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   195340篇
  免费   4027篇
  国内免费   448篇
耳鼻咽喉   2800篇
儿科学   7448篇
妇产科学   5840篇
基础医学   25098篇
口腔科学   5801篇
临床医学   15126篇
内科学   35258篇
皮肤病学   4556篇
神经病学   11543篇
特种医学   10764篇
外国民族医学   97篇
外科学   29546篇
综合类   1094篇
一般理论   1篇
预防医学   16217篇
眼科学   4331篇
药学   13502篇
  2篇
中国医学   143篇
肿瘤学   10648篇
  2018年   3526篇
  2017年   3882篇
  2016年   3173篇
  2015年   4839篇
  2014年   4253篇
  2013年   3348篇
  2012年   9769篇
  2011年   4656篇
  2010年   2163篇
  2009年   3834篇
  2008年   2031篇
  2007年   2755篇
  2006年   3016篇
  2005年   11172篇
  2004年   12665篇
  2003年   8227篇
  2002年   3476篇
  2001年   4412篇
  2000年   1775篇
  1999年   5917篇
  1998年   535篇
  1995年   404篇
  1992年   6923篇
  1991年   7139篇
  1990年   7387篇
  1989年   6990篇
  1988年   6531篇
  1987年   6275篇
  1986年   5997篇
  1985年   5272篇
  1984年   3613篇
  1983年   2925篇
  1982年   1010篇
  1981年   779篇
  1980年   838篇
  1979年   3846篇
  1978年   2376篇
  1977年   1798篇
  1976年   1569篇
  1975年   2477篇
  1974年   3117篇
  1973年   2745篇
  1972年   2767篇
  1971年   2744篇
  1970年   2561篇
  1969年   2468篇
  1968年   2239篇
  1967年   2170篇
  1966年   1902篇
  1965年   1136篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Concentration and metabolic replacement (turnover) rate of glucose and ketone bodies were determined at intervals during a 52 day postweaning fast in five grey seal (Halichoerus grypus) pups, using bolus injections of radiotracers. Blood glucose was maintained at a high level throughout the fast, while beta-hydroxybutyrate increased 26 times from day 3 to day 37, whereafter it by and large was maintained. Glucose replacement rate decreased to 56% of the day 9 value at day 37 and dropped further to only 32% of the day 9 level at day 52 in two seals, while in another 2 seals it increased at this late stage. The average ketone body replacement rate ranged between 8.6 and 13.8 mumols min-1 kg-1, but did not change significantly (P greater than 0.05) during the fasting period. These results suggest a reduced gluconeogenesis from protein and increased production of ketone bodies, which may in part replace glucose as energy source during fasting.  相似文献   
992.
Interindividual variability of lung function responses to smoking is unexplained. The aim of the present study is to inquire about a possible role of personality factors for an explanation of interindividual differences of lung function responses in smokers of both sexes. The results of canonical correlation analyses showed that there are no substantial correlations of personality with smoking behavior and also no significant associations of smoking behavior with pulmonary function in a healthy sample of smokers. In males only, personality factors were related to breathing frequency, but not to static and dynamic lung volumes.  相似文献   
993.
994.
995.
996.
997.
Amorphin--24-vicyanoside (C34H4O16(2)H2O)--in a dose of 10 mg/kg orally decreases the content of cholesterol, total lipids, atherogenic lipoproteids in the blood and organs of intact rats and rats with endogenous or ethanol hyperlipemia, inhibits the development of experimental atherosclerosis in rabbits induced by the combination of risk factors (cholesterol + glucose + hypodynamia), decreases the content of lipids in the blood and organs (especially in aorta), prevents the development of morphological manifestations of the aorta atherosclerosis.  相似文献   
998.
The purpose of the present paper was to demonstrate the antitumor activity of lymphocytes and antibodies in the antibody-dependent cell-mediated cytotoxicity test (ADCC) in relation to the tumor growth in adult and aging rats bearing a methylcholanthrene-induced sarcoma (MC-Sa). In the syngeneic system using the ADCC test effector spleen lymphocytes, 51Cr labeled MC-Sa target cells and anti-MC-Sa serum were derived from inbred male Wistar rats. It was found that adult and aging tumor-bearing rats possessed lymphocytes (LSa) and antibodies (Ab) which were active in ADCC. In comparative studies between the groups of adult and aging rats a reverse relationship between tumor growth and activity of LSa and Ab in the ADCC test has been found. Thus, the larger weight of tumors in the group of adult rats was followed by lower LSa and Ab activities in the ADCC test. On the other hand, the smaller tumor growth in the group of aging rats was followed by higher activities of LSa and Ab in this test. We suggest that the ADCC phenomenon could be one of the antitumor mechanisms especially effective in aging rats.  相似文献   
999.
Three cases of popliteal artery entrapment syndrome, one of them bilateral, are presented with a review of the literature, with special reference to the embryological development of the popliteal space and the diagnostic and therapeutic problems presented by this syndrome.  相似文献   
1000.
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