纳米金棒诱导A549细胞产生自噬的机制研究

纳米金棒(AuNRs)具有众多独特的属性,已广泛运用于生物医学领域,但其是否具有潜在的生物危害尚有争议.作者运用了激光扫描共聚焦显微镜技术、western blotting技术和其他分子生物学方法从细胞氧化应激的角度探讨了AuNRs诱导A549细胞产生自噬的分子机制.研究结果表明,4μg·mL-1的AuNRs处理6 h能够诱导A549细胞自噬标志蛋白LC3-Ⅱ表达增加,LC3蛋白从细胞核转移至细胞质并形成自噬小泡.进一步研究发现,AuNRs能够降低A549细胞线粒体膜电位、ATP含量、UCP2蛋白表达水平以及细胞抗氧化能力并导致活性氧蓄积,后者可能最终引起细胞产生自噬.而10 mmol·L-1抗氧化剂NAC能够逆转上述线粒体及细胞功能的改变,并抑制自噬的发生.这一研究为深入认识其生物危害及可能机制提供了有力的实验证据.     

人肝细胞自噬性凋亡的形态学观察

为了进一步完善形态学的分型标准以及研究调控自噬对细胞凋亡的影响 ,采用去血清诱导自噬和3ＭＡ抑制自噬 ,同时施与凋亡诱导剂 ,观察细胞超微结构的改变。正常人肝ＬＯ2细胞株去血清培养12ｈ诱导自噬之后 ,ｃｉｓｐｌａｔｉｎ(3μｌ ｍｌ)加入 16 40培养基诱导ＬＯ2细胞凋亡 16ｈ和 3-ＭＡ自噬抑制剂(6 0 0 μｇ ｍｌ) ,30ｍｉｎ后加入ｃｉｓｐｌａｔｉｎ(3μｌ ｍｌ)混合培养ＬＯ2细胞 16ｈ。ＪＥＭ 12 0 0ＥＸ透射电镜观察、摄片。正常ＬＯ2细胞胞质丰富 ,核仁明显 ,自噬现象少见。单施加凋亡诱导剂的细胞 ,可见凋亡细胞的形态多样 ,细胞…     

显微镜技术在植物细胞自噬研究中的应用

细胞自噬是真核生物对细胞内物质进行循环利用的重要途径.在植物中已发现的细胞自噬有两种形式,即微自噬和巨自噬.自噬在植物体的生长发育、免疫应答、胁迫反应、衰老等过程中具有非常重要的作用.显微镜技术是研究细胞自噬的重要手段,与生物化学和分子生物学技术相结合,荧光显微镜,激光扫描共聚焦显微镜,电子显微镜等技术的相互印证,大大地推动了对细胞自噬过程和机理的研究.本文扼要概述了显微镜技术在植物细胞自噬研究中的应用.     

Au纳米颗粒对向列相液晶取向性能的影响

液晶分子的初始排列在液晶显示器中起着关键的作用。纳米粒子掺杂到液晶体系可扰乱液晶分子的排列,从而改变液晶的自组装特性,进而影响液晶的各项性能。将制备的Au八面体纳米颗粒掺杂到向列相液晶4-氰基-4′-正戊基联苯(5CB)中,灌入液晶盒后,通过使用偏光显微镜对液晶盒的观察发现,掺杂的八面体Au纳米颗粒诱导5CB液晶分子发生了垂直取向,而球形Au纳米颗粒不能诱导液晶分子垂直取向。这归因于八面体Au纳米颗粒的表面能比较小,液晶分子间的作用力比较大,使液晶分子易于垂直取向。随着O-Au NPs的浓度增大,液晶分子的取向效果先变好又逐渐变差。这是因为O-Au NPs的浓度越高,可诱导越多的液晶分子垂直取向排列,但随着纳米粒子浓度的增加,纳米粒子团聚,减少了与液晶分子的作用,使取向效果变差。动态过程实验显示,0.1%的八面体金纳米颗粒可诱导向列相液晶5CB在2 min内快速完成垂直取向,表明O-Au NPs具有优异的诱导5CB取向的动态效果。     

光折变Bi12TiO20晶体中的波耦合性质

研究了光折变Bi12TiO20(TBO)晶体中的二波耦合矢量特性.对扩散记录全息求得信号光能量增益和偏振态改变的分析解,研究它们在3种制备可得的晶体切割面上随入射抽运光和信号光(不同)偏振方向、光栅取向以及晶体厚度的变化关系,并给出在任意光栅取向的取值范围.分析了信号光能量增益和偏振态改变量分别达到最大值时各向同性和各向异性耦合的作用,并研究旋光、压电及弹光效应在3种晶体切割面上对矢量波耦合的影响.     

自噬小体膜来源的形态学分析

目的:从形态学角度探寻自噬小体形成过程中的膜来源及自噬小体的超微结构特征.方法:应用透射电镜技术整理分析本中心收到的用于自噬研究的细胞标本,对自噬发生不同阶段及疑似自噬小体结构的图片进行分析.结果:在细胞内发现众多自噬小体结构,内质网、线粒体、细胞核和高尔基体均可形成类似自噬小体结构.结论:细胞内多种膜结构可能都是自噬小体的膜来源.     

重力矢量在SINS快速系泊自对准中的应用研究

海浪产生的扰动误差是影响舰船对准精度和快速性的关键因素,基于系泊状态下船载捷联惯导系统（SINS）自对准的特点,分析舰船运动状态并设计数字滤波器实现对重力加速度的提取。研究重力加速度在不同坐标系下的变化趋势并考虑工程应用实际情况,提出一种利用重力矢量间接建立初始捷联矩阵实现舰船系泊状态下的快速自对准方法。系泊试验结果表明,提出的基于重力矢量的自对准方法可有效地提高系统对准精度和快速性,满足舰船对初始化过程的高精度和实时性要求。     

人miR-34a靶基因的生物信息学分析及载体构建

目的对人miR-34a(hsa-miR-34a)下游靶基因进行预测,并构建含自噬相关基因靶结合序列的GFP报告基因载体。方法使用TargetScan Release 5.1和RNA22软件分析hsa-miR-34a可能的靶基因,并利用Gominer软件对靶基因功能进行分析。根据预测结果,合成含自噬相关基因hsa-miR-34a靶序列的寡核苷酸,以pEGFPC2为载体构建系列质粒,并检测各载体的真核表达情况。结果预测结果显示hsa-miR-34a共有2904个下游靶基因,功能涵盖生物过程、细胞组分、分子功能三大类,其中与自噬作用直接相关的靶基因有beclin 1和sestrin 2。构建含beclin 1和sestrin 2作用位点的GFP载体共5个,质粒转染Hela细胞后在荧光显微镜下可见绿色荧光。结论成功构建hsa-miR-34a下游自噬相关基因靶位点序列GFP报告基因载体,为进一步研究hsa-miR-34a对自噬的调控作用奠定基础。     

自噬在PDT治疗中的作用及其机制研究进展

自噬是真核生物进化过程中高度保守的分解代谢和循环再利用的过程,在维持细胞状态、内环境稳态,尤其是在细胞营养不足、氧化损伤等不利环境时起着重要作用.近来研究发现自噬参与了光动力疗法的作用过程,其机制较为复杂,而且不同程度的自噬对光动力疗法杀伤效应的影响截然不同.光动力疗法是利用特定波长的光照激活光敏剂分子,通过能量转换促...     

内分泌细胞溶酶体的超微结构研究

用电镜细胞化学方法研究内分泌细胞溶酶体的结构与功能。研究结果表明，所有内分泌细胞都存在丰富的溶酶体，分泌自噬作用普通存在于分泌肽类激素的细胞中，自体吞噬活动跃是分泌类固醇素细胞的重要特点。溶酶体通过分泌自噬和自体吞噬分别在两类内分泌细胞中参与激素分泌的调节。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

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.     

Cost-effective test solutions for smart card and other integrated flash applications

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.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

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.     

An improved parallel thinning algorithm with two subiterations

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.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

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.     

Study of waveguide coupling efficiency in hybrid silicon lasers

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

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.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

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.     

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