Funding for this research was provided by:
Medical University of Gdansk (ST-82)
Received: 20 November 2016
Accepted: 29 November 2017
First Online: 15 January 2018
Ethics approval and consent to participate
: The research was approved by The Independent Bioethics Committee for Scientific Research of the Medical University of Gdansk, Poland (NKEBN/649/01–02). All patients gave their informed written consent to participate.
: Not applicable.
: The authors declare that they have no competing interests.
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