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   2114篇
  免费   300篇
  国内免费   21篇
耳鼻咽喉   23篇
儿科学   93篇
妇产科学   31篇
基础医学   269篇
口腔科学   55篇
临床医学   292篇
内科学   413篇
皮肤病学   121篇
神经病学   69篇
特种医学   222篇
外科学   382篇
综合类   97篇
现状与发展   30篇
预防医学   86篇
眼科学   25篇
药学   90篇
中国医学   3篇
肿瘤学   134篇
  2024年   14篇
  2023年   182篇
  2022年   18篇
  2021年   24篇
  2020年   68篇
  2019年   33篇
  2018年   61篇
  2017年   57篇
  2016年   57篇
  2015年   67篇
  2014年   104篇
  2013年   91篇
  2012年   84篇
  2011年   76篇
  2010年   100篇
  2009年   122篇
  2008年   77篇
  2007年   115篇
  2006年   79篇
  2005年   66篇
  2004年   41篇
  2003年   48篇
  2002年   36篇
  2001年   36篇
  2000年   31篇
  1999年   42篇
  1998年   45篇
  1997年   58篇
  1996年   51篇
  1995年   47篇
  1994年   36篇
  1993年   46篇
  1992年   30篇
  1991年   32篇
  1990年   20篇
  1989年   36篇
  1988年   40篇
  1987年   34篇
  1986年   19篇
  1985年   22篇
  1984年   16篇
  1982年   17篇
  1981年   14篇
  1980年   19篇
  1979年   14篇
  1978年   11篇
  1977年   9篇
  1976年   21篇
  1975年   14篇
  1974年   10篇
排序方式: 共有2435条查询结果,搜索用时 15 毫秒
1.
2.
Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.  相似文献   
3.
4.
5.
J Dvorak  D Grob  H Baumgartner  N Gschwend  W Grauer  S Larsson 《Spine》1989,14(10):1057-1064
Thirty-four patients with atlanto-axial instability due to rheumatoid arthritis were examined with plain x-ray views and functional magnetic resonance imaging (MR), and were neurologically evaluated. Transcranial brain stimulation was performed in 25 patients. In 22 cases, the authors observed inflammatory tissue thicker than 3 mm behind the odontoid peg. The spinal canal diameter was significantly decreased in the flexed position. Nine patients showed signs of cranial migration of the axis. The diameter of the spinal cord was measured to be 7.4 mm in the neutral position, and 6.5 mm in flexion. The difference between the diameter of the neutral and flexed positions was highly significant. Twelve of the 34 patients displayed clinical signs of cervical myelopathy, and 13 showed a significant delay of central motor latency, as calculated from the motor evoked potentials. Surgical intervention, either by a posterior approach only or combined with a transoral dens and inflammatory tissue resection, is recommended in patients with progressive atlanto-axial instability, pathologic clinical and neurophysiologic findings, and a spinal cord diameter of less than 6 mm in flexion. Severe pain and cranial migration of the axis, as measured by the MRI, also justify a surgical intervention.  相似文献   
6.
Defecography in multiple sclerosis patients with severe constipation   总被引:3,自引:0,他引:3  
Gill  KP; Chia  YW; Henry  MM; Shorvon  PJ 《Radiology》1994,191(2):553
  相似文献   
7.
8.
J Dvorak  J Hayek  R Zehnder 《Spine》1987,12(8):726-731
Nine healthy adults and 43 patients with cervical spine injury were examined by using functional (computerized tomography) CT scanning. The ranges of axial rotation at the levels occiput C0-C1, C1-C2, and C2-C3 were measured. A rotation at C0-C1 greater than 8 degrees; at C1-C2, 56 degrees; or a right-left difference C0-C1 greater than 5 degrees and C1-2 greater than 8 degrees indicates hypermobility. A rotation at segment C1-C2 of less than 28 degrees indicates hypomobility. Surgical stabilization of rotatory instability could be considered as a possible therapeutic procedure.  相似文献   
9.
10.
A knowledge of the alteration in the fibre type profile of paraspinal muscle associated with low back pain is essential for the design of successful rehabilitation programmes. In attempting to compare the muscles of patients with low back pain with those of controls, few previous studies have considered factors such as gender, age, and size of the subjects, each of which can potentially confound interpretation of the results. We obtained samples of lumbar paraspinal muscle during spinal surgery from 21 patients with low back pain and, using the percutaneous biopsy technique, from 21 control volunteers matched for gender, age, and body mass. The samples were subject to routine histochemicsl typcal analysis to determine characteristics of muscle fibre type. Compared with controls, the muscle of the patients had a significantly higher proportion of type-IIB (fast-twitch glycolytic) fibres than type- I (slow oxidatve) fibres. The mean size of a given fibre type did not differ between the patients and the controls. Consequently, the relative area of the muscle iccupied by type-IIB fibres was higher and that by type-I fibres Was lower in the patients. The patients had a greater number of muscle samples with more than 1% type-IIC fibres, and abnormalities that could be described as pathological were more marked in the patients than in the controls. In conclusion, the paraspinal muscles of patients who have low back pain display a more glycolytic (faster) profile; this can be expected to render them less resistant to fatigue.  相似文献   
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