目的:探讨改良B超胃窦单切面法检测胃窦运动指数(MI)在危重症病人早期肠内营养(EEN)中的作用。方法:将62例拟行经鼻胃管喂养的病人随机分为研究组和对照组,每组31例。研究组病人每天应用B超行胃窦单切面法测定空腹MI,以确定当天EN计划;...目的:探讨改良B超胃窦单切面法检测胃窦运动指数(MI)在危重症病人早期肠内营养(EEN)中的作用。方法:将62例拟行经鼻胃管喂养的病人随机分为研究组和对照组,每组31例。研究组病人每天应用B超行胃窦单切面法测定空腹MI,以确定当天EN计划;对照组则由主管医师根据自己的经验制订。EN期间,根据病人胃残余量和耐受性调整EN的速度,比较两组病人的一般情况、EN实施情况和相关终点指标。结果:研究组病人EN起始速度明显高于对照组(40～75 ml/h vs 30～50 ml/h,P=0.04);达到最大喂养速度的时间也有下降趋势(4.0 h vs 9.3 h);研究组病人超过一种以上EN并发症的发生率(37.9%)明显低于对照组(62.1%),两组的终点指标无明显差异。结论:应用改良B超胃窦单切面法测定MI可以较客观地确定EN喂养速度,有助于及早实现喂养目标和降低EN相关的并发症。展开更多
The concept of critical N concentration(N_c)has been widely used in agronomy as the basis for diagnosis of crop N status,and allows discrimination between field situations of sub-optimal and supra-optimal N supply.A c...The concept of critical N concentration(N_c)has been widely used in agronomy as the basis for diagnosis of crop N status,and allows discrimination between field situations of sub-optimal and supra-optimal N supply.A critical N dilution curve of N_c=34.0W^(-0.37),where W is the aboveground biomass(Mg DM ha^(-1))and N_c the critical N concentration in aboveground dry matter(g kg^(-1)DM),was developed for spring maize in Europe.Our objectives were to validate whether this European critical N dilution curve was appropriate for summer maize production in the North China Plain(NCP)and to develop a critical N dilution curve especially for summer maize production in this region.In total 231 data points from 16 experiments were used to test the European critical N dilution curve.These observations showed that the European critical N dilution curve was unsuitable for summer maize in the NCP,especially at the early growth stage.From the data obtained,a critical N dilution curve for summer maize in the NCP was described by the equation of N_c=27.2W^(-0,27),when aboveground biomass was between 0.64 and 11.17 Mg DM ha^(-1).Based on this curve,more than 90%of the data for the N deficiency supply treatments had an N nutrition index(NNI)<1 and 92%of the data for the N excess supply treatments had an NNI>1.展开更多
文摘目的:探讨改良B超胃窦单切面法检测胃窦运动指数(MI)在危重症病人早期肠内营养(EEN)中的作用。方法:将62例拟行经鼻胃管喂养的病人随机分为研究组和对照组,每组31例。研究组病人每天应用B超行胃窦单切面法测定空腹MI,以确定当天EN计划;对照组则由主管医师根据自己的经验制订。EN期间,根据病人胃残余量和耐受性调整EN的速度,比较两组病人的一般情况、EN实施情况和相关终点指标。结果:研究组病人EN起始速度明显高于对照组(40～75 ml/h vs 30～50 ml/h,P=0.04);达到最大喂养速度的时间也有下降趋势(4.0 h vs 9.3 h);研究组病人超过一种以上EN并发症的发生率(37.9%)明显低于对照组(62.1%),两组的终点指标无明显差异。结论:应用改良B超胃窦单切面法测定MI可以较客观地确定EN喂养速度,有助于及早实现喂养目标和降低EN相关的并发症。
基金Supported by the National Basic Research Program(973 Program)of China(No.2009CB118606)the Special Fund for Agro-Scientific Research in the Public Interest of China(No.201103003)the National Natural Science Foundation of China(No.30821003)
文摘The concept of critical N concentration(N_c)has been widely used in agronomy as the basis for diagnosis of crop N status,and allows discrimination between field situations of sub-optimal and supra-optimal N supply.A critical N dilution curve of N_c=34.0W^(-0.37),where W is the aboveground biomass(Mg DM ha^(-1))and N_c the critical N concentration in aboveground dry matter(g kg^(-1)DM),was developed for spring maize in Europe.Our objectives were to validate whether this European critical N dilution curve was appropriate for summer maize production in the North China Plain(NCP)and to develop a critical N dilution curve especially for summer maize production in this region.In total 231 data points from 16 experiments were used to test the European critical N dilution curve.These observations showed that the European critical N dilution curve was unsuitable for summer maize in the NCP,especially at the early growth stage.From the data obtained,a critical N dilution curve for summer maize in the NCP was described by the equation of N_c=27.2W^(-0,27),when aboveground biomass was between 0.64 and 11.17 Mg DM ha^(-1).Based on this curve,more than 90%of the data for the N deficiency supply treatments had an N nutrition index(NNI)<1 and 92%of the data for the N excess supply treatments had an NNI>1.
