Versions of the NPO are released as OWL files through BioPortal for visualization and they can be freely download (http://purl.bioontology.org/ontology/npo
The NPO can be browsed and visualized through the EVS NCI term browser (http://ncit.nci.nih.gov/ncitbrowser/start.jsf).
The NPO is also included in the NCI metathesaurus (NCIm), which can be accessed at http://ncimeta.nci.nih.gov/. The NCI metathesaurus contains about 3,600,000 terms from over 76 vocabularies, and these terms are mapped to about 1,400,000 biomedical concepts. Terms from multiple vocabularies that are mapped to a single biomedical concept allows the user to choose from the multiple vocabularies to annotate data. Simultaneously, this facilitates discovery of vocabularies unknown to the user. By the inclusion of NPO into the NCI metathesaurus, we expect that NPO accessibility and usage will be extended within the NCIm NPO will add semantics into the NCIm; and that NCIm users will be able to take advantage of the knowledge provided by NPO.
A documentation wiki that provides the documentation for NPO is available at http://www.nano-ontology.org
The ontology URI of NPO is http://purl.bioontology.org/ontology/npo
View of the NPO
Representations of the NanoParticle Ontology provide a framework for understanding and navigating the ontology were developed by Alan Chappell and Dennis Thomas, both at Pacific Northwest National Lab.