Text and Data Mining valid from 2018-11-14
Received: 26 December 2017
Accepted: 21 October 2018
First Online: 14 November 2018
Ethics approval and consent to participate
: This study was approved by the Institutional Research Board (IRB) of the First Hospital of Guangzhou Medical University (No: 2014013). Informed consent was obtained from each patient before enrolment.
: Not applicable.
: The authors declare that they have no competing interests.
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