Funding for this research was provided by:
National Natural Science Foundation of China (81703324)
China Scholarship Council (201808535098)
Yunnan Applied Basic Research Projects-Kunming Medical University Union Foundation (2018FE001(-132))
Received: 22 May 2019
Accepted: 10 October 2019
First Online: 29 October 2019
Ethics approval and consent to participate
: This study was approved by Institutional Research Ethics Board of Kunming University. Because of its retrospective nature, as well as that no individually identifiable or sensitive information was involved, informed consent from all patients was waived.
: Not applicable.
: The authors declare that they have no competing interests.