Funding for this research was provided by:
National Natural Science Foundation of China (71673070)
Text and Data Mining valid from 2020-01-15
Received: 20 November 2018
Accepted: 8 January 2020
First Online: 15 January 2020
Ethics approval and consent to participate
: This study was approved by the Medical Ethics Committee of Harbin Medical University (Daqing). Written informed consent obtained from all individual participants (or their legal representative) is included in the study.
: Not applicable. No individual-level data are presented within this publication.
: The authors declare that they have no competing interests.