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   5486378篇
  免费   432663篇
  国内免费   16774篇
耳鼻咽喉   79802篇
儿科学   176670篇
妇产科学   149341篇
基础医学   808432篇
口腔科学   159232篇
临床医学   500793篇
内科学   1001062篇
皮肤病学   126904篇
神经病学   456523篇
特种医学   217849篇
外国民族医学   1523篇
外科学   828020篇
综合类   158853篇
现状与发展   23篇
一般理论   3014篇
预防医学   461836篇
眼科学   132916篇
药学   394606篇
  20篇
中国医学   13847篇
肿瘤学   264549篇
  2021年   57144篇
  2019年   59690篇
  2018年   77123篇
  2017年   58685篇
  2016年   65547篇
  2015年   77789篇
  2014年   112968篇
  2013年   178906篇
  2012年   151607篇
  2011年   161318篇
  2010年   134099篇
  2009年   133439篇
  2008年   147848篇
  2007年   159555篇
  2006年   166733篇
  2005年   161438篇
  2004年   162068篇
  2003年   151564篇
  2002年   142120篇
  2001年   212502篇
  2000年   211147篇
  1999年   188880篇
  1998年   79017篇
  1997年   73051篇
  1996年   70974篇
  1995年   66614篇
  1994年   60718篇
  1993年   56215篇
  1992年   144450篇
  1991年   139796篇
  1990年   135238篇
  1989年   131301篇
  1988年   122315篇
  1987年   120309篇
  1986年   114683篇
  1985年   111785篇
  1984年   89750篇
  1983年   79050篇
  1982年   56474篇
  1981年   51905篇
  1980年   48852篇
  1979年   82802篇
  1978年   63119篇
  1977年   54785篇
  1976年   51459篇
  1975年   52925篇
  1974年   61739篇
  1973年   59409篇
  1972年   56056篇
  1971年   51980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