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   145762篇
  免费   12934篇
  国内免费   9294篇
耳鼻咽喉   1654篇
儿科学   1574篇
妇产科学   1642篇
基础医学   16893篇
口腔科学   2407篇
临床医学   17623篇
内科学   20125篇
皮肤病学   1740篇
神经病学   7118篇
特种医学   6160篇
外国民族医学   59篇
外科学   16899篇
综合类   24184篇
现状与发展   34篇
一般理论   25篇
预防医学   10046篇
眼科学   4188篇
药学   15125篇
  119篇
中国医学   8213篇
肿瘤学   12162篇
  2024年   357篇
  2023年   1649篇
  2022年   4699篇
  2021年   6431篇
  2020年   4835篇
  2019年   4423篇
  2018年   4731篇
  2017年   4292篇
  2016年   4385篇
  2015年   6526篇
  2014年   8232篇
  2013年   8110篇
  2012年   11888篇
  2011年   12514篇
  2010年   8844篇
  2009年   7195篇
  2008年   8852篇
  2007年   8559篇
  2006年   8330篇
  2005年   7523篇
  2004年   5461篇
  2003年   5174篇
  2002年   4420篇
  2001年   3487篇
  2000年   2867篇
  1999年   2716篇
  1998年   1664篇
  1997年   1641篇
  1996年   1234篇
  1995年   1112篇
  1994年   934篇
  1993年   582篇
  1992年   689篇
  1991年   602篇
  1990年   537篇
  1989年   471篇
  1988年   420篇
  1987年   336篇
  1986年   285篇
  1985年   245篇
  1984年   142篇
  1983年   103篇
  1982年   58篇
  1981年   58篇
  1980年   37篇
  1979年   76篇
  1978年   33篇
  1974年   35篇
  1973年   26篇
  1969年   21篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
42.
Abstract

Background

Comorbidities are commonly seen in patients with coronavirus disease 2019 (COVID-19), but the clinical implication is not yet well-delineated. We aim to characterize the prevalence and clinical implications of comorbidities in patients with COVID-19.  相似文献   
43.
Ferroptosis is an iron-dependent novel cell death pathway. Deferoxamine, a ferroptosis inhibitor, has been reported to promote spinal cord injury repair. It has yet to be clarified whether ferroptosis inhibition represents the mechanism of action of Deferoxamine on spinal cord injury recovery. A rat model of Deferoxamine at thoracic 10 segment was established using a modified Allen's method. Ninety 8-week-old female Wistar rats were used. Rats in the Deferoxamine group were intraperitoneally injected with 100 mg/kg Deferoxamine 30 minutes before injury. Simultaneously, the Sham and Deferoxamine groups served as controls. Drug administration was conducted for 7 consecutive days. The results were as follows:(1) Electron microscopy revealed shrunken mitochondria in the spinal cord injury group.(2) The Basso, Beattie and Bresnahan locomotor rating score showed that recovery of the hindlimb was remarkably better in the Deferoxamine group than in the spinal cord injury group.(3) The iron concentration was lower in the Deferoxamine group than in the spinal cord injury group after injury.(4) Western blot assay revealed that, compared with the spinal cord injury group, GPX4, xCT, and glutathione expression was markedly increased in the Deferoxamine group.(5) Real-time polymerase chain reaction revealed that, compared with the Deferoxamine group, mRNA levels of ferroptosis-related genes Acyl-CoA synthetase family member 2(ACSF2) and iron-responsive element-binding protein 2(IREB2) were up-regulated in the Deferoxamine group.(6) Deferoxamine increased survival of neurons and inhibited gliosis. These findings confirm that Deferoxamine can repair spinal cord injury by inhibiting ferroptosis. Targeting ferroptosis is therefore a promising therapeutic approach for spinal cord injury.  相似文献   
44.
45.
46.
47.
随着对肿瘤热疗和肿瘤免疫微环境(TIME)的深入研究,近年来热疗对TIME的作用越来越受到学者们的重视。本文就目前国内外研究进展,对热疗与TIME中几类主要免疫细胞和免疫相关细胞因子的影响及作用机制作一综述。全面而透彻的了解热疗对TIME的调控作用,有助于为肿瘤治疗提供新的思路和方法。  相似文献   
48.
49.
本文报道产前超声诊断胎儿右房异构一例。孕妇孕24周产前超声检查发现胎儿左位心合并复杂心血管畸形(右心室双出口、房室间隔缺损、肺动脉发育不良、双侧上腔静脉、心下型完全型肺静脉异位引流)、胃泡位于腹腔右侧、中位肝、可疑无脾、腹主动脉与下腔静脉位于脊柱左侧、双侧支气管呈右侧支气管对称形态,综合考虑右房异构可能。引产后经尸体解剖证实脾脏发育不良、右房异构。右房异构常合并复杂心血管畸形,因此产前超声发现复杂心血管畸形时,应警惕右房异构的可能。右房异构病死率极高,产前诊断具有重要意义。  相似文献   
50.
Abstract

Oxidative stress (OS) has been proposed to play a role in the development of EMs. Peroxiredoxins are a family of antioxidant proteins that exhibit peroxidase activity in a thioredoxin-dependent manner, protecting cells against OS. The Western blotting results showed that the relative expression of PRDX4 was significantly increased in ectopic endometria compared with the normal endometria of EMs-free (p?<?.05). The H2O2 concentration was also significantly higher in the ectopic endometrium. PRDX4 siRNA was transfected into primary ectopic endometrial stromal cells (EESCs). The viability of the transfected EESCs was measured by CCK-8 assay, and the results showed significantly decreased cell viability. Furthermore, the apoptosis rate and ROS generation in flow cytometry assays were significantly increased after the knockdown of PRDX4 expression (p?<?.05). Scratch assays and transwell assays revealed that decreased expression of PRDX4 mediated by siRNA inhibited EESC migration and invasion. In conclusion, these findings indicate the potential role of PRDX4 in the development of EMs and PRDX4 as a possible therapeutic target for EMs treatment.  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