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   4278123篇
  免费   346328篇
  国内免费   15363篇
耳鼻咽喉   58609篇
儿科学   137930篇
妇产科学   113224篇
基础医学   657406篇
口腔科学   118832篇
临床医学   388221篇
内科学   766485篇
皮肤病学   108499篇
神经病学   357147篇
特种医学   167557篇
外国民族医学   544篇
外科学   655701篇
综合类   127946篇
现状与发展   23篇
一般理论   2578篇
预防医学   350936篇
眼科学   102039篇
药学   299945篇
  22篇
中国医学   12385篇
肿瘤学   213785篇
  2021年   55077篇
  2020年   35871篇
  2019年   59050篇
  2018年   74504篇
  2017年   56710篇
  2016年   62800篇
  2015年   75881篇
  2014年   110327篇
  2013年   176189篇
  2012年   119817篇
  2011年   124804篇
  2010年   125619篇
  2009年   126920篇
  2008年   110583篇
  2007年   117405篇
  2006年   125867篇
  2005年   120545篇
  2004年   122030篇
  2003年   111585篇
  2002年   100756篇
  2001年   163036篇
  2000年   157981篇
  1999年   145091篇
  1998年   71995篇
  1997年   67694篇
  1996年   65432篇
  1995年   60363篇
  1994年   54565篇
  1993年   50514篇
  1992年   104099篇
  1991年   100202篇
  1990年   95799篇
  1989年   93578篇
  1988年   85692篇
  1987年   84205篇
  1986年   79551篇
  1985年   78127篇
  1984年   65351篇
  1983年   57983篇
  1982年   47002篇
  1981年   43844篇
  1980年   41015篇
  1979年   55332篇
  1978年   45152篇
  1977年   40356篇
  1976年   37235篇
  1975年   36871篇
  1974年   40527篇
  1973年   39014篇
  1972年   36349篇
排序方式: 共有10000条查询结果,搜索用时 950 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