A capsule newsletter of science and technology news briefs from NIST written for general audiences; published monthly

September 1997

Tech Beat

In This Issue:

blueball.gif - 0.93 KThe Quietest Place on Earth
blueball.gif - 0.93 KRounding (Up) the (DNA) Basis in Record Time
blueball.gif - 0.93 KFire Research Tackles Perils of New Firefighter Technology
blueball.gif - 0.93 KCube-Shaped Carbon Molecules Don't Stack Up
blueball.gif - 0.93 KCholesterol Tests Are Much More Accurate Thanks to NIST
blueball.gif - 0.93 KAgencies Cooperate to Boost Quality of Implant Materials
blueball.gif - 0.93 KTech Trivia

[Credits] [NIST Tech Beat Archives] [Media Contacts] [Subscription Information]

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The Quietest Place on Earth

Want to get away from it all? We've found the quietest place on Earth, literally. Of course, you'll need a pressure suit to enjoy it, because it's housed inside a vacuum, but it will be a million times quieter than any place you're likely to find this side of outer space.

Researchers at JILA, a joint endeavor of the University of Colorado and the National Institute of Standards and Technology, are building the most vibration-free platform on Earth. The structure is being built to support components of an experiment to detect gravity waves coming from the cosmos, but the principles involved may be applied to many other applications. Vibration and noise isolation are important considerations for many scientific experiments and measurements and for an increasing number of manufacturing processes in industry, such as integrated circuit fabrication and diamond turning of super-smooth surfaces.

The JILA isolation system consists of three stages, each isolated from movement in all directions. The stages are suspended from helical springs (the largest similar to garage-door springs) and use extremely sensitive motion sensors, non-contacting magnetic forcers and electronic servo-control circuits to actively counteract platform motion. It filters out the vibrations from every source, even those from ocean waves pounding the beach over a thousand miles away.

Media Contact:
Collier Smith (Boulder) (303) 497-3198

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Rounding (Up) the (DNA) Bases in Record Time

A new DNA sequencing technology has been developed by GeneTrace Systems Inc. of Menlo Park, Calif., that gets results hundreds of times faster than current methods at a fraction of the cost. This research is expected to lead to highly effective new drugs and widely available tests for disease diagnosis and human identification such as forensic and paternity testing.

Co-funded by the National Institute of Standards and Technology's Advanced Technology Program, the company developed the technology needed to apply fast and accurate mass-spectrometry techniques to the identification of DNA fragments. The system identifies the sequence of base chemicals in a given DNA strand in as little as five seconds rather than the three hours required for conventional DNA separation methods.

GeneTrace reduced labor costs by using a robotics system for initial sample handling. The process combines DNA probing, sequencing and sizing reactions with mass spectrometry. Eight patents are pending. The company expects its technology to lead to genetic screening tests for as little as a few dollars, compared with the $300 to $5,000 required today.

Several companies now are using GeneTrace's technology for pilot projects focusing on gene discovery and expression, genotyping and other topics.

Media Contact:
Michael Baum (301) 975-2763

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Fire Research Tackles Perils of New Firefighter Technology

Despite advances in firefighter protective clothing and use of innovations such as the self-contained breathing apparatus, approximately 6,000 U.S. firefighters suffer from serious burns each year. Ironically, modern technology can contribute to the risk of burn injury. New attire allows firefighters to advance much farther into hostile environments. Today's building, furniture and interior design materials often release more heat energy than those of yesterday. Even water can be a two-edged sword in today's super hot fires. Water spray can cool gear for a limited period of time, but potentially life-threatening burns can occur almost instantaneously if moisture inside the garment evaporates or turns to steam.

Researchers in the National Institute of Standards and Technology's Fire Safety Engineering Division are working with industry and firefighter organizations to develop tools to measure the fire environment and effectiveness of protective clothing. They have developed computer models for predicting heat transfer through firefighters' compressed clothing as well as tests to understand the effect of moisture in the garments. In addition to laboratory work, the NIST fire safety engineers conduct field studies of the environment where injuries can occur and examine garments worn by severely or fatally injured firefighters. Information gained should help improve protective clothing and could change firefighter training, individual tactics and on-the-scene firefighting management.

Media Contact:
John Blair (301) 975-4261

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Cube-Shaped Carbon Molecules Don't Stack Up

Next time you pass by a bin full of oranges at the supermarket, consider how they're stacked. This arrangement of tightly packed spheres is often repeated when substances known as molecular solids (fullerenes being one example) are heated to a point where the individual molecules in the solid tumble rapidly about their centers, thereby looking like spheres. Such an arrangement was expected of the remarkable molecular solid known as cubane. First synthesized in 1964, cubane is a cube-shaped molecule with a carbon and hydrogen atom at each corner. The military has been studying cubane derivatives since they show potential as incredibly powerful explosives. Other cubane derivatives show potential for treating AIDS, cancer and Parkinson's disease.

Scientists at the National Institute of Standards and Technology's Center for Neutron Research recently discovered that at high temperatures, cubane molecules do not conform to the expected lattice configuration. Instead, because of the cubic geometry, the molecules organize into a rhombohedral grid (imagine a box squashed along one diagonal axis). NIST scientists measured cubane's unusual properties using neutrons and X-rays in experiments made more difficult by its tendency to convert quickly from a solid to a gas. These studies have provided scientists with a model that correctly predicts the observed structure, an important first step in developing the technological applications of other cubane-based compounds.

Media Contact:
Linda Joy (301) 975-4403

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Cholesterol Tests Are Much More Accurate Thanks to NIST

More and more Americans are aware of their own cholesterol level and risk for heart disease. However, many are unaware of how much the accuracy of cholesterol tests has improved in recent years. As recently as 1980, the measurement uncertainty for cholesterol tests was more than 10 percent. This wide margin of uncertainty meant that large numbers of people were misdiagnosed as needing treatment when they did not, or not needing treatment when they did.

Today, thanks to efforts by the National Institute of Standards and Technology and the Centers for Disease Control and Prevention, the uncertainty has been cut to 5 percent. A newly available NIST Standard Reference Material will help instrument manufacturers and clinical laboratories ensure consistently accurate patient results. SRM 1951a, Lipids in Frozen Human Serum, provides reference values for cholesterol and triglycerides in serum.

Improvements in cholesterol measurements from 1969 to the present save millions of dollars per year in unneeded treatment costs and improve the quality of health care. NIST has helped improve the measurement uncertainty in three ways: First, NIST has developed high-accuracy reference measurement methods. Secondly, NIST developed several Standard Reference Materials that are used to ensure reliable and accurate determinations of cholesterol values. Thirdly, NIST is closely linked to more than 20,000 U.S. clinical laboratories through work with the College of American Pathologists.

Media Contact:
Linda Joy (301) 975-4403

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Agencies Cooperate to Boost Quality of Implant Materials

For patients who need pacemakers or orthopedic joint implants, these miracles of modern technology can be life enhancing. But how can those patients and the medical community be sure the devices are made of high-quality materials? One way is for manufacturers to compare the plastics and other materials they use to make medical devices with reference materials that have been certified for properties such as chemical composition and structure. Even slight inconsistencies in the material could change the body's reaction to an implant, possibly even leading to a dangerous reaction.

Three government agencies are working together to develop such reference materials for "biomaterials," or the materials used for medical purposes. Because only a few reference materials, such as those for bone substitutes, are available or under development today, the National Institute of Standards and Technology, the Food and Drug Administration and the National Institutes of Health are cooperating to provide more of these critical measurement tools to ensure quality in this rapidly developing industry. Initial cooperative development efforts are aimed at cardiovascular reference materials.

Media Contact:
Anne Enright Shepherd (301) 975-4858
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Tech Trivia

Radioactive isotopes are used in 200,000 therapeutic procedures per year and 36,000 diagnostic procedures per day in the United States. Of these, 100 percent of the therapeutic procedures, such as reducing bone cancer pain, and about 60 percent of the diagnostic procedures, such as brain, heart or tumor imaging, are traceable to a NIST radiopharmaceutical standard.

In 1956, experiments at the National Bureau of Standards disproved a long-held theory known as the conservation of parity, which stated that a process and its mirror image are indistinguishable. Link to a WWW virtual exhibit on the experiments from http://physics.nist.gov by selecting "General Interest."

Take a smattering of dregs from the Irish Sea, mix it with a healthy dollop of lees from the Chesapeake Bay, and what do you get? NIST's ocean sediment Standard Reference Material, which soon will join others for measurements of radioactive elements in river and lake sediments, soil, and human lung and liver.

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U.S. Department of Commerce
Technology Administration
National Institute of Standards and Technology

Editor: Linda Joy
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Crissy Wines

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