A bread-and-butter model was proposed to evaluate the weighing uncertainty of gas standard materials by combining the preparation principles of gas standard materials by using weighing method with the differential alg...A bread-and-butter model was proposed to evaluate the weighing uncertainty of gas standard materials by combining the preparation principles of gas standard materials by using weighing method with the differential algorithms of multivariate function.The model was applied to calculate the content of CO in 10 μmol/mol CO standard materials prepared by weighing method and to evaluate its weighing uncertainty.The evaluation processes are simple and the result is reasonable.This modle is suitable for the evaluation of the uncertainty of gas standard materials in industrial processes.展开更多
目的建立一个包含多种胎儿生长受限(fetal growth restriction,FGR)风险因素的预测模型,探讨宫内FGR的相关危险因素,为产前咨询和产后护理提供参考。方法回顾性分析2023-01~12月在作者医院产科住院分娩的359例FGR孕妇的临床资料,根据围...目的建立一个包含多种胎儿生长受限(fetal growth restriction,FGR)风险因素的预测模型,探讨宫内FGR的相关危险因素,为产前咨询和产后护理提供参考。方法回顾性分析2023-01~12月在作者医院产科住院分娩的359例FGR孕妇的临床资料,根据围产结局将孕妇分为预后不良组(n=151)与良好预后组(n=208)。用决策树、随机森林模型、回归列线图模型3种方法来构建FGR孕妇不良围产结局的预测模型。通过评估受试者工作特征(receiver operating characteristic,ROC)曲线的曲线下面积(area under the curve,AUC)、准确性、精确性等参数来分析每种方法的性能。结果预后不良组较良好预后组的孕妇年龄、孕次、体质量、体质量指数(body mass index,BMI)、剖宫产率、新生儿重症监护病房(neonatal intensive care unit,NICU)转入率、产时出血量、产后24 h出血量及胎儿血流信号异常率均升高(P均<0.05),而住院孕周、诊断孕周、分娩孕周、胎盘质量、新生儿出生体质量、新生儿阿普加评分(1 min和5 min)均降低(P均<0.05)。在3种模型中,随机森林模型预测FGR的性能最高,AUC为0.914(95%CI:0.854~0.975)。结论随机森林模型可以精准的预测FGR的发生。加强对预警因素的监测和处理有助于早期预测FGR不良结局,提前采取干预措施,改善母婴预后。展开更多
文摘A bread-and-butter model was proposed to evaluate the weighing uncertainty of gas standard materials by combining the preparation principles of gas standard materials by using weighing method with the differential algorithms of multivariate function.The model was applied to calculate the content of CO in 10 μmol/mol CO standard materials prepared by weighing method and to evaluate its weighing uncertainty.The evaluation processes are simple and the result is reasonable.This modle is suitable for the evaluation of the uncertainty of gas standard materials in industrial processes.
文摘目的建立一个包含多种胎儿生长受限(fetal growth restriction,FGR)风险因素的预测模型,探讨宫内FGR的相关危险因素,为产前咨询和产后护理提供参考。方法回顾性分析2023-01~12月在作者医院产科住院分娩的359例FGR孕妇的临床资料,根据围产结局将孕妇分为预后不良组(n=151)与良好预后组(n=208)。用决策树、随机森林模型、回归列线图模型3种方法来构建FGR孕妇不良围产结局的预测模型。通过评估受试者工作特征(receiver operating characteristic,ROC)曲线的曲线下面积(area under the curve,AUC)、准确性、精确性等参数来分析每种方法的性能。结果预后不良组较良好预后组的孕妇年龄、孕次、体质量、体质量指数(body mass index,BMI)、剖宫产率、新生儿重症监护病房(neonatal intensive care unit,NICU)转入率、产时出血量、产后24 h出血量及胎儿血流信号异常率均升高(P均<0.05),而住院孕周、诊断孕周、分娩孕周、胎盘质量、新生儿出生体质量、新生儿阿普加评分(1 min和5 min)均降低(P均<0.05)。在3种模型中,随机森林模型预测FGR的性能最高,AUC为0.914(95%CI:0.854~0.975)。结论随机森林模型可以精准的预测FGR的发生。加强对预警因素的监测和处理有助于早期预测FGR不良结局,提前采取干预措施,改善母婴预后。
