open infile,$filepath;
open outfile,'>'.$outfilepath;
my $XML;
while (<infile>) {
 $XML .= $_;
 if (s/\<\ppsarticle\>(.*?)\<\/ppsarticle\>//) {
  my $Article = $1;
  my $MD5SUM = md5($Article);
  $md5{$MD5SUM} and next;
  $md5{$MD5SUM} = 1;
  print outfile $Article;
 }
}