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   4669637篇
  免费   368344篇
  国内免费   15294篇
耳鼻咽喉   65284篇
儿科学   150145篇
妇产科学   123131篇
基础医学   709430篇
口腔科学   128158篇
临床医学   428896篇
内科学   849328篇
皮肤病学   114312篇
神经病学   389768篇
特种医学   181274篇
外国民族医学   816篇
外科学   702625篇
综合类   130120篇
现状与发展   24篇
一般理论   2704篇
预防医学   386551篇
眼科学   110036篇
药学   331889篇
  27篇
中国医学   13282篇
肿瘤学   235475篇
  2021年   56681篇
  2019年   59206篇
  2018年   75486篇
  2017年   57928篇
  2016年   64101篇
  2015年   76832篇
  2014年   111118篇
  2013年   176697篇
  2012年   132786篇
  2011年   139392篇
  2010年   128938篇
  2009年   129420篇
  2008年   125171篇
  2007年   133891篇
  2006年   141876篇
  2005年   135724篇
  2004年   136899篇
  2003年   126813篇
  2002年   116068篇
  2001年   183626篇
  2000年   179470篇
  1999年   162597篇
  1998年   73802篇
  1997年   68988篇
  1996年   66979篇
  1995年   62356篇
  1994年   56304篇
  1993年   52183篇
  1992年   117822篇
  1991年   113074篇
  1990年   108900篇
  1989年   106329篇
  1988年   97742篇
  1987年   95672篇
  1986年   90050篇
  1985年   87783篇
  1984年   72003篇
  1983年   63690篇
  1982年   49355篇
  1981年   45741篇
  1980年   42903篇
  1979年   61758篇
  1978年   49115篇
  1977年   43571篇
  1976年   40384篇
  1975年   41093篇
  1974年   44928篇
  1973年   42814篇
  1972年   40139篇
  1971年   37155篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
65.
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   
66.
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   
67.
68.
69.
70.
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   
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