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   4322460篇
  免费   346452篇
  国内免费   14179篇
耳鼻咽喉   59914篇
儿科学   137975篇
妇产科学   112857篇
基础医学   664826篇
口腔科学   115913篇
临床医学   393809篇
内科学   782173篇
皮肤病学   107702篇
神经病学   361476篇
特种医学   168464篇
外国民族医学   515篇
外科学   664391篇
综合类   120723篇
现状与发展   24篇
一般理论   2678篇
预防医学   359945篇
眼科学   101754篇
药学   302917篇
  25篇
中国医学   11501篇
肿瘤学   213509篇
  2021年   57043篇
  2020年   36270篇
  2019年   59563篇
  2018年   75469篇
  2017年   57305篇
  2016年   63652篇
  2015年   76407篇
  2014年   111289篇
  2013年   177214篇
  2012年   131154篇
  2011年   137840篇
  2010年   129020篇
  2009年   129677篇
  2008年   123040篇
  2007年   131495篇
  2006年   139530篇
  2005年   134651篇
  2004年   134335篇
  2003年   124063篇
  2002年   113006篇
  2001年   150354篇
  2000年   145080篇
  1999年   134860篇
  1998年   70753篇
  1997年   66700篇
  1996年   64789篇
  1995年   60023篇
  1994年   54113篇
  1993年   50341篇
  1992年   96334篇
  1991年   92880篇
  1990年   89259篇
  1989年   87026篇
  1988年   80198篇
  1987年   78685篇
  1986年   74024篇
  1985年   73165篇
  1984年   61840篇
  1983年   55591篇
  1982年   46191篇
  1981年   43274篇
  1980年   40640篇
  1979年   53217篇
  1978年   44140篇
  1977年   38976篇
  1976年   36374篇
  1975年   36355篇
  1974年   39486篇
  1973年   37723篇
  1972年   35306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