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61.
Kang CHEN Ye MAO Shao-hua LIU Qiong WU Qing-zhi LUO Wen-qi PAN Qi JIN Ning ZHANG Tian-you LING Ying CHEN Gang GU Wei-feng SHEN Li-qun WU 《Journal of Zhejiang University. Science. B》2014,15(6):507-514
Objective
We are aimed to investigate whether right ventricular mid-septal pacing (RVMSP) is superior to conventional right ventricular apical pacing (RVAP) in improving clinical functional capacity and left ventricular ejection fraction (LVEF) for patients with high-degree atrio-ventricular block and moderately depressed left ventricle (LV) function.Methods
Ninety-two patients with high-degree atrio-ventricular block and moderately reduced LVEF (ranging from 35% to 50%) were randomly allocated to RVMSP (n=45) and RVAP (n=47). New York Heart Association (NYHA) functional class, echocardiographic LVEF, and distance during a 6-min walk test (6MWT) were determined at 18 months after pacemaker implantation. Serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured using an enzyme-linked immunosorbent assay (ELISA) kit.Results
Compared with baseline, NYHA functional class remained unchanged at 18 months, distance during 6MWT (485 m vs. 517 m) and LVEF (36.7% vs. 41.8%) were increased, but BNP levels were reduced (2352 pg/ml vs. 710 pg/ml) in the RVMSP group compared with those in the RVAP group, especially in patients with LVEF 35%–40% (for all comparisons, P<0.05). However, clinical function capacity and LV function measurements were not significantly changed in patients with RVAP, despite the pacing measurements being similar in both groups, such as R-wave amplitude and capture threshold.Conclusions
RVMSP provides a better clinical utility, compared with RVAP, in patients with high-degree atrioventricular block and moderately depressed LV function whose LVEF levels ranged from 35% to 40%. 相似文献62.
当前国内师范专业毕业生就业形势日益严峻,师范生的就业指导工作是否能适应时代的发展和就业市场的变化,体现师范生特色存在很大的疑问。为了了解师范生就业指导工作的现状,促进师范生顺利就业,本文通过问卷调查法,对滁州学院的师范生就业指导状况进行调查,具体从就业指导的内容、形式、方法、过程、队伍和效果六个方面进行调查,旨在了解师范生就业指导的现状及存在的问题,提出改善我国师范生就业指导的对策和建议。 相似文献
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基于建构主义教学观,结合大学新生研讨课教学实际,就一种以问题为焦点开展教学的方法展开探讨,说明了该方法下教学目标、特点、过程和教学体会,指出了基于建构主义思想的问题驱动式教学法能够促进新生研讨课中学生的思考、参与和知识掌握,提升教学效果,但也对学习环境、学习方法、教师素质提出了新的要求。 相似文献
66.
物质的医药用途发明是一种方法发明,其权利要求属于方法类型,应从方法权利要求的角度来分析其技术特征。通常能直接起到限定作用的是原料、制备步骤和工艺条件、药物产品形态或成分以及设备等。对於仅涉及药物使用方法的特征,如果这些特征与制药方法之间并不存在直接关联,其实质上属于在实施制药方法并获得药物后,将药物施用于人体的具体用药方法,与制药方法没有直接、必然的关联性。这种仅体现于用药行为中的特征不是制药用途的技术特征,对权利要求请求保护的制药方法本身不具有限定作用。 相似文献
67.
A focusing-based microfluidic mixer was studied. The micromixer utilizes the focusing process required for cytometry to reduce the diffusion distance of molecules to be mixed in order to facilitate the passive diffusion-controlled mixing process. It was found that both the high flow rate ratio of the sheath flow to the flows to be mixed and the low flow rate of the mixing fluids resulted in the short mixing length required within the microfluidic channel. It was shown that a complete mixing was achieved within a distance of 4 mm in the micromixer for the focused mixing fluids at a flow rate of 2 μl∕min and a flow rate ratio of the sheath flow to the flows to be mixed at 4:1. The mixer described here is simple and can be easily fabricated and controlled. 相似文献
68.
This paper studies output feedback control of hydraulic actuators with modified continuous LuGre model based friction compensation and model uncertainty compensation. An output feedback adaptive robust controller is constructed which combines the adaptive control part and the robust control part seamlessly. The adaptive part is constructed to handle the parametric uncertainties existed in the model. The residuals coming from parameter adaption and the unmodeled dynamics are taken into consideration by the robust part. Since only the position signal is available, the velocity, pressure, and internal friction states are obtained by observation or estimation. The errors coming from observation and estimation are also dealt with the robust part. Furthermore, the convergence of the closed-loop controller–observer scheme is achieved by the Lyapunov method in the presence of parametric uncertainties only. Extensive comparative experiments performed on a hydraulic actuator demonstrate the effectiveness of the proposed controller–observer scheme. 相似文献
69.
本文基于DEA的非参数方法测算了Malmquist生产率指数,并通过对其分解,计算出了东部、中部和西部地区的技术效率指数和技术进步指数,发现1987年以来,东部地区的全要素生产率增长主要是依赖技术进步,技术效率对全要素生产率增长的贡献较小,而中西部地区的全要素生产率增长主要是依赖技术效率的提高。然后从国际贸易和FDI的视角,利用省级动态面板数据实证研究发现主要是由于东部地区进出口贸易和FDI促进了技术效率和技术进步,对技术进步的影响系数大于对技术效率的影响系数,而中西部地区的进出口贸易和 FDI促进了技术效率,抑制了技术进步。 相似文献
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