Surgeons at Methodist University Hospital in Memphis prepare to transplant a liver in 2010. Karen Pulfer Focht/The Commercial Appeal/Landov hide caption

itoggle caption Karen Pulfer Focht/The Commercial Appeal/Landov

Oklahoma Gov. Mary Fallin issues a statement to the media after the execution of Clayton Lockett. Oklahoma Secretary of Safety and Security Michael C. Thompson stands behind her at the Oklahoma State Capitol in Oklahoma City. Alonzo Adams/AP hide caption

itoggle caption Alonzo Adams/AP

For someone with a serious injury, it's not just a matter of getting in the door at the closest hospital, but getting in the door at the right hospital, says Dr. Arthur Kellermann, an emergency medicine specialist. micheal kennedy/iStockphoto hide caption

itoggle caption micheal kennedy/iStockphoto

Say hello to your microbiome, Rob Stein. Our intrepid correspondent decided to get his gut bacteria analyzed. Now he's wondering if he needs to eat more garlic and onions. Morgan Walker/NPR hide caption

itoggle caption Morgan Walker/NPR

H5N1 avian flu viruses (seen in gold) grow inside canine kidney cells (seen in green). Cynthia Goldsmith/CDC hide caption

itoggle caption Cynthia Goldsmith/CDC

Virologists and other scientists are meeting at the World Health Organization's Geneva headquarters to talk about the bird flu. Pierre Virot/WHO hide caption

itoggle caption Pierre Virot/WHO

A chimpanzee eats a coconut at the Alamogordo Primate Facility at Holloman Air Force Base, N.M., in an undated photo from the National Institutes of Health. A plan to move chimps that had retired to the facility after being subjects of medical experiments sparked controversy and a review of research policies. AP hide caption

itoggle caption AP