Funding for this research was provided by:
National Natural Science Foundation of China (81871894, 81201607)
Received: 5 July 2019
Accepted: 27 August 2019
First Online: 2 September 2019
Ethics approval and consent to participate
: This research was approved by the ethic committee of the Hebei Medical University and all informed consents were signed by patients.
: Not applicable.
: The authors declare that they have no competing interests.