Carbon supported Pt（Pt/C） electrocatalysts were prepared with glucose as protection agent and NaBH 4 as reductant.The Pt nanoparticles deposited on carbon support presented reduced size and well dispersity attribute...Carbon supported Pt（Pt/C） electrocatalysts were prepared with glucose as protection agent and NaBH 4 as reductant.The Pt nanoparticles deposited on carbon support presented reduced size and well dispersity attributed to the protection effect of glucose.Glucose absorbed on the particle surface was readily removed by water washing without leading to agglomeration of the Pt nanoparticles.The as-prepared Pt/C electrocatalysts showed improved mass activity for methanol electrooxidation compared to the catalyst prepared without glucose protection.The improved performance is attributed to the larger electrochemical active surface area thus increased active sites on the Pt/C elctrocatalysts prepared under the protection of glucose.展开更多
目的了解不同流感样病例定义对住院儿童流感监测结果的影响。方法利用2017年10月-2018年5月苏州大学附属儿童医院呼吸道疾病综合监测的病原学和临床症状等数据,计算符合中国、欧盟疾病预防控制中心(European center for disease prevent...目的了解不同流感样病例定义对住院儿童流感监测结果的影响。方法利用2017年10月-2018年5月苏州大学附属儿童医院呼吸道疾病综合监测的病原学和临床症状等数据,计算符合中国、欧盟疾病预防控制中心(European center for disease prevention and control,ECDC)和世界卫生组织(world health organization,WHO)的流感样病例定义时的流感病毒检出率,以流感病毒检出为金标准,分别分析三种流感样病例定义确诊的灵敏度、特异度、阳性预测值、阴性预测值与受试者工作特征曲线(receiver operator characteristic curve,ROC)下面积,并采用多因素Logistic回归分析模型分析流感病毒阳性率的相关因素。结果研究共纳入1459例呼吸道感染住院病例,其中流感病毒阳性者204例,阳性率14.0%。ECDC定义的灵敏度最高(91.7%,95%CI:87.9%~95.5%),但其特异度最低(44.6%,95%CI:41.9%~47.4%);WHO定义的灵敏度最低(70.6%,95%CI:64.3%~76.8%);中国定义的灵敏度(91.2%,95%CI:87.3%~95.1%)和特异度(51.5%,95%CI:48.8%~54.3%)均较高,且其ROC曲线下面积最大(71.2%,95%CI:67.9%~74.5%)。多因素分析发现有发热症状(≥38℃)患儿的流感病毒检出率高于不发热患儿(OR=7.03,95%CI:3.89~12.70)。结论在住院儿童中开展流感监测时,采用中国流感监测的流感样病例定义可以获得较好的效果。展开更多
基金Supported by the National Innovative Research Program for Undergraduates,China(No.2010A33039)the Science and Technology Development Program of Jilin Province,China(No.20100420)
文摘Carbon supported Pt（Pt/C） electrocatalysts were prepared with glucose as protection agent and NaBH 4 as reductant.The Pt nanoparticles deposited on carbon support presented reduced size and well dispersity attributed to the protection effect of glucose.Glucose absorbed on the particle surface was readily removed by water washing without leading to agglomeration of the Pt nanoparticles.The as-prepared Pt/C electrocatalysts showed improved mass activity for methanol electrooxidation compared to the catalyst prepared without glucose protection.The improved performance is attributed to the larger electrochemical active surface area thus increased active sites on the Pt/C elctrocatalysts prepared under the protection of glucose.
文摘目的了解不同流感样病例定义对住院儿童流感监测结果的影响。方法利用2017年10月-2018年5月苏州大学附属儿童医院呼吸道疾病综合监测的病原学和临床症状等数据,计算符合中国、欧盟疾病预防控制中心(European center for disease prevention and control,ECDC)和世界卫生组织(world health organization,WHO)的流感样病例定义时的流感病毒检出率,以流感病毒检出为金标准,分别分析三种流感样病例定义确诊的灵敏度、特异度、阳性预测值、阴性预测值与受试者工作特征曲线(receiver operator characteristic curve,ROC)下面积,并采用多因素Logistic回归分析模型分析流感病毒阳性率的相关因素。结果研究共纳入1459例呼吸道感染住院病例,其中流感病毒阳性者204例,阳性率14.0%。ECDC定义的灵敏度最高(91.7%,95%CI:87.9%~95.5%),但其特异度最低(44.6%,95%CI:41.9%~47.4%);WHO定义的灵敏度最低(70.6%,95%CI:64.3%~76.8%);中国定义的灵敏度(91.2%,95%CI:87.3%~95.1%)和特异度(51.5%,95%CI:48.8%~54.3%)均较高,且其ROC曲线下面积最大(71.2%,95%CI:67.9%~74.5%)。多因素分析发现有发热症状(≥38℃)患儿的流感病毒检出率高于不发热患儿(OR=7.03,95%CI:3.89~12.70)。结论在住院儿童中开展流感监测时,采用中国流感监测的流感样病例定义可以获得较好的效果。
