assertion  retraction  graph  subject       predicate          object                datatype    annotation
1          0           graph  DOID:0060087  oio:creation_date  2011-07-14T12:20:52Z  xsd:string  
1          0           graph  DOID:0060086  oio:creation_date  2011-07-14T12:20:52Z  xsd:string