目的:本研究旨在探讨身体质量指数(body mass index,BMI)与子宫内膜癌之间的因果关系。方法:使用全基因组关联研究(GWAS)的公开汇总数据集进行孟德尔随机化(MR)分析。从171977名欧洲血统参与者的汇总数据中,总共提取37个单核苷酸多态性(...目的:本研究旨在探讨身体质量指数(body mass index,BMI)与子宫内膜癌之间的因果关系。方法:使用全基因组关联研究(GWAS)的公开汇总数据集进行孟德尔随机化(MR)分析。从171977名欧洲血统参与者的汇总数据中,总共提取37个单核苷酸多态性(SNP)作为暴露BMI的工具变量。子宫内膜癌的GWAS汇总数据来自子宫内膜癌协会联盟(12906例病例和108979例对照)。采用逆方差加权(IVW)作为MR的主要分析方法,并辅以加权中位数(WME)、MR-Egger法、简单众数法(SM)和加权众数法(WM)。同时进行了多效性分析、异质性分析和留一敏感性分析,以进一步评估BMI与子宫内膜癌之间的因果关系。结果:IVW分析发现,BMI与子宫内膜癌之间存在因果关系(OR:1.734,95%CI:1.442,2.084),BMI每增加一个标准差(4.77 kg/m^(2))与子宫内膜癌总体风险增加相关。异质性分析显示纳入SNP之间无异质性(P=0.055)。水平多效性分析显示BMI与子宫内膜癌之间的相关性无水平多效性(MR Egger截距=0.010,P=0.278)。结论:BMI与子宫内膜癌之间存在因果关系,BMI升高增加患子宫内膜癌的风险。展开更多
In order to suppress the harm of gas explosion,the current study researched on the body of vacuum chamber.The previous studies verifed that it could obviously lower the explosion overpressure by reasonably arranging v...In order to suppress the harm of gas explosion,the current study researched on the body of vacuum chamber.The previous studies verifed that it could obviously lower the explosion overpressure by reasonably arranging vacuum chamber on pipe.That is to say,the vacuum chamber has the effect of absorbing wave and energy.To further deeply analyze the vacuum chamber suppressing gas explosion,this research designed the L-type pipe of gas explosion,and compared the experimental results of gas explosion with vacuum chamber and without vacuum chamber.Besides,using the gas chromatograph,this study also investigated the gas compositions in the pipe before and after explosion.The results show that:(1)without vacuum chamber,the maximum value of explosion overpressure is 0.22 MPa,with60 ms duration,and after explosion,the concentration of oxygen drops to 12.07%,but the concentration of carbon monoxide increases to 4392.3 10à6,and the concentration of carbon dioxide goes up to7.848%,which can make the persons in danger suffocate and die;(2)with vacuum chamber,explosion overpressure drops to 0.18 MPa,with 20 ms duration or less,and after explosion,the concentration of oxygen still remains 12.07%,but the concentration of methane is 7.83%,however the concentration of carbon monoxide is only 727.24 10à6,and the concentration of carbon dioxide is only 1.219%,at the this moment the concentration ratio of toxic gas drops by more than 83%in comparison to be that without vacuum chamber.Consequently,the vacuum chamber can guarantee that most methane does not take part in chemical reaction,and timely quenches the deflagration reaction of gas and oxygen.Because of the two points mentioned above,it reduces the explosion energy,and lowers that the overpressure of blast wave impacts and damages on the persons and facilities,and also decreases the consumption of oxygen and the production of the toxic gas.Therefore,it is safe to conclude that the vacuum chamber not only absorbs wave and energy,but also prevents and suppresses explosion.展开更多
文摘目的:本研究旨在探讨身体质量指数(body mass index,BMI)与子宫内膜癌之间的因果关系。方法:使用全基因组关联研究(GWAS)的公开汇总数据集进行孟德尔随机化(MR)分析。从171977名欧洲血统参与者的汇总数据中,总共提取37个单核苷酸多态性(SNP)作为暴露BMI的工具变量。子宫内膜癌的GWAS汇总数据来自子宫内膜癌协会联盟(12906例病例和108979例对照)。采用逆方差加权(IVW)作为MR的主要分析方法,并辅以加权中位数(WME)、MR-Egger法、简单众数法(SM)和加权众数法(WM)。同时进行了多效性分析、异质性分析和留一敏感性分析,以进一步评估BMI与子宫内膜癌之间的因果关系。结果:IVW分析发现,BMI与子宫内膜癌之间存在因果关系(OR:1.734,95%CI:1.442,2.084),BMI每增加一个标准差(4.77 kg/m^(2))与子宫内膜癌总体风险增加相关。异质性分析显示纳入SNP之间无异质性(P=0.055)。水平多效性分析显示BMI与子宫内膜癌之间的相关性无水平多效性(MR Egger截距=0.010,P=0.278)。结论:BMI与子宫内膜癌之间存在因果关系,BMI升高增加患子宫内膜癌的风险。
基金Financial support from the State Key Laboratory Cultivation Base for Gas Geology and Gas Control of Henan Polytechnic University of China(No.WS2012A04)
文摘In order to suppress the harm of gas explosion,the current study researched on the body of vacuum chamber.The previous studies verifed that it could obviously lower the explosion overpressure by reasonably arranging vacuum chamber on pipe.That is to say,the vacuum chamber has the effect of absorbing wave and energy.To further deeply analyze the vacuum chamber suppressing gas explosion,this research designed the L-type pipe of gas explosion,and compared the experimental results of gas explosion with vacuum chamber and without vacuum chamber.Besides,using the gas chromatograph,this study also investigated the gas compositions in the pipe before and after explosion.The results show that:(1)without vacuum chamber,the maximum value of explosion overpressure is 0.22 MPa,with60 ms duration,and after explosion,the concentration of oxygen drops to 12.07%,but the concentration of carbon monoxide increases to 4392.3 10à6,and the concentration of carbon dioxide goes up to7.848%,which can make the persons in danger suffocate and die;(2)with vacuum chamber,explosion overpressure drops to 0.18 MPa,with 20 ms duration or less,and after explosion,the concentration of oxygen still remains 12.07%,but the concentration of methane is 7.83%,however the concentration of carbon monoxide is only 727.24 10à6,and the concentration of carbon dioxide is only 1.219%,at the this moment the concentration ratio of toxic gas drops by more than 83%in comparison to be that without vacuum chamber.Consequently,the vacuum chamber can guarantee that most methane does not take part in chemical reaction,and timely quenches the deflagration reaction of gas and oxygen.Because of the two points mentioned above,it reduces the explosion energy,and lowers that the overpressure of blast wave impacts and damages on the persons and facilities,and also decreases the consumption of oxygen and the production of the toxic gas.Therefore,it is safe to conclude that the vacuum chamber not only absorbs wave and energy,but also prevents and suppresses explosion.
