Synthesis and Crystal Structure of a 3-D Hydrogen-bonded Supramolecular Decavanadate Compound [Habo]_6[V_(10)O_(28)]·2C_3H_7OH·2H_2O

1 INTRODUCTION The chemistry of polyoxometalates has been at- tracting much attention due to the richness in their structures, electron and proton storage abilities, ther- mal stability and applications in catalysis, medicine and surface sciences[1～3]. In recent years, the mixed- valence as well as full oxidized vanadium polyoxo- anions have been crystallized with a variety of orga- nic molecules as counteranions[4～8]. However, the guiding principles of the crystal structures of poly- o…     

Structure of Coordination Polymer, 〔Zn(bipy)(H_2O)_3SO_4〕·2H_2O (bipy=4,4'-bipyridine)

1　INTRODUCTION4,4' bipyridine( bipy) is a good candidate for building open framework struc ture because of their rodlike rigidity and length.Framework structures formed bytransition metalsbridged by bipy vary with metaland anion.The structures of Zn bipy system include interpenetrating square grid sheets〔 Zn( bipy) 2 ( H2 O) 2 〕Si F6〔1〕,two dimensionallayer〔 Zn( bipy) ( H2 O) 4 〕( NO3) 2 · bipy〔2〕,〔 Zn( bipy) ( H2 O) 4 〕 ( NO3) 2 · 2 bipy· 3 H2 O〔2〕 and〔 Zn( bipy)…     

利用有机改性的类水滑石缓释阿维菌素

采用蒸发溶剂促进插层(evaporating solvent enhanced intercalation)的方法把农药阿维菌素(Avermectin, AVM)插层到十二烷基硫酸钠(SDS)改性的类水滑石(Hydrotalcite-like compound, HTlc)层间，合成了AVM-SDS-HTlc纳米杂化物。研究发现其能够很好的控制阿维菌素的释放，表明AVM-SDS-HTlc纳米杂化物是一种很有潜力的农药控释剂型。AVM-SDS-HTlc纳米杂化物的释放受pH、温度和电解质的影响，酸性介质、较高温度以及有电解质存在会提高其缓释速率。释放过程符合准一级释放动力学，释放的活化能为279 kJ/mol。     

Synthesis and characteristic of double hydrophilic block copolymer with amine pendant chains

Novel double hydrophilic block copolymers with amine pendant chains were synthesized by polymerization of 4-vinyl benzylamine hydrochloric salt using 4,4′-azo-bis[4-cyanopentanoate poly（ethylene glycol） ester] as macroazoinitiator. The structures of the copolymers were characterized by ^1H NMR, FTIR spectra and acid-base titration, GPC-MALS techniques.     

Preparation and Unimolecular-Micellization Behavior of Homopolymer of Surface-Active Monomer AMC14AB

采用水溶液均聚合方法,制备了阳离子型表面活性单体(2-丙烯酰胺基)乙基十四烷基二甲基溴化铵(AMC14AB)的均聚物,使用荧光探针法、表面张力测定及电导测定法,重点考察了均聚物P(AMC14AB)在水溶液中的胶束化行为与表面吸附现象. 在水溶液中,均聚物P(AMC14AB)呈现单分子链胶束的聚集形态,具有零临界胶束浓度,从开始加入P(AMC14AB)起,水溶液中随即产生单分子链胶束,不存在Krafft温度. P(AMC14AB)在溶液表面也发生表面吸附,使水的表面张力下降,即P(AMC14AB)也具有表面活性;随着浓度增大,表面吸附量增大,水的表面张力持续下降;当表面吸附达饱和时,表面张力～浓度曲线上出现突变点,该点定义为饱和的表面吸附浓度,而不应该再称为临界胶束浓度. P(AMC14AB)单分子链胶束溶液对疏水有机物(甲苯)的增溶情况,明显不同于普通小分子表面活性剂十六烷基溴化铵(CTAB)的多分子胶束溶液,甲苯增溶量～P(AMC14AB)浓度的关系曲线上无突变点,而且对甲苯的增溶能力高于CTAB的多分子胶束溶液.     

神经介素B受体与拮抗剂、激动剂的分子模拟研究

大鼠神经介素B受体(rat neuromedin B receptor, rNMBR)属于G蛋白偶联受体(G-protein coupled receptor, GPCR) A家族的成员. GPCR的结构特征和在信号传导中的重要作用决定了其可以作为很好的药物靶标. 关于rNMBR与内源性激动剂神经介素B (neuromedin B, NMB)以及与非肽类拮抗剂pd168368作用机制的研究对于合理设计受体药物分子有重要的指导意义. 在这一研究中, 我们使用同源模建, 构建受体的三维结构, 进行分子对接和分子动力学的计算. 基于受体三维结构, 通过10 ns的空载受体、激动剂-受体、拮抗剂-受体的分子动力学模拟, 探讨受体与激动剂与拮抗剂的作用机制. 研究表明rNMB-R中跨膜(transmembrane, TM)螺旋3, 5, 6, 7参与配体的结合. NMB与受体的结合, 使受体转变为活性构象, 而受体同拮抗剂pd168368恰好相反.     

Capillary electrophoresis-laser induced fluorescence analysis of endogenous damage in mitochondrial and genomic DNA

Reactive oxygen molecules are formed in vivo as by-products of normal aerobic metabolism. All organisms dependent on oxygen are inevitably exposed to these species so that DNA damage can occur in both genomic and mitochondrial DNA (mtDNA). In order to determine endogenous DNA damage we have developed an analytical method that involves the isolation and hydrolysis of genomic DNA or mtDNA, the labeling of modified and unmodified nucleotides and micellar electrokinetic chromatography with laser-induced fluorescence detection. With this method we have found etheno-adenine, thymine glycol, uracil, hypoxanthine, and 5-methylcytosine. These were identified by the addition of internal standards to the genomic or mtDNA. There are a large number of other signals in the electropherograms of mtDNA that we have never found in genomic DNA analysis because they are at lower concentration in the genome. In the DNA of untreated patients with chronic lymphocytic leukemia (CLL), uracil and high levels of etheno-adenine were found, which can be explained by antioxidant enzyme alterations and oxidative stress in the CLL lymphocytes.     

Design of ordered bimodal mesoporous silica materials by using a mixed fluorinated-hydrogenated surfactant-based system

Mesoporous silica materials have been prepared using aqueous solutions of hydrogenated-fluorinated surfactant mixtures. The phase behavior of the C18H35(OC2H4)10-C6F15C2H4(OC2H4)11OH [RH18(EO)10-RF6(EO)11] mixture in aqueous solution was first established at the temperature at which the silica source is added, i.e., 20 or 40 degrees C. We have delimited the different phase domains. Concerning the mesostructured silica, whatever the temperature at which the silica source is added, mesoporous material with a hexagonal array of their channel is formed via a cooperative templating mechanism (CTM), if the content of RF6(EO)11 in the surfactant mixture is lower than 50%. Moreover, when the silica source is added at 40 degrees C, the recovered materials exhibit a bimodal pore size distribution. The appearance of this bimodality has been related to the coexistence of hydrogenated micelles with fluorinated wormlike micelles. By contrast, the bimodality is not observed when the silica source is added at 20 degrees C.