Example fragment loading using pjax: https://github.com/defunkt/jquery-pjax

gistfile1.js

// Handle previous/next navigation
$(function() {
    // Requires jQuery 1.7+ to utilize the new "on" event attachment
    $("#contentPadding").on("click", "a.prev, a.next", function (event) {
	$.pjax({
	    "url": $(this).attr("href"),
	    "fragment": "#contentPadding",
	    "container": "#contentPadding",
	    "complete": function(data) {
		// Update the className on the BODY tag
		var bodyClass = data.responseText && data.responseText.match(/<body[^>]+class\s*=\s*['"]([^'"]+)/);
		if (bodyClass) {
		    $("body").attr("class", bodyClass[1]);
		}

		// Reinitialize AddThis if it's inside the loaded fragment
		if (window.addthis) {
		    addthis.toolbox($(".addthis_toolbox").get(0));
		    addthis.counter($(".addthis_counter").get(0));
		}
	    }
	});
	event.preventDefault();
    });
});