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   3979篇
  免费   280篇
  国内免费   78篇
耳鼻咽喉   28篇
儿科学   238篇
妇产科学   75篇
基础医学   461篇
口腔科学   83篇
临床医学   439篇
内科学   963篇
皮肤病学   86篇
神经病学   167篇
特种医学   522篇
外科学   317篇
综合类   184篇
一般理论   1篇
预防医学   319篇
眼科学   56篇
药学   180篇
  2篇
肿瘤学   216篇
  2022年   22篇
  2021年   61篇
  2020年   50篇
  2019年   63篇
  2018年   100篇
  2017年   61篇
  2016年   63篇
  2015年   76篇
  2014年   86篇
  2013年   152篇
  2012年   116篇
  2011年   134篇
  2010年   152篇
  2009年   144篇
  2008年   127篇
  2007年   194篇
  2006年   134篇
  2005年   130篇
  2004年   88篇
  2003年   69篇
  2002年   64篇
  2001年   98篇
  2000年   101篇
  1999年   83篇
  1998年   149篇
  1997年   176篇
  1996年   144篇
  1995年   119篇
  1994年   127篇
  1993年   110篇
  1992年   73篇
  1991年   68篇
  1990年   64篇
  1989年   76篇
  1988年   84篇
  1987年   87篇
  1986年   75篇
  1985年   61篇
  1984年   48篇
  1983年   35篇
  1982年   37篇
  1981年   45篇
  1980年   40篇
  1979年   19篇
  1978年   19篇
  1977年   30篇
  1976年   37篇
  1975年   23篇
  1973年   21篇
  1967年   17篇
排序方式: 共有4337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 pilot study for a sentinel health events surveillance system for deaths among persons under age 45 with diabetes was conducted in six states in 1984 and 1985. Two hundred and thirty-three events were identified. Information from death certificates, physicians, and families revealed that 22% died from acute complications of diabetes and 53% from chronic complications. Blood pressure measurement and urinalysis testing had been performed in the last year for almost all of the decedents, but other preventive practices were reported less frequently. Hypertension was present in 57% and of those, was not controlled in 73%. Forty-four percent were cigarette smokers at the time of death. Agreement between physicians and families was generally higher for clinical conditions than for care practices. This surveillance system appears to yield information about the health care of persons with diabetes not readily available from other sources, although modifications may be necessary before implementation.  相似文献   
5.
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   
6.
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.
The best quality long-lasting results require attention to the diagnosis of the precise anatomic problems followed by the architectural planning--the art of making beautiful highlights, shadows, and curves where indicated to produce a result that is aesthetically pleasing. Attention to the details of the surgical planning, execution of surgery, and postoperative care are essential to minimize untoward results and problems and produce a happy patient and pleased surgeon.  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