assertion  retraction  graph  subject       predicate          object                datatype    annotation
1          0           graph  DOID:0060072  oio:creation_date  2011-05-11T12:18:41Z  xsd:string  
1          0           graph  DOID:0060071  oio:creation_date  2011-05-11T12:18:41Z  xsd:string