my $parser = XML::LibXML->new();
my $xmldoc = $parser->load_xml(
  location => $file,
);

my $xc = XML::LibXML::XPathContext->new($xmldoc);
$xc->registerNs('gfm', 'urn:us:org:my:gfmdi:v35');

for my $sample ($xc->findnodes('/gfm:GfmDocument/gfm:GFMIEDM35/gfm:OBJ_ITEM_OO_TBL/gfm:OBJ_ITEM')) {