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   393篇
  免费   37篇
  国内免费   48篇
耳鼻咽喉   6篇
儿科学   33篇
妇产科学   3篇
基础医学   59篇
口腔科学   4篇
临床医学   50篇
内科学   106篇
皮肤病学   34篇
神经病学   25篇
特种医学   44篇
外科学   19篇
综合类   20篇
预防医学   21篇
眼科学   2篇
药学   45篇
中国医学   1篇
肿瘤学   6篇
  2024年   2篇
  2021年   4篇
  2020年   4篇
  2019年   6篇
  2018年   10篇
  2017年   4篇
  2016年   5篇
  2015年   14篇
  2014年   15篇
  2013年   16篇
  2012年   20篇
  2011年   19篇
  2010年   16篇
  2009年   14篇
  2008年   21篇
  2007年   48篇
  2006年   20篇
  2005年   16篇
  2004年   15篇
  2003年   12篇
  2002年   8篇
  2001年   13篇
  2000年   13篇
  1999年   10篇
  1998年   9篇
  1997年   11篇
  1996年   16篇
  1995年   10篇
  1994年   7篇
  1993年   16篇
  1992年   11篇
  1991年   9篇
  1990年   8篇
  1989年   6篇
  1988年   8篇
  1987年   4篇
  1984年   2篇
  1982年   6篇
  1981年   4篇
  1980年   2篇
  1978年   2篇
  1977年   5篇
  1976年   3篇
  1975年   2篇
  1973年   2篇
  1972年   1篇
  1971年   1篇
  1969年   1篇
  1966年   2篇
  1964年   1篇
排序方式: 共有478条查询结果,搜索用时 111 毫秒
51.
52.
We have successfully cloned nine NKR-P1+ TCR alpha beta + cells from PVG rat spleens, utilizing murine macrophage inflammatory protein-1 alpha (MIP-1 alpha) and IL-2. These clones are either double negative (DN, CD4-CD8-), which included clones 3.31, 3.71, 4.19, 4.59 and 4.65, or single positive (SP, CD4+CD8-), which included clones 1.64, 3.8, 3.76 and 3.78. No CD8+ clone was recovered. All nine clones are restricted in terms of their expression of the V beta antigens, since they express V beta 8.2 but not V beta 8.5, V beta 10 or V beta 16. These clones are agranular and they fall to generate NK or LAK activity upon incubation with IL-2, IL-12 or their combination. On the basis of their production of intracellular cytokines they can be divided into three categories: (I) SP clones (1.64, 3.8, 3.76 and 3.78) do not produce IL-2 or IL-4, but produce IFN-gamma and IL-12, and they vary in their production of IL-1, RANTES or tumor necrosis factor (TNF)-alpha; (II) DN clones 4.59 and 4.65 produce IL-1 alpha and IFN-gamma only, and fall to produce other cytokines; and (III) DN clones 3.31, 3.71 and 4.19 produce IL-1 alpha, IL-1 beta, IL-2, IL-12, IFN-gamma, RANTES and TNF-alpha. From all the clones examined only DN clones 3.31 and to a lesser degree 4.19 produce IL-4. In vivo tissue localization of clones 3.8, 3.31 and 4.59 shows that these cells distribute into the liver and bone marrow 24 h post i.v. administration. Their accumulation in the liver and bone marrow along with their ability to secrete various cytokines suggest that these cells may influence the generation, differentiation or apoptosis of immune or hematopoietic cells.   相似文献   
53.
A substudy of a phase I/II, prospective, multicenter clinical trial was carried out to investigate the potential benefit of therapeutic vaccination on hepatitis B e antigen-negative patients with chronic hepatitis B (CHB), treated efficiently with analogues. Patients were randomized in 2 arms, one receiving a hepatitis B virus (HBV) envelope DNA vaccine, and one without vaccination. At baseline, HBV-specific interferon (IFN)-γ–producing T cells were detected in both groups after in vitro expansion of peripheral blood mononuclear cells. Vaccine-specific responses remained stable in the vaccine group, whereas in the control group the percentage of patients with HBV-specific IFN-γ–producing T cells decreased over time. The vaccine-specific cytokine-producing T cells were mostly polyfunctional CD4+ T cells, and the proportion of triple cytokine-producer T cells was boosted after DNA injections. However, these T-cell responses did not impact on HBV reactivation after stopping analogue treatment. Importantly, before cessation of treatment serum hepatitis B surface antigen (HBsAg) titers were significantly associated with DNA or HBsAg clearance. Therapeutic vaccination in CHB patients with persistent suppression of HBV replication led to the persistence of T-cell responses, but further improvements should be searched for to control infection after treatment discontinuation.  相似文献   
54.
Thumboo J  Feng PH  Soh CH  Boey ML  Thio S  Fong KY 《Lupus》2000,9(9):702-707
The objective was to validate a Chinese translation of the Medical Outcomes Study Family and Marital Functioning Measures (FFM and MFM) in patients with systemic lupus erythematosus (SLE). Chinese-speaking SLE patients (n = 69) completed a self-administered questionnaire containing the FFM and MFM and assessing demographic and socio-economic status twice within a 2 week period. SLE activity, disease-related damage and quality of life were assessed using the BILAG, SLICC/ACR Damage Index and SF-36 Health Survey, respectively. Scale psychometric properties were assessed through factor analysis, Cronbach's alpha, quantifying test-retest differences and known-groups construct validity. Factor analysis identified 1 factor corresponding to the FFM and 2 factors corresponding to the MFM. Internal consistency for the FFM was excellent (alpha = 0.92) while that for the MFM was acceptable (alpha = 0.62). Mean (s.d.) test-retest differences were 0.06 (1.54) points for the FFM and 0.03 (2.08) points for the MFM. 11 and 10 of 13 a priori hypotheses relating the FFM and MFM, respectively, to demographic, disease and quality of life variables were confirmed, supporting the construct validity of these scales. The Chinese FFM and MFM are valid and reliable measures of family and marital functioning in Chinese-speaking SLE patients, with psychometric properties very similar to the source English version.  相似文献   
55.
56.
用[3H]TdR参入法检测小鼠脾细胞增殖能力及产生集落刺激因子(colony stimulating factor. CSF)含量.证明商陆多糖Ⅱ(PAP-Ⅱ)在31~500 μg·m-1范围内显著促进小鼠稗细胞增殖。PAP-Ⅱ,31~125 μg·ml-1可剂量依赖性地促进Con A(1,2.8μg·ml-1),LPS(3,10,30 μg·ml-1)诱导的淋巴细胞细咆增殖,随着PAP-Ⅱ剂量加大,对丝裂原诱导的淋巴细胞增殖反呈抑制作用。PAP-Ⅱ。10~500μg·ml-1呈剂量及时间依赖性地促进脾细胞产生CSF,其最适剂量为100 μg·ml-1。最佳时间为5 d,提示PAP-Ⅱ能增强免疫及促进造血功能。  相似文献   
57.
58.
59.
以培养血管平滑肌细胞(vascularsmcothmusclecell,VSMC)为模型,观察了间硝苯地平(m-nifedipine,m-Nif)对血管紧张素Ⅱ(angiotensinⅡ,ANGⅡ)促进VSMC增殖和蛋白质合成的影响。结果表明,m-Nif抑制ANGⅡ(100nmol·L ̄(-1))引起VSMC[ ̄3H]thymidine和[ ̄3H]leucine参入,并呈剂量依赖性。m-Nif(2×10 ̄(-6)mol·L ̄(-1))可抑制ANGⅡ对VSMC的刺激、DNA及蛋白质合成速率,分别降低了46%,58%,53%。提示m-Nif可抑制ANGⅡ对VSMC增殖和蛋白合成的促进作用  相似文献   
60.
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