diff --git a/config/vufind/availabilityplus-resolver-Unpaywall.yaml b/config/vufind/availabilityplus-resolver-Unpaywall.yaml
index e69de29bb..b181c68e6 100644
--- a/config/vufind/availabilityplus-resolver-Unpaywall.yaml
+++ b/config/vufind/availabilityplus-resolver-Unpaywall.yaml
@@ -0,0 +1,29 @@
+# In this file rules can be configured to change the output of a resolver.
+# These rules are used in function applyCustomChanges in the resolver class.
+#
+#TestRule:  # name of the rule, required
+#  descripton: 'description' # optional
+#  reason: 'reason for rule' # optional
+#  date: 'date yyyy-mm-dd' # optional
+#  creator: 'John Doe' # optional
+#  examples: 'e.g. an id in the index' # optional
+#  details: 'http://www.more-details.vufind'  # optional, a url
+#  conditions: # one or multiple conditions can be specified that need to match for the actions to take place
+#    - { field: 'field1->subfield1', content: '(.*)' } #field: specifies the path to a field that needs to be checked, use -> to indicate a subfield, subsubfield ... / content: can be a string or regular expression
+#  actions: # indicate what actions are to be taken, if all conditions are fullfilled
+#    - { field: 'field1->subfield1->subsubfield1', content: '' } # complete string replacement by indicating a field and the new content
+#    - { field: 'field1->subfield1', content_field: 'field2->contentfromsubfield2', pattern: '(.*?):(.*)', replacement: '$2'} # regex-based replacement, content can be from the same field or another field
+#    - { function: 'removeItem'} # a function in the resolver can be specified, currently only one function is supported for all resolvers: removeItem
+#    - { function: 'adjustScore', score: 200} # DAIA also supports the function adjustScore, requiring a score parameter with an integer
+# Example
+RemoveItemForUrl1:
+  description: 'Entfernung eines Items, mit URL, die nicht zum Volltext führt'
+  reason: ''
+  date: ''
+  creator: ''
+  examples: 'PPN 517096420'
+  detailsLink: ''
+  conditions:
+    - { field: 'url', content: 'https://www.degruyter.com/document/doi/10.1515/jag-2021-frontmatter3/pdf' }
+  actions:
+    - { function: 'removeItem'}
diff --git a/themes/availabilityplus/js/check_item_statuses.js b/themes/availabilityplus/js/check_item_statuses.js
index 34d7a916a..e1fda8e4f 100644
--- a/themes/availabilityplus/js/check_item_statuses.js
+++ b/themes/availabilityplus/js/check_item_statuses.js
@@ -1,22 +1,11 @@
 /*global Hunt, VuFind */
 /*exported checkItemStatuses, itemStatusFail */
 
-function linkCallnumbers(callnumber, callnumber_handler) {
-    if (callnumber_handler) {
-        var cns = callnumber.split(',\t');
-        for (var i = 0; i < cns.length; i++) {
-            cns[i] = '<a href="' + VuFind.path + '/Alphabrowse/Home?source=' + encodeURI(callnumber_handler) + '&amp;from=' + encodeURI(cns[i]) + '">' + cns[i] + '</a>';
-        }
-        return cns.join(',\t');
-    }
-    return callnumber;
-}
-
 function displayItemStatus(results, item) {
     item.removeClass('js-item-pending');
     item.find('.ajax-availability').removeClass('ajax-availability hidden');
     item.find('.status').empty();
-    var id = item.attr('data-id');
+    let id = item.attr('data-id');
     $.each(results, function(index, result){
         if (typeof(result.error) != 'undefined'
             && result.error.length > 0
@@ -48,18 +37,16 @@ function itemStatusFail(response, textStatus) {
         .append(typeof response.responseJSON.data === 'string' ? response.responseJSON.data : VuFind.translate('error_occurred'));
 }
 
-var itemStatusIds = [];
-var itemStatusEls = {};
-var itemStatusTimer = null;
-var itemStatusDelay = 200;
-var itemStatusRunning = false;
-var itemStatusList = false;
-var itemStatusSource = '';
-var itemStatusHideLink = '';
-var itemStatusType = '';
-var itemStatusMediatype = '';
-var itemLanguage = '';
-var itemStatusDebug = '';
+let itemStatusIds = [];
+let itemStatusEls = {};
+let itemStatusTimer = null;
+let itemStatusDelay = 200;
+let itemStatusRunning = false;
+let itemStatusList = false;
+let itemStatusSource = '';
+let itemStatusMediatype = '';
+let itemLanguage = '';
+let itemStatusDebug = '';
 
 function runItemAjaxForQueue() {
     // Only run one item status AJAX request at a time:
@@ -69,8 +56,8 @@ function runItemAjaxForQueue() {
     }
     itemStatusRunning = true;
 
-    for (var i=0; i<itemStatusIds.length; i++) {
-		var item = itemStatusEls[itemStatusIds[i]];
+    for (let i=0; i<itemStatusIds.length; i++) {
+		let item = itemStatusEls[itemStatusIds[i]];
 		itemStatusSource = item.attr('data-src');
 		itemStatusList = (item.attr('data-list') == 1);
 		itemStatusMediatype = item.attr('data-mediatype');
@@ -83,8 +70,8 @@ function runItemAjaxForQueue() {
             data: {id:[itemStatusIds[i]], list:itemStatusList, source:itemStatusSource, mediatype:itemStatusMediatype, language:itemLanguage, debug:itemStatusDebug}
         })
             .done(function checkItemStatusDone(response) {
-                for (var j = 0; j < response.data.statuses.length; j++) {
-                    var status = response.data.statuses[j];
+                for (let j = 0; j < response.data.statuses.length; j++) {
+                    let status = response.data.statuses[j];
                     displayItemStatus(status, itemStatusEls[status.id]);
                     itemStatusIds.splice(itemStatusIds.indexOf(status.id), 1);
                 }
@@ -104,7 +91,7 @@ function itemQueueAjax(id, el) {
     clearTimeout(itemStatusTimer);
     itemStatusIds.push(id);
     itemStatusEls[id] = el;
-	var item = $(el);
+	let item = $(el);
 	itemStatusSource = item.attr('data-src');
     itemStatusList = (item.attr('data-list') == 1);
     itemStatusMediatype = item.attr('data-mediatype');
@@ -117,55 +104,24 @@ function itemQueueAjax(id, el) {
     el.find('.status').removeClass('hidden');
 }
 
-//Listenansicht
-function checkItemStatus(el) {
-    var item = $(el);
-    var id = item.attr('data-id');
-    itemStatusSource = item.attr('data-src');
-    itemStatusList = (item.attr('data-list') == 1);
-    itemStatusMediatype = item.attr('data-mediatype');
-    itemLanguage = item.attr('data-language');
-    itemStatusDebug = item.attr('data-debug');
-    itemQueueAjax(id + '', item);
-}
-
-var itemStatusObserver = null;
-
-function checkItemStatuses(_container) {
-    var container = typeof _container === 'undefined'
-        ? document.body
-        : _container;
-
-    var availabilityItems = $(container).find('.availabilityItem');
-    for (var i = 0; i < availabilityItems.length; i++) {
-        var id = $(availabilityItems[i]).attr('data-id');
-        itemStatusSource = $(availabilityItems[i]).attr('data-src');
-        itemStatusList = ($(availabilityItems[i]).attr('data-list') == 1);
-        itemStatusMediatype = $(availabilityItems[i]).attr('data-mediatype');
-        itemLanguage = $(availabilityItems[i]).attr('data-language');
-        itemStatusDebug = $(availabilityItems[i]).attr('data-debug');
-        itemQueueAjax(id, $(availabilityItems[i]));
-    }
-    // Stop looking for a scroll loader
-    if (itemStatusObserver) {
-        itemStatusObserver.disconnect();
-    }
+function checkItemStatuses() {
+    $('.availabilityItem').each(function() {
+        if ($(this).offset().top < $(window).scrollTop() + $(window).height() && $(this).offset().top + $(this).height() > $(window).scrollTop() && $(this).find('.ajax-availability').length !== 0 ) {
+            let id = $(this).attr('data-id');
+            itemStatusSource = $(this).attr('data-src');
+            itemStatusList = ($(this).attr('data-list') == 1);
+            itemStatusMediatype = $(this).attr('data-mediatype');
+            itemLanguage = $(this).attr('data-language');
+            itemStatusDebug = $(this).attr('data-debug');
+            itemQueueAjax(id, $(this));
+        }
+    });
 }
 $(document).ready(function() {
-    function checkItemStatusReady() {
-        if (typeof Hunt === 'undefined') {
-            checkItemStatuses();
-        } else {
-            itemStatusObserver = new Hunt(
-                $('.availabilityItem').toArray(),
-                {
-                    enter: checkItemStatus,
-                    offset: 100000
-                }
-            );
-        }
-    }
-    checkItemStatusReady();
+    checkItemStatuses();
+    $(window).on('scroll resize', function() {
+        checkItemStatuses();
+    });
 });
 
 function initDaiaPlusOverlay () {