#!/usr/bin/perl -w
use strict;

open WORDS, "<kwords" or die;
my %kwords=();
while (<WORDS>) {
    chomp;
    $kwords{$_} = qr/\b$_\b/m;
}
close WORDS;

my %found =();

for my $f (<abstract*>) {
    local $/;
    open FILE, $f or die "$f\n";
    my $text = <FILE>;
    close FILE;
    for (keys %kwords) {
        my $val = $kwords{$_};
        $found{$f} .= "$_ " if $text =~ /$val/;
    }
}

print "$_\t$found{$_}\n" for sort keys %found;