bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural insights into the thermostability mechanism of a nitrile hydratase from Caldalkalibacillus thermarum by comparative molecular dynamics simulation
Authors: Shen Ji‐Dong , Cai Xue , Ni Ye‐Wen , Jin Li‐Qun , Liu Zhi‐Qiang , Zheng Yu‐Guo 
Published: March 2021

AbstractNitrile hydratase (NHase), an excellent bio‐catalyst for the synthesis of amide compounds, was composed of two heterologous subunits. A thermoalkaliphilic NHase NHCTA1 (Tm = 71.3°C) obtained by in silico screening in our study exhibited high flexibility of α‐subunit but excellent thermostability, as opposed to previous examples. To gain a deeper structural insight into the thermostability of NHCTA1, comparative molecular dynamics simulation of NHCTA1 and reported NHases was carried out. By comparison, we speculated that β‐subunit played a key role in adjusting the flexibility of α‐subunit and the different conformations of linker in “α5‐helix‐coil ring” supersecondary structure of β‐subunit can affect the interaction between β‐subunit and α‐subunit. Mutant NHCTA1‐α6C with a random coil linker and mutant NHCTA1‐αβγ with a truncated linker were therefore constructed to understand the impact on NHCTA1 thermostability by varying the supersecondary structure. The varied thermostability of NHCTA1‐α6C and NHCTA1‐αβγ (Tmα6C = 74.4°C, Tmαβγ = 65.6°C) verified that the flexibility of α‐subunit adjusted by β‐subunit was relevant to the stability of NHCTA1. This study gained an insight into the NNHCTA1 thermostability by virtual dynamics comparison and experimental studies without crystallization, and this approach could be applied to other industrial‐important enzymes.
A systematic review of interleaving as a concept learning strategy
Authors: Firth Jonathan , Rivers Ian , Boyle James 
Published: March 2021

AbstractA systematic review was conducted into the effect of interleaving the order of examples of concepts in terms of both memory of items and transfer to new items. This concept has important implications for how and when teachers present examples in the classroom. A total of 26 studies met the inclusion criteria; a subset of 17 studies (with 32 constituent datasets) formed the basis of a meta‐analysis, and the remainder were analysed within a narrative review. Memory (as tested by presenting studied items from a learned category) showed an interleaving benefit with effect sizes (Hedges’ g) of up to 0.65, and transfer (as tested by presenting novel items from a learned category) a benefit with effect sizes of up to 0.66. Interleaving was found to be of greatest use when differences between items are subtle, and the benefit extended to both art‐ and science‐based items, with implication for practitioner decisions over how and when to apply the technique. It also extended to delayed tests. The review revealed that the literature is dominated by laboratory studies of university undergraduates, and the need for future school‐based research using authentic classroom tasks is outlined.
Synthesis and Characterizations of High Crystallized Clinoptilolite by Structure Directing Agent Method and its Crystallization Kinetics
Authors: Zorigt Tergel , Zhai Chengwei , Jiao Jian , Sun Jihong , Wu Xia 
Published: March 2021

AbstractThe clinoptilolites (CPs) with high purity were prepared via structure directing agent (SDA) method combining with hydrothermal method using silica sol as the silica source and aluminum hydroxide as the aluminum source. Their structural features were characterized by X‐ray diffraction (XRD) patterns, Fourier transform infrared (FT‐IR) spectra, thermal gravimetric (TG) analysis, scanning electron micrograph (SEM) images, 29Si nuclear magnetic resonance (NMR) profiles. The effects of additive amount and aging time of used SDA, as well as synthetic parameters such as crystallization temperature and crystallization time on their structure and performance were emphasized. Particularly, the activation energies of their crystallization kinetics at different stages of induction period and growth period were calculated on the basis of Arrhenius equation. The results demonstrated that the obtained CPs presented the highest relative crystallinity when the additive amount of used SDA was 1 mL at aging periods of 2 d, otherwise, their relative crystallinity degree was low due to existences of a large number of heterocrystal impurities. Particularly, the apparent activation energy values for induction (En) and growth (Eg) profile were calculated by the Arrhenius equation. The En value (86.46 kJ/mol) of induction period was much higher than that Eg value (9.64 kJ/mol) of growth stage, suggesting that the induction period was the main controlling step during the synthetic CP. Finally, the synthetic CP was employed to preliminarily assess its performances for CH4/N2 separation. These demonstrations provide a promising method for the synthesis of CPs.
Ethylenediamine Functionalized Cellulose Acetate [CAEDA] Nanosized Solid Base Catalyst in the Synthesis of 2‐Amino‐4H‐Chromenes and 5‐Substituted‐1H‐Tetrazoles
Authors: Kour Jaspreet , Gupta Monika , Sharma Neha 
Published: March 2021

AbstractA series of 2‐amino‐4H‐chromenes by combining dimedone, different substituted aromatic aldehydes and malononitrile and 5‐substituted‐1H‐tetrazoles by combining variable aldehydes, hydroxylamine hydrochloride and sodium azide have been efficiently synthesized in presence of ethylenediamine functionalized cellulose acetate as a solid base catalyst i.e Cellulose acetate[1,2‐ethylenediamine][CAEDA]. This catalyst is low‐cost, non‐toxic, unexplored, easily available, reusable, eco‐friendly in nature. This synthesized solid base catalyst has been characterized by fourier transform infrared spectroscopy (FTIR), themogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) spectroscopic techniques. The new catalytic method exhibits some noteworthy advantages such as short reaction time, high yields, easy workup and purification steps, simple preparation method which makes this strategy more useful for the synthesis of chromene and tetrazole derivatives then earlier methods.
Electrochemical Reduction of CO2 on Flame Annealed Cu
Authors: Keerthiga Gopalram , Chetty Raghuram 
Published: March 2021

AbstractSurface modification of metallic Cu by conventional oxidation and an alternative method of oxidation using flame annealing and its influence on electrochemical reduction (ECR) of CO2 are reported in this study. The ECR of CO2 in aqueous KCl electrolyte yielded methane, ethane, ethylene, and hydrogen as the major products. The faradaic efficiency of ethane obtained at −1.2 V vs NHE for flame‐annealed Cu (34 %) was comparable to the conventionally oxidised Cu (40 %), while bare Cu yielded methane (10 %). The metal–metal oxide interface on the electrode aids in the formation of C2‐based products. Flame annealing can be regarded as an alternative electrode preparation method for C2 product formation, with its merits in high specific surface area, self‐rejuvenating mode on deactivation and ease of preparation.
Thermo‐Sensitive EuIII Coordination Polymers with Amorphous Networks
Authors: Hasegawa Yasuchika , Sato Natsumi , Hayashi Joe , Kitagawa Yuichi , Fushimi Koji 
Published: March 2021

AbstractLuminescent EuIII coordination polymer with amorphous transformation and thermo‐sensing abilities under higher temperature, [Eu(hfa)3(tppa)n]m (hfa: hexafluoroacetylacetonate, tppa: tri‐diphenylphosphoryl‐4,4,4‐triphenylamine) is reported. The glass transition and decomposition temperatures are found to be 142 °C and 270 °C, respectively. The intrinsic emission quantum yield Φ4f−4f of [Eu(hfa)3(tppa)n]m was estimated to be 69 % in solid state. [Eu(hfa)3(tppa)n]m shows effective decrease in the emission lifetime upon increasing the temperature from 320 to 400 K. The temperature‐depended emission lifetime is caused by the back energy transfer from emitting level of EuIII ion (5D0) to the LLCT band (tppa ligand to hfa ligand) in [Eu(hfa)3(tppa)n]m. Thermo‐sensitive lanthanide luminophore with stable glass formation in higher temperature (>100 °C) is useful for surface temperature detection in the field of high‐speed wind tunnel experiments such as aircraft and automobile designs.
Preparation of Cu−MoS2/CdS Composite and Photoelectrocatalysis for Hydrogen Evolution
Authors: Yang Huimin , Zhang Dingding , Tian Haoyang , Li Yupeng , Hu Xueyan , Gao Mengting , Liang Zhenhai 
Published: March 2021

AbstractTransition metal ion doping is an efficient method to enhance the photoelectrochemical (PEC) performance of catalytic composite materials. In this study, Cu−MoS2/CdS composite materials are successfully constructed through two‐step solvothermal and liquid exfoliation methods. CdS nanorods are decorated by fewer layers of MoS2doped with Cu2+. The properties of the composites materials, such as microstructure, crystal structure and type, element valence state, and energy band structure, are obtained by XRD, XPS, and TEM. The combination of Cu−MoS2and CdS effectively inhibits the recombination of photo‐generated electrons and holes and improves the photocatalytic properties of the composite materials. The PEC test results show that the Cu−MoS2/CdS composite have a perfect photocurrent density of 77 μA cm−2, which is 12.8 and 2.8 times of those of CdS and MoS2/CdS, respectively. Cu−MoS2/CdS composite has the lowest interfacial resistance and the best interfacial charge transfer capability due to ion doping and the inherent high conductivity of MoS2. At 5 % doping ratio of Cu2+, the photoelectrocatalytic hydrogen evolution rate of Cu−MoS2/CdS reaches 12.78 mmol h−1g−1, which is 60 times of that of CdS.
N‐Alkyl 3‐aminobut‐2‐enenitrile as a Non‐radioactive Side Product in Nucleophilic 18F‐Fluorination
Authors: Song Ruichong , Tago Tetsuro , Tatsuta Maho , Shiraishi Nana , Iwai Kumiko , Hirano Keiichi , Toyohara Jun , Tanaka Hiroshi 
Published: March 2021

AbstractWe found that acetonitrile acted as a reactant under the conventional reaction conditions for aliphatic nucleophilic 18F‐fluorination in acetonitrile to provide the N‐alkyl 3‐aminobut‐2‐enenitrile as one of the side products. Dimerization of acetonitrile promoted by a complex of K2CO3 and K222 provided 3‐aminobut‐2‐enenitrile, which acted as nucleophile to provide N‐alkyl amino derivatives. Based on the finding, avoiding acetonitrile in the drying of [18F]fluoride as well as 18F‐labeling enabled the preparation of 18F‐labeled compounds containing only a small amount of the corresponding alcohol. Finally, we used an automated synthesizer to achieve an efficient phase‐tag‐assisted synthesis of 18F‐labeled stilbene derivative as a 18F‐labeled amyloid‐β ligand.
3D Cationic Polymeric Network Nanotrap for Efficient Collection of Perrhenate Anion from Wastewater
Authors: Li Xiaorui , Li Yiming , Wang Huifang , Niu Zheng , He Yingjie , Jin Linfeng , Wu Mingyang , Wang Haiying , Chai Liyuan , Al‐Enizi Abdullah M. , Nafady Ayman , Shaikh Shoyebmohamad F. , Ma Shengqian 
Published: March 2021

AbstractRhenium is one of the most valuable elements found in nature, and its capture and recycle are highly desirable for resource recovery. However, the effective and efficient collection of this material from industrial waste remains quite challenging. Herein, a tetraphenylmethane‐based cationic polymeric network (CPN‐tpm) nanotrap is designed, synthesized, and evaluated for ReO4− recovery. 3D building units are used to construct imidazolium salt‐based polymers with positive charges, which yields a record maximum uptake capacity of 1133 mg g−1 for ReO4− collection as well as fast kinetics ReO4− uptake. The sorption equilibrium is reached within 20 min and a kd value of 8.5 × 105 mL g−1 is obtained. The sorption capacity of CPN‐tpm remains stable over a wide range of pH values and the removal efficiency exceeds 60% for pH levels below 2. Moreover, CPN‐tpm exhibits good recyclability for at least five cycles of the sorption–desorption process. This work provides a new route for constructing a kind of new high‐performance polymeric material for rhenium recovery and rhenium‐contained industrial wastewater treatment.
Multi‐upgradation software reliability growth model with dependency of faults under change point and imperfect debugging
Authors: Chatterjee Subhashis , Saha Deepjyoti , Sharma Akhilesh 
Published: March 2021

AbstractWith the improvement of innovation, software developers consistently build up a new version of software by adding new features in the previously existing version of the software. In resent day's competitive market, the reliability and release time of multi‐upgradation software are very important issues to both: customers and developers. Many researchers have proposed various software reliability growth models (SRGMs) to improve the precision of assessing the reliability of programming. For reliability estimation, a detailed study is necessary to know the characteristics of different types of faults. It has been noticed that some faults present in software remove independently at the same time some faults remove some other faults. During upgradation, new faults generate due to many reasons. Though dependency of faults is an important issue, there is no such SRGM exist for multi‐release problem. Hence, an SRGM has been proposed for multi‐release problems here with the dependency of faults under the imperfect debugging phenomenon. The effect of change point has been incorporated in SRGM due to changes in testing strategy, changes in testing environments, and so forth, during up‐gradation. Based on datasets, it can be said the performance of the proposed model is better than some other existing models. Also, it is very important for software companies to know the optimal time of release a new version of software. As testing charges change with time, it cannot be constant throughout testing phase. Hence, a new random cost model has also been proposed for release time analysis in case of a multi‐release problem.
Case report: Haemophagocytic histiocytic sarcoma in an english setter
Authors: Kerboeuf Mikael , Brun‐Hansen Hege , Oscarson Malin , Sjetne Lund Heidi 
Published: March 2021

AbstractA 4‐year‐old English setter presented with a 1‐week history of anorexia, lethargy and occasional vomiting. Blood analysis revealed moderate regenerative anaemia, mild monocytosis, thrombocytopaenia, hypoproteinaemia, hypoglobulinaemia, hypocholesterolaemia and increased C‐reactive protein. On ultrasonography, the spleen had multifocal hypoechoic lesions. Fine needle aspirates from the spleen and liver showed marked extramedullary haematopoiesis, an increased number of histiocytes, haemosiderin deposits and erythrophagocytosis. A tentative diagnosis of haemophagocytic histiocytic sarcoma (HHS) was made, and the owners elected euthanasia. On autopsy, the liver and spleen were enlarged. The spleen had an uneven surface and a yellow‐tan spotted appearance. Histologically, the red pulp was highly cellular and dominated by erythroid cells, as well as a population of larger polygonal cells and aggregates of histiocytes. HHS was confirmed by CD11d immunolabelling. This represents the first documented case of HHS in an English setter.
Nanomaterials for Agricultural and Ecological Defense Applications: Active Agents and Sensors
Authors: Sharma Pramila , Kumar Sanjay , Patel Axita , Datta Bhaskar , DeLong Robert K. 
Published: March 2021

AbstractThe world we live in today is overpopulated with an unprecedented number of people competing for fewer and fewer precious resources. The struggle to efficiently steward and manage these resources is a global problem in need of concrete and urgent solutions. Nanomaterials have driven innovation in diverse industrial sectors including military, aviation, electronic, and medical among others. Nanoscale materials possess unique surfaces and exquisite opto‐electronic properties that make them uniquely suited to environmental, biological, and ecological defense applications. A tremendous upsurge of research activity in these areas is evident from the exponential increase in publications worldwide. Here we review recent applications of nanomaterials toward soil health and management, abiotic and biotic stress management, plant defense, delivery of the RNA Interference (RNAi), plant growth, manufacture of agro‐products, and ecological investigations related to farming. For example, nanomaterial constructs have been used to counter environmental stresses and in plant defense and disease diagnosis. Nanosensor chemistries have been developed to monitor water quality and measure specific pollutant levels. Specific nanomaterials such as silver, iron oxide, and zinc oxide proffer protection to plants from pathogens. This review describes progress in nanomaterial‐based agricultural and ecological defense and seeks to identify factors that would enable their wider commercialization and deployment.This article is categorized under:
Diagnostic Tools > Biosensing
Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials
Diagnostic Tools > Diagnostic Nanodevices
Gendered Vulnerability to Climate Change Impacts in Selected Counties in Kenya
Authors: Nzengya Daniel M. , Maguta John K. 
Published: March 2021

AbstractExtreme climate change events such as frequent and prolonged droughts or floods associated with climate change can be very disruptive to peoples’ livelihoods particularly in rural settings, where people rely on the immediate environment for livelihood. Shocks in the people’s livelihoods can trigger diverse responses that include migration as a coping or adaption strategy. Migration takes many forms depending on the context and resources availability. Very few studies in Kenya have used qualitative analysis to bring up women’s voices in relation to gender, climate change, and migration, especially along hydrological gradient. This chapter presents results of qualitative research conducted from 58 participants in 2018 in three counties in Kenya, namely, Kiambu County, Machakos, and Makueni. The study sought to examine gender perceptions related to climate-induced migration, that is: whether climate change is perceived to be affecting women’s livelihood differently from that of men; examine in what ways experiences of climate induced migration differed for men and women; explore perceptions on the county government efforts to cope with climate-induced migration; and examine perceptions of the role of nongovernmental agencies in helping citizens cope with climate change. From the results obtained on ways in which climate change affected women livelihoods more than men had four themes: (1) women exerted more strain in domestic chores, child/family care, and in the farm labor; (2) women also experienced more time demands. The sources of water and firewood were getting more scarce leading to women travel long distances in search to fetch water and firewood; (3) reduced farm yields, hence inadequate food supply; and (4) the effects of time and strain demands on women was a contributory factor to women poor health and domestic conflicts. Several measures that the county government could take to assist women to cope with climate change-induced migration had five themes which include the following: (1) developing climate change mitigations, and reducing deforestation; (2) increasing water harvesting and storage; (3) develop smart agriculture through the use of drought-resistant crops and drought mitigation education; (4) encourage diversification of livelihoods; and finally (5) providing humanitarian assistance to the most vulnerable populations such as orphans and the very poor. Thirdly, the measures mentioned that NGO’s could take to assist rural communities to cope with climate change-induced migration did not vary significantly from those mentioned for county government, except probably for a new theme of increasing advocacy for climate adaption policies.
Detecting scaling in phase transitions on the truncated Heisenberg algebra
Authors: Prekrat Dragan , Todorović-Vasović Kristina Neli , Ranković Dragana 
Published: March 2021

Abstract
We construct and analyze a phase diagram of a self-interacting matrix field coupled to curvature of the non-commutative truncated Heisenberg space. The model reduces to the renormalizable Grosse-Wulkenhaar model in an infinite matrix size limit and exhibits a purely non-commutative non-uniformly ordered phase. Particular attention is given to scaling of model’s parameters. We additionally provide the infinite matrix size limit for the disordered to ordered phase transition line.
Secular polar motion observed by GRACE
Authors: Seo Ki-Weon , Kim Jae-Seung , Youm Kookhyoun , Chen Jianli , Wilson Clark R. 
Published: March 2021

AbstractA long-term drift in polar motion (PM) has been observed for more than a century, and Glacial Isostatic Adjustment (GIA) has been understood as an important cause. However, observed PM includes contributions from other sources, including contemporary climate change and perhaps others associated with Earth’s interior dynamics. It has been difficult to separate these effects, because there is considerable scatter among GIA models concerning predicted PM rates. Here we develop a new method to estimate GIA PM using data from the GRACE mission. Changes in GRACE degree 2, order 1 spherical harmonic coefficients are due both to GIA and contemporary surface mass load changes. We estimate the surface mass load contribution to degree 2, order 1 coefficients using GRACE data, relying on higher-degree GRACE coefficients that are dominantly affected by surface loads. Then the GIA PM trend is obtained from the difference between observed PM trend (which includes effects from GIA and surface mass loads) and the estimated PM trend mostly associated with surface mass loads. A previous estimate of the GIA PM trend from PM observations for the period 1900–1978 is toward 79.90° W at a speed of 3.53 mas/year (10.91 cm/year). Our new estimate for the GIA trend is in a direction of 61.77° W at a speed of 2.18 mas/year (6.74 cm/year), similar to the observed PM trend during the early twentieth century. This is consistent with the view that the early twentieth-century trend was dominated by GIA and that more recently there is an increasing contribution from contemporary surface mass load redistribution associated with climate change. Our GIA PM also agrees with the linear mean pole during 1900–2017. Contributions from other solid Earth process such as mantle convection would also produce a linear trend in PM and could be included in our GIA estimate.