微流控芯片毛细管电泳在蛋白质分离分析中的应用研究进展

重点介绍了近年来国内外在微流控芯片毛细管电泳法用于蛋白质分离分析方面的研究进展。按照分离模式的不同,综述了各种应用于蛋白质分离的微流控芯片毛细管电泳系统,讨论了抑制芯片中的蛋白吸附的各种方法,并展望了芯片毛细管电泳系统在蛋白质分离领域的发展前景。引用文献47篇。     

The evaluation and use of properties of individual ions in slution

A critical examination is given of extra-thermodynamic methods for evaluation of properties of individual ions in solution. The ways in which such data may be applied, or are required in various problems concerning specific properties of electrolyte solutions and in the fields of kinetics, electrochemistry, colloid and interfacial chemistry, are outlined. Special attention is given to the problem of evaluation of individual ionic thermodynamic functions for the hydration of ions but, in some cases, corresponding data for nonaqueous solutions are available for discussion and are of interest in a comparative way. The reliability of the various methods is assessed and estimates of numerical values for various individual ionic functions are tabulated. The question of scales of individual ionic radii, on which some of the derived data depend, is also examined. The dependence of various properties for anions and for cations on ionic radius is discussed and data are plotted comparatively. It is shown that for most, but not all, properties, the values for anions are more sensitive to increasing ionic radius than are the values for cations. This behavior, as well as the exceptions, is of theoretical interest. The significance of ion-specific behavior at interfaces is considered and the importance of interactions between ions of like sign of charge is indicated.Presented at the Symposium on Electrolytes, University of Reading, September 13, 1977.     

水、甲醇和乙醇液体微结构性质的Car-Parrinello 分子动力学模拟

采用Car-Parrinello 分子动力学(CPMD)方法分别研究了水、甲醇和乙醇的液体微结构性质.研究结果显示:在水、甲醇和乙醇三个体系中O…O径向分布函数曲线的第一个峰位置分别为0.278、0.276 和0.275nm; O…H径向分布函数曲线的第一个峰位置分别为0.178、0.176和0.177 nm.表明基团(氢原子、甲基、乙基)的差异对O…O第一个峰的位置影响很小.但基团的差异对径向分布函数峰高的影响却很显著,由水到乙醇第一个峰的高度逐渐变高.空间分布函数表明氧原子和氢原子在溶剂分子周围有取向地分布,这与径向分布函数所表现出尖锐的第一个峰相一致.氢键分布分析显示,水、甲醇和乙醇的平均氢键数分别为3.62、1.99 和1.87,表明水形成了网状氢键结构,而甲醇、乙醇形成链状氢键结构.     

Intralaboratory Quality Control of Chemical Analysis with Reference Materials at Disposal

In this problem-oriented article, regarding the author's experience, a review of the methods of intralaboratory quality control based on systematic analysis of reference samples (control materials) is given. The requirements imposed on reference samples are briefly considered. The principles of selection of an inspection plan and the requirements on the evaluation period of statistical characteristics are formulated. The techniques for graphically representing the results of intralaboratory control and the algorithms for detecting out-of-control analytical processes are considered. Control charts for average values and ranges or charts for cumulative sums and geometric (exponentially weighted) moving averages are recommended as the main or auxiliary graphical representation, respectively. Westgard rules and the simplest rules for ranges are recommended as the main algorithms for revealing out-of-control analytical processes. Multivariate statistical process control methods, which are recommended for use in the cases of a great number of simultaneously determined factors, are briefly discussed.     

Solvation and Intermolecular Exploration of Drug Molecule Fragments

The paramagnetic contributions from dioxygen to solute proton spin-lattice relaxation rate constants are reported for a series of aromatic hydrocarbons and drug molecule fragments, in order to examine the energetic factors for intermolecular exploration in solution. The measurements provide differences in local oxygen concentration at different sites on the solute molecule. The relaxation rate differences caused by steric factors are taken into account using a lattice model calculation to normalize the relaxation rates for intermolecular contact. The measurements reveal small differences in oxygen accessibility for aromatic solutes in aqueous acetone and for aliphatic drug fragments in chloroform. Larger differences are observed for aliphatic protons in dimethyl sulfoxide; however, the differences are generally small compared with previous measurements on amino acids in water. Concentration ratios between local oxygen concentrations and the solvent references are all smaller than 2.2 and high local concentrations are favored by bulky adjacent groups such as alkane chains.     

Anodic Behavior of Nickel-Chromium Alloys in Sodium Chloride Solutions: Pitting and Transpassivity

Anodic potentiodynamic and chronoamperometric curves on nickel-chromium alloys (2–50 wt % Cr) are obtained in NaCl solutions at various concentration, pH, and temperature. The dependences of pitting and repassivation potentials on the concentration and temperature are determined for alloy with 20 wt % Cr. The effect of the Cr content and pH on the anodic behavior of the alloys, in particular, the transition from a pitting breakdown of passivity to transpassivation, is shown. Quantitative time dependences of the current in the passive range are obtained and the steady-state values of this current are determined. The corrosion potential of the alloy with 20 wt % Cr is measured. Cathodic voltamograms for passive and chloride-ion-activated surface of the alloy are obtained.     

Theoretical study of methane adsorption and C─H bond activation over Fe-embedded graphene: Effect of external electric field

The effect of an external electric field (EF) on the methane adsorption and its activation on iron-embedded graphene (Fe-GPs) are investigated by using the M06-L density functional method. The EF is applied in the perpendicular direction to the graphene in the range of −0.015 to +0.015 a.u. with the interval of 0.005 a.u. The effects of EF on the adsorption, transition state and product complexes of the methane activation reaction are revealed. The binding energies of methane on Fe site in Fe-GPs are increased from −12.9 to −15.3, −18.1 and −21.5 kcal/mol for the negative EF of −0.005, −0.010 and −0.015, respectively. By applying positive EF, the activation barriers for methane activation are reduced in range of 3–8 kcal/mol (around 12–31%) and the reaction energies are more exothermic. The positive EF kinetically favors the reaction compared to the system without EF. The adsorption and activation of methane on Fe-GPs can be easily tuned by adjusting the external electric field for various applications. © 2019 Wiley Periodicals, Inc.     

A review on butanol steam reforming for renewable hydrogen production

Butanol is a renewable bio-oxygenate that can be prepared by fermentation of lignocellulosic biomass. Steam reforming of bio-derived butanol is an attractive and feasible option for producing renewable hydrogen. In the present work, all the studies on butanol steam reforming are reviewed comprehensively. The thermodynamics for the reaction, the optimized reaction conditions such as temperature, pressure, steam to carbon (S/C) ratio and the innovations in catalyst designs are described in depth. Based on the type of catalyst and support, different reaction routes for butanol reforming are possible. Ni, Co, Rh and Pt catalyst are more appropriate for butanol reforming. The challenges associated in utilizing bio-butanol as feed and design of cost effective and coke resistant catalyst are discussed. Such discussions on butanol reforming are still missing and the present work will fill this gap.     

Applications of coulometric titration for studies of oxygen non-stoichiometry in oxides

This article gives a brief overview of the modern methods for in situ studying of oxygen non-stoichiometry in oxides. The emphasis is on the techniques that are based on the use of transport properties of solid electrolytes with unipolar oxygen ion conductivity, as well as on the experimental implementation of coulometric titration. The possible sources of experimental errors are considered, and methods are discussed of their accounting and minimization. Several examples are given of the using of the data on non-stoichiometry for the determination of thermodynamic properties and defect structure in oxides.     

The fundamentals of adsorption theory for a mixture of bulky molecules in slit-shaped pores with heterogeneous wall surfaces

The fundamentals of the adsorption theory for a mixture of bulky molecules blocking more than one adsorption site on the surface in slit-shaped pores with heterogeneous wall surfaces are outlined. The adsorbate—adsorbate lateral interactions are taken into account in the quasi-chemical approximation and in the mean-field approximation. The expressions for the partial adsorption isotherms and for the binary coefficients of mixture separation and the way of isolation of the partial contributions of molecules on heterogeneous adsorption sites on pore walls are discussed. A simplified variant of adsorption theory for a binary mixture of molecules of different sizes in two-layer pores with the assumption of complete coverage of the pores is considered. The influence of the energy of binding of molecules to pore walls, lateral interactions, and the ratio of the component sizes on the shape of adsorption isotherms is analyzed. The results of calculations are compared with the experimental data for the benzene—CCl₄—microporous AC carbon adsorbent system.     

Structure and growth of self-assembling monolayers

The structural phases and the growth of self-assembled monolayers (SAMs) are reviewed from a surface science perspective, with emphasis on simple model systems. The concept of self-assembly is explained, and different self-assembling materials are briefly discussed. A summary of the techniques used for the study of SAMs is given. Different general scenarios for structures obtained by self-assembly are described. Thiols on Au(1 1 1) surfaces are used as an archetypal system to investigate in detail the structural phase diagram as a function of temperature and coverage, the specific structural features on a molecular level, and the effect of changes of the molecular backbone and the end group on the structure of the SAM. Temperature effects including phase transitions are discussed. Concepts for the preparation of more complex structures such as multi-component SAMs, laterally structured SAMs, and heterostructures, also with inorganic materials, are outlined. The growth and ways to control it are discussed in detail. Solution and gas phase deposition and the impact of various parameters such as temperature, concentration (in solution) or partial pressure (in the gas phase) are described. The kinetics and the energetics of self-assembly are analyzed. Several more complex issues of the film formation process including non-equilibrium issues are discussed. Some general conclusions are drawn concerning the impact of various molecular features on the growth behavior and concerning the relationship between growth and structural phase diagram. Finally, the potential of self-assembly as a route for the preparation of monolayers with pre-designed properties and SAMs as building blocks in heterostructures as well as application strategies are discussed.     

锂离子电池LiBOB电解质盐研究进展

本文介绍了可用于锂离子电池的新型锂盐--双乙二酸硼酸锂（LiBOB）的基本性质,包括结构组成、合成方法、物理化学性能及其与结构的关系。综述了近年来在LiBOB新型电解质锂盐研究与探索方面的新成果,重点评价了BOB-阴离子对于石墨负极和金属氧化物正极材料表面的电化学性能。讨论了这种盐在锂离子系中杂质和安全性等问题,归纳了其优缺点,指出今后电解质锂盐的研究发展方向。     

Crystal engineering as a scientific basis for modification of physicochemical properties of bioflavonoids

Flavonoids are of interest for pharmacy and medicinal chemistry due to a wide range of biological activities. The major goal for the design of new drugs based on flavonoids is to increase bioavailability of pharmaceutical substances. Crystal engineering is a useful tool for this purpose. This review presents a systematic analysis of the publications on crystal engineering of flavonoids published between 2000 and 2019. The data on objects, methods of supramolecular synthesis, analysis, and preclinical studies of its products are summarized. The trends in crystal engineering of flavonoids are considered and promising areas for further research are identified. The review may be of interest for researchers engaged in the design of drugs with low bioavailability, including bioflavonoids.

     

二(口恶)英类化合物分析研究进展

介绍了同位素稀释气相色谱与质谱联用和生物检测法测定二恶英类化合物的研究进展，概述了国际通用的二恶英类标准分析方法体系，综述了我国二恶英类化合物分析的研究现状并对我国开展二恶英类分析检测提出了建议和展望。     

TiO2光催化剂失活机理研究进展

评述了TiO₂多相光催化剂在处理环境污染物领域的催化剂失活研究进展,主要探讨了气固多相光催化反应过程影响催化剂活性的因素,液固多 相光催化反应的催化剂失活的几种途径,以及解决催化剂失活问题的办法,最后对该领域的研究提出建议.     

Second quantization for systems with a constant number of particles in the Dirac notation

The relation between the completeness condition for an appropriate one-particle basis set and the occupation number representation (second quantization) is shown for the time-independent case. The explicit expressions for the basic symmetric operators are derived in the Dirac bra–ket notation. The physical meaning of these operators, the algebra as well as the connections with the one-electron density matrix and with the projector on the Fermi sea in the one-electron approximation, follow directly from these expressions. The generalization for a nonorthogonal basis and the algebra for corresponding basic operators are formulated. The connection with the notion of the molecular diagrams of different kinds for the nonorthogonal atomic orbitals is shown. The Mulliken populations and the Chirgwin–Coulson bond orders are equal to the diagonal and offdiagonal elements of the molecular diagram 1, respectively. The matrix elements of the projector on the Fermi sea in the one-electron approximation in the representation of nonorthogonal atomic orbitals are elements of the molecular diagram 2.     

稀土药用研究的动向和问题

人们对稀土药用的兴趣普遍增加。最近Chemical Society Reviews在2006年第6期刊登了镧系元素药用研究专刊,专门介绍稀土药用研究的现状。针对该专刊和稀土药用研究的现状,作者讨论了稀土化合物药用研究的发展动向,特别讨论了需要解决的关键基础问题。从新药研究模式的转变得到启发,提出如何把负面生物效应转化为药理作用,如何从干预细胞信号网络入手进行研究,如何处理活性与毒副作用的关系,以及药物合理设计的策略等。     

THERMODYNAMIC STUDY OF ADSORPTION OF PHENOLIC COMPOUNDS FROM AQUEOUS SOLUTION BY A WATER-COMPATIBLE HYPERCROSSLINKED POLYMERIC ADSORBENT

Equilibrium data for the adsorption of phenolic compounds, i.e., phenol, p-cresol, p-chlorophenol and p-nitrophenol from aqueous solutions by a water-compatible hypercrosslinked polymeric adsorbent (NJ-8) within temperature range of 283-323 K were obtained and correlated with a Freundlich-type of isotherm equation, so that equilibrium constants KF and n were obtained. The capacities of equilibrium adsorption for all the four phenolic compounds on the NJ-8 from aqueous solutions are around 2 times as high as those of Amberlite XAD-4, which may be attributed to the unusual micropore structure and the partial polarity on the network. The values of the enthalpy (always negative) are indicative of an exothermic process, which manifests the adsorption of all the four phenolic compounds on the two polymeric adsorbents to be a process of physical adsorption. The negative values of free energy change show that the solute is more concentrated on the adsorbent than in the bulk solution. The absolute free energy values of adsorption for NJ-8 are always higher than those for Amberlite XAD-4, which indicates that phenolic compounds are preferentially adsorbed on NJ-8. The negative values of the adsorption entropy are consistent with the restricted mobilities of adsorbed molecules of phenolic compounds as compared with the molecules in solution. The adsorption entropy values of phenolic compounds for NJ-8 are lower than those for Amberlite XAD-4, which means the micropores of NJ-8 require more orderly arranged adsorbate.