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   1681篇
  免费   256篇
  国内免费   21篇
耳鼻咽喉   9篇
儿科学   59篇
妇产科学   29篇
基础医学   90篇
口腔科学   73篇
临床医学   278篇
内科学   438篇
皮肤病学   40篇
神经病学   65篇
特种医学   300篇
外科学   125篇
综合类   19篇
预防医学   300篇
眼科学   16篇
药学   31篇
肿瘤学   86篇
  2023年   49篇
  2022年   13篇
  2021年   11篇
  2020年   40篇
  2019年   22篇
  2018年   55篇
  2017年   33篇
  2016年   47篇
  2015年   56篇
  2014年   96篇
  2013年   119篇
  2012年   35篇
  2011年   54篇
  2010年   64篇
  2009年   82篇
  2008年   51篇
  2007年   76篇
  2006年   56篇
  2005年   45篇
  2004年   40篇
  2003年   19篇
  2002年   13篇
  2001年   26篇
  2000年   25篇
  1999年   31篇
  1998年   65篇
  1997年   89篇
  1996年   79篇
  1995年   57篇
  1994年   62篇
  1993年   52篇
  1992年   17篇
  1991年   13篇
  1990年   32篇
  1989年   43篇
  1988年   32篇
  1987年   34篇
  1986年   34篇
  1985年   33篇
  1984年   14篇
  1983年   16篇
  1982年   24篇
  1981年   30篇
  1980年   17篇
  1979年   8篇
  1978年   5篇
  1977年   14篇
  1976年   14篇
  1975年   10篇
  1969年   2篇
排序方式: 共有1958条查询结果,搜索用时 812 毫秒
71.
72.
To optimally demonstrate the value of risk management, our actions must show the benefits. The American Society for Healthcare Risk Management (ASHRM) board needs to provide support through tools and resources. ASHRM members must show through their actions the value of risk management. And ASHRM members need to show the organization where actions and activities should be focused in the future. Actions show the value of enterprise risk management.  相似文献   
73.
74.
75.
76.
77.
78.
79.
Interleukin-4 (IL-4) is a potent mediator of growth and differentiation of cells of several hematopoietic lineages. Interleukin-5 (IL-5) is a lineage-specific hematopoietic growth factor that stimulates the production of eosinophils and eosinophil colonies from normal human bone marrow cells. By using somatic cell hybrids and in situ chromosomal hybridization, we localized the IL-4 and IL-5 genes to human chromosome 5 at bands q23-31, a chromosomal region that is frequently deleted [del(5q)] in patients with myeloid disorders. By in situ hybridization, the IL-4 and IL-5 genes were found to be deleted in the 5q- chromosome of four patients with refractory anemia (RA) or therapy-related acute nonlymphocytic leukemia (t-ANLL), who had a del(5q). Thus a small segment of chromosome 5 contains IL-4, IL-5, IL- 3, and GM-CSF as well as other genes such as CD14 and EGR1. Our findings that each of these genes was deleted in the 5q- chromosome suggest that loss of function of one or more of these genes may play an important role in the pathogenesis of hematologic disorders associated with a del(5q).  相似文献   
80.
We have investigated the localization of thrombospondin (TSP), fibrinogen, fibronectin, and von Willebrand factor in human platelets by transmission electron microscopy of antibody-stained ultrathin frozen sections. In negatively stained thin sections, alpha granules were identified on the basis of their smooth, roughly spherical shape, size, single limiting electron-lucent 100 A membrane, and frequent presence of electron-dense nucleoid. In contrast, mitochondria exhibited characteristic double membranes and cristae. Sections were separately stained with affinity-purified polyclonal antibodies to these proteins as well as with three monoclonal anti-TSP antibodies. Antibody specificity was documented in radioimmunoassays, by immunofluorescent cross-blocking, and by staining of bands of appropriate mobility in Western blots of whole platelets. Bound antibody was visualized using a 5-nm colloidal gold-avidin conjugate. In resting cells, staining of virtually all alpha granules was observed for all four proteins. In contrast, consistent staining was absent from other organelles, including plasma membranes, mitochondria, and vacuolar structures that may represent the open canalicular system.  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