Near-Infrared Ultrashort Pulse Laser Bioeffects Studies
Near-Infrared Ultrashort Pulse Laser Bioeffects Studies

Author:

Publisher:

Published: 2003

Total Pages: 0

ISBN-13:

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Applications of ultrashort pulse laser systems have increased dramatically in the past several years. Retinal exposure to these laser pulses can produce visible lesions with pulse energies of less than 1 microjoule (microJ) per pulse. Our research has found a reduction in the energy required for retinal damage as pulse duration is decreased from the nanosecond (ns) to femtosecond (fs) regime. With this data, new laser safety standards are being proposed to reduce the dangers and uncertainties when working around these lasers.

Selected Papers on Ultrashort Laser Pulse Bioeffects
Selected Papers on Ultrashort Laser Pulse Bioeffects

Author: William P. Roach

Publisher: SPIE-International Society for Optical Engineering

Published: 2002-12-31

Total Pages: 694

ISBN-13:

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This volume contains key papers that document the initial probing of the limits of subnanosecond pulses and the resulting discoveries of nonlinear effects. The papers tell the story of effects previously thought to be impossible to produce in tissue. If you read all the references carefully, you will see the studies evolve from speculation to experimentation to theory, and culminate in policy recommendations.

Laser-Based Optical Detection of Explosives
Laser-Based Optical Detection of Explosives

Author: Paul M. Pellegrino

Publisher: CRC Press

Published: 2018-09-03

Total Pages: 409

ISBN-13: 1482233290

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Laser-Based Optical Detection of Explosives offers a comprehensive review of past, present, and emerging laser-based methods for the detection of a variety of explosives. This book: Considers laser propagation safety and explains standard test material preparation for standoff optical-based detection system evaluation Explores explosives detection using deep ultraviolet native fluorescence, Raman spectroscopy, laser-induced breakdown spectroscopy, reflectometry, and hyperspectral imaging Examines photodissociation followed by laser-induced fluorescence, photothermal methods, cavity-enhanced absorption spectrometry, and short-pulse laser-based techniques Describes the detection and recognition of explosives using terahertz-frequency spectroscopic techniques Each chapter is authored by a leading expert on the respective technology, and is structured to supply historical perspective, address current advantages and challenges, and discuss novel research and applications. Readers are left with an in-depth understanding and appreciation of each technology’s capabilities and potential for standoff hazard detection.

Laser Bioeffects Resulting from Non-Linear Interactions of Ultrashort Pulses with Biological Systems
Laser Bioeffects Resulting from Non-Linear Interactions of Ultrashort Pulses with Biological Systems

Author:

Publisher:

Published: 2004

Total Pages: 65

ISBN-13:

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The original goal of this project was to determine the role of non-linear interactions underlying the bioeffects induced by ultrashort pulse laser pulses. As initially conceived, this line of investigation was to be principally directed at understanding the contribution of multiphoton absorption. This indeed was a major focus of the research project, but for various reasons the scope of the work was expanded to include identification of the intracellular mechanisms that determine the cellular response to the absorption of optical radiation, and to develop and implement a non-invasive means for measuring the thermal gradients induced by the absorption of laser radiation in tissue. Both of these ancillary projects were successful in that (1) the transcription factor NF-B was found to be activated by visible laser exposure in a way that appeared to be dependent on the absorption of laser energy in the melanin granules of the retinal pigment epithelial cell, and (2) by exploiting the temperature-dependent nature of the proton resonance frequency (PRF), magnetic resonance thermography was successfully used to measure temperature gradients induced in tissue phantoms during laser exposure, and these gradients closely followed the spatial distributions predicted by classical heat diffusion theory.

Near Infrared, High Energy, Ultrashort Pulse Laser-Light Exposure Genetically Induces P53, a Gene in the DNA Repair and Cell Suicide Pathways in Cultured Human Cells
Near Infrared, High Energy, Ultrashort Pulse Laser-Light Exposure Genetically Induces P53, a Gene in the DNA Repair and Cell Suicide Pathways in Cultured Human Cells

Author:

Publisher:

Published: 1999

Total Pages: 0

ISBN-13:

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The use of laser light for targeting devices and weapons has sharply increased the likelihood that aircrew and support personnel will be exposed to laser light during operations. The increased potential for exposure of humans highlights the need for scientifically-based safety standards for laser exposure at the ultrashort pulse lengths. Current safety standards are largely extrapolations of exposure limits at longer pulse lengths using a minimal visible lesion endpoint in the Rhesus monkey retinal model. A non-animal model for assessing laser-light damage to tissue, particularly human, is quite desirous for obvious scientific, political, and fiduciary reasons. We assessed the sublethal insult to human cells using a tissue culture system for specific genes that have been shown to be important in several biological processes that could lead to cancer or cell death. Using the CAT-Tox (L) (Xenometrix, Inc.) assay, it appears that 1064 nm, nanosecond pulses of laser light is sensed and induces several stress response genes, including p53, a gene in the DNA repair and apoptosis (cell suicide) regulatory pathways in a dose dependent fashion. This approach provides insight into a more global methodology for characterizing environmental stressors via genetic profiling.

Bioeffects of Cultured Human Cells from High Energy, Ultrashort Pulse Laser-Light
Bioeffects of Cultured Human Cells from High Energy, Ultrashort Pulse Laser-Light

Author:

Publisher:

Published: 1999

Total Pages: 0

ISBN-13:

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The use of laser light for targeting devices and weapons has sharply increased the likelihood that aircrew and support personnel will be exposed to laser light during operations. The increased potential for exposure of humans highlights the fact that there is a need for scientifically based safety standards for laser exposure at the ultrashort pulse lengths. Current safety standards are largely extrapolations of exposure limits at longer pulse lengths using a minimal visible lesion endpoint in the Rhesus monkey retinal model. A non-animal model for assessing laser-light damage to tissue, particularly human, is quite desirous for obvious scientific, political, and fiduciary reasons. I assessed the sublethal insult to human cells using a tissue culture system for specific genes that have been shown to be important in several biological processes that could lead to cancer or cell death. Using the CAT-Tox (L) (xenometrix, Inc.) assay, it appears that 532 nm nanosecond pulse of laser light are sensed and induces several stress response genes including FOS in a roughly dose dependent fashion. This approach provides insight into a more global methodology for characterizing environmental stressors via genetic profiling.

Laser Bioeffects
Laser Bioeffects

Author: Daniel Robert Lykins

Publisher:

Published: 2002-01-01

Total Pages: 104

ISBN-13: 9781423523413

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The use of laser light for targeting devices and industry has dramatically increased the likelihood that personnel will be exposed to laser energy during military and commercial operations. The increased potential for exposure of humans to lasers highlights the need to understand laser-tissue interactions at the most basic cell and molecular levels. Current ultrashort pulse laser safety standards are based on a minimal visible lesion (MVL), i.e., histological, damage endpoint in the Rhesus monkey model (Shaver, 2001). A human model for assessing laser-light damage to tissue at the cell and molecular level is desirable for scientific, political and fiduciary reasons. This research assesses the effects of sublethal pulsed laser-light treatment to a human melanocyte (skin) cell line. Proteomic inquiry into the cellular effect of laser treatment was accomplished via parallel sample analysis with over 850 monoclonal antibodies in order to screen for changes in the levels of protein expression. In short, the data indicated dramatically increased molecular debridement, decreased apoptotic signaling and cell cycling and other cellular phenomena sufficient to propose a stress response and recovery paradigm.

Laser Bioeffects: Differential Protein Expression of Cultured Human Melanocytes Treated With 532 Nm Picosecond Pulse Laser-Light
Laser Bioeffects: Differential Protein Expression of Cultured Human Melanocytes Treated With 532 Nm Picosecond Pulse Laser-Light

Author: Daniel Robert Lykins

Publisher:

Published: 2002

Total Pages: 104

ISBN-13:

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The use of laser light for targeting devices and industry has dramatically increased the likelihood that personnel will be exposed to laser energy during military and commercial operations. The increased potential for exposure of humans to lasers highlights the need to understand laser-tissue interactions at the most basic cell and molecular levels. Current ultrashort pulse laser safety standards are based on a minimal visible lesion (MVL), i.e., histological, damage endpoint in the Rhesus monkey model (Shaver, 2001). A human model for assessing laser-light damage to tissue at the cell and molecular level is desirable for scientific, political and fiduciary reasons. This research assesses the effects of sublethal pulsed laser-light treatment to a human melanocyte (skin) cell line. Proteomic inquiry into the cellular effect of laser treatment was accomplished via parallel sample analysis with over 850 monoclonal antibodies in order to screen for changes in the levels of protein expression. In short, the data indicated dramatically increased molecular debridement, decreased apoptotic signaling and cell cycling and other cellular phenomena sufficient to propose a stress response and recovery paradigm.