Capturing airborne pathogens, breath tests for lung cancer

CLEO/QELS news conference highlights advances with lasers

When scientists invented the laser over forty years ago, no one imagined that it would revolutionize entertainment (CD/DVD players), communications (fiber optics), medicine (laser surgery) and even grocery shopping (barcode scanners). The laser's inventiveness shows no signs of letting up, as researchers have developed powerful new uses for the versatile device in homeland security and medical diagnosis. Next week in Baltimore, researchers will present some of these exciting new developments at a press luncheon to take place during the Conference on Lasers and Electro-Optics and the Quantum Electronics and Laser Science Conference (CLEO/QELS), a leading forum showcasing cutting-edge advancements in lasers and related fields.

The news luncheon will convene Tuesday, June 3 from 12 PM to 2 PM in Room 332 of the Baltimore Convention Center in Baltimore, MD. Reporters wishing to attend should fill out the reply form at the end of this release or contact Colleen Morrison (202-416-1437, [email protected]).

The meeting pressroom will be located in room 330 of the convention center from June 1 through June 5. At the pressroom, reporters can obtain a registration badge granting complimentary admission to all meeting sessions, talks, and exhibits. Those interested in obtaining a badge should fill out the reply form at the end of this release.

Other news releases on the meeting can be found at http://www.cleoconference.org/cleo_press_releases.cfm.
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CLEO/QELS 2003 PRESS LUNCHEON
Room 332
Baltimore Convention Center
Tuesday, June 3, 2003
12PM- 2 PM

CAPTURING SUSPICIOUS AGENTS IN AIR AND WATER
John Sutherland and Yong-qing Li, East Carolina University

Detecting and identifying single biological particles is challenging since these bioagents may randomly move and flow in liquid or air. At CLEO/QELS, John Sutherland, Yong-qing Li and colleagues at East Carolina University will present an optical sensor that can rapidly capture and identify individual biological and non-biological agents alike. Called the LTRS sensor, it works by combining a pair of optical technologies. One of these technologies, called laser tweezers, captures microscopic particles in a fluid by using a tightly focused light beam. Another technology, known as Raman spectroscopy, can obtain a highly personalized "fingerprint" for each substance by measuring the unique vibrations of its molecules. While the LTRS sensor has been previously shown to trap and identify biomolecules within single cells, the CLEO/QELS meeting will be the first occasion at which its developers demonstrate its feasibility as a sensor for fast, non-invasive identification of biological agents at the single-cell level. The researchers hope the LTRS sensors will find broad applications for rapidly sensing toxic bioagents (such as bacteria, spores, or viruses) in field sites (such as airports, sporting events and shopping malls) to aid in bio-terrorism defense. The instrument may also provide rapid and reliable clinical diagnosis of cellular disorders. In addition, the LTRS sensors can be used as a valuable tool to study cellular processes within single living cells or intracellular organelles and aid research in molecular and cellular biology.

ULTRAFAST LASER AUTOMATES BRAIN-TISSUE IMAGING
Jeff Squier, Colorado School of Mines

A new technique may help speed up progress in fundamental research on brain disorders such as Alzheimer's and mad-cow disease. Using a special laser, researchers have automated the process of imaging brain tissue while providing microscopic-scale pictures. Presently a manual process, microscopically imaging brain-tissue samples ordinarily requires freezing and mechanically slicing the tissue specimen of interest into thin sections that can be viewed with a microscope. Now, Jeff Squier of the Colorado School of Mines, and colleagues Phil Tsai and David Kleinfeld of the University of California, San Diego, have demonstrated, for the first time, that the whole imaging process can be automated by using a femtosecond laser beam, one that delivers powerful but very short pulses of light. In their technique, the beam is used at low power (where it does no damage) to provide 3D images (through various imaging techniques) of a tissue specimen's first layer. After taking this first image, researchers increase the laser intensity to the point where the light ablates (removes) the previously imaged layer. After the tissue layer is removed, the laser intensity is lowered again and used to image the next layer of tissue. Repeating the process many times for subsequent tissue layers, the researchers can stack together the images to produce a complete three-dimensional picture of the tissue sample. Outside the realm of the brain, this technique can potentially image other types of tissue, such as biopsy samples from patients with suspected tumors. In addition to demonstrating that their laser technique does not harm the tissue layers for imaging purposes, the researchers have been able to image tissues without freezing them (which causes damage) and have also shown that the process works with very soft tissue -- a real challenge for standard microscopic tissue-imaging processes.

BREATH TESTS FOR LUNG CANCER
Yabai He, Macquarie University, Australia

A compact, low cost, portable, and rugged detector of carbon monoxide, carbon dioxide, and many other gases has been developed at Macquarie University in Sydney, Australia. Breath analysis of carbon dioxide and carbon monoxide is important for diagnosing a range of diseases including neonatal jaundice, asthma, peptic ulcers, and blood conditions, among other things. Measuring these exhaled gases can potentially even detect lung cancer, and monitor the health of patients with lung cancer. Detection of these carbon-based gases is also important in industry, such as in the control of smelters where the carbon monoxide/carbon dioxide ratio indicates furnace efficiency. The new detector is based on cavity ring-down spectroscopy, in which laser light is reflected back and forth many times in a compact gas-filled optical cavity. The laser light may travel tens of kilometers before it escapes from the cavity. In this way, the laser light is able to interact efficiently with a gas sample, leading to very high detector sensitivity. Although cavity ring-down detectors have been around for several years, the new system is constructed of readily available photonics and fiber-optical components developed for the telecommunications industry, potentially making the highly sensitive detectors compact and cost-effective for a wide variety of medical and industrial applications.

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REPORTER'S REPLY FORM
CLEO/QELS 2003

Please return this form to Colleen Morrison at [email protected]

___Please sign me up for the CLEO/QELS news conference and luncheon.

___Please prepare an on-site registration badge for general admission to meeting sessions/talks/exhibits.

___I cannot attend but please send me additional materials as they become available.

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