Text and Data Mining valid from 2019-09-02
Received: 21 June 2019
Accepted: 9 August 2019
First Online: 2 September 2019
Ethics approval and consent to participate
: This study is a retrospective clinical study and has been approved by The First Hospital of Chongqing Medical University Ethics Committee. All patients had signed the consent form.
: Not applicable.
: The authors declare that they have no competing interests.