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   433465篇
  免费   52554篇
  国内免费   767篇
耳鼻咽喉   6412篇
儿科学   15099篇
妇产科学   8793篇
基础医学   65187篇
口腔科学   14421篇
临床医学   37848篇
内科学   102873篇
皮肤病学   16737篇
神经病学   43384篇
特种医学   12087篇
外国民族医学   129篇
外科学   57542篇
综合类   1699篇
一般理论   116篇
预防医学   37755篇
眼科学   8417篇
药学   30574篇
中国医学   2241篇
肿瘤学   25472篇
  2023年   1990篇
  2022年   2333篇
  2021年   7829篇
  2020年   8458篇
  2019年   17166篇
  2018年   19978篇
  2017年   17150篇
  2016年   17784篇
  2015年   18579篇
  2014年   19895篇
  2013年   25502篇
  2012年   27761篇
  2011年   28091篇
  2010年   20646篇
  2009年   14760篇
  2008年   22477篇
  2007年   22888篇
  2006年   21294篇
  2005年   21011篇
  2004年   19420篇
  2003年   18124篇
  2002年   17296篇
  2001年   11004篇
  2000年   11465篇
  1999年   9401篇
  1998年   1992篇
  1997年   1561篇
  1996年   1438篇
  1995年   1275篇
  1992年   4791篇
  1991年   4287篇
  1990年   4033篇
  1989年   3561篇
  1988年   3293篇
  1987年   3114篇
  1986年   2987篇
  1985年   2688篇
  1984年   2006篇
  1983年   1678篇
  1979年   1767篇
  1978年   1229篇
  1977年   1107篇
  1975年   1246篇
  1974年   1468篇
  1973年   1505篇
  1972年   1404篇
  1971年   1410篇
  1970年   1329篇
  1969年   1358篇
  1968年   1211篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
51.
52.
The present authors investigated the excretion, distribution and pharmacokinetics of the novel potential antirheumatic agent flobufen and its active metabolite after p.o. and i.v. doses of 2, 10 and 50 mg/kg administered to rats. The drug is resorbed well from the digestive tract and mostly it is metabolized to the principal metabolite M, which is only slowly excreted from the organism mainly by renal clearance. Within the whole dose range the kinetics of the drug is linear. Binding of flobufen and M to proteins is high (95-99%). The highest concentrations of radioactive metabolites (mostly M) were found in the plasma, liver, lungs, kidneys, connective tissue and inflammatory foci. The penetration of metabolites through the placenta and excretion in human milk are relatively important.  相似文献   
53.
54.
55.
We report a prevalence study of the best visual acuity in the affected eye of 100 selected patients with herpetic keratitis seen during a two-year period. Sixty-two patients retained an acuity of 6/9 or better without requiring penetrating keratoplasty (PK). The prevalence of reduced visual acuity severe enough to warrant PK was 33%. Patients requiring PK for whom full clinical records were available suffered a mean of 6.8 episodes of keratitis. In this group of patients the vision of 18 fell from 6/6 to 6/60 over a mean period of 8.5 years. Once visual acuity was permanently reduced to 6/12, 78% of patients proceeded to lose vision to 6/60. Unilateral visual impairment occurs in at least a third of patients with severe herpetic keratitis. Once vision falls permanently to 6/12, the long-term prognosis for vision appears to be poor.  相似文献   
56.
57.
58.
In establishing the liability of optometrists for negligence the courts have applied the same standard of care that is imposed upon other health care professionals, holding that optometrists must employ the minimum degree of skill, care and learning that is ordinarily exhibited by members of the profession who are in good standing. The leading cases establishing this standard have involved glaucoma, retinal detachment, and intraocular tumors. Optometrists have also been held liable under product liability law for injuries caused by ophthalmic lenses, which illustrates the trend toward strict liability. Other cases have involved the doctrine of informed consent.  相似文献   
59.
Melatonin, a pineal hormone, released photoperiodically, was administered systemically in rats, previously implanted with semimicroelectrodes into six different brain structures. The multiunit electrical activity of these structures was recorded for 10 min before and 60 min after melatonin administration in unanesthetized, freely moving rats. Different melatonin doses (100, 200, 500, and 1000 micrograms/kg) produced changes in the electrical activity of all tested structures. However, amygdala, rostral hypothalamus and mesencephalic reticular formation showed the most important changes. The main effect induced by melatonin was a dose-related decrease of the spontaneous electrical activity. The significance of these effects is discussed within the context of the behavioral and endocrinological effects of melatonin.  相似文献   
60.
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