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   4443篇
  免费   301篇
  国内免费   14篇
耳鼻咽喉   25篇
儿科学   98篇
妇产科学   53篇
基础医学   763篇
口腔科学   82篇
临床医学   437篇
内科学   762篇
皮肤病学   85篇
神经病学   784篇
特种医学   200篇
外科学   409篇
综合类   9篇
一般理论   3篇
预防医学   309篇
眼科学   55篇
药学   303篇
中国医学   6篇
肿瘤学   375篇
  2024年   8篇
  2023年   56篇
  2022年   93篇
  2021年   164篇
  2020年   110篇
  2019年   155篇
  2018年   150篇
  2017年   127篇
  2016年   151篇
  2015年   177篇
  2014年   226篇
  2013年   235篇
  2012年   420篇
  2011年   406篇
  2010年   232篇
  2009年   222篇
  2008年   328篇
  2007年   318篇
  2006年   284篇
  2005年   229篇
  2004年   204篇
  2003年   189篇
  2002年   138篇
  2001年   21篇
  2000年   19篇
  1999年   19篇
  1998年   23篇
  1997年   9篇
  1996年   12篇
  1995年   9篇
  1994年   5篇
  1993年   4篇
  1990年   1篇
  1989年   1篇
  1985年   2篇
  1982年   1篇
  1981年   1篇
  1980年   3篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1961年   1篇
排序方式: 共有4758条查询结果,搜索用时 15 毫秒
41.
ERCC1-XPF is a multifunctional endonuclease involved in nucleotide excision repair (NER), interstrand cross-link (ICL) repair, and DNA double-strand break (DSB) repair. Only two patients with bi-allelic ERCC1 mutations have been reported, both of whom had features of Cockayne syndrome and died in infancy. Here, we describe two siblings with bi-allelic ERCC1 mutations in their teenage years. Genomic sequencing identified a deletion and a missense variant (R156W) within ERCC1 that disrupts a salt bridge below the XPA-binding pocket. Patient-derived fibroblasts and knock-in epithelial cells carrying the R156W substitution show dramatically reduced protein levels of ERCC1 and XPF. Moreover, mutant ERCC1 weakly interacts with NER and ICL repair proteins, resulting in diminished recruitment to DNA damage. Consequently, patient cells show strongly reduced NER activity and increased chromosome breakage induced by DNA cross-linkers, while DSB repair was relatively normal. We report a new case of ERCC1 deficiency that severely affects NER and considerably impacts ICL repair, which together result in a unique phenotype combining short stature, photosensitivity, and progressive liver and kidney dysfunction.  相似文献   
42.
BackgroundThe prognosis for unilateral lateral medullary infarction (ULMI) is generally good but may be aggravated by respiratory failure with fatal outcome. Respiratory failure has been reported in patients with severe bulbar dysfunction and large rostral medullary lesions, but its associated factors have not been systematically studied. We aimed to assess clinical and radiological characteristics associated with respiratory failure in patients with pure acute ULMI.Materials and MethodsSeventy-one patients (median age 55 years, 59 males) with MRI-confirmed acute pure ULMI were studied retrospectively. Clinical characteristics were assessed and bulbar symptoms were scored using a scale developed for this study. MRI lesions were classified into 4 groups based on their vertical extent (localized/extensive) and the involvement of the open and/or closed medulla. Clinical characteristics, bulbar scores and MRI lesion characteristics were compared between patients with and without respiratory failure.ResultsRespiratory failure occurred in 8(11%) patients. All patients with respiratory failure were male (p = 0.336), had extensive lesions involving the open medulla (p = 0.061), progression of bulbar symptoms (p=0.002) and aspiration pneumonia (p < 0.001). Peak bulbar score (OR, 7.9 [95% CI, 2.3–160.0]; p < 0.001) and older age (OR, 1.2 [95%CI, 1.0-1.6]; p=0.006) were independently associated with respiratory failure.ConclusionsExtensive damage involving the open/rostral medulla, clinically presenting with severe bulbar dysfunction, in conjunction with factors such as aspiration pneumonia and older age appears to be crucial for the development of respiratory failure in pure ULMI. Further prospective studies are needed to identify other potential risk factors, pathophysiology, and effective preventive measures for respiratory failure in these patients.  相似文献   
43.
44.
45.
ABSTRACT

Background: Attachment Theory has become one of the leading theories in human development. Nonetheless, empirical studies focusing on how attachment unfolds during adolescence are still scarce particularly in Spain, due to the lack of adequate measures. Objective: This study aims to validate the Important People Interview (IPI) in a shorter questionnaire version (Important People- Questionnaire; IP-Q); to analyse the changes in different affiliative bonds to multiple figures -family, peers, romantic partners – over the course of adolescence; and to identify boys’ and girls’ hierarchical ordering of their specific attachment bonds. Method: 1025 Spanish adolescents, aged 12–17 years old completed the IP-Q. Results: The results showed that the IP-Q has convergent and divergent validity. Moreover, this measure indicated that peers overtake some family members in proximity-seeking and support-seeking, but not in the overall hierarchical ordering of the attachment bond during adolescence. Conclusions: The bond with the romantic partner increases in terms of scoring on the affiliative subscales as adolescence progresses. There are significant gender differences among the hierarchy patterns of attachment for boys and girls. Developmental changes in adolescent attachment are discussed.  相似文献   
46.
47.
48.
49.
50.
Die Diabetologie - Deutschland ist ein Einwanderungsland und 2019 hatte mehr als jede vierte hier lebende Person einen sog. Migrationshintergrund. Bei dieser statistisch definierten Gruppe handelt...  相似文献   
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