Funding for this research was provided by:
Liaoning Education Department Science and Technology Research Project (L2016010)
Received: 30 January 2019
Accepted: 31 May 2019
First Online: 13 June 2019
Ethics approval and consent to participate
: The study has been examined and certified by the Ethics Committee of the First Affiliated Hospital of Dalian Medical University (Ethics Reference NO: YJ-KY-FB-2017-32), and informed consent was obtained from all participants included in the study, in agreement with institutional guidelines.
: Not applicable.
: The authors declare that they have no competing interests.