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   2707篇
  免费   152篇
  国内免费   76篇
耳鼻咽喉   5篇
儿科学   209篇
妇产科学   30篇
基础医学   336篇
口腔科学   59篇
临床医学   313篇
内科学   708篇
皮肤病学   87篇
神经病学   127篇
特种医学   406篇
外国民族医学   1篇
外科学   188篇
综合类   45篇
预防医学   136篇
眼科学   20篇
药学   128篇
  2篇
肿瘤学   135篇
  2023年   5篇
  2022年   6篇
  2021年   30篇
  2020年   20篇
  2019年   30篇
  2018年   58篇
  2017年   45篇
  2016年   32篇
  2015年   52篇
  2014年   79篇
  2013年   102篇
  2012年   84篇
  2011年   105篇
  2010年   117篇
  2009年   111篇
  2008年   99篇
  2007年   127篇
  2006年   86篇
  2005年   84篇
  2004年   52篇
  2003年   40篇
  2002年   51篇
  2001年   57篇
  2000年   48篇
  1999年   39篇
  1998年   135篇
  1997年   160篇
  1996年   135篇
  1995年   110篇
  1994年   115篇
  1993年   97篇
  1992年   38篇
  1991年   40篇
  1990年   40篇
  1989年   59篇
  1988年   52篇
  1987年   55篇
  1986年   55篇
  1985年   52篇
  1984年   30篇
  1983年   22篇
  1982年   28篇
  1981年   29篇
  1980年   25篇
  1979年   7篇
  1978年   12篇
  1977年   22篇
  1976年   26篇
  1975年   14篇
  1969年   3篇
排序方式: 共有2935条查询结果,搜索用时 15 毫秒
1.
2.
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified.  相似文献   
3.
4.
The aim of this study was to evaluate the cerebral synthesis of eicosanoids in the asphyctic newborn and to investigate the relation between the prostanoid profiles in cerebrospinal fluid (CSF) and the appearance and severity of hypoxic-ischaemic encephalopathy (HIE). Levels of 6-keto-PGF 1-α, TXB2, PGE2 and PGF2-α in CSF were measured in 40 full term newborns during the first day of life. Thirty of these newborns had birth asphyxia and were divided into three groups: 10 without HIE, 12 with mild HIE and 8 with moderate-severe HIE. They were compared to a control group of 10 non-hypoxic newborns. Determinations of the metabolites in CSF were performed by RIA and expressed as pg/ml (mean ± SD). The CSF TXB2 (thromboxane A2 metabolite) in asphyxiated newborns was always higher than in the control group (28.12 ± 10.6), and related to the severity of HIE ( p = 0:005): without HIE (50.84 ± 16.4; p = 0:02), mild HIE (80.65 ± 12.64; p ± 0:01) and moderate-severe HIE (178.14 ± 20.5; p < 0:01). The CSF 6-keto-PGF 1-α (prostacyclin metabolite) in asphyxiated newborns was always higher than in the control group (80.55 ± 12.56), but indirectly related to the severity of HIE: without HIE (240.95 ± 28.12; p < 0:01), mild HIE (183.65 ± 30.1; p < 0:01) and moderate-severe HIE (140.55 ± 25.12; p < 0:01). In the moderate-severe HIE group, the increase in TXB2 was higher than the rise in 6-keto-PGF 1-α.  相似文献   
5.
6.
Occurrence of the t(2;5)(p23;q35) in non-Hodgkin's lymphoma   总被引:9,自引:3,他引:6  
Primary CD30(Ki-1)-positive anaplastic large-cell lymphoma (ALCL) is considered by some to be a distinct clinicopathologic entity associated with the t(2;5) (p23;q35). However, the specificity of t(2;5) for ALCL has not been carefully studied. Therefore, we performed a detailed analysis of all cases of ALCL with abnormal cytogenetics results in the Nebraska Lymphoma Study Group registry, as well as all other cases of non-Hodgkin's lymphoma with t(2;5) in the registry. We found the t(2;5) in only five of 10 cases of ALCL, four of whom were young patients. However, we also found the t(2;5) in 11 other cases of nonanaplastic lymphoma, including eight children with typical peripheral T-cell lymphomas of various types. The t(2;5) was also found in three older adults with B-cell lymphomas of various types. Thus, the t(2;5) was not specific for CD30+ ALCL. However, t(2;5) may define a clinicopathologic entity in children and young adults characterized by variable morphologies with a T-cell or indeterminate phenotype, CD30-positivity, nodal disease with frequent extranodal involvement, advanced stage, and an excellent response to therapy, including bone marrow transplantation for relapsed disease. The clinical relevance of the t(2;5) in older patients requires further study.  相似文献   
7.
8.
9.
10.
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