Summary Summary. Acute intermittent porphyria (AIP) is one of the liver (hepatic) porphyrias. AIP is caused by low levels of porphobilinogen deaminase (PBGD), an enzyme also often called hydroxymethylbilane synthase.
Pyridine-N-oxide is the heterocyclic compound with the formula C 5 H 5 NO. This colourless, hygroscopic solid is the product of the oxidation of pyridine. It was originally prepared using peracids as the oxidising agent. The molecule is planar.yridine-N-oxide is the heterocyclic compound with the formula C 5 H 5 NO. This colourless, hygroscopic solid is the product of the oxidation of pyridine. It was originally prepared using peracids as the oxidising agent. The molecule is planar.
Pyrite can form in extremely well-crystallized examples of cubes, pyritohedrons, and octahedrons. Combinations of these forms also occur. An icosahedron formed from a combination of an octahedron and pyritohedron is also known. Pyrite crystals frequently form penetration twinning, especially in the cubic form. Cubes are sometimes elongated in rectangular form. Also occurs massive, radiating, grainy, flaky, drusy, mammilary, encrusting, nodular, tuberose, fibrous, in concretions, and as groups of small crystals.