According to the information posted on EurekAlert, a PNAS article was anticipated to publish online this week, but I can find it on the PNAS website. What happened?
Occasionally, unforeseen production delays may cause an article to publish later than anticipated. When this occurs, interested members of the public may contact the PNAS News Office to obtain advance copies of the article. Embargo dates are unaffected by production delays that occur after the official embargo date has been posted to EurekAlert.