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Tech Beat - November 8, 2007

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Editor: Michael Baum
Date created: April 16, 2012
Date Modified: April 16, 2012 
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Bug-Zapper: A Dose of Radiation May Help Knock Out Malaria

How are physicists helping an effort to eradicate malaria, the mosquito-borne disease that kills more than one million people every year? Researchers at the National Institute of Standards and Technology (NIST) used their expertise in radiation science to help a young company create weakened, harmless versions of the malaria-causing parasite. These parasites, in turn, are being used to create a new type of vaccine that shows promise of being more effective than current malaria vaccines.

photo of mosquito on skin
Credit: Sinclair Stammers/Peter Billingsley

The new vaccine is a departure from previous approaches, which have usually depended on proteins derived from only part of the parasite Plasmodium falciparum, the most dangerous species of parasite that causes malaria. Using vaccines based on whole living parasites had been on scientists’ minds for several decades, after they discovered that volunteers built up high levels of protection to malaria after being exposed to mosquitoes containing live, radiation-weakened parasites. But manufacturing technology only recently has been developed to the point where it is possible to efficiently extract weakened parasites from their mosquito carriers in order to make a vaccine.

With their knowledge of measuring radiation doses for industrial processes such as medical equipment sterilization, NIST researchers have been lending their expertise for several years to Maryland-based biotech firm Sanaria Inc., which is creating the new vaccine. In the manufacturing process, live mosquitoes containing the parasite are exposed to gamma rays. To ensure that the parasites are sufficiently weakened for the vaccine, yet remain alive, they must be exposed to a radiation dose of at least 150 gray, but not much more. Coincidentally, this is also the dose used to delay sprouting in potatoes and onions.

One critical design issue is ensuring a relatively uniform radiation dose regardless of where the mosquito is in the chamber. Using radiation-sensitive test materials inside the chamber as well as sophisticated measuring equipment, NIST researchers mapped out the radiation dose at different parts of the chamber. They initially found there was a variation in dose within the chamber, but by suggesting that the manufacturer change the position of the chamber relative to the radiation source they were able to significantly reduce this variation in dose. This not only increases the speed of the process, but more importantly improves the quality of the process. To be safe for human trials all mosquitoes in the chamber must get their minimum dose of 150 gray.

The vaccine is currently being manufactured for the anticipated human clinical trials. NIST researchers will continue to be active in the manufacturing process by doing regularly scheduled quality-assurance tests that ensure the desired dose is being delivered to the mosquitoes.

Stephen Hoffman, Sanaria’s CEO and Chief Scientific Officer, will describe the development of the malaria vaccine at a colloquium on Nov. 16 at NIST’s Gaithersburg, Md., campus. For information on attending, see www.nist.gov/public_affairs/colloquia/20071116.htm.

Media Contact: Ben Stein, bstein@nist.gov, 301-975-3097

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Micro Microwave Does Pinpoint Cooking for Miniaturized Labs

Researchers at the National Institute of Standards and Technology (NIST) and George Mason University have demonstrated what is probably the world’s smallest microwave oven, a tiny mechanism that can heat a pinhead-sized drop of liquid inside a container slightly shorter than an ant and half as wide as a single hair. The micro microwave is intended for lab-on-a-chip devices that perform rapid, complex chemical analyses on tiny samples.

photograph of the NIST micro microwave oven
Photograph of the NIST micro microwave oven. The gold traces on the glass disk are microwave transmission lines. The 1.25 centimeter wide polymer block over one of the transmission lines houses a miniature chamber in which a pinhead-sized drop of fluid can be heated. The large devices on either side of the polymer block are microwave probes.
Credit: Denease Anderson/NIST
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photomicrograph of the NIST micro microwave oven's miniature heating chamber
Photomicrograph of the NIST micro microwave oven's miniature heating chamber (top) containing fluid and a single mouse cell (about 5 micrometers, or millionths of a meter) in diameter. Below, a human hair (about 50 micrometers in diameter) is seen as a size reference.
Credit: NIST
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Close up of the NIST micro microwave oven
NIST researcher Jayna Shah

In a paper in the November 2007 Journal of Micromechanics and Microengineering*, the research team led by NIST engineer Michael Gaitan describes for the first time how a tiny dielectric microwave heater can be successfully integrated with a microfluidic channel to control selectively and precisely the temperature of fluid volumes ranging from a few microliters (millionth of a liter) to sub-nanoliters (less than a billionth of a liter). Sample heating is an essential step in a wide range of analytic techniques that could be built into microfluidic devices, including the high-efficiency polymerase chain reaction (PCR) process that rapidly amplifies tiny samples of DNA for forensic work, and methods to break cells open to release their contents for study.

The team embedded a thin-film microwave transmission line between a glass substrate and a polymer block to create its micro microwave oven. A trapezoidal-shaped cut in the polymer block only 7 micrometers across at its narrowest—the diameter of a red blood cell—and nearly 4 millimeters long (approximately the length of an ant) serves as the chamber for the fluid to be heated.

Based on classical theory of how microwave energy is absorbed by fluids, the research team developed a model to explain how their minature oven would work. They predicted that electromagnetic fields localized in the gap would directly heat the fluid in a selected portion of the micro channel while leaving the surrounding area unaffected. Measurements of the microwaves produced by the system and their effect on the fluid temperature in the micro channel validated the model by showing that the increase in temperature of the fluid was predominantly due to the absorbed microwave power.

Once the new technology is more refined, the researchers hope to use it to design a microfluidic microwave heater that can cycle temperatures rapidly and efficiently for a host of applications.

The work is supported by the Office of Science and Technology at the Department of Justice’s National Institute of Justice.

* J.J. Shah, S.G. Sundaresan, J. Geist, D.R. Reyes, J.C. Booth, M.V. Rao and M. Gaitan. Microwave dielectric heating of fluids in an integrated microfluidic device. Journal of Micromechanics and Microengineering, 17: 2224-2230 (2007)

Media Contact: Michael E. Newman, michael.newman@nist.gov, 301-975-3025

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New Scoring System Protects Credit Card Transactions

As this year’s holiday season approaches, your credit card transactions may be a little more secure thanks to standards adopted by the payment card industry. The latest incarnation of these standards includes the Common Vulnerability Scoring System (CVSS) Version 2 that was coauthored this year by researchers at the National Institute of Standards and Technology and Carnegie Mellon University in collaboration with 23 other organizations.

compilation photo of credit card images
NIST image, photos copyright Shutterstock

When you make an electronic transaction—either swiping a card at a checkout counter or through a commercial Web site—you enter personal payment information into a computer. That information is sent to a payment-card “server,” a computer system often run by the bank or merchant that sponsors the particular card. The server processes the payment data, communicates the transaction to the vendor, and authorizes the purchase.

According to NIST’s Peter Mell, lead author of CVSS Version 2, a payment-card server is like a house with many doors. Each door represents a potential vulnerability in the operating system or programs. Attackers check to see if any of the “doors” are open, and if they find one, they can often take control of all or part of the server and potentially steal financial information, such as credit card numbers.

For every potential vulnerability, CVSS Version 2 calculates its risks on a scale from zero to 10, assessing how the vulnerability could compromise confidentiality (exposing private information such as credit card numbers), availability (could it be used to shut down the credit card system?) and integrity (can it change credit card data?). The CVSS scores used by the credit card industry are those for the 28,000 vulnerabilities provided by the NIST National Vulnerability Database (NVD), sponsored by the Department of Homeland Security.

To assess the security of their servers, payment card vendors use software that scans their systems for vulnerabilities. To promote uniform standards in this important software, the PCI (Payment Card Industry) Security Standards Council, an industry organization, maintains the Approved Scanning Vendor (ASV) compliance program, which currently covers 135 vendors, including assessors who do onsite audits of PCI information security. By June 2008, all ASV scanners must use the current version of CVSS in order to identify security vulnerabilities and score them. Requiring ASV software to use CVSS, according to Bob Russo, General Manager of the PCI Security Standards Council, promotes consistency between vendors and ultimately provides good information for protecting electronic transactions. The council also plans to use NIST’s upcoming enhancements to CVSS, which will go beyond scoring vulnerabilities to identify secure configurations on operation systems and applications.

To learn more, see:

Media Contact: Ben Stein, bstein@nist.gov, 301-975-3097

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NIST Issues Call for a New 'Hash' Algorithm

The National Institute of Standards and Technology (NIST) has opened a competition to develop a new cryptographic "hash" algorithm, a tool that converts a file, message or block of data to a short "fingerprint" for use in digital signatures, message authentication and other computer security applications. The competition is NIST’s response to recent advances in the analysis of hash algorithms. The new hash algorithm will be called Secure Hash Algorithm-3 (SHA-3) and will augment the hash algorithms currently specified in the Federal Information Processing Standard (FIPS) 180-2, Secure Hash Standard. NIST’s goal is that SHA-3 provide increased security and offer greater efficiency for the applications using cryptographic hash algorithms. FIPS standards are required for use in federal civilian computer systems and are often adopted voluntarily by private industry.

FIPS 180-2 specifies five cryptographic hash algorithms, including SHA-1 and the SHA-2 family of hash algorithms. Because serious attacks have been reported in recent years against cryptographic hash algorithms, including SHA-1, and because SHA-1 and the SHA-2 family share a similar design, NIST has decided to standardize an additional hash algorithm to augment the ones currently specified in FIPS 180-2.

NIST issued a Call for a New Cryptographic Hash Algorithm (SHA-3) Family in a Federal Register Notice on Nov. 2, 2007. The announcement specifies the submission requirements, the minimum acceptability requirements, and the evaluation criteria for candidate hash algorithms. Entries for the competition must be received by Oct. 31, 2008. Details about the competition are available at www.nist.gov/hash-competition.

Media Contact: Ben Stein, bstein@nist.gov, 301-975-3097

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Mini Magnetic Sensor May Have Biomedical, Security Applications

magnetometer
In NIST’s new mini-magnetometer, light from a laser (small gray cylinder at left) passes through a small container (green cube) containing atoms in a gas. The cell and any sample being tested are placed inside a magnetic shield (large grey cylinder). When no sample is present (top) the atoms’ “spins” align themselves with the laser beam, and virtually all the light is transmitted through the cell to the detector (blue cube). In the presence of a sample emitting a magnetic field, such as a bomb or a mouse, the atoms become more disoriented as the field gets stronger, and less light arrives at the detector. By monitoring the signal at the detector, scientists can determine the strength of the magnetic field.
Copyright Loel Barr
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A tiny sensor that can detect magnetic field changes as small as 70 femtoteslas—equivalent to the brain waves of a person daydreaming—has been demonstrated at the National Institute of Standards and Technology (NIST). The sensor could be battery-operated and could reduce the costs of noninvasive biomagnetic measurements such as fetal heart monitoring. The device also may have applications in homeland security screening for explosives.

Described in the November issue of Nature Photonics,* the prototype device is almost 1,000 times more sensitive than NIST’s original chip-scale magnetometer demonstrated in 2004 (“Tiny, Atom-based Detector Senses Weak Magnetic Fields”) and is based on a different operating principle. Its performance puts it within reach of matching the current gold standard for magnetic sensors, so-called superconducting quantum interference devices or SQUIDs. These devices can sense changes in the 3- to 40-femtotesla range but must be cooled to very low (cryogenic) temperatures, making them much larger, power hungry, and more expensive.

The NIST prototype consists of a single low-power (milliwatt) infrared laser and a rice-grain-sized container with dimensions of 3 by 2 by 1 millimeters. The container holds about 100 billion rubidium atoms in gas form. As the laser beam passes through the atomic vapor, scientists measure the transmitted optical power while varying the strength of a magnetic field applied perpendicular to the beam. The amount of laser light absorbed by the atoms varies predictably with the magnetic field, providing a reference scale for measuring the field. The stronger the magnetic field, the more light is absorbed.

“The small size and high performance of this sensor will open doors to applications that we could previously only dream about,” project leader John Kitching says.

The new NIST mini-sensor could reduce the equipment size and costs associated with some noninvasive biomedical tests. (The body’s electrical signals that make the heart contract or brain cells fire also simultaneously generate a magnetic field.) The NIST group and collaborators have used a modified version of the original sensor to detect magnetic signals from a mouse heart. The new sensor is already powerful enough for fetal heart monitoring; with further work, the sensitivity can likely be improved to a level in the 10 femtotesla range, sufficient for additional applications such as measuring brain activity, the designers say.

For additional details and a video interview with project leader John Kitching, see “New NIST Mini-Sensor May Have Biomedical and Security Applications”.

* V. Shah, S. Knappe, P.D.D. Schwindt and J. Kitching. Femtotesla atomic magnetometry with a microfabricated vapor cell. Nature Photonics. 1 Nov. 2007.

Media Contact: Laura Ost, laura.ost@nist.gov, 303-497-4880

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Wanted: Expert Reviewers for 2008 Baldrige Award

Each year the Baldrige National Quality Program recruits experts from businesses, education organizations, health care providers, nonprofits and other groups to serve as members of the Board of Examiners for the Malcolm Baldrige National Quality Award. Examiners evaluate applications for the award and prepare feedback reports to applicants that cite strengths and opportunities for improvement.

This year for the first time, all examiner applications must be submitted online. The application form is available at http://baldrige.nist.gov/Examiner_Application.htm. Deadline for submissions is on or before noon Eastern time on Jan. 8, 2008.

The board consists of more than 500 members, including 12 judges and about 60 senior examiners representing many industries, companies and organizations, including those from not-for-profit and public sectors. Service on the board provides an opportunity to enhance a board member’s knowledge, to develop a new network of expert colleagues and to help improve U.S. competitiveness.

Due to the large number of applications, highly qualified applicants may not be selected in a given year in order to balance the board with examiners from different sectors or with different work experiences. Thus, past applicants who have not been selected are encouraged to apply again.

For assistance in preparing an examiner application, contact examappl@nist.gov or call the Examiner Hotline at 877-237-9064.

Media Contact: Michael E. Newman, michael.newman@nist.gov, 301-975-3025

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Quicklinks

NIST Posts Online Database of Cryogenic Materials Properties

In response to numerous inquiries from academia, industry, and other government labs, the National Institute of Standards and Technology (NIST) recently published a new database on the properties of solid materials at temperatures ranging from cryogenic (as low as 4 K, which is -269 degrees C or -452 degrees F) to room temperature. Officially known as NIST Standard Reference Data Database #152, the Cryogenic Materials Properties Database is available online, free of charge. It is also a work in progress, with new materials and properties added as data become available.

Cryogenic temperatures place extreme demands on materials. The properties data have been collected by various organizations over many years, published in various formats such as internal reports, and often have not been publicly available. NIST researchers located the data, evaluated and validated it, resolved any conflicts resulting from different test methods and sources, then re-plotted and correlated the data over a wide temperature range using standardized equations.

The database covers a wide range of materials from traditional engineering stainless steels to fiberglass epoxy (found in magnetic resonance imaging systems, for example), exotic regenerator materials (used in cryogenic refrigerators), and Kevlar (may be combined with carbon fibers in containers used in space). The materials might be used in medicine (e.g., cryosurgery), energy applications (e.g., storage of liquid methane or liquid natural gas), electronics (e.g., superconducting microwave filters for cellular phones), transportation (e.g., liquid hydrogen fuel storage), space exploration (e.g., fuel storage), environmental research (e.g., thermal mapping and imaging of oceans), weather forecasting (e.g., infrared thermal imaging of the atmosphere) and defense (e.g., infrared guidance systems).

The database is available at www.cryogenics.nist.gov/MPropsMAY/material%20properties.htm.

Media Contact: Michael Baum, michael.baum@nist.gov, 301-975-2763

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NIST Researchers Receive Early Career Presidential Awards

National Institute of Standards and Technology (NIST) researchers Kathryn L. Beers and Joshua C. Bienfang have been awarded the Presidential Early Career Awards for Scientists and Engineers (PECASE). Presented at the White House on Nov. 1, 2007, by John H. Marburger III, Science Advisor to the President, PECASE awards are the highest honors bestowed by the U.S. Government on outstanding scientists and engineers beginning their careers.

Beers creates and studies flexible organic molecules known as polymers, found ubiquitously in the natural world (in the form of biomolecules such as DNA) as well as in industry (in applications ranging from personal care products to electronic displays). Beers has developed elegant new methods for making nanomaterials that were never before possible. Still in the early stages of her career, she has published over 40 peer-reviewed papers that have been cited more than 1,000 times. She has also distinguished herself as a scientific leader, holding multiple positions including Assistant Director in the Office of Science and Technology Policy.

Bienfang is using fundamental theories of physics, combined with the latest telecommunications technology, to develop a form of secret-message transmission known as quantum cryptography. His expertise in laser technology and high-speed electronics has enabled him to shoot particles of light through the air billions of times per second to set several new world records in quantum-cryptography transmission speeds. The technology may be useful someday for highly secure encrypted wireless communications.

As a result of this award the scientists receive additional funding from NIST for up to five years to advance their research.

See “White House Announces 2006 Awards for Early Career Scientists And Engineers” and link to official White House photo.

Media Contact: Michael Baum, michael.baum@nist.gov, 301-975-2763

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