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   381311篇
  免费   24301篇
  国内免费   2817篇
耳鼻咽喉   5198篇
儿科学   8264篇
妇产科学   10102篇
基础医学   53435篇
口腔科学   11838篇
临床医学   30229篇
内科学   78897篇
皮肤病学   8561篇
神经病学   27421篇
特种医学   13987篇
外国民族医学   82篇
外科学   60979篇
综合类   9958篇
现状与发展   1篇
一般理论   64篇
预防医学   17487篇
眼科学   9445篇
药学   31171篇
  1篇
中国医学   2195篇
肿瘤学   29114篇
  2021年   2635篇
  2019年   2755篇
  2018年   4550篇
  2017年   3465篇
  2016年   3546篇
  2015年   4070篇
  2014年   5745篇
  2013年   7451篇
  2012年   10094篇
  2011年   10297篇
  2010年   6247篇
  2009年   5889篇
  2008年   9536篇
  2007年   10392篇
  2006年   10322篇
  2005年   9394篇
  2004年   8895篇
  2003年   8644篇
  2002年   8330篇
  2001年   28306篇
  2000年   28851篇
  1999年   23732篇
  1998年   5204篇
  1997年   4292篇
  1996年   3882篇
  1995年   3523篇
  1994年   3151篇
  1993年   2871篇
  1992年   16119篇
  1991年   14871篇
  1990年   14204篇
  1989年   14010篇
  1988年   12629篇
  1987年   12090篇
  1986年   11129篇
  1985年   10348篇
  1984年   6947篇
  1983年   5618篇
  1982年   2726篇
  1979年   5489篇
  1978年   3352篇
  1977年   2978篇
  1975年   2642篇
  1974年   3064篇
  1973年   2866篇
  1972年   2829篇
  1971年   2773篇
  1970年   2512篇
  1969年   2544篇
  1968年   2250篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Bilateral cervical lymph node dissection was performed in 71 cases of papillary thyroid carcinoma, considered to be relatively early cases because of mobility, irrespective of the size of tumor or presence of node enlargement. Of these, 33 cases received additional node dissection of the anterosuperior mediastinum through longitudinal sternotomy. The number of lymph nodes examined per subject averaged 89.9, the number of metastatic nodes was 13.8, and metastasis was noted in 88.7% of all cases. Lymph node metastasis tended to be more frequent on the affected side, but was simultaneously scattered over the whole cervical area. As to sites, metastasis of paratracheal nodes on the affected side occurred at a frequency of 66.2%, inferior and superior jugular nodes at 62.0% and 59.0% respectively, pretracheal nodes at 50.7%, and tracheoesophageal nodes at 47.9%. The high incidence of para- and pretracheal nodes suggests that the lymph flow in this direction is of great importance in metastasis. In fact, lymph nodes in the mediastinum, which were directly continuous with these nodes, showed as high as 39.4% metastasis in cases of anterosuperior mediastinal extirpation. This extensive node dissection is considered to be very preferable as at least the agony of survival with carcinoma can be lessened.  相似文献   
93.
94.
95.
Liver histopathology in clinical Reye syndrome   总被引:1,自引:0,他引:1  
Analysis of the liver histopathology in 19 children with clinical Reye syndrome (RS) revealed that nine had diffuse panlobular steatosis, one giant cell hepatitis, one a mild choledochal cyst with inflammation, two multifocal spotty necrosis and one multiple centrilobular necrosis, the other five being normal. Four of the nine patients with diffuse panlobular steatosis showed microvesicular fatty droplets with central nuclei, which was consistent with findings characteristic for typical RS. Two cases showed a periportal area dominant macrovesicular fatty change, which was highly suggestive for metabolic disorder. In the other three cases, the findings were so variable in terms of the size of lipid droplets and the location of nuclei in hepatocytes that it was not possible to provide any clue for defining a diagnosis. These results confirmed the legitimacy of the diagnostic criteria of RS which included a liver biopsy as one of the mandatory conditions. They also indicated that RS-mimicking clinical pictures can be presented by miscellaneous conditions in which liver histology does not necessarily helpful in establishing definite diagnosis.  相似文献   
96.
Our experience with full-length ureteric splintage is reviewed with a note on the technique and its outcome. It is safe, effective and simple, easy to teach and easy to learn. It is recommended as the operation of choice in bilharzial ureteropathy.  相似文献   
97.
Radiation-induced meningioma. 3 cases   总被引:1,自引:0,他引:1  
During the same year (1984), we have seen 3 cases of meningiomas following radiation therapy of the brain for previously diagnosed tumors. A causal relationship between irradiation and meningioma has been postulated. Nevertheless, the coincidental occurrence in same patient of two different histological lesions is possible. The neoplasms developed after irradiation are of mesenchymal origin; they are fibrosarcomas, osteogenic sarcomas and meningiomas.  相似文献   
98.
99.
100.
Kindling of the visual cortex in cats: comparison with amygdaloid kindling   总被引:3,自引:0,他引:3  
Kindling of the primary visual cortex (VC) was compared with that of the amygdala in cats. VC kindling was basically similar to kindling of the amygdala in that daily electrical stimulation can lead to the development of a generalized convulsion in most subjects, a growth of afterdischarges in their configuration and duration, and a reduction of the afterdischarge threshold. The kindling response of the VC differed from that of the amygdala in a number of respects, i.e., a high afterdischarge threshold, a different pattern of behavioral seizure development, an abrupt growth of electroclinical seizures coincident with the onset of a generalized convulsion, an intersubject variability in seizure susceptibility, and a marked seizure instability. In VC kindling the afterdischarge propagation into the amygdala was not observed until the generalized convulsion developed, and the early involvement of afterdischarge was seen in the pulvinar, lateral geniculate body, and superior colliculus. These data suggest that a neural mechanism different from amygdaloid kindling may participate in VC kindling, and that the subcortical structures of the visual system are involved in the preferential pathway for a seizure generalization from the VC.  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