Molecular characterization of zinc metalloproteinase Nas-14 from Trichinella spiralis and its participation in intestinal invasion - Qingbo Lv; Guangquan Si; Chengyao Li; Ning Jiang; Yushu He; Zijian Dong; Hanhai Mao; Mingyuan Liu; Xiaolei Liu; Ying Zhao; Jing Ding (PLoS Neglected Tropical Diseases)