基因表达谱数据分类算法综述

基因表达谱数据的分类算法有很多种,每种分类算法有其各自的特点,不同分类算法在不同基因表达谱数据中的分类效果也有所不同。本文主要对目前应用较多的四种分类算法(判别分析、决策树、支持向量机、集成算法)的特点和研究进展进行综述,为相关研究和应用提供科学指导。     

Work‐related injuries in the Alaska logging industry, 1991‐2014

Background

Although loggers in Alaska are at high risk for occupational injury, no comprehensive review of such injuries has been performed since the mid‐1990s. We investigated work‐related injuries in the Alaska logging industry during 1991‐2014.

Methods

Using data from the Alaska Trauma Registry and the Alaska Occupational Injury Surveillance System, we described fatal and nonfatal injuries by factors including worker sex and age, timing and geographic location of injuries, and four injury characteristics. Annual injury rates and associated 5‐year simple moving averages were calculated.

Results

We identified an increase in the 5‐year simple moving averages of fatal injury rates beginning around 2005. While injury characteristics were largely consistent between the first 14 and most recent 10 years of the investigation, the size of logging companies declined significantly between these periods.

Conclusions

Factors associated with declines in the size of Alaska logging companies might have contributed to the observed increase in fatal injury rates.

     

乙肝核心抗原DNA疫苗的构建及其免疫原性分析

构建ＨＢＶ核心抗原ＤＮＡ疫苗,并探讨基实验动物内的表达及其免疫原性。方法：采用ＰＣＲ法从ＨＢＶ全基因ＤＮＡ中获得核心抗原ＤＮＡ片段,并将其重组到ｐｃＤＮＡ３载体。以此为候选疫苗分别免疫小鼠和树Ｊｕ,并检测其抗ＨＢｃＩｇＧ。结果：构建了乙肝核心抗原候选核酸疫苗ｐｃＤＮＡ３－ＨＢｃ。免疫接种该疫苗后第２周抗ＨＢｃＩｇＧ水平开始升高,小鼠至第９周,树Ｊｕ至第７周升至峰值。结论：构建ｐｃＤＮＡ３－ＨＢＣｄ     

Establishing Decision Trees for Predicting Successful Postpyloric Nasoenteric Tube Placement in Critically Ill Patients

Background

Despite the use of prokinetic agents, the overall success rate for postpyloric placement via a self‐propelled spiral nasoenteric tube is quite low.

Methods

This retrospective study was conducted in the intensive care units of 11 university hospitals from 2006 to 2016 among adult patients who underwent self‐propelled spiral nasoenteric tube insertion. Success was defined as postpyloric nasoenteric tube placement confirmed by abdominal x‐ray scan 24 hours after tube insertion. Chi‐square automatic interaction detection (CHAID), simple classification and regression trees (SimpleCart), and J48 methodologies were used to develop decision tree models, and multiple logistic regression (LR) methodology was used to develop an LR model for predicting successful postpyloric nasoenteric tube placement. The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of these models.

Results

Successful postpyloric nasoenteric tube placement was confirmed in 427 of 939 patients enrolled. For predicting successful postpyloric nasoenteric tube placement, the performance of the 3 decision trees was similar in terms of the AUCs: 0.715 for the CHAID model, 0.682 for the SimpleCart model, and 0.671 for the J48 model. The AUC of the LR model was 0.729, which outperformed the J48 model.

Conclusion

Both the CHAID and LR models achieved an acceptable discrimination for predicting successful postpyloric nasoenteric tube placement and were useful for intensivists in the setting of self‐propelled spiral nasoenteric tube insertion.     

隐结构分析与西医疾病的辨证分型（Ⅲ）：辨证规则的建立

目的：通过使用隐树模型对症状数据进行分析,为西医疾病的辨证分型提供证据,初步建立辨证分型方案和辨证规则。方法：本文为一个文章系列的第3 篇,前两篇论文探讨了通过分析症状数据为辨证分型提供证据的基本原理,展示了隐树分析可以系统地揭示数据不同侧面,并且提出基于数个相关侧面对患者群进行综合聚类,获得辨证分型方案。本文以综合聚类的结果为出发点,提出一种建立辨证分型规则的方法。结果：使用该法对一组血管源性轻度认知障碍数据进行研究,获得辨证分型方案和相应的辨证规则。结论：通过一系列文章构建一套研究西医疾病之辨证分型的完整方法,遵循该法以从疾病患者群的症状数据出发,最终得到辨证分型方案和辨证规则。     

广州市2009年新出现登革3型病毒的分子流行病学分析

目的 对广州市2009年新出现的3型登革病毒(DEN)株的E基因进行RT-PCR扩增和序列测定,探讨其来源及基因型.方法 收集广州市2009年登革热患者急性期血清,用C6/36细胞培养分离DEN,RT-PCR扩增病毒全长E基因,测序并绘制系统进化树,结合流行病学资料进行分子流行病学分析.结果 2009年采集的19份患者血清标本中,分离到7株3型DEN株,RT-PCR扩增后测序获得E基因序列,7株DEN3病毒E基因均由1479个碱基组成,编码493个氨基酸,基因序列未见插入或缺失,分析发现7株病毒来自两个不同的亚型:09/GZ/1081、09/GZ/1483和09/GZ/10806属于东南亚/南太平洋型,09/GZ/10616、09/GZ/11144、09/GZ/11194和09/GZ/13105属于印度次大陆型,各亚型群内毒株序列同源性较高.结论 广州市2009年DEN3为输入性,分属两个基因型.     

基于决策树算法的热毒宁注射液金银花青蒿醇沉过程质量控制研究

目的基于决策树算法,深入挖掘热毒宁注射液金银花青蒿醇沉过程(金青醇沉)数据并探究潜在生产规律,提升该过程质量控制水平。方法依托数字化中药提取工厂数据平台收集205批金银花和青蒿浸膏(金青浸膏)历史数据并整合成数据矩阵。将数据集随机划分为训练集和测试集后分别采用分类与回归树(classification and regression tree,CART)、随机森林(random forests,RF)和TreeNet算法建立金青醇沉过程模型,比较各模型性能并基于历史数据划分关键变量控制范围。结果 RF和TreeNet模型性能较好且性能接近,综合各模型分析结果得出醇提罐料液比及金银花浓缩收率为重要的影响因素,对重要变量进行依存度分析并优选批次,并以优选批次的金银花分配浸膏质量及加醇量做控制图,密度为1.11 g/cm3的金银花浸膏分配控制范围为557.92～639.62 kg,加醇量的控制范围为3.370～3.828 m3;密度为1.12 g/cm3的金银花浸膏的控制范围为540.4～616.9 kg,加醇量的控制范围为3.317～3.859 m~3。结论决策树算法建立的金青浸膏醇沉过程模型能够有效地挖掘潜在的生产过程规律,为生产过程的质量控制提升提供技术支撑。     

茶树油的提取工艺优化试验研究

目的:以茶树油提取率为考察指标,研究茶树油的提取工艺.方法:采用正交试验进行优选,气相色谱法测定4-羟基萜烯含量.结果:影响茶树油提取率的主要因素是提取时间,对茶树油的提取有显著影响;其次是加水量,对茶树油的提取有较大影响;浸泡时间的影响最小.各因素对4-羟基萜烯含量无影响.结论:最佳的提取工艺为浸泡时间2 h,提取时间6 h,加水800 ml.     

基于数据挖掘的低增生性骨髓增生异常综合征与再生障碍性贫血分类模型研究

目的 构建低增生性骨髓增生异常综合征(hypo-MDS)与再生障碍性贫血(AA)鉴别诊断的决策树、贝叶斯、卷积神经网络、改进的支持向量机四种模型并选择出最优模型.方法 收集2010-2019年华北理工大学附属医院的AA与hypo-MDS患者的病例资料,使用统计学方法筛选指标,将处理后的样本以4∶1随机分为训练集和测试集...