From W3C Wiki
As an example, the relevant RDF you produced with the aTag bookmarklet in one annotation looks like that:

<http://hcls.deri.org/atag/generator/#4c27eead47587>    rdf:type        sioc:Item .
<http://hcls.deri.org/atag/generator/#4c27eead47587>    rdfs:seeAlso<http://hcls.deri.org/atag/generator/>;
       sioc:topic      <http://purl.bioontology.org/ontology/SNOMEDCT/412796009> ,
               <http://purl.bioontology.org/ontology/SNOMEDCT/78799005> ,
               <http://purl.bioontology.org/ontology/SNOMEDCT/110502005> ,
               <http://purl.bioontology.org/ontology/SNOMEDCT/246261001> ,
               <http://purl.bioontology.org/ontology/SNOMEDCT/30807003> ;
       sioc:content    "IMPRESSION: 1. Loosely grouped, rounded microcalcifications in the left upper outer breast. By mammographic criteria, these microcalcifications appear benign."@en ;

If you know the URI of an aTag, you can query the RDF triples from the HCLS KB (this is how I got the RDF above).  Go to http://hcls.deri.org/sparql, then enter a query such as
DESCRIBE <http://hcls.deri.org/atag/generator/#4c27eead47587>

You can query for all triples in the pastebin with a query such as
SELECT * FROM <http://hcls.deri.org/atag/data/pastebin.html> WHERE {?p ?s ?o} LIMIT 1000