Well-oriented ZZ–PS-tag with high Fc-binding onto polystyrene surface for controlled immobilization of capture antibodies

The site specificity and bioactivity retention of antibodies immobilized on a solid substrate are crucial requirements for solid phase immunoassays. A fusion protein between an immunoglobulin G (IgG)-binding protein (ZZ protein) and a polystyrene-binding peptide (PS-tag) was constructed, and then used to develop a simple method for the oriented immobilization of the ZZ protein onto a PS support by the specific attachment of the PS-tag onto a hydrophilic PS. The orientation of intact IgG was achieved via the interaction of the ZZ protein and the constant fragment (Fc), thereby displayed the Fab fragment for binding antigen. The interaction between rabbit IgG anti-horseradish peroxidase (anti-HRP) and its binding partner HRP was analyzed. Results showed that the oriented ZZ–PS-tag yielded an IgG-binding activity that is fivefold higher than that produced by the passive immobilization of the ZZ protein. The advantage of the proposed immunoassay strategy was demonstrated through an enzyme-linked immunosorbent assay, in which monoclonal mouse anti-goat IgG and HRP-conjugated rabbit F(ab′)₂ anti-goat IgG were used to detect goat IgG. The ZZ–PS-tag presented a tenfold higher sensitivity and a wider linear range than did the passively immobilized ZZ protein. The proposed approach may be an attractive strategy for a broad range of applications involving the oriented immobilization of intact IgGs onto PS supports, in which only one type of phi-PS (ZZ–PS-tag) surface is used.     

在LiCl-KCl-AlCl3熔盐中直接电化学还原Sm2O3及Al-Sm合金的形成

在803 K LiCl-KCl熔盐中,研究了通过添加助剂AlCl3直接电化学还原Sm2O3和Al-Sm合金的形成。以SmCl3为原料作为参照,采用循环伏安和方波伏安方法,研究了Sm2O3在LiCl-KCl-AlCl3熔盐体系中的电化学行为。通过对比发现在两个体系中,峰的数量和位置基本一致,这说明在LiCl-KCl熔盐中,加入AlCl3之后,可以将Sm2O3有效氯化。计时电位结果表明,当阴极电流比-139.8 mA.cm-2更负时,Al和Sm共同还原。为了提取Sm,采用恒电流从LiCl-KCl-AlCl3-Sm2O3熔盐中电解得到Al-Sm合金样品,并进行XRD表征,结果表明可以通过调节AlCl3和Sm2O3的浓度得到不同相的Al-Sm合金。     

激光等离子体中Thomson散射光谱的拟合

依据无碰撞、无磁场、麦克斯韦速度分布等离子体模型下的Thomson散射理论编写了一维Thomson散射光谱拟合程序，并考虑了等离子体中的热流引起的电子相对漂移.研究了诊断系统的谱分辨率、收集立体角、Thomson散射参数α、等离子体参数梯度和电子的相对漂移速度对Thomson光谱拟合的影响.等离子体不均匀性和有限收集立体角对参数诊断影响很小，因此可以用无梯度无收集立体角的拟合程序简化处理；实验中为了提高信号的信噪比可以适当增加收集立体角；α较小时对拟合影响很大，实验中可以通过选取散射角提高α值和精确监测等离子体密度来减小它的影响. 关键词： Thomson散射 激光等离子体 电子相对漂移     

电声耦合对单层Bucky葱的影响

研究单层Bucky葱中电子与晶格振动耦合对其结构和电子结构的影响,发现单层Bucky葱上普遍地存在着结构畸变、电子结构的畸变和对称性的变化.利用Su-Schrieffer-Heeger(SSH)模型研究单层Bucky葱上的Peierls不稳定性,得到主要结论如下:(1)金属型的单层Bucky葱上存在结构和电子结构畸变,对称性降低并出现能隙,使之转变成窄带隙型半导体;(2)在宽带隙型的单层Bucky葱上也存在结构和电子结构的畸变,但体系的对称性没有改变,电子结构特征也没有改变;(3)这些畸变量在不同类型的Bucky葱上表现出不同的特征,但都随着单层Bucky葱体系的增大而逐渐减小;(4)宽带隙半导体类有较高的热力学和动力学的稳定性;(5)Peierls不稳定性导致的结构和电子结构的畸变不改变原来定性的结论.     

部分电离金属钛和银等离子体输运性质的计算

金属等离子体的组分为计算热力学、光学和辐射输运特性研究提供了基本的输入参数.为获得此参数,本文用部分电离等离子体模型,在考虑金属发生三次电离,以及电子与中性粒子的极化作用、离子与离子之间、电子与离子之间、电子与电子之间库仑相互作用下,计算得到了等离子体组分,进而用线性响应理论计算了金属钛和银的电导率.并与已有的实验数据进行了比较,验证了模型的可靠性.在此基础上进一步预测了密度在0.001—2.0 g/cm³、温度在1.5×10⁴—2.5×10^{4关键词： 等离子体 线性响应理论 电离度 输运系数}     

微波固相合成三(邻氯苄基)锡肉桂酸酯及其结构与量子化学研究

三(邻氯苄基)氯化锡与肉桂酸按物质的量比1∶1,通过微波固相反应合成了三(邻氯苄基)锡肉桂酸酯。经X-射线衍射方法测定了其晶体结构,化合物属三斜晶系,空间群为P1,晶体学参数a=0.974 91(3)nm,b=1.096 57(3)nm,c=1.485 91(4)nm,α=104.115 0(10)°,β=90.241 0(10)°,γ=111.715 0(10)°,V=1.423 35(7)nm3,Z=2,Dc=1.499 g.cm-3,μ(Mo Kα)=12.04 cm-1,F(000)=644,R1=0.024 9,wR2=0.083 6。中心锡与亚甲基碳和羧基氧原子构成畸型四面体。对其结构进行量子化学从头计算,探讨了配合物的稳定性、分子轨道能量以及一些前沿分子轨道的组成特征。     

Absorption Spectral Study of Mixed Chiral Amino Acid Porphyrin Langmuir-Blodgett Films

Absorption spectra were performed on Langmuir-Blodgett films of a new chiral amino acid porphyrin (Py) and its mixture with stearic acid (SA). Vertical uniformity of the LB films has been demonstrated by the linear relationship between the absorbance and the layer number of films. J-Aggregates were present when the film was transferred at various surface pressures and at different molar ratios of Py and SA. However, no aggregation was present for the molecules in the adjacent monolayers. the observed optical absorption spectra of mixed films were markedly dependent on the combination of Py. When the molar ratio of Py was increased from 0.05 to 0.75, the absorption peaks of Soret and Q bands bathochromically shifted ca. 5.5 and 2.2 nm. When the deposited pressure was increased from 5 to 35 mN/m, the absorption peaks of Soret and Q bands bathochromically shifted ca. 3.7, 3.2 nm and 3.5, 2.2 nm for pure Py and 1:3 Py-SA mixed LB films, respectively. on a hydrophobic substrate, the LB films showed a red shift of ca. 4.5 nm for Soret band compared with that on the hydrophilic substrate owing to their different environments.     

间接驱动的内爆不对称性随腔长和时间变化的研究

在激光间接驱动惯性约束聚变中, 为达到高密度压缩以实现点火, 对靶丸内爆对称性和黑腔辐射场均匀性有严格的要求. 为了研究内爆不对称性随腔长和时间的变化, 实验中采用了三种不同尺寸的黑腔, 利用X光分幅相机观测了靶丸燃料区自发光, 获得了压缩变形过程和椭圆度变化规律, 初步判断了在三种腔型中腔长1700 μm 的黑腔较接近神光Ⅲ原型装置内爆对称性要求. 根据视角因子程序计算得到辐射流不对称性随时间变化情况, 通过一个简化的解析模型推导出内爆形变不对称性随时间变化过程, 与实验结果大致符合. 由此进一步分析了黑腔辐射场不均匀性的演化导致内爆不对称性随腔长和时间变化的物理机制. 关键词： 内爆不对称性 黑腔辐射场不均匀性 腔长 视角因子程序     

Different temperature dependence of carrier transport properties between AlxGal-xN/InyGal-yN/GaN and Alx Gal-xN/GaN heterostruct ures

The temperature dependence of carrier transport properties of Alx Gal-xN/InyGal-yN/CaN and AlzGal-xN/GaN heterostructures has been investigated. It is shown that the Hall mobility in Alo.25Gao.75N/Ino.03Gao.97N/GaN heterostructures is higher than that in Alo.25Gao.75N/GaN heterostructures at temperatures above 500 K, even the mobility in the former is much lower than that in the latter at 300 K. More importantly, the electron sheet density in Alo.25Gao.75N/Ino.03Gao.97N/GaN heterostructures decreases slightly, whereas the electron sheet density in Al0.25Gao.75N/CaN heterostructures gradually increases with increasing temperature above 500 K. It is believed that an electron depletion layer is formed due to the negative polarization charges at the Iny Can-yN/GaN heterointerface induced by the compressive strain in the InyCal-yN channel, which effectively suppresses the parallel conductivity originating from the thermal excitation in the underlying GaN layer at high temperatures.