Silver, hydrogen peroxide stronger disinfectant when combined with water Experts explore steps for laundry in space

Arizona, May 14: Nasa is funding a project by Christina Morrison, undergraduate research assistant at University of Arizona College of Engineering to make life of astronauts more comfortable in space by making clothes stay cleaner for longer time.

Don Pettit, a University of Arizona College of Engineering alumnus, wore the same pair of shorts for months at a time while living on the International Space Station because doing laundry was not an option.

When clothes got too dirty, Pettit and his crewmates stored them onboard until they could be thrown out — launched with other debris on a spacecraft and incinerated upon entering Earth’s atmosphere.

Clothes add a lot of weight to spacecraft, and water is too precious to be used for cleaning them. So Morrison’s goal is to find a way for astronauts to do laundry in space without using water. Silver and hydrogen peroxide are both known germ-fighters, and research has shown they become an even stronger disinfectant when combined and applied to water.

Working with UA professor of microbiology Charles Gerba, Morrison has for the first time demonstrated that this synergistic effect works on textiles, too. Morrison and Gerba applied low concentrations of hydrogen peroxide to swatches of antimicrobial socks embroidered with silverion threads and exposed the treated material to Staphyloco-ccus aureus, a bacterium often found in the nose and on the skin. The researchers compared how the germs fared on these swatches versus how they did on untreated antimicrobial material and on regular socks.

Within an hour, they were able to achieve a nearly 5-log reduction, or about 99.999 per cent, of the bacteria on treated antimicrobial socks. That is compared with a 0.25 log reduction, or 43.76 per cent, on untreated silverion socks, said Morrison, a senior in chemical and environmental engineering who already holds a bachelor's degree in ecology and evolutionary biology from the UA.

“In a sense, we were laundering or washing the antimicrobial socks with hydrogen peroxide,” she said. — Agencies Lyon, May 13: A 19th century crown, encrusted with almost 1,800 gem stones, was stolen from a museum of religious art in central France, the museum authorities said. The thieves broke in overnight Friday and managed to overcome the “sophisticated security system” at the Museum of Fourviere in the city of Lyon, the museum said in a statement. They got away with the Crown of the Virgin, the centrepiece of the collection, which was created in 1899 with 1,791 precious stones and pearls gifted by wellto-do Lyonese families of the day. The value of the piece was put at “a little over a million euros”.

Each gemstone was painstakingly logged last year by a team of researchers, the museum said. — AFP