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Physics of Ultrasound
Published in Marvin C. Ziskin, Peter A. Lewin, Ultrasonic Exposimetry, 2020
Sometimes it is difficult to be certain whether or not cavitation is occurring. A simple direct method is to use the starch test for free iodine when a solution of potassium iodide is irradiated, indicating the production of free radicals. Cavitation-produced free radicals can also convert nonfluorescent terephthalic acid to highly fluorescent hydroxyterephthalate96 which can be assayed by spectrophotometer. Because cavitation is a nonlinear phenomenon, first-order subharmonics of the driving frequency are produced and these can be detected by a suitable hydrophone.97 At low intensities and high frequencies, resonant cavitation bubbles emit second-harmonic pulsations.98 Another method is to look for sonoluminescence, which is discussed in the next section.
Screening Smokes: Applications, Toxicology, Clinical Considerations, and Medical Management *
Published in Brian J. Lukey, James A. Romano, Salem Harry, Chemical Warfare Agents, 2019
Lawrence A. Bickford, Harry Salem
Chemistry and generation. Terephthalic acid (TA) smoke is generated pyrotechnically from grenades and smoke pots and is similar in performance to cinnamic acid as a white vaporization/condensation thermally generated smoke. The M83 grenade and the M8 smoke pot were developed by the U.S. Army for training purposes to simulate HC smokes. A typical M83 smoke grenade contains terephthalic acid, sugar, potassium chlorate, magnesium carbonate, stearic acid, and a binder (Anthony et al., 2003). Terephthalic acid is a precursor to polyethylene terephthalate (PET), which is used to manufacture beverage containers and used in some clothing fibers.
Rhododendron arboreum Sm.: A Review of its Traditional Uses, Phytochemistry, and Pharmacology
Published in V. R. Mohan, A. Doss, P. S. Tresina, Ethnomedicinal Plants with Therapeutic Properties, 2019
Green leaves of R. arboreum are reported to contain glucoside, ericolin (arbutin) (C12H16O7), ursolic acid (C30H48O4), α-amyrin (C30H50O), epifrie-delinol (C30H52O), a new triterpenoid named campanulin, quercetin, and hyperoside (C21H20O12) (Orwa et al., 2009). Chemical analysis of the leaves of R. arboreum revealed the presence of hyperoside (3-D-galactoside of quercetin), ursolic acid, and epifriedelinol, a triterpenoid compound (Rangaswamy and Sambamurthy, 1959). The leaves are also reported to contain the flavone glycoside and dimethyl ester of terephthalic acid and certain flavonoids (Verma et al., 2011a). Flavonoids isolated from the leaves of R. arboreum were found to have potent antioxidant property (Prakash et al., 2007). Thirty four phytochemicals were identified in the methanolic leaf extract of R. arboreum by using GC–MS analysis, of which 22-stigmasten-3-one showed the highest area (14.59%) and benzyl acetate showed the lowest area (0.15%). The major compounds identified were 22-stigmasten–3-one, 1,1,6-trimethyl-3-methylene-2-(3,6,10,13,14–pentamethyl–3–ethenyl– pentadec-4-enye) cyclohexane, alpha-amyrin, beta-amyrin, linoleyl alcohol, linoleic, beta-citronellol, tetradecane, 9,12-octadecadienoic acid, methyl ester, dibutyl phthalate, L-ascorbic acid 2, 6-dihexadecanoate, dodecane, and heptadecane (Painuli et al., 2016).
Impaired exercise capacity in electrostatic polyester powder paint workers
Published in Inhalation Toxicology, 2021
Ukbe Sirayder, Deniz Inal-Ince, Cihangir Acik, Ferhan Soyuer
Electrostatic powder paints (EPP) contain polyester, which is a hydrocarbon. It is a polymer that is formed by melting at a high temperature of petroleum and produced ‘terephthalic acid’ and ‘ethyl glycol,’ and it is a carcinogenic substance (Pang et al. 2016). Polyester is used in electrostatic paint production due to its electrostatic properties. Polyesters are known to cause various skin diseases (Meyers 2010). In addition, it decreases the progesterone ratio in pregnant women due to its electrostatic effect and causes miscarriage. In male subjects, the use of polyester underwear has been reported to reduce sperm count and quality. The inhalation of polyester, which has serious side effects even in contact with the skin, is hazardous (Dale et al. 2014). When animal experiments conducted to investigate the effectiveness of polyester are examined, it is seen that exposure to polyester causes damage to the lung tissue the most. At 13 weeks, it has been shown to cause an increase in the weight, the number of macrophages and inflammatory cytokines of the affected lung tissue (Katz et al. 1997). In addition to the polyester in powder paints, organic, metallic, and plastic pigments, binders, and thinners are used. Each of these may accumulate in the lungs as a result of inhalation and may cause occupational lung diseases (Meyers 2010).
Antibacterial application and toxicity of metal–organic frameworks
Published in Nanotoxicology, 2021
Wanling Zhao, Jinqiong Deng, Yan Ren, Liyuan Xie, Weirong Li, Qi Wang, Shengqing Li, Sijun Liu
The solvent/hydrothermal method employs water or other organic solvents, such as methanol, N-dimethylformamide (DMF), and dimethyl sulfoxide, to synthesize MOFs through conventional heating. Temperature and heating rate are two factors that affect this method. Ahmed et al. (2019) used the solvothermal method to synthesize the UiO-66 MOF. ZrCl4 and terephthalic acid were mixed in DMF, dissolved ultrasonically for approximately 2 min at room temperature, heated at 120 °C for 24 h, cooled to room temperature to collect the reaction solution, centrifuged to remove the supernatant, and washed three times with ethanol. Finally, the UiO-66 MOF was obtained by drying in air overnight at 70 °C. The target product can be obtained simply through this method.
Comparison of properties of dust in alveolar of rats and the workplace
Published in Experimental Lung Research, 2021
Xu Zhang, Zheng Zhang, Peng Wang, Shuyu Xiao, Ke Han, Yali Tang, Heliang Liu, Yuping Bai, Yulan Jin, Jinlong Li, Xiaoming Li, Qingan Xia, Fuhai Shen
A sample of 5.00 mg of dust was taken and uniformly dispersed in 30 ml of PBS buffer. The PBS buffer was used as a blank control group. We placed in a 37 °C water bath for 30 minutes and then added 1 ml of a terephthalic acid solution (TA) having a concentration of 1.0 × 10−2 mol/L. Based on the HOTP concentration-fluorescence intensity standard curve, we calculated the amount of free radicals produced by dust in PBS buffer.