bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Research on Tensile Mechanical Properties of NEPE Propellant under Confining Pressure
Authors: Li Hui , Wang Shi‐Xin , Li Meng , Xu Jin‐Sheng , Fan Xing‐Gui , Chen Xiong 
Published: September 2020

AbstractTo study the tensile mechanical properties of the Nitrate Ester Plasticized Polyether (NEPE) propellant under varying confining pressure conditions, uniaxial tensile tests were conducted under different strain rates (from 0.0006667 s−1 to 0.06667 s−1) and confining pressure conditions (from relative atmospheric pressure up 5.4±0.03 MPa) using a new‐designed confining pressure testing machine. Scanning electron microscopy (SEM) was employed to observe the tensile fracture surfaces. The mechanical properties and damage processes of the NEPE propellant under varying confining pressure conditions were studied and analysed. The results indicate that the mechanical properties of propellant materials are remarkably influenced by the varying confining pressure conditions. The ultimate strain and maximum tensile stress increase with increasing confining pressure. Moreover, the maximum tensile stress present a linear‐log relationship with the strain rate under various confining pressure conditions. Yet, the confining pressure has no obvious effect on the initial elastic modulus. The reason for the change of the mechanical properties of the NEPE propellant is that confining pressure delays the initiation and development of damage under the tensile loading. Based on the time‐pressure superposition principle (TPSP), the master curve of maximum tensile strength of the NEPE propellant was constructed. Furthermore, the results can provide a theoretical foundation for the analysis of the structural integrity of propellant grains of a SRM under ignition conditions. Finally, a constitutive model considering compressibility of propellant materials can be constructed.
InteBac: An integrated bacterial and baculovirus expression vector suite
Authors: Altmannova Veronika , Blaha Andreas , Astrinidis Susanne , Reichle Heidi , Weir John R. 
Published: September 2020

AbstractThe successful production of recombinant protein for biochemical, biophysical, and structural biological studies critically depends on the correct expression organism. Currently, the most commonly used expression organisms for structural studies are Escherichia coli (~70% of all PDB structures) and the baculovirus/ insect cell expression system (~5% of all PDB structures). While insect cell expression is frequently successful for large eukaryotic proteins, it is relatively expensive and time‐consuming compared to E. coli expression. Frequently the decision to carry out a baculovirus project means restarting cloning from scratch. Here we describe an integrated system that allows simultaneous cloning into E. coli and baculovirus expression vectors using the same PCR products. The system offers a flexible array of N‐ and C‐terminal affinity, solubilization and utility tags, and the speed allows expression screening to be completed in E. coli, before carrying out time and cost‐intensive experiments in baculovirus. Importantly, we describe a means of rapidly generating polycistronic bacterial constructs based on the hugely successful biGBac system, making InteBac of particular interest for researchers working on recombinant protein complexes.
Protein loops with multiple meta‐stable conformations: A challenge for sampling and scoring methods
Authors: Barozet Amélie , Bianciotto Marc , Vaisset Marc , Siméon Thierry , Minoux Hervé , Cortés Juan 
Published: September 2020

AbstractFlexible regions in proteins, such as loops, cannot be represented by a single conformation. Instead, conformational ensembles are needed to provide a more global picture. In this context, identifying statistically meaningful conformations within an ensemble generated by loop sampling techniques remains an open problem. The difficulty is primarily related to the lack of structural data about these flexible regions. With the majority of structural data coming from x‐ray crystallography and ignoring plasticity, the conception and evaluation of loop scoring methods is challenging. In this work, we compare the performance of various scoring methods on a set of eight protein loops that are known to be flexible. The ability of each method to identify and select all of the known conformations is assessed, and the underlying energy landscapes are produced and projected to visualize the qualitative differences obtained when using the methods. Statistical potentials are found to provide considerable reliability despite their being designed to tradeoff accuracy for lower computational cost. On a large pool of loop models, they are capable of filtering out statistically improbable states while retaining those that resemble known (and thus likely) conformations. However, computationally expensive methods are still required for more precise assessment and structural refinement. The results also highlight the importance of employing several scaffolds for the protein, due to the high influence of small structural rearrangements in the rest of the protein over the modeled energy landscape for the loop.
A two‐dimensional multiwell cell culture method for the production of CYP3A4‐expressing hepatocyte‐like cells from HepaRG cells
Authors: Ooeda Keiko , Kubiura‐Ichimaru Musashi , Tsuji Saori , Okuyama Shota , Yamashita Mao , Mine Akari , Kawamura Fumihiko , Ueyama Takafumi , Tada Masako 
Published: September 2020

AbstractCytochrome P450 enzymes (CYP) function in drug metabolism in the liver. To evaluate numerous drug candidates, a high‐content screening (HCS) system with hepatocyte‐like cells (HLCs) that can replace adult human hepatocytes is required. Human hepatocellular carcinoma HepaRG is the only cell line capable of providing HLCs with high CYP3A4 expression comparable to that in adult hepatocytes after cell differentiation. The aim of this study was to design an ideal multiwell culture system for HLCs using transgenic HepaRG cells expressing the EGFP coding an enhanced green fluorescent protein under CYP3A4 transcriptional regulation. HLCs were matured on five different types of 96‐well black plates. Culturing HLCs on glass‐bottom Optical CVG plates significantly promoted cell maturation and increased metabolic activity by twofold under two‐dimensional (2D) culture conditions, and these features were enhanced by 2% collagen coating. Three plates for three‐dimensional (3D) cell cultures with a gas‐exchangeable fabric or dimethylpolysiloxane membrane bottom formed multiple round colonies, whereas they were ineffective for CYP3A4 expression. Under optimized conditions presented here, HLCs lost responsiveness to nuclear receptor‐mediated transcriptional induction of CYP3A4, suggesting that CYP3A4 transcription has already been fully upregulated. Therefore, HepaRG‐derived HLCs will provide an alternative to human hepatocytes with high levels of CYP3A4 enzyme activity even under 2D culture conditions. This will improve a variety of drug screening methods.
The mediating and moderating role of neighbourhoods and regions on second‐generation immigrant youths' school‐to‐work transitions in the Netherlands
Authors: Wessling Katarina , Meng Christoph 
Published: September 2020

AbstractContexts in which people live such as neighbourhoods, cities or regions influence individuals. However, research analysing effects of different contexts simultaneously is limited. Our paper's focus is to examine the interrelation between regional and neighbourhood conditions and their influence on school‐to‐work transitions. We investigate the process of transitioning from vocational training to employment, with a specific focus on adolescents from non‐Western immigrant origin. We link Dutch survey data on almost 15,000 graduates with spatial information from Statistics Netherlands and compare results across multilevel linear probability models. Overall, we find employment prospects to be reduced in neighbourhoods and regions that are socioeconomically unfavourable. However, neighbourhood influences diminish or even disappear once accounted for the region. Deprived conditions in urban regions are particularly detrimental for adolescents of immigrant descent. However, a high share of coethnics in the neighbourhood reduces the unemployment risk of second‐generation non‐Western minorities in deprived urban regions. This finding stresses the relevance of immigrants' neighbourhood networks for education and employment prospects.
Calibration of Green‐Ampt wetting front suction for ponding and non‐ponding infiltration scenarios
Authors: Pereira Caroline Andrade , Gubiani Paulo Ivonir , de Jong Van Lier Quirijn 
Published: September 2020

AbstractMathematical formulations for layered soil profiles and corresponding parameterization to improve performance of the Green‐Ampt model (GA) have not always shown accurate. We evaluated GA maintaining its assumption of saturated flow but calibrating the effective matric suction at the wetting front (hf) by damping the initial matric suction (hi). The proposition was evaluated comparing cumulative infiltration simulated by GA to that simulated by Hydrus‐1D for five soils from three texture classes, three initial matric suctions, and five 24‐h water supply regimes. For each case, GA was run with a decreasing series of 20 values of hf from the initial matric suction (10, 100, or 1000 cm) to values near 1 cm. To minimize the relative error (RE) between cumulative infiltration simulated by GA and Hydrus‐1D for the 24‐h period we found the required damping of hf to be dependent on soil type, water supply regime and initial matric suction, the latter being the most important factor. The calibration of hf was efficient to approach GA predictions to numerical Hydrus‐1D simulations, even for cases with alternating ponding and non‐ponding conditions. Results suggest a large reduction of wetting front matric suction hf may be necessary to approach cumulative infiltration predicted by GA to corresponding Hydrus‐1D predictions, especially during rainfall events that do not imply in continuous ponding. Taking hf somewhere between 1 and 3 cm, values of RE of cumulative infiltration during the first 24 h were below 10% for all cases, independent of soil type, rainfall characteristics or initial water content.
Linear and NLO Properties of Functional Group and Position Isomers of Azo and Azomethine: Comparative Photophysical‐Electrochemical Properties, Z‐Scan and DFT Studies
Authors: Mishra Virendra R. , Ghanavatkar Chaitannya W. , Sharma Suryapratap , Premarani Aswathy , Mathew Elizabeth , Joe Isaac H. , Sekar Nagaiyan 
Published: September 2020

AbstractFunctional group and position isomers of azo and azomethine were selected to investigate their effect on linear and NLO properties. The azo and azomethine analogs show absorption maxima in the range 460–500 nm and 375–435 nm respectively. They are emissive in green, orange to the deep red region with a large Stokes shift of 100–200 nm. When we compared azo and azomethine chromophores i. e. functional group isomers, azo chromophore shows a bathochromic shift of 50–103 nm, while in case of position isomers azo and azomethine having larger conjugation effect i. e. VA‐2 and VI‐2 show a more bathochromic shift of 28 nm and 42 nm than the corresponding analogs VA‐1 and VI‐1, which show respectively 466 nm and 379 nm. Band gaps evaluated by electrochemical method and DFT method are correlated with the bathochromic shift in absorption maxima. The dyes are thermally stable (up to 280 °C). Open and closed aperture Z‐scan techniques were used to evaluate the third order non‐linear optical (NLO) parameters ‐ nonlinear absorptive coefficient (β), nonlinear refractive index (η2), and third order non‐linear optical susceptibility (χ (3)). NLO properties were theoretically calculated by using DFT method with six different functionals. Mean absolute error (MAE) and standard deviation (SD) were evaluated to get more insight into theoretical calculation. With the set of calculated data points, MAE and SD calculated to check performance of the DFT functional. Different functionals were used to evaluate vertical excitation values and compared it with experimental absorption maxima.
Solid‐State Synthesis of Silver Nanoparticles and Their Catalytic Application in Methylene Blue Reduction
Authors: Veljović Djordje N. , Gurešić Dejan M. , Jokić Anja B. , Vasić Vesna M. , Laban Bojana B. 
Published: September 2020

AbstractThe silver nanoparticles (Ag NPs) were successfully synthesized by a facile solid‐state chemical method. Ag NPs were obtained by a mechanochemical reaction between silver nitrate and sodium citrate, with the constant stirring and heating of reactants. The size and morphology characterization of NPs powder was performed by scanning electron microscopy. The obtained NPs were spherical with a 36 nm average particle size diameter. UV‐Vis spectroscopy, dynamic light scattering, and zeta potential measurements were used in order to characterize the surface plasmon band position in colloid dispersion and the NPs charges. Obtained NPs were utilized as a catalyst in the process of methylene blue (MB) reduction in the presence of sodium‐borohydride. Kinetic measurements of uncatalyzed and catalyzed reduction were carried out using the stopped‐flow technique, keeping the concentration of reactant constant. Mechanism of MB reduction in the presence of catalyst Ag NPs is elucidated as a consecutive two first‐order reactions. The results of these studies support the hypothesis that NPs participated in electron transfer.
CTAB‐PLGA Curcumin Nanoparticles: Preparation, Biophysical Characterization and Their Enhanced Antifungal Activity against Phytopathogenic Fungus Pythium ultimum
Authors: Khatua Ashapurna , Prasad Abhinav , Priyadarshini Eepsita , Virmani Ishita , Ghosh llora , Paul Bernard , Meena Ramovatar , Barabadi Hamed , Patel Amiya Kumar , Saravanan Muthupandian 
Published: September 2020

AbstractIn the current study, we utilized application of nanotechnological advancements to synthesize positively charged curcumin nanoparticles (CurNPs). In CurNPs, curcumin (Cur) was encapsulated by a stabilizer, polymer poly(lactic‐co‐glycolic acid) (PLGA) and its surface charge was modified by cationic surfactant cethyltrimetylammonium bromide (CTAB). Characterization methods involving UV‐visible spectroscopy, X‐ray diffraction (XRD), transmission electron microscopy (TEM) and dynamic light scattering (DLS) were employed to confirm their synthesis. Then, we used CurNPs to investigate their potential as fungicidal agents in vitro and the underlying mechanisms, as compared to free Cur in the two fungal strains SR1 and BP1120 of a destructive plant pathogen Pythium ultimum var. ultimum. The fungicidal activity of CurNPs were studied by several methods which resulted in comparatively more pronounced antifungal activity in BP1120 than SR1. Broth dilution and well diffusion assay revealed minimum inhibitory concentration (MIC80) for CurNPs to be 52.57 μg/mL and 44.67 μg/mL and an increase in zone of inhibition (ZOI) by 5.4 and 6.3 fold of Cur at 15 μg/mL of CurNPs in SR1 and BP1120, respectively. Study of growth curve showed prolonged lag phase, delayed and short log phase, early and prolonged stationary phase and early decline phase after CurNPs exposure. Toxicity of CurNPs in SR1 and BP1120 strains of P. ultimum was attributed to the enhancement in intracellular reactive oxygen species (ROS) generation and fall in mitochondrial membrane potential (MMP) as revealed by spectrofluorometric assay. Taken together, these CurNPs were confirmed as a novel and very potent fungicidal agents against P. ultimum var. ultimum with a great promise of controlling and treating other microbial infections.
A New Squaraine‐Linked Triazinyl‐Based Covalent Organic Frameworks: Preparation, Characterization and Application for Sensitive and Selective Determination of Fe3+ Cations
Authors: Xue Rui , Gou Hao , Zheng Yanping , Zhang Li , Liu Yinsheng , Rao Honghong , Zhao Guohu 
Published: September 2020

AbstractA new triazinyl‐based covalent organic frameworks(COFs) linked by squaraine(ST‐COF‐1) was synthesized via condensation of squaric acid (SA) and 1,3,5‐triazine‐2,4,6‐triamine (Melamine, MA). The BET surface area of ST‐COF‐1 was calculated as 484.12 m2 g−1. The suspension of this material will emit strong blue fluorescence under the irradiation of 365 nm ultraviolet lamp. Strong quenching effects of Fe3+ on the fluorescence of the COFs allowed selective chemosensing for Fe3+ cation. In addition, some nitro aromatic compounds also cause strong fluorescence quenching, which proves that this material can also be used for the qualitative detection of nitro aromatic compounds.
Flexible Solid PANI Fiber Networks/Ni‐MOF@CC Electrodes for High‐Performance Capacitors: Synthesis and Stability Study
Authors: Dong Shibo , Wang Qiguan , Zhang Wenzhi , Chen Jian , Wang Sumin 
Published: September 2020

AbstractIn this work, the nickel‐based metal organic framework (Ni‐MOF) is attached to the conductive carbon cloth (CC) by using a hydrothermal reaction. In order to make MOFs strongly interacted with CC, polymeric molecules of polyaniline (PANI) are deposited on Ni‐MOF@CC employing an in–situ polymerization method. The PANI shows a three‐dimensional fiber‐network morphology. Due to the improved electrical conductivity and the porous networks, the electrochemistry property of the obtained flexible PANI/Ni‐MOF@CC is greatly enhanced compared with Ni‐MOF@CC. The specific capacitance of PANI/Ni‐MOF@CC reaches 109 F cm−2 (573 F g−1). The optimum energy density of PANI/Ni‐MOF@CC at 0.1 A cm−2 can be 7 mWh cm−2 with power density of 70 mW cm−2. Because the fiber networks of PANI on MOF enhances the interactions between MOF and CC, the PANI/Ni‐MOF@CC shows high stability of 95 % capacitance retention after 5000 charge‐discharge cycling.
Simple Iron(III) Complex Based Highly Sensitive Fluorescent Off‐On Sensor for the Detection of Trace Amount of Water in Organic Solvents and Edible Oilseeds
Authors: Kumar Pawan , Gadiyaram Srushti , Jose D. Amilan 
Published: September 2020

AbstractMoisture detection in organic solvents and materials by using chemical sensors represent the latest research area in analytical chemistry. In this paper, we report a new fluorescent chemical sensor for the sensitive detection of trace amount of water in Tetrahydrofuran(THF), acetone and acetonitrile. The new probe L.Fe(III) complex consists of the fluorescent reporter dansyl dye attached with Fe(III) ion. Ligand L, and probe L.Fe(III) exhibits solvatochromism by intramolecular charge transfer (ICT) due to the donor‐acceptor properties of the dansyl compound. Probe L.Fe(III) is a non‐fluorescent compound and it becomes highly fluorescent in the presence of trace amount of water in THF, acetone and acetonitrile. The probe shows highly sensitive towards the water in THF with a limit of detection (LOD) as low as 0.0003 weight(wt) %. 1H‐NMR, ESI‐MS and fluorescence lifetime studies established that displacement of metal from the probe is responsible for fluorescent enhancement. Further, for the first time probe L.Fe(III) has been explored as a fluorescence indicator for the qualitative and quantitative detection of trace‐level of water content in various edible oilseeds such as groundnut, mustard, sunflower, sesame and almond.
Mode‐to‐Mode Collision Energy Transfer from Vibrationally Excited C6F6 to NO/N2 Mixed Bath with the Development of New Potential Energy Functions
Authors: Ahamed Sk. Samir , Kumar Pavan , Kalita Hrishikesh , Paul Amit K. 
Published: September 2020

AbstractChemical dynamics simulations are performed to study collisional intermolecular energy transfer (IET) from highly vibrationally excited C6F6 to NO/N2 mixed baths equilibrated at 300 K. Two baths with a respective total of 200 and 1000 molecules are considered. The simulations are performed with very accurate intramolecular and intermolecular potential energy parameters either taken from literature or developed. A new simulation methodology is implemented to prepare a three‐component bath system. There is a rise in temperature during the IET dynamics in the smaller bath. The rotational ΔT is observed as 85 K in this bath and is much higher than 20 K obtained at 600 ps from the large bath simulation. However, both the simulations show less average energy transfer as compared to the one obtained from pure N2 bath simulation done previously [J. Chem. Phys. 2014, 140, 194103]. The deviation is less for the large bath simulation. The rotational degree of freedom for NO is found less effective towards IET compared to N2, whereas, the center‐of‐mass translational and vibrational modes behave similar to those of N2.
Stabilization of Supramolecular Assembly of N‐Substituted Benzylidene Acetohydrazide Analogs by Non‐Covalent Interactions: A Concise Experimental and Theoretical Approach
Authors: Khalid Muhammad , Ali Akbar , Tariq Jahrukh , Tahir Muhammad Nawaz , Aliabad Hossein Asghar Rahnamaye , Hussain Ishtiaq , Ashfaq Muhammad , Khan Muhammad Usman 
Published: September 2020

AbstractHerein, the crystalline N‐substituted benzylidene acetohydrazide derivatives: N′‐(4‐bromo‐2‐fluorobenzylidene)‐2‐((6‐chloropyridin‐2‐yl)oxy) acetohydrazide (BFBAH) and 2‐((6‐chloropyridin‐2‐yl)oxy)‐N′‐(4‐methoxybenzylidene) acetohydrazide (MOBAH) were produced and the structures were characterized and confirmed by the NMR spectroscopy and single crystal analysis. SC‐XRD study disclosed that the molecules are connected with each other in the form of dimers through hydrogen bonding in the crystalline network of BFBAH and MOBAH. Additionally, the theoretical calculations were performed using the DFT/B3LYP/6‐311G(d,p) functional. The hyperconjugation and intermolecular hydrogen bonding were explored by using NBO analysis. Hirshfeld surface analysis analyzing intra and intermolecular interactions, uncovered that supramolecular assemblies have been stabilized by N−H⋅⋅⋅O and C−H⋅⋅⋅O intermolecular hydrogen bonds, as well as van der Waals interactions. The quantum theory of atoms in molecules (QT‐AIM) study corroborates that both significant N−H⋅⋅⋅O and C−H⋅⋅⋅O H‐bonds are strong in nature. Besides, global reactivity indices were computed via the energies of HOMO and LUMO orbitals.
Designing of Ag2S Nanowires from a Single‐Source Molecular Precursor [(PPh3)2AgS2P(OiPr)2] for Hydrogen Evolution Reaction
Authors: Khirid Samreet , Biswas Rathindranath , Meena Sangeeta , Patil Ranjit A. , Ma Yuan‐Ron , Devan Rupesh S. , Dhayal Rajendra S. , Haldar Krishna Kanta 
Published: September 2020

AbstractIn the present study, we illustrated a facile fabrication of large scale ultra‐thin silver sulfide (Ag2S) nanowires (NWs) and its promising application in hydrogen evolution reaction (HER). Ultra‐thin and highly uniform Ag2S nanostructures were fabricated from single‐source precursor [(PPh3)2AgS2P(OiPr)2], and characterized by utilizing various structural and imaging techniques. Large‐scale monodispersed ultra‐thin single‐crystalline Ag2S nanowires were generated via n‐decylboronic acid induced thermal decomposition of the single precursor in the presence of octadecyl amine and oleyl amine mixture under anaerobic conditions. We explored the catalytic activities of Ag2S nanowires for HER which showed an overpotential of−88 mV at 10 mA/cm2 and the corresponding Tafel slope was found to be 52 mV dec−1.
Ultrasonic‐Assisted Hypervalent Iodine‐Catalyzed Cyclization of (E)‐2‐Hydroxystilbenes to Benzofurans Using Iodobenzene as Pre‐catalyst
Authors: Mangaonkar Saeesh R. , Shetgaonkar Samata E. , Vernekar Amit A. , Singh Fateh V. 
Published: September 2020

AbstractA rapid, and metal‐free approach for the synthesis of functionalized benzofurans 10 is illustrated by PhI 9 catalyzed cyclization of 2‐hydroxystilbenes 8. The 2‐hydroxystilbenes 8 were cyclized using 10 mol % PhI as a precatalyst, 2.0 equiv. of m‐CPBA as an oxidant and 2.4 equiv. of TFA as an additive at room temperature under ultrasonic irradiation condition. The functionalized benzofurans 10 were gained in good to excellent yields with shorter reaction times.