Contribution to authorship
Juanzi Shi conceived the study question. He Cai and Juanzi Shi were
responsible for the design of the study. He Cai and Na Li undertook the
statistical analyses. Stephan Gordts, Tao Wang, and Hui Wang developed
the first draft of the article, and all author contributed to the
interpretation of findings and revising of drafts of the article. All
authors approved the final article for publication.