Funding for this research was provided by:
Uniwersytet Medyczny w Bialymstoku
Article History
Received: 19 March 2019
Accepted: 23 April 2019
First Online: 15 May 2019
Compliance with ethical standards
:
: The study protocol was approved by the Research Ethics Committee of our institution. An informed written consent was obtained from all the children’s parents or legal guardians.
: All authors have read and approved the final manuscript.
: The authors declare that they have no competing interests.