Atomic Particles, Isotopes, and Ions
Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk in Survival Guide to General Chemistry, 2019
Example: Write the complete symbol for the selenium ion with 44 neutrons and 36 electrons; use the periodic table as necessary. The element selenium has the symbol = SeThe periodic table indicates that Se has an atomic number (Z) = 34; the # of protons = 34Mass number (A) = # of nucleons = 34 protons + 44 neutrons = 78The # of electrons = 36; the # of protons = 34; the atom is not neutral# of positive charges (# of p+) = 34 (+)# of negative charges (# of e−) = 36 (−) total charge difference = 34 (+) plus 36 (−) = 2 (–)
Bladder and Prostate Cancer
Spyridon E. Kintzios, Maria G. Barberaki, Evangelia A. Flampouri in Plants That Fight Cancer, 2019
Selenium, named from the Greek σελήνη (‘moon’), is a naturally occurring non-metallic trace element essential to human health. It was discovered incidentally in 1817 by the Swedish chemist Jacob Berzelius, who was investigating an impurity slowing production of sulfuric acid at his chemical plant (Trofast 2011). Vitamin E refers to a family of naturally occurring, essential fat-soluble compounds found in a variety of nuts, oils, and leafy green vegetables. In 1922, researchers noted that rats were failing to reproduce when fed solely lard; introducing wheat germ and lettuce to the diet resolved the issue. They determined that these foodstuffs must contain an ‘anti-sterility factor’, which was first isolated and redubbed ‘vitamin E’ in 1935 (Evans and Bishop 1992, Oakes 2007).
Management of Trace Elements in Short Bowel Syndrome
John K. DiBaise, Carol Rees Parrish, Jon S. Thompson in Short Bowel Syndrome Practical Approach to Management, 2017
Selenium plays a role in antioxidant systems, thyroid hormone metabolism, and immune regulation [37]. Selenium is primarily absorbed in the duodenum and is excreted in urine and stool. Thus, patients who have had surgical alterations that allow ingested nutrients to bypass the proximal bowel appear to have increased selenium requirements [37–39]. Serum selenium levels are decreased in sepsis or injury, but in unstressed patients, serum selenium levels can be useful to detect deficiency or excess [40]. Selenium deficiency can cause cardiomyopathy, macrocytosis, myopathy, altered pigmentation, and growth retardation and alopecia in children [37,38]. The recommended dietary allowance for selenium is 55 μg/day for adults and between 15 and 40 μg/day for infants and children [37].
The Effect of Sildenafil on Selenite-Induced Cataract in Rats
Published in Current Eye Research, 2020
Hatice Tuba Atalay, Ahmet Yucel Ucgul, Ummuhani Ozel Turkcu, Mehmet Cuneyt Ozmen, Samet Yilmaz, Ayse Bilgihan
Many agents have been used to create a cataract formation. However, the selenite induced cataract model is the most widely accepted method today. Selenium (Se) is an indispensable rare-earth element for humans, animals and a few microscopic organisms.7 It is present in the structure of selenocysteine, an essential amino acid with antioxidant properties.8,9 However, ironically, in 1978, Ostadalova et al first demonstrated that overdose of selenite caused rapid cataract development by increasing oxidative stress.10 In the laboratory, the selenite cataract model could be induced by a single subcutaneous injection of excess sodium selenite (Na2SeO3) into the suckling rats on postpartum day 10. This model is usually presented with severe bilateral cataract development within 16 days after eye opening in rats, and could be used as a model for evaluating anti-cataract agents.
Biosynthesis of nano selenium in plants
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2023
Jonas Verstegen, Klaus Günther
Selenium is an element of the chalcogenide group and one of the most versatile trace elements. In contrast to other species, selenium is not considered essential for plants [1,2]. While among other mammals humans rely on selenocysteine (SeCys) in the catalytic centre of enzymes like glutathione peroxidase (GPx) or thioredoxin reductase (TrxR), the plant homologues contain cysteine (Cys) [3]. Though not considered essential, selenium can still have beneficial impact on plants and increase the activity of said enzymes while also improving the resistance against cold, drought and metallic stress [4]. Still, selenium accumulation bears the danger to impair cell integrity and metabolism. Toxic effects of selenium in plants are mostly caused by unintentional incorporation of SeCys and selenomethionine (SeMet) into proteins [5], but also include oxidative and nitrosative stress [2].
Ameliorative effects of nano-selenium against NiSO4-induced apoptosis in rat testes
Published in Toxicology Mechanisms and Methods, 2019
Xiaotian Zhang, Xiaoqin Gan, Qiannan E, Qiong Zhang, Yixing Ye, Yunyu Cai, Aijie Han, Minmin Tian, Yixuan Wang, Caixia Wang, Li Su, Changhao Liang
Selenium (Se), one of the essential micronutrient for both animals and humans, has been increasingly used in pharmaceutical and food industry in recent years (Fang et al. 2008). Se plays an important role in regulating chronic inflammation and immune response, and also displays an effective anti-cancer activity (Klein 2004; Huang et al. 2012). Moreover, Se possesses important antioxidant capacity because of its unique property to form the active center of antioxidant enzymes, such as glutathione peroxidase (GPx), which helps in decreasing oxidative stress (Rotruck et al. 1973; Kaur and Bansal 2015). In a previous study, Se has been clarified to inhibit cadmium-induced apoptosis in porcine renal epithelial cell line through ameliorating ROS-mediated mitochondrial dysfunction (Zhou et al. 2009). Another study has reported that dietary-supplemented Se can inhibit testicular apoptosis and damaging effect in male mice under heat stress conditions (Kaur and Bansal 2015). Currently, Se compounds are believed to be antidotal agents, having an antagonistic effect toward mercury, cadmium, silver, lead, and many other substances (Rastogi et al. 1976; Ikemoto et al. 2004), whereas the role of Se element on Ni toxicity is rarely reported. To some extent, Se can play more effective role at proper dosage, while excessive usage of Se would generate unhealthy action even serious toxicity (Umysova et al. 2009).
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