A single coronary artery is a very rare condition,commonly associated with other congenital anomalies.It could be generally considered as neither benign nor malignant form of congenital coronary artery anomalies since...A single coronary artery is a very rare condition,commonly associated with other congenital anomalies.It could be generally considered as neither benign nor malignant form of congenital coronary artery anomalies since its pathophysiological and clinical implications grossly depend on different anatomical patterns defined by the site of origin and distribution of the branches.By presenting the patient who underwent successful coronary artery bypass grafting and aortic valve replacement surgery in a presence of isolated single coronary artery,we intend to emphasize natural and procedural risks and distinguish casual from causal in this extremely rare clinical and surgical scenario.展开更多
Background: A recent survey of in-hospital reprocessing in Tanzanian hospitals identified bag-valve masks (BVM) as a commonly reused single-use device. In low- and middle-income countries (LMIC), in-hospital reprocess...Background: A recent survey of in-hospital reprocessing in Tanzanian hospitals identified bag-valve masks (BVM) as a commonly reused single-use device. In low- and middle-income countries (LMIC), in-hospital reprocessing supports neonatal resuscitation strategies by helping to maintain adequate supplies of BVM. However, there is a need for device-specific protocols defining reprocessing procedures and inspection criteria to overcome variations in reprocessing practices between hospitals. The purposes of this study were: 1) to complete a comprehensive design review and identify challenges to reprocessing BVMs;and 2) to investigate three different residual bioburden analysis methods for assessing the efficacy of decontaminating a disposable BVM. Methods: New, unused bag-valve-masks were contaminated with Staphylococcus epidermidis and Artificial Mucus Soil to simulate the worst case soiling conditions. Devices underwent one of five disinfection protocols, including one currently used in a LMIC hospital. Three analytical (two quantitative and one qualitative) methods were selected to evaluate residual bioburden on the device following decontamination. Results: Of all protocols tested, only the positive control and the Soap and Bleach protocols met disinfection targets. Most cleaning outcomes were consistent from trial to trial for each protocol. However, cleaning outcomes varied greatly for the Alcohol Wipe protocol. For the residual bioburden analyses, the two quantitative methods produced similar results, but the qualitative measurement exhibited increased variability. Conclusion: While this study revealed positive disinfection outcomes for the Tanzanian hospital decontamination protocol, more studies are required to support these findings. Design features of the BVM mask presented challenges to cleaning and drying during different decontamination protocols, as seen in the variability in the Alcohol Wipe protocol performance. These findings support the case for a device-specific protocol for the BVM. Given proper hospital personnel training and available resources, in-hospital reprocessing could support neonatal resuscitation strategies and other demands for manual resuscitation by helping to maintain adequate supplies of BVM.展开更多
Objective: To assess the outcome of valve replacement under mild hypothermia on pump-beating heart and to discuss the risk factors of cardiac valve surgery. Methods: In the period from November 1997 to May 2003, a tot...Objective: To assess the outcome of valve replacement under mild hypothermia on pump-beating heart and to discuss the risk factors of cardiac valve surgery. Methods: In the period from November 1997 to May 2003, a total of 800 cases of valve replacement were carried out in our institute. The clinical data were reviewed and the technique of mild hypothermia and pump-beating heart to replace cardiac valve was described in detail. Results: 800 patients, 308 male and 492 female, with age range from 8 to 66 years, weighing 19 to 88 kg, underwent operation. The average cardiopulmonary bypass time was (109.38± 40.64) min, the average clamping time of the vena cava was (77.87±27.99) min and the average mechanical ventilation time was (17.78±12.21) h. There were 17 patients died in the early postoperative stage with an early mortality rate of 2.13%. The causes of death were failure in the weaning of extracorporeal circulation in 2 cases, severe low output syndrome in 3 cases, ventricular fibrillation in 3 cases, obstruction of coronary ostium of mechanical prosthetic valve in 1 case, hepatic failure in 2 cases, pulmonary failure in 1 case, multiorgan failure in 4 cases, and prosthetic valve dysfunction in 1 case. Severe postopertive complications occurred in 51 cases (6.375%), which included reexploration because of excessive bleeding in 16 cases (2.0%), lavage of poststernal infection in 2 cases (0.25%), postoperative strike in 7 cases (0.875%), pulmonary failure in 5 cases (0.625%), hepatic failure in 4 cases (0.5%), multiorgan failure in 11 cases (1.375%), ventricular arrhythmia in 5 cases (0.625%) and peripheral circulation failure in 1 case (0.125%). Conclusion: Mild hypothermia and pump-beating heart result in satisfying clinical outcome in patients undergoing valve replacement. The integrated sequenced deairing procedure ensures the avoidance of air embolism during operation. Pump-beating heart technique offers a safe and practical option especially in patients with severe critical valvular disorder.展开更多
Single crystals of organic semiconductors with perfect crystal structure and minimal density of defects can exhibit high mobility and low spin scattering compared with their amorphous or polycrystalline counterparts.T...Single crystals of organic semiconductors with perfect crystal structure and minimal density of defects can exhibit high mobility and low spin scattering compared with their amorphous or polycrystalline counterparts.Therefore,these materials are promising candidates as the spin transport media to obtain long spin relaxation times and spin diffusion lengths in spintronic devices.However,the investigation of spin injection and transport properties in organic single crystals is hindered by the inability to construct devices such as single-crystalline organic spin valves(OSVs).Herein,thin and large organic single crystals of 6,13-bis(triisopropylsilylethynyl)pentacene(TIPS-pentacene)were grown on a liquid substrate and transferred to a target substrate carrying ferromagnetic electrodes to construct single-crystalline OSVs.The magnetoresistance(MR)responses of the single crystals were investigated to study their spin injection and transport properties.MR value as high as 17%was probed with an intermediate layer thickness of 269 nm.More importantly,spin transport was still observed in a single crystal of a thickness up to 457 nm,which was much larger than that of polycrystalline thin film.Our research provides a general methodology for constructing single-crystalline OSVs and paves the way to probe the intrinsic spin transport properties of organic semiconductors based on single crystals.展开更多
BACKGROUND End-stage chronic obstructive pulmonary disease(COPD)is one of the common lung diseases referred for lung transplantation.According to the international society of heart and lung transplantation,30%of all l...BACKGROUND End-stage chronic obstructive pulmonary disease(COPD)is one of the common lung diseases referred for lung transplantation.According to the international society of heart and lung transplantation,30%of all lung transplantations are carried out for COPD alone.When compared to bilateral lung transplant,singlelung transplant(SLT)has similar short-term and medium-term results for COPD.For patients with severe upper lobe predominant emphysema,lung volume reduction surgery is an excellent alternative which results in improvement in functional status and long-term mortality.In 2018,endobronchial valves were approved by the Food and Drug Administration for severe upper lobe predominant emphysema as they demonstrated improvement in lung function,exercise capacity,and quality of life.However,the role of endobronchial valves in native lung emphysema in SLT patients has not been studied.CASE SUMMARY We describe an unusual case of severe emphysema who underwent a successful SLT 15 years ago and had gradual worsening of lung function suggestive of chronic lung allograft dysfunction.However,her lung function improved significantly after a spontaneous pneumothorax of the native lung resulting in auto-deflation of large bullae.CONCLUSION This case highlights the clinical significance of native lung hyperinflation in single lung transplant recipient and how spontaneous decompression due to pneumothorax led to clinical improvement in our patient.展开更多
Background This article summarized the experience of atrioventricular valve replacement operation for func- tional single ventricle patients whose atrioventricular valve was insufficiency. The follow-up time of operat...Background This article summarized the experience of atrioventricular valve replacement operation for func- tional single ventricle patients whose atrioventricular valve was insufficiency. The follow-up time of operation was arranged from early- to medium- tenn. Methods From July 2009 to July 2015, there were 40 patients of functional single ventricle receiving the operation of atrioventricular valve replacement, including 23 male and 17 female patients. The age at A-V valve replacement was ranged from 6 days to 32 years （the medium age of 9 years）, and the body weight ranged from 2.7 to 57 kg （the medium body weight of 21.5 kg）. Moreover, the atrio- ventricular valve replacement was performed on all patients under extracorporeal circulation. Results Atrioven- tricular valve replacement was performed on 40 patients with function single ventricle in hospital, of which eight （20.0%） died in hospital including two neonate and infant （age range： 6 days-2 years old） accounting for 25% （2/ 8）, Among them, seven patients died of low cardiac output syndrome two patients with repeated hypoxemia con- current infection after operation, and one with bilateral diaphragmatic paralysis and malignant arrhythmia. For the patients suffering the severe perivalvular leakage, there was a reoperation, and the cardiac function before the first operation was class 1W. One patient received heart transplantation finally for severe heart failure after AV valve replacement. For the rest of patients, their cardiac function recovered to class I - lI after operation. Conclusions For function single ventricle patients with atrioventricular valve regurgitation, the mortality rate of atrioventricular valve replacement can be accepted if the operation was indicated. For patients with severe atrio- ventricular value regurgitation, the result of the operation in the early and medium term was satisfying. Thus, the atrioventricular valve replacement served as a useful treatment for patients diagnosed of A-V valve regurgitation and functional single ventricle.展开更多
针对纯电动商用车在连续制动时,气源压力偏低会导致驱动轴耦合制动力响应速度变慢,影响制动能量回收效率的问题,提出一种基于比例继动阀的解耦式制动能量回收系统(uncoupled braking energy recovery system,URBS)方案。首先,基于比例...针对纯电动商用车在连续制动时,气源压力偏低会导致驱动轴耦合制动力响应速度变慢,影响制动能量回收效率的问题,提出一种基于比例继动阀的解耦式制动能量回收系统(uncoupled braking energy recovery system,URBS)方案。首先,基于比例继动阀的迟滞特性,采用前馈-单神经元PID控制方法,实现制动气压的准确输出;其次,以电池SOC、车速等为约束条件,根据气源压力信号确定供压模式,并制定解耦式制动能量回收控制策略;最后,基于AMESim,MATLAB/Simulink及TruckSim搭建联合仿真平台,选取单次制动工况与循环工况验证了制动力耦合效果及系统的制动能量回收效果。结果表明,基于比例继动阀的URBS可实现耦合制动力的快速响应,达到稳态压力值75%的时间小于0.1 s,且在中国重型商用车行驶工况和中国重型商用车瞬态工况下有效制动能量回收率分别为10.13%,17.17%。所提URBS方案能有效提高驱动轴耦合制动力的响应速度及耦合精度,可为纯电动商用车气压式URBS方案设计提供参考。展开更多
文摘A single coronary artery is a very rare condition,commonly associated with other congenital anomalies.It could be generally considered as neither benign nor malignant form of congenital coronary artery anomalies since its pathophysiological and clinical implications grossly depend on different anatomical patterns defined by the site of origin and distribution of the branches.By presenting the patient who underwent successful coronary artery bypass grafting and aortic valve replacement surgery in a presence of isolated single coronary artery,we intend to emphasize natural and procedural risks and distinguish casual from causal in this extremely rare clinical and surgical scenario.
文摘Background: A recent survey of in-hospital reprocessing in Tanzanian hospitals identified bag-valve masks (BVM) as a commonly reused single-use device. In low- and middle-income countries (LMIC), in-hospital reprocessing supports neonatal resuscitation strategies by helping to maintain adequate supplies of BVM. However, there is a need for device-specific protocols defining reprocessing procedures and inspection criteria to overcome variations in reprocessing practices between hospitals. The purposes of this study were: 1) to complete a comprehensive design review and identify challenges to reprocessing BVMs;and 2) to investigate three different residual bioburden analysis methods for assessing the efficacy of decontaminating a disposable BVM. Methods: New, unused bag-valve-masks were contaminated with Staphylococcus epidermidis and Artificial Mucus Soil to simulate the worst case soiling conditions. Devices underwent one of five disinfection protocols, including one currently used in a LMIC hospital. Three analytical (two quantitative and one qualitative) methods were selected to evaluate residual bioburden on the device following decontamination. Results: Of all protocols tested, only the positive control and the Soap and Bleach protocols met disinfection targets. Most cleaning outcomes were consistent from trial to trial for each protocol. However, cleaning outcomes varied greatly for the Alcohol Wipe protocol. For the residual bioburden analyses, the two quantitative methods produced similar results, but the qualitative measurement exhibited increased variability. Conclusion: While this study revealed positive disinfection outcomes for the Tanzanian hospital decontamination protocol, more studies are required to support these findings. Design features of the BVM mask presented challenges to cleaning and drying during different decontamination protocols, as seen in the variability in the Alcohol Wipe protocol performance. These findings support the case for a device-specific protocol for the BVM. Given proper hospital personnel training and available resources, in-hospital reprocessing could support neonatal resuscitation strategies and other demands for manual resuscitation by helping to maintain adequate supplies of BVM.
文摘Objective: To assess the outcome of valve replacement under mild hypothermia on pump-beating heart and to discuss the risk factors of cardiac valve surgery. Methods: In the period from November 1997 to May 2003, a total of 800 cases of valve replacement were carried out in our institute. The clinical data were reviewed and the technique of mild hypothermia and pump-beating heart to replace cardiac valve was described in detail. Results: 800 patients, 308 male and 492 female, with age range from 8 to 66 years, weighing 19 to 88 kg, underwent operation. The average cardiopulmonary bypass time was (109.38± 40.64) min, the average clamping time of the vena cava was (77.87±27.99) min and the average mechanical ventilation time was (17.78±12.21) h. There were 17 patients died in the early postoperative stage with an early mortality rate of 2.13%. The causes of death were failure in the weaning of extracorporeal circulation in 2 cases, severe low output syndrome in 3 cases, ventricular fibrillation in 3 cases, obstruction of coronary ostium of mechanical prosthetic valve in 1 case, hepatic failure in 2 cases, pulmonary failure in 1 case, multiorgan failure in 4 cases, and prosthetic valve dysfunction in 1 case. Severe postopertive complications occurred in 51 cases (6.375%), which included reexploration because of excessive bleeding in 16 cases (2.0%), lavage of poststernal infection in 2 cases (0.25%), postoperative strike in 7 cases (0.875%), pulmonary failure in 5 cases (0.625%), hepatic failure in 4 cases (0.5%), multiorgan failure in 11 cases (1.375%), ventricular arrhythmia in 5 cases (0.625%) and peripheral circulation failure in 1 case (0.125%). Conclusion: Mild hypothermia and pump-beating heart result in satisfying clinical outcome in patients undergoing valve replacement. The integrated sequenced deairing procedure ensures the avoidance of air embolism during operation. Pump-beating heart technique offers a safe and practical option especially in patients with severe critical valvular disorder.
基金the National Natural Science Foundation of China(61674116,51873148,51633006,and 52003190)the Ministry of Science and Technology of China(2016YFA0202302)the Natural Science Foundation of Tianjin(18JC-YBJC18400)。
文摘Single crystals of organic semiconductors with perfect crystal structure and minimal density of defects can exhibit high mobility and low spin scattering compared with their amorphous or polycrystalline counterparts.Therefore,these materials are promising candidates as the spin transport media to obtain long spin relaxation times and spin diffusion lengths in spintronic devices.However,the investigation of spin injection and transport properties in organic single crystals is hindered by the inability to construct devices such as single-crystalline organic spin valves(OSVs).Herein,thin and large organic single crystals of 6,13-bis(triisopropylsilylethynyl)pentacene(TIPS-pentacene)were grown on a liquid substrate and transferred to a target substrate carrying ferromagnetic electrodes to construct single-crystalline OSVs.The magnetoresistance(MR)responses of the single crystals were investigated to study their spin injection and transport properties.MR value as high as 17%was probed with an intermediate layer thickness of 269 nm.More importantly,spin transport was still observed in a single crystal of a thickness up to 457 nm,which was much larger than that of polycrystalline thin film.Our research provides a general methodology for constructing single-crystalline OSVs and paves the way to probe the intrinsic spin transport properties of organic semiconductors based on single crystals.
文摘BACKGROUND End-stage chronic obstructive pulmonary disease(COPD)is one of the common lung diseases referred for lung transplantation.According to the international society of heart and lung transplantation,30%of all lung transplantations are carried out for COPD alone.When compared to bilateral lung transplant,singlelung transplant(SLT)has similar short-term and medium-term results for COPD.For patients with severe upper lobe predominant emphysema,lung volume reduction surgery is an excellent alternative which results in improvement in functional status and long-term mortality.In 2018,endobronchial valves were approved by the Food and Drug Administration for severe upper lobe predominant emphysema as they demonstrated improvement in lung function,exercise capacity,and quality of life.However,the role of endobronchial valves in native lung emphysema in SLT patients has not been studied.CASE SUMMARY We describe an unusual case of severe emphysema who underwent a successful SLT 15 years ago and had gradual worsening of lung function suggestive of chronic lung allograft dysfunction.However,her lung function improved significantly after a spontaneous pneumothorax of the native lung resulting in auto-deflation of large bullae.CONCLUSION This case highlights the clinical significance of native lung hyperinflation in single lung transplant recipient and how spontaneous decompression due to pneumothorax led to clinical improvement in our patient.
基金supported by the National Twelfth Five-Year Plan(No.2011BAI11B22)
文摘Background This article summarized the experience of atrioventricular valve replacement operation for func- tional single ventricle patients whose atrioventricular valve was insufficiency. The follow-up time of operation was arranged from early- to medium- tenn. Methods From July 2009 to July 2015, there were 40 patients of functional single ventricle receiving the operation of atrioventricular valve replacement, including 23 male and 17 female patients. The age at A-V valve replacement was ranged from 6 days to 32 years （the medium age of 9 years）, and the body weight ranged from 2.7 to 57 kg （the medium body weight of 21.5 kg）. Moreover, the atrio- ventricular valve replacement was performed on all patients under extracorporeal circulation. Results Atrioven- tricular valve replacement was performed on 40 patients with function single ventricle in hospital, of which eight （20.0%） died in hospital including two neonate and infant （age range： 6 days-2 years old） accounting for 25% （2/ 8）, Among them, seven patients died of low cardiac output syndrome two patients with repeated hypoxemia con- current infection after operation, and one with bilateral diaphragmatic paralysis and malignant arrhythmia. For the patients suffering the severe perivalvular leakage, there was a reoperation, and the cardiac function before the first operation was class 1W. One patient received heart transplantation finally for severe heart failure after AV valve replacement. For the rest of patients, their cardiac function recovered to class I - lI after operation. Conclusions For function single ventricle patients with atrioventricular valve regurgitation, the mortality rate of atrioventricular valve replacement can be accepted if the operation was indicated. For patients with severe atrio- ventricular value regurgitation, the result of the operation in the early and medium term was satisfying. Thus, the atrioventricular valve replacement served as a useful treatment for patients diagnosed of A-V valve regurgitation and functional single ventricle.
