Performances and efficiencies of displacement ventilation(DV) and partial ventilation(PV) for industrial halls of different configurations as well as the heat and mass transports within the industrial halls were numer...Performances and efficiencies of displacement ventilation(DV) and partial ventilation(PV) for industrial halls of different configurations as well as the heat and mass transports within the industrial halls were numerically investigated. Three levels of Rayleigh number(5.8×1010, 1.0×1012 and 2.1×1012) and two values of source contaminant flux(5 mg/s and 50 mg/s) were considered. The inlet Reynolds numbers were 2×104, 5×104, 1.5×105 and 4.5×105 for DV and 5×105, 1×106, 2×106 and 4×106 for PV, respectively. From the results, it is concluded that the above parameters have very complex impacts on the conjugated heat and mass transports. From points of view of acceptable indoor air quality and ventilation efficiency, PV at Re=1×106 with side-located sources and 65% of the supply air extracted through floor level outlets is the best choice when Ra=5.8×1010. However, DVs at Re=5×104 and Re=1.5×105with center-located sources and floor-mounted air suppliers are the best choices for Ra=1.0×1012 and Ra=2.1×1012, respectively. When source contaminant flux reaches 50 mg/s, local extraction as a supplement of general ventilation is recommended. The results can be a first approximation to 3D numerical investigation and preliminary ventilation system design guidelines for high-rise industrial halls.展开更多
Recently,there has been growing interest in knowing the best hygrometry level during high-flow nasal oxygen and non-invasive ventilation(NIV)and its potential influence on the outcome.Various studies have shown that b...Recently,there has been growing interest in knowing the best hygrometry level during high-flow nasal oxygen and non-invasive ventilation(NIV)and its potential influence on the outcome.Various studies have shown that breathing cold and dry air results in excessive water loss by nasal mucosa,reduced mucociliary clearance,in-creased airway resistance,reduced epithelial cell function,increased inflammation,sloughing of tracheal epithe-lium,and submucosal inflammation.With the Coronavirus Disease 2019 pandemic,using high-flow nasal oxygen with a heated humidifier has become an emerging form of non-invasive support among clinicians.However,we cannot always assume stable humidification.Similarly,there are no clear guidelines for using humidification dur-ing NIV,although humidification of inspired gas during invasive ventilation is an accepted standard of care.NIV disturbs the normal physiological system that warms and humidifies inspired gases.If NIV is supplied through an intensive care unit ventilator that utilizes anhydrous gases from compressed wall air and oxygen,the risk of dry-ness increases.In addition,patients with acute respiratory failure tend to breathe through the mouth during NIV,which is a less efficient route than nasal breathing for adding heat and moisture to the inspired gas.Obstructive sleep apnea syndrome is one of the most important indications for chronic use of NIV at home.Available data suggest that up to 60%of patients with obstructive sleep apnea syndrome who use continuous positive airway pressure therapy experience nasal congestion and dryness of the mouth and nose.Therefore,humidifying the inspired gas in NIV may be essential for patient comfort and compliance with treatment.We aimed to review the available bench and clinical studies that addressed the utility of hygrometry in NIV and nasal high-flow oxygen and discuss the technical limitations of different humidification systems for both systems.展开更多
目的观察老年超重行首次胃镜检查患者接受经鼻湿化高流量通气干预对其生命体征及低氧血症发生率的影响。方法依据干预方法不同,将2021年12月至2023年12月郑州市中医院的98例老年超重行首次胃镜检查患者平均分为两组,检查前,49例对照组...目的观察老年超重行首次胃镜检查患者接受经鼻湿化高流量通气干预对其生命体征及低氧血症发生率的影响。方法依据干预方法不同,将2021年12月至2023年12月郑州市中医院的98例老年超重行首次胃镜检查患者平均分为两组,检查前,49例对照组患者行常规鼻导管吸氧,49例观察组患者行经鼻湿化高流量通气,均干预到检查完毕,对比两组患者在检查期间的生命体征、苏醒时间、检查时间、低氧血症发生率及不良反应情况等。结果两组患者在麻醉前、插入胃镜后、苏醒时的心率和平均动脉压无统计学差异(P>0.05),观察组一次胃镜检查成功率高于对照组,检查和离院时间短于对照组(P<0.05),两组患者的苏醒时间无明显差异(P>0.05),观察组检查期间最低血氧饱和度(Saturation of Blood Oxygen,SpO2)较对照组高,低氧血症发生率较对照组低(P<0.05),两组患者的总不良反应发生率无统计学差异(P>0.05)。结论首次行胃镜检查的老年超重患者接受经鼻湿化高流量通气可有效维持镜检期间生命体征的稳定,缩短镜检及离院时间,提高一次检查的成功率,减少低氧血症的发生且较安全。展开更多
基金Project(2011BAJ03B07)supported by National Twelve Five-year Science and Technology Support Program of ChinaProject supported by the China Scholarship Council+1 种基金Project(51276057,51376198)supported by the National Natural Science Foundation of ChinaProject(CX2014B064)supported by Hunan Provincial Innovation Foundation for Postgraduate,China
文摘Performances and efficiencies of displacement ventilation(DV) and partial ventilation(PV) for industrial halls of different configurations as well as the heat and mass transports within the industrial halls were numerically investigated. Three levels of Rayleigh number(5.8×1010, 1.0×1012 and 2.1×1012) and two values of source contaminant flux(5 mg/s and 50 mg/s) were considered. The inlet Reynolds numbers were 2×104, 5×104, 1.5×105 and 4.5×105 for DV and 5×105, 1×106, 2×106 and 4×106 for PV, respectively. From the results, it is concluded that the above parameters have very complex impacts on the conjugated heat and mass transports. From points of view of acceptable indoor air quality and ventilation efficiency, PV at Re=1×106 with side-located sources and 65% of the supply air extracted through floor level outlets is the best choice when Ra=5.8×1010. However, DVs at Re=5×104 and Re=1.5×105with center-located sources and floor-mounted air suppliers are the best choices for Ra=1.0×1012 and Ra=2.1×1012, respectively. When source contaminant flux reaches 50 mg/s, local extraction as a supplement of general ventilation is recommended. The results can be a first approximation to 3D numerical investigation and preliminary ventilation system design guidelines for high-rise industrial halls.
文摘Recently,there has been growing interest in knowing the best hygrometry level during high-flow nasal oxygen and non-invasive ventilation(NIV)and its potential influence on the outcome.Various studies have shown that breathing cold and dry air results in excessive water loss by nasal mucosa,reduced mucociliary clearance,in-creased airway resistance,reduced epithelial cell function,increased inflammation,sloughing of tracheal epithe-lium,and submucosal inflammation.With the Coronavirus Disease 2019 pandemic,using high-flow nasal oxygen with a heated humidifier has become an emerging form of non-invasive support among clinicians.However,we cannot always assume stable humidification.Similarly,there are no clear guidelines for using humidification dur-ing NIV,although humidification of inspired gas during invasive ventilation is an accepted standard of care.NIV disturbs the normal physiological system that warms and humidifies inspired gases.If NIV is supplied through an intensive care unit ventilator that utilizes anhydrous gases from compressed wall air and oxygen,the risk of dry-ness increases.In addition,patients with acute respiratory failure tend to breathe through the mouth during NIV,which is a less efficient route than nasal breathing for adding heat and moisture to the inspired gas.Obstructive sleep apnea syndrome is one of the most important indications for chronic use of NIV at home.Available data suggest that up to 60%of patients with obstructive sleep apnea syndrome who use continuous positive airway pressure therapy experience nasal congestion and dryness of the mouth and nose.Therefore,humidifying the inspired gas in NIV may be essential for patient comfort and compliance with treatment.We aimed to review the available bench and clinical studies that addressed the utility of hygrometry in NIV and nasal high-flow oxygen and discuss the technical limitations of different humidification systems for both systems.
文摘目的观察老年超重行首次胃镜检查患者接受经鼻湿化高流量通气干预对其生命体征及低氧血症发生率的影响。方法依据干预方法不同,将2021年12月至2023年12月郑州市中医院的98例老年超重行首次胃镜检查患者平均分为两组,检查前,49例对照组患者行常规鼻导管吸氧,49例观察组患者行经鼻湿化高流量通气,均干预到检查完毕,对比两组患者在检查期间的生命体征、苏醒时间、检查时间、低氧血症发生率及不良反应情况等。结果两组患者在麻醉前、插入胃镜后、苏醒时的心率和平均动脉压无统计学差异(P>0.05),观察组一次胃镜检查成功率高于对照组,检查和离院时间短于对照组(P<0.05),两组患者的苏醒时间无明显差异(P>0.05),观察组检查期间最低血氧饱和度(Saturation of Blood Oxygen,SpO2)较对照组高,低氧血症发生率较对照组低(P<0.05),两组患者的总不良反应发生率无统计学差异(P>0.05)。结论首次行胃镜检查的老年超重患者接受经鼻湿化高流量通气可有效维持镜检期间生命体征的稳定,缩短镜检及离院时间,提高一次检查的成功率,减少低氧血症的发生且较安全。
