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   426篇
  免费   26篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   8篇
妇产科学   6篇
基础医学   67篇
口腔科学   46篇
临床医学   52篇
内科学   69篇
皮肤病学   6篇
神经病学   104篇
特种医学   2篇
外科学   12篇
综合类   3篇
预防医学   50篇
眼科学   13篇
药学   12篇
肿瘤学   2篇
  2022年   1篇
  2021年   4篇
  2020年   5篇
  2019年   7篇
  2018年   7篇
  2017年   5篇
  2016年   8篇
  2015年   7篇
  2014年   7篇
  2013年   20篇
  2012年   36篇
  2011年   27篇
  2010年   17篇
  2009年   12篇
  2008年   23篇
  2007年   26篇
  2006年   26篇
  2005年   31篇
  2004年   30篇
  2003年   38篇
  2002年   22篇
  2001年   10篇
  2000年   17篇
  1999年   11篇
  1998年   8篇
  1997年   3篇
  1996年   5篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1992年   5篇
  1991年   5篇
  1990年   6篇
  1989年   2篇
  1988年   5篇
  1987年   5篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1977年   1篇
  1971年   1篇
  1960年   1篇
  1898年   1篇
  1894年   1篇
排序方式: 共有453条查询结果,搜索用时 15 毫秒
1.
2.
Systemic cyclosporin A prophylaxis was applied in 18 high-risk corneal transplants. Immunoreactions occurred in three cases. They correlated with too low serum level of cyclosporin A. Two of them could be reversed by an increase of cyclosporin A dosage in combination with an intensive corticosteroid therapy. Four corneal transplants failed from persistent severe basic disease. Eleven corneal transplants remained clear during the follow-up (5-33 months). A constant trough cyclosporin A serum level of 100-120 ng/ml has been shown to exert efficient immunomodulating effects. We currently judge a postoperative prophylaxis period of 6 to 12 months with cyclosporin A to be sufficient in most high-risk cases.  相似文献   
3.
A total of 130 people attending psychiatric hospitals within 6 months of onset or relapse of an episode of depressive disorder were interviewed about their symptoms and treatment at the time of their initial contact. After a mean 4-month interval, 119 were reassessed to test the hypothesis that patients treated with antidepressants would be significantly more likely to be clinically improved compared with those untreated. Severity and duration of the episode emerged as the only significant clinical predictors of clinical improvement. Patients on treatment with antidepressants at the start of the study showed a nonsignificant trend for a lesser degree of clinical improvement, even when clinical severity and compliance were taken into account. Those who were not commenced on treatment until later in the study also fared no better than those who were never prescribed antidepressants. The effect of low doses of antidepressants (almost always a tricyclic) appeared to be less beneficial than either higher doses or clinical management without antidepressant drugs. The need for further experimental and naturalistic studies conducted over various periods of time and the implications for clinical practice, medical audit and the appropriate use of health outcome indicators are discussed.  相似文献   
4.
The cytotoxicity of two nitroheterocyclic compounds (NHCD), Nitracrine, 1-nitro-9(3'3'-dimethylaminopropylamino) acridine (Polfa, Poland) and Quinifuryl, 2-(5'-nitro-2'-furanyl) ethenyl-4-[N-[4-(N,N-diethylamino)-1'-methylbutyl] carbamoyl] quinoline (Dr. N. M. Sukhova, Institute of Organic Synthesis, Riga, Latvian Republic), towards two lines of leukaemic cells and a line of non-transformed cells, was determined under normoxia conditions. Although both drugs showed significant cytotoxicity to all cell lines (LC(50) for 24h, < or = 2 microM) with that of Nitracrine exceeding Quinifuryl, their toxicity towards murine leukaemia P388 was substantially higher, compared to murine fibroblasts NIH3T3. In addition, the rate of cell death was also two- to three-fold higher in case of P388 cells versus NIH3T3. Interestingly, human erythroleukaemia K562 cells were shown to uptake the drugs 10 min after their addition to the tissue culture medium, while the LC(50) values were reached after a substantial delay of 3h. This delay might be due to the intracellular transformation of drugs required for cell killing.  相似文献   
5.
6.
IntroductionMetabolic syndrome (MS) is a major health problem, and has economic effects on enterprises. The workplace is thus an important environment for primary prevention of risk factors for cardiovascular disease.ObjectiveTo determine the prevalence of MS and variables related to its development in hospital workers.MethodsWe performed a cross-sectional study of 740 workers in a large university hospital. Socioeconomic variables, anthropometric and blood pressure measurements, and laboratory exams were analyzed. MS was defined according to the criteria of the International Diabetes Federation.ResultsOf the 740 workers, 72.4% were female and mean age was 34.9±9.5 years; 27.8% worked the morning shift, 20.3% the afternoon shift, 34.1% office hours, and 17.8% the night shift. As to educational level, 86.6% had finished high school or college. Waist circumference was high in 55.4%. Overall MS prevalence was 12.8%, 16.2% in males and 11.6% in females. Logistic regression analysis showed an independent association between MS and the following variables: elementary education, period of employment >10 years, office hours shift, and age group.ConclusionA diagnosis of MS was affected by age, educational level, work shift, and prolonged period of employment. Hospital workers do not differ from other populations and also need stimuli to make preventive changes to their behavior to modify cardiovascular risk factors.  相似文献   
7.
8.
9.
BACKGROUND: Endothelial dysfunction of coronary and peripheral arteries has been demonstrated in patients with chronic heart failure (CHF) and appears to be associated with functional implications. However, it is unknown whether endothelial dysfunction in CHF is independently associated with impaired outcome or progression of the disease. METHODS AND RESULTS: We assessed the follow-up of 67 consecutive patients with CHF [New York Heart Association (NYHA) functional class II-III] in which flow-dependent, endothelium-mediated vasodilation (FDD) of the radial artery was assessed by high resolution ultrasound. The primary endpoint was defined by cardiac death, hospitalization due to worsening of heart failure (NYHA class IV, pulmonary oedema), or heart transplantation. Cox regression analysis was used to determine whether FDD was associated with these heart failure-related events. During a median follow-up of 45.7 months 24 patients had an event: 18 patients were hospitalized due to worsening of heart failure or heart transplantation, six patients died for cardiac reasons. Cox regression analysis demonstrated that FDD (P<0.01), diabetes mellitus (P<0.01), and ejection fraction (P<0.01) were independent predictive factors for the occurrence of the primary endpoint. The Kaplan-Meier survival curve revealed a significantly better clinical outcome in patients with FDD above the median (6.2%) compared with those with FDD below the median (P<0.013). CONCLUSION: These observations suggest that endothelium-mediated vasodilation represents an independent predictor of cardiac death and hospitalization in patients with CHF, consistent with the notion that endothelium-derived nitric oxide may play a protective role in heart failure.  相似文献   
10.

Objective

Tea tree oil (TTO) is an essential oil with anti-inflammatory properties, steam distilled from the plant Melaleuca alternifolia. We investigated the immunomodulatory properties of TTO and its components (terpinen-4-ol and alpha-terpineol) using lipopolysaccharide (LPS)-stimulated macrophages.

Methods

The ability of TTO, terpinen-4-ol and alpha-terpineol to modulate the macrophage response to bacterial LPS stimulation was assessed by ELISA for tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-10 cytokine production and by western blotting for the activation of nuclear factor kappa B (NF-κB) and p38 mitogen-activated protein kinase (MAPK) signaling, which are associated with the expression of pro-inflammatory cytokines. We used a human monocytic cell line (U937) differentiated into macrophages.

Results

LPS induced the production of all cytokines, and TTO and its components significantly reduced the production of IL-1β, IL-6 and IL-10. The production of TNF-α was not affected by either TTO or its major components. The modulation of cytokine production was not mediated by changes in NF-κB or p38 MAPK activation.

Conclusion

TTO, terpinen-4-ol and alpha-terpineol can suppress the production of inflammatory mediators in LPS-stimulated human macrophages; this inhibition was mediated by interfering with the NF-kB, p38 or ERK MAPK pathways.  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