title: The puzzle of periodicity.
mesh_terms: D002245:Carbon Dioxide / Q000097:blood; D002639:Cheyne-Stokes Respiration / Q000503:physiopathology; D006801:Humans; D006985:Hyperventilation / Q000503:physiopathology; D007040:Hypoventilation / Q000503:physiopathology; D000860:Hypoxia / Q000503:physiopathology; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000503:physiopathology*; D012119:Respiration
chemical_list: D002245:Carbon Dioxide