You could get your get_publications functions to return a JSON object with all sorts of information you need.
e.g
function get_publications() {
// Your query here.
$data = [
'html' => $your_html,
'found_posts' => $query->found_posts,
'current_post' => $query->current_post,
'current_page' => $page,
etc...
];
echo json_encode($data);
}
And then parse that data with your javascript.