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   931703篇
  免费   66340篇
  国内免费   1342篇
耳鼻咽喉   12957篇
儿科学   24358篇
妇产科学   23232篇
基础医学   132872篇
口腔科学   28246篇
临床医学   80525篇
内科学   183216篇
皮肤病学   19226篇
神经病学   72166篇
特种医学   36812篇
外国民族医学   79篇
外科学   152067篇
综合类   18042篇
现状与发展   1篇
一般理论   234篇
预防医学   61735篇
眼科学   21307篇
药学   72521篇
  3篇
中国医学   2162篇
肿瘤学   57624篇
  2018年   8959篇
  2017年   7025篇
  2016年   7759篇
  2015年   8856篇
  2014年   11980篇
  2013年   17492篇
  2012年   24074篇
  2011年   25025篇
  2010年   14797篇
  2009年   14263篇
  2008年   24590篇
  2007年   25681篇
  2006年   26476篇
  2005年   25421篇
  2004年   24551篇
  2003年   23595篇
  2002年   23141篇
  2001年   54724篇
  2000年   56541篇
  1999年   46947篇
  1998年   10730篇
  1997年   9465篇
  1996年   9592篇
  1995年   8926篇
  1994年   8278篇
  1993年   7593篇
  1992年   35487篇
  1991年   33912篇
  1990年   32734篇
  1989年   31869篇
  1988年   28991篇
  1987年   28249篇
  1986年   26288篇
  1985年   25144篇
  1984年   17832篇
  1983年   15141篇
  1982年   7795篇
  1981年   6771篇
  1979年   15781篇
  1978年   10598篇
  1977年   9052篇
  1976年   7871篇
  1975年   8628篇
  1974年   10466篇
  1973年   9858篇
  1972年   9357篇
  1971年   8852篇
  1970年   8426篇
  1969年   7923篇
  1968年   7200篇
排序方式: 共有10000条查询结果,搜索用时 33 毫秒
111.
112.
Polymorphonuclear leukocyte (PMN) migration was assessed in vitro using the agarose plate method in patients with psoriasis vulgaris, and compared with an age- and sex-matched control group. No significant difference was found between the two groups in the PMN response to the chemotactic substances F-Met-Leu-Phe (FMLP) or zymosan activated serum (ZAS). Equally, the chemokinetic or chemotactic potential of psoriatic serum did not differ from control serum. Our results do not support a primary abnormality of PMN function in psoriasis.  相似文献   
113.
114.
10 patients with CLL and 2 with CML were treated with gradually increasing doses of 1 alpha(OH)D3, up to 4 micrograms daily during 6 wk. 3 patients with preleukemia and 1 with myelofibrosis were treated with 2 micrograms daily of 1 alpha(OH)D3 for a prolonged period up to 17 wk. The treatment with 1 alpha (OH)D3 did not result in changes of disease parameters in any of the patients under study. Receptor studies for 1,25(OH)2D3 were performed in 8 CLL patients and revealed only 1 patient with increased specific receptor binding capacity. The maximum tolerable dose of 1 alpha(OH)D3 varied individually, but was in the range of 2-4 micrograms daily.  相似文献   
115.
116.
IgG-maleimide peroxidase, Fab'-maleimide peroxidase, polymer and monomer types of Fab'-periodate peroxidase were prepared from an antibody against rat lipoamide dehydrogenase, a component of the pyruvate dehydrogenase complex which is located in mitochondria. They were examined for immunohistochemical staining of the rat kidney. Fab'-maleimide peroxidase was the best for staining mitochondrial protein. IgG-maleimide peroxidase and the monomer type of Fab'-periodate peroxidase had the same intensity of staining. The polymer type of Fab'-periodate peroxidase could not stain the lipoamide dehydrogenase.  相似文献   
117.
118.
119.
120.
The effects of two promoters of hepatocarcinogenesis--phenobarbital and butylated hydroxytoluene (BHT)--on five hepatic biochemical parameters were examined in adult female rats. Phenobarbital given orally in two doses each of 110 mg/kg 21 and 4 hr before the rats were killed caused large increases in hepatic ornithine decarboxylase (ODC) activity and cytochrome P-450 content. Extending the number of phenobarbital treatments to five increased the hepatic enzyme induction and also caused a minor decrease in hepatic glutathione and a small increase in serum alanine aminotransferase activity. Two oral doses of 700 mg BHT/kg (20% of the LD50) caused hepatic DNA damage and induction of both ODC activity and cytochrome P-450 content. When the dose of BHT was reduced from 700 to 140 mg/kg no significant effects on the biochemical parameters were found. Both promoters of hepatocarcinogenesis were identified by their induction of ODC, a marker for promotional potential, but only BHT showed a potential for carcinogenic initiation. The biochemical parameters examined, particularly the alkaline elution technique for DNA damage, ornithine decarboxylase activity and serum alanine aminotransferase, may constitute a useful assay system for examining a compound's potential for carcinogenic initiation, carcinogenic promotion and cellular toxicity.  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