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   5037332篇
  免费   398547篇
  国内免费   17614篇
耳鼻咽喉   71064篇
儿科学   164535篇
妇产科学   136885篇
基础医学   754127篇
口腔科学   143726篇
临床医学   462110篇
内科学   913215篇
皮肤病学   119036篇
神经病学   419070篇
特种医学   197485篇
外国民族医学   1122篇
外科学   757018篇
综合类   146630篇
现状与发展   23篇
一般理论   2838篇
预防医学   427818篇
眼科学   119569篇
药学   358716篇
  25篇
中国医学   13498篇
肿瘤学   244983篇
  2021年   57398篇
  2019年   59837篇
  2018年   76855篇
  2017年   58492篇
  2016年   64885篇
  2015年   77632篇
  2014年   112606篇
  2013年   178943篇
  2012年   142404篇
  2011年   151045篇
  2010年   132704篇
  2009年   132256篇
  2008年   136392篇
  2007年   146213篇
  2006年   153953篇
  2005年   148495篇
  2004年   148749篇
  2003年   137779篇
  2002年   127448篇
  2001年   186354篇
  2000年   183099篇
  1999年   166136篇
  1998年   75465篇
  1997年   70500篇
  1996年   68460篇
  1995年   63955篇
  1994年   58089篇
  1993年   53898篇
  1992年   126140篇
  1991年   122412篇
  1990年   118587篇
  1989年   115245篇
  1988年   107335篇
  1987年   105267篇
  1986年   100554篇
  1985年   98364篇
  1984年   79979篇
  1983年   70971篇
  1982年   52918篇
  1981年   48882篇
  1980年   45984篇
  1979年   72715篇
  1978年   56318篇
  1977年   49176篇
  1976年   46348篇
  1975年   47109篇
  1974年   53810篇
  1973年   52099篇
  1972年   48891篇
  1971年   45583篇
排序方式: 共有10000条查询结果,搜索用时 31 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