Funding for this research was provided by:
National Natural Science Foundation of China (31371129)
Research Project of Sun Yat-Sen University (26000-31620003)
Text and Data Mining valid from 2019-05-31
Received: 13 February 2019
Accepted: 24 May 2019
First Online: 31 May 2019
Compliance with ethical standards
: The authors declare no competing financial interest.
: The data generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.