Funding for this research was provided by:
National Natural Science Foundation of China (81673166)
National Natural Science Foundation of China (81372118, 81372467, 81302422)
Received: 19 October 2019
Accepted: 6 March 2020
First Online: 24 March 2020
Ethics approval and consent to participate
: The ethical protocol of this study was approved by the Medical Ethics Committee of the Tianjin Medical University with the reference number of TMUhMEC 201430, in accordance with the 1975 Declaration of Helsinki (as revised in 1983). Each participant gave written informed consent prior to participation in the study.
: Not applicable.
: The authors declare that they have no competing interests.