Article History
Received: 9 January 2019
Accepted: 11 November 2019
First Online: 21 November 2019
Ethics approval and consent to participate
: This study was conducted in accordance with the Declaration of Helsinki. Ethical approval was granted by the Ethics Committee of Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College(S-K394). Written informed consents were obtained from all subjects.
: Written consent for publication was obtained from each subject.
: The authors declare that they have no competing interests.