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   1547篇
  免费   130篇
  国内免费   17篇
耳鼻咽喉   11篇
儿科学   52篇
妇产科学   75篇
基础医学   239篇
口腔科学   35篇
临床医学   144篇
内科学   337篇
皮肤病学   35篇
神经病学   188篇
特种医学   45篇
外科学   177篇
综合类   1篇
一般理论   2篇
预防医学   77篇
眼科学   21篇
药学   103篇
中国医学   2篇
肿瘤学   150篇
  2024年   4篇
  2023年   39篇
  2022年   46篇
  2021年   87篇
  2020年   66篇
  2019年   76篇
  2018年   96篇
  2017年   52篇
  2016年   72篇
  2015年   71篇
  2014年   70篇
  2013年   78篇
  2012年   111篇
  2011年   123篇
  2010年   64篇
  2009年   50篇
  2008年   101篇
  2007年   66篇
  2006年   67篇
  2005年   69篇
  2004年   65篇
  2003年   38篇
  2002年   45篇
  2001年   15篇
  2000年   12篇
  1999年   7篇
  1998年   10篇
  1997年   5篇
  1996年   2篇
  1995年   3篇
  1994年   1篇
  1993年   2篇
  1992年   3篇
  1991年   8篇
  1990年   9篇
  1989年   10篇
  1988年   11篇
  1987年   8篇
  1986年   8篇
  1985年   3篇
  1984年   7篇
  1983年   1篇
  1982年   4篇
  1981年   3篇
  1979年   1篇
  1976年   2篇
  1974年   2篇
  1973年   1篇
排序方式: 共有1694条查询结果,搜索用时 390 毫秒
41.
Background and aimIn the context of the QuED Study we assessed whether a quality of care summary score was able to predict the development of cardiovascular (CV) events in patients with type 2 diabetes.Methods and resultsThe score was calculated using process and intermediate outcome indicators (HbA1c, blood pressure, low-density lipoprotein cholesterol, microalbuminuria) and ranged from 0 to 40. Overall, 3235 patients were enrolled, of whom 492 developed a CV event after a median follow-up of 5 years. The incidence rate (per 1000 person-years) of CV events was 62.4 in patients with a score ≤10, 54.8 in those with a score between 15 and 20, and 39.8 in those with a score >20. In adjusted multilevel regression models, the risk to develop a CV event was 89% greater in patients with a score of ≤10 (rate ratio [RR] = 1.89; 95% confidence interval [CI] 1.43–2.50) and 43% higher in those with a score between 10 and 20 (RR = 1.43; 95% CI 1.14–1.79), as compared to those with a score >20. A difference between centers of 5 points in the mean quality score was associated with a difference of 16% in CV event risk (RR = 0.84; 95% CI 0.72–0.98).ConclusionOur study documented for the first time a close relationship between a score of quality of diabetes care and long-term outcomes.  相似文献   
42.

Background

Clinical trials demonstrate significant benefit from cholesterol management for patients with type 2 diabetes. The aim of this work was to explore the correlates of lipid management in patients with type 2 diabetes, including the subjective beliefs of physicians, setting of care, and patient-related factors.

Methods

This longitudinal outcomes research study involved 2359 patients with type 2 diabetes recruited by 111 general practitioners and 214 physicians practicing in diabetes clinics. Physicians' beliefs were assessed through a questionnaire administered when the study started in 1998. Main outcome measures were total cholesterol (TC) and LDL cholesterol (LDL-C) levels over 3 years and the proportion of patients treated with lipid-lowering drugs (LLDs).

Results

Less than one-third of the physicians (27%) stated that they routinely started pharmacologic therapy for TC values ≥200 mg/dL (more aggressive), whereas 46% considered a TC level ≥240 mg/dL as the threshold for the initiation of treatment (less aggressive). During 3 years of observation, mean TC and LDL-C levels decreased from 215 ± 40 mg/dL to 203 ± 37 mg/dL and from 135 ± 36 mg/dL to 126 ± 35 mg/dL respectively, while the proportion of patients treated with LLDs increased from 13.2% to 24.6%; in particular, among individuals cared for by the more aggressive physicians, 30.0% were taking LLDs after 3 years, while only 17.7% of those followed by the less aggressive physicians and 18.1% of those followed by >1 physician were being treated with LLDs. Multilevel analysis showed that physicians' beliefs were an independent predictor of TC levels over the 3-year period. In patients treated with LLDs, TC levels decreased on average by 14%, and LDL-C levels decreased by 20%.

Conclusion

Our data show that physicians' beliefs in more aggressive management strategies will result in better mean TC values over a 3-year period.  相似文献   
43.
44.
45.
AIM:To evaluate whether the effectiveness of Granulomonocyto apheresis(GMA),a technique that consists of the extracorporeal removal of granulocytes and monocytes from the peripheral blood,might vary according to the severity of ulcerative colitis(UC)in patients with mild to moderate-severe disease UC activity.METHODS:We retrospectively reviewed prospectively collected data of patients undergoing GMA at our inflammatory bowel disease centre who had at least a 6 mo of follow-up.The demographics,clinical and laboratory data were extracted from the patients’charts and electronic records.The severity of UC was scored according to the Modified Truelove Witts Severity Index(MTWSI).A clinical response was defined as a decrease from baseline of≥2 points or a value of MTWSI≤2 points.RESULTS:A total of 41(24 males/17 females;meanage 47 years)patients were included in the study.After GMA cycle completion,21/28(75%)of mild UC patients showed a clinical response compared with 7/13(54%)of patients with moderate to severe disease(P=0.27).At 6-mo,14/28(50%)of the mild UC patients maintained a clinical response compared with 2/13(15%)of the patients with moderate to severe disease(P=0.04).After the GMA cycle completion and during the 6-mo follow up period,13/16(81%)and 9/16(56%)of mild UC patients with intolerance,resistance and contraindications to immunosuppressants and/or biologics showed a clinical response compared with 2/6(33%)and 0/6(0%)of patients with moderate to severe disease activity with these characteristics(P=0.05and P=0.04,respectively).CONCLUSION:Patients with mild UC benefit from GMA more than patients with moderate to severe disease in the short-term period.GMA should be considered a valid therapeutic option in cases of contraindications to immunosuppressants,corticosteroids and/or biologics.  相似文献   
46.
47.
Because other coronaviruses enter the cells by binding to dipeptidyl-peptidase-4 (DPP-4), it has been speculated that DPP-4 inhibitors (DPP-4is) may exert an activity against severe acute respiratory syndrome coronavirus 2. In the absence of clinical trial results, we analysed epidemiological data to support or discard such a hypothesis. We retrieved information on exposure to DPP-4is among patients with type 2 diabetes (T2D) hospitalized for COVID-19 at an outbreak hospital in Italy. As a reference, we retrieved information on exposure to DPP-4is among matched patients with T2D in the same region. Of 403 hospitalized COVID-19 patients, 85 had T2D. The rate of exposure to DPP-4is was similar between T2D patients with COVID-19 (10.6%) and 14 857 matched patients in the region (8.8%), or 793 matched patients in the local outpatient clinic (15.4%), 8284 matched patients hospitalized for other reasons (8.5%), and when comparing 71 patients hospitalized for COVID-19 pneumonia (11.3%) with 351 matched patients with pneumonia of another aetiology (10.3%). T2D patients with COVID-19 who were on DPP-4is had a similar disease outcome as those who were not. In summary, we found no evidence that DPP-4is might affect hospitalization for COVID-19.  相似文献   
48.
49.
People differ in their ability to perform novel perceptual tasks, both during initial exposure and in the rate of improvement with practice. It is also known that regions of the brain recruited by particular tasks change their activity during learning. Here we investigate neural signals predictive of individual variability in performance. We used resting-state functional MRI to assess functional connectivity before training on a novel visual discrimination task. Subsequent task performance was related to functional connectivity measures within portions of visual cortex and between visual cortex and prefrontal association areas. Our results indicate that individual differences in performing novel perceptual tasks can be related to individual differences in spontaneous cortical activity.  相似文献   
50.
The aim of this study was to assess exercise test results and efficacy of therapy with a β blocker (acebutolol) in ryanodine receptor type 2 (RyR2) mutation carriers with documented ventricular arrhythmias (VAs) and long-term follow-up. Twenty RyR2 mutation carriers belonging to 8 families and regularly followed at our center were analyzed using a study protocol involving electrocardiography, exercise tests off and on β-blocker therapy, 2-dimensional echocardiography, and signal-averaged electrocardiography. Off-therapy exercise testing triggered the onset of VAs at different heart rates (mean 132 ± 13 beats/min) with various patterns that worsened while exercising and disappeared immediately after stopping. The most severe VAs detected were nonsustained ventricular tachycardia in 35% and ventricular couplets in 35%. In the remaining subjects single ventricular premature beats were recorded. In 15% of patients single monomorphic ventricular premature beats were detected and identified to be linked to RyR2 mutations owing to the presence of sudden deaths of their family members and subsequent family screening. Acebutolol made the VAs disappear completely in 20% of subjects and decreased their complexity in 50%, whereas it did not change VAs appreciably in 30% of patients with less complex VAs. After 11 ± 8 years of follow-up 2 patients developed syncope. In conclusion, exercise testing was a fundamental tool for assessing the clinical phenotype and efficacy of therapy in RyR2 mutation carriers and therapy with acebutolol led in most subjects to a decreased complexity of the arrhythmic pattern or to complete suppression.  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