Funding for this research was provided by:
Chinese Scholarship Council (-)
German Federal Ministry of Education and Research (01ER1505A)
Text and Data Mining valid from 2018-06-01
Received: 22 June 2017
Accepted: 15 May 2018
First Online: 1 June 2018
Ethics approval and consent to participate
: Not applicable.
: The authors declare that they have no competing interests.
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