Dušanka Janežič, PhD, University of Primorska, Faculty of Mathematics, Natural Sciences and Information Technologies, Koper, Slovenia Ante Miličević, PhD, The Institute for Medical Research and Occupational Health, Zagreb, Croatia Sonja Nikolić, PhD, The Rugjer Bošković Institute, Zagreb, Croatia Nenad Trinajstić, PhD, fellow of the Croatian Academy of Sciences and Arts, The Rugjer Bošković Institute, Zagreb, Croatia