Funding for this research was provided by:
Ministry of Science and Technology of the People's Republic of China (2018ZX10302206, 2017ZX10202202)
Text and Data Mining valid from 2019-09-18
Received: 22 June 2019
Accepted: 5 September 2019
First Online: 18 September 2019
Ethics approval and consent to participate
: According to the guidelines of the Helsinki declaration, all participants were approved in writing by the local research and ethics committee of Qilu hospital of Shandong University.
: Not applicable.
: The authors declare that they have no competing interest.