Developments to Watch
DIGITAL VIDEO'S NEXT GENERATION?
THE FIRST BATCH OF digital videodisks to hit the market pack full-length movies onto a single disk. But the players can't record, which means they probably won't replace VCRs in most living rooms. To address this issue, manufacturers are already hard at work on recordable DVD players, due in 1999. But at least one top maker--Sony Corp.--says current technology can't be extended to store high-definition images, which require more digital storage room than current-generation TV images.
So Sony has struck out on its own. By 2000, it hopes to commercialize an optical disk system that can record 12 gigabytes of data on one side of a standard 12-centimeter disk. That's 4.6 times as much as DVD-RAM, a recordable version of DVD, hitting the market as a computer storage device. Sony's prototype can record 5 hours of conventional TV programming or 1.2 hours of high-definition TV.
To inscribe the billions of bits that represent pictures and sounds on disks, the prototype uses a highly focused blue-green laser. Sony also changed the disk structure from that of DVDs. Eventually, Sony plans to move to pure blue lasers, which can pack data about 50% more densely. The biggest hurdle: making the lasers more robust. Sony's blue-green laser lasts only
10 hours vs. 10,000 required for a commercial
product.EDITED BY NEIL GROSS Steven V. BrullReturn to top
SNEAKING UP ON THE SUPERBUGS
IN THE BATTLE AGAINST drug-resistant superbugs, the antibiotic of choice is losing ground. Vancomycin is used in most hospitals to kill bacteria that nothing else can touch. But in May, doctors in Japan reported a strain of Staphylococcus aureus that is resistant to the drug. This bug causes nasty blood and respiratory infections, which are often fatal if left untreated.
To make the picture grimmer, vancomycin--a peptide derived from a soil microbe--has a large and complex structure, making it difficult to synthesize chemically. "Since you can't synthesize the parent compound, it's hard to spin off derivatives," says Patrick J. Loll, an assistant professor of pharmacology at the University of Pennsylvania Medical Center. So when bugs develop resistance, drugmakers are left helpless.
Earlier this year, Loll had a breakthrough. Working with Dr. Paul H. Axelsen, a fellow assistant professor and supercomputer ace, Loll identified the 3-D atomic structure of vancomycin (picture). Now, the two scientists are using computers to predict which possible variant would be most effective against resistant Staph. "Once you have something that has a reasonable chance of working, it's worth killing yourself to try to synthesize it," he says.EDITED BY NEIL GROSSReturn to top
A GAMMA CAMERA THAT'S NO MONSTER
SINCE THEIR INVENTION IN THE 1950S, GAMMA RAY cameras have offered an important window on disease. Patients are fed or injected with radioactive isotopes combined with other compounds that concentrate in certain organs or in tumors. Arrays of photomultiplier tubes detect the gamma rays and pass the signals to computers that assemble an image. But the tubes are bulky. Typical cameras weigh 3,000 pounds or more and are usually confined to nuclear medicine departments in the basements of large hospitals (picture).
Soon, however, these clumsy photo tubes may go the way of vacuum tubes in computers and TVs. After 10 years of research and testing, scientists at Digirad Corp. in San Diego have received Food & Drug Administration approval for a solid-state gamma camera that attaches to a personal computer and weighs just 50 pounds. It replaces tubes with semiconductor crystals of cadmium-zinc-telluride, sandwiched with custom silicon chips.
Physicians who have used the camera shower praise on it. Placed in an emergency room, it could, for example, help doctors decide which heart attack patients need immediate interventions, says Michael Kipper, associate professor of radiology at the University of California at San Diego. Unlike traditional gamma cameras, compact models also would be viable in small breast-cancer centers, says Kipper, who has no financial connection to Digirad. There, they might see things a mammogram would miss. "This camera lets you look at the inner aspect of the breast and see if a biopsy is needed," Kipper says.EDITED BY NEIL GROSSReturn to top