Expression of Concern: Heartbeat Sound Classification Using Mel-Spectrogram and CNN Optimized by Frilled Lizard Algorithm for Cardiovascular Disease Detection. Mesopotamian Journal of Artificial Intelligence in Healthcare, [S. l.], v. 2026, p. 21–21, 2026. DOI: 10.58496/MJAIH/2026/006. Disponível em: https://mesopotamian.press/journals/index.php/MJAIH/article/view/1075. Acesso em: 7 mar. 2026.