Funding for this research was provided by:
National Natural Science Foundation of China (81701866, 81772030)
Postdoctoral Fund of Sichuan University (2017SCU12049)
Outstanding Youth Fund of Sichuan University (2016SCU04A07)
Text and Data Mining valid from 2019-03-14
Received: 24 January 2019
Accepted: 8 March 2019
First Online: 14 March 2019
Compliance with ethical standards
: The study was approved by the Ethics Committee of Sichuan University and a written informed consent letter was obtained from each participant.
: The authors declare that they have no conflict of interest.