Text and Data Mining valid from 2018-12-01
Received: 11 April 2018
Accepted: 22 November 2018
First Online: 4 December 2018
Ethics approval and consent to participate
: The study was approved by the ethics committee of Peking Union Medical College Hospital, Chinese Academy of Medical Sciences. All participants provided written consent.
: Not applicable.
: The authors declare that they have no competing interests.
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