Systemic and Topical PUVA Therapy
John Y. M. Koo, Ethan C. Levin, Argentina Leon, Jashin J. Wu, Alice B. Gottlieb in Moderate to Severe Psoriasis, 2014
The units used in therapy are as follows: Radiant energy is the amount of radiation and is expressed in joules (J): 1 J = 103 mJ.Radiant power is the rate of delivery of energy and is expressed in watts (W): W = J/second, 1 W = 103 mW.Irradiance is the radiant power/unit area (1 cm2) at a given surface and is expressed in W/cm2, which is measured by a radiometer.Exposure dose is the radiant energy delivered/unit area of a given surface in a given exposure time and is expressed in J/cm2; exposure dose = irradiance × exposure time.
Pollutant transport modelling *
Jamie Bartram, Rachel Baum, Peter A. Coclanis, David M. Gute, David Kay, Stéphanie McFadyen, Katherine Pond, William Robertson, Michael J. Rouse in Routledge Handbook of Water and Health, 2015
At the core of this approach is the assumption that the compliance water quality measurement characterises the water quality on the bathing day and, by definition, that the water quality on any day is constant. There is growing evidence that this may not be the case (Boehm et al., 2002) and recent data from European beaches suggests that the range of faecal indicator concentration on most days averages 1000 fold on both wet and dry days and where bathing waters are very remote from pollution sources (Davies et al., 2008; Wyer et al., 2013). Associated modelling suggests that this variability is essentially diurnal and driven by bactericidal irradiance in the absence of rainfall or tidal drivers. The time in the bathing day when the compliance samples was taken therefore becomes an important consideration in compliance outcomes. This observation has great significance for any modelling effort. Faced with an actual 1000 fold variability within each bathing day, which would appear to the analyst as random variation, any attempt to model an assumed constant daily quality is likely to result in poor predictive power and hence misclassification. There is not sufficient detailed temporal within-day data available from multiple sites worldwide to assess whether this observation at EU beaches is replicated elsewhere but this observation is worthy of further study.
Photomodulation of Protonema Development
R. N. Chopra, Satish C. Bhatla in Bryophyte Development: Physiology and Biochemistry, 2019
Usually, interpretations of photo- and polarotropic responses in mosses and ferns indicate that the reorientation of tip growth in red light is directed toward the region of highest Pfr concentration. Kadota et al.58 clearly demonstrated by microbeam experiments that the cells detect the difference in the Pfr amount of the extreme tip and the subapical regions of the apical dome and that these differences in the Pfr level regulate apical growth. Unpolarized light acts on the photoreceptor molecules in the same manner as polarized light, but since unpolarized light contains all directions of electrical vectors the gradients might be less distinct. Besides polarotropic effects, the establishment of absorption gradients in an asymmetrically irradiated cell is, of course, due to differences in the light intensity striking the irradiated side and the opposite side. It is likely that these differences decrease with increasing irradiance.
A feasibility study of a novel low-level light therapy for digital ulcers in systemic sclerosis
Published in Journal of Dermatological Treatment, 2019
M. Hughes, T. Moore, J. Manning, J. Wilkinson, S. Watson, P. Samraj, G. Dinsdale, C. Roberts, L. E. Rhodes, A. L. Herrick, A. Murray
The operator had full command of the light device through a custom-built control interface on an attached computer. The device provided ±10% of the specified irradiance within a 10 cm diameter circle (78 cm2). Therefore, more than one DU could be treated simultaneously per hand, and allowed some freedom of movement for the patient for comfort. Preliminary data in four healthy controls (not included in this manuscript) indicated that the change (increase) in skin temperature as measured by an attached thermocouple was in the range of 2.5 °C–5.8 °C using 405 nm light (by a prototype lamp with identical LEDs used in this study) at irradiance values of 50 mW/cm2. We applied 10 J/cm2 in approximately 200 s and measured the skin temperature within the irradiated zone at the reference site. There was heterogeneity in response: in two subjects, the increase rapidly decayed to baseline after the irradiance finished, whereas, in two subjects, it again decayed but did not reach baseline, staying 0.5–1.0 °C higher for >30 min post-exposure. It is not clear what the contribution to the observed temperature rise is from a photothermal effect (i.e. direct conversion of the absorbed optical radiation to heat), or by the production of photochemical vasodilators.
Thermal field formation during wIRA-hyperthermia: temperature measurements in skin and subcutis of piglets as a basis for thermotherapy of superficial tumors and local skin infections caused by thermosensitive microbial pathogens
Published in International Journal of Hyperthermia, 2019
Helmut Piazena, Werner Müller, Wolfgang Pendl, Sereina von Ah, Veronika H. Cap, Petra J. Hug, Xaver Sidler, Gerd Pluschke, Peter Vaupel
As shown in Table 1, three different incident irradiances were achieved by distance variation between the exit window of the irradiator and the skin surface (37, 42 and 47 cm) in order to exclude changes of the incident wIRA-spectrum. Verification measurements were performed using a double-monochromator spectroradiometer (type SPECTRO 320D, Instrument Systems, Munich, Germany). Before starting the study, the spectroradiometer was calibrated by the manufacturer, whereas offset correction was performed before each measurement. Measured spectra of irradiance are shown in Figure 1. Irradiance data were calculated by integrating the spectral irradiance data over the wavelength within the respective spectral subranges (shown in Table 2). According to these data, about 73% of the total irradiance came from the IR-A range. During the measurements, both the exit window of the irradiator and the Ulbricht sphere used as entrance window of the spectroradiometer were parallel and centered to each other.
ALSUntangled #60: light therapy
Published in Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, 2022
Richard Bedlack, Paul Barkhaus, Ben Barnes, Michael Bereman, Tulio Bertorini, Gregory Carter, Jesse Crayle, Sky Kihuwa-Mani, Robert Bowser, Pamela Kittrell, Christopher McDermott, Gary Pattee, Kristiana Salmon, Paul Wicks
Light is a type of electromagnetic radiation, which comes in discrete quantized packages known as photons (5). It can be characterized according to its wavelength (measured in nanometers, nm). Visible light has wavelengths between 400 and 700 nm. Light with wavelengths below this range is referred to as “ultraviolet”, and light with wavelengths above this range is referred to as “infrared” (5). Light can be generated by different sources (ex. lamps, LEDs, lasers). In addition to having different wavelengths, these different sources can deliver different amounts of energy (measured in joules, J) and power (measured in watts, W). When describing power or energy, it is important to state the area the energy is delivered over. This is called “power density” or “irradiance” (measured in milliwatts per square centimeter; mW/cm2) and/or “energy density” or “fluence” (measured in joules per square centimeter; J/cm2, 5,6).
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