Received: 27 December 2018
Accepted: 30 August 2019
First Online: 5 September 2019
Ethics approval and consent to participate
: Our investigation was carried out according to the Declaration of Helsinki. The study accords with the ethics of the Second Affiliated Hospital of Chongqing Medical University. Written informed consent was obtained from all patients.
: Not applicable.
: The authors declare that they have no competing interests.