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   1264290篇
  免费   94867篇
  国内免费   1581篇
耳鼻咽喉   16320篇
儿科学   41008篇
妇产科学   34953篇
基础医学   189450篇
口腔科学   34734篇
临床医学   117793篇
内科学   247856篇
皮肤病学   27279篇
神经病学   101886篇
特种医学   46769篇
外国民族医学   265篇
外科学   178712篇
综合类   25752篇
现状与发展   3篇
一般理论   568篇
预防医学   104655篇
眼科学   28055篇
药学   92683篇
  7篇
中国医学   2022篇
肿瘤学   69968篇
  2018年   13539篇
  2017年   10396篇
  2016年   11328篇
  2015年   13079篇
  2014年   18005篇
  2013年   27501篇
  2012年   37598篇
  2011年   39994篇
  2010年   23085篇
  2009年   22276篇
  2008年   37793篇
  2007年   40420篇
  2006年   40011篇
  2005年   39129篇
  2004年   37587篇
  2003年   35984篇
  2002年   34891篇
  2001年   56039篇
  2000年   57048篇
  1999年   48109篇
  1998年   13401篇
  1997年   12229篇
  1996年   12650篇
  1995年   11921篇
  1994年   11110篇
  1993年   10402篇
  1992年   38204篇
  1991年   37677篇
  1990年   36447篇
  1989年   35259篇
  1988年   32691篇
  1987年   32029篇
  1986年   30525篇
  1985年   28787篇
  1984年   21949篇
  1983年   19195篇
  1982年   11366篇
  1981年   10322篇
  1979年   20944篇
  1978年   15393篇
  1977年   12790篇
  1976年   11846篇
  1975年   12812篇
  1974年   15589篇
  1973年   15362篇
  1972年   14512篇
  1971年   13553篇
  1970年   12786篇
  1969年   12065篇
  1968年   11229篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
Cultured keratinocytes were used as allografts on burn wounds in two patients. In both patients successful covering of the wounds was obtained. DNA fingerprinting of the epidermis covering the wounds 21 days later showed that the cultured keratinocytes were replaced by the patients' cells.  相似文献   
113.
In experiments on albino rats it was established that three administrations of indomethacin in a dose of 0.01 g/kg body weight induced a severe damage of the liver characterized by disturbances of hepatocytic membranes, bile-producing and protein-producing functions of the liver, an enhancement of lipid peroxidation, a decrease of reduced glutathione pool. Antioxidants (tocopherol acetate, essentiale, legalon, flacumin) limit manifestations of indomethacin, hepatotoxicity, as a result of which tha functional-biochemical disorders in the liver show up to a lesser degree. During the combined use of antioxidants in indomethacin-induced lesions of the liver their hepatoprotective activity increases.  相似文献   
114.
PCP and related compounds inhibit 3H-mazindol binding to the cocaine receptor on dopamine transporters. The relative potencies of these compounds are such that some of the behavioral effects of PCP could be related to its action at the cocaine receptor; however, the affinity of PCP at the cocaine site (Ki = 1.59 microM) is less than its affinity at its own receptor (Ki about 0.12 microM). More data will be needed to conclusively implicate the cocaine receptor in the action of PCP.  相似文献   
115.
Neuromuscular junctions (NJs) of fin muscles of teleostean fishes, Lebistes reticulatus, were ultrastructurally analyzed during 60 min of chronic exercise and a subsequent period of 90 min of induced recovery. NJs from 30-min-exercised fishes showed an almost complete depletion of synaptic vesicles (SVs), corresponding to 83% of SV consumption; 76% of axon terminals were branched at the end of this period. During the recovery period, it was possible to observe the reversibility of the changes induced by the exercise and the transitory events that lead to the reacquirement of the normal NJ morphology. After 15 min of rest, SV population increased to a value of 54.6 SVs/micron2 and the percentage of branched axons was 66.5%. At 60 min of recovery the number of SVs reached a value of 84.6 SVs/micron2. The SV population was fully reestablished at 80 min of rest, while the percentage of branched axons was found within normal ranges after 90 min of recovery. These results demonstrate that chronic exercise induced physiological depletion of NJ SVs and other axon terminal morphological changes, as well as that postexercise rest induces the reestablishment of the normal NJ morphology.  相似文献   
116.
We report a case of left iliofemoral vein thrombosis with extension to the inferior vena cava associated with giant right hydronephrosis secondary to ureteropelvic junction obstruction. Surgery revealed marked infrarenal vena caval compression and deviation to the left side caused by the dilated right renal pelvis, with resultant kinking of the origin of the left iliac vein. It is postulated that the reduction in blood flow caused by this compression and distortion predisposed this patient to venous thrombosis.  相似文献   
117.
The amount of endothelial cell loss that occurs to the donor cornea during the trephination process was evaluated in 40 porcine eyes. A vital staining technique (alizarin red S and acid violet 19) was used to quantify the extent of endothelial damage and removal. Two types of corneal punches (Weck and H&I0 were used for trephination. The average amount of endothelial loss from the peripheral cornea was 7.9%, accounting for only a 3% loss of endothelial cells over the total surface area of the corneal button. a comparison of the Weck and H&I corneal punches showed no significant difference (P greater than 0.1) by Student's test for both endothelial cell damage and removal.  相似文献   
118.
119.
120.
The acting or interim leadership position has been neglected in terms of selection, role identification, and status. Individuals, programs, and organizations are paying a price for this inattention.  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