A comparative molecular field analysis of cytochrome P450 2A5 and 2A6 inhibitors

Structure-activity relationships of 23 P450 2A5 and 2A6 inhibitors were analysed using the CoMFA [1] and GOLPE/GRID with smart region definition (SRD) [2]. The predictive power of the resulting models was validated using five compounds not belonging to the model set. All models have high internal and external predictive power and resulting 3D-QSAR models are supporting each other. Both Sybyl and GOLPE highlight properties near lactone moiety to be important for 2A5 and 2A6 inhibition. Another important feature for pIC₅₀ was the size of the substituent in the 7-positon of coumarin. The models suggest that the 2A5 binding site is larger that that of 2A6 due to larger steric regions in the CoMFA coefficient maps and corresponding GOLPE maps. In addition, the maps reveal that 2A6 disfavours negative charge near the lactone moiety of coumarin.     

飞行器非线性气动弹性和颤振主动控制研究进展

首先，针对发展性能先进的新一代飞行器所涉及到的非线性气动弹性理论与分析技术，结合国内外研究进展情况，着重从建模技术、求解方法、非线性气弹特性分析几个方面进行概括总结。其次，对在飞行器设计中一直颇受关注的、智能材料在飞行器结构颤振及振动主动控制中应用研究现状也给予简要的介绍。最后指出一些尚待进一步研究的问题。     

Effect of SSL and HSC on morphology and properties of PHA based SMPU synthesized by bulk polymerization method

Searching new shape memory polymer and the associating synthesis technology are critical on the development of smart materials. In this paper, a comprehensive study on Poly(hexylene adipate) PHA being the soft segment of shape memory polyurethane (SMPU) was presented. Bulk polymerization method was employed to synthesize the SMPU with different soft segment length (SSL) and hard segment content (HSC). The influences of SSL and HSC on its morphology and thermomechanical property using DSC, DMA, POM, and shape memory behavior were presented here. The results indicate that the thermal properties, dynamic mechanic properties, and crystal morphology of SMPU are influenced significantly by SSL and HSC. And it is found that the shape fixity increases with SSL but decreases with HSC. On the other hand, the shape recovery decreases with both SSL and HSC, and the associated recovery temperature increases either with the increasing SSL or with decreasing HSC. Lastly, it is concluded that in the PHA‐based‐SMPU, the lower limiting value of SSL for polyurethane having shape memory effect is 2000; their response temperature varied with SSL and HSC, changing from 41.0 to 51.9 °C. Stable hard segment crystal are formed at above 30% HSC sample in bulk polymerization, but shape memory behavior can also be observed when its physical crosslink point are formed in the lower HSC PHA‐based‐SMPU. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 444–454, 2007     

基于APP的智能家居环境监测系统的设计与实现

设计并实现了一种基于APP的智能家居环境监测系统,实时监测室内CO、CO₂、O₃及PM2.5的浓度;当被检测气体或PM2.5浓度超过标准值时,系统会立即推送报警消息到用户的智能手机,提醒用户启动相应的空气净化程序对室内进行净化处理;系统利用MQ7、MG811、MQ131及GP2Y1010AU 4种气体检测传感器分别检测室内CO、CO₂、O₃及PM2.5的浓度,然后将污染气体及PM2.5浓度信息通过GPRS传送到后台服务器,智能手机端APP通过WIFI或3G查询后台服务器即可获取污染气体及PM2.5浓度信息;经实践证明,该系统所测得污染气体及PM2.5浓度的精确率达到98%,并能将浓度变化情况用曲线展示给用户,让用户方便及时地了解到室内环境状况。     

pH敏感型智能高分子单链力学性能研究

pH敏感高分子是智能高分子的重要分支,基于其体积、质量或者弹性等参数随pH值变化的性质,可以应用在生物、化学和微/纳机械等多个领域.现有研究多集中在应用领域,缺乏从更深层次的机理上的研究,因此亟需在分子水平上对pH敏感高分子的环境敏感机理进行研究.本工作基于控制变量实验法,利用基于原子力显微镜的单分子力谱技术(SMFS...     

光响应Janus粒子体系的构建与应用

Janus粒子通常由两种或两种以上不同物理或化学性质的部分组成,其结构的不对称性导致了粒子形貌和性质具有不对称性。与“静态”Janus粒子相比,具有刺激响应性的“动态”Janus粒子能够与环境发生相互作用,在外界刺激下表达特殊功能。光响应Janus粒子是一类可以在光刺激下发生特定响应的Janus粒子,其两侧不同的组成不仅可以结合多种类型的光响应性,也能与其他类型的刺激响应进行配合,从而实现对特定体系的精确调控。由于光能易于调节的特性,光响应Janus粒子可以与无机纳米团簇或有机官能团产生特定反应,具有光热效应、色彩调节、光动力治疗等独特特性。它们还可以应用于药物递送、生物传感与成像、微纳米马达和光致发光等领域,为解决生物医学和光学器件相关的问题提供了新的方法。本文主要介绍光响应Janus粒子近期发展的制备方法,并着重阐述其独特调控机理以及其在生物医药、发光材料等领域的突出应用,最后对目前该领域的发展前景做出展望。     

Application of New Energy Thermochromic Composite Thermosensitive Materials of Smart Windows in Recent Years

Thermochromic smart windows technology can intelligently regulate indoor solar radiation by changing indoor light transmittance in response to thermal stimulation, thus reducing energy consumption of the building. In recent years, with the development of new energy-saving materials and the combination with practical technology, energy-saving smart windows technology has received more and more attention from scientific research. Based on the summary of thermochromic smart windows by Yi Long research groups, this review described the applications of thermal responsive organic materials in smart windows, including poly(N-isopropylacrylamide) (PNIPAm) hydrogels, hydroxypropyl cellulose (HPC) hydrogels, ionic liquids and liquid crystals. Besides, the mechanism of various organic materials and the properties of functional materials were also introduced. Finally, opportunities and challenges relating to thermochromic smart windows and prospects for future development are discussed.     

形状记忆聚合物变形模式研究进展

近年来,形状记忆聚合物(SMP)的发展取得了明显进步,其自身的优势也得到了充分的展示.形状记忆聚合物是一种刺激响应智能材料,在特定的外部刺激条件下可以根据预先设计的方式改变形状.形状记忆聚合物具有密度低、变形量大、驱动方式丰富、生物相容性好等一系列优势,使其在航空航天、生物医学、仿生工程、电子元件、智能机器人等领域有着巨大的应用潜力.为了更好地适应不同应用和不同领域的需求,形状记忆聚合物的变形模式也在不断地创新,本综述介绍了形状记忆聚合物不同的变形方式及其相关应用的进展,并对形状记忆聚合物面临的挑战和其潜在的研究方向进行了展望.     

Microwave-Assisted Synthesis of 5′-O-methacryloylcytidine Using the Immobilized Lipase Novozym 435

Nucleobase building blocks have been demonstrated to be strong candidates when it comes to DNA/RNA-like materials by benefiting from hydrogen bond interactions as physical properties. Modifying at the 5′ position is the simplest way to develop nucleobase-based structures by transesterification using the lipase Novozym 435. Herein, we describe the optimization of the lipase-catalyzed synthesis of the monomer 5′-O-methacryloylcytidine with the assistance of microwave irradiation. Variable reaction parameters, such as enzyme concentration, molar ratio of the substrate, reaction temperature and reaction time, were investigated to find the optimum reaction condition in terms of obtaining the highest yield.