Funding for this research was provided by:
Natural Science Foundation of Shandong Province (ZR2015HL007)
Scientific Research Project of Jining Medical University (JY2015KJ035)
Received: 9 April 2019
Accepted: 9 October 2019
First Online: 19 November 2019
Ethics approval and consent to participate
: The study protocol was approved by Ethics Committee of the Affiliated Hospital of Jining Medical University. All experimental procedures complied with the Declaration of Helsinki (2003). Written informed consent was obtained from all participates in the present study.
: Not applicable.
: The authors declare that they have no competing interests.