pyroxylin: highly flammable nitrocellulose used in making collodion and plastics and lacquers
material: the tangible substance that goes into the makeup of a physical object
heliobacter pylori: the type species of genus Heliobacter; produces urease and is associated with several gastroduodenal diseases (including gastritis and gastric ulcers and duodenal ulcers and other peptic ulcers)