Developments to Watch
Edited by Otis Port
Gila Monsters: Can They Sharpen Your Memory?
Memories are made of many things, and one of them may soon be Gila monster spit. Dr. Matthew During, a neuroscientist at Philadelphia's Thomas Jefferson University, has discovered that a peptide found in the saliva of these lizards can dramatically improve the memories of rats. The synthetic version, dubbed Gilatide, has been licensed to Axonyx Inc. in New York, which hopes the drug will be the first to successfully boost learning and memory, as well as provide help for people suffering from attention deficit disorder and age-related memory loss.
During's inspiration stems from research showing that various peptides released in the gut interact with memory receptors in the brain. This is probably an evolutionary adaptation that helped animals remember where they caught a tasty evening meal. He studied the saliva of Gila monsters because lizards sense prey with their tongues. Colin N. Haile, an assistant professor who works with During, says Gilatide produces impressive benefits in helping rats to remember how to run a maze. "Just one administration of the drug resulted in very potent memory retention," which may last as long as 21 days, he says. Rats aren't people. But Gilatide could enter human clinical trials in two years.
By Catherine Arnst
On the Trail of "Reversible" Polymers
Towering piles of plastic containers and toys at landfills testify to the durability of polymers. Once the links are formed in the long chains of molecules that make up these materials, it's almost impossible to break the bonds and retrieve the original compounds. But by custom-designing new polymers and chemical processing techniques, engineers are closing in on keys to unlock the bonds--and on a new generation of recyclable plastics.
At the American Chemical Society's annual meeting in late August, Timothy E. Long, a chemist at Virginia Polytechnic Institute, described his work on molecules with "reversible architectures." If researchers can engineer the way polymers get glued together at the molecular level, he observes, "we should be able to take them apart."
Easier said than done. The task involves a huge investment in "mapping" the chemical behavior of molecules as they join together, or polymerize, over a range of temperatures. Doing this under controlled conditions provides essential clues to how the hydrogen bonds can later be undone. In addition to boosting the recycling of plastics, Long envisions newfangled adhesives whose stickiness can be reversed simply by applying heat.
By Neil Gross
Chips Are Getting Married at Motorola
The summer of 2001 could go down as a major turning point in semiconductors, says Steve L. Cullen, chief silicon expert at market watcher Cahners In-Stat Group in Scottsdale, Ariz. He's not talking about this year's record-setting plunge in chip sales, now projected to drop 26% from last year--far eclipsing the standing worst-ever figure, a 17% fall in 1985. Instead, he's excited about Motorola Inc.'s disclosure that it has developed a way to dramatically boost production of high-performance semiconductors made from exotic materials--other than silicon--and to marry those with conventional silicon chips.
Silicon is used for about 95% of all chips. The other 5% are made from compound materials like gallium arsenide and indium phosphide. These offer much faster transistor-switching speeds, which are vital in mobile-phone handsets, for example. Cell phones have at least two chips--a nonsilicon one for processing wireless transmissions, and a silicon chip for everything else.
Gallium- and indium-based chips cost more than silicon circuits largely because they are made from wafers no bigger than 6 inches in diameter. Motorola can now crank them out on 8-inch silicon wafers. "But even more important," says Cullen, "Motorola's technology may enable hybrid chips" for one-chip cell phones.
Normally, silicon and compound materials can't be combined because the spacing between their atoms differs. This disparity creates short-circuit flaws. Motorola gets around that by putting a special buffer layer in between. The company is currently setting up a subsidiary to license the technology.
Fuel-Cell Cars: Coming Closer--and Coming Fast
Squeaky-clean fuel cells seem a sure bet to become a dominant source of power for everything from wristwatches to cars and even cities. That's because scientists have long since mastered the trick of converting hydrogen and oxygen into electricity and water. For fuel-guzzling cars, though, revamping service stations to handle hydrogen will take many years and billions of dollars. As an interim solution, researchers have turned to so-called reformers--gadgets that extract hydrogen from fossil fuels.
Now, it looks like this costly stopgap technology may not be needed. Two University of Pennsylvania scientists, Raymond J. Gorte and John M. Vohs, have developed a fuel cell that "burns" hydrocarbons such as gas, natural gas, and even diesel fuel. Gorte and Vohs designed a modified fuel injector that sprays atomized hydrocarbon particles into a fuel cell to sustain the power-generating chemical reaction. There are carbon dioxide emissions, but Vohs says the amount is much less than that from an engine. So the new fuel cell could find its way into vehicles soon.
By Adam Aston
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Copyright 2001 , by The McGraw-Hill Companies Inc. All rights reserved.
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