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   16308篇
  免费   1765篇
  国内免费   51篇
耳鼻咽喉   133篇
儿科学   352篇
妇产科学   356篇
基础医学   2471篇
口腔科学   299篇
临床医学   1570篇
内科学   3016篇
皮肤病学   235篇
神经病学   1544篇
特种医学   679篇
外科学   2473篇
综合类   543篇
一般理论   56篇
预防医学   1726篇
眼科学   496篇
药学   1222篇
中国医学   8篇
肿瘤学   945篇
  2022年   155篇
  2021年   342篇
  2020年   200篇
  2019年   327篇
  2018年   358篇
  2017年   253篇
  2016年   240篇
  2015年   334篇
  2014年   431篇
  2013年   585篇
  2012年   774篇
  2011年   843篇
  2010年   449篇
  2009年   390篇
  2008年   729篇
  2007年   721篇
  2006年   590篇
  2005年   623篇
  2004年   627篇
  2003年   562篇
  2002年   557篇
  2001年   505篇
  2000年   504篇
  1999年   476篇
  1998年   204篇
  1997年   184篇
  1996年   175篇
  1995年   184篇
  1994年   171篇
  1993年   149篇
  1992年   358篇
  1991年   368篇
  1990年   343篇
  1989年   379篇
  1988年   299篇
  1987年   322篇
  1986年   311篇
  1985年   347篇
  1984年   263篇
  1983年   216篇
  1982年   119篇
  1980年   112篇
  1979年   191篇
  1978年   134篇
  1977年   111篇
  1975年   119篇
  1974年   129篇
  1973年   122篇
  1972年   131篇
  1971年   110篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
E Morgan  M H Donaldson  A T Meadows 《Cancer》1977,40(3):1005-1009
The efficacy of intrathecal (IT) maintenance chemotherapy following central nervous system (CNS) leukemia was demonstrated in a retrospective study of 77 such episodes. The median durations of CNS and bone marrow (BM) remissions were significantly longer for the 41 maintained episodes (10+ and 9.5 months, respectively) compared with the 36 unmaintained episodes (4 and 2 months, respectively). Patients were comparable in each of these two groups. For those patients receiving maintenance therapy, there appeared to be an advantage in using four or more doses of IT medications for treatment of CNS leukemia, regardless of the number of doses necessary to clear the cerebrospinal fluid (CSF).  相似文献   
992.
993.
Publications in both the orthopedic and maxillofacial literature have noted the association of cervical spine and facial injuries. However, because the incidence of spinal injury is low, we found no study which documented the relationship between maxillofacial and cervical spine injuries. The present study reviewed 982 cervical spine injuries in two major trauma centers, finding a 19.3% incidence of facial injury. Fourteen per cent of patients had soft-tissue injuries and 8.6%, facial fractures. Important relationships were noted between fractures of the mandible and upper cervical spine, and soft-tissue injuries of the upper face and fractures of the lower cervical spine. Methods of care adapted to the combined injuries are described. The study concludes that examination of the face for soft-tissue and bony injuries may give important clues on the direction and intensity of the force injuring the cervical spine.  相似文献   
994.
995.
996.
The effects of mercuric chloride on the vasculature were studied in the perfused rat mesenteric vascular bed. Mercuric chloride inhibited the vascular response to bolus injections of norepinephrine (100 ng) and potassium chloride (2 mg) even at a low concentration (3.7 × 10?8m) and the inhibition increased in a dose-dependent manner. Mercuric chloride at concentrations of 3.7 × 10?7m or more significantly increased the baseline perfusion pressure, an effect which was rapidly reversed probably as a result of severe damage to the vascular wall. This rise of baseline was in proportion to the calcium concentration of the perfusing buffer. In calcium-free buffer, mercuric chloride, even in high concentration (3.7 × 10?5m), had no effect on baseline pressure but the vascular responses to both pressor agents were inhibited almost in the same manner as in the case of normal calcium buffer. Prepefusing the preparation with 10?5m lanthanum chloride in calcium-containing buffer and then adding mercuric chloride to this buffer, with lanthanum still present, also prevented the rise of baseline pressure by mercury. Heavy metal antagonists (d-penicillamine, N-acetyl-dl-penicillamine, dimercaprol) were effective in the treatment of early stage damage and in its prophylaxis. These results indicate that circulatory disturbances may play an important role in mercury toxicity and that the effects are in part related to modulation of calcium movements.  相似文献   
997.
Allogeneic mouse antilymphocyte serum effectively reduced the number of antibody plaque-forming cells after the natural antilytic property had been eliminated by dilution.  相似文献   
998.
999.
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