Paclitaxel formulation with stable sustained-release behavior and its biological safety evaluation

Biological safety and stable sustained-release of the drug are two crucial issues involved in the formulation of paclitaxel.Focusing on these issues, by using the FDA approved polylactide as carrier material, soybean lecithin as surfactant and maltodextrin as thickener, paclitaxel loaded PLA microspheres were simply prepared by solvent evaporation, thus guaranteeing the biological safety. The introduction of maltodextrin as a thickener aided to a stable sustained-release of paclitaxel. Surface morphology, particle size, drug loading rate, encapsulation efficiency and in vitro drug release behavior were investigated.Biological safety evaluations such as acute toxicity, allergies, hemolysis, skin stimulation and genotoxicity test were also carried out. Results showed that the obtained microspheres were biocompatible and could release paclitaxel at a desirable constant rate.Therefore, the simply prepared paclitaxel formulation with good biological safety and desirable release behavior exhibited great potential of local injection of paclitaxel for the clinical use in the future.     

灯光效果——室内环境变化的开关

灯饰作为一种装饰元素,在室内环境设计中的装饰作用正逐渐被人们所认可,本文论述住宅不同功能区域中灯饰设计的一些基本内容。     

如何保证记录的真实性

ISO9000∶2000质量管理体系中对“记录”的定义是这样的:阐明所取得的结果或提供所完成活动的证据的文件。记录可用于为可追溯性提供文件,并提供验证、预防措施和纠正措施的证据。因此保证记录的真实性,将为质量原因的分析、问题产品的追溯、质量管理体系的有效运行提供有力证据。通过ISO9001∶2000质量管理体系认证的印刷企业,在年度监督审核和企业组织的内部审核中,记录与实际不符、记录与文件不符、记录不能反映生产等情况,在不合格项中占很大的比例,并且由于记录的不真实,对改进生产、提高工作效率缺乏参考。如何保证记录的真实性?1.…     

相场法凝固数值模拟的研究进展

相场方法能有效地避免跟踪固-液相界面,已成为对各种材料建模和计算界面、相边界移动的有效方法,是目前国内外的研究热点.本文论述了相场法模拟凝固微观组织的原理和国内外的研究现状,指出了进一步的研究方向.     

注水开发油藏水驱效果评价体系研究－以南堡油田为例

正确认识注水开发油藏开发状况,系统评价水驱效果是进一步提高水驱采收率的前提。目前评价体系评价目标为油藏,无法有效指导井组、单井级别的综合治理。针对这种现状,在层次分析思想指导下,建立油藏－井组－单井三级注水开发油藏水驱效果评价体系;完成不同层次目标的评价参数优选;建立各项指标的评价标准;对水驱储量控制程度、动用程度等指标的算法进行改进,完成典型区块油藏－井组－单井注水效果评价,为综合治理提供认识基础。     

基于虚拟电阻的三相无变压器光伏并网逆变器漏电流抑制方法

无变压器光伏并网逆变器并网时,由于光伏电池板存在寄生电容,系统中将会出现漏电流,造成极大危害。因此提出了一种基于虚拟电阻的三相无变压器非隔离型光伏并网逆变器漏电流抑制方法,在对并网逆变器进行建模的基础上,分析得到系统漏电流产生原因,并考虑采用虚拟电阻抑制漏电流,首先给出了漏电流与虚拟电阻的关系,其次基于根轨迹法分析并设计了系统控制参数及虚拟电阻的大小,在保证系统稳定性条件下,尽可能大的抑制了漏电流,最终通过仿真结果验证了所提漏电流抑制方法的有效性。     

浅谈美国天然气行业的监管政策及实施效果

分析了美国天然气工业的发展阶段及相应的监管政策和实施效果,提出了加快建设我国天然气行业监管体系的几点设想和建议。     

Physically-based fluid animation: A survey

In this paper, we give an up-to-date survey on physically-based fluid animation research. As one of the most popular approaches to simulate realistic fluid effects, physically-based fluid animation has spurred a large number of new results in recent years. We classify and discuss the existing methods within three categories: Lagrangian method, Eulerian method and Lattice-Boltzmann method. We then introduce techniques for seven different kinds of special fluid effects. Finally we review the latest hot research areas and point out some future research trends, including surface tracking, fluid control, hybrid method, model reduction, etc. Supported partially by the National Basic Research Program of China (Grant No. 2009CB320804), and the National High-Tech Research & Development Program of China (Grant No. 2006AA01Z307)     

大庆油田储层研究做法及对南堡油田的启示

摘要：借鉴大庆油田储层研究成熟的做法对指导南堡油田储层研究工作的开展具有重要的意义。系统调研大庆油田资料,将大庆油田储层研究分为五个不同阶段,总结不同阶段储层研究的主要做法及认识结论;对比南堡油田沉积环境、井距条件、研究基础等方面与大庆油田的差异,参考大庆油田储层研究的做法,对南堡油田目前的储层研究给出三点建议：1.建立全凹陷范围内储层格架以指导小层级别之下的储层精细研究;2.加强表外储层的针对性研究以指导河流－三角洲体系开发中期注采完善与调整;3.构型研究应与开发阶段相对应,目前南堡油田处于开发早－中期,受井距条件及地震资料品质的限制,不宜强求构型研究的大规模开展。     

The effect of umbrella-type branching on the blood circulation and tumor targeting of star-branched PLA-PMPC copolymer micelles

The effect of branching on the blood circulation and tumor targeting of polymer nanovehicles in vivo was investigated in this study. For the purpose, star-branched poly(lactic acid) and poly(2-methacryloyloxyethyl phosphorylcholine)(PLA-PMPC)copolymers with umbrella-type AB_3,(AB_3)_2, and(AB_3)_3 architecture were synthesized by branching at the PLA core. Micelles self-assembled from these copolymers were used to evaluate the effect of core branching on blood circulation and tumor targeting. The results showed that branching changed the behavior of polymeric self-assembly in solution, thereby changing the size and surface anti-fouling performance of the polymeric micelles. Moreover, star-branched copolymer micelles with a higher branching degree allowed their payload to persist better in blood(half-time prolonged from 7.1, 8.6 to 13.8 h) and for a 1.72-fold higher content at the tumor site. These studies suggest that raising the branching degree of amphiphilic copolymer potentially offers a promising strategy for the design of carriers capable of enhanced circulation and targeting in vivo.