Text and Data Mining valid from 2020-03-28
Received: 23 July 2019
Accepted: 13 March 2020
First Online: 28 March 2020
Ethics approval and consent to participate
: This study was approved by the ethics committee of National Center for Children’s Health & Beijing Children’s Hospital Affiliated to Capital Medical University. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. All data published here are under the consent for publication. Written informed consent was obtained from all individual participants over 16 years old included in the study. A parent or guardian was on behalf of any participants under the age of 16 to write informed consent.
: Not Applicable.
: The authors declare that they have no competing interests.