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Basics of Radiation Interactions in Matter
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
The purpose of this text is to provide a basis for understanding the role of interactions in radiation dosimetry, radiation shielding, radiation protection, and radiation detection, and to provide further information on the ionizing radiation that occurs when the primary emitted radiation – for example, that emitted from a decaying radionuclide or its daughter products – interacts with its surrounding material.
Radioactivity
Published in W. P. M. Mayles, A. E. Nahum, J.-C. Rosenwald, Handbook of Radiotherapy Physics, 2021
To illustrate the decay rate of a given radionuclide, the time required for half of the existing radioactive atoms to disintegrate has been chosen as a reference and is called the half-life, T.‡ The half-life can be introduced into the equations in the previous subsection as follows:
Our Radiation Environment
Published in T. D. Luckey, Radiation Hormesis, 2020
Since radioactivity is easily detected, radionuclides are used extensively as tracers in industry, agriculture, medicine, and research. Beneficial products of ionizing radiation include medical diagnosis and treatment and sterilization of medical devices and food. Radionuclides are indispensable, routine tools for medical, physiologic, and biochemical research.
Looking for the phoenix: the current research on radiation countermeasures
Published in International Journal of Radiation Biology, 2023
Vojtěch Chmil, Alžběta Filipová, Aleš Tichý
In the case of the use of nuclear weapons and dirty bombs, but also during major accidents at nuclear power plants, various radionuclides are released into the environment, leading to contamination of water, food, and the atmosphere. During these events, a relatively large area is affected and residents have only limited options to protect themselves. Radionuclides thus enter the human body, where they cause radiation damage in addition to chemical toxicity. Decorporation therapy can be used to accelerate the excretion of radionuclides from the body, and to prevent their internalization. Decorporation agents can be divided into several groups according to the mechanism of action, such as blocking, binding (ion exchange), chelation, isotopic dilution, displacement, and mobilization. Laxatives, diuretics, and emetics can also be used to accelerate the elimination of radionuclides from the body (IAEA 2018). Four decorporating drugs have been FDA approved so far, and others are used off-label or do not need approval. Agents that may be used for decorporation treatment recommended by IAEA (2018) are summarized in Table 6.
Exploiting active nuclear import for efficient delivery of Auger electron emitters into the cell nucleus
Published in International Journal of Radiation Biology, 2023
Andrey A. Rosenkranz, Tatiana A. Slastnikova, Mikhail O. Durymanov, Georgii P. Georgiev, Alexander S. Sobolev
It is known that AE-emitting radiopharmaceuticals can also exert effects on the regulatory pathways and mediate cell death (Paillas et al. 2016). A modulation of these regulatory pathways could be interesting as a possible target in radionuclide therapy. However, the direct cytotoxicity of 125I was significantly higher with intranuclearly accumulating 5-[125I]Iodo-2′-deoxyuridine than in the case of activation of these regulatory pathways (Paillas et al. 2016). Generally, regulatory pathways as the main targets in radionuclide therapy do not appear to be the best way to treat diseases. There are several intersecting intracellular regulatory pathways, which are often specific for certain cell types and patients. Therefore, predicting the therapeutic effects may be sophisticated. The destructive effects on the nuclei of cancer cells, which result in their death due to damage to unique DNA molecules, appears to be a more reliable way to treat cancer using radionuclide therapy.
Radiological risk assessment of the Hunters Point Naval Shipyard (HPNS)
Published in Critical Reviews in Toxicology, 2022
Dennis J. Paustenbach, Robert D. Gibbons
Pu-239 has a radioactive half-life of 24,110 years and is produced when uranium absorbs a neutron. Small amounts of plutonium occur naturally, but large quantities have been produced in nuclear reactions or released from atmospheric nuclear weapons tests. Pu-239 transitions by alpha decay. Its decay products emit alpha, beta, and gamma radiation depending upon which radionuclide is being evaluated and can pose both an internal and external radiation hazard. Pu-239 is present in most soils in the United States at various concentrations (ICRP 2008; Johnson et al. 2012). The potential for Pu-239 to be present on ships returning from nuclear weapons tests in the Pacific and Pu-239 use in calibrating radiation detection equipment were primary reasons it was identified as an ROC at HPNS (USN 2004).