Microwave-assisted Sinthesis of Thymyl Ethers and Esters in Aqueous Medium

Various thymyl ethers and esters have been synthesized by reactions of thymol with alkyl halides and acid chlorides, respectively, in aqueous medium under environmentally benign conditions using micro-wave irradiation. The products are important as potent pest managing agents.     

Quantitative characterization by asymmetrical flow field-flow fractionation of IgG thermal aggregation with and without polymer protective agents

Complexes formed between poly(acrylates) and polyclonal immunoglobulin G (IgG) in its native conformation and after heat stress were characterized using asymmetric flow field-flow fractionation (AF4) coupled with on-line UV-Vis spectroscopy and multi-angle light-scattering detection (MALS). Mixtures of IgG and poly(acrylates) of increasing structural complexity, sodium poly(acrylate) (PAA), a sodium poly(acrylate) bearing at random 3 mol % n-octadecyl groups, and a random copolymer of sodium acrylate (35 mol %), N-n-octylacrylamide (25 mol %) and N-isopropylacrylamide (40 mol %), were fractionated in a sodium phosphate buffer (0.02 M, pH 6.8) in the presence, or not, of 0.1 M NaCl. The AF4 protocol developed allowed the fractionation of solutions containing free poly(acrylates), native IgG monomer and dimer, poly(acrylates)/IgG complexes made up of one IgG molecule and a few polymer chains, and/or larger poly(acrylates)/IgG aggregates. The molar mass and recovery of the soluble analytes were obtained for mixed solutions of poly(acrylates) and native IgG and for the same solutions incubated at 65 °C for 10 min. From the combined AF4 results, we concluded that in solutions of low ionic strength, the presence of PAA increased the recovery ratio of IgG after thermal stress because of the formation of electrostatically-driven PAA/IgG complexes, but PAA had no protective effect in the presence of 0.1 M NaCl. Poly(acrylates) bearing hydrophobic groups significantly increased IgG recovery after stress, independently of NaCl concentration, because of the synergistic effect of hydrophobic and electrostatic interactions. The AF4 results corroborate conclusions drawn from a previous study combining four analytical techniques. This study demonstrates that AF4 is an efficient tool for the analysis of protein formulations subjected to stress, an important achievement given the anticipated important role of proteins in near-future human therapies. ?      

Changes in the Structural Dimensionality of Selenidostannates in Ionic Liquids: Formation,Structures, Stability,and Photoconductivity

In situ transformations of selenidostannate frameworks in ionic liquids (ILs) were initiated by treatment of the starting phase K₂[Sn₂Se₅] and the consecutive reaction products by means of temperature increase and/or amine addition. Along the reaction pathway, the framework dimensionalities of the five involved selenidostannate anions develop from 3D to 1D and back, both in top‐down and bottom‐up style. Addition of ethane‐1,2‐diamine (en) led to the reversion of the 2D→1D step from 2D‐{[Sn₂₄Se₅₆]^16?} to 1D‐{[Sn₆Se₁₄]^4?}. As rationalized by DFT investigations, the 2D anion is thermodynamically favored. Photoconductivity measurements reveal that all samples show Schottky contact behavior with absolute thresholds below 10 V. One of the samples exhibits conductive states within the energy range of visible photons.     

带色散项的周期可积Hunter-Saxton方程的波的破裂

本文考虑一个带色散项的可积Hunter-Saxton方程的周期柯西问题.首先,我们得出该模型的强解的一个精确的爆破机制.其次,利用守恒量和特征方法,分别建立了有限时间内强解的爆破发生的充分条件.最后,给出了强解的爆破率.     

Mn掺杂ZnS(110)表面的电子结构和磁性

采用基于密度泛函理论的第-性原理方法,研究Mn掺杂ZnS(110)表面的电子结构和磁性.计算分析不同掺杂组态的几何参数、形成能、磁矩、电子态密度以及电荷密度.结果表明:单个Mn原子掺杂,替位于表面第二层的Zn原子时体系形成能最低,说明该层是最稳定的掺杂位置.对于两个Mn原子的掺杂,当Mn与Mn之间呈反铁磁耦合时体系最稳定.体系的总磁矩和自由Mn原子的磁矩差别很小,但是Mn原子的局域磁矩却依赖于Mn原子的3d态和近邻S原子的3p态的杂化作用,即受周围S原子环境的变化影响较大.此外,分析电荷密度图得出Mn原子替换Zn原子后与S原子形成了更强的共价键.     

高超声速三维内收缩式进气道/乘波前体一体化设计研究评述

论述了国内外在高超声速三维内收缩式进气道研究方面的最新研究动态,重点阐述了三维变截面内乘波式进气道的研究进展.介绍了常规矩形进口进气道与乘波体外形一体化相关研究,并对三维内收缩式进气道与前体的一体化问题提出了关注. 最后,对高超声速进气道与前体一体化设计的研究趋势进行了展望,提出三维内收缩式进气道与乘波前体的``双乘波'一体化设计可能为高超声速研究带来新的变革.      

ZnS(111)表面掺杂Mn的电子结构和磁性的第一性原理研究

应用基于密度泛函理论的第一性原理,研究Mn原子掺杂在ZnS(111)表面的电子结构和磁性.对于单原子的掺杂组态,替位表面第一层的Zn原子时体系形成能最低,说明该层是最稳定的掺杂位置.体系总磁矩取决于Mn原子的局域环境.而对于双掺杂组态,当Mn与Mn之间呈短程铁磁耦合作用时体系最稳定.这可由Mn原子和近邻S原子的p-d杂化作用解释.此时,体系的居里温度估算值为469 K,明显高于室温,具有理论指导意义.Mn原子和受主半导体之间的相互作用是自旋极化产生的主要原因.计算结果表明,该掺杂材料可以很好的用来制作稀磁半导体,具有良好的应用前景.     

Development and validation of an RP‐HPLC method for the quantitation of Orteronel (TAK‐700), a CYP17A1 enzyme inhibitor,in rat plasma and its application to a pharmacokinetic study

A novel, simple, specific, sensitive and reproducible high‐performance liquid chromatography assay method has been developed and validated for the estimation of Orteronel in rat plasma. The bioanalytical procedure involves extraction of Orteronel and phenacetin (internal standard) from rat plasma with a simple liquid–liquid extraction process. The chromatographic analysis was performed on a Waters Alliance system using a gradient mobile phase conditions at a flow rate of 1 mL/min and a C₁₈ column maintained at ambient room temperature. The eluate was monitored using a photodiode array detector set at 242. Orteronel and internal standard eluted at 4.8 and 6.2 min, respectively and the total run time was 9 min. Method validation was performed as per US Food and Drug Administration guidelines and the results met the acceptance criteria. The calibration curve was linear over a concentration range of 100–3149 ng/mL (r² = 0.995). The intra‐ and inter‐day precisions were in the ranges of 0.31–7.87 and 3.97–6.35, respectively, in rat plasma. The validated HPLC method was successfully applied to a pharmacokinetic study of Orteronel in rats. Copyright © 2013 John Wiley & Sons, Ltd.     

MQX-RTOS底层设备驱动构件可复用性研究

针对MQX实时操作系统下如何有效复用已经成熟的底层设备驱动构件,提高操作系统下底层设备驱动软件的开发速度、效率和质量等问题;在详细分析和研究MQX实时操作系统IO设备驱动三层管理体系构架基础上,将底层设备驱动和操作系统剥离,提出了MQX四层设备驱动管理体系框架;通过设计底层设备驱动接口构件,成功地复用了已有的底层设备驱动构件,避免底层驱动软件重复开发,有效缩短嵌入式软件开发的周期,并通过实例证明了该体系框架的可行性。 