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.     

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.     

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     

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。     

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.     

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.     

Sensitivity of drainage and imbibition to pore structures as revealed by computer simulation of displacement process

This work concerns the effects of the properties of porous media on two phase fluid displacement at slow rates. These properties include the size frequency distributions, shape and connectivity of pores and throats, the size correlation of directly connected throats and pores and the spatial arrangement of pores and throats in porous media. Computer simulations using 3-dimensional networks of pores and throats were used to determine the effects of these properties on the form of primary and secondary drainage curves, imbibition curves and scanning loops of a capillary pressure diagram.The application of the results is in deriving information about the structure of a porous medium from capillary pressure curves and understanding how predictions about the form of relative permeability curves can be made from capillary pressure curves.The concepts of finite and infinite throat and pore controlled domains are applied during the filling and emptying of a network. These concepts are then combined with considerations of the accessibility of network sites to non-wetting phase or wetting phase sources and sinks to provide information about the amounts and distribution of continuous and discontinuous wetting phase (wp) and non-wetting phase (nwp) at any stage of a displacement. The distribution of fluids Is strictly controlled by the domains. It is shown that recognition of the types, abundance and distribution of domains provides a fundamental basis for understanding boundary effects, differences in tortuosity in porous systems containing two immiscible phases, breakthrough pressures, and saturations, differences in nwp withdrawal efficiency between uncorrelated and correlated pore-throat size models, differences in hysteresis between drainage and imbibition and differences in the shapes of capillary pressure and relative permeability curves for various types of porous structures.     

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).     

数字生产力的性质与应用

数字生产力是人类应用数字技术于国民经济活动的生产能力,数字生产力为数字经济提供生产要素和发展动能。数字生产力是先进的科技生产力,是工业社会数字化阶段的标志,是信息科学与数字技术的综合体。数字生产力是生产力要素即劳动者、劳动资料和劳动对象“三位一体”的数字化;数字生产力应用是数字技术与生产力要素融合,实施数字化劳动的过程。数字生产力应用具有专用性和通用性、虚拟性和平台化、共享性和分享性、赋能性与节能性、预测性和精准性,以及“比特”与“原子”共存等特点。数字生产力的劳动应用,表现为数字技术与劳动者、劳动资料和劳动对象有机融合的数字化劳动和新价值创造过程。数字生产力的产业应用,表现为数字农业、数字工业和数字服务业兴起和价值创造。数字生产力的发展是经济增长和国际竞争的关键。     

中药指纹图谱学体系在中药创制中的作用

从整体论、系统论和复杂科学的角度论述了中药指纹图谱学体系的构成背景和核心任务。中药指纹图谱学体系具有体系科学性质,是从系统性和整体性角度研究中药(包括植物药)的物质基础和作用机制以及药代动力学规律和相关制剂技术的崭新学科。该体系以中药指纹图谱信息学为核心和桥梁,包括中药指纹图谱测试学、中药指纹图谱质控学、中药指纹图谱谱效学、中药指纹药物动力学、中药指纹药剂学和中药生物指纹图谱学。该体系的研究需采用复杂科学和体系科学的理论和方法,突破线性思维和还原分析,强调宏观和系统的有机综合,应用数学科学原理和方法来开辟中药创制的新模式。中药指纹图谱学的理论体系和方法是解析中药的主导技术和实现中药现代化的核心力量,该体系理论和技术的成熟及完善可为现代中药创制提供强有力的理论和技术支撑。中药指纹图谱学体系的最终目的是为人类和有益生物研制出疗效显著、安全、可控的现代化中药。     

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.     

“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。     

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.     

剌梨利康饮对汞中毒大鼠汞铜锌含量的影响

用高汞水喂养大鼠８周,复制出慢性汞中毒模型,再分别自由饮用利康饮饮料和腹腔注射二巯基丙磺酸钠３周,探讨剌梨利康饮和二巯基丙磺酸钠对慢性汞中毒大鼠体内汞、铜、锌含量的影响。结果显示：慢性汞中毒引起血清、肝、脑和肾中汞含量升高的同时,引起血清、脑和肾中铜、锌含量及肝中锌含量降低;利康饮可降低血清和肾中汞含量,并可提高血清、脑和肾中铜、锌含量及肝含量;二巯基丙磺酸钠虽可降低血清、肝和肾中汞含量,升高血清     

论古希腊罗马善恶观的生成与理论建构

溯源法是道德发生学的主要方法。用溯源法考察古希腊罗马感性善恶观的源流,可以发现,荷马时代的希腊人已经生成一种以善恶观念为基本工具的道德判断模式,有了自己的感性善恶观。诗人荷马和赫西俄德将这两种道德观念具体化,对众多行为提出道德判断和评价,进而提出道德训诫,从而使他们的作品发挥道德教化的作用。希腊早期和古典时期哲学家的善恶观表明,理性思维的诞生为希腊伦理思想的发展提供了助力。历代哲学家不断地对荷马、赫西俄德式的感性善恶观进行理性加工,在此基础上发展出理论形态各异的理性善恶观。理性善恶观在希腊化时期和罗马帝国时期继续扩展和传承,形成内容和结构各异的理性善恶观。     

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.