微流控技术在纳微胶囊合成中的应用研究进展

纳微胶囊在生物,医药,食品,化妆品等领域得到广泛的应用.相比于传统的制备方法,微流控技术能够产生单分散的单重和多重乳滴,并对这些乳滴的尺寸和结构进行精确的控制,是合成尺寸均一、结构可控以及释放可控的纳微胶囊的理想方法.本文首先介绍了微流控芯片的结构类型,如同轴聚焦、流动聚焦、T型、Y型以及它们的组合等;接着总结了微流控可控制备单一乳滴、双重乳滴以及多重乳滴模板以及乳滴的固化方法,最后着重介绍了微流控制备的纳微胶囊在可控释放方面的应用,其中分为持续释放（受粒径、表面形貌和形状等控制）和刺激响应释放（受外界环境刺激如pH、温度、光和离子等控制）两部分进行综述.     

不同应力路径状态下土中应力

土的性质不但与当前的应力状态有关，而且依赖于过去和新近的应力历史，即应力路径。Lambe提出的应力路径方法，为现场和实验室研究土的性质，提供了一个合理方法。不同的加载方法和加载路径对土的各项指标和性质都有很大的影响。在实际工程中，尤其是深基坑开挖、堆载予压法地基处理和打桩的过程中这几种典型的加载路径，对在实验室研究土的应力提供了一定的依据。     

PLGA-PEG—PLGA温敏水凝胶的体外释药行为

通过试管倒置法考察曲克芦丁对温敏水凝胶温敏性的影响。选用相变温度为25℃的PLGA—PEG—PLGA为载体,曲克芦丁为模型药物,物理混合法制备凝胶浓度为20％（质量分数）含药凝胶,采用无膜溶出模型研究其在体外不同温度下（40℃和30℃）的释药行为。结果显示：曲克芦丁的加入对温敏水凝胶的温敏性影响不大;通过改变PLGA—PEG—PLGA温敏水凝胶的温度可以改变其释药速度。因此可以得出结论：PLGA—PEG—PLGA水凝胶可作为药物脉冲式释放的载体,通过控制温度可控制其对药物的释放。     

细胞活性测定方法研究进展

细胞活性测定是体外筛选抗肿瘤药物和临床肿瘤药敏试验的重要方法之一;细胞活性的测定方法有MTT法、SRB法3、H-TdR掺入法、LDH法等,根据不同细胞系及其测定原理,它们有各自的优缺点及最适测定条件;概述了近年来细胞活性测定的几种常见方法、原理及应用特点。     

Effect of Starch Sources on the Release Rates of Herbicides Encapsulated

The effects of starch sources on the behaviors of starch matrices and on the rates of herbicides released from the matrices were studied for slow release. The starches considered include native corn starch, wheat starch, potato starch and cassava starch. The matrices were prepared through encapsulating 2,4-dichlorophenoxyacetic or 2,4,5 trichlorophenoxyacetic acids as model herbicides with hot-gelatinized starch pastes. The encapsulation was evaluated in terms of herbicide content, swellability, encapsulation efficiency, and release rate. The results show that starch sources play an important role on the matrix behaviors and on release rates. The rate of 2,4-D released follows the order： wheat starch 〈 potaot starch 〈 corn starch 〈 cassava starch. And for the rate of 2,4,5-T, this order is nearly the same only with an exception that the late two kinds of starch are similar. It is also demonstrated that herbicides with different water solubility show different release rates, no matter what type of starch is used as the matrices.     

基于光滑有限元的含裂纹复合材料的虚拟裂纹闭合法

为提高求解断裂参数的精度和效率,将光滑有限元法与虚拟裂纹闭合法相结合,提出光滑有限元-虚拟裂纹闭合法.对含不同长度和角度的倾斜裂纹复合材料圆板的断裂参数进行了求解,并与有限元-虚拟裂纹闭合法计算结果进行了对比.数值算例结果验证了该方法具有高精度,裂纹尖端处单元不需特殊处理,对网格尺寸要求低等优点,是分析断裂问题简洁高效的数值计算方法.     

Dialdehyde starch nanoparticles as antitumor drug delivery system: An in vitro, in vivo, and immunohistological evaluation

Sustaining the release of therapeutic nanoparticles in a cell-, tissue-, or disease-specific manner is a potentially powerful technology. A new drug carrier-dialdehyde starch nanoparticle (DASNP) that can sustain the loading and release of 5-fluorouracil (5-Fu) antitumor drug is reported in this study. IR spectrophotometer and 1H NMR confirmed the formation of aldehyde groups, and scan electron microscope determinations showed that the dialdehyde starch nanoparticles obtained had an average diameter of 90 nm. 5-Fu, the model drug, was conjugated into nanoparticles by aldehyde groups. These 5-Fu-binding nanoparticles significantly enhanced breast cancer cell (MCF-7) inhibition in vitro compared with free 5-Fu. After subcutaneous 0 injection in the breast tumor-loaded rats, 5-Fu-DASNP exhibited remarkable tumor-inhibitory efficacy determined by measuring tumor weight in vivo. The tumor inhibition of 5-Fu-DASNP was 61%±6%, whereas that of free 5-Fu was only 42%±4%. Bcl-2/Bax immunohistochem-istry studies indicated that 5-Fu-DASNP remarkably induced tumor tissue necrosis. These results demonstrated that the DASNP prepared in this work is a potentially effective drug carrier.     

聚(二聚酸-癸二酸)的合成和药物释放性能

以癸二酸和二聚酸预聚物为单体,采用高真空熔融缩聚法,得到较高相对分子质量的聚（二聚酸-癸二酸）共聚物。合成的聚合物分别用于FT-IR,GPC,DSC和TGA等进行了表征,并研究了合成聚合物的体外降解及其对模型药物盐酸环丙沙星的释放性能。     

火花助燃柴油机应用醇类燃料时的工作稳定性和放热特性

本文借助于对实测示功图的分析,研究了喷雾锥角、火花塞电极间隙的位置、点火定时和喷油定时对柴油机采用火花辅助点燃、燃用醇类燃料(甲醇和乙醇)时的失火率、燃烧循环变动率和其它一些燃烧特性参数的影响,分析了醇类燃料燃烧时的放热特性。     

双频辐照的声化学产额及其频率效应的研究

用碘释放法首次研究了２８ｋＨｚ分别与０．８７ＭＨｚ,１．０６ＭＨｚ,１．７ＭＨｚ组成的双频超声辐照的声化学效应,结果表明,双频辐照增强的声化学产额存在着明显的频率效应。