Funding for this research was provided by:
National Natural Science Foundation of China (81671501)
Shanghai Municipal Commission of Health and Family Planning (2016ZB0103)
Received: 10 February 2020
Accepted: 21 May 2020
First Online: 27 May 2020
Ethics approval and consent to participate
: This study was approved by the ethical committee of Xinhua Hospital, Shanghai Jiaotong University School of Medicine. Parents or legal guardians signed written informed consent for participation.
: Not applicable.
: The authors declare that they have no competing interests.