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   1316篇
  免费   92篇
  国内免费   7篇
耳鼻咽喉   6篇
儿科学   34篇
妇产科学   34篇
基础医学   242篇
口腔科学   36篇
临床医学   97篇
内科学   251篇
皮肤病学   16篇
神经病学   97篇
特种医学   49篇
外科学   143篇
综合类   23篇
一般理论   1篇
预防医学   87篇
眼科学   26篇
药学   161篇
中国医学   25篇
肿瘤学   87篇
  2023年   15篇
  2022年   11篇
  2021年   57篇
  2020年   45篇
  2019年   52篇
  2018年   63篇
  2017年   46篇
  2016年   64篇
  2015年   54篇
  2014年   67篇
  2013年   90篇
  2012年   138篇
  2011年   107篇
  2010年   64篇
  2009年   30篇
  2008年   75篇
  2007年   63篇
  2006年   68篇
  2005年   52篇
  2004年   40篇
  2003年   41篇
  2002年   39篇
  2001年   25篇
  2000年   17篇
  1999年   15篇
  1998年   8篇
  1997年   10篇
  1996年   5篇
  1995年   5篇
  1994年   3篇
  1993年   5篇
  1992年   9篇
  1991年   5篇
  1990年   4篇
  1989年   2篇
  1988年   4篇
  1987年   2篇
  1985年   1篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1978年   1篇
  1977年   1篇
  1975年   2篇
  1971年   2篇
  1970年   2篇
  1967年   2篇
排序方式: 共有1415条查询结果,搜索用时 15 毫秒
1.
Prior studies have conflicting findings regarding the association between gastroesophageal reflux disease (GERD) and esophageal squamous cell carcinoma (ESCC). We examined this relationship in a prospective cohort in a region of high ESCC incidence. Baseline exposure data were collected from 50 045 individuals using in-person interviews at the time of cohort entry. Participants were followed until they developed cancer, died, or were lost to follow up. Participants with GERD symptoms were categorized into any GERD (heartburn or regurgitation), mixed symptoms, or heartburn alone. Multivariable Cox regression was used to assess the relationship between GERD symptom group and histologically confirmed ESCC. The model was adjusted for known risk factors for GERD and ESCC. 49 559 individuals were included in this study, of which 9005 had GERD symptoms. Over 13.0 years of median follow up, 290 individuals were diagnosed with ESCC. We found no association between any GERD and risk of ESCC (aHR 0.90, 95% CI: 0.66-1.24, P = .54). Similar findings were observed for the GERD symptom subtypes. Significant interactions between any GERD and sex (P = .013) as well as tobacco smoking (P = .028) were observed. In post-hoc analyses, GERD was associated with a decreased risk of ESCC in men (aHR 0.51, 95% CI: 0.27-0.98 P = .04) and in smokers (aHR 0.26, 95% CI: 0.08-0.83 P = .02). While there was little evidence for an overall association between GERD symptoms and ESCC risk, significant interactions with sex and smoking were observed. Men and smokers with GERD symptoms had a lower risk of ESCC development.  相似文献   
2.
3.
Objective: The present study was performed to assess nutritional status and its relationship with clinical outcomes in elderly stroke patients.

Method: In this cross-sectional study, 253 stroke patients were studied. Mini Nutritional Assessment (MNA) was used to assign patients to three groups: malnourished, at risk of malnutrition, and well nourished. Northwestern Dysphagia Patient Check Sheet was administered to all patients. Anthropometric measures, including body mass index (BMI), calf circumferences (CC), mid-arm circumferences (MAC), and triceps skinfold thickness were brought out. In addition, National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS), and biochemical tests were performed.

Results: Of 253 patients, 34.4% were malnourished, 42.3% were at risk of malnutrition, and 23.3% were well nourished. The malnourished patients had significantly lower BMI, CC, and MAC (p?<?0.05). The levels of albumin and high-sensitivity C-reactive protein were significantly different among the groups (p?<?0.001). The admission and 3-month follow-up mRS scores, as well as dysphagia, were significantly higher in the malnourished patients and those at risk of malnutrition (p?<?0.001). In addition, mRS scores at admission and 3-month follow-up scores, as well as the length of hospital stay (LOS), were significantly correlated with MNA score, dysphagia, BMI, CC, MAC, albumin, and high-sensitivity C-reactive protein (p?<?0.05). Significant unadjusted associations were observed among MNA scores, BMI, CC, MAC, dysphagia scores, NIHSS scores, length of hospital stay (LOS), albumin, hs-C-reactive protein (hs-CRP), and erythrocyte sedimentation rate (ESR) with a poor outcome. With a multivariate logistic regression analysis, NIHSS scores and MNA scores remained significantly associated with the poor outcome in patients with ischemic stroke.

Conclusions: The findings of the present study underline the importance of nutritional status in elderly stroke patients.  相似文献   

4.
5.
Experimental autoimmune encephalomyelitis (EAE) is a mouse model for multiple sclerosis (MS), in which an inflammatory demyelination and axonal damage occurs. Kombucha tea is a fermented beverage made from kombucha mushroom, brewed tea, and sugar. In recent years kombucha tea has attracted interest due to its pharmacological properties like antioxidant effects. The aim of the present research was to test the therapeutic effect of kombucha tea in EAE. We induced EAE model in 18 female C57BL/6 mice by inoculation of myelin oligodendrocyte glycoprotein-35-55 (MOG35-55) in complete Freund’s adjuvant emulsion. Then, in order to ameliorate EAE symptoms, we used kombucha tea. During the course of study clinical evaluation was assessed, and on the day 21 post-immunization, for evaluation of nitric oxide (NO), total antioxidants capacity and tumor necrosis factor-alpha (TNF-α), blood samples were taken from the heart of mice. The mice were sacrificed and brains and cerebellums of mice were removed for histological analysis. Our findings demonstrated that kombucha tea had beneficial effects on EAE by lower incidence, attenuation in the severity, and also a delay in the onset of disease. Histological analysis showed that inflammatory criteria including the number of infiltrated immune cells and plaques as well as demyelination in kombucha tea dosed mice were significantly lower than the control group. Also, in comparison with control mice, the serum levels of NO and TNF-α in kombucha tea-treated mice were significantly decreased. Kombucha tea with its potential therapeutic effects and immunomodulatory properties might be proposed, after additional necessary tests and trials, for treatment of MS.  相似文献   
6.
7.
Ticagrelor is a cornerstone of modern antithrombotic therapy alongside aspirin in patients with acute coronary syndrome and after percutaneous coronary intervention. Adverse effects such as bleeding and dyspnea have been associated with premature ticagrelor discontinuation, which may limit any potential advantage of ticagrelor over clopidogrel. The randomized trials of ticagrelor captured adverse events, offering the opportunity to more precisely quantify these effects across studies. Therefore, a meta-analysis of 4 randomized clinical trials of ticagrelor conducted between January 2007 and June 2017 was performed to quantify the incidence and causes of premature ticagrelor discontinuation. Among 66,870 patients followed for a median 18 months, premature ticagrelor discontinuation was seen in 25%; bleeding was the most common cause of discontinuation followed by dyspnea. Versus the comparators, the relative risk of dyspnea-related discontinuation during follow-up was 6.4-fold higher, the relative risk of bleeding was 3.2-fold higher, and the relative risk of discontinuation due to any adverse event was 59% higher for patients receiving ticagrelor. Understanding these potential barriers to adherence to ticagrelor is crucial for informed patient-physician decision making and can inform future efforts to improve ticagrelor adherence. This review discusses the incidence, causes, and biological mechanisms of ticagrelor-related adverse effects and offers strategies to improve adherence to ticagrelor.  相似文献   
8.
Brucellosis is a world prevalent endemic illness that is transmitted from domestic animals to humans. Brucella spp. exploits urease for survival in the harsh conditions of stomach during the gastrointestinal infection. In this study, we examined the immune response and the protection elicited by using recombinant Brucella urease (rUrease) vaccination in BALB/c mice. The urease gene was cloned in pET28a and the resulting recombinant protein was employed as subunit vaccine. Recombinant protein was administered subcutaneously and intraperitoneally. Dosage reduction was observed with subcutaneous (SC) vaccination when compared with intraperitoneal (IP) vaccination. rUrease induced mixed Th1–Th2 immune responses with high titers of specific IgG1 and IgG2a. In lymphocyte proliferation assay, splenocytes from IP and SC‐vaccinated mice displayed a strong recall proliferative response with high amounts of IL‐4, IL‐12 and IFN‐γ production. Vaccinated mice were challenged with virulent Brucella melitensis, B. abortus and B. suis. The SC vaccination route exhibited a higher degree of protection than IP vaccination (p value ≤ 0.05). Altogether, our results indicated that rUrease could be a useful antigen candidate for the development of subunit vaccines against brucellosis.  相似文献   
9.
10.
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