检索结果-南通市图书馆

Mechanics of water pore formation in lipid membrane under electric field

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2017年第2期33卷 234-242页

作者： bing bu Dechang Li Jiajie Diao Baohua Ji Biomechanics and Biomaterials Laboratory Department of Applied MechanicsBeijing Institute of Technology Department of Cancer Biology College of MedicineUniversity of Cincinnati

Transmembrane water pores are crucial for substance transport through cell membranes via membrane fusion, such as in neural communication. However, the molecular mechanism of water pore formation is not clear. In this study, we apply all-atom molecular dynamics and bias-exchange metadynamics simulations to study the process of water pore formation under an electric field. We show that water molecules can enter a membrane under an electric field and form a water pore of a few nanometers in diameter. These water molecules disturb the interactions between lipid head groups and the ordered arrangement of lipids. Following the movement of water molecules, the lipid head groups are rotated and driven into the hydrophobic region of the membrane. The reorientated lipid head groups inside the membrane form a hydrophilic surface of the water pore. This study reveals the atomic details of how an electric field influences the movement of water molecules and lipid head groups, resulting in water pore formation.

关键词： Cell membrane Membrane fusion Water pore formation Electric field Molecular dynamics simulation

在线全文

学校读者我要写书评

暂无评论

列车控制系统的抗拒绝服务攻击弹性控制策略

控制理论与应用 2024年第2期41卷 311-320页

作者：高兵步兵北京交通大学轨道交通控制与安全国家重点实验室北京100044

当遭受拒绝服务(DoS)攻击时,分布式列车控制系统的弹性控制问题受到广泛关注.本文提出了一种基于分布式领导车状态观测器和障碍李雅普诺夫函数的弹性控制策略,不仅可以避免列车碰撞,同时实现了编队控制的目标.首先,给出了一种分布式的... 详细信息

当遭受拒绝服务(DoS)攻击时,分布式列车控制系统的弹性控制问题受到广泛关注.本文提出了一种基于分布式领导车状态观测器和障碍李雅普诺夫函数的弹性控制策略,不仅可以避免列车碰撞,同时实现了编队控制的目标.首先,给出了一种分布式的领导车状态观测器设计方法,用于实时估计领导车的状态.理论分析表明,在DoS攻击满足一定约束的条件下,该状态观测器的估计误差具有指数稳定特性.在此基础上,通过将列车碰撞避免问题转化为状态受限问题,提出一种基于障碍李雅普诺夫函数的状态受限控制律,解决了DoS攻击下确保碰撞避免的车队控制问题.最后,数值仿真证实了本文方法的有效性.

关键词：拒绝服务弹性控制状态估计障碍李雅普诺夫函数列车运行控制碰撞避免

Cell Mechanics Regulates the Dynamic Anisotropic Remodeling of Fibril Matrix at Large Scale

在线全文

学校读者我要写书评

暂无评论

Research 2024年第3期2023卷 401-415页

作者： Mingxing Ouyang Yanling Hu Weihui Chen Hui Li Yingbo Ji Linshuo Qiu Linlin Zhu Baohua Ji bing bu Linhong Deng Institute of Biomedical Engineering and Health Sciences School of Medical and Health Engineering and School of PharmacyChangzhou UniversityChangzhou213164China Institute of Biomechanics and Applications Department of Engineering MechanicsZhejang UniversityHangzhou310027China.

Living tissues often have anisotropic and heterogeneous organizations, in which developmental processes are coordinated by cells and extracellular matrix modeling. Cells have the capability of modeling matrix in long distance;however, the biophysical mechanism is largely unknown. We investigated the dynamic remodeling of collagen I (COL) fibril matrix by cell contraction with designed patterns of cell clusters. By considering cell dynamic contractions, our molecular dynamics simulations predicted the anisotropic patterns of the observed COL bundling in experiments with various geometrical patterns without spatial limitation. The pattern of COL bundling was closely related to the dynamic remodeling of fibril under cell active contraction. We showed that cell cytoskeletal integrity (actin filaments and microtubules), actomyosin contractions, and endoplasmic reticulum calcium channels acting as force generations and transductions were essential for fiber bundling inductions, and membrane mechanosensory components integrin and Piezo played critical roles as well. This study revealed the underlying mechanisms of the cell mechanics-induced matrix remodeling in large scales and the associated cellular mechanism and should provide important guidelines for tissue engineering in potential biomedical applications.

关键词： contraction Dynamic Matrix

Single-vesicle imaging quantifies calcium’s regulation of nanoscale vesicle clustering mediated by α-synuclein

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

Microsystems & Nanoengineering 2020年第1期6卷 775-784页

作者： Bin Cai Jie Liu Yunfei Zhao Xiangyu Xu bing bu Dechang Li Lei Zhang Wei Dong Baohua Ji Jiajie Diao Department of Cancer Biology University of Cincinnati College of MedicineCincinnatiOH 45267USA Biomechanics and Biomaterials Laboratory Department of Applied MechanicsBeijing Institute of TechnologyBeijing 100081China Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province Institute of Cardiovascular ResearchSouthwest Medical UniversityLuzhouSichuan 646000China Institute of Biomedical Engineering and Health Sciences Changzhou UniversityChangzhouJiangsu 213164China Institute of Applied Mechanics Department of Engineering MechanicsZhejiang UniversityHangzhou 310027China Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter(Ministry of Education) School of ScienceXi’an Jiaotong UniversityXi’an 710049China Beijing Advanced Innovation Center for Biomedical Engineering Beijing 100191China

Although numerous studies have shown that the proteinα-synuclein(α-Syn)plays a central role in Parkinson’s disease,dementia with Lewy bodies,and other neurodegenerative diseases,the protein’s physiological function remains poorly ***,despite recent reports suggesting that,under the influence of Ca^(2+),α-Syn can interact with synaptic vesicles,the mechanisms underlying that interaction are far from ***,we used single-vesicle imaging to quantify the extent to which Ca^(2+)regulates nanoscale vesicle clustering mediated by α-*** results revealed not only that vesicle clustering requiredα-Syn to bind to anionic lipid vesicles,but also that different concentrations of Ca^(2+)exerted different effects on howα-Syn induced vesicle *** particular,low concentrations of Ca^(2+)inhibited vesicle clustering by blocking the electrostatic interaction between the lipid membrane and the N terminus of α-Syn,whereas high concentrations promoted vesicle clustering,possibly due to the electrostatic interaction between Ca^(2+)and the negatively charged lipids that is independent of α-*** together,our results provide critical insights intoα-Syn’s physiological function,and how Ca^(2+) regulates vesicle clustering mediated by α-Syn.

关键词： inhibited insight promoted

Sensing Traction Strain Induces Cell-Cell Distant Communications

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

医用生物力学 2019年第A1期34卷 136-137页

作者： Zhili Qian Yang Jin bing bu Yan Pan Linhong Deng Mingxing Ouyang Institute of Biomedical Engineering and Health Sciences College of Pharmaceutical Engineering and Life ScienceChangzhou University

Mechanobiology has been a highly recognized field in studying the importance of physical forces in physiologies at the molecular,cellular,tissue,organ and *** the intensive work focusing on the fine local biomechanical forces,the long-range force which can propagate through a relatively distant scale(in hundreds of micrometers and beyond)has been an intriguing topic with increasing attentions in recent *** collective functions at cell population level often rely on cell-cell communications with or without direct *** progresses including our own work indicate that the long-range biomechanical force propagating across scales far beyond single cell size may reserve the capability to trigger coordinative biological responses within cell *** and how cells communicate mechanically in a distant manner remains largely to be *** respiratory system,the mechanical property of airway smooth muscle(ASM)is associated with asthma attack with prolonged contraction during airway *** this work,we found that ASM cells rapidly self-assembled into a well-constructed network on 3D matrigel containing type I collagen(COL I),which required the collective functions and coordination of thousands of cells completed within 12-16 *** were assembled with aligned actin stress fibers and elongated *** assembling process relied on the long-range mechanical forces across the matrix to direct cell-cell distant *** further found that single ASM cells could rapidly initiate multiple buds precisely pointing to neighboring cells in distance,which relied on cell traction force and force strain on the *** tracking assay demonstrated the long-range transmission of cellular traction force to distant locations,and modeling of maximum strain distribution on matrix by finite element method predicted the consistency with cell directional protrusions and movements in *** could sense each o

关键词： long-range biomechanical force extracellular matrix cell-cell distant communication cell traction strain sensing cell network assembly

在线全文

学校读者我要写书评

暂无评论

传输时延对CBTC影响的分析及消除

铁道学报 2014年第6期36卷 41-46页

作者：步兵唐涛北京交通大学轨道交通控制与安全国家重点实验室北京100044

基于通信的列控系统CBTC利用无线通信传递列车状态信息和控制命令,数据传输时延将引发不必要的列车牵引和制动,降低列控系统的性能。本文提出一种适用于CBTC的列控系统和数据通信系统的一体化设计方法,将CBTC的多列车控制系统等效为网... 详细信息

基于通信的列控系统CBTC利用无线通信传递列车状态信息和控制命令,数据传输时延将引发不必要的列车牵引和制动,降低列控系统的性能。本文提出一种适用于CBTC的列控系统和数据通信系统的一体化设计方法,将CBTC的多列车控制系统等效为网络控制系统,建立一体化模型,分析传输时延对列控系统性能的影响。提出消除传输时延对列控系统影响的改进措施,并通过仿真验证该方法的有效性。

关键词：列车控制车地传输网络控制系统 CBTC

Urban Morphology of Urban Village: A Case Study of Dafen Oil Painting Village in Shenzhen

在线全文

学校读者我要写书评

暂无评论

Journal of Landscape Research 2017年第4期9卷 37-40,44页

作者： bu bing CHEN Keshi School of Urban Planning and Design Peking University Shenzhen Graduate School

Dafen Oil Painting Village, the largest oil painting village in current China, takes cultural industries like creation and wholesale of oil paintings as the pillar. As one of the urban villages in Shenzhen, Dafen Village not only has the common characteristics of urban morphology as ordinary urban villages, but also has something unique. In this paper, study of the urban morphology of Dafen Oil Painting Village is mainly from 3 aspects: firstly, the formation of street space in Dafen Village; secondly, analysis of the status of urban morphology of Dafen Village; thirdly, the plane layout and public space of Dafen Village. In the end, this paper put forward some suggestions about the future development of urban morphology and space layout in Dafen Village.

关键词： Urban village Cultural industry Urban morphology Public space

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

单床方法模拟十床变压吸附提氢

现代化工 2018年第4期38卷 215-219页

作者：卜令兵四川天一科技股份有限公司四川成都610225

采用单床方法模拟了10床5组分变压吸附提H_2,考察了吸附剂配比和均压次数的影响。结果显示,在计算条件下,H_2摩尔分数99.955%,CO含量0.26 mmol/kmol,氢气回收率90%,与工业数据吻合;从吸附结束到顺放结束,负载曲线峰面动态移动,N_2和CO... 详细信息

采用单床方法模拟了10床5组分变压吸附提H_2,考察了吸附剂配比和均压次数的影响。结果显示,在计算条件下,H_2摩尔分数99.955%,CO含量0.26 mmol/kmol,氢气回收率90%,与工业数据吻合;从吸附结束到顺放结束,负载曲线峰面动态移动,N_2和CO负载曲线有"驼峰"形成;逆放和冲洗2个步骤解吸的杂质量最多,再生结束后CH_4残余3.29%,残余比例最小;随着分子筛比例的增加,H_2纯度增加,CO含量降低,进入分子筛层CO_2量增加,分子筛比例70%较为合适;均压次数从2次增加至5次,H_2回收率从83.6%增加至90%,原料气处理能力从1.4 mol/s减小至0.999 mol/s。

关键词：变压吸附吸附解吸氢模拟

在线全文

学校读者我要写书评

暂无评论

论行政主体对行政契约的单方变更权

南京大学学报（哲学．人文科学．社会科学） 2008年第6期45卷 71-78,140页

作者：步兵东南大学法学院南京210096

公共利益是行政契约得以缔结和履行的重要基础,行政契约的公法属性也决定了行政主体需要享有单方变更权等特权。为了使行政契约的目的得以更好实现,应当承认行政主体为了避免公益之重大损害,有权对行政契约予以单方变更。单方变更权的... 详细信息

公共利益是行政契约得以缔结和履行的重要基础,行政契约的公法属性也决定了行政主体需要享有单方变更权等特权。为了使行政契约的目的得以更好实现,应当承认行政主体为了避免公益之重大损害,有权对行政契约予以单方变更。单方变更权的行使不以合意为前提,但应当受到公共利益需要和比例原则的限制。同时,还需强化对该特权行使的程序控制,完善告知和听取意见、协商等程序性制度,并依据信赖保护原则对相对人的损失予以充分补偿。

关键词：行政契约单方变更程序控制