Marqui Ducarme is aided by his wife after catching chikungunya at his home in Port-au-Prince, May 23. The virus swept through Haiti this spring, infecting more than 40,000 people. Marie Arago/Reuters/Landov hide caption

itoggle caption Marie Arago/Reuters/Landov

Angelo Mosso's "human circulation balance" machine worked like a seesaw to measure blood flow changes to the brain. Stefano Sandrone et al., Brain hide caption

itoggle caption Stefano Sandrone et al., Brain

Kenyan health officials take the temperatures of passengers arriving at the Nairobi airport on Thursday. Kenya has no reported cases of Ebola, but it's a transportation hub and so is on alert. Simon Maina/AFP/Getty Images hide caption

itoggle caption Simon Maina/AFP/Getty Images

Better than Egyptian cotton: This electrically spun fabric contains anti-HIV drugs and dissolves rapidly when it gets wet. Courtesy of University of Washington hide caption

itoggle caption Courtesy of University of Washington

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