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   770篇
  免费   65篇
  国内免费   5篇
耳鼻咽喉   12篇
儿科学   39篇
妇产科学   14篇
基础医学   59篇
口腔科学   22篇
临床医学   61篇
内科学   216篇
皮肤病学   11篇
神经病学   77篇
特种医学   35篇
外科学   144篇
综合类   36篇
预防医学   40篇
眼科学   5篇
药学   42篇
中国医学   2篇
肿瘤学   25篇
  2023年   15篇
  2022年   26篇
  2021年   55篇
  2020年   18篇
  2019年   24篇
  2018年   21篇
  2017年   16篇
  2016年   22篇
  2015年   22篇
  2014年   25篇
  2013年   45篇
  2012年   61篇
  2011年   54篇
  2010年   20篇
  2009年   31篇
  2008年   36篇
  2007年   47篇
  2006年   41篇
  2005年   48篇
  2004年   29篇
  2003年   27篇
  2002年   23篇
  2001年   9篇
  2000年   13篇
  1999年   10篇
  1998年   8篇
  1997年   3篇
  1996年   4篇
  1995年   3篇
  1994年   5篇
  1993年   2篇
  1992年   6篇
  1991年   5篇
  1990年   11篇
  1989年   6篇
  1988年   6篇
  1987年   4篇
  1986年   5篇
  1985年   3篇
  1984年   7篇
  1983年   3篇
  1982年   4篇
  1979年   3篇
  1977年   1篇
  1976年   3篇
  1975年   2篇
  1974年   1篇
  1971年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有840条查询结果,搜索用时 15 毫秒
1.
2.
BACKGROUND AND PURPOSE: Recently, endovascular techniques have gained significant therapeutic potential for both treatment and prevention of stroke. Cerebral angiography, which is an essential component of these procedures, has been used to provide morphological information regarding condition of blood vessels. In this study, we propose to determine the possibility of acquiring information regarding cerebral blood flow (CBF) in addition to morphologic information from data routinely available during angiography. METHODS: Digital subtraction angiography sequences were obtained for eight patients having occlusive disease in internal carotid artery (ICA) territories. Two regions-of-interest (ROIs) corresponding to the two brain hemispheres on AP view were delineated. For each image, the average pixel value within each ROI was calculated and used to generate time-density curves. Indices obtained from each curve were compared with each other and with the results obtained from the single photon emission computed tomography (SPECT) studies performed a pre- or postangiography procedure. RESULTS: Comparison between ICA stenosis and cerebral perfusion measurements revealed that cerebral perfusion deficit can be independent of arterial occlusive disease. The indices obtained from the time-density curves exhibit a correlating trend with the results from SPECT studies. However, lack of sufficient sample data prevented any meaningful statistical analysis to be conducted. CONCLUSIONS: We have developed a technique for utilizing the angiographic data for the important task of routinely and easily measuring CBF. Availability of CBF measurements during cerebral angiography may favorably impact upon the appropriate use of endovascular procedures and potentially contribute to the reduction of morbidity and mortality associated with stroke.  相似文献   
3.
Endovascular stent-supported angioplasty is a treatment option for atherosclerotic disease of the cervical internal carotid artery in high-risk patients. The traditional transfemoral approach is not suitable for patients who suffer from common femoral artery or abdominal aorta atheropathy. We report a case of carotid stent deployment using the radial route in a 68-year-old man with type B aortic dissection, having severe right internal carotid artery origin stenosis, presenting with ipsilateral retinal ischemic events. Technical aspects of carotid stenting via the radial approach are described and the related literature is discussed.  相似文献   
4.
Startle disease, or hyperekplexia, is characterized by an exaggeratedstartle reflex and neonatal hypertonla. An autosomal dominantform of the disorder Is associated with mutations In the samecodon of the 1 subunit of the inhibitory glycine receptor (GLRA1) resulting in the substitution of an uncharged amlno acidfor Arg271 in the mature protein. However, recessive transmissionIs seen in the mouse mutant spasmodic which resembles startledisease phenotypcially and is also associated with mutationsIn Glra 1. We have confirmed the finding of Arg271 mutationsIn individuals with startle disease in a UK family showing autosomaldominant transmission. In addition we describe an apparentlysporadic case, the offspring of a consanguineous mating, whoIs homozygous for a novel mutation (T1112A) in GLRA 1, whichresults In the substitution of asparagine for isoleucine atposition 244 of the mature protein. This suggests that humanstartle disease can display recessive as well as dominant inheritanceresulting from different mutations in GLRA 1.  相似文献   
5.
6.
BackgroundHyderabad, Pakistan, was the first city to witness an outbreak of extensively drug resistant (XDR) typhoid fever. The outbreak strain is resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporin, thus greatly limiting treatment options. However, despite over 5000 documented cases, information on mortality and morbidity has been limited.ObjectiveTo address the existing knowledge gap, this study aimed to assess the morbidity and mortality associated with XDR and non-XDR Salmonella serovar Typhi infections in Pakistan.MethodsWe reviewed the medical records of culture-confirmed typhoid cases in 5 hospitals in Hyderabad from October 1, 2016, to September 30, 2018. We recorded data on age, gender, onset of fever, physical examination, serological and microbiological test results, treatment before and during hospitalization, duration of hospitalization, complications, and deaths.ResultsA total of 1452 culture-confirmed typhoid cases, including 947 (66%) XDR typhoid cases and 505 (34%) non-XDR typhoid cases, were identified. Overall, ≥1 complications were reported in 360 (38%) patients with XDR typhoid and 89 (18%) patients with non-XDR typhoid (P<.001). Ileal perforation was the most commonly reported complication in both patients with XDR typhoid (n=210, 23%) and patients with non-XDR typhoid (n=71, 14%) (P<.001). Overall, mortality was documented among 17 (1.8%) patients with XDR S Typhi infections and 3 (0.6%) patients with non-XDR S Typhi infections (P=.06).ConclusionsAs this first XDR typhoid outbreak continues to spread, the increased duration of illness before hospitalization and increased rate of complications have important implications for clinical care and medical costs and heighten the importance of prevention and control measures.  相似文献   
7.
BACKGROUND: Standardised measures of behaviour have failed to detect short term improvement in children with autism following treatment with secretin. However, it is possible that standardised measures are insensitive to dimensions of child behaviour that are nonetheless detectable by parents. AIM: To determine the ability of parents of children with autism to guess, under double blind conditions, whether their child had received secretin or placebo. METHODS: 2x2 crossover randomised blinded study, comparing the effect of synthetic human secretin 2 U/kg to placebo (saline). Sixty two children with autism (aged 43-103 months) were randomly allocated to two groups: group 1 received placebo, followed six weeks later by secretin, and group 2 received secretin followed by placebo. At the conclusion of the study, parents were asked to guess their child's group assignment. RESULTS: Twenty seven families guessed their child's group assignment correctly and 27 guessed incorrectly. In 48 instances, parents based their guess on perceived improvement; in six cases, parents based their guess on perceived deterioration. Six families saw no difference after either infusion, and offered no guess. One family dropped out after the first infusion, and one family was lost to follow up after the second infusion. CONCLUSION: In a controlled setting, parents of young children with autism are unable to distinguish the short term behavioural effects of secretin from placebo.  相似文献   
8.
9.
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