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Nanozymes and Their Applications in Biomedicine
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2020
Qian Liang, Ruofei Zhang, Xiyun Yan, Kelong Fan
In addition, a study combining Fe3O4 nanozymes with acetylcholinesterase (AChE), and choline oxidase (CHO) demonstrated a colorimetric method for the rapid detection of organophosphorus pesticides and nerve agents (Figure 15.10b). In this method, H2O2 can be formed under the catalysis of the enzymes AChE and CHO in the presence of acetylcholine, which then stimulates Fe3O4 nanozymes to catalyze the oxidation of colorimetric substrates to produce a color reaction. Moreover, the organophosphorus neurotoxins inhibit the enzymatic activity of AChE, which reduces the content of H2O2 and then results in decreased peroxidase-like catalytic activity of the Fe3O4 nanozymes, accompanied by a decrease in color intensity after the oxidation of colorimetric substrates. Using this method, as low as 1 nM Sarin, 10 nM methylparaoxon and 5 μM acephate could be easily detected (Minmin Liang 2013).
PROTECTING THE OFFICE BUILDING FROM NBCs
Published in Charles D. Reese, Office Building Safety and Health, 2004
Sarin is a human-made chemical warfare agent classified as a nerve agent. It is a clear, colorless, tasteless liquid that has no odor in its pure form. People can be exposed through skin contact, eye contact or inhalation if it is released into the air. Sarin mixes easily with water so it could be used to contaminate a public water supply. Symptoms of exposure to sarin can appear within a few seconds or up to 18 hours depending on the extent of the exposure. Sarin causes the glands and muscles of the body to be constantly stimulated, eventually tiring victims to the point where they are no longer able to sustain respirations. Sarin is a volatile nerve agent, which quickly evaporates and spreads into the environment. Because it evaporates so quickly, it presents an immediate but short-lived threat.
Chemical Terrorist Agents
Published in Robert A. Burke, Counter-Terrorism for Emergency Responders, 2017
Onset of symptoms is usually rapid, occurring within minutes of exposure. Masks, including self-contained breathing apparatus (SCBA) masks, alone do not provide adequate protection against this agent. Protective equipment (self-contained breathing equipment or gas mask with appropriate filter and barrier suit) must be used. Agent absorbed by cloth (clothing, blankets, etc.) can be released as a vapor by the cloth for 30 minutes or more after exposure. Remove victims from exposure as rapidly as possible. Remove the victims' clothing at least down to underwear and place in disposal bags. Victims must not be moved into clean treatment areas where unmasked/ungloved personnel are working until decontamination is complete. Medical treatment should include decontamination of victims at as early stage as possible. Medical personnel treating casualties should avoid direct (skin-to-skin) contact; protective gear, including breathing protection, should be worn when treating casualties prior to decontamination. Latex gloves are not adequate protection. Chemical protective (butyl rubber) gloves must be worn. If breathing has stopped, a mechanical respirator should be used to ventilate the patient. While exhaled air is not ordinarily a hazard, DO NOT ATTEMPT MOUTH-TO-MOUTH RESUCITATION without proper shields owing to the possible presence of residual agent on the face. If possible, oxygen or oxygen-enriched air should be used for ventilation. If possible, monitor the cardiac activity. Pralidoxime salts are effective in restoring acetylcholinesterase activity after exposure to sarin. Thus, as a supplement to treatment with atropine, treatment with pralidoxime salts should be initiated as soon as possible after exposure, with a slow intravenous infusion of 500 mg–1 g being given initially. Atropine eye drops reportedly gave some symptomatic relief for eye problems following the use of sarin by terrorists in the Tokyo subway system. Diazepam should be administered to control convulsions. It also has value in controlling fear on the part of the patient. An initial dose of 5 mg may be followed by additional doses at 15-minute intervals up to a total of 15 mg.
Development of a detection system for gas-phase aromatics and other molecules ionizable by soft X-rays demonstrated using methyl salicylate
Published in Aerosol Science and Technology, 2023
Dong-Bin Kwak, Seong Chan Kim, George W. Mulholland, Miles C. Owen, Changhyuk Kim, Handol Lee, David Y.H Pui
Chemical warfare agents (CWAs) were developed and used during World War I (1914–18), resulting in tens of thousands of deaths and casualties (Szinicz 2005; Stockholm International Peace Research Institute (SIPRI)) 1971). Despite the ratification of the Chemical Weapons Convention in 1997, which prohibits the development, production, stockpiling, and use of chemical weapons, rockets containing the chemical agent Sarin were used, killing thousands of people during the Syrian Civilian War in 2013 (Dolgin 2013). The impact of CWAs during the war was devastating because they not only targeted military forces but also killed civilians who lacked the means to protect themselves. However, detecting and removing the CWAs were extremely difficult during the war. In this study, the soft X-ray assisted detection method which can convert gas-phase aromatic compounds to nanoparticles is developed to nonspecifically detect methyl salicylate, a chemical warfare agent simulant.