Non linear relationship between level of folic acid in serum and apoptosis in human gastric mucosa: a cross-sectional study - Ghaffari, Aida; Alipour, Beitollah; Safaiyan, Abdolrasoul; Modaresi, Jabiz; Somi, Mohammad Hossein; Ostadrahimi, Alireza (Basic & Clinical Cancer Research, 2016)