The retinal damage thresholds for large spot size, multiple-pulse exposures to a Q-switched, frequency doubled Nd:YAG laser (532 nm wavelength, 7 ns pulses) have been measured for 100 μm and 500 μm retinal irradiance diameters. The ED50, expressed as energy per pulse, varies only weakly with the number of pulses, n, for these extended spot sizes. The previously reported threshold for a multiple-pulse exposure for a 900 μm retinal spot size also shows the same weak dependence on the number of pulses. The multiple-pulse ED50 for an extended spot-size exposure does not follow the n dependence exhibited by small spot size exposures produced by a collimated beam. Curves derived by using probability-summation models provide a better fit to the data.
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http://dx.doi.org/10.1097/HP.0000000000000121 | DOI Listing |
Phys Med
January 2025
Department of Medical Physics, Apollo Proton Cancer Centre, 100 Feet Road Taramani, Chennai, Tamil Nadu, India. Electronic address:
Objectives: The purpose of this study was to investigate the fundamental properties of spot-scanning proton beams and compare them to Monte Carlo (MC) simulations, both with and without CT calibration, using spatially diverse combinations of materials.
Methods: A heterogeneous phantom was created by spatially distributing titanium, wax, and thermocol to generate six scenarios of heterogeneous combinations. Proton pencil beams ranging in energy from 100 to 226.
Front Public Health
January 2025
Department of Internal Medicine, School of Medicine, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
BMC Microbiol
December 2024
State Key Laboratory Incubation Base for Conservation and Utilization of Bio-Resource in Tarim Basin, Alar, Xinjiang Uygur Autonomous Region, 843300, China.
Background: Pear black spot is caused by Alternaria tenuissima. It is one of the diseases of concern limiting pear production worldwide. Existing cultivation methods and fungicides are not sufficient to control early blight.
View Article and Find Full Text PDFInt J Behav Nutr Phys Act
December 2024
The George Institute for Global Health, University of New South Wales, Level 18, International Towers 3, 300 Barangaroo Ave, Sydney, NSW, 2000, Australia.
Background: Online grocery shopping is a growing source of food purchases in many countries. We investigated the effect of nudging consumers towards purchases of lower sodium products using a web browser extension.
Methods: This trial was conducted among individuals with hypertension who shopped for their groceries online in Australia.
Biosensors (Basel)
November 2024
Institute of Laser Engineering, Osaka University, Suita 565-0871, Osaka, Japan.
Biosensors operating in the terahertz (THz) region are gaining substantial interest in biomedical analysis due to their significant potential for high-sensitivity trace-amount solution detection. However, progress in compact, high-sensitivity chips and methods for simple, rapid and trace-level measurements is limited by the spatial resolution of THz waves and their strong absorption in polar solvents. In this work, a compact nonlinear optical crystal (NLOC)-based reflective THz biosensor with a few arrays of asymmetrical meta-atoms was developed.
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