Contributions to the Chemistry of the Binary Compounds of the Transition Elements

Phase and structural relationships of the sulfur, selenium, and tellurium compounds of the 4d and 5d transition elements of groups IV to VII of the periodic system are discussed. Homologous elements behave very similarly with respect to the chalcogens, and this is particularly the case for niobium and tantalum, and for molybdenum and tungsten. However, zirconium, niobium, and molybdenum have a greater tendency towards formation of chalcogen-poor phases than their homologues hafnium, tantalum, and tungsten. Subchalcogenides are known only for zirconium and niobium. The number of phases and the tendency towards formation of solid solutions are considerably smaller among the tellurides than among the sulfides and selenides. The crystal structures of the telluride phases also differ from those of the sulfide and selenide phases of analogous composition. In addition, a review of the phase and structural relationships of the arsenic and antimony compounds of the 4d and 5d transition elements of groups V to VII is given.     

Epimerization and racemization of some chiral drugs in the presence of cyclodextrin and liposomes

The effects of alpha-, beta-, gamma- and dimethyl-beta-cyclodextrins (alpha-, beta-, gamma- and DM-beta-CyDs) and liposomes on epimerization or racemization of etoposide, ethiazide and carbenicillin were examined kinetically. alpha- and beta-CyDs accelerated both epimerization and hydrolysis of carbenicillin. They had no effect on epimerization of etoposide, and did not affect racemization and hydrolysis of ethiazide. DM-beta-CyD retarded epimerization of etoposide, hydrolysis of picroetoposide (which is an epimer of etoposide), and racemization and hydrolysis of ethiazide, but had no effect on epimerization and hydrolysis of carbenicillin. gamma-CyD retarded epimerization of etoposide and hydrolysis of picroetoposide. On the other hand, gamma-CyD accelerated epimerization of carbenicillin. It is suggested that the formation of inclusion complexes between CyDs and etoposide, picroetoposide and ethiazide inhibited the attack of bases such as OH- and buffer components, thereby retarding epimerization, racemization and hydrolysis. On the other hand, alpha-, beta- and gamma-CyDs increased the reactivity of carbenicillin through the OH group, accelerating its epimerization and hydrolysis. Liposomes retarded epimerization of etoposide, hydrolysis of picroetoposide and racemization of ethiazide. Liposomes did not affect epimerization and hydrolysis of carbenicillin. These differences in the effect of liposomes on reactivity may be interpreted in terms of the solubility of the drugs.     

Application of radioisotope XRF for the determination of noble metals in aqueous solutions

Radiometric methods of determination of platium and palladium (0.1 to 5% of Pt and 0.1 to 2% of Pd), gold and indium (0.01 to 1% of Au and 1 to 4 g In/l) and of platinum and rhodium (0.1 to 9% of Pt and 0.05 to 1% of Rh) in aqueous solution has been worked out. A suitable measuring device has been designed and constructed. The methods are based on the measurement of characteristic radiation of the L_α line for gold and platinum and of the K-series for indium, palladium and rhodium, as well as on the measurement of scattered radiation from a²³⁸Pu source. The r.m.s. error of the determination varies from 0.01 to 0.10% of Pt, 0.002 to 0.01% of Au and 0.01 to 0.15% of Pd depending on the concentration. In the case of Rh and In the errors are 0.008% and 0.04 g In/l, respectively.     

视网膜脱离后PVR的形成与氧自由基和锌、铜关系的研究

为探讨氧自由基和锌、铜在视网膜脱离后增殖性玻璃体视网膜病变 (PVR)中的作用 ,收集了 48例视网膜脱离患者视网膜下液 (SRF) ,利用紫外分光光度计测定了SRF中LPO的含量和SOD的活性 ,用原子吸收光谱法测定了Zn、Cu的含量。结果表明 ,随着PVR程度及玻璃体浑浊的加重、病程的延长 ,LPO含量增加 ,SOD活性明显下降 ,P <0 0 5 ,差异有统计学意义。提示SRF中LPO、Zn、Cu含量及SOD活性的改变与视网膜脱离后PVR的发生、发展有密切关系。     

Some problerns in adsorption and calorimetric studies of the steps of catalytic processes

Principal side factors as well as technical and procedural peculiarities capable of distorting the results of measurements of adsorbed and desorbed amounts, of falsifying the nature of the processes proceeding in the systems under study, and of promoting artifacts in calorimetric and other studies of gas chemisorption on powders are considered. Modified techniques and procedures allowing the elimination of sources of side phenomena and artifacts and freeing traditional glass static adsorption apparatuses and experimental procedures from undesirable factors and peculiarities are proposed. Some available chemisorption and calorimetric data representing artifacts and also some data that are not artifacts but, due to imperfections of chemisorption techniques, show up as artifacts are presented and discussed. Several applications of the improved techniques and procedures to calorimetric and adsorption studies of the steps of catalytic processes proceeding on the basis of natural gas and of products of its pr     

Advancing the Drug Discovery and Development Process

The current state of affairs in the drug discovery and development process is briefly summarized and then ways to take advantage of the ever‐increasing fundamental knowledge and technical knowhow in chemistry and biology and related disciplines are discussed. The primary motivation of this Essay is to celebrate the great achievements of chemistry, biology, and medicine and to inform and inspire students and academics to enter the field of drug discovery and development while, at the same time, continue to advance the fundamentals of their disciplines. It is also meant to encourage and catalyze multidisciplinary partnerships between academia and industry as scientists attempt to merge their often complementary interests and expertise to achieve new improvements and breakthroughs in their respective fields, and the common goal of applying them to the discovery and invention of new and better medicines, especially in areas of unmet needs.     

聚合物光老化、光稳定机理与光稳定剂(下)

大多数聚合物材料,包括塑料、橡胶、纤维、涂料等,在户外使用时会发生光老化而使使用寿命缩短。为有效防止聚合物材料的光劣化,人们已对聚合物的光老化和光稳定机理进行了广泛的研究并先后研发出了几个类型的光稳定剂。但由于户外应用范围不断扩大和环境不断恶化正使聚合物的光老化变得越来越复杂而光防护难度也日益加大,因此国内外有关聚合物光老化、光稳定机理的研究和光稳定剂的研发一直十分活跃。本文下篇阐述光稳定剂的作用机理并综述光稳定剂的研发进展。     

Studies of surface properties of pure and modified by Mn<Superscript>2+</Superscript> and Ni<Superscript>2+</Superscript> ions of aluminium oxide samples using complex methods

Complex studies of physicochemical properties of pure and modified of aluminia oxides samples are presented. The presence of Mn²⁺ and Ni²⁺ modifiers on the aluminium oxide surface causes increase in water adsorption capacity and decrease in benzene and n-octane adsorption. This is due to decrease of specific surface area, volume and radius of pores as a result of surface impregnation and microcrystal formation during modification with manganese and nickel chlorides. Microcrystal formation on the surface and porosity decrease as confirmed by AFM, EDX and powder diffraction studies using automated diffractometer by step scanning. From the Q-TG and Q-DTG data, the energies of liquid desorption from the surface of the samples and the functions of desorption, energy distribution were calculated. High degree of nonlinearity of the functions resulting from great heterogeneity of the studied surface was found. Adsorption of cations creates more homogeneous surface in aluminium oxide, and it is responsible for the change in adsorbate molecule interaction energy and changes mechanism of adsorption and desorption as well as thickness and structure of the adsorbed film. From the experimental data some parameters characterizing adsorption properties and porosity of the studied samples were determined using the complex measuring methods (thermal analysis, sorptometry, porosimetry, AFM and EDX).     

亚麻的化学组成和微观结构对染色性能的影响

本文通过X衍射法、纤维化学成分分析法测试了亚麻纤维的微观结构、化学成分，通过对亚麻进行液氨整理改变其结晶度和取向度，从而测得亚麻的结晶度和取向度对染色性能的影响，利用碱煮、H2O2和NaOCl漂白处理降低了亚麻中木质素和半纤维素的含量，从而测量得木质素和半纤维素含量对亚麻上染率的影响。结果表明亚麻的上染率随着结晶度的降低呈线性上升，随着取向度的降低而上升；随着木质素和半纤维素含量的降低而呈上升趋势。     

DABTZ as a new reagent for solid phase extraction and spectrophotometric determination of trace amount of Hg(II) in water sample

A novel sensitive and simple method for rapid and selective extraction, preconcentration and determination of mercury as its 2,2' diamino-4,4' bithiazole (DABTZ) complex by using octadecylsilica cartridges and spectrophotometry is presented. Extraction efficiency and the influence of flow rates of sample solution and eluent, pH, amount of DABTZ, type and least amount of eluent for elution of mercury complex from cartridges, break through volume and limit of detection were evaluated. Also the effects of various cationic and anionic interferences on percent recovery of mercury were studied. Average extraction efficiency > 90% was obtained by elution of the cartridge with minimal amount of solvent in the presence of interferences. A preconcentration factor of 152 and a detection limit of 10.92 ng mL(-1) were obtained. The method was applied to the recovery and determination of mercury in different water samples.     

作为一种城市研究范式的“都市马克思主义”

非马克思主义者由于不能以实践的观点和辩证的观点理解城市而无法发展出一种总体性的城市理论。马克思和恩格斯虽然提供了以历史唯物主义分析城市问题和都市形式的线索,但也引发了“城市中的社会”研究还是“城市社会”研究的争论。随着人类城市化进程的不断深化,理论和实践两方面的诉求使澄清作为一种城市研究范式的“都市马克思主义”成为当前之需。马克思主义探究的社会现实是人类生产自己生活方式的具体的总体,而城市是人类生产自己生活的一定方式,因此研究城市必须将其放置于人类生产活动构成的社会总体之中。当今时代,都市已成为人类生产自己生活的自觉方式和社会历史发展的主导性构成。作为城市研究的马克思主义范式和马克思主义的当代哲学范式,都市马克思主义以包含着丰富矛盾性的“都市”为理论总问题,以实践的观点辩证地理解和揭示现代世界的都市现实,是一种微观视域和宏观视域相结合,真正探究现实的人的生存状况、生存矛盾、生活方式和生活意义的社会历史理论。具体来说,它致力于建构都市的社会历史解释模式,展开都市政治经济学批判和都市文化批判,提供与人类解放实践相连的都市革命理论。     

Effective Ionic Radii and Hydration Volumes for Evaluation of Solution Properties and Ionic Adsorption

Evaluation of effective ionic radii and corresponding individual hydrated-ion volumes provides data required for interpretation of various ion-specific solution properties and for understanding of specificity of ion adsorption at electrode and colloid interfaces. Principles involved in assignment of intrinsic ionic radii and hydrated-ion volumes are comparatively reviewed and examined as a basis for discussion of electrostriction volume changes. Three examples are given of applications of procedures for evaluation of individual hydrated-ion radii and volumes: (a) partial molal volumes and isentropic compressibilities of a series of oxyanions of various structures; (b) steric effects in hydration of alkylammonium and pyridinium cations; and (c) role of ion-hydration effects in specificity of chemisorption of electron donative anions at electrode surfaces.     

Impact of the physical and topographical characteristics of adsorbent solid-phases upon the fluidised bed recovery of plasmid DNA from Escherichia coli lysates

A comparison is made of the performance of two types of adsorbent solid phases (commercially sourced Streamline composites and custom-assembled Zirblast pelliculates), derivatised with similar anion exchange chemistries and applied to the recovery of plasmid DNA from Escherichia coli extracts prepared by chemical lysis and coarse filtration. Streamline and Zirblast adsorbents were characterised by average particle diameters of 200 and 95 microm, densities of 1.16 and 3.85 g/m2, and small ion capacities of 170 and 8 micromol/ml settled adsorbent, respectively. Detailed analysis of products and impurities in a full operational cycle of adsorption, washing, pre-elution, elution and regeneration processes was enabled by the harnessing of a battery of analyses for nucleic acid and organic solute content of feedstocks and bed effluents exploiting ultra-violet spectrophotometry, agarose gel electrophoresis and specific reactions with the fluorescent probe PicoGreen. In comparative tests operated under near identical conditions, Streamline and Zirblast adsorbents exhibited plasmid recoveries of 76 and 90% of bound product characterised by purity ratios (relative PicoGreen and A254 estimates of mass) of 9 and 32, respectively. Conclusions are drawn regarding the specific impact of the physical and topographical characteristics of solid-phase geometry upon product throughput, achievable product purity, process time-scales and operational economics for the manufacture of plasmid DNA.     

Measurement of protein-DNA interaction parameters by electrophoresis mobility shift assay

Native gel electrophoresis (mobility shift) assays may be used to obtain quantitative information about the site distribution, equilibria and kinetics of protein-DNA interactions. These applications depend on the ability of the electrophoretic system to resolve the reaction components, and on their stabilities during the separation process. Factors which affect the lifetimes and mobilities of protein-DNA complexes during electrophoresis include reaction and electrophoresis buffer composition, pH, and ionic strength; the presence of low molecular weight effectors and enzymatic substrates; the nature and concentration of the gel matrix; the temperature; the molecular weights of protein and DNA; the stoichiometric ratios of their complexes; and the possibility of conformational and configurational isomerization of reaction components. We discuss how these factors influence the acquisition of quantitative data from electrophoretic patterns and band intensities, and present formulas for the estimation of equilibrium constants and rate constants for prototypical DNA-protein interactions.     

质谱实验室大型仪器设备开放共享的实践与探索

介绍了大型仪器公共平台质谱室大型仪器设备的开放共享,包括各项制度的建立,开放使用运行模式的探索与实践,以及有偿共享的经验与成果.最后总结了开放共享的成效和存在的问题.     

Virtual screening of organic molecule databases. Design of focused libraries of potential ligands of NMDA and AMPA receptors

A system of virtual screening of organic molecule databases is designed, which permits preprocessing of databases, molecular docking to a three-dimensional model of receptor, and post-processing of the results obtained. Using this screening system, it is possible to reproduce positions of the known ligands in the glutamate sites of the NMDA and AMPA receptors and in the glycine site of the NMDA receptor, to substantially enrich the database with potentially active compounds, and to distinguish between the agonistic and antagonistic character of the action of these compounds in the case of docking to the open and closed forms of the binding sites. Based on the results of screening of a database of low-molecular-weight organic compounds (total of 135,000 structures) using models of the open and closed forms of the glutamate and glycine sites of the NMDA receptor and of the glutamate site of the AMPA receptor, focused libraries of potential agonists and antagonists of these sites were designed.     

Charge number effect on the miscibility of inorganic salt and surfactant in adsorbed film and micelle: inorganic salt-octyl methyl sulfoxide mixtures

Adsorption and micelle formation of a surfactant in the presence of inorganic salts with different charge numbers of cations were investigated from the viewpoint of mixed adsorption and micelle formation of salt and surfactant. Surface tension of aqueous solutions of the mixtures of octyl methyl sulfoxide (OMS) with calcium chloride and lanthanum chloride was measured as a function of the total molality of the mixture and the mole fraction of OMS in the mixture at 298.15 K under atmospheric pressure. Composition of the adsorbed film and micelle was numerically evaluated from the dependence of the total molality at a given surface tension and the mixture CMC on the bulk composition to draw phase diagrams of adsorption and micelle formation. Judging from the phase diagrams together with the ones of the sodium chloride system, miscibility of inorganic salt and OMS in the adsorbed film and micelle increases with an increase in the charge number of inorganic cation, which is attributable to the attractive interaction between inorganic cation and the polar head group of OMS molecule in the adsorbed film and micelle.     

“治气”与“养心”：荀子身心修炼的功夫论

荀子的功夫论有两个方面：一是功夫实践所指向的理想人格;一是作为功夫实践具体方法的“治气养心之术”。就前者而言,荀子在继承孔、孟的“士”“君子”和“圣人”观念的基础上,提出了“士君子”和“大儒”的特有观念,同时明确界说了理想人格的不同层次与形态。后者作为身心修炼的过程,指“虚一而静”的“大清明”之“心”,经由“师法”的学习,透过“礼乐”的熏陶,对治自身的“气”“性”,以“得师”和“由礼”为根本环节。“心”由“得师”“隆礼”而“化性起伪”,呈现为一个由外而内的“锻造”过程。“气”指“血气”,包括自然欲望、生理本能以及心理情绪在内的身体方面。“心”是认知、判断和选择的能力,并没有道德之“善”的内容,即便是“虚一而静”的“大清明心”,本身也不以“善”为其固有内容。由于“师法”和“礼乐”都是心外的候选对象,“治气养心之术”需要面对“师”“礼”最初如何产生以及“得师”“由礼”能否必然的问题,成就理想人格也随之成为一种或然的选择和他律的结果。但即便如此,无论就个体还是大多数人的普遍实践而言,“得师”“由礼”的身心修炼更为切实可行,尤其对社会文明的建设来说,即便没有“仁义内在”的预设,也更具普遍的适用性和有效性。     

Some problems in adsorption and calorimetric studies of the steps of catalytic processes

Principal side factors as well as technical and procedural peculiarities capable of distorting the results of measurements of adsorbed and desorbed amounts, of falsifying the nature of the processes proceeding in the systems under study, and of promoting artifacts in calorimetric and other studies of gas chemisorption on powders are considered. Modified techniques and procedures allowing the elimination of sources of side phenomena and artifacts and freeing traditional glass static adsorption apparatuses and experimental procedures from undesirable factors and peculiarities are proposed. Some available chemisorption and calorimetric data representing artifacts and also some data that are not artifacts but,due to imperfections of chemisorption techniques, show up as artifacts are presented and discussed. Several applications of the improved techniques and procedures to calorimetric and adsorption studies of the steps of catalytic processes proceeding on the basis of natural gas and of products of its processing are presented and discussed.