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   1148篇
  免费   55篇
  国内免费   37篇
耳鼻咽喉   9篇
儿科学   52篇
妇产科学   29篇
基础医学   67篇
口腔科学   34篇
临床医学   482篇
内科学   146篇
皮肤病学   6篇
神经病学   53篇
特种医学   119篇
外科学   44篇
综合类   30篇
预防医学   52篇
眼科学   7篇
药学   45篇
肿瘤学   65篇
  2023年   5篇
  2021年   9篇
  2020年   5篇
  2019年   6篇
  2018年   17篇
  2017年   5篇
  2016年   10篇
  2015年   20篇
  2014年   22篇
  2013年   38篇
  2012年   14篇
  2011年   11篇
  2010年   27篇
  2009年   40篇
  2008年   22篇
  2007年   32篇
  2006年   26篇
  2005年   20篇
  2004年   26篇
  2003年   24篇
  2002年   30篇
  2001年   39篇
  2000年   25篇
  1999年   42篇
  1998年   93篇
  1997年   87篇
  1996年   81篇
  1995年   68篇
  1994年   50篇
  1993年   57篇
  1992年   19篇
  1991年   30篇
  1990年   28篇
  1989年   24篇
  1988年   41篇
  1987年   15篇
  1986年   18篇
  1985年   15篇
  1984年   18篇
  1983年   9篇
  1982年   12篇
  1981年   7篇
  1980年   8篇
  1979年   7篇
  1978年   6篇
  1976年   6篇
  1975年   3篇
  1974年   4篇
  1972年   4篇
  1971年   3篇
排序方式: 共有1240条查询结果,搜索用时 15 毫秒
61.
巫山淫羊藿的化学研究   总被引:8,自引:0,他引:8  
从小檗科Berberidaceae淫羊藿属Epimedium植物巫山淫羊藿Epimedium wushanense T.S.Ying的地上部分中分得两种黄酮甙单体,经理化性质鉴定及紫外、红外、质谱、氢谱、碳谱等光谱分析,确定甙Ⅰ是新化合物,命名为巫山淫羊藿甙(wushanicariin)。甙Ⅱ是已知化合物淫羊藿甙(icariin),系首次从该种植物中分离。  相似文献   
62.
Interleukin-1 alpha (IL-1 alpha) is a macrophage-derived, multifunctional cytokine that broadly potentiates myelopoiesis and induces the synthesis of hematopoietic colony-stimulating factors (CSF) in vitro and in vivo. To evaluate the possibility for use of IL-1 alpha in ameliorating in vivo bone marrow suppression induced by drugs or radiation, we examined the in vivo effects of the cytokine on erythropoietic and other hematopoietic progenitor cells. Normal mice were treated with a single intraperitoneal (IP) injection of recombinant human IL-1 alpha at varying doses and were assayed at various times post-treatment. By six hours postinjection, a significant suppression of mature erythroid progenitors (CFU-E) was observed in animals treated with IL-1 alpha (0.5 micrograms/mouse), with maximum suppression of CFU-E and peripheral blood reticulocyte counts occurring at 24 hours. Decreases in peripheral blood hematocrit did not occur after a single IL-1 alpha injection but were observed after multiple injections of the cytokine. The suppressive effects of IL-1 alpha on late-stage erythropoiesis were abrogated by simultaneous administration of erythropoietin (EPO). At 48 hours post-treatment, a marked stimulation was observed in the numbers of spleen and marrow immature erythroid (BFU-E), macrophage (CFU-M), granulocyte (CFU-G), granulocyte- macrophage (CFU-GM), and megakaryocyte (CFU-meg) progenitor cells. These results demonstrate the potential use of IL-1 alpha as a generalized stimulator of hematopoiesis and show that the cytokine- induced suppression of late-stage erythropoiesis can be prevented by EPO.  相似文献   
63.
64.
Glioblastoma multiforme (GBM) is the most common type of primary malignant brain tumor. Although comprehensive therapeutic measures are available, recurrence is very frequent and the prognosis of GBM remains dismal. To date, little is known about the molecular pathogenesis associated with GBM recurrence. According to Knudson ' s two-hit hypothesis of tumor suppressor gene (TSG) inactivation,1 deletion of a chromosomal region, as revealed by loss of heterozygosity (LOH), is often indicative of the presence of a potential TSG. Allelotype studies involving a comprehensive LOH analysis of the whole genome can provide more detailed and thorough information for detecting genetic anomalies than traditional LOH analysis. The present study is designed to conduct a genome-wide allelotype analysis of one patient ' s primary and corresponding recurrent GBM tumors in an effort to reveal molecular genetic alterations associated with the recurrence of this malignancy.  相似文献   
65.
66.
67.
68.
69.
70.
Sternocostoclavicular hyperostosis: a review and report of 11 cases   总被引:1,自引:0,他引:1  
Sternocostoclavicular hyperostosis is a benign ossifying diathesis of unknown etiology characterized by hyperostosis and soft-tissue ossification between the clavicles, anterior portion of the upper ribs, and manubrium, with variable hyperostosis or ankylosis in the spine and sacroiliac joints. Our cumulative experience with 11 cases is reported, with emphasis on radiographic features of the condition. Scintigraphic results in five patients and computed tomographic findings in one patient are presented. A review of the literature and our own material indicates that sternocostoclavicular hyperostosis may be more common than has been previously recognized.  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