assertion retraction graph subject predicate object datatype annotation 1 0 graph DOID:3357 IAO:0000115 An osteosarcoma arising from the soft tissue. xsd:string "{""oio:hasDbXref"":[{""datatype"":""xsd:string"",""meta"":""owl:Axiom"",""object"":""url:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4080674/""}]}"