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   9395篇
  免费   470篇
  国内免费   94篇
耳鼻咽喉   97篇
儿科学   191篇
妇产科学   173篇
基础医学   1109篇
口腔科学   232篇
临床医学   805篇
内科学   2646篇
皮肤病学   164篇
神经病学   1035篇
特种医学   286篇
外科学   1175篇
综合类   28篇
预防医学   442篇
眼科学   110篇
药学   564篇
中国医学   43篇
肿瘤学   859篇
  2023年   72篇
  2022年   166篇
  2021年   282篇
  2020年   165篇
  2019年   201篇
  2018年   266篇
  2017年   180篇
  2016年   246篇
  2015年   294篇
  2014年   329篇
  2013年   507篇
  2012年   782篇
  2011年   682篇
  2010年   424篇
  2009年   399篇
  2008年   617篇
  2007年   659篇
  2006年   583篇
  2005年   635篇
  2004年   547篇
  2003年   448篇
  2002年   434篇
  2001年   71篇
  2000年   56篇
  1999年   59篇
  1998年   78篇
  1997年   74篇
  1996年   42篇
  1995年   50篇
  1994年   43篇
  1993年   38篇
  1992年   37篇
  1991年   44篇
  1990年   35篇
  1989年   32篇
  1988年   31篇
  1987年   28篇
  1986年   29篇
  1985年   31篇
  1984年   26篇
  1983年   19篇
  1982年   19篇
  1981年   25篇
  1980年   36篇
  1979年   16篇
  1978年   11篇
  1977年   12篇
  1976年   12篇
  1975年   12篇
  1974年   7篇
排序方式: 共有9959条查询结果,搜索用时 15 毫秒
121.
122.
Inflammation persists in patients infected with HIV. Reduction of inflammatory cytokines and microbial translocation might be one way that this could be managed. Purpose: The anti-inflammatory properties of certain probiotic strains prompted us to investigate whether a probiotic could reduce the inflammatory index of HIV-infected patients. Methods: The study involved 30 HIV+ males on antiretroviral therapy, who were given one bottle of fermented milk Yakult Light® containing Lactobacillus casei Shirota (LcS) twice a day for four weeks. Results: The probiotic LcS was associated with an increase of T lymphocytes and a significant increase of CD56+ cells (p = 0.04). There was also a significant decrease of mRNA levels of TGFβ, IL-10 and IL-12 (p < 0.001) and IL-1β expression (p < 0.001) and an increase of serum IL-23 (p = 0.03). In addition, decreased inflammation and cardiovascular risk were observed, as shown by a reduction of cystatin C (p < 0.001). Conclusions: These data provide preliminary evidence that probiotic supplementation may modulate certain immunological parameters and some of the cytokines that were analyzed. Thus, we propose that LcS may be an inexpensive and practical strategy to support the immune function of HIV+ patients.  相似文献   
123.
The worldwide incidence of hepatocellular carcinoma (HCC) continues to rise and liver transplantation (LT) represents an established curative treatment for early stage disease. As a result of organ shortage, guidelines have restricted transplantation to HCC patients with an expected 5-year post transplantation survival greater than 70 %. The Milan criteria (MC) remain a reliable and noninvasive instrument for selecting patients with 5-year survival meeting this criteria. Since the adoption of the MC by United Network for Organ Sharing (UNOS), attempts have been made to expand MC to account for the projected increase in the incidence of HCC over the next 20 years. An area of active debate focuses on identifying a subgroup of patients outside of MC with similar or better outcomes through either new expanded criteria or identifying other prognostic factors to enhance MC.  相似文献   
124.
125.
BackgroundInfluenza is an important public health problem, with potential severe consequences among people with chronic diseases. The aim of this study was to obtain reliable measures of seasonal influenza vaccine uptake in this population, otherwise not available in Italy.MethodsProgressi delle Aziende Sanitarie per la Salute in Italia (PASSI) is a nationwide surveillance system of health-related behaviours and acceptance of preventive interventions (including influenza immunisation) offered by the Italian National Health Service. Data are collected with telephone interviews at local health unit level for supporting local activities. The survey sample is randomly selected from local health unit lists of adult residents. The trend of annual vaccine coverage since 2008 was estimated for people aged 18–64 years who reported having at least one chronic disease. To obtain a sufficient sample size in subgroups, we analysed the characteristics of vaccinated people in the 2010–13 cumulative dataset. Univariate, multivariate, and logistic regression analyses were undertaken.FindingsIn 2008–13, 13 659 individuals with at least one chronic disease were interviewed. Vaccination coverage fell significantly from 29·7% (95% CI 27·2–32·4) in 2007–08 to 19·9% (18·0–22·1) in 2012–13. During 2010–13, the overall proportion of vaccinated people with a chronic disease was 25·6% (24·5–26·7). Vaccine coverage of people with diabetes (34·3%, 31·7–36·9) or cardiovascular diseases (31·8%, 29·6–34·2) was greater than that of people affected by renal failure, respiratory diseases, tumours, or chronic liver diseases (26·5% [22·5–30·7], 24·9% [23·2–26·7], 22·2% [20·0–24·6], and 20·6% [17·5–24·6], respectively). Vaccination coverage increased with age (from 13·1% [11·0–15·5] in the 18–34 year age group to 33·4% [31·9–35·1] in people aged 50–64 years); it was higher among people with a low educational level than among those with a high educational level, higher in those having economic difficulties than in those with no economic difficulties, and higher among Italian citizens than among non-citizens.InterpretationIn the past few years, prevalence of influenza vaccination in Italian adults with at least one chronic disease was well below the Ministry of Health's goal (75% minimum) and showed a downward trend. A major reason of this evolution is probably the changing public perception of the benefits and risks of vaccines. PASSI is a source of useful data not otherwise available for public health intervention.FundingItalian Ministry of Health.  相似文献   
126.

Aim

To compare the value of Procalcitonin (PCT) as a marker of surgical site infection to other inflammatory markers, including C-Reactive Protein (CRP), White Cell Count (WCC) and Erythrocyte Sedimentation Rate (ESR) in patients undergoing a number of spinal procedures. This study also aims to describe the biokinetic profile of the above-named markers in patients developing surgical site infection and those remaining infection-free post-operatively.

Methods

200 patients undergoing four routine elective spinal procedures were included for analysis. All patients had blood specimens taken at baseline, day 1, 2, 3, 4 and 5 post-operatively for analysis of PCT, CRP, ESR and WCC levels. All patients were monitored for early surgical site infection. Patients with other sources of infection in the early postoperative period were excluded.

Results

Procalcitonin was the most sensitive and specific marker for the detection of surgical site infection in the immediate post-operative period with sensitivity and specificity of 100% and 95.2% respectively. Although Procalcitonin is an inflammatory marker, extent of surgical physiological insult did not alter its biokinetics as opposed to the other inflammatory markers making it a valuable marker of infection.

Conclusion

Procalcitonin was found to be superior to the other inflammatory markers investigated in this study as a marker for early surgical site infection in patients undergoing spinal surgery.  相似文献   
127.
The large surface area for gas exchange makes the respiratory system particularly susceptible to oxidative stress-mediated injury. Both endogenous and exogenous pro-oxidants (e.g. cigarette smoke) trigger activation of leukocytes and host defenses. These mechanisms interact in a “multilevel cycle” responsible for the control of the oxidant/antioxidant homeostasis. Several studies have demonstrated the presence of increased oxidative stress and decreased antioxidants (e.g. reduced glutathione [GSH]) in subjects with chronic obstructive pulmonary disease (COPD), but the contribution of oxidative stress to the pathophysiology of COPD is generally only minimally discussed. The aim of this review was to provide a comprehensive overview of the role of oxidative stress in the pathogenesis of respiratory diseases, particularly COPD, and to examine the available clinical and experimental evidence on the use of the antioxidant N-acetylcysteine (NAC), a precursor of GSH, as an adjunct to standard therapy for the treatment of COPD. The proposed concept of “multilevel cycle” helps understand the relationship between respiratory diseases and oxidative stress, thus clarifying the rationale for using NAC in COPD. Until recently, antioxidant drugs such as NAC have been regarded only as mucolytic agents. Nevertheless, several clinical trials indicate that NAC may reduce the rate of COPD exacerbations and improve small airways function. The most plausible explanation for the beneficial effects observed in patients with COPD treated with NAC lies in the mucolytic and antioxidant effects of this drug. Modulation of bronchial inflammation by NAC may further account for these favorable clinical results.  相似文献   
128.
129.
130.
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