bluuebunny/crossref_metadata_2025_split huggingface dataset:
Empirical Modeling and Optimization of Base Activated Ngbo Catalysts in Esterification Reaction Using Response Surface Methodology
Authors: Nwobasi V. N. , Igbokwe Philomena K. , Okewale Akindele Oyetunde 
Published: May 2022

In this work, Box-Behnken’s Response Surface Methodology (RSM) was applied to study the esterification reaction effectiveness of base-activated Ngbo clay catalyst. The esterification was monitored based on temperature, time duration, amount of reactant, catalyst weight, and particle size. The Box-Behnken’s Response Surface Methodology indicates that the base clay-catalyzed esterification reactions proceed through dual Acid-complex and Alcohol- complex mechanisms, with the alcohol mechanism dominating. The acetic acid and ethanol esterification efficiencies by base-activated Ngbo clay catalyst optimized using RSM models indicated the esterification percentage was ˃99%. The predicted and experimental values under the same conditions showed less than 5% difference, thereby making the Box-Behnken design approach an efficient, effective, and reliable method for the esterification of acetic acid with ethanol. The produced catalyst was optimized using A-One way ANOVA modelled, which indicated that the correlation coefficient of the regression was 0.9940. The result implied that 99.40% of the total variation in the esterification reaction was due to the experimental variables. The obtained data in this study indicated that this process could be applied in the esterification of acetic acid to avoid the drawbacks of corrosion, loss of catalyst, and environmental problems.
Controlled Growth of the Interface of CdWOx/GDY for Hydrogen Energy Conversion
Authors: Luan Xiaoyu , Zheng Zhiqiang , Zhao Shuya , Xue Yurui , Li Yuliang 
Published: May 2022

AbstractDirectly extracting hydrogen energy from water in one device to achieve sustainable hydrogen energy generation‐conversion‐electricity storage system is an ideal major step forward for enabling a zero‐pollution, hydrogen‐fueled economy. The new concept of hydrogen energy conversion can be enabled by spontaneous reduction of nitrate to ammonia driven by potential differences between the well‐matched anode and cathode, leading to the full use of the electrochemical redox reactions to generate electric energy. The hydrogen energy in the acidic electrolyte can be transformed to electric energy with the rationally assembled primary battery, which can simultaneously power the electric devices and produce high value‐added ammonia. The new concept of hydrogen conversion device shows a record‐high specific capacity of 15 500 mA h g–1 and achieves the highest ammonia production rate (149 mmol gcat–1 h–1) and Faradaic Efficiency (99.2%) in acidic electrolytes. This work opens a new direction for hydrogen conversion and utilization which has obvious advantages over lithium and battery solutions.
Flexible Transparent High‐Efficiency Photoelectric Perovskite Resistive Switching Memory
Authors: Liu Xiaomin , Ren Shuxia , Li Zhenhua , Guo Jiajun , Yi Shenghui , Yang Zheng , Hao Weizhong , Li Rui , Zhao Jinjin 
Published: May 2022

AbstractPerovskite resistive random‐access memory (RRAM) is a promising candidate for next‐generation logic, adaptive and nonvolatile memory devices, because of its high ON/OFF ratio, low‐cost fabrication, and good photoelectric regulation performance. In this work, a flexible transparent CsPbBr3 quantum dots (QDs) mixed in graphene oxide (GO) RRAM device is introduced, which is controllable by both an electric field and illumination. Under illumination, the ON/OFF ratio of the Ag/CsPbBr3 QDs:GO/ITO device is ≈1.4 × 107, which is 1077 times larger than that in the dark condition (1.3 × 104). The SET/RESET voltages are +2.28/−2.04 V and +1.68/−1.08 V under the dark and illumination conditions, respectively. As a flexible memory device, the resistances are little affected by the bending curvatures and load‐cycling. Before and after 104 bending cycles with a radius of 5 mm under illumination, the ON/OFF ratios keep in the same order, which are 2.5 × 107 and 2.3 × 107, respectively. The ratio values are 8.8 × 104 and 2.9 × 104 under the dark condition, respectively. This innovative resistive memory based on the CsPbBr3 QDs:GO hybrid film supports a huge space for the development of photoelectrical dual‐controlled flexible RRAM devices.
Stability of Platinum‐Group‐Metal‐Based Electrocatalysts in Proton Exchange Membrane Fuel Cells
Authors: Zhu Enbo , Wu Menghao , Xu Haozhe , Peng Bosi , Liu Zeyan , Huang Yu , Li Yujing 
Published: May 2022

AbstractProton exchange membrane fuel cells (PEMFCs) have attracted significant interest as a promising alternative technology to the combustion engine to power next‐generation vehicles with zero emission. Among the various technological targets, system cost and durability are currently identified as the main obstacles toward large‐scale implementation of PEMFCs. Platinum‐group‐metal‐based (PGM‐based) catalysts are the most efficient catalyst for the rate‐limiting cathodic oxygen reduction reaction in PEMFCs and take the highest share in the cost breakdown. Therefore, the stability of PGM‐based electrocatalysts plays a significant role in the development of PEMFCs. This review will summarize the recent progress made on the understanding of both the fundamental chemical and structural stability of PGM‐based catalysts, and their durability in operational PEMFC devices. It calls for systematic studies on the chemical, structural, and operational durability of the PGM‐based catalyst and the need to coin practical descriptors for catalyst design with both superior activity and durability for cost‐effective and high‐performance PEMFCs.
Rational Design of High‐Performance Keratin‐Based Hemostatic Agents
Authors: Wang Yumei , Xu Yingqian , Zhang Zhi , He Ye , Hou Zongkun , Zhao Zhibin , Deng Jia , Qing Rui , Wang Bochu , Hao Shilei 
Published: May 2022

AbstractKeratins are considered ideal candidates as hemostatic agents, but the development lags far behind their potentials due to the poorly understood hemostatic mechanism and structure–function relations, owing to the composition complexity in protein extracts. Here, it is shown that by using a recombinant synthesis approach, individual types of keratins can be expressed and used for mechanism investigation and further high‐performance keratin hemostatic agent design. In the comparative evaluation of full‐length, rod‐domain, and helical segment keratins, the α‐helical contents in the sequences are identified to be directly proportional to keratins’ hemostatic activities, and Tyr, Phe, and Gln residues at the N‐termini of α‐helices in keratins are crucial in fibrinopeptide release and fibrin polymerization. A feasible route to significantly enhance the hemostatic efficiency of helical keratins by mutating Cys to Ser in the sequences for enhanced water wettability through soluble expression is then further presented. These results provide a rational strategy to design high‐efficiency keratin hemostatic agents with superior performance over clinically used gelatin sponge in multiple animal models.
Mn2+/Fe3+/Co2+ and Tetrasulfide Bond Co‐Incorporated Dendritic Mesoporous Organosilica as Multifunctional Nanocarriers: One‐Step Synthesis and Applications for Cancer Therapy
Authors: Liu Bin , Feng Lili , Bian Yulong , Yuan Meng , Zhu Yanlin , Yang Piaoping , Cheng Ziyong , Lin Jun 
Published: May 2022

AbstractEnriching the application of multifunctional dendritic mesoporous organosilica (DMOS) is still challenging in anti‐cancer research. Herein, manganese ions, iron ions, or cobalt ions and tetrasulfide bonds are co‐incorporated into the framework of DMOS to yield multifunctional nanoparticles denoted as Mn‐DMOS, Fe‐DMOS, or Co‐DMOS by directly doping metal ions during the synthetic process. Due to co‐incorporation of metal ions and tetrasulfide bonds, these designed nanocarriers have more functions rather than only for cargo delivery. As proof of concept, the nanocomposite is established based on Mn‐DMOS as an efficient nanocarrier for indocyanine green (ICG) delivery and modification with polyethylene glycol. In the tumor microenvironment, the generated hydrogen sulfide (H2S) arising from the reaction between tetrasulfide bond and over‐expressed glutathione (GSH) causes mitochondrial injury to reduce cellular respiration. The released Mn2+ from the rapidly decomposed nanocomposite catalyzes the endogenous hydrogen peroxide to produce oxygen (O2). The photothermal effect from the released ICG initiated by the near‐infrared light induces cancer cells apoptosis and simultaneously enhances the content of blood O2 at tumor sites. Therefore, due to the GSH depletion and trimodal O2 compensation, the photodynamic therapy efficiency of ICG has significantly improved. In brief, these designed nanocarriers will play advanced roles in cancer therapy.
Interface‐Modulated Resistive Switching in Mo‐Irradiated ReS2 for Neuromorphic Computing
Authors: Pam Mei Er , Li Sifan , Su Tong , Chien Yu‐Chieh , Li Yesheng , Ang Yee Sin , Ang Kah‐Wee 
Published: May 2022

AbstractCoupling charge impurity scattering effects and charge‐carrier modulation by doping can offer intriguing opportunities for atomic‐level control of resistive switching (RS). Nonetheless, such effects have remained unexplored for memristive applications based on 2D materials. Here a facile approach is reported to transform an RS‐inactive rhenium disulfide (ReS2) into an effective switching material through interfacial modulation induced by molybdenum‐irradiation (Mo‐i) doping. Using ReS2 as a model system, this study unveils a unique RS mechanism based on the formation/dissolution of metallic β‐ReO2 filament across the defective ReS2 interface during the set/reset process. Through simple interfacial modulation, ReS2 of various thicknesses are switchable by modulating the Mo‐irradiation period. Besides, the Mo‐irradiated ReS2 (Mo‐ReS2) memristor further exhibits a bipolar non‐volatile switching ratio of nearly two orders of magnitude, programmable multilevel resistance states, and long‐term synaptic plasticity. Additionally, the fabricated device can achieve a high MNIST learning accuracy of 91% under a non‐identical pulse train. The study's findings demonstrate the potential for modulating RS in RS‐inactive 2D materials via the unique doping‐induced charged impurity scattering property.
ALTEN: A High‐Fidelity Primary Tissue‐Engineering Platform to Assess Cellular Responses Ex Vivo
Authors: Law Andrew M. K. , Chen Jiamin , Colino‐Sanguino Yolanda , Fuente Laura Rodriguez de la , Fang Guocheng , Grimes Susan M. , Lu Hongxu , Huang Robert J. , Boyle Sarah T. , Venhuizen Jeron , Castillo Lesley , Tavakoli Javad , Skhinas Joanna N. , Millar Ewan K. A. , Beretov Julia , Rossello Fernando J. , Tipper Joanne L. , Ormandy Christopher J. , Samuel Michael S. , Cox Thomas R. , Martelotto Luciano , Jin Dayong , Valdes‐Mora Fatima , Ji Hanlee P. , Gallego‐Ortega David 
Published: May 2022

AbstractTo fully investigate cellular responses to stimuli and perturbations within tissues, it is essential to replicate the complex molecular interactions within the local microenvironment of cellular niches. Here, the authors introduce Alginate‐based tissue engineering (ALTEN), a biomimetic tissue platform that allows ex vivo analysis of explanted tissue biopsies. This method preserves the original characteristics of the source tissue's cellular milieu, allowing multiple and diverse cell types to be maintained over an extended period of time. As a result, ALTEN enables rapid and faithful characterization of perturbations across specific cell types within a tissue. Importantly, using single‐cell genomics, this approach provides integrated cellular responses at the resolution of individual cells. ALTEN is a powerful tool for the analysis of cellular responses upon exposure to cytotoxic agents and immunomodulators. Additionally, ALTEN's scalability using automated microfluidic devices for tissue encapsulation and subsequent transport, to enable centralized high‐throughput analysis of samples gathered by large‐scale multicenter studies, is shown.
Tunable Linearity of Weight Update in Low Voltage Synaptic Transistors with Periodic High‐k Laminates
Authors: Li Yushan , Tao Ruiqiang , Zhang Beijing , Shuai Wentao , Zhou Yue , Chang Cheng , Huang Ting , Xu Zihao , Fan Zhen , Zhou Guofu , Lu Xubing , Liu Junming 
Published: May 2022

AbstractSynaptic transistors have shown great potential in neuromorphic computing, but remain challenging to simulate linear weight updates through conductance switching under low voltage spiking operation. Here, a low voltage and near‐linear weight update synaptic transistor are proposed by developing an interfacial‐defect dominated floating gate structure, in which inter‐diffused defects are surrounded by near‐defect free and ultrathin (1 nm) dielectrics in HfO2/Al2O3 periodic high‐k laminates. In the laminates, inter‐diffused defects are surrounded by near‐defect free and ultrathin (1 nm) HfO2 and Al2O3 tunneling layers deposited by atom layer deposition, which contributes to the accurate regulation of multi‐level charge trapping confined at independent interfacial regions, and trades off the low operation voltages and the nonvolatile characteristics of the devices. A very small conductance switching nonlinearity (NL = 0.05) and an excellent image recognition accuracy (93.1%) are demonstrated under low voltages (−3 V/1.8 V) in an optimized device with (1 nm HfO2/1 nm Al2O3)3 laminates. Besides, the basic synaptic functions are successfully mimicked based on the long‐term plasticity. These results have referential significance for the future artificial synapse with low energy consumption and high efficiency.
XPEEM and MFM Imaging of Ferroic Materials
Authors: Ghidini Massimo , Maccherozzi Francesco , Dhesi Sarnjeet S. , Mathur Neil D. 
Published: May 2022

AbstractThe authors describe and compare two complementary techniques that are habitually used to image ferromagnetic and ferroelectric materials with sub‐micron spatial resolutions (typically 50 nm, at best 10 nm). The first technique is variable‐temperature photoemission electron microscopy with magnetic/antiferromagnetic/polar contrast from circularly/linearly polarized incident X‐rays (XPEEM). The second technique is magnetic force microscopy (MFM). Focusing mainly on the authors’ own work, but not exclusively, published/unpublished XPEEM and MFM images of ferroic domains and complex magnetic textures (involving vortices and phase separation) are presented. Highlights include the use of two XPEEM images to create 2D vector maps of in‐plane (IP) magnetization, and the use of imaging to detect electrically driven local reversals of magnetization. The brief and simple descriptions of XPEEM and MFM should be useful for beginners seeking to employ these techniques in order to understand and harness ferroic materials.
Fright but not fight‐or‐flight: Violent video games elevated stress markers, but did not impact muscle function, memory recall or food intake, in a randomized trial in healthy young men
Authors: Wells Jonathan C. K. , Michael Panos , Fewtrell Mary S. , Siervo Mario , Cortina‐Borja Mario 
Published: May 2022

AbstractObjectivesRegular video game playing has been linked with obesity, but the underlying mechanisms remain unclear. Drawing on evolutionary life history theory, we hypothesized that playing violent video games, through activating the stress response, might increase the immediate demand for fuel by muscle and brain tissue, resulting in elevated appetite and food consumption.MethodsWe randomized 71 young adult men to play video games, involving either violent content or nonviolent puzzle‐solving, for 1 h. Over this period, we measured stress markers (blood pressure [BP], heart rate, visual‐analogue scale [VAS] self‐ratings), muscle function (handgrip strength) and cognitive function (memory recall test). Appetite was assessed by VAS, and by food intake using a test‐meal after the intervention. Linear mixed‐effects models were fitted to assess group effects and group:time effects.ResultsDuring the intervention, the violent video game group showed elevated systolic BP (∆ = 4.7 mm Hg, 95% CI 1.0, 8.4) and reported feeling more alert but less calm or happy. They showed no difference in grip strength or memory recall. They reported lower feelings of “fullness” but consumed similar food‐energy during the test‐meal.ConclusionsAlthough playing a video game with violent content elevated physiological and perceived stress markers compared with a nonviolent game, this was not associated with markers of altered fuel distribution toward two tissues (muscle and brain) that contribute to the “fight‐or‐flight” response. Rather than more energy being allocated to the brain overall, energy may have been reallocated within the brain. This may explain why there was no compensatory increase in energy intake in the violent video game group.
A disposable ultrasensitive surface enhanced Raman spectroscopy biosensor platform fabricated from biodegradable zein nanofibers
Authors: Turasan Hazal , Cakmak Mukerrem , Kokini Jozef 
Published: May 2022

AbstractIn this paper, a natural polymer, zein, is converted into a disposable and environmentally friendly surface enhanced Raman spectroscopy (SERS) biosensor platform to detect toxins. First, protein nanofiber mats were fabricated using electrospinning. Next, the surface of the fibers was decorated with metallic nanoparticles to create hotspots for the detection of the target molecule. Four types of metallic nanoparticles were tested for sensitivity optimization: gold, silver, silver‐shelled‐gold, and a mixture of gold and silver nanoparticles. Silver‐shelled‐gold nanoparticles gave the highest SERS intensity, and at the concentration of 1012particles/ml, the highest enhancement factor (EF) of 2.49 × 106was reached, which is the highest EF ever reported for a zein‐based biodegradable platform. Acrylamide was used as the model food carcinogenic toxin and its detection with this nanofiber‐based platform gave a limit of detection of 2.06 ng/ml. This LOD is 104times lower than the limit of detection that was achieved previously with a zein‐based SERS platform. Other sensitive analytical methods (GC–MS and LC–MS/MS) gave LODs of 5–10 and 20–50 ng/ml for acrylamide, much higher than the method used in this study. This sensitivity is much lower than any other previous attempts to detect acrylamide with biodegradable sensors.
Incorporation ofCO2‐polyols into ester‐based waterborne polyurethane: An effective strategy to improve overall performance
Authors: Zhang Hongming , Han Guangping , Cheng Wanli , Liu Shunjie , Wang Xianhong 
Published: May 2022

AbstractAmorphous structural CO2‐polyol was used to modify ester‐based water‐borne polyurethanes (WPUs), resulting in improved low temperature film forming and comprehensive hydrolysis/oxidation resistance properties. Excellent intact films can be easily formed even at 3°C by adding 5% CO2‐polyol into the ester‐based WPUs (namely PU5CO2). Moreover, WPUs modified by CO2‐polyol show superior hydrolysis/oxidation resistance properties than that of control samples based on castor oil or poly(propylene oxide) glycol. PU5CO2showed significantly enhanced retention tensile strength from 40% to 68.2% than that of pure ester‐based WPU after 5 h immersion in 1.5% NaOH solution, indicating an improved hydrolysis resistance. In addition, the PU5CO2displayed boosted oxidation resistance property with retention strength increased from 39% to 65%. Notably, the all‐around aging resistance of ester‐based WPUs intensified with an increase of CO2‐polyol content. This work indicates that the CO2‐polyol may be a promising modified material to improve comprehensive hydrolysis/oxidation resistance and low temperature film forming for ester‐based WPUs.
Shape memory, thermal conductivity, and mechanical property of polylactic acid and natural rubber composites reinforced by an inorganic thermal conductive network
Authors: Shi Hui‐Hong , Ruan Hui‐Xian , Chen Zong‐Ju , Zhang Yi , Zou Cheng‐Long , Zhang Xiu‐Cheng , Liu Bing , Xu Miao‐Jun , Li Bin 
Published: May 2022

AbstractWith the development and application of thermotropic shape memory polymer materials in the biomedical field, it is very crucial for these materials to improve their thermal conductivity efficiency and shape memory recovery rate by endowing them a high thermal conductivity. In our work, a PLA/NR/T‐ZnOw/GR shape memory composite was prepared by melt blending with tetrapod zinc oxide whisker (T‐ZnOw) and graphene (GR) as the double inorganic fillers and polylactic acid (PLA) and natural rubber (NR) as the polymer matrix. The synergism of T‐ZnOw and GR constructs a three‐dimensional (3D) thermal conductive network, making the thermal conductivity of PLA/NR/5wt%T‐ZnOw/2.5wt%GR increase to 1.215 W∙(m∙K)−1. The addition of T‐ZnOw reduces the agglomeration of GR in the PLA/NR matrix and the interfacial thermal resistance between the fillers and the matrix. It also improves the heat transfer rate, resulting in an excellent shape memory of PLA/NR/T‐ZnOw/GR with a morphology recovery rate of ca. 96%, a fixed rate of 95% and high thermal stability. The presented biodegradable shape memory composite with the 3D thermal conductive network is promising in the fields of medical treatment and intelligent sensors.
Effect of graphitic additives on the rheology of cellulose solutions for the preparation of templated carbon fiber precursors
Authors: Lundahl Meri J. , Sawada Daisuke , Merilä Markus , Hummel Michael 
Published: May 2022

AbstractThe performance of biobased carbon fiber (CF) can potentially be improved to a new level by enhancing its graphitization by including graphitic additives as structural templates in the precursor. Mixing these additives in the precursor spinning solution can influence the solution rheology and thus its spinning process and ensuing carbonization, though these effects are not well understood. Herein, we analyze the influence of carbon nanotube (CNT) and graphene oxide (GO) additives on the rheology of cellulose solutions in ionic liquid as well as the subsequent precursor and CF preparation. Addition of GO both thickened the solution and clearly increased its elastic (solid‐like) nature in comparison to pure cellulose solution in ionic liquid, while CNT only made the solution moderately more elastic. Still, solutions with both additives were spinnable into continuous precursor fibers, though the inclusion of GO somewhat disturbed cellulose alignment in the fiber, as observed through X‐ray diffraction. In addition, GO induced structural order development, observed as a decrease in the intensity and ratio between the Raman peaks at ~1300 cm−1 (related to disorder) and ~1600 cm−1 (related to sp2‐hybridized carbon in general).