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   4336133篇
  免费   349916篇
  国内免费   14610篇
耳鼻咽喉   60332篇
儿科学   139723篇
妇产科学   114555篇
基础医学   665584篇
口腔科学   118119篇
临床医学   396501篇
内科学   783964篇
皮肤病学   107936篇
神经病学   368463篇
特种医学   169515篇
外国民族医学   753篇
外科学   655168篇
综合类   121168篇
现状与发展   24篇
一般理论   2630篇
预防医学   357133篇
眼科学   100760篇
药学   308000篇
  22篇
中国医学   11967篇
肿瘤学   218342篇
  2021年   56265篇
  2020年   35983篇
  2019年   59032篇
  2018年   74677篇
  2017年   56874篇
  2016年   63000篇
  2015年   75980篇
  2014年   110255篇
  2013年   175951篇
  2012年   125401篇
  2011年   130400篇
  2010年   126377篇
  2009年   128068篇
  2008年   116359篇
  2007年   123686篇
  2006年   132408篇
  2005年   126383篇
  2004年   127673篇
  2003年   117860篇
  2002年   106944篇
  2001年   166980篇
  2000年   162054篇
  1999年   148722篇
  1998年   71721篇
  1997年   67652篇
  1996年   65658篇
  1995年   61074篇
  1994年   54996篇
  1993年   51011篇
  1992年   106206篇
  1991年   101299篇
  1990年   97086篇
  1989年   94630篇
  1988年   86877篇
  1987年   85120篇
  1986年   80005篇
  1985年   78187篇
  1984年   65090篇
  1983年   57785篇
  1982年   46737篇
  1981年   43414篇
  1980年   40619篇
  1979年   54746篇
  1978年   44421篇
  1977年   39545篇
  1976年   36463篇
  1975年   36488篇
  1974年   39377篇
  1973年   37560篇
  1972年   35263篇
排序方式: 共有10000条查询结果,搜索用时 515 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