电化学人工龋的电化学腐蚀机制研究

目的 研究电化学人工龋的电化学腐蚀机制。方法 采用循环伏安法研究牙片电极在K2SO4溶液中的氧化还原反应；以失重法并结合SPSS统计软件统计分析，评价牙片在KCl和K2SO4介质中恒电位腐蚀情况，并现场监测电解液氢离子浓度的变化情况。结果 在0.0-2.5V电位范围内，牙片电极与石墨电极具有波形类似的循环伏安曲线；在KCl和K2SO4介质中牙片的腐蚀速度无显著差异；2.0V恒电位腐蚀牙片8h后，阳极池本体溶液pH值由7.0平均下降到3.87，阴极池则由7.0平均升高到10.65。结论 在外电场作用下，牙片的阳极腐蚀与介质无关；水的阳极氧化引起阳极区氢离子浓度升高，致使牙齿发生酸溶是电化学人工龋形成的主要决定因素。     

Comparative inotropic effect of calcium, endothelin-1, and forskolin on ferret papillary muscles during acidosis

Summary— Acidosis affects multiple steps in the excitation-contraction coupling pathway of myocardium, producing decreased calcium sensitivity of myofibrils and modification of the function of the sarcoplasmic reticulum. Our aim was to evaluate the effectiveness of three different classes of inotropic agents under acidotic conditions: 1) forskolin, an adenylate cyclase activator that enhances cellular cyclic AMP concentrations, 2) elevated extracellular Ca²⁺ and 3) endothelin-1, an activator of the inositol triphosphate, diacylglycerol pathway. Ferret papillary muscles were mounted in organ baths containing normal physiological solution (pH = 7.4). After baseline tension was measured, the muscles were bathed in an acidotic solution (pH = 6.98) that decreased tension to 40% of the control; subsequently, the muscles were washed with normal physiological solution until they returned to baseline. Each inotropic agent was added to the bathing solution in a concentration sufficient to increase tension by 40% above the baseline. Then the solution was made acidotic (pH = 6.98) in the continuous presence of that concentration of inotropic agent and the resultant steady-state developed tension measured. The increases in tension induced by each inotropic agent at normal pH were adjusted to be similar; in contrast, the response to each drug in acidosis was significantly different. Under acidotic conditions, endothelin-1 was the most effective inotropic agent in restoring the depressed developed tension. This was possibly due to enhancement of the myofilament sensitivity to Ca²⁺, which was more effective than increasing [Ca²⁺]_i through elevating extracellular Ca²⁺ or the addition of forskolin which increased [Ca²⁺]_i but desensitized the myofilaments to Ca²⁺.     

我国医疗保障制度改革中医院配套改革措施探讨

论述了医疗保障制度改革给医院带来的机遇与挑战,认为医院应采取调整结构,转换运行机制;完善补偿机制;加大宏观调控力度,制订和实施区域卫生规划等配套措施,来适应医疗保障制度的改革。     

Meta-analysis of gross insertions causing human genetic disease: novel mutational mechanisms and the role of replication slippage

Although gross insertions (>20 bp) comprise <1% of disease-causing mutations, they nevertheless represent an important category of pathological lesion. In an attempt to study these insertions in a systematic way, 158 gross insertions ranging in size between 21 bp and approximately 10 kb were identified using the Human Gene Mutation Database (www.hgmd.org). A careful meta-analytical study revealed extensive diversity in terms of the nature of the inserted DNA sequence and has provided new insights into the underlying mutational mechanisms. Some 70% of gross insertions were found to represent sequence duplications of different types (tandem, partial tandem, or complex). Although most of the tandem duplications were explicable by simple replication slippage, the three complex duplications appear to result from multiple slippage events. Some 11% of gross insertions were attributable to nonpolyglutamine repeat expansions (including octapeptide repeat expansions in the prion protein gene [PRNP] and polyalanine tract expansions) and evidence is presented to support the contention that these mutations are also caused by replication slippage rather than by unequal crossing over. Some 17% of gross insertions, all >or=276 bp in length, were found to be due to LINE-1 (L1) retrotransposition involving different types of element (L1 trans-driven Alu, L1 direct, and L1 trans-driven SVA). A second example of pathological mitochondrial-nuclear sequence transfer was identified in the USH1C gene but appears to arise via a novel mechanism, trans-replication slippage. Finally, evidence for another novel mechanism of human genetic disease, involving the possible capture of DNA oligonucleotides, is presented in the context of a 26-bp insertion into the ERCC6 gene.     

S-99和S-100止血作用研究

PT、APTT、TT、血小板粘附率和血栓形成试验表明S-99可溶性止血纺织材料和S·100吸收性止血綾的止血效果无显著差异。但是S-99和S-100止血纺织材料的止血机理不尽相同,S-100止血绫主要是通过溶解后的负电性液相激活内源性止血系统;而S-99止血纺织材料主要是通过溶胀胶粒粘附血小板,进而激活血小板。     

尼古丁依赖的功能影像学研究进展

在过去10年中,随着功能脑影像学技术在物质滥用领域的发展,越来越多的研究者运用这些技术以探讨尼古丁成瘾的神经生物学机制。本文主要总结了尼古丁急、慢性暴露下对脑功能影响的神经脑影像学研究进展,证实了尼古丁依赖与中脑边缘犒赏系统、调节注意、记忆、运动以及联想相关脑环路之间的相关性。这些研究发现将为揭示尼古丁依赖的神经生物学机制提供更多的证据支持,进一步促进今后戒烟治疗的发展。     

物质成瘾Stroop效应研究进展

物质成瘾Stroop任务是考察物质成瘾者对成瘾相关刺激产生注意偏向的一种研究范式。研究者们采用多种实验任务和研究方法,对物质成瘾Stroop干扰产生的心理机制进行了考察,并提出了几种理论解释,但目前这些理论解释之间还存在一定的分歧。最后,本文提出了未来研究的一些建议。     

原发性肝癌患者抑郁症状与不成熟防御机制的关系

目的：了解原发性肝癌（PLC）患者的抑郁症状和不成熟防御机制（IDM）的水平，探讨PLC患者的抑郁症状与IDM的关系。方法：采用流调用抑郁自评量表（CES－D）和防御式方式问卷（DSQ）对PLC患者和健康组各100例进行调查。结果：1）PLC患者中49％可能或肯定有抑郁症状，其中23％肯定有抑郁症状，其发生率高于健康组；2）PLC组的CES－D总分高于健康组；3）PLC组比健康组采用较多分裂和潜意显现机制，采用较少抱怨机制；4）肯定有抑郁症状者比无抑郁症状者采用较多IDM；5）两组CES－D总分与IDM均分呈显著正相关，Pearson r为0.473-0.776，其中PLC组为0．473。结论：抑郁症状是PLC患者常见的负性情绪，医护人员应引起重视，并指导患者采用成熟的防御机制代替不成熟防御机制，预防并减轻患者的抑郁症状，以提高患者的生活质量。     

电磁脉冲辐射对猕猴凝血机制影响研究

目的:探讨电磁脉冲对猕猴凝血机制影响。方法:经高场强电磁脉冲源以6×104V/m全身辐照5只猕猴,于照前及照后1、3、7、14、28及90d下肢前静脉采血,采用AYW-8001型血凝仪检测电磁脉冲对动物血浆中TT、PT、APTT及FIB的影响。结果:动物血浆中TT于伤后1d及14～28d延长,APTT于伤后1d延长,FIB含量于伤后14d减少,PT在照射前后无明显变化。结论:电磁脉冲照射可对实验猕猴凝血机制产生影响,可通过TT、APTT延长和FIB含量减少而使机体凝血机制发生障碍。     

躯体形式障碍的治疗分析

目的探讨躯体形式障碍的治疗方法。方法用钟友彬的认识领悟疗法对躯体形式障碍3案例治疗通程予以报告和分析。结果认识领悟疗法对躯体形式障碍有一定的临床治疗效果。结论认识领悟疗法治疗躯体形式障碍是有效的和可行的。