title: [A bibliometric investigation to research fronts of major sub-specialties in internal medicine].
abstract: OBJECTIVE
  To outline the research fronts of ten major sub-specialties in internal medicine.
  
  
  METHODS
  Based on their impact factor scores and the proportion of the journals of 10 subspecialties (endocrinology & metabolism, cardiac & cardiovascular systems, hematology, infectious diseases, nephrology, gastroenterology & hepatology, respiratory system, rheumatology, critical care medicine, clinical neurology) in Journal Citation Report (JCR), and careful consulation of expert clinicians, we identified 50 journals. Their bibliographic records (including references) published in 2011 were downloaded, and the frequency of the references (citations) in each sub-specialty was counted and the highly cited records were extracted. We performed a clustering analysis according to the co-cited times among any pairs of the highly cited records. To tag each cluster of highly cited records, we browsed the titles and abstracts of all highly cited records in the same cluster, and concluded the main topics of each cluster. Finally, we extracted the current published papers devoted to particular cluster by some clustering analysis indicators. The clusters of highly cited records were considered as the intelligence base, and the main topics in current papers which citing these highly cited papers were considered as research fronts.
  
  
  RESULTS
  Totally 50 journals on 10 sub-specialties in internal medicine were identified. A total of 202 highly cited papers, 38 clusters (knowledge bases) , and 152 corresponding current citing papers presenting the research fronts were selected.
  
  
  CONCLUSIONS
  We confirm and present research fronts in 10 major sub-specialties of internal medicine. This study provides a synchronic structure of contemporary research activities in internal medicine sub-specialties.
authors: Department of Medical Informatics, China Medical University, Shenyang 110001, China. lcui@mail.cmu.edu.cn
authors: Lei
authors: L
authors: Cui
authors: Xi-Bin
authors: XB
authors: Shen
authors: Li
authors: L
authors: Fang
authors: Xian-Wei
authors: XW
authors: Pan
authors: Xiu-Mei
authors: XM
authors: Zhong
authors: Xue
authors: X
authors: Gong
authors: Ying
authors: Y
authors: Yang
mesh_terms: D015706:Bibliometrics; D007388:Internal Medicine; D055811:Journal Impact Factor