QM/MM and Classical Molecular Dynamics Simulation of Histidine-Tagged Peptide Immobilization on Nickel Surface

The hybrid quantum mechanics (QM) and molecular mechanics (MM) method is employed to simulate the His-tagged peptide adsorption to ionized region of nickel surface. Based on the previous experiments, the peptide interaction with one Ni ion is considered. In the QM/MM calculation, the imidazoles on the side chain of the peptide and the metal ion with several neighboring water molecules are treated as QM part calculated by “GAMESS”, and the rest atoms are treated as MM part calculated by “TINKER”. The integrated molecular orbital/molecular mechanics (IMOMM) method is used to deal with theQMpart with the transitional metal. By using the QM/MM method, we optimize the structure of the synthetic peptide chelating with a Ni ion. Different chelate structures are considered. The geometry parameters of the QM subsystem we obtained by QM/MM calculation are consistent with the available experimental results. We also perform a classical molecular dynamics (MD) simulation with the experimental parameters for the synthetic peptide adsorption on a neutral Ni(1 0 0) surface. We find that half of the His-tags are almost parallel with the substrate, which enhance the binding strength. Peeling of the peptide from the Ni substrate is simulated in the aqueous solvent and in vacuum, respectively. The critical peeling forces in the two environments are obtained. The results show that the imidazole rings are attached to the substrate more tightly than other bases in this peptide.

有源波导环形谐振腔滤波特性分析

将掺铒有源波导材料引入环形谐振腔结构，从理论上分析了有源波导环形谐振腔的滤波特性。结果表明由于抽运光提供的增益补偿了腔内损耗，使得环形谐振腔满足临界耦合条件，实现对信号光的最佳陷波，同时发现通过改变抽运光功率，可以对精细度和带宽进行动态调谐。分析了铒离子掺杂浓度、信号光功率以及抽运光耦合系数对最佳陷波抽运功率的影响，为有源波导器件设计制作提供了理论依据。

平面弯曲波导耦合器的特性分析

根据耦合模理论和弯曲波导耦合器的结构特点,对平面弯曲波导耦合器的特性进行了分析,结果表明弯曲波导耦合器的弯曲半径和最小间距两个可调变量,增加了波导器件设计的灵活性;同时由于等效耦合长度的调制作用使得弯曲波导耦合器在波分复用/解复用中比平行直波导耦合器具有更大的复用带宽;分析了弯曲半径和最小间距对弯曲波导耦合器复用带宽的影响,为实际波导器件的设计制作提供了一定的理论依据.

沉积温度对HfO2薄膜残余应力的影响

用电子柬蒸发方法制备了HfO2薄膜，根据镀膜前后基片曲率半径的变化，用Stoney公式计算了薄膜应力。讨论了沉积温度对薄膜残余应力的影响。结果发现，HfO2薄膜的残余应力均为张应力，应力值随沉积温度的升高先增大后减小，在280℃左右出现极大值。对样品进行了XRD测试，从微观结构上对实验结果进行了分析，发现微结构演变引起的内应力变化是引起薄膜残余应力改变的主要因素，HfO2薄膜在所选沉积温度60～350℃内出现了晶态转变，堆积密度随温度升高而增大。

实验动物行为和电生理信号同步记录系统

一种实验动物行为和电生理信号的同步记录系统，属于神经生物学实验装置。该记录系统包括视频采集卡(3)、摄像机(4)、AD采样板(5)、电生理信号放大器(6)、微电极(7)、及其程序存储器中存有视频与电生理信号同步采集程序(1)的计算机(2)。本发明通过编写的相关程序保存视频和电生理数据，在数据回放过程中将电生理数据与动物行为相对应并保持高度的同步。具有视频采集与电生理信号的采集合二为一；提供多种视频压缩方式；多个通道、多种采样频率的电生理数据采样率和1-30帧/秒的视频采样率；提供视频逐帧查找的方式；可以输出高度精确时间范围的电生理数据与动物行为的同步，最高可精确到单独输出与单帧图像对应的数据等优点。

蓝藻TIM上的一个特异抑制靶位点及其应用

本发明涉及蓝藻TIM上的一个特异抑制靶位点及其应用，属生物技术领域。该抑制靶位点位于蓝藻TIM Loop-6的铰链区，为蓝藻Synechocystis sp.TIM氨基酸编号为准的半胱氨酸位点-Cys176。该抑制靶位点可作为在设计水华抑制剂中的应用。

饮用水中浮游藻类标本制作方法

目的 研究饮用水中藻类形态学鉴定样品标本制作方法。方法 分别对不同水源供水区末梢水和同一地点水箱水采样,进行藻类形态学检测。结果城市末梢水中浮游藻类检出率为89％;饮水水箱水中浮游藻类检出率为60％,并且观察到水箱水藻类在种属和数量上增加的情况。结论 该样品标本制作方法完全可以用于饮用水藻类形态学研究。

藻类生物技术在水环境保护中的应用前景探讨

简要综述了藻类生物技术在水污染生态毒理学和污水生物净化方面的研究成果及应用实例,同时对其研究前景进行了探讨。应用藻类生物检测技术对重金属、农药、有机污染物、有毒有害废弃物等的毒性评价结果证明,一些二价重金属阳离子对藻类的毒性顺序大致为Hg~(2+),Cd~(2+),Cu~(2+),Ni~(2+)和 Zn~(2+);酚类、酯类和芳烃类有机污染物对藻类生长的抑制作用十分显著;农药对藻类的毒害作用主要通过破坏藻类生物膜的结构和功能而抑制藻类的光合作用、呼吸作用和固氮作用。有关藻类污水处理的研究资料显示,阳光的强

红蛭属及其一新种的记述——(蛭纲:石蛭科)

<正> 关于红蛭属Dina Blanchard,1892的系统位置,一个多世纪以来一直是个有争议的问题。最初在Blainville 1818年命名石蛭属Erpobdella时,曾将红蛭属的种类都包括在内,直至1892年Blanchard以完全体节的第5环是否较宽和有无次生环沟将石蛭属分成红蛭属和石蛭属两个属。1930 Moorc用Dina quaternaria记述了从中国得到的一新

Molecular cloning and characterization of crucian carp (Carassius auratus L.) interferon regulatory factor 7

Interferon (IFN) can induce an antiviral state via interferon-regulatory transcription factors (IRFs), which bind to and control genes directed by the interferon-stimulated response element (ISRE). Here we describe a fish IRF, termed CaIRF7, cloned from a subtractive cDNA library which is constructed with mRNAs obtained from crucian carp (Carassius auratus L.) blastulae embryonic (CAB) cells infected by UV-inactivated GCHV and mock-infected cells. CaIRF7 cDNA was found to be 1816 bp in length, with a 42 bp 5' UTR and a 508 bp 3' UTR. The open reading frame translates into 421 amino acids in which a DNA-binding domain (DBD) containing the repeated tryptophan motif and IRFs association domain have been identified. Like chicken GgIRF3, CaIRF7 was most similar to mammalian IRF7 with 27 to 30% identity overall and some 37% identity in their DBDs. A single transcript of 1.9 kb was detected in virally induced CAB cells by virtual Northern blotting. RT-PCR analysis revealed a wide tissue distribution of CaIRF7 constitutive expression, with detectable transcript in non-infected CAB cells and various tissues of healthy crucian carp. In addition, CaIRF7 expression was differentially increased by stimulation of the CAB cells with active GCHV, UV-inactivated GCHV or CAB IFN, indicating that the activation of CaIRF7 was directly regulated by IFN. (C) 2003 Published by Elsevier Ltd.

The intrinsic temperature effect of the Raman spectra of graphite

The Raman spectra of ion-implanted highly oriented pyrolytic graphite (HOPG) are reported, in which an additional mode at 1083 cm(-1) and three doublet structures in the positions of similar to 1350, similar to 2450, and similar to 2710 cm(-1) are revealed. Noticeable frequency shifts are observed for all the Raman bands between the spectra excited with different laser powers, which are interpreted as the pure temperature effect and a downshift in the C-C stretching frequency induced by the thermal expansion. Moreover, the pure temperature effect (d omega/dT)(V) without anharmonic contribution is achieved in pristine HOPG. The results suggest that the pure temperature effect without anharmonic contribution plays an important role in the frequency shifts with temperature. (C) 1999 American Institute of Physics. [S0003-6951(99)01313-3].

基于加同态公钥密码体制的匿名数字指纹方案

提出了一种基于加同态公钥密码算法的匿名数字指纹方案，并给出了具有匿名功能的公钥和私钥对的具体构造方法，从而使该匿名指纹方案在发现盗版的情况下，销售商不需要第三方的帮助就能鉴别出数字多媒体作品的非法分发者，解决版权纠纷时也不需要购买者参与并提供相关的秘密信息，从而达到实现两方审判的目的．分析结果表明，该方案具有用户匿名及不可关联、销售商的可保证安全性和用户的可保证安全性等特点．