Seleniumis achemical element;it has thesymbolSeandatomic number34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elemental state or as pureorecompounds inEarth's crust.Selenium (fromAncient Greekσελήνη(selḗnē)'moon') was discovered in 1817 byJöns Jacob Berzelius,who noted the similarity of the new element to the previously discoveredtellurium(named for the Earth).
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Selenium | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Pronunciation | /sɪˈliːniəm/ | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Appearance | grey metallic-looking, red, and vitreous black (not pictured) allotropes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Standard atomic weightAr°(Se) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Selenium in theperiodic table | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Atomic number(Z) | 34 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Group | group 16 (chalcogens) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Period | period 4 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Block | p-block | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Electron configuration | [Ar] 3d104s24p4 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Electrons per shell | 2, 8, 18, 6 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Physical properties | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
PhaseatSTP | solid | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Melting point | 494K(221 °C, 430 °F) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Boiling point | 958 K (685 °C, 1265 °F) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density(nearr.t.) | gray: 4.81 g/cm3 alpha: 4.39 g/cm3 vitreous: 4.28 g/cm3 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
when liquid (atm.p.) | 3.99 g/cm3 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Critical point | 1766 K, 27.2 MPa | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Heat of fusion | gray: 6.69kJ/mol | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Heat of vaporization | 95.48 kJ/mol | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Molar heat capacity | 25.363 J/(mol·K) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vapor pressure
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Atomic properties | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Oxidation states | −2,−1, 0,[3]+1,[4]+2,+3,+4,+5,+6(a stronglyacidicoxide) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Electronegativity | Pauling scale: 2.55 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ionization energies |
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Atomic radius | empirical: 120pm | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Covalent radius | 120±4 pm | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Van der Waals radius | 190 pm | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Other properties | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Natural occurrence | primordial | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Crystal structure | grey: hexagonal(hP3) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lattice constants | a= 436.46 pm c= 495.77 pm (at 20 °C)[5] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Thermal expansion | amorphous: 37 µm/(m⋅K) (at 25 °C) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Thermal conductivity | amorphous: 0.519 W/(m⋅K) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Magnetic ordering | diamagnetic[6] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Molar magnetic susceptibility | −25.0×10−6cm3/mol (298 K)[7] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Young's modulus | 10 GPa | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shear modulus | 3.7 GPa | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bulk modulus | 8.3 GPa | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Speed of soundthin rod | 3350 m/s (at 20 °C) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Poisson ratio | 0.33 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mohs hardness | 2.0 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brinell hardness | 736 MPa | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
CAS Number | 7782-49-2 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
History | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Naming | afterSelene,Greek goddess of the moon | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Discoveryand first isolation | Jöns Jakob BerzeliusandJohann Gottlieb Gahn(1817) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Isotopes of selenium | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Selenium is found inmetal sulfide ores,where it substitutes for sulfur. Commercially, selenium is produced as abyproductin the refining of these ores. Minerals that are pureselenideorselenatecompounds are rare. The chief commercial uses for selenium today areglassmakingandpigments.Selenium is asemiconductorand is used inphotocells.Applications inelectronics,once important, have been mostly replaced withsiliconsemiconductor devices. Selenium is still used in a few types ofDC powersurge protectorsand one type offluorescentquantum dot.
Althoughtraceamounts of selenium are necessary forcellular functionin many animals, including humans, both elemental selenium and (especially) seleniumsaltsare toxic in even small doses, causingselenosis.[9]Selenium is listed as an ingredient in many multivitamins and other dietary supplements, as well as ininfant formula,and is a component of the antioxidant enzymesglutathione peroxidaseandthioredoxin reductase(which indirectly reduce certainoxidizedmolecules in animals and some plants) as well as in threedeiodinaseenzymes. Selenium requirements in plants differ by species, with some plants requiring relatively large amounts and others apparently not requiring any.[10]
Characteristics
editPhysical properties
editSelenium forms severalallotropesthat interconvert withtemperaturechanges, depending somewhat on the rate of temperature change. When prepared in chemical reactions, selenium is usually anamorphous,brick-red powder. When rapidly melted, it forms the black, vitreous form, usually sold commercially as beads.[11]The structure of black selenium is irregular and complex and consists ofpolymericrings with up to 1000 atoms per ring. Black selenium is a brittle, lustrous solid that is slightly soluble inCS2.Upon heating, it softens at 50 °C and converts to gray selenium at 180 °C; the transformation temperature is reduced by presence ofhalogensandamines.[12]
The red α, β, and γ forms are produced from solutions of black selenium by varying the evaporation rate of the solvent (usually CS2). They all have a relatively low,monocliniccrystal symmetry (space group14) and contain nearly identical puckeredcyclooctaselenium(Se8) rings as insulfur.[13]The eight atoms of a ring are not equivalent (i.e. they are not mapped one onto another by any symmetry operation), and in fact in the γ-monoclinic form, half the rings are in one configuration (and its mirror image) and half in another.[14][15]The packing is most dense in the α form. In the Se8rings, the Se–Se distance varies depending on where the pair of atoms is in the ring, but the average is 233.5 pm, and the Se–Se–Se angle is on average 105.7°. Other selenium allotropes may contain Se6or Se7rings.[12]
The most stable and dense form of selenium is gray and has achiralhexagonalcrystal lattice (space group 152 or 154 depending on the chirality)[16]consisting of helical polymeric chains, where the Se–Se distance is 237.3 pm and Se–Se–Se angle is 103.1°. The minimum distance between chains is 343.6 pm. Gray selenium is formed by mild heating of other allotropes, by slow cooling of molten selenium, or by condensing selenium vapor just below the melting point. Whereas other selenium forms areinsulators,gray selenium is asemiconductorshowing appreciablephotoconductivity.Unlike the other allotropes, it is insoluble in CS2.[12]It resists oxidation by air and is not attacked by nonoxidizingacids.With strong reducing agents, it forms polyselenides. Selenium does not exhibit the changes in viscosity that sulfur undergoes when gradually heated.[11][17]
Isotopes
editSelenium has seven naturally occurringisotopes.Five of these,74Se,76Se,77Se,78Se,80Se, are stable, with80Se being the most abundant (49.6% natural abundance). Also naturally occurring is the long-livedprimordial radionuclide82Se, with ahalf-lifeof 8.76×1019years.[8]The non-primordial radioisotope79Sealso occurs in minute quantities inuraniumores as a product ofnuclear fission.Selenium also has numerous unstablesynthetic isotopesranging from64Se to95Se; the most stable are75Se with a half-life of 119.78 days and72Se with a half-life of 8.4 days.[18]Isotopes lighter than the stable isotopes primarily undergobeta plus decaytoisotopes of arsenic,and isotopes heavier than the stable isotopes undergobeta minus decaytoisotopes of bromine,with some minorneutron emissionbranches in the heaviest known isotopes.
Isotope | Nature | Origin | Half-life |
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74Se | Primordial | Stable | |
76Se | Primordial | Stable | |
77Se | Primordial | Fission product | Stable |
78Se | Primordial | Fission product | Stable |
79Se | Trace | Fission product | 327000yr[19][20] |
80Se | Primordial | Fission product | Stable |
82Se | Primordial | Fission product* | 8.76×1019yr[8][a] |
Chemical compounds
editSelenium compounds commonly exist in theoxidation states−2, +2, +4, and +6. It is anonmetal(more rarely considered ametalloid) with properties that are intermediate between the elements above and below in theperiodic table,sulfurandtellurium,and also has similarities toarsenic.[12]
Chalcogen compounds
editSelenium forms twooxides:selenium dioxide(SeO2) andselenium trioxide(SeO3). Selenium dioxide is formed by combustion of elemental selenium:[11]
It is apolymericsolid that forms monomeric SeO2molecules in the gas phase. It dissolves in water to formselenous acid,H2SeO3.Selenous acid can also be made directly by oxidizing elemental selenium withnitric acid:[21]
Unlike sulfur, which forms a stabletrioxide,selenium trioxide is thermodynamically unstable and decomposes to the dioxide above 185 °C:[11][21]
Selenium trioxide is produced in the laboratory by the reaction ofanhydrouspotassium selenate(K2SeO4) and sulfur trioxide (SO3).[22]
Saltsof selenous acid are called selenites. These includesilver selenite(Ag2SeO3) andsodium selenite(Na2SeO3).
Hydrogen sulfidereacts with aqueous selenous acid to produceselenium disulfide:
Selenium disulfide consists of 8-membered rings. It has an approximate composition of SeS2,with individual rings varying in composition, such as Se4S4and Se2S6.Selenium disulfide has been used in shampoo as an antidandruffagent, an inhibitor in polymer chemistry, a glass dye, and a reducing agent infireworks.[21]
Selenium trioxide may be synthesized by dehydratingselenic acid,H2SeO4,which is itself produced by the oxidation of selenium dioxide withhydrogen peroxide:[23]
Hot, concentrated selenic acid reacts with gold to form gold(III) selenate.[24]
Halogen compounds
editSelenium reacts withfluorineto formselenium hexafluoride:
In comparison with its sulfur counterpart (sulfur hexafluoride),selenium hexafluoride(SeF6) is more reactive and is a toxicpulmonaryirritant.[25]Selenium tetrafluorideis a laboratory-scalefluorinating agent.
The only stablechloridesareselenium tetrachloride(SeCl4) andselenium monochloride(Se2Cl2), which might be better known as selenium(I) chloride and is structurally analogous todisulfur dichloride.Metastable solutions ofselenium dichloridecan be prepared fromsulfuryl chlorideand selenium (reaction of the elements generates thetetrachlorideinstead), and constitute an important reagent in the preparation of selenium compounds (e.g. Se7). The correspondingbromidesare all known, and recapitulate the same stability and structure as the chlorides.[26]
Theiodidesof selenium are not well known, and for a long time were believed not to exist.[27]There is limitedspectroscopicevidence that the lower iodides may form in bi-elemental solutions with nonpolar solvents, such ascarbon disulfide[28]andcarbon tetrachloride;[27]but even these appear todecompose under illumination.[29]
Some selenium oxyhalides—seleninyl fluoride(SeOF2) andselenium oxychloride(SeOCl2)—have been used as specialty solvents.[11]
Metal selenides
editAnalogous to the behavior of other chalcogens, selenium formshydrogen selenide,H2Se. It is a stronglyodiferous,toxic, and colorless gas. It is more acidic than H2S. In solution it ionizes to HSe−.The selenide dianion Se2−forms a variety of compounds, including the minerals from which selenium is obtained commercially. Illustrative selenides includemercury selenide(HgSe),lead selenide(PbSe),zinc selenide(ZnSe), andcopper indium gallium diselenide(Cu(Ga,In)Se2). These materials aresemiconductors.With highly electropositive metals, such asaluminium,these selenides are prone to hydrolysis, which may be described by this idealized equation:[11]
Alkali metal selenides react with selenium to form polyselenides,Se2−
n,which exist as chains and rings.
Other compounds
editTetraselenium tetranitride, Se4N4,is an explosive orange compound analogous totetrasulfur tetranitride(S4N4).[11][31][32]It can be synthesized by the reaction ofselenium tetrachloride(SeCl4) with[((CH
3)
3Si)
2N]
2Se.[33]
Selenium reacts withcyanidesto yieldselenocyanates:[11]
Organoselenium compounds
editSelenium, especially in the II oxidation state, forms a variety of organic derivatives. They are structurally analogous to the correspondingorganosulfur compounds.Especially common are selenides (R2Se, analogues ofthioethers), diselenides (R2Se2,analogues ofdisulfides), andselenols(RSeH, analogues ofthiols). Representatives of selenides, diselenides, and selenols include respectivelyselenomethionine,diphenyldiselenide,andbenzeneselenol.Thesulfoxidein sulfur chemistry is represented in selenium chemistry by the selenoxides (formula RSe(O)R), which are intermediates in organic synthesis, as illustrated by theselenoxide eliminationreaction. Consistent with trends indicated by thedouble bond rule,selenoketones, R(C=Se)R, and selenaldehydes, R(C=Se)H, are rarely observed.[34]
History
editSelenium (Greekσελήνηselenemeaning "Moon" ) was discovered in 1817 byJöns Jacob BerzeliusandJohan Gottlieb Gahn.[35]Both chemists owned a chemistry plant nearGripsholm,Sweden, producingsulfuric acidby thelead chamber process.Pyrite samples from theFalun Mineproduced a red solid precipitate in the lead chambers, which was presumed to be an arsenic compound, so the use of pyrite to make acid was discontinued. Berzelius and Gahn, who wanted to use the pyrite, observed that the red precipitate gave off an odor likehorseradishwhen burned. This smell was not typical of arsenic, but a similar odor was known fromtelluriumcompounds. Hence, Berzelius's first letter toAlexander Marcetstated that this was a tellurium compound. However, the lack of tellurium compounds in theFalun Mineminerals eventually led Berzelius to reanalyze the red precipitate, and in 1818 he wrote a second letter to Marcet describing a newly found element similar tosulfurand tellurium. Because of its similarity to tellurium, named for the Earth, Berzelius named the new element after theMoon.[36][37]
In 1873,Willoughby Smithfound that theelectrical conductivityof grey selenium was affected by light.[38][39]This led to its use as a cell for sensing light. The first commercial products using selenium were developed byWerner Siemensin the mid-1870s. The selenium cell was used in thephotophonedeveloped byAlexander Graham Bellin 1879. Selenium transmits an electric current proportional to the amount of light falling on its surface. This phenomenon was used in the design oflight metersand similar devices. Selenium's semiconductor properties found numerous other applications in electronics.[40][41][42]The development ofselenium rectifiersbegan during the early 1930s, and these replacedcopper oxiderectifiers because they were more efficient.[43][44][45]These lasted in commercial applications until the 1970s, following which they were replaced with less expensive and even more efficientsilicon rectifiers.
Selenium came to medical notice later because of its toxicity to industrial workers. Selenium was also recognized as an important veterinary toxin, which is seen in animals that have eaten high-selenium plants. In 1954, the first hints of specific biological functions of selenium were discovered inmicroorganismsby biochemist,Jane Pinsent.[46][47]It was discovered to be essential for mammalian life in 1957.[48][49]In the 1970s, it was shown to be present in two independent sets ofenzymes.This was followed by the discovery ofselenocysteinein proteins. During the 1980s, selenocysteine was shown to be encoded by thecodon UGA.The recoding mechanism was worked out first inbacteriaand then inmammals(seeSECIS element).[50]
Occurrence
editNative (i.e., elemental) selenium is a rare mineral, which does not usually form good crystals, but, when it does, they are steep rhombohedra or tiny acicular (hair-like) crystals.[51]Isolation of selenium is often complicated by the presence of other compounds and elements.
Selenium occurs naturally in a number of inorganic forms, includingselenide,selenate,andselenite,but these minerals are rare. The common mineralseleniteis not a selenium mineral, and contains noselenite ion,but is rather a type ofgypsum(calcium sulfate hydrate) named like selenium for the moon well before the discovery of selenium. Selenium is most commonly found as an impurity, replacing a small part of the sulfur in sulfide ores of many metals.[52][53]
In living systems, selenium is found in the amino acidsselenomethionine,selenocysteine,andmethylselenocysteine.In these compounds, selenium plays a role analogous to that of sulfur. Another naturally occurringorganoselenium compoundisdimethyl selenide.[54][55]
Certain soils are selenium-rich, and selenium can bebioconcentratedby some plants. In soils, selenium most often occurs in soluble forms such as selenate (analogous to sulfate), which are leached into rivers very easily by runoff.[52][53]Ocean water contains significant amounts of selenium.[56][57]
Typical background concentrations of selenium do not exceed 1 ng/m3in the atmosphere; 1 mg/kg in soil and vegetation and 0.5 μg/L in freshwater and seawater.[58]
Anthropogenic sources of selenium include coal burning, and the mining and smelting of sulfide ores.[59]
Production
editSelenium is most commonly produced fromselenidein manysulfideores,such as those ofcopper,nickel,orlead.Electrolytic metal refining is particularly productive of selenium as a byproduct, obtained from theanodemud of copper refineries. Another source was the mud from thelead chambersofsulfuric acidplants, a process that is no longer used. Selenium can be refined from these muds by a number of methods. However, most elemental selenium comes as a byproduct ofrefiningcopper or producingsulfuric acid.[60][61]Since its invention,solvent extraction and electrowinning(SX/EW) production of copper produces an increasing share of the worldwide copper supply.[62]This changes the availability of selenium because only a comparably small part of the selenium in the ore is leached with the copper.[63]
Industrial production of selenium usually involves the extraction ofselenium dioxidefrom residues obtained during the purification of copper. Common production from the residue then begins by oxidation withsodium carbonateto produce selenium dioxide, which is mixed with water andacidifiedto formselenous acid(oxidationstep). Selenous acid is bubbled withsulfur dioxide(reductionstep) to give elemental selenium.[64][65]
About 2,000 tonnes of selenium were produced in 2011 worldwide, mostly in Germany (650 t), Japan (630 t), Belgium (200 t), and Russia (140 t), and the total reserves were estimated at 93,000 tonnes. These data exclude two major producers: the United States and China. A previous sharp increase was observed in 2004 from $4–$5 to $27/lb. The price was relatively stable during 2004–2010 at about US$30 per pound (in 100 pound lots) but increased to $65/lb in 2011. The consumption in 2010 was divided as follows: metallurgy – 30%, glass manufacturing – 30%, agriculture – 10%, chemicals and pigments – 10%, and electronics – 10%. China is the dominant consumer of selenium at 1,500–2,000 tonnes/year.[66]
Applications
editManganese electrolysis
editDuring theelectrowinningof manganese, the addition ofselenium dioxidedecreases the power necessary to operate theelectrolysis cells.China is the largest consumer of selenium dioxide for this purpose. For every tonne of manganese, an average 2 kg selenium oxide is used.[66][67]
Glass production
editThe largest commercial use of selenium, accounting for about 50% of consumption, is for the production of glass. Selenium compounds confer a red color to glass. This color cancels out the green or yellow tints that arise from iron impurities typical for most glass. For this purpose, various selenite and selenate salts are added. For other applications, a red color may be desired, produced by mixtures of CdSe and CdS.[68]
Alloys
editSelenium is used withbismuthinbrassesto replace more toxiclead.The regulation of lead in drinking water applications such as in the US with theSafe Drinking Water Actof 1974, made a reduction of lead in brass necessary. The new brass is marketed under the name EnviroBrass.[69]Like lead and sulfur, selenium improves the machinability of steel at concentrations around 0.15%.[70][71]Selenium produces the same machinability improvement in copper alloys.[72]
Lithium–selenium batteries
editThe lithium–selenium (Li–Se) battery is one of the most promising systems for energy storage in the family of lithium batteries.[73]The Li–Se battery is an alternative to thelithium–sulfur battery,with an advantage of high electrical conductivity.
Solar cells
editSelenium was used as the photoabsoring layer in the first solid-state solar cell, which was demonstrated by the English physicistWilliam Grylls Adamsand his student Richard Evans Day in 1876.[74]Only a few years layer,Charles Frittsfabricated the first thin-film solar cell, also using selenium as the photoabsorber. However, with the emergence of silicon solar cells in the 1950s, research on selenium thin-film solar cells declined. As a result, the record efficiency of 5.0% demonstrated by Tokio Nakada and Akio Kunioka in 1985 remained unchanged for more than 30 years.[75]In 2017, researchers fromIBMachieved a new record efficiency of 6.5% by redesigning the device structure.[76]Following this achievement, selenium has gained renewed interest as a wide bandgap photoabsorber with the potential of being integrated intandemwith lower bandgap photoabsorbers.[77]In 2024, the first selenium-based tandem solar cell was demonstrated, showcasing a selenium top cell monolithically integrated with a silicon bottom cell.[78]However, a significant deficit in theopen-circuit voltageis currently the main limiting factor to further improve the efficiency, necessitating defect-engineering strategies for selenium thin-films to enhance thecarrier lifetime.[79]As of now, the only defect-engineering strategy that has been investigated for selenium thin-film solar cells involvescrystallizing selenium using a laser.[80]
Photoconductors
editAmorphous selenium (α-Se) thin films have found application as photoconductors inflat-panel X-ray detectors.These detectors use amorphous selenium to capture and convert incident X-ray photons directly into electric charge. Selenium has been chosen for this application among other semiconductors owing to a combination of its favorable technological and physical properties:[81][82]
- Amorphous selenium has a low melting point, high vapor pressure, and uniform structure. These three properties allow quick and easy deposition of large-area uniform films with a thickness up to 1 mm at a rate of 1–5 μm/min. Their uniformity and lack of grain boundaries, which are intrinsic to polycrystalline materials, improve the X-ray image quality. Meanwhile the large area is essential for scanning the human body or luggage items.
- Selenium is less toxic than many compound semiconductors that contain arsenic or heavy metals such as mercury or lead.
- The mobility in applied electric field is sufficiently high both for electrons and holes, so that in a typical 0.2 mm thick device, c. 98% of electrons and holes produced by X-rays are collected at the electrodes without being trapped by various defects. Consequently, device sensitivity is high, and its behavior is easy to describe by simple transport equations.
Rectifiers
editSelenium rectifierswere first used in 1933. They have mostly been replaced by silicon-based devices. One notable exception is in power DCsurge protection,where the superior energy capabilities of selenium suppressors make them more desirable thanmetal-oxide varistors.[citation needed]
Other uses
editThe demand for selenium by the electronics industry is declining.[66]Itsphotovoltaicandphotoconductiveproperties are still useful inphotocopying,[83][84][85][86]photocells,light metersandsolar cells.Its use as a photoconductor in plain-paper copiers once was a leading application, but in the 1980s, the photoconductor application declined (although it was still a large end-use) as more and more copiers switched to organic photoconductors.[citation needed]
Zinc selenidewas the first material for blueLEDs,butgallium nitridedominates that market.[87]Cadmium selenidewas an important component inquantum dots.[citation needed]Sheets of amorphous selenium convertX-rayimages to patterns of charge inxeroradiographyand in solid-state, flat-panel X-ray cameras.[88]Ionized selenium (Se+24, where 24 of the outer D, S and P orbitals are stripped away due to high input energies[clarification needed]) is one of the active mediums used in X-ray lasers.[89]75Se is used as a gamma source in industrial radiography.[90]
Selenium catalyzes some chemical reactions, but it is not widely used because of issues with toxicity.[91]InX-ray crystallography,incorporation of one or more selenium atoms in place of sulfur helps with multiple-wavelength anomalous dispersion andsingle wavelength anomalous dispersionphasing.[92]
Selenium is used in thetoning of photographic prints,and it is sold as a toner by numerous photographic manufacturers. Selenium intensifies and extends the tonal range of black-and-white photographic images and improves the permanence of prints.[93][94][95]Small amounts of organoselenium compounds have been used to modify the catalysts used for thevulcanizationfor the production of rubber.[63]Selenium is used in some anti-dandruff shampoos in the form ofselenium disulfidesuch as Selsun and Vichy Dereos[96]brands.
Pollution
editSelenium pollution might impact some aquatic systems and may be caused by anthropogenic factors such as farming runoff and industrial processes.[97]People who eat more fish are generally healthier than those who eat less,[98]which suggests no major human health concern from selenium pollution, although selenium has a potential effect on humans.[99]
Selenium poisoning of water systems may result whenever newagricultural run-offcourses through dry lands. This process leaches natural soluble selenium compounds (such as selenates) into the water, which may then be concentrated in wetlands as the water evaporates. Selenium pollution of waterways also occurs when selenium is leached from coal flue ash, mining andmetal smelting,crude oil processing, and landfill.[100]High selenium levels in waterways were found to cause congenital disorders in oviparous species, including wetland birds[101]and fish.[102]Elevated dietarymethylmercurylevels can amplify the harm of selenium toxicity in oviparous species.[103][104]
Selenium isbioaccumulatedin aquatic habitats, which results in higher concentrations in organisms than the surrounding water. Organoselenium compounds can be concentrated over 200,000 times byzooplanktonwhen water concentrations are in the 0.5 to 0.8 μg Se/L range. Inorganic selenium bioaccumulates more readily inphytoplanktonthan zooplankton. Phytoplankton can concentrate inorganic selenium by a factor of 3000. Further concentration through bioaccumulation occurs along the food chain, as predators consume selenium-rich prey. It is recommended that a water concentration of 2 μg Se/L be considered highly hazardous to sensitive fish andaquatic birds.Selenium poisoning can be passed from parents to offspring through the egg, and selenium poisoning may persist for many generations. Reproduction of mallard ducks is impaired at dietary concentrations of 7 μg Se/L. Manybenthicinvertebrates can tolerate selenium concentrations up to 300 μg/L of selenium in their diet.[105]
Bioaccumulation of selenium in aquatic environments causes fish kills depending on the species in the affected area. There are, however, a few species that have been seen to survive these events and tolerate the increased selenium. It has also been suggested that the season could have an impact on the harmful effects of selenium on fish.[106]Substantial physiological changes may occur in fish with high tissue concentrations of selenium. Fish affected by selenium may experience swelling of thegill lamellae,which impedes oxygen diffusion across the gills and blood flow within the gills. Respiratory capacity is further reduced due to selenium binding tohemoglobin.Other problems include degeneration of liver tissue, swelling around the heart, damaged egg follicles in ovaries,cataracts,and accumulation of fluid in the body cavity and head. Selenium often causes a malformed fish fetus which may have problems feeding or respiring; distortion of the fins or spine is also common. Adult fish may appear healthy despite their inability to produce viable offspring.[citation needed]
Examples
editInBelews LakeNorth Carolina, 19 species of fish were eliminated from the lake due to 150–200 μg Se/L wastewater discharged from 1974 to 1986 from aDuke Energycoal-fired power plant. At theKesterson National Wildlife Refugein California, thousands of fish and waterbirds were poisoned by selenium in agricultural irrigation drainage.[citation needed]
Biological role
editHazards | |
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NFPA 704(fire diamond) |
Although it is toxic in large doses, selenium is an essentialmicronutrientfor animals. In plants, it occurs as a bystander mineral,[107]sometimes in toxic proportions inforage(some plants may accumulate selenium as a defense against being eaten by animals,[108]but other plants, such aslocoweed,require selenium, and their growth indicates the presence of selenium in soil).[109]The selenium content in the human body is believed to be in the range of 13–20 mg.[110]
Selenium is a component of the unusualamino acidsselenocysteineandselenomethionine.[citation needed]In humans, selenium is atrace elementnutrient that functions ascofactorforreductionofantioxidantenzymes, such asglutathione peroxidases[111]and certain forms ofthioredoxin reductasefound in animals and some plants (this enzyme occurs in all living organisms, but not all forms of it in plants require selenium).[citation needed]Theglutathione peroxidasefamily of enzymes (GSH-Px) catalyze reactions that remove reactive oxygen species such ashydrogen peroxideand organichydroperoxides.[citation needed]
Thethyroid glandand every cell that uses thyroid hormone also use selenium,[112]which is a cofactor for the three of the four known types ofthyroid hormone deiodinases,which activate and then deactivate variousthyroid hormonesand their metabolites; theiodothyronine deiodinasesare the subfamily of deiodinase enzymes that use selenium as the otherwise rare amino acid selenocysteine. Only the deiodinaseiodotyrosine deiodinase,which works on the last breakdown products of thyroid hormone, does not use selenium.[113]Selenium may also inhibitHashimoto's diseasein the thyroid, in which the body's own thyroid cells are attacked as foreign. A reduction of 21% on TPO antibodies is reported with the dietary intake of 0.2 mg of selenium.[114]
Increased dietary selenium reduces the effects of mercury toxicity,[115][116][117]although it is effective only at low to modest doses of mercury.[118]Evidence suggests that the molecular mechanisms of mercury toxicity includes the irreversible inhibition of selenoenzymes that are required to prevent and reverse oxidative damage in brain and endocrine tissues.[119][120]The selenium-containing compoundselenoneineis present in the blood ofbluefin tuna.[121][122]Certain species of plants are considered indicators of high selenium content of the soil because they require high levels of selenium to thrive. The main selenium indicator plants areAstragalusspecies (including somelocoweeds), prince's plume (Stanleyasp.), woody asters (Xylorhizasp.), and false goldenweed (Oonopsissp.).[123]
Evolution in biology
editFrom about three billion years ago,prokaryoticselenoprotein families drive the evolution of selenocysteine, an amino acid. Selenium is incorporated into several prokaryotic selenoprotein families in bacteria, archaea, and eukaryotes as selenocysteine,[124]where selenoprotein peroxiredoxins protect bacterial and eukaryotic cells against oxidative damage. Selenoprotein families of GSH-Px and the deiodinases of eukaryotic cells seem to have a bacterialphylogeneticorigin. The selenocysteine-containing form occurs in species as diverse as green algae, diatoms, sea urchins, fish, and chickens. Selenium enzymes are involved in the small reducing moleculesglutathioneandthioredoxin.One family of selenium-bearing molecules (theglutathione peroxidases) destroys peroxide and repairs damaged peroxidized cell membranes, using glutathione. Another selenium-bearing enzyme in some plants and in animals (thioredoxin reductase) generates reduced thioredoxin, a dithiol that serves as an electron source for peroxidases and also the important reducing enzymeribonucleotide reductasethat makes DNA precursors from RNA precursors.[125]
Trace elements involved in GSH-Px and superoxide dismutase enzymes activities, i.e. selenium,vanadium,magnesium,copper,andzinc,may have been lacking in some terrestrial mineral-deficient areas.[124]Marine organisms retained and sometimes expanded their selenoproteomes, whereas the selenoproteomes of some terrestrial organisms were reduced or completely lost. These findings suggest that, with the exception ofvertebrates,aquatic life supports selenium use, whereas terrestrial habitats lead to reduced use of this trace element.[126]Marine fishes and vertebrate thyroid glands have the highest concentration of selenium and iodine. From about 500 million years ago, freshwater and terrestrial plants slowly optimized the production of "new" endogenous antioxidants such asascorbic acid(vitamin C),polyphenols(including flavonoids),tocopherols,etc. A few of these appeared in the last 50–200 million years, in fruits and flowers ofangiospermplants. In fact, the angiosperms (the dominant type of plant today) and most of their antioxidant pigments evolved during the lateJurassicperiod.[citation needed]
The deiodinaseisoenzymesconstitute another family of eukaryotic selenoenzymes. Deiodinases are involved in thyroid-hormone regulation, participating in the protection ofthyrocytesfrom damage by H2O2produced for thyroid-hormone biosynthesis.[127]About 200 million years ago, new selenoproteins were developed as mammalian GSH-Px enzymes.[128][129][130][131]
Toxicity
editAlthough selenium is an essentialtrace element,it is toxic if taken in excess. Exceeding theTolerable Upper Intake Levelof 400 micrograms per day can lead to selenosis.[133]This 400 μg Tolerable Upper Intake Level is based primarily on a 1986 study of five Chinese patients who exhibited overt signs of selenosis and a follow-up study on the same five people in 1992.[134]The 1992 study found the maximum safe dietary selenium intake to be approximately 800 micrograms per day (15 micrograms per kilogram body weight), but suggested 400 micrograms per day to avoid creating an imbalance of nutrients in the diet and to accord with data from other countries.[135]In China, people who ingested corn grown in extremely selenium-rich stony coal (carbonaceousshale) have suffered from selenium toxicity. This coal was shown to have selenium content as high as 9.1%, the highest concentration in coal ever recorded.[136]
Signs and symptoms of selenosis include a garlic odor on the breath, gastrointestinal disorders, hair loss,sloughingof nails, fatigue, irritability, and neurological damage. Extreme cases of selenosis can exhibitcirrhosisof the liver,pulmonary edema,or death.[137]Elemental selenium and most metallicselenideshave relatively low toxicities because of lowbioavailability.By contrast,selenatesandseleniteshave an oxidant mode of action similar to that ofarsenic trioxideand are very toxic. The chronic toxic dose of selenite for humans is about 2400 to 3000 micrograms of selenium per day.[138]Hydrogen selenideis an extremely toxic, corrosive gas.[139]Selenium also occurs in organic compounds, such as dimethyl selenide,selenomethionine,selenocysteineandmethylselenocysteine,all of which have highbioavailabilityand are toxic in large doses.
On 19 April 2009, 21poloponies died shortly before a match in the United States Polo Open. Three days later, a pharmacy released a statement explaining that the horses had received an incorrect dose of one of the ingredients used in a vitamin/mineral supplement compound that had been incorrectly prepared by acompounding pharmacy.Analysis of blood levels ofinorganic compoundsin the supplement indicated the selenium concentrations were 10 to 15 times higher than normal in theblood samples,and 15 to 20 times higher than normal in the liver samples. Selenium was later confirmed to be the toxic factor.[140]
In fish and other wildlife, selenium is necessary for life, but toxic in high doses. Forsalmon,the optimal concentration of selenium is about 1 microgram selenium per gram of whole body weight. Much below that level, young salmon die from deficiency;[142]much above, they die from toxic excess.[141]
TheOccupational Safety and Health Administration(OSHA) has set the legal limit (permissible exposure limit) for selenium in the workplace at 0.2 mg/m3over an 8-hour workday. TheNational Institute for Occupational Safety and Health(NIOSH) has set aRecommended exposure limit(REL) of 0.2 mg/m3over an 8-hour workday. At levels of 1 mg/m3,selenium isimmediately dangerous to life and health.[144]
Detection in biological fluids
editSelenium may be measured in blood, plasma, serum, or urine to monitor excessive environmental or occupational exposure, to confirm a diagnosis of poisoning in hospitalized victims, or investigate a suspected case of fatal overdose. Some analytical techniques are capable of distinguishing organic from inorganic forms of the element. Both organic and inorganic forms of selenium are largely converted to monosaccharide conjugates (selenosugars) in the body prior to elimination in the urine. Cancer patients receiving daily oral doses of selenothionine may achieve very high plasma and urine selenium concentrations.[145]
Deficiency
editSelenium deficiency can occur in patients with severely compromisedintestinalfunction, those undergoingtotal parenteral nutrition,and[146]in those of advanced age (over 90). Also, people dependent on food grown from selenium-deficient soil are at risk. AlthoughNew Zealandsoil has low levels of selenium, adverse health effects have not been detected in the residents.[147]
Selenium deficiency, defined by low (<60% of normal) selenoenzyme activity levels in brain and endocrine tissues, occurs only when a low selenium level is linked with an additional stress, such as high exposures tomercury[148]or increased oxidant stress from vitamin E deficiency.[149]
Selenium interacts with other nutrients, such asiodineandvitamin E.The effect of selenium deficiency on health remains uncertain, particularly in relation toKashin–Beck disease.[150]Also, selenium interacts with other minerals, such aszincandcopper.High doses of selenium supplements in pregnant animals might disturb the zinc:copper ratio and lead to zinc reduction; in such treatment cases, zinc levels should be monitored. Further studies are needed to confirm these interactions.[151]
In the regions (e.g. various regions within North America) where low selenium soil levels lead to low concentrations in the plants, some animal species may be deficient unless selenium is supplemented with diet or injection.[152]Ruminantsare particularly susceptible. In general, absorption of dietary selenium is lower in ruminants than other animals, and is lower from forages than from grain.[153]Ruminants grazing certain forages, e.g., somewhite clovervarieties containingcyanogenic glycosides,may have higher selenium requirements,[153]presumably because cyanide is released from theaglyconebyglucosidaseactivity in the rumen[154]and glutathione peroxidases is deactivated by the cyanide acting on the glutathionemoiety.[155]Neonate ruminants at risk ofwhite muscle diseasemay be administered both selenium and vitamin E by injection; some of the WMDmyopathiesrespond only to selenium, some only to vitamin E, and some to either.[156]
Nutritional sources of selenium
editDietary selenium comes from meat, nuts, cereals and mushrooms.Brazil nutsare the richest dietary source (though this is soil-dependent, since the Brazil nut does not require high levels of the element for its own needs).[157][158]
The USRecommended Dietary Allowance(RDA) of selenium for teenagers and adults is 55μg/day. Selenium as a dietary supplement is available in many forms, including multi-vitamins/mineral supplements, which typically contain 55 or 70 μg/serving. Selenium-specific supplements typically contain either 100 or 200 μg/serving.[citation needed]In June 2015, the USFood and Drug Administration(FDA) published its final rule establishing a requirement for minimum and maximum levels of selenium ininfant formula.[159]
General health effects
editThe effects of selenium intake on cancer have been studied in severalclinical trialsandepidemiologicstudies in humans. Selenium may have achemo-preventiverole incancerrisk as ananti-oxidant,and it might trigger the immune response. At low levels, it is used in the body to create anti-oxidantselenoproteins,at higher doses than normal it causes cell death.[132]
Selenium (in close interrelation withiodine) plays a role in thyroid health. Selenium is a cofactor for the three thyroid hormonedeiodinases,helping activate and then deactivate various thyroid hormones and their metabolites. Isolated selenium deficiency is now being investigated for its role in the induction of autoimmune reactions in the thyroid gland inHashimoto's disease.[160]In a case of combined iodine and selenium deficiency was shown to play a thyroid-protecting role.[161]
See also
editNotes
edit- ^For all practical purposes,82Se is stable.
References
edit- ^"Standard Atomic Weights: Selenium".CIAAW.2013.
- ^Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04)."Standard atomic weights of the elements 2021 (IUPAC Technical Report)".Pure and Applied Chemistry.doi:10.1515/pac-2019-0603.ISSN1365-3075.
- ^A Se(0) atom has been identified using DFT in [ReOSe(2-pySe)3]; seeCargnelutti, Roberta; Lang, Ernesto S.; Piquini, Paulo; Abram, Ulrich (2014). "Synthesis and structure of [ReOSe(2-Se-py)3]: A rhenium(V) complex with selenium(0) as a ligand".Inorganic Chemistry Communications.45:48–50.doi:10.1016/j.inoche.2014.04.003.ISSN1387-7003.
- ^Greenwood, Norman N.;Earnshaw, Alan (1997).Chemistry of the Elements(2nd ed.).Butterworth-Heinemann.ISBN978-0-08-037941-8.
- ^Arblaster, John W. (2018).Selected Values of the Crystallographic Properties of Elements.Materials Park, Ohio: ASM International.ISBN978-1-62708-155-9.
- ^Magnetic susceptibility of the elements and inorganic compounds,inLide, D. R., ed. (2005).CRC Handbook of Chemistry and Physics(86th ed.). Boca Raton (FL): CRC Press.ISBN0-8493-0486-5.
- ^Weast, Robert (1984).CRC, Handbook of Chemistry and Physics.Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110.ISBN0-8493-0464-4.
- ^abcKondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021)."The NUBASE2020 evaluation of nuclear properties"(PDF).Chinese Physics C.45(3): 030001.doi:10.1088/1674-1137/abddae.
- ^Fernández-Bautista, Tamara; Gómez-Gómez, Beatriz; Palacín-García, Roberto; Gracia-Lor, Emma; Pérez-Corona, Teresa; Madrid, Yolanda (2022-01-15)."Analysis of Se and Hg biomolecules distribution and Se speciation in poorly studied protein fractions of muscle tissues of highly consumed fishes by SEC-UV-ICP-MS and HPLC-ESI-MS/MS".Talanta.237:122922.doi:10.1016/j.talanta.2021.122922.ISSN0039-9140.PMID34736659.S2CID243761320.
- ^Ruyle, George."Poisonous Plants on Arizona Rangelands"(PDF).The University of Arizona. Archived fromthe original(PDF)on 15 July 2004.Retrieved5 January2009.
- ^abcdefghHouse, James E. (2008).Inorganic chemistry.Academic Press. p. 524.ISBN978-0-12-356786-4.
- ^abcdGreenwood, Norman N.;Earnshaw, Alan (1997).Chemistry of the Elements(2nd ed.).Butterworth-Heinemann.pp. 751–752.ISBN978-0-08-037941-8.
- ^Olav Foss and Vitalijus Janickis (1980). "Crystal structure of γ-monoclinic selenium".Journal of the Chemical Society, Dalton Transactions(4): 624–627.doi:10.1039/DT9800000624.
- ^"β–Se (Al) Structure: A_mP32_14_8e".Encyclopedia of Crystallographic Prototypes.
- ^"Se (Ak) Structure: A_mP64_14_16e ".Encyclopedia of Crystallographic Prototypes.
- ^"γ–Se (A8) Structure: A_hP3_152_a".Encyclopedia of Crystallographic Prototypes.
- ^Video of selenium heatingonYouTube
- ^Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017)."The NUBASE2016 evaluation of nuclear properties"(PDF).Chinese Physics C.41(3): 030001.Bibcode:2017ChPhC..41c0001A.doi:10.1088/1674-1137/41/3/030001.
- ^"The half-life of79Se ".Physikalisch-Technische Bundesanstalt. 23 September 2010. Archived fromthe originalon 27 September 2011.Retrieved29 May2012.
- ^Jörg, Gerhard; Bühnemann, Rolf; Hollas, Simon; et al. (2010). "Preparation of radiochemically pure79Se and highly precise determination of its half-life ".Applied Radiation and Isotopes.68(12): 2339–2351.Bibcode:2010AppRI..68.2339J.doi:10.1016/j.apradiso.2010.05.006.PMID20627600.
- ^abcWiberg, Egon; Wiberg, Nils; Holleman, Arnold Frederick (2001).Inorganic chemistry.San Diego: Academic Press. p. 583.ISBN978-0-12-352651-9.
- ^Greenwood, Norman N.;Earnshaw, Alan (1997).Chemistry of the Elements(2nd ed.).Butterworth-Heinemann.p. 780.ISBN978-0-08-037941-8.
- ^Seppelt, K.; Desmarteau, Darryl D. (1980). "Selenonyl Difluoride".Inorganic Syntheses.Vol. 20. pp. 36–38.doi:10.1002/9780470132517.ch9.ISBN978-0-471-07715-2.The report describes the synthesis of selenic acid.
- ^Lenher, V. (April 1902)."Action of selenic acid on gold".Journal of the American Chemical Society.24(4): 354–355.doi:10.1021/ja02018a005.
- ^Proctor, Nick H.; Hathaway, Gloria J. (2004). Hughes, James P. (ed.).Proctor and Hughes' chemical hazards of the workplace(5th ed.). Wiley-IEEE. p. 625.ISBN978-0-471-26883-3.
- ^Xu, Zhengtao (2007). Devillanova, Francesco A. (ed.).Handbook of chalcogen chemistry: new perspectives in sulfur, selenium and tellurium.Royal Society of Chemistry. p. 460.ISBN978-0-85404-366-8.
- ^abGopal, Madhuban; Milne, John (October 1992)."Spectroscopic evidence for selenium iodides in carbon disulfide solution: Se3I2, Se2I2, and SeI2".Inorganic Chemistry.31(22): 4530–4533.doi:10.1021/ic00048a017.ISSN0020-1669.
- ^McCullough, James D. (December 1939)."Evidence for Existence of a Selenium Iodide".Journal of the American Chemical Society.61(12): 3401–3402.doi:10.1021/ja01267a052.ISSN0002-7863.
- ^Rao, M. R. Aswatha Narayana."Selenium iodide".InProceedings of the Indian Academy of Sciences-Section A,vol. 12, pp. 410-415. Springer India, 1940.
- ^Greenwood, Norman N.;Earnshaw, Alan (1997).Chemistry of the Elements(2nd ed.).Butterworth-Heinemann.p. 763-765.ISBN978-0-08-037941-8.
- ^Woollins, Derek; Kelly, Paul F. (1993). "The Reactivity of Se4N4in Liquid Ammonia ".Polyhedron.12(10): 1129–1133.doi:10.1016/S0277-5387(00)88201-7.
- ^Kelly, P.F.; Slawin, A.M.Z.; Soriano-Rama, A. (1997). "Use of Se4N4and Se(NSO)2in the preparation of palladium adducts of diselenium dinitride, Se2N2;crystal structure of[PPh
4]
2[Pd
2Br
6(Se
2N
2)]".Dalton Transactions(4): 559–562.doi:10.1039/a606311j. - ^Siivari, Jari; Chivers, Tristram; Laitinen, Risto S. (1993). "A simple, efficient synthesis of tetraselenium tetranitride".Inorganic Chemistry.32(8): 1519–1520.doi:10.1021/ic00060a031.
- ^Erker, G.; Hock, R.; Krüger, C.; Werner, S.; Klärner, F.G.; Artschwager-Perl, U. (1990). "Synthesis and Cycloadditions of Monomeric Selenobenzophenone".Angewandte Chemie International Edition in English.29(9): 1067–1068.doi:10.1002/anie.199010671.
- ^Berzelius, J.J. (1818)."Lettre de M. Berzelius à M. Berthollet sur deux métaux nouveaux"[Letter from Mr. Berzelius to Mr. Berthollet on two new metals].Annales de Chimie et de Physique.2nd series (in French).7:199–206.From p. 203:"Cependant, pour rappeler les rapports de cette dernière avec le tellure, je l'ai nommée sélénium."(However, in order to recall the relationships of this latter [substance (viz, selenium)] to tellurium, I have named it "selenium".)
- ^Weeks, Mary Elvira(1932). "The Discovery of the Elements. VI. Tellurium and Selenium".Journal of Chemical Education.9(3): 474.Bibcode:1932JChEd...9..474W.doi:10.1021/ed009p474.
- ^Trofast, Jan (2011)."Berzelius' Discovery of Selenium".Chemistry International.33(5): 16–19.PDF
- ^Smith, Willoughby (1873)."The action of light on selenium".Journal of the Society of Telegraph Engineers.2(4): 31–33.doi:10.1049/jste-1.1873.0023.
- ^Smith, Willoughby (20 February 1873)."Effect of light on selenium during the passage of an electric current".Nature.7(173): 303.Bibcode:1873Natur...7R.303..doi:10.1038/007303e0.
- ^Bonnier Corporation (1876)."Action of light on selenium".Popular Science.10(1): 116.
- ^Levinshtein, M.E.; Simin, G.S. (1 December 1992).Earliest semiconductor device.Getting to Know Semiconductors. pp. 77–79.ISBN978-981-02-3516-1.
- ^Winston, Brian (29 May 1998).Media Technology and Society: A History: From the Telegraph to the Internet.Psychology Press. p. 89.ISBN978-0-415-14229-8.
- ^Morris, Peter Robin (1990).A History of the World Semiconductor Industry.p. 18.ISBN978-0-86341-227-1.
- ^Bergmann, Ludwig (1931). "Über eine neue Selen-Sperrschicht-Photozelle".Physikalische Zeitschrift.32:286–288.
- ^Waitkins, G.R.; Bearse, A.E.; Shutt, R. (1942). "Industrial Utilization of Selenium and Tellurium".Industrial & Engineering Chemistry.34(8): 899–910.doi:10.1021/ie50392a002.
- ^Pinsent, Jane (1954)."The need for selenite and molybdate in the formation of formic dehydrogenase by members of the Coli-aerogenes group of bacteria".Biochem. J.57(1): 10–16.doi:10.1042/bj0570010.PMC1269698.PMID13159942.
- ^Stadtman, Thressa C. (2002). "Some Functions of the Essential Trace Element, Selenium".Trace Elements in Man and Animals 10.Vol. 10. pp. 831–836.doi:10.1007/0-306-47466-2_267.ISBN978-0-306-46378-5.
- ^Schwarz, Klaus; Foltz, Calvin M. (1957). "Selenium as an Integral Part of Factor 3 Against Dietary Necrotic Liver Degeneration".Journal of the American Chemical Society.79(12): 3292–3293.doi:10.1021/ja01569a087.
- ^Oldfield, James E. (2006). "Selenium: A historical perspective".Selenium.pp. 1–6.doi:10.1007/0-387-33827-6_1.ISBN978-0-387-33826-2.
- ^Hatfield, D. L.; Gladyshev, V.N. (2002)."How Selenium Has Altered Our Understanding of the Genetic Code".Molecular and Cellular Biology.22(11): 3565–3576.doi:10.1128/MCB.22.11.3565-3576.2002.PMC133838.PMID11997494.
- ^"Native Selenium".Webminerals.Retrieved6 June2009.
- ^abKabata-Pendias, A.(1998). "Geochemistry of selenium".Journal of Environmental Pathology, Toxicology and Oncology.17(3–4): 173–177.PMID9726787.
- ^abFordyce, Fiona (2007)."Selenium Geochemistry and Health"(PDF).Ambio: A Journal of the Human Environment.36(1): 94–97.doi:10.1579/0044-7447(2007)36[94:SGAH]2.0.CO;2.PMID17408199.S2CID18925825.
- ^Wessjohann, Ludger A.; Schneider, Alex; Abbas, Muhammad; Brandt, Wolfgang (2007). "Selenium in chemistry and biochemistry in comparison to sulfur".Biological Chemistry.388(10): 997–1006.doi:10.1515/BC.2007.138.PMID17937613.S2CID34918691.
- ^Birringer, Marc; Pilawa, Sandra; Flohé, Leopold (2002). "Trends in selenium biochemistry".Natural Product Reports.19(6): 693–718.doi:10.1039/B205802M.PMID12521265.
- ^Amouroux, David; Liss, Peter S.; Tessier, Emmanuel; et al. (2001). "Role of oceans as biogenic sources of selenium".Earth and Planetary Science Letters.189(3–4): 277–283.Bibcode:2001E&PSL.189..277A.doi:10.1016/S0012-821X(01)00370-3.
- ^Haug, Anna; Graham, Robin D.; Christophersen, Olav A.; Lyons, Graham H. (2007)."How to use the world's scarce selenium resources efficiently to increase the selenium concentration in food".Microbial Ecology in Health and Disease.19(4): 209–228.doi:10.1080/08910600701698986.PMC2556185.PMID18833333.
- ^Rieuwerts, John (2015).The Elements of Environmental Pollution.London and New York: Earthscan Routledge. p. 262.ISBN978-0-415-85919-6.OCLC886492996.
- ^"Public Health Statement: Selenium"(PDF).Agency for Toxic Substances and Disease Registry.Retrieved5 January2009.
- ^"Public Health Statement: Selenium – Production, Import/Export, Use, and Disposal"(PDF).Agency for Toxic Substances and Disease Registry.Retrieved5 January2009.
- ^"Chemistry: Periodic Table: selenium: key information".webelements.Retrieved2009-01-06.
- ^Bartos, P.J. (2002). "SX-EW copper and the technology cycle".Resources Policy.28(3–4): 85–94.Bibcode:2002RePol..28...85B.doi:10.1016/S0301-4207(03)00025-4.
- ^abNaumov, A. V. (2010). "Selenium and tellurium: State of the markets, the crisis, and its consequences".Metallurgist.54(3–4): 197–200.doi:10.1007/s11015-010-9280-7.S2CID137066827.
- ^Hoffmann, James E. (1989). "Recovering selenium and tellurium from copper refinery slimes".JOM.41(7): 33–38.Bibcode:1989JOM....41g..33H.doi:10.1007/BF03220269.S2CID138253358.
- ^Hyvärinen, Olli; Lindroos, Leo; Yllö, Erkki (1989). "Recovering selenium from copper refinery slimes".JOM.41(7): 42–43.Bibcode:1989JOM....41g..42H.doi:10.1007/BF03220271.S2CID138555797.
- ^abc"Selenium and Tellurium: Statistics and Information".United States Geological Survey.Retrieved2012-05-30.
- ^Sun, Yan; Tian, Xike; He, Binbin; et al. (2011). "Studies of the reduction mechanism of selenium dioxide and its impact on the microstructure of manganese electrodeposit".Electrochimica Acta.56(24): 8305–8310.doi:10.1016/j.electacta.2011.06.111.
- ^Bernd E. Langner (2005), "Selenium and Selenium Compounds",Ullmann's Encyclopedia of Industrial Chemistry,Wiley-VCH, Weinheim.doi:10.1002/14356007.a23_525.
- ^Davis, Joseph R. (2001).Copper and Copper Alloys.ASM Int. p. 91.ISBN978-0-87170-726-0.
- ^Isakov, Edmund (2008-10-31).Cutting Data for Turning of Steel.Industrial Press. p. 67.ISBN978-0-8311-3314-6.
- ^Gol'Dshtein, Ya. E.; Mushtakova, T. L.; Komissarova, T. A. (1979). "Effect of selenium on the structure and properties of structural steel".Metal Science and Heat Treatment.21(10): 741–746.Bibcode:1979MSHT...21..741G.doi:10.1007/BF00708374.S2CID135853965.
- ^Davis, Joseph R. (2001).Copper and Copper Alloys.ASM International.p. 278.ISBN978-0-87170-726-0.
- ^Eftekhari, Ali (2017). "The rise of lithium–selenium batteries".Sustainable Energy & Fuels.1:14–29.doi:10.1039/C6SE00094K.
- ^Adams, William Grylls; Day, Richard Evans. "The Action of Light on Selenium".Philosophical Transactions of the Royal Society of London.167:313–349.
- ^Nakada, Tokio; Kunioka, Akio (1 July 1985). "Polycrystalline Thin-Film TiO 2 /Se Solar Cells".Japanese Journal of Applied Physics.24(7A): L536.Bibcode:1985JaJAP..24L.536N.doi:10.1143/JJAP.24.L536.S2CID118838432.
- ^Todorov, Teodor K.; Singh, Saurabh; Bishop, Douglas M.; Gunawan, Oki; Lee, Yun Seog; Gershon, Talia S.; Brew, Kevin W.; Antunez, Priscilla D.; Haight, Richard (25 September 2017)."Ultrathin high band gap solar cells with improved efficiencies from the world's oldest photovoltaic material".Nature Communications.8(1): 682.Bibcode:2017NatCo...8..682T.doi:10.1038/s41467-017-00582-9.PMC5613033.PMID28947765.
- ^Youngman, Tomas H.; Nielsen, Rasmus; Crovetto, Andrea; Seger, Brian; Hansen, Ole; Chorkendorff, Ib; Vesborg, Peter C. K. (July 2021). "Semitransparent Selenium Solar Cells as a Top Cell for Tandem Photovoltaics".Solar RRL.5(7).doi:10.1002/solr.202100111.S2CID235575161.
- ^Nielsen, Rasmus; Crovetto, Andrea; Assar, Alireza; Hansen, Ole; Chorkendorff, Ib; Vesborg, Peter C.K. (12 March 2024). "Monolithic Selenium/Silicon Tandem Solar Cells".PRX Energy.3(1): 013013.arXiv:2307.05996.Bibcode:2024PRXE....3a3013N.doi:10.1103/PRXEnergy.3.013013.
- ^Nielsen, Rasmus; Youngman, Tomas H.; Moustafa, Hadeel; Levcenco, Sergiu; Hempel, Hannes; Crovetto, Andrea; Olsen, Thomas; Hansen, Ole; Chorkendorff, Ib; Unold, Thomas; Vesborg, Peter C. K. (2022). "Origin of photovoltaic losses in selenium solar cells with open-circuit voltages approaching 1 V".Journal of Materials Chemistry A.10(45): 24199–24207.doi:10.1039/D2TA07729A.S2CID253315416.
- ^Nielsen, Rasmus; Hemmingsen, Tobias H.; Bonczyk, Tobias G.; Hansen, Ole; Chorkendorff, Ib; Vesborg, Peter C. K. (11 September 2023). "Laser-Annealing and Solid-Phase Epitaxy of Selenium Thin-Film Solar Cells".ACS Applied Energy Materials.6(17): 8849–8856.arXiv:2306.11311.doi:10.1021/acsaem.3c01464.S2CID259203956.
- ^Huang, Heyuan; Abbaszadeh, Shiva (2020)."Recent Developments of Amorphous Selenium-Based X-Ray Detectors: A Review".IEEE Sensors Journal.20(4): 1694–1704.Bibcode:2020ISenJ..20.1694H.doi:10.1109/JSEN.2019.2950319.S2CID208833373.
- ^Kasap, Safa; Frey, Joel B.; Belev, George; Tousignant, Olivier; Mani, Habib; Laperriere, Luc; Reznik, Alla; Rowlands, John A. (2009). "Amorphous selenium and its alloys from early xeroradiography to high resolution X-ray image detectors and ultrasensitive imaging tubes".Physica Status Solidi B.246(8): 1794–1805.Bibcode:2009PSSBR.246.1794K.doi:10.1002/pssb.200982007.S2CID122848842.
- ^Springett, B. E. (1988). "Application of Selenium-Tellurium Photoconductors to the Xerographic Copying and Printing Processes".Phosphorus and Sulfur and the Related Elements.38(3–4): 341–350.doi:10.1080/03086648808079729.
- ^Williams, Rob (2006).Computer Systems Architecture: A Networking Approach.Prentice Hall. pp. 547–548.ISBN978-0-321-34079-5.
- ^Diels, Jean-Claude; Arissian, Ladan (2011)."The Laser Printer".Lasers.Wiley-VCH. pp. 81–83.ISBN978-3-527-64005-8.
- ^Meller, Gregor & Grasser, Tibor (2009).Organic Electronics.Springer. pp. 3–5.ISBN978-3-642-04537-0.
- ^Normile, Dennis (2000)."The birth of the Blues".Popular Science.p. 57.
- ^Kasap, Safa; Frey, Joel B.; Belev, George; et al. (2009). "Amorphous selenium and its alloys from early xeroradiography to high resolution X-ray image detectors and ultrasensitive imaging tubes".Physica Status Solidi B.246(8): 1794–1805.Bibcode:2009PSSBR.246.1794K.doi:10.1002/pssb.200982007.S2CID122848842.
- ^Svelto, Orazio (1998).Principles of LASERs fourth ed.Plenum. p. 457.ISBN978-0-306-45748-7.
- ^Hayward, Peter; Currie, Dean."Radiography of Welds Using Selenium 75, Ir 192 and X-rays"(PDF).
- ^Singh, Fateh V.; Wirth, Thomas (2019)."Selenium reagents as catalysts".Catalysis Science & Technology.9(5): 1073–1091.doi:10.1039/C8CY02274G.S2CID104468775.
- ^Hai-Fu, F.; Woolfson, M. M.; Jia-Xing, Y. (1993). "New Techniques of Applying Multi-Wavelength Anomalous Scattering Data".Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences.442(1914): 13–32.Bibcode:1993RSPSA.442...13H.doi:10.1098/rspa.1993.0087.S2CID122722520.
- ^MacLean, Marion E. (1937). "A project for general chemistry students: Color toning of photographic prints".Journal of Chemical Education.14(1): 31.Bibcode:1937JChEd..14...31M.doi:10.1021/ed014p31.
- ^Penichon, Sylvie (1999). "Differences in Image Tonality Produced by Different Toning Protocols for Matte Collodion Photographs".Journal of the American Institute for Conservation.38(2): 124–143.doi:10.2307/3180042.JSTOR3180042.
- ^McKenzie, Joy (2003).Exploring Basic Black & White Photography.Delmar. p.176.ISBN978-1-4018-1556-1.
- ^"What is Dandruff?"(PDF).Vichy UK.Retrieved3 October2023.
- ^Lemly, A. Dennis (2004-09-01)."Aquatic selenium pollution is a global environmental safety issue".Ecotoxicology and Environmental Safety.59(1): 44–56.Bibcode:2004EcoES..59...44L.doi:10.1016/S0147-6513(03)00095-2.ISSN0147-6513.PMID15261722.
- ^Estruch, Ramon; Sacanella, Emilio; Ros, Emilio (4 January 2021)."Should we all go pesco-vegetarian?".European Heart Journal.42(12): 1144–1146.doi:10.1093/eurheartj/ehaa1088.ISSN0195-668X.PMID33393612.
- ^Gribble, Matthew; Karimi, Roxanne; Feingold, Beth; Nyland, Jennifer; O'Hara, Todd; Gladyshev, Michail; Chen, Celia (September 8, 2015)."Mercury, selenium and fish oils in marine food webs and implications for human health".Journal of the Marine Biological Association of the United Kingdom.1(96): 43–59.doi:10.1017/S0025315415001356.PMC4720108.PMID26834292.
at higher doses, selenium might be toxic to a range of animals including humans
- ^Lemly, D. (2004)."Aquatic selenium pollution is a global environmental safety issue".Ecotoxicology and Environmental Safety.59(1): 44–56.Bibcode:2004EcoES..59...44L.doi:10.1016/S0147-6513(03)00095-2.PMID15261722.
- ^Ohlendorf, H. M. (2003).Ecotoxicology of selenium.Handbook of ecotoxicology. Boca Raton: Lewis Publishers. pp. 466–491.ISBN978-1-56670-546-2.
- ^Lemly, A. D. (1997)."A teratogenic deformity index for evaluating impacts of selenium on fish populations".Ecotoxicology and Environmental Safety.37(3): 259–266.Bibcode:1997EcoES..37..259L.doi:10.1006/eesa.1997.1554.PMID9378093.
- ^Penglase, S.; Hamre, K.; Ellingsen, S. (2014). "Selenium and mercury have a synergistic negative effect on fish reproduction".Aquatic Toxicology.149:16–24.Bibcode:2014AqTox.149...16P.doi:10.1016/j.aquatox.2014.01.020.PMID24555955.
- ^Heinz, G. H.; Hoffman, D. J. (1998). "Methylmercury chloride and selenomethionine interactions on health and reproduction in mallards".Environmental Toxicology and Chemistry.17(2): 139–145.doi:10.1002/etc.5620170202.S2CID95466655.
- ^Lemly, Dennis (1998).Selenium Assessment in Aquatic Ecosystems: A guide for hazard evaluation and water quality criteria.Springer.ISBN0-387-95346-9.
- ^Hamilton, Steven J. (2004-06-29)."Review of selenium toxicity in the aquatic food chain".Science of the Total Environment.326(1): 1–31.Bibcode:2004ScTEn.326....1H.doi:10.1016/j.scitotenv.2004.01.019.ISSN0048-9697.PMID15142762.
- ^Atroshi, Faik (2014-05-28).Pharmacology and Nutritional Intervention in the Treatment of Disease.BoD – Books on Demand.ISBN978-953-51-1383-6.
- ^Freeman, John L.; Lindblom, Stormy Dawn; Quinn, Colin F.; Fakra, Sirine; Marcus, Matthew A.; Pilon-Smits, Elizabeth A. H. (2007)."Selenium accumulation protects plants from herbivory by Orthoptera via toxicity and deterrence".The New Phytologist.175(3): 490–500.doi:10.1111/j.1469-8137.2007.02119.x.ISSN0028-646X.PMID17635224.S2CID2330947.
- ^Selenium concentrations in leaf material from Astragalus Oxyphysus (diablo locoweed) and Atriplex Lentiformis (quail bush) in the interior Coast Ranges and the western San Joaquin Valley, California(Report). U.S. Geological Survey. 1986. Water-Resources Investigations Report 86-4066.
- ^A common reference for this isSchroeder, H. A.; Frost, D. V.; Balassa, J. J. (1970). "Essential trace metals in man: Selenium".Journal of Chronic Diseases.23(4): 227–243.doi:10.1016/0021-9681(70)90003-2.OSTI6424964.PMID4926392.
- ^Linus Pauling Institute at Oregon State Universitylpi.oregonstate.edu
- ^Pakdel, Farzad; Ghazavi, Roghayeh; Heidary, Roghayeh; Nezamabadi, Athena; Parvizi, Maryam; Haji Safar Ali Memar, Mahsa; Gharebaghi, Reza; Heidary, Fatemeh (2019)."Effect of Selenium on Thyroid Disorders: Scientometric Analysis".Iranian Journal of Public Health.48(3): 410–420.ISSN2251-6085.PMC6570790.PMID31223567.
- ^"Selenium".Linus Pauling Institute at Oregon State University.Retrieved2009-01-05.
- ^Mazokopakis, E. E.; Papadakis, J. A.; Papadomanolaki, M. G.; et al. (2007). "Effects of 12 months treatment with L-selenomethionine on serum anti-TPO Levels in Patients with Hashimoto's thyroiditis".Thyroid.17(7): 609–612.doi:10.1089/thy.2007.0040.PMID17696828.
- ^Ralston, N. V.; Ralston, C. R.; Blackwell, JL III; Raymond, L. J. (2008)."Dietary and tissue selenium in relation to methylmercury toxicity"(PDF).Neurotoxicology.29(5): 802–811.Bibcode:2008NeuTx..29..802R.CiteSeerX10.1.1.549.3878.doi:10.1016/j.neuro.2008.07.007.PMID18761370.Archived fromthe original(PDF)on 2012-07-24.Retrieved2012-09-28.
- ^Penglase, S.; Hamre, K.; Ellingsen, S. (2014). "Selenium prevents downregulation of antioxidant selenoprotein genes by methylmercury".Free Radical Biology and Medicine.75:95–104.doi:10.1016/j.freeradbiomed.2014.07.019.hdl:1956/8708.PMID25064324.
- ^Usuki, F.; Yamashita, A.; Fujimura, M. (2011)."Post-transcriptional defects of antioxidant selenoenzymes cause oxidative stress under methylmercury exposure".The Journal of Biological Chemistry.286(8): 6641–6649.doi:10.1074/jbc.M110.168872.PMC3057802.PMID21106535.
- ^Ohi, G.; Seki, H.; Maeda, H.; Yagyu, H. (1975)."Protective effect of selenite against methylmercury toxicity: observations concerning time, dose and route factors in the development of selenium attenuation".Industrial Health.13(3): 93–99.doi:10.2486/indhealth.13.93.
- ^Ralston, N. V. C.; Raymond, L. J. (2010). "Dietary selenium's protective effects against methylmercury toxicity".Toxicology.278(1): 112–123.Bibcode:2010Toxgy.278..112R.doi:10.1016/j.tox.2010.06.004.PMID20561558.
- ^Carvalho, C. M. L.; Chew, Hashemy S. I.; Hashemy, J.; et al. (2008)."Inhibition of the human thioredoxin system: A molecular mechanism of mercury toxicity".Journal of Biological Chemistry.283(18): 11913–11923.doi:10.1074/jbc.M710133200.PMID18321861.
- ^Michiaki Yamashita, Shintaro Imamura, Md. Anwar Hossain, Ken Touhata, Takeshi Yabu, and Yumiko Yamashita,"Strong antioxidant activity of the novel selenium-containing imidazole compound 'selenoneine'",The FASEB Journal,vol. 26 no. 1, supplement 969.13, April 2012
- ^Yamashita, Y.; Yabu, T.; Yamashita, M. (2010)."Discovery of the strong antioxidant selenoneine in tuna and selenium redox metabolism".World Journal of Biological Chemistry.1(5): 144–150.doi:10.4331/wjbc.v1.i5.144.PMC3083957.PMID21540999.
- ^Zane Davis, T. (2008-03-27)."Selenium in Plants"(PDF).p. 8.Retrieved2008-12-05.
- ^abGladyshev, Vadim N.; Hatfield, Dolph L. (1999)."Selenocysteine-containing proteins in mammals".Journal of Biomedical Science.6(3): 151–160.doi:10.1007/BF02255899.PMID10343164.
- ^Stadtman, T. C. (1996). "Selenocysteine".Annual Review of Biochemistry.65(1): 83–100.doi:10.1146/annurev.bi.65.070196.000503.PMID8811175.
- ^Lobanov, Alexey V.; Fomenko, Dmitri E.; Zhang, Yan; et al. (2007)."Evolutionary dynamics of eukaryotic selenoproteomes: large selenoproteomes may associate with aquatic life and small with terrestrial life".Genome Biology.8(9): R198.doi:10.1186/gb-2007-8-9-r198.PMC2375036.PMID17880704.
- ^Venturi, Sebastiano; Venturi, Mattia (2007)."Evolution of Dietary Antioxidant Defences".European EpiMarker.11(3): 1–11.
- ^Castellano, Sergi; Novoselov, Sergey V.; Kryukov, Gregory V.; et al. (2004)."Reconsidering the evolution of eukaryotic selenoproteins: a novel nonmammalian family with scattered phylogenetic distribution".EMBO Reports.5(1): 71–7.doi:10.1038/sj.embor.7400036.PMC1298953.PMID14710190.
- ^Kryukov, Gregory V.; Gladyshev, Vadim N. (2004)."The prokaryotic selenoproteome".EMBO Reports.5(5): 538–43.doi:10.1038/sj.embor.7400126.PMC1299047.PMID15105824.
- ^Wilting, R.; Schorling, S.; Persson, B. C.; Böck, A. (1997). "Selenoprotein synthesis in archaea: identification of an mRNA element ofMethanococcus jannaschiiprobably directing selenocysteine insertion ".Journal of Molecular Biology.266(4): 637–41.doi:10.1006/jmbi.1996.0812.PMID9102456.
- ^Zhang, Yan; Fomenko, Dmitri E.; Gladyshev, Vadim N. (2005)."The microbial selenoproteome of the Sargasso Sea".Genome Biology.6(4): R37.doi:10.1186/gb-2005-6-4-r37.PMC1088965.PMID15833124.
- ^abRazaghi, Ali; Poorebrahim, Mansour; Sarhan, Dhifaf; Björnstedt, Mikael (2021-09-01)."Selenium stimulates the antitumour immunity: Insights to future research".European Journal of Cancer.155:256–267.doi:10.1016/j.ejca.2021.07.013.ISSN0959-8049.PMID34392068.
- ^"Dietary Supplement Fact Sheet: Selenium".National Institutes of Health; Office of Dietary Supplements.Retrieved2009-01-05.
- ^Panel on Dietary Antioxidants and Related Compounds, Subcommittees on Upper Reference Levels of Nutrients and Interpretation and Uses of DRIs, Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine (August 15, 2000).Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids.Institute of Medicine. pp. 314–315.doi:10.17226/9810.ISBN978-0-309-06949-6.PMID25077263.
{{cite book}}
:CS1 maint: multiple names: authors list (link) - ^Yang, G.; Zhou, R. (1994). "Further Observations on the Human Maximum Safe Dietary Selenium Intake in a Seleniferous Area of China".Journal of Trace Elements and Electrolytes in Health and Disease.8(3–4): 159–165.PMID7599506.
- ^Yang, Guang-Qi; Xia, Yi-Ming (1995). "Studies on Human Dietary Requirements and Safe Range of Dietary Intakes of Selenium in China and Their Application in the Prevention of Related Endemic Diseases".Biomedical and Environmental Sciences.8(3): 187–201.PMID8561918.
- ^"Public Health Statement: Health Effects"(PDF).Agency for Toxic Substances and Disease Registry.Retrieved2009-01-05.
- ^Wilber, C. G. (1980). "Toxicology of selenium".Clinical Toxicology.17(2): 171–230.doi:10.3109/15563658008985076.PMID6998645.
- ^Olson, O. E. (1986)."Selenium Toxicity in Animals with Emphasis on Man".International Journal of Toxicology.5:45–70.doi:10.3109/10915818609140736.S2CID74619246.
- ^"Polo pony selenium levels up to 20 times higher than normal".2009-05-06. Archived fromthe originalon 2016-08-19.Retrieved2009-05-05.
- ^abHamilton, Steven J.; Buhl, Kevin J.; Faerber, Neil L.; et al. (1990). "Toxicity of organic selenium in the diet to chinook salmon".Environ. Toxicol. Chem.9(3): 347–358.doi:10.1002/etc.5620090310.
- ^abPoston, H. A.; Combs, G. F. Jr.; Leibovitz, L. (1976). "Vitamin E and selenium interrelations in the diet of Atlantic salmon (Salmo salar): gross, histological and biochemical signs ".Journal of Nutrition.106(7): 892–904.doi:10.1093/jn/106.7.892.PMID932827.
- ^Brain, P.; Cousens, R. (1989). "An equation to describe dose responses where there is stimulation of growth at low doses".Weed Research.29(2): 93–96.Bibcode:1989WeedR..29...93B.doi:10.1111/j.1365-3180.1989.tb00845.x.
- ^"NIOSH Pocket Guide to Chemical Hazards – Selenium".United States: National Institute for Occupational Safety & Health.Retrieved2015-11-21.
- ^Baselt, R. (2008).Disposition of Toxic Drugs and Chemicals in Man(8th ed.). Foster City, California: Biomedical Publications. pp. 1416–1420.ISBN978-0-9626523-5-6.
- ^Ravaglia, G.; Forti, P.; Maioli, F.; et al. (2000)."Effect of micronutrient status on natural killer cell immune function in healthy free-living subjects aged ≥90 y".American Journal of Clinical Nutrition.71(2): 590–598.doi:10.1093/ajcn/71.2.590.PMID10648276.
- ^MedSafe Editorial Team."Selenium".Prescriber Update Articles.New Zealand Medicines and Medical Devices Safety Authority.Retrieved2009-07-13.
- ^Ralston, N. V. C.; Raymond, L. J. (2010). "Dietary selenium's protective effects against methylmercury toxicity".Toxicology.278(1): 112–123.Bibcode:2010Toxgy.278..112R.doi:10.1016/j.tox.2010.06.004.PMID20561558.
- ^Mann, Jim; Truswell, A. Stewart (2002).Essentials of Human Nutrition(2nd ed.). Oxford University Press.ISBN978-0-19-262756-8.
- ^Moreno-Reyes, R.; Mathieu, F.; Boelaert, M.; et al. (2003)."Selenium and iodine supplementation of rural Tibetan children affected by Kashin-Beck osteoarthropathy".American Journal of Clinical Nutrition.78(1): 137–144.doi:10.1093/ajcn/78.1.137.PMID12816783.
- ^Kachuee, R.; Moeini, M.; Suori, M. (2013). "The effect of dietary organic and inorganic selenium supplementation on serum Se, Cu, Fe and Zn status during the late pregnancy in Merghoz goats and their kids".Small Ruminant Research.110(1): 20–27.doi:10.1016/j.smallrumres.2012.08.010.
- ^National Research Council, Subcommittee on Sheep Nutrition (1985).Nutrient requirements of sheep.6th ed., National Academy Press, Washington,ISBN0309035961.
- ^abNational Research Council, Committee on Nutrient Requirements of Small Ruminants (2007).Nutrient requirements of small ruminants.National Academies Press, Washington,ISBN0-309-10213-8.
- ^Coop, I. E.; Blakely, R. L. (1949). "The metabolism and toxicity of cyanides and cyanogenic glycosides in sheep".New Zealand Journal of Science and Technology.30:277–291.
- ^Kraus, R. J.; Prohaska, J. R.; Ganther, H. E. (1980). "Oxidized forms of ovine erythrocyte glutathione peroxidase. Cyanide inhibition of 4-glutathione:4-selenoenzyme".Biochimica et Biophysica Acta (BBA) - Enzymology.615(1): 19–26.doi:10.1016/0005-2744(80)90004-2.PMID7426660.
- ^Kahn, C. M. (ed.) (2005).Merck Veterinary Manual.9th ed. Merck & Co., Inc., Whitehouse Station,ISBN0911910506.
- ^Barclay, Margaret N. I.; MacPherson, Allan; Dixon, James (1995). "Selenium content of a range of UK food".Journal of Food Composition and Analysis.8(4): 307–318.doi:10.1006/jfca.1995.1025.
- ^"Selenium Fact Sheet".United States: The Office of Dietary Supplements,National Institutes of Health.Includes a list of selenium-rich foods.
- ^"FDA Issues Final Rule to Add Selenium to List of Required Nutrients for Infant Formula".Food and Drug Administration. Archived fromthe originalon November 14, 2017.RetrievedSeptember 10,2015.
- ^Rostami, Rahim; Nourooz-Zadeh, Sarmad; Mohammadi, Afshin; Khalkhali, Hamid Reza; Ferns, Gordon; Nourooz-Zadeh, Jaffar (2020-10-31)."Serum Selenium Status and Its Interrelationship with Serum Biomarkers of Thyroid Function and Antioxidant Defense in Hashimoto's Thyroiditis".Antioxidants.9(11): E1070.doi:10.3390/antiox9111070.ISSN2076-3921.PMC7692168.PMID33142736.
- ^Vanderpas, J. B.; Contempré, B.; Duale, N. L.; Deckx, H.; Bebe, N.; Longombé, A. O.; Thilly, C. H.; Diplock, A. T.; Dumont, J. E. (February 1993)."Selenium deficiency mitigates hypothyroxinemia in iodine-deficient subjects".The American Journal of Clinical Nutrition.57(2 Suppl): 271S–275S.doi:10.1093/ajcn/57.2.271S.ISSN0002-9165.PMID8427203.