## Text Mining Medline

### Thesauri

Oracle Text thesauri are used to automatically expand the query phrases into longer lists of synonyms or hierarchically related phrases. The thesarui are user generated. Tis demo includes 2 thesauri. The NCI Thesaurus (NCIT) and a transcription factor gene thesaurus (TFT). Both thesauri are hierarchical and can be viewer in a Stretch Viewer applet.
Query syntax examples:

Expand the NCI thesaurus (NCIT) phrase 'growth factor' into all children up to 4 levels deep.

NT(growth factor,4,NCIT)

Expand the NCI thesaurus (NCIT) phrase 'Developmental Process' into all children up to 6 levels deep.

NT(Developmental Process,6,NCIT)

Combine two thesauri-expanded phrases.

NT(Helix-turn-helix,6,TFT) AND NT(Developmental Process,6,NCIT)