The Clinical Measurement Ontology (CMO), Measurement Methods Ontology (MMO), and Experimental Condition Ontology (XCO) are currently being developed at the Rat Genome Database. For more information about these vocabularies please see Shimoyama et al. Three ontologies to define phenotype measurement data. Front Genet. 2012;3:87. Epub 2012 May 28 or contact us (http://rgd.mcw.edu/contact/index.shtml).
Any condition in which the main influencing factor is a particle, i.e. a body whose internal motion and structure, if any, are irrelevant in a specific problem, with a size between 1 and 100 nanometers composed of any substance having a specific molecular composition obtained by or used in a reaction involving changes to atoms or molecules.