$args = array( 'posts_per_page' => $nr ? $nr : get_option('posts_per_page'), 'paged' => get_query_var('paged', 1), 'post_type' => 'post', ... );

$wp_query = new WP_Query($args);

while ($wp_query->have_posts()) : $wp_query->the_post(); // display endwhile;