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   5714810篇
  免费   431072篇
  国内免费   16316篇
耳鼻咽喉   81896篇
儿科学   185477篇
妇产科学   154135篇
基础医学   840854篇
口腔科学   162146篇
临床医学   531600篇
内科学   1041191篇
皮肤病学   133694篇
神经病学   469026篇
特种医学   221049篇
外国民族医学   1396篇
外科学   854584篇
综合类   158067篇
现状与发展   24篇
一般理论   3183篇
预防医学   476879篇
眼科学   138441篇
药学   410285篇
  28篇
中国医学   14517篇
肿瘤学   283726篇
  2021年   57730篇
  2019年   59911篇
  2018年   78601篇
  2017年   60114篇
  2016年   66959篇
  2015年   78339篇
  2014年   113002篇
  2013年   178989篇
  2012年   166692篇
  2011年   179866篇
  2010年   139440篇
  2009年   136123篇
  2008年   164403篇
  2007年   177942篇
  2006年   183935篇
  2005年   177891篇
  2004年   177741篇
  2003年   166844篇
  2002年   155278篇
  2001年   229058篇
  2000年   227614篇
  1999年   201524篇
  1998年   80064篇
  1997年   73278篇
  1996年   71303篇
  1995年   66652篇
  1994年   60628篇
  1993年   55920篇
  1992年   150533篇
  1991年   145964篇
  1990年   141641篇
  1989年   137810篇
  1988年   126994篇
  1987年   124977篇
  1986年   118143篇
  1985年   114853篇
  1984年   91008篇
  1983年   79594篇
  1982年   56063篇
  1981年   51743篇
  1980年   48375篇
  1979年   81985篇
  1978年   62558篇
  1977年   54314篇
  1976年   50917篇
  1975年   53047篇
  1974年   60898篇
  1973年   58415篇
  1972年   54814篇
  1971年   51272篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
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   
65.
Cognitive Therapy and Research - Despite interest in psychological inflexibility as a marker of suicide risk, no measure of psychological inflexibility specific to SI exists. The present study...  相似文献   
66.
67.
68.
69.
Gestational trophoblastic neoplasia (GTN) patients are treated according to the eight-variable International Federation of Gynaecology and Obstetrics (FIGO) scoring system, that aims to predict first-line single-agent chemotherapy resistance. FIGO is imperfect with one-third of low-risk patients developing disease resistance to first-line single-agent chemotherapy. We aimed to generate simplified models that improve upon FIGO. Logistic regression (LR) and multilayer perceptron (MLP) modelling (n = 4191) generated six models (M1-6). M1, all eight FIGO variables (scored data); M2, all eight FIGO variables (scored and raw data); M3, nonimaging variables (scored data); M4, nonimaging variables (scored and raw data); M5, imaging variables (scored data); and M6, pretreatment hCG (raw data) + imaging variables (scored data). Performance was compared to FIGO using true and false positive rates, positive and negative predictive values, diagnostic odds ratio, receiver operating characteristic (ROC) curves, Bland-Altman calibration plots, decision curve analysis and contingency tables. M1-6 were calibrated and outperformed FIGO on true positive rate and positive predictive value. Using LR and MLP, M1, M2 and M4 generated small improvements to the ROC curve and decision curve analysis. M3, M5 and M6 matched FIGO or performed less well. Compared to FIGO, most (excluding LR M4 and MLP M5) had significant discordance in patient classification (McNemar's test P < .05); 55-112 undertreated, 46-206 overtreated. Statistical modelling yielded only small gains over FIGO performance, arising through recategorisation of treatment-resistant patients, with a significant proportion of under/overtreatment as the available data have been used a priori to allocate primary chemotherapy. Streamlining FIGO should now be the focus.  相似文献   
70.
Heart Failure Reviews - The nitric oxide (NO)–guanylate cyclase (GC)–cyclic guanosine monophosphate (cGMP) pathway plays an important role in cardiovascular, pulmonary and renal...  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