assertion  retraction  graph  subject    predicate                                         object        datatype    annotation
1          0           graph  DOID:2452  <http://www.w3.org/2004/02/skos/core#exactMatch>  MESH:D019851  xsd:string  
1          0           graph  DOID:2452  oio:hasDbXref                                     MESH:D019851  xsd:string