Funding for this research was provided by:
National Natural Science Foundation of China (No. 81901044, No. 81571004, No. 81500884)
Sichuan Province Science and Technology Support Program (No. 2018JY0558)
Text and Data Mining valid from 2019-12-01
Received: 26 April 2019
Accepted: 11 December 2019
First Online: 29 December 2019
Ethics approval and consent to participate
: No ethics approval is considered necessary.
: Not applicable
: The authors declare that they have no competing interests.