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Basics of Radiation Interactions in Matter
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
It should also be mentioned here that the word ‘photon’ is a general name for the energy quantum that describes electromagnetic radiation. In quantum mechanics, every quantum of energy can be regarded as either a particle or a wave, that is, they can have the properties of both. For electromagnetic radiation, the properties of low-energy radiation are best described in terms of waves with a certain amplitude and frequency, while those of high-energy electromagnetic radiation are best described as independent particles that can be scattered in different directions. The particles in these energy ranges are called photons and have energy , where is the corresponding frequency and h is Planck’s constant (6.62607×10−34 Js). The electromagnetic radiation used in medical physics applications is generally very high in energy because the particle properties best describe the effects and behaviour of the radiation.
External Beam Radiotherapy and Brachytherapy
Published in Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple, Basic Urological Sciences, 2021
Sophia C. Kamran, Jason A. Efstathiou
Includes electromagnetic radiation:Radio waves, microwavesInfrared, visible light, ultravioletX-raysGamma radiation
Health Physics Problems in Electromagnetically Induced Hyperthermia
Published in Leopold J. Anghileri, Jacques Robert, Hyperthermia in Cancer Treatment, 2019
A large number of various experiments on animals have been performed in order to evaluate potential hazards of exposure to nonionizing electromagnetic radiation. Several comprehensive reviews have recently been published.3-6,18,19 Only a brief account of representative biological effects is given in this chapter.
Possible health effects on the human brain by various generations of mobile telecommunication: a review based estimation of 5G impact
Published in International Journal of Radiation Biology, 2022
Hiie Hinrikus, Tarmo Koppel, Jaanus Lass, Hans Orru, Priit Roosipuu, Maie Bachmann
Electromagnetic radiation is a physical stressor that can affect electrophysiological processes in humans, animals and plants. During the last decades, thousands of studies have detected RF EMF biological effects in humans, animals and cells. The studies have shown that the exposure to RF EMF increases the level of reactive oxygen species (ROS) and oxidative stress (Schuermann and Mevissen 2021), and causes alterations in brain physiology and behavior (Valentini et al. 2007; Marino and Carrubba 2009; Kwon and Hämäläinen 2011). The International Agency for Research on Cancer has classified the RF EMF as possibly carcinogenic to humans (IARC 2013). The IARC classified RF-EMF class 2B as a hazard (at any exposure level) and not the exposure as a risk (at limited exposure levels). These conclusions have been derived based on data from studies using RF EMF exposure characteristic for the previous generations (2G, 3G, and 4G) of telecommunication technologies. However, the frequencies and signal structure used in 5G differ from the previous generations.
The effect of red-to-near-infrared (R/NIR) irradiation on inflammatory processes
Published in International Journal of Radiation Biology, 2019
Tomasz Walski, Krystyna Dąbrowska, Anna Drohomirecka, Natalia Jędruchniewicz, Natalia Trochanowska-Pauk, Wojciech Witkiewicz, Małgorzata Komorowska
Experiments from the 1980s of the last century and appearing in recent years sufficiently document the water’s contribution to the photochemical mechanism of R/NIR radiation. The width of the absorption bands in this range of electromagnetic radiation is the reason for obtaining similar effects for different wavelengths. The formation of OH− and H+ ions, and changes in the structure of hydrogen bonds under the influence of radiation, and their further reactivity depends on the recombination of these ions and hence the distance between them. This effect could be the cause of non-linearity between the radiation dose and exposition time. Therefore, the primary photochemical mechanism consisting in excitation vibrational overtones in ground electronic states should be seriously taken into account.
UVGD 1.0: a gene-centric database bridging ultraviolet radiation and molecular biology effects in organisms
Published in International Journal of Radiation Biology, 2019
Hao Xu, Yan Wang, Lihong Diao, Xun Wang, Yi Zhang, Jiarun Zhu, Jinying Liu, Jingwen Yao, Zhongyang Liu, Yang Li, Fuchu He, Zhidong Wang, Yuan Liu, Dong Li
Ultraviolet (UV), or ultraviolet radiation, is electromagnetic radiation with a wavelength from 10 to 400 nm. Exposing to ultraviolet for a certain time will trigger some significant molecular biology effects in an organism. Firstly, ultraviolet can directly damage DNA sequences, leading to gene mutations. And accumulation of mutations in proto-oncogenes and tumor suppressor genes could result in abnormal cell proliferation, which can develop into tumorigenesis eventually. Secondly, ultraviolet can depress the immune system, leading to immunosuppression or even tumorigenesis. Thirdly, ultraviolet can affect the molecular components of cells and impact on the life functions of organisms by causing photoreactions and oxidative stress, bringing about consequences such as synthesis of Vitamin D and skin aging.