1. Department of Pediatric Surgery, Medical University of Bialystok, Bialystok, Poland;
2. Department of Electrochemistry, University of Bialystok, Bialystok, Poland;
3. Department of Medical Statistics, University of Bialystok, Bialystok, Poland;
4. Department of Biophysics, Medical University of Bialystok, Bialystok, Poland