Received: 1 December 2019
Accepted: 5 December 2019
First Online: 18 December 2019
Ethics approval and consent to participate
: The Institutional Review Board of the First Affiliated Hospital of Chongqing Medical University approved the study. Informed consent was obtained from patients or their family members.
: All authors have reviewed and approved the manuscript for publication.
: The authors declare that they have no competing interests.