Dear Authors,

The “Guide for Authors” has been transformed and improved: the rules of manuscript presentation and submission have been changed. For your convenience, a unified form of “Cover letter” has been designed. In “Instructions for Authors” a required summary structure has been clarified: relevance, aim, materials and methods, results, conclusion and acknowledgments. You can also find a number of links to the recommendations how to write a scientific paper for successful publication. An obligatory condition for Authors is to transform references to National Library of Medicine style after submitting.