Funding for this research was provided by:
Natural Science Foundation of Beijing Municipality (7182133, 7194309)
Received: 8 February 2020
Accepted: 8 July 2020
First Online: 18 July 2020
Ethics approval and consent to participate
: This study was approved by the Peking Union Medical College Hospital Ethics Committee (NO. S509). A written consent form was obtained from each patient prior to measurement.
: Not applicable.
: The authors declare that they have no competing interests.