Funding for this research was provided by:
National Natural Science Foundation of China (41030127)
Research Special Fund for Public Welfare of Health from the Ministry of Health, the People's Republic of China
Text and Data Mining valid from 2018-09-25
Received: 6 June 2018
Accepted: 10 September 2018
First Online: 25 September 2018
: The authors declare no competing interests.