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Article History

Received: 27 October 2017

Accepted: 26 January 2018

First Online: 20 February 2018

Authors’ information

: No further information.

: All procedures performed in the 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.

: Informed consent was obtained from all individual participants (children and their parents) included in the study.

: All authors declare that they have no competing interest.

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