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   692篇
  免费   24篇
耳鼻咽喉   1篇
儿科学   18篇
妇产科学   12篇
基础医学   74篇
口腔科学   19篇
临床医学   109篇
内科学   168篇
皮肤病学   76篇
神经病学   30篇
外科学   48篇
预防医学   71篇
眼科学   2篇
药学   82篇
肿瘤学   6篇
  2022年   10篇
  2021年   5篇
  2017年   7篇
  2016年   13篇
  2015年   9篇
  2014年   13篇
  2013年   29篇
  2012年   9篇
  2011年   7篇
  2010年   32篇
  2009年   37篇
  2007年   11篇
  2006年   8篇
  2004年   3篇
  2003年   5篇
  2002年   5篇
  2001年   7篇
  2000年   11篇
  1999年   13篇
  1998年   32篇
  1997年   36篇
  1996年   59篇
  1995年   47篇
  1994年   21篇
  1993年   25篇
  1992年   24篇
  1991年   15篇
  1990年   18篇
  1989年   14篇
  1988年   18篇
  1987年   11篇
  1986年   10篇
  1985年   9篇
  1984年   11篇
  1983年   7篇
  1982年   15篇
  1981年   17篇
  1980年   6篇
  1979年   9篇
  1978年   6篇
  1976年   5篇
  1975年   3篇
  1974年   3篇
  1971年   7篇
  1969年   5篇
  1958年   4篇
  1957年   9篇
  1956年   5篇
  1955年   4篇
  1954年   4篇
排序方式: 共有716条查询结果,搜索用时 15 毫秒
701.
Indirect immunofluorescence(IIF) and double immunodiffusion (DID) were performed on the sera of 64 patients who had a nucleolar immunofluorescence pattern on HEp-2 cells. Forty-nine of the sera were from 296 patients with systemic scleroderma (SSc) and 15 sera were from 214 patients with systemic lupus erythematosus (SLE). A homogeneous nucleolar staining pattern was found in 45 of the 64 sera (70.3%), a clumpy fluorescence associated with fibrillarin antibody in 14 (21.8%) and a speckled pattern was found in five of the sera (7.8%). There was a clear correlation between the sera which showed a homogeneous nucleolar staining pattern with symptoms of the polymyositis/scleroderma overlap syndrome that differed from SSc with concomitant myositis. The clumpy pattern was mainly associated with diffuse scleroderma and the speckled pattern with limited scleroderma (previously called acrosclerosis).  相似文献   
702.
703.
704.
A 39-year-old female patient was referred for ablation of recurrent episodes of atrioventricular nodal reentrant tachycardia. A combination of an anomalous inferior vena cava with azygos continuation and a persistent left superior vena cava was discovered. A nonfluoroscopic navigation system was very useful for catheter ablation of the tachycardia in this unusual case of anomalous venous system of the heart.  相似文献   
705.
Background: Increase in adrenomedullin (ADM) plasma levels in congestive heart failure (HF) patients is due to many cardiac and systemic factors, particularly to greater fluid retention and to activation of sympathetic nervous system. Aim of this study was to assess the role of plasma ADM levels in HF patients treated by cardiac resynchronization therapy (CRT). Methods: 50 patients, mean age 70 years, 34 male, New York Heart Association (NYHA) Class III–IV HF, left ventricular ejection fraction (LVEF) < 35%, underwent CRT. All patients were in sinus rhythm and with complete left bundle branch block (QRS duration 138 ± 6 msec). A complete echoDoppler exam, blood samples for brain natriuretic peptide (BNP), and ADM were obtained from 2 to 7 days before implantation. Results: At 16 ± 6 months follow‐up, ≥1 NYHA Class improvement was observed in 38 patients. However, a >10% reduction in end‐systolic dimensions (ESD) was reported in 21 patients (Group I): ?16.6 ± 1.8%; in the remaining 29 patients ESD change was almost negligible: ?2.0 ± 1.03% (Group II), P < 0.0001. The two groups were comparable for age, sex, cause of LV dysfunction, therapy, QRS duration at baseline, preimplantation ESD, LVEF%, and BNP. Significantly higher pre implantation ADM levels were present in Group I than in Group II (27.2 ± 1.8 pmol/l vs 17.9 ± 1.4, P = 0.0003). Conclusions: Significantly higher ADM levels indicate a subgroup of patients in whom reverse remodeling can be observed after CRT. Patients with lower ADM basal values before CRT could represent a group in whom the dysfunction is so advanced that no improvement can be expected. (PACE 2010; 865–872)  相似文献   
706.
707.
Increases of pacing threshold stimulation are well documented with different antiarrhythmic drugs, but not with amiodarone. We report a case of a patient with dual‐chamber pacing, with stable thresholds on repeated measurements on the last year, who presented severe increase of atrial pacing threshold resulting in loss of atrial capture after a year of treatment with amiodarone. Thresholds were normalized once amiodarone was removed. Ventricular thresholds were not affected.  相似文献   
708.
After more than 30 years since the first magnetocardiographic (MCG) recording was carried out with induction coils, MCG is now approaching the threshold of clinical use. During the last 5 years, in fact, there has been a growing interest of clinicians in this new method which provides an unrivalled accuracy for noninvasive, three-dimensional localization of intracardiac source. An increasing number of laboratories are reporting data validating the use of MCG as an effective method for preoperative localization of arrhythmogenic substrates and for planning the best catheter ablation approach for different arrhythmogenic substrates. In this article, available data from literature have been reviewed. We consider the clinical use of MCG to localize arrhythmogenic substrates in patients with Wolff-Parkinson-White syndrome and in patients with ventricular tachycardia in order to assess the state-of-the-art of the method on a large number of patients. This article also addresses some suggestions for industrial development of more compact, medically oriented MCG equipments at reasonable cost.  相似文献   
709.
Background: Much information is available regarding the possible negative effects of long-term right ventricular (RV) apical pacing, which may cause worsening of heart failure. However, very limited data are available regarding the effects of RV pacing in patients with a previous myocardial infarction (MI).
Methods and Results: We screened 115 consecutive post-MI patients and matched a group of 29 pacemaker (PM) recipients with a group of 49 unpaced patients, for age, left ventricular (LV) ejection fraction, and site of MI. During a median follow-up of 54 months, echocardiograms showed a decrease in LV ejection fraction in the paced group, from 51 ± 10 to 39 ± 11 (P < 0.01), and a minimal change in the unpaced group, from 57 ± 8 to 56 ± 7 (P = 0.98). Similar change was observed in systolic and diastolic diameters and volumes.
Conclusions: The study showed that, in post-MI patients, RV apical pacing was associated with a worsening of LV function, suggesting that, among MI survivors, the need for a PM is a marker of worse outcome .  相似文献   
710.
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