Enantioselective determination of (R)‐ and (S)‐lansoprazole in human plasma by chiral liquid chromatography with mass spectrometry and its application to a stereoselective pharmacokinetic study

A simple and enantioselective method was developed and validated for the simultaneous determination of (R)‐ and (S)‐lansoprazole in human plasma by chiral liquid chromatography with tandem mass spectrometry. Lansoprazole enantiomers and internal standard (esomeprazole) were extracted from plasma using acetonitrile as protein precipitating agent. Baseline chiral separation was achieved within 9.0 min on a Chiralpak IC column (150 mm × 4.6 mm, 5 μm) with the column temperature of 30°C. The mobile phase consisted of 10 mM ammonium acetate solution containing 0.05% acetic acid/acetonitrile (50:50, v/v). The mass spectrometric analysis was performed using a QTrap 5500 mass spectrometer coupled with an electrospray ionization source in positive ion mode. The multiple reactions monitoring transitions of m/z 370.1→252.1 and 346.1→198.1 were used to quantify lansoprazole enantiomers and esomeprazole, respectively. For each enantiomer, no apparent matrix effect was found, the calibration curve was linear over 5.00–3000 ng/mL, the intra‐ and inter‐day precisions were below 10.0%, and the accuracy was –3.8 to 3.3%. Analytes were stable during the study. No chiral inversion was observed during sample storage, preparation procedure and analysis. The method was applied to the stereoselective pharmacokinetic studies in human after intravenous administration of dexlansoprazole or racemic lansoprazole.     

Preparation,characterization and catalytic behavior of hierachically porous CuO/α-Fe_2O_3/SiO_2 composite material for CO and o-DCB oxidation

Hierachically porous (HP) CuO/α-Fe2O3/SiO2 composite material was fabricated by sol-gel method and multi-hydrothermal processes using HP-SiO2 as support.The resulting material was characterized by N2 adsorption-desorption,X-ray diffraction and scanning electron microscopy.The as-prepared CuO/Fe2O3/HP-SiO2 sample,with α-Fe2O3 and CuO nanocrystals,possessed a co-continuous skeleton,through-macroporous and mesoporous structure.Its catalytic behavior for CO and o-DCB oxidation was investigated.The result showed that CuO/Fe2O3/HP-SiO2 catalyst exhibited high catalytic activity for both CO and o-DCB oxidation,indicating its potential application in combined abatement of CO and chlorinated volatile organic compounds.     

Mechanism in Brill transition of polyamide 66 studied by two-dimensional correlation infrared spectroscopy

The Brill transition of polyamide 66 was investigated by temperature-dependent infrared spectroscopy combined with moving-window two-dimensional (MW2D) correlation spectroscopy. The temperature range of the Brill transition determined by MW2D correlation spectroscopy was 90–170 °C. We employed generalized 2D correlation spectroscopy to study the sequential order of polyamide 66 chains with linear increment of temperature. The movement of the methylene segments near to NH is earlier than those on the CO sides. At the same time, the methylene which is close to NH varies before the inner methylene. Three kinds of NH groups in polyamide 66 were found. The sequential order of their motions is as follows. The free hydrogen-bonded NH groups change first, and then the disordered hydrogen-bonded NH groups. Finally, the ordered hydrogen-bonded NH groups start to change. We also found that the changes of the ordered hydrogen-bonded NH groups follow with the methylene groups.     

β-环糊精共聚物及其金属配合物的制备与性能

合成了顺丁烯二酸酐酯化β-环糊精与苯乙烯的共聚物及其金属配合物。 利用红外、紫外、元素分析、差示扫描量热法及热失重分析法对其进行了结构表征和性能测试。 这种含有β-环糊精的共聚物金属配合物作为脲酶抑制剂,对大豆脲酶催化尿素水解的抑制效果显著,其铜金属配合物为4 g/L时,抑制率达96.67%。     

新型聚合物分散液晶相位光栅的制备

把具有光敏特性的预聚物与向列相液晶按一定比例混合 ,注入表面经过取向处理的液晶盒中。以紫外灯为光源 ,通过光掩膜法 ,使混合物在光场的引发下发生相分离 ,形成液晶 /聚合物相位光栅。由于相分离后液晶在取向膜的作用下沿液晶盒面方向旋转 180° ,克服了传统液晶光栅器件对入射光偏振方向的依赖 ,提高了光的有效利用率。采用光学显微镜和He Ne激光器进行测试 ,结果表明所制样品具有较好的栅结构 ,其衍射效率不受入射光偏振方向的影响且具有电场可调性。该光栅制作方法简便 ,驱动电压低 ,在光通信器件、衍射光学、投影显示、光开关等领域有广泛的应用前景     

漂移量反馈控制式激光准直方法

提出一种集光纤准直与光束漂移量反馈控制准直技术于一体的激光光束准直方法 ,它是在单模光纤对激光器出射光束漂移量进行初级准直的基础上 ,进一步对光束的漂移量进行反馈控制 ,进而提高出射光束的方向稳定性。准直系统中利用漂移量分离光路和光电检测系统对光束的平漂量和角漂量进行了分离检测 ,并各自构成相应的光束空间平漂量反馈控制系统和光束空间角漂量反馈控制系统 ,减小了平漂量和角漂量反馈控制中的相互耦合。引入单模光纤使激光器与光束漂移量反馈控制准直系统相隔离 ,减小了激光管热源温度变化等因素对准直系统的影响 ,同时还便于准直系统使用中的安装布置。上述方法的应用 ,提高了准直精度及准直效率。实验表明目前该方法准直精度可达 0 .7× 10 -7rad。     

虚二次域的L-函数在中心点的值

给出了虚二次数域的一类L-函数在中心点的值,这为研究Dirichlet L-函数在中心点的算术意义提供了一条新的途径.     

溶剂效应和取代基效应对2-(2-氨基苯基)苯并噻唑光谱性质及激发态分子内质子转移的影响

合成了多种2-(2-氨基苯基)苯并噻唑(APBT)氨基氢原子被供电子及吸电子基团取代的衍生物, 并用紫外光谱﹑荧光光谱等方法和密度泛函理论(DFT)计算研究了溶剂效应和取代基效应对衍生物的光谱性质及激发态分子内质子转移(ESIPT)的影响规律. 结果表明, 相比于非极性溶剂环己烷, 随溶剂极性的增加及APBT-溶剂分子间氢键的形成, APBT的紫外-可见最大吸收峰和荧光最大发射峰均发生了一定程度的红移, 并对APBT的ESIPT产生了影响. 在APBT分子的氨基氮原子上引入不同的吸电子或斥电子取代基, 对氮原子的电荷性质有较大的影响. 在环己烷溶剂中, 甲基取代后的APBT仅有单重荧光发射峰, 体系未发生ESIPT过程; 而COCH₂Cl等吸电子基团能促进APBT的ESIPT, 其荧光发射光谱出现了明显的双重峰, 表明体系发生了激发态分子内质子转移反应. 量子化学的理论计算较好地验证了光谱实验结果.     

High‐Rate,Tunable Syngas Production with Artificial Photosynthetic Cells

An artificial photosynthetic (APS) system consisting of a photoanodic semiconductor that harvests solar photons to split H₂O, a Ni‐SNG cathodic catalyst for the dark reaction of CO₂ reduction in a CO₂‐saturated NaHCO₃ solution, and a proton‐conducting membrane enabled syngas production from CO₂ and H₂O with solar‐to‐syngas energy‐conversion efficiency of up to 13.6 %. The syngas CO/H₂ ratio was tunable between 1:2 and 5:1. Integration of the APS system with photovoltaic cells led to an impressive overall quantum efficiency of 6.29 % for syngas production. The largest turnover frequency of 529.5 h^?1 was recorded with a photoanodic N‐TiO₂ nanorod array for highly stable CO production. The CO‐evolution rate reached a maximum of 154.9 mmol g^?1 h^?1 in the dark compartment of the APS cell. Scanning electrochemical–atomic force microscopy showed the localization of electrons on the single‐nickel‐atom sites of the Ni‐SNG catalyst, thus confirming that the multielectron reduction of CO₂ to CO was kinetically favored.     

Anti-sticking treatment for a nanoimprint stamp

Nanoimprint lithography (NIL), as a low-cost and mass production technique, has played an important role in micro/nano fabrication. However, the sticking problem between the stamp and resist blocks its further application. In order to modify the contact surface, a molecular dynamics (MD) method was used to choose the proper material to coat on the surface of the stamp. According to the MD analysis, CF₂ was found to be a good choice for this purpose. It was applied to the nanoimprint stamp by using the gases in reactive ion etching (RIE). A self-assembly monolayer (SAM) layer was also used in the experiment to release the contact surface energy. Both dry and wet methods were demonstrated as excellent anti-sticking approaches by measuring the contact angles and calculating the surface energy. Both the stamps after anti-sticking treatment can be used more times than the untreated stamps.