Additional non-English language abstract
Background
List of abbreviations used (if any)
Competing interests
Endnotes
Illustrations and figures (if any)
Preparing additional files
Background
The Background section should be written in a way that is accessible to researchers without specialist knowledge in that area and must clearly state - and, if helpful, illustrate - the background to the research and its aims. The section should end with a brief statement of what is being reported in the article.