bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved NMR‐data‐compliant protein structure modeling captures context‐dependent variations and expands the scope of functional inference
Authors: Das Niladri R. , Chaudhury Kunal N. , Pal Debnath 
Published: October 2022

AbstractNuclear magnetic resonance (NMR) spectroscopy can reveal conformational states of a protein in physiological conditions. However, sparsely available NMR data for a protein with large degrees of freedom can introduce structural artifacts in the built models. Currently used state‐of‐the‐art methods deriving protein structure and conformation from NMR deploy molecular dynamics (MD) coupled with simulated annealing for building models. We provide an alternate graph‐based modeling approach, where we first build substructures from NMR‐derived distance‐geometry constraints combined in one shot to form the core structure. The remaining molecule with inadequate data is modeled using a hybrid approach respecting the observed distance‐geometry constraints. One‐shot structure building is rarely undertaken for large and sparse data systems, but our data‐driven bottom‐up approach makes this uniquely feasible by suitable partitioning of the problem. A detailed comparison of select models with state‐of‐art methods reveals differences in the secondary structure regions wherein the correctness of our models is confirmed by NMR data. Benchmarking of 106 protein‐folds covering 38–282 length structures shows minimal experimental‐constraint violations while conforming to other structure quality parameters such as the proper folding, steric clash, and torsion angle violation based on Ramachandran plot criteria. Comparative MD studies using select protein models from a state‐of‐art method and ours under identical experimental parameters reveal distinct conformational dynamics that could be attributed to protein structure–function. Our work is thus useful in building enhanced NMR‐evidence‐based models that encapsulate the contextual secondary and tertiary structure variations present during the experimentation and expand the scope of functional inference.
Preliminary design and evaluation of a generic surgical scope adapter
Authors: Khorasani Mohammad , Abdurahiman Nihal , Padhan Jhasketan , Zhao Haoran , Al‐Ansari Abdulla , Becker Aaron T. , Navkar Nikhil 
Published: October 2022

AbstractBackgroundRobotic scope assistant systems are used to visualise and navigate the operative field during a laparoscopic surgery. The objective of this work is to design a surgical scope adapter that enables control of different scope types (zero‐degree, angulated, and articulated), and can be connected to any six degree‐of‐freedom robotic manipulator for usage as a robotic scope assistant system.MethodsA surgical scope adapter compatible with different camera heads and scope types was designed and prototyped. The technical performance of the scope adapter was evaluated and a user study was conducted to assess the human‐in‐the‐loop control.ResultsAll the subjects were able to navigate the simulated operative field. The scope adapter permits continuous motion to explore the operative field as well as intermittent motion to accurately focus on the targeted anatomical landmarks.ConclusionThe modular and generic nature of the surgical scope adapter may enable its usage across different minimally invasive surgeries.
Preparation of Multiwalled Carbon Nanotubes: Electrochemically Treated Pencil Graphite Electrodes for Nanomolar Detection of L‐Tryptophan in Complex Samples
Authors: Yıldız Ceren , Bayraktepe Dilek Eskiköy , Yazan Zehra 
Published: October 2022

AbstractThe present work reports a sensitive and simple sensor based on an electrochemically treated pencil graphite electrode (pre‐PGE) modified with multi‐walled carbon nanotubes (MWCNTs) for electrochemical determination of L‐tryptophan (L‐Try) detection in the presence of uric acid. Electrochemical and physical characterizations of the MWCNTs/pre‐PGE were investigated using cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) techniques. Under the optimized conditions, the linear working range was 0.030–200.0 μM with a limit of detection of 9.0 nM using the differential pulse adsorptive stripping voltammetry (DPAdSV) method. The proposed sensor exhibited good sensitivity, repeatability, reproducibility, and stability. The MWCNTs/pre‐PGE were successfully applied to L‐Try determination in commercial poly‐amino acid supplements with good recovery and accuracy.
Recent Developments of Methanol Electrooxidation Using Nickel‐based Nanocatalysts
Authors: Majumdar Dipanwita , Bhattacharya Swapan Kumar 
Published: October 2022

AbstractStudies of methanol electrooxidation reactions have achieved considerable advancements in the recent years for their encouraging contributions in the exciting fields of energy conversion and storage, organic syntheses, wastewater treatment, sensing, medicinal and environmental analyses, and many others thriving fields of modern technology. Accordingly, the fabrication of less expensive, efficient and decent quality electrocatalysts with high material stability, faster electro‐oxidation kinetics, as well as less carbonation and decent corrosion inhibition activities are highly urged. Consequently, scientists around the globe are in continuous search for alternative economical smart anode‐nanocatalysts for methanol oxidations with superior electrochemical performances. In the recent years, various inexpensive and readily‐available nanocatalysts of non‐noble metals like Ni, Co, Cu, etc., in reference to electrooxidation of organic molecules have been reported. The present work highlights the recent progress accomplished by rapidly flourishing nickel‐based electrocatalysts for electrooxidation of methanol. The discussion comprehensively includes the basic mechanistic understandings and fundamentals for achieving high efficacy of methanol electrooxidation with nickel‐based electrocatalysts. Also, the current challenges faced in this emerging area have been outlined to achieve superior, productive, and commercially viable catalysts for methanol electrooxidation in the near future.
Copper Pyrrole‐imine Incorporated Fe3O4‐Nanocomposite: A Magnetically Separable and Reusable Catalyst for the Oxidative Amination of Aryl Aldehydes
Authors: Hasan Kamrul , Joseph Reshma G. , Patole Shashikant P. 
Published: October 2022

AbstractThe present work represents the fabrication of a Fe3O4‐based nanocomposite Fe3O4@CS@PyL‐imin@Cu and its application towards oxidative amination of aryl aldehydes to important amides. First, magnetic Fe3O4 was coated with chitosan (CS) and then treated with pyrrole‐2‐carboxaldehyde that produces the desired magnetic nanocatalyst by depositing Cu on its pyrrole‐imine functionalized surface. The structure and property of the nanocatalyst are confirmed by all physicochemical technics. The Cu‐based magnetic nanocatalyst shows excellent catalytic efficiency toward the oxidative amination of aldehydes with secondary amines to produce corresponding amides (up to 97 % yield) in presence of environmentally benign oxidant H2O2. The magnetic nanocatalyst is easily separable with an external magnet and reusable up to the 5th catalytic cycle without any significant loss of catalytic activity. Overall, a low loading (1.5 mol % of Cu) nanocatalyst has proven to be a practical approach to an alternative to the existing protocol for the preparation of amides.
CO2 Cycloaddition to Styrene Oxide Catalysed by ZnBr2 Impregnated Rice Husk Ash Silica: Structural and Kinetics Studies
Authors: Yao Swee Yi , Iqbal Anwar , Abu Bakar N. H. H. , Yusop Muhammad Rahimi , Pauzi Hariy , Kanakaraju Devagi 
Published: October 2022

AbstractA series of ZnBr2 impregnated on rice husk ash silica catalysts were synthesised via the wet impregnation method for the CO2 cycloaddition to styrene oxide reaction. The X‐ray diffraction (XRD) analysis indicates that the impregnation resulted in the deterioration of the silica's pore channels. Catalyst with 0.5 w/w% of Zn (0.5 wt %ZnBr2‐SiO2) was highly active in the CO2 cycloaddition to styrene oxide. The conversion of styrene oxide (StO) was 89.1 %, with the styrene carbonate (SC) selectivity of 92.1 % under the optimum conditions (130 °C, 60 bar, 3 h and solventless). Additionally, the universality of 0.5 wt %ZnBr2‐SiO2 was also studied with other epoxides, and it shows good to excellent activity. The catalytic performance of the 0.5 wt %ZnBr2‐SiO2 remains constant after being reused three consecutive times. The activation energy of the reaction was determined to be 89.06 kJ/mol.
Electrochemical Sensor for Ascorbic Acid, Acetaminophen and Nitrite Based on Organoclay/Zr‐MOF Film Modified Glassy Carbon Electrode
Authors: Ngwem Marcelline Carine Ngo , Kemmegne‐Mbouguen Justin Claude , Langmi Henrietta W. , Musyoka Nicholas M. , Mokaya Robert 
Published: October 2022

AbstractA composite (Sa‐HTDMA/UiO‐66) consisting of organoclay (Sa‐HTDMA) and a metal‐organic framework (UiO‐66) was prepared using organically modified natural Cameroonian clay and Zr‐MOF. The organoclay was obtained by intercalating in its interlayer hexadecyltrimethyl ammonium cation (HTDMA). The composite was then used to form a film onto a glassy carbon electrode (GCE) by drop coating (Sa‐HTDMA/UiO‐66/GCE). Electrochemical responses recorded at the as‐prepared modified electrodes for ascorbic acid (AA), acetaminophen (AC) and nitrite (NO2−) were investigated using cyclic and linear sweep voltammetry. The results revealed that Sa‐HTDMA/UiO‐66/GCE exhibited a favorable behavior for individual and simultaneous sensing of AA, AC and NO2−. Additionally, compared with UiO‐66 modified GCE, the composite enabled good performance of the electrode. Under the optimum conditions, the linear calibration curves were attained in the following ranges: 1–650 μM for AA, 1–700 μM for AC and 1–600 μM for NO2− with the respective detection limits of 0.01, 0.19 and 0.33 μM. Application of the sensors to determine AA and AC in pharmaceutical preparations, and NO2− in tap water, was successful.
A Dual‐Function Carbon Quantum Dot Fluorescent Probe for the Detection of Fe3+ and Sunset Yellow
Authors: Bao Wenbin , Lan Yuwei , Lu Haiqin , Li Guowei , Yu Meihua , Yang Jiachu , Wei Liubai , Su Qionghua 
Published: October 2022

AbstractThere are few researches on the application of multifunctional carbon quantum dots (CQDs) in analysis and detection. In this study, carbon quantum dots (CQDs) with dual‐function detection were synthesized by the one‐step hydrothermal method with citric acid as the carbon source and o‐phenylendiamine as the nitrogen source to detect Fe3+ and sunset yellow. The morphology of the prepared CQDs and the surface functional groups were characterized using TEM, FTIR, XPS, UV‐Vis spectroscopy, and fluorescence spectrophotometer. The results show that the morphology of CQDs is nearly spherical and well dispersed, with a particle size range of 1.24∼6 nm and the average particle size was 3.23 nm. The surface of the CQDs has hydrophilic groups, such as OH, −COOH and −NH2. CQDs exhibited good acid and alkali resistance, salt resistance, and photobleaching resistance under different conditions. The detection limits of CQDs for Fe3+ and sunset yellow were 1.52 μM and 0.812 μM, respectively. The recoveries of actual samples were 96.65 %∼104.85 % and 95.4 %∼104.55 %, with relative standard deviations (RSDs) of less than 6 %. Therefore, CQDs can be employed as dual‐function fluorescent probes in the practical detection of samples and have promising application prospects.
Synthesis of Nitrogen‐Doped Hierarchical Carbon Derived from Water Hyacinth with High Catalytic Activity for Oxygen Reduction Reaction
Authors: Liao Tianhao , Wang Minkang , Pu Yi , He Yuling , Hua Shiyang , Zhang Xinglong , Li Peiwen , Wan Xinming , Tang Hui 
Published: October 2022

AbstractNitrogen‐doped carbon materials as durable high‐performance oxygen reduction reaction (ORR) catalysts showed great potential to replace Pt‐based catalysts. In this paper, a N‐self‐doped carbon catalyst is fabricated from natural biomass (water hyacinth) via a facile pyrolysis process. The as‐prepared catalysts with high specific surface area (828.50 m2 g−1) possess hierarchical porous structures and excellent ORR efficiency. The catalysts exhibit a high onset potential (Eonset=0.948 V), half‐wave potential (E1/2=0.827 V) and limiting current density (JL=4.95 mA cm−2), which is comparable to commercial Pt/C. Moreover, the long‐term stability and tolerance to methanol of the as‐prepared catalysts are also superior to those of Pt/C. The outstanding electrochemical performance is ascribed to the hierarchical porous structure with accessible active sites, which originated from the natural properties of water hyacinth. This work opens a new door for the synthesis of NC catalysts using biomass as a precursor. The as‐prepared catalysts have great potential for further study and applications in energy.
Simultaneous Bio‐oxidation and Bio‐reduction of Chlortetracycline and Paracetamol Using a Sequenced Batch Reactor (SBR)
Authors: Celik Aytekin 
Published: October 2022

AbstractChlortetracycline (CTC) and paracetamol (PCT), which are among the most widely used drugs today, have started to be detected in groundwater and surface waters. For this reason, water resources are exposed to more and more drug pollution every day. For this purpose, it is important to remove these pollutants from the environments where they are located. In this study, CTC and PCT drugs together with ammonium (NH4‐N) and nitrate (NO3‐N) pollutants were simultaneously removed in a single reactor. At the end of the study, PCT and CTC were removed at maximum 99.8 % and 66 % under the same conditions, respectively. At the same time, nitrification and denitrification efficiency were obtained as 99 %. In terms of volumetric removal flux, chlortetracycline and equivalent O2 flux of chlortetracycline maximum were calculated as 2.05 and 3.56 mg/L.d. Likewise, the maximum removal volumetric flux of paracetamol and its O2 equivalent flux were determined as 136 and 301.5 mg/L.d. The results showed that, aerobic nitrified bacteria preferred paracetamol rather than chlortetracycline. In other words, nitrified bacteria preferred paracetamol/chlortetracycline as the second electron acceptor after O2. As a result, chlortetracycline and paracetamol were successfully eliminated in the SBR system. In addition, simultaneous biological removal of these drugs with nitrogenous pollutants has been successfully achieved.
Total Synthesis of the Marine Sponge Alkaloid Motuporamine C Using a Ramberg‐Bäcklund Ring Contraction Strategy
Authors: Song Zijie , Meng Shuyu , Wang Quanrui 
Published: October 2022

AbstractA new total synthesis of the marine alkaloid motuporamine C, a macrocyclic polyamine alkaloid from the marine sponge Xestospongia exigua, has been accomplished. Key steps of this synthesis include application of Ramberg‐Bäcklund rearrangement for achieving the 15‐membered aza‐macrocyclic alkene and Rh(II)‐catalyzed deoxygenation of epoxide for the conversion of E‐ to Z‐configuration of the double bond within the cyclic structure.
Aminopyridinyl Tricosanamide Based Pseudoplastic and Thermoreversible Oleogels for pH‐Dependant in vitro Release of Metronidazole
Authors: Yadav Eqvinshi , Sebastian Sharol , Gupta Manoj K. 
Published: October 2022

AbstractOleogels are semi‐solid, thermo‐reversible and viscoelastic self‐assembled 3‐D networking structures in which edible oils are immobilized through physical interactions with oleogelators. Nowadays, oleogels have attracted the attention of researchers for its wide applications in pharmaceuticals, cosmetics and food industries. Therefore, we have prepared a new oleogel formulation for topical and transdermal applications of antimicrobial and antiseptic agent metronidazole with enhanced properties. Aminopyridinyl tricosanamide fatty acid amide oleogelator self‐assembled in edible oils, form stable/thermoreversible gel with good shear thinning and pseudoplasticity. Such oleogels may be excellent drug delivery vehicles for topical/transdermal applications due to their shear thinning and pseudoplastic behaviour. In addition, the pH of these gels fall in the range of skin pH which bodes well for potential applications on skin. These gels show a slow and controlled release of the drug in both acidic and slightly basic buffers, indicating long‐term antibacterial activity associated with such drug loaded oleogels.
S‐g‐C3N4/N−TiO2 @PTFE Membrane for Photocatalytic Degradation of Tetracycline
Authors: You Xuehui , Liu Fang , Jiang Guofei , Chen Shuhua , An Beiya , Cui Rongli 
Published: October 2022

AbstractHerein we synthesized S‐g‐C3N4 and N−TiO2 catalysts by hydrothermal and calcination technologies and SCN/NT@PTFE membrane by a vacuum filtration method. The morphology and composition of the synthesized materials were analyzed by different characterization methods (SEM/HRTEM/XRD/XPS/UV‐vis et.). The effects of different catalysts, pollutant concentrations, mass of catalyst and pH on the photo‐degradation of tetracycline were investigated. The degradation rate of tetracycline by SCN/NT‐2@PTFE membrane was as high as 99.9 % after 2 h of illumination. This was mainly because heterogeneous structure between S‐g‐C3N4 and N−TiO2 broadened the light absorption range and suppressed the carrier complex. Superoxide radicals (⋅O2−) were proved to play a dominant role in the degradation reaction. After 20 days of stirring in water, the photocatalytic performance of membrane decreased slightly, demonstrating its good stability. The study of SCN/NT‐2@PTFE membrane provides a new direction for the development of photocatalysis and membrane.
Catalytic Synthesis of Energy‐rich Fuel Additive Levulinate Esters from Levulinic Acid using Modified Ultra‐stable Zeolite Y
Authors: Gautam Priyanka , Barman Sanghamitra , Ali Amjad 
Published: October 2022

AbstractIn the present investigation, the esterification reaction of levulinic acid with ethanol was performed using sulfuric acid‐modified zeolite Y catalyst to synthesize ethyl levulinate. Characterization of zeolite catalysts was performed using SEM‐EDS, XRD, and FTIR techniques. The experiments were performed to find the optimum reaction parameters to obtain the maximum yield of 96 % of the product, levulinate ester by varying catalyst concentration (2–12 wt %), levulinic acid to ethanol mole ratio (1 : 1 to 1 : 13), reaction temperature (40 °C–100 °C). The esterification of levulinic acid with ethanol followed pseudo‐first‐order reaction kinetics. The activation energy for this reaction was found to be 19.570 KJmol−1.
Amorphous Cr2O3 Sheets: A Novel Supercapacitor Electrode Material
Authors: Joseph Anit , Sunny Joe , Thomas Tiju , Anantharaman M. R. 
Published: October 2022

AbstractAn ongoing field of study involves improving the performance and stability of benchmarked metal catalysts employing nanostructured non‐metallic materials, which is both fascinating from a fundamental and an application standpoint. By rapidly thermally exfoliating CrCl3 6H2O precursors, amorphous few‐layered nanosheets of Cr2O3 (3‐5 nm) are synthesized. The exfoliated Cr2O3 was characterized using structural and electrochemical techniques. Cyclic Voltammetry (CV) revealed that the material delivers a specific capacitance of 1100 F/g at 10 mV/s, which is among the best‐reported values for this material. This sample has a modest surface area of 155 m2/g with a mesoporous structure. Electrochemical impedance spectra (EIS) for amorphous Cr2O3 revealed lower series resistance (Rs) and charge transfer resistance (Rct) of 0.6 Ω and 0.88 Ω, respectively. Additionally, this material delivers a desirable energy and power density of 20.2 Wh/kg and 125 W/kg, respectively.
Eu‐doped ZnAl‐LDH as a Fluorescent Labeling Carrier for the Delivery and Controlled Release of Camptothecin
Authors: Li Tingting , Qiu Xingxing , Li Chao , Shang Xiaoqiang , Chen Yufeng 
Published: October 2022

AbstractEuropium doped Zinc‐aluminum layered double hydroxide (Eu‐doped ZnAl‐LDH) as a fluorescent labeling carrier for the delivery and controlled release of camptothecin (CPT) has been studied. X‐ray diffraction (XRD) patterns showed that the basal spacing of the Eu‐doped ZnAl‐LDH intercalated with CPT (2.27 nm) was larger than that of the initial Eu‐doped ZnAl‐LDH (0.88 nm), indicating the successful intercalation of CPT into the Eu‐doped ZnAl‐LDH carrier. X‐ray photoelectron spectroscopy (XPS) suggested that some Eu(III) were reduced to Eu(II) after the intercalation of CPT into the Eu‐doped ZnAl‐LDH. The release of the CPT from drug carrier was carried out in a simulated medium. It was found that the cumulative concentration of the released CPT was exponential with releasing time, and well conformed to the exponential equation: C=A‐Bexp(‐kt). It took 720 minutes (min) for the complete release of CPT from drug carrier. Fluorescent analyses revealed that the fluorescence attributed to the drug delivery system changed from red, blue‐green, to blue emission during delivery and release of CPT, which may be a favorable signal for “detecting” the delivery and release of CPT. Thus, the present Eu‐doped ZnAl‐LDH may be a feasible drug carrier with fluorescent labeling function.
Development of ICP‐OES Based Analytical Method with Prior Preferential Removal of Emission Rich Matrix by Elevated Temperature Ionic Liquid Based Extractive Mass Transfer for Determination of Metallic Constituents in U‐Mo Alloy: The Next Generation Nuclear Fuel
Authors: Bhoir Seema , Pathak Sunita , Jayabun Sk. , Sengupta Arijit 
Published: October 2022

AbstractAn (ICP‐OES) based analytical methodology was developed for the determination of metallic constituents (Al, Ca, Co, Cr, Cu, Fe, Ga, In, Mn, Mg, Na, Ni, Si, V, W and Zn) at minor and trace level in U−Mo alloy fuel after preferential separation of emission rich major matrix using TBP‐HDBO‐NTf2 without any compromise on the determination of analytes at trace levels. Application of ionic liquid, HDBO‐NTf2 drastically reduced the time of analysis (30 min reduction per sample) and generation of toxic organic waste (20 mL per sample) containing U and Mo. The method was optimized by identification of analytical lines of the elements free from spectral interference of U and Mo, establishing the calibration curves using those lines and evaluation of analytical performances (detection limit, linear dynamic range etc.) in U−Mo matrix. The preferential separation of U and Mo were found to follow anion exchange and cation exchange mechanism involving UO2((NO)3)3.2TBP− and MoO2(NO3) TBP+ species, respectively, which differ in their conventional separation by solvation mechanism involving ML2 and ML1 neutral species, respectively. Preferential separation by HDBO‐NTf2 based system can be effectively used for determination of analytes of 10 ppm concentration at 10 % error limit. The total uncertainty in estimation of each analyte have been estimated. The real sample analyses data were compared to that obtained by n‐dodecane based ICP‐OES method and direct analysis of Energy Dispersive X‐ray Fluorescence spectroscopic (EDXRF) method. The data were found to be in good agreement with each other. The experimentally obtained results were subjected to t‐test with 95 % confidence limit and 10 degrees of freedom. The texpt was found to be less than tcrit 2.228 revealing reliability of the methods. The experimentally obtained variance values (Fexpt) were found to be less than Fcrit∼2.980 revealing the variance values are within acceptable statistical error limit.