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   3183篇
  免费   241篇
  国内免费   78篇
耳鼻咽喉   8篇
儿科学   235篇
妇产科学   49篇
基础医学   401篇
口腔科学   92篇
临床医学   446篇
内科学   662篇
皮肤病学   77篇
神经病学   219篇
特种医学   423篇
外科学   214篇
综合类   81篇
预防医学   208篇
眼科学   44篇
药学   159篇
  2篇
中国医学   1篇
肿瘤学   181篇
  2021年   26篇
  2020年   28篇
  2019年   30篇
  2018年   52篇
  2017年   36篇
  2016年   39篇
  2015年   56篇
  2014年   65篇
  2013年   94篇
  2012年   94篇
  2011年   84篇
  2010年   119篇
  2009年   109篇
  2008年   100篇
  2007年   133篇
  2006年   105篇
  2005年   109篇
  2004年   71篇
  2003年   82篇
  2002年   78篇
  2001年   88篇
  2000年   67篇
  1999年   64篇
  1998年   146篇
  1997年   170篇
  1996年   139篇
  1995年   121篇
  1994年   123篇
  1993年   105篇
  1992年   49篇
  1991年   67篇
  1990年   66篇
  1989年   89篇
  1988年   81篇
  1987年   69篇
  1986年   78篇
  1985年   66篇
  1984年   45篇
  1983年   26篇
  1982年   28篇
  1981年   36篇
  1980年   30篇
  1979年   16篇
  1978年   24篇
  1977年   24篇
  1976年   37篇
  1975年   20篇
  1972年   14篇
  1971年   13篇
  1970年   14篇
排序方式: 共有3502条查询结果,搜索用时 15 毫秒
1.
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   
2.
3.
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   
4.
5.
A review of the complications of urethral instrumentation performed at our institution during the last 15 years revealed 2 cases of urethrorectal perforation. These patients were managed with loop colostomy and suprapubic cystostomy diversion with excellent healing and no evidence of fistula formation at 24-month followup. This rare complication is described and the principles of diagnosis, prevention and prompt aggressive management are emphasized.  相似文献   
6.
Caring for elderly people at home: the consequences to caregivers   总被引:2,自引:1,他引:1       下载免费PDF全文
The emphasis on home-based care is one important aspect of health services restructuring initiatives in Canada. Fundamental to the preference for home-based care over institutional care is the expectation that family caregivers will be available in the home to support patients who would otherwise be in an institution. The authors explore the potential impact of this devolution of services from institutions to the home in 2 vulnerable patient populations--elderly patients with dementia and elderly patients with terminal illnesses. Community-based surveillance strategies are needed to determine the true health, quality-of-life and economic outcomes of these restructuring initiatives.  相似文献   
7.
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   
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