Starting from 1^st January 2021, a fee of 300,00 € will be due for the accepted papers that will indexed in PubMed. The fee for the articles submitted starting from 1-1-2021 should be paid after the acceptation of the article and before the publication. The corresponding authors are responsible for making the payment or arranging it through their institutions. After that payment we will proceed with the publication. The article will be published in the first next available publishing issue.

Letters to the Editor as well as reviews, editorial papers, and all articles requested by the Editor in Chief and Section Editors will be published free of charge.