Received: 14 March 2020
Accepted: 30 April 2020
First Online: 1 July 2020
Ethics approval and consent to participate
: All procedures performed in studies involving human participants were in accordance with the ethical standards and approved by the Ethics Committee of Beijing TianTan Hospital, Capital Medical University (KY 2017-012-02).
: Not applicable.
: The authors declare that they have no competing interests.