首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   923篇
  免费   0篇
化学工业   1篇
建筑科学   3篇
轻工业   1篇
石油天然气   1篇
冶金工业   916篇
自动化技术   1篇
  2012年   1篇
  2011年   1篇
  2010年   1篇
  2003年   2篇
  2002年   1篇
  2000年   1篇
  1999年   22篇
  1998年   243篇
  1997年   154篇
  1996年   94篇
  1995年   56篇
  1994年   51篇
  1993年   53篇
  1992年   3篇
  1991年   24篇
  1990年   10篇
  1989年   18篇
  1988年   12篇
  1987年   10篇
  1986年   11篇
  1985年   14篇
  1983年   2篇
  1982年   4篇
  1981年   8篇
  1980年   11篇
  1978年   4篇
  1977年   28篇
  1976年   81篇
  1975年   3篇
排序方式: 共有923条查询结果,搜索用时 0 毫秒
921.
We performed a histologic and morphometric study of spastic muscle from 10 children with diplegic cerebral palsy, comparing muscle structure with the gait parameters of energy expenditure index and dynamic electromyography. Variations in fiber area within and between fiber types were increased significantly in children with cerebral palsy. In each of the control subjects, the combined coefficient of variation for type-1 and type-2 fiber area was less than 25% and the average was 17%; in the subjects with cerebral palsy, the combined coefficient of variation was more than 25% and the average was 36% (p < or = 0.004). The average difference between the mean area of type-1 and type-2 fibers was 26.7 +/- 18.9% for subjects with cerebral palsy and 4.2 +/- 2.4% for control subjects (p < or = 0.004). There was a 67% predominance of one fiber type in the subjects with cerebral palsy compared with a 55% predominance in the control subjects (p < or = 0.03). The difference between the total area of type-1 and type-2 fibers was 57% in the subjects with cerebral palsy and 17% in the control subjects (p < or = 0.002). There was a significant correlation between the combined coefficient of variation of fiber area and the energy expenditure index (r = 0.77, p < or = 0.03). The difference between the mean area of type-1 and type-2 fibers correlated with prolongation of electromyographic activity (r = 0.69, p < or = 0.05). No abnormalities in fiber ultrastructure were found in the subjects with cerebral palsy. Children with cerebral palsy had abnormal variation in the size of muscle fibers and altered distribution of fiber types. The values for variation in fiber area correlated with the energy expenditure index and with prolongation of electromyographic activity during walking.  相似文献   
922.
Thirty-six HIV-1-infected predominantly well-functioning subjects were followed up for one year by repeated neuropsychological, clinical neurological, neuroradiological, and immunological examinations. Changes in cognitive performance related to the severity of HIV-1 infection as well as to neuroradiological or immunological changes were studied. A decline in cognitive speed and flexibility was found in symptomatic subjects (ARC, AIDS). The impairment was especially pronounced in patients with progression of brain atrophy. These findings suggest a brain pathology underlying the cognitive decline in ambulatory outpatients with symptomatic HIV-1 infection. A practice effect was found in asymptomatic subjects (ASX, LAS) and in those with unchanged CT/MRI scans. No systematic relationship was found between cognitive change and immunological change.  相似文献   
923.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号