magnets

In 2008, scientists at the Georgia Institute of Technology and the Ovarian Cancer Institute developed a potential treatment to fight cancer using magnetic nanoparticles designed to attach themselves to cancer cells. They found in their groundbreaking tests on mice that the particles not only attached to cancer cells, but they also moved those cells.

In what may well prove to be some of the most exciting health news in the year to come, the group announced in the journal Nanomedicine in December and further publicized on Tuesday that it has replicated the study on human cancer cells, with the nanoparticles … Read more

Every year product life cycles in the consumer marketplace grow ever shorter and we see ever faster turnover in cameras, phones computers, and so on. On the audio side, the latest and greatest receivers become yesterday's news faster than you can say "HDMI 1.4." It seems like no receiver can stay current for more than a year or so.

Speaker companies show a little more restraint and "refresh" their lines every few years, but even then new models rarely demonstrate actual performance improvements over the previous generations' models. Speaker manufacturer Magnepan doesn't play by those rules; it invests years of development in each of its models before introducing a new speaker. It has to sound better--a lot better--than the outgoing model before it's released to the world.

And not just in the opinion of the designers. New-model Magnepans undergo extensive "blind" listening tests with a wide range of audiophile and non-audiophile listeners (the listeners don't know whether they're hearing the old or new model). The new speaker must consistently score better than the old model before it goes into production.

When I first heard the Magneplanar 1.6 back in 2008 I said it was the best under-$2,000 speaker on the market. Incredibly enough it was 10 years old at the time! The Magneplanar 1.6 has stayed in production for 12 years, but now it's about to be replaced with the new Magneplanar 1.7.

Magnepan, based in White Bear Lake, Minn., builds nothing but panel (boxless) speakers. Not only that, Magnepan designs forgo conventional dome tweeters and cone-type woofers. As I pointed out in my August 14, 2008, blog that's why the company's Magneplanar 1.6 speaker mostly avoids sounding like a speaker. The speaker earned the top position in my Top 10 greatest audiophile speakers blog earlier this year.

The new Magneplanar 1.7 is also a flat-panel design, 64.5 inches tall and a mere 2 inches thick! The new speaker looks a little more contemporary, thanks to its aluminum, wrap-around edge molding. The old model was a two-way design, with a 48-inch-tall aluminum ribbon tweeter and a 442-square-inch mid/bass panel. The Magneplanar 1.7 is a three-way design, with a woofer, tweeter, and super-tweeter. The super-tweeter comes in around 10,000 hertz and is said to produce wider dispersion and better-resolved treble than the Magneplanar 1.6 did.

The other big difference is the Magneplanar 1.7 is a "full-range" ribbon design.… Read more

For centuries, humans have looked for signs of diseased tissue and organs by tapping the outside of the body to measure stiffness. Obviously such a method is only so effective, especially when trying to evaluate someone's liver, say, or heart. And more modern biopsies, while highly effective, are invasive procedures that involve removing tissue for examination.

Since 2007, researchers at the Mayo Clinic in Rochester, Minn., have been working with magnetic resonance elastography (MRE), a medical imaging technique developed to non-invasively diagnose and monitor disease.

The device they use, MR-Touch, uses low-frequency sound waves for just 15 seconds at … Read more

I've recently reviewed most of the contenders for the world's best headphones: the Audio Technica ATH-W5000, Denon AH-D7000, Sennheiser HD 800, Grado PS-1000, Ultrasone Edition 8, and the best headphones I've heard so far, the Stax electrostatic SR-007Mk2. I listened to the Stax with the Woo Audio WES headphone amplifier. If you want and can afford the best, go for the Stax-Woo combination.

But now I have yet another headphone to check out, and this one is a very different-sounding design. Oh, and it's less than half the price of the least expensive of those models!

It's called the Hifiman HE-5, and it uses planar-magnetic drivers to create sound. A planar magnetic driver is a large, flat Mylar diaphragm, coated with superthin aluminum, suspended between rows of slender bar magnets. The HE-5's diaphragm is therefore driven over its entire area, which dramatically reduces distortion; conventional dynamic headphone drivers are "driven" by a voice coil on the outer edge of the diaphragm, so the inner portion is more likely to distort.

The HE-5's driver is similar to the Stax electrostatic 'phones in that way, but the HE-5 doesn't use the bias charging scheme that all electrostatic headphones use, which also means the HE-5 can be used with standard headphone amplifiers. The Stax cannot.

The HE-5 is incredibly detailed sounding, but at the same time it's very smooth and laid back. Swapping between the HE-5 and the Sennheiser HD 800--considered by many to be the world's best dynamic headphone--the two headphones are opposites. The HD 800 is brighter, crisper, with more apparent treble detail; the HE-5 is softer, warmer, and more natural-sounding. … Read more

Germany has the high-end headphone market covered, as Beyer Dynamic, Sennheiser, and Ultrasone are all headquartered there.

Ultrasone is the newcomer of the group, but it's hardly new. It was founded in 1991 in Tutzing, close to the Alps in southern Germany. The headphones are manufactured in the U.S., Germany, Austria, and Taiwan.

Ultrasone has just announced a new flagship model, the HFI-2400 ($329). It features Ultrasone's S-Logic technology that promises to create "natural surround sound" by reducing pressure on the eardrum up to 40 percent. The new headphone also features ULE-technology that reduces electro-magnetic … Read more

There are many medical conditions that involve medication with intermittent doses on an as-needed basis, and often, that medication cannot be taken orally.

Scientists have long struggled with how best to deliver medication under these circumstances, where the delivery system might meet three key needs: intermittent dosing, with extreme precision, over the long term.

Research led by Daniel Kohane at Children's Hospital Boston may have hit on an effective new approach: a tiny, implantable device that releases the medication through a membrane whose porousness responds to the switching on or off of a magnetic field.

The membrane is embedded … Read more

Besides releasing the Alias 2, Samsung on Monday announced the availability of its Magnet messaging phone for AT&T. Unveiled last month at CTIA, the Magnet is a very affordable $19.99 with service and a $30 mail-in rebate.

In case you don't remember, the Magnet has a standard candy bar design in bright orange. It's positioned as a low-end messaging phone and in many ways it looks the part. The display sits above the large navigation array and full alphabetic keyboard. Features include a camera, a personal organizer, and a speakerphone. We'll post a review … Read more

Samsung is never one to be a wallflower at CTIA, but this year it arrived in Las Vegas with all cylinders firing. On Monday, two full days before the show began, Samsung announced not only the Propel Pro, but also its new Impression SGH-A877 and Magnet SGH-A257. Both offer full keyboards for messaging and e-mail. Check out our Samsung CTIA photo gallery for the beauty shots.

The Impression offers a candy-bar design with a large 3.2-inch touch-screen display. Samsung says that the Impression is the first phone in the United States with an active-matrix organic light-emitting diode (AMOLED), which … Read more

Researchers at the universities of Miami, Tokyo, and Tohoku have discovered a new form of battery.

Charged by the application of a very strong magnetic field, the Magnetic Tunnel Junction (MTJ) contains a set of nano-magnets--zones some 5 nanometers across in a zinc-gallium-arsenic-magnesium matrix--which absorb energy and then release it over time. Although the effect had been predicted, the size and duration of the result was not.

"We had anticipated the effect, but the device produced a voltage over a hundred times too big and for tens of minutes, rather than for milliseconds as we had expected," said … Read more