1. IMMOBILIZATION OF PHENYLALANINE AMMONIA-LYASE ON HYDROXYAPATITE AND HYDROXYAPATITE COMPOSITES. Authors: JUDITH-HAJNAL BARTHA-VARI, RENÁTA ELEKES-DARABONT, LAURA-EDIT BARABÁS, RÉKA BARABÁS.2. SYNTHESYS AND CHARACTERIZATION OF SILVER-DOPED HYDROXYAPATITE. Authors: REGINA PETKES, NOÉMI-IZABELLA FARKAS, LAURA MARINCAȘ, JUDITH-HAJNAL BARTHA-VARI, RÉKA BARABÁS.