Funding for this research was provided by:
European Social Fund
Received: 22 November 2017
Accepted: 23 January 2018
First Online: 9 February 2018
Ethics approval and consent to participate
: Investigations were carried out in accordance with the Declaration of Helsinki of 1975, revised in 2008. All aspects of this study were approved by the Institutional Review Board and the Independent Ethics Committee of Vilnius University. Approval was also provided for research involving the use of material (data records or biopsy specimens) that had been collected for non-research purposes (Vilnius Regional Biomedical Research Ethics Committee, No. 158200-580-PPI-17, 11 June 2013).
: The authors declare that they have no competing interests.
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