Difluorocarbene-Induced Ring-Opening Difluoromethylation-Halogenation of Cyclic (Thio)Ethers with TMSCF2X (X=Br,Cl)**

The ring-opening difluoromethylation-halogenation of cyclic (thio)ethers is reported through a simple strategy relying on carbon-chalcogen bond activation with difluorocarbene. The reaction proceeds through in situ protonation of the previously little-known difluoromethylene oxonium or sulfonium ylide intermediate followed by ring-opening with halide ion to afford halogenated acyclic difluoromethyl (thio)ethers that can then be employed for further elaboration. TMSCF₂X (X=Br, Cl) are unique reagents to achieve this synthetic purpose, which serve as both the difluorocarbene source and the halide ion source.     

Double Orthogonal Click Reactions for the Development of Antimicrobial Peptide Nanotubes

A new class of amphipathic cyclic peptides, which assemble in bacteria membranes to form polymeric supramolecular nanotubes giving them antimicrobial properties, is described. The method is based on the use of two orthogonal clickable transformations to incorporate different hydrophobic or hydrophilic moieties in a simple, regioselective, and divergent manner. The resulting cationic amphipathic cyclic peptides described in this article exhibit strong antimicrobial properties with a broad therapeutic window. Our studies suggest that the active form is the nanotube resulted from the parallel stacking of the cyclic peptide precursors. Several techniques, CD, FTIR, fluorescence, and STEM, among others, confirm the nanotube formation.     

Functionalized Porphyrin Discotic Liquid Crystals: Photoinduced Charge Separation and Trapping

Individual members of a family of highly absorptive porphyrins bearing symmetrically positioned flexible side chains form discotic liquid crystalline mesophases at modest temperature ranges. The order of this phase is preserved when a thin layer of this self-assembled material is cooled to room temperature. Exposure of such films to visible excitation, with or without an externally applied electrical field, produces photovoltaic effects and/or charge trapping. The latter effect constitutes the basis for optoelectronic information storage.     

Applying magnetic soft mold imprint technology with ultraviolet light‐emitting‐diode array on the fabrication of microlens arrays

This study proposed a novel technology, which uses exposed technology with ultraviolet light‐emitting‐diode (UV‐LED) arrays and the polydimethylsiloxane (PDMS) magnetic flexible soft mold imprint technology, to develop exposed equipments with UV‐LED arrays. This study used magnetic soft mold imprint technology to replicate the structure of microlens, providing a more effective alternative for imprint technology and application. The measurement results showed that PDMS with magnetic iron powder can precisely cast mold to replicate the structures of microlens. Electromagnetic plates were used to control even imprinting with magnetic force, in order to fill the mold of micro‐structure of the photo‐resist. Magnetic iron powder was added to PDMS to produce composite material, which can effectively avoid the transformation of pure PDMS during soft mold imprinting, and increase mechanical strength. Magnetic PDMS soft mold is easy to make, and the casting time is short, so that costs can be effectively reduced. Also with advantages of less free energy on its surface, and unlikely to adhere to the photo‐resist during imprinting, it can be combined with electromagnetic plates evenly to control the magnetic soft mold. This imprinting technology is a big advantage to the production process of micro‐structures during imprinting. Copyright © 2009 John Wiley & Sons, Ltd.     

A Novel Preprocessing Algorithm for Three-Way HPLC Data

Orthogonal signal correction (OSC) was a data preprocessing algorithm. It ensured that the filtered information was irrelevant to concentration data while using it to filter the noise from the original data. This paper extended the OSC application range from two-way data to three-way data. Two drug data sets, Enoxacin, Norfloxacin, Ciprofloxacin and Betamethasone, cortisone acetate, prednisone acetate, showed that the application of the OSC algorithm to three-way HPLC data was feasible and needed further research.     

有序金属纳米壳材料

有序金属纳米壳结构特别是有序中空纳米壳及大孔结构兼具了光子晶体和金属纳米壳结构的光学特性,引起了国内外学者的广泛关注。本文详细介绍了有序金属纳米壳材料的制备方法与步骤,主要包括胶体晶模板的组装、所需金属壳层的制备以及胶体晶模板的去除三步,并对各步的制备方法及特点进行了描述。此外,本文还对金属纳米壳有序材料的各种应用进行了综述,简要分析了目前存在的问题并展望了今后该材料的研究方向。     

主链型阳离子表面活性剂聚季铵盐的制备

以N,N-二甲基-1,3-丙二胺、尿素及1,4-二氯丁烷为原料,通过共缩聚反应两步法制备了一种新的主链型的水溶性聚季铵盐.采用正交试验获得了制备聚季铵盐的最佳条件：N,N-二甲基-1,3-丙二胺与尿素的物质的量比为2∶1,反应温度为135℃,反应时间为11h,得到中间体双[3-（N,N-二甲基丙胺基）]丙脲,产率高达99％;中间体与1,4-二氯丁烷的物质的量比为1∶1,于90℃下反应6h.采用红外光谱和核磁氢谱对产物结构进行表征,测定了其热稳定性和特性粘数.     

Breath Figure Arrays: Unconventional Fabrications,Functionalizations, and Applications

A breath figure (BF) is the water droplet array that forms when moisture comes in contact with a cold substrate. This water droplet array has been widely utilized in the past two decades as a versatile soft template for the fabrication of polymeric porous films. Accordingly, the ordered pores on the polymer films formed with such a method are named a breath figure array (BFA).The BF templating technique is undergoing rapid development. Several unconventional BF processes have been established to prepare porous films with unique morphologies or primary materials, and various newly developed functionalization techniques have significantly improved the performance of polymeric films with BFA, leading to novel applications, including templates, biosensors, and separation membranes. These recent achievements will be described in this Minireview.     

辣根过氧化物酶反应的化学动力学分析

用辣根过氧化物酶来处理废水中的苯酚和氯酚为许多人所关注。采用停流快速混合技术，利用快速扫描紫外可见分光光度计得到辣根过氧化物酶催化过氧化氢氧化苯酚聚合过程的瞬态光谱数据。对此测量数据矩阵用正交投影及遗传算法解析后，确定体系中产生紫外吸收的物种数，及辣根过氧化物酶中间体形式的纯光谱信息，进而解出反应过程中各组分的动力学曲线。     

Classification of chromatographic data using multidimensional polynomials

Summary A pattern recognition methodology has been developed for analysis of chromatographic data. The method uses a new class of multidimensional orthogonal polynomials developed by Cohen in conjunction with a supervised learning technique. The method is applicable to any chromatographic data for which classification into two or more categories is desired. The algorithm analyzes both elution times and peak areas. An application is shown for the analysis of organic acids in ascitic fluid obtained from patients with liver disorders. Classification of these patients for presence or absence of bacterial infection shows over ninety percent correct classification.