线粒体热化学研究──Ⅳ．鱼类肝脏线粒体代谢的微量热学研究

线粒体热化学研究──Ⅳ．鱼类肝脏线粒体代谢的微量热学研究谭安民，刘义，谢昌礼，屈松生，顾贫，邓凤姣（武汉大学化学系武汉４３００７２）（武汉大学生命科学院武汉）关键词鱼肝脏，线粒体，微量热学，热化学线粒体在能量代谢的过程中，除一部分能量用于合成ＡＴＰ外...     

三价铬与丙二酸形成的配合物的热解过程研究

利用热重分析及原位红外光谱等方法，定性、定量地研究了三价铬和丙二酸形成的配合物［Ｃｒ（Ｃ３Ｈ２Ｏ４）（Ｈ２Ｏ）］［Ｃｒ（Ｃ３Ｈ２Ｏ４）２（Ｈ２Ｏ）２］·４Ｈ２Ｏ的热解过程，提出了室温至４００℃下的详细热解途径．基于多种实验结果，分析了螯合物中六员环的化学键断裂方式，并由配合物的快原子轰击质谱（ＦＡＢ－ＭＳ）加以佐证．     

One-dimensional coordination polymers containing penta-supertetrahedral sulfide clusters linked by dipyridyl ligands

Three new one-dimensional coordination polymers [Zn8S(SC6H5)14.C12H10N2](1), [Zn7CoS(SC6H5)14.C13H14N2](2) and [Zn8S(SC6H5)14.C13H14N2](3) have been prepared containing penta-supertetrahedral clusters and linear crosslinking dipyridyl ligands; the two complexes show optical transitions with band gaps of approximately 3.44 eV (1) and approximately 3.54 eV (2).     

Binding of wogonin to human serum albumin: a common binding site of wogonin in subdomain IIA

The binding of wogonin to human serum albumin (HSA) has been studied by spectroscopic method including circular dichroism (CD), infrared spectra (IR) and fluorescence spectra. The fluorescence properties of HSA were examined in presence of wogonin and the fluorescence intensity of HSA was significantly decreased in the presence of wogonin. The binding parameters of wogonin were studied from the fluorescence decreasing of HSA by the fluoremetric titrations. The Stern-Volmer plots indicated that the binding of wogonin to HSA at 296, 303, 310 K is characterized by one binding site with the binding constant K(S-V) at 1.872 x 10(5), 1.561 x 10(5), 1.392 x 10(5), respectively, which are good agreement with the results from the Scatchard plots. The binding process was exothermic, enthalpy driven and spontaneous, as indicated by the thermodynamic analyses, and the major part of the binding energy is hydrophobic interaction, which were consistent with the result of molecule modelling study, and there are also a numbers of hydrogen bonds between wogonin and HSA. Furthermore, the displacement experiments indicate that wogonin can bind to the subdomain IIA, that is, the site I of HSA, which is also good agreement with the result of molecule modelling study.     

Quality evaluation of fingerprints of herbal medicine with chromatographic data

In this study, local least squares (LLS) and principal component analysis (PCA) were applied to deal with the disturbances in a data set of chromatographic fingerprints after necessary data transformations. It has been demonstrated that PCA with standard normal variate (SNV) transformation of data led to meaningful classification of 33 different Erigeron breviscapus herbal samples. The result was also corroborated by variance squares discriminant method. The quality of herbal objects was further evaluated, and the causes of this fact have been explained from a chemical point of view. At the same time, it implied an idea for qualitative evaluation of the herbal objects with a common class pattern of chromatographic fingerprints.     

SnO2TiO2 复合半导体纳米薄膜的研究进展

本文概述了SnO₂TiO₂ 复合半导体纳米薄膜的发展历史和研究现状,对比分析了“混合”、“核壳”和“叠层”3 种复合薄膜的结构和性能特点,着重论述了叠层结构的SnO₂ /TiO₂复合薄膜的光电化学和光催化特性。结合作者的研究工作,探讨了SnO₂ /TiO₂双层复合薄膜上下层厚度对其光催化活性的影响,指出复合薄膜光催化活性的提高可归因于电子从TiO₂ 向SnO₂ 的迁移。最后对SnO₂ /TiO₂复合薄膜的局限性和发展潜势做一简要分析,强调了该复合薄膜本身的应用特点。     

A new approach to phosphoserine and phosphothreonine analysis in peptides and proteins: chemical modification,enrichment via solid-phase reversible binding,and analysis by mass spectrometry

beta-Elimination of the phosphate group on phosphoserine and phosphothreonine residues and addition of an alkyldithiol is a useful tool for analysis of the phosphorylation states of proteins and peptides. We have explored the influence of several conditions on the efficiency of this PO(4)(3-) elimination reaction upon addition of propanedithiol. In addition to the described influence of different bases, the solvent composition was also found to have a major effect on the yield of the reaction. In particular, an increase in the percentage of DMSO enhances the conversion rate, whereas a higher amount of protic polar solvents, such as water or isopropanol, induces the opposite effect. We have also developed a protocol for enrichment of the modified peptides, which is based on solid-phase covalent capture/release with a dithiopyridino-resin. The procedure for beta-elimination and isolation of phosphorylated peptides by solid-phase capture/release was developed with commercially available alpha-casein. Enriched peptide fragments were characterized by MALDI-TOF mass spectrometric analysis before and after alkylation with iodoacetamide, which allowed rapid confirmation of the purposely introduced thiol moiety. Sensitivity studies, carried out in order to determine the detection limit, demonstrated that samples could be detected even in the low picomolar range by mass spectrometry. The developed solid-phase enrichment procedure based on reversible covalent binding of the modified peptides is more effective and significantly simpler than methods based on the interaction between biotin and avidin, which require additional steps such as tagging the modified peptides and work-up of the samples prior to the affinity capture step.     

磺酰脲类除草剂的三维药效团模型

磺酰脲类除草剂是七十年代末期[1，2]开发的一类超高效除草剂，杀草谱广，用量极低．它通过抑制植物体内乙酰乳酸合成酶（ALS，acetolactatesynthase）的活性[3]，破坏支链氨基酸缬氨酸、亮氨酸和异亮氨酸的合成，造成杂草的死亡．本文从三维角度出发，利用先进的三维分子设计软件APEX（ActivityPredictionExpertSystem）－3D[4]，建立破酸豚类除草剂药效团模型（biophoremodel），辅助设计、筛选活性化合物；再由药效团构造出模拟ALS酶活性位点（activesites）的空间结构，以该模拟结构为基点，以期设计出全新结构的ALS酶抑制剂的…     

缓慢炭化部分氧化对制备煤质活性炭的影响

研究了炭化升温速度、炭化低温区引入空气部分氧化对活性炭制备过程中炭化阶段、炭化物结构、活性炭性能等的影响。结果表明，炭化时低温部分氧化可提高炭化物得率，使炭化物微晶的ｄ００２值升高和Ｌｃ值减小；而较慢的炭化升温速度有利于制备优质活性炭。缓慢炭化、部分氧化可以在一定程度上控制炭化路径，使炭化向生成取向性差、难石墨化、各向同性、呒定形炭多的炭化物的方向进行；并讨论了它们控制炭化的作用机理。以此为指导，     

电化学法测定几种稀土贮氢合金的热力学函数

贮氢材料由于能可逆地吸放氢,得到了广泛地应用.特别是以贮氢材料为负极制成的氢镍二次电池,容量为同类型镉镍电池的1.5～2倍,且电压又相近,是镉镍电池的理想换代产品,受到人们普遍的关注。LaNi_(4.5)Mn_(0.5),LaNi_(4.9)Sn_(0.1)和La_(0.8)Nd_(0.2)Ni_(2.5)Co_(2.4)Al_(0.1)是电化学性能较优越的贮氢合金。LaNi_(4.5)Mn_(0.5)的电化学容量高,理论容量可达400mAh.g~(-1).LaNi_(4.9)Sn_(0.1)和La_(0.8) Nd_(0.2)