Xiaoming Xu and Arun Ghosh (IMAGE) Purdue University Caption Arun Ghosh, at right, a Purdue professor of chemistry and medicinal chemistry, and graduate student Xiaoming Xu discuss the structure of an enzyme inhibitor designed to treat Alzheimer's disease. Credit Purdue News Service photo/David Umberger Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.