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   6504篇
  免费   311篇
  国内免费   22篇
耳鼻咽喉   79篇
儿科学   358篇
妇产科学   84篇
基础医学   817篇
口腔科学   144篇
临床医学   393篇
内科学   1437篇
皮肤病学   220篇
神经病学   332篇
特种医学   185篇
外科学   967篇
综合类   201篇
一般理论   3篇
预防医学   367篇
眼科学   320篇
药学   407篇
  1篇
中国医学   35篇
肿瘤学   487篇
  2024年   18篇
  2023年   56篇
  2022年   151篇
  2021年   235篇
  2020年   146篇
  2019年   124篇
  2018年   165篇
  2017年   123篇
  2016年   159篇
  2015年   182篇
  2014年   255篇
  2013年   294篇
  2012年   449篇
  2011年   467篇
  2010年   251篇
  2009年   207篇
  2008年   355篇
  2007年   392篇
  2006年   365篇
  2005年   304篇
  2004年   272篇
  2003年   237篇
  2002年   244篇
  2001年   115篇
  2000年   138篇
  1999年   109篇
  1998年   62篇
  1997年   38篇
  1996年   34篇
  1995年   38篇
  1994年   14篇
  1993年   25篇
  1992年   78篇
  1991年   66篇
  1990年   74篇
  1989年   64篇
  1988年   53篇
  1987年   54篇
  1986年   51篇
  1985年   58篇
  1984年   46篇
  1983年   26篇
  1981年   23篇
  1980年   16篇
  1979年   24篇
  1978年   22篇
  1977年   13篇
  1976年   11篇
  1975年   13篇
  1971年   12篇
排序方式: 共有6837条查询结果,搜索用时 15 毫秒
991.
Gastrointestinal tract (GIT) involvement in Langerhans cell histiocytosis (LCH) is not commonly described. We present two children presenting with GIT involvement with LCH, one successfully treated on standard protocol and other being treated on a protocol for relapsed disease. A review of literature showed almost 95% children were less than 2 years of age and 62% were females. Vomiting, abdominal pain, constipation, intractable diarrhea, malabsorption, bloody stools, protein‐losing enteropathy, and even intestinal perforation are some of the reported symptoms. More than 50% patients died within 18 months from diagnosis. Pediatr Blood Cancer. 2010;55:748–753. © 2010 Wiley‐Liss, Inc.  相似文献   
992.
993.
Bilateral breast cancer is a rare event accounting for 2-5% of all breast malignancies. A second tumor in contralateral breast may be either synchronous or metachronous lesion. Synchronous bilateral invasive ductal carcinoma is known but medullary carcinoma is rare. The etiology of bilateral breast cancer is uncertain and prognosis in these cases once thought to be poor but recent data suggest a similar survival compared to unilateral disease. We report a case of triple negative synchronous bilateral medullary carcinoma in a 38-year-old female who presented with lump in both the breasts for three months. Multidetector computed tomography breast scan revealed bilateral heterogeneously enhancing well-defined lesion in both the breasts. Fine needle aspiration cytology from both the breast lump was suggestive of malignancy. Patient underwent bilateral modified radical mastectomy with axillary clearance in a single sitting. Histopathology showed synchronous bilateral medullary carcinoma of breast with ER, PR and HER- 2/ neu negativity. Patient was treated with chemoradiation and she is on regular follow up for one year without any recurrence or metastasis.  相似文献   
994.
Malignant gliomas are highly invasive and chemoresistant brain tumors with extremely poor prognosis. Targeting of the soluble factors that trigger invasion and resistance, therefore, could have a significant impact against the infiltrative glioma cells that are a major source of recurrence. Fibulin-3 is a matrix protein that is absent in normal brain but upregulated in gliomas and promotes tumor invasion by unknown mechanisms. Here, we show that fibulin-3 is a novel soluble activator of Notch signaling that antagonizes DLL3, an autocrine inhibitor or Notch, and promotes tumor cell survival and invasion in a Notch-dependent manner. Using a strategy for inducible knockdown, we found that controlled downregulation of fibulin-3 reduced Notch signaling and led to increased apoptosis, reduced self-renewal of glioblastoma-initiating cells, and impaired growth and dispersion of intracranial tumors. In addition, fibulin-3 expression correlated with expression levels of Notch-dependent genes and was a marker of Notch activation in patient-derived glioma samples. These findings underscore a major role for the tumor extracellular matrix in regulating glioma invasion and resistance to apoptosis via activation of the key Notch pathway. More importantly, this work describes a noncanonical, soluble activator of Notch in a cancer model and shows how Notch signaling can be reduced by targeting tumor-specific accessible molecules in the tumor microenvironment.  相似文献   
995.
996.
997.
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