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   773篇
  免费   43篇
  国内免费   8篇
耳鼻咽喉   1篇
儿科学   50篇
妇产科学   20篇
基础医学   87篇
口腔科学   22篇
临床医学   73篇
内科学   164篇
皮肤病学   9篇
神经病学   37篇
特种医学   82篇
外科学   90篇
综合类   65篇
预防医学   44篇
眼科学   12篇
药学   37篇
中国医学   1篇
肿瘤学   30篇
  2023年   4篇
  2022年   7篇
  2021年   12篇
  2020年   8篇
  2019年   6篇
  2018年   13篇
  2017年   5篇
  2016年   12篇
  2015年   22篇
  2014年   17篇
  2013年   25篇
  2012年   25篇
  2011年   22篇
  2010年   30篇
  2009年   46篇
  2008年   24篇
  2007年   31篇
  2006年   45篇
  2005年   17篇
  2004年   22篇
  2003年   16篇
  2002年   18篇
  2001年   16篇
  2000年   23篇
  1999年   22篇
  1998年   47篇
  1997年   38篇
  1996年   44篇
  1995年   20篇
  1994年   20篇
  1993年   23篇
  1992年   12篇
  1991年   10篇
  1990年   5篇
  1989年   10篇
  1988年   27篇
  1987年   10篇
  1986年   9篇
  1985年   17篇
  1984年   8篇
  1983年   4篇
  1982年   3篇
  1981年   4篇
  1980年   3篇
  1977年   3篇
  1976年   5篇
  1975年   4篇
  1974年   3篇
  1967年   2篇
  1909年   1篇
排序方式: 共有824条查询结果,搜索用时 0 毫秒
101.
BackgroundMinority blood donation, especially from individuals of African ethnicity, is a focus for many countries with diverse populations. As the need for antigen-negative RBC transfusions for patients with Sickle Cell Disease (SCD) continues to grow, inclusion of more African blood donors is essential to ensure this demand is met.Materials and methodsThis study aims to explore barriers and motivators to blood donation and awareness of SCD among potential donors of diverse ethnic backgrounds in Ireland. Following ethical approval, patients attending the National Sickle Cell Disease and Thalassemia service at St James’s Hospital were invited to share an online anonymous survey within their local communities to achieve snowball-sampling.Results387 respondents completed the survey, including 311 non-donors (median age 25 years, 67% female). Ethnic backgrounds included: African or African-Irish (59%), White or Caucasian (25%), Asian (8%), Hispanic or Latino (3%), Middle Eastern (3%), Multiracial or Biracial (2%). The most commonly identified barrier overall was lack of information on blood donation. African respondents were significantly more likely to report lack of information and malaria-related barriers than Caucasians. Motivators also varied across ethnic groups, with African respondents more likely to donate to help someone within their own community or for religious motivators. Awareness of SCD was higher among African respondents.DiscussionWhile some barriers to blood donation are shared across all ethnic groups including lack of information, notable differences exist between Caucasian and African respondents. Specific actions to recruit and retain African blood donors should focus on these key areas.  相似文献   
102.
103.
104.
Holocarboxylase synthetase (HCS) catalyses the biotinylation of the four biotin-dependent carboxylases found in humans. A deficiency in HCS results in biotin-responsive multiple carboxylase deficiency (MCD). We have identified six different point mutations in the HCS gene in nine patients with MCD. Two of the mutations are frequent among the MCD patients analyzed. Four of the mutations cluster in the putative biotin- binding domain as deduced from the corresponding Escherichia coli enzyme and consistent with an explanation for biotin-responsiveness based on altered affinity for biotin. The two others may define an additional domain involved in biotin-binding or biotin-mediated stabilization of the protein.   相似文献   
105.
106.
107.
108.
In a retrospective study of proved pseudoaneurysms (PAs) in 15 patients with transplanted organs (11 liver, three kidney, one pancreas), the results of computed tomography (CT), duplex sonography, and angiography were reviewed. Of the 15 cases of PA, eight occurred at the arterial anastomosis and seven were nonanastomotic. Three of the eight anastomotic PAs were caused by infection. Of the seven nonanastomotic PAs, four were caused by percutaneous biopsy, two were caused by infection, and one was of undetermined cause. In nine (60%) of the 15 patients the PAs were incidentally detected at imaging studies performed for other reasons. Diagnosis requires a high degree of suspicion. CT was performed in nine cases and duplex sonography in ten. The diagnosis of PA was made with CT in six (67%) patients and with duplex sonography in five (50%). CT and duplex sonography could not enable diagnosis when the PA was small, when the arterial anastomosis was not included in the field of study, or when enhancement with intravenously administered contract material was suboptimal. Angiography depicted the PAs in all 15 patients. In three liver transplant recipients with gastrointestinal tract bleeding, the causative PAs were detected only with angiography.  相似文献   
109.
OBJECTIVE: To assess the reported association between field trisomy 13 and maternal pre-eclampsia. DESIGN: A retrospective case-control study. SUBJECTS: Twenty-five women who gave birth to trisomy 13 infants in southwest England between 1971 and 1989; 38 women who gave birth to trisomy 18 infants in the same region over the same time and 50 women with normal karyotype infants matched for age, parity, and date of delivery with the trisomy 13 group. MAIN OUTCOME MEASURES: The medical records of all the women in the three groups were analysed for evidence of pre-eclampsia. Four different thresholds of pre-eclampsia were used. The incidence of pre-eclampsia was compared between the three study groups and analysed separately for primigravid and multigravid women. RESULTS: The incidence of pre-eclampsia in pregnancies complicated by trisomy 13 was significantly higher than the incidence in the trisomy 18 and the normal karyotype control groups. This association was more pronounced in primigravid pregnancies. CONCLUSIONS: This, the largest survey of trisomy 13 and pre-eclampsia to date, suggests an association between the two conditions. It also supports the argument for a fetal factor in the pathogenesis of pre-eclampsia. We speculate on how genes encoded on chromosome 13 may be responsible.  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