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   371篇
  免费   28篇
耳鼻咽喉   7篇
儿科学   6篇
妇产科学   6篇
基础医学   24篇
口腔科学   5篇
临床医学   28篇
内科学   168篇
皮肤病学   10篇
神经病学   3篇
特种医学   3篇
外科学   74篇
综合类   7篇
预防医学   15篇
眼科学   5篇
药学   20篇
中国医学   1篇
肿瘤学   17篇
  2023年   6篇
  2022年   9篇
  2021年   25篇
  2020年   12篇
  2019年   15篇
  2018年   27篇
  2017年   8篇
  2016年   9篇
  2015年   9篇
  2014年   21篇
  2013年   27篇
  2012年   28篇
  2011年   28篇
  2010年   15篇
  2009年   9篇
  2008年   12篇
  2007年   19篇
  2006年   23篇
  2005年   16篇
  2004年   14篇
  2003年   24篇
  2002年   8篇
  2001年   3篇
  2000年   7篇
  1999年   5篇
  1998年   1篇
  1996年   2篇
  1994年   1篇
  1992年   2篇
  1991年   1篇
  1989年   1篇
  1988年   5篇
  1987年   1篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1969年   1篇
排序方式: 共有399条查询结果,搜索用时 921 毫秒
1.
The dopamine transporter gene (DAT1) has been reported to be associated with attention-deficit hyperactivity disorder (ADHD) in a number of studies [Cook et al. (1995): Am J Human Genet 56(4):9993-998; Gill et al. (1997): Mol Psychiatry 2(4):311-313; Waldman et al. (1998): Am J Human Genet 63(6):1767-1776; Barr et al. (2001): Biol Psychiatry 49(4):333-339; Curran et al. (2001): Mol Psychiatry 6(4):425-428; Chen et al. (2003): Mol Psychiatry 8(4):393-396]. Specifically, the 10-repeat allele of the 40-bp variable number of tandem repeats (VNTR) polymorphism located in the 3' untranslated region (UTR) of the gene has been found to be associated with ADHD. There is evidence from in vitro studies indicating that variability in the repeat number, and sequence variation in the 3'-UTR of the DAT1 gene may influence the level of the dopamine transporter protein [Fuke et al. (2001): Pharmacogenomics J 1(2):152-156; Miller and Madras (2002): Mol Psychiatry 7(1):44-55]. In this study, we investigated whether DNA variation in the DAT1 3'UTR contributed to ADHD by genotyping DNA variants around the VNTR region in a sample of 178 ADHD families. These included a MspI polymorphism (rs27072), a DraI DNA change (T/C) reported to influence DAT1 expression levels, and a BstUI polymorphism (rs3863145) in addition to the VNTR. We also screened the VNTR region by direct resequencing to determine if there was sequence variation within the repeat units that could account for the association. Our results indicate that DAT1 is associated with ADHD in our sample but not with alleles of the VNTR polymorphism. We did not find any variation in the sequence for either the 10- or 9-repeat alleles in the probands screened nor did we observe the reported DraI (T/C) variation. Our results therefore refute the possibility of the reported DraI variation or alleles of the VNTR as the functional variants contributing to the disorder.  相似文献   
2.
Defects in structures or functions of mitochondria, mainly involving the oxidative phosphorylation, mitochondrial biogenesis and other metabolic pathways have been shown to be associated with a wide spectrum of clinical phenotypes. The ubiquitous nature of mitochondria and their unique genetic features contribute to the clinical, biochemical and genetic heterogenecity of mitochondrial diseases. This article focuses on the recent advances in the field of mitochondrial disorders with respect to the consequences for an advanced clinical and genetic diagnostics. In addition, an overview on recently identified genetic defects and their pathogenic molecular mechanisms are given.  相似文献   
3.
A middle aged woman presented to us with a localised well defined swelling of 3 months duration. It was located just below the lower eyelid punctum and was constantly discharging whitish granules. We suspected it to be arising from the lacrimal apparatus and posted the patient for Dacryocystectomy. On the operating table we found a swelling in the region of the lacrimal sac which was later excised. Histopathology revealed Botryomycosis and Chronic Dacryocystitis. Botryomycosis is a rare condition and requires a high index of suspicion to diagnose it. It is confirmed by histopathology and culture. Surgical debridement is the treatment of choice in such cases with an assessment of the immune status. Long term antibiotic treatment is required in all conditions as recurrence is common.  相似文献   
4.
Bulletin of Environmental Contamination and Toxicology - This study shows the effect of soil type and temperature on the adsorption and desorption behaviour of pendimethalin using a batch...  相似文献   
5.
6.
International Journal of Diabetes in Developing Countries -  相似文献   
7.
Paravalvular regurgitation (PVR) after transcatheter aortic valve replacement (TAVR) is one of the major complications with negative clinical prognosis. Therefore, its prediction is important for further improvement of the outcome. We present a case with TAVR, in which we successfully evaluated aortic valve calcification protruding inward and into the left ventricular outflow tract by real time three‐dimensional transesophageal echocardiography, and predicted significant PVR after the procedure. In conclusion, device landing zone calcification protruding inward is a key for the prediction of significant PVR after TAVR.  相似文献   
8.

Background

Damage to the cardiac conduction system requiring permanent pacemaker (PPM) implantation is a known adverse outcome of transcatheter aortic valve replacement (TAVR). A permanent-temporary pacemaker (PTPM) is a device that involves an active-fixation lead attached to an external pulse generator taped to the skin. We reviewed the utility of PTPMs as a temporary bridge measure after TAVR in patients with conduction abnormalities that do not meet conventional criteria for PPM placement.

Methods

Between January 01, 2013 and December 31, 2015, we analyzed 67 patients who received PTPM after TAVR. Baseline demographics, comorbidities, type and size of the valve, pre-TAVR electrocardiograms (ECGs), post-TAVR ECGs at 1 day, 1 month, and 6 months, and pacemaker interrogation results were reviewed for each patient if available.

Results

The mean age of patients was 80.5?±?9.1 years. PTPM were placed for 2.3?±?2.4 days. Among these patients, 44.8% (n?=?30) received a PPM prior to discharge. Male gender (OR 2.84, 95% CI 1.05–7.69, p?=?0.05) and an increase in QRS duration post-TAVR (p?=?0.01) were associated with PPM placement. Pacemaker interrogation data of 11 patients with PPM revealed that 27% (n?=?3) had <?1% V-pacing requirements and <?10% A-pacing requirements.

Conclusions

In post-TAVR patients who develop conduction abnormalities that do not meet conventional PPM implantation indications, PTPM safely provides a time period for further assessment and may prevent unnecessary PPM implantation. Male gender and an increase in QRS duration post-TAVR are associated with PPM implantation. Additionally, some patients may recover from their conduction disturbances and demonstrate low pacemaker utilization.
  相似文献   
9.
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - This is the first account of molecular and morphological characteristics of the stingless bee, Tetragonula...  相似文献   
10.
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