Anomalous diffusion of drug release from a slab matrix: fractional diffusion models

Mathematical models for the release of drug from both non-degradable and degradable slab matrices in which the initial drug loading is greater than the solubility are presented in this paper. Taking the anomalous diffusions in the drug release processes into account, the fractional calculus is introduced to model the related phenomena. To describe different kinds of anomalous diffusions, corresponding fractional diffusion equations are adopted. By employing the integral transform methods, similarity solution method and perturbation method, exact and approximation solutions to the models are obtained.     

Higuchi equation: derivation, applications, use and misuse

Fifty years ago, the legendary Professor Takeru Higuchi published the derivation of an equation that allowed for the quantification of drug release from thin ointment films, containing finely dispersed drug into a perfect sink. This became the famous Higuchi equation whose fiftieth anniversary we celebrate this year. Despite the complexity of the involved mass transport processes, Higuchi derived a very simple equation, which is easy to use. Based on a pseudo-steady-state approach, a direct proportionality between the cumulative amount of drug released and the square root of time can be demonstrated. In contrast to various other “square root of time” release kinetics, the constant of proportionality in the classical Higuchi equation has a specific, physically realistic meaning. The major benefits of this equation include the possibility to: (i) facilitate device optimization, and (ii) to better understand the underlying drug release mechanisms. The equation can also be applied to other types of drug delivery systems than thin ointment films, e.g., controlled release transdermal patches or films for oral controlled drug delivery. Later, the equation was extended to other geometries and related theories have been proposed. The aim of this review is to highlight the assumptions the derivation of the classical Higuchi equation is based on and to give an overview on the use and potential misuse of this equation as well as of related theories.     

血管壁稳态促进机制与动脉粥样硬化

脂质经渗漏或有缺陷的血管内皮沉积,在血管壁上是动脉粥样硬化的始动过程.机体通过三大防御机制:内皮祖细胞修复内皮,血管新生,高密度脂蛋白抑制机制,以减少对血管壁的侵害和促进血管壁功能的恢复,维持血管壁内环境稳态.     

运用益气方调节化疗所致红细胞减少症的作用机理研究

目的:研究中药制剂益气方对环磷酰胺(CY)化疗小鼠红细胞减少症的治疗作用,筛选益气方最佳用药剂量。方法:50只ICR小鼠随机分为模型组、正常对照组、益气方高剂量组、中剂量组、低剂量组。各治疗组小鼠分别灌胃给药,正常对照组与模型组小鼠灌服等容量生理盐水,连续15 d。从第8天起模型组与各治疗组小鼠腹腔注射环磷酰胺80mg/kg,连续3 d,正常对照组小鼠注射等体积生理盐水。检测各组小鼠红细胞膜C3b受体花环率、免疫复合物花环率及红细胞、血红蛋白、血清红细胞集落刺激因子水平,观察益气方对CY化疗小鼠红细胞减少症的治疗作用。结果:①与正常对照组比较,其余各组小鼠体重降低。②与模型组比较,益气方各组小鼠血液中红细胞、血红蛋白含量增加,红细胞膜上C3b受体显著升高,免疫复合物花环率明显降低,红细胞集落刺激因子浓度升高,差异有统计学意义(P0.05,P0.01)。结论:益气方可改善化疗所致小鼠红细胞减少症,以益气方中剂量治疗组疗效最佳。     

试析药品因素对医疗机构收入的影响

近十年来,药品因素对各级医疗机构的收入影响程度从依赖、主要收入,向逐渐摆脱依赖、成为次要收入的方向发展。而以国家财政加大投入力度、实施全民覆盖的基本医疗保险制度等建立起来的补偿机制,将是解决各级医疗机构因药品收入减少而产生影响的根本措施,同时也是各级医疗机构正常发展的重要保障。本文根据对吉林省的调查获得的一组数据,试分析药品收入对各级医疗机构经济运行状况的影响,为各级医疗机构的经济运行中的决策提供参考依据。     

适应研究型医院建设需求努力创新科研管理机制

解放军总医院着眼建设一流现代化研究型医院对科研工作提出的新要求,以改革创新为牵引,狠抓科研质量建设和支撑平台建设,努力营造创新氛围,加强管理创新,对于建立研究型医院科研工作运行机制,促进医院全面建设又好又快发展起到了积极推动作用     

第三方调解机制在处理医疗纠纷中的运用

国内医疗纠纷案件的大量增加,占据了大量的司法资源,也严重影响了医患双方的利益,本文通过对第三方调解模式的探讨,希望建立医患之间的第三者,在医疗纠纷案件的处理中发挥积极作用,妥善有效地处理医疗纠纷案件、促进社会的和谐发展。     

烧山火透天凉机理探讨

目的：整理传统针刺补泻手法的典型代表烧山火和透天凉的治病机理。方法：查阅历代前贤的针灸著作,摘录出与烧山火、透天凉机理相关的文献,整合和合理推论出烧山火和透天凉治病取效的理论依据。结果：烧山火机理概括为＂引阳入阴＂;透天凉机理概括为＂引阳（阳邪）出阴＂,经络中运行的经气,即营、卫、宗、元四气是烧山火、透天凉发挥治疗作用和取效的关键。结论：完整的理论指导是针刺补泻的使用依据,且能增加针刺手法的适应病症和使用范围。     

D-半乳糖诱导衰老动物模型的机制及其在中医药方面的应用

利用D-半乳糖特殊的代谢机制,诱导衰老动物模型是常用的揭示衰老机制的实验工具。造模方法上,D-半乳糖诱导剂量具有靶向器官的选择性,比较合适的诱导剂量是100mg·kg^-1·d^-1;其作用机制与氧化应激损伤、钙稳态失调、线粒体老化、非酶糖基化反应、端粒短缩及端粒酶的活性下降,以及免疫功能减退有关。D-半乳糖诱导衰老的动物模型体现了现代系统生物学的观点,有特定的应用价值,然而对该模型衰老机制的整体研究还不够全面。中医药具有整体治疗的优势,在抗衰老多脏器、多靶点研究方面有积极的作用,因而中药对D-半乳糖诱导衰老治疗作用影响的研究越来越多,占所有报道的2／3;但中医药作用可重复性低,未来应集中于全面合理的实验设计,并应用标准化中药干预模型,以及充分考虑诱导衰老与自然衰老的差异。     

篮球运动踝关节损伤的预防

针对在篮球教学与训练中发生的踝关节扭伤问题,对篮球技术动作特点和局部解剖结构特点,从解剖学角度阐述踝关节的结构特点、运动规律及损伤机理,分析其损伤成因,并提出预防措施,旨在为篮球教学训练中的广大教练员和运动员建立一种系统的预防、治疗和伤后恢复训练模式体系,以防止和减少此类扭伤的发生,确保篮球教学与训练的顺利进行。