Funding for this research was provided by:
National Natural Science Foundation of China (81560550, 81260441)
Text and Data Mining valid from 2019-07-08
Received: 2 November 2017
Accepted: 25 June 2019
First Online: 8 July 2019
Ethics approval and consent to participate
: The study was approved by the Institutional Review Board of Nanchang University, and written informed consent had been obtained from all participants. Those who lose cognitive ability were deemed to be incapable of giving informed consent and such informed consent was obtained from their immediate family members.
: Not applicable.
: The authors declare that they have no competing interests.