目的：评价自主呼吸锻炼对成年人心率、收缩压的影响。方法计算机检索 CENTRAL （Cochrane Central Register of Controlled Trials）、MEDLINE、EMbase、PEDro、OVID、中国知网（CNKI）、维普数据库（VIP）、万方数据库（Wanfang Data...目的：评价自主呼吸锻炼对成年人心率、收缩压的影响。方法计算机检索 CENTRAL （Cochrane Central Register of Controlled Trials）、MEDLINE、EMbase、PEDro、OVID、中国知网（CNKI）、维普数据库（VIP）、万方数据库（Wanfang Data）和中国生物医学文献数据库（CBM）。所有关于自主呼吸锻炼的随机对照试验，检索时限均为从建库至2014年11月，同时追索纳入文献的参考文献。由2名研究者根据 PEDro 量表进行评价，对符合纳入标准的 RCT 提取有效数据进行 Meta 分析。统计学分析采用RevMan 5．0软件。结果共纳入5项随机对照试验（RCT）。Meta 分析结果显示与对照组相比，自主呼吸锻炼对成年人心率、收缩压影响的差异均有统计学意义（P ＜0．05）。结论自主呼吸锻炼能够降低成年人的心率、收缩压，且不良反应甚小，操作简便，是较好的物理治疗方法，可推荐应用于自我保健和疾病康复护理中。展开更多
A miniaturized H 2/air self-breathing proton exchange membrane fuel cell(μPEMFC) was designed and fabricated with 1 cm 2 active area. All the basic parts of a conventional H 2/air PEMFC were incorporated in a smaller...A miniaturized H 2/air self-breathing proton exchange membrane fuel cell(μPEMFC) was designed and fabricated with 1 cm 2 active area. All the basic parts of a conventional H 2/air PEMFC were incorporated in a smaller and simpler package. The electrodes of the μPEMFC were constructed on silicon wafer substrates by means of standard micro electromechanical systems (MEMS) techniques. The obtained results show that the peak power density of a single cell has exceeded 110 mW/cm 2 when it was operated in ambient atmosphere at 20 ℃. Furthermore, the cells can yield over 400 W/L specific power density.展开更多
Respirator breathing resistance impacts performance of wearers during constant work load. However, it is less clear as to how breathing resistance affects the tolerant capacity of users during graded work load. The pr...Respirator breathing resistance impacts performance of wearers during constant work load. However, it is less clear as to how breathing resistance affects the tolerant capacity of users during graded work load. The present study investigated the tolerant capacity of 8 individuals during incremental work load. The 8 subjects were required to wear two matched respirators （respirators Ⅰ and Ⅱ which were designed to have different breathing resistances and the same dead space） respectively on separate days and then work to end points. Minute ventilation （VE）, breathing frequency （BF）, oxygen consumption （VO2） and heart rate （HR） were recorded during exercise, while tolerant time, response time and breathing discomfort were measured at the end of each test trial. The test variables were com-pared between the two respirators by using matched-pairs t-test. The results showed that the tolerant time was significantly reduced for the respiratorⅠwith higher level of breathing resistance when compared with its counterpart with lower breathing resistance （respirator Ⅱ） （P〈0.05）. The same changes occurred for response time. Results also showed a significant increase in VE and BF for respirator Ⅰwearers when the work load was above 125 W. The O2 consumption was similar under the two breathing resistance conditions. These findings suggested that the respiratory resistance caused by self-contained breathing apparatus （SCBA） has an impact on the tolerant capacity of users.展开更多
文摘目的：评价自主呼吸锻炼对成年人心率、收缩压的影响。方法计算机检索 CENTRAL （Cochrane Central Register of Controlled Trials）、MEDLINE、EMbase、PEDro、OVID、中国知网（CNKI）、维普数据库（VIP）、万方数据库（Wanfang Data）和中国生物医学文献数据库（CBM）。所有关于自主呼吸锻炼的随机对照试验，检索时限均为从建库至2014年11月，同时追索纳入文献的参考文献。由2名研究者根据 PEDro 量表进行评价，对符合纳入标准的 RCT 提取有效数据进行 Meta 分析。统计学分析采用RevMan 5．0软件。结果共纳入5项随机对照试验（RCT）。Meta 分析结果显示与对照组相比，自主呼吸锻炼对成年人心率、收缩压影响的差异均有统计学意义（P ＜0．05）。结论自主呼吸锻炼能够降低成年人的心率、收缩压，且不良反应甚小，操作简便，是较好的物理治疗方法，可推荐应用于自我保健和疾病康复护理中。
文摘A miniaturized H 2/air self-breathing proton exchange membrane fuel cell(μPEMFC) was designed and fabricated with 1 cm 2 active area. All the basic parts of a conventional H 2/air PEMFC were incorporated in a smaller and simpler package. The electrodes of the μPEMFC were constructed on silicon wafer substrates by means of standard micro electromechanical systems (MEMS) techniques. The obtained results show that the peak power density of a single cell has exceeded 110 mW/cm 2 when it was operated in ambient atmosphere at 20 ℃. Furthermore, the cells can yield over 400 W/L specific power density.
文摘Respirator breathing resistance impacts performance of wearers during constant work load. However, it is less clear as to how breathing resistance affects the tolerant capacity of users during graded work load. The present study investigated the tolerant capacity of 8 individuals during incremental work load. The 8 subjects were required to wear two matched respirators （respirators Ⅰ and Ⅱ which were designed to have different breathing resistances and the same dead space） respectively on separate days and then work to end points. Minute ventilation （VE）, breathing frequency （BF）, oxygen consumption （VO2） and heart rate （HR） were recorded during exercise, while tolerant time, response time and breathing discomfort were measured at the end of each test trial. The test variables were com-pared between the two respirators by using matched-pairs t-test. The results showed that the tolerant time was significantly reduced for the respiratorⅠwith higher level of breathing resistance when compared with its counterpart with lower breathing resistance （respirator Ⅱ） （P〈0.05）. The same changes occurred for response time. Results also showed a significant increase in VE and BF for respirator Ⅰwearers when the work load was above 125 W. The O2 consumption was similar under the two breathing resistance conditions. These findings suggested that the respiratory resistance caused by self-contained breathing apparatus （SCBA） has an impact on the tolerant capacity of users.
