Text and Data Mining valid from 2020-03-17
Received: 12 September 2019
Accepted: 19 February 2020
First Online: 17 March 2020
Ethics approval and consent to participate
: The protocol and informed consent documents were approved by the ethics committee of the Third Affiliated Hospital, Sun Yat-sen University. All participants provided written, informed consent.
: Not applicable.
: The authors declare that they have no competing interests.