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   30697篇
  免费   2923篇
  国内免费   2162篇
耳鼻咽喉   218篇
儿科学   441篇
妇产科学   351篇
基础医学   3538篇
口腔科学   569篇
临床医学   4047篇
内科学   4711篇
皮肤病学   276篇
神经病学   1559篇
特种医学   1303篇
外国民族医学   12篇
外科学   3546篇
综合类   4806篇
现状与发展   6篇
一般理论   3篇
预防医学   2018篇
眼科学   713篇
药学   3314篇
  27篇
中国医学   1582篇
肿瘤学   2742篇
  2024年   92篇
  2023年   447篇
  2022年   1111篇
  2021年   1397篇
  2020年   1049篇
  2019年   972篇
  2018年   1004篇
  2017年   959篇
  2016年   972篇
  2015年   1352篇
  2014年   1656篇
  2013年   1559篇
  2012年   2026篇
  2011年   2421篇
  2010年   1551篇
  2009年   1218篇
  2008年   1572篇
  2007年   1667篇
  2006年   1578篇
  2005年   1560篇
  2004年   1198篇
  2003年   1216篇
  2002年   1097篇
  2001年   868篇
  2000年   799篇
  1999年   757篇
  1998年   443篇
  1997年   507篇
  1996年   338篇
  1995年   305篇
  1994年   241篇
  1993年   195篇
  1992年   230篇
  1991年   223篇
  1990年   185篇
  1989年   168篇
  1988年   138篇
  1987年   142篇
  1986年   122篇
  1985年   77篇
  1984年   54篇
  1983年   32篇
  1982年   17篇
  1981年   20篇
  1980年   26篇
  1979年   47篇
  1978年   23篇
  1976年   13篇
  1975年   20篇
  1974年   20篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
The value of adding simeprevir (SMV) vs placebo (PBO) to peginterferon and ribavirin (PR) for treatment of chronic hepatitis C virus infection was examined using patient‐reported outcomes (PROs); further, concordance of PROs with virology endpoints and adverse events (AEs) was explored. Patients (= 768 SMV/PR,= 393 PBO/PR) rated fatigue (FSS), depressive symptoms (CES‐D) and functional impairment (WPAI: Hepatitis C Productivity, Daily Activity and Absenteeism) at baseline and throughout treatment in three randomised, double‐blind trials comparing the addition of SMV or PBO during initial 12 weeks of PR. PR was administered for 48 weeks (PBO group) and 24/48 weeks (SMV group) using a response‐guided therapy (RGT) approach. Mean PRO scores (except Absenteeism) worsened from baseline to Week 4 to the same extent in both groups but reverted after Week 24 for SMV/PR and only after Week 48 for PBO/PR. Accordingly, there was a significantly lower area under the curve (baseline–Week 60, AUC60) and fewer weeks with clinically important worsening of scores in the SMV/PR group at any time point. Incidences of patients with fatigue and anaemia AEs were similar in both groups, but FSS scores showed that clinically important increases in fatigue lasted a mean of 6.9 weeks longer with PBO/PR (P < 0.001). PRO score subgroup analysis indicated better outcomes for patients who met the criteria for RGT or achieved sustained virological response 12 weeks post‐treatment (SVR12); differences in mean PRO scores associated with fibrosis level were only observed with PBO/PR. Greater efficacy of SMV/PR enabled reduced treatment duration and reduced time with PR‐related AEs without adding to AE severity.  相似文献   
4.
5.
Esophageal adenocarcinoma is the fastest rising cancer in the United States. It develops from long‐standing gastroesophageal reflux disease which affects >20% of the general population. It carries a very poor prognosis with 5‐year survival <20%. The disease is known to sequentially progress from reflux esophagitis to a metaplastic precursor, Barrett''s esophagus and then onto dysplasia and esophageal adenocarcinoma. However, only few patients with reflux develop Barrett''s esophagus and only a minority of these turn malignant. The reason for this heterogeneity in clinical progression is unknown. To improve patient management, molecular changes which facilitate disease progression must be identified. Animal models can provide a comprehensive functional and anatomic platform for such a study. Rats and mice have been the most widely studied but disease homology with humans has been questioned. No animal model naturally simulates the inflammation to adenocarcinoma progression as in humans, with all models requiring surgical bypass or destruction of existing antireflux mechanisms. Valuable properties of individual models could be utilized to holistically evaluate disease progression. In this review paper, we critically examined the current animal models of Barrett''s esophagus, their differences and homologies with human disease and how they have shaped our current understanding of Barrett''s carcinogenesis.  相似文献   
6.
7.
8.
9.
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   
10.
HIV-1 infection usually leads to systemic chronic inflammation that is associated with gut microbial translocation. The recently defined group 3 innate lymphoid cells (ILC3s) are critical for maintenance of intestinal barrier function; however, it is not clear whether and how HIV-1 infection influences the function of these cells. In this issue of the JCI, Zhang and colleagues present compelling evidence that the survival and function of ILC3s are dramatically impaired by HIV-1 infection. The authors provide evidence that HIV-1 infection induces persistent activation of plasmacytoid dendritic cells (pDCs) and production of type I IFNs, which together increase expression of death receptor CD95 on ILC3s and thereby promote subsequent ILC3 apoptosis. Together, these results identify a mechanism that explains the impaired intestinal barrier function that results from chronic HIV-1 infection and shed light on the role of pDCs in HIV-1 immunopathogenesis and therapy.  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