Funding for this research was provided by:
National Aerospace Science Foundation of China (81670372)
Received: 20 August 2019
Accepted: 7 January 2020
First Online: 21 January 2020
Ethics approval and consent to participate
: The research project is in accordance with the ethical principles of “Declaration of Helsinki” and “International Ethical Guidelines for Biomedical Research Involving Human Subjects” promulgated by the Council for International Organization of Medical Sciences. After carefully reviewing, the research was approved by the Ethical Committee of Shanghai Children’s Medical Center. All patients were free of informed consent because the study was a retrospective study. The approved number is SCMCIRB-K2016047.
: This study was a retrospective study, it did not contain any individual person’s data and all data has been desensitized. So, all patients were free of informed consent.
: The authors declare no competing interests.