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   397篇
  免费   17篇
妇产科学   5篇
基础医学   18篇
口腔科学   3篇
临床医学   43篇
内科学   280篇
神经病学   19篇
特种医学   3篇
外科学   18篇
综合类   12篇
预防医学   2篇
眼科学   3篇
药学   8篇
  2021年   3篇
  2020年   3篇
  2019年   6篇
  2018年   8篇
  2017年   5篇
  2016年   4篇
  2015年   2篇
  2014年   14篇
  2013年   13篇
  2012年   19篇
  2011年   21篇
  2010年   16篇
  2009年   7篇
  2008年   17篇
  2007年   26篇
  2006年   30篇
  2005年   24篇
  2004年   22篇
  2003年   20篇
  2002年   19篇
  2001年   12篇
  2000年   16篇
  1999年   10篇
  1998年   3篇
  1997年   3篇
  1996年   2篇
  1995年   2篇
  1993年   2篇
  1992年   7篇
  1991年   7篇
  1989年   3篇
  1988年   10篇
  1987年   5篇
  1986年   4篇
  1985年   5篇
  1984年   1篇
  1983年   2篇
  1982年   2篇
  1981年   6篇
  1980年   5篇
  1978年   5篇
  1977年   4篇
  1976年   7篇
  1975年   4篇
  1973年   4篇
  1968年   1篇
  1966年   2篇
  1965年   1篇
排序方式: 共有414条查询结果,搜索用时 46 毫秒
1.
E Lindmark  E Diderholm  L Wallentin  A Siegbahn 《JAMA》2001,286(17):2107-2113
CONTEXT: Inflammatory activity is associated with high rates of long-term mortality in unstable coronary artery disease (CAD). Interleukin 6 (IL-6) induces C-reactive protein and fibrinogen, systemic markers of inflammation. OBJECTIVES: To determine whether plasma levels of IL-6 are predictive of mortality and to evaluate the interaction of IL-6 levels with the effects of invasive vs noninvasive treatment strategies in unstable CAD patients. DESIGN, SETTING, AND PATIENTS: The prospective, randomized Fragmin and Fast Revascularisation During Instability in Coronary Artery Disease II trial, conducted among 3489 patients, 3269 of whom had plasma samples analyzed for IL-6 levels, with diagnosed unstable CAD (67% male; median age, 67 years) at 58 Scandinavian hospitals between June 1996 and August 1998. INTERVENTIONS: Patients were randomly assigned to receive either an early invasive (n = 1222) or a noninvasive treatment strategy (n = 1235). The latter group, as well as 666 patients with contraindications to invasive therapy, were further randomized to 90-day treatment with low-molecular-weight heparin (dalteparin, 5000-7500 IU twice per day; n = 1140) or placebo (n = 1127). MAIN OUTCOME MEASURE: Mortality at 6 and 12 months in the medically and interventionally randomized cohorts, respectively, in relation to IL-6 levels, measured at randomization. RESULTS: Plasma levels of IL-6 that were at least 5 ng/L compared with levels lower than 5 ng/L were associated with greatly increased mortality in the noninvasive group (7.9% vs 2.3%; relative risk [RR], 3.47; 95% confidence interval [CI], 1.94-6.21) and in the placebo-treated group (7.9% vs 2.5%; RR, 3.19; 95% CI, 1.77-5.74). The association remained significant after adjustment for most established risk indicators. An early invasive treatment strategy strongly reduced 12-month mortality among those with elevated IL-6 levels (5.1% absolute reduction; P =.004) whereas mortality was not reduced among patients without elevated IL-6 concentrations. Those taking dalteparin with elevated IL-6 levels experienced lower 6-month mortality than those who did not take dalteparin (3.5% absolute reduction; P =.08). CONCLUSIONS: Circulating IL-6 is a strong independent marker of increased mortality in unstable CAD and identifies patients who benefit most from a strategy of early invasive management.  相似文献   
2.
The additional value of thallium-201 SPECT to a conventional exercise test for the identification of patients with severe coronary lesions was evaluated in 170 men, one month after an episode of unstable coronary artery disease. Severe coronary lesions at coronary angiography — defined as three vessel disease, left main stenosis or proximal left anterior descending artery stenosis as part of two vessel disease — were observed in 45.9%. In the SPECT image, the left ventricular myocardium was divided into nine segments and each segment was classified as either normal (=0), reduced uptake (=1) or uptake defect (=2). The sum of gradings in all segments post-exercise was denoted SPECT score. The patients were divided into nine different groups regarding ST-depression during exercise (no ST-depression, ST-depression in 1–2 leads or 3 leads) and SPECT score (no SPECT score, 1–3 scores or 4 scores). Severe coronary lesions were, in 68% identified by SPECT score 4 and in 65% by ST-depression in 1 lead at exercise test. The specificity for identification of severe coronary lesions was, for both tests, 65%. SPECT score 4 and/or ST-depression in 3 leads identified 82% of the patients with severe coronary lesions with a specificity of 63%. Furthermore, SPECT score 3 identified more patients with isolated proximal left anterior descending artery stenosis than ST-depression alone at exercise test.  相似文献   
3.
Natriuretic peptides in unstable coronary artery disease.   总被引:1,自引:0,他引:1  
Patients with unstable coronary artery disease (CAD), i.e., unstable angina or non-ST-elevation myocardial infarction, vary widely in clinical presentation, prognosis and response to treatment. To select appropriate therapy, early risk stratification has become increasingly important. This review focuses on the emerging role of natriuretic peptides in the early assessment of patients with unstable CAD. We conclude that levels of brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are strongly associated to mortality and the risk of future congestive heart failure, and carry important prognostic information independent from previously known risk factors in unstable CAD. There are some data indicating that these markers can also be helpful in the selection of appropriate therapy in these patients but further studies are needed. Before a routine use of BNP or NT-proBNP in unstable CAD can be recommended, the cost-effectiveness of adding these new markers to the currently routine markers and their impact on selection of treatment needs further evaluation.  相似文献   
4.
Purpose

Describe CYP2C19 sequencing results in the largest series of clopidogrel-treated cases with stent thrombosis (ST), the closest clinical phenotype to clopidogrel resistance. Evaluate the impact of CYP2C19 genetic variation detected by next-generation sequencing (NGS) with comprehensive annotation and functional studies.

Methods

Seventy ST cases on clopidogrel identified from the PLATO trial (n =?58) and Mayo Clinic biorepository (n =?12) were matched 1:1 with controls for age, race, sex, diabetes mellitus, presentation, and stent type. NGS was performed to cover the entire CYP2C19 gene. Assessment of exonic variants involved measuring in vitro protein expression levels. Intronic variants were evaluated for potential splicing motif variations.

Results

Poor metabolizers (n =?4) and rare CYP2C19*8, CYP2C19*15, and CYP2C19*11 alleles were identified only in ST cases. CYP2C19*17 heterozygote carriers were observed more frequently in cases (n =?29) than controls (n =?18). Functional studies of CYP2C19 exonic variants (n =?11) revealed 3 cases and only 1 control carrying a deleterious variant as determined by in vitro protein expression studies. Greater intronic variation unique to ST cases (n =?169) compared with controls (n =?84) was observed with predictions revealing 13 allele candidates that may lead to a potential disruption of splicing and a loss-of-function effect of CYP2C19 in ST cases.

Conclusion

NGS detected CYP2C19 poor metabolizers and paradoxically greater number of so-called rapid metabolizers in ST cases. Rare deleterious exonic variation occurs in 4%, and potentially disruptive intronic alleles occur in 16% of ST cases. Additional studies are required to evaluate the role of these variants in platelet aggregation and clopidogrel metabolism.

  相似文献   
5.
6.
AIMS: To demonstrate the feasibility and clinical utility of developing dynamic risk assessment models for ST-segment elevation myocardial infarction (STEMI) patients. METHODS AND RESULTS: In 6066 STEMI patients enrolled in the Assessment of the Safety and Efficacy of a New Thrombolytic-3 (ASSENT-3) trial with complete electrocardiographic data, we assessed the probability of 30-day mortality over the following forecasting periods beginning at day 0 (baseline), 3 h, day 2, and day 5 using multiple-logistic regression. These models were validated and simplified in independent samples of 1622 similar fibrinolytic-treated patients from the ASSENT-3 PLUS trial and in 814 STEMI patients undergoing primary percutaneous coronary intervention in the COMplement inhibition in Myocardial infarction treated with Angioplasty (COMMA) trial. The discriminatory power of these predictive models, from baseline to day 5, was excellent (c-statistics 0.80 to 0.87); and their predictive ability was supported by strong gradients in mortality outcomes as the risk score increased. Dynamic modelling also provided information on the change in prognosis over time which may be used to advise more appropriate therapeutic decisions, e.g. the identification of high-risk patients for possible co-interventions. CONCLUSION: Dynamic modelling for STEMI patients enhances the risk assessment and stratification and should provide valuable ongoing guidance for their management.  相似文献   
7.
8.
A patient underwent mitral valve replacement in 1966 for severe mitral valve disease. The initial clinical result was excellent but symptoms recurred nine years later, and since 1969 he has had progressive cardiac enlargement. At present he is in functional class II and has massive cardiomegaly with gross enlargement of the left atrium, right ventricle, and right atrium. Cardiac catherisation showed "normal" prosthetic valve function, but on moderate exercise he developed severe left atrial and pulmonary arterial hypertension. His clinical course illustrates a long-term sequela of "valve prosthesis--patient mismatch".  相似文献   
9.
AIMS: No antithrombotic therapy has been shown to reduce mortality when used with thrombolytics in acute myocardial infarction (AMI). In the OASIS-6 trial, fondaparinux significantly reduced mortality and reinfarction without increasing bleeding in 12 092 patients with acute ST elevation MI. METHODS AND RESULTS: We report the results of a subgroup analysis in the 5436 patients (45%) receiving thrombolytics. According to local practice, 4415 patients did not have an indication for unfractionated heparin (stratum 1) and 1021 did (stratum 2). Fondaparinux reduced the primary study outcome of death or MI at 30 days [Hazard ratio (HR) 0.79, 95% confidence interval (CI) 0.68-0.92] with consistent reductions in both mortality (HR and CI) and reinfarction (HR and CI). There was a non-significantly lower rate of stroke (HR 0.77, CI 0.48-1.25). The risk of severe bleeding was significantly reduced (HR 0.62, CI 0.40-0.94), and thus the balance of benefit and risk (death, MI and severe haemorrhage) was clearly reduced by fondaparinux (HR 0.77, 95% CI 0.67-0.90). Results were consistent in the two strata, by the different types of thrombolytics and across various time intervals from symptom onset to treatment. CONCLUSION: In STEMI patients treated with thrombolytic agents (predominantly streptokinase), fondaparinux significantly reduced the risk of death, re-MI and severe bleeds.  相似文献   
10.
AIMS: To better delineate the characteristics, treatments, and outcomes of patients with acute coronary syndromes (ACS) in representative countries across Europe and the Mediterranean basin, and to examine adherence to current guidelines. METHODS AND RESULTS: We performed a prospective survey (103 hospitals, 25 countries) of 10484 patients with a discharge diagnosis of acute coronary syndromes. The initial diagnosis was ST elevation ACS in 42.3%, non-ST elevation ACS in 51.2%, and undetermined electrocardiogram ACS in 6.5%. The discharge diagnosis was Q wave myocardial infarction in 32.8%, non-Q wave myocardial infarction in 25.3%, and unstable angina in 41.9%. The use of aspirin, beta-blockers, angiotensin converting enzyme inhibitors, and heparins for patients with ST elevation ACS were 93.0%, 77.8%, 62.1%, and 86.8%, respectively, with corresponding rates of 88.5%, 76.6%, 55.8%, and 83.9% for non-ST elevation ACS patients. Coronary angiography, percutaneous coronary interventions, and coronary bypass surgery were performed in 56.3%, 40.4%, and 3.4% of ST elevation ACS patients, respectively, with corresponding rates of 52.0%, 25.4%, and 5.4% for non-ST elevation ACS patients. Among patients with ST elevation ACS, 55.8% received reperfusion treatment; 35.1% fibrinolytic therapy and 20.7% primary percutaneous coronary interventions. The in-hospital mortality of patients with ST elevation ACS was 7.0%, for non-ST elevation ACS 2.4%, and for undetermined electrocardiogram ACS 11.8%. At 30 days, mortality was 8.4%, 3.5%, and 13.3%, respectively. CONCLUSIONS: This survey demonstrates the discordance between existing guidelines for ACS and current practice across a broad region in Europe and the Mediterranean basin and more extensively reflects the outcomes of ACS in real practice in this region.  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