The Chemical Environment
Vilma R. Hunt, Kathleen Lucas-Wallace, Jeanne M. Manson in Work and the Health of Women, 2020
Investment or lost-wax casting produces the most ornate or detailed jewelry, such as fine filigreed designs of school rings that require little finishing. Copper alloys and precious metals are generally cast at approximately 3000°F, though low-temperature white metal is occasionally cast by this method. The lost-wax molds are made from a pastry mixture of lime- or clay-base plaster (up to 30% silica) and very fine silica powder (up to 70% silica). “Shakeout” is the industry’s term for the breaking of the plaster molds about the newly cast jewelry piece and is traditionally done by hand with the sand flying into the workers’ breathing area. The Rhode Island Department of Health has measured levels of silica during shakeout at 32 times the threshold limit value. In die casting, molten metal is forced into a metal mold or die. Zinc-aluminum and copper alloys are commonly used, while white metal is used only occasionally. Muriatic acid (impure hydrochloric acid) is employed as an industrial cleaner for the metal dies.
Preparation and Health Benefits of Rice Beverages From Ethnomedicinal Plants: Case Study in North-East of India
Megh R. Goyal, Arijit Nath, Rasul Hafiz Ansar Suleria in Plant-Based Functional Foods and Phytochemicals, 2021
Macronutrients and micronutrients function as cofactors of several cellular enzymes. Examples of these metals include sodium (Na), iron (Fe), copper (Cu), potassium (K), manganese (Mn), and zinc (Zn). Metal ions provide various structural, regulatory, and metabolic/catalytic activities in the cell (s). These metals involve the formation and development of bones, amino acid synthesis, cholesterol, and carbohydrate metabolisms; reduce toxicity; and participate in the oxido-reduction processes. Presence of Na, Cu, and Zn has been reported within the permissible limits in rice beer in different communities in Assam (namely: Ahom, Mising, and Deori) [14]. In comparison to barley and wheat beers, there was no significant change in levels of K, Fe, Ni, Mn, and Zn, while the levels of Co, Pb, and Cd were varied. The estimated intake of these metals in rice beer by an individual of that community was found to be within limits of the recommended dietary allowance, which indicated safe consumption of the local rice beer [14].
Human Noroviruses
Dongyou Liu in Handbook of Foodborne Diseases, 2018
Park et al.170 inoculated HNoV GI.1 and GII.4 on fluorinated titanium oxide (TiO2) coated surfaces followed by photoactivation at a wavelength of 365 nm. HNoV GI titers were reduced by 1.1 log, whereas HNoV GII.4 was reduced by less than 1 log following 120 minutes of exposure. They observed oxidation of virus capsid proteins, indicating potential loss of infectivity. Warnes171 reported inactivation of more than 4 log of MNV-1 on copper and copper nickel (89% copper) surfaces after 30 and 60 minutes, respectively, at room temperature (RT) on both wet and dry surfaces. The rate of inactivation was proportional to copper content and Cu(II), and especially Cu(I) ions were responsible for the virucidal effect by loss of capsid integrity.172 In alloys, zinc also showed some antiviral effect.172
Hydroxyapatite as a biomaterial – a gift that keeps on giving
Published in Drug Development and Industrial Pharmacy, 2020
Behrad Ghiasi, Yahya Sefidbakht, Sina Mozaffari-Jovin, Behnaz Gharehcheloo, Mehrnoush Mehrarya, Arash Khodadadi, Maryam Rezaei, Seyed Omid Ranaei Siadat, Vuk Uskoković
Electrospraying is often used to deposit HA coating onto metallic implants. It was used to coat titanium implants with bisphosphonate (BP)-loaded HA, which led to a significant increase in the peri-implant bone volume and bone area from the implant surfaces compared to control implants in osteoporotic rats [134] after the material demonstrated a positive in vitro response [135]. HA has also been deposited on the surface of a Mg-3Zn alloy via electrophoretic deposition technique [112]. The Mg-3Zn alloy is one of the best options for the temporary, slowly resorbable orthopedic implants because magnesium is biodegradable, while zinc acts to mitigate the very high corrosion rate of Mg in the aqueous environments and make the alloy more resistant to corrosion. HA coating on the surface of the alloy did not only further inhibit the corrosion in the biological environments, but it also provided a better contact with the bone cells at the surface of the alloy (Figure 5(f)). Radiofrequency magnetron sputtering was another method used to deposit HA coatings on titanium implants [136,137]. For this method, the tilt angle, among other deposition parameters, appeared particularly critical, as it allowed for the tuning of both the scratch resistance of the films and their roughness on the nano scale [138], with the potential of affecting the cellular attachment and proliferation as well as the implant fixation thereby.
Zinc-induced hypocupremia and pancytopenia, from zinc supplementation to its toxicity, a case report
Published in Journal of Community Hospital Internal Medicine Perspectives, 2021
Ahsan Wahab, Kamran Mushtaq, Aqsa Khan, Muhammad Shahzeb Khan Khakwani, Adeel Masood, Jeremey Henderson, Faizan Malik
The patient had history of macular degeneration and was taking MVMs for many years. For possible zinc-induced hypocupremia, we ordered serum zinc and serum copper levels. Zinc level was 168 ug/dl (RR: 60–130) and the copper level was <10 ug/l (RR: 810–1990). MVMs containing 80 mg of zinc (this MVMs contained 2 mg of copper as well but apparently dose was not sufficient enough to compensate for zinc excess) was discontinued and the patient was started on oral copper 8 mg daily. With the two-week treatment of oral copper, the patient’s white blood cell count improved from 1.35 to 7.13 × 109/l, hemoglobin from 7.1 to 9.8 g/dl and platelet from 99 to 216 × 109/l. Absolute neutrophil count improved to 5.1 × 109 from 0.1 × 109/l (Table 1). Serum zinc and copper levels normalized in 4 weeks period.
Effect of curcuma on zinc, lipid profile and antioxidants levels in blood and tissue of streptozotocin-induced diabetic rats fed zinc deficiency diet
Published in Archives of Physiology and Biochemistry, 2021
Imene Tebboub, Zine Kechrid
Basal diet of animals was prepared as described by Southon et al. (1988) and it consisted of (in g/kg diet): cornstarch 326, glucose 326, protein 168 (soya), lipids 80 (corn oil), fiber 40 (cellulose), vitamin mix (ONAB Harrouche, Algeria) and mineral mix 40. The latter was formulated to contain either adequate (54 mg/kg) or inadequate (1.2 mg/kg) quantities of zinc, as determined by atomic absorption spectroscopy. The mineral mix was supplied (g/kg diet) by calcium hydrogen orthophosphate, 13; disodium hydrogen orthophosphate, 7.4; calcium carbonate, 8.2; potassium chloride, 7.03; magnesium sulfate, 4; ferrous sulfate, 0.144; copper sulfate, 0.023; potassium iodide, 0.001; manganese sulfate, 0.180; and zinc carbonate, 0.1. The low zinc diet contained no additional zinc carbonate.
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