Funding for this research was provided by:
Young Scientists Fund (81602893)
Natural Science Foundation of Shandong Province (ZR2015YL049)
Key Technology Research and Development Program of Shandong (2018GSF118018)
Medical and Health Technology Development Plan Project of Shandong Province (2016WS0540)
Text and Data Mining valid from 2020-04-15
Received: 21 July 2019
Accepted: 3 February 2020
First Online: 15 April 2020
Ethics approval and consent to participate
: Ethics and approvals were sought and granted from Xizang Autonomous Region Center for Disease Control and Prevention (Approval for ethical review of biomedical research involving humans, 2017–025), and obtained the written informed consent of all the participants. Participation of subjects was voluntary and written consent was obtained from all participants before data collection.
: Not applicable.
: The authors declare that they have no competing interests.