CAPE CANAVERAL, Fla., Aug. 21 (UPI) -- Space shuttle Endeavour landed safety Tuesday at the Kennedy Space Center in Florida, completing a 13-day mission to the International Space Station.

The spacecraft landed without incident about 12:32 p.m. EDT Tuesday on a 15,000-foot long, 300-foot-wide space center runway that's about twice the size of a regular runway, officials said.

A National Aeronautics and Space Administration physician conducted a brief physical examination of the seven astronauts shortly after the landing and before the crew was transported five miles back to the space center's astronaut headquarters.

Endeavour returned two weeks after it was launched from the Florida spaceport. While at the station, the astronauts conducted four spacewalks to continue in-orbit construction and repair work at the station.

STS-118’s stay at the space station also included the successful test of a station-to-shuttle power transfer system that allows power generated by the station to be routed to a docked shuttle. The system will allow future shuttle missions to remain at the station for longer periods of time.

NASA said the next space station shuttle mission is targeted for a late October launch.

Hydrogen peroxide may be disease indicator

ATLANTA, Aug. 21 (UPI) -- U.S. scientists have, for the first time, imaged hydrogen peroxide in animals as an early indicator of disease.

Georgia Institute of Technology and Emory University researchers created a nanoparticle capable of detecting and imaging trace amounts of hydrogen peroxide in animals. The scientists said such non-toxic nanoparticles might be used as a simple, all-purpose diagnostic tool to detect the earliest stages of any chronic inflammatory disease, such as cancer, Alzheimer’s disease and arthritis.

Hydrogen peroxide is thought to be over-produced by cells during the early stages of most diseases. But since there have been no imaging techniques available to capture that process in the body, details of how hydrogen peroxide is produced and its role in a developing disease must still be determined.

"These nanoparticles are incredibly sensitive so you can detect nanomolar concentrations of hydrogen peroxide," said Niren Murthy of Georgia Tech. "That’s important because researchers aren’t yet certain what amounts of hydrogen peroxide are present in various diseases."

The research led by Murthy and Robert Taylor at Emory University will appear in journal Nature Materials.

Advanced prosthetic arm is developed

NASHVILLE, Aug. 21 (UPI) -- U.S. scientists have developed a mechanical arm powered by a miniature rocket motor that is the closest thing yet to a bionic arm.

Vanderbilt University researchers created the prototype device as part of a $30 million federal program to advance prosthetic device technology.

"Our design … is closer in terms of function and power to a human arm than any previous prosthetic device that is self-powered and weighs about the same as a natural arm," said Professor Michael Goldfarb, who led the research. The prototype can lift about 20 to 25 pounds -- three to four times more than current commercial arms -- and can do so three to four times faster.

The Vanderbilt arm is believed the most unconventional of three prosthetic arms under development. The other two are being designed by researchers at Johns Hopkins University in Baltimore.

The federal program is also supporting teams of neuroscientists at the University of Utah, the California Institute of Technology and the Rehabilitation Institute of Chicago who are developing advanced methods for controlling the arms by connecting them to nerves in the users' bodies or brains.

Common virus may contribute to obesity

BATON ROUGE, La., Aug. 21 (UPI) -- A U.S. study suggested that infection with a common virus might be a contributing factor in the development of obesity.

Louisiana State University researchers said they've found laboratory evidence that infection with human adenovirus-36 -- long recognized as a cause of respiratory and eye infections -- transforms adult stem cells obtained from fat tissue into fat cells. Stem cells not exposed to the virus, in contrast, were unchanged.

In addition the researchers at LSU's Pennington Biomedical Research Center identified a specific gene in the virus that appears to be involved in the obesity-promoting effect.

"We're not saying that a virus is the only cause of obesity but this study provides stronger evidence that some obesity cases may involve viral infections," said Dr. Magdalena Pasarica.

The findings, which could lead to a vaccine or antiviral medication to help fight viral obesity, were presented Monday in Boston during the 234th national meeting of the American Chemical Society.