磷酸氯喹与过氧化氢缔合催化作用的极谱研究

在2.0×10-2mol/LNH3·H2O NH4Cl(pH9.5)-1.0×10-2mol/LH2O2支持电解质中,磷酸氯喹于-1.87V(vs.SCE)产生一缔合平行催化波。该波的二阶导数峰峰电流与磷酸氯喹浓度在2.0×10-9～1.0×10-5mol/L范围内呈线性关系(r=0.9986,n=10)。可用于片剂中磷酸氯喹的测定。H2O2有双重作用:(1)H2O2作为配位体与磷酸氯喹形成缔合物,使峰电位Ep负移;(2)H2O2作为氧化剂氧化磷酸氯喹经单电子单质子还原生成的中间体自由基,产生极谱催化波。     

核糖核酸与天青A作用机理及含量测定

在弱酸性介质中,小分子天青A与生物大分子核糖核酸（RNA）强烈相互作用,导致分子构象的变化,引起分子光谱最大吸收波长和吸收值的变化。应用光谱法研究了反应体系酸度、天青A用量、反应时间等影响反应速度的因素,确定了最佳实验条件,建立了测定核糖核酸的新方法。线性范围为0．2～7．2mg／L。相关系数为0．9986。直接测定样品中核糖核酸获得满意结果;对作用机理进行了初步探讨,静电缔合作用使天青A分子与凝聚在RNA分子链上的反离子交换,然后,以协同方式与RNA分子发生键合,使天青A的π-电子叠合程度降低,颜色变浅,吸收值降低,最大吸收波长紫移。     

广义的M(o)bius反演公式及其在一个物理逆问题中的应用

用偏序集上广义的Mobius反演公式去求解一类物理逆问题（晶体对势反演）.这种方法是解决此类问题的一般性数学方法.文章中给出的两个应用实例说明了这种方法的有效性.     

On spherical designs obtained from Q‐polynomial association schemes

We characterize that the image of the embedding of the Q ‐polynomial association scheme into the first eigenspace by primitive idempotent E ₁ is a spherical t‐design in terms of the Krein numbers. Furthermore, we show that the strengths of P‐ and Q‐polynomial schemes as spherical designs are bounded by a constant. Copyright © 2011 John Wiley & Sons, Ltd. 19:167‐177, 2011     

理解和应用疏水相互作用的尺度依赖原理

Lum，Chandler 和Week 三人建立起来的尺度依赖的疏水相互作用理论为人们提供了一个 重要的理论框架（LCW 理论）去理解和进一步研究与疏水相互作用相关的现象。按照LCW 理 论，当一个疏水粒子的半径小于1 纳米，它的疏水水合自由能与其半径的三次方成线性关系；而当 一个疏水粒子的半径大于1 纳米，它的疏水水合自由能与其半径的二次方成线性关系。1 纳米是一 个较为普适的转变半径。小于这个尺度，水合的热力学过程是由熵主导的，大于这个尺度，水合的 热力学过程是由焓主导的。在这篇综述里，我们介绍了温度，压强和水里面的添加物对疏水水合自 由能的影响。在实验上，我们对基于原子力显微镜的单分子力谱方法研究疏水高分子水合能作了重 点介绍。同时，对这一理论在蛋白质折叠和膜组装等体系中的应用也做了介绍。     

Entropy Calculations for Charged Spheres and the Entropy of Molten Salts

Abstract

We derive an expression for the entropy S of a system of charged hard spheres within the Mean Spherical Approximation (MSA). We study the behaviour of the coulombic contribution as a function of both the charging process and the ionic radii ratio. We find that the latter gives an important ordering contribution to S, which is greatly exaggerated in the MSA. We have also calculated S using the data appropriate for the molten alkali halides. The results compare poorly with the experimental entropies and therefore cast doubts on the MSA as a suitable reference system for molten salts.     

Rapid analysis of interaction between six drugs and β2‐adrenergic receptor by injection amount‐dependent method

Drug–protein interaction analysis has become a considerable topic in life science which includes clarifying protein functions, explaining drug action mechanisms and uncovering novel drug candidates. This work was to determine the association constants (K _A ) of six drugs to β ₂‐adrenergic receptor by injection amount‐dependent method using stationary phase containing the immobilized receptor. The values of K _A were calculated to be (25.85 ± 0.035) × 10⁴ m ⁻¹ for clorprenaline, (42.51 ± 0.054) × 10⁴ m ⁻¹ for clenbuterol, (6.67 ± 0.008) × 10⁴ m ⁻¹ for terbutaline, (33.99 ± 0.025) × 10⁴ m ⁻¹ for tulobuterol, (7.59 ± 0.011) × 10⁴ m ⁻¹ for salbutamol and (78.52 ± 0.087) × 10⁴ m ⁻¹ for bambuterol. This rank order agreed well with the data determined by zonal elution, frontal analysis and nonlinear chromatography, even using different batches of β ₂‐AR column. A good correlation was found between the association constants by the current method and radio‐ligand binding assay. Our data indicates that the injection amount‐dependent method is a powerful alternative for rapid analysis of ligand–receptor interactions.     

A new equation of state for associating Lennard–Jones fluids with two sites: small bond angle

ABSTRACT

We developed a new equation of state for Lennard–Jones spheres with two short-ranged, directional association sites. The theory is novel in that association is dependent on bond angle between the two sites, and formation of self-assembled linear and cyclic clusters is predicted in the model. The competition between ring and chain formations at various densities and temperatures is predicted by the theory and verified by Monte Carlo simulations. It was found that closed-loop structures become important at low temperatures and densities. Also, at fixed association energy, intensifying the Lennard–Jones energy reduces the extent of association in the fluid. The theory and simulation are in excellent agreement.     

Robust dependence measure for detecting associations in large data set

In this paper, we proposed a new statistical dependency measure for two random vectors based on copula, called copula dependency coefficient (CDC). The CDC is proved to be robust to outliers and easy to be implemented. Especially, it is powerful and applicable to high-dimensional problems. All these properties make CDC practically important in related applications. Both experimental and application results show that CDC is a good robust dependence measure for association detecting.     

Simultaneous correlation of hydrophobic interactions in HIC and protein solubility in aqueous salt solutions and mixed solvents

The chromatographic retention in hydrophobic and reversed phase chromatography and the solubility of proteins display some common features. The chromatographic retention, as well as the solubility, is modulated by the thermodynamic properties of the solute in the fluid phase. The retention measurements at linear conditions provide information of the solution properties of the protein at infinite dilution, and the solubility measurements produce the supplementary information about the solution properties at the saturation limit. This provides a useful approach to simultaneous correlation of the chromatographic retention and the solubility.The experimental data, used for the correlation, comprise retention measurements of lysozyme on different HIC adsorbents using an aqueous ammonium sulphate eluant, an aqueous ammonium sulphate eluant with an admixture of ethanol, as well as published solubility data.The chromatographic retention data and the corresponding solubility data have been correlated using a chemical potential model derived from Kirkwood's theory of solutions of charged macro-ions and zwitterions in electrolyte solutions. The model correlated the chromatographic retention factor and the solubility data within the precision of the measurements. The model was applied in a pH range from 4 to 11. It was demonstrated experimentally, as well as theoretically, that an admixture of ethanol to the aqueous eluant changes the thermodynamic retention factor on various adsorbents identically when compared to the thermodynamic retention factor in an ethanol free eluant.