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May 24, 2004

  In This Issue:
bullet New Standard to Help Diagnose Heart Attacks
bullet Scaling Friction Down to the Nano/Micro Realm
bullet Developing Tools for Reliable "Gene Chip" Measurements
bullet Reducing Standards-Related Barriers to Trade
bullet New Security Certification Guidelines for IT Systems
bullet Quick Links

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New Standard to Help Diagnose Heart Attacks

Crystal structure of cardiac troponin

Computer model of the complex crystal structure of the human protein cardiac troponin.

Graphic Courtesy Protein Data Bank

Diagnosing heart attacks will become a more precise science thanks to the first of a new series of clinical standards just issued by the National Institute of Standards and Technology (NIST). Standard Reference Material (SRM) 2921 (human cardiac troponin complex) will help manufacturers develop and calibrate assays that measure specific protein concentrations in patient blood samples to determine whether a heart attack has occurred.

The SRM is a solution containing certified concentrations of three related proteins, including cardiac troponin I, purified from human heart tissue from cadavers. Users can calibrate their assays by analyzing the SRM and comparing the results to the NIST-certified value for troponin I. The standard is expected to help reduce variations in clinical test results from as much as 50-fold on the same sample to just twofold. “It’s a big first step toward getting the system under control,” says Michael Welch, leader of the NIST development team.

NIST already produces more than 60 SRMs for the clinical diagnostics community, but this is the first one designed to help measure concentrations of large, protein-based health status markers. Troponin I is difficult to measure because it can exist in low concentrations and in different chemical forms, sometimes attached to other related proteins. NIST is developing additional standards and methods for measuring other health status indicators of this type, including hormones used to assess thyroid function, and other markers for heart attack risk such as homocysteine and C-reactive protein.

SRM 2921 is intended to help U.S. makers of in vitro diagnostic (IVD) medical devices sell their products in Europe. A European Union directive requires that such devices be calibrated with standards that are traceable to internationally recognized certified reference materials or procedures. SRM 2921 has been nominated for inclusion on the international list of higher order reference materials. The list currently contains approximately 150 entries for 96 health status markers; NIST SRMs provide traceability for 72 of these.

Media Contact:
Laura Ost, (301) 975-4034

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Scaling Friction Down to the Nano/Micro Realm

3D computer images of a round tip used to make friction measurements

3D computer image of a eliptical tip used to make friction measurements.

Three-dimensional images showing the topography of both round and elliptical tips used in making friction measurements.

An improved method for correcting nano- and micro-scale friction measurements has been developed by researchers at the National Institute of Standards and Technology (NIST). The new technique should help designers produce more durable micro- and nano-devices with moving parts, such as tiny motors, positioning devices or encoders.

Friction measurements made at the micro- and nano-scale can differ substantially due to changes in applied load. In a series of experiments described by nanotribologist Stephen Hsu at a technical meeting held May 17-20 in Toronto,* NIST scientists confirmed that many of the measured differences appear to be caused by unintended scratching of the surface by the sharp tips used in making the measurements themselves.

The NIST team used a specially designed friction tester developed jointly by NIST and Hysitron Inc. of Minneapolis. A carefully calibrated force was applied to diamond tips having a range of sizes. Friction forces were then measured as each tip was slid across a very smooth surface of silicon. Friction at the macroscopic scale is usually straightforwarddoubling the force between two objects produces twice the friction. However, work at NIST and elsewhere has shown that friction at the microscale does not always obey this scaling rule. Forces greater than about 2 milliNewton** produced substantially greater friction values than expected.

Images of the test surface made with an atomic force microscope confirmed that unintentional scratching produced the extra friction. To correct for this effect, NIST researchers developed a way to measure precisely the size, shape and orientation of the diamond tips so that friction forces caused by "plowing" can be subtracted to produce a more accurate final measurement.

Media Contact:
Scott Nance, (301) 975-5226


*The work was presented at the Society of Tribology and Lubrication Engineers annual meeting.
** For comparison, a penny held against Earth's gravity produces a force of about 25 milliNewtons.

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Developing Tools for Reliable "Gene Chip" Measurements

Microarrays, sometimes called "gene chip" devices, enable researchers to monitor the activities of thousands of genes from a single tissue sample simultaneously, identifying patterns that may be novel indicators of disease status. But generating consistent, verifiable results is difficult because of a lack of standards to validate these analyses, scientists from the National Institute of Standards and Technology (NIST) and collaborators warn in the May 20 online issue of Clinical Chemistry.

Microarrays are keychain-sized devices with as many as several million tiny spots, each of which examines genes of interest simultaneously using minute sample volumes. This highly sensitive technology is relatively new, and standard procedures to ensure the reliability and comparability of results are only beginning to emerge. For instance, results can change as a result of differences in how tissues are collected and processed; variations in how the molecules are counted, attached to substrates and labeled for detection; deviations from recommended protocols by lab personnel; and malfunctioning or miscalibrated equipment. Such variations need to be controlled before this technology can be used reliably in clinical settings and in devices requiring regulatory approval, according to the paper.

As a first step toward addressing reliability issues, a consortium co-led by NIST and industry is developing standards that will satisfy needs identified at a 2003 workshop. At the workshop, organized and hosted by NIST, leaders in the microarray field from industry, government and universities recommended the development of a well-characterized set of ribonucleic acid (RNA) molecules whose identity and concentration are known. RNA is an important product of gene activity. Users will be able to validate the results of gene chip analyses by adding such a reference material to their samples and comparing the measured values to what would be expected for them. Such a reference material also will enable technology developers and researchers to assess the performance of their assays.

The paper was co-authored by scientists from Genomic Health, Inc., Agilent Technologies, the U.S. Food and Drug Administration, and The Institute for Genome Research.

Media Contact:
Laura Ost, (301) 975-4034

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Reducing Standards-Related Barriers to Trade

A new report from the U.S. Department of Commerce released on May 18 makes more than 50 recommendations for reducing standards-related trade barriers and calls for broader collaboration across government and with U.S. industry to prevent technical obstacles that impede U.S. exports.

“Standards and related technical regulations affect an estimated 80 percent of world trade,” Commerce Secretary Donald L. Evans told an audience of industry and standards community representatives. “The recommendations in this report can improve how we tackle standards-related issues that distort trade and undermine our competitiveness.”

“In the face of intensifying global competition, neither industry nor government can be complacent about standards-related issues,” said Under Secretary for Technology Phil Bond. “The Secretary’s Standards Initiative emphasizes best practices, provides critical education and training, expands our early warning tools, and creates greater collaboration with industry and government. Collectively, these actions will go a long way towards an effective rapid response system when standards become trade barriers.”

The new report, Standards and Competitiveness—Coordinating for Results, also summarizes key industry standards issues in international markets. Some of this information was gathered from more than 200 industry associations and standards organizations in 13 industry roundtables convened over the past year.

The report seeks to improve the efficiency and effectiveness of the Department’s standards-related programs and policies. Its recommendations will help the Department identify new opportunities and better ways to work with the private sector and other U.S. government agencies on standards-related issues.

In March 2003, Evans launched the Department of Commerce Standards Initiative, an eight-point plan that responds to industry concerns that divergent standards, redundant testing and compliance procedures, and regulatory red tape are becoming one of the greatest challenges to expanding exports.

The report can be accessed at http://www.technology.gov.

Media Contact:
Mark Bello, (301) 975-3776

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New Security Certification Guidelines for IT Systems

The National Institute of Standards and Technology (NIST) recently published guidelines on the security certification and accreditation of federal information systems. NIST Special Publication 800-37, Guide for the Security Certification and Accreditation of Federal Information Systems, is one of several key documents being developed by NIST to support the implementation of the Federal Information Security Management Act (FISMA) of 2002.

The new guidelines provide a standardized approach for assessing the effectiveness of the management, operational and technical security controls in an information system. In addition, they can aid management officials in making a determination about the acceptable level of risk to an agency's operations and assets brought about by the operation of that system.

NIST Special Publication 800-37 will be used in conjunction with the new mandatory security standard, Federal Information Processing Standard Publication 199, Standards for Security Categorization of Federal Information and Information Systems, and NIST Special Publication 800-53, Recommended Security Controls for Federal Information Systems (currently in draft), to help improve the security posture of federal agencies and their information systems.

The security certification and accreditation guidelines are applicable to all federal information systems other than those systems designated as national security systems as defined in FISMA. Federal agencies are required to conduct security certification and accreditation in accordance with standing policy from the Office of Management and Budget. State, local and tribal governments, as well as private-sector organizations comprising the critical infrastructure of the United States, are encouraged to consider the use of these guidelines, as appropriate.

NIST Special Publication 800-37 is available from NIST’s Computer Security Resource Center at http://csrc.nist.gov/publications. A complete description of the NIST FISMA Implementation Project also is available at http://csrc.nist.gov/sec-cert.

Media Contact:
Phil Bulman, (301) 975-5661

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Quick Links

Usability Standards Urged for Voting Systems

The federal government’s Election Assistance Commission (EAC) recently submitted a report to Congress that recommends the development and implementation of voluntary standards, accompanying test methods and guidelines to ensure that voting systems in the United States are usable by and accessible to all Americans. Computer scientists and usability experts at the National Institute of Standards and Technology (NIST) researched and wrote the report for the EAC, as mandated under the Help America Vote Act of 2002 (HAVA). A copy of the usability and accessibility report may be downloaded from the EAC Web site at www.eac.gov.

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Editor: Gail Porter

Date created: 05/21/04
Date updated:05/24/04
Contact: inquiries@nist.gov