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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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Wild Arterial Rides
8 May 1998 7:00 pm
Blood is known to spiral as it flows through arteries, but researchers at a Royal Academy of Engineering conference announced yesterday in London that these helical streams themselves whirl like a corkscrew. What's more, the turns and branches of blood vessels encourage the swirling flow, which scours them of plaque and helps prevent atherosclerosis.
Until recently, researchers have lacked the computer power to accurately model blood flow in complex, three-dimensional geometries, says Spencer Sherwin, a fluid dynamicist at London's Imperial College of Science, Technology and Medicine. But a new computer program written by Sherwin and his colleagues appears to have at last succeeded in accurately modeling arterial blood flow: Their computations correspond well with MRI data on blood velocity within arteries, says Danesh Tafti of the National Center for Supercomputing Applications in Champaign, Illinois.
The new program could pave the way for more durable arterial grafts, natural or artificial replacements for nonfunctioning arteries, says team-member Colin Caro, a physiologist also at Imperial College. About half of all arterial grafts fail within 10 years, after becoming blocked by a thickening of the inner wall. This might happen because surgeons tend to join grafts at right angles to vessel walls in a single flat plane, rather than having them curve in like a freeway onramp as natural vessels do.
Sherwin's team now plans to use simulations and MRI scans of actual arteries to determine the optimum angle of arterial grafts to maintain swirling blood flow that could prevent blockages.
"The blood flow findings are obviously important for improving arterial graft construction," says Michael Bettmann, a cardiovascular specialist at Dartmouth-Hitchcock Medical Center of Dartmouth in New Hampshire, "but they also may be relevant to evolving new techniques, primarily nonoperative ones for treating peripheral arterial diseases."