Synthesis and Crystal Structure of 3,3,6,6-Tetramethyl-N-hydroxy-9-ethyl-1,8-dioxo-1,2,3,4,5,6,7,8,9,10-decahydroacridine

1 INTRODUCTION 1,4-Dihydropyridines (1,4-DHPs) are well-knowncompounds because of their pharmacological pro-perty as calcium channel modulators[1, . The che- 2]mical modifications, such as the introduction of dif-ferent substituents[3, or heteroatoms[5], of the DHP 4]ring have allowed the expansion of researches onthe structure-activity relationship to gain new in-sights into the molecular interactions at the receptorlevel. In fact, it is well established th…     

The first example of enantioselective isocyanosilylation of meso epoxides with TMSCN catalyzed by novel chiral organogallium and indium complexes

The desymmetrization ring opening of meso epoxides using trimethylsilyl cyanide catalyzed by organogallium and indium complexes with binaphthol monoether derivatives as chiral ligands gave beta-isocyanohydrins with moderate to excellent enantioselectivities of up to 95% ee.     

Carbon nanotube array-based biosensor

Aligned multi-wall carbon nanotubes (MWNT) grown on platinum substrate are used for the development of an amperometric biosensor. The opening and functionalization by oxidation of the nanotube array allows for the efficient immobilization of the model enzyme, glucose oxidase. The carboxylated open-ends of nanotubes are used for the immobilization of the enzymes, while the platinum substrate provides the direct transduction platform for signal monitoring. It is also shown that carbon nanotubes can play a dual role, both as immobilization matrices and as mediators, allowing for the development of a third generation of biosensor systems, with good overall analytical characteristics.     

Binary mixtures based on polycaprolactone and cellulose derivatives

Pyrolytic process has a promising potential for the environmentally friendly upgrading of lignocellulosic and plastic waste. Thermogravimetry and pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) were used to get information about the reactive decomposition of PCL in binary mixtures with microcrystalline cellulose (MC) or sisal fibres (SF). Preliminary thermogravimetric investigation showed that biomass is thermally degraded at lower temperatures than PCL and this process has a predominant influence on the thermal behaviour of the mixtures. Discrepancies between the experimental and predicted TG/DTG profiles were considered as a measurement of the extent of interactions occurring on co-pyrolysis. It was found that reactivity of PCL was slightly increased in PCL-SF binary mixtures. Evolution of acidic products from cellulose and hemicelluloses decomposition may promote PCL degradation in binary mixtures with SF. It seems that the co-pyrolysis process could have potential for the environmentally friendly transformation of biocomposites.     

水介质中N-芳基-N'-(2-苯并呋喃甲酰基)硫脲及1-芳甲酰基-4-(2'-苯并呋喃甲酰基)氨基硫脲的合成

苄基三乙基氯化铵(TEBA)存在的水介质中, 2-苯并呋喃甲酰氯、硫氰酸铵与芳胺或芳甲酰肼在室温条件下经一步反应合成N-芳基-N'-(2-苯并呋喃甲酰基)硫脲或1-芳甲酰基-4-(2'-苯并呋喃甲酰基)氨基硫脲, 其中前者尚未见文献报道. 与其它合成方法相比, 该法操作简单、反应条件温和、环境友好.     

芯片式流通池顺序注射可更新表面反射光谱法用于酶反应检测

将芯片式流通池顺序注射可更新表面反射光谱法用于酶反应检测。HRP催化H2O2氧化BPR底物的反应用于对H2O2的检测。此反应体系与葡萄糖氧化酶联用，用于对血清中葡萄糖的检测。     

Studies on the refolding of the reduced-denatured insulin with size exclusion chromatography

The refolding of the reduced-denatured insulin from bovine pancreas was investigated with the size exclusion chromatography (SEC). It was shown that the reduced-denatured insulin originally denatured with 7.0 mol L^?1 guanidine hydrochloride (GuHCI) or 8.0 mol L^?1 urea could not be refolded with a non-oxidized mobile phase. Although the oxidized and reduced glutathione (GSSG and GSH) were employed in the oxidized mobile phase, the reduced-denatured insulin still could not be renatured. However, in the presence of 2.0 mol L^t-1 urea in the oxidized mobile phase employed, the reduced-denatured insulin can be refolded with SEC, and the aggregation of denatured insulin can be diminished by urea. In addition, the disulfide exchange of reduced-denatured insulin also can be accelerated with GSSG/GSH in the oxidized mobile phase. The three disulfide bridges of insulin were formed correctly and the reduced-unfolded insulin can be renatured completely. The results were further tested with reversed-phase liquid chromatography (RPLC) and hydrophobic interaction chromatography (HIC).     

A new series of pyrimidine-containing linear molecules: their elegant crystal structures and intriguing photophysical properties

A new series of aza-substituted analogues 3-5 based on the 1,4-bis(phenylethynyl)benzene moiety have been synthesized by the selective Pd-catalyzed Sonogashira coupling reaction from 5-bromo-2-iodopyrimidine (1). In these linear molecules, the dipolar pyrimidine moiety is introduced as a probe to investigate factors that control the intermolecular interactions over the crystal engineering. The results reveal that the manner of packing changes both dipolar interactions between linear pyrimidine-containing molecules and transition moments simultaneously, resulting in remarkably different photophysical properties. Due to their versatile dipole-dipole and face-to-face pi-piinteractions in a crystal motif, further applications on the design of ordered crystalline materials for the field effect transistors are promising.     

单链高分子通过薄膜上纳米孔隙的输运过程: 链间相互作用的影响

从理论上研究了高分子链通过位于薄膜上的一个纳米孔隙的输运问题. 考虑在膜的一侧引入与传输高分子链有特殊相互作用的高分子链段, 研究链间相互作用致使高分子链构型的改变对其平均首次通过时间的影响, 进而在不同条件下进行了相应的数值模拟, 并讨论了其它一些相关问题.     

FTIR-ATR技术研究聚氨酯类文物保护材料的光降解

Polyurethanes are one kind of relic protection materials commonly used. During artificial photo-ageing, three polyurethanes, HDI-based polyurethane, MDI-based polyurethane and TDI-based polyurethane, have been considered to undergo UV radiation. Photochemical degradation of the polyurethanes has been monitored by means of Fourier transform infrared spectroscopy with attenuated total reflection accessory （FTIR-ATR）. It was proved that the mechanism of the photochemical degradation of polyurethanes might be the scissions of carbamate （urethane） groups and the re-reactions of radical groups formed in the scission reactions. From the experiment results HDI-based polyurethane, an aliphatic diisocyanate, could be considered to be more suitably used as relic protection materials among these three polyurethanes for its ageing products with less color.