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Article History

Received: 19 May 2018

Accepted: 3 October 2018

First Online: 25 October 2018

Compliance with ethical standards

:

: The authors declare they have no conflict of interest.

: The manuscript has not been submitted elsewhere. The manuscript has not been published previously (partly or in full). It has not been split up into several parts and submitted to various journals or to one journal over time. No data have been fabricated or manipulated (including images) to support the conclusions. No data, text, or theories by others are presented as if they are the author’s own. All co-authors have contributed sufficiently to the scientific work.

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