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   4866917篇
  免费   399133篇
  国内免费   16269篇
耳鼻咽喉   69321篇
儿科学   153655篇
妇产科学   130195篇
基础医学   732510篇
口腔科学   136991篇
临床医学   445413篇
内科学   888925篇
皮肤病学   114979篇
神经病学   413422篇
特种医学   192260篇
外国民族医学   1212篇
外科学   734356篇
综合类   143557篇
现状与发展   24篇
一般理论   2821篇
预防医学   411370篇
眼科学   116222篇
药学   345704篇
  21篇
中国医学   13099篇
肿瘤学   236262篇
  2021年   56478篇
  2019年   59183篇
  2018年   75293篇
  2017年   57361篇
  2016年   63971篇
  2015年   76502篇
  2014年   111471篇
  2013年   176979篇
  2012年   138700篇
  2011年   145300篇
  2010年   129123篇
  2009年   130328篇
  2008年   131413篇
  2007年   140679篇
  2006年   148701篇
  2005年   143596篇
  2004年   143789篇
  2003年   133689篇
  2002年   123490篇
  2001年   188121篇
  2000年   185660篇
  1999年   167419篇
  1998年   75678篇
  1997年   70836篇
  1996年   68733篇
  1995年   64462篇
  1994年   58383篇
  1993年   54115篇
  1992年   124138篇
  1991年   118692篇
  1990年   113170篇
  1989年   109942篇
  1988年   101980篇
  1987年   100287篇
  1986年   94755篇
  1985年   92481篇
  1984年   76378篇
  1983年   67461篇
  1982年   51774篇
  1981年   47919篇
  1980年   44985篇
  1979年   67790篇
  1978年   53460篇
  1977年   46649篇
  1976年   43513篇
  1975年   43260篇
  1974年   49398篇
  1973年   47534篇
  1972年   44634篇
  1971年   41032篇
排序方式: 共有10000条查询结果,搜索用时 15 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