Funding for this research was provided by:
China Scholarship Council (1200 euro)
Leids Universitair Medisch Centrum (700 euro)
Received: 7 February 2019
Revised: 5 September 2019
Accepted: 16 September 2019
First Online: 12 October 2019
Compliance with ethical standards
: There is no conflict of interest for the current study.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.