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Inhalation Toxicity of Metal Particles and Vapors
Published in Jacob Loke, Pathophysiology and Treatment of Inhalation Injuries, 2020
Gallium is obtained as a byproduct of copper, zinc, lead, and aluminum. It is used in high-temperature thermometers, as a substitute for mercury in arc lamps, in the manufacture of alloys, and as a liquid sealant for glass joints and vacuum equipment. Gallium arsenide and phosphide are used in light-emitting diodes (LEDs).
Interstitial Microwave Hyperthermia for the Treatment of Brain Tumors *
Published in Leopold J. Anghileri, Jacques Robert, Hyperthermia in Cancer Treatment, 2019
Bernard E. Lyons, John W. Strohbehn, David W. Roberts, Terence Z. Wong, Richard H. Britt
The 12-probe gallium-arsenide (GaAs) system (Clini-Therm, Model 1200, Dallas, Tex.) based on the original work of Christensen57 is the system used in the experimental and clinical studies that are ongoing at Dartmouth College. Gallium-arsenide is a semiconductor whose band-edge absorption lies in the near infrared region of the spectrum. When radiation is passed through the sensor, a variable amount is absorbed by the process of exciting valence band electrons. The absorbed energy of GaAs varies with temperature, so the amount of return radiation is a function of the temperature of the sensor. For clinical applications these thermometer probes may be inserted in the nylon afterloading catheters alongside the antennas. In this fashion, direct power control at each antenna can be determined by a computer and multiple temperature points can be measured throughout the tumor volume using pull-back techniques during thermal mapping.
Chapter Paper 1 Answers
Published in James Day, Amy Thomson, Tamsin McAllister, Nawal Bahal, Get Through, 2014
James Day, Amy Thomson, Tamsin McAllister, Nawal Bahal
Solids are classified as conductors, semi-conductors and insulators. This division is based on the solid’s ability to conduct electrons. This ability is due to the presence of unpaired electrons in the outer shells of the solid’s atoms. Most conductors are metallic, although the atomic structure of carbon in graphite allows it to act as a conductor. Insulators have firmly bound outer electrons such as rubber and glass, and will not allow an electrical current to flow. Semi-conductors under certain conditions, usually temperature, will allow an electrical current to flow. Examples include silicon, germanium, and gallium arsenide. Semi-conductors are used in thermistors, transistors and diodes. Electrical fuses are made of a metal wire and transformers consist of metal wire coiled around a ferromagnetic material.
Arsenic: an emerging role in adipose tissue dysfunction and muscle toxicity
Published in Toxin Reviews, 2022
Kaviyarasi Renu, Aditi Panda, Balachandar Vellingiri, Alex George, Abilash Valsala Gopalakrishnan
Arsenic presence in the environment can be both man-made and natural activities. It enters the environment naturally through groundwater, mineral ore, and geothermal processes. Its dispersion and spread in the environment are mainly provoked through mining, leaching, and commercial uses. It's a common by-product through the smelting process of metal ores like cobalt, gold, lead, nickel, and zinc, respectively. Other sources of arsenic include algaecides, herbicides, non-ferrous alloys, pesticides, defoliants, etc. It is also vastly used in glass manufacturing industries in the form of gallium arsenide and arsine gases used in semiconductor devices. However, both organic and inorganic forms of Arsenic can also be found in seafood like oysters, scallops, mussels, prawns, lobsters, etc. (Barringer and Reilly 2013).
Mechanisms of platelet release: in vivo studies and in vitro modeling
Published in Platelets, 2020
Vittorio Abbonante, Christian A. Di Buduo, Alessandro Malara, Pierre-Alexandre Laurent, Alessandra Balduini
Calculations of platelet consumption and estimated platelet number released from each Mk in humans and mice suggested that platelet production via proplatelet formation is sufficient to maintain the physiological platelet turnover [1,5]. While, rapid platelet turnover, especially under conditions of increased demand (20-fold or more), such as during inflammatory reactions, may require different mechanisms of Mk fragmentation. Kowata et al., using intravital microscopy in thrombocytopenic mice, identified immature thick Mk protrusions, characterized by a peripheral zone, abundant endoplasmic reticulum, and demarcation membrane system, and random microtubule arrays, as an alternative Mk intravascular product in addition to proplatelets [52]. Consistently, Nishimura and co-workers detected an alternative Mk rupture in mice under inflammatory conditions, which entails rapid cytoplasmic fragmentation and release of much larger numbers of platelets, primarily into blood vessels [53]. Using high-speed two-photon microscopy with multicolor high-sensitive gallium arsenide (GaAs) detectors, authors demonstrated that the inflammatory cytokine IL-1α primarily regulated this novel Mk rupture-dependent pathway and this process was morphologically and mechanically distinct from proplatelet formation and typical Fas Ligand-induced apoptosis [53].
Dose-response for assessing the cancer risk of inorganic arsenic in drinking water: the scientific basis for use of a threshold approach
Published in Critical Reviews in Toxicology, 2019
Joyce S. Tsuji, Ellen T. Chang, P. Robinan Gentry, Harvey J. Clewell, Paolo Boffetta, Samuel M. Cohen
Lastly, administration of gallium arsenide produced an increased incidence of lung tumors in female rats in an inhalation study, but not in male rats or male or female mice (NTP 2000). However, this was likely due to the particulate matter of the gallium arsenide that produced a marked inflammatory reaction similar to that seen with other particulates and was not due to the chemical itself (Bomhard et al. 2013).