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   907篇
  免费   46篇
  国内免费   10篇
耳鼻咽喉   1篇
儿科学   28篇
妇产科学   23篇
基础医学   69篇
口腔科学   15篇
临床医学   105篇
内科学   249篇
皮肤病学   12篇
神经病学   22篇
特种医学   115篇
外科学   76篇
综合类   30篇
预防医学   120篇
眼科学   4篇
药学   62篇
肿瘤学   32篇
  2019年   6篇
  2018年   16篇
  2017年   11篇
  2016年   5篇
  2015年   14篇
  2014年   15篇
  2013年   28篇
  2012年   21篇
  2011年   30篇
  2010年   36篇
  2009年   35篇
  2008年   28篇
  2007年   46篇
  2006年   47篇
  2005年   31篇
  2004年   39篇
  2003年   27篇
  2002年   31篇
  2001年   22篇
  2000年   20篇
  1999年   17篇
  1998年   31篇
  1997年   26篇
  1996年   40篇
  1995年   24篇
  1994年   19篇
  1993年   21篇
  1992年   13篇
  1991年   10篇
  1990年   18篇
  1989年   20篇
  1988年   29篇
  1987年   20篇
  1986年   23篇
  1985年   17篇
  1984年   17篇
  1983年   15篇
  1982年   12篇
  1981年   15篇
  1980年   9篇
  1979年   3篇
  1978年   8篇
  1977年   9篇
  1976年   8篇
  1975年   6篇
  1974年   3篇
  1973年   3篇
  1971年   4篇
  1970年   3篇
  1969年   2篇
排序方式: 共有963条查询结果,搜索用时 0 毫秒
71.
INTRODUCTION: Hereditary hemorrhagic teleangiectasia (HHT) is an autosomal dominant disorder with mucocutaneous teleangiectasia and visceral arteriovenous malformations. Mutations of endoglin and Activin A receptor like kinase-1 have different phenotypes, HHT1 and HHT2, respectively. The gastrointestinal tract is frequently affected, but limited information is available on the relationship with genotype. AIM: To determine whether different genotypes have different phenotypes with respect to intestinal teleangiectasia. METHODS: HHT patients, referred for anemia, underwent videocapsule endoscopy. Chart review was performed for information on genotype and HHT manifestations. RESULTS: Twenty-five patients were analyzed (men/women 13/9, mean age 49+/-15 years.), 14 HHT1, eight HHT2 and three without known mutation. Epistaxis occurred in 96% of patients. Gastroduodenoscopy revealed teleangiectasia in 7/12 (58%) HHT1 and 3/8 (38%) HHT2 patients. Videocapsule endoscopy found teleangiectasia in all HHT1 and 5/8 (63%) HHT2 patients. In 9/14 HHT1 patients, teleangiectasia were large. Teleangiectasia in the colon was restricted to 6/11 (55%) HHT1 patients. Hepatic arteriovenous malformations were present in 1/7 HHT1 and 5/6 HHT2 patients. CONCLUSION: Large teleangiectasia in small intestine and colon appear to occur predominantly in HHT1. Hepatic arteriovenous malformations are mainly found in HHT2. In HHT patients with unexplained anemia, videocapsule endoscopy should be considered to determine the size and extent of teleangiectasia and exclude other abnormalities.  相似文献   
72.
BACKGROUND: COX-2 inhibitors (COX-2i) have been reported to have beneficial effects on schizophrenia. This observational study assesses the association between exposure to COX-2i or/and NSAIDs and schizophrenia deterioration. METHODS: We conducted a case-control study within a cohort (n=3,485) of antipsychotic users with a schizophrenia diagnosis (ICD-9=295.x) in IMS-Lifelink, a US claims database. Case events indicating exacerbation of schizophrenia were: switching antipsychotic medication, starting combination therapy, using parenteral antipsychotics or an increasing dose. For each case one control was selected. Exposure to COX-2i/NSAIDs (current/recent/none) and cumulative exposure in Defined Daily Doses 90 days before the index/event date were assessed. Age, sex and co-medication were evaluated as confounders. Logistic regression analysis was used to assess the association. RESULTS: 1,443 case events occurred. For current use, no benefit on schizophrenia case events from exposure to COX-2i was found (adjusted OR 1.16; 95% CI 0.83-1.62). Instead, recent COX2i use with a duration of 0 to 93 days was associated with an increased risk for schizophrenia deterioration (adjusted OR 2.56; 95% CI 1.35-4.87). This association was strongest in rofecoxib. No relation was found for NSAIDs. CONCLUSION: The use of COX-2i was not associated with a decreased risk for schizophrenia deterioration in this population.  相似文献   
73.
74.

Background  

Mandatory vaccination has contributed to the success of immunisation programmes but voluntary vaccination allows people to be responsible for their own health. There are benefits from both policies and the arguments between them remain subject to debate within and without the scientific community, both nationally and internationally. The aim of this study is to assess the opinions of those who actually work in the Vaccination Service.  相似文献   
75.
76.
Since 2008, (pre)pandemic vaccines against H5N1 influenza have been available and pandemic vaccines against new influenza H1N1 are currently produced. In The Netherlands, the vaccination call for seasonal influenza among the recommended groups approximates 70%. These statistics raise the question if adults in Western societies are willing to get a (pre)pandemic influenza vaccination, for example, against avian H5N1 or swine-like H1N1 virus. A questionnaire was performed to determine the predictors of a negative intention to be immunized against pandemic influenza among adults. Demographical, behavioural and organisational determinants were studied. Thirty-four and five percent of the respondents were negatively intended to get a pandemic influenza vaccination in a pre-pandemic or pandemic phase, respectively. On the basis of six behavioural determinants negative intention to get a pandemic influenza vaccination can be predicted correctly in almost 80% of the target group. These determinants should be targeted in pandemic preparedness plans.  相似文献   
77.
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a respiratory disorder with increasing prevalence and mortality. It is associated with airway obstruction, increased airway hyper-responsiveness (AHR), and ongoing airway and lung inflammation dominated by CD8 lymphocytes and neutrophils. Single-nucleotide polymorphisms (SNPs) in a disintegrin and metalloprotease 33 (ADAM33) gene have been associated with AHR and COPD. OBJECTIVE: To assess whether SNPs in ADAM33 are associated with the severity of AHR and airway inflammation in COPD. METHODS: Eight SNPs in ADAM33 (F+1, Q-1, S_1, S_2, ST+5, T_1, T_2, V_4) were genotyped in 111 patients with COPD (96 males, 69 current smokers, mean (standard deviation (SD)), aged 62 (8) years, median pack-years 42 (IQR 31-55), mean postbronchodilator forced expiratory volume in 1 s (FEV(1))% predicted 63 (9). Provocative concentration of methacholine causing a decrease in FEV(1) of 20% (PC(20) methacholine), sputum and bronchial biopsies were collected. RESULTS: Patients with the ST+5 AA genotype had more severe AHR, higher numbers of sputum inflammatory cells and CD8 cells in bronchial biopsies than patients with the GG genotype (p = 0.03, 0.05 and 0.01, respectively). CD8 cell numbers were lower in patients carrying the minor allele of SNP T_1 and T_2, and homozygotic minor variants of SNP S_2 compared with the wild type (p = 0.02, 0.01 and 0.02, respectively). CONCLUSIONS: This is the first study revealing that SNPs in a gene that confers susceptibility to COPD in the general population-that is, ADAM33-are associated with AHR and airway inflammation in COPD. These findings constitute an important step forward in linking gene polymorphisms with COPD pathophysiology, thereby possibly contributing to better treatments for this progressive and disabling disease in the future.  相似文献   
78.
79.
80.
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