A5002116022- Ocular and Laser Science Research
- Skin Protection and Aging
- Advanced Optical Sensing Technologies
- Visual perception and processing mechanisms
- Retinal Development and Disorders
- Laser Design and Applications
- Impact of Light on Environment and Health
- Laser Applications in Dentistry and Medicine
- Intraocular Surgery and Lenses
- Corneal surgery and disorders
- Circadian rhythm and melatonin
- Traumatic Ocular and Foreign Body Injuries
- Radiation Dose and Imaging
- Laser Material Processing Techniques
- Optical Imaging and Spectroscopy Techniques
- Glaucoma and retinal disorders
- Climate Change and Health Impacts
- Air Quality and Health Impacts
- Safety Warnings and Signage
- Connexins and lens biology
- Dermatologic Treatments and Research
- Solid State Laser Technologies
- Photoreceptor and optogenetics research
- Infection Control and Ventilation
- Animal testing and alternatives
Johns Hopkins University
2013-2023
U.S. Army Center for Health Promotion and Preventive Medicine
2003-2021
SimulConsult
2009-2019
Seibersdorf Laboratories (Austria)
2002-2019
United States Department of the Army
1991-2019
Public Health England
2019
University of Miami
2014
Illumina (United States)
2012-2013
Scientific Consulting Group
2013
Bridge University
2011
Light suppresses melatonin in humans, with the strongest response occurring short-wavelength portion of spectrum between 446 and 477 nm that appears blue. Blue monochromatic light has also been shown to be more effective than longer-wavelength for enhancing alertness. Disturbed circadian rhythms sleep loss have described as risk factors astronauts NASA ground control workers, well civilians. Such disturbances can result impaired alertness diminished performance. Prior exposing subjects from...
Far UV-C, informally defined as electromagnetic radiation with wavelengths between 200 and 230 nm, has characteristics that are well-suited to control of airborne pathogens. Specifically, UV-C been shown be highly effective for inactivation pathogens; yet this same minimal potential cause damage human skin eye tissues. Critically, unlike UV-B, does not substantially penetrate the dead cell layer (stratum corneum) reach germinative cells in basal layer. Similarly, through corneal epithelium...
The circadian and neurobehavioral effects of light are primarily mediated by a retinal ganglion cell photoreceptor in the mammalian eye containing photopigment melanopsin. Nine action spectrum studies using rodents, monkeys, humans for these responses indicate peak sensitivities blue region visible ranging from 459 to 484 nm, with some disagreement short-wavelength sensitivity spectrum. aim this work was quantify human volunteers monochromatic 420-nm plasma melatonin suppression. Adult...
Methodology for the evaluation of potential optical radiation hazards has been developed in response to increasing use high radiance sources, such as lasers, compact arc lamps, tungsten-halogen and electronic flash lamps. Recent biological investigations injury from ultraviolet studies chorioretinal sources permit a realistic ocular hazard evaluation. Safe exposure criteria that may be readily applied practical situations have available data experience with occupational hazards. Hazard...
Background: Light-emitting diodes (LEDs) deliver higher levels of blue light to the retina than do conventional domestic sources. Chronic exposure high-intensity (2,000–10,000 lux) has previously been found result in light-induced retinal injury, but chronic relatively low-intensity (750 not assessed with LEDs a rodent model.Objective: We examined LED-induced neuronal cell damage Sprague-Dawley rat using functional, histological, and biochemical measurements.Methods: used (460 nm)...
A variety of optical and electro-optical instruments are used for both diagnostic therapeutic applications to the human eye. These generally expose ocular structures either coherent or incoherent radiation (ultraviolet, visible, infrared radiation) under unique conditions. We convert laser exposure guidelines derived normal conditions application ophthalmic sources.
To characterize photobiological and photochemical phenomena, standardized terms units are required. Without a uniform set of descriptors, much the scientific value publications can be lost. Attempting to achieve an international consensus for common language has always been difficult, but now with truly publications, it is all more important. As photobiology photochemistry both represent fusion several disciplines, not surprising that physical used describe exposures dosimetric concepts vary...
To examine light-emitting-diode (LED)-induced retinal neuronal cell damage and its wavelength-driven pathogenic mechanisms.Sprague-Dawley rats were exposed to blue LEDs (460 nm), green (530 red (620 nm). Electroretinography (ERG), Hematoxylin eosin (H&E) staining, transmission electron microscopy (TEM), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), immunohistochemical (IHC) Western blotting (WB) the detection of superoxide anion (O2-·), hydrogen peroxide (H2O2), total...
The derivations of human exposure limits for laser radiation rely heavily upon experimental ocular injury studies. are derived by committees ophthalmic experts through a review all available threshold data and an understanding mechanisms laser/tissue interaction. A major point discussion in this derivation process relates to the level uncertainty injury. An indication slope transformed dose-response curve, or "probit plot" data. most cited on probit plot is that represents 50% probability...
The UV doses of Americans were never measured, but are needed for assessing the risks UV-related health effects. We calculated these using a novel approach. Environmental Protection Agency's (EPA) National Human Activity Pattern Survey (NHAPS) recorded activity profiles 9386 over 24 months to assess their exposure environmental pollutants, one which is radiation. NHAPS used randomized telephone interviews get previous day's minute-by-minute activities. From we extracted only outdoor-daylight...