Funding for this research was provided by:
National Natural Science Foundation of China (31370086, 31700062)
the Shandong Provincial Natural Science Foundation, China (ZR2019MC007)
the Program for HaiYou Talents of Jinan
the Program for Thousands of Talents of Jinan
Text and Data Mining valid from 2019-08-20
Received: 24 January 2019
Accepted: 6 August 2019
First Online: 20 August 2019
Ethics approval and consent to participate
: Not applicable.
: All authors read and approved the final manuscript.
: The authors declare that they have no competing interests.