New clotting drug antidote could cut surgery risk

Chemistry WorldJon Cartwright

Published in Chemistry World, 20 Apr 2011

Chemists in the UK have developed a possible alternative to protamine, a molecule used by doctors to counteract the effects of anti-clotting drugs. Unlike protamine, the new molecule should easily break down into less toxic metabolites, although it hasn’t yet been tested in human blood or plasma.

Physicians often use anti-clotting agents to treat blood disorders, or to prevent blood clotting during surgery. One of the most popular anti-clotting agents is heparin, which has been used since the 1930s. But in order to combat dangerous overdoses of heparin, or to inactivate it after surgery is complete, physicians need a heparin binder. The only clinically approved heparin binder is protamine, but this agent sometimes causes severe allergic reactions, so scientists are keen to develop alternatives. […]

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Brightest bubble bursting yet

Physics WorldJon Cartwright

Published in Physics World, 15 Apr 2011

Physicists in the US claim to have broken the record for the brightness of light generated by “sonoluminescence”, the imploding of a bubble when it is blasted with sound waves. With a peak power of 100 W, the light is 100 times as bright as seen in previous sonoluminescence experiments, and may help scientists understand how the strange phenomenon works.

Sonoluminesence was discovered in the first half of the 20th century but it was only in the 1990s that physicists began to investigate the phenomenon seriously. Although no-one is sure how it works, the basic idea is that sound waves are fed into a vessel containing one or more bubbles inside a liquid. The sound causes the bubbles to expand momentarily before water pressure takes over, imploding the bubbles in bursts of heat and light. […]

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How to Keep a Riderless Bike From Crashing

ScienceJon Cartwright

Published in ScienceNOW, 14 Apr 2011

Give a riderless bike a push, and chances are it will cruise along for a bit without tipping over. Scientists have long thought they understood the physics of what keeps the bike upright. But a new study shows that much of what they believed is wrong.

Researchers assumed that two mechanisms kept a riderless bike upright. First is the “caster effect,” which relies on the position of the front wheel relative to the steering axis—the imaginary line that extends from the front forks downward. On most bikes, the front wheel meets the ground just behind this axis, so it tends to center itself like the casters on a shopping cart. The other mechanism is known as gyroscopic precession: Because the front wheel is spinning forward, any tilt to the left or right creates a force that will steer the bike in that direction, pulling it out of the fall. […]

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A Vase Made From DNA

ScienceJon Cartwright

Published in ScienceNOW, 14 Apr 2011

Scientists have fashioned perhaps the most elaborate piece of DNA origami yet: a tiny three-dimensional vase just 70 nanometers tall. For 5 years, researchers have been able to create nanostructures out of DNA, but until now most of the shapes have been fairly boring, like boxes or polygons, because they needed to be folded around a grid of DNA pegs or “pixels.” In their paper published online today in Science, researchers describe a new origami technique, in which they begin by forming rings of different radii with DNA strands. […]

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New cream blocks nickel allergy

Chemistry WorldJon Cartwright

Published in Chemistry World, 4 Apr 2011

Researchers in the US claim to have made a cream to combat nickel allergy. The treatment uses nanoparticles to trap nickel on the skin of mice before it is absorbed- but there is some doubt whether it will work equally well with humans.

Nickel sensitivity occurs when the metal accumulates inside the skin and triggers an immune reaction, including rashes and inflammation. The condition is not inherited but develops from prolonged skin contact with the metal -from working in nickel environments, such as battery manufacture, or wearing nickel-plated jewellery. In the UK, around ten per cent of the population is affected. […]

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Nanotubes spot damage

Chemistry WorldJon Cartwright

Published in Chemistry World, 30 Mar 2011

Researchers in the US have created a new system for monitoring structural damage in real time. Based on a carbon nanotube composite, the system uses thermal imaging to reveal areas of unsafe cracks and stresses.

Damage detection systems are already used in some civil structures and aircraft. In helicopters, for instance, systems monitor the vibration of gearboxes and bearings to spot dangerous behaviour before anything fails. Other systems use strain gauges with computer models to predict when structures are close to fracture. […]

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Superconductivity from nowhere

Physics WorldJon Cartwright

Published in Physics World, 29 Mar 2011

In just over a week scientists will celebrate the centenary of superconductivity: the discovery, in 1911, that some materials cooled towards absolute zero allow electric charge to flow without resistance. But now one physicist believes superconductivity can appear when there is no material at all.

According to Maxim Chernodub of the Université François-Rabelais Tours in France, superconductivity can appear – provided there is a very strong magnetic field – in the vacuum of empty space. If Chernodub is correct, the phenomenon could explain the origin of the extensive magnetic-field patterns seen in the cosmos. “This suggested vacuum superconductivity is very unusual,” he says. “It has a few crazy properties that do not exist in ‘normal’ superconductors.” […]

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Antibacterial clays kill with iron

Chemistry WorldJon Cartwright

Published in Chemistry World, 23 Mar 2011

US researchers have made a step towards understanding why some natural clays are antibacterial, boosting the chances that they could one day be used as alternatives to antibiotic drugs. According to the researchers, the clays supply iron that kills bacteria by generating radicals that attack cell components.

People have used clays throughout history for healing. More recently, patients in Ivory Coast suffering from a flesh-eating disease known as Buruli ulcer were treated with French green clays. The clays appeared to ease the swelling of the lesions like an antibiotic, but no-one knew how they did it. […]

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The Strange Symphony of the Stock Traders

ScienceJon Cartwright

Published in ScienceNOW, 17 Mar 2011

Phones incessantly ringing, people shouting “Buy! Sell!” across the office, prices flashing across computer screens—it looks like chaos. But stock trading firms are actually home to a remarkable harmony, according to a new study. Researchers have found that, in at least one firm, traders synchronize their buying and selling behavior with amazing precision. And that seems to tie in with greater profits.

Sociologist Brian Uzzi of Northwestern University in Evanston, Illinois, and colleagues analyzed all trades taking place in a single firm of 66 employees over 2 years. As is usual in trading firms, the employees specialized in different markets—housing, autos, or health care, for example—so they had no obvious incentive to copy one another’s behavior. Each trader typically bought or sold stocks about 80 times a day, which the researchers allotted to second-long time windows. […]

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Light Slows at the Nanoscale

ScienceJon Cartwright

Published in ScienceNOW, 16 Mar 2011

It sounds like a magic trick: slowing down light, often to a standstill. Yet physicists have done it many times in a variety of media, from gases to diamonds. Now a U.S. group has achieved the feat on nanoscale silicon chips—an advance that could be a step toward building “quantum” networks that are fundamentally secure.

Some of the most effective ways to slow light came in the late 1990s. Researchers were learning how to take an opaque medium—typically a gas of atoms—and turn it transparent by zapping it with a laser tuned to a certain frequency. The laser would jolt the gas’s atoms into a new energy state in which they could no longer absorb light and had to let it pass—the definition of transparency. […]

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