Structure and mechanical properties of polylactide copolymer microspheres and capsules

Polylactide homopolymers, polylactide and poly(ethylene oxide) diblock and triblock copolymers are used to prepare spherical microparticles by using the single oil-in-water emulsion and solvent evaporation technique. We are able to create both bulk and hollow microspheres by altering the conditions of preparation. The experiments are carried out at two fixed temperatures of 15 and 22 °C. We show, from scanning electron microscopy data, that the microspheres produced from the homopolymers are bulk and homogeneous at both temperatures whereas they are hollow when the triblock copolymers are used. The diblock copolymers yield bulk microspheres at 15 °C and microcapsules at 22 °C. Compression experiments emphasize once more the inner morphology of the spheres. As it is expected, bulk microspheres have higher Young’s modulus than the microcapsules. Nevertheless, comparative compression analysis of both morphologies shows that the microcapsules retain relatively high compressive moduli. These results have implications for the design of rigid and biodegradable microcapsules.     

压力式温控器控温组件泄漏的在线检测

通过对压力式温控器控温组件的温度－力特性的分析，首次提出了检测感温波纹管组件泄漏的原理，数学方法和实验结果。依据此原理，设计了一套微机控制的检测系统。     

双机械臂碰撞检测算法研究

为保障双机械臂在公共活动空间的安全性,提出了一种准确高效的碰撞检测算法。采用球体和胶囊体包围盒简化机械臂模型,根据包围盒之间的相交情况判断是否发生碰撞。通过二次投影法实现快速检测,将包围盒投影为线段,若投影线段未重叠则包围盒未相交;若投影线段有重叠,则将问题进一步转化为空间点到点、点到线段、线段到线段的最短距离求解。通过仿真软件和实体机械臂实验平台对算法进行了分析,结果说明,该算法检测效率高,可直接植入机械臂控制器程序中,满足安全性需要。     

包油胶囊的制备

探讨了水溶性材料制备包油胶囊的方法（锐孔－凝固溶法）和用界面聚合法制备包油胶囊的方法，考查了不同条件对胶囊收率及其性质的影响，得出了制备稳定包油胶囊的最佳实验条件。     

Fabrication of fluorescent hollow capsule with CdS–polyelectrolyte composite films

CdS–polyelectrolyte (CdS–PE) clusters were synthesized by using polyelectrolyte as the stabilizing agent in the aqueous solution. The blue shift of UV–Vis and Fluorescent spectra, the TEM images show the formation of nanoparticles within the polyelectrolyte chains. Using the normal polyelectrolyte hollow capsules as template, the CdS–PE clusters as functional layer materials, the uniform organic–inorganic hollow microspheres have been produced by layer-by-layer (LbL) self-assembly technology.     

无胶囊式纤维过滤器

论述二种过滤器的优缺点 ,说明改装后的无胶囊式过滤器的特点。     

Preparation of porous PVDF-NiB capsules as catalytic adsorbents for hydrogen generation from sodium borohydride

Porous poly(vinylidene fluoride) (PVDF)-NiB capsules were prepared by phase inversion of PVDF, nickel salt and sodium borohydride (NaBH₄) mixtures in water. During the process, nickel salt was reduced to NiB particles by NaBH₄, and the excess NaBH₄ was hydrolyzed to produce hydrogen gas bubbles which aided the formation of the large holes inside the porous capsules. It was proved that the porous capsules can adsorb about 33 wt.% NaBH₄ in THF/NaBH₄ solution for about 4 h. Most of NiB particles were attached on the surface of the porous capsules with inside holes according to the observation of scanning electron microscopy (SEM) and EDS. The special structure of the capsules was successfully used as catalysts and container simultaneously for hydrogen production via catalytic hydrolysis of NaBH₄ in aqueous solution.     

Suitability of a colorimetric method for the selective determination of chitosan in dietary supplements

A colorimetric method previously described for the determination of chitosan has been evaluated because lack of linearity had been observed at certain concentrations. Calibration curves of varied-characteristic chitosans, recovery studies and chitosan quantification in seven commercial dietary supplements have been performed. Some analysis conditions including the solvent of the samples have been studied and optimised. Different data combinations have been checked in order to select the widest range of concentrations where no serial correlation was found. With the selected conditions the method is linear, reproducible and provides reliable results in the analysis of the chitosan content in capsules. Its selectivity has been proved by the lack of interference with other compounds present in the dietary supplements. But in the case of tablet products, the presence of cellulose and magnesium stearate may produce an underestimation of the chitosan content.     

慢性阻塞性肺疾病大鼠支气管上皮MRP1 mRNA及蛋白水平变化及化痰降气方逆转的作用

目的: 研究慢性阻塞性肺疾病(COPD)大鼠支气管上皮MRP1 mRNA及蛋白水平变化及化痰降气方逆转的作用。方法: 采用烟熏复合木瓜蛋白酶雾化吸入法制备COPD大鼠模型,将造模后的大鼠随机分为治疗组和模型组,另以正常大鼠作为对照组。治疗组予以化痰降气方(生药 5.8 g/kg)i.g.治疗给药,2次/d,连续 15 d 后,分别采用RT-PCR、Western blot 技术检测各组大鼠肺支气管上皮MRP1 mRNA及蛋白水平的表达。结果: 化痰降气方治疗能明显改善COPD模型大鼠的肺功能;COPD模型组MRP1 mRNA及蛋白水平较正常对照组显著降低(P<0.01);与COPD模型组比较,化痰降气方治疗组MRP1 mRNA及蛋白水平显著升高(P<0.01)。结论: 化痰降气方能逆转COPD状态下MRP1 mRNA及蛋白水平表达的降低,这可能是其治疗COPD作用机制之一。     

Manipulation and Control of Micro-Organic Matter in Architecture

Steve Pike looks to a future in which architects will work alongside microbiologists and mycologists, in much the same way as they now engage with a team of engineering consultants. He explains how, with the merging of the design studio and laboratory, the manipulation and control of micro-organisms themselves have to take precedence in any successful design and production process. Copyright © 2008 John Wiley & Sons, Ltd.