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5 December 2013 11:26 am ,
Vol. 342 ,
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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Can Pac-Man Save Us From Radioactive Waste?
16 January 2008 (All day)
If chemicals were people, uranium dioxide would be the guy standing alone with his drink at a party. The world's most commonly used radioactive substance--and its heaviest natural element--clutches its two oxygen atoms so tightly, it almost never reacts with other compounds. Now researchers report finding a way to pry one oxygen atom loose, potentially opening up safer ways to handle and dispose of this nuclear antisocialite.
Uranium's heavy atomic weight makes it radioactive but only weakly so. Its greatest hazard to the environment is that it's a toxic metal. Worse, uranium's chemistry makes it very difficult to remove from water, causing it to be a very persistent and dangerous pollutant. To make uranium more reactive, a team of U.K. researchers employed what they call a "Pac-Man" strategy--named for the popular 1980s video game. After testing many alternatives, the chemists found an organic molecule that clamps down--like Pac-Man--on one of uranium dioxide's oxygen atoms. This weakens uranium's grip on the other oxygen, the researchers report tomorrow in Nature, allowing it to react with one of the new molecule's silicon atoms.
It's only a first step, says lead author Polly Arnold of the University of Edinburgh, U.K. The resulting compound is not stable enough to be useful in waste disposal just yet, but the new insights about uranium chemistry could eventually pay off with new technologies, she says. For one, the new molecule might help environmental scientists discover novel ways of extracting uranium dissolved in contaminated water, which constitutes a large portion of uranium pollution.
The findings "constitute breakthrough research in this area," says chemist William Evans of the University of California, Irvine. This approach to making uranium reactive suggests new directions for attacking the element's inert nature and may "model the principles that lead to [uranium] degradation in nature," which remain unknown, he says.