Functional MRI changes in the central motor system in myotonic dystrophy type 1

Myotonic dystrophy type 1 (DM1) is a multisystemic disease involving multiple organ systems including central nervous system (CNS) and muscles. Few studies have focused on the central motor system in DM1, pointing to a subclinical abnormality in the CNS. The aim of our study was to investigate patterns of cerebral activation in DM1 during a motor task using functional MRI (fMRI). Fifteen DM1 patients, aged 20 to 59 years, and 15 controls of comparable age were scanned during a self-paced sequential finger-to-thumb opposition task of their dominant right hand. Functional MRI images were analyzed using SPM99. Patients underwent clinical and genetic assessment; all subjects underwent a conventional MR study. Myotonic dystrophy type 1 patients showed greater activation than controls in bilateral sensorimotor areas and inferior parietal lobules, basal ganglia and thalami, in the ipsilateral premotor area, insula and supplementary motor area (corrected P<.05). Analysis of the interaction between disease and age showed that correlation with age was significantly greater in patients than in controls in bilateral sensorimotor areas and in contralateral parietal areas. Other clinical and MR characteristics did not correlate with fMRI. Functional changes in DM1 may represent compensatory mechanisms such as reorganization and redistribution of functional networks to compensate for ultrastructural and neurochemical changes occurring as part of the accelerated aging process.     

区域经济一体化过程中的“轮轴-辐条”结构研究

20世纪90年代以来,全球范围内区域经济一体化的发展成为潮流,而新一轮双边自由贸易区的兴起和繁荣给区域经济一体化进程带来了新的问题,即"轮轴—辐条"结构的形成。这种结构给区域经济一体化带来的影响主要表现为:它的膨胀、生殖、交错维持了区域经济一体化的趋势;进一步拉大了区域内国家间的经济实力;降低了区域经济一体化效益和总福利水平。     

电液加载系统的多变量模型与控制

本文建立了阀控油马达力矩加载系统的多变量模型,提出了相对多余力的概念和评价加载系统性能的指标参数,根据多变量控制理论,实现了微机解耦控制。     

多车致一人损伤交通事故之责任承担

多车致一人损伤事故情形下,应将受害人的权利救济作为考量的首要因素。部分机动车未投保交强险,认定交强险保险人和投保义务人的责任方式,应考虑交强险的功能定位;部分机动车不承担事故责任,认定交强险的责任主体,可突破事故的关联基础事实。对于超出或不属于交强险责任限额范围的部分,认定多侵权人的责任方式,应区分多人侵权类型。     

低速潜油电机的研究

以１８槽电机为基础，分析和研究了电机设计的最多磁级数．通过分析提出１８槽电机分数槽绕组的镜像方法，并确定出能满足螺杆泵转速要求的最少槽数．     

湖北野生蔬菜资源及开发利用

介绍了湖北野生蔬菜资源的种类、性状、分布和食用类型;对湖北野生蔬菜资源的现状,开发利用过程中存在的问题进行了分析;提出了开发利用湖北野生蔬菜资源的对策和措施。     

隐极迭片转子同步电动机启动特性计算机仿真

本文提出了用多回路法来计算隐极迭片转子同步电动机的启动特性,包括各回路的电流;导出了用于似稳态和动态分析的数学模型;提出了用转子电阻分布系数来描述转子不对称性的方法.文中以一台22kW电动机为例,对不同阻尼绕组情况下的不同电阻分布系数γ进行了计算和分析,结果表明当γ接近零时,其启动特性接近于异步电动机的启动特性.实验还表明,计算结果与实验结果吻合较好.     

Coherent and turbulent process analysis of the effects of a longitudinal vortex on boundary layer detachment on a NACA0015 foil

In this paper, the influence of a single tip vortex on boundary layer detachment is studied. This study offers a preliminary approach in order to better understand the interaction between a propeller hub vortex and the rudder installed in its wake. This configuration belongs to the field of marine propulsion and encompasses such specific problem as cavitation inception, modification of propulsive performances and induced vibrations. To better understand the complex mechanisms due to propeller–rudder interactions it was decided to emphasize configurations where the hub vortex is generated by an elliptical 3-D foil and is located upstream of a 2-D NACA0015 foil at high incidences for a Reynolds number of 5×10⁵. The physical mechanisms were studied using Time Resolved Stereoscopic Particle Image Velocimetry (TR-SPIV) techniques. Particular attention was paid to the detachment at 25° incidence and a detailed cartography of the mean and turbulent properties of the wake is presented. Proper Orthogonal Decomposition (POD) analysis was applied in order to highlight the unsteady nature of the flow using phase averaging based on the first POD coefficients to characterize the turbulent and coherent process in the near wake of the rudder.     

Dynamics and mechanics of motor-filament systems

Motivated by the cytoskeleton of eukaryotic cells, we develop a general framework for describing the large-scale dynamics of an active filament network. In the cytoskeleton, active cross-links are formed by motor proteins that are able to induce relative motion between filaments. Starting from pair-wise interactions of filaments via such active processes, our framework is based on momentum conservation and an analysis of the momentum flux. This allows us to calculate the stresses in the filament network generated by the action of motor proteins. We derive effective theories for the filament dynamics which can be related to continuum theories of active polar gels. As an example, we discuss the stability of homogenous isotropic filament distributions in two spatial dimensions.