Text and Data Mining valid from 2018-11-14
Received: 19 December 2017
Accepted: 31 October 2018
First Online: 14 November 2018
Ethics approval and consent to participate
: This retrospective study was approved by the Ethics Review Committee at the Second Affiliated Hospital of Zhejiang University, with patient consent waived.
: Not applicable.
: The authors declare that they have no competing interests.
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