Credentialed Persons, Credentialed Knowledge

The vast experimental literature on human error agrees with history of medicine, folklore, and superstition In discrediting knowledge claims based solely on anecdotal impressions. Since clinical experience consists of anecdotal impressions by practitioners, tt Is unavoidably a mixture of truths, half-truths, and falsehoods. The scientific method is the only known way to distinguish these, and it is both unscholariy and unethical for psychologists who deal with other persons' health, careers, money, freedom, and even life itself to pretend that clinical experience suffices and that quantitative research on diagnostic and therapeutic procedures is not needed. Disputes about philosophy of science (e.g., logical positivism) are irrelevant to this issue, which is simply one of distinguishing knowledge claims that bring reliable credentials and others that do not.     

Mouthguards: difference in longitudinal dimensional stability between single- and double-laminated fabrication techniques

Abstract –  Though the use of mouthguards (MGs) has increased with the increase in sporting activities, little is known about the influence of their fabrication methods on longitudinal dimensional stability. The objective of this study was to compare the difference in the longitudinal dimensional stability between single and laminated MGs. Single-layer MGs were made from a 4.0 mm thick ethylene vinyl acetate (EVA) sheet and laminated MGs were made from two 2.0 mm thick sheets of EVA. MGs were kept in a 37°C water bath for 60 h, equivalent to the time period of 3-months inter-oral use. MG deformation was analyzed by measuring designated points on the MG border using a profile projector (J-12, Nikon Inc., Tokyo, Japan) before and after the water immersion. A finite-element model was also created to examine the time course of stress accumulation during the sheet forming process using Finite Element software. Longitudinal deformation was smaller in the laminated MGs than in the single-layer MGs in the anterior area ( P  < 0.05). Finite element method (FEM) analysis also showed the largest stress accumulation in the anterior incisal area where deformations were mainly observed. Laminated double layer MGs have advantages over single-layer MGs in terms of longitudinal stability due to lower stress accumulation during the fabrication process.     

下前牙桩核冠三维有限元模型的建立

目的：建立桩核冠修复后的下颌中切牙及其牙周支持组织的三维有限元模型。方法：利用薄层CT技术、UG软件与ALGOR软件相结合，对层厚为0．2mm的CT断层影像进行分析处理。结果：模型共有单元45153个，节点27763个，可以根据要求任意旋转、缩放、透视、剖开，进行多种方式观察；并可以按照不同研究目的，对模型进行修改和调整，来模拟不同程度牙槽骨吸收、联冠修复以及各种约束和加载条件下前牙的力学反应。结论：利用薄层CT扫描技术、UG自由曲面功能以及ALGOR软件相结合建立的三维有限元模型，能较精确地模拟临床口腔实际情况，为进一步研究下颌前牙不同牙周情况下的修复奠定了良好的基础。     

额、枕部直接冲击导致中脑损伤的力学机制研究

目的分析额、枕部直接冲击造成中脑应力响应,探讨颅脑直接冲击导致脑干损伤的力学机制。方法构建头颅三维有限元模型,模拟计算额、枕部直接冲击损伤,分析中脑上、下交界面节点应力分布,总结中脑应力响应。结果中脑-间脑界面在冲击初始阶段,2ms即出现应力增高,中脑-桥脑界面应力升高开始于冲击后期(10ms),两交界面节点应力在冲击时程中均持续升高,额部冲击比枕部冲击在中-间脑界面造成的应力峰值高。结论中脑在颅脑直接冲击伤的致伤机制中占有突出地位,中脑的应力改变可解释脑震荡的意识障碍及部分原发脑干伤的临床表现。     

我院在新生中实施"预防艾滋病健康教育处方"的近期效果评价

目的 :了解医学院校新生对艾滋病知识掌握的程度 ,探索在预防艾滋病健康教育中的有效途径。方法 :采用投影胶片讲解“预防艾滋病健康教育处方” ,在教育前后进行两次调查 ,对比研究教育前后调查结果。结果 :在教育前学生对艾滋病基本知识的认识存在很大误区 ,教育后 ,对艾滋病基本知识的认识有很大程度提高。结论 :讲解“预防艾滋病健康教育处方”是提高医学生艾滋病知识水平有效的途径。     

某部性病基本知识调查分析

目的　探讨部队性病防治情况。方法　设计 10个与性病有关的问题 ,对随机抽样某师 4个营官兵现场无记名调查。结果　有关性病的基本知识已被大部分官兵所认知 ,但也有一部分官兵对性病缺乏了解 ,甚至误解。结论　在官兵中加强性病基本知识的宣传 ,强调性病的危害对部队防治性病很有必要。     

孔边裂纹J积分失效评定曲线

计算了单边椭圆缺口试件（ＳＥＮＣＰ）高应变区裂纹的Ｊ积分失效评定曲线（ＦＡＣ），考察了影响ＦＡＣ的几种因素。结果表明：在外加载荷与塑性屈服载荷之比（Ｌｒ）１．０时，用Ｒ６通用失效评定曲线进行结构高应变区裂纹断裂评定与疲劳剩余寿命估算是安全的。     

消化性溃疡中医辨证分型与胃液微量元素 前列腺素E_2及IgG的关系

为了探讨消化性溃疡中医辨证分型与胃液生化、免疫成分的关系,笔者将胃镜确诊的65例患者进行辨证分型,并同步检测其胃液常量元素、微量元素、前列腺素E_2-(PGE_2)、IgG等指标。结果发现,肝胃不和型胃液镁、铜、锌含量低于正常值,IgG高于正常值;脾虚胃热型胃液钠、铜、锌、PGE_2、IgG低于正常值,而钙含量高于正常值;脾胃虚寒型铜、锌、PGE_2低于正常值,而IgG无差异。说明消化性溃疡辨证分型有其客观生化、免疫基础。     

北京、广州、上海城市居民营养知识、态度、行为的调查

对北京、广州和上海三大城市随机抽取的９６５名年龄在２０～５０岁的城市居民进行有关营养知识、态度和行为（Ｋ－Ａ－Ｐ）的调查。结果显示，三地区调查对象的营养知识水平不高。营养知识的得分与其自身受教育程度有相关性（ｒ＝０．３０１１，Ｐ＜０．０１）。年龄在３５岁以上的对象，营养知识的得分高于年轻人；三地区调查对象对营养知识的获取，合理的膳食模式，卫生的饮食习惯均持有积极、肯定的态度。食物消费频度调查结果表明，米／面、肉／禽、蔬菜、水果、奶及奶制品的消费量较高。此外，８９．５％，７８．８％和４７．８％的调查对象分别选择报纸、电视、广播作为其主要营养信息来源。本次调查为将来的营养宣教的内容和方法提供依据。     

无机汞对男工内分泌和大鼠睾丸微量元素的影响

应用放射免疫分析法（ＲＩＡ）和流行病学调查，对４０名接触汞和４０名非接触汞男工进行了血清甲状腺激素、性激素水平和生殖功能的测定。结果表明，接触组男工的阳萎、早泄、性欲减退发生率和男工妻子的早产、自然流产发生率以及血清甲状腺激素（ＦＴ３和ＦＴ４）含量明显增多，每周性交次数和血清睾酮含量显著减少。上述各项与对照组比较差异非常显著。应用火焰光度法，对氯化汞染毒后大鼠睾丸组织的微量元素进行测定，实验组的锌值明显降低。结果提示氯化汞能够影响甲状腺激素、睾酮和锌元素水平。