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41.
Dr. Ying Wang Prof. Dr. Andrew Ewing 《Chembiochem : a European journal of chemical biology》2021,22(5):807-813
Exocytosis plays an essential role in the communication between cells in the nervous system. Understanding the regulation of neurotransmitter release during exocytosis and the amount of neurotransmitter content that is stored in vesicles is of importance, as it provides fundamental insights to understand how the brain works and how neurons elicit a certain behavior. In this minireview, we summarize recent progress in amperometric measurements for monitoring exocytosis in single cells and electrochemical cytometry measurements of vesicular neurotransmitter content in individual vesicles. Important steps have increased our understanding of the different mechanisms of exocytosis. Increasing evidence is firmly establishing that partial release is the primary mechanism of release in multiple cell types. 相似文献
42.
Manik Chandra Biswas Samit Chakraborty Abhishek Bhattacharjee Zaheeruddin Mohammed 《Advanced functional materials》2021,31(19):2100257
Shape memory materials (SMMs) in 3D printing (3DP) technology garnered much attention due to their ability to respond to external stimuli, which direct this technology toward an emerging area of research, “4D printing (4DP) technology.” In contrast to classical 3D printed objects, the fourth dimension, time, allows printed objects to undergo significant changes in shape, size, or color when subjected to external stimuli. Highly precise and calibrated 4D materials, which can perform together to achieve robust 4D objects, are in great demand in various fields such as military applications, space suits, robotic systems, apparel, healthcare, sports, etc. This review, for the first time, to the best of the authors’ knowledge, focuses on recent advances in SMMs (e.g., polymers, metals, etc.) based wearable smart textiles and fashion goods. This review integrates the basic overview of 3DP technology, fabrication methods, the transition of 3DP to 4DP, the chemistry behind the fundamental working principles of 4D printed objects, materials selection for smart textiles and fashion goods. The central part summarizes the effect of major external stimuli on 4D textile materials followed by the major applications. Lastly, prospects and challenges are discussed, so that future researchers can continue the progress of this technology. 相似文献
43.
Hui Liu Yaohui Fu Jinhai Yuan Lei Yu Zhefei Wang Quan Liu Bo Wei Xuhong Wang 《Ceramics International》2021,47(12):16570-16578
To provide a basis for the high-temperature oxidation of ultra-high temperature ceramics (UHTCs), the oxidation behavior of Zr3[Al(Si)]4C6 and a novel Zr3[Al(Si)]4C6-ZrB2-SiC composite at 1500 °C were investigated for the first time. From the calculation results, the oxidation kinetics of the two specimens follow the oxidation dynamic parabolic law. Zr3[Al(Si)]4C6 exhibited a thinner oxide scale and lower oxidation rate than those of the composite under the same conditions. The oxide scale of Zr3[Al(Si)]4C6 exhibited a two-layer structure, while that of the composite exhibited a three-layer structure. Owing to the volatilization of B2O3 and the active oxidation of SiC, a porous oxide layer formed in the oxide scale of the composite, resulting in the degradation of its oxidation performance. Furthermore, the cracks and defects in the oxide scale of the composite indicate that the reliability of the oxide scale was poor. The results support the service temperature of the obtained ceramics. 相似文献
44.
Marc Neumann Patrick Gehre Rapuruchukwu Ifeyinwa Nwokoye Hans Jelitto Gerold A. Schneider Christos G. Aneziris 《Ceramics International》2021,47(13):18656-18661
Main objective of the presented research is the life time prediction of self-supporting flame-sprayed Al2O3- and Al2O3 -ZrO2 -TiO2-materials under constant load. The characteristic life time and its scatter were derived from stable crack growth tests and Weibull-statistics including the four-point-bending and ball-on-three-balls method. The potential life time was estimated in order to assess room-temperature handling and long term storage of self-supporting flame-sprayed alumina components. In terms of flexural strength, energy release, and subcritical crack growth parameters, distinct differences between both materials were shown. In turn, the characteristic life times only barely deviated from each other. From that the conclusion was drawn that life time performance under constant load application is governed by the characteristic flame-spray microstructure. However, advantages in the flame-spray processing of Al2O3 - ZrO2 -TiO2 are still given, attributed to its lower melting temperature. 相似文献
45.
46.
电力系统维护是电力系统稳定运行的重要保障,应用智能算法的无人机电力巡检则为电力系统维护提供便捷。电力线提取是自主电力巡检以及保障飞行器低空飞行安全的关键技术,结合深度学习理论进行电力线提取是电力巡检的重要突破点。本文将深度学习方法用于电力线提取任务,结合电力线图像特点嵌入改进的图像输入策略和注意力模块,提出一种基于阶段注意力机制的电力线提取模型(SA-Unet)。本文提出的SA-Unet模型编码阶段采用阶段输入融合策略(Stage input fusion strategy, SIFS),充分利用图像的多尺度信息减少空间位置信息丢失。解码阶段通过嵌入阶段注意力模块(Stage attention module,SAM)聚焦电力线特征,从大量信息中快速筛选出高价值信息。实验结果表明,该方法在复杂背景的多场景中具有良好的性能。 相似文献
47.
《Ceramics International》2022,48(16):23341-23347
In recent years, the rapid development of Li(NixCoyMn1-x-y)O2 (LNCM) materials for application in ternary lithium-ion batteries has led to an increased demand for refractory kiln saggars in industries. However, saggars used for firing ternary Li-ion battery cathode materials are often subjected to severe corrosion and spalling. To investigate the damage mechanism of the saggar materials, non-contact corrosion experiments were designed to study the effects of the precursor additions, calcination temperature, and number of calcinations during the interaction between mullite saggar and LNCM materials. The phase composition and microstructure of the mullite saggar specimens before and after corrosion were characterized using X-ray diffraction and scanning electron microscopy, respectively, to obtain a comprehensive understanding of the causes of the deterioration of mullite saggar materials during corrosion. 相似文献
48.
探索五种异喹啉类生物碱抗肝癌的作用机制。借助TCMSP、String、venny数据库与WebGestalt在线分析软件获取靶点并进行蛋白互作网络(PPI)、基因本体(GO)、基因相互作用(KEGG)功能富集分析,利用Cytoscape软件构建网络。同时查阅文献并进行归纳、整理和分析得到小檗碱型中的小檗碱、双苄基类生物碱的粉防己碱、苯菲啶喹啉类的血根碱、吗啡烷类中的青藤碱和吡咯菲里啶中的石蒜碱等几种常见的生物碱,根据结构作用机制阐述每一类代表性异喹啉类生物碱治疗肝癌的潜力及抗肝癌作用机制。五个活性成分共筛选得到52个作用靶标如p53(抑癌基因)、NCOA2(核受体共激活剂2)、IL-2(白介素2),主要涉及钙离子信号通路、雌激素受体信号通路和PI3K/Akt信号传导途径等通路。通过网络药理学和文献收集证实异喹啉类生物碱可能参与调控PI3K-Akt通路等,可以通过多靶点、多通路对肝癌产生治疗作用,为进一步研究异喹啉类生物碱抗肝癌的临床研究提供参考和依据。 相似文献
50.
通过压实试验、无侧限抗压强度试验和劈裂试验,分析不同木质纤维含量、水泥含量和固化时间对软土力学性能的影响规律,探讨木质纤维、水泥改良软土的微观机制。结果表明,木质纤维的加入对水泥改良软土的击实特性有显著的影响;木质纤维与水泥可有效改善土体的抗压和劈裂抗拉强度,随着木质纤维含量的增加,改良土的抗压和劈裂抗拉强度呈现出明显的“驼峰”现象,并在木质纤维含量为0.25%时最大;木质纤维与水化产物、软土颗粒形成互锁效应,增大了改良土的摩擦力,同时木质纤维还承担一定的拉伸强度,使改良土的劈裂强度增加。 相似文献