Received: 19 February 2020
Accepted: 29 June 2020
First Online: 4 July 2020
Ethics approval and consent to participate
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the Affiliated Hospital of Shandong Medical College and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Written informed consents were obtained from all enrolled patients.
: Not applicable.
: The authors declare no conflict of interest.