目的临床常采用末梢血氧饱和度对儿科重症监护室(pediatric intensive care unit,PICU)机械通气过程中的生命体征监测,但此种监测方式对儿科重症患儿缺乏一定的直观性。近年来,呼气末二氧化碳波形图在临床上广泛应用。本研究对呼气末二...目的临床常采用末梢血氧饱和度对儿科重症监护室(pediatric intensive care unit,PICU)机械通气过程中的生命体征监测,但此种监测方式对儿科重症患儿缺乏一定的直观性。近年来,呼气末二氧化碳波形图在临床上广泛应用。本研究对呼气末二氧化碳波形图监测在PICU机械通气患儿中的应用效果进行评估与分析,为临床监测提供思路和方案支持。方法选取2017-07-01-2018-07-01郑州大学附属儿童医院PICU实施机械通气治疗的106例患儿为研究对象,根据患儿的性别、年龄等因素选择对照组与观察组,每组53例。观察组实施呼气末二氧化碳波形图监测,对照组未实施呼气末二氧化碳波形图监测。分析两组患儿病情的监测情况,对比分析两组不良事件发生、响应情况以及预后。结果观察组机械通气不良事件的发生率为28.3%,与对照组的45.3%比较,差异无统计意义,χ2=3.295,P=0.070。观察组错误插管响应时间为(0.58±0.17)min,短于对照组的(2.11±0.42)min,t=24.583,P<0.001;呼吸机管路脱落响应时间为(0.24±0.12)min,短于对照组的(0.88±0.15)min,t=24.255,P<0.001;呼吸机管路打折或扭曲响应时间为(1.05±0.34)min,短于对照组的(1.87±0.26)min,t=13.947,P<0.001;通气不足响应时间为(4.12±0.78)min,短于对照组的(7.61±1.23)min,t=17.445,P<0.001。观察组治愈出院率为98.11%,高于对照组的94.34%;死亡率为1.89%,低于对照组的5.66%;治愈出院率与死亡率两组比较差异均无统计学意义,χ2值分别为0.139和0.266,P值分别为0.308和0.610。结论呼气末二氧化碳波形图监测在PICU机械通气患儿中的应用效果显著,能及时发现机械通气不良事件,改善患者的预后。展开更多
CO2 concentrations at different heights in a broadleaved/Korean forest (with a mean height of 26 m) were measured with infrared gas analyzer IRGA (model 2250D, LI-COR Inc. and LI-COR, 820) from Aug. to Oct. of 1999, A...CO2 concentrations at different heights in a broadleaved/Korean forest (with a mean height of 26 m) were measured with infrared gas analyzer IRGA (model 2250D, LI-COR Inc. and LI-COR, 820) from Aug. to Oct. of 1999, Apr. to Jul. of 2000, and from Aug. 2002 to Sept. 2003. Based on the collected dada, the diurnal and seasonal dynamics of profiles and storage of carbon dioxide in the forest were analyzed. The diurnal CO2 profiles showed that the vertical distribution of CO2 concentration were different for daytime and nighttime, and the CO2 concentration was highest close to forest floor, no matter at daytime and nighttime. The seasonal profiles of CO2 showed that stratification in the canopy was evident during growth season. CO2 concentrations at different heights (60 m to 2.5 m) had a little change in March, with a difference of 10 mmolmol-1, but had a significant change in July, with a difference of 60 mmolmol-1. In July, there also existed a greater gradient of CO2 concentrations at canopy (22, 26 and 32 m), with a difference of 8 mmolmol-1. The calculated total storage (ΔC/Δt ) of CO2 in the air column with height of 40 m beneath eddy covariance instrument was negative, and made a little contribution to NEE.展开更多
The effect of the fracture distribution on CO 2 injection into coal seams was studied with a heterogeneous model having dual porosity to represent both the primary medium (the coal matrix) and the secondary medium (th...The effect of the fracture distribution on CO 2 injection into coal seams was studied with a heterogeneous model having dual porosity to represent both the primary medium (the coal matrix) and the secondary medium (the fractures) under variable stress conditions. A numerical generation method and a digital image processing method were used to model the heterogeneous fracture distribution in the coal. The model solutions demonstrate that: (1) the fractures are the main channel for gas flow and their distribution has an important impact on the gas injection rate; (2) the fractures only affect the injection rate of CO 2 into the coal but not the final storage amount; (3) when gas is injected into coal the fractures will first expand and then close due to the changing effective stresses and the adsorption induced swelling of coal grains. This fully coupled dual-porosity model with a heterogeneous fracture distribution provides a way to predict the CO 2 injection into a coal seam.展开更多
文摘目的临床常采用末梢血氧饱和度对儿科重症监护室(pediatric intensive care unit,PICU)机械通气过程中的生命体征监测,但此种监测方式对儿科重症患儿缺乏一定的直观性。近年来,呼气末二氧化碳波形图在临床上广泛应用。本研究对呼气末二氧化碳波形图监测在PICU机械通气患儿中的应用效果进行评估与分析,为临床监测提供思路和方案支持。方法选取2017-07-01-2018-07-01郑州大学附属儿童医院PICU实施机械通气治疗的106例患儿为研究对象,根据患儿的性别、年龄等因素选择对照组与观察组,每组53例。观察组实施呼气末二氧化碳波形图监测,对照组未实施呼气末二氧化碳波形图监测。分析两组患儿病情的监测情况,对比分析两组不良事件发生、响应情况以及预后。结果观察组机械通气不良事件的发生率为28.3%,与对照组的45.3%比较,差异无统计意义,χ2=3.295,P=0.070。观察组错误插管响应时间为(0.58±0.17)min,短于对照组的(2.11±0.42)min,t=24.583,P<0.001;呼吸机管路脱落响应时间为(0.24±0.12)min,短于对照组的(0.88±0.15)min,t=24.255,P<0.001;呼吸机管路打折或扭曲响应时间为(1.05±0.34)min,短于对照组的(1.87±0.26)min,t=13.947,P<0.001;通气不足响应时间为(4.12±0.78)min,短于对照组的(7.61±1.23)min,t=17.445,P<0.001。观察组治愈出院率为98.11%,高于对照组的94.34%;死亡率为1.89%,低于对照组的5.66%;治愈出院率与死亡率两组比较差异均无统计学意义,χ2值分别为0.139和0.266,P值分别为0.308和0.610。结论呼气末二氧化碳波形图监测在PICU机械通气患儿中的应用效果显著,能及时发现机械通气不良事件,改善患者的预后。
基金This study is supported by The Development Plan of State Key Fundamental Research of China (973) (contract No. 2002CB412502),by Knowledge Innovation Project of CAS (KZCX1-SW-01-03) and by Natural Science Foundation of China (30170167).
文摘CO2 concentrations at different heights in a broadleaved/Korean forest (with a mean height of 26 m) were measured with infrared gas analyzer IRGA (model 2250D, LI-COR Inc. and LI-COR, 820) from Aug. to Oct. of 1999, Apr. to Jul. of 2000, and from Aug. 2002 to Sept. 2003. Based on the collected dada, the diurnal and seasonal dynamics of profiles and storage of carbon dioxide in the forest were analyzed. The diurnal CO2 profiles showed that the vertical distribution of CO2 concentration were different for daytime and nighttime, and the CO2 concentration was highest close to forest floor, no matter at daytime and nighttime. The seasonal profiles of CO2 showed that stratification in the canopy was evident during growth season. CO2 concentrations at different heights (60 m to 2.5 m) had a little change in March, with a difference of 10 mmolmol-1, but had a significant change in July, with a difference of 60 mmolmol-1. In July, there also existed a greater gradient of CO2 concentrations at canopy (22, 26 and 32 m), with a difference of 8 mmolmol-1. The calculated total storage (ΔC/Δt ) of CO2 in the air column with height of 40 m beneath eddy covariance instrument was negative, and made a little contribution to NEE.
基金supported by the Chinese National Science Foundation (51104147)the Fundamental Research Funds for the Central Universities (2011QNA17)+1 种基金National Basic Research Program of China (2010CB226800)State Key Laboratory for Geo-mechanics and Deep Underground Engineering in China
文摘The effect of the fracture distribution on CO 2 injection into coal seams was studied with a heterogeneous model having dual porosity to represent both the primary medium (the coal matrix) and the secondary medium (the fractures) under variable stress conditions. A numerical generation method and a digital image processing method were used to model the heterogeneous fracture distribution in the coal. The model solutions demonstrate that: (1) the fractures are the main channel for gas flow and their distribution has an important impact on the gas injection rate; (2) the fractures only affect the injection rate of CO 2 into the coal but not the final storage amount; (3) when gas is injected into coal the fractures will first expand and then close due to the changing effective stresses and the adsorption induced swelling of coal grains. This fully coupled dual-porosity model with a heterogeneous fracture distribution provides a way to predict the CO 2 injection into a coal seam.
