1. Department of Preventive Medicine, Shantou University Medical College, Shantou, China
2. School of Mathematics, Sun Yat-Sen University, Guangzhou, Guangdong, China
3. The First People's Hospital of Yun Nan Province, Kunming, China
4. Department of Optoelectronic Information Science and Engineering, Physical and Materials Science College, Guangzhou University, Guangzhou, China
5. School of Management, University of Science and Technology of China, Hefei, Anhui, China