Funding for this research was provided by:
Hunan Provincial Science and Technology Department (2012SK3062)
Text and Data Mining valid from 2018-08-23
Received: 30 January 2018
Accepted: 14 August 2018
First Online: 23 August 2018
Ethics approval and consent to participate
: The study was approved by the Independent Ethics Committee of Brains Hospital of Hunan Province and was conducted in accordance with the ethical standards of the committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. In the study, informed consent was obtained from all individual participants and their guardians in writing. To guarantee the validity of information, all the participations were anonymous and voluntary. The questionnaires were completed in the classroom and required 30 to 45 min for completion.
: Not applicable.
: The authors declare that they have no competing interests.
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