1. School of Pharmacy, North China University of Science and Technology, 063210 Caofeidian District, Tangshan, P.R. China
2. School of Public Health, North China University of Science and Technology, 063210 Caofeidian District, Tangshan, P.R. China
3. Jia Mu Si University, School of Continuing Education, No.148 Xuefu St, Jiamusi, Heilongjiang, P.R. China