Funding for this research was provided by:
Natural Science Foundation of Beijing Municipality (A73509-03)
Article History
Received: 3 May 2018
Accepted: 3 January 2019
First Online: 11 January 2019
Ethics approval and consent to participate
: This study was approved by the Peking University Third Hospital Ethical Committee and taken out under the direction of Declaration of Helsinki. Written consents were obtained from all the participants.
: Consent for publication had been obtained from the participants.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.