Objective This study evaluated the effect of maximal oxygen pulse(O_(2)P_(max))on patients with chronic obstructive pulmonary disease(COPD)and confirmed the predictive effect on acute exacerbations of COPD(AECOPD).Met...Objective This study evaluated the effect of maximal oxygen pulse(O_(2)P_(max))on patients with chronic obstructive pulmonary disease(COPD)and confirmed the predictive effect on acute exacerbations of COPD(AECOPD).Methods This retrospective study included 91 participants who underwent cardiopulmonary exercise testing(CPET),lung function testing,a dyspnea scale assessment,and a 3-year follow-up.The participants were divided into two groups according to the O_(2)P_(max)value.Exercise capacity,ventilatory conditions,gas exchange efficiency,and dyspnea symptoms were compared,and the correlations between O_(2)P_(max)and these indices were evaluated.The ability of O_(2)P_(max)to predict AECOPD was examined.Results Exercise capacity,ventilatory conditions,and gas exchange efficiency were lower,and dyspnea symptom scores were higher in the impaired O_(2)P_(max)group(P<0.05).O_(2)P_(max)was positively correlated with forced vital capacity(FVC)%,forced expiratory volume in 1 sec(FEV_(1))%,FEV_(1)/FVC%,anaerobic threshold(AT),work rate(WR)%,aximal oxygen uptake(VO_(2))%,VO_(2)/kg_(max),VO_(2)/kg_(max)%,WR_(AT),WR_(max),VO_(2AT),VO_(2max),and V,and was negatively correlated with EqCO_(2AT),and EqCO_(2max)(P<0.05).Most importantly,O_(2)P_(max)could be used to predict AECOPD,and the best cut-off value was 89.5%(area under the curve,0.739;95%CI,0.609–0.869).Conclusion O_(2)P_(max)reflected exercise capacity,ventilation capacity,gas exchange capacity,and dyspnea symptoms in patients with COPD and may be an independent predictor of AECOPD.展开更多
The pulse detonation rocket engine （PDRE） requires periodic supply of oxidizer, fuel and purge gas. A rotary-valve assembly is fabricated to control the periodic supply in this research. Oxygen and liquid aviation k...The pulse detonation rocket engine （PDRE） requires periodic supply of oxidizer, fuel and purge gas. A rotary-valve assembly is fabricated to control the periodic supply in this research. Oxygen and liquid aviation kerosene are used as oxidizer and fuel respectively. An ordinary automobile spark plug, with ignition energy as low as 50 mJ, is used to initiate combustion. Steady operation of the PDRE is achieved with operating frequency ranging from 1 Hz to 10 Hz. Experimentally measured pressure is lower than theoretical value by 13% at 1 Hz and 37% at 10 Hz, and there also exists a velocity deficit at different operating frequencies. Both of these two phenomena are believed mainly due to droplet size which depends on atomization and vaporiza-tion of liquid fuel.展开更多
Trajectories of pulse oxygen saturation(SpO_(2))within the first few days after birth are important to inform the strategy for identifying asymptomatic hypoxemic disease but remain poorly substantiated at higher altit...Trajectories of pulse oxygen saturation(SpO_(2))within the first few days after birth are important to inform the strategy for identifying asymptomatic hypoxemic disease but remain poorly substantiated at higher altitudes.Methods We performed a longitudinal cohort study with consecutive neonates at a local hospital in Luchun County,China,at an altitude of 1650 m between January and July 2020.We repeatedly measured the pre-and post-ductal SpO_(2)values at 6,12,18,24,36,48,and 72 hours after birth for neonates without oxygen supplements.All neonates underwent echocardiography and were followed up to 42 days after discharge.We included neonates without hypoxemic diseases to characterize the trajectories of SpO_(2)over time using a linear mixed model.We considered the 2.5th percentile as the reference value to define hypoxemic conditions.Results A total of 1061 neonates were enrolled.Twenty-five had non-cardiac hypoxemic diseases,with 84%(21/25)presenting with abnormal SpO_(2)within 24 hours.One had tetralogy of Fallot identified by echocardiography.Among the 1035 asymptomatic neonates,SpO_(2)values declined from 6 hours after birth,reached a nadir at 48 hours,and tended to level off thereafter,with identical patterns for both pre-and post-ductal SpO_(2).The reference percentile was 92%for both pre-and post-ductal SpO_(2)and was time independent.Conclusions A decline within 48 hours features SpO_(2)trajectories within the first 72 hours at moderate altitude.Our findings suggest that earlier screening may favorably achieve a benefit–risk balance in identifying asymptomatic hypoxemic diseases in this population.展开更多
Background The protective effects of transient limb ischemia （TLI） induced by several cycles of intermittent pressure cuff inflation and deflation for a period have been widely investigated,however the reliability o...Background The protective effects of transient limb ischemia （TLI） induced by several cycles of intermittent pressure cuff inflation and deflation for a period have been widely investigated,however the reliability of this protocol has not been clearly verified.Our study aimed to investigate the reliability of pressure cuff induced TLI in conscious rabbits.Methods Eight New Zealand rabbits were subjected to TLI without anesthesia.TLI consisted of 3 cycles of ischemia and reperfusion induced by inflating the cuff placed on the left lower limb to 200 mmHg for 5 minutes followed by deflating the cuff for 5 minutes.Skin color,pulse oxygen saturation （SpO2）,pulse rate （PR）,plethysmogram waveform （Pleth）,and ultrasound detection of the blood flow in the extremity distal to the ischemic segment were observed to confirm ischemia and reperfusion during TLI.The frequency of severe limb movement during TLI was also recorded to assess the amenability of this protocol in conscious rabbits.Results The skin color of the extremity distal to the ischemic segment changed from bright red to dark purple after inflating the cuff to 200 mmHg,and returned to normal after cuff deflation.Pleth,PR and SpO2 disappeared during ischemia and restored during reperfusion in the monitor.Blood flow of the left posterior tibial artery was completely blocked by a pressure of 200 mmHg during ischemia,and recovered immediately after cuff deflation.The frequency of severe limb movement in supine position was higher than that in prone position （P〈0.05）,but there was no severe limb movement that could result in disturbance to ischemia when the rabbits were placed in prone position.Conclusion Pressure cuff inflating to 200 mmHg for 5 minutes and deflating for 5 minutes is a reliable regimen to induce TLI in conscious rabbits.展开更多
OBJECTIVE:The study aim was to use existing relevant indexes to establish an index series for the quantitative measurement of Qi deficiency pattern(QDP) in Traditional Chinese Medicine(TCM).METHODS:Seventeen indexes o...OBJECTIVE:The study aim was to use existing relevant indexes to establish an index series for the quantitative measurement of Qi deficiency pattern(QDP) in Traditional Chinese Medicine(TCM).METHODS:Seventeen indexes of arterial oxygen saturation(SaO_2),TCM pulse diagnosis,heart rate,and blood pressure were integrated into an index series,and 94 selected subjects were divided into a healthy control group,a mild QDP group,and a typical QDP group.All three groups were then synchronously given a breath-holding(BH) test and index detections using TCM apparatus for auxiliary diagnosis and treatment and a photoplethysmograph.The detections were carried out repeatedly until there was no monotonic change in the value of the minimal SaO_(2d)uring a BH measurement(SaO_(2 min)) or in the duration of BH during a BH measurement(TBH).RESULTS:BH measurement and index detection data from 380 eligible cases were analyzed and a significant intergroup difference was found for 12 indexes.CONCLUSION:An index series for quantitative QDP measurement could comprise the 12 effective indexes:RSaO_(2d)(rate of decline of SaO_(2d)uring a BH measurement),RSaO_(2r)(recovery rate of SaO_2 after a BH measurement),SaO_(2 min),BFV(blood flow velocity),TSaO_(2d)(the time at which SaO_2 started declining during a BH measurement),TBH,TSa_(O2 min)(the time of occurrence of the minimal SaO_(2d)uring a BH measurement),TSa O_(2 max)(the time of occurrence of the maximal SaO_2 after a BH measurement),PTP(pulse-touching pressure),SBP(systolic blood pressure),PWV(pulse wave velocity),and DBP(diastolic blood pressure).Of the indexes,RSaO_(2d)could play akey role in quantitative QDP measurement;RSaO_(2r) and Sa O_2 mincould be used to differentiate the QDP symptom of shortness of breath and as early-warning indexes for chronic obstructive pulmonary disease.BFV,TSaO_(2d),and TBHcould be used to quantitatively assess the QDP symptoms of spontaneous perspiration and shortness of breath.展开更多
基金supported by the National Natural Science Foundation of China[No.82000043]Key Clinical Specialty Construction Program of Beijing(2020-2022)Beijing Hospitals Authority Youth Program[No.QML20180107]。
文摘Objective This study evaluated the effect of maximal oxygen pulse(O_(2)P_(max))on patients with chronic obstructive pulmonary disease(COPD)and confirmed the predictive effect on acute exacerbations of COPD(AECOPD).Methods This retrospective study included 91 participants who underwent cardiopulmonary exercise testing(CPET),lung function testing,a dyspnea scale assessment,and a 3-year follow-up.The participants were divided into two groups according to the O_(2)P_(max)value.Exercise capacity,ventilatory conditions,gas exchange efficiency,and dyspnea symptoms were compared,and the correlations between O_(2)P_(max)and these indices were evaluated.The ability of O_(2)P_(max)to predict AECOPD was examined.Results Exercise capacity,ventilatory conditions,and gas exchange efficiency were lower,and dyspnea symptom scores were higher in the impaired O_(2)P_(max)group(P<0.05).O_(2)P_(max)was positively correlated with forced vital capacity(FVC)%,forced expiratory volume in 1 sec(FEV_(1))%,FEV_(1)/FVC%,anaerobic threshold(AT),work rate(WR)%,aximal oxygen uptake(VO_(2))%,VO_(2)/kg_(max),VO_(2)/kg_(max)%,WR_(AT),WR_(max),VO_(2AT),VO_(2max),and V,and was negatively correlated with EqCO_(2AT),and EqCO_(2max)(P<0.05).Most importantly,O_(2)P_(max)could be used to predict AECOPD,and the best cut-off value was 89.5%(area under the curve,0.739;95%CI,0.609–0.869).Conclusion O_(2)P_(max)reflected exercise capacity,ventilation capacity,gas exchange capacity,and dyspnea symptoms in patients with COPD and may be an independent predictor of AECOPD.
基金National Natural Science Foundation of China (50976094)Doctoral Program Foundation of Education Ministry of China (20096102110022)+1 种基金Doctorate Foundation of Northwestern Polytechnical University (CX201112)Graduate Innovation Lab Center of Northwestern Polytechnical University (10006,10013)
文摘The pulse detonation rocket engine （PDRE） requires periodic supply of oxidizer, fuel and purge gas. A rotary-valve assembly is fabricated to control the periodic supply in this research. Oxygen and liquid aviation kerosene are used as oxidizer and fuel respectively. An ordinary automobile spark plug, with ignition energy as low as 50 mJ, is used to initiate combustion. Steady operation of the PDRE is achieved with operating frequency ranging from 1 Hz to 10 Hz. Experimentally measured pressure is lower than theoretical value by 13% at 1 Hz and 37% at 10 Hz, and there also exists a velocity deficit at different operating frequencies. Both of these two phenomena are believed mainly due to droplet size which depends on atomization and vaporiza-tion of liquid fuel.
基金supported by the National Key Research and Development Program of China(2021YFC2701004 and 2016YFC1000506)the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2019-I2M-5-002).
文摘Trajectories of pulse oxygen saturation(SpO_(2))within the first few days after birth are important to inform the strategy for identifying asymptomatic hypoxemic disease but remain poorly substantiated at higher altitudes.Methods We performed a longitudinal cohort study with consecutive neonates at a local hospital in Luchun County,China,at an altitude of 1650 m between January and July 2020.We repeatedly measured the pre-and post-ductal SpO_(2)values at 6,12,18,24,36,48,and 72 hours after birth for neonates without oxygen supplements.All neonates underwent echocardiography and were followed up to 42 days after discharge.We included neonates without hypoxemic diseases to characterize the trajectories of SpO_(2)over time using a linear mixed model.We considered the 2.5th percentile as the reference value to define hypoxemic conditions.Results A total of 1061 neonates were enrolled.Twenty-five had non-cardiac hypoxemic diseases,with 84%(21/25)presenting with abnormal SpO_(2)within 24 hours.One had tetralogy of Fallot identified by echocardiography.Among the 1035 asymptomatic neonates,SpO_(2)values declined from 6 hours after birth,reached a nadir at 48 hours,and tended to level off thereafter,with identical patterns for both pre-and post-ductal SpO_(2).The reference percentile was 92%for both pre-and post-ductal SpO_(2)and was time independent.Conclusions A decline within 48 hours features SpO_(2)trajectories within the first 72 hours at moderate altitude.Our findings suggest that earlier screening may favorably achieve a benefit–risk balance in identifying asymptomatic hypoxemic diseases in this population.
基金This study was supported by the Project for Science and Technology from the Department of Science and Technology of Guangdong Province （No.2011B080701029）,the Guangdong Natural Science Foundation from the Department of Science and Technology of Guangdong Province （No.S2012010009396）,Guangdong Medical Science Research Grant from the Health Department of Guangdong Province （No.A2011217）,and the Research Grant for Doctoral Supervisor from the State Ministry of Education （No.20130171110083）.Acknowledgement： We gratefully thank Doctor Jan Hendrickx from Department of Anesthesiology, OLV Hospital, Belgium and Doctor Luc De Baerdemaeker from Department of Anesthesia, Ghent University Hospital, Belgium for their kind help to revise the manuscript. We also gratefully thank Wei Xiaoxiao, Li Jing, Chen Wenpei, Liu Xiang and Mo Xiaofei from the Department of Anesthesia, and Chen Ruonan, Wang Weili from the Department of Ultrasound, Sixth Affiliated Hospital, Sun Yat-sen University for their assistance during the experiment.
文摘Background The protective effects of transient limb ischemia （TLI） induced by several cycles of intermittent pressure cuff inflation and deflation for a period have been widely investigated,however the reliability of this protocol has not been clearly verified.Our study aimed to investigate the reliability of pressure cuff induced TLI in conscious rabbits.Methods Eight New Zealand rabbits were subjected to TLI without anesthesia.TLI consisted of 3 cycles of ischemia and reperfusion induced by inflating the cuff placed on the left lower limb to 200 mmHg for 5 minutes followed by deflating the cuff for 5 minutes.Skin color,pulse oxygen saturation （SpO2）,pulse rate （PR）,plethysmogram waveform （Pleth）,and ultrasound detection of the blood flow in the extremity distal to the ischemic segment were observed to confirm ischemia and reperfusion during TLI.The frequency of severe limb movement during TLI was also recorded to assess the amenability of this protocol in conscious rabbits.Results The skin color of the extremity distal to the ischemic segment changed from bright red to dark purple after inflating the cuff to 200 mmHg,and returned to normal after cuff deflation.Pleth,PR and SpO2 disappeared during ischemia and restored during reperfusion in the monitor.Blood flow of the left posterior tibial artery was completely blocked by a pressure of 200 mmHg during ischemia,and recovered immediately after cuff deflation.The frequency of severe limb movement in supine position was higher than that in prone position （P〈0.05）,but there was no severe limb movement that could result in disturbance to ischemia when the rabbits were placed in prone position.Conclusion Pressure cuff inflating to 200 mmHg for 5 minutes and deflating for 5 minutes is a reliable regimen to induce TLI in conscious rabbits.
基金National Natural Science Foundation-funded project:Construction of the Qi-Blood-Body Fluid Network Based on the Dynamic Detection of Human Biological Information and Research on the Network's Mechanism of Identification,a program funded by the of China(No.81473553)National Natural Science Foundation-funded project:Construction of TCM Qi-Function Biological Network Based on the Body Odor and Voice and Research on the Network's Mechanism(No.81573880)+1 种基金Science and Technology Assistance Project of the Ministry of Science and Technology of China to the Developing Countries:Sino-Mexican Cooperation Study on the Strategies for Hospice Care with the Intervention of Acupuncture and Moxibustion and the Related Clinical Research(No.KYZ201302010)Longitudinal scientific research development fund,Beijing University of Chinese Medicine:Key Technology of Photographic Identification for Meridian-Visceral Recuperation Device(No.2017-zxfzjj-024)
文摘OBJECTIVE:The study aim was to use existing relevant indexes to establish an index series for the quantitative measurement of Qi deficiency pattern(QDP) in Traditional Chinese Medicine(TCM).METHODS:Seventeen indexes of arterial oxygen saturation(SaO_2),TCM pulse diagnosis,heart rate,and blood pressure were integrated into an index series,and 94 selected subjects were divided into a healthy control group,a mild QDP group,and a typical QDP group.All three groups were then synchronously given a breath-holding(BH) test and index detections using TCM apparatus for auxiliary diagnosis and treatment and a photoplethysmograph.The detections were carried out repeatedly until there was no monotonic change in the value of the minimal SaO_(2d)uring a BH measurement(SaO_(2 min)) or in the duration of BH during a BH measurement(TBH).RESULTS:BH measurement and index detection data from 380 eligible cases were analyzed and a significant intergroup difference was found for 12 indexes.CONCLUSION:An index series for quantitative QDP measurement could comprise the 12 effective indexes:RSaO_(2d)(rate of decline of SaO_(2d)uring a BH measurement),RSaO_(2r)(recovery rate of SaO_2 after a BH measurement),SaO_(2 min),BFV(blood flow velocity),TSaO_(2d)(the time at which SaO_2 started declining during a BH measurement),TBH,TSa_(O2 min)(the time of occurrence of the minimal SaO_(2d)uring a BH measurement),TSa O_(2 max)(the time of occurrence of the maximal SaO_2 after a BH measurement),PTP(pulse-touching pressure),SBP(systolic blood pressure),PWV(pulse wave velocity),and DBP(diastolic blood pressure).Of the indexes,RSaO_(2d)could play akey role in quantitative QDP measurement;RSaO_(2r) and Sa O_2 mincould be used to differentiate the QDP symptom of shortness of breath and as early-warning indexes for chronic obstructive pulmonary disease.BFV,TSaO_(2d),and TBHcould be used to quantitatively assess the QDP symptoms of spontaneous perspiration and shortness of breath.
