RETRACTED: Correlation of Parameters of Endogenous Opioid System with Personality Traits and Anxiety Level in Patients with Mitral Valve Prolapse.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief The authors have plagiarized part of a paper that had already appeared in Neurochemistry" (Russian), 2000.V.17, No2, pp.150-156 and Cell-surface aminopeptidases: basic and clinical aspects», P.413-415, ICS 1218. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process."