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   383篇
  免费   26篇
  国内免费   14篇
耳鼻咽喉   1篇
儿科学   5篇
妇产科学   1篇
基础医学   126篇
口腔科学   7篇
临床医学   26篇
内科学   165篇
皮肤病学   11篇
神经病学   4篇
特种医学   8篇
外科学   26篇
综合类   6篇
预防医学   6篇
眼科学   6篇
药学   13篇
肿瘤学   12篇
  2022年   2篇
  2021年   1篇
  2020年   1篇
  2019年   1篇
  2018年   3篇
  2017年   4篇
  2016年   2篇
  2014年   6篇
  2013年   7篇
  2012年   16篇
  2011年   17篇
  2010年   13篇
  2009年   15篇
  2008年   20篇
  2007年   32篇
  2006年   14篇
  2005年   16篇
  2004年   9篇
  2003年   7篇
  2002年   14篇
  2001年   15篇
  2000年   10篇
  1999年   12篇
  1998年   9篇
  1997年   11篇
  1996年   6篇
  1995年   10篇
  1994年   7篇
  1993年   5篇
  1992年   15篇
  1991年   8篇
  1990年   11篇
  1989年   9篇
  1988年   10篇
  1987年   11篇
  1986年   10篇
  1985年   13篇
  1984年   13篇
  1983年   8篇
  1982年   13篇
  1981年   3篇
  1979年   4篇
  1977年   2篇
  1959年   1篇
  1958年   2篇
  1957年   2篇
  1956年   2篇
  1954年   1篇
排序方式: 共有423条查询结果,搜索用时 15 毫秒
61.
62.
微波和磁疗治疗膝关节骨性关节炎300例   总被引:11,自引:0,他引:11  
1临床资料①对象:本组骨性关节炎患者300(男130,女170)例,年龄36~78(56±1.0)岁,病程1 mo~10 a,其中左膝120例,右膝112例,双膝68例.临床表现为关节疼痛、僵直、活动受限,偶尔会关节肿胀、关节腔积液.X线表现为关节间隙变窄,关节软骨下骨质致密,骨密度增高,骨小梁有断裂,髁间嵴变尖及髌骨后缘和外侧缘增生形成骨刺[1].  相似文献   
63.
BAFF and APRIL are two members of the TNF superfamily that have co-stimulatory activity on B cells and contribute to autoimmunity. While BAFF is processed at the cell surface, APRIL is processed inside the cell by a furin-convertase and is able to perform its function only as a soluble factor. However, APRIL can be expressed as a cell surface fusion protein with TWEAK called TWE-PRIL. BAFF can also exist as a soluble molecule and can be detected in human serum. Whether the biological functions controlled by membrane-bound BAFF differ from those triggered by soluble BAFF is unclear. In addition to this complexity, DeltaBAFF, an alternative splice isoform of BAFF shows different properties. BAFF can also, in autoimmune disease form heterotrimers with APRIL but the control and function of these heterotrimers remain unclear. In order to understand the function of these molecules we need to elucidate the complexity of the various forms of these members of the TNF family.  相似文献   
64.
Given the prominent role currently assigned to B lymphocytes in systemic lupus erythematosus, it is not surprising that the B cell activity factor belonging to the tumor necrosis factor family (BAFF) is involved in its pathogenesis. This cytokine is produced in excess, and inserted into its receptors on the surface of circulating B cells. Up-regulation of BAFF is most likely to lead to breach of tolerance by aberrant survival of B cells directed to the self. Trials aimed at blocking BAFF have thus been set out. Yet the results are awaited.  相似文献   
65.
Serum IgG and IgA are glycoprotein and significant glycoform abnormalities have been established in primary Sj?gren's syndrome. The proportion of asialylated IgG is abnormally high in the patients, whereas IgA1 and IgA2 appear to be over-sialylated. This peculiarity might explain the defective binding of IgA to asialoglycoreceptors. Furthermore, the activity of alpha 2,6 sialyl transferase is higher in the IgA-producing B cells from the patients than in the controls, whereas the alpha 2,3 sialyl transferase operates in the former cells but not in the latter. The mechanism of this enzyme dysregulation warrants elucidation.  相似文献   
66.
The pathogenic role of antiendothelial cell antibodies (AECA) remains unclear. They are frequently associated with antibodies to anionic phospholipids (PL), such as phosphatidylserine (PS), which is difficult to reconcile with the distribution of PL molecular species within the plasma membrane. Since it is already known that PS is transferred to the outer face of the membrane as a preclude to apoptosis, the possibility exists that apoptosis is initiated by AECA. AECA-positive/anti-PL antibody-negative sera from eight patients with systemic sclerosis (SS) and 21 control patients were evaluated. Endothelial cells (EC) were incubated with AECA and the exposure of PS was established through the binding of annexin V. Hypoploid cell enumeration, DNA fragmentation, and optical and ultrastructural analyses of EC were used to confirm apoptosis. Incubation of EC with AECA derived from six of eight patients with SS led to the expression of PS on the surface of the cells. This phenomenon was significantly more frequent in SS (P < 0.04) than in control diseases. The redistribution of plasma membrane PS preceded other events associated with apoptosis: hypoploidy, DNA fragmentation, and morphology characteristic for apoptosis. Apoptosis-inducing AECA did not recognize the Fas receptor. We conclude that AECA may be pathogenic by inducing apoptosis.  相似文献   
67.
68.
69.
A subset of B cells expressing the CD5 marker, a 67 KD molecule, has been implicated in the pathogenesis of autoimmune disease. To study the immunoglobulin repertoire of CD5+ B cells we investigated chronic lymphocytic leukemic (CLL) cells, since the majority of the malignant clones express CD5. CLL were induced to secrete their IgM in vitro by phorbol 12-myristate 13-acetate (PMA) and the supernatants screened for binding to a panel of autoantigens. Twelve out of 14 CLL clones were autoreactive, binding to Fc of IgG, ssDNA, dsDNA, histones, cardiolipin, or cytoskeletal components. Many also bound to more than one antigen tested for, showing multispecificity. Our data suggest that a high proportion of CD5+ B cells are programmed to secrete multispecific autoantibodies.  相似文献   
70.
Increased serum immunoglobulin A (IgA) level is a common finding in primary Sjögren's syndrome (pSS). IgA might not be properly eliminated because of an abnormal glycosylation. We reported previously that IgA1 from patients with pSS was oversialylated. We extend this finding by showing that monomeric IgA1 contains more sialic acid (SA) in patients than in controls, as determined by enzyme‐linked immunosorbent assay (ELISA) and Western blot with Sambucus nigra agglutinin (SNA), a lectin specific for SA. To localize this excess of SA on the N‐ and/or O‐linked oligosaccharides, we analysed them separately, using N‐ and O‐linked oligosaccharide profiling kits based on fluorophore‐assisted carbohydrate electophoresis. N‐linked, but not O‐linked, oligosaccharides of patients' IgA1 were oversialylated, and this seemed to be linked to an excess of SA on the same number of polysaccharides as normal IgA1. To localize the abnormality to the Fab and/or Fc fragments, monomeric IgA1 was digested with protease, separated and transferred to nitrocellulose, where SA was identified by SNA. Both Fab and Fc fragments appeared to be oversialylated. Oversialylation of N‐linked oligosaccharides of IgA1 from patients with pSS might prevent the recognition of IgA by receptors that are responsible for their clearance, resulting in an excess of serum IgA and related immune complexes.  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