目的:系统评价血流限制训练(BFRT)在老年人群中应用的安全性。方法:计算机检索PubMed、EMbase、the Cochrane Library、Web of Science、中国知网、万方、维普、中国生物医学文献数据库中与BFRT在老年人群中应用安全性评价有关的随机对...目的:系统评价血流限制训练(BFRT)在老年人群中应用的安全性。方法:计算机检索PubMed、EMbase、the Cochrane Library、Web of Science、中国知网、万方、维普、中国生物医学文献数据库中与BFRT在老年人群中应用安全性评价有关的随机对照研究,检索时限均为建库至2021年8月31日,筛选文献、提取资料并评估偏倚风险后,采用RevMan 5.3统计软件进行Meta分析。结果:共纳入12项随机对照研究,Meta分析结果显示,BFRT对收缩压(SBP)[MD=8.77,95%CI(2.36,15.18),P=0.007]、踝臂压力指数(ABI)[MD=0.03,95%CI(0.00,0.06),P=0.03]、心踝血管指数(CAVI)[MD=0.48,95%CI(0.05,0.92),P=0.03]、血流介导性舒张(FMD)[MD=1.30,95%CI(0.68,1.92),P<0.0001]、反应性充血指数(RHI)[MD=0.30,95%CI(0.16,0.44),P<0.0001]有影响。30%肌肉一次举起的最大重量以上的训练强度对SBP[MD=2.85,95%CI(0.75,4.95),P=0.008]、DBP[MD=2.71,95%CI(0.62,4.79),P=0.01]有影响,加压程度大于静息肢体闭塞压对SBP有影响[MD=9.03,95%CI(0.49,17.58),P=0.04]。结论:现有证据表明,BFRT对老年人是安全的,BFRT训练过程中应注意训练强度及加压程度。展开更多
This paper studies the development on the first order sea clutter cross section for bistatic high frequency surface wave radar (HFSWR). Based on the received first order electric field expression, a closed-form of cro...This paper studies the development on the first order sea clutter cross section for bistatic high frequency surface wave radar (HFSWR). Based on the received first order electric field expression, a closed-form of cross sections is derived to account for the case of receiving antenna array being mounted on the shipborne platform. The uniform linear motion and sway motion components are assumed to be responsible for the observed differences in comparison with the bistatic fixed antenna case. Correspondingly, simulations are conducted to study the sea clutter spectral characteristics for these two cases versus different system parameters and sea state conditions. It is shown numerically that the forward motion component will spread the Bragg lines severely and the influence triggered by the sway motion can be explained as the Bessel function modulation of the ordinary sea clutter spectra. The obtained results have important implications in the application of shipborne HFSWR technology to ocean remote sensing and target detection.展开更多
基金泸州市重点实验室开放基金项目(HYJH-2102-B)四川省高校重点实验室开放基金项目(2020JXY03)+1 种基金广西石化资源加工及过程强化技术重点试验室开放基金项目(2020K005)The Opening Foundation of State Key Laboratory of Molecular Engineering of Polymers(K2020-24)。
基金supported by the National Natural Science Foundation of China(61471144)
文摘This paper studies the development on the first order sea clutter cross section for bistatic high frequency surface wave radar (HFSWR). Based on the received first order electric field expression, a closed-form of cross sections is derived to account for the case of receiving antenna array being mounted on the shipborne platform. The uniform linear motion and sway motion components are assumed to be responsible for the observed differences in comparison with the bistatic fixed antenna case. Correspondingly, simulations are conducted to study the sea clutter spectral characteristics for these two cases versus different system parameters and sea state conditions. It is shown numerically that the forward motion component will spread the Bragg lines severely and the influence triggered by the sway motion can be explained as the Bessel function modulation of the ordinary sea clutter spectra. The obtained results have important implications in the application of shipborne HFSWR technology to ocean remote sensing and target detection.
