Toxicological Profiling of Silver and Copper Oxide Nanoparticles on Saccharomyces cerevisiae BY4741 Wild-Type and its Single-Gene Deletion Mutants. Hõbeda ja vaskoksiidi nanoosakeste toksilisuse iseloomustamine pärmi Saccharomyces cerevisiae BY4741 metsiktüvele ning geenikatkestusmutantidele