水性巴布剂基质配方研究

目的:研究以卡波姆和聚丙烯酸钠作为水性巴布剂基质的最优配方。方法:通过正交设计实验,以配方中卡波姆、聚丙烯酸钠、PVPK30、CMCNa、PVA为因素,以用量为水平,设计L18(37)正交表,以内聚力、剥离强度作为考察指标。结果:配方中各因素对内聚力的作用大小依次为卡波姆、CMCNa、PVA,对剥离强度的作用大小依次为卡波姆、PVPK30、聚丙烯酸钠。结论:巴布剂基质的最优配方为卡波姆:聚丙烯酸钠:PVPK30∶CMCNa∶PVA=3．0∶4．0∶0．5∶0．2∶0．5。     

正交试验法优选益宫散结口服液水煎醇沉工艺

目的:优选益宫散结口服液的提取工艺。方法:采用正交试验法,以芍药苷含量和干膏得率为指标,考察煎煮次数、煎煮时问、加水量及醇沉浓度对提取率的影响。结果:最佳提取工艺为加8倍量水煎煮3次,每次1 h,醇沉浓度为50％。结论:优化后的提取方法稳定,提取效率较高。     

正交设计试验优选神农心脑康胶囊的制备工艺

目的:优选神农心脑康胶囊的最佳制备工艺。方法:对君药银杏叶、川芎的提取工艺用正交试验进行优选。结果:银杏叶、川芎粉碎成粗粉,用15倍量60%的乙醇渗漉条件最佳,总黄酮和川芎嗪的含量最高。结论:银杏叶、川芎粉碎过10目筛,用15倍60%乙醇渗漉,既经济又实用。     

离心造粒法制备盐酸二甲双胍微丸的研究

目的:制备盐酸二甲双胍微丸。方法:采用离心造粒法制备盐酸二甲双胍微丸,分别对影响微丸粒径分布及收率的处方和工艺因素进行考察,并采用均匀设计法对成丸过程中影响收率的主要工艺因素进行优化。结果:主药与辅料的比例、黏合剂的浓度、主机转速和滚圆时间对微丸的粒径分布和收率有较显著的影响。喷浆和供粉速度是成丸过程中影响微丸收率的主要因素。结论:按优化后的处方及工艺采用离心造粒法制得18~24目微丸的收率为89.7%,且表面光滑,圆整度高。     

正交试验法优选双氯芬酸锌缓释片处方

目的:以HPMC为主要材料,制备水溶性骨架片缓释片。方法:通过正交设计优化双氯芬酸锌缓释片处方,按中国药典2000年版所载,溶出方法的第一法测其释放度。结果:所制备的缓释片优选处方2h体外累积释放量为24.67%,控制在药典规定的15%~40%之间,5h体外累积释放量为69.61%,10h体外累积释放量在90%以上。结论:经正交设计优化的双氯芬酸锌缓释片处方可行。     

影响小儿多平面经胸三维超声心脏成像因素的探讨

目的　建立小儿多平面经胸 (TTO)三维超声检查的优化方案。方法　选择影响TTO检查的采集途径、采样角度间隔、原始图像增益、对比度、灰价阈值及透明度等 6个因素 ,各因素下设三个水平 ,按年龄段分组进行正交试验分析 (L1837) ,以三维重建效率为考核指标 ,评价各因素各水平的重要性。结果　各因素对三维重建效率均起到一定的作用 ,其中采样角度间隔所起作用最大。按各因素平均极差值大小排序 ,各因素最大值分别位于 :采样角度间隔 3°、采样途径经剑突下、图像增益 90、对比度 2 0、灰阶阈值 10及透明度 2 0。采用上述方案能在较短时间内获得较理想的TTO三维超声成像。结论　探索合理的TTO三维超声检查方法 ,有利于促进该技术在小儿心脏病中的应用。     

Virtual reality modeling and computer-aided design in pediatric surgery: applications in laparoscopic pyloromyotomy

As a test of the applicability of modern bioengineering tools to pediatric surgery, we developed by computer-aided design (CAD) methods and evaluated a virtual reality (VR) model of laparoscopic pyloromyotomy (LP) and created a set of retractable hook instruments, called Pylorohooks. Our VR model of LP incorporated the infant's body wall, stomach, and hypertrophied pylorus as well as laparoscopic cannulas and two Pylorohooks. CAD software was used to design the 3-mm-diameter, retractable, double-pronged, minimally-traumatic hook instrument. A rapid prototype processor was employed to create a plastic model of the instrument. Surgical-grade stainless-steel prototypes were then manufactured and used in actual LPs. A working VR model was achieved. Following an initial correction in the angulation of the hooks, the instruments were successfully employed in nine consecutive LPs in infants weighing from 3.4 to 5.7 kg. VR and CAD thus proved instrumental in the development of a new LP approach. Because of increasing pressure to limit human and animal experimentation, computer-based bioengineering methods offer promising alternatives that are clearly applicable to pediatric surgery. Accepted: 13 March 2001     

Incorporating prior knowledge into beam orientaton optimization in IMRT

: Selection of beam configuration in currently available intensity-modulated radiotherapy (IMRT) treatment planning systems is still based on trial-and-error search. Computer beam orientation optimization has the potential to improve the situation, but its practical implementation is hindered by the excessive computing time associated with the calculation. The purpose of this work is to provide an effective means to speed up the beam orientation optimization by incorporating a priori geometric and dosimetric knowledge of the system and to demonstrate the utility of the new algorithm for beam placement in IMRT.

: Beam orientation optimization was performed in two steps. First, the quality of each possible beam orientation was evaluated using beam’s-eye-view dosimetrics (BEVD) developed in our previous study. A simulated annealing algorithm was then employed to search for the optimal set of beam orientations, taking into account the BEVD scores of different incident beam directions. During the calculation, sampling of gantry angles was weighted according to the BEVD score computed before the optimization. A beam direction with a higher BEVD score had a higher probability of being included in the trial configuration, and vice versa. The inclusion of the BEVD weighting in the stochastic beam angle sampling process made it possible to avoid spending valuable computing time unnecessarily at “bad” beam angles. An iterative inverse treatment planning algorithm was used for beam intensity profile optimization during the optimization process. The BEVD-guided beam orientation optimization was applied to an IMRT treatment of paraspinal tumor. The advantage of the new optimization algorithm was demonstrated by comparing the calculation with the conventional scheme without the BEVD weighting in the beam sampling.

: The BEVD tool provided useful guidance for the selection of the potentially good directions for the beams to incident and was used to guide the search for the optimal beam configuration. The BEVD-guided sampling improved both optimization speed and convergence of the calculation. A comparison of several five-field IMRT treatment plans obtained with and without BEVD guidance indicated that the computational efficiency was increased by a factor of 10.

: Incorporation of BEVD information allows for development of a more robust tool for beam orientation optimization in IMRT planning. It enables us to more effectively use the angular degree of freedom in IMRT without paying the excessive computing overhead and brings us one step closer to the goal of automated selection of beam orientations in a clinical environment.     

基因转染的pH敏感脂质体的最优处方和制备工艺的研究

目的　寻找用于基因转染的pH敏感脂质体的最佳处方和制备工艺。方法　采用正交设计法 ,考虑制备的pH值、组成摩尔比、制备方法三因素 ;即 1个四水平因素和 2个二水平因素混合状态。选用L16(4 1·2 12 )正交设计表安排试验 ,各水平组合条件下 ,通过基因转染实验 ,以基因转染荧光测定值作为观测指标 ,实验重复 4次。结果　在基因与脂质体重量比为 (1∶8)时 ,组成大豆磷脂与DC 胆固醇摩尔比为 (6∶4)和在超声法制备的特定条件下 ,pH5 .4与pH7.4基因转染荧光测定值之间差别非常显著 ;均值都较大 ,但是以 pH5 .4时基因转染荧光测定值均值最大。 结论　基因转染荧光测定值最高的脂质体为在 pH5 .4、组成大豆磷脂与DC 胆固醇摩尔比为 (6∶4)时采用超声法制备的脂质体。     

苦参提取工艺的优化选择

目的　为苦参中苦参碱的提取工艺提供依据。方法　用正交设计。结果　确定了适宜的乙醇浓度、乙醇用量、提取时间、次数等因素。结论　苦参中苦参碱的最佳提取工艺为加药材 6倍量的 6 0 %乙醇 ,回流提取 3次 ,每次 2 h