Funding for this research was provided by:
the Science Research Project of the Sichuan Provincial Department of Health,China (090103)
Text and Data Mining valid from 2018-07-27
Received: 24 February 2018
Accepted: 10 July 2018
First Online: 27 July 2018
Ethics approval and consent to participate
: The study was approved by the Institutional Review Board of The First People’s Hospital of Longquanyi District, Chengdu/ West China Longquan Hospital Sichuan University. Written informed consent was obtained from the participants’ parents prior to the study.
: Not applicable.
: The authors declare that they have no competing interests.
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