检索结果-南通市图书馆

维普期刊数据库博看期刊

戊型肝炎病毒衣壳蛋白同源二聚体的相互作用结构域

在线全文

学校读者我要写书评

暂无评论

生物工程学报 2004年第1期20卷 90-98页

作者：李少伟何志强王颖彬陈毅歆刘如石林鉴顾颖张军夏宁邵厦门大学细胞生物学与肿瘤细胞工程教育部重点实验室厦门361005

为了探讨戊型肝炎病毒衣壳蛋白同源二聚体形成的关键区域和相互作用结构域 ,以及二聚体形成与主要天然中和表位的形成之间的关系 ,通过末端缺失、定点突变技术研究戊型肝炎病毒 (HEV)ORF2的aa394_aa6 0 6片段NE2的聚合现象 ,发现其C端的... 详细信息

为了探讨戊型肝炎病毒衣壳蛋白同源二聚体形成的关键区域和相互作用结构域 ,以及二聚体形成与主要天然中和表位的形成之间的关系 ,通过末端缺失、定点突变技术研究戊型肝炎病毒 (HEV)ORF2的aa394_aa6 0 6片段NE2的聚合现象 ,发现其C端的aa5 97_aa6 0 2 (AVAVLA)疏水区是该片段同源聚合的核心区域 ,提高该区域氨基酸的亲水性将妨碍聚合现象的发生 ;半胱氨酸化学交联实验表明NE2形成同源二聚体时 ,aa5 97在空间位置上相接近 ,处于可生成化学键的距离 ,提示所处区域为疏水聚合的作用结构域 ;通过Blast程序估算核心区域的天然突变率 ,发现其疏水性高度保守 ;N端缺失实验表明 ,至少 6 5个氨基酸既不影响同源聚合也不直接参与主要的天然中和表位的形成 ,但可协助中和表位构象的形成 ,而这种协助作用可被ORF2的末端肽段所代替。aa5 97_aa6 0 2 (AVAVLA)疏水区为戊肝病毒衣壳组装的第一步骤的核心区域 ,并与重要的天然中和表位的形成直接相关 ,从而为戊肝病毒疫苗的研究提供更详细的信息。

关键词：戊型肝炎病毒基因突变同源聚合作用结构域

Discrete numerical modeling of granular materials considering crushability

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2017年第4期14卷 758-770页

作者： QIAN jian-gu gu jian-bo gu Xiao-qiang HUANG Mao-song Key Laboratory of Geotechnieal and Underground Engineering of Ministry of Education Tongji UniversityShanghai 200092China Department of Geotechnical Engineering Tongji UniversityShanghai 200092China

The aim of this study is to numerically investigate the influence of particle breakage on the mechanical behavior of granular materials using a discrete element method(DEM). To enable particle crushing, non-crushable elementary particles are boned together to represents the granular aggregates which can be crushed when the external force exceeds its strength. The flaw of the aggregate was also modeled by randomly distributed void. Single particle crushing tests were carried out to determine the distribution of particle strength. The results of single particle crushing tests illustrate that the simulated single particle fracture strength and pattern agree well with the Weibull's distribution *** oedometer tests, drained monotonic and cyclic triaxial tests were also carried out to investigate the crushing of the aggregates and the associated mechanical behaviors. The effect of confining pressure on the crushing of aggregates and the mechanical behavior was also analyzed. It was found that the peak stress and dilation decrease significantly when particle crushing was *** deformation behavior of the specimen is essentially controlled by two factors: particle rearrangement-induced dilation and particle crushing-induced contraction. The increase of permanent strain and the reduction of dilation were observed during cyclic loading and they tend to reach a stable state after a certain number of cycles. The crushing of aggregate is most significant in the first two cycles. The results also indicated that for the same axial strain the volumetric strain and the bound breakage in the cyclic loading tests are significantly larger than that in the monotonic loading tests,especially at high cyclic stress ratio.

关键词： DEM simulation Granular materials Crushing Monotonic and Cyclic triaxial test

NASTCNN: a spatio-temporal convolutional neural network with non-local attention mechanism for image-induced brain activity pattern recognition

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2025年

作者： TAN Xiangxin SHAO Mingxiong ZENG Ke gu Yue School of Computer Science and Engineering， Tianjin University of Technology Engineering Research Center of Learning-Based Intelligent System (Ministry of Education)， Tianjin University of Technology Krembil Research Institute， University Health Network

Deciphering the brain’s visual processing mechanisms has always been a hot topic. Using neural signal patterns to predict the corresponding external visual stimuli is crucial in understanding the interaction of real visual scenes. There are some challenges in the study of image-induced brain activity pattern recognition based on electroencephalogram (EEG)， e.g. how to fully utilize the effective features of EEG signals to improve the classification， and how the frequency and the length of EEG effect the model performance. We design an experimental paradigm that minimizes the interaction between visual stimuli， and propose a spatio-temporal convolutional neural network with non-local attention mechanism (NASTCNN) for image-induced brain activity pattern recognition. The framework utilizes non-local feature extraction operations to realize global information interaction between EEG signals over long distances and enhance the feature expression of some important information. Our model achieves the best performance on both MNIST-EEG and ImageNet-EEG datasets. The classification results are 24.00% and 50.10% respectively， higher than the random probability. We also analyze the effects of different EEG frequency bands and time subsequences of different lengths on the classification performance and which brain regions are activated over time. The results show that when full frequency band and entire length sequence are selected， the classification result is optimal. The occipital region is essential for processing visual tasks， and the temporal region and some frontal regions also play important role in the later stage of visual decoding. This research can help us better understand the visual processing mechanism of the brain.

关键词：

GdCl₃ abates hepatic ischemia-reperfusion injury by inhibiting apoptosis in rats

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2009年第5期8卷 518-523页

作者： jian-Yi Li Xi gu Wen-Hai Zhang shi Jia Yong Zhou Department of General Surgery Shengjing Hospital China Medical University Shenyang 110004 China.

BACKGROUND:Gadolinium chloride(GdCl3)is a specific inhibitor of Kupffer cells(KCs),which are important promoters of various liver *** is therefore of interest to explore the role of KCs in liver ischemia-reperfusion injury and their relations with apoptosis caused by ischemia-reperfusion injury. METHODS:One hundred male Wistar rats(190-210 g, 6-7 weeks old)were divided into two groups at random, GdCl3 group and control *** were collected at 0.5,1,6,12,and 24 hours from each group after *** alanine aminotransferase(ALT)and aspartate aminotransferase(AST)were measured by an automatic biochemical ***-αin serum was measured by enzyme-linked immunosorbent assay(ELISA). Malondialdehyde(MDA)in the liver mitochondria was measured by a colorimetric *** changes in the liver and immunohistochemical staining for caspase-3 were observed under an optical *** ratio of apoptotic cells was measured by TdT-mediated dUTP nick-end labeling(TUNEL),and ultrastructural features of apoptosis were observed with a transmission electron microscope(TEM). RESULTS:The levels of ALT in the GdCl3 group were lower than those in the control group after reperfusion for 0.5, 1,6 and 12 hours(P<0.05);and the levels of AST in the GdCl3 group were lower than those in the control group after reperfusion for 6 and 12 hours(P<0.05).The levels of TNF-αin the GdCl 3 group were lower than those in the control group after reperfusion for each time(P<0.05). The concentrations of MDA after reperfusion in the GdCl3 group were lower than those in the control group after reperfusion for 6,12 and 24 hours(P<0.05).After reperfusion for 0.5,1,6 and 12 hours,the integral optical density(IOD)of caspase-3-positive cells was lower in theGdCl3 group than in the control group(P<0.05).After reperfusion for 1,6,and 12 hours,the IOD of cells stained by TUNEL in the GdCl3 group was lower than that in the control group(P<0.05). CONCLUSIONS:GdCl3

关键词： gadolinium chloride Kupffer cell ischemia-reperfusion injury caspase-3 apoptosis

A Framework of Convergence Analysis of Mini-batch Stochastic Projected Gradient Methods

在线全文

学校读者我要写书评

暂无评论

Journal of the Operations Research Society of China 2023年第2期11卷 347-369页

作者： jian gu Xian-Tao Xiao School of Sciences Dalian Ocean UniversityDalian 116023China School of Mathematical Sciences Dalian University of TechnologyDalian 116023China

In this paper,we establish a unified framework to study the almost sure global convergence and the expected convergencerates of a class ofmini-batch stochastic(projected)gradient(SG)methods,including two popular types of SG:stepsize diminished SG and batch size increased *** also show that the standard variance uniformly bounded assumption,which is frequently used in the literature to investigate the convergence of SG,is actually not required when the gradient of the objective function is Lipschitz ***,we show that our framework can also be used for analyzing the convergence of a mini-batch stochastic extragradient method for stochastic variational inequality.

关键词： Stochastic projected gradient method Variance uniformly bounded Convergence analysis

Optimal placement of piezoelectric active bars in vibration control by topological optimization

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2008年第6期24卷 699-708页

作者： guozhong Zhao jian Wang Yuanxian gu State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering Mechanics Dalian University of Technology Dalian 116024 China

A continuous variable optimization method and a topological optimization method are proposed for the vibration control of piezoelectric truss structures by means of the optimal placements of active bars. In this optimization model, a zero-one discrete variable is defined in order to solve the optimal placement of piezoelectric active bars. At the same time, the feedback gains are also optimized as continuous design variables. A two-phase procedure is proposed to solve the optimization problem. The sequential linear programming algorithm is used to solve optimization problem and the sensitivity analysis is carried out for objective and constraint functions to make linear approximations. On the basis of the Newmark time integration of structural transient dynamic responses, a new sensitivity analysis method is developed in this paper for the vibration control problem of piezoelectric truss structures with respect to various kinds of design variables. Numerical examples are given in the paper to demonstrate the effectiveness of the methods.

关键词： Piezoelectric intelligent truss Vibrationcontrol Design optimization Sensitivity analysis

AN INTEGRO-DIFFERENTIAL PARABOLIC VARIATIONAL INEQUALITY ARISING FROM THE VALUATION OF DOUBLE BARRIER AMERICAN OPTION

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2014年第2期27卷 276-288页

作者： SUN Yudong shi Yimin gu Xin Department of Applied Mathematics Northwestern Polytechnical University Department of Methodology and Statistics Utrecht University

This paper studies the nonlinear variational inequality with integro-differential term arising from valuation of American style double barrier option. First, the authors use the penalty method to transform the variational inequality into a nonlinear parabolic initial boundary problem(i.e., penalty problem). Second, the existence and uniqueness of solution to the penalty problem are proved by using the Scheafer fixed point theory. Third, the authors prove the existence of variational inequality' solution by showing the fact that the penalized PDE converges to the variational inequality. The uniqueness of solution to the variational inequality is also proved by contradiction.

关键词： American style barrier option existence integro-differential uniqueness variational inequality.

AIEgens-lightened Functional Polymers: Synthesis, Properties and Applications

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2019年第4期37卷 302-326,I0005页

作者： shi-Yuan Zhou Hai-Bo Wan Feng Zhou Pei-Yang gu Qing-Feng Xu jian-Mei Lu College of Chemistry Chemical Engineering and Materials ScienceCollaborative Innovation Center of Suzhou Nano Science and TechnologySoochow University

Recently, polymers with aggregation-induced emission(AIE) effects have attracted significant attention due to their broad applications in luminescence sensors, stimuli responsive materials, electroluminescence devices, etc. In this review, we summarize recent advances concerning AIE polymers. Four types of AIE polymers including end-functionalized polymers, side-chain polymers, main-chain polymers, and other polymers according to the location of AIEgens, are described. Their synthetic preparation, optical property, AIE effects, and applications are also illustrated in this review.

关键词： Aggregation-induced emission Functional polymers Synthetic method Application

Simultaneously mastering operando strain and reconstruction effects via phase-segregation strategy for enhanced oxygen-evolving electrocatalysis

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2023年第7期82卷 572-580,I0012页

作者： Daqin guan Chenliang shi Hengyue Xu Yuxing gu jian Zhong Yuchen Sha Zhiwei Hu Meng Ni Zongping Shao State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211800JiangsuChina Department of Building and Real Estate Research Institute for Sustainable Urban Development(RISUD)and Research Institute for Smart Energy(RISE)The Hong Kong Polytechnic UniversityHung HomKowloon 999077Hong KongChina Institute of Biopharmaceutical and Health Engineering Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055GuangdongChina Max-Planck-Institute for Chemical Physics of Solids Nöthnitzer Str.40Dresden 01187Germany WA School of Mines:Minerals Energy and Chemical EngineeringCurtin UniversityPerthWestern Australia 6845Australia

Material strain and reconstruction effects are critical for catalysis reactions,but current insights into operando strain effects during reaction and means to master catalyst reconstruction are still ***,we propose a facile thermal-induced phase-segregation strategy to simultaneously master material operando strain and reconstruction effects for enhanced oxygen-evolving reaction(OER).Specifically,self-assembled and controllable layered LiCoO_(2)phase and Co_(3)O_(4)spinel can be generated from pristine Li2Co_(2)O_(4)spinel via Li and O volatilization under different temperatures,realizing controllable proportions of two phases by calcination *** operando and ex-situ characterizations reveal that obvious tensile strain along(003)plane appears on layered LixCoO_(2)phase during OER,while low-valence Co_(3)O_(4)phase transforms into high-valence CoOOHx,realizing simultaneous operando strain and reconstruction *** experimental and computational investigations demonstrate that both strained LixCoO_(2)phase and reconstructed CoOOHxcompound contribute to the beneficial adsorption of important OH-reactants,while respective roles in activity and stability are uncovered by exploring their latticeoxygen participation *** work not only reveals material operando strain effects during OER,but also inaugurates a new thermal-induced phase-segregation strategy to artificially master material operando strain and reconstruction effects,which will enlighten rational material design for many potential reactions and applications.

关键词： Operando strain Structural reconstruction Phase-segregation strategy Operando synergistic effects Oxygen-evolving reaction