Received: 3 January 2018
Accepted: 5 March 2018
First Online: 21 March 2018
Ethics approval and consent to participate
: Ethical approval was obtained by the institutional ethical committee in accordance with local ethical regulations; the study was conducted in accordance with the ethical principles of the declaration of Helsinki. Written informed consent was obtained from the patient or the legal guardians in case of minors according to local requirements.
: Not applicable
: The authors declare that they have no competing interests.
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