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   4847456篇
  免费   384873篇
  国内免费   17538篇
耳鼻咽喉   67159篇
儿科学   157127篇
妇产科学   131531篇
基础医学   732969篇
口腔科学   135474篇
临床医学   453473篇
内科学   878664篇
皮肤病学   116202篇
神经病学   405210篇
特种医学   186906篇
外国民族医学   1032篇
外科学   719375篇
综合类   141729篇
现状与发展   24篇
一般理论   2863篇
预防医学   415351篇
眼科学   113709篇
药学   340387篇
  26篇
中国医学   13446篇
肿瘤学   237210篇
  2021年   56842篇
  2019年   59321篇
  2018年   76053篇
  2017年   57974篇
  2016年   64084篇
  2015年   76680篇
  2014年   111393篇
  2013年   177287篇
  2012年   141435篇
  2011年   150085篇
  2010年   131457篇
  2009年   131001篇
  2008年   134580篇
  2007年   144364篇
  2006年   151327篇
  2005年   146145篇
  2004年   146065篇
  2003年   135278篇
  2002年   124017篇
  2001年   180900篇
  2000年   177456篇
  1999年   160710篇
  1998年   74171篇
  1997年   69693篇
  1996年   67707篇
  1995年   63143篇
  1994年   57278篇
  1993年   53106篇
  1992年   118486篇
  1991年   114589篇
  1990年   110202篇
  1989年   106758篇
  1988年   98970篇
  1987年   96892篇
  1986年   92026篇
  1985年   89734篇
  1984年   74189篇
  1983年   65926篇
  1982年   50789篇
  1981年   47207篇
  1980年   44274篇
  1979年   65884篇
  1978年   52428篇
  1977年   45738篇
  1976年   42942篇
  1975年   42945篇
  1974年   48683篇
  1973年   47433篇
  1972年   44567篇
  1971年   41333篇
排序方式: 共有10000条查询结果,搜索用时 422 毫秒
61.
62.
63.
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   
64.
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