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   835篇
  免费   57篇
  国内免费   10篇
耳鼻咽喉   7篇
儿科学   16篇
妇产科学   7篇
基础医学   126篇
口腔科学   11篇
临床医学   60篇
内科学   244篇
皮肤病学   6篇
神经病学   42篇
特种医学   17篇
外科学   124篇
综合类   22篇
预防医学   69篇
眼科学   3篇
药学   82篇
中国医学   5篇
肿瘤学   61篇
  2024年   3篇
  2023年   11篇
  2022年   25篇
  2021年   41篇
  2020年   24篇
  2019年   31篇
  2018年   35篇
  2017年   24篇
  2016年   31篇
  2015年   30篇
  2014年   28篇
  2013年   36篇
  2012年   61篇
  2011年   63篇
  2010年   51篇
  2009年   30篇
  2008年   43篇
  2007年   62篇
  2006年   41篇
  2005年   49篇
  2004年   40篇
  2003年   29篇
  2002年   27篇
  2001年   10篇
  2000年   11篇
  1999年   13篇
  1998年   10篇
  1997年   2篇
  1996年   7篇
  1995年   2篇
  1994年   5篇
  1993年   5篇
  1992年   3篇
  1991年   2篇
  1990年   4篇
  1989年   4篇
  1988年   2篇
  1987年   1篇
  1983年   2篇
  1978年   1篇
  1977年   1篇
  1974年   1篇
  1969年   1篇
排序方式: 共有902条查询结果,搜索用时 15 毫秒
91.

Aim

Ventricular arrhythmias (VAs) are the most common cause of death in patients with repaired Tetralogy of Fallot (rTOF). However, risk stratifying remains challenging. We examined outcomes following programmed ventricular stimulation (PVS) with or without subsequent ablation in patients with rTOF planned for pulmonary valve replacement (PVR).

Methods

We included all consecutive patients with rTOF referred to our institution from 2010 to 2018 aged ≥18 years for PVR. Right ventricular (RV) voltage maps were acquired and PVS was performed from two different sites at baseline, and if non-inducible under isoproterenol. Catheter and/or surgical ablation was performed when patients were inducible or when slow conduction was present in anatomical isthmuses (AIs). Postablation PVS was undertaken to guide implantable cardioverter-defibrillator (ICD) implantation.

Results

Seventy-seven patients (36.2 ± 14.3 years old, 71% male) were included. Eighteen were inducible. In 28 patients (17 inducible, 11 non-inducible but with slow conduction) ablation was performed. Five had catheter ablation, surgical cryoablation in 9, both techniques in 14. ICDs were implanted in five patients. During a follow-up of 74 ± 40 months, no sudden cardiac death occurred. Three patients experienced sustained VAs, all were inducible during the initial EP study. Two of them had an ICD (low ejection fraction for one and important risk factor for arrhythmia for the second). No VAs were reported in the non-inducible group (p < .001).

Conclusion

Preoperative EPS can help identifying patients with rTOF at risk for VAs, providing an opportunity for targeted ablation and may improve decision-making regarding ICD implantation.  相似文献   
92.
Thrombotic thrombocytopenic purpura (TTP) is a rare syndrome of unknown cause with an estimated incidence of one case per million. The disease is characterized by a pentad of symptoms: Thrombocytopenia, microangiopathic hemolytic anemia, neurologic changes, renal dysfunction, and fever. It causes thrombosis in the microvasculature of several organs, producing diverse manifestations. Acute pancreatitis (AP) is a well-described consequence of TTP. Acute pancreatitis triggering TTP is uncommon.  相似文献   
93.

OBJECTIVE

To examine uric acid (UA) as a possible predictor of the progression of coronary artery calcification (CAC) using data from the prospective Coronary Artery Calcification in Type 1 Diabetes (CACTI) Study.

RESEARCH DESIGN AND METHODS

CAC was measured by electron beam tomography at the baseline and at a follow-up 6.0 ± 0.5 years later. The study population included 443 participants with type 1 diabetes and 526 control subjects who were free of diagnosed coronary artery disease at baseline. The presence of renal disease was defined by the presence of albuminuria and/or low glomerular filtration rate.

RESULTS

In subjects without renal disease, serum UA predicted CAC progression (odds ratio 1.30 [95% CI 1.07–1.58], P = 0.007) independent of conventional cardiovascular risk factors including diabetes and the presence of metabolic syndrome.

CONCLUSIONS

Serum UA levels predict the progression of coronary atherosclerosis and may be useful in identifying who is at risk for vascular disease in the absence of significant chronic kidney disease.Elevated serum uric acid (UA) is associated with kidney disease, but it has also been linked to endothelial dysfunction and development of hypertension irrespective of renal involvement (1). UA may contribute to the atherosclerotic process through induction of endothelial dysfunction (2) and inflammation (3).Serum UA levels have been correlated with negative cardiovascular outcomes in the general population (4) and type 2 diabetic subjects (5) and predict the progression of diabetic nephropathy (6) in type 1 diabetic subjects. The objective of this study was to evaluate UA levels as a predictor of subclinical atherosclerosis progression in the Coronary Artery Calcification in Type 1 Diabetes (CACTI) Study.  相似文献   
94.
95.
Research has shown that brain regions mediating disgust (e.g., the insula) become activated when viewing others’ disgust, a response mediated, perhaps by the mirror neuron system or the Theory of Mind module. In a novel behavioral experiment, we explore vicarious disgust and relief, in individuals with obsessive–compulsive disorder (OCD) symptoms. Participants (N = 10) provided disgust ratings to self-contamination or watching the contamination of an experimenter; and to the experimenter washing his own hands after the subjects had been contaminated. To our surprise, we found that subjects experienced disgust from merely watching the experimenter contaminating himself. More intriguingly, after subjects had contaminated themselves, they obtained relief from merely watching the experimenter washing his own hands; even while recognizing the logical absurdity of this. The result is counterintuitive since neither the subjects nor anyone else would have predicted this. These preliminary findings – if confirmed in placebo-controlled studies – might pave the way toward novel therapeutic approaches for OCD.  相似文献   
96.
97.
Adolescent girls have high nutrient needs and are susceptible to micronutrient deficiencies. The objective of this study was to test the effect of a multiple-micronutrient-fortified beverage on hemoglobin (Hb) concentrations, micronutrient status, and growth among adolescent girls in rural Bangladesh. A total of 1125 girls (Hb > or = 70 g/L) enrolled in a randomized, double-blind, placebo-controlled trial and were allocated to either a fortified or nonfortified beverage of similar taste and appearance. The beverage was provided at schools 6 d/wk for 12 mo. Concentrations of Hb and serum ferritin (sFt), retinol, zinc, and C-reactive protein were measured in venous blood samples at baseline, 6 mo, and 12 mo. In addition, weight, height, and mid-upper arm circumference (MUAC) measurements were taken. The fortified beverage increased the Hb and sFt and retinol concentrations at 6 mo (P < 0.01). Adolescent girls in the nonfortified beverage group were more likely to suffer from anemia (Hb <120 g/L), iron deficiency (sFt <12 microg/L), and low serum retinol concentrations (serum retinol <0.70 micromol/L) (OR = 2.04, 5.38, and 5.47, respectively; P < 0.01). The fortified beverage group had greater increases in weight, MUAC, and BMI over 6 mo (P < 0.01). Consuming the beverage for an additional 6 mo did not further improve the Hb concentration, but the sFt level continued to increase (P = 0.01). The use of multiple-micronutrient-fortified beverage can contribute to the reduction of anemia and improvement of micronutrient status and growth in adolescent girls in rural Bangladesh.  相似文献   
98.
99.
Objective: Enterobacter cowanii is a genus of common gram-negative, facultatively anaerobic, rod-shaped, non-spore-forming bacterium of the Enterobacteriaceae family. This organism can be potentially a powdered infant milk formula-borne opportunistic pathogen. The aim of this study was to isolate and identify E. cowanii from consumed powdered infant formula milk (PIF) in intensive care units (NICU) and to determine antimicrobial susceptibility patterns of this bacterium. Methods: E. cowanii was isolated according to FDA method in 125 samples of PIF milk purchased from drug stores between Jun 2011 and March 2012. For final confirmation, biochemical tests embedded in API-20E system were used. The drug susceptibility test was performed using the disc diffusion method according to CLSI recommendations. Findings : Out of the 125 PIF samples investigated, 4 (3.2%) samples were positive for E. cowanii. All four isolates from PIF samples were uniformly susceptible to imipenem, meropenem, ceftazidime, ciprofloxacin, and colistin. Fifty percent of isolates were resistant to ampicillin, amoxicillin, and cotrimoxazole Conclusion: Analysis of the results indicated that complementary studies are necessary to clarify the possible role of E. cowanii as a food contaminant, in common NICU infections and high risk groups including persons with underlying disease and immunocompromised individuals.Key Words: Powdered Infant Formula Milk; Neonatal Intensive Care Unit; E. Cowanii; Antimicrobial Susceptibility  相似文献   
100.
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