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   4382668篇
  免费   357580篇
  国内免费   15540篇
耳鼻咽喉   62726篇
儿科学   141209篇
妇产科学   117785篇
基础医学   666199篇
口腔科学   121643篇
临床医学   390929篇
内科学   797754篇
皮肤病学   107316篇
神经病学   366527篇
特种医学   175199篇
外国民族医学   1112篇
外科学   677665篇
综合类   129989篇
现状与发展   24篇
一般理论   2550篇
预防医学   362077篇
眼科学   102744篇
药学   309551篇
  20篇
中国医学   11830篇
肿瘤学   210939篇
  2021年   55736篇
  2019年   58635篇
  2018年   73492篇
  2017年   55916篇
  2016年   61948篇
  2015年   75180篇
  2014年   109562篇
  2013年   174967篇
  2012年   118904篇
  2011年   123335篇
  2010年   124337篇
  2009年   126460篇
  2008年   110751篇
  2007年   118524篇
  2006年   126933篇
  2005年   122583篇
  2004年   124036篇
  2003年   114978篇
  2002年   104432篇
  2001年   155790篇
  2000年   151566篇
  1999年   141140篇
  1998年   71408篇
  1997年   67349篇
  1996年   65257篇
  1995年   60609篇
  1994年   54925篇
  1993年   51123篇
  1992年   104770篇
  1991年   101230篇
  1990年   97694篇
  1989年   94803篇
  1988年   88199篇
  1987年   86631篇
  1986年   82142篇
  1985年   80726篇
  1984年   67930篇
  1983年   60356篇
  1982年   48449篇
  1981年   45108篇
  1980年   42476篇
  1979年   60341篇
  1978年   48361篇
  1977年   42910篇
  1976年   39790篇
  1975年   40327篇
  1974年   44832篇
  1973年   43298篇
  1972年   40618篇
  1971年   37166篇
排序方式: 共有10000条查询结果,搜索用时 562 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