assertion retraction graph subject predicate object datatype annotation 1 0 graph DOID:4302 IAO:0000115 A nodular basal cell carcinoma that is characterized by a homogenous blue/black area. xsd:string "{""oio:hasDbXref"":[{""datatype"":""xsd:string"",""meta"":""owl:Axiom"",""object"":""url:https://www.hindawi.com/journals/jsc/2011/450472/""}]}"