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   34042篇
  免费   8762篇
  国内免费   248篇
耳鼻咽喉   292篇
儿科学   770篇
妇产科学   775篇
基础医学   5933篇
口腔科学   1140篇
临床医学   4596篇
内科学   8696篇
皮肤病学   600篇
神经病学   2910篇
特种医学   2171篇
外科学   7230篇
综合类   299篇
一般理论   14篇
预防医学   3221篇
眼科学   550篇
药学   1864篇
  1篇
中国医学   31篇
肿瘤学   1959篇
  2022年   397篇
  2021年   625篇
  2020年   406篇
  2019年   384篇
  2018年   638篇
  2017年   591篇
  2016年   789篇
  2015年   1144篇
  2014年   1846篇
  2013年   2569篇
  2012年   1383篇
  2011年   1264篇
  2010年   1534篇
  2009年   1659篇
  2008年   1085篇
  2007年   868篇
  2006年   1002篇
  2005年   933篇
  2004年   833篇
  2003年   751篇
  2002年   731篇
  2001年   541篇
  2000年   440篇
  1999年   657篇
  1998年   881篇
  1997年   849篇
  1996年   879篇
  1995年   825篇
  1994年   708篇
  1993年   638篇
  1992年   651篇
  1991年   611篇
  1990年   546篇
  1989年   617篇
  1988年   664篇
  1987年   638篇
  1986年   598篇
  1985年   635篇
  1984年   559篇
  1983年   549篇
  1982年   612篇
  1981年   572篇
  1980年   546篇
  1979年   518篇
  1978年   513篇
  1977年   513篇
  1976年   439篇
  1975年   397篇
  1974年   363篇
  1972年   348篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Cementoblastomas are benign lesions of the odontogenic ectomesenchyme that rarely occur related to the primary dentition, especially on the left side of the mandible. This study describes a case of a true cementoblastoma related to the left second primary mandibular molar in a 7-year-old child (the largest one seen in the left side of the mandible). Additionally, the radiographic and histologic findings of the lesion are described in details.  相似文献   
42.
43.
44.
45.
46.
Epidemiological studies have shown dietary magnesium (Mg) intake and serum Mg levels to be inversely correlated with the development of atherosclerosis. We hypothesized that low levels of Mg would promote atherosclerotic plaque development in rabbits. New Zealand white rabbits (4 months old, n = 22) were fed an atherogenic diet containing 0.12% (−Mg), 0.27% (control), or 0.43% (+Mg) Mg for 8 weeks. Blood samples were obtained at baseline, 2, 4, 6, and 8 weeks and were assayed for total cholesterol, high-density lipoprotein (HDL), non-HDL, triglycerides (TG), C-reactive protein, serum Mg, and erythrocyte Mg. Aortas from −Mg had significantly more plaque, with an intima thickness 42% greater than control and 36% greater than +Mg. Serum cholesterol levels rose over time, and at 8 weeks, −Mg had the highest and +Mg the lowest total and non-HDL cholesterol and TG levels, although these results did not reach significance. Over time, serum Mg levels increased, and erythrocyte Mg levels decreased. C-reactive protein significantly increased in all groups at 4 and 6 weeks but returned to baseline levels by 8 weeks. This study supports the hypothesis that inadequate intake of Mg results in an increase in atherosclerotic plaque development in rabbits.  相似文献   
47.
Sir, The comment of Attilio Di Spiezio Sardo et al. was very interesting.They reported the results of their studies on the effects ofintranasal and transdermal  相似文献   
48.
49.
50.
Results of a recent study have demonstrated that exposure to multiple ethanol concentrations and repeated ethanol deprivation periods in Indiana ethanol-preferring (P) rats resulted in the development of an alcohol deprivation effect (ADE; the temporary increase in voluntary ethanol intake after a period of deprivation from ethanol) characterized by consumption of intoxicating amounts of ethanol. The current study was designed to possibly extend these results to Sardinian alcohol-preferring (sP) rats, generated with the same selective program previously used for P rats. To this aim, ethanol-naive sP rats were exposed initially to the home cage four-bottle choice [10%, 20%, and 30% (vol./vol.) ethanol solutions and water] for eight consecutive weeks. Subsequently, rats were divided into two groups: The first group had continuous access to the four-bottle regimen (nondeprived rats), and the second group was exposed to five cycles of 14-day periods of deprivation from ethanol and 14-day periods of reexposure to the four-bottle regimen. An ADE developed after each deprivation period. However, the extra intake of ethanol was limited to the first hour of each reaccess period. Magnitude of ADE did not change with repeated periods of deprivation. However, a shift in preference toward the two highest concentrations of ethanol solutions was evident from the first reexposure to ethanol and was maintained throughout the study. These results provide further evidence on the heterogeneity of ethanol-drinking behavior among rat lines selectively bred for high ethanol preference and consumption.  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