非对称独塔混合梁斜拉桥的异形索塔不同状态力学性能分析

以一座跨度为314 m的不对称混合梁独塔斜拉桥为工程背景,首选建立整体桥梁有限元模型研究了不同施工阶段的桥梁结构受力特征;再通过实体有限元分析了"佛手"型曲线性索塔锚固区的局部应力分布规律.结果表明:最大悬臂状态的桥塔最大位移和应力要明显大于桥塔自立状态和满堂支架状态;桥塔最大变形在塔顶第一个锚固区,约为0.742 m...     

电致孔经皮给药：表面活性剂对孔道存在时间和药物传输的影响

Electroporation creates aqueous pathways by short high-voltage pulses resulting in a transient perme- abilization of stratum corneum and an increase in the transdermal delivery rate.However the aqueous pathways will reseal after pulsing,which leads to the rapid drop of transdermal flux.In the present study,the surfactants were added to the donor solution to hinder the shrinkage and resealing of the electropore,and to prolong the lifetime of the aqueous pathways with the consideration that the surfactants could reduce the surface energy of the electropore. These effects of surfactants were demonstrated by the dynamic electrical resistance of the skin and the fluorescent imaging of the local transport regions.Piroxicam（PIX）was transported percutaneously in the presence of surfactants in vitro.Owing to the longer lifetime of aqueous pathways,together with the promotion of PIX availability at the barrier exterior and the improvement in the partition of PIX into the aqueous pathways,the presence of surfactants led to a remarkable increase in the transdermal delivery rate during electroporation and a significant growth of the accumulative transdermal amount of PIX.     

银纳米立方体对诺丹明分子的荧光增强或猝灭效应实验研究

用乙二醇还原硝酸银,成功制备了平均边长约97 nm的银纳米立方体以用于诺丹明(RhB)分子的荧光实验。实验中,将探针分子 RhB 粉末掺杂于PMMA苯甲醚溶液中,制得不同厚度参杂有RhB探针分子的PMMA薄膜,运用光谱技术和共焦显微技术研究了银纳米立方体与荧光分子的间隔、银纳米立方体不同浓度分布对RhB分子的荧光强度的影响。荧光光谱表明,荧光强度随PMMA厚度变薄而增强,当PMMA厚度为10nm时,荧光增强因子最大,获得了56倍的荧光增强效果,而继续减小PMMA厚度时,其荧光增强因子又变小,说明发生了荧光猝灭效应。共焦荧光像则更直观地表现了银纳米立方体的浓度分布对荧光分子辐射增强的影响。因而,可通过调控银纳米立方体与荧光分子的距离及银纳米立方体的分布优化荧光增强因子以用于基于荧光的单分子探测,这一实验结果在生物成像和生物传感领域有潜在应用价值。     

葡萄糖氧化酶的固定化及其性能的研究

本文对葡萄糖氧化酶的固定化进行了研究,考查了载体、缓冲溶液pH值,以及酶担载量对固定化酶性能的影响,确定了固定化过程的工艺条件,并对固定化葡萄糖氧化酶的自由态葡萄氧化酶的性能进行了比较。研究结果表明,以TiCl_4处理的5A分子筛作载体所制备的固定化葡萄糖氧化酶具有良好的化学与物理性能,在主要指标上优于文献报道的结果。     

体内植入型药物释放系统研究进展

体内植入型药物释放系统为一类经手术植入体内或皮下,或经穿刺导入皮下的控制释药制剂,适用于靶向给药或长期给药。本文根据系统植入形式和释药机制的不同,将植入型药物释放系统进行了分类,并对各种植入药物体系的特点和存在的问题作了评述。反向温敏型注射式原位凝胶植入系统是一类最具潜力的长期释药系统,可实现药物的长期、安全、有效释放,具有广泛的应用前景。     

走近无线Mesh网络

介绍了Mesh网络技术，其中包括概念、网络结构、其优点和关键技术以及未来该技术的发展应用领域。     

氟脲嘧啶微粒-壳聚糖微敏性水凝胶复合释药系统的制备

The auto-gelling and drug release properties of the thermosensitive chitosan-β-glycerophosphate formulation were investigated. According to rheological study, gelation lag time of chitosan/β-glycerophosphate （GP） solutions varied from 2 to 60min with different deacetylation degree of chitosan, pH, gelation temperature, and the particles in the sol. The gelation properties were also found to influence the release profilles of a hydrophilic drug, 5-fluorouracil （5-FU）. Morphological examination by scanning electron microphotography demonstrated that large ＂pores＂ occurred during the gel-forming process, which created hydrophilic environment and led to the rapid initial release of the drug （85% in f＇LrSt 8h）. Poly-3-hydroxybutyrate （PHB）, a biodegradable material, was applied here as scaffold to capture 5-FU into microparticles with high encapsulation efficiency by solvent-nonsolvent method. Combination of these microparticles into the chitosan-β-GP formulation could drop the rapid initial release from 85% down to 29% in the optimized PHB content （75%, by mass）. The release could sustain for about 10 months. Tiffs study provided an understanding of the potential of injectable implant using thermosensitive chitosan-β-GP formulation containing PHB based particles for the water soluble drugs that need the property of long-term delivery.     

电致孔经皮给药:表面活性剂对孔道存在时间和药物传输的影响(英文)

Electroporation creates aqueous pathways by short high-voltage pulses resulting in a transient perme- abilization of stratum corneum and an increase in the transdermal delivery rate.However the aqueous pathways will reseal after pulsing,which leads to the rapid drop of transdermal flux.In the present study,the surfactants were added to the donor solution to hinder the shrinkage and resealing of the electropore,and to prolong the lifetime of the aqueous pathways with the consideration that the surfactants could reduce the surface energy of the electropore. These effects of surfactants were demonstrated by the dynamic electrical resistance of the skin and the fluorescent imaging of the local transport regions.Piroxicam(PIX)was transported percutaneously in the presence of surfac- tants in vitro.Owing to the longer lifetime of aqueous pathways,together with the promotion of PIX availability at the barrier exterior and the improvement in the partition of PIX into the aqueous pathways,the presence of surfac- tants led to a remarkable increase in the transdermal delivery rate during electroporation and a significant growth of the accumulative transdermal amount of PIX.     

电致孔经皮传输胰岛素:胰岛素在电脉冲下的稳定性研究

在电致孔下的经皮传输是胰岛素给药的重要途径.表面活性剂十六烷基三甲基溴化铵（CTAB）可阻止胰岛素聚集, 减小经皮渗透阻力;但CTAB和电致孔采用的高压脉冲将影响胰岛素的活性,因而研究了在峰值电压为200～400 V、长度为1～12 ms的脉冲下,CTAB和电脉冲对胰岛素稳定性的影响.结果表明,随溶液中CTAB含量的升高,胰岛素的聚集程度降低,但失活比例迅速增加;当CTAB与胰岛素的物质量比达到60：1 时,即使在小强度脉冲下,失活胰岛素的比例也接近80%.胰岛素的变性主要发生在电极周围,与电极表面积有关.采用透析膜将电极与胰岛素分子隔离的方法可克服胰岛素在脉冲下的失活.此时,脉冲后活性胰岛素比例可达80%,且该值随CTAB含量的增加仅有轻微下降;而以活性胰岛素计量的电致孔下的经皮渗透速率则提高2～3倍.     

基质型经皮给药缓释贴片的体外释放研究

研究了基质中雌二醇 (E2 )的质量分数wE 对透皮贴片的释放影响。实验结果表明E2 的释放度在wE 为 1 5 %～ 3%是相近的 ,不受wE 的影响 ;wE 提高 1倍 ,累计释药量平均提高 80 %。动力学研究表明 ,前 12h内 ,释放度满足Higuchi公式 ,即与t1/2 成线性关系 ;12h后与t0 .7成线性关系 ,为非Fick扩散