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   5917篇
  免费   275篇
  国内免费   50篇
耳鼻咽喉   85篇
儿科学   117篇
妇产科学   58篇
基础医学   738篇
口腔科学   168篇
临床医学   376篇
内科学   1548篇
皮肤病学   75篇
神经病学   349篇
特种医学   228篇
外科学   1129篇
综合类   31篇
预防医学   144篇
眼科学   26篇
药学   442篇
中国医学   9篇
肿瘤学   719篇
  2023年   49篇
  2022年   110篇
  2021年   166篇
  2020年   56篇
  2019年   130篇
  2018年   121篇
  2017年   101篇
  2016年   132篇
  2015年   136篇
  2014年   203篇
  2013年   199篇
  2012年   298篇
  2011年   337篇
  2010年   189篇
  2009年   155篇
  2008年   270篇
  2007年   287篇
  2006年   303篇
  2005年   334篇
  2004年   350篇
  2003年   328篇
  2002年   351篇
  2001年   135篇
  2000年   134篇
  1999年   141篇
  1998年   81篇
  1997年   55篇
  1996年   62篇
  1995年   40篇
  1994年   44篇
  1993年   53篇
  1992年   83篇
  1991年   76篇
  1990年   66篇
  1989年   76篇
  1988年   76篇
  1987年   52篇
  1986年   51篇
  1985年   58篇
  1984年   40篇
  1983年   33篇
  1982年   19篇
  1981年   15篇
  1980年   20篇
  1979年   34篇
  1978年   15篇
  1975年   21篇
  1973年   21篇
  1971年   15篇
  1969年   20篇
排序方式: 共有6242条查询结果,搜索用时 0 毫秒
101.
102.
Beta-1-adrenergic receptor (beta1-AR) blockers reduce both the incidence of sudden death and the ventricular volume in heart failure. In vitro, the Gly389 variant of beta1-AR mediates less adenylyl cyclase activities than the Arg389 variant, so Arg389Gly polymorphism was investigated with regard to the genesis, progression, or arrhythmogenesis of dilated cardiomyopathy (DCM). Allele and genotype frequencies of the Arg389Gly polymorphism were determined in 163 DCM patients and 157 age- and sex-matched controls. There were no differences in genotype and allele frequencies between patients and controls. Echocardiograms, left ventriculograms and 24h-Holter electrocardiograms were evaluated in the DCM patients and none of the clinical indices, other than ventricular tachycardia (VT), differed among the 3 genotypes. The Gly389 allele was more frequent in the VT(-) group than in the VT(+) group (0.46 vs 0.24, p=0.001). In univariate analysis, the odds ratio for VT in patients carrying 1 or 2 copies of the Gly389 allele was 0.29 ([95% confidence interval, 0.13-0.64], p=0.002), when compared with the Arg389 homozygotes. The Gly389 variant supressed the occurrence of VT in DCM, suggesting that this allele confers a decreased risk of sudden death.  相似文献   
103.
From 1982 to 1986, 1230 sudden death cases were autopsied in Osaka Medical Examiner's Office. Among them, 810 cases were sudden cardiac deaths (SCD) including coronary heart disease (77%), cardiomyopathy (7%), valvular disease (3%). All SCD cases were dead within 24 hours of the appearance of the fatal symptoms, and most of them (72%) were considered instantaneous death. Many of the fatal symptoms began in bed (31%), at bath (17%), at toilet (8%), or at work (8%). Thirty-four percent of them were thought by themselves or by their families to be healthy before the death. Hypertension (38%), coronary heart disease (13%) and diabetes mellitus (11%) were the major past history recorded. Microscopic observation of the hearts of 200 cases autopsied in 1986 showed various cardiac lesions: hypertrophy, atrophy, degenerations of myocytes, cellular and fatty infiltrations of the interstitium. According to their cardiac lesions and degrees of severity of coronary sclerosis, patients who died suddenly were divided into 8 groups as follows: 1. myocardial infarction (41) 2. myocarditis (6) 3. hypertrophic cardiomyopathy (19) 4. chronic ischemia with severe coronary sclerosis (65) 5. chronic ischemia with moderate coronary sclerosis (27) 6. small vessel disease (18) 7. amyloidosis (1) 8. unknown (23). These results suggest that coronary heart disease and hypertension play an important role in SCD.  相似文献   
104.
Atrial fibrillation is the most frequently encountered sustained arrhythmia in clinical practice. Electrical cardioversion of atrial fibrillation using damped sine wave shocks has been a mainstay of therapy for nearly 4 decades; its limitation remains a failure rate that approaches 20%. Although several alternatives have been proposed, including delivering 720 J shocks using dual monophasic defibrillators, ibutilide pretreatment and internal cardioversion, each of these approaches has significant limitations, which preclude its routine use. Recent data demonstrate that routine use of biphasic shocks for cardioversion of atrial fibrillation is associated with a marked improvement in cardioversion efficacy and suggest that biphasic shocks may be the preferred method for the transthoracic electrical cardioversion of atrial fibrillation.  相似文献   
105.
European Journal of Clinical Microbiology & Infectious Diseases - The aim of this study is to clarify the characteristics of gram-negative bacteremia (GNB), including extended-spectrum...  相似文献   
106.
Oral Radiology - We report a rare case of schwannoma arising from the sublingual glandular branch of the lingual nerve radiologically masquerading as sublingual gland tumor. A 42-year-old female...  相似文献   
107.
108.
Bioartificial renal tubule devices (BTD) use cell therapy to improve conditions commonly observed in recipients of artificial kidneys for treatment of kidney diseases. We previously reported significant improvement of the condition of acute kidney injury (AKI) animals after treatment with BTD prepared with lifespan-extended human renal proximal tubular cells (hRPTEC). However, a major obstacle to use of BTD for patients is their biological safety, because hRPTEC are cultured in medium containing fetal calf serum. To establish the biological safety of BTD, we prepared BTD with lifespan-extended hRPTEC cultured in a newly developed serum-free medium and compared these with BTD prepared with hRPTEC cultured in serum-containing conventional medium. Lifespan-extended hRPTEC cultured in serum-free medium (hRPTEC-SFM) can proliferate similar to hRPTEC cultured in serum-containing conventional medium (hRPTEC-CM). Comparison of leakage and of reabsorption of small molecules for BTD prepared with hRPTEC-SFM (BTD-SFM) with those for our previous BTD prepared with hRPTEC-CM (BTD-CM) showed transportation in these two types of BTD was almost identical. When AKI goats were treated with BTD-SFM for 26 h, increase of survival time and reduction of cytokine expression in blood cells were almost same as for AKI goats treated with BTD-CM. Quantification of the expression of some genes of hRPTEC in BTD revealed significant changes during BTD treatment for AKI goats. In conclusion, lifespan-extended hRPTEC-SFM work as well as hRPTEC-CM, and the biological safety of BTD for patients could be elevated without loss of function by preparation from hRPTEC-SFM.  相似文献   
109.
Journal of Medical Ultrasonics - Ultrasound (US) is a cost-effective and noninvasive procedure without radiation exposure, with real-time evaluation and high spatial resolution. Although it is...  相似文献   
110.
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