尼美舒利对乳腺癌细胞放射增敏作用的研究；Radiosensitizing Effect of Nimesulide on Breast Cancer Cells and Corresponding Mechanisms

目的综述近年来banoxantrone(AQ4N)作为肿瘤治疗增敏药物在国外的研究进展,为国内开发和应用AQ4N提供参考。方法分析、归纳、总结近年来发表的相关文献。结果与结论AQ4N本身对细胞没有毒性,在乏氧条件下经还原酶的催化生成活性药物AQ4,后者通过抑制乏氧细胞中的拓扑异构酶Ⅱ活性而杀死肿瘤乏氧细胞。AQ4N选择性作用于乏氧细胞,与富氧细胞毒性剂如放疗或化疗联合应用,疗效显著。

Dendrimer films as matrices for electrochemical fabrication of novel gold/palladium bimetallic nanostructures

Electrodeposition of novel Au/Pd bimetallic nanostructures with dendrimer films as matrices has been reported. The dendrimers exhibited highly open structures arising from protonation of amines and this made them have good penetrability for solvent molecules. The unique properties of dendrimers obviously affected the morphologies and compositions of deposited bimetallic nanostructures compared with those from unmodified surfaces. Field-emitted scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy and UV-vis spectroscopy were used to characterize these nanostructures.

Nd~(3+)掺杂对LiFePO_4结构及电化学性能的改善

采用两步加热高温固相法合成了掺杂Nd3+的LiFe1-xNdxPO4/C复合材料(x=0,0.01,0.02,0.04,0.06,0.08)。用TG-DSC对前驱体进行分析和SQUID(超导量子干涉仪)对样品中Fe3+的磁性测定,优化了合成工艺条件;采用XRD、FE-SEM、EDS等方法分析了样品的结构并对其电化学性能进行了测试。结果表明:LiFe1-xNdxPO4/C复合材料具有橄榄石型结构;当Nd3+的掺杂量6%(物质的量分数)、煅烧温度700℃、煅烧时间16 h时,样品在0.2C(1C=170.0 mA.g-1)电流密度下的最大放电比容量可达165.2 mAh.g-1,循环100次后的容量保持率仍为92.8%,在1C、2C、5C下的最大放电比容量分别为146.8、125.7和114.8 mAh.g-1。通过测定样品在不同较低倍率下的放电比容量,采用外推法得出制备样品的实测理论比容量为168.7 mAh.g-1。

Starburst substituted hexaazatriphenylene compounds: synthesis, photophysical and electrochemical properties

Starburst-substituted hexaazatriphenylene Compounds have been designed and synthesized by introducing various peripheral aryl substituents to the central heterocyclic core. The effects of various substituent groups on the photophysical and electrochemical properties of the substituted hexaazatriphenylene have been investigated. Significant red-shifts of the absorption peak (from 413 nm to 530 nm) and emission peak (from 432 nm to 700 nm) were observed when the electron-donating ability of the aryl substituents was increased, corresponding to a decrease in the band gap from 2.90 eV to 2.05 eV. Introducing bulky substituents with weak electron-donating ability enhances the fluorescence quantum yield from 23% to 87%. In contrast, incorporating aryl substituents with strong electron-donating ability decreases the fluorescence quantum yield.

含铜氧化酶在活性炭上的固定及直接电化学

以吸附的方法将两种具有代表性的含铜氧化酶酪氨酸酶(Tyr)和漆酶(Lac)固定在活性炭粉表面, 结果表明, 活性炭能促进Tyr和Lac的直接电子转移反应, 循环伏安曲线上表现出一对准可逆的氧化还原峰; 式量电位E0' 几乎不随扫速而变化. 进一步的实验结果显示, 固定在活性炭上的Tyr和Lac能保持对O2还原的电催化作用. 本文固定酶的方法具有简单、易于操作和酶活性保持良好等优点, 可用于获得其他生物氧化还原蛋白质和酶的直接电子转移以及制备生物燃料电池电极催化剂.

Glucose-lowering activity of amino acid-N-phosphonic acid oxovanadium complexes and its interaction with DNA

Vanadium has well-documented lowering glucose properties both in vitro and in vivo. The design of new oxovanadium(IV) coordination compounds, intended for use as insulin-enhancing agents in the treatment of diabetes mellitus, can potentially benefit from a synergistic approach, in which the whole complex has more than an additive effect from its component parts. Biological testing with oxovanadium(IV) organic phosphonic acid, for insulin-enhancing potential included acute administration, by oral gavage in streptozotocin (STZ) diabetic rats. The complexes of oxovanadium(IV) amino acid-N-phosphonic acid exhibit higher lowering glucose activity in vivo. The interaction of the complexes of oxovanadium(IV) amino acid-N-phosphonic acid with DNA was investigated by agarose gel electrophoresis. The results indicated that these complexes have strong interaction with DNA.

Characterization of organic-inorganic multilayer films by cyclic voltammetry, UV-Vis spectrometry, X-ray photoelectron spectroscopy, small-angle X-ray diffraction and electrochemical impedance spectroscopy

We have employed several techniques, including cyclic voltammetry, UV-Vis spectrometry, small-angle X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy, to characterize the formation processes and interfacial features of ultrathin multilayer films of silicotungstate and a cationic redox polymer on cysteamine-coated Au electrodes self-assembled monolayers. All of these techniques confirm that the multilayer films are built up stepwise as well as uniformly in a layer-by-layer fashion. In particular, the electrochemical impedance spectroscopy is successfully used to monitor the multilayer deposition processes. It has been proved that the electrochemical impedance spectroscopy is a very useful technique in characterization of multilayer films because it provides valuable information about the interfacial impedance features.

(C_5H_9C_5H_4)_2 LnCl·nTHF的合成及[(C_5H_9C_5H_4)_2SmCl(THF)]_2和[(C_5H_9C_5H_4)_2ErCl]_2的晶体结构

1980年以来,取代环戊二烯基稀土配合物化学取得了较快的发展,合成了许多取代环戊二烯基稀土氧化物。这些大体积的配体如—C_5Me_5—(Me_3Si)_2C_5H_5-t-BuCp等,可以稳定低配位数的络合物,特别是单或双取代的环戊二烯基稀土氯化物。我们用环

Regulation of autoinducer 2 production and luxS expression in a pathogenic Edwardsiella tarda strain

Edwardsiella tarda is a bacterial pathogen that can infect both humans and animals. TX1, an Ed. tarda strain isolated from diseased fish, was found to produce autoinducer 2 (Al-2)-like activity that was growth phase dependent and modulated by growth conditions. The gene coding for the Al-2 synthase was cloned from TX1 and designated luxS(Et). LuxS(Et) was able to complement the Al-2 mutant phenotype of Escherichia coli strain DH5 alpha. Expression Of luxS(Et) correlated with Al-2 activity and was increased by glucose and decreased by elevated temperature. The effect of glucose was shown to be mediated through the cAMP-CRP complex, which repressed luxS(Et) expression. Overexpression of luxS(Et) enhanced Al-2 activity in TX1, whereas disruption of luxS(Et) expression by antisense RNA interference (i) reduced the level of Al-2 activity, (ii) impaired bacterial growth under various conditions, (iii) weakened the expression of genes associated with the type III secretion system and biofilm formation, and (iv) attenuated bacterial virulence. Addition of exogenous Al-2 was able to complement the deficiencies in the expression of TTSS genes and biofilm production but failed to rescue the growth defects. Our results (i) demonstrated that the Al-2 activity in TX1 is controlled at least in part at the level of luxS(Et) expression, which in turn is regulated by growth conditions, and that the temporal expression of luxS(Et) is essential for optimal bacterial infection and survival; and (ii) suggested the existence in Ed. tarda of a LuxS/Al-2-mediated signal transduction pathway that regulates the production of virulence-associated elements.

Cadinane Sesquiterpenes from the brown alga Dictyopteris divaricata

Seven new cadinane sesquiterpenes, (-)-(1R,6S,7S,10R)-1-hydroxycadinan-3-en-5-one (1), (+)-(1R,5S,6R,7S, 10R)-cadinan-3-ene-1,5-diol (2), (+)-(1R,5R,6R,7S,10R)-cadinan-3-ene-1,5-diol (3), (+)-(1R,5S,6R,7S,10R)-cadinan-4(11)-ene-1,5-diol (4), (+)-(1R,5R,6R,7R,10R)-cadinan-4(11)-ene-1,5,12-triol (5), (-)-(1R,4R,5S,6R,7S, 10R)-cadinan-1,4,5-triol (6), and (-)-(1R,6R,7S,10R)-11-oxocadinan-4-en-1-ol (7), together with nine known compounds were isolated from the brown alga Dictyopteris divaricata. The structures of the new natural products, as well as their absolute configuration, were established by means of spectroscopic data including IR, HRMS, 1D and 2D NMR, single-crystal X-ray diffraction, and CD. All compounds were inactive against several human cancer cell lines including lung adenocarcinoma (A549), stomach cancer (BGC-823), breast cancer (MCF-7), hepatoma (Bel7402), and colon cancer (HCT-8) cell lines.

ZNB-Ⅰ型沼气浓度计

叙述了ZNB-Ⅰ历沼气浓度计的原理、特性及参数选择,并对其误差进行了分析。

藏北可可西里碰撞后钾质火山作用和岩石成因

Post-collisional, potassic igneous rocks are widely distributed in the Hoh Xil area of the northern Tibetan Plateau. Based on the field work, petrography, mineral chemistry, K-Ar geochronology, element and Sr-Nd-Pb isotope geochemistry, this thesis systematically studied the spatial and temporal distribution of the volcanic rocks, chemical characteristics, formation mechanism and partial melting mechanism of the magma source region, geodynamic setting of magmatism, as well as crustal assimilation and fractional crystallization (AFC). The results show that: 1. The Miocene (7.77-17.82 Ma) volcanic products dominantly are trachandesite and trachy, and subordinate rhyolites, associated with stike-slip faults and thrust faults, formed morphology of small lava platforms and cinder cones. 2. Phenocrysts in the lavas are augite, andesine, sanidine, calcic amphibole and subordinate orthopyroxene, biotite and Ti-Fe oxides, displaying typical quench texture. Equilibrium temperatures and pressures of clinopyroxene phenocrysts indicate the magma chamber is located in upper-middle crust. 3. Rhyolites are the products of crustal melting and fractionation of shoshonitic magmas. The source region of intermediate magmas is enriched continental lithospheric mantle, which contains residual minerals such as phlogopite, rutile and spinel, and enriched by subducted sediments during earlier multi-episodes of subduction. 4. Upwelling of asthenosphere provides heat for source region melting, and faults provide channels for magma eruption. 5. Northward underthrusting of Indian continental lithosphere and southward of backstop of Asian continental lithosphere resulted in upwelling of hot asthenosphere. Geochemical characteristics of the potassic magmatism in North Tibet are dominantly controlled by source region composition, partial melting, and crustal assimilation and fractional crystallization (AFC).