Article History
Received: 18 September 2019
Accepted: 14 January 2020
First Online: 23 January 2020
Ethics approval and consent to participate
: No treatments were performed on patients before this study. Written informed consent was signed by every patient, the study protocol was accepted by the Ethics Committee of the Second Hospital of Shandong University.
: The publication was approved by all the authors.
: The authors declare that they have no competing interests.