Other Cyclotron Radionuclides
Frank Helus, Lelio G. Colombetti in Radionuclides Production, 2019
For the separation of radiobromine from an arsenic or selenium target, the following three methods have been used: (1) distillation from a solution,25,31,34 (2) volatilization by fusion of the target,32 and (3) coprecipitation with AgCl followed by the dissolution of the precipitate in NH3 water and subsequent removal of cations by ion exchange.33 Each method has its advantage, but the volatilization by radio-frequency heating seems to be well suited for a large-scale production. Possible contamination of nonradioactive bromine from reagents and laboratory atmosphere should always be kept in mind in chemical processing.25 A method is shown to obtain no-carrier-added 77Br in water containing no other solute.25 Bromine in this state is gradually lost when the solution is concentrated by evaporation.
A Comparative Study of the Kinetics and Bioavailability of Pure and Soil-Adsorbed Benzene, Toluene, and M-Xylene after Dermal Exposure
Rhoda G. M. Wang, James B. Knaak, Howard I. Maibach in Health Risk Assessment, 2017
Under the conditions of the previous studies, the applied compound quickly volatilized and was lost to the atmosphere. Our research utilized a glass cap to minimize volatilization losses of compound and loss of soil. Susten et al., using a stainless-steel skin depot to minimize volatilization losses of benzene, applied a rubber solvent mixture containing 0.5% (v/v) benzene to the skin of hairless mice for 4 h.33 Data derived from their study, together with observations made during tire-building operations, suggest that a worker could absorb 4 to 8 mg of benzene daily through the skin. Hanke et al. showed that benzene penetrated the skin of human forearm at a rate of 0.24 to 0.48 mg/cm2/h after 1.25 h of continuous occluded exposure.34 Longer skin contact (72 h) may have been a factor in increasing the percentage of absorption in our investigation. Although occlusive coverings have been known to enhance the percutaneous absorption of a compound by increasing the temperature and hydration of the skin,5 it should be kept in mind that individuals living in the community or waste disposal site workers could be exposed to contaminated soil during seasons of high heat and humidity. Use of the occlusive covering would mimic these conditions.
Granulation and Production Approaches of Orally Disintegrating Tablets
Dilip M. Parikh in Handbook of Pharmaceutical Granulation Technology, 2021
Rapid disintegration property can be obtained by formulating into a porous mass by incorporating solid substances that volatilize fast like camphor, menthol, ammonium bicarbonate, thymol, and urea. In the sublimation method, ODTs are compressed by using tablet components, and after compression, the volatile substance is vaporized by pressure with the application of heat, and while the volatile substance leaves the mass, a porous structure is formed. Compressed tablets containing mannitol and camphor have been prepared by the sublimation technique. The tablets dissolve within 10–20 seconds and exhibit sufficient mechanical strength for practical use [26]. The most important advantage of this method is that the volatilization of these materials eliminates the complicated process associated with the lyophilization process [1].
Recent advances in electrochemical and optical sensing of the organophosphate chlorpyrifos: a review
Published in Critical Reviews in Toxicology, 2022
Athira Sradha S, Louis George, Keerthana P, Anitha Varghese
Due to its non-judicious application, CP residues persist 10–14 days in crops after applied to plant leaves, either in undissociated forms or in residual forms like 3,5,6-trichloropyridinol (TCP) (Figure 3(C)) (Solomon et al. 2014). It was observed that CP was absorbed by wheat seedlings (0.257–4.50 µgg−1) and by oilseed rape seedlings (0.249–2.02 µgg−1) when it was added in single irrigation (1–10 µgg−1) (Wang L et al. 2007). CP’s solubility in water was found to be 0.7 mg/L (Solomon et al. 2014) and only very little amount of CP actually enters water to leach underground and most of it is adsorbed onto soil particles and plant materials. The CP that enters the water, however, undergo volatilization from the water surface as volatilization dominates over dissipation (Solomon et al. 2014; Ubaid ur Rahman et al. 2021).
Acute exposure to C60 fullerene damages pulmonary mitochondrial function and mechanics
Published in Nanotoxicology, 2021
Dayene de Assis Fernandes Caldeira, Flávia Muniz Mesquita, Felipe Gomes Pinheiro, Dahienne Ferreira Oliveira, Luis Felipe Silva Oliveira, Jose Hamilton Matheus Nascimento, Christina Maeda Takiya, Leonardo Maciel, Walter Araujo Zin
C60 was prepared as previously reported (Park et al. 2010). Considering that C60 fullerenes between 45 and 60 nm in diameter were detected in several sources such as coal, oil refinery, rivers, atmosphere, this study used the same fullerene-C60 with purity greater than 99.5% from Sigma-Aldrich (St. Louis, MO) used in previous studies (Sanchís et al. 2013; Oliveira et al. 2018; Gredilla et al. 2019). Briefly, 16.7 mg of fullerene C60 were suspended (Sigma-Aldrich, St. Louis, MO) and added to 50 mL of toluene (Merck, Damstadt, Germany) under continuous stirring for 2 h at 150 rpm on a magnetic stirrer. The C60 solution in toluene was added to the saline solution (0.9% NaCl) with 1.0% polysorbate 80/Tween 80 (Merck, Darmstadt, Germany) yielding a 20-mL total volume. A heated (37 °C) ultrasonic bath (Bransonic® M2800H, Danbury, CT) allowed the complete volatilization of the toluene shortly thereafter. The suspension was passed through a 0.22-µm sterile disposable filter (Merck, Darmstadt, Germany). Samples were stored in aliquots in a freezer (−20 °C).
Optimisation of the microencapsulation of lavender oil by spray drying
Published in Journal of Microencapsulation, 2019
Ayah M. Burhan, Sameh M. Abdel-Hamid, Mahmoud E. Soliman, Omaima A. Sammour
One of the most interesting essential oils in use is lavender essential oil (LO). In addition to its extensive traditional use as a potent antibacterial and antifungal, recent studies have shown that lavender oil possesses a lot of other pharmacological activities including analgesic, anti-inflammatory, and antithrombotic effects. It is also reported to be very effective in the treatment of burns and insect bites. However, one of its most outstanding bioactivities is its use in aromatherapy which highlights its central nervous system (CNS) activities (Cavanagh and Wilkinson 2002, Hajhashemi et al. 2003, Mahboobi et al. 2006). Lavender oil is characterised by its high content of linalyl acetate in addition to many other volatile and lipophilic compounds that belong to different chemical classes. Those components are susceptible to loss by volatilisation as well as different types of conversion, and degradation reactions leading to decreased essential oil quality, that may end up in complete loss of its different pharmacological properties (Turek and Stintzing 2013). An intervention for formulating essential oils is important; however, this task is challenging where the formulator has to deal with such a complex system of many different components.
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