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   834篇
  免费   37篇
  国内免费   5篇
耳鼻咽喉   2篇
儿科学   34篇
妇产科学   8篇
基础医学   80篇
口腔科学   80篇
临床医学   42篇
内科学   179篇
皮肤病学   54篇
神经病学   34篇
特种医学   16篇
外科学   187篇
预防医学   57篇
眼科学   24篇
药学   49篇
中国医学   4篇
肿瘤学   26篇
  2024年   1篇
  2023年   1篇
  2022年   15篇
  2021年   20篇
  2020年   16篇
  2019年   27篇
  2018年   31篇
  2017年   20篇
  2016年   14篇
  2015年   20篇
  2014年   32篇
  2013年   37篇
  2012年   60篇
  2011年   66篇
  2010年   41篇
  2009年   38篇
  2008年   60篇
  2007年   73篇
  2006年   49篇
  2005年   53篇
  2004年   59篇
  2003年   25篇
  2002年   18篇
  2001年   18篇
  2000年   10篇
  1999年   17篇
  1998年   5篇
  1997年   2篇
  1996年   5篇
  1995年   5篇
  1994年   5篇
  1993年   2篇
  1992年   8篇
  1991年   3篇
  1990年   6篇
  1989年   6篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1971年   1篇
  1969年   1篇
  1968年   1篇
  1966年   1篇
排序方式: 共有876条查询结果,搜索用时 156 毫秒
61.
62.
BACKGROUND AND AIM: The aetiology of ulcerative colitis is still controversial, however, recent studies have emphasised the possible role of infectious agents or ingested substances and their breakdown products, which might activate immune-mediated mechanisms eventually leading to tissue damage. Aim of this investigation was to ascertain the occurrence and the potential role of Epstein-Barr virus infection in large bowel mucosa of ulcerative colitis patients. PATIENTS AND METHODS: Twenty-three biopsies and six total colectomies from 17 patients were analysed for the expression of Epstein-Barr virus proteins and RNAs. Polymerase chain reaction experiments were also carried out to detect Epstein-Barr virus DNA. For comparison, ten biopsies from patients with Crohn's disease, ten biopsies from patients with different types of colitis, seven biopsies and five surgical margins of normal colonic mucosa from the small and large bowels were studied (controls). RESULTS: Six biopsies and four colectomies from seven ulcerative colitis patients showed scattered lymphocytes expressing nuclear EBER 1-2 and harbouring polymerase chain reaction-amplifiable Epstein-Barr virus-DNA. In some cases, linear viral DNA (typical of lytic Epstein-Barr virus infection) was also found. Epithelial cells were invariably negative in all cases. All control tissues from non-ulcerative colitis patients were also invariably non-reactive. CONCLUSION: Evidence of Epstein-Barr virus infection in the mucosal inflammatory cells of ulcerative colitis patients suggests a possible role of this virus in the chronicity of ulcerative colitis.  相似文献   
63.
64.
65.
Lipopolysaccharides (LPS) can be used to induce experimental endotoxic shock, which is characterized by a significant decrease in mean arterial pressure (MAP) and a decreased vasoconstrictor response that have been attributed to excessive nitric oxide production. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase), in addition to lowering serum cholesterol levels, exert many pleiotropic effects, including anti-inflammatory action. In the present study, we investigated the effect of simvastatin, an HMG-CoA reductase inhibitor, on the production of nitric oxide and the cardiovascular response to LPS. Male Wistar rats were pretreated with different doses of simvastatin (10, 20, 40, and 80 mg/kg, i.p.) or saline 20 min before i.v. injection of LPS (1.5 mg/kg) or saline (control). MAP was continuously recorded and nitrate plasma concentration was determined during the 6-h experimental session at 1-h intervals. The pressor response to phenylephrine (1 microg/kg) was evaluated before and 6 h after LPS administration. In the LPS-treated group, there was a time-dependent increase in nitrate plasma concentration (P<0.001), and this response was decreased in simvastatin pretreated rats (P<0.001). We also observed that LPS decreased the pressor response to phenylephrine (P<0.001), an effect that was reverted by simvastatin pretreatment (P<0.05). However, simvastatin did not modify the decrease of MAP induced by LPS. We concluded that simvastatin decreases nitrate plasma concentration in response to LPS and recovers vascular responsiveness during an experimental endotoxic shock. These data suggest the potential use of HMG-CoA reductase inhibitors as a coadjuvant in the treatment of septic shock.  相似文献   
66.

Objective

To translate and cross-culturally adapt the Pelvic Girdle Questionnaire (PGQ) into Brazilian Portuguese and test the measurement properties of the PGQ and the Roland Morris Disability Questionnaire (RMDQ) in women with pelvic pain during pregnancy.

Methods

Thirty pregnant women were included in the assessment of the pre-test of the final version of the PGQ and 100 were included in the assessment of the measurement properties. In the initial assessment, the PGQ, RMDQ, pain numerical rating scale, and WHOQOL-BREF were applied to test the internal consistency and construct validity. In the 48-hour assessment, only the PGQ and RMDQ were applied to test reliability and measurement error; in the reassessment after one month, the PGQ, RMDQ, and global perceived effect scale were applied to evaluate responsiveness.

Results

The PGQ showed adequate internal consistency (Cronbach's alpha = 0.83), substantial reliability (ICC2,1 = 0.85), very good measurement error (5%), and good responsiveness (r = ?0.62). We also observed good correlation with disability and quality of life in the physical health domain, moderate correlation with pain and quality of life in the psychological domain, and poor correlation with quality of life in the domains social relationships and environment. The RMDQ showed adequate internal consistency (Cronbach's alpha = 0.80), substantial reliability (ICC2,1 = 0.76), good measurement error (9%), moderate responsiveness (r = ?0.51), moderate correlation with quality of life in the physical health and psychological domains, and weak correlation with pain and quality of life in the social relationships and environment domains.

Conclusion

The Brazilian Portuguese version of the PGQ showed superior measurement properties compared to the RMDQ, being a valid, reliable, and responsive instrument for assessing patients with pelvic pain during pregnancy.  相似文献   
67.
68.
69.
70.
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