Funding for this research was provided by:
National Natural Science Foundation of China (81672363, 81372641, 81571525, 81873863, 81802082)
Received: 2 July 2019
Accepted: 27 September 2019
First Online: 10 October 2019
Ethics approval and consent to participate
: The meta-analysis was based on previous published studies. Therefore, no ethical approval is required.
: Not applicable.
: The authors declare that they have no competing interests.