Funding for this research was provided by:
Nanjing Municipal Science and Technology Development Foundation (2007ZD011)
Text and Data Mining valid from 2018-06-28
Received: 18 February 2018
Accepted: 20 June 2018
First Online: 28 June 2018
Ethics approval and consent to participate
: Written informed consent was obtained from each alive participant or from his/her next of kin for the died. This study was approved by the Academic and Ethical Committee of Nanjing First Hospital.
: Not applicable.
: The authors declare that they have no competing interests.
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