use XML::DOM;
                                                                                    
                                                                                    
my $xml = 'jj.xml';
my $parser = new XML::DOM::Parser;
my $doc = $parser->parsefile($xml);
                                                                                    
my $nodes = $doc->getElementsByTagName ("ISSN");
                                                                                    
foreach my $node (@{$nodes})
{
   if ( $node->getFirstChild()->toString() eq '1742-7061' )
   {
      my $parent = $node->getParentNode();
      $doc->getFirstChild()->removeChild($parent);
   }
                                                                                    
}
                                                                                    
print $doc->toString();