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Organization and Management of a Laser Safety Program
Published in Kenneth L. Miller, Handbook of Management of Radiation Protection Programs, 2020
While the biological impact is not generally considered of the same magnitude as that for eye exposure, accidental skin exposure can cause severe skin burns depending on the absorbed energy.19,23,27 The radiant exposure (J/cm2) must be quite high to cause skin injury. Radiation from 310 to 700 nm may cause a photosensitive reaction; from 200 to 315 nm, erythema is evident, and chronic exposure may accelerate aging and cause skin cancer; from 700 to 106 nm, skin bums and dry skin are the principle reactions.
Measuring and Quantifying Ultraviolet Radiation Exposures
Published in Francis N. Marzulli, Howard I. Maibach, Dermatotoxicology Methods: The Laboratory Worker’s Vade Mecum, 2019
Irradiance (surface dose rate) and radiant exposure (surface dose) are units specifying power or energy incident upon a plane. As shown in Figure 2, these quantities are the dose rate (irradiance) and exposure dose (radiant exposure) that are the most fundamental quantities used in all of photobiology. The units most commonly used are W/cm2 and J/cm2, respectively (1 W = 1 J/s).
Neurophotonics for Peripheral Nerves
Published in Yu Chen, Babak Kateb, Neurophotonics and Brain Mapping, 2017
Ashfaq Ahmed, Yuqiang Bai, Jessica C. Ramella-Roman, Ranu Jung
Infrared stimulation, due to its wavelength-dependent optical penetration depth, variable spot size, and laser radiant exposure, excels in applications where a precisely controlled and quantifiable volume of action in biological tissue is required (van Hillegersberg, 1997; Vogel and Venugopalan, 2003). As a consequence of this spatial confinement of energy deposition, optical stimulation is used in cases where closely spaced fascicles (small groups of axons within a nerve) need to be selectively targeted, resulting in selective muscle contraction (Wells et al., 2007c). Figure 27.3 illustrates one such situation and compares it with that of electrical stimulation.
Adjuncts to pulsed dye laser for treatment of port wine stains: a literature review
Published in Journal of Cosmetic and Laser Therapy, 2021
Bing Wang, Xianglin Mei, Yanlong Wang, Xin Hu, Fuqiu Li
Studies conducted in animal models have shown the damaging effect of Talaporfin sodium PDT on blood vessels. The results indicated that Talaporfin sodium PDT destroyed target microvessels while maintaining the integrity of epidermis. It might be a viable modality for the treatment of cutaneous vascular hyperplasia (16). A study on determining the period of skin photosensitivity in healthy subjects demonstrated relatively quick clearance of Talaporfin sodium from the body; moreover, the skin reaction was generally mild asymptomatic erythema. Within 1 to 3 weeks, all subjects showed subsidence of photosensitivity, which indicated good tolerance of the clinically effective dose of Talaporfin sodium (17). Kelly used Talaporfin sodium PDT combined with PDL for PWS in animal models. The results indicated that the combination reduced the PDT radiant exposure required to achieve persistent vascular shutdown (18).
Monowave and polywave light-curing of bulk-fill resin composites: degree of conversion and marginal adaptation following thermomechanical aging
Published in Biomaterial Investigations in Dentistry, 2021
Sheila Celia Mondragón Contreras, Ana Luiza Barbosa Jurema, Evaniele Santos Claudino, Eduardo Bresciani, Taciana Marco Ferraz Caneppele
Two different LCUs were selected for this study, an MW LED curing unit (3M ESPE, Sumaré, Brazil) and a blue-violet PW LED curing unit (Bluephase N, Ivoclar Vivadent, Schaan, Liechtenstein). The LCUs were used in the high-intensity continuous mode, with a curing time of 20 s. Table 1 presents information about the LCUs. The irradiance (mW/cm2), radiant exposure (J/cm2) and spectral emission (nm) delivered by the LCUs were checked using a simulation device (Managing Accurate Resin Curing – Patient Simulator (MARC-PS)) (BlueLight Analytics, Halifax, Canada).
Stabilized tetraether lipids based particles guided prophyrins photodynamic therapy
Published in Drug Delivery, 2018
Gihan Mahmoud, Jarmila Jedelská, Samia Mohamed Omar, Boris Strehlow, Marc Schneider, Udo Bakowsky
A prototype light emitting diode (Lumundus GmbH Eisenach, Germany) adopted for 96 well plates, providing irradiance (I) of 22.4 W.m−2 at 625 nm was used. The radiant exposure dose (D) in J.m−2 equal to irradiance (I) in W.m−2 times the time of exposure (t) in seconds (Kochevar & Anderson, 1983). Different exposure times of 60, 90, 180 and 300 s were applied and hence the cells were receiving radiant exposure doses of 134, 202, 403 or 672 mJ.cm−2, respectively thence, cells were further incubated for 24 h.