1. School of Public Health, Wannan Medical College, 22 West Wenchang Road, Wuhu, Anhui Province 241002, People's Republic of China (ORCID: http://orcid.org/0000-0002-9505-6693 [Y.C.])
2. School of Economics and Management, Nanjing Forestry University, Longpan Road 159, Nanjing 210037, People's Republic of China