function open_masonry_entries_in_new_tab( ) {
?>
<script>
(function($) {
  MutationObserver = window.MutationObserver || window.WebKitMutationObserver;
  var observer = new MutationObserver(function() {
    $("a.av-masonry-entry").attr("target", "_blank");
  });
  observer.observe(document, { subtree: true, childList: true });
})(jQuery);
</script>
<?php
}
add_action('wp_footer', 'open_masonry_entries_in_new_tab', 999);