Funding for this research was provided by:
National Natural Science Funding (81870834)
Special Fund of The Pediatric Medical Coordinated Development Center of Beijing Municipal Administration (XTYB201817)
Article History
Received: 9 December 2018
Revised: 17 February 2019
Accepted: 18 February 2019
First Online: 27 February 2019
Compliance with ethical standards
:
: All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge, or beliefs) in the subject matter or materials discussed in this manuscript.
: 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. For this type of study, formal consent is not required.
: Informed consent was obtained from all individual participants included in the study.