Article History
Received: 1 April 2019
Accepted: 24 May 2019
First Online: 19 June 2019
Compliance with ethical standards
:
: The authors declare that they have no competing interests.
: 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 9864 Helsinki declaration and its later amendments or comparable ethical standards. Ethics approval (approval no. SD02872) was approved by the Ethics Committee of Shandong University. This article does not contain any studies with animals performed by any of the authors. The informed consent for participation was obtained from all patients and their parents who participated in this study in an appropriate method.
: Written informed consent for publication was obtained. A copy of the consent form is available for review by the Editor of this journal.