基于文献计量学的PBL教学法研究现状分析

目的　系统分析以问题为基础的学习（problem-based learning,PBL）的相关文献,了解PBL的现状和发展趋势,为PBL进一步的改进、创新和应用提供参考。方法　计算机检索web of science数据库,搜集公开发表的PBL相关文献,检索时限从建库到2018年3月19日。利用文献计量学方法和R语言tm程序包等进行分析。结果　共筛选出5 710篇文献,发表于77种期刊,1976年至2018年PBL相关文献的发表量呈上升趋势,多数文献作为论著（article）发表,作者来自全世界84个国家或地区,5 710篇文献的总被引次数为54 768次,平均被引用的次数为9.59次。研究方向集中于医学教育、保健科学、工程学。结论　PBL已经广泛应用于各学科,尤其是医学教育领域。但研究的质量和深度尚需提高。     

大肠癌平均风险人群进展期肿瘤的年龄分布分析

目的 探讨汉族大肠癌无症状平均风险人群中不同年龄组进展期肿瘤的患病率,从而为确定最佳的大肠癌筛查开始年龄提供科学依据。方法 采用横断面研究设计,利用自制调查表对就诊于全国19家医院并接受结肠镜检查的大肠癌平均风险人群进行调查。调查内容包括人口学特征、生活方式、饮食习惯、肠镜检查结果等。基于之前已建立的平均风险人群大肠进展期肿瘤发生风险评分系统（由年龄、性别、吸烟、糖尿病、绿色蔬菜、腌制食品、油炸熏制食品、白肉等8个变量组成,总分为0-14分）,对研究对象进行发生风险评估,计算各风险等级进展期肿瘤患病率。不同风险等级、不同年龄组、不同性别之间进展期肿瘤患病率比较采用X2检验。结果 共7541例患者完成全结肠镜检查。随着危险评分增加,进展期肿瘤发生率也明显升高。风险评估得分为0-2分的研究人群中,70岁以下的年龄组进展期肿瘤发生率处于1.3-4.0%较低水平;70岁以上的年龄组进展期肿瘤的发生率处于8.9-15.3%较高水平;两组人群进展期肿瘤的发病风险差异有统计学意义（P <0.01）。风险评估得分为3-4分的研究人群中,45岁以下的年龄组进展期肿瘤的发生率处于3.6%较低水平;45岁以上的年龄组进展期肿瘤的发生率处于5.4-14.8%;两组人群进展期肿瘤的发病风险差异有统计学意义（P <0.01）。风险评估得分为＞4分的研究人群中,进展期肿瘤发生率处于9.8-22.7%较高水平,其40-44岁年龄组进展期肿瘤的发生率9.8%高于风险评估得分为0-2分的研究人群中70-74岁年龄组。在研究总体人群中,55岁以下的年龄组进展期肿瘤的发生率处于2.9-4.5%的较低水平;55岁以上的年龄组进展期肿瘤的发生率处于6.8-17.6%的较高水平;两组人群进展期肿瘤的发病风险差异有统计学意（P <0.01）。男、女性进展期肿瘤的高发年龄分别为45岁以后和60岁以后。 结论 不同风险人群、不同性别的最佳大肠癌筛查开始年龄不同。风险评估得分为0-2分的研究群体、风险评估得分为3-4分的研究群体、风险评估得分为＞4分的研究群体的最佳开始筛查年龄分别为70岁、45岁和40岁。女性开始筛查年龄可以比男性推迟15年。     

老年风湿性心脏病患者瓣膜手术前冠心病风险预测模型的建立及评价

目的筛选危险因素,建立老年风湿性心脏病(RHVD)患者瓣膜手术前冠心病危险度预测模型,以指导冠脉造影检查的选择。方法基于1998~2009年我院连续585例患者的资料,通过Logistic回归筛选老年RHVD患者瓣膜手术前冠心病的危险因素,建立危险度预测模型并以bootstrap方法优化,以预测概率P<0.05为低危险度。以接受者操作特性曲线(ROC曲线)比较该模型和国外类似模型的诊断效能。结果老年RHVD患者并发冠心病的危险因素中影响突出的是:男性、年龄、心绞痛、高血压、高胆固醇血症。成功建立危险度预测模型。151例患者被定义为低危险度,其中4例合并冠心病,均为单支血管病变。ROC曲线下面积0.793,对国人老年RHVD患者术前冠心病危险度具有较优预测效能。结论成功构建了老年RHVD患者瓣膜手术前冠心病风险预测模型,有利于我国老年RHVD患者瓣膜手术前冠心病的筛查。     

Phenotypic characterization of second generation offspring of alcohol-sensitive ANT and alcohol-insensitive AT rat lines

The alcohol-sensitive ANT and the alcohol-insensitive AT rat lines developed by selective breeding for differential sensitivity to motor impairment on the tilting plane by a moderate ethanol dose (2 g/kg, IP), were cross-bred to produce second generation (F₂) offspring to study phenotypic correlations between various behavioral and biochemical properties and the degree of initial alcohol sensitivity in the tilting plane test. The F₂ population (n = 75) was subjected to alcohol sensitivity tests using a tilting plane test and a sleep time test, and to the elevated plus-maze test of sober activity and anxiety. Finally, the animals were sacrificed and the concentrations of dopamine and its acidic metabolites were analyzed in their striatal tissues. Serum corticosterone was determined to obtain information about the stress responses of the animals after the tilting plane test. The behaviors studied had no significant correlations with each other, suggesting that the various genetic and environmental factors affecting these behavioral phenotypes are different for each behavior. The biochemical measures yielded some correlations with the tilting plane test results that were contrary to the differences between the parent rat lines (dopaminergic indices) or that were confounded by the correlations with the body weight of the animals (corticosterone). Body-weight independent correlational tendency between the alcohol-induced impairment in motor performance and serum corticosterone concentration, however, fitted the differences between the parent lines, suggesting that stress mechanisms cannot be fully excluded as factors contributing to the differential alcohol sensitivity between the ANT and AT rat lines.