Perbandingan mekanisme penghambatan antivirus ekstrak daun kenikir fraksi n-heksana pada saat akan infeksi dan sesudah infeksi virus dengue pada galur sel HUH7it-1 secara in vitro = The comparison of inhibitory antiviral mechanism of cosmos caudatus leaves etil acetate fraction at post-entry and entry-post entry step against dengue virus in HUH7it-1 cell line in vitro