Funding for this research was provided by:
the Ministry of Education Innovation Team Development Program of China (IRT16R57)
Received: 21 October 2019
Accepted: 6 February 2020
First Online: 17 February 2020
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of the First Affiliated Hospital of Xi’an Jiaotong University (XJTU1AF2015LSL-057). Written informed consent were waived as a retrospective research. There was no further permission from the hospital.
: Not applicable.
: The authors declare that they have no competing financial interests.