Funding for this research was provided by:
National Natural Science Foundation of China (81872715)
Received: 15 August 2019
Accepted: 11 December 2019
First Online: 19 December 2019
Ethics approval and consent to participate
: The study was approved by Shanxi Medical University Ethics Committee and obtained written consent from each individual.
: No applicable.
: The authors declare that they have no competing interests.