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1.
膜筏微区(membrane microdomains)是细胞质膜上富含固醇类和鞘脂类的高度动态的微结构域.膜筏微区及其动力学特性在植物的先天免疫反应中具有十分重要的作用.本文简要介绍了膜筏微区的概念及其功能,并着重总结了膜筏微区蛋白参与病原菌防御反应的研究进展,为阐明病原菌与宿主细胞的相互作用机制和病原菌侵染的防治提供了新思路.  相似文献   

2.
本文主要通过原子力显微镜(AFM)和Langmuir单层膜技术研究不同浓度的髓鞘碱性蛋白(MBP)与"脂筏"(PC/SM/Cholesterol)模型相互作用形成仿生膜的物理特性.利用表面压缩模量(Cs-1)和二维维里状态方程对π-A曲线进行分析,计算了MBP与"脂筏"单层膜分子间相互作用的第二维里系数.根据二维维里状...  相似文献   

3.
超分辨近场功能薄膜的膜层结构及其机理研究进展   总被引:1,自引:0,他引:1  
超分辨近场结构光盘是最有希望达到100 GB以上的存储容量方式之一,而其记录和读出机理是研究中的重点,在近年文献研究的基础上,阐述了超分辨近场功能薄膜的膜层结构及其机理的研究进展.  相似文献   

4.
基于结构的丝氨酸蛋白酶超家族进化分析   总被引:4,自引:0,他引:4       下载免费PDF全文
季星来  孙之荣 《电子学报》2001,29(Z1):1756-1758
丝氨酸蛋白酶是一类水解酶,得名于Ser195对底物的亲核攻击.丝氨酸蛋白酶在长期进化过程中,虽然蛋白质序列之间的差异性很大,但仍然保持了一个稳定的核心催化结构 ;同时,丝氨酸蛋白酶也衍生出各种各样的生物学功能.但是,序列的差异以及大量的复制现象使得丝氨酸蛋白酶超家族的进化研究进展缓慢.本文用SSAP算法从结构比较的层次上进行蛋白质超家族进化的研究,分析了丝氨酸蛋白酶超家族结构与功能的演化,研究了丝氨酸蛋白酶结构上的进化及其对功能的影响,对于蛋白质结构与功能关系的研究以及蛋白质分子设计都有一定的指导意义.  相似文献   

5.
丙型肝炎在全球范围内继续传播,每年增加300万新感染病例。丙型肝炎病毒(Hepatitis virus, HCV)属于黄病毒科肝炎病毒属的病毒,被认为是肝硬化和肝细胞癌的主要病因。HCV具有单个正链RNA基因组,其编码由大约3 000个氨基酸组成的多聚蛋白前体。该蛋白在多个位点被切割生成结构蛋白和非结构蛋白。过去几年中,在阐明HCV蛋白质的结构方面取得了很大进展,其中大部分蛋白质可作为抗病毒靶标进行研究。但是,HCV蛋白在病毒生命周期期间执行多种功能,且这些功能可以通过不同的结构构象和/或与病毒和/或细胞蛋白的相互作用进行调节。本文总结了近几年在HCV结构生物学领域的现有知识并介绍该领域的最新进展。  相似文献   

6.
胞吞作用(Endocytosis)通过对质膜脂类、整合蛋白以及胞外物质的内化严格控制物质和信号的交流,是细胞与外界环境交流和细胞内稳态维持的重要方式之一。相较于动物和酵母细胞,植物细胞胞吞作用的研究相对滞后。随着拟南芥突变体库的建立以及药理学等方法的应用,人们对植物细胞膜泡运输的调节机制有了新的认识。本文阐述植物细胞中主要的胞吞途径,并着重总结植物细胞胞吞途径研究常用的成像技术和生物化学方法,为今后开展胞吞途径的系统研究提供技术和方法上的参考。  相似文献   

7.
锌转运蛋白(zinc transporter;ZnT)家族是一组具有六个跨膜区域并富含组氨酸的结构和功能相近的蛋白质,参与游离锌离子的跨膜转运。现已克隆出7个成员即ZnT1-7。其中ZnT3主要分布在神经系统并与含锌神经元突触小泡内锌离子的积聚关系密切。本研究应用免疫电镜技术对ZnT3在  相似文献   

8.
GPV和IBRV的超微结构与形态发生的冰冻蚀刻研究   总被引:1,自引:0,他引:1  
用冰冻断裂技术并结合其它电镜技术,研究了GPV和IBRV囊膜和核壳体的形态和发生。GPV发育早期,病毒从中部断裂,围绕病毒的膜样结构是均匀排列的两层颗粒,而成熟病毒在囊膜中间断裂,说明发育早期的囊膜脂质很少,主要成分是蛋白质颗粒,随后脂质才进入囊膜。而细胞质内成熟GPV囊膜的PF和EF都仍有大量膜内蛋白颗粒,GPV释放到细胞外后囊膜膜内蛋白颗粒大为减少。成熟的IBRV囊膜PF上膜内蛋白比EF上多。在囊膜周缘有时可见剌突样结构。在与疾毒接触的细胞质膜的区域有规则排列的颗粒,似与病毒释放有关。在感染细胞核内同时装配着IBRV的核心、空衣壳和核壳体。细胞核内核壳体固断裂部位不同可分为5种类型,深度蚀刻后对其形态进行了观察。文中还对不同方法制备的样品的形态进行了比较。  相似文献   

9.
闫天宇  何颖  王鑫宇  徐欣怡  谢晖  陈雪利 《红外与激光工程》2022,51(11):20220546-1-20220546-14
荧光显微成像具有高分辨率、高灵敏度、高分子特异性以及非介入性的优点,可以在微米乃至纳米尺度下表征样本的形态学与分子功能学信息,成为了生命科学研究的重要工具。随着微观生物学研究的不断深入,荧光显微成像被期待能够动态且立体地观测微观生物结构与分子事件。文中系统性地梳理了近年来快速三维荧光显微成像技术的研究进展,包括点扫描式成像、宽场成像与投影断层成像在提高成像速度、拓展成像维度以及增强成像质量等方面的主要技术手段、改进策略与代表性研究成果,并展望了快速三维荧光显微成像技术的未来挑战与发展前景。  相似文献   

10.
汪相如  周庄奇 《红外与激光工程》2018,47(1):103006-0103006(9)
综述了液晶光学相控阵器件在高功率激光应用方面的研究进展。从器件的实现原理出发,阐述制约器件在高功率应用的原因,并基于器件的多层结构,着重介绍了各个功能膜层对高功率激光的耐受情况,并详细介绍透明导电层、配向层、液晶层的最新研究进展;同时,针对器件工作模式和散热结构对高功率的约束关系进行详细分析,并综述相关的研究进展。  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

15.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

16.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

17.
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.  相似文献   

18.
A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.  相似文献   

19.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.  相似文献   

20.
Call for Papers     
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks  相似文献   

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