Introduction: Partial liquid ventilation may benefit the lung disease in preterm neonates but intratracheal instillation of perfluorocarbon increases cerebral blood flow and may cause brain injury. We aimed to determi...Introduction: Partial liquid ventilation may benefit the lung disease in preterm neonates but intratracheal instillation of perfluorocarbon increases cerebral blood flow and may cause brain injury. We aimed to determine if the effects of perfluorocarbon administration on cerebral blood flow vary by dose-volume, rate of administration, endotracheal tube portal of entry, or closely targeting PaCO2. Methods: Forty-two dosing events (in eleven rabbits) were randomised to different dosing strategies, including a sham (i.e., placebo/control) dose of air over 20 min, 20 mL/kg of perfluorocarbon slowly over 20 min, 10 mL/kg of perfluorocarbon slowly over 20 min, 10 mL/kg of perfluorocarbon moderately fast over 10 min, 10 mL/kg of perfluorocarbon rapidly over 5 min, 10 mL/kg of perfluorocarbon slowly over 20 min via the endotracheal tube tip lumen (as opposed to the proximal end of the tube used in all other groups), or 10 mL/kg of perfluorocarbon slowly over 20 min whilst targeting a PaCO2 of 45 - 50 mmHg. Blood gases, haemodynamics, cortical cerebral blood flow and carotid flow were recorded continuously for 30 minutes from the start of each dose. Results: Carotid flow increased with 20 mL/kg perfluorocarbon and cortical cerebral blood flow was significantly more variable. Carotid and cortical cerebral blood flow increased using 10 mL/kg or 20 mL/kg with no difference between the two dose-volumes. There was no difference in cerebral blood flow by rate of administration, but carotid blood flow was more variable during slow administration. There were no differences in the increase in cerebral blood flow by portal of entry. If PaCO2 was maintained between 45 - 50 mmHg there was no increase in cerebral blood flow and there was less variable carotid flow. Conclusions: Cerebral blood flow increases with perfluorocarbon dosing. This occurs regardless of the dose-volume of perfluorocarbon. These effects were mitigated by closely targeting PaCO2.展开更多
Wall-mounted swirling ventilation is a new type of system in mechanized excavation faces with a dust sup-pression performance that is closely related to the blowing-to-suction flow ratio.Physical and simulation models...Wall-mounted swirling ventilation is a new type of system in mechanized excavation faces with a dust sup-pression performance that is closely related to the blowing-to-suction flow ratio.Physical and simulation models were developed according to the No.C103 mechanized excavation face in the Nahe Coal Mine of the Baise Mining Bureau,Guangxi Province to optimize the blowing-to-suction flow ratio for wall-mounted swirling ventilation.Both the k-εturbulence model and the discrete phase model were utilized to simulate airflow field structures and dust concentration distribution patterns at various blowing-to-suction flow ratios.The results suggest that higher blowing-to-suction flow ratios increase the airflow field disturbance around the working face and weaken the intensity of the axial air curtain.On the other hand,both the intensity of the radial air curtain and the dust suppression effect are enhanced.At a blowing-to-suction flow ratio of 0.8,the wall-mounted swirling ventilation system achieved the most favorable dust suppression performance.Both the total dust and respirable dust had their lowest concentrations with maximum efficiencies of reducing both types at 90.33%and 87.16%,respectively.展开更多
We examined the effect of androgens on bladder blood flow （BBF）, bladder function and histological changes in castrated male rats. Male Wistar rats were classified into unoperated group （control group）, groups cas...We examined the effect of androgens on bladder blood flow （BBF）, bladder function and histological changes in castrated male rats. Male Wistar rats were classified into unoperated group （control group）, groups castrated at the age of 8weeks （group 8wPC） and groups castrated at the age of 4weeks （group 4wPC）. Each rat was used at the age of 20weeks. BBF was measured using fluorescent microspheres. Bladder cystometry was performed without anesthesia or restraint; the bladder was first irrigated with saline and then with 0.25% acetic acid （AA） solution. Maximum voiding pressure and voiding interval were measured. The bladder and lilac artery were histologically examined for differences in smooth muscle and quantity of collagen fiber to analyze the effect of castration on the smooth muscle content. No differences were noted in BBF following castration. The voiding intervals for all groups were shortened （P 〈 0.001） following AA irrigation. No significant difference was noted in the maximum voiding pressure. Histological changes were observed in bladder and lilac artery. Smooth muscle/collagen ratio at the bladder was lower in groups 8wPC and 4wPC compared to the control group （P 〈 0.01）, while that at the lilac artery was decreased in group 4wPC compared to the control group （P〈 0.001）. In conclusion, our findings indicate that castration does not alter BBF, but leads to histological changes in the bladder as well as its associated blood vessels.展开更多
目的:探究尿素氮与白蛋白比值(blood urea nitrogen to serum albumin ratio,B/A)对老年慢性阻塞性肺疾病急性加重期(acute exacerbation of chronic obstructive pulmonary disease,AECOPD)合并肾功能不全患者,无创机械通气(non-invasi...目的:探究尿素氮与白蛋白比值(blood urea nitrogen to serum albumin ratio,B/A)对老年慢性阻塞性肺疾病急性加重期(acute exacerbation of chronic obstructive pulmonary disease,AECOPD)合并肾功能不全患者,无创机械通气(non-invasive mechanical ventilation,NIV)预后的预测价值。方法:选择2021年1月至2023年1月,在连云港市第二人民医院肾内科,收治的老年AECOPD合并肾功能不全患者接受NIV患者220例,依据患者住院NIV治疗后28 d的生存情况分为:生存组(180例)和死亡组(40例),比较两组患者的B/A,运用Logistic回归性分析和受试者工作特征曲线ROC评价入院初24 h的B/A预测AECOPD合并肾功能不全患者NIV治疗后28 d预后的价值。结果:生存组白蛋白、血红蛋白和血小板显著高于死亡组患者(P <0.05),生存组尿素氮、B/A、急性生理和慢性健康评分(acutephysiology and chronic health evaluationⅡ,APACHEⅡ)显著低于死亡组患者(P <0.05)。Logistic回归分析结果显示B/A和APACHEⅡ评分是导致患者死亡的危险因素(P <0.05)。ROC分析显示,B/A的曲线下面积、敏感度、特异度均较APACHEⅡ评分增高,B/A与APACHEⅡ评分的AUC差异无统计学意义(t=1.686,P=0.093)。结论:B/A和APACHEⅡ评分均可用于评估老年AECOPD合并肾功能不全患者NIV预后,与APACHEⅡ评分比,B/A在评估老年AECOPD患者NIV预后的效能更高。展开更多
文摘Introduction: Partial liquid ventilation may benefit the lung disease in preterm neonates but intratracheal instillation of perfluorocarbon increases cerebral blood flow and may cause brain injury. We aimed to determine if the effects of perfluorocarbon administration on cerebral blood flow vary by dose-volume, rate of administration, endotracheal tube portal of entry, or closely targeting PaCO2. Methods: Forty-two dosing events (in eleven rabbits) were randomised to different dosing strategies, including a sham (i.e., placebo/control) dose of air over 20 min, 20 mL/kg of perfluorocarbon slowly over 20 min, 10 mL/kg of perfluorocarbon slowly over 20 min, 10 mL/kg of perfluorocarbon moderately fast over 10 min, 10 mL/kg of perfluorocarbon rapidly over 5 min, 10 mL/kg of perfluorocarbon slowly over 20 min via the endotracheal tube tip lumen (as opposed to the proximal end of the tube used in all other groups), or 10 mL/kg of perfluorocarbon slowly over 20 min whilst targeting a PaCO2 of 45 - 50 mmHg. Blood gases, haemodynamics, cortical cerebral blood flow and carotid flow were recorded continuously for 30 minutes from the start of each dose. Results: Carotid flow increased with 20 mL/kg perfluorocarbon and cortical cerebral blood flow was significantly more variable. Carotid and cortical cerebral blood flow increased using 10 mL/kg or 20 mL/kg with no difference between the two dose-volumes. There was no difference in cerebral blood flow by rate of administration, but carotid blood flow was more variable during slow administration. There were no differences in the increase in cerebral blood flow by portal of entry. If PaCO2 was maintained between 45 - 50 mmHg there was no increase in cerebral blood flow and there was less variable carotid flow. Conclusions: Cerebral blood flow increases with perfluorocarbon dosing. This occurs regardless of the dose-volume of perfluorocarbon. These effects were mitigated by closely targeting PaCO2.
基金support for this work was provided by the National Natural Science Foundation of China(No.51574123)the Scientific Research Project of Hunan Province Office of Education(No.18A185),which are gratefully acknowledged.
文摘Wall-mounted swirling ventilation is a new type of system in mechanized excavation faces with a dust sup-pression performance that is closely related to the blowing-to-suction flow ratio.Physical and simulation models were developed according to the No.C103 mechanized excavation face in the Nahe Coal Mine of the Baise Mining Bureau,Guangxi Province to optimize the blowing-to-suction flow ratio for wall-mounted swirling ventilation.Both the k-εturbulence model and the discrete phase model were utilized to simulate airflow field structures and dust concentration distribution patterns at various blowing-to-suction flow ratios.The results suggest that higher blowing-to-suction flow ratios increase the airflow field disturbance around the working face and weaken the intensity of the axial air curtain.On the other hand,both the intensity of the radial air curtain and the dust suppression effect are enhanced.At a blowing-to-suction flow ratio of 0.8,the wall-mounted swirling ventilation system achieved the most favorable dust suppression performance.Both the total dust and respirable dust had their lowest concentrations with maximum efficiencies of reducing both types at 90.33%and 87.16%,respectively.
文摘We examined the effect of androgens on bladder blood flow （BBF）, bladder function and histological changes in castrated male rats. Male Wistar rats were classified into unoperated group （control group）, groups castrated at the age of 8weeks （group 8wPC） and groups castrated at the age of 4weeks （group 4wPC）. Each rat was used at the age of 20weeks. BBF was measured using fluorescent microspheres. Bladder cystometry was performed without anesthesia or restraint; the bladder was first irrigated with saline and then with 0.25% acetic acid （AA） solution. Maximum voiding pressure and voiding interval were measured. The bladder and lilac artery were histologically examined for differences in smooth muscle and quantity of collagen fiber to analyze the effect of castration on the smooth muscle content. No differences were noted in BBF following castration. The voiding intervals for all groups were shortened （P 〈 0.001） following AA irrigation. No significant difference was noted in the maximum voiding pressure. Histological changes were observed in bladder and lilac artery. Smooth muscle/collagen ratio at the bladder was lower in groups 8wPC and 4wPC compared to the control group （P 〈 0.01）, while that at the lilac artery was decreased in group 4wPC compared to the control group （P〈 0.001）. In conclusion, our findings indicate that castration does not alter BBF, but leads to histological changes in the bladder as well as its associated blood vessels.
文摘目的:探究尿素氮与白蛋白比值(blood urea nitrogen to serum albumin ratio,B/A)对老年慢性阻塞性肺疾病急性加重期(acute exacerbation of chronic obstructive pulmonary disease,AECOPD)合并肾功能不全患者,无创机械通气(non-invasive mechanical ventilation,NIV)预后的预测价值。方法:选择2021年1月至2023年1月,在连云港市第二人民医院肾内科,收治的老年AECOPD合并肾功能不全患者接受NIV患者220例,依据患者住院NIV治疗后28 d的生存情况分为:生存组(180例)和死亡组(40例),比较两组患者的B/A,运用Logistic回归性分析和受试者工作特征曲线ROC评价入院初24 h的B/A预测AECOPD合并肾功能不全患者NIV治疗后28 d预后的价值。结果:生存组白蛋白、血红蛋白和血小板显著高于死亡组患者(P <0.05),生存组尿素氮、B/A、急性生理和慢性健康评分(acutephysiology and chronic health evaluationⅡ,APACHEⅡ)显著低于死亡组患者(P <0.05)。Logistic回归分析结果显示B/A和APACHEⅡ评分是导致患者死亡的危险因素(P <0.05)。ROC分析显示,B/A的曲线下面积、敏感度、特异度均较APACHEⅡ评分增高,B/A与APACHEⅡ评分的AUC差异无统计学意义(t=1.686,P=0.093)。结论:B/A和APACHEⅡ评分均可用于评估老年AECOPD合并肾功能不全患者NIV预后,与APACHEⅡ评分比,B/A在评估老年AECOPD患者NIV预后的效能更高。
