retroworks sends word that a group of researchers has found a chemical that successfully rejuvenated muscle tissue in mice. The scientists "said it was the equivalent of transforming a 60-year-old's muscle to that of a 20-year-old — but muscle strength did not improve." The study (abstract) is being called an "exciting finding" but the researchers are quick to point out the chemical only reverses one aspect of aging. Damage to DNA and shortening of telomeres continues. Still, it's one piece of the puzzle, and the group is hoping to begin clinical trials in 2015.