title: Demonstration of rotational symmetries in alpha-keratin microfibrils of porcupine quill tip.
mesh_terms: D000818:Animals; D006197:Hair / Q000032:analysis* / Q000166:cytology; D007633:Keratins / Q000032:analysis*; D008854:Microscopy, Electron; D008961:Models, Structural; D009940:Organoids / Q000032:analysis; D011487:Protein Conformation; D012377:Rodentia
chemical_list: D007633:Keratins