RETRACTED: Activation of the PI3K-Akt pathway promotes neuroprotection of the δ-opioid receptor agonist against cerebral ischemia-reperfusion injury in rat models.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The authors contacted the journal to request a retraction: "Recently, we found that some experimental animal samples from another research were mistakenly used in this paper, resulting in the results and conclusions unreliable". Concern was also raised about the reliability of the brain section images in Figure 1, which seem to appear in other publications, as detailed here: https://pubpeer.com/publications/8AF402957928F3F27A1F46B6D556AD; and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. In addition, suspected image duplications were detected in Figures 2A, 3B and 4B. The journal requested the corresponding author comment on these concerns and provide the raw data. The author did not fulfil this request and the Editor-in-Chief decided to retract the article.