Affiliation: | 1. School of Nursing, Fourth Military Medical University, Xi’an, Shaanxi Province 710032, PR China.; 2. Department of Epidemiology, School of Preventive Medicine, Fourth Military Medical University, Xi’an, Shaanxi Province 710032, PR China.; 3. National Institutes of Health, Clinical Center, Bethesda, MD 20892, United States of America.; Nathan Kline Institute and New York University School of Medicine, UNITED STATES, |