金属酞菁化合物在TiO2表面的分散研究

Dispersion of copper(Ⅱ) phthalocyanine (CuPc), copper(Ⅱ) phthalocyaninesulfonate (CuPcS) and cobalt(Ⅱ)phthalocyaninetetrasulfonate (CoPcTS) on the surface of titanium dioxide was investigated by XRD, XPS, FT-IR and UV-Vis techniques. Results show that interaction between CuPc and TiO2 was very weak and CuPc was difficult to disperse on the surface of the support. While partly sulfurized CuPcS could be dispersed on the surface of support through sulfo-groups and its dispersion capacity was determined to be 0.085 g CuPcS/g TiO2. Completely sulfurlzed CoPcTS could also be dispersed on the surface of TiO2 as a monolayer and its dispersion capacity was 0.12 g CoPcTS/g TiO2. Interactions of the sulfo-groups as well as the electrons of CoPcTS with the surface of TiO2 could be evidenced by FT-IR characterization. Therefore, it was suggested that CoPcTS molecules be adsorbed on the surface of TiO2 in a flat-lying mode while CuPcS in a slanting one. UV-Vis spectra show that the dispersed CuPcS and CoPcTS molecules exist in both forms of monomers and dimers.     

A basket tetradecavanadate cluster with blue luminescence

A blue luminescent tetradecavanadate compound, [Et4N]5[V14O36Cl], has been synthesized. It possesses an unprecedented half-open basket framework. Through the {ABAB}-type stacking, the {V14O36} clusters form infinite one-dimensional channels with considerable accessible volume in the crystalline state.     

Uniformity of ionization response of structurally diverse analytes using a chip-based nanoelectrospray ionization source

The major drawback of liquid chromatography/mass spectrometry (LC/MS) for the analysis of mixtures is the non-quantitative nature of these studies. The ionization efficiency of the various components in the mixture (e.g., a compound and its metabolites) can vary greatly and, therefore, relative intensities of signals cannot be related to relative abundance. A chip-based nanoelectrospray ionization source was used to compare the ionization efficiencies of compounds with different physical-chemical characteristics. The data indicate that the ionization efficiencies vary much less with the chip-based device than by LC/MS. This was ascribed to the generation of a much higher electric field around the nozzles, which supplies a large excess of protons to the small droplets and reduces/eliminates the differences in the ionization efficiency for the analytes.     

基于核酸探针的光学传感方法和细胞成像研究

许多疾病的特征在于各种生物分子表现出的异常活性,这些物质通常在细胞内外显示过表达现象,因此对其灵敏靶向识别可以提供诊断和治疗效用。由于基因诊疗和化学传感技术的发展,用于灵敏检测细胞内外生物化学物质的核酸探针突显优势。核酸探针可以在稳定进入细胞的同时,特异性地结合目标物质,通过光学方法检测或通过成像技术标识出来。本文综述了采用光学传感方法和成像技术,基于核酸探针检测生物分子的新进展。根据检测对象进行分类,概括分析了几个代表性体系:核酸序列、蛋白质和酶、化学物质和物理化学条件,并详细阐述其关键设计原理、灵敏度及样品检测等结果,同时指出了各类核酸探针的优缺点。     

Simultaneous Determination of Oxytetra- cycline, Doxycycline, Tetracycline and Chlortetracycline in Tetracycline Antibiotics by High-Performance Liquid Chromatog- raphy with Fluorescence Detection

A simple, rapid and sensitive high-performance liquid chromatographic method with fluorescence detection for the simultaneous determination of oxytetracycline, doxycycline, tetracycline and chlortetracycline was developed, and successfully applied to the analysis of commercial tetracycline antibiotics. The separation was performed on a reverse-phase C₁₈ column with a gradient elution composed of methanol and sodium acetate buffer (containing disodium ethylenediaminetetraacetate and calcium chloride, pH 8.10) as the mobile phase, and fluorescence detection at 532 nm (excitation at 380 nm). The detection limits for oxytetracycline, doxycycline, tetracycline and chlortetracycline were 0.1, 0.5, 0.3 and 0.4 g L^–1, respectively. Data with respect to precision and accuracy were reported and discussed.     

Nanjiols D and E, Two New Uncommon Steroids from the Chinese Soft Coral Nephthea bayeri

Marine organisms have been found to be a storehouse of steroids, particularly in term ofunique side-chain structures and unusual functionalization. Marine steroids are oftenfound in highly oxygenated forms and possessing various biological activities1.Previously, we reported the isolation and structural elucidation of three new marinesteroids, nanjiols A-C, which showed cytotoxicity against HL-60 and BEL 7402 celllines, from a soft coral Nephthea bayeri in East China Sea2. In continuation …     

Agonist–PPARγ interactions: Molecular modeling study with docking approach

Docking simulation of 18 agonists with the ligand binding pocket (LBP) of PPARγ has been performed. The binding conformations and binding affinities of these agonists were obtained by use of the flexible docking protocol FlexX. Test compound calculations indicated that FlexX can reproduce the binding conformation of the crystal structure (root mean square deviation = 1.43 Å); moreover, the predicted binding affinities correlate well with the activities of these agonists. The interaction model and pharmacophore of PPARγ agonists were derived and the difference in biologic activities of these agonists can be well explained. The PPARγ agonists must have both polar head and the hydrophobic tail, which form hydrogen bonds and hydrophobic contacts with hydrophilic and hydrophobic regions of the LBP of PPARγ, respectively. In addition, a suitable linker is also necessary. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 405–410, 2003     

燃烧催化剂中LaAlO3作为第2载体的研究

在载体堇青石表面涂覆一层LaAlO3作为第二载体，用浸渍法制备负载型LaMnO3、LaCoO3等钙钛矿型燃烧催化剂时，发现能促进LaMnO3等活性相的生长，从而提高了二甲苯完全氧化的催化活性；对于负载型LaCo3O3催化剂，可避免因用γ－Al2O35作第二载体而生成的低活性CoAl2O4类尖晶石相，因而有利于提高催化剂的耐热性。     

17电子钒开环夹心羰基配合物的合成及XRD,IR,EPR研究

以４种甲基取代戊二烯基为配体合成了４个过渡金属钒开环夹心羰基配合物［２，４－（ＣＨ３）２Ｃ５Ｈ５］２ＶＣＯ（Ｉ），［２，３－（ＣＨ３）２Ｃ５Ｈ５］ＶＣＯ（Ⅱ），［２－ＣＨ３Ｃ５Ｈ６］２ＶＣＯ（Ⅲ）和［３－ＣＨ３Ｃ５Ｈ６］２ＶＣＯ（Ⅳ），其中Ⅱ，Ⅲ，Ⅳ为新配合物，用Ｘ射线单晶衍射，ＩＲ，ＥＰＲ法对所合成配合物进行了结构表征，发现Ｉ具有两种晶相。     

Differential expression of the skeletal muscle proteome in mdx mice at different ages

The mdx mouse is the most commonly used animal model for Duchenne muscular dystrophy (DMD), a disease caused by the absence of dystrophin. Although much has been done to elucidate the structure and function of dystrophin and the dystrophin-associated glycoprotein complex (DGC), little is known about the cascade of molecular events triggered by the absence of dystrophin that lead to muscle degeneration. To study the molecular basis of DMD, we decided to systematically study the skeletal muscle proteome in mdx mice at different ages. By using two-dimensional (2-D) gel electrophoresis, we defined changes in the protein expression pattern between mdx and control muscles. Approximately 46 differentially expressed proteins from the cytosolic fraction of mdx hindlimb muscles at three months of age were detected by 2-D gel analysis, of which 24 were identified by matrix assisted laser desorption/ionization- mass spectrometry. Most of the proteins fell into five groups of functionally related proteins. These functional categories are (i) metabolism and energy production, (ii) serine protease inhibitor family, (iii) growth and differentiation, (iv) calcium homeostasis, and (v) cytoskeletal reorganization and biogenesis. The potential roles of the differentially expressed proteins are discussed in the context of the mdx phenotype. Finally, we analyzed alterations of protein expression in mdx mice at one and six months of age to determine how protein expression changes with disease progression.