用于结构可靠度分析的多响应面法

在分析单响应面法精度的影响因素基础上 ,提出了改进的多响应面法 .然后以两个因子功能函数为例 ,推导了多响应面的设计与估计公式 ,并通过算例比较了多响应面法与JC法、Monte Carlo法及单响应面法的计算精度 .结果表明多响应面法的精度好于单响应面法 .

Optimizing rhamnolipid production by Pseudomonas aeruginosa ATCC 9027 grown on waste frying oil using response surface method and batch-fed fermentation

Rhamnolipid production by Pseudomonas aeruginosa ATCC 9027 with waste frying oil as sole carbon source was studied using response surface method. Cultures were incubated in shaking flask with temperature, NO3- and Mg2+ concentrations as the variables. Meanwhile, fed-batch fermentation experiments were conducted. The results show that the three variables are closely related to rhamnolipid production. The optimal cultivation conditions are of 6.4 g/L NaNO3 , 3.1 g/L MgSO4 at 32 ℃, with the maximum rhamnolipid production of 6.6 g/L. The results of fed-batch fermentation experiments show that feeding the oil in two batches can enhance rhamnolipid production. The best time interval is 72 h with the maximum rhamnolipid production of 8.5 g/L. The data are potentially useful for mass production of rhamnolipid on oil waste with this bacterium.

新型“硬核软膜”结构纳米缓释制剂对瑞戈非尼的载药实验研究

目的建立的一种新型的、以聚丁二酰亚胺(polysuccinimide,PSI)与羟基磷灰石(hydroxyapatite,HAP)为基本构成成分的纳米缓释递药系统PSI-HAP,并对抗肿瘤药物瑞戈非尼的载药释药能力进行研究。方法本实验合成了制剂所需辅料HAP与PSI;建立了紫外分光光度法对瑞戈非尼的含量进行检测;采用单因素结合响应面曲线法(box-behnken design,BBD)对不同方式制备的瑞戈非尼纳米缓释递药系统的处方与工艺进行考察;对制剂的载药与释药能力、制剂形态,Zeta电位与粒径等制剂学性质进行了考察。采用荧光染料尼罗红对载药PSI-HAP纳米粒进行标记,通过小动物活体成像技术观察纳米粒在小鼠体内的分布情况。结果经紫外扫描确定瑞戈非尼检测波长为264 nm,标准曲线为A=94.461ρ+0.0304,r^(2)=0.9998,精密度准确度实验显示,瑞戈非尼在0.002~0.02 mg·mL^(-1)内线性关系良好;BBD确定采用乳液法制备瑞戈非尼PSI-HAP制剂处方为药物浓度7.28 mg·mL^(-1),HAP与药物质量比为0.63,PSI与HAP质量比为3.93;体外释放实验结果显示,该递药系统具备pH敏感性,在pH值大于7时,药物会得到较为完全的释放。扫描电镜(SEM)结果显示,制剂粒径在300 nm上下,Zeta电位为负,与人体生物膜荷电性相同。体内分布实验结果显示,PSI-HAP制剂可显著延长制剂在动物体内的滞留时间。结论本实验建立的新型纳米递药系统的制备工艺极其简单,易于灭菌,无需高压、挤压、过滤等工艺即可制备出粒径均一的纳米粒子,药物释放平稳且具备pH敏感性,PSI与纳米HAP都具备抗肿瘤细胞增殖的作用,非常适用于抗肿瘤药物的体内递送。