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Showing papers on "Selenium published in 1972"


Journal ArticleDOI
10 Mar 1972-Science
TL;DR: Japanese quail given 20 parts per million of mercury as methylmercury in diets containing 17 percent tuna survived longer than quails given this concentration of methylmerCury in a corn-soya diet.
Abstract: Japanese quail given 20 parts per million of mercury as methylmercury in diets containing 17 percent (by weight) tuna survived longer than quail given this concentration of methylmercury in a corn-soya diet. Tuna has a relatively high content of selenium and tends to accumulate additional selenium when mercury is present. A content of selenium in the diet comparable to that supplied by tuna decreased methylmercury toxicity in rats. Selenium in tuna, far from being a hazard in itself, may lessen the danger to man of mercury in tuna.

574 citations





Journal ArticleDOI
TL;DR: A strain of Penicillium which produced dimethylselenide from inorganic selenium compounds was isolated from raw sewage and alkylation did not appear to be a significant mechanism of selenia detoxication by this organism.
Abstract: A strain of Penicillium which produced dimethylselenide from inorganic selenium compounds was isolated from raw sewage. Sulfate and methionine enhanced growth of the fungus and its production of dimethylselenide in media containing selenite. In solutions containing selenate, methionine inhibited dimethylselenide formation while stimulating proliferation of the fungus. Dimethylselenide was also generated from inorganic selenide. Alkylation did not appear to be a significant mechanism of selenium detoxication by this organism. Dimethyltelluride was also produced by the organism from several tellurium compounds, but this product was synthesized only in the presence of both tellurium and selenium. The yields of dimethylselenide and dimethyltelluride varied with the relative concentrations of selenium and tellurium in the medium.

108 citations


Journal ArticleDOI
01 Oct 1972
TL;DR: The Two Faces of Selenium - Can Selenophobia Be Cured? CRC Critical Reviews in Toxicology: Vol. 1, No. 4, pp. 467-514 as discussed by the authors.
Abstract: (1972). The Two Faces of Selenium - Can Selenophobia Be Cured? CRC Critical Reviews in Toxicology: Vol. 1, No. 4, pp. 467-514.

105 citations


Journal ArticleDOI
TL;DR: The effect of dietary selenium on N-2 Fluorenyl-Acetamide (FAA)-Induced Cancer in Vitamin E Supplemented, Selenium Depleted Rats was discussed in this paper.
Abstract: (1972). Effect of Dietary Selenium on N-2 Fluorenyl-Acetamide (FAA)-Induced Cancer in Vitamin E Supplemented, Selenium Depleted Rats. Clinical Toxicology: Vol. 5, No. 2, pp. 187-194.

100 citations




Journal ArticleDOI
TL;DR: The role of selenium and molybdenum in the metabolism of Escherichia coli was explored by growing cells in a simple salts medium and examining the metabolic consequences of altering the concentration of molyBdenum and selenum compounds in the medium.
Abstract: The role of selenium and molybdenum in the metabolism of Escherichia coli was explored by growing cells in a simple salts medium and examining the metabolic consequences of altering the concentration of molybdenum and selenium compounds in the medium. The addition of tungstate increased the molybdate deficiency of this medium, as reflected by lowered levels of enzyme systems previously recognized to require compounds of molybdenum and selenium for their formation [formate-dependent oxygen reduction, formate dehydrogenase (FDH) (EC 1.2.2.1), and nitrate reductase (EC 1.9.6.1)]. The requirement for selenium and molybdenum appears to be unique to the enzymes of formate and nitrate metabolism since molybdate- and selenite-deficient medium had no effect on the level of several dehydrogenase and oxidase systems, for which the electron donors were reduced nicotinamide adenine dinucleotide, succinate, d- or l-lactate, and glycerol. In addition, no effect was observed on the growth rate or cell yield with any carbon source tested (glucose, glycerol, dl-lactate, acetate, succinate, and l-malate) when the medium was deficient in molybdenum and selenium. dl-Selenocystine was about as effective as selenite in stimulating the formation of formate dehydrogenase, whereas dl-selenomethionine was only 1% as effective. In aerobic cells, an amount of FDH was formed such that 3,200 or 3,800 moles of formate were oxidized per min per mole of added selenium (added as dl-selenocystine or selenite, respectively).

88 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of added selenium in the atmosphere and waters in combination with other contaminants is not known and should be studied and studied and the effect on human health and animal health is discussed.
Abstract: Soils producing crop plants that are toxic because of selenium are confined to small areas, but occur throughout the world. Such soils are confined to semiarid regions or areas of impeded drainage. They contribute no significant hazard to human health and only locally to animal health. Environmental contamination with selenium is increasing, but will probably stay well below a hazardous concentration. Locally, mining and industrial wastes may produce minor hazards. However, the effect of added selenium in the atmosphere and waters in combination with other contaminants is not known and should be studied.

Journal ArticleDOI
TL;DR: A review of the medical toxicology of cadmium, cobalt, selenium, arsenic, nickel, copper, manganese, tellurium, vanadium, molybdenum, zinc, and tin; emphasis is on industrial sources of these metals.
Abstract: A review of the medical toxicology of cadmium, cobalt, selenium, arsenic, nickel, copper, manganese, tellurium, vanadium, molybdenum, zinc, and tin; emphasis is on industrial sources of in...

Book ChapterDOI
01 Jan 1972
TL;DR: In this paper, the effect of added selenium in the atmosphere and waters in combination with other contaminants is not known and should be studied and studied and the effect on human health and animal health is discussed.
Abstract: Soils producing crop plants that are toxic because of selenium are confined to small areas, but occur throughout the world. Such soils are confined to semiarid regions or areas of impeded drainage. They contribute no significant hazard to human health and only locally to animal health. Environmental contamination with selenium is increasing, but will probably stay well below a hazardous concentration. Locally, mining and industrial wastes may produce minor hazards. However, the effect of added selenium in the atmosphere and waters in combination with other contaminants is not known and should be studied.


Journal ArticleDOI
TL;DR: In this paper, double-resonance experiments have been used to determine selenium chemical shifts in 80 organoselenium compounds containing 77Se in natural abundance, and the shifts cover a range of over 1500 p.p.m.
Abstract: 1 H–{77Se} Double-resonance experiments have been used to determine selenium chemical shifts in 80 organoselenium compounds containing 77Se in natural abundance. The shifts cover a range of over 1500 p.p.m. and are relatively insensitive to solvent effects. Electronegative substituents give shifts to low field, and in general the shifts parallel those found in similar phosphorus compounds, but are several times larger for a given electronic change. Correlations are found with the extent of α-chain branching in alkyl derivatives, and with Hammett σ-constants in substituted aryl derivatives. The chemical shifts show greater promise as diagnostic tools than do coupling constants involving selenium.

Journal ArticleDOI
TL;DR: Astragalus species were cultured on solutions of repurified nutrients in a greenhouse provided with carbon-filtered air as discussed by the authors, and loss of selenium, presumably organovolatiles, from cultures were confirmed; concomitant inadvertent accretions occurred.
Abstract: Astragalus species were cultured on solutions of repurified nutrients in a greenhouse provided with carbon-filtered air. Earlier results of others which had demonstrated pronounced growth increases with selenium application are now considered to have been largely related to ameliorated toxicity of phosphate through suppressed sorption induced by selenium. Manganese sorption was similarly repressed. Losses of selenium, presumably organovolatiles, from cultures were confirmed; concomitant inadvertent accretions occurred. Essentiality of selenium for growth has not been conclusively established, but certain observations confirm the possibility. If selenium is required for growth of these species, the critical concentration will probably approximate one µg-atom Se/kg dry weight in leaves or whole plant tops.



Journal ArticleDOI
TL;DR: None of the four compounds affected the incidence of spontaneous tumors significantly, andSelenium level was increased in tissues when selenium was fed, and amyloidosis occurred more frequently in mice fed selenum than in controls or those fed tellurium.
Abstract: In order to ascertain innate toxicities of selenium and tellurium, 427 mice were given selenite, selenate, tellurite, and tellurate in drinking water for life, at 3 ppm selenium and 2 ppm tellurium, in an environment controlled as to contaminating trace elements. There were 209 controls. No signs of toxic effects in terms of growth, survival, or longevity appeared in males. Selenite-fed males were heavier and females were lighter than their controls at various ages, and female longevity was decreased. No toxic effects were observed in the groups fed tellurate, but in females fed tellurite longevity was decreased. Selenium level was increased in tissues when selenium was fed. None of the four compounds affected the incidence of spontaneous tumors significantly. Amyloidosis occurred more frequently in mice fed selenium than in controls or those fed tellurium.

Journal ArticleDOI
TL;DR: Sucrose gradient centrifugation of a partially purified enzyme demonstrated a coincidence of selenite incorporation and formic dehydrogenase activity.
Abstract: The effects of selenite, selenocystine, and selenomethionine in a defined growth medium on formic dehydrogenase biosynthesis in aerobically and anaerobically grown Escherichia coli have been studied. Sucrose gradient centrifugation of a partially purified enzyme demonstrated a coincidence of 75Se incorporation and formic dehydrogenase activity.

Journal ArticleDOI
TL;DR: Thiobacillus ferrooxidans can derive its energy from the oxidation of copper selenide through this metabolic oxidation process and elemental selenium is deposited.
Abstract: Thiobacillus ferrooxidans can derive its energy from the oxidation of copper selenide. In this metabolic oxidation process, copper goes into solution and elemental selenium is deposited.

Patent
01 Jun 1972
TL;DR: A method of purifying gases containing gaseous mercury is described in this paper, where the gas is passed through a mass of purification material containing as an active constituent a material consisting of selenium or other compounds or mixtures thereof.
Abstract: A method of purifying gases containing gaseous mercury. Mercury containing gas is passed through a mass of purifying material containing as an active constituent a material consisting of selenium, selenium sulphide or other selenium compounds or mixtures thereof.

Journal ArticleDOI
TL;DR: Growth of Astragalus species was shown to be adversely affected by concentrations of phosphate in solution which are often used in inorganic nutrient media.
Abstract: SummaryGrowth of Astragalus species was shown to be adversely affected by concentrations of phosphate in solution which are often used in inorganic nutrient media. Several ionic interactions in sorption by plants were demonstrated including depression of phosphate and the micronutrient metals by seleniteselenium, depression of selenium by phosphate, and direct or indirect enhancement of the macronutrient cations and the micronutrient metals by phosphate. Plant growth affects sorption and, conversely, repressed or excessive sorption may limit yield if the element is essential and deficient, or too high in effective concentration in the plant. Relevant interactions are considered.



Journal ArticleDOI
TL;DR: In this article, the interaction energy between cobalt vacancies was found to be 7780 cal/g-atom for the nonstoichiometric Co1−xSe phase with NiAs-type structure.

Journal ArticleDOI
TL;DR: Some synthetic approaches used to generate a variety of aliphatic, benzylic and aromatic oligomers and polymers with the general formula (RSe2) designated as polydiselenides and characterized by having a selenium-selenium bond per monomer unit as an integral part of the backbone are discussed.
Abstract: The remarkable photoelectric properties of elemental selenium form the basis for the major industrial application of this element in xerographic photoreceptors. The physics of the photoexcitation and electrical charge transport phenomena has been the subject of numerous investigations, but little is known about the molecular basis of the photoelectric effect. Since the element consists of linear sequences of selenium atoms, variously assembled into cyclic structures and polymer chains, it seemed of interest to investigate model polymers that contained organic residues interspersed between short selenium chains. Such species might then combine various desirable properties of selenium with those of organic polymers. In this paper we shall discuss some synthetic approaches used to generate a variety of aliphatic, benzylic and aromatic oligomers and polymers with the general formula (RSe2). , all designated as polydiselenides and characterized by having a selenium-selenium bond per monomer unit as an integral part of the backbone. The discussion of polymer properties will be restricted to data incidental to their structural identification.

Patent
Takeru Onoda1, Junzo Haji
13 Apr 1972
TL;DR: In this paper, at least one ELEMENT selected from the group consisting of an tommony, BISMUTH, TELLURIUM and SELENIUM is preferred.
Abstract: UNSATURATED GLYCOL DIESTERS ARE PREPARED AT HIGH REACTION VELOCITIES, HIGH DEGREES OF CONVERSION AND HIGH SELECTIVITY, BY REACTING A CONJUGATED DIENE, A CARBOXYLIC ACID AND OXYGEN, IN THE PRESENCE OF A SOLID CATALYST CONTAINING PALLADIUM, AT LEAST ONE ELEMENT SELECTED FROM THE GROUP CONSISTING OF ANTOMONY, BISMUTH, TELLURIUM AND SELENIUM TELLURIUM AND SELENIUM ARE PREFERRED SINCE THEY AID IN REDUCING THE QUANTITY OF PALLADIUM LOST IN THE REACTION MEDIUM

Journal ArticleDOI
TL;DR: A hypothesis is proposed to account for the experimental data describing erythrocyte uptake and metabolism of selenite and the likely selenocompound extruded from the cells.
Abstract: 75SeO32− was found to be actively metabolized by bovine erythrocytes. Release of 75Se from red cells was inhibited by 20 mM arsenate, 1.3 mM chromate, 0.5 mM iodoacetamide, 1.0 mM p-chloromercuribenzoate, or high levels of selenite while 20 mM fluoride or 1.0 mM azide had no effect. None of these metabolic inhibitors affected red cell transport of 75SeO42− or 75Se-selenomethionine, which apparently occurred by diffusion. Dialysis of erythrocytes caused an increased uptake of 75SeO32− due to an impairment of 75Se efflux. This effect was prevented by dialysis against 14 mM glucose but not by the presence of 10 mM inosine and 1 mM adenine, the latter added to maintain ATP levels. A hypothesis is proposed to account for the experimental data describing erythrocyte uptake and metabolism of selenite and the likely selenocompound extruded from the cells.

Journal ArticleDOI
Arne Fredga1
TL;DR: In his day, when the chemistry of the moon is highly topical, it is sometimes difficult to make clear to people that the connections between the element and the moon are purely mythological, but Jons Jacob Berzelius lived long enough to witness the birth of organic selenium chemistry.
Abstract: In 1818 Jons Jacob Berzelius discovered the element selenium in deposits from the lead chambers of a sulfuric acid plant at Gripsholm in Sweden. He had invested money in the plant and undertook the examination partly from scientific curiosity and partly to find out if the deposits could have injurious effects on the sulfuric acid. The presence of arsenic had been suspected but instead he found a new element, which of course gave him great delight and satisfaction. It was, however, the only profit he got from his investment. The business did not pay but his money was finally retrieved-or at least the main part of it-when the insured buildings were destroyed by fire. Berzelius realized that the new element was related to tellurium, which had been discovered in the late 1700’s and named for Tellus, the Latin word for the planet Earth. Similarly, Berzelius called his new element selenium, after Selene, the goddess of the Moon in ancient Greece. In our day, when the chemistry of the moon is highly topical, it is sometimes difficult to make clear to people that the connections between the element and the moon are purely mythological. Berzelius also emphasized the strong similarity between selenium and sulfur. He said in his first publication that selenium “stands just half-way between sulfur and tellurium, having perhaps more of the characteristics of sulfur than of tellurium,” which is perhaps a little contradictory but true enough. He also stated that it stands between the metals and the metalloids. Berzelius studied only inorganiccompounds of selenium but he lived long enough to witness the birth of organic selenium chemistry. The birthday can be given exactly. On January 23, 1847 Wilhelm Wohler, at this time professor at Gottingen, wrote to Berzelius : “ Today a small grandchild of yours has come into the world, a child of selenium, the selenomercaptan.” This was ethyl selenol, which C. Siemens, one of Wohler’s students, had prepared from calcium ethyl sulfate and potassium hydroselenide. His procedure was published in the Annalen later that year. For many years, however, organoselenium chemistry was a neglected field. The element was not readily accessible. Now and then a sulfur chemist made an occasional digression into the selenium field, prepared a few compounds and found them similar to the sulfur analogs but often less stable. Methyl selenol, the first homolog of the series, was not described until 1930. It is obvious to any worker in this field that the carbon-selenium bond is less stable than the carbon-sulfur bond. Often we get blood-red smears instead of the expected products and red spots on desks, papers, books, and fingers are a common experience, especially to the novice in the field. Sometimes the instability may be difficult to explain. Selenols are very easily oxidized, e.g., by air, but otherwise stable. However, carboxylic acids with a selenol group in a-position like (I) decompose spontaneously. They can be prepared in alkaline solution and used for various reactions but if one tries to liberate the acid,