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   3707683篇
  免费   312191篇
  国内免费   14438篇
耳鼻咽喉   50557篇
儿科学   118549篇
妇产科学   97526篇
基础医学   579656篇
口腔科学   101933篇
临床医学   334945篇
内科学   656797篇
皮肤病学   98304篇
神经病学   311055篇
特种医学   146393篇
外国民族医学   262篇
外科学   576483篇
综合类   113524篇
现状与发展   23篇
一般理论   2354篇
预防医学   303256篇
眼科学   88350篇
药学   258990篇
  21篇
中国医学   11016篇
肿瘤学   184318篇
  2021年   49764篇
  2020年   35376篇
  2019年   58460篇
  2018年   72691篇
  2017年   55136篇
  2016年   61015篇
  2015年   74729篇
  2014年   108986篇
  2013年   174410篇
  2012年   104252篇
  2011年   106090篇
  2010年   120659篇
  2009年   123614篇
  2008年   92691篇
  2007年   97256篇
  2006年   106749篇
  2005年   101519篇
  2004年   103209篇
  2003年   92768篇
  2002年   81974篇
  2001年   135355篇
  2000年   128503篇
  1999年   119562篇
  1998年   62767篇
  1997年   59419篇
  1996年   57073篇
  1995年   57957篇
  1994年   52061篇
  1993年   48414篇
  1992年   84605篇
  1991年   80842篇
  1990年   76478篇
  1989年   74889篇
  1988年   68738篇
  1987年   66999篇
  1986年   63330篇
  1985年   62581篇
  1984年   54547篇
  1983年   49144篇
  1982年   43158篇
  1981年   40537篇
  1980年   37986篇
  1979年   44477篇
  1978年   37895篇
  1977年   34472篇
  1976年   31581篇
  1975年   30462篇
  1974年   32237篇
  1973年   30980篇
  1972年   28934篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
Fecal microbiota transplantation (FMT) is a successful method for treating recurrent Clostridioides difficile (C. difficile) infection (rCDI) with around 90% efficacy. Due to the relative simplicity of this approach, it is being widely used and currently, thousands of patients have been treated with FMT worldwide. Nonetheless, the mechanisms underlying its effects are just beginning to be understood. Data indicate that FMT effectiveness is due to a combination of microbiological direct mechanisms against C. difficile, but also through indirect mechanisms including the production of microbiota-derived metabolites as secondary bile acids and short chain fatty acids. Moreover, the modulation of the strong inflammatory response triggered by C. difficile after FMT seems to rely on a pivotal role of regulatory T cells, which would be responsible for the reduction of several cells and soluble inflammatory mediators, ensuing normalization of the intestinal mucosal immune system. In this minireview, we analyze recent advances in these immunological aspects associated with the efficacy of FMT.  相似文献   
92.
Major depressive disorder and other neuropsychiatric disorders are often managed with long-term use of antidepressant medication. Fluoxetine, an SSRI antidepressant, is widely used as a first-line treatment for neuropsychiatric disorders. However, fluoxetine has also been shown to increase the risk of metabolic diseases such as non-alcoholic fatty liver disease. Fluoxetine has been shown to increase hepatic lipid accumulation in vivo and in vitro. In addition, fluoxetine has been shown to alter the production of prostaglandins which have also been implicated in the development of non-alcoholic fatty liver disease. The goal of this study was to assess the effect of fluoxetine exposure on the prostaglandin biosynthetic pathway and lipid accumulation in a hepatic cell line (H4-II-E-C3 cells). Fluoxetine treatment increased mRNA expression of prostaglandin biosynthetic enzymes (Ptgs1, Ptgs2, and Ptgds), PPAR gamma (Pparg), and PPAR gamma downstream targets involved in fatty acid uptake (Cd36, Fatp2, and Fatp5) as well as production of 15-deoxy-Δ12,14PGJ2 a PPAR gamma ligand. The effects of fluoxetine to induce lipid accumulation were attenuated with a PTGS1 specific inhibitor (SC-560), whereas inhibition of PTGS2 had no effect. Moreover, SC-560 attenuated 15-deoxy-Δ12,14PGJ2 production and expression of PPAR gamma downstream target genes. Taken together these results suggest that fluoxetine-induced lipid abnormalities appear to be mediated via PTGS1 and its downstream product 15d-PGJ2 and suggest a novel therapeutic target to prevent some of the adverse effects of fluoxetine treatment.  相似文献   
93.
94.
95.
96.
Biomedical Engineering - We present here an experimental study demonstrating the action of noninvasive high-intensity focused ultrasound (HIFU) on vein walls in the treatment of varicose disease....  相似文献   
97.
Bulletin of Experimental Biology and Medicine - Using the biomicroscopy method, we studied the reaction of arterial and venous vessels of the broad ligament of the uterus in outbred female rats to...  相似文献   
98.
99.

Interstitial lung disease (ILD) represents a significant cause of morbidity and mortality in systemic sclerosis (SSc). The purpose of this study was to examine recirculating lymphocytes from SSc patients for potential biomarkers of interstitial lung disease (ILD). Peripheral blood mononuclear cells (PBMCs) were isolated from patients with SSc and healthy controls enrolled in the Vanderbilt University Myositis and Scleroderma Treatment Initiative Center cohort between 9/2017–6/2019. Clinical phenotyping was performed by chart abstraction. Immunophenotyping was performed using both mass cytometry and fluorescence cytometry combined with t-distributed stochastic neighbor embedding analysis and traditional biaxial gating. This study included 34 patients with SSc-ILD, 14 patients without SSc-ILD, and 25 healthy controls. CD21lo/neg cells are significantly increased in SSc-ILD but not in SSc without ILD (15.4 ± 13.3% vs. 5.8 ± 0.9%, p = 0.002) or healthy controls (5.0 ± 0.5%, p < 0.0001). While CD21lo/neg B cells can be identified from a single biaxial gate, tSNE analysis reveals that the biaxial gate is comprised of multiple distinct subsets, all of which are increased in SSc-ILD. CD21lo/neg cells in both healthy controls and SSc-ILD are predominantly tBET positive and do not have intracellular CD21. Immunohistochemistry staining demonstrated that CD21lo/neg B cells diffusely infiltrate the lung parenchyma of an SSc-ILD patient. Additional work is needed to validate this biomarker in larger cohorts and longitudinal studies and to understand the role of these cells in SSc-ILD.

  相似文献   
100.
Lersch  F.  Zingg  T. J. G.  Knapp  J.  Stüber  F.  Hight  D.  Kaiser  H. A. 《Der Anaesthesist》2023,72(9):662-676
Die Anaesthesiologie - Die Elektroenzephalogramm(EEG)-gesteuerte Anästhesie ist aus modernen Operationssälen nicht mehr wegzudenken und hat sich als Standard-Monitoring etabliert. Viele...  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