An identifier for an atom; the smallest unit of naming in a source, viz, a specific string with specific code values and identifiers from a specific source. As such, they can be thought of as representing a single meaning with a source Atoms are the units of terminology that come from sources and form the building blocks of the concepts in the Metathesaurus.
umls.aui
Local identifiers in Unified Medical Language System Atomic Unique Identifier should match this
regular expression:
^A\d+$
Compact URIs (CURIEs) constructed from Unified Medical Language System Atomic Unique Identifier should match
this regular expression:
^umls\.aui:A\d+$