
Jarernporn Thawornprasert - and
Krit Somnuk *
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In this study, high-intensity ultrasound (1000 W ultrasonic power and 18 kHz frequency) was employed in conjunction with heterogeneous acid catalysts to reduce the free fatty acid (FFA) content in palm fatty acid distillate (PFAD). The aim was to convert the FFAs in PFAD to methyl esters (MEs) through an esterification process. The use of Amberlyst-15 as a heterogeneous acid catalyst offers environmental advantages over homogeneous catalysts and the potential for reuse in the biodiesel production process. The ME purity in the esterified oil was optimized by varying four independent variables: methanol content (25–65 wt %), Amberlyst-15 loading (20–60 wt %), soaking time (30–130 min), and sonication time (30–630 s). Furthermore, the efficiency of reused solid acid catalysts in reducing FFA over multiple cycles was investigated. The results indicated that under optimal conditions of 36.73 wt % methanol content, 60 wt % Amberlyst-15 loading, 130 min soaking time, and 505 s sonication time at a reaction temperature of 60 °C, the ME purity reached 89.44 wt %. Moreover, the potential of the recovered solid catalyst to reduce FFA in fresh PFAD under optimal conditions was examined. It was found that recovered Amberlyst-15 could be reused for at least two cycles with ultrasound to achieve an ME purity of over 80 wt %.
Delafloxacin-Loaded Poly(d,l-lactide-co-glycolide) Nanoparticles for Topical Ocular Use: In Vitro Characterization and Antimicrobial Activity
Abdullah K. Alshememry - ,
Mohd Abul Kalam - ,
Mudassar Shahid - ,
Raisuddin Ali - ,
Sulaiman S. Alhudaithi - ,
Nada A. Alshumaimeri - ,
Ziyad A. BinHudhud - ,
Abdulrazzaq A. Aldaham - ,
Ziyad Binkhathlan - , and
Aliyah A. Almomen *
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Objective: We developed delafloxacin (Dela)-loaded PLGA nanoparticles (PNPs) for potential ocular application via a topical route to treat eye infections caused by Gram-positive and Gram-negative bacteria. Methodology: Dela-PNPs were formulated using the emulsification-solvent evaporation method and stabilized using poly(vinyl alcohol) (PVA). Size and morphology were characterized by using dynamic light scattering (DLS) and scanning electron microscopy (SEM). Drug loading and encapsulation efficiency were measured via HPLC. Differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FTIR) assessed the physical state and drug–polymer interaction. The in vitro drug release was evaluated using the dialysis bag method in simulated tear fluid (STF, pH 7.4) with Tween 80 (0.5%). The antimicrobial efficacy was determined by a minimum inhibitory concentration (MIC) and zone of inhibition tests against various bacteria. Results: Optimally sized PNPs were produced (238.9 ± 10.2 nm) with a PDI of 0.258 ± 0.084 and a ζ-potential of 2.78 ± 0.34 mV. Using 40 mg of PLGA, 4 mg of Dela, and 1% PVA, drug encapsulation and loading were 84.6 ± 7.3 and 12.9 ± 1.7%, respectively. DSC indicated that Dela was entrapped in an amorphous state within the PNPs. FTIR spectra showed no drug–polymer interactions. The formulation showed 40.6 ± 4.2% drug release within 24 h and 84.4 ± 6.1% by 96 h. MIC tests showed high susceptibility of Streptococcus pneumoniae, Klebsiella pneumoniae, and Escherichia coli (∼0.31 μg/mL) compared to Staphylococcus aureus and MRSA-6538 (∼0.63 μg/mL) and Bacillus subtilis (2.5 μg/mL). Stability studies showed minimal changes in particle characteristics over 3- and 6-month storage at 25 and 37 °C. Conclusion: Dela-PNPs exhibit significant potential as a nanoformulation for ocular applications.
Novel, Rapid, and Simple Isocratic UPLC-UV Method for Estimating Nitrate and Nitrite Contents in Environmental Water Samples Using an Analytical Quality by Design Approach
Pradeep Kumar Gollapudi *- ,
Kranthi Kumar Gollapudi - , and
Dr Nimmagadda Padmaja
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In this study, we reported a novel reverse-phase UPLC method for the simultaneous estimation of nitrite and nitrate ions using a Quality by Design (QbD) approach. Nitrite and nitrate ions were separated on an ACQUITY CSH Fluoro-Phenyl column (100 × 2.1 mm, 1.7 μm) in isocratic mode with a mobile phase composition of solvent A and solvent B in a ratio of 980:20 v/v. Solvent A consisted of 100% Milli-Q water, while solvent B comprised 0.5 mL of formic acid in 1000 mL of methanol. The column temperature was maintained at 40 °C, and the flow rate was 0.6 mL/min. Detection was carried out at 214 nm with an injection volume of 5.0 μL. The method was developed and validated in accordance with ICH Q2 (R2) guidelines Validation parameters, including system suitability, sensitivity, precision, linearity, and accuracy, were within acceptable ranges. These findings suggest that the developed RP-UPLC method is highly sensitive and suitable for the estimation of nitrite and nitrate ions in various environmental water samples.
Use of Luminescence Modulation in a New Series of Mixed Lanthanide Metal–Organic Frameworks for Selective Firearm Ammunition Marking
Júlia P. De Oliveira Silva - ,
Marcos V. Colaço - ,
Alexandre de Resende Camara - ,
Renato de Almeida Pereira - ,
Eduardo de Oliveira Fernandes - ,
Claudiane Costa Canuto - ,
Diego Rissi Carvalhosa - , and
Lippy Faria Marques *
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Metal–organic frameworks (MOFs) are coordination polymers that can generally be described by secondary building units (SBUs). These include lanthanide MOFs, specifically mixed lanthanide MOFs (m-LnMOFs), encompassing coordination polymers formed by two or more different Ln3+ ions. These compounds have been the subject of study by inorganic chemists worldwide, mainly due to the possibility of obtaining long-awaited tunable luminescence, i.e., compounds that emit luminescence in various visible spectrum regions. A wide range of emission color scan be obtained by inserting different Eu3+, Tb3+, and Gd3+ ion molar fractions in m-LnMOFs, which can also be adjusted by choosing the Ln3+ ion or its amount in each network. This study presents a new series of m-LnMOFs supported by 1,2,4,5-benzenetetracarboxylic acid (H4btec). These compounds were completely characterized in their solid state through different analytical and spectroscopic techniques, and an in-depth photophysical study was conducted. Due to their high thermal stability and multicolored emissions, these complexes were applied, for the first time, as selective ammunition markers, allowing for the unequivocal identification of the type of weapon used in forensic scenarios and the promotion of stricter ammunition trade control.
Exploring p-Type Contact for Monolayer WS2 FETs Using Halogen Doping and Intermediate Layers
D Sharda Devi *- and
Nihar R. Mohapatra *
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This work presents a density functional theory (DFT) study of substitutional and adsorption-based halogen (I or F) doping of WS2-based transistors to enhance their contact properties. Substitutional doping of the WS2 monolayer with halogens results in n-type behavior, while halogen adsorption on the surface of the WS2 monolayer induces p-type behavior. This is attributed to differing directions of charge flow, as supported by the Mulliken analysis. However, due to Fermi-level pinning (FLP) at the WS2-metal interface, the p-type behavior resulting from halogen adsorption is not very prominent. To achieve better p-type contact, intermediate layers of graphene and h-BN are used to mitigate the FLP effect, showing significant improvement. The F-adsorbed WS2-graphene-Pt interface demonstrates excellent p-type contact with a substantial reduction in the hole Schottky barrier height, making it ideal for efficient WS2-based p-type MOS transistors in CMOS technology.
Amended Ferrozine Assay for Quantifying Magnetosome Iron Content in Magnetotactic Bacteria.
Ya-Chun Zhao - ,
Li-Fen Wu - , and
Siang Chen Wu *
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Magnetospirillum gryphiswaldense MSR-1 can biomineralize the magnetosome, nanoscale magnetite (Fe3O4) surrounded by a lipid bilayer, inside the cell. The magnetosome chain(s) enables MSR-1 to move along with the magnetic field (magnetoaerotaxis). Due to its unique characteristics, MSR-1 has attracted attention for biotechnological applications. During cultivation, not only the optical density but also the magnetosome content in MSR-1 should be monitored. The ferrozine assay had been utilized to quantify the iron content in magnetosomes. However, the effectiveness of the ferrozine assay on iron oxide nanoparticles is still unknown. Here, we examined the experimental factors, and the amended ferrozine assay demonstrates a recovery of 88.71% for Fe2O3 nanoparticles relative to the stock solution. Next, we apply the assay to analyze MSR-1 samples, which successfully reveals the difference in iron contents between magnetic and nonmagnetic MSR-1 samples and highlights the amount of MSR-1 cell density suitable for amended ferrozine assay. The assay further helps us examine the effects of centrifugation compared to magnetic separation (MS). The detection of residual magnetosomes in the supernatant indicates that MS remains a suitable method for collecting magnetosomes. We anticipate the amended ferrozine assay will facilitate research on MSR-1 by enabling investigators to measure iron content in cells in a fast, easy, and cost-effective manner.
Streamlined Vitamin D Metabolite Fingerprinting Analysis Using Isotope-Coded Multiplexing MS with Cost-Effective One-Pot Double Derivatization
Pascal Schorr - ,
Caroline S Stokes - , and
Dietrich A Volmer *
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In this study, we extended a previously developed one-pot double derivatization reaction to establish the first routine isotope-coded multiplex derivatization for vitamin D and its metabolites for application in clinical environments, using commercial reagents, without the need for specialized reagents and advanced synthesis requirements. The original derivatization process consisted of using both a Cookson-type reagent and derivatization of hydroxyl groups. Initially, the analytes are derivatized by a Diels–Alder reaction using 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), followed by acetylation using acetic anhydride, catalyzed by 4-dimethylaminopyridine at room temperature. To enable sample multiplexing, we utilized acetic anhydride as well as the d3- isotopologue of acetic anhydride, generating d3- and d6-products of the investigated vitamin D3 metabolites. This approach not only allowed for the simultaneous measurement of two samples within a single LC-MS/MS run but also improved the LC separation of the important 25-hydroxyvitamin D3 epimers (3α-25(OH)D3 and 3β-25(OH)D3) on a conventional C-18 column, addressing a significant challenge in vitamin D analysis. Typically, the separation of these epimers after PTAD derivatization cannot be performed on C-18 columns, necessitating the use of pentafluorophenylpropyl (PFP) stationary phases. However, PFP columns are not as stable as C-18 in long-term use, wherein the acetylation of the C-3 hydroxyl group provided a solution by enhancing chromatographic selectivity and achieving the baseline separation of the metabolites 24,25(OH)2D3, 3α-25(OH)D3, 3β-25(OH)D3, and vitamin D3 using a C-18 column with methanol/water gradient elution. The described duplex derivatization was tested on 40 serum samples of patients with chronic liver diseases (CLD). Additionally, the method was evaluated in terms of linearity, accuracy, precision, and interferences between heavy and light tag samples using both commercial quality control samples and in-house quality control and calibration samples.
Analysis of an Unsaturated Seepage Mechanism in Coal Seam Water Injection
Wan Jiang *- ,
Zhenhua Li - ,
Jianping Wei - ,
Leilei Si - , and
Yang Su
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The wetting process of coal seam water injection is a typical unsaturated flow, but the steady-state method for measuring liquid permeability cannot reflect the unsaturated flow process of water in coal. The principle of wetting and expanding process of liquid in coal medium is very complex, and the multiscale pore characteristics of coal make the liquid permeability show multiscale characteristics. Therefore, liquid-phase triaxial seepage experiments under different working conditions are carried out, and a one-way multiscale dynamic apparent permeability coefficient model D(t) = D0 exp(−βt) is established to analyze the influence of pressure, liquid wettability, and pore structure on the unsaturated wetting process of coal seam water injection. The results show that the apparent permeability coefficient of liquid phase decreases gradually with time due to the multiscale pore characteristics of coal. The dynamic apparent permeability coefficient model can well describe the unsaturated seepage process of liquid in coal, which is helpful to characterize the liquid permeability of low permeability coal seam. The water injection pressure has a great influence on the attenuation coefficient of apparent permeability coefficient, and the higher the water pressure is, the smaller the attenuation coefficient is. The surfactant increases the permeability coefficient by enhancing the capillary wetting, while the capillary force, as an internal factor, has less influence on the model attenuation coefficient than the water pressure.
Progressive Evolution of Flow and Heat Transfer Channels in Hot Dry Rock Stimulated by Liquid Nitrogen Cold Shock
Yong Sun *- ,
Long Feng - ,
Hongrui Xu - ,
Cheng Zhai - ,
Wei Tang - ,
Yuzhou Cong - ,
Xu Yu - , and
Jizhao Xu
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Hot dry rock (HDR) is a novel green, low-carbon energy. Its development requires the creation of fracture channels in deep thermal reservoirs. Traditional methods such as hydraulic fracturing have limited effectiveness in reservoir stimulation, so a method of liquid nitrogen cold shock was proposed. The ultralow temperature of liquid nitrogen induces a quenching effect on hot rock, thereby promoting the formation of a complex fracture network. In this study, hot rocks at different temperatures were subjected to cyclic liquid nitrogen cold shocks. The cascading evolution of the “temperature field-thermal stress-pore fracture development-three-dimensional seepage network” was analyzed. The main conclusions are as follows: As the cold-shock duration increased, the core temperature decreased exponentially, with a slower cooling rate at the center and a faster rate at the edges. Additionally, local temperature fluctuations existed at the edges. The maximum radial thermal stress at 200–600 °C ranged from 2.57 to 9.29 MPa. The initial cold shock and temperatures above 300 °C contributed the most to the reduction in wave velocity, with maximum decreases of 70.25 and 55%, respectively. The more developed the pores and fractures within the damaged core, the more pronounced the arrival time lag, frequency shift, and energy attenuation will be. Microscopic pore evolution followed two patterns. At 200–300 °C, the first peak increased significantly, with a few new micropores forming along grain boundaries. At 400–600 °C, the second peak grew and expanded to be dominant. Numerous mesopores formed both along grain boundaries and within grain interiors, interconnecting with the original pores. As the temperature shock effect intensified, the fracture increased and expanded. Branch fractures developed from the main fractures, ultimately forming a fracture network. The orientations of these fractures became more randomly distributed. What’s more, the proportion of larger-sized and higher-connectivity pores increased. The flow velocity and flow rate increased significantly, with the maximum values in the representative elementary volume reaching 0.167 m/s and 1.75 × 10–7 m3/s, respectively. When HDR underwent liquid nitrogen cold shock, the mineral grains contracted. Due to the various thermal expansion coefficients of different types of grains, local stress was concentrated. When the stress exceeded the tensile strength, tensile fractures were induced. The cyclic shock effect not only intensified the stress concentration but also lowered the damage threshold of the grains. The convergence of these two factors led to the continuous development of pore-fracture channels in the HDR.
“Alkyl-Substituted Phenoxy” Spacer Strategy: Antiaggregated and Highly Soluble Zinc Phthalocyanines for Color Films
Shi Li - ,
Yong Qi - ,
Jiahui Wang - ,
Wenbin Niu - ,
Wei Ma - ,
Bingtao Tang - , and
Shufen Zhang *
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A series of zinc phthalocyanine derivatives (ZnPcs) were designed by introducing different volumes of steric hindrance groups (chlorine atom, n-propyloxy, isopropyloxy, n-butoxy, isobutoxy, tert-butoxy, 2,4-di-tert-butylphenoxy, 2,4-di-tert-pentylphenoxy) on the peripheral and nonperipheral positions of phthalocyanine. Density functional theory (DFT) calculations presented that the substitution of sterically hindered 2,4-di-tert-butylphenoxy or 2,4-di-tert-pentylphenoxy on the peripheral positions effectively reduced the aggregation of ZnPcs, improving the solubility of ZnPcs, and the simultaneous substitution on the peripheral and nonperipheral positions could achieve ZnPcs with different colors. From the calculation results, six low-aggregation ZnPcs were synthesized for the first time. The solubilities of the synthesized ZnPcs are above 6.0/100 g. Furthermore, their color films displayed excellent transmittance because of the introduction of sterically hindered 2,4-di-tert-butoxyphenoxy or 2,4-di-tert-pentylphenoxy moieties. Also, the color films exhibit great photo and thermal stability (ΔE < 3).
In Silico Study of the Anti-MYC Potential of Lanostane-Type Triterpenes
José A. C. Oliveira - ,
Jonatas M. Negreiro - ,
Fátima M. Nunes - ,
Francisco G. Barbosa - ,
Jair Mafezoli - ,
Marcos C. Mattos - ,
Maria C. R. Fernandes - ,
Claudia Pessoa - ,
Cristiana L. M. Furtado - ,
Geancarlo Zanatta *- , and
Maria C. F. Oliveira *
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One of the most investigated molecular targets for anticancer therapy is the proto-oncogene MYC, which is amplified and thus overexpressed in many types of cancer. Due to its structural characteristics, developing inhibitors for the target has proven to be challenging. In this study, the anti-MYC potential of lanostane-type triterpenes was investigated for the first time, using computational approaches that involved ensemble docking, prediction of structural properties and pharmacokinetic parameters, molecular dynamics (MD), and binding energy calculation using the molecular mechanics-generalized born surface area (MM-GBSA) method. The analysis of physicochemical properties, druglikeness, and pharmacokinetic parameters showed that ligands ganoderic acid E (I), ganoderlactone D (II), ganoderic acid Y (III), ganoderic acid Df (IV), lucidenic acid F (V), ganoderic acid XL4 (VI), mariesiic acid A (VII), and phellinol E (VIII) presented properties within the filter used. These eight ligands, in general, could interact with the molecular target favorably, with interaction energy values between −8.3 and −8.6 kcal mol–1. In MD, the results of RMSD, RMSF, radius of gyration, and hydrogen bonds of the complexes revealed that ligands I, IV, VI, and VII interacted satisfactorily with the protein during the simulations and assisted in its conformational and energetic stabilization. The binding energy calculation using the MM-GBSA method showed better results for the MYC-VII and MYC-I complexes (−44.98 and −41.96 kcal mol–1, respectively). These results support the hypothesis that such molecules can interact with MYC for a considerable period, which would be an essential condition for them to exert their inhibitory activity effectively.
December 11, 2024
Factors Influencing the Vertical Migration of Microplastics up and down the Soil Profile
Han Luo - ,
Lei Chang - ,
Tianhang Ju - , and
Yuefen Li *
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Soil ecosystems are under serious threat from microplastics (MPs), and this is causing worldwide concern. The relationship between soil and MPs has become a popular research topic, and the vertical migration of soil MPs is of increasing interest. This Review summarizes the current status of research into the factors affecting the vertical migration of soil MPs. Published research shows that the characteristics of MPs and the physicochemical properties of the soil affect the infiltration process. Soil organisms play a key role in the vertical migration by acting as vectors or as a result of adsorption. Dissolved organic matter and metal oxides transfer MPs by adsorption–desorption. In addition, rainfall and dry–wet cycles alter the mobility of soil MPs, leading to changes in migration processes. Agricultural activities such as tillage and irrigation may distribute MPs throughout the topsoil. Vertical migration of soil MPs is a process influenced by a combination of factors, and the role of these factors in MP deposition needs to be explored further.
Mechanism of Optical and Electrical H2S Gas Sensing of Pristine and Surface Functionalized ZnO Nanowires
Angelika Kaiser *- ,
Tanja Mauritz - ,
Joachim Bansmann - ,
Johannes Biskupek - ,
Ulrich Herr - , and
Klaus Thonke
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In this work, the sensing ability and the underlying reaction pathways of H2S adsorption on two nanomaterial systems, pristine zinc oxide (ZnO) nanowires (NWs) and gold functionalized zinc oxide nanowires (Au@ZnO NWs), were explored in a side-by-side comparison of optical and electrical gas sensing. The properties of optical sensing were analyzed by photoluminescence intensity-over-time measurements (PL-t) of as-grown ZnO NW samples, and the electrical gas-sensing properties were analyzed by current-over-time measurements (I-t) of ZnO NW chemically sensitive field-effect transistor (ChemFET) structures with a gas-sensitive open gate. The ZnO NWs were grown by high-temperature chemical vapor deposition (CVD) and thereafter surface-functionalized with a thin Au nanoparticle layer by magnetron sputtering. Detailed X-ray photoelectron spectroscopy (XPS) analysis, alongside an experimental estimation of activation energies (EA) involved in the H2S sensing process, and the application of a simple analytical test allowed us to propose a complete picture of the sensing mechanism on the pristine ZnO surface and the Au@ZnO surface. The combined results hint at H2S dissociation via surface interaction and irreversible adsorption dynamics for both material systems occurring already at room temperature. Our findings specifically emphasize the impact of Au functionalization morphology on sensor sensitivity and the beneficial importance of chemical affinity between Au and H2S for superior H2S sensing results, aiming at enhanced response and selectivity for potential medical H2S detection in human breath.
Exploring the Electronic and Mechanical Properties of TPDH Nanotube: Insights from Ab Initio and Classical Molecular Dynamics Simulations
Juan Gomez Quispe - ,
Douglas Soares Galvao - , and
Pedro Alves da Silva Autreto *
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Tetra–Penta–Deca–Hexa graphene (TPDH) is a new two-dimensional (2D) carbon allotrope with attractive electronic and mechanical properties. It is composed of tetragonal, pentagonal, decagonal and hexagonal carbon rings. When TPDH graphene is sliced into quasi-one-dimensional (1D) structures such as nanoribbons, it exhibits a range of behaviors, from semimetallic to semiconducting. An alternative approach to achieving these desirable electronic properties (electronic confinement and nonzero electronic band gap) is the creation of nanotubes (TPDH-NTs). In the present work, we carried out a comprehensive study of TPDH-NTs combining Density Functional Theory (DFT) and classical reactive Molecular Dynamics (MD). Our results show structural stability and a chiral dependence on the mechanical properties. Similarly to standard carbon nanotubes, TPDH-NT can be metallic or semiconductor. MD results show Young’s modulus values exceeding 700 GPa, except for nanotubes with very small radii. However, certain chiral TPDH-NTs (n, m) display values both below and above 700 GPa, particularly for those with small radii. Analysis of the evolution of von Mises stress and the distribution of C–C bond angles and lengths throughout the stress–strain process indicates the important role of tetragonal, pentagonal, and hexagonal rings for the mechanical response of TPDH-NTs. Tetragonal and pentagonal rings provide a rigid mechanical framework for TPDH-NTs (n, 0), whereas pentagonal and hexagonal rings provide TPDH-NTs (0, n) with greater flexibility.
Developing Gingerol-Based Analogs against Pseudomonas aeruginosa Infections
Taehyeong Lim - ,
Soyoung Ham - ,
Han-Shin Kim - ,
Ji-Eun Yang - ,
Hyunwoong Lim - ,
Hee-Deung Park *- , and
Youngjoo Byun *
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Pseudomonas aeruginosa (P. aeruginosa), a Gram-negative opportunistic pathogen, produces virulent factors and forms biofilms through a quorum sensing (QS) mechanism. Modulating QS networks is considered an effective strategy for treating P. aeruginosa infections. Particularly, the rhl system, one of the QS networks, can be a potential target in treating patients with chronic infections. We previously discovered that gingerol acts as a RhlR antagonist of P. aeruginosa. Based on the chemical structure of gingerol, we have designed and synthesized gingerol derivatives by introducing various functional groups in the middle and tail regions. A comprehensive structure–activity relationship study showed that compound 5a substituted with phenyl group in the tail region was the most potent in various biological assessments, such as RhlR binding affinity, rhl gene expression, and virulence factor production of P. aeruginosa. Furthermore, compound 5a decreased the biofilm formation and pathogenicity of P. aeruginosa. Interestingly, compound 5a also influenced las system in addition to the rhl system. Taken together, compound 5a can be utilized as a potent compound for controlling P. aeruginosa infection.
Physicochemical Properties of Carbon Fiber Formulated from Melt-Spun Raw Asphaltene
Shahrad Khodaei Booran - ,
Jiawei Chen - ,
Md Minhajul Islam - ,
Idaresit Ekaette - ,
TriDung Ngo - ,
Mark McDermott - ,
Tian Tang - , and
Cagri Ayranci *
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One of the challenges in carbon fiber production centers around the high cost of raw materials required for fiber precursors or complex production processes involving multiple steps. This research paper delves into the utilization of asphaltene sourced from Alberta oil sands as an alternative precursor material that is low cost for carbon fiber production. We investigated the carbon fiber production process using a blend of different asphaltene types via melt-spinning technology. Carbon fibers produced from asphaltene-based precursors exhibit an average diameter of 12.66 ± 3.06 μm, an ultimate tensile strength (UTS) of 524.07 ± 218.53 MPa, an elastic modulus of 34.68 ± 15.61 GPa, and a strain at the UTS of 2.48 ± 0.97%. The results validate the viability of asphaltene as a precursor fiber and highlight the potential of carbon fibers.
Water-Resistant Poly(vinyl alcohol)/ZnO Nanopillar Composite Films for Antibacterial Packaging
Yuanjian Xie - ,
Pingxiong Cai *- ,
Xiaofeng Cao - ,
Bo Chen - , and
Yuanfeng Pan *
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To solve the problems that poly(vinyl alcohol) (PVA) easily breeds bacteria and swells in a humid environment, PVA and ZnO nanopillar (ZnO NP) components were composed to generate PVA/ZnO NP composite films via a simple combination process of blending and heat treatment in this study. Here, ZnO NPs endowed composite films with good antibacterial properties, and the etherification and dehydration of hydroxyl groups between PVA molecular chains induced by heat treatment resulted in the composite films having excellent water-swelling resistance. Most importantly, PVA/ZnO NP composite films revealed excellent tensile strength in both humid (52.85 MPa) and dry (74.63 MPa) environments. In addition, PVA/ZnO NP composite films showed good antibacterial and antisepsis abilities as well as preservation functions in the packaging test of half-cut apples. The current work disclosed an easy strategy for producing a PVA-based antibacterial film for packaging materials that are water-resistant and highly strong, making them suitable for applications in humid environments.
Hierarchically Porous Anatase Nanoparticles Derived from One-Dimensional Lepidocrocite Titanate for Bisphenol-A Photodegradation
Treesa Reji - ,
Adam D. Walter - ,
Yasunori Hioki - ,
Tracey Curran - ,
Mary Qin Hassig - ,
Hussein O. Badr - ,
Gregory R. Schwenk - ,
Takeshi Torita - ,
Megan A. Creighton - , and
Michel W. Barsoum *
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Herein, we discuss the conversion of one-dimensional lepidocrocite (1DL) titanate nanofilaments to anatase. Upon heating at temperatures >400 °C, the hierarchical 1DLs porous mesostructured particles transform to anatase, while retaining their morphology. These assemblies are characterized via X-ray diffraction, scanning and transmission electron microscopy, Fourier transform infrared spectroscopy, and solid-state ultraviolet absorbance. The assemblies were tested in the photodegradation of a water-soluble, endocrine-disrupting organic compound, bisphenol A (BPA). Using ultraviolet–visible spectroscopy, we show that 95% of BPA is degraded in 1 h under 1 sun of the simulated solar spectrum. Under the same conditions, the total organic carbon of the solution was reduced by 70%.
Effect of Variations of Amine Content and Network Branching on Thermomechanical Properties of Epoxy Systems
Michael Robert Kelly *- ,
Arpenik Kroyan - ,
Ingrid Hallsteinsen - ,
Sondre Kvalvåg Schnell - , and
Hilde Lea Lein
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In thermosetting epoxies, thermomechanical properties can be enhanced by conscious selection of curing agents. Full cross-linking leads to a maximum in the glass- transition temperature. However, the relation between the glass transition temperature and the epoxy matrix depends on several factors beyond the cross-linking degree, such as the molecular weight of the polymers, network organization, amount of branching, and the presence of hydrogen bonds. In this study, we investigated adding non- stoichiometric ratios of the epoxy resin Epikote 828 and the curing agent Jeffamine D230. The investigations were done through a combination of molecular dynamics simulations and experiments, primarily differential scanning calorimetry and nanoindentation. Reorganization of the network to fewer clusters with a higher degree of linearity overcomes the effect of cross-linking and leads to a reduction of glass-transition temperature with increasing concentrations of curing agent to epoxy. The elastic, shear, and compressive moduli remained constant. Hence, moderating the curing agent con- tent has the potential to improve thermal properties while maintaining mechanical properties for this epoxy system.
In Situ Polymerization Electrospinning of Amine–Epoxy/Poly(vinyl alcohol) Nanofiber Webs for Direct CO2 Capture from the Air
Chisato Okada *- ,
Zongzi Hou - ,
Hiroaki Imoto - ,
Kensuke Naka - ,
Takeshi Kikutani - , and
Midori Takasaki
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To achieve carbon neutrality by 2050, there is a growing need to actively capture carbon dioxide (CO2) from the atmosphere. As a method to capture CO2 directly from the atmosphere, direct air capture (DAC) is attracting attention and amine-based compounds have been extensively studied as CO2 adsorbents. In this research, we developed thermosetting DAC nanofibers with excellent low-temperature desorption properties and good heat resistance by polymerizing an amine with epoxy. For the fabrication of epoxy-cross-linked amine nanofibers through the electrospinning process, poly(vinyl alcohol) (PVA) was added for the improvement of spinnability, and the direct spin-line heating was conducted for the in situ thermal polymerization. As a result, nanofiber webs with fiber diameters of approximately 300–400 nm were fabricated successfully. The investigation of the CO2 adsorption and desorption performance of the obtained amine/epoxy/PVA (AE/PVA) nanofiber webs verified the high adsorption amount of 1.8 mmol/g at a CO2 concentration of 400 ppm. Additionally, 93% of adsorbed CO2 could be desorbed at a low temperature of 65 °C. These results suggested the possibility of low-energy-consumption CO2 recovery. By improving the adsorption rate and by making desorption possible at low temperatures, the adsorption/desorption cycle can be repeated more quickly, increasing the amount of CO2 that can be recovered in a day. The prepared webs also exhibited an excellent adsorption retention ratio of 75% after 100 h of operation at 85 °C, while general amine-filled mesoporous silica usually shows a retention ratio of only 13%. In addition, FT-IR, DSC, and elemental analysis of amine/epoxy/PVA nanofibers were carried out to analyze the reaction mechanism during fiber production. It was revealed that PVA was not involved in the reaction, and as in the bulk state, almost all primary amines were converted to secondary amines due to the in situ polymerization of amines and epoxy to form nanofibers.
Phloroglucinol-Based Antimicrobial Shape-Memory Photopolymers for Microimprint Lithography
Ausrine Pabricaite - ,
Vilte Sereikaite - ,
Aukse Navaruckiene - ,
Vita Raudoniene - ,
Danguole Bridziuviene - , and
Jolita Ostrauskaite *
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In this study, for the first time, biobased photopolymers were synthesized from phloroglucinol tris epoxy with and without different comonomers, phloroglucinol, 1,4:3,6-dianhydro-D-sorbitol, and 1,4-cyclohexanedimethanol. The rheological, thermal, mechanical, shape-memory, and antimicrobial properties of photopolymers were investigated. The addition of comonomers reduced the photocuring rate (gel time increased from 325 s to 434–861 s) and rigidity (storage modulus decreased from 330.76 to 15.42–85.77 MPa), reduced their brittleness, and increased the flexibility (elongation at break increased from 0.9 to 1.89–4.51%), although the tensile strength of the polymers remained sufficiently high (tensile strength was reduced from 292.00 to 132.62–234.54 MPa). All polymers exhibited a thermoresponsive shape-memory behavior as they could maintain a temporary shape below their glass-transition temperature and return to the permanent shape when the temperature was raised again above the glass-transition temperature. All polymers showed high antibacterial activity against Staphylococcus aureus (90.3–96.4%) and Escherichia coli (97.8–99.6%) even after 1 h of contact with bacteria. The photoresins were tested in microimprint lithography and confirmed to accurately reproduce the shape features of the 3D printed target. Compositions prepared with 1,4-cyclohexanedimethanol were the most promising due to fast photocuring and the highest flexibility. Synthesized biobased photopolymers have a wide range of properties, making them potential candidates for the production of functional coatings, biomedical devices, or flexible electronics.
Design, Synthesis, and Bioactivity of Novel Coumarin-3-carboxylic Acid Derivatives Containing a Thioether Quinoline Moiety
Yuanquan Zhang - ,
Zhiyuan Xu - ,
Minxiang Dou - ,
Yan Xu - ,
Xin Fu - ,
Fadi Zhu - ,
Huochun Ye - ,
Jing Zhang *- , and
Gang Feng *
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A series of coumarin-3-carboxylic acid derivatives containing a thioether quinoline moiety were designed and synthesized. The structures of these compounds were determined using 1H NMR, 13C NMR, and HRMS. The antibacterial activity of the compounds was evaluated against Xanthomonas oryzae pv oryzae (Xoo), Ralstonia solanacearum (Rs), and Acidovorax citrulli (Aac). The results showed that most of the compounds exhibited significant antibacterial activity against these pathogens. Particularly, compound A9 demonstrated potent activity against Xoo and Aac, with EC50 values of 11.05 and 8.05 μg/mL respectively. In addition, A9 indicated strong protective and curative effects against Aac in vivo, with efficacy rates of 61.50 and 54.86%, respectively, surpassing those of the positive control thiodiazole copper. The scanning electron microscopy observations revealed that treatment of Aac cells with A9 at a concentration of 2EC50 resulted in a curved and sunken cell morphology, along with destroyed cell membrane integrity. Additionally, the motility and exopolysaccharide production of Aac were inhibited, and biofilm formation was prevented. Consequently, these newly developed derivatives of coumarin-3-carboxylic acid, incorporating the thioether quinoline moiety, hold promise as potential templates for the development of innovative antibacterial agents.
Experimental Study on the Effects of Washing Time, Washing Temperature, and Particle Size on the Combustion and Ash Formation Characteristics of Rice Husk
Shuo Yang *- ,
Jintao Luo - ,
Yu Gao - ,
Shaohui Wang - ,
Yupeng Zhang - ,
Yuhang Wang - ,
Pushi Ge - ,
Wanqi Li - ,
Yunyi Zheng - ,
Jie Cui - ,
Yudong Fu - , and
Honggang Pan
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There are many problems in the direct combustion of biomass, such as low combustion efficiency and easy slagging. In this paper, rice husk (RH) was taken as the research object, and the effects of different washing pretreatment conditions (washing time (WTI), washing temperature (WTE), and particle size) on the combustion characteristics and ash formation characteristics were discussed. The results show that the combustion characteristics of RH were significantly coupling-affected by the WTE and WTI, and the comprehensive characteristics of volatile release were significantly coupling-affected by the particle size and WTI. Specifically, under the condition of high-temperature washing, prolonging the WTI will increase the ignition temperature of washed RH powder. The particle size could affect the temperature of the maximum rate of decomposition. Under the same conditions, the temperature difference of maximum rate of decomposition between washed RH powder and RH was 5–10 °C. For the original RH, the longer the WTI, the more unfavorable it was to increase the maximum weight loss rate, and the opposite was true for RH powder. With the increase in WTE, the flammability index, burnout temperature, and volatile devolatilization initial temperature increased obviously. In addition, washing pretreatment could reduce the ashing quality of RH and RH powder to varying degrees, and the ash quality was decreased by about 15% compared with that of unwashed RH. The alkali metal removal effect of washed RH powder was better than that of washed RH. The proportion of alkali metal K was decreased from 1 to 4% (washed RH) to 0.2–1% (washed RH powder). The ash deposit and slagging phenomenon were obviously improved. Under the same WTI, the higher the WTE was, the better the removal effect of alkali metals was. Correspondingly, the proportion of the eutectic composite salt of Mg–Fe–Al with a high melting point increased in the high-temperature sintering stage, which effectively improved the ash melting point and reduced the probability of ash deposit and slagging.
Hydrogen Production by the Ruthenium(II) Complex Bearing a Bulky PNP Ligand: A Catalyst for the Decomposition of Formic Acid and/or Ammonium Formate
André L. Bogado *- ,
Leon Kambiz Paschai Darian - ,
David Bürgy - ,
Lucas da Silva dos Santos - , and
Leonardo Tsuyoshi Ueno
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The five-coordinate complex [RuCl2(PNP)] (1) was synthesized from the binuclear [RuCl2(p-cym)]2 with a PNP-type ligand (PNP = 3,6-di-tert-butyl-1,8-bis(diisopropylphosphino)methyl)-9H-carbazole – (CbzdiphosiPr)H) in a toluene solution, within 20 h at 110 °C, producing a green solid, which was precipitated with a 1/1 mixture of n- pentane/HMDSO. The complex was characterized by NMR─1H, 13C, and 31P{1H}, mass spectroscopy─LIFDI, FTIR, UV/vis spectroscopy, and cyclic voltammetry, as well as a description of the optimized structure by DFT calculation. The reactivity of 1 was investigated in the presence of potassium triethylborohydride (KBEt3H, in THF solution of 1.0 mol L–1) and ammonium formate (NH4HCO2), producing an in situ hydride complex and a formate intermediate species coordinated to the ruthenium center. The complex 1, loaded with 0.08%, catalyzed the decomposition of ammonium formate (AF) into H2, CO2, and NH3 in THF solutions at 80 °C, with 94% of H2 and TOF = 206 h–1 (molar ratio [Ru]/AF = 1/1204). The catalytic activity increased remarkably for the decomposition of formic acid (FA) as a substrate to produce H2 and CO2. In the HMDSO solution at 80 °C, a conversion of 100% was obtained in relation to H2 and TOF = 3010 h–1 (molar ration [Ru]/FA/NEt3 = 1/1204/843). In an equimolar mixture of AF/FA in HMDSO solution at 80 °C, without additives, the complex 1 catalyzed the decomposition of both with 100% of H2 and TOF = 987 h–1 (molar ratio [Ru]/AF/FA= 1/602/602). Under the later conditions, as well as upon AF decomposition, carbamic acid [HO(C═O)NH2] was obtained as a coproduct of a secondary reaction between NH3 and CO2 (yield = 50% in relation to the amount of AF). A kinetic study for decomposing FA, in the range of 60–100 °C, provided ΔS‡ = −9.7 e.u, ΔG‡ = 13.35 kJ mol–1, and Ea = 64 kJ mol–1, suggesting that the mechanism is more associative than for the known complexes.
Aminoglycoside/Hexadecanoic Acid Complex Lamellar Core Nanoparticles
Ajay J. Khopade *- and
Nitin Chitranshi
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An aminoglycoside, tobramycin sulfate (TbS), was complexed with hexadecanoic acid (HdA), resulting in a TbS/HdA complex with a repeat unit of 5.3 nm of a lamellar nanostructure. The nanometer-sized TbS/HdA particles were produced using poloxamer 188 as a dispersing agent. The particles were agglomerate-free with sizes in the range of 90–450 nm. The particle size was controlled by optimizing the homogenization conditions and the concentration of poloxamer-188. The lamellar nanostructure of the TbS/HdA complex was retained in the nanoparticle cores, even after the rigorous homogenization step. These core–shell-type nanoparticles were called lamellosomes because each particle consisted of a TbS/HdA lamellar core surrounded by a crown of hydrophilic poloxamer. The ζ-potentials of nanoparticles were in the range of −20 to −26 mV and did not aggregate even after exposing them up to the concentrations of 0.2 mol L–1 NaCl. However, the nanoparticles were sensitive to the changes in the pH in terms of their aggregation or disintegration. Thus, the steric effects and ionic charge seem to be responsible for the stabilization of the nanoparticles. The TbS/HdA matrix or HdA lamella could dissolve dexamethasone up to ∼2% (w/w) without causing crystallization. The release of the entrapped drug was significantly retarded. The TbS/HdA lamellosomes could serve as aminoglycoside carriers, which can further load drugs, showing potential as a multidrug cargo.
QSAR Classification Modeling Using Machine Learning with a Consensus-Based Approach for Multivariate Chemical Hazard End Points
Yunendah Nur Fuadah - ,
Muhammad Adnan Pramudito - ,
Lulu Firdaus - ,
Frederique J. Vanheusden - , and
Ki Moo Lim *
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This study introduces an innovative computational approach using hybrid machine learning models to predict toxicity across eight critical end points: cardiac toxicity, inhalation toxicity, dermal toxicity, oral toxicity, skin irritation, skin sensitization, eye irritation, and respiratory irritation. Leveraging advanced cheminformatics tools, we extracted relevant features from curated data sets, incorporating a range of descriptors such as Morgan circular fingerprints, MACCS keys, Mordred calculation descriptors, and physicochemical properties. The consensus model was developed by selecting the best-performing classifier─Random Forest (RF), eXtreme Gradient Boosting (XGBoost), or Support Vector Machines (SVM)─for each descriptor, optimizing predictive accuracy and robustness across the end points. The model obtained strong predictive performance, with area under the curve (AUC) scores ranging from 0.78 to 0.90. This framework offers a reliable, ethical, and effective in silico approach to chemical safety assessment, underscoring the potential of advanced computational methods to support both regulatory and research applications in toxicity prediction.
Machine Learning Models for a Novel Optical Memory Approach
Tal Raviv *- ,
Zeev Kalyuzhner - , and
Zeev Zalevsky
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In recent years, there has been growing interest in optical data processing, driven by the demand for high-speed and high-bandwidth data handling in data centers. One of the key milestones for enabling effective all-optical data processing systems is the development of efficient optical memory. Previously, we introduced a novel approach for establishing nonvolatile optical memory, based on the classification of scattering fields generated by gold nanoparticles. In this ongoing research, we apply advanced machine learning techniques to enhance the performance of the proposed nonvolatile memory element. By utilizing Random Forest and t-SNE algorithms, we successfully classified and analyzed the scattered images obtained from the optical memory device. The classification model presented in this study achieved an accuracy and average F1-score of 0.81 across nine distinct classes.
December 10, 2024
A Review on Polyaniline-Supported Catalyst for Organic Transformations
Satyaranjan Behera *
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Organic transformations are very important in synthetic organic chemistry and are used immensely in pharmaceuticals. Polyaniline is a marvelous and exceptional conducting polymer because of its extensive and valuable applications. Various modified polyaniline derivatives were developed by researchers and explored as solid heterogeneous catalysts for synthesizing important organic compounds through different organic transformations. Polyaniline-supported catalysts have many advantages: easy synthesis, environmental stability, environmental friendliness, high yield, short reaction times, the requirement for green solvent or solventless medium, and excellent reusability. In past years, polyaniline-supported catalysts have been widely used in various important organic syntheses under solvent-free or green reaction conditions. Hence, here is a comprehensive, detailed review of the application of polyaniline catalysts in organic transformations with all of their advantages and future scope.
Novel Stepped Combined Constructed Wetland For Surface Water Removal: Enhancing the Performance and Responses of Microbial Communities
Zhen Sun - ,
Zongli Yao - ,
Pengcheng Gao - ,
Kai Zhou - ,
Yan Li - ,
Yuxing Wei - ,
Qinhong Liu - , and
Qifang Lai *
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Micro-polluted surface waters (MPSWs) draw increased concern for environmental protection. However, traditional treatment methods such as activated sludge, ozone activated carbon, and membrane filtration suffer from high cost and susceptibility to secondary pollution and are rarely used to address MPSWs. Herein, a new stepped combined constructed wetland planted with Eichhornia crassipes without additional inputs was developed. In a 60-day experiment conducted in a drainage canal, we evaluated contaminant removal and bacterial communities using laboratory analysis and amplicon sequencing. Our results showed that the stepped combined constructed wetland achieved impressive removal rates for various contaminants. It was able to remove 70% of suspended solids, 51% of total nitrogen, 55% of total phosphorus, 70% of ammonia nitrogen, and 64% of the chemical oxygen demand. The dominant bacterial phyla found in stepped combined constructed wetland was Proteobacteria and Actinobacteria, with average relative abundances of 43.4 and 19.9%, respectively. We also observed clear differences in bacterial genera between the influent and effluent water samples. Specifically, we found that the stepped combined constructed wetland significantly reduced the abundance of bacteria such as hgcl clade, Rhizorhapis, and Cyanobacteria, while increasing the abundance of bacteria like Flavobacterium, Limnohabitans, Alpinimonas, Erwinia, and Saccharibacteria. The dominant bacterial community comprised nitrifying bacteria (Azoarcus and Nitrospira), denitrifying bacteria (e.g., Mycobacterium, Paracoccus, Ralstonia, Rhodobacter, Escherichia Shigella), and nitrogen-fixing bacteria (Rhizobium, Bradyrhizobium, Azospirillum). Notably, the abundance of nitrogen-fixing bacteria, nitrite-oxidizing bacteria, and denitrifying bacteria increased with the stepped combined constructed wetland presence. The stepped combined constructed wetland technology is highly cost-effective, with a total investment of only 259.83 USD. The majority of this investment is used for construction, with minimal expenditure required for operation and maintenance. Therefore, the stepped combined constructed wetland presents an economical and environmentally friendly solution for pollutant removal in slow flow and still water areas. It offers numerous benefits, including improved pollutant removal efficiency, low cost, ecological advantages, and extensive development potential, in various fields.
Energy Conservation in Blast Furnace: Analysis on the Replaceability of Coke with Varying Reactivity and Postreaction Strength
Zhexi Li - ,
Sunny Song - ,
Junchen Huang *- ,
Qi Wang *- ,
Tingle Li - ,
Songtao Yang - , and
Song Zhang
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Currently, coke with significant differences in CRI/CSR (coke reactivity index and coke strength after reaction) can already be effectively utilized in blast furnaces (BFs). However, there remains a considerable controversy on the replaceability of high and low CRI/CSR coke. Therefore, an analysis was conducted on the metallurgical performance of C1, C2, and C3(CRI:C3 > C2 > C1&CSR:C3 < C2 < C1) through simulated BF under the ore-coke coexistence (OCC) experiment. The behavior of solution loss and degradation, reduction, and thermal function of coke was investigated, and the difference of C1 ∼ C3 was quantified through deviation analysis. The findings are as follows: opposite to the result of CRI/CSR testing, the solution loss and degradation behavior of the cokes is similar under OCC. This behavior results in roughly equivalent impacts of coke on the gasification point, indirect and direct reduction. Thermodynamic analysis reveals that there is minimal difference in heat flux trend, particularly within key temperature zones. The deviation analysis result of C2 and C3 comparing to C1 is less than 5%. Therefore, it can be inferred that coke exhibiting significant variations in CRI/CSR may demonstrate same metallurgical performance. Based on this inference, the replacement of C2 and C3 to C1 in BF production could be considered as a potential strategy to optimize resource utilization and cost saving.
Facile and Highly Selective Deprotection of Aryl Propionates/Acetates Using a Supported Lewis Acid Catalyst (20% InCl3/MCM-41)
Vikram G. Bhumkar - ,
Sumit B. Kamble - ,
Rohidas M. Jagtap - ,
Sudhir S. Arbuj - , and
Sachin S. Sakate *
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The selective deprotection of substituted aryl esters like acetates and propionates in the presence of different electron-donating and -withdrawing functional groups to the corresponding phenols in good yields was reported using the Lewis acid supported solid acid catalyst 20% InCl3/MCM-41 prepared by the wet impregnation method. The textural and microscopic properties of the catalyst were studied, which revealed a high degree of dispersion of InCl3 over MCM-41, promising quantification of Lewis acidity, and well-ordered honeycomb structure. The methodology was further explored for the selective deprotection of acetates and propionates in the presence of substituted amides that remain unaltered. Reusability studies revealed the robust nature of the catalyst without losing the catalytic activity for up to six recycles corroborated with hot leaching test studies monitored by ICP-AES analysis, which was further authenticated with XPS studies of the catalyst before and after the reaction.
Release of Crystalline Silica Nanoparticles during Engineered Stone Fabrication
Kabir Rishi - ,
Bon Ki Ku *- ,
Chaolong Qi - ,
Drew Thompson - ,
Chen Wang - ,
Alan Dozier - ,
Vasileia Vogiazi - ,
Orthodoxia Zervaki - , and
Pramod Kulkarni
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Inhalation exposure to respirable crystalline silica (RCS) during the fabrication of engineered stone-based kitchen countertops has been on the rise in recent years and has become a significant occupational health problem in the United States and globally. Little is known about the presence of nanocrystalline silica (NCS), i.e., particles below 100 nm. We present a methodology to quantify the crystalline silica content in the sub-100 nm size fraction of the aerosol released during engineered stone fabrication using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Aerosol was generated in a test chamber designed per EN 1093-3 and sampled using cascade impactors. XRD and FTIR analysis showed the presence of both α-quartz (15–60%) and cristobalite (10–50%) polymorphs in all size fractions. With increasing particle size, the cristobalite content increased. Seventy percent of the total aerosol mass in the sub-100 nm fraction was found to be crystalline silica, qualitatively confirmed by electron diffraction and electron energy loss spectroscopy. The presence of other minerals was detected in all size fractions; no polymeric resin binder was detected in the sub-100 nm fraction. Although the sub-100 nm fraction was about 1% of the aerosol mass, it accounted for 4–24% of the aerosol surface area based on the total lung deposition. If the surface area is a more relevant exposure metric, the assessment of the efficacy of current engineering control systems using mass as an exposure metric may not provide adequate protection.
Miniature Mass Spectrometry for Point-of-Care Testing the GPIIb/IIIa Inhibitor Tirofiban during Perioperative Period of Percutaneous Coronary Intervention
Dongchen Zhou - ,
Jiahui Wu - ,
Qingcheng Wang - ,
Yong Liu - ,
Shiqi Wang - ,
Weizong Zhang - ,
Yunfeng Zhang - ,
Huizhi Ding - ,
Yunfei Shao - ,
Haixing Wang *- , and
Qing Shen *
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Precise administration of tirofiban must be carefully considered to achieve the best treatment efficacy and maximize safety for patients. Herein, a paper spray ionization (PSI) linear ion trap (LIT) portable mass spectrometer (pMS) based point-of-care testing (POCT) technique was developed for on-site sampling, clinical testing, and immediate analysis of tirofiban blood drug concentrations. The results showed that tirofiban formed a significant and stable parent ion peak at m/z 441.3 by MS1 full scan in positive ion mode, which fragmented into product ions at m/z 395.4, m/z 321.3, m/z 276.3, and m/z 260.3 through collision-induced dissociation (CID) in MS/MS. To improve ion response, the parameters were optimized to the voltages of ionization 3600 V, ion isolation 1 (ISO1) 8 V, ion isolation 2 (ISO2) 2 V, and collision-induced dissociation (CID) 3 V. This method was validated, and the limit of detection (LOD) and limit of quantification (LOQ) were found to be 10.1 and 33.7 μg·L–1, respectively. For precision, it had the relative standard deviation (RSD) of interday precision of 4.8 to 6.7% and the RSD of intraday precision of 7.8 to 8.3%. The recovery of the method ranged from 87.5 to 93.4%. Although matrix effects in blood samples had some inhibitory effects on the target signal formation, the method compensated for part of the matrix effects by establishing a matrix-matched calibration curve, which exhibited good linearity with a R2 of 0.9987. Finally, the method was applied to the detection of tirofiban in clinically collected blood samples. Out of 12 samples, ten had tirofiban concentrations between 35.4 and 72.1 μg·L–1 while the remaining two were below the LOQ. The method needs further optimization and validation in the future to improve its sensitivity and stability.
Air Storage Impact on Surface Evolution of Stoichiometric and Li-Rich NMC811
Magdalena Winkowska-Struzik - ,
Dominika A. Buchberger *- ,
Witold Uhrynowski - ,
Michał Struzik - , and
Andrzej Czerwinski
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In recent years, a type of layered oxide, LiNixMnyCozO2 (NMC) where x+y+z = 1, has become the preferred cathode material for electric vehicle (EV) batteries. Despite some disorder in the crystal structure due to Li+/Ni2+ cation mixing, the composition offers a high specific capacity of up to 200 mAh g–1 at 4.3 V vs Li|Li+. The objective of this study is to comprehensively evaluate the structural and electrochemical changes in NMC811 after storage in ambient conditions. In this report, we study stoichiometric and Li-rich NMC811 in terms of their structural, morphological, and electrochemical differences. Following literature reports, a rigorous aqueous washing procedure was used alternatively to remove a possible lithium excess from the NMC surface. The findings of this study hold immense significance as they focus on the potential challenges that may arise due to the remaining lithium content or Li+ extraction from the near-surface NMC811 materials. There is no consensus in the literature on whether excess lithium can harm the material’s structural and electrochemical properties, reduce performance and safety concerns, or be beneficial regarding its protective properties, for Ni-rich NMC. Proper treatment of as-synthesized Ni-rich NMCs helps to develop procedures to address the residual lithium compounds issues, leading to enhanced performance and safety. Here with this report, we show another aspect not being considered in the literature before, regarding morphological NMC811 reshaping and a mechanism of LRC transition and growth due to aging. In addition, we linked the selected structural parameters to the electrochemical performance of various NMC811 materials. We discuss the well-known structural factors and their limitations and introduce a doublet resolution criterion that can help in predicting electrochemical performance.
Machine Learning Prediction of Nitric Acid Extraction Behavior in PUREX Process
Sankar V. Harilal - ,
Matilda I. Duffy - ,
Eva Brayfindley - ,
Tatiana G. Levitskaia - ,
Elisabeth Moore - ,
Gregg J. Lumetta - ,
Brienne N. Seiner - , and
Towfiq Ahmed *
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Plutonium uranium reduction extraction (PUREX) is a liquid–liquid extraction process used to recover plutonium (Pu) and uranium (U) from irradiated uranium fuel for various nuclear-related applications. Despite extensive efforts, quantitative prediction of liquid–liquid extraction parameters, i.e., distribution ratios and separation factors, of the process remains challenging. Existing thermodynamic models are difficult to develop and often have limited utility due to the complexity of the aqueous feed. Nitric acid is a critical component of the PUREX system, both as a driving force for dissolving irradiated fuels in preprocessing stages, as well as being efficiently extracted by tributyl phosphate (TBP). Models to understand nitric acid’s distribution behavior is therefore a prerequisite to predict actinide extraction. In this work, we compiled a wealth of solvent extraction literature data and built machine learning (ML) models capable of predicting the organic phase nitric acid equilibrium concentration from initial acid and TBP concentrations across a variety of diluents. Our results demonstrate that ML is highly capable of predicting nitric acid extraction behavior in PUREX systems, and the resultant ML-aided response surfaces demonstrate promising progress as an in silico aid for optimizing the design of experiments for future work with the PUREX process.
Zeaxanthin Production by an Antarctic Flavobacterium sp.: Effect of Dissolved Oxygen Concentration and Modeling Kinetics in Batch and Fed-Batch Fermentation
Eugenia Vila *- ,
Jimena Ferreira - ,
Claudia Lareo - , and
Verónica Saravia
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Zeaxanthin is a high-value carotenoid, found naturally in fruits and vegetables, flowers, and microorganisms. Flavobacterium genus is widely known for the production of zeaxanthin in its free form. Nowadays, the production of zeaxanthin from bacteria is still noncompetitive with traditional methods. The study of different operational conditions to enhance carotenoid production, along with the development of better models, is critical to improve the optimization, prediction, and control of the bioprocess. In this work, the influence of dissolved oxygen concentration was studied on zeaxanthin, β-cryptoxanthin, and β-carotene production. It was found that 10% pO2 was the best condition for zeaxanthin production in a batch bioprocess, reaching a total carotenoid concentration of 3280 ± 88 μg/L, with 86% of zeaxanthin. To enhance carotenoid production, a fed-batch culture was performed. Although biomass and total carotenoid productivity were similar between batch and fed-batch processes, the total carotenoid concentration in the fed-batch was the highest (8.3 mg/L) but with lower zeaxanthin content and productivity. Two kinetic models were proposed based on a modified Monod and Luedeking–Piret model, as well as glucose, biomass, oxygen, and each carotenoid concentration mass balance. The binary model that considers oxygen in biomass growth and product formation presented a better fit to the experimental data.
Peng–Robinson or Redlich–Kwong? Twu or Soave α-Function? Which Combination of Cubic Equation of State (CEoS) and α-Function Produces More Accurate and Consistent Results for Pure Components
Twaha Mohamed - ,
Janusz Kozinski - , and
Francisco Ramos-Pallares *
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This study tested the accuracy and thermodynamic consistency of four CEoS/α-function models. The objective was to find the most suitable CEoS/α-function combo for producing accurate and consistent physical and derivative properties for nonpolar, polar and hydrogen bonding components at subcritical conditions. The models tested were PR-Twu, PR-Soave, RK-Twu, and RK-Soave. The first term in the model’s name refers to the CEoS used: Peng–Robinson (PR) or Redlich–Kwong (RK). The second term indicates the α-function used, i.e., Twu’s or Soave’s. The models were tested on a data set containing saturation pressure, enthalpy of vaporization and saturated liquid heat capacity of 147 pure components classified as polar, nonpolar, and hydrogen bonding. The three Twu α-function parameters were fitted to data and constrained to produce thermodynamic consistent values across the phase diagram; and, the Soave α-function parameter was predicted from a well-known correlation. The thermodynamic consistency of the models was assessed by calculating the Waring number and the saturated liquid speed of sound of 147 and 79 pure components, respectively. The results showed that PR-Twu and RK-Twu produced more accurate pure component properties compared to those from PR-Soave and RK-Soave. However, there was not a significant difference between the performance of PR-Twu and RK-Twu for calculating pure component properties. The same result was obtained when comparing PR-Soave and RK-Soave. Interestingly, the consistency analysis showed that only PR-Twu and PR-Soave produced consistent Waring number trends for components with acentric factors below 0.7. It was also observed that the saturated liquid speed of sound calculated from all four models tested was not accurate as the models cannot produce precise −(∂P∂v)T and liquid volumes. Besides, using volume translation is detrimental to the accuracy of the calculated saturated liquid speed of sound. The most accurate and consistent model was PR-Twu; however, caution should be exercised when modeling the saturated liquid heat capacity of hydrogen bonding components.
Catalytic and Noncatalytic in Situ Hydrogen Production from Heavy Oil: A Review of Experimental Studies
Mohamed Abdalsalam Hanfi - ,
Olalekan Saheed Alade - ,
Abdulkadir Tanimu - ,
Mohamed Mahmoud - , and
Sulaiman A. Alarifi *
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Hydrogen (H2) offers a less carbon-intensive energy production method than natural gas. The potential of utilizing hydrogen at a large scale within the future energy mix to fuel the world opens the door to investigating hydrogen production from heavy and extra-heavy oil reservoirs. Various reaction mechanisms are involved in the in situ combustion gasification of heavy oil to produce sustainable and low carbon intensive hydrogen. In-situ catalytic hydrogen production involves injecting a catalyst into the reservoir or utilizing the in situ reservoir materials to catalyze the various reactions. Clay minerals and formation water were found to serve as in situ catalytic materials and enhance the in situ hydrogen production process. This work presents a comparative review of the catalytic and noncatalytic experimental studies carried out on in situ hydrogen production. The formation damage induced by the in situ combustion and its effect on hydrogen production was highlighted. In addition, the impact of the formation damage induced by the in situ combustion on the hydrogen production process is discussed. This study categorized the experimental studies conducted on the hydrogen production from heavy oil into catalytic and noncatalytic processes to highlight the effect of the synthetic and natural reservoir catalytic materials on in situ hydrogen production.
Effect of Interface Passivation on the Performance of the Cu2ZnSnS4 Solar Cells
Adèle Debono - ,
Filipe Martinho - ,
Jørgen Schou - , and
Stela Canulescu *
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This study examines the effect of ultrathin aluminum oxide (Al2O3) passivation layer on the performance of the kesterite Cu2ZnSnS4 (CZTS) solar cells. The Al2O3 layer was applied at the back CZTS/Mo interface using atomic layer deposition (ALD). Our findings indicate that the interface passivation with Al2O3 can significantly enhance the adhesion of CZTS to Mo, preventing delamination during annealing. An optimal Al2O3 thickness of 1–2.5 nm yielded a more than 30% increase in efficiency, primarily through enhancements of the open-circuit voltage (Voc) and short-circuit current (Isc), which resulted from reduced interface recombination and improved charge collection within the CZTS bulk. Furthermore, the Al2O3 layer modified MoS2 formation at the CZTS/Mo back interface, reducing series resistance (Rs). Nevertheless, a thicker Al2O3 layer led to a sharp decrease in efficiency due to increased series resistance and hindered the extraction of holes. Our work reveals that precise control of the Al2O3 layer thickness is essential to optimize CZTS solar cell performance by balancing the benefits of passivation with its potential drawbacks.
Exploring the Anti-inflammatory Potential of Novel Chrysin Derivatives through Cyclooxygenase-2 Inhibition
Yuna Lee - ,
Eun Ji Gu - ,
Ha-Yeon Song - ,
Bo-Gyeong Yoo - ,
Jung Eun Park - ,
Jongho Jeon *- , and
Eui-Baek Byun *
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Inducible cyclooxygenase-2 (COX-2) is a crucial enzyme involved in the processes of inflammation and carcinogenesis, primarily by catalyzing the production of prostaglandin E2 (PGE2), a significant mediator of inflammation. In this study, we designed and synthesized a series of novel chrysin derivatives to evaluate their anti-inflammatory potential through COX-2 inhibition using in vitro cultures of RAW264.7 macrophages and in silico molecular docking assays. Among the synthesized derivatives, compounds 1a and 8 demonstrated significant inhibition of lipopolysaccharide (LPS)-stimulated proinflammatory cytokine production, including interleukin-6 and tumor necrosis factor-alpha, in RAW264.7 cells. Additionally, these derivatives effectively inhibited PGE2 secretion through COX-2 enzyme inhibition in LPS-stimulated RAW264.7 cells. Molecular docking simulation results revealed that 1a and 8 possess high binding affinities for the COX-2 active site, indicating a strong potential for enzyme inhibition. Furthermore, druglikeness and ADMET predictions for these compounds indicated favorable pharmacokinetic properties, suggesting their suitability as drug candidates. Therefore, compounds 1a and 8 hold promise as potential anti-inflammatory agents for further development.
Effects of Ferrosilicon Fineness on the Multiphase Flow Field and Separation Performance of Dense Medium Cyclones for Low-Grade Ores
Shuli Wang - ,
Jun Wang *- ,
Guanzhou Qiu - , and
Li Shen
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As natural resources continue to be exploited, dense medium cyclones (DMCs) are increasingly utilized for the preconcentration of low-grade ores to meet the demands for higher feed grade, increased processing capacity, and reduced energy consumption. However, determining the optimal fineness of ferrosilicon remains ambiguous for different types of ores and is often described as more of an art than a science. This paper investigates the subtle effects of ferrosilicon fineness on flow field characteristics, medium classification, and the ore separation process using a validated numerical approach, which integrates a two-fluid model, a turbulence dispersion model, and a discrete phase model. The results reveal that, under consistent operating conditions, increasing the ferrosilicon fineness enhances the tangential velocity and pressure drop while having minimal impact on axial velocity and water split. The ferrosilicon fineness also influences the distribution of the turbulence field, and in combination with the changes in the particle size distribution (PSD) itself, it modifies the characteristics of the density field. This results in a reduction in the density difference between the overflow and underflow with finer ferrosilicon particles, thereby lowering the cut density but improving the separation accuracy. Moreover, the residence time of particles with different densities in the DMC also varies significantly with changes in separation density. The study underscores that even minor changes in ferrosilicon fineness can impact separation performance, highlighting the need for careful consideration of this factor in process design and medium recovery.
Curcumin Encapsulation in Aluminum Fumarate Metal–Organic Frameworks for Enhanced Stability and Antioxidant Activity
Pamela Al Azzi - ,
Riham El Kurdi - , and
Digambara Patra *
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Curcumin (Cur) is a great candidate for antioxidant applications; however, due to its low solubility and poor bioavailability, it remains only hardly employed as a therapeutic agent. Moreover, curcumin is very unstable and tends to degrade quickly. Metal–organic frameworks (MOFs) have gained great attention in the field of drug loading due to their diversity and tunability, so they are seen as great candidates for hosting curcumin. Aluminum fumarate MOF (AlMOF) was able to hold curcumin successfully by the wet impregnation technique. The resulting system significantly increased the stability of curcumin, so it went from degrading to 58.9% after 3 days to degrading to 16% after 10 days when entrapped in AlMOF. In addition, the antioxidant activity of curcumin was also greatly boosted in the MOF-Cur system compared to curcumin in its free state. These results open the door to an in-depth study of MOF-Cur systems as great therapeutic agents due to the enhancement of the therapeutic properties of curcumin, all while protecting it, favoring its solubility, and maintaining its stability.
Predicting Irida-Silicene: A Novel 2D Silicon Allotrope
Djardiel da S. Gomes - ,
Luiz A. Ribeiro Jr.- , and
Marcelo L. Pereira Jr.*
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Two-dimensional (2D) silicon-based materials have garnered significant attention for their promising properties, making them suitable for various advanced technological applications. Here, we present Irida-Silicene (ISi), a novel 2D silicon allotrope inspired by Irida-Graphene (IG), which was recently proposed and is entirely composed of carbon atoms. ISi exhibits a buckled structure composed of 3–6–8 membered rings, unlike its planar carbon counterpart. Using density functional theory (DFT) calculations, we discuss its stability, structural, electronic, optical, and mechanical properties. Our results indicate that ISi exhibits bond lengths ranging from 2.27 to 2.32 Å, with buckling of 0.78 Å, the latter significantly larger than that reported for silicene. The nanomaterial demonstrates good dynamical and thermal stability at room temperature, without phonon dispersion with imaginary frequencies, and a cohesive energy of −4.98 eV/atom. ISi is a metallic monolayer with a Dirac cone above the Fermi level in the center of the band, and it is also a nonmagnetic material. Furthermore, the system displays anisotropic electronic properties, showing semiconducting behavior depending on the direction, with a region devoid of electronic states between −0.2 and −0.8 eV. The optical activity of ISi is primarily observed in the infrared and ultraviolet regions, with a peak for photons with an energy of 5.5 eV in the latter case. Finally, regarding mechanical properties, we report estimated elastic and bulk moduli of approximately 34 and 41 N/m, respectively. The system can withstand up to 15% of strain, depending on the direction and type of deformation. These findings suggest that ISi holds potential for various technological applications, expanding the potential uses of 2D silicon-based materials beyond silicene.
Targeting Protein Disorder for the Remediation of Antimicrobial Resistance
Jack O’ Callaghan - ,
Michael P Ryan - ,
Sarah Hudson *- , and
Damien Thompson *
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The remediation of antimicrobial resistance (AMR) is a fundamental challenge for global healthcare. Intrinsically disordered proteins (IDPs) are recognized drug targets for neurodegeneration and cancer but have not been considered to date for AMR. Here, a novel link between structural disorder and AMR is identified by mapping predicted disorder profiles onto existing transcriptomic data for resistant and susceptible E. coli isolates. The AMR-relevant IDPs fall into two distinct classes, those involved in the bacterial stress response and those differentially expressed between resistant and susceptible strains following antibiotic exposure. A residue-wise conservation analysis of relevant bacterial IDPs identified mutations within intrinsically disordered regions that correlate with pronounced changes in antimicrobial susceptibility, providing valuable insight into the functional importance of bacterial intrinsic disorder in the ESKAPEE pathogens. The identification of susceptibility-inducing IDPs in E. coli highlights the potential of disorder-based antimicrobial drug discovery for the remediation of drug-resistant bacterial infections.
Impact of Pressure and Gas/Oil Ratios (GORs) on the Optimal Parameters for Surfactant Formulations in Chemical EOR: Experimental Study
Murad Hajiyev - ,
Ahmed Farid Ibrahim - ,
Mohammed B. Alotaibi - ,
Mohanad Fahmi - ,
Shirish Patil - ,
Noof Al-Aqeel - , and
Khaled Abdelgawad *
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Surfactant chemical-enhanced oil recovery plays a crucial role in achieving ultralow interfacial tension between remaining crude oil and injected water, thereby enhancing oil recovery rates. This study aims to investigate the impact of pressure and gas/oil ratios (GORs) on surfactant flooding for enhanced oil recovery, focusing on high-pressure and high-temperature (HPHT) conditions. High-temperature salinity screening was employed to identify optimal surfactant formulations for Type III microemulsions. HPHT phase behavior tests were conducted to examine water and oil solubilization under pressure, with a particular focus on how GOR affects these parameters. The research utilized a unique approach to analyzing GOR variations at different pressure levels in a crude oil sample through salinity screening experiments and HPHT phase behavior tests using methane-containing live oil. With increasing pressure, while maintaining a lower GOR, the water solubilization ratio in the microemulsion increased dramatically, whereas the solubilization ratio of oil decreased. Furthermore, both oil and water solubilization ratios decreased at higher GOR and pressure compared to dead oil results. The optimum salinity was found to be equal to 17,283 ppm at a GOR of 180 scf/stb and decreased to 14,403 ppm at a GOR of 280 scf/stb, validating that the optimum salinity decreases with increasing GOR value. The tendency of microemulsion generation also decreased with increasing GOR from 180 to 280 and 380 scf/stb. Additionally, the minimum bubble point pressure required to solubilize the total amount of gas in the oil increased from 2500 psi at a GOR of 280 scf/stb to 3000 psi at a GOR of 380 scf/stb. The microemulsion was not observed at any pressure level and at any salinity at a higher GOR (380 scf/stb). This study provides valuable insights into the petroleum industry, offering potential improvements in reservoir management, forecasting accuracy, and recovery efficiency. The research’s innovative approach to analyzing GOR variations and its impact on surfactant flooding under HPHT conditions contributes to the field’s knowledge and could lead to more effective and efficient oil recovery strategies.
Performance Analysis of Pipe-Jacking Waste Soils Solidified with Quick Lime and Fly Ash under Balanced Earth Pressure Conditions
Youjun Xu - ,
Zhenyu Li *- , and
Zhigang Chen
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With its advantages of high cross-sectional utilization, shallow depth, and uninterrupted surface road traffic, the pipe-jacking method has been widely used in underground passages, metro stations, and other projects. However, this leads to a large volume of pipe-jacking waste soils that must be processed. Pipe-jacking waste soils are different from shield-tunneling waste soils. Therefore, it is not appropriate to simply use the same treatment method for shield-tunneling waste soils in the treatment of pipe-jacking waste soils. In this study, pipe-jacking waste soil samples were improved with 7% polyacrylamide (PAM) and 12% sodium-based bentonite solutions, with good performance being achieved. Based on this, quick lime and fly ash were used in the solidification of pipe-jacking waste soils, and experiments with different solution concentrations and solidification material additions were conducted, involving tests of compression, freeze–thaw cycling, wet–dry cycling, and microstructure. The results indicate that within the ranges of PAM and sodium-based bentonite addition ratios applied in this study, the solidification effects of quick lime and fly ash will not be significantly reduced during the improvement processes of pipe-jacking waste soils under balanced earth pressure conditions. Instead, it was found that there was an increase of up to 16% in the strength of pipe-jacking waste soils. Structural compactness can be primarily enhanced by gelatinous PAM, while sodium-based bentonite can promote the formation of hydrated colloids (such as C–S–H) and fill soil pores with hydrated gelatinous bentonite particles, thereby enhancing soil stability.
Study on Fluidity and Deposition Characteristics of Air-Containing Filling Slurry
Chunming Ai - ,
Haichuan Lin *- ,
Ziqi Chen - , and
Chao Liu
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With the continuous exploitation of global mineral resources, backfill technology for gob areas has become a crucial aspect of mine safety and sustainable development. As a primary method of gob area backfill, slurry backfill directly relates its flow properties and filling height to the efficiency and safety of mine extraction. To enhance the flow properties of the slurry and increase its filling height, a research study on the flow and deposition characteristics of a gas-containing filling slurry was conducted using a combination of theoretical analysis, laboratory experiments, and field tests. Experiments on the gas content were conducted using a concrete gas content tester, rheological property experiments were performed using a paddle rheometer, slump flow tests were carried out using a slump cone, and slurry deposition experiments were conducted using gob area similarity models. Analysis of viscosity characteristics revealed that the slurry gas content increased with the addition of air-entraining agents and the yield stress of the slurry decreased by 49.27% with an increase in the gas content at the same mix ratio, resulting in a 48% reduction in slurry viscosity. By analyzing the mechanism of gas phase enhancement on slurry flow, it was found that the anionic strength of bubbles generated by adding air-entraining agents was greater than the anionic strength within the slurry, changing the original particle arrangement and disrupting the tailings flocculation, thereby increasing the distance between floccules and enhancing the slurry’s fluidity. Based on field tests, a semiindustrial flow and deposition experimental platform was established based on similarity theory, which found that the settlement rate of filling slurry with air-entraining agents decreased, improving the expansion ratio. This research is of significant importance for improving the effectiveness of the slurry backfill.
December 9, 2024
Genome-Wide Exploration of Thiamin Pyrophosphate Riboswitches in Medically Relevant Fungi Reveals Diverse Distribution and Implications for Antimicrobial Drug Targeting
Valdemir Vargas-Junior - ,
Ana Carolina Ramos Guimarães - ,
Ernesto Raul Caffarena - , and
Deborah Antunes *
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The rising incidence of fungal infections coupled with limited treatment options underscores the urgent need for novel antifungal therapies. Riboswitches, particularly thiamin pyrophosphate (TPP) class, have emerged as promising antimicrobial targets. This study presents a comprehensive genome-wide analysis of TPP riboswitches in 156 medically relevant fungi utilizing advanced covariance models (CMs) tailored for fungal sequences. Our investigation identified 378 conserved TPP riboswitch sequences distributed across 140 distinct species, revealing a broader prevalence than that previously recognized. Notably, we provide evidence for a novel putative group of TPP riboswitches, designated TPPswSUGAR, associated with sugar transporters in Mucoromycota and Basidiomycota. This group exhibits distinctive structural features while maintaining key TPP-binding motifs, potentially expanding our understanding of the riboswitch diversity in fungi. Our analysis highlights the impact of P3 stem variability on riboswitch detection and characterization, demonstrating the superiority of fungal-specific CMs over generic models. We observed multiple TPP riboswitches in over 50% of the examined species, including clinically significant pathogens involved in aspergillosis and mucormycosis. Remarkably, Aspergillus latus, a species associated with COVID-19 coinfections, harbors six distinct TPP riboswitch sequences, whereas the extremophilic black fungus Hortaea werneckii possesses nine. These findings not only elucidate the diverse distribution of TPP riboswitches in pathogenic fungi but also emphasize their potential as multifaceted targets for antifungal drug development. By addressing key limitations of previous detection methods and providing insights into riboswitch structural diversity, this study lays a foundation for future investigations into riboswitch-mediated regulation in fungi and the development of novel antifungal strategies.
Application of Carbon Quantum Dots Derived from Waste Tea for the Detection of Pesticides in Tea: A Novel Biosensor Approach
Nitu Sinha - and
Sonali Ray *
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Chemical pesticide residues have negative consequences for human health and the environment. Prioritizing a detection method that is both reliable and efficient is essential. Our innovative research explored the application of biosensors based on carbon quantum dots (CQDs) derived from waste tea to detect commonly used pesticides in tea. CQDs have been synthesized using a simple one-pot hydrothermal approach and thoroughly characterized using advanced techniques such as high-resolution transmission electron microscopy, ultraviolet–visible spectroscopy, photoluminescence (PL) spectroscopy, Raman spectroscopy, X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy. The fluorescence resonance energy transfer-based fluorescence “turn on–off” mechanism has been successfully employed to study the detection of four different pesticides, viz., quinalphos 25 EC, thiamethoxam 25 WG, propargite 57 EC, and hexaconazole 5 EC. The detection limits for quinalphos 25 EC, thiamethoxam 25 WG, and propargite 57 EC were determined to be 0.2, 1, and 10 ng/mL, respectively. Notably, these values are significantly lower than the maximum residue level for each pesticide. We achieved a strong linear correlation (R = −0.96) with a detection limit of 0.2 ng/mL for quinalphos 25 EC. The quantum yield was determined to be 40.05%. Our research demonstrates that the developed nanobiosensor reliably and accurately detects pesticides, including those present in experimental samples containing mixtures of pesticides.
The Effect of Water Co-adsorption on the Adsorption of Formaldehyde in Fe-HHTP-MOF Metal–Organic Materials
Sanjiang Bie *- and
Siyu Nie
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Because of the existence of moisture in indoor air, it is still a serious challenge to capture formaldehyde indoors with the metal–organic material Fe-HHTP-MOF. To explore the relationship between the structure and performance of Fe-HHTP-MOF in dry and humid air, molecular dynamics simulation was used to study the adsorption amount of Fe-HHTP-MOF for formaldehyde and water under different temperatures and adsorption pressures, as well as the adsorption amount of Fe-HHTP-MOF for formaldehyde in the presence of both water and formaldehyde, and the differences in adsorption of formaldehyde and water by Fe-HHTP-MOF were compared and analyzed when water coexisted. The results show that under single-component isothermal adsorption, the hydrogen bond energy formed by Fe-HHTP-MOF adsorbing H2O molecules is much greater than the van der Waals energy formed by adsorbing HCHO molecules. In a dry state, as the temperature increases, the adsorption amount of HCHO molecules decreases. When the temperature rises to 313.15 K, even if the temperature is further increased, the effect on the adsorption amount of HCHO molecules is small. Moreover, after the adsorption pressure is greater than 7.78 MPa, the adsorption amount of HCHO molecules tends to flatten. When H2O molecules coexist, at the same adsorption pressure and temperature, H2O molecules with polar functional groups preferentially occupy the adsorption sites, and the adsorption amount of HCHO molecules in the presence of H2O is lower than that in the dry state. As the temperature increases, under the same adsorption pressure, the intermolecular interaction strengthens, and the molecular activity increases. The influence of water molecules on the adsorption of HCHO by Fe-HHTP-MOF weakens, and HCHO molecules reach the saturated adsorption site ahead of time. The adsorption energy of H2O is greater than that of HCHO, indicating that the presence of water may hinder the capture of HCHO.
Predicting Source Rock Distribution of the Ninth Member of the Upper Triassic Yanchang Formation Based on Well-Logging Parameters and TOC Values in the Longdong Area, Ordos Basin, China
Xiao Hui - ,
Xuan Ke - ,
Yalin Qi - ,
Shuyong Shi *- ,
Jing Zhu - , and
Yunpeng Wang *
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In recent years, new oil reservoirs have been discovered and exploited in the ninth member (Chang 9 Member, T3y9) of the Upper Triassic Yanchang Formation (T3y) in the Longdong area, Ordos Basin. Some studies have shown that the crude oils of the Chang 9 Member may originate from the Chang 9 source rock in some areas, which may be related to the distribution of the source rock. However, the distribution of the Chang 9 source rock in the Longdong area is still unclear, which hinders further exploration and development of petroleum. In this study, we established a multiple linear regression model for predicting total organic carbon (TOC) based on the relationship between well-logging parameters and measured TOC values of shale core samples from 30 wells in the study area. The results show that the Chang 9 shale is mainly composed of gray and dark mudstones, which mainly belong to the interdistributary bay and front delta depositional subfacies. The TOC values of the shale core samples from this member vary in a range of 0.11–4.8%, with an average value of 0.96%. Compared with traditional and improved Δlog R models, our model shows a higher accuracy of TOC prediction with R2 = 0.9181, which meets the requirements for predicting the distribution of the Chang 9 source rock. In the map of the Chang 9 source rock predicted by our model, the thickness of the source rock (TOC ≥ 1.0%) varies in the range of 1–12 m, showing a decreasing trend from northeast to southwest in the Longdong area. The crude oil in the northeastern areas enjoys a high ratio of 17α(H)-C30 rearranged hopane and C30 hopane (C30*/C30), and the thickness of the Chang 9 source rock is also greater than in other areas. It is speculated that the Chang 9 Member tight oil in the northeast area is mainly from the Chang 9 source rock, while the oil in other areas is from the Chang 7 source rock. In our study, we presented a method for predicting the source rock distribution, which can be widely used for exploring the tight oil of the Chang 9 Member in the study area.
Tumor-Targeted Magnetic Micelles for Magnetic Resonance Imaging, Drug Delivery, and Overcoming Multidrug Resistance
Hui-Qin Liu - ,
Xi-Dong Wu - ,
Xue-Wen Fang - ,
Yun-Song An - ,
Meng Xia - ,
Xiao-Hua Luo - ,
Jun-Zheng Li *- ,
Guan-Hai Wang *- , and
Tao Liu *
This publication is Open Access under the license indicated. Learn More
Nasopharyngeal carcinoma (NPC) is prevalent in Southern China. Unfortunately, current treatments encounter multidrug resistance (MDR). Overexpression of P-glycoprotein (P-gp), resulting in the efflux of chemotherapy drugs, is one of the significant mechanisms causing MDR. d-α-Tocopheryl poly(ethylene glycol) 1000 succinate (TPGS) has been demonstrated to effectively inhibit P-gp expression. The objectives of this study are to improve tumor MRI imaging, optimize docetaxel (DOC) administration, and target P-gp to overcome NPC resistance. Multifunctional micelles of TPGS (MM@DOC), loaded with magnetic nanoparticles, were synthesized for the targeted delivery of the first-line anticancer drug. MM@DOC exhibited greater toxicity and induced higher levels of apoptosis in DOC-resistant NPC cells (C666–1/DOC) compared to DOC. MM@DOC loaded with magnetic nanoparticles improved the quality of tumor MRI imaging. MM@DOC also demonstrated significant antitumor effects in nude mice with C666–1/DOC NPC. In conclusion, MM@DOC exhibited promising inhibitory effects on resistant tumors both in vitro and in vivo, optimized tumor MRI imaging, and showed great potential in drug delivery and overcoming resistance.
Microwave-Assisted Buchwald–Hartwig Double Amination: A Rapid and Promising Approach for the Synthesis of TADF Compounds
Nor Shafiq Mohd Jamel - ,
Levani Skhirtladze - ,
Aqeel A. Hussein *- ,
Yumiao Ma - ,
Kai Lin Woon - ,
Muhammad Kumayl Abdulwahab - ,
Juozas V. Grazulevicius *- , and
Azhar Ariffin *
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We herein report a microwave-assisted Buchwald–Hartwig double amination reaction to synthesize potential thermally activated delayed fluorescence compounds, forming C(sp2)-N bonds between donor and acceptor units. Our approach reduces reaction times from 24 h to 10–30 min and achieves moderate to excellent yields, outperforming conventional heating methods. The method is compatible with various aryl bromides and secondary amines, including phenoxazine, phenothiazine, acridine, and carbazole. Density functional theory calculations have attributed the lack of reactivity with high energy barriers in the reductive elimination (RE) steps. Electron-withdrawing groups such as CF3 increase the RE barrier, resulting in a 0% yield, while substituting carbazole with acridine lowers the barriers and enhances higher yields. Distortion–interaction analysis highlights steric hindrance as a key factor affecting the reaction outcome when the RE barrier is low and steric hindrance is minimal. This microwave-assisted method not only demonstrates a superior performance in terms of higher yields and shorter reaction times but also offers significant potential for reducing production costs of these materials.
Unraveling the Effects of Hexametaphosphate: Insights into Trypsin Aggregation and Structural Reversal
Ajamaluddin Malik *- ,
Abdulaziz Alamri - ,
Nojood Altwaijry - ,
Abir Alamro - ,
Abdullah Alhomida - ,
Rashid Ayub - , and
Hamza Odeibat
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Elevated serum phosphate levels have been linked to increased mortality rates. This study investigated the effect of millimolar (mM) concentrations of sodium hexametaphosphate (SHMP) on trypsin’s aggregation and structural stability at intestinal pH levels. We used various spectroscopic and microscopic techniques to investigate the structural changes of trypsin aggregates. Turbidity and light scattering results revealed that trypsin aggregates began to solubilize at SHMP concentrations above 1 mM, with maximum solubilization observed at 6 mM SHMP. Intrinsic, thioflavin T (ThT) fluorescence, and far-UV CD spectra indicated that trypsin amorphous aggregates turn into native-like structures in the presence of 6 mM SHMP. Transmission electron microscope (TEM) imaging also showed the disappearance of amorphous aggregates at higher SHMP concentrations. This study showed that higher SHMP concentrations solubilized the trypsin aggregates and induced a native-like conformation. These findings highlighted that SHMP could be a good protein aggregate solubilizer, with future applications in inclusion body solubilization and protein refolding.
Assessing the Interactions between Snake Venom Metalloproteinases and Hydroxamate Inhibitors Using Kinetic and ITC Assays, Molecular Dynamics Simulations and MM/PBSA-Based Scoring Functions
Raoni A. de Souza *- ,
Natalia Díaz - ,
Luis G. Fuentes - ,
Adriano Pimenta - ,
Ronaldo A. P. Nagem - ,
Carlos Chávez-Olórtegui - ,
Francisco S. Schneider - ,
Franck Molina - ,
Eladio F. Sanchez - ,
Dimas Suárez - , and
Rafaela S. Ferreira *
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Bothrops species are the main cause of snake bites in rural communities of tropical developing countries of Central and South America. Envenomation by Bothrops snakes is characterized by prominent local inflammation, hemorrhage and necrosis as well as systemic hemostatic disturbances. These pathological effects are mainly caused by the major toxins of the viperidae venoms, the snake venom metalloproteinases (SVMPs). Despite the antivenom therapy efficiency to block the main toxic effects on bite victims, this treatment shows limited efficacy to prevent tissue necrosis. Thus, drug-like inhibitors of these toxins have the potential to aid serum therapy of accidents inflicted by viper snakes. Broad-spectrum metalloprotease inhibitors bearing a hydroxamate zinc-binding group are potential candidates to improve snake bites therapy and could also be used to study toxin-ligand interactions. Therefore, in this work, we used both docking calculations and molecular dynamics simulations to assess the interactions between six hydroxamate inhibitors and two P–I SVMPs selected as models: Atroxlysin-I (hemorrhagic) from Bothrops atrox, and Leucurolysin-a (nonhemorrhagic) from Bothrops leucurus. We also employed a large variety of end-point free energy methods in combination with entropic terms to produce scoring functions of the relative affinities of the inhibitors for the toxins. Then we identified the scoring functions that best correlated with experimental data obtained from kinetic activity assays. In addition, to the characterization of these six molecules as inhibitors of the toxins, this study sheds light on the main enzyme–inhibitor interactions, explaining the broad-spectrum behavior of the inhibitors, and identifies the energetic and entropic terms that improve the performance of the scoring functions.
TiO2–Mo2C Heterostructure for Enhanced Electrocatalytic Nitrogen Reduction to Ammonia
Junmei Wang *- ,
Qingkun Tian - ,
Li Chen - ,
Maoyou Yang - ,
Xia Zhang - , and
Xiaodan Wang
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The development of catalysts with high activity and selectivity for the electrochemical nitrogen reduction reaction (NRR) remains crucial. Molybdenum carbide (Mo2C) shows promise as an electrocatalyst for NRR but faces challenges due to the difficulty of N2 adsorption and activation as well as the competitive hydrogen evolution reaction. In this study, we propose a strategy of combining TiO2 with Mo2C to form heterostructure catalysts. Our first-principles theoretical calculations indicate that the TiO2–Mo2C heterostructure exhibits enhanced N2 adsorption and activation, attributed to the increased interaction between the π4d* orbital of Mo and the π2p* orbital of N2, facilitated by the directional modulation of Mo’s d-orbitals by TiO2. A more positive integrated crystal orbital Hamilton population and an elongated N≡N bond length prove this. Additionally, the higher Gibbs free energy for N2 compared to that for H demonstrates a preference for N2 adsorption. We further elucidate the catalytic mechanism for converting N2 to NH3 on the TiO2–Mo2C surface, identifying the associative distal pathway as the dominant route over the associative alternating pathway. This work highlights unique advantages of the TiO2–Mo2C heterostructure for the NRR and provides theoretical guidance for designing efficient NRR electrocatalysts.
December 8, 2024
Three Dihydroquinolin-4-one Derivatives as Potential Biodiesel Additives: From the Molecular Structure to Machine Learning Approach
Leonardo R. de Almeida *- ,
Antônio S. N. Aguiar - ,
Alex B. R. M. da Anunciação - ,
Giulio D. C. d’Oliveira - ,
Wesley F. Vaz - ,
Jean M. F. Custódio - ,
Caridad N. Pérez - , and
Hamilton B. Napolitano *
This publication is Open Access under the license indicated. Learn More
Biodiesel offers an alternative to fossil fuels, primarily because it is derived from renewable sources, with the potential to mitigate issues such as pollutant and greenhouse gas emissions, resource scarcity, and the market instability of petroleum derivatives. However, lower durability and stability pose challenges. To address this, researchers worldwide are exploring technologies that employ specific molecules to slow down biodiesel’s oxidation process, thereby preserving its key physicochemical properties. This study investigates heterocyclic dihydroquinolinone derivatives as potential additives to enhance the oxidative stability of diesel-biodiesel blends. Comprehensive structural and computational analyses were carried out by density functional theory to investigate the reactivity aspects of these compounds as potential additive candidates. The supramolecular arrangements were predominantly stabilized by weak molecular interactions, such as C–H···O and C–H···π, which are associated with antioxidant and antibacterial properties. We demonstrate that these groups can act as electron-donating or electron-withdrawing substituents. We explored frontier molecular orbitals, which provide insights into chemical reactivity, acidity, basicity, and the best oxidizing and reducing agents. Finally, the molecular chemical potential maps indicate the nucleophilic and electrophilic regions and the Fukui indices show the sites of nucleophilic, electrophilic, and radical attacks. This comprehensive study paves the way to understanding how dihydroquinolinone-based compounds serve as alternatives for fuel additives.
An Efficient and Accessible Hectogram-Scale Synthesis for the Selective O-GlcNAcase Inhibitor Thiamet-G
Viktor Holicek - ,
Matthew Deen - ,
Sandeep Bhosale - ,
Roger A. Ashmus - , and
David J. Vocadlo *
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Altered levels of intracellular protein glycosylation with O-linked β-N-acetylglucosamine (O-GlcNAc) have emerged as being involved in various cancers and neurodegenerative diseases. OGA inhibitors have proven critically useful as tools to help understand the roles of O-GlcNAc, yet accessing large quantities of inhibitors necessary for many animal studies remains a challenge. Herein is described a scalable method to produce Thiamet-G, a potent, selective, and widely used brain-permeable OGA inhibitor. This synthetic route begins with inexpensive precursor, requires no column chromatography, employs simple nontoxic reagents, and in a single campaign can furnish several hundred grams of crystalline Thiamet-G in an overall yield of 44% over six steps.
Synthesis of Tin Oxide Nanoparticles from E-Waste for Photocatalytic Mixed-Dye Degradation under Sunlight
Mandira Ghosh - ,
Debdyuti Mukherjee - ,
Celin Selvaraj - ,
Pritam Ghosh - , and
Sujoy Sarkar *
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Electronic waste (e-waste) has become a significant environmental concern worldwide due to the rapid advancement of technology and short product lifecycles. Waste-printed electronic boards (WPCBs) contain valuable metals and semiconductors; among them, tin can be recycled and repurposed for sustainable material production. This study presents a potential ecofriendly methodology for the recovery of tin from WPCBs in the form of tin oxide nanostructured powders. The soldering points in the WPCBs are extracted and dissolved in the dilute HNO3 solution, followed by the formation of metastannic acid, which is subsequently transformed into SnO2 nanoparticles. Different characterization techniques (XRD, XPS, FE-SEM, and TEM) are employed to confirm the morphology and composition of nanoparticles. The prepared SnO2 NPs, having a size range of <50 nm, show excellent photocatalytic degradation of cationic (methylene blue, MB) and anionic (eosin Y, EY) dyes for wastewater treatment. The as-synthesized SnO2 can degrade the mixed dyes (MB+EY) under the illumination of natural sunlight at rate constants of 0.0153 and 0.1103 min–1 for MB and EY, respectively. The positive zeta potential and smaller particle size of the SnO2 NPs possess the extra advantage of the adsorption of anionic over cationic dye, resulting in faster degradation of EY, which is further supported by DFT calculation. The synthesis of SnO2 from waste-printed electronic boards offers a dual benefit: It not only provides a sustainable solution for managing electronic waste but also contributes to the production of useful photocatalysts for wastewater treatment. By converting waste into valuable resources, this approach aligns with the principles of the circular economy and mitigates the environmental impact associated with e-waste disposal.
Charging and Discharging of Poly(m-aminophenylboronic Acid) Doped with Phytic Acid for Enzyme-Free Real-Time Monitoring of Human Sweat Lactate
Ryujiro Kishi - ,
Shoichi Nishitani - ,
Hiroyuki Kudo - , and
Toshiya Sakata *
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In this study, we realized a real-time and enzyme-free measurement of lactate in sweat in the same way as an enzyme-based amperometric method. A conductive polymer, which is based on polyaniline (PANI), was strongly coated on a glassy carbon electrode as a poly m-aminophenylboronic acid (PANI–PBA) membrane by drop-casting, which is a convenient method, owing to adhesive phytic acid (PA) molecules with negative charges included as a dopant. This polymer membrane had a functional structure with PBA in the PANI main chain, which expectedly induced electrical charges upon diol binding to lactate, owing to the formation of deprotonated boronate esters with negative charges. This indicates that PBA served as the self-dopant and as the site of binding to lactate. On the basis of the fundamental electrochemical characteristics such as the membrane resistance, the change in the current density of the PA-doped PANI–PBA electrode was quantitatively monitored with the change in lactate concentration from 1 to 300 mM under acidic conditions in real time, considering pH and interfering substances in sweat. Moreover, the sweat lactate concentration was determined to be ca. 60 mM using the PA-doped PANI–PBA electrode in a microfluidic system in measurements using sweat samples collected during exercise load. A change in current density induced a change in the density of charges in the capacitive PA-doped PANI–PBA membrane. This means that the detection mechanism for the change in the lactate concentration in sweat was based on repeated charging and discharging in the PA-doped PANI–PBA electrode.
Cooperative Molecular Interaction-Based Highly Efficient Capturing of Ultrashort- and Short-Chain Emerging Per- and Polyfluoroalkyl Substances Using Multifunctional Nanoadsorbents
Avijit Pramanik - ,
Olorunsola Praise Kolawole - ,
Sanchita Kundu - ,
Kaelin Gates - ,
Shivangee Rai - ,
Manoj K. Shukla - , and
Paresh Chandra Ray *
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The short-chain (C4 to C7) and ultrashort-chain (C3 to C2) per- and polyfluoroalkyl substances (PFAS) are bioaccumulative, carcinogenic to humans, and harder to remove using current technologies, which are often detected in drinking and environmental water samples. Herein, we report the development of nonafluorobutanesulfonyl (NFBS) and polyethylene-imine (PEI)-conjugated Fe3O4 magnetic nanoparticle-based magnetic nanoadsorbents and demonstrated that the novel adsorbent has the capability for highly efficient removal of six different short- and ultrashort-chain PFAS from drinking and environmental water samples. Reported experimental data indicates that by capitalizing the cooperative hydrophobic, fluorophilic, and electrostatic interaction processes, NFBS-PEI-conjugated magnetic nanoadsorbents can remove ∼100% short-chain perfluorobutanesulfonic acid within 30 min from the water sample with a maximum absorption capacity qm of ∼234 mg g–1. Furthermore, to show how cooperative interactions are necessary for effective capturing of ultrashort and short PFAS, a comparative study has been performed using PEI-attached magnetic nanoadsorbents without NFBS and acid-functionalized magnetic nanoadsorbents without PEI and NFBS. Reported data show that the ultrashort-chain perfluoropropanesulfonic acid capture efficiency is the highest for the NFBS-PEI-attached nanoadsorbent (qm ∼ 187 mg g–1) in comparison to the PEI-attached nanoadsorbent (qm ∼ 119 mg g–1) or carboxylic acid-attached nanoadsorbent (qm ∼ 52 mg g–1). In addition, the role of cooperative molecular interactions in highly efficient removal of ultrashort-chain PFAS has been analyzed in detail. Moreover, reported data demonstrate that nanoadsorbents can be used for effective removal of short-chain PFAS (<92%) and ultrashort-chain PFAS (<70%) simultaneously from reservoir, lake, tape, and river water samples within 30 min, which shows the potential of nanoadsorbents for real-life PFAS remediation.
Room-Temperature Deposition of δ-Ni5Ga3 Thin Films and Nanoparticles via Magnetron Sputtering
Filippo Romeggio *- ,
Rasmus Bischoff - ,
Clara B. Møller - ,
Victor L. Jensen - ,
Esteban Gioria - ,
Rikke Egeberg Tankard - ,
Rasmus S. Nielsen - ,
Ole Hansen - ,
Ib Chorkendorff - ,
Jakob Kibsgaard - , and
Christian D. Damsgaard *
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Magnetron sputtering is a versatile method for investigating model system catalysts thanks to its simplicity, reproducibility, and chemical-free synthesis process. It has recently emerged as a promising technique for synthesizing δ-Ni5Ga3 thin films. Physically deposited thin films have significant potential to clarify certain aspects of catalysts by eliminating parameters such as particle size dependence, metal–support interactions, and the presence of surface ligands. In this work, we demonstrate the potential of magnetron sputtering for the synthesis and analysis of thin film catalysts, using Ni5Ga3 as a model system. Initially, deposition conditions were optimized by varying the deposition pressure, followed by an investigation of the temperature effects, aiming to map a structure zone dependence on temperature and pressure as in the Thornton model. The evolution of film crystallinity was monitored using a combination of grazing incidence X-ray diffraction (GI-XRD) and high-resolution scanning electron microscopy (HR-SEM). Additionally, ultrathin films were synthesized and annealed in H2 at high temperatures to demonstrate the possibility of producing size-controlled nanoparticles by adjusting the annealing conditions. This work demonstrates the full potential of magnetron sputtering as a technique for synthesizing model system catalysts in various forms, opening new avenues for the research and development of additional catalytic systems.
Electrorefining of Crude Solder for the Production of Fine Solder in Methanesulfonic Acid Medium: Electrolyte Conductivity and Electrorefining Process
Yuhui Zhang - ,
Kunyun He - ,
Bingjie Jin *- , and
Jin Luan
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At present, the refining of crude solder has many drawbacks such as high energy consumption, high environmental pollution, equipment corrosion, and low current efficiency. Therefore, a new technique for refining crude solder is of great practical importance. In this work, the electrorefining of crude solder in methanesulfonic acid (MSA) medium was studied. The conductivities of tin─MSA solutions had been measured and modeled to characterize the electrolyte. The effects of the electrorefining conditions on the electrorefining process were investigated systematically. The cell voltage, current efficiency, and fine solder appearance were used to characterize the electrorefining performance. Some operating parameters of the electrorefining process are established as follows: current density 207 A/m2, tin concentration 120–160 g/L, free-MSA concentration 90–120 g/L, electrode spacing 4 cm, and temperature 305.15–315.15 K. Under these conditions, the average cell voltage is 0.30 V and the current efficiency is 99.31%. The total content of tin and lead of the fine solder with good product appearance is >99.99%. This technique offers low energy consumption, high productivity, and low environmental pollution.
Tunneling Times in an Asymmetric Harmonic Double-Well with Application to Electron Transfers in Biological Macromolecules
João Marcos Costa Monteiro *- and
Elso Drigo Filho
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Tunneling times were calculated in electron transfer processes using an asymmetric harmonic double-well model. The simplicity of a direct variational calculation in the approximate solution of the Schrödinger equation, along with the interpretation of tunneling times within the probabilistic framework of a two-level system, allows for the efficient and accurate determination of tunneling times with minimal computational cost. These calculations were applied to electron transfer processes in the study of the photosynthetic reaction center and in the context of catalysis in UV-induced DNA lesion repair and are in agreement with the experimental, computational, and theoretical results with which they were compared. It was seen that the donor–acceptor distance needed to be adjusted for closer agreement between the calculated and experimentally observed times. However, the adjusted values for this distance remain close to those reported in the literature.
Metal-Free Synthesis of Functionalized Indolizines via a Cascade Michael/SN2/Aromatization Reaction of 2-Alkylazaarene Derivatives with Bromonitroolefins
Kangbiao Chen - ,
Rui Zhou - ,
Gaofeng Zhu - ,
Lei Tang - ,
Lu Huang *- , and
Qing He *
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A transition metal-free domino Michael/SN2/aromatization annulation of 2-pyridylacetates with bromonitroolefins has been developed. A wide range of substrates containing various substituted groups was compatible with the present methodology and afforded functionalized indolizines with moderate to excellent yield (up to 99% yield). In addition, the potential practicality of the method stood out through scale-up reactions and further transformations to other valuable compounds. In our view, this study is an essential complement for the rapid construction of indolizine derivatives through a metal-free strategy.
December 7, 2024
Fast and Facile Synthesis of Cobalt-Doped ZIF-8 and Fe3O4/MCC/Cobalt-Doped ZIF-8 for the Photodegradation of Organic Dyes under Visible Light
Amin Mehrehjedy - ,
Piyush Kumar - ,
Zachary Ahmad - ,
Penelope Jankoski - ,
Anuraj S. Kshirsagar - ,
Jason D. Azoulay - ,
Xuyang He - ,
Mahesh K. Gangishetty - ,
Tristan D. Clemons - ,
Xiaodan Gu - ,
Wujian Miao - , and
Song Guo *
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Co-doped ZIF-8 as a water-stable visible light photocatalyst was prepared by using a one-pot, fast, cost-effective, and environmentally friendly method. The band structure of ZIF-8 was tuned through the incorporation of different percentages of cobalt to attain an optimal band gap (Eg) that enables the activation of ZIF-8 under visible light and minimizes the recombination of photogenerated charge carriers. A magnetic composite of Co-doped ZIF-8 was also synthesized to facilitate catalyst recycling and reusability through the application of an external magnetic field. Surface modification of magnetic Fe3O4 nanoparticles with microcrystalline cellulose (MCC) was used to reduce the level of agglomeration. The photocatalytic activities of Co-doped ZIF-8 (Co-ZIF-8) and Fe3O4/MCC/Co-ZIF-8 were evaluated for the photodegradation of methylene blue (MB) under visible light irradiation from a 20 W LED source. Co-ZIF-8 showed considerably higher photocatalytic activity than pure ZIF-8, confirming the success of the doping strategy. Both Co20%-ZIF-8 and Fe3O4/MCC/Co20%-ZIF-8 exhibited similar and remarkable photocatalytic activity under visible light (achieving 97% MB removal). The mechanism of photodegradation of MB by Fe3O4/MCC/Co20%-ZIF-8 was studied, revealing a first-order degradation kinetics (k = 13.78 × 10–3 min–1), with peroxide and hole species as the predominant active reagents. The magnetic composite successfully displayed recyclability and reusability over multiple cycles with negligible reduction in MB photodegradation efficiency.
Flexible Nanostructured NiS-Based Electrochemical Biosensor for Simultaneous Detection of DNA Nucleobases
Prajakta N. Gaikwad - ,
Trishala R. Desai - ,
Souradyuti Ghosh - , and
Chitra Gurnani *
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Herein, we demonstrate a one-step, scalable, solution-processed method for the growth of nickel sulfide (NiS) nanostructures using single-source precursors (SSPs) on a flexible substrate as a versatile framework for simultaneous detection of four DNA nucleobases. The as-grown NiS nanostructures exhibit a broad bandgap range and spherical morphology with high surface area and significant porosity, as confirmed by SEM, TEM, and BET surface area analysis. Consequently, the NiS/Ni-foam electrode exhibited remarkable electrochemical performance toward the oxidation of A, G, T, and C due to its large surface area, high electrode activity, and efficient electron transfer capacity. Under the optimum conditions, the electrode demonstrated selective and simultaneous detection of all four nucleobases over a wide linear range from 200 to 1000 μM for A and G, and 50 to 500 μM for T and C, with a low limit of detection of 159 μM for A, 147.6 μM for G, 16.8 μM for T, and 45.9 μM for C, along with high sensitivity of 1.2 × 10–4 A M–1 for A, 6.1 × 10–4 A M–1 for G, 1.2 × 10–3 A M–1 for T, and 3.0 × 10–4 A M–1 for C. The as-fabricated electrode revealed excellent reproducibility and stability toward nucleobase detection and demonstrated a reliable DPV response under different bending and twisting conditions. For immediate practical application, NiS/Ni-foam was utilized to quantify the concentration of all nucleobases in calf thymus and Escherichia coli (E. coli) DNA, resulting in a (G + C)/(A + T) ratio of 0.79 and 1.10, respectively. This simple, cost-effective, and flexible NiS/Ni-foam electrode paves the way for the development of non-invasive, wearable biosensors for potential applications in early disease detection.
Innovative Approach to Sustainable Fertilizer Production: Leveraging Electrically Assisted Conversion of Sewage Sludge for Nutrient Recovery
Gerardine G. Botte *- ,
Dayana Donneys-Victoria - ,
Christian E. Alvarez-Pugliese - ,
Jedidian Adjei - ,
Selin Sahin - ,
Nathan W. Wilson - ,
Kayleigh Millerick - ,
Amy Hardberger - ,
Ariel L. Furst - ,
Nicole Hu - , and
Andrew J. Medford
This publication is Open Access under the license indicated. Learn More
Efforts addressing sludge management, food security, and resource recovery have led to novel approaches in these areas. Electrically assisted conversion of sludge stands out as a promising technology for sewage sludge valorization, producing nitrogen and phosphorus-based fertilizers. The adoption of this technology, which could lead to a fertilizer circular economy, holds the potential to catalyze a transformative change in wastewater treatment facilities toward process intensification, innovation, and sustainability. This paper provides insights into the economic aspects of the technology, policy considerations, and challenges involved in realizing the potential of electrified processes for sludge valorization. To demonstrate the impact of the technology, a case study for its implementation in the United States assuming the municipal wastewater treatment plants market is discussed. It was found that electrically assisted sludge conversion could enable the recovery of nitrogen and phosphorus from waste, representing up to 9% of the nitrogen and 32% of the phosphorus consumption of the U.S. for fertilizer use. This technology also enables full electrification and modularization of the process, thereby presenting significant economic and environmental opportunities.
December 6, 2024
Photocatalytic Estrogen Degradation by the Composite of Tin Oxide Fine Particles and Graphene-like Carbon Nitride
Yuzuki Amino - ,
Ayar Al-zubaidi - ,
Yosuke Ishii - , and
Shinji Kawasaki *
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This study investigates whether 17β-estradiol (E2), a natural estrogen and one of the endocrine-disrupting chemicals responsible for water pollution, can be oxidatively decomposed under simulated solar light using a composite of tin oxide nanoparticles and graphene-like carbon nitride (g-CN) as a photocatalyst. The composite photocatalyst was prepared by heating a mixture of urea and tin acetate. FT-IR measurements revealed that g-CN possesses structural units similar to g-C3N4, a well-studied graphite-like carbon nitride. However, unlike g-C3N4, sharp diffraction lines were not observed in the XRD diffraction pattern of g-CN, indicating lower crystallinity. Elemental analysis showed that g-CN is slightly nitrogen-rich compared to g-C3N4, and UV–vis measurements indicated that the band gap of g-CN is slightly smaller than that of g-C3N4. The presence of tin in the composite of tin oxide and g-CN was clearly confirmed by XPS, although no sharp diffraction peaks were observed in the XRD patterns, suggesting the presence of microcrystals. Furthermore, FE-SEM observations did not reveal large tin oxide crystals, although EDS mapping indicated the presence of tin oxide. It was found that the prepared tin oxide and g-CN composites function effectively as photocatalysts for degrading E2 under simulated solar light. The degradation rate constant was evaluated to be k = 3.34 (0.14) × 10–2 min–1. Peroxide ion radicals were detected in ESR measurements from the irradiated solution, suggesting that peroxide ion radicals are generated through oxygen photoreduction as the counter-reaction of the oxidative decomposition of E2.
Internal State of Vesicles Affects Higher Order State of Vesicle Assembly and Interaction
Silvia Holler - ,
Federica Casiraghi - , and
Martin Michael Hanczyc *
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Dynamic soft matter systems composed of functionalized vesicles and liposomes are typically produced and then manipulated through external means, including the addition of exogenous molecules. In biology, natural cells possess greater autonomy, as their internal states are continuously updated, enabling them to effect higher order properties of the system. Therefore, a conceptual and technical gap exists between the natural and artificial systems. We engineered functionalized vesicles to form multicore aggregates capable of self-assembly due to the presence of complementary ssDNA strands. A dynamic process was then triggered through an exogenously triggered on-demand release of an endogenously produced displacer molecule, resulting in multicore aggregate disassembly. This approach explores how internal states of vesicles can affect the external organization, demonstrating a very simple programmable strategy for assembly and then endogenous disassembly. This framework supports the exploration of larger and more complex multicore entities, opening a path toward community behavior and a higher degree of autonomy.
Mechanochemical Synthesis of Molecular Chemoreceptors
Jakub S. Cyniak - and
Artur Kasprzak *
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The design of environmentally friendly methods for synthesizing molecular receptors is an expanding area within applied organic chemistry. This work systematically summarizes advances in the mechanochemical synthesis of molecular chemoreceptors. It discusses key achievements related to the synthesis of chemoreceptors containing azine, Schiff base, thiosemicarbazone, hydrazone, rhodamine 6G, imide, or amide moieties. Additionally, it highlights the application potential of mechanochemically synthesized molecular chemoreceptors in the recognition of ions and small molecules, along with a discussion of the mechanisms of detection processes.
TIHI Toolkit: A Peak Finder and Analyzer for Spectroscopic Data
Kyunghoon Han *- ,
Ariadni Boziki - ,
Alexandre Tkatchenko - , and
Joshua T. Berryman
This publication is Open Access under the license indicated. Learn More
Complex signal vectors, particularly spectra, are integral to many scientific domains. Interpreting these signals often involves decomposing them into contributions from independent components and subtraction or deconvolution of the channel and instrument noise. Despite the fundamental nature of this task, researchers frequently rely on costly commercial tools. To make such tools accessible to all, we present Tihi, interactive, open-source multiplatform software for interpolation, denoising, baseline correction, peak detection, and signal decomposition. Tihi provides a user-friendly graphical interface (GUI) that facilitates the analysis of spectroscopic data and more. It allows researchers to contribute to and freely distribute these tools, ensuring broad accessibility and fostering collaborative improvements. We present examples demonstrating the efficiency of the program using the spectra of different systems acquired by different spectroscopic techniques, including Raman (aspirin), IR (solid ammonia), XRD (anatase), and UV–vis (petal tip from the Puya alpestris flower). These examples showcase a variety of spectra that differ significantly, from signals with narrow profiles to signals with very broad profiles. This demonstrates the versatility of Tihi for peak identification in a wide range of spectroscopic techniques.
Origin, Distribution, and Influential Factors of Organic Acids in Deep and Ultradeep Clastic Reservoirs within the Fukang Sag of the Junggar Basin
Wenjun Pang - ,
Jing Li *- ,
Shixin Zhou *- ,
Liangliang Liu - ,
Yaoyu Li - ,
Hao Wang - , and
Gengrong Chen
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In deep and ultradeep clastic reservoirs, secondary porosity functions as the primary space for hydrocarbon storage, intricately associated with the dissolution processes of water-soluble organic acids (WSOAs). However, conventional theories concerning secondary porosity predominantly emphasize medium-depth or shallow reservoirs, lacking a thorough investigation into how WSOA-driven mechanisms affect deeper strata formations. To bridge this gap, our research involved selecting 36 samples from Mesozoic Permian clastic rock formations situated in western China’s Fukang Sag within the Junggar Basin region. We performed comprehensive analyses utilizing the Soxhlet extraction method combined with qualitative and quantitative assessments via 940 ion chromatography (Metrohm AG). These findings were integrated with oilfield production data to investigate the sources, composition, distribution characteristics, and influencing factors associated with organic acids in deep and ultradeep clastic reservoirs. Our investigation revealed that WSOAs persist even within ultradeep reservoirs; increased buried depths initially lead to a rise in WSOA concentrations followed by a subsequent decline. Similarly, effective porosities closely mirrored these trends alongside variations observed across WSOA concentrations while permeability remained consistently low yet stable throughout these transitions. This indicated significant involvement of WSOAs during dissolution processes contributing to the creation and maintenance of secondary pore spaces. Furthermore, notable positive correlations have emerged establishing a direct relationship between WSOA generation concentrations and corresponding shifts in formation pressures and temperatures. In deep and ultradeep reservoirs, the concentration of organic acids exhibits an initial increase followed by a subsequent decrease in response to escalating formation temperature and pressure. These findings underscore the critical roles played by key influential factors associated with WSOAs in these geological settings.
Thermodynamics of Tl2PrBr5 Compound and Re-examination of Phase Equilibria in the PrBr3–TlBr System
Beata Salamon-Baran *- ,
Jan Kapała - ,
Leszek Rycerz - , and
Irena Szczygieł
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The PrBr3–TlBr phase diagram was first established in the 1970s. Due to some inaccuracies, it was redetermined using differential scanning calorimetry. The results obtained differ significantly from those in the literature, which has been discussed in this paper. Only one congruently melting Tl2PrBr5 was confirmed, and the thermodynamic characterization of molar heat capacity temperature dependence was carried out for this compound. The compatibility of the obtained data was examined by using the CALPHAD method. The dependences of mixing enthalpy and mixing entropy of the liquid phase on the mole fraction were estimated.
Phase Change Materials for Energy Storage Applications from PEG and PBAT with AlN and CNT as Fillers
Eyob Wondu - ,
Wondu Lee - ,
Minsu Kim - ,
Dabin Park - , and
Jooheon Kim *
This publication is Open Access under the license indicated. Learn More
This study investigates the fabrication of phase change material–poly(butylene adipate-co-terephthalate) (PCM–PBAT) composites through melt blending techniques, focusing on the impact of isophorone diisocyanate (IPDI) treatment on carbon nanotubes (CNTs) and (3-aminopropyl)triethoxysilane (APTES) treatment on aluminum nitride (AlN) particles. Analysis of mechanical properties highlights an enhancement in tensile strength with APTES-treated AlN particles, while dynamic mechanical analysis (DMA) reveals an increase in stiffness. Laser flash analysis (LFA) investigation demonstrates a significant increase, up to 325%, in thermal conductivity compared to PCM–PBAT composites without filler. Moreover, the fabricated composites exhibit enhanced latent heat storage capabilities, with the PCM–PBAT composite containing 30% filler (20PCM–PBAT–30F) showing promising latent heat values. These findings underscore the efficacy of selecting an appropriate PCM–PBAT ratio and surface functionalization of the filler particles in enhancing the latent heat storage and thermal and mechanical properties of the polymer composites, suggesting their potential application across diverse fields.
Structure-Based QSAR Modeling of RET Kinase Inhibitors from 49 Different 5,6-Fused Bicyclic Heteroaromatic Cores to Patent-Driven Validation
Sumin Jin - ,
Surendra Kumar - , and
Mi-hyun Kim *
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RET receptor tyrosine kinase is crucial for nerve and tissue development but can be an important oncogenic driver. This study focuses on exploring the design principles of potent RET inhibitors through molecular docking and 3D-QSAR modeling of 5,6-fused bicyclic heteroaromatic derivatives. First of all, RET inhibitors of 49 different bicyclic substructures were collected from five different data sources and selected through molecular docking simulations. QSAR models were built from the 3399 conformers of 952 RET inhibitors using the partial least-squares method and statistically evaluated. The optimal QSAR model exhibited high predictive performance, with R2 (of training data) and Q2 (of test data) values of 0.801 and 0.794, respectively, effectively predicting known inhibitors. The optimal model was doubly verified by patent-filed RET inhibitors as the out-of-set data to demonstrate acceptable residual analysis results. Moreover, feature importance analysis of the QSAR model outlined the impact of substituent characteristics on the inhibitory activity within the 5,6-fused bicyclic heteroaromatic core structures. Furthermore, the relationship between structure and inhibitory activity was successfully applied to the RET screening of known clinical and nonclinical kinase inhibitors to afford accurate off-target prediction.
Sensing the Future─Frontiers in Biosensors: Exploring Classifications, Principles, and Recent Advances
Sumitha Manoharan Nair Sudha Kumari *- and
Xavier Thankappan Suryabai *
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Biosensors are transforming healthcare by delivering swift, precise, and economical diagnostic solutions. These analytical instruments combine biological indicators with physical transducers to identify and quantify biomarkers, thereby improving illness detection, management, and patient surveillance. Biosensors are widely utilized in healthcare for the diagnosis of chronic and infectious diseases, tailored treatment, and real-time health monitoring. This thorough overview examines several categories of biosensors and their uses in the detection of numerous biomarkers, including glucose, proteins, nucleic acids, and infections. Biosensors are commonly classified based on the type of transducer employed or the specific biorecognition element utilized. This review introduces a novel classification based on substrate morphology, offering a comprehensive perspective on biosensor categorization. Considerable emphasis is placed on the advancement of point-of-care biosensors, facilitating decentralized diagnostics and alleviating the strain on centralized healthcare systems. Recent advancements in nanotechnology have significantly improved the sensitivity, selectivity, and downsizing of biosensors, rendering them more efficient and accessible. The study examines problems such as stability, reproducibility, and regulatory approval that must be addressed to enable the widespread implementation of biosensors in clinical environments. The study examines the amalgamation of biosensors with wearable devices and smartphones, emphasizing the prospects for ongoing health surveillance and individualized medical care. This viewpoint clarifies the distinct types of biosensors and their particular roles, together with recent developments in the “smart biosensor” sector, facilitated by artificial intelligence and the Internet of Medical Things (IoMT). This novel approach seeks to deliver a comprehensive evaluation of the present condition of biosensor technology in healthcare, recent developments, and prospective paths, emphasizing their significance in influencing the future of medical diagnostics and patient care.
Enhancing Optical and Electrical Performances via Nanocrystalline Si-Based Thin Films for Si Heterojunction Solar Cells
Bingquan Liang - ,
Xinliang Chen *- ,
Heze Yuan - ,
Xuejiao Wang - ,
Guofu Hou - ,
Ying Zhao - , and
Xiaodan Zhang
This publication is Open Access under the license indicated. Learn More
Silicon heterojunction (SHJ) solar cells, as one of the most promising passivated contact solar cell technologies of the next generation, have the advantages of high conversion efficiency, high open-circuit voltage, low-temperature coefficient, and no potential-induced degradation. For the single-side rear-emitter SHJ solar cells, the n-type carrier selective layer, which serves as the light-incident side, plays a pivotal role in determining the performance of heterojunction devices. Consequently, a superior n-doped layer should exhibit high optical transmittance and minimal optical absorption, along with a substantial effective doping level to guarantee the formation of dark conductivity (σd) and electron-transport capacity. In this work, we investigated the optical and electrical properties of different n-type monolayers and stacked gradient multilayers, including monolayer, bilayer, and trilayer Si-based thin films, acting as electron-transport layers (ETL) prepared by plasma-enhanced chemical vapor deposition, and studied the influences of these above layers on the performance of SHJ solar cells. The experimental results demonstrate that the ETL with an n-nc-Si:H/n-nc-SiOx:H/n+-nc-Si:H trilayer structure exhibits the potential to boost highly efficient solar cells. The bottom highly crystallized, lightly phosphorus-doped n-nc-Si:H film promotes rapid nucleation of the intermediate n-nc-SiOx:H film and thus reduces the thickness of the incubation layer, as well as improves the passivation contact. The n-nc-SiOx:H film in the middle layer provides excellent optical properties and reduces parasitic absorption, thereby increasing the short-circuit current density. Furthermore, the highly doped n+-nc-Si:H at the top offers an optimal ohmic contact with the reactive plasma deposition-grown TCO layer, which ultimately enhances the fill factor. Ultimately, a conversion efficiency of 20.41%, with an open-circuit voltage of 720 mV, a short-circuit current density of 39.34 mA/cm2, and a filling factor of 72.05%, was achieved in the SHJ solar cell using a typical trilayer structure. This kind of trilayer structure has a particular significance for potential industrialized applications as it allows for efficient utilization of solar energy.
Formulation of Polymer-Augmented Surfactant-Based Oil–Water Microemulsions for Application in Enhanced Oil Recovery
Debanjan Ray - ,
Lavisha Jangid - ,
Dinesh Joshi - ,
Shubham Prakash - ,
Keka Ojha - ,
Ofer Manor - , and
Ajay Mandal *
This publication is Open Access under the license indicated. Learn More
This research explores the development of engineered oil–water microemulsions stabilized by a synergistic combination of polymer and surfactant to enhance stability and interfacial properties for improved enhanced oil recovery (EOR). Conventional surfactant-stabilized emulsions often suffer from phase instability and limited wettability alteration during water flooding and chemical injection, hindering the EOR efficiency. In contrast, our formulations incorporating polymers significantly increase the emulsion viscosity and resilience to temperature fluctuations, resulting in enhanced phase stability. Experimental investigations reveal that while the water-microemulsion interfacial tension (IFT) increases with salinity, the oil-microemulsion IFT decreases substantially, achieving an optimal IFT of 4.43 × 10–4 mN/m at balanced salinity levels. The microemulsions exhibit remarkable stability across varying temperatures, successfully transitioning between Winsor type II and III phases, which is critical for effective EOR applications. Notably, the addition of polymers enhances the viscosity of the surfactant-stabilized emulsion from 50 mPa·s at a shear rate of 10 s–1 to 300 mPa·s, significantly improving emulsion stability, as confirmed by measured zeta potential values of −31.1 mV for the surfactant system and −33.2 mV for the polymer-augmented surfactant system. These enhancements contribute to improved sweep efficiency during the oil recovery processes. Furthermore, the microemulsions effectively alter the sandstone wettability from oil-wet to water-wet, promoting better oil displacement. Core flooding experiments demonstrate that injecting one pore volume of the polymer-augmented surfactant-stabilized microemulsion results in an additional 20.58% oil recovery compared with conventional water flooding.
December 5, 2024
Ellagic Acid Induces DNA Damage and Apoptosis in Cancer Stem-like Cells and Overcomes Cisplatin Resistance
Tanima Mandal - ,
Devendra Shukla - ,
Subhamoy Pattanayak - ,
Raju Barman - ,
Rahail Ashraf - ,
Amit Kumar Dixit - ,
Sanjay Kumar - ,
Deepak Kumar - , and
Amit Kumar Srivastava *
This publication is Open Access under the license indicated. Learn More
Cancer stem cells (CSCs) are responsible for chemoresistance and tumor relapse in many solid malignancies, including lung and ovarian cancer. Ellagic acid (EA), a natural polyphenol, exhibits anticancer effects on various human malignancies. However, its impact and mechanism of action on cancer stem-like cells (CSLCs) are only partially understood. In this study, we evaluated the therapeutic potential and underlying molecular mechanism of EA isolated from tropical mango against CSLCs. Herein, we observed that EA treatment reduces the stem-like phenotypes in cancer cells, thereby lowering the cell survival and self-renewal potential of ovarian and lung CSLCs. Additionally, EA treatment limits the populations of lung and ovarian CSLCs characterized by CD133+ and CD44+CD117+, respectively. A mechanistic investigation showed that EA treatment induces ROS generation by altering mitochondrial dynamics, causing changes in the levels of Drp1 and Mfn2, which lead to an increased level of accumulation of DNA damage and eventually trigger apoptosis in CSLCs. Moreover, pretreatment with EA sensitizes CSLCs to cisplatin treatment by enhancing DNA damage accumulation and impairing the DNA repair ability of the CSLCs. Furthermore, EA pretreatment significantly reduces cisplatin-induced mutation frequency and improves drug retention in CSLCs, potentially suppressing the development of acquired drug resistance. Taken together, our results demonstrate an unreported finding that EA inhibits CSLCs by targeting mitochondrial function and triggering apoptosis. Thus, EA can be used either alone or in combination with other chemotherepeutic drugs for the management of cancer.
Validation of a Simple HPLC/UV Method for Assay and In Vitro Release of Glycosaminoglycan from Pharmaceutical Formulations
Gokselin Ozgen - ,
Nahide Zeren Arda Ozturk - ,
Gokce Turan - ,
Merve Turk - ,
Evren Homan Gokce - ,
Ozgen Ozer - ,
Hayriye Icin - ,
Gonul Kayar - ,
Enis Isik - ,
Udaya Kumar Dude - , and
Sakine Tuncay Tanrıverdi *
This publication is Open Access under the license indicated. Learn More
This study encompasses the validation of a simple, rapid, and sensitive HPLC/UV method developed in accordance with the guidelines set by ICH Q2(R2) for obtaining the active pharmaceutical ingredient from the glycosaminoglycan family in topical formulations. Previous methods reported for analyzing glycosaminoglycans in semisolid formulations are relatively complex and time-consuming, involving extraction, purification, and derivatization. This developed analytical method allows for straightforward extraction of the active pharmaceutical ingredient from the matrix, enabling the direct injection of samples. This method was performed and validated for the assay of the pharmaceutical gel and cream formulations to investigate the parameters of linearity (r = 0.9997 for the gel formulation and r = 0.9993 for the cream formulation), precision, accuracy, specificity, and robustness by HPLC/UV. Additionally, this method was used to determine the active ingredient in in vitro release studies. In vitro similarity correlation against commercial products was performed according to the Mann–Whitney U statistical test. The similarity results were 96.5–102.7% for the gel formulation and 98.0–106.0% for the cream formulation, which remained within the limits (75–133.33%) according to USP 1724. This proved that in vitro release profiles for both formulations were like those of the commercial product. In light of the research findings, we believe that the HPLC/UV analysis presented can be further enhanced in the future for determining the levels of active ingredients in various pharmaceutical formulations or for monitoring the levels of glycosaminoglycans in biological matrixes.
Silver Nanowire-Coated Porous Alginate Films for Wound Dressing Applications: Antibacterial Activity, Cell Proliferation, and Physical Characterization
Nilay Kahya - ,
Aslin Kartun - ,
Işık Neslişah Korkut - ,
Canan Usta - ,
Dürdane Serap Kuruca - , and
Alper Gürarslan *
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In the present study, porous calcium alginate films have been developed by the addition of 0.02, 0.1, and 0.5% (w/v) PVA to sodium alginate film solutionss. Poly(vinyl) alcohol played the role of a pore-forming agent for calcium alginate films, and the controlled pore sizes of the films were investigated by scanning electron microscopy and Fourier transform infrared spectroscopy analyses. Human fibroblast cell attachment was performed on the porous calcium alginate films (0.5-Ca-Alg), and then the film was coated with 1 and 3 wt % silver nanowires. Cell proliferation was enhanced on films after the coating of the silver nanowires. The MTT assay was performed on the calcium alginate films and silver nanowire-coated films, and the films were found to be nontoxic to human foreskin fibroblast cells at the end of 72 h of exposure. The existence of silver nanowires on the porous calcium alginate film endowed the material with good antibacterial activity. The swelling ability of the porous and silver nanowire-coated film (0.5-Ca-Alg-1/AgNW) increased by ∼64% in simulated body fluid (pH = 7.4) and distilled water compared to a nonporous film (Ca-Alg). The water vapor transmission rate of Ca-Alg was ∼45% enhanced thanks to the porosity of films and the existence of AgNW. Hereby, it is demonstrated that the novel silver nanowire-doped porous alginate materials would be potential wound dressing agents with desired physical properties, antibacterial activity, and availability to cell proliferation.
C–H Functionalization of Imidazo[1,5-a]pyridines: A Metal-Free Approach for Methylene Insertion to Access C(sp2)–C(sp3)–H–C(sp2) Bond Formation
Shivangani Mahajan - and
Sanghapal D. Sawant *
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Formaldehyde has been used as a solvent and a source of carbon to insert a methylene group for bridging two imidazo[1,5-a]pyridine molecules without using any metal catalysis. This strategy has been extended on other alkyl-, aryl-, and heteroaryl aldehydes as well. This C(sp2)–C(sp3)–H–C(sp2) bond forming reaction proceeds via C(sp2)H functionalization of imidazo[1,5-a]pyridine and was applied on a wide range of substrates offering moderate to good yields of methylene-bridged/inserted bis-imidazo[1,5-a]pyridines. Most importantly, as an application, the bis-heteroarene product has been demonstrated as a ligand. The ligand-like behavior of bis-imidazo[1,5-a]pyridines has been demonstrated as an extension of current methodology. This reaction works well at the gram scale level.
Strategically Designed Ternary Nanohybrids of Titanate Nanosheet and Polydopamine-Coated Carbon Nanotubes for Highly Efficient Enrichment of Uranium(VI)
Zhiyang Jiang - ,
Yuzhi Zhou *- ,
Wenshuo Wang - ,
Zheng Yin - ,
Mingze Zhao - ,
Lei Yu - ,
Sijie Ren - ,
Han Xiao - , and
Yanfang Ma
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A strategically designed ternary nanohybrid (TNS-PDA/CNT), consisting of titanate nanosheet (TNS) and polydopamine-modified multiwalled carbon nanotube (PDA/CNT composite), was synthesized by the facile hydrothermal method and wet impregnation method for removal of U(VI) from aqueous solution and were characterized by transmission electron microscopy (TEM), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), Raman spectroscopy, Brunauer–Emmett–Teller (BET), and X-ray photoelectron spectroscopy (XPS). TNSs were introduced into the PDA/CNT composite, which effectively averted the agglomeration of the CNT and further exposed more adsorption sites. PDA thin layer exposing more active sites was conducive to enhance adsorption capacity and kinetic. The adsorption process was largely influenced by pH values and weakly affected by ionic strength, indicating that the adsorption process was controlled by inner-sphere surface complexes because of TNS-PDA/CNT with multiple functional groups, including imine, catechol, amine, and hydroxyl groups. The isotherm data could be well described by the Langmuir model, and the monolayer maximum adsorption was determined to be 309.60 mg/g at pH = 5.0 and temperature = 45 °C. Thermodynamic parameters (ΔG° < 0, ΔS° > 0, and ΔH° < 0) showed that the nature of adsorption was endothermic and spontaneous. By XRD, FT-IR, and XPS analyses, the adsorption mechanism mainly involved surface complexation and ion exchange. In summary, the TNS-PDA/CNT materials are fully qualified as a satisfactory adsorbent for the purification and recovery of U(VI) from wastewater.
Dopant-Free Spiro-OMe2 Imidazole-Based Hole-Transporting Material for Stable and Low-Cost Organic–Inorganic Perovskite Solar Cell
Leila Haji-khan Mirzaei - ,
Hashem Shahroosvand *- ,
Afsaneh Farokhi - ,
Elahe Bayat - ,
Sebastiano Bellani *- ,
Cosimo Anichini - ,
Mohsen Ameri - , and
Francesco Bonaccorso *
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The engineering of charge transport materials, with electronic characteristics that result in effective charge extraction and transport dynamics, is pivotal for the realization of efficient perovskite solar cells (PSCs). Herein, we elucidate the critical role of terminal substituent methoxy groups (−OCH3) on the bandgap tuning of the spiro-like hole transport materials (HTMs) to realize performant and cost-effective PSCs. By considering spiro-OMeTAD as the benchmark HTM, we kept the backbone of spiro while replacing diphenylamine with phenanthrenimidazole. This approach significantly decreases the cost of spiro-OMeTAD by reducing the cost of the ancillary group from 0.051 to 0.012 $/g. By increasing the number of methoxy groups on the ancillary ligand from four to eight, the power conversion efficiency (PCE) of the corresponding PSCs containing dopants passed from 17.10% to 18.70%, approaching the value achieved using spiro-OMeTAD containing dopants (PCE = 19.26%). Remarkably, the devices based on dopant-free spiro-OMeTAD have shown a significant loss of PCE, which decreased from 12.9% to 10.1% after 300 h (to 8.2% after 600 h) of light soaking at an open circuit voltage. On the contrary, the cells based on the designed dopant-free HTM demonstrated optimal PCE retention, experiencing a minor drop from 14.4% to 14.1% and 13.2% after 300 and 600 h, respectively, of light soaking at open-circuit voltage.
Toward Pore Size-Selective Photoredox Catalysis Using Bifunctional Microporous 2D Triazine-Based Covalent Organic Frameworks
Melika Eshaghi Kenari - ,
Sayan Maiti - ,
Jianheng Ling - ,
Xena El-Shamy - ,
Hiren Bagga - ,
Matthew A. Addicoat - ,
Phillip J. Milner - , and
Anindita Das *
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The design and synthesis of photoactive metal-free 2D materials for selective heterogeneous photoredox catalysis continue to be challenging due to issues related to nonrecyclability, and limited photo- and chemical stability. Herein, we report the photocatalytic properties of a triazine-based porous COF, TRIPTA, which is found to be capable of facilitating both SET (single electron transfer) for photocatalytic reductive debromination of phenacyl bromide in absence of oxygen and generation of reactive oxygen species (ROS) for benzylamine photo-oxidation in the presence of oxygen, respectively, under visible light irradiation. Inspired by the latter results, we further systematically investigated different-sized benzylamine substrates in this single-component reaction and compared the results with an analogous COF (Micro-COF-2) exhibiting a larger pore size. We observed a marked improvement in the conversion of larger-sized substrates with the latter COF, thereby demonstrating angstrom-level pore size-selective photocatalytic activity of COFs.
Experimental Study of Sawdust Syngas Gasification in Bench-Scale Gasifier and Three-Dimensional Numerical Analysis for Syngas Cocombustion in a 600 MW Coal-Fired Boiler Furnace
Lachun Ren - ,
Xinxin Shang - ,
Jingjing Xie *- ,
Jiechao Chen *- , and
Yanan Gu
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To comprehensively explore syngas cocombustion technology, gasification experiments in a bench-scale circulating fluidized bed (CFB) and three-dimensional (3D) numerical simulations of a coal-fired boiler furnace have been conducted. In the amplification experiment of biomass gasification, sawdust has been gasified using air, oxygen-enriched air, and steam. The highest heating value of the syngas products reaches 12.3 MJ/m3 when the equivalence and steam/biomass ratios are adjusted in the ranges of 0.21–0.31 and 0.1–0.5, respectively. Subsequently, 3D numerical simulation has been performed with several kinds of syngas product to analyze the cocombustion characteristics of the boiler furnace. Results demonstrate that the velocity field of the boiler furnace exhibits a well-formed tangential velocity circle and full degree of streamlines. Syngas cocombustion in the coal-fired furnace reduces the temperature extremum in the combustion zone. Radiant heat flux accounts for >88% of the total heat flux in the furnace. The outlet NO concentration in the case of syngas cocombustion is less than that of pure coal combustion, and it is reduced approximately 25 and 40 mg/m3 at cocombustion ratios of 0.1 and 0.15, respectively.
Decreased Secondary Electron Emission from Aluminum Surface by a Fluorocarbon–Titanium Composite Film
Feipeng Wang *- ,
Jie He - ,
Qi Zhao *- ,
Zhicheng Zhang - , and
Xiao Zhang
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Multipactor, a vacuum discharge under microwave conditions triggered by secondary electron emission (SEE), plays a critical role in managing the power level of microwave devices. In this study, we developed a fluorocarbon–titanium composite film on aluminum by cosputtering polytetrafluoroethylene (PTFE) and titanium via a controlled temperature and sputtering power ratio (RF power for PTFE to DC power for Ti) to suppress the SEE of Al. The evolution of microtopography and chemical composition of the composite film was evaluated. An increasing power ratio varying from 0.5 to 3.0 is found to change the film surface from scattered island-like bumps to a prominent peak–valley pattern and eventually to a smooth surface with few flat swellings. Elemental analysis revealed that the fluorine-to-carbon (F/C) mole ratio in samples was more significantly influenced by the sputtering power ratio than by the substrate temperature. The SEE yield indicates that the peak–valley pattern prepared by a power ratio of 2 leads to the maximum of the SEE yield curve reducing steeply from 2.99 to 1.23, which is attributed not only to the roughed pattern but also to the high F/C mole ratio owing to the higher capacity of electron trapping by the fluorine atoms.
Innovative Emulsifiers in Cosmetic Products: A Patent Review (2013–2023)
Natalia Cortes - ,
Izabel Almeida Alves - , and
Diana Marcela Aragón *
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The cosmetics industry, characterized by innovation and dynamism, is constantly undergoing research, often guided by market trends. Although it covers various sectors, emulsifiers have had a notable impact on its development. Numerous products depend on these components, and continuous research has led to the creation of ever-better products. This Review analyzes emulsifiers for cosmetic use patented between 2013 and 2023, using Espacenet as the main database. Fifty-one patents were examined, considering the annual growth in publications, their geographic distribution, types of emulsifiers, their chemical and physical properties, chemical structures, emulsification mechanisms, and systems formed. An increase in the publication of patents was observed, with some decreases in certain years, highlighting that 86% of the patents come from China. The classification of emulsifiers revealed a predominance of those of natural origin, followed by polymeric, synthetic, and defined molecule compounds. The emulsification mechanisms of each group and the systems they formed according to the patents were also reviewed. In addition, trends in the physical and chemical properties of the emulsifiers were identified. This characterization demonstrates the growth in emulsifier research, which allows for the improvement of emulsions on the market, offering greater stability and functionality to develop superior cosmetic products.
Guiding Competitive Binding Assays Using Protein–Protein Interaction Prediction: The HER2–Affitin Use Case
Anna Ranaudo *- ,
Ugo Cosentino - ,
Claudio Greco - ,
Giorgio Moro - ,
Alessandro Maiocchi - , and
Elisabetta Moroni
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Affitins are a class of small artificial proteins, designed as alternatives to antibodies for therapeutic, diagnostic, and biotechnological applications. Recent patents by Bracco Imaging S.p.A have demonstrated the potential of two engineered affitins for designing imaging probes to detect and monitor human epidermal growth-factor receptor 2 (HER2) levels in vivo. Targeting HER2 is critical, as its overexpression is linked to poor prognosis of several cancer diseases, making it a key marker for treatment strategies and diagnostic tools. Interestingly, these affitins do not compete with the commonly used monoclonal antibodies trastuzumab and pertuzumab for HER2 binding sites, allowing their concurrent use in vivo and making them suitable for imaging or diagnostic purposes. Since these two affitins compete for the same yet unidentified binding site on HER2, structural insights into these interactions are essential for facilitating the design and development of more effective diagnostic tools and treatments. In this study, we used protein–protein docking and molecular dynamics simulations to model the binding of these affitins to HER2. The stability of the predicted complexes was quantified by using the DockQ parameter, a widely used metric for evaluating protein–protein docking predictions. The docking poses were then compared with HER2 sites likely to interact with a protein partner, as predicted by the matrix of local coupling energies method. The combination of these two computational methods allowed for the identification of the most likely docking poses. Comparative analysis with HER2-protein complexes from the Protein Data Bank suggests that both affitins may bind HER2 at the same epitopes as an antibody fragment and an affibody. These findings indicate that targeted competitive binding assays could efficiently reduce the experimental efforts to map the HER2–affitin interactions. The computational approach proposed in this study not only provides insights into this specific case but also establishes a robust framework applicable for facilitating the structural modeling and interaction prediction of other affitin–protein systems.
Insights into Rock Wettability Influencing Factors: A Review
Xiao Deng - ,
Ahmed Bashir - ,
Muhammad Shahzad Kamal *- ,
Arshad Raza - ,
Shirish Patil - ,
Xianmin Zhou - ,
Mohamed Mahmoud - , and
Syed Muhammad Shakil Hussain *
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Wetting characteristics of a hydrocarbon reservoir are generally quantified for cost-effective field development. The wetting process of rock by oil is a complex process involving reactions among compounds (rock, oil, and brine), the impact of environmental conditions (temperature, pressure, etc.), and treatment history (coring, transportation, etc.). There has not been much attention given to understanding the mechanisms causing different rock wetting states to quantify rock’s wettability. This work aims to provide an in-depth insight into rock wettability influencing factors including CO2 & H2. In addition, advanced computational approaches such as molecular dynamics simulation, computational fluid dynamics, and machine learning for wettability have also been reviewed to govern the undiscovered interactions and mechanisms of this complex process. The key observation is that the polarity of organic components (asphaltenes and long-chain acids) determines the oil wetness in crude oil. In addition, acidic polar organics dominate oil-wetting in carbonate rocks; basic polar organics are key in sandstone. Also, environmental factors such as water films, brine salinity, and pH influence wettability significantly.
Nonlinear Optical Response of Tetrel-Modified Tetraphenyl-Adamantane Clusters
Ferdinand Ziese *- and
Simone Sanna *
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The second harmonic generation (SHG) properties of adamantane-based tetraphenyl clusters are predicted from first principles and analyzed on the basis of the involved electronic transitions. In particular, the effect of a tetrel substitution in the cluster core on the nonlinear optical response is investigated. Electronic transitions spatially localized at the substituents are found to be responsible for the optical nonlinearities. The intensity of the SHG signal grows with the atomic number of the considered tetrel. As the substitution does not distort the cluster core or substantially alter its symmetry, the enhanced SHG intensity is traced to a higher electron density at the substituents. The latter results in a larger spatial overlap of the states involved in the electronic transitions, which increases their probability. The presented results provide a theoretical foundation for the design of tailored nonlinear optical sources.
Adaptations of Escherichia coli K 12 to Synchrotron Sourced THz Radiation
Elena P. Ivanova *- ,
The Hong Phong Nguyen - ,
Denver P. Linklater - ,
Phuc H. Le - ,
Zoltan Vilagosh - ,
Palalle G. Tharushi Perera - ,
Dominique R. T. Appadoo - ,
Jitraporn Vongsvivut - ,
Tanavi Sharma - ,
Michael G. Leeming - ,
Nicholas A. Williamson - ,
Eric Hanssen - ,
Chaitali Dekiwadia - ,
Mark J. Tobin - ,
Saulius Juodkazis - , and
Rodney J. Croft
This publication is Open Access under the license indicated. Learn More
The biological effects of electromagnetic field (EMF) irradiation in the terahertz (THz) range remain ambiguous, despite numerous studies that have been conducted. In this paper, the metabolic response of Escherichia coli K 12 to EMF irradiation was examined using a 1.0 W m–2 incident synchrotron source (SS) in the range of 0.5–18.0 THz for over 90 min of continuous exposure at 25 °C. This continuous SS THz exposure induced periodic decreases in the cell growth after 10, 20, and 40 min of exposure compared to a time-matched control; however, the number of viable cells thereafter grew. The physiological status of treated cells immediately after exposure was assessed by using the direct plate counting technique and electron microscopy. Analysis of scanning electron microscopy (SEM) and high-resolution cryogenic transmission electron (cryo-TEM) micrographs showed that approximately 20% of the SS THz-exposed E. coli cells exhibited a deformed outer membrane, membrane perturbations, and leakage of cytosol. The proteome changes in E. coli cells after 18 h postexposure were associated with cellular response to plasma membrane regulation including phospholipid biosynthetic process and osmotic stress. The results of this study highlighted that E. coli cells can promptly activate the fundamental mechanisms in response to prolonged exposure to THz radiation that are evolutionarily developed to withstand other environmental stressors.
Supramolecular Dimeric MnIII Complexes: Synthesis, Structure, Magnetic Properties, and Catalytic Oxidation Studies
Narayan Ch. Jana - ,
Zvonko Jagličić - ,
Paula Brandão - , and
Anangamohan Panja *
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In this study, a tetradentate Schiff-base ligand (H2L), synthesized by the condensation of ethylenediamine with 2-hydroxy-3-methoxy-5-methylbenzaldehyde, was reacted with either manganese salts or manganese salts in the presence of various pseudohalides in methanol. This reaction resulted in the formation of five mononuclear MnIII complexes: [Mn(L)(H2O)2](NO3)·1/2H2O·1/2CH3OH (1), [Mn(L)(H2O)2](ClO4)·H2O (2), [Mn(L)(N3)(H2O)]·1/3H2O (3), [Mn(L)(NCS)(H2O)] (4), and [Mn(L)(H2O)2](dca) (5) (where dca is dicyanamide ion). X-ray crystallography revealed that the MnIII centers adopt a hexa-coordinate pseudo-octahedral geometry, where the equatorial plane is constructed with phenoxo oxygen and imine nitrogen atoms from the Schiff base ligand, while the axial positions are occupied by water molecules or a combination of water and pseudohalides. Supramolecular interactions, primarily π–π stacking and hydrogen bonding, contribute to the formation of pseudodimeric structures in the solid state. Magnetic susceptibility measurements indicated antiferromagnetic coupling within quasi-dimers, primarily through hydrogen bonds. Catalytic studies showed that the complexes effectively catalyze the aerobic oxidation of substrates such as 2-aminophenol and 3,5-di-tert-butylcatechol to yield 2-aminophenoxazin-3-one and 3,5-di-tert-butylquinone, respectively. They also catalyze the oxidation of styrene to its corresponding oxirane, demonstrating their versatile catalytic proficiency. Mechanistic insights, supported by ESI mass spectrometry and EPR studies, suggest that catalysis involves the formation of a complex–substrate aggregate, followed by an intramolecular electron transfer.
Influence of Renewable Nano-Al2O3 on Engine Characteristics and Health Impact under Variable Injection Timings and Excess Air Coefficients
Zhefeng Guo - ,
Yu-Lun Hsieh - ,
Sheng-Lun Lin *- ,
Yen-Yi Lee - , and
Timothy H. Lee
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Nano-Al2O3 derived from recyclable sources emerges as a promising sustainable solution for enhancing diesel engine efficiency while mitigating emissions. However, a lack of an in-depth understanding of the health hazard aspect still challenges its commercial applications. To this end, nano-Al2O3/diesel (NAD) blends prepared via ultrasonic homogenization were experimentally and analytically investigated under various injection timings and excess air coefficients to explore the potential of nano-Al2O3 for balancing energy performance and emissions. Results revealed a synergistic effect between the NAD blends and optimized combustion control strategies. NAD blends presented enhanced heat release and pressure rise rates even under late injection or hypoxic conditions, indicating a faster and more complete combustion. Specifically, NAD blends promoted the partially premixed combustion phase and reduced postcombustion duration. While a slight increase in fuel consumption and a decrease in thermal efficiency were observed, potentially due to minor chamber compatibility issues, a significant improvement in emissions was identified. NAD blends effectively mitigated the well-known soot-particulate number-nitrogen oxide (NOx) trade-off inherent in diesel engines. NAD blends achieved lower NOx emissions through the even temperature distribution promoted by nano-Al2O3, minimizing the formation of NOx precursors. Simultaneously, NAD blends contributed to a reduction in soot emissions as well as an increment in nucleation mode particles, which are smaller and more harmful than conventional engine-out particulates. Notably, deposition modes highlighted that a higher nano-Al2O3 addition leads to an increase in nucleation mode particles, resulting in a higher alveolar deposition (dp = 5–100 nm) and lower nasal deposition (dp = 200–800 nm). These findings suggest that, by optimizing injection timing and excess air coefficients, NAD blends offer a promising approach to enhance combustion and achieve cleaner emissions simultaneously, making them a valuable contribution to the development of more sustainable diesel engine technologies.
Conformational Flexibility of D1-Glu189: A Crucial Determinant in Substrate Water Selection, Positioning, and Stabilization within the Oxygen-Evolving Complex of Photosystem II
Hiroshi Isobe *- ,
Takayoshi Suzuki - ,
Michihiro Suga - ,
Jian-Ren Shen - , and
Kizashi Yamaguchi
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Photosynthetic water oxidation is a vital process responsible for producing dioxygen and supplying the energy necessary to sustain life on Earth. This fundamental reaction is catalyzed by the oxygen-evolving complex (OEC) of photosystem II, which houses the Mn4CaO5 cluster as its catalytic core. In this study, we specifically focus on the D1-Glu189 amino acid residue, which serves as a direct ligand to the Mn4CaO5 cluster. Our primary goal is to explore, using density functional theory (DFT), how the conformational flexibility of the D1-Glu189 side chain influences crucial catalytic processes, particularly the selection, positioning, and stabilization of a substrate water molecule within the OEC. Our investigation is based on a hypothesis put forth by Li et al. (Nature, 2024, 626, 670), which suggests that during the transition from the S2 to S3 state, a specific water molecule temporarily coordinating with the Ca ion, referred to as O6*, may exist as a hydroxide ion (OH–). Our results demonstrate a key mechanism by which the detachment of the D1-Glu189 carboxylate group from its coordination with the Ca ion allows the creation of a specialized microenvironment within the OEC that enables the selective attraction of O6* in its deprotonated form (OH–) and stabilizes it at the catalytic metal (MnD) site. Our findings indicate that D1-Glu189 is not only a structural ligand for the Ca ion but may also play an active and dynamic role in the catalytic process, positioning O6* optimally for its subsequent participation in the oxidation sequence during the water-splitting cycle.
Celebrating 50 Years of Surface Enhanced Spectroscopy
Alexandre G. Brolo *- and
Nathan C. Lindquist *
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December 4, 2024
Effect of Oxygen Concentration on Volatile Precipitation and Critical Ignition Point
Yulong Li - ,
Xuechao Su - ,
Chaosheng Wang - ,
Wenjuan Wu - , and
Jie Liang *
This publication is Open Access under the license indicated. Learn More
The purpose of this study was to investigate the impact of the oxygen concentration on the ignition of bituminous coal. Different oxygen concentrations and temperatures were used in the large-scale oxidation experiments to collect oxidized coals, which were then extracted with chloroform. And compare the critical ignition temperature of different mass samples. The liquid samples obtained were analyzed by using GC-MS and Fourier transform infrared spectroscopy. Fourier transform infrared spectroscopy was also used to characterize extracted oxidized coal. The results revealed that the critical ignition point of bituminous coal decreases by 229.4 °C when the mass sample increases from 5 to 300g. Furthermore, at the same temperature, an increase in the oxygen concentration in the atmosphere was found to enhance the pyrolysis of bituminous coal. The oxidation activity of coal initially decreased and then increased with the temperature rise. The ether bond formed below 150 °C is oxidized and decomposed above 175 °C, which is closely related to the ignition of the coal seam.
Rolling Circle Amplification Integrating with Exonuclease-III-Assisted Color Reaction for Sensitive Telomerase Activity Analysis
Xiaoya Liu - ,
Xianxian Zhao - ,
Jie Zhang - ,
Yihan Wang - , and
Xiaoping Ye *
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Telomerase activation can lead to the escape from cell senescence and immortalization, playing a crucial role in the growth and proliferation of cancer cells. Therefore, the detection of telomerase activity is essential for cancer diagnosis and treatment. Herein, we develop a novel ultrasensitive and visually detectable platform. By incorporation of exonuclease-III (Exo-III), this platform achieves dual signal amplification of rolling circle amplification products. Additionally, the colorimetric analysis of 3,3′,5,5′-tetramethylbiphenyl (TMB) chromogenic reaction system provides this approach with unique advantages such as simplicity, speediness, and sensitivity. The detection platform exhibits high sensitivity and specificity in actual sample testing, which aligns closely with results obtained using commercial kits. Moreover, it offers ease-of-use through visual determination by the naked eyes. This finding indicates that our proposed sensing method performs satisfactorily in detecting telomerase in real biological samples. Henceforth, we believe that this sensing platform holds great potential for clinical diagnosis and anticancer drug development.
Ionic Dissolution Products of Lithium-, Strontium-, and Boron-Substituted Silicate Glasses Influence the Viability and Proliferation of Adipose Stromal Cells, Fibroblasts, Urothelial and Endothelial Cells
Inari Lyyra *- ,
Mari Isomäki - ,
Heini Huhtala - ,
Minna Kellomäki - ,
Susanna Miettinen - ,
Jonathan Massera - , and
Reetta Sartoneva
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While bioactive glasses (BaGs) have been studied mainly for bone applications, studies have also shown their potential for soft tissue engineering. Incorporating therapeutic ions, such as lithium (Li+), strontium (Sr2+), and boron (B3+) into the BaGs, has been found to promote angiogenesis and wound healing. However, a systematic study on the impact of Li+, Sr2+, B3+, and the other ions in the BaGs, has not been conducted on a wide range of cells. Although the interactions between the BaGs and cells have been studied, it is difficult to compare the results between studies and conclude the impact of BaGs between cell types due to the variability of culture conditions, cells, and materials. We aim to evaluate the dissolution behavior of Li-, Sr-, and B-substituted BaGs and the effects of their ionic dissolution products on the viability, proliferation, and morphology of multiple cell types: human adipose stromal cells (hASCs), human lung fibroblasts (cell line WI-38), human urothelial cells (hUCs), and human umbilical vein endothelial cells (HUVECs). In the dissolution study, the B-substituted glasses induced a higher increase in pH and released more ions than the silicate glasses. The undiluted BaG extracts supported the viability and proliferation of all the other cell types except the hUCs. Diluting the BaG extracts to 1:10 restored the viability of hUCs but induced distinctive morphological changes. Diluting the extracts more (1:100) almost fully restored the hUC morphology. To conclude, the ionic dissolution products of Li-, Sr-, and B-substituted BaGs seem beneficial for hASCs, WI-38, hUCs, and HUVECs, but attention must be paid to the ion concentrations.
Cooling Performance of TiO2-Based Radiative Cooling Coating in Tropical Conditions
Bhrigu Rishi Mishra - ,
Sreerag Sundaram - , and
Karthik Sasihithlu *
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The cooling power of radiative cooling (RC) coatings depends not only on the radiative properties of the coating but also on environmental variables. In tropical environments, the cooling performance of RC coatings deteriorates due to high humidity and high solar radiation. Previous studies focused on developing high solar-reflective coatings to achieve subambient cooling in tropical environments. However, these coatings have not demonstrated the ability to be used at a large scale, mainly due to their high cost or less durability. Herein, we test an RC paint coating composed of TiO2 and polydimethylsiloxane (PDMS) in three different cities with high and moderate humidity levels. Though a significant reduction in the internal temperature of an RC paint-coated aluminum (Al) box is observed, compared to an uncoated Al box, in both high and moderate humidity environments, subambient cooling is not achieved. A comprehensive analysis is conducted to clarify the reasons behind the inability to attain subambient cooling.
Soyasaponin Bb/Gelatin-Methacryloyl Hydrogel for Cartilage Inflammation Inhibition
Yuhan Jiang - ,
Tenghai Li - ,
Bingzhang Liu - ,
Yufeng Tian - ,
Yixin Wang - ,
Tian Li *- , and
Duo Zhang *
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The main causes of failure for cartilage tissue engineering implants are tissue integration, inflammation, and infection. The development of biomaterials with antiforeign body response (FBR) is of particular importance. Herein, we developed a hydrogel loaded with anti-inflammatory drugs to reduce the inflammatory response that follows implantation. The human chondrocytes were used for in vitro study, and cell-laden hydrogel samples were implanted with the backs of rabbits for in vivo study. Soyasaponin Bb (SsBb) as a traditional Chinese medicine could significantly (P < 0.05) downregulate the expression levels of inflammation-related markers including iNOS, COX-2, and IL-6 in chondrocytes induced by IL-1β through the NF-κB signaling pathway. The in vitro experiments demonstrated that a gelatin-methacryloyl (GelMA) hydrogel loaded with SsBb (SsBb/GelMA) could similarly reduce the gene and protein expression levels of inflammation-related markers (iNOS, COX-2, and IL-6). The in vivo anti-inflammatory effects of the SsBb/GelMA hydrogels were assessed by immunohistochemical staining. The results demonstrated that SsBb/GelMA hydrogels inhibited the inflammatory response and downregulated the expression of the inflammatory cytokine IL-6. Therefore, SsBb/GelMA hydrogels are promising candidates for promoting anti-inflammation and cartilage tissue regeneration of implant surfaces.
Tunable Transparent Conductors Based on SnO2: Theoretical and Experimental Studies of Codoping
Wenjing Qian - ,
Xianghui Feng - ,
Yanxue Wang - ,
Ahmet Nazligul - ,
Yiwen Lu - ,
Mingqing Wang *- ,
Wei Wu *- , and
Kwang Leong Choy *
This publication is Open Access under the license indicated. Learn More
Transparent conducting oxides (TCOs) are widely used in modern electronics because they have both high transmittance and good conductivity, which is beneficial for many applications such as light-emitting diodes. Tailoring electronic states and hence the conductive types by design is important for developing new materials with optimal properties for TCOs. SnO2, with a wide band gap, low cost, no toxins, and high stability, is a promising host material for TCOs. Here, we performed a set of hybrid-exchange density functional theory calculations on the two-element and three-element codoped SnO2 by using Sr, Ta, Al, Ga, V, and Nb, which were then validated by the relevant experimental works on SnO2. As predicted by the first-principles calculations, the controllability of the electronic states to be n- or p-type can be demonstrated experimentally by varying the relative doping concentration between donors (Ta/Nb) and acceptors (Al/Ga). One of the main advantages for these codoping methods is that the charge neutrality problem caused by the dopant can be circumvented. The thin films fabricated showed a low sheet resistance (down to ∼450 Ω/□) and a high optical transparency (above 80%). The combination of our calculations and experimental material fabrication and characterizations has shown a great potential for codoping SnO2 for (i) the efficient processing of the integrated circuit composed of both p-type and n-type transistors (using the same target precursors during the deposition) and (ii) a good lattice matching for p–n junctions. Most importantly, our calculations, supported by the experimental works, point to a promising route to accelerate the discovery process for the alternative cost-effective and high-performance indium-free TCOs using computational material design.
Revealing Local Structure of Angiotensin Receptor-Neprilysin Inhibitor (S086) Drug Cocrystal by Linear and Nonlinear Infrared Spectroscopies
Wenjie Xu - ,
Haiyan Xu - ,
Jie Yan - ,
Song Li - ,
Pengyun Yu - ,
Juan Zhao - ,
Fan Yang - , and
Jianping Wang *
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Structurally knowing the active sites of a drug is important for understanding its therapeutic functions. S086 is a novel angiotensin receptor-neprilysin inhibitor that consists of the molecular moieties of EXP3174 (the active metabolite of the angiotensin receptor blocker losartan) and sacubitril (a neprilysin inhibitor prodrug) in a 1:1 molar ratio. There are two forms of cocrystals of S086, namely, ξ-crystal and α-crystal, which were formed both via intermolecular coordination bonding to calcium ions, with the aid of internal water. The binding state of multiple carboxyl anions (COO–) to Ca2+ of EXP3174 and sacubitril was examined in this study using infrared (IR) absorption spectroscopy, in which the asymmetric stretching (as) and symmetric stretching (ss) modes of the COO– groups were used as IR probes. Ultrafast two-dimensional (2D) IR spectroscopy was utilized for spectrally assigning the origin of multiple COO– groups by the presence or absence of interchromophore vibrational coupling. Key structural variation between the two crystal forms was found: in the unit cell of ξ-crystal, the ratio of “bridging” and “bidentate” types of COO– binding to Ca2+ for four EXP3174 molecules is 2:2, while the ratio is predicted to be 3:1 in the case of α-crystal. However, in both crystals, four sacubitril molecules are believed to similarly form a “trident” type of COO– binding to Ca2+. Our study demonstrates that linear and nonlinear IR spectroscopies can be used to characterize local crystal structures of drugs and reveal subtle difference between similar crystal structures.
Predicting the Rate of Penetration while Horizontal Drilling through Unconventional Reservoirs Using Artificial Intelligence
Hassan Almomen - ,
Ahmed Abdulhamid Mahmoud *- ,
Salaheldin Elkatatny *- , and
Abdulazeez Abdulraheem
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Estimating the rate of penetration (ROP) is one of most critical tasks for evaluating the efficiency and profitability of drilling operation, which will aim in decision-making related to well planning, time estimation, cost estimation, bit selection, operational troubles, and logistics in drilling operation. The rise in unconventional resource development underscores the need for accurate ROP prediction to optimize drilling operations in these valuable reserves. ROP prediction and optimization in unconventional hydrocarbon reservoirs are challenging due to the formations’ heterogeneity, high strength, and brittleness. These reservoirs often involve complex well designs, high pressures, and high temperatures, making it difficult to maintain optimal drilling conditions. This study presents the optimization and validation of the artificial neural network (ANN) model to predict the ROP during horizontal drilling through unconventional hydrocarbon reservoirs. The ANN model was trained using 34,869 data points from five wells (Well-1 to Well-5) and achieved a high correlation coefficient of 0.96 and an average absolute percentage error (AAPE) of 4.68%. An empirical correlation was developed based on the weights and biases of the optimized ANN model. The empirical correlation performance was rigorously tested with 23,246 data points, representing 40% of the data from the same wells, yielding an AAPE of 4.75% and a correlation coefficient of 0.96. Validation of the developed equation on data from Well-6 further confirmed the model’s robustness, maintaining a correlation coefficient of 0.91 and an AAPE of 5.75%. These results demonstrate the ANN model's and empirical equation's accuracy and reliability in predicting the ROP, highlighting their potential to optimize drilling operations in unconventional hydrocarbon reservoirs.
Magnetic Nanocarriers for pH/GSH/NIR Triple-Responsive Drug Release and Synergistic Therapy in Tumor Cells
Di Zhang - ,
Wanyu Wei - ,
Tianxiang Xie - ,
Xue Zhou - ,
Xu He - ,
Jie Qiao - ,
Rui Guo *- ,
Gang Jin *- , and
Ningbo Li *
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In this study, the mesoporous Fe3O4 nanodrug carriers containing disulfide bonds (CHO-SMNPs) were successfully synthesized and characterized. Doxorubicin (DOX) was loaded onto the CHO-SMNPs as a model drug and gatekeeper through the formation of imine bonds with the aldehyde groups on the surface of the mesoporous materials. This drug carrier demonstrates effective drug release triggered by pH, glutathione (GSH), and near-infrared (NIR) light, along with satisfactory photothermal conversion efficiency under NIR irradiation at 808 nm. Furthermore, CHO-SMNPs exhibit excellent blood compatibility and biodegradability. They also show good biocompatibility and efficient cellular uptake in HeLa and MCF-7 cancer cells. Most importantly, the CHO-SMNPs/DOX has shown significant effectiveness in killing both HeLa and MCF-7 cancer cells. Consequently, CHO-SMNPs/DOX presents substantial potential as a magnetic-targeted, pH/GSH/NIR triple-triggered drug delivery system for synergistic chemo-photothermal therapy in tumor treatment.
Enhancing Aqueous Stability of Anionic Surfactants in High Salinity and Temperature Conditions with SiO2 Nanoparticles
Mohammed H. Alyousef - ,
Muhammad Shahzad Kamal *- ,
Mobeen Murtaza - ,
Syed Muhammad Shakil Hussain - ,
Arshad Raza - ,
Shirish Patil - , and
Mohamed Mahmoud
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In chemical-enhanced oil recovery (cEOR), surfactants are widely used but face significant stability challenges in high-salinity brine, where they often degrade or precipitate. Existing methods, such as adding cosurfactants, offer limited compatibility with anionic surfactants and raise economic concerns, creating a need for more robust solutions. This study introduces a novel approach to enhance the stability of anionic surfactants in extreme salinity conditions by incorporating silicon dioxide (SiO2) nanoparticles (NPs). Our optimized formulation effectively prevents surfactant precipitation and NP aggregation, demonstrating stability in brine with salinity as high as 57,000 ppm and temperatures up to 70 °C, thus addressing the salt tolerance issues seen with conventional anionic surfactants like sodium dodecyl sulfate (SDS). To validate our formulation, we employed multiple experimental techniques, including turbidity, ζ-potential (ZP), and hydrodynamic diameter (HDD) measurements, which confirmed the efficacy of our approach. Results indicated that an optimal SiO2 NP concentration (0.01 wt %) significantly enhanced SDS stability, with no observed aggregation or precipitation over 7 days. High absolute ZP values (>25 mV), a small HDD (∼37 nm), and a consistent turbidity profile underscored the stability and dispersion of the formulation. This nanoparticle-based method offers a cost-effective and sustainable solution for cEOR, providing enhanced surfactant stability and improved NP dispersibility under high-salinity and high-temperature conditions, representing a valuable advancement in chemical-enhanced oil recovery technology.
Single-Step Deposition of Chalcopyrite (CuFeS2) Thin Films
Valmar da Silva Severiano Sobrinho - ,
Thercio Henrique de Carvalho Costa *- ,
Michelle Cequeira Feitor - ,
Maxwell Santana Libório - ,
Rômulo Ribeiro Magalhães de Sousa - ,
Álvaro Albueno da Silva Linhares - ,
Pâmala Samara Vieira - ,
Luciano Lucas Fernandes Lima - ,
Cleânio da Luz Lima - , and
Edcleide Maria Araújo
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Thin films of chalcopyrite, CuFeS2, are promising candidates for use as absorber layers in photovoltaic cells due to their low band gap and high absorbance. These films are typically deposited in two or three steps, always involving an annealing process. In this work, the CuFeS2 film was deposited on a glass substrate in a single deposition step using the cathodic cylindrical plasma deposition (CCyPD) technique. The film samples deposited were analyzed by X-ray diffraction (XRD) and Raman spectroscopy, the film thickness was measured using the optical method, and FEG-SEM analyzed the surface structural morphology. The results showed a strong dependence on the deposition temperature for phase formation, with chalcopyrite being obtained for films deposited at 600 °C. At this temperature, a uniformly distributed film with uniform grain sizes was obtained, and the experimentally obtained band gap values of the films were consistent with the theoretical values reported in the literature, demonstrating the technique’s effectiveness and precision in producing high-quality films.
In Vitro and In Vivo Comparison of Random versus Site-Specific Conjugation of Bifunctional Chelating Agents to the CD33-Binding Antibody for Use in Alpha- and Beta-Radioimmunotherapy
Kevin J. H. Allen - ,
Connor Frank - ,
Rubin Jiao - ,
Mackenzie E. Malo - ,
Michele Bello - ,
Laura De Nardo - ,
Laura Meléndez-Alafort - , and
Ekaterina Dadachova *
This publication is Open Access under the license indicated. Learn More
Radiometal chelator conjugation is a cornerstone of radioimmunotherapy (RIT). Continued interest in selective placement of chelators remains an active topic of discussion in the field. With several simple site-specific methods being recently reported, it was of interest to investigate the benefits and potential drawbacks of the site-specific method with a full comparison to a more typical random conjugation method that is currently utilized in clinical applications. In this study, the conjugation methods were evaluated side by side to determine the utility of both methods using commercially available random and site-specific conjugation reagents by performing antigen binding; radiolabeling with 64Cu, 177Lu, and 225Ac radioisotopes; antibody-conjugate stability, cytotoxicity, in vivo distribution, pharmacokinetics analyses, and dosimetry to gather a whole data set for preclinical investigation. Evaluation revealed that both methods performed similarly during most experiments with the site-specific method, resulting in higher binding capacity of the antibody conjugate via flow cytometry. Radiolabeling was not significantly different between two methods, while stability showed that the site-specifically conjugated antibody was somewhat more stable at 37 °C in human serum over 1 week. In vitro experiments demonstrated less cell killing with the random conjugation method, while in vivo experiments showed no statistical differences in tumor uptake between conjugation methods. Dosimetry calculations were performed using the acquired PET/CT data and showed that apart from the liver, there was no significant difference in radiation doses delivered by either antibody conjugate. These results demonstrate that both methods are viable for future work, while the site-specific method offers several potential advantages and, in some cases, improved efficacy.
December 3, 2024
Unveiling the Molecular Secrets: A Comprehensive Review of Raman Spectroscopy in Biological Research
Anshuman Chandra - ,
Vimal Kumar - ,
Umesh Chandra Garnaik - ,
Rima Dada - ,
Imteyaz Qamar - ,
Vijay Kumar Goel - , and
Shilpi Agarwal *
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Raman spectroscopy has been proven to be a fast, convenient, and nondestructive technique for advancing our understanding of biological systems. The Raman effect originates from the inelastic scattering of light which directly probe vibration/rotational states in biological molecules and materials. Despite numerous advantages over infrared spectroscopy and continuous technical as well as operational improvement in Raman spectroscopy, an advanced development of the device and more applications have become possible. In this review, we explore the principles, techniques, and myriad applications of Raman spectroscopy in the realm of biology. We begin by providing an overview of Raman spectroscopy, highlighting its significance in unraveling the complexities of biological research. The focus of this review is on Raman spectroscopy concepts and methods, clarifying the fundamentals of Raman scattering and spectral interpretation. The review also highlights the key experimental considerations for productive biological applications. We explore the broad range of Raman applications including molecular structure, biomolecular composition, disease detection, and medication discovery. The Raman imaging and mapping can also be used to visualize biological samples at the molecular level. Raman spectroscopy is still developing, giving fresh insights and remedies, from biosensing to its use in tissue engineering and regenerative medicine. This review sheds light on the past, present, and future of Raman spectroscopy; it also highlights promising directions of future research developments and serves as a thorough resource for all researchers.
Simple Preparation and Bone Regeneration Effects of Poly(vinyl alcohol)–Resveratrol Self-Cross-Linked Hydrogels
Pengyin Li - ,
Shaoqing Chen - ,
Yanyan Meng - ,
Cheli Wang *- , and
Xinye Ni *
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Hydrogels have broad application prospects in bone repair. Pure poly(vinyl alcohol) (PVA) hydrogels have limited applications because of their low hardness and poor mechanical properties. This study found that resveratrol (Res) and PVA self-assembled and cross-linked through the formation of strong hydrogen bonds after freeze–thawing, forming an easily available PVA–Res supramolecular hydrogel through a green process. PVA–Res hydrogels with different Res wt %:10 wt % PVA ratios were prepared through freeze–thawing and designated as 0.4, 1.2, and 2.0 wt % PVA–Res hydrogels. Rheological studies demonstrated that the viscoelastic modulus of the PVA–Res hydrogels was significantly improved compared to pure PVA hydrogels. The viscoelastic modulus G′ of 1.2% PVA–Res hydrogel was 2299 Pa, which was 8.5-fold that of the pure PVA hydrogel. We conducted a study on cell proliferation and osteogenic differentiation using MC3T3-E1 (preosteoblasts from newborn mouse calvaria). The results showed that the 0.4% PVA-Res hydrogel promotes alkaline phosphatase activity and mineral deposition. Real-time quantitative PCR (RT-qPCR) analysis demonstrated that the 0.4% PVA–Res hydrogel upregulated the expression of osteogenic differentiation-related genes (BMP-9, OCN, and ALP). Furthermore, RT-qPCR and flow cytometry demonstrated that the 0.4% PVA–Res hydrogel could effectively promote the M2 transformation and polarization of mouse mononuclear macrophage leukemia cells (Raw 264.7). The expression of related genes, such as Arg-1 and CD206, significantly increased, whereas that of M1 polarization-related genes, such as iNOS and TNF-α, significantly decreased. In summary, PVA–Res supramolecular hydrogels are potential materials for use in bone repair.
Oviduct Glycoprotein 1 (OVGP1) Diagnoses Polycystic Ovary Syndrome (PCOS) Based on Machine Learning Algorithms
Fengjuan Wang - ,
Xinran Liu - ,
Xiaoyan Hao - ,
Jing Wang - ,
Jiayun Liu *- , and
Congxia Bai *
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Aims: To investigate the diagnostic value of oviduct glycoprotein 1 (OVGP1) levels for polycystic ovary syndrome (PCOS). Materials and Methods: Serum OVGP1 concentrations were measured by enzyme-linked immunosorbent assay (ELISA). Associations between OVGP1 and endocrine parameters were evaluated by Spearman’s correlation analysis. Diagnostic capacity was assessed by utilizing machine learning algorithms and receiver operating characteristic (ROC) curves. Results: OVGP1 levels were significantly decreased in PCOS patients and correlated with the serum follicle-stimulating hormone (FSH) concentration and the luteinizing hormone/follicle-stimulating hormone (LH/FSH) ratio, which are predictors of PCOS occurrence. The diagnostic value of OVGP1 combined with six signatures (LH/FSH, progesterone, total cholesterol, triglyceride, high-density lipoprotein cholesterol, and anti-Müllerian hormone) or three clinical indicators has the potential to significantly improve the accuracy of diagnosing PCOS patients. Conclusion: OVGP1 enhances the ability to diagnose when combined with clinical indicators.
New Re–Os Geochronological Data from the Upper Doushantuo Formation: Age Constraint on the Shuram Excursion and Implication for the Ediacaran Fluctuated Continental Weathering
Zhaozhao Tan *- ,
Jianlan Luo - ,
Xuesheng Xu - ,
Wanglu Jia - ,
Jie Li - , and
Liran Chen
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The largest negative carbon-isotope excursion in geological history has been reported by several studies of the upper Doushantuo Formation of South China, which has been correlated to the middle Ediacaran-Shuram excursion (SE). Due to a scarcity of radiometric age constraints on the excursion in South China, however, global correlations and comparisons of this event remain a debate. Here, we present Re–Os and carbon isotope data on organic-rich sediments obtained from a drill-core sample in the Chengkou area, the northeastern margin of the Yangtze Platform, and South China. The Re–Os geochronology yields a depositional age of 568 ± 15 Ma (Model 3, MSWD = 1.9, n = 13; 2σ), indicating a middle-late Ediacaran age for the upper Doushantuo Formation. This is supported by a negative δ13Ccarb excursion, which can be reliably correlated to the SE sequences. This age is consistent with the Re–Os radioisotopic dates bracketing the Shuram peaks in Northwest Canada and Oman. A compilation of 187Os/188Os and 87Sr/86Sr isotope ratios as well as the contents of redox-sensitive elements (RSE) from organic-rich sediments deposited between 635 and 540 Ma shows that the radiogenic 187Os/188Os ratios (>1.0) associated with enhanced oxidative weathering occurred at ca. 635, 580, and 560 Ma. As a result, accelerated influxes of nutrients stimulated primary productivity, promoting organic carbon burial and leading to ocean oxygenation. Additionally, elevated continental weathering could have delivered high fluxes of oxidants (e.g., sulfates) to oceans, resulting in transient ocean oxygenation. Corresponding to elevated radiogenic Os and Sr isotope ratios, the significant RSE enrichments at these three times indicate the presence of large marine RSE reservoirs and an oxygenated ocean. Therefore, the Re–Os age and initial Os isotope composition of organic-rich shale can be a sensitive tool for constraining the time interval of enhanced continental weathering and resulting pulses of ocean oxygenation during the Neoproterozoic era.
Correlation Analysis of Ecosystem Reduction and Retention Effects and Spatial Distribution of Soil Potential Toxicity Elements
Junlei Wang - ,
Sijing Sun - ,
Liyuan Mu - ,
Naiming Zhang - , and
Li Bao *
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Soil contamination by potentially toxic elements (PTEs) poses a significant threat to crop quality and human health, making it a global concern. However, the distribution patterns of PTEs across different land-use types are not well understood. To investigate the relationship between the reduction and retention effects of various ecosystem types on soil PTEs, we analyzed five categories of target elements in 299 soil samples from the southeastern Yunnan Province. Using the intelligent urban ecosystem management system’s surface source control (runoff) model, descriptive statistical methods, spatial interpolation analyses, and GIS, we simulated the effects of different ecosystem types on soil heavy metals. This approach allowed us to examine the spatial correlations among ecosystem reduction, retention, and PTE distribution in soils. Our results indicate that soil PTE concentrations were indicative of a high-background value area, with concentrations of arsenic, cadmium, copper, lead, and zinc exceeding risk screening values. The coefficients of variation for arsenic, cadmium, and lead were extremely high and attributable to high external anthropogenic interference. Soil heavy metal reduction and spatial distribution were affected by the ecosystem’s control function, and different ecosystems had different reduction effects. The reduction simulations for As and Pb were concentrated in building areas, while those for Cd and Zn were primarily focused on water bodies. The reduction simulations for Cu were concentrated in the forested areas. In conclusion, ecosystem reduction and retention influence heavy metal distribution, which is essential when planning green ecological development and construction.
Experimental Study and Hydration Mechanism Analysis of Geopolymer Multielement Net Slurry Self-Leveling Slurry Material
Haotian Jiang *- ,
Ruohao Zhang - ,
Chenhua Jin - ,
Jingjing Cao - , and
Wei Lu
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In this project, cement-based composites reinforced with slag powder (abbreviated as SP), steel slag powder (abbreviated as SSP), and desulfurization gypsum (abbreviated as FGD) were used as the research objects, and the preparation, mechanical properties, and strengthening mechanism of the composites were systematically studied. A laser particle analyzer (Malvern Instruments Analysis) was used to determine that the particle sizes of the raw SSP, SP, and FGD materials were concentrated between 5 and 40 μm, indicating that they were fine-grained minerals. SSP and SP are highly active alkaline substances. With the two ratios of 6:3:1 (SP/SSP/FGD) and 7:2:1 (SP/SSP/FGD), the macroscopic mechanical properties and mechanism analysis results revealed that the alkali activator was incorporated into the composite material and that the compressive strength activation effects of the activators from strong to weak were as follows: Ca(OH)2, Na2SiO4, and NaOH. Microscopic scanning revealed that many AFt and C–S–H gels formed after hydration of the cementitious system. After water curing, efflorescence occurred on the surface of the test block, resulting in the formation of many pores inside the cementitious system.
Effect of Gold Nanoparticles on the Conformation of Bovine Serum Albumin: Insights from CD Spectroscopic Analysis and Molecular Dynamics Simulations
Samal Kaumbekova - ,
Naoya Sakaguchi - ,
Dhawal Shah - , and
Masakazu Umezawa *
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With the development of nanotechnology, there is growing interest in using nanoparticles (NPs) for biomedical applications, such as diagnostics, drug delivery, imaging, and nanomedicine. The protein’s structural stability plays a pivotal role in its functionality, and any alteration in this structure can have significant implications, including disease progression. Herein, we performed a combined experimental and computational study of the effect of gold NPs with a diameter of 5 nm (5 nm Au-NPs) on the structural stability of bovine serum albumin (BSA) protein in the absence and presence of NaCl salt. Circular dichroism spectroscopy showed a loss in the secondary structure of BSA due to the synergistic effect of Au-NPs and NaCl, and Thioflavin T fluorescence assays showed suppressed β-sheet formation in the presence of Au-NPs in PBS, emphasizing the intricate interplay between NPs and physiological conditions. Additionally, molecular dynamics (MD) simulations revealed that 5 nm Au-NP induced changes in the secondary structure of the BSA monomer in the presence of NaCl, highlighting the initial binding mechanism between BSA and Au-NP. Furthermore, MD simulations explored the effect of smaller Au-NP (3 nm) and nanocluster (Au-NC with the size of 1 nm) on the binding sites of the BSA monomer. Although the formation of stable BSA-Au conjugates was revealed in the presence of NPs of different sizes, no specific protein binding sites were observed. Moreover, due to its small size, 1 nm Au-NC decreased helical content and hydrogen bonds in the BSA monomer, promoting protein unfolding more significantly. In summary, this combined experimental and computational study provides comprehensive insights into the interactions among Au nanosized substances, BSA, and physiological conditions that are essential for developing tailored nanomaterials with enhanced biocompatibility and efficacy.
Enhancing Oil Recovery in Low Permeability Reservoirs through CO2 Miscible Flooding: Mechanisms and Dynamics
Xinliang Chen *- ,
Zhengming Yang *- ,
Hongwei Yu *- ,
Zhongkun Niu *- ,
Wen Li - ,
Ninghong Jia - ,
Wenming Wang - ,
Yapu Zhang - ,
Haibo Li - , and
Yilin Chang
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Understanding the dynamic characterization of the CO2 miscible flooding process in low permeability reservoirs and its mechanism for oil recovery enhancement is crucial for controlling CO2 miscible flooding sweep efficiency and further enhancing oil recovery. This study was conducted in a low permeability reservoir in Jilin, China, using both online nuclear magnetic resonance CO2 miscible flooding and long-core CO2 miscible flooding experiments. A refined dynamic characterization of the CO2 miscible flooding process from the macroscopic core scale to the microscopic pore scale was achieved through multiple spatial online nuclear magnetic resonance testing methods. Analysis of dynamic characteristics of physical parameters was based on long-core displacement experiments and gas chromatography. This study summarizes the influence mechanism of CO2 miscible flooding on enhanced oil recovery in low permeability reservoirs and demonstrates the feasibility of CO2 miscible flooding. The results indicated that (1) CO2 miscible flooding enables simultaneous oil recovery from micro-, meso-, and macropores, significantly improving displacement efficiency. (2) The recovery process unfolds in two stages: the initial CO2 miscible flooding stage before gas breakthrough and the subsequent CO2 miscible transport stage after gas breakthrough. (3) Both stages are instrumental in expanding the macroscopic swept range of CO2, thereby enhancing oil recovery. (4) The miscibility of CO2 with crude oil can affect the oil’s composition. (5) The combined effect of miscible flooding and transport underpins the high displacement efficiency of CO2 miscible flooding. Emphasizing these critical aspects could enhance oil recovery from CO2 miscible flooding in field production.
Illite Dissolution under Sodium Hydroxide Solution: Insights from Reactive Molecular Dynamics
Wenguo Ma - ,
Wenhang Yuan *- ,
Peng Wang - ,
Xuan Liu - , and
Yueqi Wang
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In alkali/surfactant/polymer (ASP) flooding systems, alkalis react with clay minerals such as Illite, montmorillonite, and kaolinite, leading to reservoir damage and impacting oil recovery rates. Therefore, studying the dissolution effects of strong alkalis on clay minerals is crucial for improving oil recovery. This study uses Illite as a representative clay mineral and employs the ReaxFF reactive force field and molecular dynamics simulations to model its dissolution in NaOH solution. We investigated the diffusion coefficients of metal cations in Illite and their interactions with hydroxide ions at various NaOH concentrations. The study also explores the evolution of dissolution products and protonation characteristics during the dissolution of Illite. By calculating the changes in ionic energy throughout the dissolution process, we analyzed variations in ionic reactivity within the system. Simulation results show that as the NaOH concentration increases, metal cations in Illite form stable chemical bonds with hydroxide ions, creating highly aggregated clusters with strong ionic interactions that hinder migration. Consequently, the diffusion coefficients of metal cations gradually decrease. During the reaction, water dissociates to produce hydrogen ions and hydroxide ions. Ion exchange occurs between the solution cations and Illite cations. Illite cations gradually precipitate and form metal hydroxides by combining with hydroxide ions under electrostatic forces. Protonation propagates from the surface to the internal structure during the reaction. Moreover, the degree of protonation increases with higher NaOH concentrations. Changes in the average ionic energy before and after the reaction indicate that K+ exhibits the highest reactivity. Intermediate silicate products are unstable in NaOH solution, with some Si4+ ions showing higher energy and stronger reactivity.
Antibacterial Coatings of Poly(ethylenimine)/Poly(l-lactide)-Grafted Hyaluronic Acid Multilayers Surface-Functionalized with Bacteriophages
Luise Wirth - ,
Birgit Urban - ,
Eva Bittrich - ,
Gopala-Krishna Mannala - ,
Volker Alt - , and
Martin Müller *
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The infestation of tissue after implantation is a major problem as a bacterial biofilm can form on the surface of the implants, leading to implant-associated infections (IAIs). One approach to prevent such IAI is to apply antibacterial coatings consisting of polyelectrolyte multilayers (PEM) and bacteriophages (PHAGs). PEM were constructed by alternately adsorbing oppositely charged polyelectrolytes on a substrate according to the layer-by-layer concept. Poly(ethylenimine) (PEI) was used as the cationic polyelectrolyte, and a graft polymer of hyaluronic acid and poly(l-lactide) (DAC) was used as the anionic polyelectrolyte. Comparing PEM-5 (PEI/DAC/PEI/DAC/PEI) and PEM-6 (PEI/DAC/PEI/DAC/PEI/DAC), a higher amount of PHAG was bound to PEM-5 with cationic surface charge, which was detected by atomic force microscopy (AFM) measurements and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The binding of PHAG to the PEM is suggested to be based on electrostatic interactions between the anionic capsid proteins of PHAG and the outermost PEM surface. For antibacterial tests, PEM-5 and PEM-6 each with and without contact to PHAG were deposited at agar plates and infected with bacteria. For the coatings consisting of PEM and PHAG, a significant eradicative effect toward bacteria was obtained, while the pure PEM coatings showed no eradication, which proves the dominant antibacterial contribution originated by PHAG.
Multiple Cross Displacement Amplification Combined with Real-Time Fluorescence Monitoring for Efficient, Specific, and Sensitive Neisseria meningitidis Detection
Rui Huang - ,
DaWei Huang - ,
Chunrong Sun - ,
Juan Zhou - ,
Nan Jia - ,
Fei Xiao - ,
Xiaolan Huang - ,
Shijun Li *- , and
Yi Wang *
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Invasive meningococcal disease, caused by Neisseria meningitidis (N. meningitidis), is a critical global health issue, necessitating swift and precise diagnostics for effective management and control. Here, we introduce a novel diagnostic assay, NM-RT-MCDA, that combines multiple cross displacement amplification (MCDA) with real-time fluorescence detection, targeting a specific ctrA gene region in the N. meningitidis genome. The assay utilizes a primer set designed for high specificity and incorporates a fluorophore-quencher pair with a restriction endonuclease site for real-time monitoring. Optimized at 65 °C for 40 min, NM-RT-MCDA demonstrates exceptional specificity, with no cross-reactivity observed with nontarget species. It achieves a remarkable sensitivity, detecting as low as 100 fg of genomic DNA per reaction, and has been successfully applied to clinical sputum samples, matching the sensitivity of nanoparticle-based lateral flow biosensors. The assay’s rapid turnaround time, completed within an hour including DNA extraction and amplification, positions NM-RT-MCDA as a promising diagnostic tool for various clinical scenarios, potentially facilitating timely diagnosis and intervention in invasive meningococcal disease management.
Cysteine-Grafted Cu MOF/ZnO/PANI Nanocomposite for Nonenzymatic Electrochemical Sensing of Dopamine
Mariam Basharat - ,
Zakir Hussain *- ,
Dooa Arif - , and
Waheed Miran
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Electrochemical sensing has shown great promise in monitoring neurotransmitter levels, particularly dopamine, essential for diagnosing neurological illnesses like Parkinson’s disease. Such techniques are easy, cost-effective, and extremely sensitive. The present investigation discusses the synthesis, characterization, and potential use of a cysteine-grafted Cu MOF/ZnO/PANI nanocomposite deposited on the modified glassy carbon electrode surface for nonenzymatic electrochemical sensing of dopamine. The synthesized nanocomposite was confirmed through X-ray diffraction, Fourier transform infrared, Raman, and scanning electron microscopy characterization techniques. Additionally, electrochemical analysis was conducted using cyclic voltammogram, differential pulse voltammetry, and chronoamperometry. The process was determined to be the diffusion-controlled oxidation of dopamine. Dopamine underwent spontaneous adsorption on the electrode surface through an electrochemically reversible mechanism. Despite various biological interfering factors, the nonenzymatic electrochemical sensor demonstrated a remarkable level of selectivity toward dopamine. Cysteine-grafted Cu MOF/ZnO/PANI produced the lowest dopamine detection limit, at 0.39 μM, and the sensitivity was observed as 122.57 μAmM–1 cm–2. Results have demonstrated that enhanced catalytic and conductive properties of MOFs, combined with nanostructured materials, are the primary factors affecting the sensor’s performance.
Characteristics of Three-Dimensional Pore-Fracture Network Development and Enhanced Seepage Heat Transfer in Hot Dry Rock Stimulated by Temperature Shock Effects
Yong Sun *- ,
Long Feng - ,
Cheng Zhai - ,
Xu Yu - ,
Jizhao Xu - ,
Yuzhou Cong - ,
Yangfeng Zheng - ,
Wei Tang - ,
Yu Wang - , and
Shuai Wang
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Hot dry rock (HDR) geothermal is a sustainable and clean energy source. However, its development progress is hindered by creating seepage channels in deep reservoirs with low porosity and permeability. Traditional hydraulic fracturing techniques are ineffective for enhancing the permeability of these high-strength reservoirs. To address this, a cyclic nitrogen injection technique was proposed, which leverages the thermal gradients of the hot reservoir to stimulate a complex thermally induced fracture network. To study the three-dimensional pore-fracture structure and the flow characteristic of HDR under temperature shock effects, various high-temperature rock samples (200–500 °C) were treated with 5 cycles of liquid nitrogen cold shock. Using digital core technology, a visual pore-fracture network was reconstructed and the simulation of flow and heat exchange within this network was further performed. The main conclusions are as follows: Following the liquid nitrogen cold shock treatment with rock cores of 200–300 °C, only a few isolated micropores were formed, marked by low porosity and poor connectivity, yielding effective porosities of 0.79 and 1.52%, respectively. In contrast, the cold shock at 400–500 °C induced the formation of a reticulated pore-fracture network. This development was attributed to the combined effects of thermal stress and grain expansion, with an effective porosity reaching 12.58%. Further, a pore network model revealed a substantial increase in both the pore number and size, especially under the cold shock of 500 °C cores, where the largest pore radius reached 2133 μm. The permeability of the representative elementary volume increased significantly with the rising cold shock temperature difference, escalating from 13.79 μm2 at 200 °C to 1101.39 μm2 at 500 °C. This shift signifies a transition from localized to more extensive flow paths. Based on the actual pore-fracture network, a simulation of heat extraction from HDR was conducted, showing that the exchanged heat increased from 4.51 × 10–8 to 8.34 × 10–8 W with the rise in the temperature difference. Within the temperature range of 300–400 °C, a singular flow path was observed, characterized by minimal fluid transport but elevated exit temperatures. Meanwhile, at 500 °C, a superior heat exchange network was established, featuring improved fluid transport and heat exchange efficiency.
Tailoring the Mechanical Properties of Fungal Mycelium Mats with Material Extrusion Additive Manufacturing of PHBH and PLA Biopolymers
Huaiyou Chen *- ,
Sophie Klemm - ,
Antonia G. Dönitz - ,
Yating Ou - ,
Bertram Schmidt - ,
Claudia Fleck - ,
Ulla Simon - , and
Christina Völlmecke
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To advance the concept of a circular economy, fungal mycelium-based materials are drawing increased attention as substitutes for nonsustainable materials, such as petroleum-based and animal-derived products, due to their biodegradability, low carbon footprint, and cruelty-free nature. Addressing the challenge of mechanical properties in fungal mycelium products, this study presents a straightforward approach for reinforcing fungal mycelium mats. This is achieved by using two bio-based and biodegradable polymers, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) and polylactic acid (PLA), via material extrusion additive manufacturing (MEX AM), commonly known as 3D printing, to produce fungal mycelium-biopolymer composites. By analyzing the mechanical properties, roughness, and morphology, this study demonstrates significant improvements in ultimate tensile strength with the application of PHBH and even more with PLA, while elasticity is reduced. The study also discusses potential improvements to enhance the quality of the fungal mycelium-biopolymer composites without trading off bio-based and biodegradable features, offering a promising pathway for the development of more durable and sustainable fungal mycelium products.
Dynamic Detection of the E3-PROTAC-Target Protein Ternary Complex In Vitro and In Vivovia Bimolecular Fluorescence Complementation
Kunjian Lei - ,
Yilei Sheng - ,
Yishuang Li - ,
Zhihong Zhou - ,
Xingen Zhu *- , and
Kai Huang *
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Proteolysis-targeting chimeras (PROTACs) have played an important role in the development of protein-targeted degradation drugs. However, effective tools are urgently required for the further development and validation of PROTACs. We developed a high-potency reporter (AKT-PROTAC-Reporter; APR) for PROTACs that specifically targets AKT. The APR successfully detected the status and levels of the AKT-PROTAC-CRBN ternary complex in vivo and in vitro. The APR is based on a bimolecular fluorescence complementation system, where EGFP and luciferase were used as reporter signals for in vitro and in vivo experiments, respectively, with remarkable success. The absence of E3 ligase ubiquitin recruitment activity in the APR can significantly improve the reporting performance of the APR; however, this results in difficulties in the detection of the degradation efficiency of PROTAC target proteins. Our results show that the APR can sensitively, quickly, and effectively detect the presence of terpolymers. Furthermore, the APR can determine the specificity and degradation efficiency of the PROTAC via a fluorescence signal or bioluminescence signal intensity and can efficiently screen PROTACs for a certain target protein.
Rapid Gluten Allergen Detection Using an Integrated Photoimaging Assay and Ionic Liquid Extraction Sensor
Wen-Hao Chen - ,
Chuan-Chih Hsu - ,
Hsin-Jung Ho - ,
Jill Smith - ,
Seaton Smith - ,
Hui-Yin Huang - ,
Huan-Chi Chang - , and
Yu-Cheng Hsiao *
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In recent years, food allergies and food sensitivities have remained critical public health problems that affect approximately 15% of the global population. Wheat is a major food source worldwide, but it is also a common food allergen. Celiac disease is chronic immune-mediated enteropathy triggered by exposure to dietary gluten in genetically predisposed individuals; it can be treated only through strict gluten avoidance. Therefore, rapid gluten detection is crucial for protecting the health of patients. Gluten contains two primary water-insoluble proteins: gliadin and glutenin. Gliadin is a key contributor to celiac disease and poses challenges for sample pretreatment owing to its insolubility, thereby reducing the accuracy and sensitivity of detection systems. Rapid sample processing is a critical problem in gliadin detection. In this report, we developed a gliadin sensor system called the integrated food allergy and microorganism sensor (iFAMs). The iFAMs comprises a gliadin lateral flow chip, a one-pot extraction solution, and an image assay app. The iFAMs enables gliadin extraction and detection in under 2 min with high sensitivity (0.04 mg/kg for gliadin, lower than the regulatory limit of 20 mg/kg). Users can easily measure gluten concentrations in samples and quantify gliadin levels using the smartphone-based image assay app. In samples collected from restaurants, the iFAMs successfully detected hidden gluten within “gluten-free” food items. The compact size and user-friendly design of the iFAMs render it suitable for not only consumers but also clinicians, food industries, and regulators to enhance food safety.
Mechanism and Process Optimization in the Electrooxidation of Oxalic Acid Using BDD Electrode under Nitric Acid Environment
Lu Qiao - ,
Hu Zhang *- ,
Jing Zhao - ,
Zhijun Cen - , and
Ting Yu
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Various electrochemical tests were carried out to elucidate the electrolytic oxidation mechanism of oxalic acid on a boron-doped diamond electrode in a nitric acid environment. These included cyclic voltammetry, AC impedance, constant current electrolysis, and electron paramagnetic resonance spectroscopy. The impact of electrode potential, current density, nitric acid concentration, and electrode plate spacing on the oxidation of oxalic acid was investigated. In the electrolysis mechanism, indirect oxidation of· •OH plays a major role and direct oxidation at the electrode plays a minor role. Excessive nitric acid concentration will reduce the electrooxidation rate of oxalic acid. The optimal process conditions for electrolyzing oxalic acid are obtained as follows: the plate spacing is 2 cm, and the current density is 60 mA cm–2. Finally, the BDD electrode can electrolyze the oxalic acid concentration to below 0.001 mol/L, which can meet the process requirements.
Stachys byzantina K. Koch in the Treatment of Skin Inflammation: A Comprehensive Evaluation of Its Therapeutic Properties
José Alisson da Silva Lima - ,
Victor Campana Leite - ,
Jéssica Pereira Silva - ,
Marcelle Andrade Ferrarez - ,
Guilherme Dessupoio Bahia - ,
Luan Vianelo Netto Rezende - ,
Maria Clara Machado Resende Guedes - ,
Gilson Costa Macedo - ,
Natália Prado da Silva - ,
Guilherme Diniz Tavares - ,
Ana Carolina Cruz Reis - ,
Giovanna Oliveira Follis - ,
Vanessa Viana Lempk - ,
Maria Fernanda Fernandes - ,
Elita Scio - , and
Nícolas de Castro Campos Pinto *
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Stachys byzantina is a plant widely cultivated for food and medicinal purposes. Stachys species have been reported as anti-inflammatory, antibacterial, anxiolytic, and antinephritic agents. This study aimed to evaluate the anti-inflammatory potential of the ethanolic extract (EE) from the aerial parts of S. byzantina and its most promising fraction in models of acute and chronic inflammation, including a psoriasis-like mouse model. The EE was fractionated into hexane (HF), dichloromethane (DF), ethyl acetate (AF), and hydroalcoholic (HD) fractions. Screening for anti-inflammatory activity based on nitric oxide inhibition (IC50 μg/mL: HF 24.29 ± 5.87, EE 176.45 ± 18.65), hydroxyl radical scavenging (HF 3.89 ± 0.61, EE 6.38 ± 2.25), β-carotene/linoleic acid assay (HF 10.13 ± 3.81, EE 25.64 ± 2.12), and ORAC identified HF as the most active fraction. Topical application of HF effectively reduced croton oil- and phenol-induced ear edema in mice, with no statistical difference to the reference drugs. A formulation containing HF showed significant activity in the imiquimod-induced psoriasis model, reducing pro-inflammatory cytokines and nitric oxide production in macrophages, with no cytotoxicity to skin cells. Phytochemical analysis of HF revealed the presence of terpenes, steroids (491.68 ± 4.75 mg/g), phenols (34.30 ± 4.96 mg/g), flavonoids (151.77 ± 6.66 mg/g), and α-tocopherol, which was identified and quantified by HPLC-UV analysis (10.56 ± 0.97 mg/g of HF). These findings highlight the therapeutic potential of S. byzantina for skin inflammation, particularly contact dermatitis and psoriasis, encouraging further studies, including in human volunteers.
Systematic Analysis of Disulfidptosis-Related lncRNAs in Hepatocellular Carcinoma with Vascular Invasion Revealed That AC131009.1 Can Promote HCC Invasion and Metastasis through Epithelial–Mesenchymal Transition
Xuefeng Gu - ,
Yanyan Wei - ,
Mao Lu - ,
Duo Shen - ,
Xin Wu - , and
Jin Huang *
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Disulfidptosis, a recently identified pathway of cellular demise, served as the focal point of this research, aiming to pinpoint relevant lncRNAs that differentiate between hepatocellular carcinoma (HCC) with and without vascular invasion while also forecasting survival rates and responses to immunotherapy in patients with vascular invasion (VI+). First, we identified 300 DRLRs in the TCGA database. Subsequently, utilizing univariate analysis, LASSO-Cox proportional hazards modeling, and multivariate analytical approaches, we selected three DRLRs (AC009779.2, AC131009.1, and LUCAT1) with the highest prognostic value to construct a prognostic risk model for VI+ HCC patients. Multivariate Cox regression analysis revealed that this model is an independent prognostic factor for predicting overall survival that outperforms traditional clinicopathological factors. Pathway analysis demonstrated the enrichment of tumor and immune-related pathways in the high-risk group. Immune landscape analysis revealed that immune cell infiltration degrees and immune functions had significant differences. Additionally, we identified valuable chemical drugs (AZD4547, BMS-536924, BPD-00008900, dasatinib, and YK-4-279) for high-risk VI+ HCC patients. In-depth bioinformatics analysis was subsequently conducted to assess immune characteristics, drug susceptibility, and potential biological pathways involving the three hub DRLRs. Furthermore, the abnormally elevated transcriptional levels of the three DRLRs in HCC cell lines were validated through qRT-PCR. Functional cell assays revealed that silencing the expression of lncRNA AC131009.1 can inhibit the migratory and invasive capabilities of HCC cells, a finding further corroborated by the chorioallantoic membrane (CAM) assay. Immunohistochemical analysis and hematoxylin–eosin staining (HE) staining provided preliminary evidence that AC131009.1 may promote the invasion and metastasis of HCC cells by inducing epithelial–mesenchymal transition (EMT) in both subcutaneous xenograft models and orthotopic HCC models within nude mice. To summarize, we developed a risk assessment model founded on DRLRs and explored the potential mechanisms by which hub DRLRs promote HCC invasion and metastasis.
Antibacterial Potential of Ethyl 3,5-Dibromoorsellinate, a Derivative of Diphenyl Ethers from Graphis handelii, against Methicillin-Resistant Staphylococcus aureus
Dao Dinh Nguyen - ,
Thuc-Huy Duong - ,
Thi-Phuong Nguyen - ,
Huy Truong Nguyen *- , and
Chuong Hoang Nguyen *
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Staphylococcus aureus is a human pathogen responsible for a variety of diseases, from skin, soft tissue, and lung infections to severe cases such as meningitis, infective endocarditis, and bacteremia. The high level of antibiotic resistance in these pathogens, exemplified by methicillin-resistant Staphylococcus aureus (MRSA), necessitates the development of effective antibiotics. Thus, this work introduced the chemical synthesis of ethyl 3,5-dibromoorsellinate, a derivative of ethyl orsellinate from the lichen mycobiont of Graphis handelii, and its effectiveness against MRSA was assessed. Results showed that ethyl 3,5-dibromoorsellinate efficiently inhibited MRSA with a minimum inhibitory concentration (MIC) of 4 μg/mL, and the time-kill analysis showed the bactericidal effect of ethyl 3,5-dibromoorsellinate on MRSA at 8× MIC after 24 h. The compound also exhibited selective activity against MRSA compared with the human cell line, with a selectivity index of 12.5-fold. While ethyl 3,5-dibromoorsellinate exhibited an indifferent effect with ampicillin, this compound demonstrated antagonistic effects with kanamycin in the synergistic assessment. Additionally, ethyl 3,5-dibromoorsellinate demonstrated antibiofilm activity against MRSA starting from 0.25× MIC. The molecular docking investigation illustrated that ethyl 3,5-dibromoorsellinate binds with the penicillin-binding protein 2A of MRSA with a free energy of −42.5 to −45.7 kcal/mol. Given its promising antibacterial activities, ethyl 3,5-dibromoorsellinate warrants further investigation as a potential antibiotic option against MRSA.
December 2, 2024
Epidermal Sensors Constructed by a Stabilized Nanosilver Hydrogel with Self-Healing, Antimicrobial, and Temperature-Responsive Properties
Xiongbiao Zheng - ,
Jiachang Chen - , and
Xia Huang *
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The development of conductive hydrogels has garnered significant attention in the field of wearable devices and smart sensors. However, the fabrication of hydrogels that possess both multifunctionality and structural stability remains a challenging task. In this study, a novel hydrogel, PAgHCB, was synthesized using a mild method and exhibited outstanding characteristics such as electrical conductivity, self-healing capability, antimicrobial activity, dimensional stability, and temperature sensitivity. The exceptional mechanical performance (∼120 kPa at a strain of 450%) of PAgHCB is attributed to the incorporation of hydroxypropylmethylcellulose (HPMC) and the mechanical reinforcement of the gel network by carboxylated carbon nanotubes (CNT-COOH). The borate bonds between or within poly(vinyl alcohol) (PVA) chains confer self-healing capabilities upon PAgHCB, with a healing efficiency of 74.1%. The in situ reduction of silver nanoparticles through ultraviolet irradiation imparts antimicrobial characteristics to the hydrogel [against Escherichia coli, zone of inhibition (ZOI) = 3.7 mm; against Staphylococcus aureus, ZOI = 6.3 mm]. The linear temperature responsiveness of the PAgHCB hydrogel (R = −3.99T + 608.84 and COD = 0.9988) arises from the migration of silver ions within the gel matrix and the dissociation of borate bonds. Furthermore, PAgHCB was seamlessly integrated into sensors designed for monitoring human motion. The gel-based sensors exhibited three distinct sensing strain ranges corresponding to three different gauge factors (GF1 = 2.976, GF2 = 1.063, and GF3 = 2.97). Notably, PAgHCB gel sensors demonstrated the capability to detect electrical signals generated by finger and wrist joint movements and even discerned signals arising from subtle deformations induced by activities such as speaking. Additionally, the PAgHCB gel was utilized as a pressure sensor to detect external pressures applied to the skin (from 0.373 to 15.776 kPa). This work expands the avenues for designing and synthesizing multifunctional conductive hydrogels, promoting the application of hydrogel sensors with comfortable wear and high sensitivity.
Isolation, Characterization, In Vitro and In Silico Assessment of Undescribed Bioactive Constituents from Pterocarpus santalinus L. Heartwood
Priya Darshani - ,
Shreya Sen Sarma - ,
Rahul L. Gajbhiye - ,
Amit K. Srivastava - , and
Deepak Kumar *
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Pterocarpus santalinus heartwood is well acknowledged for its medicinal properties and use in the furniture and handicraft industries. Owing to its medicinal properties, the present investigation aims to isolate and characterize the secondary metabolites from the heartwood. The investigation led to the isolation of one undescribed dehydropterocarpan and eleven known compounds. P. santalinusheartwood is found to be a new source for six compounds. Interestingly, the undescribed dehydropterocarpan is transformed into an artifact, which led us to understand the biosynthetic correlations. The isolated compounds displayed moderate inhibition of α-glucosidase and α-amylase. The enzymatic assay outcome is further complimented with the in silico docking analysis. We have also evaluated the compounds for their drug-likeness properties, which align with the desired characteristics of potential drug candidates.
Cavity Ring-Down Spectroscopy Analysis of Radiocarbon from Nuclear Waste Materials
Johannes Lehmuskoski *- ,
Guillaume Genoud - ,
Anumaija Leskinen - ,
Hannu Vasama - ,
Juho Salminen - ,
Jouni Hokkinen - , and
Antti Räty
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Radiocarbon analysis of nuclear waste produced in nuclear facilities lacks fast, in situ detection methods. Moreover, the amount of radiocarbon desorbing from graphitic waste is not well known. In this study, we demonstrate the use of mid-infrared cavity ring-down spectroscopy combined with an automatic sample processing unit as a method to examine radiocarbon concentration in three types of nuclear waste: spent ion-exchange resin, graphite, and graphite outgassing in sealed storage crates. The solid samples were gasified, which allowed analyzing the effect of heating on the radiocarbon outgassing from the samples. The presented method also enabled examination of molecular speciation of the radiocarbon in the samples. The method performed well with the graphite and gaseous samples, but the analysis of the spent ion-exchange resin did not produce repeatable results due to high N2O concentrations. In the future, the presented method can be used in situ at nuclear facilities and expanded to a wider variety of sample materials than those presented here.
Study on the Effect of Structure and Acidity of Hydrocracking Catalyst Support on the Selectivity of Middle Distillate
SongTao Dong *- ,
Ping Yang - , and
Qinghe Yang
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Hydrocracking has become the main technology for producing diesel fuel in many refineries, the key process to meeting new product specifications as environmental regulations for transportation fuels become more stringent. The efficacy of the hydrocracking catalyst is a pivotal determinant of the reaction performance. This study leveraged high-throughput experimentation to closely examine the impact of support properties on both the catalytic activity and the selectivity of middle distillates. The findings show that the catalyst’s activity is mainly controlled by the amount of Brönsted acid sites and the presence of strong Lewis acid sites within the carrier. An inverse relationship was observed between middle distillate selectivity and catalyst activity, highlighting a trade-off between these two measures of performance. Furthermore, the hydrocracking performance index (HPI), serving as a composite measure of catalyst efficacy, revealed that an optimal pore size and strong Brönsted acidity are important for increasing the HPI value, thereby signifying enhanced catalytic performance. The experimental result matches the bimolecular hydrogen transfer reaction, which is essential in determining the hydrocracking performance index (HPI) value.
Cellulose–Starch Composite Aerogels as Thermal Superinsulating Materials
Safoura Ahmadzadeh - ,
Angelina Sagardui - ,
David Huitink - ,
Jingyi Chen - , and
Ali Ubeyitogullari *
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The demand for sustainable packaging materials is rapidly increasing due to growing environmental concerns over the impact of plastic waste. In this study, biodegradable, porous, lightweight, and high-surface-area microcrystalline cellulose–starch (MCC-S) hybrid aerogels were synthesized via supercritical carbon dioxide (SC–CO2) drying. The samples were generated using five different MCC-S weight ratios and characterized for their morphology, crystallinity, and structural and thermal properties. When MCC and S were used together, aerogels with superior properties were obtained compared to those made from each component individually. Specifically, the 1:2 MCC-S aerogel exhibited the highest porosity (97%), the lowest density (0.058 g/cm3), and the lowest thermal conductivity (0.012 W/(m·K)) along with a high specific surface area (258 m2/g). Therefore, MCC-S aerogels are promising insulators for advanced packaging applications, potentially serving as a sustainable alternative to Styrofoam.
In Silico Modeling and Characterization of Epstein–Barr Virus Latent Membrane Protein 1 Protein
Dayang-Sharyati D. A. Salam - ,
Kavinda Kashi Juliyan Gunasinghe - ,
Siaw San Hwang - ,
Irine Runnie Henry Ginjom - ,
Xavier Chee Wezen *- , and
Taufiq Rahman *
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Latent membrane protein 1 (LMP1) plays a crucial role in Epstein–Barr virus (EBV)’s ability to establish latency and is involved in developing and progressing EBV-associated cancers. Additionally, EBV-infected cells affect the immune responses, making it challenging for the immune system to eliminate them. Due to the aforementioned reasons, it is crucial to understand the structural features of LMP1, which are essential for the development of novel cancer therapies that target its signaling pathways. To date, there is yet to be a complete LMP1 protein structure; therefore, in our work, we modeled the full-length LMP1 containing the short cytoplasmic N-terminus, six transmembrane domains (TMDs), and a long-simulated C-terminus. Our model showed good stability and protein compactness evaluated through accelerated-molecular dynamics, where the conformational ensemble exhibited compact folds, particularly in the TMDs. Our results suggest that specific domains or motifs, predominantly in the C-terminal domain of LMP1, show promise as potential drug targets. As a whole, our work provides insights into key structural features of LMP1 that will allow the development of novel LMP1 therapies.
Water-Induced Turn-on of Lanthanide Photoluminescence Emission and Application in Colorimetric Sensing of Trace Water
Malee Sinchow - ,
Rania Chaicharoen - ,
Thammanoon Chuasaard - ,
Bunlawee Yotnoi - ,
Chalermpong Saenjum - ,
Athipong Ngamjarurojana - , and
Apinpus Rujiwatra *
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To examine the water-induced photoluminescence turn-on and its potential application in trace water sensing, a new series of [LnIII(dmba)3(H2O)2]·2H2O, where LnIII = LaIII (I), PrIII (II), NdIII (III), SmIII (IV), EuIII (V), GdIII (VI), TbIII (VII), DyIII (VIII), HoIII (IX), and ErIII (X), were synthesized using dimethoxybenzoic acid (Hdmba). Their single-crystal structures and thermal and chemical robustness were investigated, and the effects of lanthanide contraction and noncovalent interactions were discussed. The photoluminescence and colorimetric properties of I–X were investigated. Their dependence on dehydration and rehydration was disclosed, from which the significant role of noncovalent interactions was proposed. Based on the dehydration–rehydration-dependent responses in the forms of photoluminescence emission and color, the turn-off (dehydration) and turn-on (rehydration) of the red emission of EuIII (V) were demonstrated. Using a mobile phone camera and freeware application, its use in the colorimetric sensing of trace water in polar organic solvents was successfully achieved. With respect to ethanol, acetonitrile, and acetone, linear correlations were established from 0 to 3–5% by volume of water with an R2 of over 0.98. The detection and quantification limits were less than 0.5 and 1.5%, respectively. The percentage recoveries were 92 and 110%. The underlying mechanism was postulated.
Development of Amino-Functionalized Silica by Co-condensation and Alkylation for Direct Air Capture
Soichi Kikkawa *- ,
Miori Kataoka - , and
Seiji Yamazoe *
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CO2 chemisorption using amine-based sorbents is one of the most effective techniques for carbon capture and storage. Solid CO2 sorbents with amines immobilized on their surface have been attracting attention due to the easy collection of sorbents and reusability. In this study, we developed a solid CO2 adsorbent by co-condensation of a silanizing reagent having a chloroalkyl group and tetraethyl ethoxysilane, followed by alkylation of the chloroalkyl group with diamine. The fabricated amine-immobilized silica with a high density of amino groups on its surface achieved the chemical adsorption of 400 ppm of CO2 with 4.3 wtCO2 % loading, CO2 release upon heating at 80 °C, and reusability for adsorption and desorption cycles with high amine utilization efficiency (0.20 molCO2/mol–N). This surface modification method is applicable to various amines bearing more than two amino functional groups, enabling the development of solid CO2 sorbents for the selective capture of low-concentration CO2 directly from the air.
Prediction of Hydrate Formation in Long-Distance Transportation Pipeline for Supercritical-Dense Phase CO2 Containing Impurities
Chunli Tang - ,
Bing Chen *- ,
Wenjiao Qi - ,
Qiong Zhao - , and
Xiangzeng Wang
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Supercritical-dense phase CO2 pipeline transportation has been proven to have excellent economic and safety benefits for long-distance CO2 transportation in large-scale. Hydrates are easily generated in the high-pressure and low-temperature sections, resulting in blockage, so it is necessary to build the prediction model for hydrate formation in the long-distance CO2 pipeline transportation. In the prediction model of hydrate formation of our work, the phase equilibrium was determined by the Chen–Guo model, and the lateral growth of hydrate was calculated by the comprehensive growth model, and the hydrate growth was estimated by analogy with the condensation process. Subsequently, the prediction model for hydrate volume in the CO2 pipeline was established considering the process of hydrate growth and water droplet distribution. The effects of thermodynamic conditions, impurities, and operating conditions on the hydrate formation were analyzed. The impurities can expand the temperature and pressure ranges for hydrate generation. The increase in the moisture content, the increase in the pressure, the decrease in the temperature, or the increase in the fluid velocity could increase the volume of hydrates in the pipeline. After running for 10 h, the hydrates volume in the pipeline with the moisture molar fraction of 0.05% is over 10 times that with the moisture molar fraction of 0.005%. In addition, by using the proposed hydrate formation prediction model, the hydrate formation in a supercritical-dense phase CO2 long-distance pipeline was predicted, and a suggested cleaning cycle was achieved. This study can guide the operation of CO2 long-distance transportation pipelines.
Metal–Metalloid Modified C36 Fullerene: A Dual Role in Drug Delivery and Sensing for Anticancer Chlormethine Explored through DFT and MD Simulations
Sourav Kanti Jana - ,
Namrata A. Tukadiya - ,
Adisak Boonchun *- , and
Prafulla K. Jha *
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Spurred by the latest developments and growing utilization of zero-dimensional (0D) drug delivery and drug sensors, this investigation examines the possibilities of the 0D C36 fullerene for drug delivery and the detection of the anticancer drug chlormethine (CHL), the overabundance of which poses a significant threat to living organisms. This study employs density functional theory and ab initio molecular dynamics (AIMD) simulations (AIMD) to evaluate and gain insights into the interaction mechanisms between pristine C36 fullerene, metal–metalloid (MM)-modified C36 fullerene (with Al, Fe, and B), and the anticancer drug CHL. It is observed that in the gas phase, the CHL drug molecule adsorbs onto the fullerenes in the following order: B–C36 > Fe–C36 > Al–C36 > C36. However, when considering the solvent effect, the adsorption energy of the CHL drug molecule on B–C36 increases, indicating chemisorption behavior. This implies that B–C36 could be a promising candidate for drug delivery applications, particularly for the CHL anticancer drug. In contrast, the adsorption energy of the CHL drug molecule on Fe–C36 decreases with the presence of the solvent, resulting in intermediate physisorption. Due to its minimal recovery time, excellent sensing response, intermediate physisorption, and shorter interatomic distance compared to C36 and Al–C36 fullerenes, Fe–C36 is well-suited as a drug sensor for CHL. AIMD simulations demonstrate that the B–C36/CHL and Fe–C36/CHL complexes are well-equilibrated and highly stable in the aqueous phase at 300 and 310 K respectively, with no evidence of bond breakage or formation. The structural stability observed, even with temperature fluctuations, indicates that the electrostatic interactions are robust enough to maintain cohesion of the fragments.
Electrochemically Induced Synthesis of N-Allyloxyphthalimides via Cross-Dehydrogenative C–O Coupling of N-Hydroxyphthalimide with Alkenes Bearing the Allylic Hydrogen Atom
Stanislav A. Paveliev - ,
Oleg O. Segida - ,
Andrey Dvoretskiy - , and
Alexander O. Terent’ev *
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The electrochemically induced reaction between alkenes, bearing an allylic hydrogen atom, and N-hydroxyphthalimide was investigated. Cross-dehydrogenative C–O coupling with phthalimide-N-oxyl radical, derived from N-hydroxyphthalimide, occurs instead of oxidation of the allylic site, with the formation of a carbonyl group or functionalization of the double C═C bond. The discovered transformation proceeds in an undivided electrochemical cell equipped with a carbon felt anode and a platinum cathode. Coupling products were obtained with yields up to 79%. The developed process is based on the abstraction of hydrogen atom from the allylic position for functionalization while the C═C bond remains unreacted. The method exploits the ability of the phthalimide-N-oxyl radical to abstract hydrogen atoms with the following interception of the intermediate C-centered radical.
Luminescence Properties of Samarium-Doped Hydroxyapatite Nanoparticles and Cytotoxicity Assessment on SH-SY5Y Neuroblastoma Cells
Stephanie Enríquez - ,
Sarah Briceño *- ,
Lenin Ramirez-Cando - ,
Alexis Debut - ,
Luis J. Borrero-González - , and
Gema González *
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Samarium-doped nanohydroxyapatite is a biomaterial with nerve regeneration activity and bioimaging. In this work, Sm/HAp; (Ca10–xSmx(PO4)6(OH)2) (0 ≤ x ≤ 1) was synthesized using the hydrothermal method and thermally treated from 200 to 800 °C. The samples were characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, and luminescence spectroscopy. The results confirmed the successful integration of Sm3+ ions into the hydroxyapatite. Our findings revealed the influence of the Sm3+ content and thermal treatment on the emission properties, obtaining a maximum emission at Sm = 0.05 thermally treated at 800 °C. The SH-SY5Y neuroblastoma cell viability study revealed a Sm3+ concentration-and particle size-dependent response. This research emphasizes the optical and cell viability of Sm/HAp in SH-SY5Y neuroblastoma cells, making them suitable for further research as agents that activate regenerative processes in cells and neurons.
Facile CVD Fabrication of Vertically Aligned MoS2 Nanosheets with Embedded MoO2 on Molybdenum for High-Performance Binder-Free Lithium-Ion Battery Anodes
Navanya Raveendran - ,
Sruthy Subash - ,
Krishna Moorthy Ponnusamy - ,
Jong Bae Park - ,
Keun Heo - ,
K. Kamala Bharathi *- , and
S. Chandramohan *
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The demand for compact energy storage devices necessitates the development of high-performance anode materials directly integrated with current collectors, minimizing or eliminating the need for binders or additives. With its layered structure and high theoretical capacity, molybdenum disulfide (MoS2) is regarded as a promising anode material for lithium-ion batteries (LIBs). Here, we report chemical vapor deposition (CVD) growth of self-integrated, vertically aligned MoS2 nanosheets with embedded molybdenum dioxide (MoO2) directly on a molybdenum foil and explore its potential as an anode material for LIBs. The results show that the formation of the MoO2/MoS2 hybrid structure occurs through partial conversion of the initially grown MoO2 crystals to MoS2 layers under controlled sulfurization reactions. The self-integrated hybrid material, devoid of additional conductive or binder agents, exhibits remarkably efficient transfer of ions and electrons, facilitated by the high electrical conductivity of MoO2 and exposed active sites of MoS2. Electrochemical studies reveal an impressive areal capacity of 253 μA h cm–2 for the MoO2/MoS2 hybrid material on a molybdenum foil. In addition, the Li-ion diffusion coefficient value is estimated to be 0.798 × 10–10 and 1.14 × 10–10 cm2/s for the delithiation and lithiation processes, respectively. The capacity of LIBs can be significantly enhanced by engineering the MoO2/MoS2 anode material, making it a promising candidate for overcoming the limitations of single-anode materials. Our findings show that CVD can be a potential approach toward the fabrication of binder and conducting agent-free anodes directly on current collectors for advanced LIBs.
A Structurally Diverse Compound Screening Library to Identify Substrates for Diamine, Polyamine, and Related Acetyltransferases
Hazel Leiva - ,
Pamela L. Caro De Silva - ,
Ron Painter - ,
Van Thi Bich Le - ,
Patricia Uychoco - ,
Daniel Figueroa Paniagua - ,
Michael Endres - ,
Natalia Maltseva - ,
Andrzej Joachimiak - , and
Misty L. Kuhn *
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Spermidine/spermine N-acetyltransferases (SSATs) and other types of polyamine acetyltransferases (PAATs) acetylate diamines and/or polyamines. These enzymes are evolutionarily related and belong to the Gcn5-related N-acetyltransferase (GNAT) superfamily, yet we lack a fundamental understanding of their substrate specificity and/or promiscuity toward different compounds. Many of these enzymes are known or are predicted to acetylate polyamines, but in the cell there are other types of compounds that contain moieties derived from polyamines that may be the native substrates for these enzymes. To learn more about the identity of substrates that are acetylated, we selected and screened 17 different GNAT enzymes for activity toward a set of structurally diverse compounds that contained different types of amine moieties (e.g., aminopropyl, aminobutyl, etc.). These compounds included diamines, triamines, and polyamines containing primary amino groups, and they had structural diversity with variation of the chain length and presence or absence of internal amino groups and other functional groups. We found 12 of the 17 enzymes acetylated at least one of the compounds. Some enzymes were selective toward acetylating only one compound while others exhibited substrate promiscuity toward numerous compounds. Our experimental results ultimately allowed us to pinpoint specific substrates that could be further investigated to more fully understand substrate specificity versus promiscuity of GNAT enzymes and the role of acetylated small molecules in cells.
Targeting Non-Apoptotic Pathways with the Cell Permeable TAT-Conjugated NOTCH1 RAM Fragment for Leukemia and Lymphoma Cells
Ryota Uchimura - ,
Shinpei Nishimura - ,
Mikako Ozaki - ,
Manami Kurogi - ,
Kohichi Kawahara - ,
Masaki Makise - , and
Akihiko Kuniyasu *
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Targeting nonapoptotic cell death offers a promising strategy for overcoming apoptosis resistance in cancer. In this study, we developed Tat-Ram13, a 25-mer peptide that fuses the NOTCH1 intracellular domain fragment RAM13 with a cell-penetrating HIV-1 TAT, for the treatment of T-cell acute lymphoblastic leukemia with aberrant NOTCH1 mutation. Tat-Ram13 significantly downregulated NOTCH1-target genes in T-ALL cell lines. Furthermore, the peptide had potent cytotoxic effects on various human leukemia and lymphoma cell lines. However, it did not affect normal lymphocytes and monocytes, some subsets of leukemia cells, or adherent tumor cells. This cell-selective cytotoxic activity was closely correlated with the peptide uptake via macropinocytosis in leukemia cells. In leukemia cells, Tat-Ram13 triggered rapid cell death. This cell death involved mitochondrial membrane depolarization and extracellular release of lactate dehydrogenase and high-mobility group box-1 protein without activation of caspase-3 or cleavage of PARP-1. These results suggest that Tat-Ram13 cell death is nonapoptotic and mediated by rapid plasma membrane rupture. Moreover, alanine scanning analysis identified four critical hydrophobic amino acids in the RAM13 domain essential for its cytotoxicity. Consequently, these results suggest that Tat-Ram13 is a tumor-selective, nonapoptotic cell death-inducing agent for treating refractory leukemia and lymphomas with apoptosis resistance.
December 1, 2024
Theoretical Insights into High-Tc Superconductivity of Structurally Ordered YThH18: A First-Principles Study
Abdul Ghaffar *- ,
Peng Song - ,
Ryo Maezono - , and
Kenta Hongo *
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There has been a marked increase in interest in high-temperature superconductors over the past few years, sparked by their potential to revolutionize multiple fields, including energy generation and transportation. A particularly promising avenue of exploration has emerged in the form of ternary superhydrides, compounds composed of hydrogen along with two other rare-earth elements. Our investigation focuses on the search for Y–Th–H ternary compounds; employing an evolutionary search methodology complemented by electron–phonon calculations reveals a stable superhydride, P6̅m2-YThH18, capable of exhibiting a critical temperature (Tc) as high as 222 K at 200 GPa along a few low-Tc novel hydrides. Our analysis explores the possibility of alloyed structure formation from the disordered condition of Th-doped YH9 and establishes that the P6̅m2-YThH18 is indeed a structurally ordered structure. This opens up an exciting avenue for research on multinary superhydrides, which could facilitate experimental synthesis and provides potential implications for high-temperature superconductivity research.
November 30, 2024
Spider Webs as Passive Monitors of Microplastic and Its Copollutants in Indoor Environments
Kadamparambil Sivasankaran Aradhana - ,
Vishnu S. Moorchilot - ,
Taiha Joo - ,
Charuvila T. Aravindakumar - , and
Usha K. Aravind *
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Indoor environments are particularly vulnerable to microplastics (MPs) and associated copollutants due to limited air circulation and particulate matter accumulation. Continuous monitoring is essential to evaluate exposure levels and health risks. We propose using indoor spider webs as passive monitors for MPs and their copollutants. MPs were found in both web and dust samples with nonuniform distribution (p < 0.05), indicating contamination hotspots. Web samples had significantly higher MP levels (138–33,570 MPs/g) compared to dust samples (59–9324 MPs/g). A strong positive correlation (r = 0.93, p < 0.05) between MPs in dust and webs suggests that spider webs are effective bioindicators of indoor MP contamination. The study also revealed the presence of Bisphenol A and various phthalic acid esters (PAEs). Co-pollutant concentrations ranged from 52.02–1971.78 μg/kg in webs and 43.18–518.42 μg/kg in dust. Diethyl phthalate (DEP) was more common in webs, while Dibutyl phthalate (DBP) predominated in dust. These findings highlight spider webs’ potential as both effective biomonitoring tools and significant sinks for MPs and their cocontaminants in indoor environments.
November 29, 2024
Digital Light Processing (DLP) 3D Printing Fabrication of Hydrophobic Meshes Incorporating Fluorinated and Silicone-Based Acrylates Combined with Surface Engineering: Comparison of Their Oil–Water Separation Efficiency
Wai Hin Lee *- and
David Haddleton *
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Hydrophobic materials have been fabricated by DLP vat photopolymerization of isobornyl acrylate-based resins with chemical modification and/or surface geometry engineering. Fluorinated and polydimethylsiloxane (PDMS)-based acrylic monomers are used for chemical modification and are incorporated into the printed materials. The water wettability was significantly reduced and plateaued with as low as 5% (w/w) of the auxillary hydrophobic monomer. Regarding surface geometry, meshes with different pore sizes are 3D printed, and the surface hydrophobicity increased with the pore size. We compare the oil–water separation efficiency of the 3D-printed meshes hydrophobized by these three approaches. It was found that the isobornyl acrylate-based resin already demonstrated separation at the optimum pore size. Modification with PDMS showed a further improvement in separation efficiency, whereas no significant increase was observed by use of the fluorinated monomer. This highlights that careful design of surface geometry should be considered to avoid the use of environmentally unfriendly and potentially toxic chemicals when making hydrophobic materials.
Evaluating the Anticancer Properties of Novel Piscidinol A Derivatives: Insights from DFT, Molecular Docking, and Molecular Dynamics Studies
Humaera Noor Suha - ,
Syed Ahmed Tasnim - ,
Shofiur Rahman *- ,
Abdullah Alodhayb - ,
Hamad Albrithen - ,
Raymond A. Poirier *- , and
Kabir M. Uddin *
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Cancer is characterized by uncontrolled cell growth and spreading throughout the body. This study employed computational approaches to investigate 18 naturally derived anticancer piscidinol A derivatives (1–18) as potential therapeutics. By examining their interactions with 15 essential target proteins (HIF-1α, RanGAP, FOXM1, PARP2, HER2, ERα, NGF, FAS, GRP78, PRDX2, SCF complex, EGFR, Bcl-xL, ERG, and HSP70) and comparing them with established drugs such as camptothecin, docetaxel, etoposide, irinotecan, paclitaxel, and teniposide, compound 10 emerged as noteworthy. In molecular dynamics simulations, the protein with the strongest binding to the crucial 1A52 protein exceeded druglikeness criteria and displayed extraordinary stability within the enzyme’s pocket over varied temperatures (300–320 K). Additionally, density functional theory was used to calculate dipole moments and molecular orbital characteristics, as well as analyze the thermodynamic stability of the putative anticancer derivatives. This finding reveals a well-defined, potentially therapeutic relationship supported by theoretical analysis, which is in good agreement with subsequent assessments of their potential in vitro cytotoxic effects of piscidinol A derivatives (6–18) against various cancer cell lines. Future in vivo and clinical studies are required to validate these findings further. Compound 10 thus emerges as an intriguing contender in the fight against cancer.
Impact of the Metal–Organic Frameworks Polymorphism on the Electrocatalytic Properties of CeO2 toward Oxygen Evolution
Nicolle Pauline de Araújo Mendes - ,
Antonio Lopes de Souto Neto - ,
Johnnys da Silva Hortêncio - ,
André L. Menezes de Oliveira - ,
Rafael A. Raimundo - ,
Daniel Araújo Macedo - , and
Fausthon Fred da Silva *
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Hydrogen (H2) is a viable alternative as a sustainable energy source, however, new highly efficient electrocatalysts for water splitting are still a research challenge. In this context, metal–organic frameworks (MOFs)-derived nanomaterials are prominent high-performance electrocatalysts for hydrogen production, especially in the oxygen evolution reaction (OER). Here, a new synthesis of two cerium oxide (CeO2) electrocatalysts using Ce-succinates MOFs as templates is proposed. The cerium succinates polymorphs ([Ce2(Succ)3(H2O)2], Succ = succinate ligand) were obtained via hydrothermal reaction and room temperature crystallization, adopting monoclinic (C/2c) and triclinic (P1̅) crystalline structures, respectively, confirmed by X-ray diffraction (XRD). MOFs-Ce were also characterized by infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). CeO2 electrocatalysts were obtained via MOFs-Ce calcination at 350 °C in air, and characterized by XRD with Rietveld refinement, HRTEM, SEM, FT-IR, and Raman spectroscopy, UV–vis spectroscopy, X-ray photoelectron spectroscopy. Electrocatalytic performances were investigated in KOH 1.0 M solution, and overpotentials were η = 326 mV (for CeO2 (H) from monoclinic MOF-Ce) and η = 319 mV (for CeO2 (RT) from the triclinic MOF-Ce) for a current density of 10 mAcm–2. The Tafel slope values show the adsorption of intermediate oxygenated species as the rate-determining step. The high values of double-layer capacitance, the presence of oxygen vacancies, and low charge transfer resistance agree with the high performance in OER. Additionally, the materials were stable for up to 24 h, according to chronopotentiometry results.
November 28, 2024
Design, Characterization, and Evaluation of Textile Systems and Coatings for Sports Use: Applications in the Design of High-Thermal Comfort Wearables
Ian C. Orjuela-Garzón *- ,
Cristian F. Rodríguez - ,
Juan C. Cruz - , and
Juan C. Briceño
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Exposure to high temperatures during indoor and outdoor activities increases the risk of heat-related illness such as cramps, rashes, and heatstroke (HS). Fatal cases of HS are ten times more common than serious cardiac episodes in sporting scenarios, with untreated cases leading to mortality rates as high as 80%. Enhancing thermal comfort can be achieved through heat loss in enclosed spaces and the human body, utilizing heat transfer mechanisms such as radiation, conduction, convection, and evaporation, which do not require initial energy input. Among these, two primary mechanisms are commonly employed in the textile industry to enhance passive cooling: radiation and conduction. The radiation approach encompasses two aspects: (1) reflecting solar spectrum (SS) wavelengths and (2) transmitting and emitting in the atmospheric window (AW). Conduction involves dissipating heat through materials with a high thermal conductivity. Our study focuses on the combined effect of these radiative and conductive approaches to increase thermal energy loss, an area that has not been extensively studied to date. Therefore, the main objective of this project is to develop, characterize, and evaluate a nanocomposite polymeric textile system using electrospinning, incorporating graphene oxide (GO) nanosheets and titanium dioxide nanoparticles (TiO2 NPs) within a recycled polyethylene terephthalate (r-PET) matrix to improve thermal comfort through the dissipation of thermal energy by radiation and conduction. The textile system with a 5:1 molar ratio between TiO2 NPs and GO demonstrates 89.26% reflectance in the SS and 98.40% transmittance/emittance in the AW, correlating to superior cooling performance, with temperatures 20.06 and 1.27 °C lower than skin temperatures outdoors and indoors, respectively. Additionally, the textile exhibits a high thermal conductivity index of 0.66 W/m K, contact angles greater than 120°, and cell viability exceeding 80%. These findings highlight the potential of the engineered textiles in developing high-performance sports cooling fabrics, providing significant advancements in thermal comfort and safety for athletes.
Electrostatic Orientation of Optically Asymmetric Janus Particles
Mohammad Mojtaba Sadafi - ,
Achiles Fontana da Mota - , and
Hossein Mosallaei *
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Janus micro- and nanoparticles, featuring unique dual-interface designs, are at the forefront of rapidly advancing fields such as optics, medicine, and chemistry. Accessible control over the position and orientation of Janus particles within a cluster is crucial for unlocking versatile applications, including targeted drug delivery, self-assembly, micro- and nanomotors, and asymmetric imaging. Nevertheless, precise mechanical manipulation of Janus particles remains a significant practical challenge across these fields. The current predominant methods, based on fluid flow, thermal gradients, or chemical reactions, have their precision and applicability limited by the properties of their background fluids. Therefore, this study proposes electrostatics to deliberately control the local orientation of optically asymmetric Janus particles (spherical and matchstick-like hybrid metal–dielectric objects) within a cluster to overcome the aforementioned restraints. We introduce a sophisticated multiphysics platform and employ it to explore and unveil the infrastructural physics behind the mechanical behavior of the particles when subjected to electrostatic stimuli in an ionic environment. We investigate how different deterministic and stochastic variables affect the particles’ short- and long-term responses. By judicious engineering of amplitude, direction, and polarization of the external excitation, we demonstrate that the particles tend to undergo the desired rotational motion and converge to favorable orientations. The functionality of our approach is showcased in the context of an asymmetric imaging system based on optically asymmetric Janus particles. Our findings suggest a viable platform for adequate mechanical manipulation of Janus particles and pave the way for enabling numerous state-of-the-art applications in various fields.
Comparison of the Performance of ICP-MS, CV-ICP-OES, and TDA AAS in Determining Mercury in Marine Sediment Samples
Carolina S. Provete - ,
Bruna M. Dalfior - ,
Rafael Mantovaneli - ,
Maria Tereza W. D. Carneiro - , and
Geisamanda P. Brandão *
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Mercury (Hg) determination in marine sediment is an analytical challenge due to the toxicity of this element even at low concentrations (up to 130 μg kg–1 in marine sediments) and complex matrices. Therefore, it is necessary to use analytical techniques that have high sensitivity, selectivity, and low limits of quantification (LoQ). In this study, two methods that require sample treatment and one method with direct sampling were studied. The techniques studied were inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectrometry with cold vapor generation (CV-ICP-OES), and atomic absorption spectrometry with thermodecomposition and amalgamation (TDA AAS) for Hg determination in marine sediment samples. Since ICP-MS has more studies in the literature, optimization with design of experiments was developed for CV-ICP-OES and TDA AAS. Although it was found to have low levels of instrumental LoQ for all three techniques, differences were found once the method LoQ was calculated. The calculation for method LoQ considers all analytical procedures executed, including sample treatment, which provides a 100-fold dilution for ICP-MS and CV-ICP-OES. The method LoQ obtained were 1.9, 165, and 0.35 μg kg–1 for ICP-MS, CV-ICP-OES, and TDA AAS, respectively. Comparing marine sediment sample analyses, Hg concentrations had no statistical difference when determined by ICP-MS and TDA AAS. It was not possible to determine Hg in marine sediment samples by CV-ICP-OES due to the high method LoQ obtained (165 μg kg–1). Although ICP-MS has the advantage of being a multielemental technique, it is high-value equipment and needs a large volume of argon, which has a high cost in the market, and it requires sample treatment. On the other hand, TDA AAS-based spectrometer DMA-80 performs direct sampling, avoiding the pretreatment stage, and has a relatively lower cost, both in terms of initial investment and maintenance, while maintaining the high sensitivity, accuracy, and precision required for Hg determination on marine sediment samples.
Fc–FcγRI Complexes: Molecular Dynamics Simulations Shed Light on Ectodomain D3′s Potential Role in IgG Binding
Aslı Kutlu *- ,
Eda Çapkın - ,
Kaan Adacan - , and
Meral Yüce *
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FcγRI plays a crucial role in the effector function of IgG antibodies, interacting with the lower hinge region of IgG1 with nanomolar affinity. Binding occurs specifically in domain 2 (D2) of the FcγRI ectodomain, while domain 3 (D3) is a flexible linker. The D3 domain is positioned away from the IgG binding site on the FcγRI and does not directly contact the Fc region. This study investigates the structural and functional properties of FcγRI D3 using 200 ns classical MD simulations of two models: (1) a full FcγRI ectodomain complex with Fc and (2) a truncated model excluding D3. Our findings suggest that the D3 ectodomain provides additional structural flexibility to the FcγRI–Fc complex without altering the C backbone motion or flexibility of the KHR binding motif in the FG loop. Critical residues involved in binding and contributing to complex stability were evaluated regarding changes in intramolecular interactions and destabilization tendency upon D3 truncation. Truncation did not significantly alter interactions around glycan-interacting residues in Fc chains or FcγRI–Fc binding interfaces. These findings provide valuable insights into the role of FcγRI D3 in modulating the structural dynamics of the FcγRI–Fc complex. While D3 does not directly contact Fc, its mobility and positioning may modulate the receptor’s affinity, accessibility, and ability to bind IgG immune complexes. We suggest that a truncated FcγRI construct lacking the D3 domain may be a promising candidate for biosensor or capturing agents’ development and optimization, offering improved performance in IgG capture assays without compromising critical binding interactions.
Quality and Safety in Asparagus Cultivation: A Three-Year Case Study Comparing Standardized Agricultural Bases and Small-Scale Farmers
Yuhong Liu - ,
Gangjun Wang - ,
Guoguang Yu - ,
Weiran Zheng - , and
Caixia Sun *
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To investigate the quality and safety difference between agricultural standardization bases and small-scale farmers, we carried out a three-year investigation of asparagus from seven production sites of different sizes in Pinghu city, Zhejiang Province, China, from 2021 to 2023. We documented trace elements (Fe, Zn, Mn, and Cu), quality indicators (vitamin B1, vitamin B2, vitamin C, total sugar, and proteins), and pesticide residues. The evaluation indicated that the quality of asparagus in standardization bases 1–4 was higher than that in small farmer sites 5–7. The detection rate of pesticides in asparagus was 23.81% (15/63), with a low concentration range of 0.001–0.130 mg mL–1. Low pesticide levels reflect Pinghu’s effective green pest control measures. Results showed that the quality and safety of asparagus at the standardization bases are superior to those at small-scale farmer sites, and our findings may inform better management practices for both large-scale and small-scale asparagus farmers.
Modeling and Simulation of Micron Particle Agglomeration in a Turbulent Flow: Impact of Cylindrical Disturbance and Particle Properties
Shuang Wang - ,
Lin Mu - ,
Chu Wang - ,
Xue Li - ,
Jun Xie - ,
Yan Shang - ,
Hang Pu - , and
Ming Dong *
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The fly ash generated by coal combustion is one of the main sources of PM2.5, so the particulate matter removal technology of coal-fired boilers is receiving increasing attention. Turbulent agglomeration has emerged as a powerful tool for improving the efficiency of removing fine particulates from environments, sparking interest in its study. Our research meticulously investigated the influence of cylindrical vortex wakes on particle flow, agglomeration patterns, and the dynamics between fluids and particles. By employing a novel hybrid computational approach that integrates the discrete element method (DEM) with large Eddy simulation (LES), we were able to accurately simulate particle–particle interactions. The study focused on understanding how particles with different diameters (2, 5, 10, and 20 μm), densities (2,500, 5,000, 7,500, and 10,000 kg·m–3), and surface energies (0.01, 0.1, and 1 J·m–2) behaved within transitioning shear layer flow conditions. Our findings revealed that particles tended to congregate in areas of lower vorticity, with larger and denser particles demonstrating greater agglomeration efficiency due to their resilience against turbulent forces. Conversely, particles of lower density formed smaller agglomerates as their susceptibility to shear forces increased. Additionally, the study discovered that higher surface energies enhance adhesion, leading to the formation of larger agglomerates.
Influence of Gold Nanoparticles on eNOS Localization in Gill Tissues: Advancements in Immunofluorescence Techniques
Ramla Gary - ,
Manel Ben Salah - ,
Taoufik Soltani - ,
Patrizia Formoso - , and
Souhaira Hbaieb *
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This study optimizes immunofluorescence techniques using gold nanoparticles (AuNPs) to improve visualization of endothelial nitric oxide synthase (eNOS) in gill tissue. Two types of AuNP dispersions, stabilized in phosphate buffered saline (PBS) and citrate buffer (CB), were evaluated for their imaging performance. AuNPs suspended in PBS provided significantly better optical contrast due to uniform distribution and effective tissue attachment, whereas citrate-suspended AuNPs exhibited aggregation, resulting in reduced contrast. These results highlight the influence of suspension media on AuNP performance, particularly in balancing fluorescence signals to improve contrast. The PBS suspension allowed clearer visualization of eNOS, highlighting the role of AuNP compatibility in improving immunofluorescence results. This study highlights the importance of strategic selection of AuNP dispersions in contrast agent design and provides insights for advanced imaging applications where sensitivity and accurate localization of biomolecules are essential. By refining the use of AuNPs as contrast enhancers, this approach offers potential improvements in bioimaging accuracy, facilitating more precise visualization in complex tissue environments.
Exploring the Mechanisms Underlying Cellular Uptake and Activation of Dendritic Cells by the GK-1 Peptide
Jacquelynne Cervantes-Torres - ,
Juan A. Hernández-Aceves - ,
Julián A. Gajón Martínez - ,
Diego Moctezuma-Rocha - ,
Ricardo Vázquez Ramírez - ,
Sergio Sifontes-Rodríguez - ,
Gemma L. Ramírez-Salinas - ,
Luis Mendoza Sierra - ,
Laura Bonifaz Alfonzo - ,
Edda Sciutto *- , and
Gladis Fragoso *
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The use of peptides for cancer immunotherapy is a promising and emerging approach that is being intensively explored worldwide. One such peptide, GK-1, has been shown to delay the growth of triple-negative breast tumors in mice, reduce their metastatic capacity, and reverse the intratumor immunosuppression that characterizes this model. Herein, it is demonstrated that GK-1 is taken up by bone marrow dendritic cells in a dose-dependent manner 15 min after exposure, more efficiently at 37 °C than at 4 °C, implying an entrance into the cells by energy-independent and -dependent processes through clathrin-mediated endocytosis. Theoretical predictions support the binding of GK-1 to the hydrophobic pocket of MD2, preventing it from bridging TLR4, thereby promoting receptor dimerization and cell activation. GK-1 can effectively activate cells via a TLR4-dependent pathway based on in vitro studies using HEK293 and HEK293-TLR4-MD2 cells and in vivo using C3H/HeJ mice (hyporesponsive to LPS). In conclusion, GK-1 enters the cells by passive diffusion and by activation of the transmembrane Toll-like receptor 4 triggering cell activation, which could be involved in the GK-1 antitumor properties.
Assessing Lettuce Exposure to a Multipharmaceutical Mixture under Hydroponic Conditions: Findings through LC-ESI-TQ Analysis and Ecotoxicological Assessments
Ludmila Mravcová - ,
Vojtěch Jašek - ,
Marie Hamplová - ,
Jitka Navrkalová - ,
Anna Amrichová - ,
Helena Zlámalová Gargošová - , and
Jan Fučík *
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The escalating global water scarcity demands innovative solutions, one of which is hydroponic vegetable cultivation systems that increasingly use reclaimed wastewater. Nevertheless, even treated wastewater may still harbor various emerging organic contaminants, including pharmaceuticals. This study aimed to comprehensively assess the impact of pharmaceuticals, focusing on bioconcentration factors (BCFs), translocation factors (TFs), pharmaceutical persistence in aqueous environment, ecotoxicological end points, and associated environmental and health risks. Lettuce (Lactuca sativa) was cultivated hydroponically throughout its entire growth cycle, exposed to seven distinct concentration levels of contaminants ranging from 0 to 500 μg·L–1 over a 35-day period. The findings revealed a diverse range of BCFs (2.3 to 880 L·kg–1) and TFs (0.019–1.48), suggesting a high potential of pharmaceutical uptake and translocation by L. sativa. The degradation of 20 pharmaceuticals within the water-lettuce system followed first-order degradation kinetics. Substantial ecotoxicological effects on L. sativa were observed, including increased mortality, alterations in root morphology and length, and changes in biomass weight (p < 0.05). Furthermore, the estimated daily intake of pharmaceuticals through L. sativa consumption suggested considerable health risks, even if lettuce would be one of the many vegetables consumed. It is hypothetical, as the values were calculated. Moreover, this study assessed the environmental risk associated with the emergence of antimicrobial resistance (AMR) in aquatic environments, revealing a significantly high risk of AMR emergence. In conclusion, these findings emphasize the multifaceted challenges posed by pharmaceutical contamination in aquatic environments and the necessity of proactive measures to mitigate associated risks to both environmental and human health.
November 27, 2024
Improvement of Photocatalytic and Photodegradable ZnSe Nanorods by a Vulcanization Strategy
Long Chen *- ,
Kai Ou *- ,
Zhaosen Fan - ,
Lingyu Liu - ,
Fanggong Cai - ,
Yudong Xia - , and
Hongyan Wang
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Photocatalysts composed of ZnSe nanorods were prepared by using a glancing angle deposition technique facilitated by electron beam evaporation equipment. To enhance the photocatalytic efficiency of ZnSe, a vulcanization process was introduced. The impact of various parameters, including curing temperature, duration, and nanorod length, on the photocatalytic performance was systematically examined. Comprehensive analysis using X-ray diffraction, scanning electron microscopy, and photocurrent density–potential curves identified optimal vulcanization conditions at 300 °C for 45 min for 170 nm ZnSe nanorods. Under these conditions, the photocurrent reached 44.53 μA/cm2, approximately 7-fold greater than that of untreated ZnSe nanorods. Furthermore, the degradation efficiency of Rhodamine B increased by 50%. Detailed analysis of the photocatalytic mechanism revealed that sulfurization not only enhances light absorption but also facilitates the separation of photogenerated carriers through the formation of ZnS.
Synthesis of N-Heteroaryl C-Glycosides and Polyhydroxylated Alkanes with Diaryl Groups from Unprotected Sugars
Yixuan Liu - ,
Jilai Wu *- ,
Likai Zhou - ,
Chao Wei - , and
Hua Chen *
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HCl-catalyzed C-glycosylation was described herein for the convenient preparation of N-heteroaryl C-glycosides and polyhydroxylated alkanes with diaryl groups using hetereoaryl amines and unprotected sugars as starting materials. The reaction temperature and the amounts of aryl amines and HCl had significant effects on reactions. The method provided a highly efficient and environmentally friendly route for constructing C-glycosides at low cost.
November 25, 2024
Quantification of Antiretroviral Drug Emtricitabine in Human Plasma by Surface Enhanced Raman Spectroscopy
Marguerite R. Butler - ,
Terry A. Jacot - ,
Sucharita M. Dutta - ,
Gustavo F. Doncel - , and
John B. Cooper *
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In this study, reproducible label-free detection and quantification of the antiretroviral drug emtricitabine (FTC) down to 78 ng/mL in human plasma by surface enhanced Raman spectroscopy (SERS) is presented. A novel plasma sample pretreatment method using silver nitrate and silver colloidal nanoparticles (Ag CNPs) was used to prepare the plasma samples for analysis. The pretreated plasma samples were evaporated to dryness on an aluminum surface and a computer-controlled Raman scanning system was used to collect spatially resolved SERS spectra of the entire surface. Calibration curves of commercial human plasma samples containing FTC in a concentration range of 5000 to 78 ng/mL were calculated using three different methods. First, a conventional approach was taken, where all the spectra collected for each concentration were averaged, then the SERS intensity of a known FTC peak (792 cm–1) was used for calibrations (total population method). This approach was refined by utilizing a figure-of-merit (FOM) quality index (Qi) to sample spectra from each concentration that contained the highest signal-to-noise (S/N), before averaging and calculating the SERS intensity of the 792 cm–1 FTC peak (Qi sample method). Finally, the distribution of all Qi values for each concentration were modeled using cumulative distribution functions (CDFs) and were used for calibrations (CDF method). The CDF method exhibited the highest analytical sensitivity (slope = 3702.47) compared to the Qi sample method (slope = 1591.05) and the total population method (slope = 754.21). The Qi sample method exhibited the highest linearity (R2 = 0.99) compared to the CDF method (R2 = 0.95) and the total population average (R2 = 0.97). The CDF method exhibited the highest S/N in the concentration range of 5000 to 312 ng/mL (S/N range of 31.5–16.6). The Qi sample method exhibited the highest S/N for concentrations 156 and 78 ng/mL (S/N = 9.7 and 7.4, respectively). These results show that the Qi sample method is advantageous over all other methods when approaching the LOQ while the CDF method is advantageous over all methods at higher concentrations. The LOQ (78 ng/mL) was confirmed by principal component analysis (PCA). Together these results show that statistical treatment of a large population of SERS spectra, where the analyte signal intensity follows an exponential distribution, is superior to standard methods of averaging populations of spectra in terms of analytical sensitivity, linearity, and S/N. Additionally, it was found that the background signal had no interference with the quantitative data calculated for the total population and Qi sample methods after repeating both analyses with baseline-subtracted spectra. The results and methodology presented in this study establish a framework for integrating SERS into drug adherence monitoring for FTC-based treatment and prevention of infections by demonstrating consistent SERS detection and quantification of FTC in human plasma at therapeutically relevant concentrations.
November 19, 2024
Laser-Induced Graphene for Electrochemical Sensing of Antioxidants in Biodiesel
Daniel R. Sevene - ,
Tiago A. Matias *- ,
Diele A. G. Araújo - ,
Nélio I. G. Inoque - ,
Marcelo Nakamura - ,
Thiago R.L.C. Paixão - , and
Rodrigo A. A. Muñoz *
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Synthetic antioxidants are often introduced to biodiesel to increase its oxidative stability, and tert-butyl hydroquinone (TBHQ) has been selected due to its high efficiency for this purpose. The monitoring of antioxidants in biodiesel therefore provides information on the oxidative stability of biodiesels. Herein, a laser-induced graphene (LIG) electrode is introduced as a new sensor for detecting tert-butyl hydroquinone (TBHQ) in biodiesel samples. An infrared CO2 laser was applied for LIG formation from the pyrolysis of polyimide (Kapton). Based on the voltammetric profile of a reversible redox probe, the fabrication of LIG electrodes was set using 1.0 W power and 40 mm s–1 speed, which presented an electroactive area of 0.26 cm2 (higher than the geometric area of 0.196 cm2). Importantly, lower engraving speed resulted in higher electroactive area, probably due to a more efficient graphene formation. Scanning-electron microscopy and Raman spectroscopy confirmed the creation of porous graphene induced by laser. The sensing platform enabled the differential-pulse voltammetric determination of TBHQ from 5 and 450 μmol L–1. The values of detection limit (LOD) of 2 μmol L–1 and RSD (relative standard deviation) of 2.5% (n = 10, 10 μmol L–1 of TBHQ) were obtained. The analysis of spiked biodiesel samples revealed recoveries from 88 to 106%. Also, the method provides a satisfactory selectivity, as it is free of interference from metallic ions (Fe3+, Mn2+, Cr2+, Zn2+, Pb2+, and Cu2+) commonly presented in the biofuel. These results show that LIG electrodes can be a new electroanalytical tool for detecting and quantifying TBHQ in biodiesel.