Li, Shenghua
Xu, Fei
He, Jing
Wang, Zhiyong
Tse, Lap Ah.
Xiong, Yaqing
Chen, Daowen
Funding for this research was provided by:
Nanjing Municipal Science and Technology Development Foundation (201503054)
Article History
Received: 5 August 2017
Accepted: 8 March 2018
First Online: 20 March 2018
Ethics approval and consent to participate
: Written informed consent was obtained from each participant prior to each survey. This study was approved by the Academic and Ethical Committee of Nanjing Municipal Center for Disease Control and Prevention.
: Not applicable.
: The authors have declared that no competing interests exist.
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