化学气相淀积过程中钛酸丁酯热解反应机理及动力学

利用热解-色质联用分析系统,对文题进行了研究,发现其热解过程是一个复杂的多元反应过程。在500～800℃,钛酸丁酯(Ⅰ)热解尾气产物主要是烯烃、醇、醚和醛类化合物。经热解机理分析,发现Ⅰ的重排断裂反应是整个热解过程的主反应,其反应动力学常数为3.87×10~5,活化能为69.3 kJ/     

Evidence for a reflex provoking contraction of the renal pelvis (with some comments on its clinical implications)

The effect of swallowing a small quantity of water or of solid food (biscuit) on the renogram curve was observed in 177 patients. Swallowing provoked contraction of the renal pelvis in 63% of the kidneys with a pelvicalyceal system which was neither obstructed nor dilated, with expulsion of a substantial fraction of the contents within 30 s. This did not occur in obstructed or denervated kidneys, nor in patients with a high transection of the spinal cord. Evidence is adduced that this contraction is mediated reflexly. This effect may be used diagnostically to distinguish physiological dilatation from obstruction. The implications when performing and interpreting renography are discussed. Correspondence to: M.V. Merrick     

Expanding Our Strategies to Study the Process of Change

The conceptual and methodological framework proposed by Doss (this issue) makes valuable suggestions for strategic choices in future research. This commentary addresses conceptual and terminological distinctions adopted by Doss, as well as his criticism of add-on/ dismantling studies. We also suggest research topics and methodological developments that could be integrated in Doss's framework to further expand understanding of therapeutic change.     

Consistent control of psoriasis by continuous long-term therapy: the promise of biological treatments

Psoriasis is a chronic, incurable disease that frequently requires long-term treatment. Although many patients benefit from effective traditional systemic therapies, namely methotrexate, cyclosporin, retinoids and fumaric acid esters, and some patients achieve long-term disease control, unrestricted long-term administration is not recommended due to the potential for cumulative toxicity. In order to diminish the risk of toxicity, physicians have adopted various treatment approaches (e.g. rotational, sequential, intermittent, and combination). However, these approaches may not provide continuous disease control or a stable treatment regimen. The recent advent of targeted biological therapeutics such as etanercept, infliximab, adalimumab, alefacept and efalizumab may offer physicians and their patients treatment options with improved safety profiles that may permit continuous disease control.     

医院管理"四部曲"

结合医院管理实际,实施管理四部曲。即:完善机制、教育先行、督察到位、奖惩分明。阐明持续改进是完善机制的内在需求;及时清理是完善机制的有力保障;易于操作是完善机制的必备条件。同时,突出教育的基础性地位;强调监督的关键性环节;放大奖惩的激励性效应。     

低温蒸汽甲醛气体灭菌效果观察

为观察低温蒸汽甲醛气体灭菌效果及其使用的可行性,采用每包内放置化学指示卡和生物指示剂,进行了实际灭菌效果检测。结果,灭菌程序记录曲线清晰,可清楚地记录灭菌日期、抽真空次数、进甲醛次数、灭菌维持时间、灭菌温度、压力、抽甲醛气体次数、空气脉冲次数和结束时间。所有包装袋外甲醛化学指示色块均由原来的橙色变为棕色;所有包内化学指示卡均由原来的深兰色变为合格的绿色。26锅次灭菌后生物指示剂全部无菌生长;对 36件灭菌后物品进行无菌检验均无细菌生长。结论,低温蒸汽甲醛灭菌效果可靠,操作简便,使用安全。     

生物制品GMP认证检查的几点体会

本文从生物制品的特点、生物制品对厂房设备的特殊要求、GMP验证和人员素质几个方面。阐述了对生物制品实施GMP认证检查的感想和体会。     

低分子量肝素化学及生物活性的不均一性

综述了低分子量肝素的化学和生物活性的不均一性,以及药理作用,药物动力学、临床应用等方面的差异。     

Controlled Release of Substituted Benzole and Naphthoic Acids Using Carbopol ® Gels: Measurement of Drug Concentration Profiles and Correlation to Release Rate Kinetics

Purpose. The objective of this study is to correlate drug release mechanism with measured drug concentration profiles in gel layers of Carbopol^® matrices containing mesalamine or benzoic acid. Methods. Release rate experiments with Carbopol^® matrices were performed using a rotating disk apparatus. Matrices were frozen and the gel layer in the matrices was sliced using a microtome in a cryostat. Drug concentration profiles were determined by direct measurement of the concentration of the drug in the gel slices. The pH of the slices was measured using microelectrodes, and water content was measured by Karl Fisher titration. Results. The concentration gradient in mesalamine matrices decreased over time and correlated with square root of time release rate kinetics. The concentration profiles of benzoic acid were unchanged over time and correlated with zero order release rate kinetics. Carbopol gel layers were highly hydrated (93–95% water). Gel layers in matrices with mesalamine had a more alkaline microenvironmental pH. This higher pH resulted in increased growth of the thickness of the gel layer and a reduction drug diffusivity in comparison to benzoic acid matrices. Conclusions. The release rate kinetics of mesalamine and benzoic acid correlated to the measured concentration profiles. The shape of the concentration profiles is determined by the rate of growth of the Carbopol^® gel layer and drug diffusivity.