Funding for this research was provided by:
National Natural Science Foundation of China (81801906)
Natural Science Foundation of Shandong Province (ZR2018PH024)
Received: 12 June 2019
Accepted: 10 February 2020
First Online: 19 February 2020
Ethics approval and consent to participate
: The experimental design was approved by the ethical review committee of the Jining No.1 People’s Hospital before the initiation of the study and a signed consent form was obtained from each subject. And all experiments were in accordance with The Code of Ethics of the World Medical Association (Declaration of Helsinki).
: All involved subjects and the authors listed have approved the publication of the manuscript.
: The authors declare that they have no competing interests.