Document is current

Article History

Received: 19 June 2018

Accepted: 29 November 2018

First Online: 10 December 2018

Ethics approval and consent to participate

: The ethics committees of the Beijing Capital Medical University and Beijing Chaoyang Hospital approved this study, and informed consent was obtained from all patients.

: Not applicable.

: The authors declare that they have no competing interests.

: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.