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   595篇
  免费   43篇
  国内免费   3篇
耳鼻咽喉   11篇
儿科学   23篇
妇产科学   30篇
基础医学   117篇
口腔科学   7篇
临床医学   66篇
内科学   111篇
皮肤病学   1篇
神经病学   12篇
特种医学   20篇
外科学   44篇
综合类   34篇
预防医学   40篇
眼科学   1篇
药学   73篇
中国医学   3篇
肿瘤学   48篇
  2023年   2篇
  2022年   7篇
  2021年   14篇
  2020年   12篇
  2019年   13篇
  2018年   12篇
  2017年   7篇
  2016年   10篇
  2015年   16篇
  2014年   25篇
  2013年   21篇
  2012年   35篇
  2011年   34篇
  2010年   15篇
  2009年   14篇
  2008年   28篇
  2007年   19篇
  2006年   19篇
  2005年   18篇
  2004年   11篇
  2003年   18篇
  2002年   27篇
  2001年   22篇
  2000年   30篇
  1999年   14篇
  1998年   13篇
  1997年   7篇
  1996年   4篇
  1995年   9篇
  1994年   7篇
  1993年   8篇
  1992年   17篇
  1991年   23篇
  1990年   21篇
  1989年   10篇
  1988年   9篇
  1987年   8篇
  1986年   12篇
  1985年   9篇
  1984年   13篇
  1983年   3篇
  1981年   3篇
  1980年   3篇
  1978年   4篇
  1977年   3篇
  1974年   1篇
  1969年   2篇
  1967年   2篇
  1966年   2篇
  1965年   1篇
排序方式: 共有641条查询结果,搜索用时 15 毫秒
61.
62.
A technique was developed for the isolation of purified endothelial cells from first trimester decidual tissue, using QB End/40-coated magnetic polystyrene beads (Dynabeads). QB End/40 is an endothelial-specific monoclonal antibody which reacts with the coagulation cascade co-factor, thrombomodulin. Small endothelial cell aggregates were released from first trimester decidua by the sequential use of collagenase and trypsin. This dissociation method yielded 15-20% endothelial cells which were further purified to greater than 90% homogeneity by rosetting with QB End/40-Dynabeads. Cultures of purified decidual endothelial cells provide a useful tool for investigating cell-cell interaction in the first trimester placental bed.  相似文献   
63.
At the time of implantation, the extracellular matrix proteinslaminin and fibronectin are abundant in the decidua and aredistributed pericellularly around each individual stromal cell.First trimester human trophoblast expresses both laminin andfibronectin receptors, specifically the 1ß1 5ß16ß1 and 6ß4 integrin heterodimers. In thisstudy we have demonstrated that in-vitro adhesion of first trimesterhuman trophoblast to purified extracellular matrix proteinsand to purified decidual stromal cell monolayers can be inhibitedby monoclonal antibodies directed against appropriate integrinsubunits and by synthetic peptides containing an arginine-glycine-asparticacid sequence. Monoclonal antibodies (mAbs) to the 5 and ß1integrin subunits and a synthetic peptide significantly inhibitedadhesion to fibronectin. Binding of trophoblast to laminin wasblocked with mAbs to the 6 and ß1 but not 1 and ß4integrinsubunits. Similarly, integrin-mediated adhesion to monolayersof decidual stromal cells could be blocked with mAbs to the5, 6, ß6 and ß4 integrin subunits. Integrin-mediatedsignal transduction in normal and malignant trophoblast wasinvestigated by Western blotting. A 115 kDa protein was themajor tyrosine phosphorylated protein detected in trophoblastafter binding to laminin or fibronectin. The profile of tyrosinephosphorylated proteins differed for malignant trophoblast. integrins/matrix/signal transduction/trophoblast  相似文献   
64.
We report a patient admitted with acute pulmonary edema 3 months after mitral valve repair, with no history of inter‐current febrile illness. Transesophageal echocardiography (TEE) demonstrated severe mitral regurgitation (MR) and an abnormally positioned annuloplasty ring, suggestive of dehiscence. The extreme extent of ring dehiscence was visualized on 3‐dimensional TEE (3D), with near‐complete separation of the ring. Strept.Mitis and Cristatus were isolated from the ring following redo mitral valve surgery, confirming endocarditis as the mechanism for dehiscence. This report highlights the additive role and superior ability of 3D TEE in the identification and anatomic delineation of mitral ring dehiscence.  相似文献   
65.
Our objective was to determine the precise role of endothelial nitric oxide synthase (eNOS) as a modulator of cardiac O2 consumption and to further examine the role of nitric oxide (NO) in the control of mitochondrial respiration. Left ventricle O2 consumption in mice with defects in the expression of eNOS [eNOS (-/-)] and inducible NOS [iNOS (-/-)] was measured with a Clark-type O2 electrode. The rate of decreases in O2 concentration was expressed as a percentage of the baseline. Baseline O2 consumption was not significantly different between groups of mice. Bradykinin (10(-4) mol/L) induced significant decreases in O2 consumption in tissues taken from iNOS (-/-) (-28+/-4%), wild-type eNOS (+/+) (-22+/-4%), and heterozygous eNOS(+/-) (-22+/-5%) but not homozygous eNOS (-/-) (-3+/-4%) mice. Responses to bradykinin in iNOS (-/-) and both wild-type and heterozygous eNOS mice were attenuated after NOS blockade with N-nitro-L-arginine methyl ester (L-NAME) (-2+/-5%, -3+/-2%, and -6+/-5%, respectively, P<0.05). In contrast, S-nitroso-N-acetyl-penicillamine (SNAP, 10(-4) mol/L), which releases NO spontaneously, induced decreases in myocardial O2 consumption in all groups of mice, and such responses were not affected by L-NAME. In addition, pretreatment with bacterial endotoxin elicited a reduction in basal O2 consumption in tissues taken from normal but not iNOS (-/-)-deficient mice. Our results indicate that the pivotal role of eNOS in the control of myocardial O2 consumption and modulation of mitochondrial respiration by NO may have an important role in pathological conditions such as endotoxemia in which the production of NO is altered.  相似文献   
66.
67.
68.
69.
70.
Seventeen patients with non-Hodgkin's lymphoma involving the orbit were studied. There were 12 males and 5 females and their median age was 53 years. Three cases were classified as stage I, two as stage II and 12 as stage IV. the histology was small lymphocytic type in 4 of the 5 stage I and II cases, and immunophenotyping, confirming their B-cell origin, was performed in two of these cases. All stage I and II patients responded favourably to local radiotherapy alone. the 12 stage IV patients had a marked male predominance and more commonly an intermediate grade histology and T-immunophenotype. Several of the orbital lesions seemed to represent extension of nasal lymphomas. the stage IV patients had a poorer survival than the stage I and II patients but the difference was not statistically significant, probably due to the small number of patients.  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