bluuebunny/crossref_metadata_2025 huggingface dataset:
Mental Distress after 1st Wave of COVID-19 among Medical Students
Authors: Khurram Rabia , Razzak Daniyal Abdul , Ahmad Waqas , Qamar Ambreen , Mumtaz Tayyaba , Sameed Qurat Ul Ain
Published: February 2021

Aim: The aim of the current study is to evaluate the mental distress facing by the MBBSs students during the first wave of COVID-19.

Study Design: Cross-sectional.

Place and Duration of Study: Study was conducted at Quaid-e Azam medical college Bahawalpur during the period of May 2020 to July 2020.

Methodology: MBBS undergraduate students were included in the study. For assessing mental stress, the questionnaire used was the modified form of Impact of Event Scale Revised (IES-R). The proforma was prepared by using Google Docs and disseminated through the student’s WhatsApp groups. Data was analyzed by using Special Package for Social Science version-20. Frequency and percentages were calculated for the qualitative variables while association was analyzed by using Chi-square test. p-value ≤0.05 was considered as significant.

Results: About half of the participants were female students i.e. 55.2%. The frequency distribution of stress level among students showed that the majority of participants were facing mild level of stress i.e. 130 participants out of total 310 participants (41.9%), 112 participants were having moderate stress level (36.2%), followed by 53 participants with severe level of stress (17.1%) while 15 participants (4.8%) were having extremely severe intensity of stress. It was also found out that the gender and socioeconomic status have a significant association with the mental stress but the year of study has no any association with the mental stress as reported statistically non-significant p-value.

Conclusion: The current study concluded that the mental distress experienced by medical undergraduate during COVID-19 is more severe than that of the general population and the female students are more prone to develop depressive symptoms. So there is a need of counselling session to improve the mental health of our medical under graduates as they are the future handlers of medical profession.
Comparative Antimicrobiotic Efficacy Test of Triple Antibiotic Paste, Double Antibiotic Paste with Fungicide and Calcium Hydroxide with Chitosan as Vehicle against Enterococcus faecalis: An In vitro Study
Authors: Naidu Sudhakar , Nadimpalli Mahendravarma , Dondapati Gowtam Dev , Sowjanya Thangi , Podili Srivalli , Babu Mattapudi Basavaiah
Published: February 2021

Introduction: This present research aimed to assess the in vitro antimicrobial efficacy of triple antibiotic paste and calcium hydroxide with two different vehicles against Enterococcus faecalis (E. faecalis).

Materials and Methodology: An agar well diffusion assay was used to determine the experimental medicaments' efficacy against E. faecalis. Medicaments were divided into six groups, which includes Triple antibiotic powder (TAP) with saline or chitosan, Double antibiotic powder with fungicide (DAP 1) with saline or Chitosan, and calcium hydroxide with saline or Chitosan. These medicines were tested in an agar well diffusion test for three days, i.e., 1,4,7 days. The diameters of growth inhibition zones were recorded and compared for each group were tested in an agar well diffusion test for three days, i.e., 1,4,7 days. The diameters of growth inhibition zones were recorded and compared for each group. These medicaments were evaluated for three days an agar well diffusion test, i.e., on 1,4,7 days. The inhibition zones diameters for each group were recorded and compared — the differences between groups analyzed by Kruskal-Wallis and Mann-Whitney U tests.

Results: The largest inhibition zones were observed for the triple antibiotic powder with chitosan and the smallest for Ca(OH)2 with saline. As days progress, they produced lesser antibacterial effects in all groups.

Conclusion: Triple antibiotic paste and Chitosan were more effective in eliminating microorganisms than calcium hydroxide and DAP 1.
Synthesis of Novel 2(3H)-Benzoxazolone Mannich Bases as Potential Agents for Future Studies of Cancer Treatment
Authors: Erdag Emine
Published: February 2021

Aims: In this study, a series of new Mannich bases of 2(3H)-benzoxazolone derivatives containing substituted cyclic amine moieties with a potential to show cytotoxic activity have been prepared. In order to develop effective anticancer agents against various cancer cell lines, it is essential to study the structure activity relationship and the effect of different substituents on the activity of heterocyclic scaffolds which were known to have cytotoxic activities.

Study Design: In silico and experimental design.

Place and Duration of Study: Pharmaceutical Chemistry Department, Faculty of Pharmacy, Near East University, Nicosia, Cyprus, between January 2019- September 2020.

Methodology: In this work, 2(3H)-benzoxazolone derivatives were prepared by Mannich reaction. The synthesis and structural characterization of the compounds were performed experimentally by FT-IR, 1H NMR, 13C NMR spectra and elemental analysis. In silico prediction of cell line cytotoxicity with PASS based CLC-Pred tool was performed to predict cytotoxicity of the compounds against different tumor cell lines.

Results: In silico prediction results for the compounds showed that all benzoxazolone derivatives have cytotoxic activity against different cell lines and tumor types. It was clearly understood that the cytotoxicity of the compounds was affected by the substituents on their piperazine moieties and by the substituents on benzoxazolone core structure.

Conclusion: In conclusion, newly synthesized Mannich bases of benzoxazolone derivatives were reported for the first time which may have a potential to show anticancer activities at different cancer cell lines. The efficiency of new compounds against cancer could be found via PASS based CLC-Pred database and could be further investigated by in vivo experimental cytotoxicity studies in the future to design new anticancer drug candidates.
Association between Maternal Thyroid Hormone Level and Fetal Weight
Authors: Mueed Zeba , Rai Pankaj Kumar , Jain Arun Kumar , Deval Ravi
Published: February 2021

Aims: Present study is aimed to find out the association between maternal thyroid hormone at delivery and weight of delivered fetus.

Study Design: This is a case-control study in which low birth weight was cases and appropriate for gestational age were considered as control.

Place and Duration of Study: Study was conducted at National Institute of Pathology (ICMR), New Delhi and Department of Biotechnology, Invertis University, Bareilly from July 2018 to July 2020.

Subjects and Methods: A total of 193 maternal blood samples were collected and fetal parameters were recorded as per inclusion criteria. Quantitative estimation of Triiodothyronine (T3), Thyroxine (T4), and Thyroid Stimulating Hormone (TSH) was done in the separated serum samples by pre-coated ELISA kits and data analysis was performed using SigmaStat. Cases include women having full-term deliveries with birth weight < 2.5Kg i.e. Low Birth Weight (LBW) and Controls includes women having Appropriate for Gestational Age (AGA) delivery with birth weight > 2.5Kg.

Results: No significant difference was observed in maternal age as well as age at marriage and other demographic parameters, while maternal weight and BMI is significantly less in LBW as compared to AGA i.e. 49.62±5.34 & 53.96±6.92 and 21.32±4.01 and 22.66±1.57 respectively having P<0.001. Pearson correlation coefficient also revealed a significant negative correlation of T4 with both fetal weight and fetal length and a positive correlation of T3 with fetal weight, fetal length, and fetal head circumference, whereas TSH did not show any significant association with fetal parameters.

Conclusion: It was concluded that maternal T3 and T4 affects the fetal development during gestational period, TSH did not show any significant association with fetal parameters.
Heat Exchanger Performance and Stability Improvement Using H2 Synthesis Control Design Technique
Authors: Udeani Henrietta U. , Inyiama Hyacinth C. , Akpado Kenneth A. , Agbaraji Chukwudi E.
Published: February 2021

The heat exchanger is a device that helps to circulate calculated amount of heat in a system. It can be applied in order to reduce the number of heat sources while maintaining a precise level of heat. Heat exchanger is expected to be part of the solution to CO2 emission and climate issues since its application reduces the sources of heat and cost of production such as in electrical power plant. Due to the critical need for the solution to the enormous emission of CO2 and the need to reduce cost of running power plants, the study and improvement of the heat exchanger has become very important.  The heat exchanger suffers from disturbances due to its harsh environment. In order to maintain desired performance the heat exchanger requires an adequate control measure. Many types of controllers have been designed, however from the review it was observed that most of the controllers produced marginal stability which will not maintain good performance of the system in the presence of significant disturbance. The major objectives of this work are to reduce the tracking error for performance improvement, to reduce the peak sensitivity for better disturbance rejection and to improve the stability margins for stability robustness. In this work, an optimal robust control was developed for the heat exchanger using H2 synthesis technique. From the results, the controlled system trajectory tracking error and overshoot were reduced to zero and the peak sensitivity to disturbance was reduced to 0.189 dB. Gain and phase margins satisfied the robust stability characteristics; gain margin was greater than 20 dB and phase margin was greater 60 dB. This means that the designed optimal controller will guarantee robust performance and stability of the system even in the presence of large disturbance.
The Impact of Training and Development on Employee Performance and Productivity: An Empirical Study on Private Bank of Noakhali Region in Bangladesh
Authors: Jeni Fatema Akter , Momotaj . , Al-Amin Md.
Published: February 2021

Human Resources Management literature regards training as the bloodstream of any organization because the success of an organization to achieve its objectives and goals highly depends on its workforce. For this reason, organizations should invest in employees’ training to enhance their performance and that of an organization. Nonetheless, some organizations regard training as an unnecessary expenditure and always cut training budgets to improve their financial standing to the detriment of their employees’ welfare because that action incapacitates staff to adapt to the ever-changing working environment and uncertain conditions on account of, inter alia, rapid technological innovation and organizational change. This study employed stratified sampling technique to draw a sample of 60 employees from a population of 70 employees through self-administered questionnaire to examine the impact of training on employees’ performance, employee’s motivation and job satisfaction in the banking sector in Private bank  of Noakhali region in Bangladesh. This results show that the mean for on the job training and development located from 3.23 to 4.4 and for off the job training and development from 2.36 to 4.05. The overall impact of training and development from the perspective of employees of private banking sector in Noakhali region has mean and standard deviation respectively 3.54 and 0.95 in total. This result indicates that training and development has a high impact on the employee’s performance and productivity in the perspective of employees of private bank in Noakhali region. The findings of the study generally revealed that training not only increases employees’ performance but also positively affects employees’ motivation and job satisfaction within the  Private banking sector in Bangladesh Therefore, the banking sector in Bangladesh should regularly allocate resources for employees’ training based on identified skill gaps to sharpen employees’ skills, knowledge and abilities to capacitate them to cope with the ever-changing working environment and uncertain conditions and to improve their motivation and job satisfaction.
Chemically Stable, Strongly Adhesive Sealant Patch for Intestinal Anastomotic Leakage Prevention
Authors: Anthis Alexandre H. C. , Hu Xueqian , Matter Martin T. , Neuer Anna L. , Wei Kongchang , Schlegel Andrea A. , Starsich Fabian H.L. , Herrmann Inge K.
Published: February 2021

Intestinal anastomotic leaking, which involves the discharge of chemically aggressive, non‐sterile fluids into the abdomen, remains one of the most dreaded postoperative complications of abdominal surgery. Depending on the site and the patient condition, incidence ranging between 4% and 21% and mortality rates up to 27% are reported. Currently available surgical sealants only poorly address the issue, especially since most commonly used fibrin glues fail due to insufficient adhesion and chemical instability. Here, a chemically highly resistive, leak‐tight, and mucoadhesive hydrogel sealant, which is grafted on the surface of the intestinal wall using a mutually interpenetrating network that traverses hydrogel and tissue is presented. In contrast to clinically used fibrin‐based sealants (including Tachosil), the developed adhesive poly(acrylamide‐methyl acrylate‐acrylic acid) patch does not degrade and exhibits strong tissue adhesion even when exposed to intestinal fluid. The biocompatible hydrogel patch effectively seals anastomotic leaks in ex vivo intestinal models, greatly surpassing commercial sealants (time to patch‐failure >24 h compared to 5 min for commonly used Tachosil). Importantly, the developed adhesive patch paves the way for the application of both mechanically and chemically robust sealants suitable for the treatment and prevention of intestinal leaks.
Nanowire‐Based Soft Wearable Human–Machine Interfaces for Future Virtual and Augmented Reality Applications
Authors: Wang Kaixuan , Yap Lim Wei , Gong Shu , Wang Ren , Wang Stephen Jia , Cheng Wenlong
Published: February 2021

A virtual world has now become a reality as augmented reality (AR) and virtual reality (VR) technology become commercially available. Similar to how humans interact with the physical world, AR and VR systems rely on human–machine interface (HMI) sensors to interact with the virtual world. Currently, this is achieved via state of‐the‐art wearable visual and auditory tools that are rigid, bulky, and burdensome, thereby causing discomfort during practical application. To this end, a skin sensory interface has the potential to serve as the next‐generation AR/VR technology because skin‐like wearable sensors have advantages in that they can be ultrathin, ultra‐soft, conformal, and imperceptible, which provides the ultimate comfort and immersive experience for users. In this progress report, nanowire‐based soft wearable HMI sensors including acoustic, strain, pressure sensors, and physiological sensors are reviewed that may be adopted as skin sensory inputs in future AR/VR systems. Further, nanowire‐based soft contact lenses, haptic force, and thermal and vibration actuators are covered as potential means of feedback for future AR/VR systems. Considering the possible effects of the virtual world on human health, skin‐like wearable artery pulses, glucose, and lactate sensors are also described, which may enable imperceptible health monitoring during future AR/VR practices.
Green Tea Derivative Driven Smart Hydrogels with Desired Functions for Chronic Diabetic Wound Treatment
Authors: Zhao Xiaodan , Pei Dandan , Yang Yuxuan , Xu Kai , Yu Jing , Zhang Yuchen , Zhang Qiang , He Gang , Zhang Yanfeng , Li Ang , Cheng Yilong , Chen Xuesi
Published: February 2021

Current treatments for chronic diabetic wounds remain unsatisfactory due to the lack of ideal wound dressings that can integrate matching mechanical strength, fast self‐healability, facile dressing change, and multiple therapeutic effects into one system. In this work, benefiting from the catechol groups and therapeutic effect of epigallocatechin‐3‐gallate (EGCG, green tea derivative), a smart hydrogel dressing can be conveniently obtained through copolymerization of the complex formed by EGCG and 3‐acrylamido phenylboronic acid (APBA) (the formation of boronate ester bond) and acrylamide. The resulting hydrogel features adequate mechanical properties, self‐healing capability, and tissue adhesiveness. Otherwise, the substantial release of EGCG can not only realize anti‐oxidation, antibacterial, anti‐inflammatory and proangiogenic effect, and modulation of macrophage polarization to accelerate wound healing, but also facilitate easy dressing change. This advanced hydrogel provides a facile and effective way for diabetic chronic wound management and may be extended for the therapy of other complicated wound healings.
Multitasking MXene Inks Enable High‐Performance Printable Microelectrochemical Energy Storage Devices for All‐Flexible Self‐Powered Integrated Systems
Authors: Zheng Shuanghao , Wang Hui , Das Pratteek , Zhang Ying , Cao Yuexian , Ma Jiaxin , Liu Shengzhong (Frank) , Wu Zhong‐Shuai
Published: February 2021

The future of mankind holds great promise for things like the Internet of Things, personal health monitoring systems, and smart cities. To achieve this ambitious goal, it is imperative for electronics to be wearable, environmentally sustainable, and safe. However, large‐scale manufacture of self‐sufficient electronic systems by exploiting multifunctional materials still faces significant hurdles. Herein, multitasking aqueous printable MXene inks are reported as an additive‐free high‐capacitance electrode, sensitive pressure‐sensing material, highly conducting current collector, metal‐free interconnector, and conductive binder. By directly screen printing MXene inks, MXene‐based micro‐supercapacitors (MSCs) and lithium‐ion microbatteries (LIMBs) are delicately fabricated on various substrates. The as‐prepared MSCs exhibit ultrahigh areal capacitance of 1.1 F cm−2 and the serially connected MSCs offer a record voltage of 60 V. The quasi‐solid‐state LIMBs deliver a robust areal energy density of 154 μWh cm−2. Furthermore, an all‐flexible self‐powered integrated system on a single substrate based on the multitasking MXene inks is demonstrated through seamless integration of a tandem solar cell, the LIMB, and an MXene hydrogel pressure sensor. Notably, this integrated system is exceptionally sensitive to body movements with a fast response time of 35 ms. Therefore, this multipurpose MXene ink opens a new avenue for powering future smart appliances.
3D‐Printed Biomimetic Systems with Synergetic Color and Shape Responses Based on Oblate Cholesteric Liquid Crystal Droplets
Authors: Yang Chenjing , Wu Baiheng , Ruan Jian , Zhao Peng , Chen Li , Chen Dong , Ye Fangfu
Published: February 2021

Living organisms in nature have amazing control over their color, shape, and morphology in response to environmental stimuli for camouflage, communication, or reproduction. Inspired by the camouflage of the octopus via the elongation or contraction of its pigment cells, oblate cholesteric liquid crystal droplets are dispersed in a polymer matrix, serving as the role of pigment cells and showing structural color due to selective Bragg reflection by their periodic helical structure. The color of 3D‐printed biomimetic systems can be tuned by changing the helical pitch via the chiral dopant concentration or temperature. When the oblate liquid crystal droplets are heated up to isotropic, the opaque and colored biomimetic systems become transparent and colorless. Meanwhile, the isotropic liquid crystal droplets tend to become spherical, causing volume contraction along the film plane and volume dilation in the perpendicular direction. The internal strain combined with the gradient distribution of the oblate isotropic liquid crystal droplets result in corresponding shape transformations. The camouflage of a biomimetic octopus and the blossom of a biomimetic flower, both of which show synergetic color and shape responses, are demonstrated to inspire the design of functional materials and intelligent devices.
General Programmable Growth of Hybrid Core–Shell Nanostructures with Liquid Metal Nanodroplets
Authors: Ren Long , Cheng Ningyan , Man Xingkun , Qi Dongchen , Liu Yundan , Xu Guobao , Cui Dandan , Liu Nana , Zhong Jianxin , Peleckis Germanas , Xu Xun , Dou Shi Xue , Du Yi
Published: February 2021

Core–shell and hollow nanostructures have been receiving significant interest due to their potential in wide scientific and technological fields. Given such large scope, however, they still lag far behind in terms of the ambition toward controllably, or even programmatically, synthesizing libraries of core–shell structures on a large scale. Here, a general route for the programmable preparation of complex core–shell nanostructures by using liquid metal (LM) droplets as reformable templates is presented, and the triggering of a localized galvanic replacement reaction in one ultrasonication system is demonstrated. Benefiting from the activity and mobility of the metal components in LM templates, high‐level compositional diversity control and quantitative regulation of both the core and the shell layers of the heterogeneous products are achieved, which cannot be realized with a solid‐template synthetic route.
Assessing the Influence of Temperature‐Memory Creation on the Degradation of Copolyesterurethanes in Ultrathin Films
Authors: Machatschek Rainhard , Saretia Shivam , Lendlein Andreas
Published: February 2021

Copolyesterurethanes (PDLCLs) based on oligo(ε‐caprolactone) (OCL) and oligo(ω‐pentadecalactone) (OPDL) segments are biodegradable thermoplastic temperature‐memory polymers. The temperature‐memory capability in these polymers with crystallizable control units is implemented by a thermomechanical programming process causing alterations in the crystallite arrangement and chain organization. These morphological changes can potentially affect degradation. Initial observations on the macroscopic level inspire the hypothesis that switching of the controlling units causes an accelerated degradation of the material, resulting in programmable degradation by sequential coupling of functions. Hence, detailed degradation studies on Langmuir films of a PDLCL with 40 wt% OPDL content are carried out under enzymatic catalysis. The temperature‐memory creation procedure is mimicked by compression at different temperatures. The evolution of the chain organization and mechanical properties during the degradation process is investigated by means of polarization‐modulated infrared reflection absorption spectroscopy, interfacial rheology and to some extend by X‐ray reflectivity. The experiments on PDLCL Langmuir films imply that degradability is not enhanced by thermal switching, as the former depends on the temperature during cold programming. Nevertheless, the thin film experiments show that the leaching of OCL segments does not induce further crystallization of the OPDL segments, which is beneficial for a controlled and predictable degradation.
An Overview of Cellulose‐Based Nanogenerators
Authors: Annamalai Pratheep K. , Nanjundan Ashok Kumar , Dubal Deepak P. , Baek Jong‐Beom
Published: February 2021

Developing nanogenerators (NGs) is achieved by exploiting the piezoelectric, triboelectric, and pyroelectric effects of both organic and inorganic materials. Many exhibit beneficial electrical properties (dielectric, conductive, or insulating) or have surfaces that are polarizable upon friction or physical contact. Recently, biomass‐derived materials and recycled materials, whose electrical activity can be induced, are explored for application in the design of more sustainable, cost‐effective, biodegradable, disposable NGs, and have demonstrated a wide range of output (microenergy) power densities. Among them, cellulose, the most abundant biopolymer, is found to offer excellent opportunities for designing and manufacturing NGs with multifunctional capacities. Cellulose can be derived into varied forms with multifunctionalities and physical morphologies. This account provides an overview of how cellulose is utilized in creating NGs based on piezoelectric, triboelectric, and pyroelectric effects. Because the mechanical properties of cellulose are tunable, current research trends on NGs originate with the triboelectric effect. The discussion here focuses on design, fabrication methods, achievable electrical power output, and combinations with other materials and devices. Challenges in efficient fabrication and consistent power densities, and opportunities for integrating different technologies and developing more sustainable (in terms of economic, environmental, and ecological) nature–human–machine interfacial devices are also discussed.
Hairpin‐Spacer crRNA‐Enhanced CRISPR/Cas13a System Promotes the Specificity of Single Nucleotide Polymorphism (SNP) Identification
Authors: Ke Yuqing , Huang Shiyi , Ghalandari Behafarid , Li Sijie , Warden Antony R. , Dang Jingqi , Kang Lin , Zhang Yu , Wang Yunqing , Sun Yiqing , Wang Jinglin , Cui Daxiang , Zhi Xiao , Ding Xianting
Published: February 2021

The Cas13a system has great potential in RNA interference and molecular diagnostic fields. However, lacking guidelines for crRNA design hinders practical applications of the Cas13a system in RNA editing and single nucleotide polymorphism identification. This study posits that crRNAs with hairpin spacers improve the specificity of CRISPR/Cas13a system (termed hs‐CRISPR). Gibbs free energy analysis suggests that the hairpin‐spacer crRNAs (hs‐crRNAs) suppress Cas13a's affinity to off‐target RNA. A hepatitis B virus DNA genotyping platform is established to further validate the high‐specificity of hs‐CRISPR/Cas13a system. Compared to ordinary crRNA, hs‐crRNAs increase the specificity by threefold without sacrificing the sensitivity of the CRISPR/Cas13a system. Furthermore, the mechanism of the Cas13a/hs‐crRNA/target RNA composition is elucidated with theoretical simulations. This work builds on the fundamental understanding of Cas13a activation and offers significant improvements for the rational design of crRNA for the CRISPR/Cas13a system.
Metallic Co Nanoarray Catalyzes Selective NH3 Production from Electrochemical Nitrate Reduction at Current Densities Exceeding 2 A cm−2
Authors: Deng Xiaohui , Yang Yongpeng , Wang Lei , Fu Xian‐Zhu , Luo Jing‐Li
Published: February 2021

Electrochemical nitrate reduction (NITRR) offers a promising alternative toward nitrogen recycling and ammonia production under ambient conditions, for which highly active and selective electrocatalyst is desired. In this study, metallic cobalt nanoarrays as facilely prepared from the electrochemical reduction of Co(OH)2 nanoarrays (NAs) are demonstrated to exhibit unprecedented NH3 producing capability from catalyzing NITRR. Benefitting from the high intrinsic activity of Co0, intimate contact between active species and conductive substrate and the nanostructure which exposes large number of active sites, the Co‐NAs electrode exhibits current density of −2.2 A cm−2 and NH3 production rate of 10.4 mmol h−1 cm−2 at −0.24 V versus RHE under alkaline condition and significantly surpasses reported counterparts. Moreover, the close‐to‐unity (≥96%) Faradaic efficiency (FE) toward NH3 is achieved over wide application range (potential, NO3− concentration and pH). Density function theory calculation reveals the optimized adsorption energy of NITRR intermediates on Co surface over Co(OH)2. Furthermore, it is proposed that despite the sluggish kinetics of Volmer step (H2O → *H + *OH) which provides protons in conventional hydrogenation mechanism, the proton‐supplying water dissociation process on Co surface is drastically facilitated following a concerted water dissociation–hydrogenation pathway.
Co–Fe–Cr (oxy)Hydroxides as Efficient Oxygen Evolution Reaction Catalysts
Authors: Chen Junsheng , Li Hao , Chen Shuangming , Fei Jingyuan , Liu Chang , Yu Zixun , Shin Kihyun , Liu Zongwen , Song Li , Henkelman Graeme , Wei Li , Chen Yuan
Published: February 2021

Transition metal cobalt (oxy)hydroxides are promising catalyst candidates for the oxygen evolution reaction (OER). Their activity can be significantly enhanced by doping chromium; however, the optimal catalyst elemental composition is unknown, and the exact role of Cr remains elusive. Here, density functional theory (DFT) calculations and comprehensive catalyst characterization are combined to address these two questions. Guided by DFT calculations, a series of amorphous ternary Co‐iron(Fe)‐Cr (oxy)hydroxides with systematically tuned elemental compositions are synthesized. Performance atlases of these catalysts are established based on different experimental descriptors, which show that the optimal Co5Fe3Cr2 (oxy)hydroxide reaches a current density of 10 mA cm−2 at an overpotential of 232 mV. It delivers a Co‐based mass activity of 1486 A g−1 and a high turnover frequency of 0.23 s−1, over two orders higher than monometallic Co (oxy)hydroxide. X‐ray absorption and photoelectron spectroscopies reveal that Cr promotes Co atoms to occupy octahedral sites and modifies the Co electronic structure. Quasi‐operando electron energy loss spectroscopy further experimentally confirm that Cr accelerates the pre‐oxidation of Co2+ to higher valence species, resulting in significantly higher catalytic activity. The findings here pave the way to use Co–Fe–Cr (oxy)hydroxides as an efficient OER catalyst.
Metallic MoS2 Nanoflowers Decorated Graphene Nanosheet Catalytically Boosts the Volumetric Capacity and Cycle Life of Lithium–Sulfur Batteries
Authors: Cheng Zhibin , Chen Yilong , Yang Yisi , Zhang Linjie , Pan Hui , Fan Xi , Xiang Shengchang , Zhang Zhangjing
Published: February 2021

High sulfur loading is the key to achieve high energy density promised by Li–S batteries. However, serious problems such as poor rate performance and cycle stability are exposed during the scaling up of the sulfur loading. Systematic modification of both the cathode and separator has the potential to address these issues by enhancing the adsorption and catalytic conversion of polysulfides. Herein, sulfur‐deficient metallic 1T‐MoS2 nanoflowers decorated graphene (FM@G) is proposed to be systematically modified on both cathode and separator. The as‐developed cell exhibits superior cyclability with a capacity retention of 71.7% over 500 cycles. Importantly, steady cyclability and high volumetric capacity of 1360 mAh cm−3 with a high sulfur loading of 5.1 mg cm−2 are also attained even at high current density of 4.27 mA cm−2. The electrochemical performance is comparable to or even superior to the state‐of‐the‐art carbon‐based sulfur batteries. This work provides valuable guidance for the implementation of high‐energy‐density Li–S batteries furnished with high sulfur loading.
Reviving Anode Protection Layer in Na‐O2 Batteries: Failure Mechanism and Resolving Strategy
Authors: Lin Xiaoting , Sun Yipeng , Sun Qian , Luo Jing , Zhao Yang , Zhao Changtai , Yang Xiaofei , Wang Changhong , Huo Hanyu , Li Ruying , Sun Xueliang
Published: February 2021

Na‐O2 batteries are attractive for energy storage due to their high theoretical energy density. In order to alleviate Na dendrite formation, artificial protective coatings have been widely investigated in Na‐metal batteries (NMBs). Although it can be intuitive to expect transferable Na protection methodologies from NMBs to Na‐O2 batteries, the performance of anode protection coatings in Na‐O2 batteries remains obscure, because Na‐O2 batteries undergo a unique reaction mechanism involving superoxide. Here, the effect of superoxide crossover on the polymeric Na protection layer in Na‐O2 batteries is revealed, and an effective strategy to eliminate the implications of a superoxide‐sensitive protecting layer is proposed. Using polymeric alucone protected Na anode as an example, the alucone layer actually decomposes under superoxide attack and is incapable of facilitating long‐term cycling of Na‐O2 batteries in sharp contrast to its stable performance in NMBs. By blocking superoxide crossover with solid‐state electrolytes (SSEs), significantly improved Na‐O2 cell performance is demonstrated, recovering the Na dendrite suppressing effect of the alucone film. Benefiting from the synergistic effect of SSE and alucone layer, Na‐O2 batteries can achieve a long life of 325 cycles at 0.2 mA cm−2. This work indicates that the stability of the Na protection layer against superoxide should be taken into serious consideration.
Probing the Energy Storage Mechanism of Quasi‐Metallic Na in Hard Carbon for Sodium‐Ion Batteries
Authors: Wang Zhaohua , Feng Xin , Bai Ying , Yang Haoyi , Dong Ruiqi , Wang Xinran , Xu Huajie , Wang Qiyu , Li Hong , Gao Hongcai , Wu Chuan
Published: February 2021

Hard carbon (HC) is the most promising anode material for sodium‐ion batteries (SIBs), nevertheless, the understanding of sodium storage mechanism in HC is very limited. As an important aspect of storage mechanism, the steady state of sodium stored in HC has not been revealed clearly to date. Herein, the formation mechanism of quasi‐metallic sodium and the quasi‐ionic bond between sodium and carbon within the electrochemical reaction on the basis of theoretical calculations are disclosed. The presence of quasi‐metallic sodium is further confirmed with the assistance of a specific reaction between the sodiated HC electrode and ethanol, by analyzing the reaction products with Fourier‐transform infrared spectroscopy, gas chromatography, and nuclear magnetic resonance. Moreover, based on the specific chemical reaction, the composition of fully sodiated HC is estimated to be NaC6.7, and the corresponding capacity of sucrose‐derived HC is calculated to be 333.4 mAh g−1 in SIBs, matching well with the experimental result. This work helps to reveal the steady state of sodium and improve the understanding of sodium storage behavior in HC from the aspect of charge transfer. In addition, the proposed method is also expected to pave the way to investigate sodium storage mechanisms in other electrode systems.
Cargo‐Templated Crosslinked Polymer Nanocapsules and Their Biomedical Applications
Authors: Zhao Yu , Li Qiushi , Chai Jingshan , Liu Yang
Published: February 2021

Cargo‐templated crosslinked polymer nanocapsules (CT‐CPNCs) are mainly synthesized by in situ formation of crosslinked polymer shells on the surface of particulate cargoes, such as therapeutic proteins, siRNA/miRNA, liposomes, chitosans, metal‐organic frameworks (MOFs), and inorganic nanoparticles. CT‐CPNCs exhibit many advantages in biomedical applications, including 1) easy preparation and purification procedures, 2) high structural stability to inhibit undesired leakage of cargoes, and 3) high specific surface area for surface modification (e.g., loading of therapeutic agents and conjugation of targeting ligands). Importantly, CT‐CPNCs are designed with stimuli–responsive properties to release their cargoes in response to internal or external stimuli, including acidic pH values, redox potentials, enzymes (e.g., cathepsin B, hyaluronidase, and matrix metalloproteinases), light exposure, and heat. Herein, the design strategies and recent advances in CT‐CPNCs are focused upon and their potential applications are discussed. Furthermore, the advantages, limitations, future opportunities, and challenges of CT‐CPNCs are also discussed.
The morphology evolution of polyethylene produced in the presence of a Ziegler‐type catalyst anchored on the surface of multi‐walled carbon nanotubes
Authors: Zdanovich Aleksandr A. , Moseenkov Sergey I. , Ishchenko Arcady V. , Kuznetsov Vladimir L. , Matsko Mikhail A. , Zakharov Vladimir A.
Published: February 2021

Data are presented on the evolution of the morphology of polyethylene (PE) formed via in situ polymerization with different polymer yield over a Ziegler‐type titanium‐magnesium catalyst anchored on the CNT surface. Individual polymer microparticles are formed on the CNT surface at the initial polymerization stage (the yield of 2.5–10 g PE/g CNT) with the formation of PE/CNT composites having a shish‐kebab structure. As the polymer yield increases above 10 g PE per g CNT, the size of microparticles increases and the CNT surface gets totally covered with the polymer. We have found also a great effect produced by the morphology of initial CNT particle aggregates of individual nanotubes on the morphology of macroparticles in PE/CNT composites and the uniformity of CNTs distribution in PE/CNT composites. In the case of CNT samples with a loose structure of macroparticles (aggregates of entangled nanotubes), it is possible to obtain a homogeneous distribution of nanotubes in the polymer matrix of composites and increase the electrical conductivity of composites by 1–8 orders of magnitude by varying the CNT content in the composites from 0.9 to 2.8 wt%.
Do some viruses use growth hormone, prolactin and their receptors to facilitate entry into cells?
Authors: Wallis Michael
Published: February 2021

The molecular evolution of pituitary growth hormone and prolactin in mammals shows two unusual features: episodes of markedly accelerated evolution and, in some species, complex families of related proteins expressed in placenta and resulting from multiple gene duplications. Explanations of these phenomena in terms of physiological adaptations seem unconvincing. Here, I propose an alternative explanation, namely that these evolutionary features reflect the use of the hormones (and their receptors) as viral receptors. Episodes of rapid evolution can then be explained as due to “arms races” in which changes in the hormone lead to reduced interaction with the virus, and subsequent changes in the virus counteract this. Placental paralogues of the hormones could provide decoys that bind viruses, and protect the foetus against infection. The hypothesis implies that the extensive changes introduced into growth hormone, prolactin and their receptors during the course of mammalian evolution reflect viral interactions, not endocrine adaptations.
Sex‐specific in‐hospital outcomes of transcatheter aortic valve replacement with third generation transcatheter heart valves
Authors: Simard Trevor , Alqahtani Fahad , Hibbert Benjamin , Mamas Mamas A. , El‐Hajj Stephanie , Harris Alyssa H. , Hohmann Samuel F. , Alkhouli Mohamad
Published: February 2021

Background

Sex‐based differences in transcatheter aortic valve replacement (TAVR) outcomes have been previously documented. However, whether these differences persist with contemporary third generation transcatheter heart valves (THVs) is unknown.

Methods

We utilized Vizient's clinical database/resource manager (CDB/RM™) to identify patients who underwent TAVR between January 1, 2018 and March 31, 2020 to compare in‐hospital outcomes between males and females. The primary endpoint was in‐hospital mortality. Secondary endpoints included key in‐hospital complications, length of stay, discharge disposition, and cost. Unadjusted, propensity‐score matched and risk‐adjusted analyses of outcomes were performed.

Results

During the study period, 44,280 patients (24,842 males, 19,438 females) underwent TAVR. The primary endpoint of in‐hospital mortality was higher in females than in males (1.6 vs. 1.1% p < .001) in unadjusted analysis and persisted following propensity matching (1.6 vs. 0.9%, p < .001) and multivariable logistic regression with various risk‐adjustment models. In the most comprehensive model adjusting for age, race, and clinical comorbidities, female sex was associated with 34% greater odds of in‐hospital death (95% CI 20–50%, p < .001). Unadjusted and risk‐adjusted rates of post‐TAVR stroke, vascular complication, and blood transfusion were higher in females. Moreover, females demonstrated longer hospitalizations, higher costs and reduced rates of independent discharge home.

Conclusion

Sex‐based differences in TAVR in‐hospital outcomes persist in contemporary practice with third generation transcatheter heart valves. Further research is needed to assess the reasons for these observed disparities and to identify effective mitigation strategies.
Ausgleich der Volatilität der Erneuerbaren Energien mittels Wärmespeichern auf Salzbasis
Authors: Maaß Hans‐Jürgen , Möckel Hans‐Otto
Published: February 2021

Zum Ausgleich der Volatilität der Erneuerbaren Energien mit Schwerpunkt auf der Solarenergie sind Lösungen jenseits fossiler Reservekraftwerke erforderlich. Ein Ansatz sind Wärmespeicher auf Salzbasis mit Phasenwechselmaterialien (phase change materials, PCM). Um dafür Wirtschaftlichkeit zu erreichen, bedarf es ambitionierter Zielstellungen. Es wird ein System von Speichern (sensibel und latent) für den Temperaturbereich um 400 °C basierend auf Salzen und Thermoölen mit hohem Entwicklungspotenzial vorgestellt.
Internal cathodic protection to study the erosion‐corrosion of AISI 1018 carbon steel
Authors: McChesney Kasia , Trask Michael , Penner Dakota , Evitts Richard , Kennell Glyn , Oguocha Ikechukwuka , Odeshi Akindele
Published: February 2021

Steel elbows used in pipelines carrying potash slurry may undergo material loss due to mechanical erosion and/or electrochemical corrosion. Cathodic protection was used to study the effects of flow velocity and slurry concentration on the protection current density required to maintain AISI 1018 carbon steel elbows at a set electric potential. A flow loop with a peristaltic pump was used to pump a slurry consisting of silica sand in a saturated potash brine through the steel elbows. The protection current density measurements were performed under varying slurry flow velocities of 2.5, 3.0, 3.5, and 4.0 m/s and varying slurry concentrations ranging from 0‐35 wt%. The results show maximum values of protection current density were required for mid‐range slurry concentrations. It is concluded that, within the parameters of study, high flow velocities require higher protection current density than low flow velocities. Furthermore, high flow velocities result in a local maximum protection current density being reached at lower slurry concentrations; conversely, a local maximum protection current density is reached at higher slurry concentrations in lower flow velocities. The contrast in local maximum protection current densities likely occurs due to additional particle‐particle collisions at higher velocities causing the maximum mass transfer rate of oxygen to be reached at lower slurry concentrations. SEM micrographs show that wear becomes more evenly distributed with increasing flow velocity due to the homogeneous distribution of particles in the flowing medium.
Regulating Circularly Polarized Luminescence of Axially Chiral Anthracene Derivatives through Solvatochromism and Supramolecular Self‐assembly
Authors: Zheng Shuyuan , Jin Xue , Zhou Jin , Duan Pengfei , Ye Qiang , Han Jianlei
Published: February 2021

Two axially chiral fluorophores derived from anthracene were designed and synthesized, and the chiroptical behaviour were thoroughly investigated including solvent‐dependent emission and circularly polarized luminescence (CPL). Interestingly, unexpected supramolecular self‐assembly of the chiral molecules driven by strong π−π interaction can enable significant hypsochromic shift and fluorescence intensity enhancement. Meanwhile, the luminescence dissymmetry factor of CPL activity exhibited significant enhancement through self‐assembly process. This work provides a novel approach to achieve the supramolecular CPL materials possessing both high luminescence quantum efficiency and high circular polarization.
Differential survival of alfalfa varieties interseeded into corn silage
Authors: Grabber John H. , Osterholz William R. , Riday Heathcliffe , Cassida Kimberly A. , Williamson Jessica A. , Renz Mark J.
Published: February 2021

Interseeding alfalfa (Medicago sativa L.) into silage corn (Zea mays L.) can improve forage yield, farm profitability, and soil conservation, but unreliable alfalfa establishment hampers on‐farm adoption. This study evaluated seedling survival and growth of 36 alfalfa varieties differing in reported plant traits when interseeded at two Wisconsin sites in 2015 and at single sites in Wisconsin, Michigan, and Pennsylvania in 2016. Subplots of alfalfa varieties were sprayed with prohexadione‐calcium (PHD) at 0 or 0.42 kg acid equivalent (a.e.) ha–1 to assess changes in seedling survival mediated by this growth retardant. After corn harvest in 2015, average stand density of varieties in Wisconsin ranged from 15 to 94 plants m–2 without PHD and from 52 to 199 plants m–2 with PHD. Stand density largely determined subsequent first‐cut alfalfa dry matter yield, which ranged from 1.1 to 6.3 Mg ha–1. After corn harvest in 2016, stand density of varieties averaged across PHD treatments ranged from 113 to 248 plants m–2 in Michigan and Pennsylvania, compared with only 0.5 to 26 plants m–2 in Wisconsin; PHD treatment improved stand density only in Wisconsin but could not ensure adequate establishment under wet conditions that favored vigorous corn growth and foliar disease on alfalfa. Overall, establishment was poorly related to measured or reported alfalfa traits, but ‘55H94’ and hybrids were consistently among the best performing cultivars. Further work is needed to understand seedling survival mechanisms and to develop improved germplasm and production practices to ensure reliable establishment of interseeded alfalfa.
Patient‐derived organoids of bladder cancer recapitulate antigen expression profiles and serve as a personal evaluation model for CAR‐T cells in vitro
Authors: Yu Lei , Li Zhichao , Mei Hongbin , Li Wujiao , Chen Dong , Liu Lisa , Zhang Zhongfu , Sun Yangyang , Song Fei , Chen Wei , Huang Weiren
Published: February 2021

Objectives

Recent advances in patient‐derived cancer organoids have opened a new avenue for personalised medicine. We aimed to establish an in vitro technological platform to evaluate chimeric antigen receptor (CAR)‐T cell‐mediated cytotoxicity against bladder cancer.

Methods

Patient‐derived bladder cancer organoids (BCOs) were derived using classic medium containing R‐spondin 1 and noggin. The features of BCOs were characterised via H&E, whole‐exome sequencing and immunofluorescence of specific markers. Surface antigen expression profiles of the recently identified CAR‐recognisable targets were determined with a panel of antibodies via immunohistochemistry. A co‐cultivation system consisting of BCOs and engineered T cells targeting a specific antigen was utilised to test its efficacy to model immunotherapy by cytotoxic assays and ELISA.

Results

Bladder cancer organoid lines of basal and luminal subtypes were established. The histopathological morphology, genomic alteration, and specific marker expression profiles showed that the BCO lines retained the characteristics of the original tumors. Among all tested CAR‐recognisable antigens in other solid tumors, MUC1 was simultaneously expressed in organoids and parental tumor tissues. Given the surface antigen profiles, second‐generation CAR‐T cells targeting MUC1 were prepared for modelling in vitro immunotherapy responses in BCOs. Specific immune cytotoxicity occurred only in the MUC1+ organoids but not in the MUC1‐ organoids or control CAR‐T cells.

Conclusion

Patient‐derived BCOs recapitulate the heterogeneity and key features of parental cancer tissues, and these BCOs could be useful for preclinical testing of CAR‐T cells in vitro.