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   4889773篇
  免费   394724篇
  国内免费   17865篇
耳鼻咽喉   69407篇
儿科学   154517篇
妇产科学   130264篇
基础医学   735625篇
口腔科学   138187篇
临床医学   453931篇
内科学   887653篇
皮肤病学   113888篇
神经病学   413548篇
特种医学   192357篇
外国民族医学   1154篇
外科学   730536篇
综合类   143345篇
现状与发展   23篇
一般理论   2811篇
预防医学   421690篇
眼科学   115808篇
药学   347316篇
  29篇
中国医学   13200篇
肿瘤学   237073篇
  2021年   56733篇
  2019年   59364篇
  2018年   75767篇
  2017年   57955篇
  2016年   64401篇
  2015年   77135篇
  2014年   112080篇
  2013年   178034篇
  2012年   139657篇
  2011年   146857篇
  2010年   130384篇
  2009年   130759篇
  2008年   132459篇
  2007年   141801篇
  2006年   149687篇
  2005年   144359篇
  2004年   144175篇
  2003年   134045篇
  2002年   123995篇
  2001年   182767篇
  2000年   180115篇
  1999年   163469篇
  1998年   75152篇
  1997年   70475篇
  1996年   68215篇
  1995年   64138篇
  1994年   58230篇
  1993年   53950篇
  1992年   123110篇
  1991年   118644篇
  1990年   113781篇
  1989年   110222篇
  1988年   102405篇
  1987年   100629篇
  1986年   95772篇
  1985年   93455篇
  1984年   76870篇
  1983年   67901篇
  1982年   51842篇
  1981年   48080篇
  1980年   45205篇
  1979年   68764篇
  1978年   54055篇
  1977年   47136篇
  1976年   44357篇
  1975年   44238篇
  1974年   50690篇
  1973年   48876篇
  1972年   45799篇
  1971年   42325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.
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