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Radiometry
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
One of the earliest types of detectors is photographic film, which is an example of a chemical detector. The active material of the film consists of grains of silver bromide (AgBr) embedded in a thin emulsion. This emulsion is placed on a transparent base and covered with a protective coating. Upon irradiation with ionizing radiation (or light, as in conventional photography), a latent image is created. This latent image is then made visible by exposing the film to a chemical (developing) that reduces the exposed silver halides to metallic Ag. In order to make the film insensitive to further exposure, the image is fixed by a chemical that produces soluble salts with Ag ions in the remaining silver halide crystals. These salts are then removed when the film is rinsed.
Two-dimensional and Three-dimensional Dosimetry
Published in W. P. M. Mayles, A. E. Nahum, J.-C. Rosenwald, Handbook of Radiotherapy Physics, 2021
Mark Oldham, Devon Godfrey, Titania Juang, Andrew Thomas
The primary strengths of silver halide radiographic film include high contrast (image quality), high spatial resolution and high sensitivity. The basic physical mechanisms of image formation and development are the same for both radiographic and photographic film. The active component of film consists of a gelatin emulsion, which suspends small radiation sensitive silver halide crystals* (e.g. silver bromide [AgBr]). The emulsion is evenly coated onto both sides of a polyester base, which provides the stiffness and mechanical stability of the film. Details of film manufacture and the active chemical ingredients can be found in Carlton and Adler (1996). Film can be used to measure dose distributions, but the accuracy is dependent on the performance and stability of the processor and the consistency between different films in the same batch. Absolute dose error may exceed 10% unless strict controls are imposed on the developing solutions.
Inhalation Toxicity of Metal Particles and Vapors
Published in Jacob Loke, Pathophysiology and Treatment of Inhalation Injuries, 2020
Silver is used in electrical applications because of its excellent properties of conduction. Jewelry, coins, and eating utensils are some of the principal uses of this metal. Silver halides are used in photography; silver nitrate is used for making indelible inks and for medicinal purposes.
Genotoxic potential of different nano-silver halides in cultured human lymphocyte cells
Published in Drug and Chemical Toxicology, 2023
Devrim Güzel, Merve Güneş, Burçin Yalçın, Esin Akarsu, Eyyüp Rencüzoğulları, Bülent Kaya
One of the remarkable breakthroughs in the domain of nanotechnology is the use of silver halides (AgBr, AgCl, and AgI) in many medical applications as antimicrobial agents (Bahri-Kazempourab et al.2013). In line with this, is the present research aims to investigate the possible genotoxic, clastogenic, and cytotoxic effects of silver ion (Ag+), AgNP and nano-sized silver halides/salts (AgBr, AgCl, and AgI) on healthy human peripheral blood lymphocyte cells in vitro. The chromosomal and DNA damages that these test substances may cause with clastogenic or aneugenic effects are evaluated on healthy human cells through the CA test and cytokinesis-blocked micronucleus (CBMN) test. The genotoxic effects resulting from the DNA strand breaks are evaluated through the Comet test on healthy human lymphocyte cells.
Interaction of nanoparticles with endotoxin Importance in nanosafety testing and exploitation for endotoxin binding
Published in Nanotoxicology, 2021
Maria Mangini, Alessandro Verde, Diana Boraschi, Victor F. Puntes, Paola Italiani, Anna Chiara De Luca
Kalita et al. (2015) proposed a colorimetric assay employing AuNPs functionalized with PMB combined with the use CMOS sensor to detect the AuNP optical properties with high sensitivity. Serum and water samples spiked with LPS from E. coli O55:B5 were first drop-casted onto a silanized glass substrate and then tagged with PMB-AuNPs. The binding was visualized using a silver halide reduction process that leads to an increase of the particle size and the deposition of a silver layer where LPS is present. Signal intensities (measured with a CMOS sensor on images captured with an optical microscope) increased monotonically with rising LPS concentrations, showing a LOD of 5 and 50 fg/mL for water and serum, respectively. This device showed an excellent recognition of O55:B5 LPS, and it can be used to detect other LPS serogroups thanks to the high binding affinity of PMB to any kind of LPS.