中性点不接地系统接地故障的探讨

中性点不接地系统的接地故障是变配电系统中比较常见的故障现象,对于故障的处理快慢,也决定着以故障现象转变的事故的可能性大小,所以,对这种故障发生及处理过程必须安全、严谨、高效、准确。     

幽门螺杆菌ureA、ureB基因克隆、序列分析及在E.coli中表达

目的　构建含幽门螺杆菌 （Hp） ure A、ure B基因重组质粒 ,测定、分析其核酸序列及推定的氨基酸序列 ,在 E.coli中高效表达两基因 ,为检测试剂和疫苗研究提供基础依据和抗原。方法　PCR法扩增 Hp菌株 HPSH4的 ure A、ure B基因 ,分别与 p GEX- 2 T载体连接并转化大肠杆菌JM10 5 ,测定克隆基因的核酸序列并与 Gen Bank公布的国外 5株 Hp菌株 （2 6 6 95 ,HPK 5 ,J99,CPM6 30 ,M6 0 398）的 ure A、ure B基因作序列比较 ,以 IPTG诱导 ,ure A、ure B基因在 E.coli中高效表达。结果　 ure A核酸同源性 96 .3%～ 98.1% ,氨基酸同源性 98.3%～ 10 0 % ;ure B核酸同源性95 .8%～ 98.0 % ,氨基酸同源性 96 .4 %～ 99.6 %。以 IPTG诱导 ,在 E.coli中表达 rure A融合蛋白5 5 6 0 0 D,rure B融合蛋白 85 5 0 0 D。结论　不同地区 Hp菌株的 ure A、ure B存在程度不同的变...     

小儿肠胃康颗粒治疗小儿腹泻疗效及安全性的Meta分析

目的:采用Meta分析的方法评价小儿肠胃康颗粒治疗小儿腹泻的疗效及安全性。方法:计算机检索Pub Med、EMbase、The Cochrane Library(2015年第6期)、CBM、中国知网、维普数据库和万方数据库,搜集小儿肠胃康颗粒治疗小儿腹泻的相关随机对照试验或半随机对照试验,检索时限均为从建库至2015年6月。由2位研究者独立按纳入排除标准进行文献筛选、资料提取和方法学质量评价,然后采用Rev Man 5.3软件进行Meta分析。结果:最终纳入13个研究共计1 395例患者。Meta分析结果显示在对照组的基础上联用小儿肠胃康颗粒治疗小儿腹泻的总有效率显著高于对照组4.2倍[RR=4.20,95%CI(2.93-6.03),P0.05]。按腹泻类型的亚组分析结果显示:小儿肠胃康颗粒治疗秋季腹泻的总有效率显著高于对照组4.3倍[RR=4.30,95%CI(2.24-8.27),P0.05],小儿肠胃康颗粒治疗消化不良性腹泻的总有效率也显著高于对照组3.92倍[RR=3.92,95%CI(2.51-6.11),P0.05]。结论:当前证据表明与单用其他药物比较,联合应用小儿肠胃康颗粒能显著改善小儿腹泻,特别是秋季腹泻和消化不良性腹泻。但受纳入研究质量和样本量的限制,当前的结果建议开展更多高质量和大样本的研究加以验证。     

头孢拉定及其胶囊剂中有关物质检查方法的探讨

目的:对头孢拉定原料及制剂的有关物质检查方法进行探讨.方法:对现行版药典中的头孢拉定及其制剂的有关物质检查方法进行比较和实验观察.结论:可用<中国药典>中检查拉定原料有关物质的方法对胶囊剂进行检查,并认为有必要增加此项目.同时建议对原料有关物质检查项中杂质对照的点样方法进行修改.     

肤宁洗剂的质量标准

目的:建立肤宁洗剂进行质量标准.方法:采用薄层色谱法鉴别制剂中的白鲜皮、川椒;采用紫外-可见分光光度法测定肤宁洗剂中总黄酮含量.结果:以TLC法鉴别白鲜皮、川椒,方法具有专属性.芦丁在0.004～0.024 mg·ml-1范围内有良好的线性关系(r=0.999 2).平均加样回收率为99.37%,RSD为0.91%(n=6).结论:本方法简便、准确,所建标准可用于肤宁洗剂质量控制.     

Cajal间质细胞的研究进展

Cajal间质细胞(interstitial cells of Cajal,ICC)是一类主要分布于胃肠道的间质细胞,是胃肠道的起搏细胞(pacemaker cell)和信号传导细胞,与肌细胞以及末梢神经元有着紧密的关系,具有激发和促进胃肠蠕动的作用.借助于电子显微镜技术,清楚观察到了ICC位置分布和内部精细结构;应用免疫荧光等生化技术,发现了其特殊表达的C-kit蛋白;利用电生理技术,得知多种胃肠动力障碍疾病也与其异常有关.多年来,学者逐渐在胃肠道、胆道、膀胱、子宫等部位发现了ICC的踪迹,并试图阐述其与某些疾病的发生机制.本文就ICC的起源、形态学、受体和功能、以及与其相关的疾病等作一综述.     

Preconditioning threshold of brief pressure overload of the left ventricle

BackgroundWe previously reported that pressure overload of the left ventricle reduced myocardial infarct (MI) size in rabbits. The threshold of pressure overload was investigated in this study.MethodsPressure overload of the left ventricle was induced by partial snare of the ascending aorta in anesthetized, open-chest rabbits. Systolic left ventricular pressure (SLVP) was elevated 50% or 30% above baseline value by varying the degree of partial snaring. Different duration of pressure overload, including 10 minutes, 5 minutes, 3 minutes, or 2 minutes, was applied to determine the threshold of protective effects. Ischemic preconditioning was elicited by two 10-minute coronary artery occlusions and reperfusions. Ten minutes after different pretreatment, 1 hour occlusion of the left anterior descending coronary artery followed by 3 hours reperfusion was done to induce MI. The size of area at risk and MI were determined by blue dye injection and triphenyl tetrazolium chloride staining after experiments.ResultsPressure overload increase of SLVP 50% above baseline value for 10 minutes, 5 minutes, and 3 minutes significantly reduced MI size (18.5 ± 3.6%, 21.4 ± 1.9% and 21.6 ± 1.7%, respectively, vs. 26.6 ± 1.0% in the control group, mean ± standard deviation, p < 0.01). A 30% increase of SLVP by pressure overload for 10 minutes, 5 minutes and 3 minutes also significantly decreased MI size (20.5 ± 2.5%, 21.6 ± 2.3%, and 21.5 ± 2.3%, p < 0.01). Ischemic preconditioning significantly decreased MI size (19.9 ± 2.8%, p < 0.001). Pressure overload to elevate SLVP 50% or 30% above baseline value for 2 minutes did not significantly alter MI size (25.0 ± 2.3% and 26.0 ± 1.7%, p = 0.122 and p = 0.457). Two episodes of 2 minutes pressure overload did not significantly decrease MI size (25.0 ± 2.2% and 25.5 ± 2.2%, p = 0.118 and p = 0.281). The hemodynamics, area at risk, and mortality were not significantly different among all groups of animals.ConclusionPressure overload to raise SLVP either 50% or 30% above baseline value reduced MI size. A minimum duration of 3 minutes was necessary to induce the protective effects.     

Physician performance assessment: prevention of cardiovascular disease

Given the rising burden of healthcare costs, both patients and healthcare purchasers are interested in discerning which physicians deliver quality care. We proposed a methodology to assess physician clinical performance in preventive cardiology care, and determined a benchmark for minimally acceptable performance. We used data on eight evidence-based clinical measures from 811 physicians that completed the American Board of Internal Medicine’s Preventive Cardiology Practice Improvement Module^SM to form an overall composite score for preventive cardiology care. An expert panel of nine internists/cardiologists skilled in preventive care for cardiovascular disease used an adaptation of the Angoff standard-setting method and the Dunn-Rankin method to create the composite and establish a standard. Physician characteristics were used to examine the validity of the inferences made from the composite scores. The mean composite score was 73.88 % (SD = 11.88 %). Reliability of the composite was high at 0.87. Specialized cardiologists had significantly lower composite scores (P = 0.04), while physicians who reported spending more time in primary, longitudinal, and preventive consultative care had significantly higher scores (P = 0.01), providing some evidence of score validity. The panel established a standard of 47.38 % on the composite measure with high classification accuracy (0.98). Only 2.7 % of the physicians performed below the standard for minimally acceptable preventive cardiovascular disease care. Of those, 64 % (N = 14) were not general cardiologists. Our study presents a psychometrically defensible methodology for assessing physician performance in preventive cardiology while also providing relative feedback with the hope of heightening physician awareness about deficits and improving patient care.     

20种活血化瘀药对实验性微循环障碍影响的观察

观察20种活血化瘀中药对小鼠肠系膜实验性微循环障碍改善作用的影响,结果表明:红花、莪术、刘寄奴、元胡、五灵脂的作用最好;其次为川芎、益母草、丹皮、没药、山楂、苏木;再次为当归、乳香;最后是丹参、大黄、桃仁,郁金、三棱、赤芍。而鸡血藤却有促进微循环障碍发展作用,有待进一步研究。