Funding for this research was provided by:
Natural Science Foundation of Inner Mongolia (2017MS(LH)0801, 2017MS08165)
Natural Science Foundations of China (81501151, 81660234)
Text and Data Mining valid from 2019-06-27
Received: 28 March 2019
Accepted: 20 June 2019
First Online: 27 June 2019
Ethics approval and consent to participate
: The study was approved by the Ethics Committee of Inner Mongolia University for Nationalities and Tongliao Institute of Mental Health, Tongliao, China, and it is also in accordance with the principles of the Declaration of Helsinki. Before conducting this study, we obtained the written consent from all participants.
: Not applicable.
: The authors declare no competing interests.