WorldWideScience

Sample records for selenites

  1. Ontogenic changes in selenite metabolism in rats

    International Nuclear Information System (INIS)

    Ostadalova, I.; Babicky, A.; Kopoldova, J.

    1982-01-01

    Radioselenium concentration and excretion was studied after administration of 75 Se-labelled selenite to male rats during ontogeny. The concentration of radioselenium in individual organs decreases with increasing age. The largest differences between young and adults were in the quantity and quality of excreted substances. During 2 h after the administration of 20 μmol selenite/kg young rats excreted 2.4% of the dose, essentially in the urine only, whilst adults excreted a total of 11%, distributed equally in breath and urine. The part excreted as methylated metabolites was 0.1% of the administered dose in young and 6.3% in adult rats. These results support the hypothesis that the differences in the sensitivity to the toxic action of selenite between young and adult rats can be due to ontogenic differences in selenium metabolism. (orig.)

  2. Radioactive sodium selenite in the differentiation of hepatic lesions

    Energy Technology Data Exchange (ETDEWEB)

    Houlder, A E [King Edward VIII Hospital, Durban (South Africa). Dept. of Radiophysics

    1977-06-11

    Selenium-75 selenite and technetium-99m sulphur colloid scans were performed on 38 South African Blacks with intrahepatic space-occupying lesions. Uptake of selenite was demonstrated in the 'cold area' on the sulphur colloid scan in 17 out of 19 patients with hepatocellular carcinoma, but in 16 patients with amoebic liver abscess there was no uptake of selenite in the 'cold area'. In 3 patients with secondary involvement in the liver, 2 had positive uptake of selenite in the affected region. /sup 75/Se selenite was found to be useful in the differential diagnosis of intrahepatic lesions.

  3. Short range order of selenite glasses

    Czech Academy of Sciences Publication Activity Database

    Neov, S.; Gerasimova, I.; Yordanov, S.; Lakov, L.; Mikula, Pavol; Lukáš, Petr

    1999-01-01

    Roč. 40, č. 2 (1999), s. 111-112 ISSN 0031-9090 R&D Projects: GA AV ČR KSK1010104 Keywords : short range * selenite glasses Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.822, year: 1999

  4. Sodium selenite as a new rodenticide

    Directory of Open Access Journals (Sweden)

    Goran Jokić

    2014-09-01

    Full Text Available Rodents are the most destructive group of small mammalian pests considering the overall damage that they cause by feeding and other activities, or as vectors of many disease agents. In practice, chemical rodenticides have been the most widespread and most effective method of control of commensal (Mus musculus, Rattus norvegicus and R. rattus and most harmful field rodent pests (Apodemus sylvaticus, A. agrarius and Microtus arvalis. After anticoagulant and vitamin D3 rodenticides, which were introduced worldwide in the 1980s, no other chemical compound has had a comparable role as a rodenticide in practice. In the past decade, commercial baits containing 0.1% sodium selenite have also been registered in Serbia in various formulations both for controlling rodents indoors and in the field. Data on sodium selenite as a rodenticide have been scarce. The present paper surveys research data reported so far, analyzing and drawing conclusions regarding the validity and feasibility of sodium selenite as a method of rodent control with reference to the available ecotoxicological data.

  5. Differential diagnosis of scintigraphic brain centres by 75Se selenite

    International Nuclear Information System (INIS)

    Bestagno, M.; Garraffa, V.; Rembado, R.; Guerra, U.

    1975-01-01

    Since standard brain scintigraphy with sup(99m)Tc is not always adequate for a satisfactory differential diagnosis of the radioactive foci detected, the possibilities of 75 Se sodium selenite were investigated. It was observed that in centres due to a vascular lesion the selenite concentration is always low, rising steeply in neoplasmic foci. The 75 Se-selenite scintigraphic method is considered highly valid, complementing that of sup(99m)Tc when this latter is unsuitable for diagnosis of the nature of cerebral foci [fr

  6. Selenite cataract and its attenuation by vitamin E in wistar rats.

    Directory of Open Access Journals (Sweden)

    Mathew Joe

    2003-01-01

    Full Text Available Purpose: To study the role of vitamin E in preventing cataract formation in experimental animals. Methods: An experimental model (selenite cataract was selected for this study. Selenite cataract was produced in rats by subcutaneous administration of sodium selenite. Biochemical and histological changes following induction of selenite cataract in weanling wistar rats were studied vis-à-vis the role of vitamin E in attenuating or preventing cataractogenesis. Results: Vitamin E was capable of preventing selenite cataractogenesis. Selenite cataract did not develop in 91.6% (11 of 12 and 76.7% (8 of 12 vitamin E treated rats, when administered on the 12th and 10th post partum day respectively. Conclusion: The study confirmed that selenite induced cataract in wistar rats is attenuated by vitamin E.

  7. The mechanism of interaction between cisplatin and selenite

    NARCIS (Netherlands)

    Baldew, G S; Mol, J G; de Kanter, F J; van Baar, B; De Goeij, J J; Vermeulen, N P

    1991-01-01

    Cisplatin is a widely used antitumor drug, highly effective in the treatment of several tumors. Cisplatin exerts its antitumor activity through an interaction with DNA, which results in the formation of bidentate adducts. An important side-effects of cisplatin is nephrotoxicity. Selenite can reduce

  8. Experimental and iatrogenic poisoning by sodium selenite in pigs

    Directory of Open Access Journals (Sweden)

    Paulo V. Peixoto

    Full Text Available ABSTRACT: Following a case of iatrogenic selenium poisoning in a young pig, an experimental study was carry out. Sodium selenite was orally and parenterally administered to 13 pigs that were subdivided into three groups (G1, G2 and G3. The animals in groups G1 and G3 received sodium selenite intramuscularly (IM, G1 received a comercial formula, and G3 received sodium selenite mixed with distilled water at different dosages, and those in group G2 were fed commercial sodium selenite. Acute and subacute poisoning was observed in both groups, although the onset of clinical signs was slower in group G2. Only one pig (in group G1 that had received the highest dose showed a peracute course. Apathy, anorexia, dyspnea, vomiting, muscular tremors, proprioceptive deficit, ataxia and paresis of the hind limbs progressing to the front limbs evolving to tetraplegia were observed. Postmortem findings differed whether the animals received the injected (G1 and G3 or oral (G2 sodium selenite. The liver was moderately atrophic in some animals of G2. Some of the animals in groups G1 and G3 presented with lung edema. One pig in G3 had yellowish-brown areas in the ventral horns of the cervical intumescences of the spinal cord. The most important histological changes were present in the ventral horns of the cervical and lumbar intumescences of the spinal cord. In one animal, changes were present in the brainstem and mesencephalon. The initial lesion was a perivascular and astrocyte edema that progressing to lysis and death of astrocytes and neurons. In the chronic stage of the lesions, there were extensive areas of liquefaction necrosis with perivascular lymphocytic and histiocytic infiltration and occasional eosinophils. It seems that disruption of the blood-brain barrier due to astrocyte edema is the most likely mechanism of CNS lesion.

  9. Characterization of the selenite uptake mechanism in the coccolithophore Emiliania huxleyi (Haptophyta).

    Science.gov (United States)

    Araie, Hiroya; Sakamoto, Kou; Suzuki, Iwane; Shiraiwa, Yoshihiro

    2011-07-01

    The marine coccolithophore Emiliania huxleyi (Haptophyta) requires selenium as an essential element for growth, and the active species absorbed is selenite, not selenate. This study characterized the selenite uptake mechanism using ⁷⁵Se as a tracer. Kinetic analysis of selenite uptake showed the involvement of both active and passive transport processes. The active transport was suppressed by 0.5 mM vanadate, a membrane-permeable inhibitor of H⁺-ATPase, at pH 8.3. When the pH was lowered from 8.3 to 5.3, the selenite uptake activity greatly increased, even in the presence of vanadate, suggesting that the H⁺ concentration gradient may be a motive force for selenite transport. [⁷⁵Se]Selenite uptake at selenite-limiting concentrations was hardly affected by selenate, sulfate and sulfite, even at 100 μM. In contrast, 3 μM orthophosphate increased the K(m) 5-fold. These data showed that HSeO₃⁻, a dominant selenite species at acidic pH, is the active species for transport through the plasma membrane and transport is driven by ΔpH energized by H⁺-ATPase. Kinetic analysis showed that the selenite uptake activity was competitively inhibited by orthophosphate. Furthermore, the active selenite transport mechanism was shown to be induced de novo under Se-deficient conditions and induction was suppressed by the addition of either sufficient selenite or cycloheximide, an inhibitor of de novo protein synthesis. These results indicate that E. huxleyi cells developed an active selenite uptake mechanism to overcome the disadvantages of Se limitation in ecosystems, maintaining selenium metabolism and selenoproteins for high viability.

  10. Selenite protects Caenorhabditis elegans from oxidative stress via DAF-16 and TRXR-1.

    Science.gov (United States)

    Li, Wen-Hsuan; Shi, Yeu-Ching; Chang, Chun-Han; Huang, Chi-Wei; Hsiu-Chuan Liao, Vivian

    2014-04-01

    Selenium is an essential micronutrient. In the present study, trace amount of selenite (0.01 μM) was evaluated for oxidative stress resistance and potential associated factors in Caenorhabditis elegans. Selenite-treated C. elegans showed an increased survival under oxidative stress and thermal stress compared to untreated controls. Further studies demonstrated that the significant stress resistance of selenite on C. elegans could be attributed to its in vivo free radical-scavenging ability. We also found that the oxidative and thermal stress resistance phenotypes by selenite were absent from the forkhead transcription factor daf-16 mutant worms. Moreover, selenite influenced the subcellular distribution of DAF-16 in C. elegans. Furthermore, selenite increased mRNA levels of stress-resistance-related proteins, including superoxide dismutase-3 and heat shock protein-16.2. Additionally, selenite (0.01 μM) upregulated expressions of transgenic C. elegans carrying sod-3::green fluorescent protein (GFP) and hsp-16.2::GFP, whereas this effect was abolished by feeding daf-16 RNA interference in C. elegans. Finally, unlike the wild-type N2 worms, the oxidative stress resistance phenotypes by selenite were both absent from the C. elegans selenoprotein trxr-1 mutant worms and trxr-1 mutants feeding with daf-16 RNA interference. These findings suggest that the antioxidant effects of selenite in C. elegans are mediated via DAF-16 and TRXR-1. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Surface complexation of selenite on goethite: MO/DFT geometry and charge distribution

    NARCIS (Netherlands)

    Hiemstra, T.; Rietra, R.P.J.J.; Riemsdijk, van W.H.

    2007-01-01

    The adsorption of selenite on goethite (alpha-FeOOH) has been analyzed with the charge distribution (CD) and the multi-site surface complexation (MUSIC) model being combined with an extended Stem (ES) layer model option. The geometry of a set of different types of hydrated iron-selenite complexes

  12. The Comparative Studies of Binding Activity of Curcumin and Didemethylated Curcumin with Selenite: Hydrogen Bonding vs Acid-Base Interactions

    Science.gov (United States)

    Liao, Jiahn-Haur; Wu, Tzu-Hua; Chen, Ming-Yi; Chen, Wei-Ting; Lu, Shou-Yun; Wang, Yi-Hsuan; Wang, Shao-Pin; Hsu, Yen-Min; Huang, Yi-Shiang; Huang, Zih-You; Lin, Yu-Ching; Chang, Ching-Ming; Huang, Fu-Yung; Wu, Shih-Hsiung

    2015-12-01

    In this report, the in vitro relative capabilities of curcumin (CCM) and didemethylated curcumin (DCCM) in preventing the selenite-induced crystallin aggregation were investigated by turbidity tests and isothermal titration calorimetry (ITC). DCCM showed better activity than CCM. The conformers of CCM/SeO32- and DCCM/SeO32- complexes were optimized by molecular orbital calculations. Results reveal that the selenite anion surrounded by CCM through the H-bonding between CCM and selenite, which is also observed via IR and NMR studied. For DCCM, the primary driving force is the formation of an acid-base adduct with selenite showing that the phenolic OH group of DCCM was responsible for forming major conformer of DCCM. The formation mechanisms of selenite complexes with CCM or DCCM explain why DCCM has greater activity than CCM in extenuating the toxicity of selenite as to prevent selenite-induced lens protein aggregation.

  13. Transcriptional Response of Selenopolypeptide Genes and Selenocysteine Biosynthesis Machinery Genes in Escherichia coli during Selenite Reduction.

    Science.gov (United States)

    Tetteh, Antonia Y; Sun, Katherine H; Hung, Chiu-Yueh; Kittur, Farooqahmed S; Ibeanu, Gordon C; Williams, Daniel; Xie, Jiahua

    2014-01-01

    Bacteria can reduce toxic selenite into less toxic, elemental selenium (Se(0)), but the mechanism on how bacterial cells reduce selenite at molecular level is still not clear. We used Escherichia coli strain K12, a common bacterial strain, as a model to study its growth response to sodium selenite (Na2SeO3) treatment and then used quantitative real-time PCR (qRT-PCR) to quantify transcript levels of three E. coli selenopolypeptide genes and a set of machinery genes for selenocysteine (SeCys) biosynthesis and incorporation into polypeptides, whose involvements in the selenite reduction are largely unknown. We determined that 5 mM Na2SeO3 treatment inhibited growth by ∼ 50% while 0.001 to 0.01 mM treatments stimulated cell growth by ∼ 30%. Under 50% inhibitory or 30% stimulatory Na2SeO3 concentration, selenopolypeptide genes (fdnG, fdoG, and fdhF) whose products require SeCys but not SeCys biosynthesis machinery genes were found to be induced ≥2-fold. In addition, one sulfur (S) metabolic gene iscS and two previously reported selenite-responsive genes sodA and gutS were also induced ≥2-fold under 50% inhibitory concentration. Our findings provide insight about the detoxification of selenite in E. coli via induction of these genes involved in the selenite reduction process.

  14. Transcriptional Response of Selenopolypeptide Genes and Selenocysteine Biosynthesis Machinery Genes in Escherichia coli during Selenite Reduction

    Directory of Open Access Journals (Sweden)

    Antonia Y. Tetteh

    2014-01-01

    Full Text Available Bacteria can reduce toxic selenite into less toxic, elemental selenium (Se0, but the mechanism on how bacterial cells reduce selenite at molecular level is still not clear. We used Escherichia coli strain K12, a common bacterial strain, as a model to study its growth response to sodium selenite (Na2SeO3 treatment and then used quantitative real-time PCR (qRT-PCR to quantify transcript levels of three E. coli selenopolypeptide genes and a set of machinery genes for selenocysteine (SeCys biosynthesis and incorporation into polypeptides, whose involvements in the selenite reduction are largely unknown. We determined that 5 mM Na2SeO3 treatment inhibited growth by ∼50% while 0.001 to 0.01 mM treatments stimulated cell growth by ∼30%. Under 50% inhibitory or 30% stimulatory Na2SeO3 concentration, selenopolypeptide genes (fdnG, fdoG, and fdhF whose products require SeCys but not SeCys biosynthesis machinery genes were found to be induced ≥2-fold. In addition, one sulfur (S metabolic gene iscS and two previously reported selenite-responsive genes sodA and gutS were also induced ≥2-fold under 50% inhibitory concentration. Our findings provide insight about the detoxification of selenite in E. coli via induction of these genes involved in the selenite reduction process.

  15. Protective effects of ebselen on sodium-selenite-induced experimental cataract in rats.

    Science.gov (United States)

    Aydemir, Orhan; Güler, Mete; Kaya, Mehmet Kaan; Deniz, Nurettin; Üstündağ, Bilal

    2012-12-01

    To determine whether ebselen has a protective effect or antioxidative potential in a sodium-selenite-induced experimental cataract model. Fırat University, Elazığ, Turkey. Experimental study. Twenty-one Sprague-Dawley rat pups were randomly divided into a control group, a sodium-selenite-induced-cataract group, and an ebselen-treated group; each group contained 7 rat pups. Rats in the control group received dimethyl sulfoxide (DMSO) intraperitoneally only and rats in the sodium-selenite-induced-cataract group received 30 nmol/g body weight sodium selenite subcutaneously and DMSO intraperitoneally 10 days postpartum. Rats in the ebselen group received 30 nmol/g body weight sodium selenite subcutaneously 10 days postpartum and were treated with 5 mg/kg body weight ebselen once a day for 4 consecutive days. Cataract development was assessed weekly for 3 weeks by slitlamp examination and graded using a scale. Reduced glutathione (GSH), total nitrite, and malondialdehyde (MDA) levels in lens supernatants were measured at the end of 3 weeks. In the control group, all lenses were clear. In the ebselen-treated group, the mean cataract stage was significantly lower than in the sodium-selenite-induced-cataract group (P = .022). The GSH levels were significantly lower in the sodium-selenite-induced-cataract group than in the control and ebselen groups (P ebselen group than in the sodium-selenite-induced-cataract group (P ebselen group (P = .001). Ebselen had a protective effect on cataract development in a sodium-selenite-induced experimental model. The protective effect of ebselen appears to be due to inhibition of oxidative stress. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  16. Biological 60Co radiation effects on mouse embryos in the presence of sodium selenite

    International Nuclear Information System (INIS)

    Bellini, M.H.; Mastro, N.L. del.

    1988-09-01

    A single dose of sodium selenite (0,5 mg Se/Kg b.w.) was injected intraperitoneally into mice on day 17 pregnancy, 2h before 1.5 and 3.0 Gy whole body gamma irradiation. Irradiation produced a growth impairment in the newborns. Weight improvement as a function of age offspring from irradiated mice decreased proportionally to applied dose. Administration of selenite results also in a decrease of growth rate. Nevertheless, when irradiation and selenite treatments were combined, no additive effect can be observed, suggesting that selenium pretreatment would exert some protection against radiation-induced retardation of growth. (author) [pt

  17. Arsenic uptake and accumulation in rice (Oryza sativa L.) with selenite fertilization and water management.

    Science.gov (United States)

    Wan, Yanan; Camara, Aboubacar Younoussa; Huang, Qingqing; Yu, Yao; Wang, Qi; Li, Huafen

    2018-07-30

    The accumulation of arsenic (As) in rice grain is a potential threat to human health. Our study investigated the possible mediatory role of selenite fertilization on As uptake and accumulation by rice (Oryza sativa L.) under different water management regimes (aerobic or flooded) in a pot experiment. Soil solutions were also extracted during the growing season to monitor As dynamics. Results showed that As contents in the soil solutions, seedlings, and mature rice were higher under flooded than under aerobic water management. Under aerobic conditions, selenite additions slightly increased As concentrations in soil solutions (in the last two samplings), but decreased As levels in rice plants. Relative to the control, 0.5 mg kg -1 selenite decreased rice grain As by 27.5%. Under flooded conditions, however, selenite additions decreased As in soil solutions, while increased As in rice grain. Tendencies also showed that selenite additions decreased the proportion of As in rice shoots both at the seedling stage and maturity, and were more effective in aerobic soil. Our results demonstrate that the effect of selenite fertilizer on As accumulation by rice is related to water management. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Study of the selenite reduction in Rhodobacter sphaeroides f. sp. denitrificans

    International Nuclear Information System (INIS)

    Bernier-Pierru, B.

    2006-05-01

    Selenium is an essential element for all living organisms at the low level; however it becomes toxic and mutagenic at higher concentrations. The predominant forms of selenium in natural environments are selenate and selenite which are toxic. Bacteria can use several mechanisms of detoxification such as methylation in volatile compounds or reduction in elemental selenium. In this way, our model, Rhodobacter sphaeroides f. sp. denitrificans, is able to reduce selenite into selenium. We have combined biochemical and molecular approaches to better characterize the mechanism and protagonists of this reduction. After studying the physiological response of the bacterium in the presence of selenite, we screened a transposon library in order to isolate mutants with a weakened reduction ability. Two of these selected mutants are affected in genes involved in the molybdenum cofactor synthesis, moaA and mogA. Several reductases, the molybdo enzymes, required this cofactor. Furthermore the addition of tungsten, a competitor for the molybdenum, in the culture medium, dramatically reduces the rate of selenite reduction. These results strongly suggest that a molybdo enzyme is involved in one of the selenite reduction pathways. The potential role of different proteins has been investigated, especially for the nitrate reductase, the DMSO reductase and the biotin sulfoxide reductase. We have also selected a mutant affected in the smoM gene which encodes a peri-plasmic component of a TRAP transporter. The phenotype of this mutant suggests the involvement of this transporter in the selenite import. (author)

  19. Selenite exacerbates hepatic insulin resistance in mouse model of type 2 diabetes through oxidative stress-mediated JNK pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jun, E-mail: hustzhj@hust.edu.cn; Xu, Gang; Bai, Zhaoshuai; Li, Kaicheng; Yan, Junyan; Li, Fen; Ma, Shuai; Xu, Huibi; Huang, Kaixun, E-mail: hxxzrf@hust.edu.cn

    2015-12-15

    Recent evidence suggests a potential pro-diabetic effect of selenite treatment in type 2 diabetics; however, the underlying mechanisms remain elusive. Here we investigated the effects and the underlying mechanisms of selenite treatment in a nongenetic mouse model of type 2 diabetes. High-fat diet (HFD)/streptozotocin (STZ)-induced diabetic mice were orally gavaged with selenite at 0.5 or 2.0 mg/kg body weight/day or vehicle for 4 weeks. High-dose selenite treatment significantly elevated fasting plasma insulin levels and insulin resistance index, in parallel with impaired glucose tolerance, insulin tolerance and pyruvate tolerance. High-dose selenite treatment also attenuated hepatic IRS1/Akt/FoxO1 signaling and pyruvate kinase gene expressions, but elevated the gene expressions of phosphoenolpyruvate carboxyl kinase (PEPCK), glucose 6-phosphatase (G6Pase), peroxisomal proliferator-activated receptor-γ coactivator 1α (PGC-1α) and selenoprotein P (SelP) in the liver. Furthermore, high-dose selenite treatment caused significant increases in MDA contents, protein carbonyl contents, and a decrease in GSH/GSSG ratio in the liver, concurrent with enhanced ASK1/MKK4/JNK signaling. Taken together, these findings suggest that high-dose selenite treatment exacerbates hepatic insulin resistance in mouse model of type 2 diabetes, at least in part through oxidative stress-mediated JNK pathway, providing new mechanistic insights into the pro-diabetic effect of selenite in type 2 diabetes. - Highlights: • Selenite exacerbates hepatic insulin resistance in HFD/STZ-induced diabetic mice. • Selenite elevates hepatic gluconeogenesis and reduces glycolysis in diabetic mice. • Selenite exacerbates hepatic oxidative stress and triggers JNK signaling pathway. • Selenite elevates hepatic selenoprotein P expression in diabetic mice.

  20. Selenite exacerbates hepatic insulin resistance in mouse model of type 2 diabetes through oxidative stress-mediated JNK pathway

    International Nuclear Information System (INIS)

    Zhou, Jun; Xu, Gang; Bai, Zhaoshuai; Li, Kaicheng; Yan, Junyan; Li, Fen; Ma, Shuai; Xu, Huibi; Huang, Kaixun

    2015-01-01

    Recent evidence suggests a potential pro-diabetic effect of selenite treatment in type 2 diabetics; however, the underlying mechanisms remain elusive. Here we investigated the effects and the underlying mechanisms of selenite treatment in a nongenetic mouse model of type 2 diabetes. High-fat diet (HFD)/streptozotocin (STZ)-induced diabetic mice were orally gavaged with selenite at 0.5 or 2.0 mg/kg body weight/day or vehicle for 4 weeks. High-dose selenite treatment significantly elevated fasting plasma insulin levels and insulin resistance index, in parallel with impaired glucose tolerance, insulin tolerance and pyruvate tolerance. High-dose selenite treatment also attenuated hepatic IRS1/Akt/FoxO1 signaling and pyruvate kinase gene expressions, but elevated the gene expressions of phosphoenolpyruvate carboxyl kinase (PEPCK), glucose 6-phosphatase (G6Pase), peroxisomal proliferator-activated receptor-γ coactivator 1α (PGC-1α) and selenoprotein P (SelP) in the liver. Furthermore, high-dose selenite treatment caused significant increases in MDA contents, protein carbonyl contents, and a decrease in GSH/GSSG ratio in the liver, concurrent with enhanced ASK1/MKK4/JNK signaling. Taken together, these findings suggest that high-dose selenite treatment exacerbates hepatic insulin resistance in mouse model of type 2 diabetes, at least in part through oxidative stress-mediated JNK pathway, providing new mechanistic insights into the pro-diabetic effect of selenite in type 2 diabetes. - Highlights: • Selenite exacerbates hepatic insulin resistance in HFD/STZ-induced diabetic mice. • Selenite elevates hepatic gluconeogenesis and reduces glycolysis in diabetic mice. • Selenite exacerbates hepatic oxidative stress and triggers JNK signaling pathway. • Selenite elevates hepatic selenoprotein P expression in diabetic mice.

  1. High Pressure Reduction of Selenite by Shewanella oneidensis MR-1

    Science.gov (United States)

    Picard, A.; Daniel, I.; Testemale, D.; Letard, I.; Bleuet, P.; Cardon, H.; Oger, P.

    2007-12-01

    High-pressure biotopes comprise cold deep-sea environments, hydrothermal vents, and deep subsurface or deep-sea sediments. The latter are less studied, due to the technical difficulties to sample at great depths without contamination. Nevertheless, microbial sulfate reduction and methanogenesis have been found to be spatially distributed in deep deep-sea sediments (1), and sulfate reduction has been shown to be actually more efficient under high hydrostatic pressure (HHP) in some sediments (2). Sulfate-reducing bacteria obtained from the Japan Sea are characterized by an increased sulfide production under pressure (3,4). Unfortunately, investigations of microbial metabolic activity as a function of pressure are extremely scarce due to the experimental difficulty of such measurements at high hydrostatic pressure. We were able to measure the reduction of selenite Se(IV) by Shewanella oneidensis MR-1 as a function of pressure, to 150 MPa using two different high-pressure reactors that allow in situ X-ray spectroscopy measurements on a synchrotron source. A first series of measurements was carried out in a low-pressure Diamond Anvil Cell (DAC) of our own design (5) at ID22 beamline at ESRF (European Synchrotron Radiation Facility); a second one was performed in an autoclave (6) at the BM30B beamline at ESRF. Selenite reduction by strain MR-17 was monitored from ambient pressure to 150 MPa over 25 hours at 30 deg C by XANES spectroscopy (X-ray Analysis of Near Edge Structure). Spectra were recorded hourly in order to quantify the evolution of the oxidation state of selenium with time. Stationary-phase bacteria were inoculated at a high concentration into fresh growth medium containing 5 or 10 M of sodium selenite and 20 mM sodium lactate. Kinetic parameters of the Se (IV) reduction by Shewanella oneidensis strain MR-1 could be extracted from the data, as a function of pressure. They show 1) that the rate constant k of the reaction is decreased by a half at high pressure

  2. Protective effects of sodium selenite on lead nitrate-induced hepatotoxicity in diabetic and non-diabetic rats.

    Science.gov (United States)

    Kalender, Suna; Apaydin, Fatma Gökçe; Baş, Hatice; Kalender, Yusuf

    2015-09-01

    In the present study, the effect of sodium selenite on lead induced toxicity was studied in Wistar rats. Sodium selenite and lead nitrate were administered orally for 28 days to streptozotocin induced diabetic and non-diabetic rats. Eight groups of rats were used in the study: control, sodium selenite, lead nitrate, lead nitrate+sodium selenite, streptozotocin-induced diabetic-control, diabetic-sodium selenite, diabetic-lead nitrate, diabetic-lead nitrate+sodium selenite groups. Serum biochemical parameters, lipid peroxidation, antioxidant enzymes and histopathological changes in liver tissues were investigated in all groups. There were statistically significant changes in liver function tests, antioxidant enzyme activities and lipid peroxidation levels in lead nitrate and sodium selenite+lead nitrate treated groups, also in diabetic and non-diabetic groups. Furthermore, histopathological alterations were demonstrated in same groups. In the present study we found that sodium selenite treatment did not show completely protective effect on diabetes mellitus caused damages, but diabetic rats are more susceptible to lead toxicity than non-diabetic rats. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Uptake and Distribution of Added Selenite and Selenate by Barley and Red Clover as Influenced by Sulphur

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel

    1973-01-01

    The uptake of added Se from selenite and selenate by barley and red clover was investigated in a pot experiment. Much more of selenate than of selenite was taken up but the Se concentrations in the plants declined more with time when selenate was the source. Increasing sulphate addition to the soil...

  4. In situ time-resolved X-ray near-edge absorption spectroscopy of selenite reduction by siderite

    International Nuclear Information System (INIS)

    Badaut, V.; Schlegel, M.L.; Descostes, M.; Moutiers, G.

    2012-01-01

    The reduction oxidation-reaction between aqueous selenite (SeO 3 2- ) and siderite (FeCO 3 (s)) was monitored by in situ, time-resolved X-ray absorption near-edge structure (XANES) spectroscopy at the selenium K edge in a controlled electrochemical environment. Spectral evolutions showed that more than 60% of selenite was reduced at the siderite surface after 20 h of experiment, at which time the reaction was still incomplete. Fitting of XANES spectra by linear combination of reference spectra showed that selenite reaction with siderite is essentially a two-step process, selenite ions being immobilized on siderite surface prior to their reduction. A kinetic model of the reduction step is proposed, allowing to identify the specific contribution of surface reduction. These results have strong implications for the retention of selenite by corrosion products in nuclear waste repositories and in a larger extent for the fate of selenium in the environment. (authors)

  5. Selenopeptides and elemental selenium in Thunbergia alata after exposure to selenite: quantification method for elemental selenium.

    Science.gov (United States)

    Aborode, Fatai Adigun; Raab, Andrea; Foster, Simon; Lombi, Enzo; Maher, William; Krupp, Eva M; Feldmann, Joerg

    2015-07-01

    Three month old Thunbergia alata were exposed for 13 days to 10 μM selenite to determine the biotransformation of selenite in their roots. Selenium in formic acid extracts (80 ± 3%) was present as selenopeptides with Se-S bonds and selenium-PC complexes (selenocysteinyl-2-3-dihydroxypropionyl-glutathione, seleno-phytochelatin2, seleno-di-glutathione). An analytical method using HPLC-ICPMS to detect and quantify elemental selenium in roots of T. alata plants using sodium sulfite to quantitatively transform elemental selenium to selenosulfate was also developed. Elemental selenium was determined as 18 ± 4% of the total selenium in the roots which was equivalent to the selenium not extracted using formic acid extraction. The results are in an agreement with the XAS measurements of the exposed roots which showed no occurrence of selenite or selenate but a mixture of selenocysteine and elemental selenium.

  6. The microbial impact on the sorption behaviour of selenite in an acidic, nutrient-poor boreal bog

    International Nuclear Information System (INIS)

    Lusa, M.; Bomberg, M.; Aromaa, H.; Knuutinen, J.; Lehto, J.

    2015-01-01

    79 Se is among the most important long lived radionuclides in spent nuclear fuel and selenite, SeO 3 2− , is its typical form in intermediate redox potential. The sorption behaviour of selenite and the bacterial impact on the selenite sorption in a 7-m-deep profile of a nutrient-poor boreal bog was studied using batch sorption experiments. The batch distribution coefficient (K d ) values of selenite decreased as a function of sampling depth and highest K d values, 6600 L/kg dry weight (DW), were observed in the surface moss and the lowest in the bottom clay at 1700 L/kg DW. The overall maximum sorption was observed at pH between 3 and 4 and the K d values were significantly higher in unsterilized compared to sterilized samples. The removal of selenite from solution by Pseudomonas sp., Burkholderia sp., Rhodococcus sp. and Paenibacillus sp. strains isolated from the bog was affected by incubation temperature and time. In addition, the incubation of sterilized surface moss, subsurface peat and gyttja samples with added bacteria effectively removed selenite from the solution and on average 65% of selenite was removed when Pseudomonas sp. or Burkholderia sp. strains were used. Our results demonstrate the important role of bacteria for the removal of selenite from the solution phase in the bog environment, having a high organic matter content and a low pH. - Highlights: • Sterilization of bog samples inhibited the SeO 3 2− removal from simulated bog water. • Bacteria isolated from the bog samples removed selenite from the solution. • Bacteria affect the removal of SeO 3 2− from the solution in a nutrient-poor bog. • Selenite is reduced by the bacteria present in the bog both under oxic and anoxic conditions within the different microniches therein. • That is a prerequisite to read the record of the deformational history in metamorphic rocks

  7. Polarographic behaviour and determination of selenite and tellurite in simple solutions or in a binary mixture

    International Nuclear Information System (INIS)

    Hassan, A.

    1991-01-01

    The polarographic behaviour of simple solutions of selenite and tellurite in 1 M ammonium salts of formate, acetate, tartrate, oxalate, and benzoate solutions in absence and in presence of Triton X-100 as a maximum suppressor and a temperature of 25 O C has been investigated. Schemes for the mechanism of reductions occuring at the DME have been deduced. A method for analytical determination of selenite and tellurite in simple solutions as well as in a binary mixture in the presence of 4-14 . 10 -3 % Triton X-100 is reported. (author)

  8. The thermodynamics of arsenates, selenites, and sulfates in the oxidation zone of sulfide ores. XI. Solubility of synthetic chalcomenite analog and zinc selenite at 25°C

    Science.gov (United States)

    Charykova, M. V.; Krivovichev, V. G.; Ivanova, N. M.; Semenova, V. V.

    2015-12-01

    The aim of this study is the synthesis of CuSeO3·2H2O (chalcomenite analog), ZnSeO3·2H2O, and ZnSeO3·H2O and the investigation of their solubility in water. CuSeO3·2H2O has been synthesized from solutions of Cu nitrate and Na selenite, while Zn selenites were synthesized from solutions of Zn nitrate and Na selenite. The samples obtained have been examined with X-ray diffraction and infrared and Raman spectroscopy. The solubility has been determined using the isothermal saturation method in ampoules at 25°C. The solubility has been calculated using the Geochemist's Workbench (GMB 9.0) software package. Solubility products have been calculated for CuSeO3·2H2O (10-10.63), ZnSeO3·2H2O (10-8.35), and ZnSeO3·H2O (10-7.96). The database used comprises thermodynamic characteristics of 46 elements, 47 base particles, 48 redox pairs, 551 particles in solution, and 624 solid phases. The Eh-pH diagrams of the Zn-Se-H2O and Cu-Se-H2O systems were plotted for the average contents of these elements in underground water in oxidation zones of sulfide deposits.

  9. Experimental Study and modelling of the Sorption of Selenite and Europium Onto Smectite and Illite Clays

    International Nuclear Information System (INIS)

    Missana, T.; Alonso, U.; Garcia-Gutierrez, M.

    2009-01-01

    This study provides a large set of experimental selenite sorption data for pure smectite and illite. Similar sorption behavior existed in both clays: linear within a large range of the Se concentrations investigated and independent of ionic strength. Selenite sorption was also analysed in the illite/smectite system with the clays mixed in two different proportions. The objective of the study was to provide the simplest model possible to fit the experimental data, a model also capable of describing selenite sorption in binary illite/smectite clay systems. Selenite sorption data were modeled using both a one-and a two-site non-electrostatic model that took into account the formation of two complexes at the edge sites of the clay. The complexation constants obtained by fitting sorption data of the individual minerals were incorporated into a model to predict the adsorption of selenium in the illite/ smectite mixtures; the models predictions were consistent with the experimental adsorption data. (Author) 42 refs

  10. Experimental Study and modelling of the Sorption of Selenite and Europium Onto Smectite and Illite Clays

    Energy Technology Data Exchange (ETDEWEB)

    Missana, T.; Alonso, U.; Garcia-Gutierrez, M.

    2009-10-12

    This study provides a large set of experimental selenite sorption data for pure smectite and illite. Similar sorption behavior existed in both clays: linear within a large range of the Se concentrations investigated and independent of ionic strength. Selenite sorption was also analysed in the illite/smectite system with the clays mixed in two different proportions. The objective of the study was to provide the simplest model possible to fit the experimental data, a model also capable of describing selenite sorption in binary illite/smectite clay systems. Selenite sorption data were modeled using both a one-and a two-site non-electrostatic model that took into account the formation of two complexes at the edge sites of the clay. The complexation constants obtained by fitting sorption data of the individual minerals were incorporated into a model to predict the adsorption of selenium in the illite/ smectite mixtures; the models predictions were consistent with the experimental adsorption data. (Author) 42 refs.

  11. Effect of sodium selenite on bone repair in tibiae of irradiated rats

    International Nuclear Information System (INIS)

    Rocha, Anna Silvia Setti da; Ramos-Perez, Flavia Maria de Moraes; Boscolo, Frab Norberto; Almeida, Solange Maria; Manzi, Flavio Ricardo; Chicareli, Mariliani

    2009-01-01

    This study evaluated the radioprotective effect of sodium selenite on the bone repair process in tibiae of female rats. For such purpose, 100 female Wistar rats (Rattus norvegicus, albinus) were randomly assigned to 4 groups (n=25), according to the treatment received: administration of distilled water (control); administration of sodium selenite; gamma radiation; and administration of sodium selenite plus gamma radiation. A bone defect was prepared on both tibiae of all animals. Three days after surgery, the gamma radiation and selenium/ gamma radiation groups received 8 Gy gamma rays on the lower limbs. Five animals per group were sacrificed 7, 14, 21, 28 days after surgery for evaluation of the repair process by bone volumetric density analysis. The 5 animals remaining in each group were sacrificed 45 days postoperatively for examination of the mature bone by scanning electron microscopy. Based on all analyzed parameters, the results of the present study suggest that sodium selenite exerted a radioprotective effect in the bone repair of tibia of irradiated rats. (author)

  12. Experimental study and modelling of selenite sorption onto illite and smectite clays.

    Science.gov (United States)

    Missana, T; Alonso, U; García-Gutiérrez, M

    2009-06-15

    This study provides a large set of experimental selenite sorption data for pure smectite and illite. Similar sorption behavior existed in both clays: linear within a large range of the Se concentrations investigated (from 1x10(-10) to 1x10(-3) M); and independent of ionic strength. Selenite sorption was also analysed in the illite/smectite system with the clays mixed in two different proportions, as follows: (a) 30% illite-70% smectite and (b) 43% illite-57% smectite. The objective of the study was to provide the simplest model possible to fit the experimental data, a model also capable of describing selenite sorption in binary illite/smectite clay systems. Selenite sorption data, separately obtained in the single mineral systems, were modeled using both a one- and a two-site non-electrostatic model that took into account the formation of two complexes at the edge sites of the clay. Although the use of a two-site model slightly improved the fit of data at a pH below 4, the simpler one-site model reproduced satisfactorily all the sorption data from pH 3 to 8. The complexation constants obtained by fitting sorption data of the individual minerals were incorporated into a model to predict the adsorption of selenium in the illite/smectite mixtures; the model's predictions were consistent with the experimental adsorption data.

  13. Mechanisms regulating the reduction of selenite by aerobic gram (+) and (-) bacteria

    International Nuclear Information System (INIS)

    Garbisu, C.; Ishii, Takahisa; Yee, B.C.; Carlson, D.E.; Buchanan, B.B.; Leighton, T.; Smith, N.R.; Yee, A.

    1995-01-01

    Toxic species of selenium are pollutants found in agricultural and oil refinery wastestreams. Selenium contamination is particularly problematic in areas that have seleniferous subsurface geology, such as the central valley of California. The authors are developed a bacterial treatment system to mitigate selenium-contaminated wastestreams using Bacillus subtilis and Pseudomonas fluorescens, respectively, as model gram (+) and (-) soil bacteria. They have found that, during growth, both organisms reduce selenite, a major soluble toxic species, to red elemental selenium--an insoluble product generally regarded as nontoxic. In both cases, reduction depended on growth substrate and was effected by an inducible system that effectively removed selenite at concentrations typical of polluted sites--i.e., 50 to 300 microg/L. The bacteria studied differed in one respect: when grown in medium supplemented with nitrate or sulfate, the ability of P. fluorescens to remediate selenite was enhanced, whereas that of B. subtilis was unchanged. Current efforts are being directed toward understanding the biochemical mechanism(s) of detoxification and determining whether bacteria occurring in polluted environments such as soils and sludge systems are capable of selenite remediation

  14. The intensity of tyrosine nitration is associated with selenite and selenate toxicity in Brassica juncea L.

    Science.gov (United States)

    Molnár, Árpád; Feigl, Gábor; Trifán, Vanda; Ördög, Attila; Szőllősi, Réka; Erdei, László; Kolbert, Zsuzsanna

    2018-01-01

    Selenium phytotoxicity involves processes like reactive nitrogen species overproduction and nitrosative protein modifications. This study evaluates the toxicity of two selenium forms (selenite and selenate at 0µM, 20µM, 50µM and 100µM concentrations) and its correlation with protein tyrosine nitration in the organs of hydroponically grown Indian mustard (Brassica juncea L.). Selenate treatment resulted in large selenium accumulation in both Brassica organs, while selenite showed slight root-to-shoot translocation resulting in a much lower selenium accumulation in the shoot. Shoot and root growth inhibition and cell viability loss revealed that Brassica tolerates selenate better than selenite. Results also show that relative high amounts of selenium are able to accumulate in Brassica leaves without obvious visible symptoms such as chlorosis or necrosis. The more severe phytotoxicity of selenite was accompanied by more intense protein tyrosine nitration as well as alterations in nitration pattern suggesting a correlation between the degree of Se forms-induced toxicities and nitroproteome size, composition in Brassica organs. These results imply the possibility of considering protein tyrosine nitration as novel biomarker of selenium phytotoxicity, which could help the evaluation of asymptomatic selenium stress of plants. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Reduction of selenite by Azospirillum brasilense with the formation of selenium nanoparticles.

    Science.gov (United States)

    Tugarova, Anna V; Vetchinkina, Elena P; Loshchinina, Ekaterina A; Burov, Andrei M; Nikitina, Valentina E; Kamnev, Alexander A

    2014-10-01

    The ability to reduce selenite (SeO(3)(2-)) ions with the formation of selenium nanoparticles was demonstrated in Azospirillum brasilense for the first time. The influence of selenite ions on the growth of A. brasilense Sp7 and Sp245, two widely studied wild-type strains, was investigated. Growth of cultures on both liquid and solid (2 % agar) media in the presence of SeO(3)(2-) was found to be accompanied by the appearance of the typical red colouration. By means of transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS) and X-ray fluorescence analysis (XFA), intracellular accumulation of elementary selenium in the form of nanoparticles (50 to 400 nm in diameter) was demonstrated for both strains. The proposed mechanism of selenite-to-selenium (0) reduction could involve SeO(3)(2-) in the denitrification process, which has been well studied in azospirilla, rather than a selenite detoxification strategy. The results obtained point to the possibility of using Azospirillum strains as endophytic or rhizospheric bacteria to assist phytoremediation of, and cereal cultivation on, selenium-contaminated soils. The ability of A. brasilense to synthesise selenium nanoparticles may be of interest to nanobiotechnology for "green synthesis" of bioavailable amorphous red selenium nanostructures.

  16. Effect of sodium selenite on bone repair in tibiae of irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Anna Silvia Setti da [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR, (Brazil). Dept. of Physics; Ramos-Perez, Flavia Maria de Moraes; Boscolo, Frab Norberto; Almeida, Solange Maria [Universidade Estadual de Campinas (UNICAMP), Piracicaba, SP (Brazil). Piracicaba Dental School. Dept. of Oral Diagnosis], e-mail: flaviamaria@fop.unicamp.br; Manzi, Flavio Ricardo [Pontifical Catholic University of Minas Gerais (PUC-MG), Belo Horizonte, MG (Brazil). Dept. of Stomatology; Chicareli, Mariliani [State Univ. of Maringa, PR (Brazil). Dept. of Oral Diagnosis

    2009-07-01

    This study evaluated the radioprotective effect of sodium selenite on the bone repair process in tibiae of female rats. For such purpose, 100 female Wistar rats (Rattus norvegicus, albinus) were randomly assigned to 4 groups (n=25), according to the treatment received: administration of distilled water (control); administration of sodium selenite; gamma radiation; and administration of sodium selenite plus gamma radiation. A bone defect was prepared on both tibiae of all animals. Three days after surgery, the gamma radiation and selenium/ gamma radiation groups received 8 Gy gamma rays on the lower limbs. Five animals per group were sacrificed 7, 14, 21, 28 days after surgery for evaluation of the repair process by bone volumetric density analysis. The 5 animals remaining in each group were sacrificed 45 days postoperatively for examination of the mature bone by scanning electron microscopy. Based on all analyzed parameters, the results of the present study suggest that sodium selenite exerted a radioprotective effect in the bone repair of tibia of irradiated rats. (author)

  17. Deletion of thioredoxin reductase and effects of selenite and selenate toxicity in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Christopher J Boehler

    Full Text Available Thioredoxin reductase-1 (TRXR-1 is the sole selenoprotein in C. elegans, and selenite is a substrate for thioredoxin reductase, so TRXR-1 may play a role in metabolism of selenium (Se to toxic forms. To study the role of TRXR in Se toxicity, we cultured C. elegans with deletions of trxr-1, trxr-2, and both in axenic media with increasing concentrations of inorganic Se. Wild-type C. elegans cultured for 12 days in Se-deficient axenic media grow and reproduce equivalent to Se-supplemented media. Supplementation with 0-2 mM Se as selenite results in inverse, sigmoidal response curves with an LC50 of 0.20 mM Se, due to impaired growth rather than reproduction. Deletion of trxr-1, trxr-2 or both does not modulate growth or Se toxicity in C. elegans grown axenically, and (75Se labeling showed that TRXR-1 arises from the trxr-1 gene and not from bacterial genes. Se response curves for selenide (LC50 0.23 mM Se were identical to selenite, but selenate was 1/4(th as toxic (LC50 0.95 mM Se as selenite and not modulated by TRXR deletion. These nutritional and genetic studies in axenic media show that Se and TRXR are not essential for C. elegans, and that TRXR alone is not essential for metabolism of inorganic Se to toxic species.

  18. Effects Of Erdosteine On Oxidative-Antioxidative Equilibrium And On Cataract Formation In Rat Pups With Selenite-Induced Cataract

    OpenAIRE

    Kılıç, Adil; Selek, Şahbettin; Erel, Özcan

    2015-01-01

    Aim: To investigate whether erdosteine supplementation following selenite exposure affects oxidant-antioxidant equilibrium and prevents cataract formation in rat pups. Methods: Thirty-nine Wistar-albino rat pups were divided into 3 groups. In Group 1 (n=16) only s.c saline was injected. In Group 2 (n=10) subcutaneous (s.c.) sodium selenite (30 nmol / g body weight) was injected on postpartum day 10. In Group 3 (n=13) s.c. sodium selenite (30 nmol/g body weight) were injected on postpartum day...

  19. Mechanisms of inhibition of zinc-finger transcription factors by selenium compounds ebselen and selenite.

    Science.gov (United States)

    Larabee, Jason L; Hocker, James R; Hanas, Jay S

    2009-03-01

    The anti-inflammatory selenium compounds, ebselen (2-phenyl-1,2-benzisoselenazol-3[2H]-one) and selenite, were found to alter the DNA binding mechanisms and structures of cysteine-rich zinc-finger transcription factors. As assayed by DNase I protection, DNA binding by TFIIIA (transcription factor IIIA, prototypical Cys(2)His(2) zinc finger protein), was inhibited by micromolar amounts of ebselen. In a gel shift assay, ebselen inhibited the Cys(2)His(2) zinc finger-containing DNA binding domain (DBD) of the NF-kappaB mediated transcription factor Sp1. Ebselen also inhibited DNA binding by the p50 subunit of the pro-inflammatory Cys-containing NF-kappaB transcription factor. Electrospray ionization mass spectrometry (ESI-MS) was utilized to elucidate mechanisms of chemical interaction between ebselen and a zinc-bound Cys(2)His(2) zinc finger polypeptide modeled after the third finger of Sp1 (Sp1-3). Exposing Sp1-3 to micromolar amounts of ebselen resulted in Zn(2+) release from this peptide and the formation of a disulfide bond by oxidation of zinc finger SH groups, the likely mechanism for DNA binding inhibition. Selenite was shown by ESI-MS to also eject zinc from Sp1-3 as well as induce disulfide bond formation through SH oxidation. The selenite-dependent inhibition/oxidation mechanism differed from that of ebselen by inducing the formation of a stable selenotrisulfide bond. Selenite-induced selenotrisulfide formation was dependent upon the structure of the Cys(2)His(2) zinc finger as alteration in the finger structure enhanced this reaction as well as selenite-dependent zinc release. Ebselen and selenite-dependent inhibition/oxidation of Cys-rich zinc finger proteins, with concomitant release of zinc and finger structural changes, points to mechanisms at the atomic and protein level for selenium-induced alterations in Cys-rich proteins, and possible amelioration of certain inflammatory, neurodegenerative, and oncogenic responses.

  20. Effects of sodium selenite supplementation on lead nitrate-induced oxidative stress in lung tissues of diabetic and non-diabetic rats

    OpenAIRE

    APAYDIN, Fatma; KALENDER, Suna; DEMİR, Filiz; BAŞ, Hatice

    2014-01-01

    In this study, diabetic and non-diabetic male rats were given to sodium selenite, lead nitrate and sodium selenite plus lead nitrate through gavage. At the end of the 4th week, lipid peroxidation and antioxidant enzyme activities was investigated compared to control group. No significant differences were observed between control and sodium selenite treated groups. By the end of the fourth week, lead nitrate led to increase the levels of MDA, and decrease in antioxidant activities compared wit...

  1. In vitro uptake of 75Se-selenite by lens of young and adult rats

    International Nuclear Information System (INIS)

    Sladkova, J.; Ostadalova, I.; Babicky, A.; Obenberger, J.

    1988-01-01

    The uptake was observed of 75 Se-selenite by the lens in Wistar strain rats in adult animals, in 17-day old rats kept with their mothers and in prematurely weaned rats. Also measured was the excretion of 75 Se by the lens of young and adult rats following incubation in the medium with radioselenium. The metabolites were analysed which were discharged by the lens containing 75 Se. In Brattleboro rats the uptake of 75 Se-selenite was also measured by the lens in young and adult rats. The uptake of 75 Se-selenite by the lens in young Wistar rats was found to be 1.6 times higher than by the lens of adult rats and the time course of the radioselenium uptake was slightly different. In the lens of prematurely weaned rats no significant difference was found in the uptake of radioselenium after 4 hours as compared with rats of the same age kept with their mothers. In homozygous Brattleboro rats, a higher uptake of 75 Se-selenite was found as compared with both young and adult heterozygous rats. The time course and the quantity of 75 Se efflux from the lens of young and adult Wistar rats differed significantly after 0.5 hour of pre-incubation. From metabolites containing 75 Se excreted by the lens following preincubation, glutathione selenotrisulfide and a not yet accurately determined fraction with a large share of radioactivity were isolated. The stated results provide yet more proof that selenium cataract is a manifestation of the ontogenic dependence of selenium metabolism in the lens and in the entire organism. (author). 4 tabs., 30 refs

  2. Determination of glutathione in apoptotic SMMC-7221 cells induced by xylitol selenite using capillary electrophoresis.

    Science.gov (United States)

    Wu, Xue; Cao, Yu; Zhang, Jian; Lei, Ming; Deng, Xiaojie; Zahid, Kashif Rafiq; Liu, Yanli; Liu, Ke; Yang, Jihong; Xiong, Guomei; Yao, Hanchao; Qi, Chao

    2016-05-01

    To determine the glutathione (GSH) content in a human hepatoma cell line (SMMC-7221) treated with xylitol/selenite, providing a part of an investigation of its anti-cancer mechanisms. The nuclei of SMMC-7221 cells were stained with Hoechst 33258 in an apoptosis assay, and their morphology subsequently changed from circular to crescent shape. The calibration curve (r(2) = 0.992) was established, and GSH content markedly decreased after treated with 0.5 and 1 mg xylitol/selenite l(-1) for 12, 36 and 60 h (12 h: from 95.57 ± 19.57 to 29.09 ± 7.74 and 24.27 ± 11.15; 36 h: from 70.73 ± 11.35 to 19.54 ± 6.39 and 9.35 ± 6.69; 60 h: from 72.63 ± 16.94 to 7.432 ± 3.84 and 0). The depletion rate of GSH was more related to the concentration of xylitol/selenite than the treatment time (from 69.95 ± 1.87 to 100 % vs. 0.22 ± 0.2 to 100 %). Xylitol/selenite is a promising anti-cancer drug to induce apoptosis in SMMC-7221 cells. It may regulate the apoptosis through the co-action of multiple mechanisms related to GSH depletion.

  3. Relationship between blood-retinal barrier development and formation of selenite nuclear cataract in rat

    Directory of Open Access Journals (Sweden)

    Ping Lu

    2017-12-01

    Full Text Available AIM: To investigate the relationship between development of blood-retinal barrier and formation of selenite nuclear cataract in rat. METHODS: Activity of GPx, MDA level in lens and selenium content in the eyeballs of different ages rats were determined. Besides, lanthanum hydroxide \\〖La(OH3\\〗 tracer method was used to detect development status of blood-retina barrier at different ages. RESULTS: The result showed that the enzyme activity of GPx was highest in young rats before open eyes, but then decreased gradually with age. Distribution of La(OH3 in retinal pigment epithelial layer of 20-day-old rats was significantly less than 11-day-old rats. Injecting sodium selenite to 9-day-old rats, lanthanum hydroxide increased obviously and extended to the inner layers of the retina after 48h, and the retinal pigment epithelial layer was damaged seriously; while injecting sodium selenite to 18-day-old rats with the same dose, number of lanthanum hydroxide decreased significantly and did not extend to the inner layer after 48h.Before opening eyes, the content of MDA in the lens of rats was the highest, and decreased significantly after opening eyes. The Se group was 5 times as that of the control group. Besides, in these groups of rats, selenium content in the eyeballs and MDA level in the lens were in agreement with the change of La(OH3 distribution. CONCLUSION: These results indicated that antioxidant capacity in the eyelid unopened rats is not the main reason for selenite induced cataract formation. The real reason is that blood-retina barrier development is not mature in the eyelid unopened rats.

  4. Potassium vanadium selenite, K(VO2)3(SeO3)2

    International Nuclear Information System (INIS)

    Harrison, W.T.A.; Dussack, L.L.; Jacobson, A.J.

    1995-01-01

    The hydrothermal synthesis and single-crystal structure of potassium vanadium(V) selenite, K(VO 2 ) 3 (SeO 3 ) 2 , are reported. K(VO 2 ) 3 (SeO 3 ) 2 is a layered phase based on a hexagonal tungsten-oxide-like array of corner-sharing VO 6 octahedra capped by Se atoms, and is isostructural with NH 4 (VO 2 ) 3 (SeO 3 ) 2 . (orig.)

  5. Acute selenium toxicity in lambs following intramuscular injection of sodium selenite

    Energy Technology Data Exchange (ETDEWEB)

    Caravaggi, C; Clark, F L; Jackson, A R.B.

    1970-01-01

    The LD50 in lambs from a farm where selenium deficiency has not been recorded was found to be 45..mu..g. of Se/kg. body weight when sodium selenite was administered as a single intramuscular injection. Marked pulmonary congestion and oedema were constantly present with degenerative changes in liver and kidney. A similarity was noted between the autopsy findings of acute selenosis and those described for enterotoxaemia. 13 references, 4 figures.

  6. Comparative study of selenite adsorption on carbon based adsorbents and activated alumina.

    Science.gov (United States)

    Jegadeesan, G; Mondal, K; Lalvani, S B

    2003-08-01

    The sorption characteristics of carbon-based adsorbents such as activated carbon and chitin for the removal of selenite, Se (IV), an anionic, hazardous contaminant, are compared with those of alpha and gamma alumina. Batch experiments were conducted to determine the influence of pH, concentration of adsorbate, adsorbent loading and temperature on the sorption characteristics of the adsorbents. Generally, low pH of the solution resulted in favorable selenium removal. With the exception of activated carbon, uptakes decreased with increase in temperature. In comparison, chitin was found to be far less effective for the removal of Se (IV) from aqueous solutions. The data also showed that gamma alumina provided higher selenium removal percentages (99%) compared to alpha alumina (94%), activated carbon (87%) and chitin (49%). The selenite removal was found to decrease with increasing initial Se (IV) concentration in the solution. Adsorption capacities of the adsorbents are reported in terms of their Langmuir adsorption isotherms. The adsorption capacity (on unit mass basis) of the adsorbents for selenite is in the order: chitin (specific area (sa) = 9.58 m2 g(-1)) activated carbon (sa = 96.37 m2 g(-1)) < alpha alumina (sa = 6 m2 g(-1)) < gamma alumina (sa = 150 m2 g(-1)).

  7. Distribution and metabolism of selenite and selenomethionine in the Japanese quail.

    Science.gov (United States)

    Anan, Yasumi; Ohbo, Ai; Tani, Yuta; Hatakeyama, Yoshiko; Yawata, Ayako; Ogra, Yasumitsu

    2012-05-01

    Compared to the many studies on the physiological and toxicological effects of selenium (Se) in mammals, avian Se metabolism is still an unexplored topic. Some birds are useful as poultry for human nutrition. Moreover, birds belong to higher trophic levels in the biosphere and thus may play an important role in Se circulation in the ecosystem in the same way as mammals do. In this study, we analyzed the distribution and metabolism of Se in an experimental bird, the Japanese quail, which was fed drinking water containing sodium selenite or selenomethionine (SeMet). The highest concentration of Se was detected in the pancreas, followed by down feathers, liver, and kidneys. SeMet was more efficiently incorporated into the quail than selenite. The specific and preferable distribution of Se to the high molecular weight fraction in the serum of the quail was observed only in the SeMet-ingestion group. As in mammals, selenosugar and trimethylselenonium were the major metabolites in quail excreta. Three unknown Se metabolites were detected by HPLC-ICP-MS. Although part of the metabolic pathway of Se in the Japanese quail fed selenite and SeMet was the same as that observed in mammals, the bird also showed certain avian-specific metabolic process for Se.

  8. Analysis of the improvement of selenite retention in smectite by adding alumina nanoparticles.

    Science.gov (United States)

    Mayordomo, Natalia; Alonso, Ursula; Missana, Tiziana

    2016-12-01

    Smectite clay is used as barrier for hazardous waste retention and confinement. It is a powerful material to retain cations, but less effective for retaining anionic species like selenite. This study shows that the addition of a small percentage of γ-Al 2 O 3 nanoparticles to smectite significantly improves selenite sorption. γ-Al 2 O 3 nanoparticles provide high surface area and positively charged surface sites within a wide range of pH, since their point of zero charge is at pH8-9. An addition of 20wt% of γ-Al 2 O 3 to smectite is sufficient to approach the sorption capacity of pure alumina. To analyze the sorption behavior of the smectite/oxide mixtures, a nonelectrostatic surface complexation model was considered, accounting for the surface complexation of HSeO 3 - and SeO 3 2- , the anion competition, and the formation of surface ternary complexes with major cations present in the solution. Selenite sorption in mixtures was satisfactorily described with the surface parameters and complexation constants defined for the pure systems, accounting only for the mixture weight fractions. Sorption in mixtures was additive despite the particle heteroaggregation observed in previous stability studies carried out on smectite/γ-Al 2 O 3 mixtures. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Selenium homeostasis and induction of thioredoxin reductase during long term selenite supplementation in the rat

    DEFF Research Database (Denmark)

    Erkhembayar, Suvd; Mollbrink, Annelie; Eriksson, Malin

    2011-01-01

    -dependent increase in blood and liver selenium levels, with plateaus at 6 and 8weeks, respectively. These plateaus were reached at the same level of selenium regardless of dose, and no further accumulation was observed. A selenium-dependent increase in the activity of TrxR1 in parallel with the increase in liver...... selenium levels was also seen, and the induction of TrxR1 mRNA was seen only during the first three days of treatment, when the levels of selenium in the liver were increasing. Sodium selenite at 1 and 5μg/mL did not affect body weight or relative liver mass. We concluded that long-term treatment...... with selenite did not cause accumulation of selenium and that the activity of TrxR1 in the liver rose with the selenium levels. We therefore suggest that sodium selenite at doses up to 5μg/mL could be used for long-term tumour prevention....

  10. Effect of hesperetin on chaperone activity in selenite-induced cataract

    Directory of Open Access Journals (Sweden)

    Nakazawa Yosuke

    2016-01-01

    Full Text Available Background. Chaperone activity of α-crystallin in the lens works to prevent protein aggregation and is important to maintain the lens transparency. This study evaluated the effect of hesperetin on lens chaperone activity in selenite-induced cataracts. Methodology. Thirteen-day-old rats were divided into four groups. Animals were given hesperetin (groups G2 and G4 or vehicle (G1 and G3 on Days 0, 1, and 2. Rats in G3 and G4 were administered selenite subcutaneously 4 hours after the first hesperetin injection. On Days 2, 4, and 6, cataract grades were evaluated using slit-lamp biomicroscopy. The amount of a-crystallin and chaperone activity in water-soluble fraction were measured after animals sacrificed. Results. G3 on day 4 had developed significant cataract, as an average cataract grading of 4.6 ± 0.2. In contrast, G4 had less severe central opacities and lower stage cataracts than G3, as an average cataract grading of 2.4 ± 0.4. The a-crystallin levels in G3 lenses were lower than in G1, but the same as G4. Additionally, chaperone activity was weaker in G3 lenses than G1, but the same as in G4. Conclusions. Our results suggest that hesperetin can prevent the decreasing lens chaperone activity and a-crystallin water solubility by administered of selenite.

  11. Sorption mechanisms of selenium species (selenite and selenate) on copper-based minerals

    International Nuclear Information System (INIS)

    Devoy, J.

    2001-09-01

    The sorption of radionuclides on the surface of minerals represents a process capable to delay the migration of the elements from a spent fuel deep repository towards the biosphere. In the framework of a deep underground repository, an engineered clay barrier has a high trapping capacity for cationic radio-elements, in particular because of the negative charge of clay surfaces. However, anionic radioelements like selenium species, would be only weakly retained by chemical processes. In order to optimize the trapping capacity of a clay barrier with respect to anionic species, prospective studies are carried out in order to find and evaluate some minerals with specific chemical trapping functions. Among radionuclides, the case of selenium has to be considered because its isotope 79 Se is present in radioactive wastes and has a half life time of 6.5 10 4 years. It is also judicious to find a mineral capable of trapping simultaneously several anionic radio-elements. Copper oxides and sulfides (Cu 2 O, CuO, Cu 2 S, CuS, CuFeS 2 and Cu 5 FeS 4 ) are good adsorbents with respect to selenium species (selenite and selenate). These minerals, with their selenium retention properties, could be used also for the decontamination of soils and waters or to process industrial effluents. The sorption mechanisms have been studied in details for copper oxides (Cu 2 O and CuO) with respect to selenite and selenate. Chalcomenite precipitates in acid pH conditions when selenite is added to a Cu 2 O and CuO suspension. Selenate, in contact with cuprite (Cu 2 O) leads also to a selenium-based precipitate in acid pH environment. For higher pH values, selenite and selenate are adsorbed on copper oxides (Cu 2 O and CuO) and lead to internal and external sphere complexes, respectively. In the case of a selenite/cuprite mixture in basic pH environment and at the equilibrium, a chemical reaction occurs between the oxidation product of cuprite, Cu(OH) 2 and HSeO 3 . A preliminary study of

  12. Pharmacokinetics and Toxicity of Sodium Selenite in the Treatment of Patients with Carcinoma in a Phase I Clinical Trial: The SECAR Study

    DEFF Research Database (Denmark)

    Brodin, Ola; Eksborg, Staffan; Wallenberg, Marita

    2015-01-01

    and the MTD of sodium selenite. The secondary endpoint was primary response evaluation. Results and Conclusion: MTD was defined as 10.2 mg/m(2), with a calculated median plasma half-life of 18.25 h. The maximum plasma concentration of selenium from a single dose of selenite increased in a nonlinear pattern...

  13. Effects of 14-day oral low dose selenium nanoparticles and selenite in rat—as determined by metabolite pattern determination

    Directory of Open Access Journals (Sweden)

    Niels Hadrup

    2016-10-01

    Full Text Available Selenium (Se is an essential element with a small difference between physiological and toxic doses. To provide more effective and safe Se dosing regimens, as compared to dosing with ionic selenium, nanoparticle formulations have been developed. However, due to the nano-formulation, unexpected toxic effects may occur. We used metabolite pattern determination in urine to investigate biological and/or toxic effects in rats administered nanoparticles and for comparison included ionic selenium at an equimolar dose in the form of sodium selenite. Low doses of 10 and 100 fold the recommended human high level were employed to study the effects at borderline toxicity. Evaluations of all significantly changed putative metabolites, showed that Se nanoparticles and sodium selenite induced similar dose dependent changes of the metabolite pattern. Putative identified metabolites included increased decenedioic acid and hydroxydecanedioic acid for both Se formulations whereas dipeptides were only increased for selenite. These effects could reflect altered fatty acid and protein metabolism, respectively.

  14. Lifelong consumption of sodium selenite: gender differences on blood-brain barrier permeability in convulsive, hypoglycemic rats.

    Science.gov (United States)

    Seker, F Burcu; Akgul, Sibel; Oztas, Baria

    2008-07-01

    The aim of this study was to compare the effects of hypoglycemia and induced convulsions on the blood-brain barrier permeability in rats with or without lifelong administration of sodium selenite. There is a significant decrease of the blood-brain barrier permeability in three brain regions of convulsive, hypoglycemic male rats treated with sodium selenite when compared to sex-matched untreated rats (p0.05). The blood-brain barrier permeability of the left and right hemispheres of untreated, moderately hypoglycemic convulsive rats of both genders was better than their untreated counterparts (peffect against blood-brain barrier permeability during convulsions and that the effects of sodium selenite are gender-dependent.

  15. Determination of selenite and selenate in human urine by ion chromatography and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Jons, O.

    2000-01-01

    The selenium species selenite, selenate and selenomethionine were separated in aqueous solution by ion chromatography. The separation was performed on an IonPac AG11 in series with an AS11 anion exchange column by elution with 25 mM sodium hydroxide in 2% methanol. The Se-78 and Se-82 isotopes were...... monitored in the inductively coupled plasma mass spectrometry (ICP-MS) detector. When the chromatographic system was applied to analysis of urine samples diluted 1 + 1, the selenomethionine signal appeared in the front together with other unresolved selenium species, while the selenite and selenate signals...... and selenate, respectively, corresponding to absolute amounts of 8 and 16 pg, respectively. Calculations were based on peak height measurements of the Se-82 isotope. In 23 analysed urine samples, the concentration of selenite was in the range selenium...

  16. Syntheses, structures and characterizations of three novel vanadium selenites with organically bonded copper/nickel complex

    Science.gov (United States)

    Qian, Cheng; Kong, Fang; Mao, Jiang-Gao

    2016-06-01

    A series of vanadium selenites covalently bonded with metal-organic complex, namely, Ni(2,2-bipy)2V2O4(SeO3)2 (1), Cu(2,2-bipy)V2O4(SeO3)2·0.5H2O (2) and Cu2(2,2-bipy)2V5O12(SeO3)2 (3) (2,2-bipy=2,2-bipyridine) have been hydrothermally synthesized and structurally characterized. They exhibit three different structural dimensions, from 0D cluster, 1D chain to 2D layer. Compound 1 features a 0D {Ni(2,2-bipy)2V2O4(SeO3)2}2 dimeric cluster composed of two {Ni(2,2-bipy)2}2+ moieties connected by the {V4O8(SeO3)4}4- cluster. Compound 2 shows a 1D {Cu(2,2-bipy)V2O4(SeO3)2}n chain in which the {Cu2(2,2-bipy)2}4+ moieties are bridged by the {V4O8(SeO3)4}4- clusters. Compound 3 displays a 2D structure consisted of mixed valence vanadium selenites layers {VIVVV4SeIV2O18}n4- and {Cu(2,2-bipy)}2+ complex moieties. The adjacent layers are further interconnected via π-π interactions between the 2,2-bipy ligands exhibiting an interesting 3D supramolecular architecture. Both compound 1 and 2 contain a new {V4O8(SeO3)4}4- cluster and compound 3 exhibits the first 2D vanadate polyhedral layer in vanadium selenites/tellurites with organic moieties.

  17. Selenite and tellurite form mixed seleno- and tellurotrisulfides with CstR from Staphylococcus aureus.

    Science.gov (United States)

    Luebke, Justin L; Arnold, Randy J; Giedroc, David P

    2013-04-01

    Staphylococcus aureus CstR (CsoR-like sulfur transferase repressor) is a member of the CsoR family of transition metal sensing metalloregulatory proteins. Unlike CsoR, CstR does not form a stable complex with transition metals but instead reacts with sulfite to form a mixture of di- and trisulfide species, CstR2(RS-SR') and CstR2(RS-S-SR')n)n=1 or 2, respectively. Here, we investigate if CstR performs similar chemistry with related chalcogen oxyanions selenite and tellurite. In this work we show by high resolution tandem mass spectrometry that CstR is readily modified by selenite (SeO3(2-)) or tellurite (TeO3(2-)) to form a mixture of intersubunit disulfides and selenotrisulfides or tellurotrisulfides, respectively, between Cys31 and Cys60'. Analogous studies with S. aureus CsoR reveals no reaction with selenite and minimal reaction with tellurite. All cross-linked forms of CstR exhibit reduced DNA binding affinity. We show that Cys31 initiates the reaction with sulfite through the formation of S-sulfocysteine (RS-SO3(2-)) and Cys60 is required to fully derivatize CstR to CstR2(RS-SR') and CstR2(RS-S-SR'). The modification of Cys31 also drives an allosteric switch that negatively regulates DNA binding while derivatization of Cys60 alone has no effect on DNA binding. These results highlight the differences between CstRs and CsoRs in chemical reactivity and metal ion selectivity and establish Cys31 as the functionally important cysteine residue in CstRs.

  18. Sorption and reduction of selenite on chlorite surfaces in the presence of Fe(II) ions.

    Science.gov (United States)

    Baik, Min Hoon; Lee, Seung Yeop; Jeong, Jongtae

    2013-12-01

    The sorption and reduction of selenite on chlorite surfaces in the presence of Fe(II) ions were investigated as a function of pH, Se(IV) concentration, and Fe(II) concentration under an anoxic condition. The sorption of Se(IV) onto chlorite surfaces followed the Langmuir isotherm regardless of the presence of Fe(II) ions in the solution. The Se(IV) sorption was observed to be very low at all pH values when the solution was Fe(II)-free or the concentration of Fe(II) ions was as low as 0.5 mg/L. However, the Se(IV) sorption was enhanced at a pH > 6.5 when the Fe(II) concentration was higher than 5 mg/L because of the increased sorption of Fe(II) onto the chlorite surfaces. XANES (X-ray absorption near edge structure) spectra of the Se K-edge showed that most of the sorbed Se(IV) was reduced to Se(0) by Fe(II) sorbed onto the chlorite surfaces, especially at pH > 9. The combined results of field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) also showed that elemental selenium and goethite were formed and precipitated on the chlorite surfaces during the sorption of selenite. Consequently it can be concluded that Se(IV) can be reduced to Se(0) in the presence of Fe(II) ions by the surface catalytic oxidation of Fe(II) into Fe(III) and the formation of goethite at neutral and particularly alkaline conditions. Thus the mobility of selenite in groundwater is expected to be reduced by the presence of a relatively higher concentration of Fe(II) in subsurface environments. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Selenite and tellurite form mixed seleno- and tellurotrisulfides with CstR from Staphylococcus aureus

    OpenAIRE

    Luebke, Justin L.; Arnold, Randy J.; Giedroc, David P.

    2013-01-01

    Staphylococcus aureus CstR (CsoR-like sulfur transferase repressor) is a member of the CsoR family of transition metal sensing metalloregulatory proteins. Unlike CsoR, CstR does not form a stable complex with transition metals but instead reacts with sulfite to form a mixture of di- and trisulfide species, CstR2(RS-SR′) and CstR2(RS-S-SR′)n, n = 1 or 2, respectively. Here, we investigate if CstR performs similar chemistry with related chalcogen oxyanions selenite and tellurite. In this work w...

  20. Influence of selenite and selenate supplementation on the chromium uptake and translocation in Allium cepa

    International Nuclear Information System (INIS)

    Karuna Shanker; Setia, Seema; Srivastava, Shalini; Dass, Sahab; Srivastava, Rohit; Satya Prakash; Srivastava, M.M.

    1997-01-01

    Pot experiments were conducted on onion plant to study the effects of selenite and selenate treatments (0.5-6.0) μg ml -1 on the uptake and translocation of root absorbed chromium irrigated with 2 and 5 μg ml -1 of chromium in sand and soil. Both the form of selenium (SeO 3 2- , and SeO 4 2- ) were found equally effective in reducing the chromium burden of the plant. No significant difference (p>0.05) in dry matter yields among various selenium treatments exist suggesting no salt injury occurred in the plants under prevailing conditions. (author). 10 refs., 1 tab

  1. Selenium intoxication with selenite broth resulting in acute renal failure and severe gastritis

    Directory of Open Access Journals (Sweden)

    Kamble P

    2009-01-01

    Full Text Available Selenium (Se is an essential trace element in human and animal nutrition. It is also widely utilized in industrial processes. Reports of acute selenium toxicity in humans are rare. We report a case of a 23-year-old female who consumed about 100 mL of liquid selenite broth and presented with severe nausea, vomiting, abdominal pain, hematemesis and acute renal failure (ARF. The serum selenium level was significantly increased. Gastro-duodenoscopy revealed severe corrosive gastritis. Renal biopsy showed features of acute tubular necrosis (ATN, affecting primarily the proximal tubules. The patient was managed with gastric lavage, blood transfusions, infusion of fresh frozen plasma (FFP and platelet concentrates and hemo-dialysis. The patient was discharged five weeks after admission and her renal functions reco-vered completely by eight weeks after admission. She continues to be on regular follow-up for any possible sequelae of mucosal corrosive damage. This case highlights a case of selenium intoxication from selenite broth resulting in ARF and corrosive gastritis. The recovery was complete.

  2. Separation of Selenite from Inorganic Selenium Ions using TiO{sub 2} Magnetic Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongmin; Lim, H. B. [Donkook Univ., Yongin (Korea, Republic of)

    2013-11-15

    A simple and quick separation technique for selenite in natural water was developed using TiO{sub 2} SiO{sub 2}/Fe{sub 3}O{sub 4} nanoparticles. For the synthesis of nanoparticles, a polymer-assisted sol-gel method using hydroxypropyl cellulose (HPC) was developed to control particle dispersion in the synthetic procedure. In addition, titanium butoxide (TBT) precursor, instead of the typical titanium tetra isopropoxide, was used for the formation of the TiO{sub 2} shell. The synthesized nanoparticles were used to separate selenite (Se{sup 4+}) in the presence of Se{sup 6+} or selenium anions for the photocatalytic reduction to Se{sup 0} atom on the TiO{sub 2} shell, followed by magnetic separation using Fe{sub 3}O{sub 4} nanoparticles. The reduction efficiency of the photocatalytic reaction was 81.4% at a UV power of 6W for 3 h with a dark adsorption of 17.5% to the nanoparticles, as determined by inductively coupled plasma-mass spectrometry (ICP-MS). The developed separation method can be used for the speciation and preconcentration of selenium cations in environmental and biological analysis.

  3. Nanocrystalline hydroxyapatite enriched in selenite and manganese ions: physicochemical and antibacterial properties

    Science.gov (United States)

    Kolmas, Joanna; Groszyk, Ewa; Piotrowska, Urszula

    2015-07-01

    In this work, we used the co-precipitation method to synthesize hydroxyapatite (Mn-SeO3-HA) containing both selenium IV (approximately 3.60 wt.%) and manganese II (approximately 0.29 wt.%). Pure hydroxyapatite (HA), hydroxyapatite-containing manganese (II) ions (Mn-HA), and hydroxyapatite-containing selenite ions alone (SeO3-HA), prepared with the same method, were used as reference materials. The structures and physicochemical properties of all the obtained samples were investigated. PXRD studies showed that the obtained materials were homogeneous and consisted of apatite phase. Introducing selenites into the hydroxyapatite crystals considerably affects the size and degree of ordering. Experiments with transmission electron microscopy (TEM) showed that Mn-SeO3-HA crystals are very small, needle-like, and tend to form agglomerates. Fourier transform infrared spectroscopy (FT-IR) and solid-state nuclear magnetic resonance (ssNMR) were used to analyze the structure of the obtained material. Preliminary microbiological tests showed that the material demonstrated antibacterial activity against Staphylococcus aureus, yet such properties were not confirmed regarding Escherichia coli. PACS codes: 61, 76, 81

  4. Molecular structure, vibrational, HOMO-LUMO, MEP and NBO analysis of hafnium selenite

    Science.gov (United States)

    Yankova, Rumyana; Genieva, Svetlana; Dimitrova, Ginka

    2017-08-01

    In hydrothermal condition hafnium selenite with estimated chemical composition Hf(SeO3)2·n(H2O) was obtained and characterized by powder X-Ray diffraction, IR spectroscopy and thermogravimetrical analysis. The composition of the obtained crystalline phase was established as dihydrate of tetraaqua complex of the hafnium selenite [Hf(SeO3)2(H2O)4]·2H2O. The results of the thermogravimetrical analysis are shown that the two hydrated water molecules are released in the temperature interval 80-110°C, while the four coordinated water molecules - at 210-300°C. By DFT method, with Becke's three parameter exchange-functional combined with gradient-corrected correlation functional of Lee, Yang and Parr and 6-31G(d), 6-311 + G(d,p) basis sets and LANL2DZ for Hf atom were calculated the molecular structure, vibrational frequencies and thermodynamic properties of the structure. The UV-Vis spectra and electronic properties are presented. The energy and oscillator strength calculated by time-dependent density functional theory corresponds well with the experimental ones. Molecular electrostatic potential (MEP) was performed. Mulliken population analysis on atomic charges was also calculated. The stability and intramolecular interactions are interpreted by NBO analysis.

  5. Nephrotoxic effects of lead nitrate exposure in diabetic and nondiabetic rats: Involvement of oxidative stress and the protective role of sodium selenite.

    Science.gov (United States)

    Baş, Hatice; Kalender, Yusuf

    2016-10-01

    Heavy metals are known to be toxic to organisms. The present study was undertaken to evaluate the protective effect of sodium selenite against lead nitrate (LN)-induced nephrotoxicity in diabetic and nondiabetic rats. Animals were divided into eight groups where the first was served as a control, whereas the remaining groups were treated with sodium selenite (1 mg/kg b.w.), LN (22.5 mg/kg b.w.) and a combination of LN and sodium selenite and diabetic forms of these groups. Changes in antioxidant enzyme activities, malondialdehide levels, serum urea, uric acid, creatinine levels, body, and kidney weights and histopathological changes were determined after 28 days. LN caused severe histopathological changes, increment in urea, uric acid, creatinine, and MDA levels, also decreasing in antioxidant enzyme activities, body, and kidney weights. In sodium selenite + LN group, we observed the protective effect of sodium selenite on examining parameters. Also diabetes caused alterations on these parameters compared with nondiabetic animals. We found that sodium selenite did not show protective effect on diabetes caused damages. As a result, LN caused nephrotoxicity and sodium selenite alleviated this toxicity but sodium selenite did not protect kidneys against diabetes mediated toxicity. Also, LN caused more harmfull effects in diabetic groups compared with nondiabetic groups. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1229-1240, 2016. © 2015 Wiley Periodicals, Inc.

  6. Selenite and ebselen supplementation attenuates D-galactose-induced oxidative stress and increases expression of SELR and SEP15 in rat lens.

    Science.gov (United States)

    Dai, Jie; Zhou, Jun; Liu, Hongmei; Huang, Kaixun

    2016-12-01

    Selenite and ebselen supplementation has been shown to possess anti-cataract potential in some experimental animal models of cataract, however, the underlying mechanisms remain unclear. The present study was designed to evaluate the anti-cataract effects and the underlying mechanisms of selenite and ebselen supplementation on galactose induced cataract in rats, a common animal model of sugar cataract. Transmission electron microscopy images of lens fiber cells (LFC) and lens epithelial cells (LEC) were observed in D-galactose-induced experimental cataractous rats treated with or without selenite and ebselen, also redox homeostasis and expression of proteins such as selenoprotein R (SELR), 15kD selenoprotein (SEP15), superoxide dismutase 1 (SOD1), catalase (CAT), β-crystallin protein, aldose reductase (AR) and glucose-regulated protein 78 (GRP78) were estimated in the lenses. The results showed that D-galactose injection injured rat lens and resulted in cataract formation; however, selenite and ebselen supplementation markedly alleviated ultrastructural injury of LFC and LEC. Moreover, selenite and ebselen supplementation could mitigate the oxidative damage in rat lens and increase the protein expressions of SELR, SEP15, SOD1, CAT and β-crystallin, as well as decrease the protein expressions of AR and GRP78. Taken together, these findings for the first time reveal the anti-cataract potential of selenite and ebselen in galactosemic cataract, and provide important new insights into the anti-cataract mechanisms of selenite and ebselen in sugar cataract.

  7. Absorption, distribution, metabolism and excretion of selenium following oral administration of elemental selenium nanoparticles or selenite in rats

    DEFF Research Database (Denmark)

    Löschner, Katrin; Hadrup, Niels; Hansen, Marianne

    2014-01-01

    A suspension of nanoparticles of BSA-stabilized red amorphous elemental selenium (Se) or an aqueous solution of sodium selenite was repeatedly administered by oral gavage for 28 days at 0.05 mg/kg bw/day (low dose) or at 0.5 mg/kg bw/day (high dose) as Se to female rats. Prior to administration...

  8. Selenium balance in the adult cat in relation to intake of dietary sodium selenite and organically bound selenium

    NARCIS (Netherlands)

    Todd, S.E.; Thomas, D.G.; Hendriks, W.H.

    2012-01-01

    The response of cats to dietary sodium selenite (Na2SeO3) and organically bound selenium was studied in two separate studies with four cats per treatment and three levels of selenium supplementation (targets 1.0, 1.5 and 2.0 µg/g DM) for each Se source. Whole blood and plasma selenium concentrations

  9. Altered selenium status in Huntington's disease: neuroprotection by selenite in the N171-82Q mouse model.

    Science.gov (United States)

    Lu, Zhen; Marks, Eileen; Chen, Jianfang; Moline, Jenna; Barrows, Lorraine; Raisbeck, Merl; Volitakis, Irene; Cherny, Robert A; Chopra, Vanita; Bush, Ashley I; Hersch, Steven; Fox, Jonathan H

    2014-11-01

    Disruption of redox homeostasis is a prominent feature in the pathogenesis of Huntington's disease (HD). Selenium an essential element nutrient that modulates redox pathways and has been reported to provide protection against both acute neurotoxicity (e.g. methamphetamine) and chronic neurodegeneration (e.g. tauopathy) in mice. The objective of our study was to investigate the effect of sodium selenite, an inorganic form of selenium, on behavioral, brain degeneration and biochemical outcomes in the N171-82Q Huntington's disease mouse model. HD mice, which were supplemented with sodium selenite from 6 to 14 weeks of age, demonstrated increased motor endurance, decreased loss of brain weight, decreased mutant huntingtin aggregate burden and decreased brain oxidized glutathione levels. Biochemical studies revealed that selenite treatment reverted HD-associated changes in liver selenium and plasma glutathione in N171-82Q mice and had effects on brain selenoprotein transcript expression. Further, we found decreased brain selenium content in human autopsy brain. Taken together, we demonstrate a decreased selenium phenotype in human and mouse HD and additionally show some protective effects of selenite in N171-82Q HD mice. Modification of selenium metabolism results in beneficial effects in mouse HD and thus may represent a therapeutic strategy. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Relationship of membrane-bound sulfhydryl groups to vitamin D-stimulated uptake of [75Se]Selenite by the brush border membrane vesicles from chick duodenum

    International Nuclear Information System (INIS)

    Mykkanen, H.M.; Wasserman, R.H.

    1990-01-01

    The uptake of selenite by purified brush border membrane vesicles isolated from duodena of rachitic or vitamin D-treated chicks was studied by using radioactive selenite and a rapid filtration technique. Cholecalciferol treatment (500 IU at 72 h) significantly enhanced selenite uptake, a response that decreased when the vesicles were stored at room temperature for 2.5 h prior to the uptake measurement. Preincubation of the vesicles in 1.0 mmol/L H2O2 reduced [75Se]selenite uptake, indicating the involvement of oxidizable groups in the uptake reaction. Iodoacetic acid (IAA), a sulfhydryl-blocking reagent, at 1-2 mmol/L concentration eliminated the difference in selenite uptake due to cholecalciferol and had no effect on vesicles from rachitic animals. A higher concentration of IAA (10 mmol/L) enhanced selenite uptake manyfold and increased the absolute difference due to cholecalciferol treatment. Single intravenous doses of 100 IU cholecalciferol, 100 IU ergocalciferol, or 0.1 micrograms 1,25-dihydroxycholecalciferol also stimulated selenite uptake, suggesting a general response to vitamin D compounds. Normal animals given a single dose of 1,25-dihydroxycholecalciferol 12 h prior to killing also responded. Treatments that enhanced the uptake of [75Se]selenite also increased the amount of membrane-bound sulfhydryl groups, suggesting the involvement of membrane-bound sulfhydryl groups in the vitamin D response. A significant increase in selenite uptake by intravenous 1,25-dihydroxycholecalciferol occurred within 10 min. This rapid effect provides a new tool to probe early biochemical effects of vitamin D on intestinal epithelium

  11. Selenite Treatment Inhibits LAPC-4 Tumor Growth and Prostate-Specific Antigen Secretion in a Xenograft Model of Human Prostate Cancer

    International Nuclear Information System (INIS)

    Bhattacharyya, Rumi S.; Husbeck, Bryan; Feldman, David; Knox, Susan J.

    2008-01-01

    Purpose: Selenium compounds have known chemopreventive effects on prostate cancer. However selenite, an inorganic form of selenium, has not been extensively studied as a treatment option for prostate cancer. Our previous studies have demonstrated the inhibition of androgen receptor expression and androgen stimulated prostate-specific antigen (PSA) expression by selenite in human prostate cancer cell lines. In this study, we investigated the in vivo effects of selenite as a therapy to treat mice with established LAPC-4 tumors. Methods and Materials: Male mice harboring androgen-dependent LAPC-4 xenograft tumors were treated with selenite (2 mg/kg intraperitoneally three times per week) or vehicle for 42 days. In addition, androgen-independent LAPC-4 xenograft tumors were generated in female mice over 4 to 6 months. Once established, androgen-independent LAPC-4 tumor fragments were passaged into female mice and were treated with selenite or vehicle for 42 days. Changes in tumor volume and serum PSA levels were assessed. Results: Selenite significantly decreased androgen-dependent LAPC-4 tumor growth in male mice over 42 days (p < 0.001). Relative tumor volume was decreased by 41% in selenite-treated animals compared with vehicle-treated animals. The inhibition of LAPC-4 tumor growth corresponded to a marked decrease in serum PSA levels (p < 0.01). In the androgen-independent LAPC-4 tumors in female mice, selenite treatment decreased tumor volume by 58% after 42 days of treatment (p < 0.001). Conclusions: These results suggest that selenite may have potential as a novel therapeutic agent to treat both androgen-dependent and androgen-independent prostate cancer

  12. Study of the Cupriavidus metallidurans CH34 resistance of selenite and selenate oxy-anions: accumulation, localisation and transformation of selenium

    International Nuclear Information System (INIS)

    Avoscan, L.

    2007-06-01

    Selenium is an essential trace element for the living organisms but it is very toxic at high concentration. Selenite and selenate oxides, soluble forms, highly toxic and bio-assimilable, are the most prevalent forms in the environment. Some soil micro-organisms play a dominant role and contribute to the natural cycle of selenium. Our study model, Cupriavidus (formerly Ralstonia) metallidurans CH34, a telluric bacterium characteristic of metal-contaminated biotopes, is known to resist selenite by reducing it into elemental selenium, an insoluble and less toxic form of selenium. In order to better understand the mechanisms of selenium reduction in the bacteria, three methods of speciation were combined (XAS (XANES and EXAFS), HPLC-ICP-MS and SDS-PAGEPIXE). They were completed by the direct quantification of selenium accumulated in the bacteria. Speciation analyses highlighted the existence of two mechanisms of reduction of selenium oxides in C. metallidurans CH34. Assimilation transforms selenite and selenate into organic selenium, identified as seleno-methionine and leads to its non-specific incorporation into bacterial proteins (presence of selenious proteins). Detoxication precipitates selenite in nano-particles of elemental selenium. This way of detoxication is not set up after an exposure to selenate although it is nevertheless possible to detect elemental selenium but in very small amount compared to the exposure of selenite. Seleno-diglutathion is detected in bacteria stressed by an exposure to selenate in medium limited in sulphate. Bacteria exposed to selenite accumulate 25 times more selenium than when they are exposed to selenate. The study of mutants resistant to selenite, which do not express the membrane protein DedA, showed that the accumulation of selenium after exposure to selenite is decreased compared with the wild strain meaning probable link between the transport of selenite and the DedA protein. Finally, selenate would use the sulphate permease

  13. Effect of sulfide, selenite and mercuric mercury on the growth and methylation capacity of the sulfate reducing bacterium Desulfovibrio desulfuricans

    Energy Technology Data Exchange (ETDEWEB)

    Truong, Hoang-Yen T. [Department of Biology, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Chen, Yu-Wei [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Belzile, Nelson, E-mail: nbelzile@laurentian.ca [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Cooperative Freshwater Ecology Unit, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada)

    2013-04-01

    Cultures of the sulfate reducing bacteria Desulfovibrio desulfuricans were grown under anoxic conditions to study the effect of added sulfide, selenite and mercuric ions. A chemical trap consisting in a CuSO{sub 4} solution was used to control the poisoning effect induced by the bacterial production of hydrogen sulfide via the precipitation of CuS. Following the addition of Hg{sup 2+}, the formation of methylmercury (MeHg) was correlated to bacterial proliferation with most of MeHg found in the culture medium. A large fraction (50–80%) of added Hg{sup 2+} to a culture ended up in a solid phase (Hg{sup 0} and likely HgS) limiting its bioavailability to cells with elemental Hg representing ∼ 40% of the solid. Following the addition of selenite, a small fraction was converted into Se(0) inside the cells and, even though the conversion to this selenium species increased with the increase of added selenite, it never reached more than 49% of the added amount. The formation of volatile dimethylselenide is suggested as another detoxification mechanism. In cultures containing both added selenite and mercuric ions, elemental forms of the two compounds were still produced and the increase of selenium in the residual fraction of the culture suggests the formation of mercuric selenite limiting the bioavailability of both elements to cells. - Highlights: ► Detoxification mechanisms of D. desulfuricans were studied in presence of added sulfide, selenite and mercuric ions. ► The poisoning effect of H{sub 2}S added to or generated by cultures of D. desulfuricans can be controlled with a chemical trap. ► The addition of selenite to cultures triggered the formation of elemental Se and other forms of volatile and non-volatile Se. ► The addition of mercuric ions to cultures led to the production of methylmercury, volatile Hg and solid mercuric sulfide. ► With both Se and Hg added to cultures, fractionation of species in solid and liquid phases suggests the formation of HgSe.

  14. Extracellular thiol-assisted selenium uptake dependent on the x(c)(-) cystine transporter explains the cancer-specific cytotoxicity of selenite

    DEFF Research Database (Denmark)

    Olm, E.; Fernandes, A. P.; Hebert, C.

    2009-01-01

    The selenium salt selenite (SeO32-) is cytotoxic in low to moderate concentrations, with a remarkable specificity for cancer cells resistant to conventional chemotherapy. Our data show that selenium uptake and accumulation, rather than intracellular events, are crucial to the specific selenite...... cytotoxicity observed in resistant cancer cells. We show that selenium uptake depends on extracellular reduction, and that the extracellular environment is a key factor specific to selenite cytotoxicity. The extracellular reduction is mediated by cysteine, and the efficacy is determined by the uptake...

  15. Explorations of new selenites of the group IIIA and IVA metals

    International Nuclear Information System (INIS)

    Kong Fang; Li Peicin; Zhang Suyun; Mao Jianggao

    2012-01-01

    Systematic explorations of new phases in the Ga III /In III /Ge IV –Se IV –O systems by hydrothermal syntheses or solid-state reactions at high-temperature led to six new ternary compounds, namely, M 2 Se 2 O 7 (M=Ga 1, In 2), M(OH)(SeO 3 ) (M=Ga 3, In 4), α-Ge(SeO 3 ) 2 5 and β-Ge(SeO 3 ) 2 6. Ga 2 Se 2 O 7 1 displays a 3D open framework composed of 2D gallium oxide layers being further bridged and capped by SeO 3 groups. In 2 Se 2 O 7 2 features a 3D indium oxide framework formed by corner- and edge- sharing InO 6 octahedra with SeO 3 groups attached on the cavities and the 8-member ring tunnels of the structure. The isostructural of M(OH)(SeO 3 ) (M=Ga 3, In 4) exhibit a 2D metal selenite layer composed of 1D edge-sharing MO 6 octahedral chains that are interconnected by SeO 3 groups. α-Ge(SeO 3 ) 2 (P2 1 /n) 5 displays a 3D open framework with 1D 8-member ring tunnels along the a-axis while β-Ge(SeO 3 ) 2 (Pa-3) 6 exhibits a condensed 3D network. - Graphical abstract: Highlights: ► Up to now, selenites of the group IIIA and IVA metals are still rare. ► Hydrothermal or solid state reactions yielded six new compounds in this system. ► They are M 2 Se 2 O 7 (M=Ga, In), M(OH)(SeO 3 ) (M=Ga, In), α-Ge(SeO 3 ) 2 and β-Ge(SeO 3 ) 2 . ► They exhibit four different 3D and one 2D structural types. ► α-Ge(SeO 3 ) 2 and β-Ge(SeO 3 ) 2 represent the first examples of germanium selenites.

  16. Influence of dietary sodium selenite on tissue selenium levels of growing pigs

    International Nuclear Information System (INIS)

    Moksnes, K.; Tollersrud, S.; Larsen, H.J.

    1982-01-01

    Twenty Norwegian Landrace pigs were divided into 5 groups and fed a basal diet consisting of a mixture of dried skim milk and whey powder together with ground barley. The diet was supplemented with 0, 0.2, 0.8, 1.2, and 2.2 μg/g selenium as sodium selenite and was fed for 12 weeks. The muscle selenium level was increased by a factor of about 4 and the liver selenium by a factor of about 12 when the dietary selenium supplement was increased from zero to 2.2μg/g. There was a significant linear correlation between dietary selenium and selenium concentrations in tissues. Possible benefit for humans consuming meat from animals having received the selenium doses used in this experiment are discussed. (author)

  17. Effects of Foliar Selenite on the Nutrient Components of Turnip (Brassica rapa var. rapa Linn.

    Directory of Open Access Journals (Sweden)

    Xiong Li

    2018-03-01

    Full Text Available We administered foliar applications of 50, 100, and 200 mg L−1 selenium (Se, selenite on turnip (Brassica rapa var. rapa Linn. and detected the changes in the main nutrient components in fleshy roots. Results showed that the foliar application of Se (IV significantly increased the Se content in turnip, and Se (IV positively affected the uptake of several mineral elements, including magnesium, phosphorus, iron, zinc, manganese, and copper. Se (IV treatments also improved the synthesis of protein and multiple amino acids instead of crude fat and total carbohydrate in turnip, indicating that the foliar application of Se (IV could enhance Se biofortification in turnip and promote its nutritional value. We recommended 50–100 mg L−1 Se treatment for foliar application on turnip based on the daily intake of Se for adults (96–139 μg person−1 day−1 and its favorable effects on the nutrient components of turnip.

  18. Effects of foliar selenite on the nutrient components of turnip (Brassica rapa var. rapa Linn.)

    Science.gov (United States)

    Li, Xiong; Li, Boqun; Yang, Yongping

    2018-03-01

    We administered foliar applications of 50, 100 and 200 mg L‑1 selenium (Se, selenite) on turnip (Brassica rapa var. rapa Linn.) and detected the changes in the main nutrient components in fleshy roots. Results showed that the foliar application of Se (Ⅳ) significantly increased the Se content in turnip, and Se (Ⅳ) positively affected the uptake of several mineral elements, including magnesium, phosphorus, iron, zinc, manganese and copper. Se (Ⅳ) treatments also improved the synthesis of protein and multiple amino acids instead of crude fat and total carbohydrate in turnip, indicating that the foliar application of Se (Ⅳ) could enhance Se biofortification in turnip and promote its nutritional value. We recommended 50–100 mg L‑1 Se treatment for foliar application on turnip based on the daily intake of Se for adults (96–139 µg person‑1 day‑1) and its favourable effects on the nutrient components of turnip.

  19. Syntheses, structures and characterizations of three novel vanadium selenites with organically bonded copper/nickel complex

    International Nuclear Information System (INIS)

    Qian, Cheng; Kong, Fang; Mao, Jiang-Gao

    2016-01-01

    A series of vanadium selenites covalently bonded with metal-organic complex, namely, Ni(2,2-bipy) 2 V 2 O 4 (SeO 3 ) 2 (1), Cu(2,2-bipy)V 2 O 4 (SeO 3 ) 2 ·0.5H 2 O (2) and Cu 2 (2,2-bipy) 2 V 5 O 12 (SeO 3 ) 2 (3) (2,2-bipy=2,2-bipyridine) have been hydrothermally synthesized and structurally characterized. They exhibit three different structural dimensions, from 0D cluster, 1D chain to 2D layer. Compound 1 features a 0D {Ni(2,2-bipy) 2 V 2 O 4 (SeO 3 ) 2 } 2 dimeric cluster composed of two {Ni(2,2-bipy) 2 } 2+ moieties connected by the {V 4 O 8 (SeO 3 ) 4 } 4- cluster. Compound 2 shows a 1D {Cu(2,2-bipy)V 2 O 4 (SeO 3 ) 2 } n chain in which the {Cu 2 (2,2-bipy) 2 } 4+ moieties are bridged by the {V 4 O 8 (SeO 3 ) 4 } 4− clusters. Compound 3 displays a 2D structure consisted of mixed valence vanadium selenites layers {V IV V V 4 Se IV 2 O 18 } n 4− and {Cu(2,2-bipy)} 2+ complex moieties. The adjacent layers are further interconnected via π-π interactions between the 2,2-bipy ligands exhibiting an interesting 3D supramolecular architecture. Both compound 1 and 2 contain a new {V 4 O 8 (SeO 3 ) 4 } 4− cluster and compound 3 exhibits the first 2D vanadate polyhedral layer in vanadium selenites/tellurites with organic moieties. - Graphical abstract: We got three new vanadium selenites with organically linked copper/nickel complex, namely, Ni(2,2-bipy) 2 V 2 O 4 (SeO 3 ) 2 (1), Cu(2,2-bipy)V 2 O 4 (SeO 3 ) 2 ·0.5H 2 O (2) and Cu 2 (2,2-bipy) 2 V 5 O 12 (SeO 3 ) 2 (3) by hydrothermally syntheses. They display three different structural dimensions, from 0D cluster, to 1D chain and 2D layer. Display Omitted - Highlights: • Three new compounds display three different structural dimensions, from 0D cluster, to 1D chain and 2D layer. • The Tetranuclear {V 4 O 8 (SeO 3 ) 4 } 4− cluster and the vanadate {V 5 O 17 } n 2D layer are observed firstly. • Optical Properties and Magnetic Properties of three compounds are reported.

  20. Syntheses, structures and characterizations of three novel vanadium selenites with organically bonded copper/nickel complex

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Cheng [College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Kong, Fang [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Mao, Jiang-Gao, E-mail: mjg@fjirsm.ac.cn [College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China)

    2016-06-15

    A series of vanadium selenites covalently bonded with metal-organic complex, namely, Ni(2,2-bipy){sub 2}V{sub 2}O{sub 4}(SeO{sub 3}){sub 2} (1), Cu(2,2-bipy)V{sub 2}O{sub 4}(SeO{sub 3}){sub 2}·0.5H{sub 2}O (2) and Cu{sub 2}(2,2-bipy){sub 2}V{sub 5}O{sub 12}(SeO{sub 3}){sub 2} (3) (2,2-bipy=2,2-bipyridine) have been hydrothermally synthesized and structurally characterized. They exhibit three different structural dimensions, from 0D cluster, 1D chain to 2D layer. Compound 1 features a 0D {Ni(2,2-bipy)_2V_2O_4(SeO_3)_2}{sub 2} dimeric cluster composed of two {Ni(2,2-bipy)_2}{sup 2+} moieties connected by the {V_4O_8(SeO_3)_4}{sup 4-} cluster. Compound 2 shows a 1D {Cu(2,2-bipy)V_2O_4(SeO_3)_2}{sub n} chain in which the {Cu_2(2,2-bipy)_2}{sup 4+} moieties are bridged by the {V_4O_8(SeO_3)_4}{sup 4−} clusters. Compound 3 displays a 2D structure consisted of mixed valence vanadium selenites layers {V"I"VV"V_4Se"I"V_2O_1_8}{sub n}{sup 4−} and {Cu(2,2-bipy)}{sup 2+} complex moieties. The adjacent layers are further interconnected via π-π interactions between the 2,2-bipy ligands exhibiting an interesting 3D supramolecular architecture. Both compound 1 and 2 contain a new {V_4O_8(SeO_3)_4}{sup 4−} cluster and compound 3 exhibits the first 2D vanadate polyhedral layer in vanadium selenites/tellurites with organic moieties. - Graphical abstract: We got three new vanadium selenites with organically linked copper/nickel complex, namely, Ni(2,2-bipy){sub 2}V{sub 2}O{sub 4}(SeO{sub 3}){sub 2} (1), Cu(2,2-bipy)V{sub 2}O{sub 4}(SeO{sub 3}){sub 2}·0.5H{sub 2}O (2) and Cu{sub 2}(2,2-bipy){sub 2}V{sub 5}O{sub 12}(SeO{sub 3}){sub 2} (3) by hydrothermally syntheses. They display three different structural dimensions, from 0D cluster, to 1D chain and 2D layer. Display Omitted - Highlights: • Three new compounds display three different structural dimensions, from 0D cluster, to 1D chain and 2D layer. • The Tetranuclear {V_4O_8(SeO_3)_4}{sup 4−} cluster and the vanadate {V

  1. Use of 75Se-labelled selenite ion for metabolic studies in various animal species

    International Nuclear Information System (INIS)

    Rico, A.G.; Benard, P.; Braun, J.P.

    1976-01-01

    This work was carried out by autoradiography (mice, pigs) and liquid scintillation (rats, rabbits, pigs, ewes). The results obtained show that after intramuscular administration sodium selenite is rapidly absorbed. It is distributed in the different organs, preferentially in the liver, kidney, bone-marrow and heart, where it remains fixed for a long time. In the blood it decreases only slowly. Much of the selenium is excreted, partly during the first 48 hours in urine (20-30%, depending on species), mainly in the seleniate form, and partly in the faecal matter, the latter type of excretion being spread over a longer time (5-8 days). Transfer to milk in the ewes is only slight. From these results it can be stated with certainty that the selenium that is not excreted during the first few hours in the urine or faeces is translocated to the cell structure, particularly the proteic structures. Its chemical relationship to sulphur easily explains this metabolic peculiarity. (author)

  2. New indium selenite-oxalate and indium oxalate with two- and three-dimensional structures

    International Nuclear Information System (INIS)

    Cao Junjun; Li Guodong; Chen Jiesheng

    2009-01-01

    Two new indium(III) compounds with extended structures, [In 2 (SeO 3 ) 2 (C 2 O 4 )(H 2 O) 2 ].2H 2 O (I) and [NH 3 (CH 2 ) 2 NH 3 ][In(C 2 O 4 ) 2 ] 2 .5H 2 O (II), have been prepared under mild hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. Compound I crystallizes in the triclinic system, space group P-1, with a=5.2596(11) A, b=6.8649(14) A, c=9.3289(19) A, α=101.78(3) o , β=102.03(3) o , γ=104.52(3) o , while compound II crystallizes in the orthorhombic system, space group Fdd2, with a=15.856(3) A, b=31.183(6) A, c=8.6688(17) A. In compound I, indium-selenite chains are bridged by oxalate units to form two-dimensional (2D) In 2 (SeO 3 ) 2 C 2 O 4 layers, separated by non-coordinating water molecules. In compound II, the indium atoms are connected through the oxalate units to generate a 3D open framework containing cross-linked 12- and 8-membered channels. - Graphical abstract: Two new indium(III) compounds have been hydrothermally synthesized and structurally characterized. In I, the indium-selenite chains are bridged by oxalate units to form 2D In 2 (SeO 3 ) 2 C 2 O 4 layers. In II, the indium atoms are connected through the oxalate units to generate a 3D open framework containing cross-linked 12- and 8-membered ring channels

  3. Effects of Sodium Selenite on Formaldehyde Induced Renal Toxicity in Mice

    Directory of Open Access Journals (Sweden)

    Shabnam Mohammadi 1,2 * , Maryam Moghimian 3, Hanieh Torabzadeh 4, Mahla Langari 4, Roghayeh Nazeri 4, Zahra Karimi 4, Elham Sangari 4, Najmeh Jagarmi 5, Alireza Mohammad Zadeh 3, Mehdi Karimi 7, Kamyar Tavakkoli 8, Ali Delshad 9, Fatemeh Mohammadzadeh 3, Majid Ghayour-Mobarhan 10

    2016-12-01

    Full Text Available Background: Formaldehyde is widely used for industrial applications. Renal injury is an adverse effect associated with formaldehyde. Few studies have explored the potential benefits of protective factors on formaldehyde induced renal toxicity. This study evaluated the dose dependent effects of sodium selenite on the biochemical and histopathological effects of formaldehyde on murine kidney. Methods: Forty eight adult Balb/c male mice were randomized into six groups: a control group, a formaldehyde group and experimental III-VI groups. Formaldehyde group was injected with 10 mg/kg formaldehyde and groups III-VI received intraperitoneally doses of 0.1, 0.2, 0.4, 0.8 mg/kg selenium. After two weeks, a stereological study was done in accordance with the principle of Cavalieri and serum concentrations of urea and creatinine were measured. Data were analyzed using ANOVA and SPSS software. Results: Glomerosclerosis, necrosis and vacuolization were observed in the convoluted tubules of animals treated with formaldehyde. The biochemical markers, volume and count of glomeruli in the group treated with formaldehyde was significantly difference compared to the control group (P<0.05. The volume of the glomeruli in the group treated with 0.2 and 0.4 mg selenium and urea level in the group treated with 0.4 and 0.1 mg/kg selenium was significantly difference compared to the control group (P <0.05. The count of glomeruli and creatinine level in the selenium group was significantly difference compared to the control group (P ≤ 0.0001. Conclusions: A dose of 0.2 mg/kg of sodium selenite caused partial protective effect on the renal tissue and function in exposed to formaldehyde.

  4. Study of the Cupriavidus metallidurans CH34 resistance of selenite and selenate oxy-anions: accumulation, localisation and transformation of selenium; Etude de la resistance de Cupriavidus metallidurans CH34 aux oxyanions selenite et seleniate: accumulation, localisation et transformation du selenium

    Energy Technology Data Exchange (ETDEWEB)

    Avoscan, L

    2007-06-15

    Selenium is an essential trace element for the living organisms but it is very toxic at high concentration. Selenite and selenate oxides, soluble forms, highly toxic and bio-assimilable, are the most prevalent forms in the environment. Some soil micro-organisms play a dominant role and contribute to the natural cycle of selenium. Our study model, Cupriavidus (formerly Ralstonia) metallidurans CH34, a telluric bacterium characteristic of metal-contaminated biotopes, is known to resist selenite by reducing it into elemental selenium, an insoluble and less toxic form of selenium. In order to better understand the mechanisms of selenium reduction in the bacteria, three methods of speciation were combined (XAS (XANES and EXAFS), HPLC-ICP-MS and SDS-PAGEPIXE). They were completed by the direct quantification of selenium accumulated in the bacteria. Speciation analyses highlighted the existence of two mechanisms of reduction of selenium oxides in C. metallidurans CH34. Assimilation transforms selenite and selenate into organic selenium, identified as seleno-methionine and leads to its non-specific incorporation into bacterial proteins (presence of selenious proteins). Detoxication precipitates selenite in nano-particles of elemental selenium. This way of detoxication is not set up after an exposure to selenate although it is nevertheless possible to detect elemental selenium but in very small amount compared to the exposure of selenite. Seleno-diglutathion is detected in bacteria stressed by an exposure to selenate in medium limited in sulphate. Bacteria exposed to selenite accumulate 25 times more selenium than when they are exposed to selenate. The study of mutants resistant to selenite, which do not express the membrane protein DedA, showed that the accumulation of selenium after exposure to selenite is decreased compared with the wild strain meaning probable link between the transport of selenite and the DedA protein. Finally, selenate would use the sulphate permease

  5. Tellurite-, tellurate-, and selenite-based anaerobic respiration by strain CM-3 isolated from gold mine tailings.

    Science.gov (United States)

    Maltman, Chris; Piercey-Normore, Michele D; Yurkov, Vladimir

    2015-09-01

    The newly discovered strain CM-3, a Gram-negative, rod-shaped bacterium from gold mine tailings of the Central Mine in Nopiming Provincial Park, Canada, is capable of dissimilatory anaerobic reduction of tellurite, tellurate, and selenite. CM-3 possesses very high level resistance to these oxides, both aerobically and anaerobically. During aerobic growth, tellurite and tellurate resistance was up to 1500 and 1000 µg/ml, respectively. In the presence of selenite, growth occurred at the highest concentration tested, 7000 µg/ml. Under anaerobic conditions, resistance was decreased to 800 µg/ml for the Te oxides; however, much like under aerobic conditions, growth with selenite still took place at 7000 µg/ml. In the absence of oxygen, CM-3 couples oxide reduction to an increase in biomass. Following an initial drop in viable cells, due to switching from aerobic to anaerobic conditions, there was an increase in CFU/ml greater than one order of magnitude in the presence of tellurite (6.6 × 10(3)-8.6 × 10(4) CFU/ml), tellurate (4.6 × 10(3)-1.4 × 10(5) CFU/ml), and selenite (2.7 × 10(5)-5.6 × 10(6) CFU/ml). A control culture without metalloid oxides showed a steady decrease in CFU/ml with no recovery. ATP production was also increased in the presence of each oxide, further indicating anaerobic respiration. Partial 16S rRNA gene sequencing revealed a 99.0 % similarity of CM-3 to Pseudomonas reactans.

  6. Uptake of 75Se-selenite by brush border membrane vesicles from chick duodenum stimulated by vitamin D

    International Nuclear Information System (INIS)

    Mykkanen, H.M.; Wasserman, R.H.

    1989-01-01

    Brush border membrane vesicles were isolated from mucosal homogenates of duodena from normal, rachitic and vitamin D-treated rachitic chicks using a discontinuous sucrose gradient, and further purified by glycerol gradient centrifugation. In vitro uptake of 75Se-selenite by purified brush border membrane vesicles was studied using a rapid filtration technique. The time course of 75Se uptake was non-linear; rapid initial binding was followed by a gradual decrease in the rate of uptake until an equilibrium value was reached at 60-120 min. The initial binding at 36 s was not affected by selenite concentration in the incubation buffer, while the fractional rate of uptake between the 36 s and 2 min time periods was clearly lower with 1 mM Se than with 4-100 microM Se. 75Se uptake did not show any dependency on the external Na-gradient, nor could it be inhibited by other anions (arsenate, phosphate). Treatment of rachitic chicks either with cholecalciferol (500 Iu, 72 h) or with 1,25(OH)2-cholecalciferol (0.5 microgram given 16 h prior to isolation of the vesicles) significantly enhanced 75Se uptake. A threefold excess of mannitol in the outside buffer reduced 75Se uptake by vesicles from vitamin D-deficient and D-treated chicks 60% and 35% respectively, but had no effect on vesicles from vitamin D-treated chicks preloaded with 75Se. Neither saponin treatment nor excess cold selenite could release the label from the vesicles preloaded with 75Se. These data are compatible with the hypothesis that selenite easily crosses the brush border membrane into the intravesicular space and, once inside, is tightly bound by the membrane

  7. Attenuating the toxicity of cisplatin by using selenosulfate with reduced risk of selenium toxicity as compared with selenite

    International Nuclear Information System (INIS)

    Zhang Jinsong; Peng Dungeng; Lu Hongjuan; Liu Qingliang

    2008-01-01

    It has been reported that high doses of sodium selenite can reduce side effects of cisplatin (CDDP) without compromising its antitumor activity, thus substantially enhancing the cure rate in tumor-bearing mice. However, the toxicity of selenite at high doses should be a concern. The present study revealed that selenosulfate had much lower toxicity, but possessed equal efficacy in selenium (Se) utilization, as compared with selenite at similar doses when used for the intervention of CDDP. In addition, Se accumulation in whole blood and kidney of mice treated with selenosulfate was highly correlated with the survival rate of mice treated with CDDP (both r > 0.96 and both p < 0.05), suggesting that whole blood Se is a potential clinical biomarker to predict host tolerance to CDDP. In either Se-deficient or -sufficient mice bearing solid tumors of hepatoma 22 (H22), selenosulfate did not disturb the therapeutic effect of CDDP on tumors but effectively attenuated the toxicity of CDDP. Furthermore, in a highly malignant cancer model, with Se-sufficient mice bearing ascitic H22 cells, 8 or 10 mg/kg CDDP alone only achieved a null or 25% cure rate, whereas coadministration of selenosulfate with the above two doses of CDDP achieved cure rates of 87.5% or 75%. These results together argue for consideration of selenosulfate as an agent to enhance the therapeutic efficacy of CDDP

  8. Detoxification of selenite and mercury by reduction and mutual protection in the assimilation of both elements by Pseudomonas fluorescens

    International Nuclear Information System (INIS)

    Belzile, Nelson; Wu Gaojun; Chen, Yu-Wei; Appanna, Vasu D.

    2006-01-01

    A study on the assimilation and detoxification of selenium and mercury and on the interaction between these two elements was conducted on Pseudomonas fluorescens. P. fluorescens was able to convert separately both elements to their elemental forms, which are less toxic and biologically less available. To study the converting mechanism of selenite to elemental Se, cells were grown in the presence of various selenite concentrations and several parameters such as extracellular protein concentrations, pH, carbohydrate concentrations, isocitrate dehydrogenase (ICDH) and malic enzyme were monitored. Transmission electron microscopy (TEM) and various analytical methods were applied to confirm the interaction between selenium and cell. The former appeared as a red precipitate localized predominantly in the consumed culture medium. P. fluorescens also resisted to the toxic effect of mercury by converting Hg 2+ to the volatile and less toxic form Hg . Mercury reductase was likely responsible for the conversion of Hg 2+ to Hg . More importantly, the interaction between mercury and selenium was also studied. The presence of selenite significantly reduced the accumulation of mercury in P. fluorescens. It was also interesting to note that mercury appeared to behave as a protecting agent against selenium intoxication as the bioaccumulation of Se was also inhibited by this metal. The formation of Se-Hg complexes could explain this mutual protective effect. No precipitate of elemental Se could be detected when Hg was present in the cultures

  9. Simultaneous tracing of 76Se-selenite and 77Se-selenomethionine by absolute labeling and speciation

    International Nuclear Information System (INIS)

    Suzuki, Kazuo T.; Somekawa, Layla; Kurasaki, Kazuki; Suzuki, Noriyuki

    2006-01-01

    Nutritional selenocompounds are transformed into the assumed common intermediate selenide, which is utilized for the synthesis of selenoenzymes or transformed into methylated metabolites for excretion. Hence, selenocompound metabolites can be traced only with labeled selenium. Here we applied a new tracer method for the metallomics of biometals using simultaneous speciation of each metallome labeled with different homo-elemental isotopes to metabolism and availability of selenium. Rats were depleted of endogenous natural abundance selenium by feeding a single selenium stable isotope ( 82 Se-selenite) and then administered 76 Se-selenite and 77 Se-selenomethionine ( 77 Se-SeMet)simultaneously. Biological samples were subjected to quantification and speciation analysis by HPLC-ICPMS. Metabolites of the labeled 76 Se and 77 Se and interaction with endogenous selenium were traced and examined without interference from the corresponding endogenous natural abundance isotopes. Differences in the distribution and metabolism among organs and between the two nutritional selenocompounds were compared under exactly identical biological and analytical conditions: (1) selenite was distributed more efficiently than SeMet in organs and body fluids except the pancreas. (2) SeMet was taken up by organs in its intact form. (3) Selenium of SeMet origin was distributed selectively in the pancreas and mostly bound to a protein together with intact SeMet. (4) Selenosugars A and B but not trimethylselenonium (TMSe) were detected in the liver. (5) Selenosugar B and TMSe were detected in the kidneys

  10. Sorption mechanisms of selenium species (selenite and selenate) on copper-based minerals; Mecanismes de sorption des especes du selenium (selenite et seleniate) sur des mineraux a base de cuivre

    Energy Technology Data Exchange (ETDEWEB)

    Devoy, J

    2001-09-01

    The sorption of radionuclides on the surface of minerals represents a process capable to delay the migration of the elements from a spent fuel deep repository towards the biosphere. In the framework of a deep underground repository, an engineered clay barrier has a high trapping capacity for cationic radio-elements, in particular because of the negative charge of clay surfaces. However, anionic radioelements like selenium species, would be only weakly retained by chemical processes. In order to optimize the trapping capacity of a clay barrier with respect to anionic species, prospective studies are carried out in order to find and evaluate some minerals with specific chemical trapping functions. Among radionuclides, the case of selenium has to be considered because its isotope {sup 79}Se is present in radioactive wastes and has a half life time of 6.5 10{sup 4} years. It is also judicious to find a mineral capable of trapping simultaneously several anionic radio-elements. Copper oxides and sulfides (Cu{sub 2}O, CuO, Cu{sub 2}S, CuS, CuFeS{sub 2} and Cu{sub 5}FeS{sub 4}) are good adsorbents with respect to selenium species (selenite and selenate). These minerals, with their selenium retention properties, could be used also for the decontamination of soils and waters or to process industrial effluents. The sorption mechanisms have been studied in details for copper oxides (Cu{sub 2}O and CuO) with respect to selenite and selenate. Chalcomenite precipitates in acid pH conditions when selenite is added to a Cu{sub 2}O and CuO suspension. Selenate, in contact with cuprite (Cu{sub 2}O) leads also to a selenium-based precipitate in acid pH environment. For higher pH values, selenite and selenate are adsorbed on copper oxides (Cu{sub 2}O and CuO) and lead to internal and external sphere complexes, respectively. In the case of a selenite/cuprite mixture in basic pH environment and at the equilibrium, a chemical reaction occurs between the oxidation product of cuprite, Cu

  11. Interaction of selenite with reduced Fe and/or S species: An XRD and XAS study.

    Science.gov (United States)

    Finck, Nicolas; Dardenne, Kathy

    2016-05-01

    In this study, we investigated the interaction between selenite and either Fe((II))aq or S((-II))aq in solution, and the results were used to investigate the interaction between Se((IV))aq and FeS in suspension. The reaction products were characterized by a combination of methods (SEM, XRD and XAS) and the reaction mechanisms were identified. In a first experiment, Se((IV))aq was reduced to Se((0)) by interaction with Fe((II))aq which was oxidized to Fe((III)), but the reaction was only partial. Subsequently, some Fe((III)) produced akaganeite (β-FeOOH) and the release of proton during that reaction decreased the pH. The pH decrease changed the Se speciation in solution which hindered further Se((IV)) reduction by Fe((II))aq. In a second experiment, Se((IV))aq was quantitatively reduced to Se((0)) by S((-II))aq and the reaction was fast. Two sulfide species were needed to reduce one Se((IV)), and the observed pH increase was due to a proton consumption. For both experiments, experimental results are consistent with expectations based on the oxidation reduction potential of the various species. Upon interaction with FeS, Se((IV))aq was reduced to Se((0)) and minute amounts of pyrite were detected, a consequence of partial mackinawite oxidation at surface sulfur sites. These results are of prime importance with respect to safe deep disposal of nuclear waste which contains the long-lived radionuclide (79)Se. This study shows that after release of (79)Se((IV)) upon nuclear waste matrix corrosion, selenite can be reduced in the near field to low soluble Se((0)) by interaction with Fe((II))aq and/or S((-II))aq species. Because the solubility of Se((0)) species is significantly lower than that of Se((IV)), selenium will become much less (bio)available and its migration out of deep HLW repositories may be drastically hindered. Copyright © 2016. Published by Elsevier B.V.

  12. Favreauite, a new selenite mineral from the El Dragon mine, Bolivia

    International Nuclear Information System (INIS)

    Mills, Stuart J.; Kampf, Anthony R.; Christy, Andrew G.; Housley, Robert M.; Chen, Yu-Sheng; Steele, Ian M.; Thorne, Brent

    2014-01-01

    Favreauite, ideally PbBiCu_6O_4(SeO_3)_4.H_2O, is a new secondary selenite mineral from the El Dragon mine, Antonio Quijarro Province, Potosi Department, Bolivia. The mineral occurs in vughs in a matrix of (Co, Cu)-rich penroseite, dolomite and goethite. Associated minerals are: ahlfeldite, allophane, calcite, chalcomenite, malachite, molybdomenite and an unnamed Al selenite. Favreauite forms tiny green square tbular crystals, flattened on {001}, up to 0.1 mm on edge and 0.01 mm thick, occurring in subparallel and divergent groups. The Mohs hardness of favreauite is estimated as ∼3; it has perfect cleavage on {001}, an irregular fracture and a vitreous lustre. The calculated density based on the empirical formula is 4.851 g cm"-"3. Favreauite is uniaxial (-), with mean refractive index estimated as 1.854 from the Gladstone-Dale relationship. It is pleochroic in shades of green, O 4σF_o] and 0.0356 for all 1432 unique reflections. Favreauite is a close structural relative of nabokoite, KCu_7Te"4"+O_4(SO_4)_5Cl, and atlasovite, KCu_6Fe"3"+BiO_4(SO_4)_5Cl. In all cases, oxygen-centred tetrahedra share edges to form corrugated [Cu_6MO_4] layers (M = Bi or Te) which can be derived from the framework structure of murdochite, Pb"4"+Cu"2"+_6O_8_-_x(Cl,Br)_2_x by selective deletion of atoms. In favreauite, additional OH and H_2O between the layers are weakly bound to Cu, giving it Jahn-Teller distorted 4 + 2 coordination. The Cu-Bi-O layer is braced by SeO_3 pyramids. The Bi"3"+ and interlayer Pb"2"+ form an approximately face-centred cubic array analogous to the Pb"4"+ sites in murdochite. Unlike Bi"3"+, Pb"2"+ is in a site with nonpolar anti 4 point symmetry, which suppresses the stereoactivity of its lone pair.

  13. Selenite -Se(4)- uptake mechanisms in the unicellular green alga Chlamydomonas reinhardtii: bioaccumulation and effects induced on growth and ultrastructure

    International Nuclear Information System (INIS)

    Morlon, H.

    2005-03-01

    Selenium is an essential element, but becomes very toxic at higher concentrations. It occurs in the environment at concentrations ranging from nM to μM and selenium pollution is a worldwide phenomenon. This works aims at improving the knowledge on the interactions between selenite - Se(IV) - and a freshwater phyto-planktonic organism: the unicellular green algae Chlamydomonas reinhardtii. The aim of the performed experiments were: i) to investigate selenite -Se(IV)- uptake mechanisms in C. reinhardtii, using Se 75 as a tracer in short term exposures ( -2 .nM -1 .h -1 . The uptake was proportional to ambient levels in a broad range of intermediate concentrations (from nM to μM). However, fluxes were higher at very low concentrations ( μM), suggesting that a high affinity but rapidly saturated transport mechanism could be used at low concentrations, in parallel with a low affinity mechanism that would only saturate at high concentrations (∼mM). The latter could involve transporters used by sulphate and nitrates, as suggested by the inhibition of selenite uptake by those element. Se(IV) speciation changes with pH did not induce significant effect on bioavailability. On the basis of the relationship between Se concentration and maximal cell density achieved, an EC50 of 80 μM ([64; 98]) was derived. No adaptation mechanism were observed as the same the same toxicity was quantified for Se-pre-exposed algae. Observations by TEM suggested chloroplasts as the first target of selenite cytotoxicity, with effects on the stroma, thylakoids and pyrenoids. At higher concentrations, we could observe an increase in the number and volume of starch grains. For the cell collected at 96 h, electron-dense granules were observed. Energy-dispersive X-ray microanalysis revealed that they contained selenium and were also rich in calcium and phosphorus. Finally, growth inhibition was highly correlated to the bioaccumulation of selenite. The latter was inhibited by increasing

  14. [Effect of glutathione and sodium selenite on the metabolism of arsenic in mice exposed to arsenic through drinking water].

    Science.gov (United States)

    Yu, Xiao-Yun; Zhong, Yuan; Niu, Yu-Hong; Qu, Chun-Qing; Li, Ge-Xin; Lü, Xiu-Qiang; Sun, Gui-Fan; Jin, Ya-Ping

    2008-09-01

    To explore the effect of glutathione (GSH) and sodium selenite on the metabolism of arsenic in the liver, kidney and blood of mice exposed to iAsIII through drinking water. The mice were randomly divided into control, arsenic, GSH and sodium selenite group, respectively. And each group had eight mice and the mice were exposed to 50 mg/L arsenite by drinking water for 4 weeks. Mice were intraperitoneally injected with GSH (600 mg/kg) and sodium selenite (1 mg/kg) for seven days from the beginning of the fourth week. At the end of the fourth week, liver, kidney and blood were sampled to assess the concentrations of inorganic arsenic (iAs), monomethylarsenic acid (MMA), dimethylarsenic acid (DMA) by hydride generation trapping by ultra-hypothermia coupled with atomic absorption spectrometry. The liver DMA (233.76 +/- 60.63 ng/g) concentration in GSH group was significantly higher than the arsenic group (218.36 +/- 42.71 ng/g). The concentration of DMA (88.52 +/- 30.86 ng/g) and total arsenic (TAs) (162.32 +/- 49.45 ng/g) in blood of GSH group was significantly higher than those [(45.32 +/- 12.19 ng/g), (108.51 +/- 18.00 ng/g), respectively] of arsenic groups(q values were 3.06, 6.40, 10.72 respectively, P < 0.05). The primary methylated index (PMI) (0.65 +/- 0.050) and secondary methylated index (SMI) (0.55 +/- 0.050) in liver sample of GSH group were significantly higher than those (0.58 +/- 0.056, 0.44 +/- 0. 093) in arsenic group. In blood samples, the PMI (0.85 +/- 0.066) in GSH group was significantly higher than that (0.54 +/- 0.113) in arsenic group (q values were 3.75, 5.26, 4.21 respectively, P < 0.05). However, no significant difference was identified between sodium selenite and arsenic groups in liver, kidney or blood samples. And no significant difference was detected in kidney samples among all arsenic exposing groups. Exogenous GSH could promote the methylated metabolism of iAsIII, but sodium selenite showed no significant effects.

  15. Selenite resistant rhizobacteria stimulate SeO(3) (2-) phytoextraction by Brassica juncea in bioaugmented water-filtering artificial beds.

    Science.gov (United States)

    Lampis, Silvia; Ferrari, Anita; Cunha-Queda, A Cristina F; Alvarenga, Paula; Di Gregorio, Simona; Vallini, Giovanni

    2009-09-01

    Selenium is a trace metalloid of global environmental concern. The boundary among its essentiality, deficiency, and toxicity is narrow and mainly depends on the chemical forms and concentrations in which this element occurs. Different plant species-including Brassica juncea-have been shown to play a significant role in Se removal from soil as well as water bodies. Furthermore, the interactions between such plants, showing natural capabilities of metal uptake and their rhizospheric microbial communities, might be exploited to increase both Se scavenging and vegetable biomass production in order to improve the whole phytoextraction efficiency. The aim of the present study was to evaluate the capability of selenite removal of B. juncea grown in hydroponic conditions on artificially spiked effluents. To optimize phytoextraction efficiency, interactions between B. juncea and rhizobacteria were designedly elicited. Firstly, B. juncea was grown on water-filtering agriperlite beds in the presence of three different selenite concentrations, namely, 0.2, 1.0, and 2.0 mM. Plant growth was measured after 3 and 6 weeks of incubation in order to establish the selenite concentration at which the best plant biomass production could be obtained. Afterwards, water-filtering agriperlite beds were inoculated either with a selenium-acclimated microbial community deriving from the rhizosphere of B. juncea grown, erstwhile, in a selenite-amended soil or with axenic cultures of two bacterial strains, vicelike Bacillus mycoides SeITE01 and Stenotrophomonas maltophilia SeITE02, previously isolated and described for their high resistance to selenite. These latter were seeded separately or as a dual consortium. Selenite was amended at a final concentration of 1.0 mM. Total Se content in plant tissues (both shoots and roots), plant biomass production, and persistence of bioaugmented microbial inocula during the experimental time were monitored. Moreover, parameters such as bioconcentration

  16. The Protective Effect of Sesamol in the Selenite-induced Experimental Cataract Model

    Directory of Open Access Journals (Sweden)

    Burak Turgut

    2017-12-01

    Full Text Available Objectives: To investigate the potential protective effects of sesamol in an experimental cataract model. Materials and Methods: Twenty-one Spraque Dawley rat pups were randomly assigned into three groups, seven rats in each. All the rats except for those in the control group were injected subcutaneously with a single dose of sodium selenite on postpartum day 9. On days 10-14, rats in the sham group were intraperitoneally administered 50 mg/kg/day saline solution, while rats in the sesamol group were given 50 mg/kg/day sesamol by the same route. Following cataract grading, the lenses and capsules were extracted and the mean levels of reduced glutathione (GSH, malondialdehyde (MDA, total antioxidant status (TAS and total oxidant status (TOS in lens supernatants were biochemically analyzed. Results: The control group did not show any development of cataract. It was found that the mean cataract grade in the sesamol group was significantly lower than that of the sham group (p<0.05. The mean GSH level and TAS in the sesamol group were significantly higher than those of the sham group while the mean TOS and MDA level in the sesamol group were significantly lower than those of the sham group (p<0.05. Conclusion: Our study shows that sesamol reduces TOS and MDA level and increases TAS and GSH level in the lens and inhibits cataract formation.

  17. Application of Sodium Selenite in the Prevention and Treatment of Cancers

    Directory of Open Access Journals (Sweden)

    Marek Kieliszek

    2017-10-01

    Full Text Available Selenium is an essential trace element that occurs in nature, in both inorganic and organic forms. This element participates in numerous biochemical processes, including antioxidant potential, but the mechanism of its anti-cancer action is still not well known. It should be noted that the anti-cancer properties of selenium depends on its chemical form, therapeutic doses, and the tumor type. Higher nutritional doses of selenium can stimulate human immune system. There are several hypotheses concerning the anticancer activity of selenium, including oxidation of sulfhydryl groups in proteins causing their conformational alterations. Conformational changes in proteins have the ability to weaken the activity of enzymes involved in the metabolism of cancer cells. In case of human fibrinogen sodium selenite, but not selenate, it inhibits protein disulfide exchange reactions, thus preventing formation of a hydrophobic polymer termed parafibrin, circulatory accumulation, of which is associated with numerous degenerative diseases. Parafibrin can specifically form a protein coat around tumor cells that is completely resistant to degradation induced with lymphocyte protease. In this way, cancer cells become protected against destruction by the organism’s immune system. Other possible mechanisms of anticancer action of selenium are being still investigated.

  18. Switching to instant black coffee modulates sodium selenite-induced cataract in rats

    Directory of Open Access Journals (Sweden)

    El Okda, E. A.

    2016-04-01

    Full Text Available The influence of daily consumption of some common beverages on the development of cataract in rats was investigated. Total phenol content was determined in the beverages and an oral standardized dose of total phenols from each beverage was given to the treated rats. Weaned male albino rats were used and divided into five groups (n=7. Rats were fed Ain 93G and administered the standardized dose of instant coffee, black tea and hibiscus beverages for 30 days. On day 14 all rats were injected with a single dose of sodium selenite (NaSeO bodyweight, except the control groups NC (negative control, did not receive NaSeO and PC (positive control, was already injected on day 1 of the study. The rats were continued on Ain 93G and the standardized dose for another 16 days. Positive control rats were used. Total phenols were 210, 40, and 44 mg/g dry weight gallic acid equivalent in black coffee, black tea, and hibiscus, respectively. Decreased levels (statistically significant P<0.05 of malondialdehyde, total nitric oxide, Ca-Ae, tumor necrosis factor-α, interleukin-1β, superoxide dismutase, and conversely, increased levels (statistically significant P<0.05 of total protein, reduced glutathione, catalase were found in the lenses of the coffee group compared to PC. There are co-phenol substances in the instant black coffee that promoted coffee to be the most effective beverage.

  19. Synthesis, structure, and photoluminescence properties of an organically-templated uranyl selenite

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dong-Sheng; Kuang, Han-Mao; Chen, Wen-Tong; Luo, Qiu-Yan; Sui, Yan [Institute of Applied Chemistry, School of Chemistry and Chemical Engineering, Jinggangshan University, Ji' an, Jiangxi 343009 (China)

    2015-09-15

    The organically-templated uranyl selenite, (H{sub 2}en)[(UO{sub 2})(SeO{sub 3})(HSeO{sub 3})](NO{sub 3}).0.5H{sub 2}O (1) (en = 1,2-ethylenediamine) was synthesized and characterized by elemental analyses, IR spectroscopy, TG, and single-crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic system, space group Pbca, with a = 13.170(3) Aa, b = 11.055(2) Aa, c = 18.009(4) Aa, V = 2621.8(9) Aa{sup 3}, M = 1316.19, Z = 4, D{sub cal} = 3.334 g.cm{sup -3}, μ(Mo-K{sub α}) = 17.998 mm{sup -1}, GOF = 1.059, R{sub 1} = 0.0263, wR{sub 2} = 0.0532 [I>2σ(I)]. The X-ray diffraction analysis reveals that compound 1 has a three-dimensional (3D) supramolecular structure. It contains negatively charged [UO{sub 2}(HSeO{sub 3})(SeO{sub 3})]{sup -} inorganic anion layers and is balanced by [H{sub 2}en]{sup 2+} cations and NO{sub 3}{sup -} anions located in the interlayers. Furthermore, the photoluminescence properties of 1 were investigated. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Tocopherol and selenite modulate the transplacental effects induced by sodium arsenite in hamsters.

    Science.gov (United States)

    Sampayo-Reyes, Adriana; Taméz-Guerra, Reyes S; Bermúdez de León, Mario; Vargas-Villarreal, Javier; Lozano-Garza, Héctor Gerardo; Rodríguez-Padilla, Cristina; Cortés, Constanza; Marcos, Ricard; Hernández, Alba

    2017-12-01

    Human studies suggest that in utero exposure to arsenic results in adverse pregnancy outcomes. The use of dietary supplements, such as sodium selenite (SS) or α-tocopherol succinate (α-TOS), is a reasonable approach to ameliorate such health effects. Sodium arsenite at 100ppm was administered via drinking water to female hamsters from gestational days 1 or 8 to the time of delivery. Viable fetuses, fetal resorptions and non-viable fetuses were recorded during and after pregnancy and total arsenic and its metabolites were characterized in pregnant animals, placentas and fetuses. Arsenic was found to accumulate in the placenta and fetus, increasing fetal mortality, non-viable fetuses and resorptions. Co-administration of SS and α-TOS significantly reduced the observed teratogenic effects. SS influenced arsenic biotransformation by reducing the MMA/InAs index and increasing the DMA/MMA, whereas α-TOS more likely exerts its protective effect through its potent antioxidant activity. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Abiotic pyrite reactivity versus nitrate, selenate and selenite using chemical and electrochemical methods

    International Nuclear Information System (INIS)

    Ignatiadis, I.; Betelu, S.; Gaucher, E.; Tournassat, C.; Chainet, F.

    2010-01-01

    Document available in extended abstract form only. This work is part of ReCosy European project (www.recosy.eu), whose main objectives are the sound understanding of redox phenomena controlling the long-term release/retention of radionuclides in nuclear waste disposal and providing tools to apply the results to performance assessment/safety case. Redox is one of the main factor affecting speciation and mobility of redox-sensitive radionuclides. Thus, it is of a great importance to investigate the redox reactivity of the host radioactive waste formations, particularly when exposed to redox perturbations. Callovo-Oxfordian formation (COx), a clay rock known as an anoxic and reducing system, was selected in France as the most suitable location to store nuclear waste. Iron (II) sulfide, mostly constituted of pyrite (FeS 2 ), iron (II) carbonate, iron(II) bearing clays and organic matter are considered to account almost entirely for the total reducing capacity of the rock. We report here the redox reactivity of pyrite upon exposure to nitrate (N(V)), selenate (Se(VI)) and selenite (Se(IV)) that possibly occur in the nuclear storage. Both, chemical and electrochemical kinetic approaches were simultaneously conducted such as to (i) determine the kinetics parameters of the reactions and (ii) understand the kinetic mechanisms. In order to reach similar conditions that are encountered in the storage system, all experiments were realised in NaCl 0.1 M, near neutral pH solutions, and an abiotic glove box (O 2 less than 10 -8 M). Chemical approach has consisted to set in contact pyrite in grains with solutions containing respectively nitrate, selenate and selenite. Reactants and products chemical analyses, conducted at different contact times, allowed us to assess the kinetics of oxidant reduction. Electrochemical approach has consisted in the continuous or semi-continuous analysis of large surface pyrite electrodes immersed in solutions with or without oxidant (nitrate

  2. Investigating different mechanisms for biogenic selenite transformations: Geobacter sulfurreducens, Shewanella oneidensis and Veillonella atypica

    Science.gov (United States)

    Pearce, C.I.; Pattrick, R.A.D.; Law, N.; Charnock, J.M.; Coker, V.S.; Fellowes, J.W.; Oremland, R.S.; Lloyd, J.R.

    2009-01-01

    The metal-reducing bacteria Geobacter sulfurreducens, Shewanella oneidensis and Veillonella atypica, use different mechanisms to transform toxic, bioavailable sodium selenite to less toxic, non-mobile elemental selenium and then to selenide in anaerobic environments, offering the potential for in situ and ex situ bioremediation of contaminated soils, sediments, industrial effluents, and agricultural drainage waters. The products of these reductive transformations depend on both the organism involved and the reduction conditions employed, in terms of electron donor and exogenous extracellular redox mediator. The intermediary phase involves the precipitation of elemental selenium nanospheres and the potential role of proteins in the formation of these structures is discussed. The bionanomineral phases produced during these transformations, including both elemental selenium nanospheres and metal selenide nanoparticles, have catalytic, semiconducting and light-emitting properties, which may have unique applications in the realm of nanophotonics. This research offers the potential to combine remediation of contaminants with the development of environmentally friendly manufacturing pathways for novel bionanominerals. ?? 2009 Taylor & Francis.

  3. Synthesis, vibrational and quantum chemical investigations of hydrogen bonded complex betaine dihydrogen selenite

    Science.gov (United States)

    Arjunan, V.; Marchewka, Mariusz K.; Kalaivani, M.

    2012-10-01

    The molecular complex of betaine with selenious acid namely, betaine dihydrogen selenite (C5H13NO5Se, BDHSe) was synthesised by the reaction of betaine and SeO2 in a 1:1:1 solution of isopropanol, methanol and water. Crystals were grown from this solution by cooling to 253 K for few days. The complex was formed without accompanying proton transfer from selenious acid molecule to betaine. The complete vibrational assignments and analysis of BDHSe have been performed by FTIR, FT-Raman and far-infrared spectral studies. More support on the experimental findings was added from the quantum chemical studies performed with DFT (B3LYP) method using 6-311++G∗∗, 6-31G∗∗, cc-pVDZ and 3-21G basis sets. The structural parameters, energies, thermodynamic parameters and the NBO charges of BDHSe were determined by the DFT method. The 1H and 13C isotropic chemical shifts (δ ppm) of BDHSe with respect to TMS were also calculated using the gauge independent atomic orbital (GIAO) method and compared with the experimental data. SHG experiment was carried out using Kurtz-Perry powder technique. The efficiency of second harmonic generation for BDHSe was estimated relatively to KDP: deff = 0.97 deff (KDP).

  4. Radioprotective effect of sodium selenite on bone repair in the tibia of ovariectomized rats

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Deborah Queiroz de; Neves, Ellen Gaby; Boscolo, Frab Norberto; Almeida, Solange Maria de [University of Campinas (UNICAMP), Piracicaba, SP (Brazil). Piracicaba Dental School. Department of Oral Diagnosis. Oral Radiology Area; Ramos-Perez, Flavia Maria de Moraes [Federal University of Pernambuco, Recife, PE (Brazil). Department of Clinical and Preventive Dentistry; Marques, Marcelo Rocha [University of Campinas (UNICAMP), Piracicaba, SP (Brazil). Piracicaba Dental School. Division of Histology. Department of Morphology

    2012-07-01

    This study evaluated protection by selenium (Se) in the bone repair process in ovariectomized rats after irradiation. For such purpose, 80 ovariectomized female Wistar rats were randomly divided into 4 experimental groups: ovariectomized (Ov), Ov/Se, Ov/irradiated (Irr) and Ov/ Se/Irr. A bone defect was created on the tibia of all animals 40 days after ovariectomy. Two days after surgery, only the Ov/Se and Ov/Se/Irr rats received 0.8 mg Se/kg. Three days after surgery, only the Ov/Irr and Ov/Se/Irr rats received 10 Gy of x-rays on the lower limb region. The animals were euthanized at 7, 14, 21 and 28 days after surgery to assess the repair process, which was evaluated by analysis of trabecular bone number (Masson Trichrome) and birefringence analysis (Picrosirius). It was possible to observe a delay in the bone repair process in the ovariectomized/irradiated group and similarity between the ovariectomized, Ov/Se and Ov/Se/Irr groups. In conclusion, sodium selenite exerted a radioprotective effect in the bone repair of tibia of ovariectomized rats without toxicity. (author)

  5. Effects of lead nitrate and sodium selenite on DNA damage and oxidative stress in diabetic and non-diabetic rat erythrocytes and leucocytes.

    Science.gov (United States)

    Baş, Hatice; Kalender, Yusuf; Pandir, Dilek; Kalender, Suna

    2015-05-01

    The adverse effects of lead nitrate (LN) and the preventive role of sodium selenite were investigated in diabetic and non-diabetic rat blood by measuring trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP), malondialdehyde (MDA) levels and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) also by evaluating DNA damage with comet assay. LN increased the levels of MDA, tail DNA%, mean tail length and tail moment, decreased the enzymes activities, FRAP and TEAC values. In sodium selenite+LN group, we observed the protective effect of sodium selenite on examining parameters. Diabetes caused alterations on these parameters, too. We found that sodium selenite did not protect against diabetes caused damages. As a result, LN caused toxic effects on blood cells and sodium selenite alleviated this toxicity but it did not show preventive effect against diabetes. Also, LN caused more harmfull effects in diabetic groups than non-diabetic groups. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Mechanism(s of Toxic Action of Zn2+ and Selenite: A Study on AS-30D Hepatoma Cells and Isolated Mitochondria

    Directory of Open Access Journals (Sweden)

    Elena A. Belyaeva

    2011-01-01

    Full Text Available Mitochondria of AS-30D rat ascites hepatoma cells are found to be the main target for Zn2+ and sodium selenite (Na2SeO3. High [mu]M concentrations of Zn2+ or selenite were strongly cytotoxic, killing the AS-30D cells by both apoptotic and necrotic ways. Both Zn2+ and selenite produced strong changes in intracellular generation of reactive oxygen species (ROS and the mitochondrial dysfunction via the mitochondrial electron transport chain (mtETC disturbance, the membrane potential dissipation, and the mitochondrial permeability transition pore opening. The significant distinctions in toxic action of Zn2+ and selenite on AS-30D cells were found. Selenite induced a much higher intracellular ROS level (the early event compared to Zn2+ but a lower membrane potential loss and a lower decrease of the uncoupled respiration rate of the cells, whereas the mtETC disturbance was the early and critical event in the mechanism of Zn2+ cytotoxicity. Sequences of events manifested in the mitochondrial dysfunction produced by the metal/metalloid under test are compared with those obtained earlier for Cd2+, Hg2+, and Cu2+ on the same model system.

  7. Favreauite, a new selenite mineral from the El Dragon mine, Bolivia

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Stuart J. [Museum Victoria, Melbourne, VIC (Australia). Geosciences; Kampf, Anthony R. [Natural History Museum of Los Angeles, CA (United States). Mineral Sciences Dept.; Christy, Andrew G. [Australian National Univ., Canberra, ACT (Australia). Centre for Advanced Microscopy; Housley, Robert M. [California Institute of Technology, Pasadena, CA (United States). Div. of Geological and Planetary Sciences; Chen, Yu-Sheng [Chicago Univ., IL (United States). Center for Advanced Radiation Sources; Steele, Ian M. [Chicago Univ., IL (United States). Center for Advanced Radiation Sources; Thorne, Brent

    2014-07-01

    Favreauite, ideally PbBiCu{sub 6}O{sub 4}(SeO{sub 3}){sub 4}.H{sub 2}O, is a new secondary selenite mineral from the El Dragon mine, Antonio Quijarro Province, Potosi Department, Bolivia. The mineral occurs in vughs in a matrix of (Co, Cu)-rich penroseite, dolomite and goethite. Associated minerals are: ahlfeldite, allophane, calcite, chalcomenite, malachite, molybdomenite and an unnamed Al selenite. Favreauite forms tiny green square tbular crystals, flattened on {001}, up to 0.1 mm on edge and 0.01 mm thick, occurring in subparallel and divergent groups. The Mohs hardness of favreauite is estimated as ∼3; it has perfect cleavage on {001}, an irregular fracture and a vitreous lustre. The calculated density based on the empirical formula is 4.851 g cm{sup -3}. Favreauite is uniaxial (-), with mean refractive index estimated as 1.854 from the Gladstone-Dale relationship. It is pleochroic in shades of green, O < E. Electron microprobe analyses gave the empirical formula Pb{sub 0.95}Ca{sub 0.17}Bi{sub 0.90}Cu{sub 5.81}Se{sub 4.10}O{sub 16}(OH) . 1H{sub 2}O, based on 18 O pfu. The Raman spectrum shows strong SeO{sub 3} bands at 847 cm{sup -1} (ν{sub 1}), 764 and 795 cm{sup -1} (ν{sub 3}), 493 and 542 cm{sup -1} (ν{sub 2}), and 320 and 392 cm{sup -1} (ν{sub 4}). Favreauite is tetragonal, space group P4/n, with the unit-cell parameters: a = 9.860(4) Aa, c = 9.700(5) Aa, V = 943.0(9) Aa{sup 3} and Z = 2. The eight strongest lines in the X-ray powder diffraction pattern are [d{sub obs}/Aa (I) (hkl)]: 5.67(100)(111), 3.470(76)(220,202), 3.190(35)(003), 2.961(40)(311,113), 2.709(33)(302,203), 2.632(34)(231,312), 2.247(36)(331,133), and 1.6652(33)(305,513,531). The crystal structure was refined to R{sub 1} = 0.0329 for 1354 observed reflections [F{sub o} > 4σF{sub o}] and 0.0356 for all 1432 unique reflections. Favreauite is a close structural relative of nabokoite, KCu{sub 7}Te{sup 4+}O{sub 4}(SO{sub 4}){sub 5}Cl, and atlasovite, KCu{sub 6}Fe{sup 3+}BiO{sub 4}(SO

  8. Field study of time-dependent selenium partitioning in soils using isotopically enriched stable selenite tracer

    International Nuclear Information System (INIS)

    Di Tullo, Pamela; Pannier, Florence; Thiry, Yves; Le Hécho, Isabelle; Bueno, Maïté

    2016-01-01

    A better understanding of selenium fate in soils at both short and long time scales is mandatory to consolidate risk assessment models relevant for managing both contamination and soil fertilization issues. The purpose of this study was thus to investigate Se retention processes and their kinetics by monitoring time-dependent distribution/speciation changes of both ambient and freshly added Se, in the form of stable enriched selenite-77, over a 2-years field experiment. This study clearly illustrates the complex reactivity of selenium in soil considering three methodologically defined fractions (i.e. soluble, exchangeable, organic). Time-dependent redistribution of Se-77 within solid-phases having different reactivity could be described as a combination of chemical and diffusion controlled processes leading to its stronger retention. Experimental data and their kinetic modeling evidenced that transfer towards less labile bearing phases are controlled by slow processes limiting the overall sorption of Se in soils. These results were used to estimate time needed for "7"7Se to reach the distribution of naturally present selenium which may extend up to several decades. Ambient Se speciation accounted for 60% to 100% of unidentified species as function of soil type whereas "7"7Se(IV) remained the more abundant species after 2-years field experiment. Modeling Se in the long-term without taking account these slow sorption kinetics would thus result in underestimation of Se retention. When using models based on K_d distribution coefficient, they should be at least reliant on ambient Se which is supposed to be at equilibrium.

  9. Field study of time-dependent selenium partitioning in soils using isotopically enriched stable selenite tracer

    Energy Technology Data Exchange (ETDEWEB)

    Di Tullo, Pamela, E-mail: pamela.ditullo@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l' Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France); Andra, Research and Development Division, Parc de la Croix Blanche, 1-7 rue Jean Monnet, 92298 Châtenay-Malabry Cedex (France); Pannier, Florence, E-mail: florence.pannier@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l' Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France); Thiry, Yves, E-mail: yves.thiry@andra.fr [Andra, Research and Development Division, Parc de la Croix Blanche, 1-7 rue Jean Monnet, 92298 Châtenay-Malabry Cedex (France); Le Hécho, Isabelle, E-mail: isabelle.lehecho@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l' Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France); Bueno, Maïté, E-mail: maite.bueno@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l' Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 9 (France)

    2016-08-15

    A better understanding of selenium fate in soils at both short and long time scales is mandatory to consolidate risk assessment models relevant for managing both contamination and soil fertilization issues. The purpose of this study was thus to investigate Se retention processes and their kinetics by monitoring time-dependent distribution/speciation changes of both ambient and freshly added Se, in the form of stable enriched selenite-77, over a 2-years field experiment. This study clearly illustrates the complex reactivity of selenium in soil considering three methodologically defined fractions (i.e. soluble, exchangeable, organic). Time-dependent redistribution of Se-77 within solid-phases having different reactivity could be described as a combination of chemical and diffusion controlled processes leading to its stronger retention. Experimental data and their kinetic modeling evidenced that transfer towards less labile bearing phases are controlled by slow processes limiting the overall sorption of Se in soils. These results were used to estimate time needed for {sup 77}Se to reach the distribution of naturally present selenium which may extend up to several decades. Ambient Se speciation accounted for 60% to 100% of unidentified species as function of soil type whereas {sup 77}Se(IV) remained the more abundant species after 2-years field experiment. Modeling Se in the long-term without taking account these slow sorption kinetics would thus result in underestimation of Se retention. When using models based on K{sub d} distribution coefficient, they should be at least reliant on ambient Se which is supposed to be at equilibrium.

  10. Tissue concentration-time profile of selenium after sodium selenite administration to rats

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, Megumi; Natsuhori, Masahiro; Ito, Nobuhiko [Department of Veterinary Radiology and Radiation Biology, Kitasato University School of Veterinary Medicine, Towada, Aomori (Japan); Sera, Koichiro [Cyclotron Research Center, Iwate Medical University, Takizuka, Iwate (Japan); Futatsugawa, Shoji [Nishina Memorial Cyclotron Center (NMCC), Takizuka, Iwate (Japan)

    1999-07-01

    Selenium (Se) concentration-time profiles in plasma and organs including liver, kidney, heart, lung, spleen and brain of rats (Jcl Wister, 9 wks old, n=32) were investigated after a single intravenous (iv) / oral (po) administration of sodium selenite (dose is equivalent to 2 mg/kg b.w. of Se). The Se concentration was determined by PIXE analysis. Among the investigated biological samples, Se concentration was the highest in the kidney or liver, followed by the heart, lung or spleen, then plasma, and the brain. Se concentrations in these organs were 0.5 to 5 times of plasma Se. The distribution profiles of Se in the organs were dependent on the route of administration. Furthermore, their profiles appeared almost parallel to the plasma Se-concentration in a logarithmic scale. Compared to the Se concentration-time profiles in plasma and organs by the route of administration, po group showed about 1/4-1/2 of the Se concentration in iv group except for kidney. Kidney kept relatively higher concentration of Se, which was similar in the both groups. This may explain our recently published data that urinary excretion was similar in the both groups. The relative oral bioavailability of plasma and each organ was calculated by the ratio of area under the concentration-time curve after oral administration (AUCpo) to AUCiv. Each organ appeared to have their own bioavailability (i.e., liver 39%, kidney 97%, heart 37%, lung 18%, spleen 10%, and brain 72%), where plasma was 46%. These results highly suggested that different Se distribution in organs by the different route of administration was due to the different metabolic profile. (author)

  11. PIGMENT CONTENT OF Chlorella vulgaris BEIJ. UNDER INFLUENCE OF THE SODIUM SELENITE AND METALS IONS

    Directory of Open Access Journals (Sweden)

    O. I.

    2016-02-01

    Full Text Available The aim of the research was to determine the conditions obtaining in the aquaculture of Chlorella vulgaris Beij. algosubstantion enriched with selenium and bioactive metals. For this purpose, the content of seaweed pigments studied by the action of sodium selenite in a concentration based on Se4+: 0.5, 5.0, 10.0 and 20.0 mg / dm3 for 1, 3 and 7 days and while exposed 10.0 mg Se4 +/dm3 and Zn2+, Mn2 +, Co2 +, Cu2 +, Fe3 + in concentrations of 5.0 mg/dm 3, 0.25, 0.002, 0.008 and 0.05 mg/dm3, respectively, within 7 days of culturing. The content of pigments was determined spectrophotometrically, the cellular walls were given off in the percoll gradient and investigated microscopically. The pigments content in Ch. vulgaris increase by 1,5–2,5 times in comparison with control sample under the influence of 10 mg Se(IV/dm3 with and without metal ions. In the same condition a ratio of chlorophylls a/b increased, that accompanied by the formation in cells of the second cell wall as the sign of successful adaptation process in the Chlorella cells under the influence of these factors. Thus, the cultivation of chlorella, enriched with selenium and bioactive metals, is possible within 7 days under the influence of 10 mg Se (IV/dm3 and mentioned concentration of these metal ions.

  12. Syntheses and structures of three f-element selenite/hydroselenite compounds

    International Nuclear Information System (INIS)

    Burns, Wendy L.; Ibers, James A.

    2009-01-01

    The selenite/hydroselenite compounds Ce(SeO 3 )(HSeO 3 ), Tb(SeO 3 )(HSeO 3 ).2H 2 O, and Cs[U(SeO 3 )(HSeO 3 )].3H 2 O were synthesized by hydrothermal means at 453 K from the reaction of CeO 2 or Tb 4 O 7 or UO 2 with SeO 2 and CsCl (as a mineralizer). Ce(SeO 3 )(HSeO 3 ) crystallizes in the non-centrosymmetric orthorhombic space group Pca2 1 . The structure comprises a two-dimensional network of interconnected CeO 10 bicapped distorted square antiprisms and SeO 3 trigonal pyramids. Tb(SeO 3 )(HSeO 3 ).2H 2 O crystallizes in the non-centrosymmetric orthorhombic space group P2 1 2 1 2 1 . The structure features a two-dimensional layer of interconnected TbO 8 distorted square antiprisms and SeO 3 trigonal pyramids. Cs[U(SeO 3 )(HSeO 3 )].3H 2 O crystallizes in the centrosymmetric monoclinic space group P2 1 /n. The structure consists of two-dimensional layers of interconnected UO 7 pentagonal bipyramids and SeO 3 trigonal pyramids. The layers in all three structures are held together by hydrogen-bonding networks. - Graphical abstract: Structure of Ce[U(SeO 3 )(HSeO 3 )].3H 2 O (Cs, purple; U, black; Se, blue; O, red; O w , green; H, gray).

  13. Tissue concentration-time profile of selenium after sodium selenite administration to rats

    International Nuclear Information System (INIS)

    Kaneko, Megumi; Natsuhori, Masahiro; Ito, Nobuhiko; Sera, Koichiro; Futatsugawa, Shoji

    1999-01-01

    Selenium (Se) concentration-time profiles in plasma and organs including liver, kidney, heart, lung, spleen and brain of rats (Jcl Wister, 9 wks old, n=32) were investigated after a single intravenous (iv) / oral (po) administration of sodium selenite (dose is equivalent to 2 mg/kg b.w. of Se). The Se concentration was determined by PIXE analysis. Among the investigated biological samples, Se concentration was the highest in the kidney or liver, followed by the heart, lung or spleen, then plasma, and the brain. Se concentrations in these organs were 0.5 to 5 times of plasma Se. The distribution profiles of Se in the organs were dependent on the route of administration. Furthermore, their profiles appeared almost parallel to the plasma Se-concentration in a logarithmic scale. Compared to the Se concentration-time profiles in plasma and organs by the route of administration, po group showed about 1/4-1/2 of the Se concentration in iv group except for kidney. Kidney kept relatively higher concentration of Se, which was similar in the both groups. This may explain our recently published data that urinary excretion was similar in the both groups. The relative oral bioavailability of plasma and each organ was calculated by the ratio of area under the concentration-time curve after oral administration (AUCpo) to AUCiv. Each organ appeared to have their own bioavailability (i.e., liver 39%, kidney 97%, heart 37%, lung 18%, spleen 10%, and brain 72%), where plasma was 46%. These results highly suggested that different Se distribution in organs by the different route of administration was due to the different metabolic profile. (author)

  14. Effects of 14-day oral low dose selenium nanoparticles and selenite in rat—as determined by metabolite pattern determination

    DEFF Research Database (Denmark)

    Hadrup, Niels; Löschner, Katrin; Skov, Kasper

    2016-01-01

    Selenium (Se) is an essential element with a small difference between physiological and toxic doses. To provide more effective and safe Se dosing regimens, as compared to dosing with ionic selenium, nanoparticle formulations have been developed. However, due to the nano-formulation, unexpected...... toxic effects may occur. We used metabolite pattern determination in urine to investigate biological and/or toxic effects in rats administered nanoparticles and for comparison included ionic selenium at an equimolar dose in the form of sodium selenite. Low doses of 10 and 100 fold the recommended human...

  15. Selenite modulates the level of phenolics and nutrient element to alleviate the toxicity of arsenite in rice (Oryza sativa L.).

    Science.gov (United States)

    Chauhan, Reshu; Awasthi, Surabhi; Tripathi, Preeti; Mishra, Seema; Dwivedi, Sanjay; Niranjan, Abhishek; Mallick, Shekhar; Tripathi, Pratibha; Pande, Veena; Tripathi, Rudra Deo

    2017-04-01

    Arsenic (As) contamination of paddy rice is a serious threat all over the world particularly in South East Asia. Selenium (Se) plays important role in protection of plants against various abiotic stresses including heavy metals. Moreover, arsenite (AsIII) and selenite (SeIV) can be biologically antagonistic due to similar electronic configuration and sharing the common transporter for their uptake in plant. In the present study, the response of oxidative stress, phenolic compounds and nutrient elements was analyzed to investigate Se mediated As tolerance in rice seedlings during AsIII and SeIV exposure in hydroponics. Selenite (25µM) significantly decreased As accumulation in plant than As (25µM) alone treated plants. Level of oxidative stress related parameters viz., reactive oxygen species (ROS), lipid peroxidation, electrical conductivity, nitric oxide and pro-oxidant enzyme (NADPH oxidase), were in the order of As>As+Se>control>Se. Selenium ameliorated As phytotoxicity by increased level of phenolic compounds particularly gallic acid, protocatechuic acid, ferulic acid and rutin and thiol metabolism related enzymes viz., serine acetyl transferase (SAT) and cysteine synthase (CS). Selenium supplementation enhanced the uptake of nutrient elements viz., Fe, Mn, Co, Cu, Zn, Mo, and improved plant growth. The results concluded that Se addition in As contaminated environment might be an important strategy to reduce As uptake and associated phytotoxicity in rice plant by modulation of phenolic compounds and increased uptake of nutrient elements. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. A comparative study of ion exchange properties of antimony (III) tungstoselenite with those of antimony (III) tungstate and antimony (III) selenite

    International Nuclear Information System (INIS)

    Janardanan, C.; Nair, S.M.K.

    1996-01-01

    A new inorganic ion exchanger, antimony (III) tungstoselenite, has been prepared and characterised. Its exchange capacity and distribution coefficients for various metal ions and the effects of temperature and electrolyte concentrations on ion exchange capacity have been compared with antimony (III) tungstate and antimony (III) selenite. Six binary separations using the exchanger have been carried out. (author). 7 refs., 1 tab

  17. Effect of dietary sodium selenite, Se-enriched yeast and Se-enriched Chlorella on egg Se concentration, physical parameters of eggs and laying hen production

    Czech Academy of Sciences Publication Activity Database

    Skřivan, M.; Šimáně, J.; Dlouhá, G.; Doucha, Jiří

    2006-01-01

    Roč. 51, č. 4 (2006), s. 163-167 ISSN 1212-1819 Institutional research plan: CEZ:AV0Z50200510 Keywords : sodium selenite * se-yeast * se-chlorella Subject RIV: EE - Microbiology, Virology Impact factor: 0.421, year: 2006

  18. Separation and identification of selenotrisulfides in epithelial cell homogenates by LC-ICP-MS and LC-ESI-MS after incubation with selenite

    DEFF Research Database (Denmark)

    Gabel-Jensen, Charlotte; Gammelgaard, Bente; Bendahl, Lars

    2006-01-01

    . The presence of Cys-Se-SG and GS-Se-SG was verified by LC-ESI-MS. Selenotrisulfides were synthesized by reaction of L-cysteine and L-glutathione with sodium selenite. The reaction mixture contained three main products: selenodicysteine (Cys-Se-Cys), selenocysteine glutathione (Cys...

  19. Sodium selenite supplementation during pregnancy and lactation promotes anxiolysis and improves mnemonic performance in wistar rats' offspring.

    Science.gov (United States)

    Laureano-Melo, Roberto; Império, Güínever Eustáquio do; da Silva-Almeida, Claudio; Kluck, George Eduardo Gabriel; Cruz Seara, Fernando de Azevedo; da Rocha, Fábio Fagundes; da Silveira, Anderson Luiz Bezerra; Reis, Luís Carlos; Ortiga-Carvalho, Tania Maria; da Silva Côrtes, Wellington

    2015-11-01

    Selenium is a micronutrient which is part of selenoprotein molecules and participates in a vast number of physiological roles and, among them,we have fetal and neonatal development. Therefore, the aimof this studywas to evaluate possible behavioral changes in offspring of female rats supplemented during pregnancy and lactation with sodium selenite. To address that, we treated two groups of female rats by saline or sodium selenite at a dose of 1mg/kg through oral route and performed neurochemical and behavioral tests. In the offspring, the thyroid profile and hippocampal neurochemistrywere evaluated. Behavioral testswere performed in pups both during childhood and adulthood. We found out that selenium (Se) supplementation increased serum levels of triiodothyronine (25%, p b 0.001) and thyroxine (18%, p b 0.05) and promoted a tryptophan hydroxylase 2 (TPH 2) expression decrease (17%, p b 0.01) and tyrosine hydroxylase (TH) expression increase (202%, p b 0.01) in the hippocampus. The cholinesterase activity was decreased (28%, p b 0.01) in Se supplemented rats, suggesting a neurochemical modulation in the hippocampal activity. During childhood, the Sesupplemented offspring had a reduction in anxiety-like behavior both in elevated plus maze test and in light–dark box test. In adulthood, Se-treated pups had an increase in the locomotor activity (36%, p b 0.05) and in rearing episodes (77%, p b 0.001) in the open field test, while in the elevated plus maze test they also exhibited an increase in the time spent in the open arms (243%, p b 0.01). For the object recognition test, Se-treated offspring showed increase in the absolute (230.16%, p b 0.05) and relative index discrimination (234%, p b 0.05). These results demonstrate that maternal supplementation by sodium selenite promoted psychobiological changes both during childhood and adulthood. Therefore, the behavioral profile observed possibly can be explained by neurochemical changes induced by thyroid hormones during

  20. Selenite -Se(4)- uptake mechanisms in the unicellular green alga Chlamydomonas reinhardtii: bioaccumulation and effects induced on growth and ultrastructure; Mecanismes de prise en charge du selenite - Se(4)-chez l'algue verte unicellulaire Chlamydomonas reinhardtii. Bioaccumulation et effets induits sur la croissance et l'ultrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Morlon, H

    2005-03-15

    Selenium is an essential element, but becomes very toxic at higher concentrations. It occurs in the environment at concentrations ranging from nM to {mu}M and selenium pollution is a worldwide phenomenon. This works aims at improving the knowledge on the interactions between selenite - Se(IV) - and a freshwater phyto-planktonic organism: the unicellular green algae Chlamydomonas reinhardtii. The aim of the performed experiments were: i) to investigate selenite -Se(IV)- uptake mechanisms in C. reinhardtii, using Se{sup 75} as a tracer in short term exposures (<1 h); ii) to assess selenite toxicity as measured with growth impairment and ultrastructural damage (with EDAX-TEM analysis), using long term exposures (96 h) to stable selenite; iii) to evaluate the bioaccumulation capacity of selenite and its potential links with toxicity. Short-term experiments revealed a negligible adsorption and a time-dependent linear absorption with an estimated absorbed flux of about 0.2 nmol.m{sup -2}.nM{sup -1}.h{sup -1}. The uptake was proportional to ambient levels in a broad range of intermediate concentrations (from nM to {mu}M). However, fluxes were higher at very low concentrations (< nM), and decrease with increasing high concentrations ( > {mu}M), suggesting that a high affinity but rapidly saturated transport mechanism could be used at low concentrations, in parallel with a low affinity mechanism that would only saturate at high concentrations ({approx}mM). The latter could involve transporters used by sulphate and nitrates, as suggested by the inhibition of selenite uptake by those element. Se(IV) speciation changes with pH did not induce significant effect on bioavailability. On the basis of the relationship between Se concentration and maximal cell density achieved, an EC50 of 80 {mu}M ([64; 98]) was derived. No adaptation mechanism were observed as the same the same toxicity was quantified for Se-pre-exposed algae. Observations by TEM suggested chloroplasts as the first

  1. Pigments content in Сhlorella vulgaris under the influence of the sodium selenite and the ions of metals

    Directory of Open Access Journals (Sweden)

    O. I. Bodnar

    2016-01-01

    Full Text Available We investigated the content of pigments in Chlorella vulgaris Beij. (Chlorophyta under the influence of sodium selenite in concentrations based on Se4+ 0.5, 5.0, 10.0 and 20.0 mg/dm3 during one, three and seven days and under the influence of the simultaneous action of selenite in concentrations 10 mg Se4+/dm3 and ions of Zn2+, Mn2+, Co2+,Cu2+, Fe3+ in concentrations 5.00, 0.25, 0.05, 0.008 and 0.002 mg/dm3over seven days. This research was carried out to establish the conditions for obtaining algal lipidis substance enriched with selenium and biogenic metals in the aquaculture. The content of pigments was determined spectrophotometrically, the cellular walls were separatedby centrifuge in the percoll gradient and investigated microscopically. The pigments content in the Ch. vulgaris increased by 1.5–2.5 times in comparison with the control sample under the influence of 10 mg Se4+/dm3 with and without metal ions, in all variants of experimental influence due to binding of SeО32– with proteins and lipids. We found that selenium was included in all lipid fractions (triacylglycerols, dyacylglycerols, phospholipids, nonetherified fatty acids; the maximum amount of selenium-containing lipids wasrecorded in chloroplasts. The increase in the contents of carotenoids caused by the actions of experimental factors played an exceptional role in the mechanism of antioxidant protection that prevents destruction of chlorophyll and, accordingly, increases its amount in cells. Changes in the functioning of the photosynthetic apparatus of Ch. vulgaris affect the whole complex of metabolic transformation. Thus, the successful cultivation of chlorella, enriched with selenium and biogenic metals, is possible within seven days under the influence of 10 mg Se4+/dm3 and the above-mentioned concentration of metal ions.

  2. Interaction of Coenzyme Q10 with Liposomes and its Impact on Suppression of Selenite – Induced Experimental Cataract

    Directory of Open Access Journals (Sweden)

    Medhat Wahba Shafaa

    2018-03-01

    Full Text Available Purpose: To stress the influence of Coenzyme Q10 (CoQ10 on the structural properties of liposomes as model membranes and to investigate the possible role of CoQ10 or CoQ10 doped in liposomes when topically instilled as eye drops, in preventing cataract. Methods: The molecular interaction between liposomes and Coenzyme Q10 was examined using differential scanning calorimetry (DSC and Fourier transform infrared spectroscopy (FTIR. Rat pups were randomly divided into six groups comprising 15 pups. Group (1, control group. Group (2, untreated model of cataract, received a single subcutaneous injection of sodium selenite. Instillation of pure CoQ10 (Group 3, CoQ10 encapsulated into neutral (Group 4, positive (Group 5 and negative (Group 6 Dipalmitoyl phosphatidylcholine (DPPC liposomes on the opacification of lenses in rat pups after sodium selenite injection was topically received. Results: The incorporated CoQ10 is probably associated with lipid bilayers where it interacts to a large extent and perturbs them. This results in strong broadening and shift to lower temperature (94°C of the major characteristic endothermic peak of pure DPPC at 105°C. FTIR showed that the incorporation of CoQ10 into DPPC induces a conformational change in the polar region of DPPC. Ophthalmological and Biochemical studies revealed that CoQ10 alone followed by negatively charged liposomes doped with CoQ10 are more effective in reducing the progress of cataract as well as improving the lens soluble proteins levels and total antioxidant capacity. Conclusion: The interactions of CoQ10 with membrane systems may contribute to a better understanding of CoQ10 physiological properties and the development of therapeutically advanced systems.

  3. Topologically and geometrically flexible structural units in seven new organically templated uranyl selenates and selenite-selenates

    Science.gov (United States)

    Gurzhiy, Vladislav V.; Kovrugin, Vadim M.; Tyumentseva, Olga S.; Mikhaylenko, Pavel A.; Krivovichev, Sergey V.; Tananaev, Ivan G.

    2015-09-01

    Single crystals of seven novel uranyl oxysalts of selenium with protonated methylamine molecules, [C2H8N]2[(UO2)(SeO4)2(H2O)] (I), [C2H8N]2[(UO2)2(SeO4)3(H2O)] (II), [C4H15N3][H3O]0.5[(UO2)2(SeO4)2.93(SeO3)0.07(H2O)](NO3)0.5 (III), [C2H8N]3[H5O2][(UO2)2(SeO4)3(H2O)2]2(H2O)5 (IV), [C2H8N]2[H3O][(UO2)3(SeO4)4(HSeO3)(H2O)](H2SeO3)0.2 (V), [C4H12N]3[H3O][(UO2)3(SeO4)5(H2O)] (VI), and [C2H8N]3(C2H7N)[(UO2)3(SeO4)4(HSeO3)(H2O)] (VII) have been prepared by isothermal evaporation from aqueous solutions. Their crystal structures have been solved by direct methods and their uranyl selenate and selenite-selenate units investigated using black-and-white graphs from the viewpoints of topology of interpolyhedral linkages and isomeric variations. The crystal structure of IV is based upon complex layers with unique topology, which has not been observed previously in uranyl selenates. Investigations of the statistics and local distribution of the U-Obr-Se bond angles demonstrates that shorter angles associate with undulations, whereas larger angles correspond to planar areas of the uranyl selenite layers.

  4. Toxicity of selenite in the unicellular green alga Chlamydomonas reinhardtii: Comparison between effects at the population and sub-cellular level

    International Nuclear Information System (INIS)

    Morlon, Helene; Fortin, Claude; Floriani, Magali; Adam, Christelle; Garnier-Laplace, Jacqueline; Boudou, Alain

    2005-01-01

    The toxicity of selenium in aquatic ecosystems is mainly linked to its uptake and biotransformation by micro-organisms, and its subsequent transfer upwards into the food chain. Thus, organisms at low trophic level, such as algae, play a crucial role. The aim of our study was to investigate the biological effects of selenite on Chlamydomonas reinhardtii, both at the sub-cellular level (effect on ultrastructure) and at the population level (effect on growth). The cells were grown under batch culture conditions in well-defined media and exposed to waterborne selenite at concentrations up to 500 μM; i.e. up to lethal conditions. Based on the relationship between Se concentration and cell density achieved after a 96 h exposure period, an EC 50 of 80 μM with a 95% confidence interval ranging between 64 and 98 μM was derived. No adaptation mechanisms were observed: the same toxicity was quantified for algae pre-contaminated with Se. The inhibition of growth was linked to impairments observed at the sub-cellular level. The intensity of the ultrastructural damages caused by selenite exposure depended on the level and duration of exposure. Observations by TEM suggested chloroplasts as the first target of selenite cytotoxicity, with effects on the stroma, thylakoids and pyrenoids. At higher concentrations, we could observe an increase in the number and volume of starch grains. For cells collected at 96 h, electron-dense granules were observed. Energy-dispersive X-ray microanalysis revealed that these granules contained selenium and were also rich in calcium and phosphorus. This study confirms that the direct toxicity of selenite on the phytoplankton biomass is not likely to take place at concentrations found in the environment. At higher concentrations, the link between effects at the sub-cellular and population levels, the over-accumulation of starch, and the formation of dense granules containing selenium are reported for the first time in the literature for a

  5. Mechanism of Selenite Removal by a Mixed Adsorbent Based on Fe–Mn Hydrous Oxides Studied Using X-ray Absorption Spectroscopy

    KAUST Repository

    Chubar, Natalia

    2014-11-18

    © 2014 American Chemical Society. Selenium cycling in the environment is greatly controlled by various minerals, including Mn and Fe hydrous oxides. At the same time, such hydrous oxides are the main inorganic ion exchangers suitable (on the basis of their chemical nature) to sorb (toxic) anions, separating them from water solutions. The mechanism of selenite adsorption by the new mixed adsorbent composed of a few (amorphous and crystalline) phases [maghemite, MnCO3, and X-ray amorphous Fe(III) and Mn(III) hydrous oxides] was studied by extended X-ray absorption fine structure (EXAFS) spectroscopy [supported by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) data]. The complexity of the porous adsorbent, especially the presence of the amorphous phases of Fe(III) and Mn(III) hydrous oxides, is the main reason for its high selenite removal performance demonstrated by batch and column adsorption studies shown in the previous work. Selenite was bound to the material via inner-sphere complexation (via oxygen) to the adsorption sites of the amorphous Fe(III) and Mn(III) oxides. This anion was attracted via bidentate binuclear corner-sharing coordination between SeO3 2- trigonal pyramids and both FeO6 and MnO6 octahedra; however, the adsorption sites of Fe(III) hydrous oxides played a leading role in selenite removal. The contribution of the adsorption sites of Mn(III) oxide increased as the pH decreased from 8 to 6. Because most minerals have a complex structure (they are seldom based on individual substances) of various crystallinity, this work is equally relevant to environmental science and environmental technology because it shows how various solid phases control cycling of chemical elements in the environment.

  6. Mechanism of Selenite Removal by a Mixed Adsorbent Based on Fe–Mn Hydrous Oxides Studied Using X-ray Absorption Spectroscopy

    KAUST Repository

    Chubar, Natalia; Gerda, Vasyl; Szlachta, Małgorzata

    2014-01-01

    © 2014 American Chemical Society. Selenium cycling in the environment is greatly controlled by various minerals, including Mn and Fe hydrous oxides. At the same time, such hydrous oxides are the main inorganic ion exchangers suitable (on the basis of their chemical nature) to sorb (toxic) anions, separating them from water solutions. The mechanism of selenite adsorption by the new mixed adsorbent composed of a few (amorphous and crystalline) phases [maghemite, MnCO3, and X-ray amorphous Fe(III) and Mn(III) hydrous oxides] was studied by extended X-ray absorption fine structure (EXAFS) spectroscopy [supported by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) data]. The complexity of the porous adsorbent, especially the presence of the amorphous phases of Fe(III) and Mn(III) hydrous oxides, is the main reason for its high selenite removal performance demonstrated by batch and column adsorption studies shown in the previous work. Selenite was bound to the material via inner-sphere complexation (via oxygen) to the adsorption sites of the amorphous Fe(III) and Mn(III) oxides. This anion was attracted via bidentate binuclear corner-sharing coordination between SeO3 2- trigonal pyramids and both FeO6 and MnO6 octahedra; however, the adsorption sites of Fe(III) hydrous oxides played a leading role in selenite removal. The contribution of the adsorption sites of Mn(III) oxide increased as the pH decreased from 8 to 6. Because most minerals have a complex structure (they are seldom based on individual substances) of various crystallinity, this work is equally relevant to environmental science and environmental technology because it shows how various solid phases control cycling of chemical elements in the environment.

  7. Towards a selective adsorbent for arsenate and selenite in the presence of phosphate: Assessment of adsorption efficiency, mechanism, and binary separation factors of the chitosan-copper complex.

    Science.gov (United States)

    Yamani, Jamila S; Lounsbury, Amanda W; Zimmerman, Julie B

    2016-01-01

    The potential for a chitosan-copper polymer complex to select for the target contaminants in the presence of their respective competitive ions was evaluated by synthesizing chitosan-copper beads (CCB) for the treatment of (arsenate:phosphate), (selenite:phosphate), and (selenate:sulfate). Based on work by Rhazi et al., copper (II) binds to the amine moiety on the chitosan backbone as a monodentate complex (Type I) and as a bidentate complex crosslinking two polymer chains (Type II), depending on pH and copper loading. In general, the Type I complex exists alone; however, beyond threshold conditions of pH 5.5 during synthesis and a copper loading of 0.25 mol Cu(II)/mol chitosan monomer, the Type I and Type II complexes coexist. Subsequent chelation of this chitosan-copper ligand to oxyanions results in enhanced and selective adsorption of the target contaminants in complex matrices with high background ion concentrations. With differing affinities for arsenate, selenite, and phosphate, the Type I complex favors phosphate chelation while the Type II complex favors arsenate chelation due to electrostatic considerations and selenite chelation due to steric effects. No trend was exhibited for the selenate:sulfate system possibly due to the high Ksp of the corresponding copper salts. Binary separation factors, α12, were calculated for the arsenate-phosphate and selenite-phosphate systems, supporting the mechanistic hypothesis. While, further research is needed to develop a synthesis method for the independent formation of the Type II complexes to select for target contaminants in complex matrices, this work can provide initial steps in the development of a selective adsorbent. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Supplementation with Sodium Selenite and Selenium-Enriched Microalgae Biomass Show Varying Effects on Blood Enzymes Activities, Antioxidant Response, and Accumulation in Common Barbel (Barbus barbus)

    Czech Academy of Sciences Publication Activity Database

    Kouba, A.; Velíšek, J.; Stará, A.; Masojídek, Jiří; Kozák, P.

    2014-01-01

    Roč. 2014, Article ID 408270 (2014) ISSN 2314-6141 R&D Projects: GA ČR GA521/09/0656; GA MŠk ED2.1.00/03.0110; GA MŠk LO1205; GA MŠk ED2.1.00/01.0024 Grant - others:GA JU(CZ) 087/2013/Z Institutional support: RVO:61388971 Keywords : selenite * selenium * antioxidant response Subject RIV: EE - Microbiology, Virology

  9. Dynamic equilibrium of endogenous selenium nanoparticles in selenite-exposed cancer cells: a deep insight into the interaction between endogenous SeNPs and proteins.

    Science.gov (United States)

    Bao, Peng; Chen, Song-Can; Xiao, Ke-Qing

    2015-12-01

    Elemental selenium (Se) was recently found to exist as endogenous nanoparticles (i.e., SeNPs) in selenite-exposed cancer cells. By sequestrating critical intracellular proteins, SeNPs appear capable of giving rise to multiple cytotoxicity mechanisms including inhibition of glycolysis, glycolysis-dependent mitochondrial dysfunction, microtubule depolymerization and inhibition of autophagy. In this work, we reveal a dynamic equilibrium of endogenous SeNP assembly and disassembly in selenite-exposed H157 cells. Endogenous SeNPs are observed both in the cytoplasm and in organelles. There is an increase in endogenous SeNPs between 24 h and 36 h, and a decrease between 36 h and 72 h according to transmission electron microscopy results and UV-Vis measurements. These observations imply that elemental Se in SeNPs could be oxidized back into selenite by scavenging superoxide radicals and ultimately re-reduced into selenide; then the assembly and disassembly of SeNPs proceed simultaneously with the sequestration and release of SeNP high-affinity proteins. There is also a possibility that the reduction of elemental Se to selenide pathway may lie in selenite-exposed cancer cells, which results in the assembly and disassembly of endogenous SeNPs. Genome-wide expression analysis results show that endogenous SeNPs significantly altered the expression of 504 genes, compared to the control. The endogenous SeNPs induced mitochondrial impairment and decreasing of the annexin A2 level can lead to inhibition of cancer cell invasion and migration. This dynamic flux of endogenous SeNPs amplifies their cytotoxic potential in cancer cells, thus provide a starting point to design more efficient intracellular self-assembling systems for overcoming multidrug resistance.

  10. Effect of dietary supplementation with selenium-enriched yeast or sodium selenite on ruminal enzyme activities and blood chemistry in sheep

    Directory of Open Access Journals (Sweden)

    Zita Faixová

    2016-01-01

    Full Text Available The experiment was conducted to evaluate the effect of feeding a diet supplemented with different forms of selenium on the rumen fluid, blood and serum enzyme activity and osmotic fragility of red blood cells in sheep. The experiment was carried out on 18 sheep of the Valashka breed at the age of 18 months, divided into 3 groups. The first group was given basal diet (BD with a Se content of 0.17 mg/kg of dry matter (DM. The second group received BD supplemented with 0.4 mg Se/kg of (DM in the form of sodium selenite. The third group received BD supplemented with 0.4 mg Se/kg of (DM in the form of Se-yeast extract. Duration of the trial was 12 weeks. Selenium concentration in blood and total rumen fluid were elevated in both supplemented groups with the highest values in Se-yeast-treated sheep. Blood glutathione peroxidase (GPx activity was significantly increased, regardless of the source of selenium. Osmotic resistance of red blood cells was not affected by selenium supplementation. The results indicate that feeding a diet supplemented with selenium from Se-yeast or selenite improved selenium status in blood and total rumen fluid. Selenium from sodium selenite was as effective as selenium from Se-yeast in the availability of selenium for the blood GPx activity. The effect of selenium supplementation on the ruminal enzyme activity depends on the selenium form; GGT and GDH were significantly higher in the Se-yeast supplement group, AST and ALP were significantly higher in the selenite supplement group.

  11. The effect of nano-selenium particles and sodium selenite on humoral immunity indices of quails using foods contaminated with aflatoxin B1

    Directory of Open Access Journals (Sweden)

    Ebrahim Talebi

    2017-08-01

    Full Text Available This experiment was conducted to evaluate the ability of inhibition of aflatoxin B1 by various sources of selenium and to compare the effect of nano selenium and sodium selenite on humoral immunity of quails. The experiment was performed in a completely randomized design (CRD using six treatments and four replicates of ten quail chicks per replicate. Two hundred forty quails were divided in six groups vis. control: without aflatoxin B1 and without selenium. Group2: 1ppm aflatoxin B1 and without selenium. Group3: 1 ppm aflatoxin B1 and 0.3 ppm nano selenium. Group4: 1 ppm aflatoxin B1 and 0.3 ppm sodium selenite. Group5: 1 ppm aflatoxin B1 and 0.6 ppm nano selenium. Group6: 1ppm aflatoxin B1 and 0.6 ppm sodium selenite. To evaluate the humoral immunity response 0.2­ml of sheep red blood cell (SRBC solution was injected into breast muscle of quails at day 35 and blood sampling was conducted after a week. Newcastle vaccine was injected at day 28 and the antibody titer was determined after two weeks. The highest level of titer of antibody against the SRBC solution was related to the group which received 0.06 ppm nano selenium (p

  12. Increasing Selenium and Yellow Pigment Concentrations in Foxtail Millet (Setaria italica L.) Grain with Foliar Application of Selenite.

    Science.gov (United States)

    Ning, Na; Yuan, Xiang-Yang; Dong, Shu-Qi; Wen, Yin-Yuan; Gao, Zhen-Pan; Guo, Mei-Jun; Guo, Ping-Yi

    2016-03-01

    Although addition of selenium (Se) is known to increase Se in crops, it is unclear whether exogenous Se is linked to nutritional and functional components in foxtail millet (Setaria italica L.). In this study, we examined the potential of increasing Se and yellow pigment (YP) in foxtail millet grain by foliar application of Se. Field experiments were conducted during the growing season of foxtail millet in 2013 and 2014 to assess the effects of foliar spray of sodium selenite (10-210 g Se ha(-1)) on the yield, Se uptake and accumulation, total YP, and microminerals in the grain. Average grain yields with Se application were 5.60 and 4.53 t ha(-1) in the 2 years, showing no significant differences from the unfertilized control. However, grain Se concentration increased linearly with Se application rate, by 8.92 and 6.09 μg kg(-1) in the 2 years with application of 1 g Se ha(-1) (maximum grain recovery rates of Se fertilizer, 52 and 28 %). Likewise, total grain YP concentration markedly increased by 0.038 and 0.031 mg kg(-1) in the 2 years with application of 1 g Se ha(-1). Grain Mn, Cu, Fe, and Zn concentrations were not significantly affected by Se application. This study indicated that foliar application of Se effectively and reliably increased the concentrations of Se and YP in foxtail millet grain without affecting the yield or mineral micronutrient concentrations. Thus, foliar-applied selenite has a significant potential to increase the concentrations of selenium and YP (putative lutein (Shen, J Cereal Sci 61:86-93, 2015; Abdel-Aal, Cereal Chem 79:455-457, 2002; Abdel-Aal, J Agric Food Chem 55:787-794, 2007)) of foxtail millet and, thus, the health benefits of this crop.

  13. Role of pirenoxine in the effects of catalin on in vitro ultraviolet-induced lens protein turbidity and selenite-induced cataractogenesis in vivo.

    Science.gov (United States)

    Hu, Chao-Chien; Liao, Jiahn-Haur; Hsu, Kuang-Yang; Lin, I-Lin; Tsai, Ming-Hsuan; Wu, Wen-Hsin; Wei, Tzu-Tang; Huang, Yi-Shiang; Chiu, Shih-Jiuan; Chen, Hsiang-Yin; Wu, Shih-Hsiung; Wu, Tzu-Hua

    2011-01-01

    In this study, we investigated the biochemical pharmacology of pirenoxine (PRX) and catalin under in vitro selenite/calcium- and ultraviolet (UV)-induced lens protein turbidity challenges. The systemic effects of catalin were determined using a selenite-induced cataractogenesis rat model. In vitro cataractogenesis assay systems (including UVB/C photo-oxidation of lens crystallins, calpain-induced proteolysis, and selenite/calcium-induced turbidity of lens crystallin solutions) were used to screen the activity of PRX and catalin eye drop solutions. Turbidity was identified as the optical density measured using spectroscopy at 405 nm. We also determined the in vivo effects of catalin on cataract severity in a selenite-induced cataract rat model. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was applied to analyze the integrity of crystallin samples. PRX at 1,000 μM significantly delayed UVC-induced turbidity formation compared to controls after 4 h of UVC exposure (pturbidity induced by 4 h of UVC exposure was ameliorated in the presence of catalin equivalent to 1~100 μM PRX in a concentration-dependent manner. Samples with catalin-formulated vehicle only (CataV) and those containing PRX equivalent to 100 μM had a similar protective effect after 4 h of UVC exposure compared to the controls (pturbidity formation compared to controls on days 0~4 (pturbidity on day 1 (pturbidity but required millimolar levels to protect against UVC irradiation. The observed inhibition of UVC-induced turbidity of lens crystallins by catalin at micromolar concentrations may have been a result of the catalin-formulated vehicle. Transient protection by catalin against selenite-induced turbidity of crystallin solutions in vitro was supported by the ameliorated cataract scores in the early stage of cataractogenesis in vivo by subcutaneously administered catalin. PRX could not inhibit calpain-induced proteolysis activated by calcium or catalin itself, and may be

  14. Sodium selenite/selenium nanoparticles (SeNPs) protect cardiomyoblasts and zebrafish embryos against ethanol induced oxidative stress.

    Science.gov (United States)

    Kalishwaralal, Kalimuthu; Jeyabharathi, Subhaschandrabose; Sundar, Krishnan; Muthukumaran, Azhaguchamy

    2015-10-01

    Alcoholic cardiomyopathy is the damage caused to the heart muscles due to high level of alcohol consumption resulting in enlargement and inflammation of the heart. Selenium is an important trace element that is beneficial to human health. Selenium protects the cells by preventing the formation of free radicals in the body. In the present study, protein mediated synthesis of SeNPs was investigated. Two different sizes of SeNPs were synthesized using BSA and keratin. The synthesized SeNPs were characterized by scanning electron microscopy (SEM) with elemental composition analysis Energy Dispersive X-ray spectroscopy(EDX) and X-ray diffraction (XRD). This study demonstrates the in vitro and in vivo antioxidative effects of sodium selenite and SeNPs. Further selenium and SeNPs were evaluated for their ability to protect against 1% ethanol induced oxidative stress in H9C2 cell line. The selenium and SeNPs were found to reduce the 1% ethanol-induced oxidative damage through scavenging intracellular reactive oxygen species. The selenium and SeNPs could also prevent pericardial edema induced ethanol treatment and reduced apoptosis and cell death in zebrafish embryos. The results indicate that selenium and SeNPs could potentially be used as an additive in alcoholic beverage industry to control the cardiomyopathy. Copyright © 2015 Elsevier GmbH. All rights reserved.

  15. Puzzolanic cements of greater resistance at the attack of selenitic waters than the high sulfate resistance portland cements, and viceverse

    Directory of Open Access Journals (Sweden)

    Talero, Rafael

    1987-09-01

    Full Text Available This work confirms the certainty of the predictions of useful service given by Kaluosek and al. for the sulphate resistant portland cements (type V, USA, subject to severe selenitic attack. Two sulphate resistant portland cements, were tested by means of the Le Chatelier Anstett method. The tarts were destroyed at ages of three years, having detected in them the presence of thaumasite by XRD. Even so, the impossibility and possibility thaumasite formation was confirmed in pozzolanic cements tarts, which either had or did not have adequate amount of pozzolana (diatomite for such purpose.

    Este trabajo confirman las predicciones de vida útil dadas por Kalousek y colaboradores, para los cementos portland de elevada resistencia al ataque de los iones sulfato (tipo V, USA, sometidos a un severo ataque selenitoso. Se ensayaron dos cementos portland de elevada resistencia al ataque del yeso, mediante el ensayo de Le Chatelier-Anstett. Sus tortas correspondientes se destruyeron a la edad de tres años, habiéndose detectado en las mismas la presencia de thaumasita por DRX. Asimismo se confirmó la imposibilidad y posibilidad de formación de thaumasita en tortas de cementos puzolánicos, los cuales tenían, o no, respectivamente, una adecuada cantidad de puzolana (diatomita para tales fines.

  16. A comparison of the uptake of [75Se]Selenite [75Se] Selenomethionine and [35S]methionine by the tissues of ewes and lambs

    International Nuclear Information System (INIS)

    Fuss, C.N.; Godwin, K.O.

    1975-01-01

    The fate of selenium, given as Na 2 75 SeO 3 , or [ 75 Se] selenomethionine, and of [ 35 S]methionine administered intravenously to ewes and lambs, has been examined. The main intention was to follow the incorporation of selenium into protein in a number of tissues, including liver and kidney, and to measure the extent of that incorporation of selenoamino acid, particularly with respect to the administration of selenite. The ewes chosen were lactating ewes with lambs at foot, and the lambs were animals which had been weaned on to fodder low in selenium and were recovering from white muscle disease with selenium therapy. These two experimental situations were chosen as they offered conditions under which selenium incorporation might be considered to be maximal. Entry of isotope into milk was rapid and was greater when 75 Se was given as the selenoamino acid than as selenite. In both ewes and lambs greater amounts of activity, derived from selenite, were bound to plasma proteins than to the proteins of milk. This was particularly evident in samples taken some hours after administration. This ability of the plasma to bind selenium was demonstrated by alkaline dialysis. Small, though significant amounts of selenium, derived from Na 2 75 SeO 3 , were incorporated as selenoamino acids into the proteins of liver, kidney and pancreas, as well as into the proteins of milk and plasma. In ewes, both selenomethionine and selenocystine were identified chromatographically in enzyme digests of defatted liver and kidney. Some differences occurred in the distribution of labelled compounds in organs from lactating ewes and recovering lambs. The incorporation of selenium into protein is discussed briefly in relation to the recent findings of an association between selenium and the enzyme glutathione peroxidase. (author)

  17. Selenium Accumulation Characteristics and Biofortification Potentiality in Turnip (Brassica rapa var. rapa Supplied with Selenite or Selenate

    Directory of Open Access Journals (Sweden)

    Xiong Li

    2018-01-01

    Full Text Available Selenium (Se is an essential trace element for humans. About 70% of the regions in China, including most of the Tibetan Plateau, are faced with Se deficiency problems. Turnip is mainly distributed around the Tibetan Plateau and is one of the few local crops. In the present study, we compared the absorption and translocation differences of Se (IV selenite and Se (VI selenate in turnip. The results showed that Se treatment, either by soil addition (0.2–2 mg Se kg−1 dry soil or by foliar spraying (50–200 mg L−1 Se, could significantly increase the Se concentrations in turnips, and 0.5 mg Se (IV or Se (VI kg−1 dry matter in soils could improve the biomasses of turnips. Moreover, turnip absorbed significantly more Se (VI than Se (IV at the same concentration and also transferred much more Se (VI from roots to leaves. Based on the Se concentrations, as well as the bioconcentration factors and translocation coefficients, we considered that turnip might be a potential Se indicator plant. Subsequently, we estimated the daily Se intake for adults based on the Se concentrations in turnip roots. The results indicated that Se (IV should be more suitable as an artificial Se fertilizer for turnips, although the levels found in most samples in this study could cause selenosis to humans. In addition, we also estimated the optimum and maximum Se concentrations for treating turnips based on the linear relations between Se concentrations in turnip roots and Se treatment concentrations. The results provided preliminary and useful information about Se biofortification in turnips.

  18. Selenite reduction by anaerobic microbial aggregates: Microbial community structure, and proteins associated to the produced selenium spheres.

    Directory of Open Access Journals (Sweden)

    Graciela eGonzalez-Gil

    2016-04-01

    Full Text Available Certain types of anaerobic granular sludge, which consists of microbial aggregates, can reduce selenium oxyanions. To envisage strategies for removing those oxyanions from wastewater and recovering the produced elemental selenium (Se0, insights into the microbial community structure and synthesis of Se0 within these microbial aggregates are required. High-throughput sequencing showed that Veillonellaceae (c.a. 20 % and Pseudomonadaceae (c.a.10 % were the most abundant microbial phylotypes in selenite reducing microbial aggregates. The majority of the Pseudomonadaceae sequences were affiliated to the genus Pseudomonas. A distinct outer layer (~200 m of selenium deposits indicated that bioreduction occurred in the outer zone of the microbial aggregates. In that outer layer, SEM analysis showed abundant intracellular and extracellular Se0 (nano spheres, with some cells having high numbers of intracellular Se0 spheres. Electron tomography showed that microbial cells can harbor a single large intracellular sphere that stretches the cell body. The Se0 spheres produced by the microorganisms were capped with organic material. X-ray photoelectron spectroscopy (XPS analysis of extracted Se0 spheres, combined with a mathematical approach to analyzing XPS spectra from biological origin, indicated that proteins and lipids were components of the capping material associated to the Se0 spheres. The most abundant proteins associated to the spheres were identified by proteomic analysis. Most of the proteins or peptide sequences capping the Se0 spheres were identified as periplasmic outer membrane porins and as the cytoplasmic elongation factor Tu protein, suggesting an intracellular formation of the Se0 spheres. In view of these and previous findings, a schematic model for the synthesis of Se0 spheres by the microorganisms inhabiting the granular sludge is proposed.

  19. Removal mechanism of selenite by Fe{sub 3}O{sub 4}-precipitated mesoporous magnetic carbon microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jianwei; Fu, Fenglian, E-mail: fufenglian2006@163.com; Ding, Zecong; Li, Na; Tang, Bing

    2017-05-15

    Highlights: • MCMSs were prepared via green hydrothermal carbonization and coprecipitation. • MCMSs displayed effective removal of Se(IV) from wastewater. • Se(IV) formed inner-sphere complexes with MCMSs and was reduced to insoluble Se{sup 0}. • MCMSs can be easily separated and recycled by an external magnetic field. - Abstract: A mesoporous composite of magnetic carbon microspheres (MCMSs) was synthesized via introducing Fe{sub 3}O{sub 4} nanoscale particles to the surface of carbon microspheres (CMSs) by coprecipitation. Scanning electron microscopy and transmission electron microscopy showed the Fe{sub 3}O{sub 4} nanoscale particles were dispersedly immobilized on the surface of CMSs. The MCMSs demonstrated effective removal of selenite (Se(IV)) from wastewater. MCMSs showed the regular pattern where the lower pH value, the lower residual Se(IV) concentration. The coexisting sulfate, nitrate, chloride, carbonate, and silicate had no significant effect on Se(IV) removal, whereas phosphate hindered the removal of Se(IV) by competing with Se(IV) and formed inner–sphere complexes with Fe{sub 3}O{sub 4} on the surface of MCMSs. Through X–ray photoelectron spectroscopy analysis, Se(IV) can not only form inner–sphere complexes with MCMSs, but also be reduced to insoluble elemental selenium (Se{sup 0}) by Fe{sub 3}O{sub 4} which was oxidized and formed γ–Fe{sub 2}O{sub 3}. Moreover, the superparamagnetic MCMSs can be easily separated from solution by means of an external magnetic field. The high removal efficiency for Se(IV) and rapid separability of MCMSs made them promising materials for the application in the practice.

  20. Effect of sodium selenite on chosen anti- and pro-oxidative parameters in rats treated with lithium: A pilot study.

    Science.gov (United States)

    Musik, Irena; Kocot, Joanna; Kiełczykowska, Małgorzata

    2015-06-01

    Selenium is an essential element of antioxidant properties. Lithium is widely used in medicine but its administration can cause numerous side effects including oxidative stress. The present study aimed at evaluating if sodium selenite could influence chosen anti- and pro-oxidant parameters in rats treated with lithium. The experiment was performed on four groups of Wistar rats: I (control) - treated with saline; II (Li) - treated with lithium (2.7 mgLi/kg b.w. as Li2CO3), III (Se) - treated with selenium (0.5 mgSe/kg b.w. as Na2SeO3), IV (Li+Se) - treated with Li2CO3 and Na2SeO3 together at the same doses as in group II and III, respectively. All treatments were performed by stomach tube for three weeks in form of water solutions. The following anti- and pro-oxidant parameters: total antioxidant status (TAS) value, catalase (CAT) activity, concentrations of ascorbic acid (AA) and malonyldialdehyde (MDA) in plasma as well as whole blood superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were measured. Selenium given alone markedly enhanced whole blood GPx and diminished plasma CAT vs. Lithium significantly decreased plasma CAT and slightly increased AA vs. Selenium co-administration restored these parameters to the values observed in control animals. Furthermore, selenium co-administration significantly increased GPx in Li-treated rats. All other parameters (TAS, SOD and MDA) were not affected by lithium and/or selenium. Further research seems to be warranted to decide if application of selenium as an adjuvant in lithium therapy is worth considering. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  1. Selenite Reduction by Anaerobic Microbial Aggregates: Microbial Community Structure, and Proteins Associated to the Produced Selenium Spheres

    KAUST Repository

    Gonzalez-Gil, Graciela

    2016-04-26

    Certain types of anaerobic granular sludge, which consists of microbial aggregates, can reduce selenium oxyanions. To envisage strategies for removing those oxyanions from wastewater and recovering the produced elemental selenium (Se0), insights into the microbial community structure and synthesis of Se0 within these microbial aggregates are required. High-throughput sequencing showed that Veillonellaceae (c.a. 20%) and Pseudomonadaceae (c.a.10%) were the most abundant microbial phylotypes in selenite reducing microbial aggregates. The majority of the Pseudomonadaceae sequences were affiliated to the genus Pseudomonas. A distinct outer layer (∼200 μm) of selenium deposits indicated that bioreduction occurred in the outer zone of the microbial aggregates. In that outer layer, SEM analysis showed abundant intracellular and extracellular Se0 (nano)spheres, with some cells having high numbers of intracellular Se0 spheres. Electron tomography showed that microbial cells can harbor a single large intracellular sphere that stretches the cell body. The Se0 spheres produced by the microorganisms were capped with organic material. X-ray photoelectron spectroscopy (XPS) analysis of extracted Se0 spheres, combined with a mathematical approach to analyzing XPS spectra from biological origin, indicated that proteins and lipids were components of the capping material associated to the Se0 spheres. The most abundant proteins associated to the spheres were identified by proteomic analysis. Most of the proteins or peptide sequences capping the Se0 spheres were identified as periplasmic outer membrane porins and as the cytoplasmic elongation factor Tu protein, suggesting an intracellular formation of the Se0 spheres. In view of these and previous findings, a schematic model for the synthesis of Se0 spheres by the microorganisms inhabiting the granular sludge is proposed.

  2. Ethylenediammonium dication: H-bonded complexes with terephthalate, chloroacetate, phosphite, selenite and sulfamate anions. Detailed vibrational spectroscopic and theoretical studies of ethylenediammonium terephthalate

    Science.gov (United States)

    Marchewka, M. K.; Drozd, M.

    2012-12-01

    Crystalline complexes between ethylenediammonium dication and terephthalate, chloroacetate, phosphite, selenite and sulfamate anions were obtained by slow evaporation from water solution method. Room temperature powder infrared and Raman measurements were carried out. For ethylenediammonium terephthalate theoretical calculations of structure were performed by two ways: ab-initio HF and semiempirical PM3. In this case the PM3 method gave more accurate structure (closer to X-ray results). The additional PM3 calculations of vibrational spectra were performed. On the basis theoretical approach and earlier vibrational studies of similar compounds the vibrational assignments for observed bands have been proposed. All compounds were checked for second harmonic generation (SHG).

  3. Change of selenium in plasma of dairy cows receiving two levels of sodium-selenite during the transition period

    Directory of Open Access Journals (Sweden)

    A. Giubbiotti

    2010-04-01

    Full Text Available With the aim to study the plasma Se content during transition period, 2 groups of 12 dairy cows were monitored the month before and after calving. In stall 1 (S1 cows were tied and individually fed, in stall2 (S2 cows were free and fed TMR. In both stalls cows were supplied with Se as Na-selenite. In S1 3 mg/d of Se were fed mixed with corn silage while, in S2, Se was offered with TMR, in dry period 2 mg/d were added with a mineral-vitamin supplement, in lactation 2.6 mg/d (when DMI was 22.2 kg/d with the concentrate. Forages, the same for both stalls, and concentrates were sampled for chemical composition and Se determination. Cows were checked for milk yield and its content of somatic cells (SCC, health problems, and bled for Se determination in plasma. Average Se intake was higher in S1, in both dry (4.08 vs 2.76 mg/d and lactating (5.80 vs 2.11 mg/d period. Besides the supplementation, differences depended on high Se intake in S1 with the concentrate (increased after calving to 11.5 kg/DM on d 30 and containing 0.24 mg/kg DM of Se. According to the intake, plasma Se content resulted higher in S1 in dry (1.20 vs 0.74 μmol/L and lactating (1.47 vs 0.62 μmol/L cows. In close-up plasma Se decreased in both groups, in first days of lactation increased in S1, while decreased in S2 to level indicating a deficient intake (0.50 μmol/L. These results confirm the link between Se intake and its plasma level. Finally, Se plasma content did not seem related to cow health status during transition period.

  4. Insights into selenite reduction and biogenesis of elemental selenium nanoparticles by two environmental isolates of Burkholderia fungorum.

    Science.gov (United States)

    Khoei, Nazanin Seyed; Lampis, Silvia; Zonaro, Emanuele; Yrjälä, Kim; Bernardi, Paolo; Vallini, Giovanni

    2017-01-25

    Microorganisms capable of transforming toxic selenium oxyanions into non-toxic elemental selenium (Se°) may be considered as biocatalysts for the production of selenium nanoparticles (SeNPs), eventually exploitable in different biotechnological applications. Two Burkholderia fungorum strains (B. fungorum DBT1 and B. fungorum 95) were monitored during their growth for both capacity and efficiency of selenite (SeO 3 2- ) reduction and elemental selenium formation. Both strains are environmental isolates in origin: B. fungorum DBT1 was previously isolated from an oil refinery drainage, while B. fungorum 95 has been enriched from inner tissues of hybrid poplars grown in a soil contaminated by polycyclic aromatic hydrocarbons. Our results showed that B. fungorum DBT1 is able to reduce 0.5mM SeO 3 2- to Se° when cultured aerobically in liquid medium at 27°C, while B. fungorum 95 can reduce more than 1mM SeO 3 2- to Se° within 96h under the same growth conditions, with the appearance of SeNPs in cultures of both bacterial strains. Biogenic SeNPs were spherical, with pH-dependent charge and an average hydrodynamic diameter of 170nm and 200nm depending on whether they were produced by B. fungorum 95 or B. fungorum DBT1, respectively. Electron microscopy analyses evidenced that Se nanoparticles occurred intracellularly and extracellularly. The mechanism of SeNPs formation can be tentatively attributed to cytoplasmic enzymatic activation mediated by electron donors. Biogenic nanoparticles were then probably released outside the bacterial cells as a consequence of a secretory process or cell lysis. Nevertheless, formation of elemental selenium nanoparticles under aerobic conditions by B. fungorum DBT1 and B. fungorum 95 is likely due to intracellular reduction mechanisms. Biomedical and other high tech sectors might exploit these biogenic nanoparticles in the near future, once fully characterized and tested for their multiple properties. Copyright © 2016 Elsevier B.V. All

  5. Histotopography of the radiopharmaceuticals 75Se-selenomethionine and 75Se-selenite in critical organs of adult and embryonic mice

    International Nuclear Information System (INIS)

    Khant, S.E.; Norets, T.A.

    1981-01-01

    Adult male and pregnant mice received 75 Se-labelled methionine and selenite, resp. The critical organs and the embryos were examined histoautoradiographically at different time intervals as to the organ distribution of the radiopharmaceuticals. All organs revealed a heterogeneity of the 75 Se distribution with an intensity being unequally organo-specific and depending on the type of the radiopharmaceutical. 75 Se-selenomethionine was deposited mainly in functional areas of kidneys, liver, bone marrow and testes thus causing a long-term retention and an intensive irradiation of these organs. In the embryos 75 Se-seleno-methionine was distributed unequally preferring liver, hematopoietic areas of the bone marrow and the lens

  6. Removal of selenite by zero-valent iron combined with ultrasound: Se(IV) concentration changes, Se(VI) generation, and reaction mechanism.

    Science.gov (United States)

    Fu, Fenglian; Lu, Jianwei; Cheng, Zihang; Tang, Bing

    2016-03-01

    In this paper, the performance and application of zero-valent iron (ZVI) assisted by ultrasonic irradiation for the removal of selenite (Se(IV)) in wastewater was evaluated and reaction mechanism of Se(IV) with ZVI in such systems was investigated. A series of batch experiments were conducted to determine the effects of ultrasound power, pH, ZVI concentration, N2 and air on Se(IV) removal. ZVI before and after reaction with Se(IV) was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Results indicated that ultrasound can lead to a significant synergy in the removal of Se(IV) by ZVI because ultrasound can promote the generation of OH and accelerate the advanced Fenton process. The primary reaction products of ZVI and Se(IV) were Se(0), ferrihydrite, and Fe2O3. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Effects of foliar dressing of selenite and silicate alone or combined with different soil ameliorants on the accumulation of As and Cd and antioxidant system in Brassica campestris.

    Science.gov (United States)

    Ding, Yongzhen; Wang, Yongjiu; Zheng, Xiangqun; Cheng, Weimin; Shi, Rongguang; Feng, Renwei

    2017-08-01

    This study was conducted to investigate the possibility of using a combined technology to synchronously reduce As and Cd accumulation in the edible parts of Brassica campestris. The results showed that a foliar application of selenite (Se) and silicon (Si) combined with soil ameliorants (including Ca-Mg-P fertilizer, sodium silicate and red mud) showed limited effects on the growth of B. campestris. The As concentration in the leaves of B. campestris in all treatments was below the Chinese safety standard. When sodium silicate and Ca-Mg-P fertilizer were added to the soil, the additional foliar application of Se and Si could in some cases help further reduce the concentrations of As and Cd in the leaves of B. campestris. However, when red mud was applied to the soil, the foliar application of Se and Si enhanced the Cd concentration in the leaves of B. campestris. In most cases, high levels of soil ameliorants plus foliar application of Se and Si significantly enhanced the As concentrations in both the soil solution and the roots of B. campestris but reduced the soil solution Cd concentration and the leaf As concentration. Most of the treatments reduced the thiobarbituric acid reactive substances (TBARS) concentration in the leaves of B. campestris, and the foliar application of Se and Si helped the soil ameliorants alleviate the oxidative stress resulting from As and Cd exposure. In this study, several treatments significantly increased the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX). However, the enzymes peroxidase (POD) and catalase (CAT) were not induced by most treatments. In summary, the combined treatment of 1gkg -1 Ca-Mg-P fertilizer plus foliar spraying 2mmolL -1 sodium selenite was most effective in reducing the Cd concentration and a rather strong ability to reduce the As concentration and trigger the activities of SOD and APX in the leaves of B. campestris. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Pseudomonas moraviensis subsp. stanleyae, a bacterial endophyte of hyperaccumulator Stanleya pinnata, is capable of efficient selenite reduction to elemental selenium under aerobic conditions.

    Science.gov (United States)

    Staicu, L C; Ackerson, C J; Cornelis, P; Ye, L; Berendsen, R L; Hunter, W J; Noblitt, S D; Henry, C S; Cappa, J J; Montenieri, R L; Wong, A O; Musilova, L; Sura-de Jong, M; van Hullebusch, E D; Lens, P N L; Reynolds, R J B; Pilon-Smits, E A H

    2015-08-01

    To identify bacteria with high selenium tolerance and reduction capacity for bioremediation of wastewater and nanoselenium particle production. A bacterial endophyte was isolated from the selenium hyperaccumulator Stanleya pinnata (Brassicaceae) growing on seleniferous soils in Colorado, USA. Based on fatty acid methyl ester analysis and multi-locus sequence analysis (MLSA) using 16S rRNA, gyrB, rpoB and rpoD genes, the isolate was identified as a subspecies of Pseudomonas moraviensis (97.3% nucleotide identity) and named P. moraviensis stanleyae. The isolate exhibited extreme tolerance to SeO3(2-) (up to 120 mmol l(-1)) and SeO4(2-) (>150 mmol l(-1)). Selenium oxyanion removal from growth medium was measured by microchip capillary electrophoresis (detection limit 95 nmol l(-1) for SeO3(2-) and 13 nmol l(-1) for SeO4(2-)). Within 48 h, P. moraviensis stanleyae aerobically reduced SeO3(2-) to red Se(0) from 10 mmol l(-1) to below the detection limit (removal rate 0.27 mmol h(-1) at 30 °C); anaerobic SeO3(2-) removal was slower. No SeO4(2-) removal was observed. Pseudomonas moraviensis stanleyae stimulated the growth of crop species Brassica juncea by 70% with no significant effect on Se accumulation. Pseudomonas moraviensis stanleyae can tolerate extreme levels of selenate and selenite and can deplete high levels of selenite under aerobic and anaerobic conditions. Pseudomonas moraviensis subsp. stanleyae may be useful for stimulating plant growth and for the treatment of Se-laden wastewater. © 2015 The Society for Applied Microbiology.

  9. THE EFFECTS OF SODIUM SELENITE AND SELENIZED YEAST SUPPLEMENTATION INTO DIET FOR LAYING HENS ON SELECTED QUALITATIVE PARAMETERS OF TABLE EGGS

    Directory of Open Access Journals (Sweden)

    HENRIETA ARPÁŠOVÁ

    2009-10-01

    Full Text Available In this experiment the effects of supplementation of the diet for laying hens with sodium selenite (SS or selenized yeast (SY on whole egg and egg shell quality of layers were studied. The chickens of Shaver Starcross 288 strain were randomly divided at the day of hatching into 4 groups (n=12; in each. The birds were fed from Day 1 of life to 9 months of age with diets differing in amounts and/or forms of selenium. Control group received basal diet (BD containing selenium naturally occurring in feeds (0.1 mg Se/kg of dry matter (DM. First and second experimental group of chickens were fed with a same BD enriched with equivalent dose of Se 0.4 mg/kg DM in form of sodium selenite or selenized yeast, respectively. The feed for third experimental group of birds consisted of BD supplemented with selenized yeast to the final amount of selenium 1.0 mg/kg DM. The egg weight was significantly higher in the groups with SY supplementation only. On the contrary the egg shell ratio was significantly lower in the groups with SY supplementation in both amounts. The width of egg was significantly increased in the groups with selenium supplementation in both forms. The value of egg shell strength was significantly decreased in group with SY in the highest amount 0.9 mg/kg DM The average egg shell thickness was the highest in the experimental group with Se-yeast in amount 0.9 mg/kg DM, however different was not significant compared with control group. The results showed that the most of selected parameters of egg quality appeared to be significantly influenced by selenium supplementation into laying hen’s basal diet.

  10. Comparing the influence of selenite (Se4+) and selenate (Se6+) on the inhibition of the mercury (Hg) phytotoxicity to pak choi.

    Science.gov (United States)

    Tran, Thi Anh Thu; Dinh, Quang Toan; Cui, Zeiwei; Huang, Jie; Wang, Dan; Wei, Tianjiao; Liang, Dongli; Sun, Xin; Ning, Ping

    2018-01-01

    Selenite (Se (IV)) and selenate (Se (IV)) have recently been demonstrated to be equally effective in inhibiting mercury (Hg) phytotoxicity to plants. This assertion is still unclear. In this study, we aimed to explore the potential effects of Se species (Se 4+ and Se 6+ ) on the inhibition of the mercury (Hg) bioavailability to pak choi in dry land. Pot experiments with exposure to different dosages of mercuric chloride (HgCl 2 ) and selenite (Na 2 SeO 3 ) or selenate (Na 2 SeO 4 ) were treated. To compare the influence of Se (IV) and Se (VI) on the bioaccumulation and bioavailability of Hg, the levels of total Hg in different pak choi (Brassica chinensis L.) tissues (roots and shoots) and the distribution changes of Hg fractions in soil before planting and after harvest were determined as well as the Hg I R values in soils (relative binding intensity) were analyzed. Results showed that application Se (IV) reduced the concentrations of Hg in pak choi roots more than Se (VI). Hg concentrations were also decreased in pak choi shoots in Se (IV) treatments, while which notably increased in Se (VI) treatments. Thus, Se (IV) plays a more important role than Se (VI) in limiting the absorption and bioaccumulation of Hg in pak choi. Moreover, this inhibition may only significantly occur when Se (IV) is at an appropriate level (2.5mg/kg). In addition, the good correlations between the proportions of mobile Hg fractions (soluble and exchangeable fractions), I R values with the Hg concentrations in plants were observed. This affirmed the importance of the Hg fractions transformation and the I R indicator of Hg in the assessment of their bioavailability. Our findings regarding the importance of Se (IV) influence in reducing Hg bioaccumulation not only provided the correct appraisal about the effect of Se species on the inhibition of the Hg phytotoxicity to pak choi in dry land, but also be a good reference for selecting Se fertilizer forms (Se 4+ or Se 6+ ). Copyright © 2017

  11. Optical absorption of selenite single crystals subjected to high electric fields and irradiated with X-rays or γ-rays

    International Nuclear Information System (INIS)

    Mishra, Sakuntala; Rao, A.V.K.; Rao, K.V.

    1988-01-01

    Measurements of the optical absorption coefficient of selenite single crystals show two peaks at 236 and 400 nm when plotted as a function of wavelength. These peaks decrease with increasing irradiation time for both γ and X-rays. Subsequent thermal bleaching increases the absorption coefficient at all wavelengths and flattens out the peaks at 140 0 C and 330 0 C respectively. The imposition of an a.c. or d.c. field prior to irradiation preserves the thermal bleaching characteristics with an overall increase in absorption coefficient. These effects are attributed to two different types of bond formed by water of crystallization giving rise to the two absorption peaks. Irradiation may destroy some of the bands of loosely bound water molecules near defect regions leading to a decrease in absorption. Thermal bleaching removes water molecules reducing the transparency of the samples, the more strongly bound molecules being removed at the higher temperature. Irradiation after a.c. or d.c. field treatment may introduce more defect regions enabling the removal of more water molecules by bleaching and hence increasing the absorption. (U.K.)

  12. New inorganic (an)ion exchangers with a higher affinity for arsenate and a competitive removal capacity towards fluoride, bromate, bromide, selenate, selenite, arsenite and borate

    KAUST Repository

    Chubar, Natalia

    2011-12-01

    Highly selective materials and effective technologies are needed to meet the increasingly stronger drinking water standards for targeted ionic species. Inorganic ion exchangers based on individual and mixed-metal hydrous oxides (or mixed adsorbents that contain inorganic ion exchangers in their composition) are adsorptive materials that are capable of lowering the concentrations of anionic contaminants, such as H 2AsO 4 -, H 3AsO 3, F -, Br -, BrO 3 -, HSeO 4 -, HSeO 3 - and H 3BO 3, to 10 μg/L or less. To achieve a higher selectivity towards arsenate, a new ion exchanger based on Mg-Al hydrous oxides was developed by a novel, cost-effective and environmentally friendly synthesis method via a non-traditional (alkoxide-free) sol-gel approach. The exceptional adsorptive capacity of the Mg-Al hydrous oxides towards H 2AsO 4 - (up to 200 mg[As]/gdw) is due to the high affinity of this sorbent towards arsenate (steep equilibrium isotherms) and its fast adsorption kinetics. Because of the mesoporous (as determined by N 2 adsorption and SEM) and layered (as determined by XRD and FTIR) structure of the ion-exchange material as well as the abundance of anion exchange sites (as determined by XPS and potentiometric titration) on its surface the material demonstrated very competitive (or very high) removal capacity towards other targeted anions, including fluoride, bromide, bromate, selenate, selenite, and borate. © 2011 IWA Publishing.

  13. Allium cepa L. Response to Sodium Selenite (Se(IV)) Studied in Plant Roots by a LC-MS-Based Proteomic Approach.

    Science.gov (United States)

    Karasinski, Jakub; Wrobel, Kazimierz; Corrales Escobosa, Alma Rosa; Konopka, Anna; Bulska, Ewa; Wrobel, Katarzyna

    2017-05-17

    Liquid chromatography-high-resolution mass spectrometry was used for the first time to investigate the impact of Se(IV) (10 mgSe L -1 as sodium selenite) on Allium cepa L. root proteome. Using MaxQuant platform, more than 600 proteins were found; 42 were identified based on at least 2 razor + unique peptides, score > 25, and were found to be differentially expressed in the exposed versus control roots with t-test difference > ±0.70 (p roots. Different abundances of proteins involved in transcriptional regulation, protein folding/assembly, cell cycle, energy/carbohydrate metabolism, stress response, and antioxidant defense were found in the exposed vs nonexposed roots. New evidence was obtained on the alteration of sulfur metabolism due to S-Se competition in A. cepa L. which, together with the original analytical approach, is the main scientific contribution of this study. Specifically, proteins participating in assimilation and transformation of both elements were affected; formation of volatile Se compounds seemed to be favored. Changes observed in methionine cycle suggested that Se(IV) stress might repress methylation capability in A. cepa L., potentially limiting accumulation of Se in the form of nonprotein methylated species and affecting adversely transmethylation-dependent signaling pathways.

  14. EXAFS and FTIR studies of selenite and selenate sorption by alkoxide-free sol–gel generated Mg–Al–CO 3 layered double hydroxide with very labile interlayer anions

    KAUST Repository

    Chubar, Natalia

    2014-01-01

    © the Partner Organisations 2014. Current research on Layered Double Hydroxides (LDHs, also known as hydrotalcites, HTs) is predominantly focused on their intercalations, but the industrial application of LDHs for anion exchange adsorption has not yet been achieved. It was recently recognized that, to develop LDH applications, these materials should be produced using methods other than direct co-precipitation. Mg-Al-CO3LDH produced using an alkoxide-free sol-gel synthesis showed exceptional removal properties for aqueous selenium species. Se K-edge EXAFS/XANES and FTIR studies (supporting the data by XRD patterns) were performed to explain the unusual adsorptive performance of Mg-Al LDH by revealing the molecular-level mechanism of HSeO3 -, SeO4 2-and {HSeO3 -+ SeO4 2-} uptake at pH 5, 7 and 8.5. The role of inner-sphere complexation (exhibited by inorganic adsorbents with good performance) in adsorption of both selenium aqueous species was not confirmed. However, Mg-Al LDH fully met the other expectations regarding the involvement of the interlayer anions. The interlayer carbonate (due to its favorable speciation and generous HT hydration) gave a "second breath" to selenite sorption and was the only mechanism that controlled the removal of Se(vi). Because inner sphere complexation was the leading mechanism for selenite removal, ion exchange via surface OH-and interlayer CO3 2-species was the only mechanism for selenate removal; both of these species were easily bound to Mg-Al LDH (on its surface and gently parked into the interlayer forming a multilayer without violation of the structure of Mg-Al-CO3LDH). This work provides the first theoretical explanation of why it is more difficult to sorb selenate than selenite and which material should be used for this purpose. This journal is

  15. EXAFS and FTIR studies of selenite and selenate sorption by alkoxide-free sol–gel generated Mg–Al–CO 3 layered double hydroxide with very labile interlayer anions

    KAUST Repository

    Chubar, Natalia

    2014-08-08

    © the Partner Organisations 2014. Current research on Layered Double Hydroxides (LDHs, also known as hydrotalcites, HTs) is predominantly focused on their intercalations, but the industrial application of LDHs for anion exchange adsorption has not yet been achieved. It was recently recognized that, to develop LDH applications, these materials should be produced using methods other than direct co-precipitation. Mg-Al-CO3LDH produced using an alkoxide-free sol-gel synthesis showed exceptional removal properties for aqueous selenium species. Se K-edge EXAFS/XANES and FTIR studies (supporting the data by XRD patterns) were performed to explain the unusual adsorptive performance of Mg-Al LDH by revealing the molecular-level mechanism of HSeO3 -, SeO4 2-and {HSeO3 -+ SeO4 2-} uptake at pH 5, 7 and 8.5. The role of inner-sphere complexation (exhibited by inorganic adsorbents with good performance) in adsorption of both selenium aqueous species was not confirmed. However, Mg-Al LDH fully met the other expectations regarding the involvement of the interlayer anions. The interlayer carbonate (due to its favorable speciation and generous HT hydration) gave a "second breath" to selenite sorption and was the only mechanism that controlled the removal of Se(vi). Because inner sphere complexation was the leading mechanism for selenite removal, ion exchange via surface OH-and interlayer CO3 2-species was the only mechanism for selenate removal; both of these species were easily bound to Mg-Al LDH (on its surface and gently parked into the interlayer forming a multilayer without violation of the structure of Mg-Al-CO3LDH). This work provides the first theoretical explanation of why it is more difficult to sorb selenate than selenite and which material should be used for this purpose. This journal is

  16. FTIR spectroscopic studies of selenite reduction by cells of the rhizobacterium Azospirillum brasilense Sp7 and the formation of selenium nanoparticles

    Science.gov (United States)

    Kamnev, Alexander A.; Mamchenkova, Polina V.; Dyatlova, Yulia A.; Tugarova, Anna V.

    2017-07-01

    Microbially driven reduction of selenium oxyanions to elementary selenium, often in the form of nanoparticles (NPs), is widespread in nature. A diversity of possible applications of such biogenic NPs, including those in nanobiotechnology, as well as the specificity of methodologies and mechanisms of their formation via ;green synthesis; are very attractive features justifying further studies of the processes of selenium oxyanion bioreduction and the resulting Se0 nanostructures. In this study, live biomass of the rhizobacterium Azospirillum brasilense Sp7 (harvested after the logarithmic growth phase and washed from culture medium components) was used to obtain extracellular Se NPs relatively homogeneous in size (with average diameters within 50-100 nm) in the process of selenite reduction. Both the control cultures of A. brasilense Sp7 and those incubated with SeO32- (producing Se NPs), as well as the resulting separated Se NPs were studied using Fourier transform infrared (FTIR) spectroscopy in the transmission mode (measured as dried layers on a ZnSe disc), in addition to transmission electron microscopy (TEM), to compare metabolic changes in cells and the bioorganic layers associated with the Se NPs. In the control culture (stored for 24 h in physiological saline), FTIR spectroscopic signs of poly-3-hydroxybutyrate (a 'reserve' biopolyester) were observed as a response to the lack of nutrients (trophic stress), whereas they were virtually absent in cells incubated for 24 h in physiological saline with 10 mM SeO32- (toxicity stress). FTIR spectra of Se NPs separated from bacterial cells showed bands typical of proteins, polysaccharides and lipids associated with the particles (in line with their TEM images showing a thin layer over the NPs), in addition to strong carboxylate bands, which evidently stabilise the NP structure and morphology.

  17. LD/sub 50/ and selenium concentration in organs of rabbit following oral application of sodium selenite and toxicity verification of Ursoselevit-Praemix

    Energy Technology Data Exchange (ETDEWEB)

    Berschneider, F.; Hess, M.; Neuffer, K.; Willer, S.

    1976-07-01

    LC/sub 50/24 hr/ was established in the first of a series of experiments on 72 rabbits for orally applied sodium selenite. The dosage was 8.62 mg/kg live weight, the confidence interval being (1 - ..cap alpha.. = 0.95) +/- 0.13 mg/kg. The value was four times as high following intravenous application. Complete lethality was recorded from 15 mg Na/sub 2/SeO/sub 3//kg live weight within 21 hours. Thirty-six animals were involved in the second experiment of the series. They had 50 or 100 percent Ursoselevit-Praemix (30 ppm Se) in their rations. Body mass development of the test animals was superior to that recorded from the controls in the first 50 days, after which limit the former declined strongly in a few days. Their general condition worsened. Postmortem finding, following slaughter, included catarrhal enteritis, toxic liver dystrophy, scattered pulpous tumors in the spleen, and interstitial nephritis. In the third experiment (50 percent Ursoselevit-Praemix with 60 ppm Se in the rations), the test animals developed better than the controls during the first two months, after which point they exhibited the same clinical symptoms as those observed in the second experiment, stopped putting on weight, and eventually turned cachectic. The pathomorphological findings were identical with those obtained from the second experiment. The selenium concentrations in the organs of the test animals all were much higher than those of the controls. Their amounts in excess to base values were up to eleven times in the blood, nine times in the liver, twelve times in the kidneys, and 13 times in the muscles. 11 references, 2 figures, 2 tables.

  18. Synthesis and crystal structure of a new neodymium(III) selenate-selenite: Nd2(SeO4)(SeO3)2(H2O)2

    International Nuclear Information System (INIS)

    Feng Meiling; Mao Jianggao

    2005-01-01

    The title new neodymium(III) selenate-selenite was obtained by hydrothermal reactions of neodymium(III) oxide, H 2 SeO 4 and 1,10-phenanthroline at 140 o C. Its structure was established by single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic space group C2/c with cell parameters of a = 12.258(2) A, b 7.1024(15) A, c = 13.391(3) A, β = 104.250(2) o . The structure of Nd 2 (SeO 4 )(SeO 3 ) 2 (H 2 O) 2 is isomorphous with that of Er 2 (SeO 4 )(SeO 3 ) 2 (H 2 O) 2 , which was refined in the monoclinic space group C2 with the disordered selenate group. It features an ordered 3D network with channels along b-axis. The selenate or selenite groups alone can form a 2D layer with the Nd(III) ions. IR spectrum, TGA and luminescent studies have also been performed

  19. The synthesis and crystal structures of the first rare-earth alkaline-earth selenite chlorides MNd10(SeO3)12Cl8 (M=Ca and Sr)

    International Nuclear Information System (INIS)

    Berdonosov, P.S.; Olenev, A.V.; Dolgikh, V.A.; Lightfoot, P.

    2007-01-01

    Two new alkaline-earth Nd selenite chlorides MNd 10 (SeO 3 ) 12 Cl 8 (M=Ca, Sr) were obtained using crystal growth from alkaline-earth chloride melts in quartz tubes. These new compounds crystallize in the orthorhombic system in space group C cca (no. 68). The compounds were studied by energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction. It was shown that both compounds adopt the same structure type, constructed by complex [M 11 (SeO 3 ) 12 ] 8+ slabs separated by chloride anion layers perpendicular to the longest cell parameter. The SeO 3 groups show a pyramidal shape and may be described as SeO 3 E tetrahedra. Such SeO 3 groups decorate the Nd-O skeletons forming the [M 11 (SeO 3 ) 12 ] 8+ slabs. - Graphical abstract: Two new alkaline-earth Nd selenite chlorides MNd 10 (SeO 3 ) 12 Cl 8 (M=Ca, Sr) were synthesized. These structures are constructed by [M 11 (SeO 3 ) 12 ] 8+ slabs separated by chloride anion layers

  20. Comparative study of DL-selenomethionine vs sodium selenite and seleno-yeast on antioxidant activity and selenium status in laying hens.

    Science.gov (United States)

    Jing, C L; Dong, X F; Wang, Z M; Liu, S; Tong, J M

    2015-05-01

    The aim of this study was to compare the effect of DL-selenomethionine (SM) with 2 routinely used Se sources, sodium selenite (SS) and seleno-yeast (SY), on relative bioavailability based on antioxidant activity and tissue Se content. Six hundred thirty 131-day-old brown laying hens were randomly assigned to 7 treatments for 168 d (24 wks) with 6 replicates of 15 hens per replicate. The SS and SY animals were supplemented a cornmeal and soybean diet that supplied a total Se 0.3 mg/kg whereas SM was added at 4 different levels to the total Se at 0.1, 0.3, 0.5 and 0.7 mg/kg. All hens fed the Se-supplemented diet showed higher glutathione peroxidase (GSH-Px) activity (P < 0.01), higher superoxide dismutase (SOD) activity (P < 0.05), lower malondialdehyde (MDA) content (P < 0.05) in plasma, and greater Se contents in egg yolks, albumen, leg muscle, breast muscle, liver, and plasma compared with those fed the control diet (P < 0.01). The organic sources (SY and SM) exhibited a greater ability to increase the GSH-Px activity (P < 0.01) and Se content in albumen (P < 0.01), leg, and breast muscles (P = 0.0099 and P = 0.0014, respectively) than the SS that was added at 0.3 mg Se/kg. The higher SM added levels increased the GSH-Px activity until the dose of 0.5mg Se/kg (P < 0.01).The greater Se concentrations in albumen, muscle and liver appeared in the higher SM-added level, as well as above the dose of 0.1 mg Se/kg (P < 0.01). In addition, hens fed the diet with SM accumulated more Se in albumen, leg, and breast muscle than those fed diets with SY (P < 0.05). These results confirmed the higher ability of organic Se sources to increase the antioxidant activity and Se deposition in egg albumen, leg, and breast muscles compared with SS, and demonstrated a significantly better efficiency of SM compared with SY for albumen and muscle Se enrichment. © 2015 Poultry Science Association Inc.

  1. Solid-state synthesis, structure and properties of a novel open-framework cadmium selenite bromide: [Cd10(SeO3)8Br4]·HBr·H2O

    International Nuclear Information System (INIS)

    Chen, Wen-Tong; Wang, Ming-Sheng; Wang, Guan-E; Chen, Hui-Fen; Guo, Guo-Cong

    2013-01-01

    A novel open-framework cadmium selenite bromide, [Cd 10 (SeO 3 ) 8 Br 4 ]·HBr·H 2 O (1), has been obtained by a solid-state reaction at 450 °C, and the structure has been determined by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in Pbcm of the orthorhombic system: a=10.882(3), b=16.275(5), c=18.728(6) Å, V=3317(2) Å 3 , R1/wR2=0.0411/0.0659. Compound 1 is characteristic of a novel 3-D open-framework structure, composing ∞ 2 [CdSeO 3 ] layers and the pillars of edge-shared CdO 3 Br 2 square pyramids. The lattice water molecules and the HBr molecules locate in the voids of the framework. Optical absorption spectrum of 1 reveals the presence of an optical gap of 1.65 eV. Solid-state photoluminescent study indicates that compound 1 exhibits strong violet emission. TG–DSC measurement shows that compound 1 is thermally stable up to 200 °C. - Graphical abstract: A metal selenite halide has been synthesized and features a 3-D open-framework structure, composing edge-shared CdO 8 decahedra and pillars of edge-sharing pentahedra. UV–vis, TG–DSC and luminescent measurements are also reported. Highlights: • This paper reports a novel cadmium selenite bromide obtained by an intermediate-temperature solid-state reaction. • The title compound is characteristic of a novel 3-D open-framework structure, composing ∞ 2 [CdSeO 3 ] layers and the pillars of edge-shared CdO 3 Br 2 square pyramids. • The title compound is thermally stable up to 200 °C. • The title compound has an optical gap of 1.65 eV and exhibits strong violet emission

  2. Effect of dietary selenium and vitamin E on the ultrastructure and ATP concentration of boar spermatozoa, and the efficacy of added sodium selenite in extended semen on sperm motility.

    Science.gov (United States)

    Marin-Guzman, J; Mahan, D C; Whitmoyer, R

    2000-06-01

    Three experiments evaluated the effects of dietary Se and vitamin E on the ultrastructure of spermatozoa, ATP concentration of spermatozoa, and the effects of adding sodium selenite to semen extenders on subsequent sperm motility. The experiment was a 2 x 2 arrangement of treatments in a randomized complete block design. A total of 10 mature boars were fed from weaning to 18 mo of age diets fortified with two levels of supplemental Se (0 or .5 ppm) or vitamin E (0 or 220 IU/kg diet). The nonfortified diets contained .06 ppm Se and 4.4 IU vitamin E/kg. In Exp. 1, the spermatozoa from all boars were examined by electron microscopy. Vitamin E had no effect on structural abnormalities in the spermatozoa. When the low-Se diet was fed the acrosome or nuclei of the spermatozoa was unaffected, but the mitochondria in the tail midpiece were more oval with wider gaps between organelles. The plasma membrane connection to the tail midpiece was not tightly bound as when boars were fed Se. Immature spermatozoa with cytoplasmic droplets were more numerous when boars were fed the low-Se diet, but the occurrence of midpiece abnormalities occurred in boars fed diets with or without Se or vitamin E. Our results suggest that Se may enhance spermatozoa maturation in the epididymis and may reduce the number of sperm with cytoplasmic droplets. In Exp. 2, the concentration of ATP in the spermatozoa was evaluated in the semen of all treatment boars. When the low-Se diet was fed, ATP concentration was lower (P boar semen with a semen extender with sodium selenite added at 0, .3, .6, or .9 ppm Se. Three ejaculates from each boar were used to evaluate these effects on sperm motility to 48 h after dilution. Sperm motility declined (P extender, and this decline was exacerbated as the concentration of added Se increased (P boars resulted in abnormal spermatozoal mitochondria, a lower ATP concentration in the spermatozoa, and a loose apposition of the plasma membrane to the helical coil of the

  3. Synthesis, structure, and characterization of two new bismuth(III) selenite/tellurite nitrates: [(Bi3O2)(SeO3)2](NO3) and [Bi(TeO3)](NO3)

    Science.gov (United States)

    Meng, Chang-Yu; Wei, Ming-Fang; Geng, Lei; Hu, Pei-Qing; Yu, Meng-Xia; Cheng, Wen-Dan

    2016-07-01

    Two new bismuth(III) selenite/tellurite nitrates, [(Bi3O2)(SeO3)2](NO3) and [Bi(TeO3)](NO3), have been synthesized by conventional facile hydrothermal method at middle temperature 200 °C and characterized by single-crystal X-ray diffraction, powder diffraction, UV-vis-NIR optical absorption spectrum, infrared spectrum and thermal analylsis. Both [(Bi3O2)(SeO3)2](NO3) and [Bi(TeO3)](NO3) crystallize in the monoclinic centronsymmetric space group P21/c with a=9.9403(4) Å, b=9.6857(4) Å, c=10.6864(5) Å, β=93.1150(10)° for [(Bi3O2)(SeO3)2](NO3) and a=8.1489(3) Å, b=9.0663(4) Å, c=7.4729(3) Å, β=114.899(2)° for Bi(TeO3)(NO3), respectively. The two compounds, whose structures are composed of three different asymmetric building units, exhibit two different types of structures. The structure of [(Bi3O2)(SeO3)2](NO3) features a three-dimensional (3D) bismuth(III) selenite cationic tunnel structure [(Bi3O2)(SeO3)2] 3∞ with NO3- anion group filling in the 1D tunnel along b axis. The structure of [Bi(TeO3)](NO3) features 2D bismuth(III) tellurite [Bi(TeO3)2]2∞ layers separated by NO3- anion groups. The results of optical diffuse-reflectance spectrum measurements and electronic structure calculations based on density functional theory methods show that the two compounds are wide band-gap semiconductors.

  4. Three new d10 transition metal selenites containing PO4 tetrahedron: Cd7(HPO4)2(PO4)2(SeO3)2, Cd6(PO4)1.34(SeO3)4.66 and Zn3(HPO4)(SeO3)2(H2O)

    Science.gov (United States)

    Ma, Yun-Xiang; Gong, Ya-Ping; Hu, Chun-li; Mao, Jiang-Gao; Kong, Fang

    2018-06-01

    Three new d10 transition metal selenites containing PO4 tetrahedron, namely, Cd7(HPO4)2(PO4)2(SeO3)2 (1), Cd6(PO4)1.34(SeO3)4.66 (2) and Zn3(HPO4)(SeO3)2(H2O) (3), have been synthesized by hydrothermal reaction. They feature three different structural types. Compound 1 exhibits a novel 3D network composed of 3D cadmium selenite open framework with phosphate groups filled in the 1D helical tunnels. The structure of compound 2 displays a new 3D framework consisted of 2D cadmium oxide layers bridged by SeO3 and PO4 groups. Compound 3 is isostructural with the reported solids of Co3(SeO3)3-x(PO3OH)x(H2O) when x is equal to 1.0. Its structure could be viewed as a 3D zinc oxide open skeleton with SeO3 and HPO4 polyhedra attached on the wall of the tunnels. They represent the only examples in metal selenite phosphates in addition to the above cobalt compounds. Optical diffuse reflectance spectra revealed that these solids are insulators, which are consistent with the results of band structure computations based on DFT algorithm.

  5. New quaternary alkali metal cadmium selenites, A2Cd(SeO3)2 (A = K, Rb, and Cs) and Li2Cd3(SeO3)4

    Science.gov (United States)

    Lü, Minfeng; Jo, Hongil; Oh, Seung-Jin; Ok, Kang Min

    2017-12-01

    A series of new alkali metal cadmium selenites, A2Cd(SeO3)2 (A = K, Rb, and Cs) and Li2Cd3(SeO3)4 have been synthesized in phase pure forms through hydrothermal and solid-state reactions. Structural analyses using single crystal X-ray diffraction indicate that while A2Cd(SeO3)2 and Li2Cd3(SeO3)4 reveal layered structures consisting of CdO6 and SeO3 polyhedra, their symmetry, bonding modes, and the orientation of lone pairs on Se4+ cations are different. A closer examination suggests that the observed structural variations found in the reported materials are attributed to the structure-directing effect of alkali metal cations with different sizes. Scanning electron microscopy/energy dispersive analysis by X-ray, thermogravimetric analysis, Infrared and UV-vis diffuse reflectance spectroscopy, transformation reactions under hydrothermal conditions, and local dipole moment calculations for the reported materials are also reported.

  6. Synthesis, second-harmonic generation (SHG), and photoluminescence (PL) properties of noncentrosymmetric bismuth selenite solid solutions, Bi2-xLnxSeO5 (Ln = La and Eu; x = 0-0.3)

    Science.gov (United States)

    Qi, Hai-Xin; Jo, Hongil; Oh, Seung-Jin; Ok, Kang Min

    2018-02-01

    A series of La3+ or Eu3+-doped noncentrosymmetric (NCS) bismuth selenite solid solutions, Bi2-xLnxSeO5 (x = 0.1, 0.2, and 0.3), have been successfully synthesized via standard solid-state reactions under vacuum with Bi2O3, La2O3 (or Eu2O3), and SeO2 as starting materials. Crystal structures and phase purities of the resultant materials were thoroughly characterized by powder X-ray diffraction using the Rietveld method. The results clearly show that the reported materials crystallize in the orthorhombic space group, Abm2 (No. 39), and exhibit pseudo-three-dimensional frameworks consisting of BiO3, BiO5, and SeO3 polyhedra that share edges and corners. Detailed diffraction studies indicate that the cell volume of Bi2-xLnxSeO5 decreases with an increasing amount of Ln3+ on the Bi3+ sites. However, no ordering between Ln3+ and Bi3+ was observed in the Bi2-xLnxSeO5 solid solutions. Powder second-harmonic generation (SHG) measurements, using 1064 nm radiation, reveal that SHG efficiencies of Bi2-xLnxSeO5 solid solutions continuously decrease as more Ln3+ cations are added to the sites of polarizable Bi3+ cations. Photoluminescence (PL) measurements on Bi2-xEuxSeO5 exhibit three specific emission peaks at 592, 613, and 702 nm (5D0 → 7F1, 2, 4) owing to the 4f-4f intrashell transitions of Eu3+ ions.

  7. Chemical and structural evolution in the Th-SeO3(2-)/SeO4(2-) system: from simple selenites to cluster-based selenate compounds.

    Science.gov (United States)

    Xiao, Bin; Langer, Eike; Dellen, Jakob; Schlenz, Hartmut; Bosbach, Dirk; Suleimanov, Evgeny V; Alekseev, Evgeny V

    2015-03-16

    While extensive success has been gained in the structural chemistry of the U-Se system, the synthesis and characterization of Th-based Se structures are widely unexplored. Here, four new Th-Se compounds, α-Th(SeO3)2, β-Th(SeO3)2, Th(Se2O5)2, and Th3O2(OH)2(SeO4)3, have been obtained from mild hydrothermal or low-temperature (180-220 °C) flux conditions and were subsequently structurally and spectroscopically characterized. The crystal structures of α-Th(SeO3)2 and β-Th(SeO3)2 are based on ThO8 and SeO3 polyhedra, respectively, featuring a three-dimensional (3D) network with selenite anions filling in the Th channels along the a axis. Th(Se2O5)2 is a 3D framework composed of isolated ThO8 polyhedra interconnected by [Se2O5](2-) dimers. Th3O2(OH)2(SeO4)3 is also a 3D framework constructed by octahedral hexathorium clusters [Th6(μ3-O)4(μ3-OH)4](12+), which are interlinked by selenate groups SeO4(2-). The positions of the vibrational modes associated with both Se(IV)O3(2-) and Se(VI)O4(2-) units, respectively, were determined for four compounds, and the Raman spectra of α- and β-Th(SeO3)2 are compared and discussed in detail.

  8. Variable dimensionality and framework found in a series of quaternary zinc selenites, A2Zn3(SeO3)4·xH2O (A = Na, Rb, and Cs; 0≤x≤1) and Cs2Zn2(SeO3)3·2H2O

    International Nuclear Information System (INIS)

    Lü, Minfeng; Jo, Hongil; Oh, Seung-Jin; Ok, Kang Min

    2017-01-01

    Five new alkali metal zinc selenites, A 2 Zn 3 (SeO 3 ) 4 ·xH 2 O (A = Na, Rb, and Cs; 0≤x≤1) and Cs 2 Zn 2 (SeO 3 ) 3 ·2H 2 O have been synthesized by heating a mixture of ZnO, SeO 2 and A 2 CO 3 (A = Na, Rb, and Cs), and characterized by X-ray diffraction (XRD) and spectroscopic analyses techniques. All of the reported materials revealed a rich structural chemistry with different frameworks and connection modes of Zn 2+ . While Rb 2 Zn 3 (SeO 3 ) 4 and Cs 2 Zn 3 (SeO 3 ) 4 ·H 2 O revealed three-dimensional frameworks consisting of isolated ZnO 4 tetrahedra and SeO 3 polyhedra, Na 2 Zn 3 (SeO 3 ) 4 , Cs 2 Zn 3 (SeO 3 ) 4 , and Cs 2 Zn 2 (SeO 3 ) 3 ·2H 2 O contained two-dimensional [Zn 3 (SeO 3 ) 4 ] 2- layers. Specifically, whereas isolated ZnO 4 tetrahedra and SeO 3 polyhedra are arranged into two-dimensional [Zn 3 (SeO 3 ) 4 ] 2- layers in two cesium compounds, circular [Zn 3 O 10 ] 14- chains and SeO 3 linkers are formed in two-dimensional [Zn 3 (SeO 3 ) 4 ] 2- layers in Na 2 Zn 3 (SeO 3 ) 4 . Close structural examinations suggest that the size of alkali metal is significant in determining the framework geometry as well as connection modes of transition metal cations. - Graphical abstract: Variable dimensions and frameworks were found in a series of quaternary zinc selenites, A 2 Zn 3 (SeO 3 ) 4 (A = Na, Rb and Cs). - Highlights: • Five novel quaternary zinc selenites are synthesized. • All the selenites with different structures contain polarizable d 10 and lone pair cations. • The size of alkali metal cations is significant in determining the framework geometry.

  9. Variable dimensionality and new uranium oxide topologies in the alkaline-earth metal uranyl selenites AE[UO2)(SeO3)2] (AE=Ca, Ba) and Sr[UO2)(SeO3)2] · 2H2O

    International Nuclear Information System (INIS)

    Almond, Philip M.; Peper, Shane M.; Bakker, Eric; Albrecht-Schmitt, Thomas E.

    2002-01-01

    Three new alkaline-earth metal uranyl selenites, Ca[UO 2 )(SeO 3 ) 2 ] (1), Sr[UO 2 )(SeO 3 ) 2 ] · 2H 2 O (2), and Ba[UO 2 )(SeO 3 ) 2 ] (3), have been prepared from the reactions of CaCO 3 and Ca(OH) 2 , SrCl 2 and Sr(OH) 2 , or BaCl 2 and Ba(OH) 2 with UO 3 and SeO 2 under mild hydrothermal conditions. Single-crystal X-ray diffraction experiments reveal that the structures of 1-3 differ in both connectivity and dimensionality even though all contain the same fundamental building unit, namely [UO 2 (SeO 3 ) 4 ]. This polyhedron consists of a linear uranyl unit that is bound by one chelating and three bridging selenite anions creating a pentagonal bipyramidal environment around the U(VI) center. The crystal structure of 1 contains one-dimensional ribbons where the edges are terminated by monodentate selenite anions. The interior of the ribbons are constructed from edge-sharing pentagonal bipyramidal UO 7 units. The structure of 2 is also one-dimensional; however, here there are chains of edge-sharing pentagonal bipyramidal UO 7 dimers that are connected by bridging selenite anions. Ba[(UO 2 )(SeO 3 ) 2 ] (3) is two-dimensional, and the highly ruffled anionic sheets present in this structure are formed from both bridging and chelating/bridging selenite anions bound to uranyl moieties. The anionic substructures in 1-3 are separated by Ca 2+ , Sr 2+ , or Ba 2+ cations. Crystallographic data (193 K, MoKα, λ=0.71073): 1, triclinic, space group P1-bar, a=5.5502(6) A, b=6.6415(7) A, c=11.013(1) A, α=104.055(2) deg., β=93.342(2) deg., γ=110.589(2) deg. , Z=2, R(F)=4.56% for 100 parameters with 1530 reflections with I>2σ(I); 2, triclinic, space group P1-bar, a=7.0545(5) A, b=7.4656(5) A, c=10.0484(6) A, α=106.995(1) deg., β=108.028(1) deg., γ=98.875(1) deg., Z=2, R(F)= 2.43% for 128 parameters with 2187 reflections with I>2σ(I); 3, monoclinic, space group P2 1 /c, a=7.3067(6) A, b=8.1239(7) A, c=13.651(1) A, β=100.375(2) deg., Z=4, R(F)=4.31% for 105 parameters

  10. XAS studies on selenite reduction by pyrite

    International Nuclear Information System (INIS)

    Kang Mingliang; Liu Chunli; Chen Fanrong; Charlet, Laurnet

    2012-01-01

    The interaction of aqueous Se (IV) with pyrite were systematically investigated in light of thermodynamic calculations and X-ray Absorption Spectroscopy (XAS). The results from the speciation study reveal that the reduction product is Se (O) when natural pyrite reacts with Se (N) at pH≤5.65, while small amount of FeSeO 3 or iron selenides may be formed at pH 6.1. At pH≥6.94, due to the precipitation of Fe (Ⅲ) -oxyhydroxide, the formation of the thermodynamically most stable species, FeSe 2 , is inhibited. However, when the reactive nanopyrite-greigite was used for reaction, the thermodynamically most stable species, FeSe 2 , was found for the first time as the predominant product in the present study, suggesting that 79 Se can be immobilized in its most insoluble form, FeSe 2 , in Fe (Ⅱ) -sulfide containing environment. This study confirms that pyrite can significantly attenuate the mobility of Se by reductive precipitation, and that the reaction process does not produce protons under acidic or neutral condition when Se (O) is formed. (authors)

  11. Short range order of selenite glasses

    Czech Academy of Sciences Publication Activity Database

    Neov, Dimitar; Gerasimova, I.; Yordanov, S.; Lakov, L.; Mikula, Pavol; Lukáš, Petr; Dimitriev, Y.

    1999-01-01

    Roč. 40, č. 2 (1999), s. 111-112 ISSN 0031-9090 R&D Projects: GA ČR GV202/97/K038; GA AV ČR KSK1048601 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.822, year: 1999

  12. Avaliação do efeito radioprotetor do selenito de sódio no processo de reparação tecidual em ratos Evaluation of the radioprotective effect of sodium selenite in the tissue repair process in rats

    Directory of Open Access Journals (Sweden)

    Fabrício M. Tuji

    2005-09-01

    Full Text Available OBJETIVO: Avaliar a ação radioprotetora do selenito de sódio no processo de reparação tecidual. MATERIAIS E MÉTODOS: Ratos Wistar foram submetidos a procedimento cirúrgico para a realização de ferida na região dorsal. Os animais foram divididos em quatro grupos experimentais: controle, selênio, irradiado e selênio-irradiado. Os grupos selênio e selênio-irradiado receberam 2,0 mg/kg de selenito de sódio, 48 horas após a cirurgia. Os grupos irradiado e selênio-irradiado foram submetidos à irradiação em dose única de 6 Gy, administrada somente nas bordas das feridas. Após 4, 7, 13 e 21 dias do procedimento cirúrgico, os animais foram sacrificados e avaliados por meio de análise morfológica, histoquímica e birrefringência do tecido. RESULTADOS: O aspecto estrutural e morfológico, assim como a qualidade do tecido e sua maturação através da quantidade e disposição dos feixes de fibras colágenas, juntamente com o seu grau de orientação macromolecular, permitiu observar a presença de intenso retardo provocado pela irradiação, bem como o efeito radioprotetor do selenito de sódio no processo de reparação. CONCLUSÃO: Dentro das condições experimentais utilizadas, o selenito de sódio apresentou-se como radioprotetor eficaz, visto que o processo de reparação no grupo selênio-irradiado comportou-se, histologicamente, semelhante ao grupo controle.OBJECTIVE: To evaluate the radioprotective effect of sodium selenite in the tissue repair process. MATERIALS AND METHODS: Male Wistar rats submitted to a surgical procedure to produce a wound in the dorsal region. These animals were then divided in four experimental groups: control, selenium, irradiated and selenium-irradiated. The selenium and selenium-irradiated groups received sodium selenite (2.0 mg/kg, 48 hours after surgery. The irradiated and selenium-irradiated groups received a single dose of 6 Gy, administered only in the borders of the wound. The animals were

  13. Synthesis and crystal structure of new uranyl selenite(IV)-selenate(VI) [C5H14N][(UO2)3(SeO4)4(HSeO3)(H2O)](H2SeO3)(HSeO4)

    International Nuclear Information System (INIS)

    Krivovichev, S.V.; Tananaev, I.G.; Myasoedov, B.F.; Kalenberg, V.

    2006-01-01

    Crystals of new uranyl selenite(IV)-selenate(VI) [C 5 H 14 N][(UO 2 ) 3 (SeO 4 ) 4 (HSeO 3 )(H 2 O)](H 2 SeO 3 )(HSeO 4 ) are obtained by the method of evaporation from aqueous solutions. Compound has triclinic lattice, space group P1-bar, a=11.7068(9), b=14.8165(12), c=16.9766(15), α=73.899(6), β=76.221(7), γ=89.361(6) Deg, V=2743.0(4) A 3 , Z=2. Laminated complexes (UO 2 ) 3 (SeO 4 ) 4 (HSeO 3 )(H 2 O)] 3- are the basis of the structure. [HSe(VI)O 4 ] - , [H 2 Se(IV)O 3 ] complexes and protonated methylbutylamine cations are disposed between layers [ru

  14. Variable dimensionality and framework found in a series of quaternary zinc selenites, A{sub 2}Zn{sub 3}(SeO{sub 3}){sub 4}·xH{sub 2}O (A = Na, Rb, and Cs; 0≤x≤1) and Cs{sub 2}Zn{sub 2}(SeO{sub 3}){sub 3}·2H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Lü, Minfeng; Jo, Hongil; Oh, Seung-Jin; Ok, Kang Min, E-mail: kmok@cau.ac.kr

    2017-01-15

    Five new alkali metal zinc selenites, A{sub 2}Zn{sub 3}(SeO{sub 3}){sub 4}·xH{sub 2}O (A = Na, Rb, and Cs; 0≤x≤1) and Cs{sub 2}Zn{sub 2}(SeO{sub 3}){sub 3}·2H{sub 2}O have been synthesized by heating a mixture of ZnO, SeO{sub 2} and A{sub 2}CO{sub 3} (A = Na, Rb, and Cs), and characterized by X-ray diffraction (XRD) and spectroscopic analyses techniques. All of the reported materials revealed a rich structural chemistry with different frameworks and connection modes of Zn{sup 2+}. While Rb{sub 2}Zn{sub 3}(SeO{sub 3}){sub 4} and Cs{sub 2}Zn{sub 3}(SeO{sub 3}){sub 4}·H{sub 2}O revealed three-dimensional frameworks consisting of isolated ZnO{sub 4} tetrahedra and SeO{sub 3} polyhedra, Na{sub 2}Zn{sub 3}(SeO{sub 3}){sub 4}, Cs{sub 2}Zn{sub 3}(SeO{sub 3}){sub 4}, and Cs{sub 2}Zn{sub 2}(SeO{sub 3}){sub 3}·2H{sub 2}O contained two-dimensional [Zn{sub 3}(SeO{sub 3}){sub 4}]{sup 2-} layers. Specifically, whereas isolated ZnO{sub 4} tetrahedra and SeO{sub 3} polyhedra are arranged into two-dimensional [Zn{sub 3}(SeO{sub 3}){sub 4}]{sup 2-} layers in two cesium compounds, circular [Zn{sub 3}O{sub 10}]{sup 14-} chains and SeO{sub 3} linkers are formed in two-dimensional [Zn{sub 3}(SeO{sub 3}){sub 4}]{sup 2-} layers in Na{sub 2}Zn{sub 3}(SeO{sub 3}){sub 4}. Close structural examinations suggest that the size of alkali metal is significant in determining the framework geometry as well as connection modes of transition metal cations. - Graphical abstract: Variable dimensions and frameworks were found in a series of quaternary zinc selenites, A{sub 2}Zn{sub 3}(SeO{sub 3}){sub 4} (A = Na, Rb and Cs). - Highlights: • Five novel quaternary zinc selenites are synthesized. • All the selenites with different structures contain polarizable d{sup 10} and lone pair cations. • The size of alkali metal cations is significant in determining the framework geometry.

  15. Synthesis, structure, and characterization of two new bismuth(III) selenite/tellurite nitrates: [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and [Bi(TeO{sub 3})](NO{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Chang-Yu; Wei, Ming-Fang [Department of Chemistry and Materials, Yulin Normal University,Yulin, Guangxi 537000 (China); Geng, Lei, E-mail: lgeng.cn@gmail.com [Department of Materials Science and Engineering, Huaibei Normal University, Huaibei, Anhui 235000 (China); Hu, Pei-Qing; Yu, Meng-Xia [Department of Chemistry and Materials, Yulin Normal University,Yulin, Guangxi 537000 (China); Cheng, Wen-Dan [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

    2016-07-15

    Two new bismuth(III) selenite/tellurite nitrates, [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and [Bi(TeO{sub 3})](NO{sub 3}), have been synthesized by conventional facile hydrothermal method at middle temperature 200 °C and characterized by single-crystal X-ray diffraction, powder diffraction, UV–vis–NIR optical absorption spectrum, infrared spectrum and thermal analylsis. Both [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and [Bi(TeO3)](NO3) crystallize in the monoclinic centronsymmetric space group P2{sub 1}/c with a=9.9403(4) Å, b=9.6857(4) Å, c=10.6864(5) Å, β=93.1150(10)° for [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and a=8.1489(3) Å, b=9.0663(4) Å, c=7.4729(3) Å, β=114.899(2)° for Bi(TeO3)(NO3), respectively. The two compounds, whose structures are composed of three different asymmetric building units, exhibit two different types of structures. The structure of [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) features a three-dimensional (3D) bismuth(III) selenite cationic tunnel structure [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}] {sup 3}{sub ∞} with NO{sub 3}{sup −} anion group filling in the 1D tunnel along b axis. The structure of [Bi(TeO{sub 3})](NO{sub 3}) features 2D bismuth(III) tellurite [Bi(TeO{sub 3}){sub 2}]{sup 2}{sub ∞} layers separated by NO{sub 3}{sup −} anion groups. The results of optical diffuse-reflectance spectrum measurements and electronic structure calculations based on density functional theory methods show that the two compounds are wide band-gap semiconductors. - Graphical abstract: Two novel bismuth{sup III} selenite/tellurite nitrates [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) with 3D tunnel structure and [Bi(TeO{sub 3})](NO{sub 3}) with 2D layer structure have been firstly synthesized and characterized. Display Omitted - Highlights: • Two novel bismuth{sup III} nitrates [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and [Bi(TeO{sub 3})](NO{sub 3}) were firstly

  16. Syntheses and structural characterization of vanado-tellurites and vanadyl-selenites: SrVTeO{sub 5}(OH), Cd{sub 2}V{sub 2}Te{sub 2}O{sub 11}, Ca{sub 3}VSe{sub 4}O{sub 13}·H{sub 2}O and Ba{sub 2}VSe{sub 3}O{sub 10}

    Energy Technology Data Exchange (ETDEWEB)

    Konatham, Satish; Vidyasagar, Kanamaluru, E-mail: kvsagar@iitm.ac.in

    2017-05-15

    Four new quaternary vanado-tellurites and vanadyl-selenites, namely, SrVTeO{sub 5}(OH)(1), Cd{sub 2}V{sub 2}Te{sub 2}O{sub 11}(2), Ca{sub 3}VSe{sub 4}O{sub 13}·H{sub 2}O(3) and Ba{sub 2}VSe{sub 3}O{sub 10}(4) have been synthesized and structurally characterized by single crystal X-ray diffraction. The oxidation state of vanadium is +5 in tellurites 1 and 2 and +4 in selenites 3 and 4. The structures of SrVTeO{sub 5}(OH)(1) and Cd{sub 2}V{sub 2}Te{sub 2}O{sub 11}(2) compounds consist of (VTeO{sub 5}(OH)){sup 2-} and (V{sub 2}Te{sub 2}O{sub 11}){sup 4-}anionic chains respectively, which are built from tetrahedral VO{sub 4} and disphenoidal TeO{sub 4} moieties. Similarly the structures of Ca{sub 3}VSe{sub 4}O{sub 13}·H{sub 2}O(3) and Ba{sub 2}VSe{sub 3}O{sub 10}(4) respectively contain (VSe{sub 2}O{sub 7}){sup 2-} and (VSe{sub 3}O{sub 10}){sup 4-} anionic chains, which are made up of octahedral VO{sub 6} and pyramidal SeO{sub 3} units. Compounds 1 and 3 have been characterized by thermogravimetric and infrared spectroscopic methods. Compounds 1 and 2 are wide band gap semiconductors. - Graphical abstract: Ca{sub 3}VSe{sub 4}O{sub 13}·H{sub 2}O and Ba{sub 2}VSe{sub 3}O{sub 10} compounds contain (VSe{sub 2}O{sub 7}){sup 2-} and (VSe{sub 3}O{sub 10}){sup 4-} chains. - Highlights: • Four new vanado-tellurites and vanadyl-selenites are synthesized. • Their structural features are different. • The vanado-tellurites are wide band gap semiconductors.

  17. Variable dimensionality and framework found in a series of quaternary zinc selenites, A2Zn3(SeO3)4·xH2O (A = Na, Rb, and Cs; 0≤x≤1) and Cs2Zn2(SeO3)3·2H2O

    Science.gov (United States)

    Lü, Minfeng; Jo, Hongil; Oh, Seung-Jin; Ok, Kang Min

    2017-01-01

    Five new alkali metal zinc selenites, A2Zn3(SeO3)4·xH2O (A = Na, Rb, and Cs; 0≤x≤1) and Cs2Zn2(SeO3)3·2H2O have been synthesized by heating a mixture of ZnO, SeO2 and A2CO3 (A = Na, Rb, and Cs), and characterized by X-ray diffraction (XRD) and spectroscopic analyses techniques. All of the reported materials revealed a rich structural chemistry with different frameworks and connection modes of Zn2+. While Rb2Zn3(SeO3)4 and Cs2Zn3(SeO3)4·H2O revealed three-dimensional frameworks consisting of isolated ZnO4 tetrahedra and SeO3 polyhedra, Na2Zn3(SeO3)4, Cs2Zn3(SeO3)4, and Cs2Zn2(SeO3)3·2H2O contained two-dimensional [Zn3(SeO3)4]2- layers. Specifically, whereas isolated ZnO4 tetrahedra and SeO3 polyhedra are arranged into two-dimensional [Zn3(SeO3)4]2- layers in two cesium compounds, circular [Zn3O10]14- chains and SeO3 linkers are formed in two-dimensional [Zn3(SeO3)4]2- layers in Na2Zn3(SeO3)4. Close structural examinations suggest that the size of alkali metal is significant in determining the framework geometry as well as connection modes of transition metal cations.

  18. Bioreduction of selenite and tellurite by Phanerochaete chrysosporium

    NARCIS (Netherlands)

    Espinosa‐Ortiz, E.J.

    2015-01-01

    Selenium (Se) and tellurium (Te) are elements, they are part of the chalcogens (VI‐A group of the periodic table) and share common properties. These metalloids are of commercial interest due to their physicochemical properties, and they have been used in a broad range of applications in advanced

  19. Effects of various doses of selenite on stinging nettle (Urtica dioica L.).

    Science.gov (United States)

    Krystofova, Olga; Adam, Vojtech; Babula, Petr; Zehnalek, Josef; Beklova, Miroslava; Havel, Ladislav; Kizek, Rene

    2010-10-01

    The aim of this study was to investigate the effects of selenium (Se) on the growth, accumulation and possible mechanisms of Se transport in certain parts (roots, leaves, stamp and apex) of nettle (Urtica dioica L.) plants. Se was supplemented by one-shot and two repeated doses to the soil (2.0 and 4.0 mg Se per kg of substrate). Selenium content in roots increased linearly with dose and was significantly higher compared to other plant parts of interest. However, growth of the above-ground parts of plant as well as roots was slightly inhibited with increasing selenium concentration in comparison to the untreated plants. The content of phytochelatin2, a low molecular mass peptide containing a sulfhydryl group, correlated well with the Se content. This suggests a possible stimulation of synthesis of this plant peptide by Se.

  20. Effects of Various Doses of Selenite on Stinging Nettle (Urtica dioica L.)

    Science.gov (United States)

    Krystofova, Olga; Adam, Vojtech; Babula, Petr; Zehnalek, Josef; Beklova, Miroslava; Havel, Ladislav; Kizek, Rene

    2010-01-01

    The aim of this study was to investigate the effects of selenium (Se) on the growth, accumulation and possible mechanisms of Se transport in certain parts (roots, leaves, stamp and apex) of nettle (Urtica dioica L.) plants. Se was supplemented by one-shot and two repeated doses to the soil (2.0 and 4.0 mg Se per kg of substrate). Selenium content in roots increased linearly with dose and was significantly higher compared to other plant parts of interest. However, growth of the above-ground parts of plant as well as roots was slightly inhibited with increasing selenium concentration in comparison to the untreated plants. The content of phytochelatin2, a low molecular mass peptide containing a sulfhydryl group, correlated well with the Se content. This suggests a possible stimulation of synthesis of this plant peptide by Se. PMID:21139861

  1. Lead and selenite adsorption at water-goethite interfaces from first principles

    Science.gov (United States)

    Leung, Kevin; Criscenti, Louise J.

    2017-09-01

    The complexation of toxic and/or radioactive ions on to mineral surfaces is an important topic in geochemistry. We apply periodic-boundary-conditions density functional theory (DFT) molecular dynamics simulations to examine the coordination of Pb(II), SeO_32- , and their contact ion pairs to goethite (1 0 1) and (2 1 0) surfaces. The multitude of Pb(II) adsorption sites and possibility of Pb(II)-induced FeOH deprotonation make this a complex problem. At surface sites where Pb(II) is coordinated to three FeO and/or FeOH groups, and with judicious choices of FeOH surface group protonation states, the predicted Fe-Pb distances are in good agreement with EXAFS measurements. Trajectories where Pb(II) is in part coordinated to only two surface Fe-O groups exhibit larger fluctuations in Pb-O distances. Pb(II)/SeO_32- contact ion pairs are at least metastable on goethite (2 1 0) surfaces if the SeO_32- has a monodentate Se-O-Fe bond. Our DFT-based molecular dynamics calculations are a prerequisite for calculations of finite temperature equilibrium binding constants of Pb(II) and Pb(II)/SeO_32- ion pairs to goethite adsorption sites.

  2. Inhibition and Inactivation of Uropathogenic Escherichia coli Biofilms on Urinary Catheters by Sodium Selenite

    Directory of Open Access Journals (Sweden)

    Amoolya Narayanan

    2018-06-01

    Full Text Available Urinary tract infections (UTI are the most common hospital-acquired infections in humans and are caused primarily by uropathogenic Escherichia coli (UPEC. Indwelling urinary catheters become encrusted with UPEC biofilms that are resistant to common antibiotics, resulting in chronic infections. Therefore, it is important to control UPEC biofilms on catheters to reduce the risk for UTIs. This study investigated the efficacy of selenium for inhibiting and inactivating UPEC biofilms on urinary catheters. Urinary catheters were inoculated with UPEC and treated with 0 and 35 mM selenium at 37 °C for 5 days for the biofilm inhibition assay. In addition, catheters with preformed UPEC biofilms were treated with 0, 45, 60, and 85 mM selenium and incubated at 37 °C. Biofilm-associated UPEC counts on catheters were enumerated on days 0, 1, 3, and 5 of incubation. Additionally, the effect of selenium on exopolysacchride (EPS production and expression of UPEC biofilm-associated genes was evaluated. Selenium at 35 mM concentration was effective in preventing UPEC biofilm formation on catheters compared to controls (p < 0.05. Further, this inhibitory effect was associated with a reduction in EPS production and UPEC gene expression. Moreover, at higher concentrations, selenium was effective in inactivating preformed UPEC biofilms on catheters as early as day 3 of incubation. Results suggest that selenium could be potentially used in the control of UPEC biofilms on urinary catheters.

  3. Effects of Various Doses of Selenite on Stinging Nettle (Urtica dioica L.

    Directory of Open Access Journals (Sweden)

    Miroslava Beklova

    2010-10-01

    Full Text Available The aim of this study was to investigate the effects of selenium (Se on the growth, accumulation and possible mechanisms of Se transport in certain parts (roots, leaves, stamp and apex of nettle (Urtica dioica L. plants. Se was supplemented by one-shot and two repeated doses to the soil (2.0 and 4.0 mg Se per kg of substrate. Selenium content in roots increased linearly with dose and was significantly higher compared to other plant parts of interest. However, growth of the above-ground parts of plant as well as roots was slightly inhibited with increasing selenium concentration in comparison to the untreated plants. The content of phytochelatin2, a low molecular mass peptide containing a sulfhydryl group, correlated well with the Se content. This suggests a possible stimulation of synthesis of this plant peptide by Se.

  4. Selenite Reduction by Anaerobic Microbial Aggregates: Microbial Community Structure, and Proteins Associated to the Produced Selenium Spheres

    KAUST Repository

    Gonzalez-Gil, Graciela; Lens, Piet N. L.; Saikaly, Pascal

    2016-01-01

    that stretches the cell body. The Se0 spheres produced by the microorganisms were capped with organic material. X-ray photoelectron spectroscopy (XPS) analysis of extracted Se0 spheres, combined with a mathematical approach to analyzing XPS spectra from

  5. High Dietary Intake of Sodium Selenite Does Not Affect Gene Mutation Frequency in Rat Colon and Liver

    Science.gov (United States)

    Previously we reported that both Se deficiency and Cu deficiency decreased plasma homocysteine (pHcys) and increased plasma glutathione (pGSH) in rats. We also showed that the catalytic subunit of glutamate-cysteine ligase (Gclc), which catalyzes the rate limiting step in glutathione biosynthesis, w...

  6. Effects of mercury and selenite on δ-aminolevulinate dehydratase activity and on selected oxidative stress parameters in rats

    International Nuclear Information System (INIS)

    Perottoni, Juliano; Lobato, L.P.; Silveira, Aline; Rocha, J.B.T.; Emanuelli, Tatiana

    2004-01-01

    The present study evaluates the effects of Na 2 SeO 3 and HgCl 2 on kidney and liver of adult rats. In vivo, HgCl 2 (17 μmol/kg, sc) reduced ascorbic acid levels in liver (∼15%), whereas in kidney it reduced ALA-D activity (∼60%) and ascorbic acid levels (∼35%) and increased TBARS content (∼50%). Na 2 SeO 3 (17 μmol/kg, sc) exposure increased the content of nonprotein thiol groups in liver (35-60%) and kidney (∼50-160%), partially prevented mercury-induced ALA-D inhibition in kidney, and completely prevented a mercury-induced increase of TBARS content and decrease of ascorbic acid levels in kidney. In vitro, HgCl 2 and Na 2 SeO 3 inhibited renal and hepatic ALA-D, while HgCl 2 increased TBARS in renal and hepatic tissue preparations. Na 2 SeO 3 increased the rate of glutathione oxidation in vitro. Results indicated that Na 2 SeO 3 protected against HgCl 2 effects in vivo (prevention of mercury interaction with thiol groups and of mercury-induced oxidative damage). In vitro, Na 2 SeO 3 did not prevent mercury effects, but potentiated ALA-D inhibition by mercury, probably due to its ability to oxidize thiol groups

  7. Adsorption of arsenite and selenite using an inorganic ion exchanger based on Fe–Mn hydrous oxide

    KAUST Repository

    Szlachta, Małgorzata; Gerda, Vasyl; Chubar, Natalia

    2012-01-01

    The adsorption behaviour and mechanism of As(III) and Se(IV) oxyanion uptake using a mixed inorganic adsorbent were studied. The novel adsorbent, based on Fe(III)-Mn(III) hydrous oxides and manganese(II) carbonate, was synthesised using a hydrothermal precipitation approach in the presence of urea. The inorganic ion exchanger exhibited a high selectivity and adsorptive capacity towards As(III) (up to 47.6mg/g) and Se(IV) (up to 29.0mg/g), even at low equilibrium concentration. Although pH effects were typical for anionic species (i.e., the adsorption decreased upon pH increase), Se(IV) was more sensitive to pH changes than As(III). The rates of adsorption of both oxyanions were high. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) studies showed that the ion exchange adsorption of both anions took place via OH - groups, mainly from Fe(III) but also Mn(III) hydrous oxides. MnCO 3 did not contribute directly to As(III) and Se(IV) removal. A higher adsorptive capacity of the developed material towards As(III) was partly due to partial As(III) oxidation during adsorption. © 2011 Elsevier Inc.

  8. Selenite and selenate affect the fatty acid profile in in vitro incubated ovine ruminal fluid containing linseed oil

    Czech Academy of Sciences Publication Activity Database

    Czauderna, M.; Kowalczyk, J.; Marounek, Milan

    2013-01-01

    Roč. 58, č. 7 (2013), s. 328-341 ISSN 1212-1819 Institutional support: RVO:67985904 Keywords : vegetable oil * selenium * biohydrogenation * bacterial isomerization Subject RIV: GH - Livestock Nutrition Impact factor: 0.871, year: 2013

  9. Effects of Selenite on Unicellular Green Microalga Chlorella pyrenoidosa: Bioaccumulation of Selenium, Enhancement of Photosynthetic Pigments, and Amino Acid Production.

    Science.gov (United States)

    Zhong, Yu; Cheng, Jay J

    2017-12-20

    Microalgae were studied as function bioaccumulators of selenium (Se) for food and feed supplement. To investigate the bioaccumulation of Se and its effects on the unicellular green alga Chlorella pyrenoidosa, the algal growth curve, fluorescence parameters, antioxidant enzyme activity, and fatty acid and amino acid profiles were examined. We found that Se at low concentrations (≤40 mg L -1 ) positively promoted algal growth and inhibited lipid peroxidation and intracellular reactive oxygen species. The antioxidative effect was associated with an increase in the levels of glutathione peroxidase, catalase, linolenic acid, and photosynthetic pigments. Meanwhile, a significant increase in amino acid and organic Se content was also detected in the microalgae. In contrast, we found opposite effects in C. pyrenoidosa exposed to >60 mg L -1 Se. The antioxidation and toxicity appeared to be correlated with the bioaccumulation of excess Se. These results provide a better understanding of the effect of Se on green microalgae, which may help in the development of new technological applications for the production of Se-enriched biomass from microalgae.

  10. Change of choline compounds in sodium selenite-induced apoptosis of rats used as quantitative analysis by in vitro 9.4T MR spectroscopy

    DEFF Research Database (Denmark)

    Cao, Zhen; Wu, Lin-Ping; Li, Yun-Xia

    2008-01-01

    staining was employed to detect and confirm the change of liver cells. RESULTS: Good (1)H-MR spectra of perchloric acid extract from liver tissue of rats were obtained. The conventional metabolites were detected and assigned. Concentrations of different ingredient choline compounds in treatment group vs...

  11. The influence of pH and reaction time on the formation of FeSe{sub 2} upon selenite reduction by nano-sized pyrite-greigite

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Mingliang [Sun Yat-sen Univ., Zhuhai (China). Sino-French Institute of Nuclear Engineering and Technology; Bardelli, Fabrizio; Ma, Bin; Charlet, Laurent [Grenoble Univ. (France). Environmental Geochemistry Group; Chen, Fanrong; Yang, Yongqiang [Chinese Academy of Sciences, Guangzhou (China). Key Laboratory of Mineralogy and Metallogeny; Chinese Academy of Sciences, Guangzhou (China). Guangdong Provincial Key Laboratory of Mineral Physics and Materials

    2016-11-01

    The influence of pH and reaction time on the formation of FeSe{sub 2} by reductive precipitation of Se(IV) with nano-sized pyrite-greigite was investigated. Reductive precipitation is an effective method of attenuating the mobility of {sup 79}Se, which is foreseen to be a dangerous radioisotope for the geological disposal of high-level radioactive waste (HLW). The results indicated that Se(0)was formed at pH <4.05, whereas, at pH > 6.07, considerable amount of FeSe{sub 2} was formed along with Se(0). These observations are in agreement with the thermodynamic predictions reported in this work. Furthermore, the formation of FeSe{sub 2} was found to continue by increasing the reaction time, indicating that the Se(0) formed in the early reaction stage is gradually transformed to FeSe{sub 2} upon the depletion of aqueous Se(IV). Since FeSe{sub 2} has a stronger reactivity than pyrite, it was proposed that greigite, rather than pyrite, was responsible for the formation of FeSe{sub 2}. The findings in this study are of interest for key geochemical processes governing the mobility of toxic {sup 79}Se in the environment in presence of iron sulfides.

  12. New inorganic (an)ion exchangers with a higher affinity for arsenate and a competitive removal capacity towards fluoride, bromate, bromide, selenate, selenite, arsenite and borate

    KAUST Repository

    Chubar, Natalia

    2011-01-01

    Highly selective materials and effective technologies are needed to meet the increasingly stronger drinking water standards for targeted ionic species. Inorganic ion exchangers based on individual and mixed-metal hydrous oxides (or mixed adsorbents

  13. Selenite reduction by the obligate aerobic bacterium Comamonas testosteroni S44 isolated from a metal-contaminated soil

    DEFF Research Database (Denmark)

    Zheng, Shixue; Su, Jing; Wang, Liang

    2014-01-01

    impacted cellular growth and subsequent resistance to multiple heavy metal(loid)s. Conclusions: C. testosteroni S44 could be very useful for bioremediation in heavy metal(loid) polluted soils due to the ability to both reduce toxic Se(VI) and Se(IV) to non-toxic Se (0) under aerobic conditions...

  14. Quantification of low molecular weight selenium metabolites in human plasma after treatment with selenite in pharmacological doses by LC-ICP-MS

    DEFF Research Database (Denmark)

    Flouda, Konstantina; Dersch, Julie Maria; Gabel-Jensen, Charlotte

    2016-01-01

    The paper presents an analytical method for quantification of low molecular weight (LMW) selenium compounds in human plasma based on liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS) and post column isotope dilution-based quantification. Prior to analysis, samples were...

  15. Sensitivities of selenite, selenate, selenomethionine and trimethylselenonium ion in aqueous solution and in blood plasma - ETAAS compared with ICP-MS

    DEFF Research Database (Denmark)

    Gammelgaard, B.; Larsen, Erik Huusfeldt

    1998-01-01

    coupled plasma mass spectrometry (ICP-MS). Using ETAAS, the sensitivities for Se(IV), SeMet and TMSe in aqueous solution were similar, whereas the sensitivity of Se(VI) was 63% of that value. In blood plasma, the ETAAS sensitivities of Se(IV) and Se(VI) were equal, whereas the sensitivities of Se......Met and TMSe were 87 and 56%, respectively, of that value. In contrast, the ICP-MS sensitivities obtained for Se(VI), TMSe and SeMet were between 96 and 98% of that obtained for Se(IV) in aqueous solution and in blood plasma. It is concluded, that ICP-MS is superior to ETAAS as the problem of differences...... in sensitivity of the selenium species when using ETAAS are not prevalent when using the ICP-MS technique....

  16. Microbial selenium sulfide reduction for selenium recovery from wastewater

    NARCIS (Netherlands)

    Hageman, S.P.W.; Weijden, van der R.D.; Stams, A.J.M.; Cappellen, van P.; Buisman, C.J.N.

    2017-01-01

    Microbial reduction of selenium sulfide (SeS2) is a key step in a new treatment process to recover selenium from selenate and selenite streams. In this process, selenate is first reduced to selenite, and subsequently selenite is reduced by sulfide and precipitates from the solution as SeS2. The

  17. Synthesis of rare-earth selenate and selenite materials under 'sol-gel' hydrothermal conditions: crystal structures and characterizations of La(HSeO3)(SeO4) and KNd(SeO4)2

    International Nuclear Information System (INIS)

    Liu Wei; Chen Haohong; Yang Xinxin; Li Mangrong; Zhao Jingtai

    2004-01-01

    Two rare-earth compounds containing selenium atoms, La(HSeO 3 )(SeO 4 ) with a new open framework structure and KNd(SeO 4 ) 2 with a layered structure, have been synthesized under ''sol-gel'' hydrothermal conditions for the first time. Single-crystals of La(HSeO 3 )(SeO 4 ) crystallize in the monoclinic system (P2 1 , a=8.5905(17)A, b=7.2459(14)A, c=9.5691(19)A, β=104.91(3) o , Z=2, RAll=0.032). The structure contains puckered polyhedral layers made of LaO x (x=9,10) and SeO 4 groups, which are connected via SeO 3 -uints to the 3D structure. The crytal structure of KNd(SeO 4 ) 2 (monoclinc, P2 1 /c, a=8.7182(17)A, b=7.3225(15)A, c=11.045(2)A, β=91.38(3) o , Z=4, RAll=0.051) contains honeycomb-like six-ring NdO 9 polyhedra forming layers which are further decorated with SeO 4 tetrahedra. The K + ions occupy the interspaces of these layers and provide the charge balance

  18. Hydrothermal syntheses and characterization of two layered molybdenum selenites, Rb2(MoO3)3SeO3 and Tl2(MoO3)3SeO3

    International Nuclear Information System (INIS)

    Dussack, L.L.; Harrison, W.T.A.; Jacobson, A.J.

    1996-01-01

    The hydrothermal syntheses of Rb 2 (MoO 3 ) 3 SeO 3 , and Tl 2 (MoO 3 ) 3 SeO 3 are described. These compounds have structures built up from hexagonal-WO 3 -type sheets and are isostructural with the previously reported Cs 2 (MoO 3 ) 3 SeO 3 and (NH 4 ) 2 (MoO 3 ) 3 SeO 3 . Powder X-ray, thermogravimetric, and spectroscopic data are presented and discussed

  19. EXAFS and FTIR studies of selenite and selenate sorption by alkoxide-free sol-gel generated Mg-Al-CO3 layered double hydroxide with very labile interlayer anions

    NARCIS (Netherlands)

    Chubar, N.

    Current research on Layered Double Hydroxides (LDHs, also known as hydrotalcites, HTs) is predominantly focused on their intercalations, but the industrial application of LDHs for anion exchange adsorption has not yet been achieved. It was recently recognized that, to develop LDH applications, these

  20. Selenium Treatment Technologies

    Science.gov (United States)

    Selenium (Se) is a metalloid that is a dietary requirement in small quantities, but toxic at higher quantities. It also is known to bioaccumulate. In oxic environments, it exists as selenate (+6) and selenite (+4), both of which are soluble. Selenite will sorb more strongly to...

  1. Gypsum crystals in the inner shelf sediments off Maharashtra, India

    Digital Repository Service at National Institute of Oceanography (India)

    Hashimi, N.H.; Ambre, N.V.

    Gypsum crystals have been found in the inner shelf silty clay/clayey silt off the Maharashtra Coast between Vengurla and Bombay. Generally these occur as euhedral single or twinned crystals of selenite. Very often shells are found embedded within...

  2. Comparison of Chemical Modifiers for Simultaneous Determination of Different Selenium-Compounds in Serum and Urine by Zeeman-Effect Electrothermal Atomic-Absorption Spectrometry

    DEFF Research Database (Denmark)

    Johannessen, J.K.; Gammelgaard, Bente; Jons, O.

    1993-01-01

    The thermal stability of selenite, selenate, selenomethionine and trimethylselenonium was studied using different chemical modifiers in various amounts. The normally recommended amounts of nickel nitrate, magnesium nitrate, copper nitrate, copper nitrate mixed with magnesium nitrate, palladium ni...

  3. Study of the potential effect of selenium on gamma-radiation induced ovarian failure

    International Nuclear Information System (INIS)

    Said, R.S.M.

    2012-01-01

    Radiotherapy is a major factor contributing to female infertility by inducing premature ovarian failure (POF). Therefore, the need for an effective radioprotective agent is evident. The present study investigated the mechanism of potential radioprotective effect of sodium selenite on radiation-induced ovarian failure and whether sodium selenite can stimulate in vivo follicular development in experimental rats. Immature female Sprague-Dawely rats were either exposed to gamma radiation (3.2 Gy, LD 20 ), once and/or treated with sodium selenite (0.5 mg/kg), once daily for one week before irradiation. Follicular and oocyte development, apoptotic markers, proliferation marker as well as oxidative stress markers were assessed 24-h after irradiation. In addition, fertility assessment was performed after female rats became completely mature at two months of age. Sodium selenite significantly enhanced follicular development as compared to the irradiated group. Sodium selenite significantly reversed the oxidative stress effects of radiation that was evidenced by increasing in lipid peroxide level and decreasing in glutathione level, and glutathione peroxidase (GPx) activity. Assessment of apoptosis and cell proliferation markers revealed that caspase 3 and cytochrome c expressions markedly-increased, whereas, PCNA expression markedly-decreased in the irradiated group; in contrast, sodium selenite treatment prevented these alterations. Histopathological examination further confirmed the radioprotective efficacy of sodium selenite and its in-vivo effect on ovarian follicles’ maturation. In conclusion, sodium selenite showed a radioprotective effect and improved folliculogenesis through increasing ovarian granulosa cells proliferation, estradiol and FSH secretion, and GPx activity, whilst decreasing lipid peroxidation and oxidative stress, leading to inhibition of the apoptosis pathway through decreasing the expressions of caspase 3 and cytochrome c.

  4. Improvement of Selenium Status of Pasture Crops

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel

    1984-01-01

    Selenium was applied to pasture crops in a field experiment (1) by foliar application of 10 g Se/ha as selenite in the spring, (2) or by 5 g Se/ha in the spring plus 5 g in early August, (3) as selenite-enriched calcium ammonium nitrate (CAN) at 4 g Se/ha after each cut, and (4) as 4 g Se after...

  5. Thermodynamic modeling of iodine and selenium retention in solutions with high salinity

    International Nuclear Information System (INIS)

    Hagemann, Sven; Moog, Helge C.; Herbert, Horst-Juergen; Erich, Agathe

    2012-04-01

    The report on iodine and selenium retention in saline solutions includes the following chapters: (1) Introduction and scope of the work. (2) Actual status of knowledge. (3) Experimental and numerical models. (4) Thermodynamic properties of selenite and hydrogen selenite in solutions of oceanic salts. (5) Thermodynamic properties of selenate in solutions of oceanic salts. (6) Thermodynamic properties of iodide in solutions of oceanic salts. (7) Experimental studies on the retention of iodine and selenium in selected sorbents. (8) Summary and conclusions.

  6. A combined chemical, spectroscopic and ab initio modelling approach to surface reactivity: application to the retention of anions by siderite

    International Nuclear Information System (INIS)

    Badaut, V.; Schlegel, M.; Zeller, Ph.; Moutiers, G.

    2010-01-01

    79 Selenium may be one of the few radioelements possibly migrating out of nuclear geological repositories. Selenium may yet be retain this Se, but the possible interactions between Se and siderite are yet poorly known. In this work, the interactions between selenium oxi-anions - selenate and selenite - and siderite were investigated. Solution experiments have showed that dissolved selenite (≤ 10 -3 M) is quantitatively immobilized by siderite (75 g/L) after 48 h of reaction time, when selenate is only partly immobilized after 10 days. In the selenite case, XAS showed that immobilized selenium is initially present as Se(IV) probably sorbed on siderite surface. After 10 days of reaction, selenite ions are quantitatively reduced and form poorly crystalline elementary selenium. On the other hand, selenate retained b y siderite does not appear to be significantly reduced over the probed timescale (10 days). To better understand the mechanism of selenite reduction by siderite, the properties of bulk and perfect surfaces of siderite were modelled using DFT. The properties of the valence electrons could be correctly described only if the symmetry of the fundamental state electronic density is lower than the experimental crystallographic symmetry. We we modelled the retention of simple molecules as O 2 or H 2 O on siderite and magnesite (10-14) perfect surfaces. Our results are in good agreement with the literature. Finally, the modelling of selenite surface complexes on magnesite is performed with and without hydration. (authors)

  7. Species-specific sensitivity to selenium-induced impairment of cortisol secretion in adrenocortical cells of rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis)

    International Nuclear Information System (INIS)

    Miller, L.L.; Hontela, A.

    2011-01-01

    Species differences in physiological and biochemical attributes exist even among closely related species and may underlie species-specific sensitivity to toxicants. Rainbow trout (RT) are more sensitive than brook trout (BT) to the teratogenic effects of selenium (Se), but it is not known whether all tissues exhibit this pattern of vulnerability. In this study, primary cultures of RT and BT adrenocortical cells were exposed to selenite (Na 2 SO 3 ) and selenomethionine (Se-Met) to compare cell viability and ACTH-stimulated cortisol secretion in the two fish species. Cortisol, the primary stress hormone in fish, facilitates maintenance of homeostasis when fish are exposed to stressors, including toxicants. Cell viability was not affected by Se, but selenite impaired cortisol secretion, while Se-Met did not (RT and BT EC 50 > 2000 mg/L). RT cells were more sensitive (EC 50 = 8.7 mg/L) to selenite than BT cells (EC 50 = 90.4 mg/L). To identify the targets where Se disrupts cortisol synthesis, selenite-impaired RT and BT cells were stimulated with ACTH, dbcAMP, OH-cholesterol, and pregnenolone. Selenite acted at different steps in the cortisol biosynthesis pathway in RT and BT cells, confirming a species-specific toxicity mechanism. To test the hypothesis that oxidative stress mediates Se-induced toxicity, selenite-impaired RT cells were exposed to NAC, BSO and antioxidants (DETCA, ATA, Vit A, and Vit E). Inhibition of SOD by DETCA enhanced selenite-induced cortisol impairment, indicating that oxidative stress plays a role in Se toxicity; however, modifying GSH content of the cells did not have an effect. The results of this study, with two closely related salmonids, provided additional evidence for species-specific differences in sensitivity to Se which should be considered when setting thresholds and water quality guidelines. - Research Highlights: → We investigated species-specific sensitivity to Se in trout adrenocortical cells. → Selenite, not Se-Met, disrupts

  8. Influence of Se concentrations and species in hydroponic cultures on Se uptake, translocation and assimilation in non-accumulator ryegrass.

    Science.gov (United States)

    Versini, Antoine; Di Tullo, Pamela; Aubry, Emmanuel; Bueno, Maïté; Thiry, Yves; Pannier, Florence; Castrec-Rouelle, Maryse

    2016-11-01

    The success of biofortification and phytoremediation practices, addressing Se deficiency and Se pollution issues, hinges crucially on the fate of selenium in the plant media in response to uptake, translocation and assimilation processes. We investigate the fate of selenium in root and shoot compartments after 3 and 6 weeks of experiment using a total of 128 plants grown in hydroponic solution supplied with 0.2, 2, 5, 20 and 100 mg L -1 of selenium in the form of selenite, selenate and a mixture of both species. Selenate-treated plants exhibited higher root-to-shoot Se translocation and total Se uptake than selenite-treated plants. Plants took advantage of the selenate mobility and presumably of the storage capacity of leaf vacuoles to circumvent selenium toxicity within the plant. Surprisingly, 28% of selenate was found in shoots of selenite-treated plants, questioning the ability of plants to oxidize selenite into selenate. Selenomethionine and methylated organo-selenium amounted to 30% and 8% respectively in shoots and 35% and 9% in roots of the identified Se, suggesting that selenium metabolization occurred concomitantly in root and shoot plant compartments and demonstrating that non-accumulator plants can synthesize notable quantities of precursor compound for volatilization. The present study demonstrated that non-accumulator plants can develop the same strategies as hyper-accumulator plants to limit selenium toxicity. When both selenate and selenite were supplied together, plants used selenate in a storage pathway and selenite in an assimilation pathway. Plants might thereby benefit from mixed supplies of selenite and selenate by saving enzymes and energy required for selenate reduction. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  9. Adsorption of selenium by amorphous iron oxyhydroxide and manganese dioxide

    Science.gov (United States)

    Balistrieri, L.S.; Chao, T.T.

    1990-01-01

    This work compares and models the adsorption of selenium and other anions on a neutral to alkaline surface (amorphous iron oxyhydroxide) and an acidic surface (manganese dioxide). Selenium adsorption on these oxides is examined as a function of pH, particle concentration, oxidation state, and competing anion concentration in order to assess how these factors might influence the mobility of selenium in the environment. The data indicate that 1. 1) amorphous iron oxyhydroxide has a greater affinity for selenium than manganese dioxide, 2. 2) selenite [Se(IV)] adsorption increases with decreasing pH and increasing particle concentration and is stronger than selenate [Se(VI)] adsorption on both oxides, and 3. 3) selenate does not adsorb on manganese dioxide. The relative affinity of selenate and selenite for the oxides and the lack of adsorption of selenate on a strongly acidic surface suggests that selenate forms outer-sphere complexes while selenite forms inner-sphere complexes with the surfaces. The data also indicate that the competition sequence of other anions with respect to selenite adsorption at pH 7.0 is phosphate > silicate > molybdate > fluoride > sulfate on amorphous iron oxyhydroxide and molybdate ??? phosphate > silicate > fluoride > sulfate on manganese dioxide. The adsorption of phosphate, molybdate, and silicate on these oxides as a function of pH indicates that the competition sequences reflect the relative affinities of these anions for the surfaces. The Triple Layer surface complexation model is used to provide a quantitative description of these observations and to assess the importance of surface site heterogeneity on anion adsorption. The modeling results suggest that selenite forms binuclear, innersphere complexes with amorphous iron oxyhydroxide and monodentate, inner-sphere complexes with manganese dioxide and that selenate forms outer-sphere, monodentate complexes with amorphous iron oxyhydroxide. The heterogeneity of the oxide surface sites

  10. Chemical, spectroscopic, and ab initio modelling approach to interfacial reactivity applied to anion retention by siderite

    International Nuclear Information System (INIS)

    Badaut, V.

    2010-07-01

    Among the many radionuclides contained in high-level nuclear waste, 79 Se was identified as a potential threat to the safety of long term underground storage. However, siderite (FeCO 3 ) is known to form upon corrosion of the waste container, and the impact of this mineral on the fate of selenium was not accounted for. In this work, the interactions between selenium oxyanions - selenate and selenite - and siderite were investigated. To this end, both experimental characterizations (solution chemistry, X-ray Absorption Spectroscopy - XAS) and theoretical studies (ab initio modelling using Density Functional Theory - DFT ) were performed. Selenite and selenate (≤ 10 3 M) retention experiments by siderite suspensions (75 g/L ) at neutral pH in reducing glovebox (5 % H 2 ) showed that selenite is quantitatively immobilized by siderite after 48 h of reaction time, when selenate is only partly immobilized after 10 days. In the selenite case, XAS showed that immobilized selenium is initially present as Se(IV) probably sorbed on siderite surface. After 10 days of reaction, selenite ions are quantitatively reduced and form poorly crystalline elementary selenium. Selenite retention and reduction kinetics are therefore distinct. On the other hand, the fraction of immobilized selenate retained in the solid fraction does not appear to be significantly reduced over the probed timescale (10 days). For a better understanding of the reduction mechanism of selenite ions by siderite, the properties of bulk and perfect surfaces of siderite were modelled using DFT. We suggest that the properties of the valence electrons can be correctly described only if the symmetry of the fundamental state electronic density is lower than the experimental crystallographic symmetry. We then show that the retention of simple molecules as O 2 or H 2 O on siderite and magnesite (10 -14 ) perfect surfaces (perfect cleavage plane, whose surface energy is the lowest according to DFT) can be modelled with

  11. Effects of selenium oxyanions on the white-rot fungus Phanerochaete chrysosporium

    KAUST Repository

    Espinosa-Ortiz, Erika J.

    2014-10-24

    The ability of Phanerochaete chrysosporium to reduce the oxidized forms of selenium, selenate and selenite, and their effects on the growth, substrate consumption rate, and pellet morphology of the fungus were assessed. The effect of different operational parameters (pH, glucose, and selenium concentration) on the response of P. chrysosporium to selenium oxyanions was explored as well. This fungal species showed a high sensitivity to selenium, particularly selenite, which inhibited the fungal growth and substrate consumption when supplied at 10 mg L−1 in the growth medium, whereas selenate did not have such a strong influence on the fungus. Biological removal of selenite was achieved under semi-acidic conditions (pH 4.5) with about 40 % removal efficiency, whereas less than 10 % selenium removal was achieved for incubations with selenate. P. chrysosporium was found to be a selenium-reducing organism, capable of synthesizing elemental selenium from selenite but not from selenate. Analysis with transmission electron microscopy, electron energy loss spectroscopy, and a 3D reconstruction showed that elemental selenium was produced intracellularly as nanoparticles in the range of 30–400 nm. Furthermore, selenite influenced the pellet morphology of P. chrysosporium by reducing the size of the fungal pellets and inducing their compaction and smoothness.

  12. Estimation of the behaviors of selenium in the near field of repository

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Soo; Min, Jae Ho; Baik, Min Hoon; Kim, Gye Nam; Choi, Jong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-12-15

    The sorption of selenium ions onto iron and iron compounds as a disposal container material and its corrosion products, and onto bentonite as a buffer material, was studied to understand the behaviors of selenium in a waste repository. Selenite was sorbed onto commercial magnetite very well in solutions at around pH 9, but silicate hindered their sorption onto both magnetite and ferrite. Unlike commercial magnetite and ferrite, flesh synthesized magnetite, green rust and iron greatly decreased selenium concentration even in a silicate solution. These results might be due to the formation of precipitates, or the sorption of selenide or selenite onto an iron surface at below Eh= -0.2 V. Red-colored Se(Cr) was observed on the surface of a reaction bottle containing iron powder added into a selenite solution. Silicate influences on the sorption onto magnetite and iron for selenide are the same as those for selenite. Even though bentonite adsorbed a slight amount of selenite, the sorption cannot be ignored in the waste repository since a very large quantity of bentonite is used.

  13. Hazard assessment of inorganics to three endangered fish in the Green River, Utah

    Science.gov (United States)

    Hamilton, S.J.

    1995-01-01

    Acute toxicity tests were conducted with three life stages of Colorado squawfish (Ptychocheilus lucius), razorback sucker (Xyrauchen texanus), and bonytail (Gila elegans) in a reconstituted water quality simulating the middle part of the Green River of Utah. Tests were conducted with boron, lithium, selenate, selenite, uranium, vanadium, and zinc. The overall rank order of toxicity to all species and life stages combined from most to least toxic was vanadium = zinc > selenite > lithium = uranium > selenate > boron. There was no difference between the three species in their sensitivity to the seven inorganics based on a rank-order evaluation at the species level. Colorado squawfish were 2-5 times more sensitive to selenate and selenite at the swimup life stage than older stages, whereas razorback suckers displayed equal sensitivity among life stages. Bonytail exhibited equal sensitivity to selenite, but were five times more sensitive to selenate at the swimup life stage than the older stages. Comparison of 96-hr LC50 values with a limited number of environmental water concentrations in Ashley Creek, Utah, which receives irrigation drainwater, revealed moderate hazard ratios for boron, selenate, selenite, and zinc, low hazard ratios for uranium and vanadium, but unknown ratios for lithium. These inorganic contaminants in drainwaters may adversely affect endangered fish in the Green River.

  14. Uranium and selenium resistance in Cupriavidus metallidurans CH34

    International Nuclear Information System (INIS)

    Avoscan, L.; Untereiner, G.; Carriere, M.; Gouget, B.; Degrouard, J.

    2007-01-01

    Cupriavidus metallidurans CH34, a soil bacterium, is known to resist a variety of heavy metals and metalloids. Its capacity to resist, accumulate and transform selenium (Se as selenite or selenate) and uranium (U as uranyl-carbonate and uranyl-citrate) was investigated. C. metallidurans CH34 resists to high U concentrations (up to 10 mM) whatever its speciation. However, no major accumulation could be measured: U-carbonate and U-citrate are not bio-available for the bacteria. The anaerobic response of C. metallidurans CH34 to U will be looked for. C. metallidurans CH34 resists to high Se concentrations (up to 4 mM of selenite and 8 mM of selenate). Bacteria exposed to 2 mM of selenite accumulate 25 times more Se than when they are exposed to same concentration of selenate. Se resistance is characterized by the reduction of oxy-anions in the bacteria. Selenite is reduced to elemental Se by an intracellular process, but the metabolic fate of selenate is unknown. By combining three methods of speciation (X-ray absorption spectroscopy (XANES and EXAFS), HPLC-ICP-MS and SDS-PAGE coupled with particle induced X-ray emission (PIXE)), we both identified and specified the chemical intermediates formed by this bacterium upon exposure to these oxy-anions. Two mechanisms of reduction of Se oxides in C. metallidurans CH34 were highlighted. Assimilation transforms selenite and selenate into organic Se, identified as seleno-methionine and leads to its non-specific incorporation into bacterial proteins (presence of selenious proteins). Detoxication precipitates selenite in nano-particles of elemental Se. (authors)

  15. In vitro binding of selenium by rat liver mitochondrial selenium-binding protein

    International Nuclear Information System (INIS)

    Brian, W.R.; Hoekstra, W.G.

    1986-01-01

    Last year the authors reported that upon freezing and thawing mitochondria from rats injected with [ 75 Se]Na 2 SeO 3 ( 75 Se-selenite), a 75 Se-binding protein (SeBP) was released. They have studied further in vitro labelling of SeBP. This matrix protein was labelled in vitro when lysed mitochondria (containing non-matrix material) were incubated with 75 Se-selenite but not when matrix material alone was incubated with 75 Se-selenite. Thus, there are one or more promoters of in vitro SeBP labelling in the non-matrix fraction. SeBP was also labelled in vitro when 75 Se-selenite was added to matrix alone and dialyzed. Dialysis tubing, and not the dialysis process, promoted labelling by affecting SeBP and not by affecting 75 Se-selenite. Labelling did not occur when matrix alone and 75 Se-selenite were incubated (not dialyzed) in a glass test tube but did occur in a polystyrene test tube. They hypothesize that non-covalent interactions occur between SeBP and dialysis tubing or polystyrene that expose Se binding sites on the protein. A similar mechanism involving mitochondrial non-matrix material may function in vivo. Non-denaturing disc gel electrophoresis of partially purified SeBP labelled in vivo or in vitro suggested that the same protein was labelled in both conditions. Using in vitro binding techniques, SeBP was also found in sheep liver mitochondrial matrix. This supports the theory that SeBP is important in Se metabolism

  16. Effect of selenium compounds on murine B16 melanoma cells and pigmented cloned pB16 cells

    International Nuclear Information System (INIS)

    Siwek, B.; Bahbouth, E.; Serra, M.A.; Sabbioni, E.; Pauw-Gillet, M.C. de; Bassleer, R.

    1994-01-01

    The effects of selenium compounds such as sodium selenite, sodium selenate, seleno-DL-cystine and seleno-DL-methionine (100 μM and 10 μM) on B16 and pigmented cloned pB 16 murine melanoma cells were investigated in vitro. At the tested concentrations, B16 cells showed a greater sensitivity to the toxic effects of sodium selenite and seleno-DL-cystine than pB 16 cells, whereas no decrease of B 16 and pB 16 cell number was observed after incubation with sodium selenate or seleno-DL-methionine. Glutathione (GSH) percentages were strongly decreased only by selenite and seleno-DL-cystine; it was marked more in B 16 than in pB 16 cells. The pretreatment of B 16 cells with a GSH depleting agent (10 μM buthionine-[S,R]-sulfoximine) did not significantly influence the cytotoxic effects of selenite and seleno-DL-cystine. On both cell populations. GSH preincubation (50 μM) enhanced the cytotoxicity of selenite whereas the survival of seleno-DL-cystine treated cells was increased. Glutathione peroxidase (GSH-Px) activity in B 16 cells was more sensitive than in pB 16 cells to the activating effect of selenite, and particularly of seleno-DL-cystine; however, cell-free controls indicated that activation was mainly due to glutathione reductase. The rate of 75 Se (as sodium selenite) uptake in both cell populations was maximal within the first hour of incubation, with a preferential accumulation in the cytosol; after 24 h of incubation, the amount of 75 Se in cytosol and pellet was approximately the same. Gel filtration chromatography of lysed cells after incubation for 6 h with 10 μM 75 Se-selenite showed that the radioactivity was eluted as two peaks corresponding to low (4-9 kDa) and high (280-320 kDa) molecular weights. Possible toxicological mechanisms are discussed at molecular level. (orig./MG)

  17. Sensitivity of Trout to Chronic Acute Exposure to Selenium

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel; Nielsen, M. Gissel

    1978-01-01

    Trout were exposed to selenite (Na2SeO3) solutions of varying concentrations (0.1-100 ppm Se) for periods of up to 4 wk. A chronic exposure to 0.1 ppm Se or less is non-lethal to trout. Lethality at higher concentrations depends on the length of exposure. Trout that survive for 10 days in tap...

  18. Metabolism in rats of selenium from intrinsically and extrinsically labeled isolated soy protein

    International Nuclear Information System (INIS)

    Mason, A.C.; Weaver, C.M.

    1986-01-01

    Absorption, retention and tissue accumulation by rats of 75 Se from intrinsically labeled isolated soy protein were compared with utilization of 75 Se from the extrinsic sources of [ 75 Se]selenite, [ 75 Se]selenate or [ 75 Se]selenomethionine. Extrinsic sources of selenium were given by gavage or mixed with isolated soy protein. There were no differences in absorption and retention of 75 Se from intrinsically labeled soy diet compared to the three extrinsically labeled soy diets. Of the three extrinsic sources tested, 75 Se from selenate was better absorbed than from selenite or selenomethionine when incorporated into a soy diet. Absorption of 75 Se was significantly lower when given to animals in gavage solution than when mixed with soy diets. After a 14-d test period, retention of 75 Se was the same for all four soy diet groups. In gavaged groups, 75 Se from selenomethionine was retained to a greater extent than 75 Se from selenite. The liver, testes and kidney accumulated more 75 Se from the test meal than did the blood and lungs. In the testes more 75 Se from selenite and selenate was accumulated than from selenomethionine-labeled diets. Selenium absorption from the soy isolate source was very high (86-96%), indicating that, although soy does not normally contain high levels of selenium, the selenium present is well absorbed from this plant source

  19. Untitled

    African Journals Online (AJOL)

    synthesis of zirconium selenite and thorium tellurite ion exchangers and chromatographic ... necessary to separate and recover quantitatively Pb2+ from other metal ions from ... Metal ion concentrations were determined by using a Varian Techtron AAS model AA6 (the .... Similarly Cd2+ from Co2+ and Znºt from Cu* (Fig.

  20. Leaching of Added Selenium in Soils Low in Native Selenium

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel; Hamdy, A. A.

    1977-01-01

    A soil column experiment was performed to evaluate the influence of organic matter and lime on the leaching and distribution of added selenite. 75Se-labeled Na2SeO3 was added to water-saturated soil columns with a diameter of 4.25 cm and a length of 16-20 cm. Leaching started immediately, one l...... water being added per column during the course of 1 wk. Most of the selenite did not move through the soil, and only a few per cent were found in the leaching water. Leaching was greatest in sandy soil. It was increased by the addition of lime, but decreased by addition of organic matter. Most...... of the leaching took place within the 1st few days. In other experiments, selenite fixation in soils took several days to reach equilibrium. Leaching of the selenite added to mineral soils under Danish field conditions was insignificant in the short time-cycle of Se in the environment....

  1. Selenium prevents tumor development in a rat model for chemical carcinogenesis

    DEFF Research Database (Denmark)

    Bjorkhem-Bergman, L.; Torndal, U. B.; Eken, S.

    2005-01-01

    Previous studies in animals and humans have shown that selenium compounds can prevent cancer development. In this work we studied the tumor preventive effect of selenium supplementation, administrated as selenite, in the initiation, promotion and progression phases in a synchronized rat model for...

  2. Activity of glutathione peroxidase (GGSH-Px) in the blood of ewes and their lambs receiving the selenium-enriched unicellular alga Chlorella

    Czech Academy of Sciences Publication Activity Database

    Trávníček, J.; Racek, J.; Trefil, L.; Rodinová, H.; Kroupová, V.; Illek, J.; Doucha, Jiří; Písek, L.

    2008-01-01

    Roč. 53, č. 7 (2008), s. 292-298 ISSN 1212-1819 Institutional research plan: CEZ:AV0Z50200510 Keywords : selenite * organic selenium * blood selenium Subject RIV: EE - Microbiology, Virology Impact factor: 0.735, year: 2008

  3. Biological selenium removal from wastewaters

    NARCIS (Netherlands)

    Lenz, M.

    2008-01-01

    In this thesis, microbial conversion of water-soluble, highly toxic forms of selenium (selenate, selenite) to less bioavailable elemental selenium was investigated. By the exploitation of different groups of microorganisms (selenium-respiring, nitrate-reducing and sulfate-reducing bacteria,

  4. Selenium Adsorption To Aluminum-Based Water Treatment Residuals

    Science.gov (United States)

    Aluminum-based water treatment residuals (WTR) can adsorb water-and soil-borne P, As(V), As(III), and perchlorate, and may be able to adsorb excess environmental selenium. WTR, clay minerals, and amorphous aluminum hydroxide were shaken for 24 hours in selenate or selenite solut...

  5. Influence of Selenium on Innate Immune Response in Kids

    Czech Academy of Sciences Publication Activity Database

    Malá, D.; Kovářů, František; Mišurová, Ľ.; Pavlata, L.; Dvořák, R.; Číž, Milan

    2009-01-01

    Roč. 54, č. 6 (2009), s. 545-548 ISSN 0015-5632 R&D Projects: GA AV ČR IAA601680801 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z50040702 Keywords : Se-75 labeled rats * Sodium selenite * Metabolism Subject RIV: ED - Physiology Impact factor: 0.978, year: 2009

  6. SPECIATION OF SELENIUM AND ARSENIC COMPOUNDS BY CAPILLARY ELECTROPHORESIS WITH HYDRODYNAMICALLY MODIFIED ELECTROOSMOTIC FLOW AND ON-LINE REDUCTION OF SELENIUM(VI) TO SELENIUM(IV) WITH HYDRIDE GENERATION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRIC DETECTION

    Science.gov (United States)

    Capillary electrophoresis (CE) with hydride generation inductively coupled plasma mass spectrometry was used to determine four arsenicals and two selenium species. Selenate (SeVI) was reduced on-line to selenite (SeIV') by mixing the CE effluent with concentrated HCl. A microporo...

  7. Download this PDF file

    African Journals Online (AJOL)

    acer

    GP IV: rats were pretreated orally with selenium as sodium selenite for one week (0.1 mg/kg b.w. per day) via gavage. ... Serum Nitric oxide, IL-6 and tumor necrosis factor were ..... Protective effects of selenium, vitamin C and vitamin E against.

  8. Glycine buffered synthesis of layered iron(II)-iron(III) hydroxides (green rusts)

    DEFF Research Database (Denmark)

    Yin, Weizhao; Huang, Lizhi; Pedersen, Emil Bjerglund

    2017-01-01

    Layered Fe(II)-Fe(III) hydroxides (green rusts, GRs) are efficient reducing agents against oxidizing contaminants such as chromate, nitrate, selenite, and nitroaromatic compounds and chlorinated solvents. In this study, we adopted a buffered precipitation approach where glycine (GLY) was used...

  9. Mercury-selenium interactions in relation to histochemical staining of mercury in the rat liver

    DEFF Research Database (Denmark)

    Baatrup, E; Thorlacius-Ussing, O; Nielsen, H L

    1989-01-01

    micrograms of Se g-1 body weight as sodium [75Se]selenite. All the rats were killed 1 h later. Homogenized liver samples were prepared for mercury analysis by two different methods: alkaline digestion and ultrasonic disintegration. Quantitative chemical analysis based on benzene extraction...

  10. Determination of trimethylselenonium ion in urine by ion chromatography and inductively coupled plasma mass spectrometry detection

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Jessen, K.D.; Kristensen, F.H.

    2000-01-01

    The selenium species selenite, selenate, selenomethionine (SeMet), and trimethylselenonium iodide (TMSe+) were separated in aqueous solution by ion chromatography. The separation was performed on an Ionpac CS5 cation exchange column by elution with 10 mM oxalic acid and 20 mM potassium sulphate, p...

  11. Resistance, accumulation and transformation of selenium by the cyanobacterium Synechocystis sp. PCC 6803 after exposure to inorganic SeVI or SeIV

    International Nuclear Information System (INIS)

    Gouget, B.; Avoscan, L.; Collins, R.; Carriere, M.; Sarret, G.

    2005-01-01

    Our purpose was to investigate the ability of Synechocystis sp. PCC 6803, a photosynthetic prokaryote isolated from fresh water, to resist, incorporate and reduce the oxidized forms of selenium including selenite and selenate, the major selenium species present in aquatic systems. Selenium speciation and the chemical intermediates during selenium transformation were determined by X-ray absorption near edge structure (XANES) spectroscopy. The possible internalisation pathways involving selenium and the metabolic fate of selenate and selenite were examined. Selenate metabolism seemed to proceed via the sulfate reduction pathway resulting in the formation of the R-Se-H, R-Se-R and R-Se-Se-R species. The transformation of selenate to toxic amino acids may explain the high sensitivity of Synechocystis to selenate. Several mechanisms of selenium reduction seem to complete during selenite assimilation. A specific mechanism may transform internalised selenite into selenide and, subsequently induce the biosynthesis of selenoproteins. A non-specific mechanism may interfere with thiols, such as glutathione in the cell cytoplasm, or with proteins in the periplasm of the bacteria, notably thioredoxins. Several hypotheses concerning the complex transformation of selenium in Synechocystis could therefore be proposed. (orig.)

  12. SE-ENRICHMENT OF CARROT AND ONION VIA FOLIAR APPLICATION

    OpenAIRE

    Kapolna, Emese; Laursen, Kristian H.; Hillestrøm, Peter; Husted, Søren; Larsen, Erik H.

    2008-01-01

    The aim of this work was to study the selenium accumulation in carrot and onion plants using foliar application by sodium selenite and sodium selenate. Furthermore, we aimed at identifying the Se species biosynthesised by onion and carrot plants. The results were used to prepare for production of 77Se enriched plants for an ongoing human absorption study.

  13. Spraying of Crops with Selenium

    DEFF Research Database (Denmark)

    Sima, Per; Nielsen, Gunnar Gissel

    1985-01-01

    A frame experiment was carried out in 1983 to test the effect of foliar application of selenate and selenite and the effect of simultaneous addition of a micronutrient solution on the Se concentration of barley and potatoes. In general, selenate was the more effective; however, both forms of Se p...

  14. Selenium speciation and isotope composition in 77Se-enriched yeast using gradient elution HPLC separation and ICP-dynamic reaction cell-MS

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Sloth, Jens Jørgen; Hansen, M.

    2003-01-01

    using the enriched Se-77-selenite as substrate, were released by enzymatic hydrolysis using (I), a beta-glucosidase followed by a protease mixture, and (II), a commercial protease preparation. For selenium speciation the chromatographic selectivity of the cation exchange HPLC system was adjusted...

  15. Bio-induced solid selenium for recovery from water

    NARCIS (Netherlands)

    Hageman, S.P.W.

    2015-01-01

    Selenium in the form of selenate or selenite in wastewater needs to be removed due to its potential toxicity in the environment. Also, selenium is a valuable element that is used in several industries and current selenium resources are likely to be exhausted in less than 50 years. Waste streams

  16. Selenium in the central nervous system of the rat after exposure to L-selenomethionine

    DEFF Research Database (Denmark)

    Grønbæk, Henning; Thorlacius-Ussing, O.

    1990-01-01

    in the anterior pituitary of rats exposed to sodium selenite (Thorlacius-Ussing and Danscher 1985). This histochemical method demonstrates complexes of exogenous selenium and endogenous metal. In the central nervous system and the anterior pituitary, selenium is suggested to form bonds with zinc (Danscher 1984...

  17. Selenium enrichment on Cordyceps militaris link and analysis on its main active components.

    Science.gov (United States)

    Dong, Jing Z; Lei, C; Ai, Xun R; Wang, Y

    2012-03-01

    To investigate the effects of selenium on the main active components of Cordyceps militaris fruit bodies, selenium-enriched cultivation of C. militaris and the main active components of the fruit bodies were studied. Superoxide dismutase (SOD) activity and contents of cordycepin, cordycepic acid, and organic selenium of fruit bodies were sodium selenite concentration dependent; contents of adenosine and cordycep polysaccharides were significantly enhanced by adding sodium selenite in the substrates, but not proportional to sodium selenite concentrations. In the cultivation of wheat substrate added with 18.0 ppm sodium selenite, SOD activity and contents of cordycepin, cordycepic acid, adenosine, cordycep polysaccharides, and total amino acids were enhanced by 121/145%, 124/74%, 325/520%, 130/284%, 121/145%, and 157/554%, respectively, compared to NS (non-selenium-cultivated) fruit bodies and wild Cordyceps sinensis; organic selenium contents of fruit bodies reached 6.49 mg/100 g. So selenium-enriched cultivation may be a potential way to produce more valuable medicinal food as a substitute for wild C. sinensis.

  18. The effect of selenium on the biliary excretion and organ distribution of mercury in the rat after exposure to methyl mercuric chloride

    International Nuclear Information System (INIS)

    Alexander, J.; Norseth, T.

    1979-01-01

    The influence of selenium compounds on the biliary excretion and the organ distribution of mercury after injection of methyl mercuric chloride(4μmol/kg) have been tested. Selenite, seleno-di-N-acetylglycine and seleno-methionine strongly inhibited the biliary excretion of mercury. Selenite even in a molar dose of 1/40 of the methyl mercury dose inhibited the biliary excretion of mercury. The loss toxic seleno-di-N-acetylglycine was needed in larger molar doses and did not act as rapidly as selenite. Biliary excreted methyl mercury is known to be partly reabsorbed in the gut. Subsequently a part of it is deposited in the kidneys since drainage of the bile lowered the kidney content of mercury. Rats given selenium compounds in combination with bile drainage showed further reduction of the kidney mercury content than bile duct drainage alone. Thus the demonstrated lowering effect of selenium compounds on the kidney mercury content cannot be completely explained by an inhibition of biliary excretion of mercury. The mercury concentration in the brain was increased by the selenium compounds; the effect being dependent of the selenium dose reaching a maximum at an equimolar selenite - to methyl mercury dose ratio. The mechanisms by which selenium influences the methyl mercury kinetics are discussed. (author)

  19. The Thermodynamics of Selenium Minerals in Near-Surface Environments

    Directory of Open Access Journals (Sweden)

    Vladimir Krivovichev

    2017-10-01

    Full Text Available Selenium compounds are relatively rare as minerals; there are presently only 118 known mineral species. This work is intended to codify and systematize the data of mineral systems and the thermodynamics of selenium minerals, which are unstable (selenides or formed in near-surface environments (selenites, where the behavior of selenium is controlled by variations of the redox potential and the acidity of solutions at low temperatures and pressures. These parameters determine the migration of selenium and its precipitation as various solid phases. All selenium minerals are divided into four groups—native selenium, oxide, selenides, and oxysalts—anhydrous selenites (I and hydrous selenites and selenates (II. Within each of the groups, minerals are codified according to the minimum number of independent elements necessary to define the composition of the mineral system. Eh–pH diagrams were calculated and plotted using the Geochemist’s Workbench (GMB 9.0 software package. The Eh–pH diagrams of the Me–Se–H2O systems (where Me = Co, Ni, Fe, Cu, Pb, Zn, Cd, Hg, Ag, Bi, As, Sb, Al and Ca were plotted for the average contents of these elements in acidic waters in the oxidation zones of sulfide deposits. The possibility of the formation of Zn, Cd, Ag and Hg selenites under natural oxidation conditions in near surface environments is discussed.

  20. Effects of selenium oxyanions on the white-rot fungus Phanerochaete chrysosporium

    KAUST Repository

    Espinosa-Ortiz, Erika J.; Gonzalez-Gil, Graciela; Saikaly, Pascal; van Hullebusch, Eric D.; Lens, Piet N L

    2014-01-01

    and substrate consumption when supplied at 10 mg L−1 in the growth medium, whereas selenate did not have such a strong influence on the fungus. Biological removal of selenite was achieved under semi-acidic conditions (pH 4.5) with about 40 % removal efficiency

  1. Radio protective effects of selenium on rats

    International Nuclear Information System (INIS)

    Bakir, A.; Alya, G

    2005-11-01

    Potential radio-protective effects of different selenium supplement concentrations of 4, 8, 15 and 30 ppm were evaluated in rats. Four groups of rats were administered different concentrations of selenium in drinking water for 30 days before irradiation starting from the ablactation which considered as day 0. The results showed that the sodium selenite of 4 ppm and 8 ppm enhance the 30-day survival of irradiated rats at 7 Gy ( sup 6 sup 0 Co source, whole body irradiation dose rate of 1 Gy x min sup - sup 1) compared to the control group. The mean cumulated probability of survival of rats was 69%+-6 (mean+-S.E.) and 77%+-6 in 4 and 8 ppm groups, respectively, versus 42%+-9 for control group (P<0.001). It was also indicated that sodium selenite with concentrations of 15 and 30 ppm had no significant reduction in mortality. The mean cumulated probability of survival of rats was 50%+-12 (P=0.39) and 49%+-14 (P=0.04), respectively. The toxic effects of selenium were observed at 15 ppm and 30 ppm, survivals after 30 days of selenium intake were 76% and 46%, respectively. It was concluded that 4 and 8 ppm sodium selenite have a radio-protective effect. 15 and 30 ppm sodium selenite had no radio-protective effects in rats, this may be due to a synergism of toxicity and radiation effects. (author)

  2. Selenium Sequestration in a Cationic Layered Rare Earth Hydroxide: A Combined Batch Experiments and EXAFS Investigation.

    Science.gov (United States)

    Zhu, Lin; Zhang, Linjuan; Li, Jie; Zhang, Duo; Chen, Lanhua; Sheng, Daopeng; Yang, Shitong; Xiao, Chengliang; Wang, Jianqiang; Chai, Zhifang; Albrecht-Schmitt, Thomas E; Wang, Shuao

    2017-08-01

    Selenium is of great concern owing to its acutely toxic characteristic at elevated dosage and the long-term radiotoxicity of 79 Se. The contents of selenium in industrial wastewater, agricultural runoff, and drinking water have to be constrained to a value of 50 μg/L as the maximum concentration limit. We reported here the selenium uptake using a structurally well-defined cationic layered rare earth hydroxide, Y 2 (OH) 5 Cl·1.5H 2 O. The sorption kinetics, isotherms, selectivity, and desorption of selenite and selenate on Y 2 (OH) 5 Cl·1.5H 2 O at pH 7 and 8.5 were systematically investigated using a batch method. The maximum sorption capacities of selenite and selenate are 207 and 124 mg/g, respectively, both representing the new records among those of inorganic sorbents. In the low concentration region, Y 2 (OH) 5 Cl·1.5H 2 O is able to almost completely remove selenium from aqueous solution even in the presence of competitive anions such as NO 3 - , Cl - , CO 3 2- , SO 4 2- , and HPO 4 2- . The resulting concentration of selenium is below 10 μg/L, well meeting the strictest criterion for the drinking water. The selenate on loaded samples could be desorbed by rinsing with concentrated noncomplexing NaCl solutions whereas complexing ligands have to be employed to elute selenite for the material regeneration. After desorption, Y 2 (OH) 5 Cl·1.5H 2 O could be reused to remove selenate and selenite. In addition, the sorption mechanism was unraveled by the combination of EDS, FT-IR, Raman, PXRD, and EXAFS techniques. Specifically, the selenate ions were exchanged with chloride ions in the interlayer space, forming outer-sphere complexes. In comparison, besides anion exchange mechanism, the selenite ions were directly bound to the Y 3+ center in the positively charged layer of [Y 2 (OH) 5 (H 2 O)] + through strong bidentate binuclear inner-sphere complexation, consistent with the observation of the higher uptake of selenite over selenate. The results presented in

  3. Selenium bioavailability of infant milk diets

    International Nuclear Information System (INIS)

    Raghib, H.; Chan, W.Y.; Rennert, O.M.

    1986-01-01

    The effects of age, types of milk diet and chemical forms of SE on its bioavailability were studied using suckling rats as a model. Human milk, bovine milk and infant formula (regular Similac) extrinsically labeled with either ( 75 Se) selenite or ( 75 Se) selenomethionine were fed by gastric intubation to 8, 10, 15 and 20 (or 30)-day-old rats. Retention of 75 Se in gut free carcass and liver was measured 3 hours after feeding. At any given age the corresponding absorption of 75 Se from the 3 diets was similar except at 15 days of age when significantly more ( 75 Se) selenomethionine was absorbed from human milk (83%) than from bovine milk or formula (72%). Much higher amount of ( 75 Se) selenomethionine was absorbed by any age group from the 3 milk diets compared to ( 75 Se) selenite. An age related change in both ( 75 Se) selenite and ( 75 Se) selenomethionine absorption was noticed in all 3 diets. Gut free carcass ( 75 Se) selenite absorption was 32% in 8-d-old rats and increased to 46% in 20-d-old rats. The corresponding liver 75 Se retention was 7.5 and 19.5%. On the other hand, ( 75 Se) selenomethionine retention by the gut free carcass decreased with age from an average of 83% in 8-d-old rats to 72% in 20-d-old rats. The corresponding 75 Se incorporation into the liver increased from 15.5% in 8-d-old rats to 21.9% in 20-d-old rats. It is concluded that twice as much 75 Se) selenite and an age related change in 75 Se absorption was noticed between the 2 chemical forms of Se and between human milk and the other 2 milk diets

  4. Microbial Preservation in Sulfates in the Haughton Impact Structure Suggests Target in Search for Life on Mars

    Science.gov (United States)

    Parnell, J.; Osinski, G. R.; Lee, P.; Cockell, C. S.

    2005-01-01

    Microbes in Haughton Crater Sulfates: Impact craters are of high interest in planetary exploration because they are viewed as possible sites for evidence of life [1]. Hydrothermal systems in craters are particularly regarded as sites where primitive life could evolve. Evidence from the Miocene Haughton impact structure shows that crater hydrothermal deposits may also be a preferred site for subsequent colonization and hence possible extant life: Hydrothermal sulfates at Haughton are colonized by viable cyanobacteria [2]. The Haughton impact structure, Devon Island, Canadian High Arctic, is a 24 km-diameter crater of mid-Tertiary age. The structure preserves an exceptional record of impact-induced hydrothermal activity, including sulfide, and sulfate mineralization [3]. The target rocks excavated at the site included massive gypsum-bearing carbonate rocks of Ordovician age. Impact-remobilized sulfates occur as metre-scale masses of intergrown crystals of the clear form of gypsum selenite in veins and cavity fillings within the crater s impact melt breccia deposits [4]. The selenite is part of the hydrothermal assemblage as it was precipitated by cooling hot waters that were circulating as a result of the impact. Remobilization of the sulfate continues to the present day, such that it occurs in soil crusts (Fig. 1) including sandy beds with a gypsum cement. The sulfate-cemented beds make an interesting comparison with the sulfate-bearing sandy beds encountered by the Opportunity MER [5]. The selenite crystals are up to 0.3 m in width, of high purity, and transparent. They locally exhibit frayed margins where cleavage surfaces have separated. This exfoliation may be a response to freeze-thaw weathering. The selenite contains traces of rock detritus, newly precipitated gypsum, and microbial colonies. The rock detritus consists of sediment particles which penetrated the opened cleavages by up to 2cm from the crystal margins. Some of the detritus is cemented into place

  5. Bioaccumulation of selenium and induced biological effects in the filter feeding bivalve Corbicula fluminea: influence of ventilatory activity, selenium speciation and route of transfer

    International Nuclear Information System (INIS)

    Fournier, E.

    2005-10-01

    Selenium is an essential micro-nutrient for most of living organisms. However, toxic effects in several ecosystems have been reported in the literature. Toxicity comprehension is difficult due to the complexity of Se oxidation states in the environment. The aim of this thesis work was to acquire knowledge on the physiological and environmental factors involved in bioaccumulation and toxicity processes in the freshwater filter-feeding bivalve C. fluminea. The aims were: i) to define what the factors involved in Se bioaccumulation processes in the bivalve are, ii) to characterize Se bioaccumulation at different biological organisation levels, iii) to investigate Se toxic effects. First experiments, carried out for short term exposure duration (3 days), have permitted to underline the importance of Se chemical speciation in bioaccumulation processes in C. fluminea. It has been shown that the organic form, seleno-methionine, was much more bio-available than the inorganic forms, selenite and selenate. Moreover, the route of transfer was determinant in those processes. Inorganic forms have been better extracted by trophic route, whereas seleno-methionine has been better extracted by the direct route. In our experimental conditions, ventilation of the bivalve has not been a limiting factor for Se bioaccumulation by the direct route, whereas it has been for bioaccumulation by the trophic route. Ventilation has been largely modified by the presence of dissolved selenite and seleno-methionine. We have shown that the kinetics of seleno-methionine bioaccumulation are much more fast than those of selenite. Moreover, when introduced as SeMet, internalized Se appeared to be relatively remanent in soft tissues of C. fluminea in comparison with Se internalized when introduced as selenite. Subcellular and molecular distributions of these forms were very different. Finally, it has been shown that seleno-methionine and selenite could generate weak alterations of the anti

  6. Sorption of selenium on Mg-Al and Mg-Al-Eu layered double hydroxides

    International Nuclear Information System (INIS)

    Curtius, H.; Paparigas, Z.; Kaiser, G.

    2008-01-01

    Salt domes represent deep geological formations which are under consideration as final repositories for irradiated research reactor fuel elements. For long-term safety aspects the mobilisation of the radionuclides due to a water ingress is intensively investigated. At the Institute of Energy Research (IEF-6), leaching experiments were performed in a hot cell facility with UAl x -Al and U 3 Si 2 -Al dispersed research reactor fuel elements in repository-relevant MgCl 2 -rich salt brines under anaerobic conditions. The fuel plates corroded completely within one year and a Mg-Al-layered double hydroxide (LDH) with chloride as interlayer anion was identified as one crystalline phase component of the corrosion products (secondary phases). This Mg-Al-LDH was synthesized, characterized, and the ability to retard europium by an incorporation process was investigated. Europium, as a representative for lanthanides, was identified to be one of the radionuclides which were found in the corrosion products. We could show that europium was incorporated in the lattice structure. LDHs have high anion exchange capacities that enhance their potential to remove anionic contaminants from aqueous systems. In this work the sorption behaviour of selenium in the chemical form as selenite (SeO 3 2- ) on Mg-Al-LDH and on Mg-Al-Eu-LDH was investigated. Especially the influence of the larger europium-III ion was of interest. It represents in the Mg-Al-Eu-LDH about 10% of the molar aluminium amount. The sorption has been experimentally studied in a wide range of pH, ionic strength, radionuclide and sorbent concentration. Both LDHs with chloride as interlayer anion were synthesized by a coprecipitation method under controlled conditions, and their main physico-chemical properties were analyzed prior to the sorption experiments. The sorption kinetics of selenite on the LDHs in water and in MgCl 2 -rich brine were rapid using a LDH concentration of 10 g/L. Equilibrium, indicated by stable p

  7. Bioaccumulation of selenium and induced biological effects in the filter feeding bivalve Corbicula fluminea: influence of ventilatory activity, selenium speciation and route of transfer; Bioaccumulation du selenium et effets biologiques induits chez le bivalve filtreur Corbicula fluminea: prise en compte de l'activite ventilatoire, de la speciation du selenium et de la voie de contamination

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, E

    2005-10-15

    Selenium is an essential micro-nutrient for most of living organisms. However, toxic effects in several ecosystems have been reported in the literature. Toxicity comprehension is difficult due to the complexity of Se oxidation states in the environment. The aim of this thesis work was to acquire knowledge on the physiological and environmental factors involved in bioaccumulation and toxicity processes in the freshwater filter-feeding bivalve C. fluminea. The aims were: i) to define what the factors involved in Se bioaccumulation processes in the bivalve are, ii) to characterize Se bioaccumulation at different biological organisation levels, iii) to investigate Se toxic effects. First experiments, carried out for short term exposure duration (3 days), have permitted to underline the importance of Se chemical speciation in bioaccumulation processes in C. fluminea. It has been shown that the organic form, seleno-methionine, was much more bio-available than the inorganic forms, selenite and selenate. Moreover, the route of transfer was determinant in those processes. Inorganic forms have been better extracted by trophic route, whereas seleno-methionine has been better extracted by the direct route. In our experimental conditions, ventilation of the bivalve has not been a limiting factor for Se bioaccumulation by the direct route, whereas it has been for bioaccumulation by the trophic route. Ventilation has been largely modified by the presence of dissolved selenite and seleno-methionine. We have shown that the kinetics of seleno-methionine bioaccumulation are much more fast than those of selenite. Moreover, when introduced as SeMet, internalized Se appeared to be relatively remanent in soft tissues of C. fluminea in comparison with Se internalized when introduced as selenite. Subcellular and molecular distributions of these forms were very different. Finally, it has been shown that seleno-methionine and selenite could generate weak alterations of the anti

  8. Effect of foliar application of selenium on its uptake and speciation in carrot

    DEFF Research Database (Denmark)

    Kápolna, Emese; Hillestrøm, Peter René; Laursen, K.H.

    2009-01-01

    Carrot (Daucus carota) shoots were enriched by selenium using foliar application. Solutions of sodium selenite or sodium selenate at 10 and 100 mu g Se ml(-1), were sprayed on the carrot leaves and the selenium content and uptake rate of selenium were estimated by ICP-MS analysis. Anion and cation......(-1) (dry mass) in the carrot root whereas the selenium concentration in the controls was below the limit of detection at 0.045 mu g Se g(-1) (dry mass). Selenate-enriched carrot leaves accumulated as much as 80 mu g Se g(-1) (dry mass), while the selenite-enriched leaves contained approximately 50 mu...... g Se g(-1) (dry mass). The speciation analyses showed that inorganic selenium was present in both roots and leaves. The predominant metabolised organic forms of selenium in the roots were selenomethionine and gamma-glutamyl-selenomethyl-selenocysteine, regardless of which of the inorganic species...

  9. Isolation of Salmonellae from Foods Samples

    Science.gov (United States)

    Taylor, Welton I.; Silliker, John H.

    1961-01-01

    A comparison of various methods of enhancing frequency of Salmonella isolations revealed that inoculation of a second enrichment broth, with culture from the first, was no improvement over the single direct enrichment method. It was inferior to centrifugation. Selenite was observed to produce more positive isolations at 48 hr than at 24. No change occurred in tetrathionate. Reconstitution of dried albumen with water produced a significant increase in isolations over direct inoculation of enrichment broth in the case of tetrathionate but not selenite broth. Pre-enrichment in lactose broth before inoculation of enrichment media was vastly superior to reconstitution in water for both enrichment broths. A comparison of results obtained using dulcitol, mannitol, lactose and carbohydrate-free purple broths in pre-enrichment indicated that the carbohydrate added was immaterial. PMID:13920002

  10. Nanocrystalline hydroxyapatite doped with selenium oxyanions: a new material for potential biomedical applications.

    Science.gov (United States)

    Kolmas, Joanna; Oledzka, Ewa; Sobczak, Marcin; Nałęcz-Jawecki, Grzegorz

    2014-06-01

    Selenium-substituted hydroxyapatites containing selenate SeO4(2-) or selenite SeO3(2-) ions were synthesized using a wet precipitation method. The selenium content was determined by atomic absorbance spectrometry. The raw, unsintered powders were also characterized using powder X-ray diffraction, middle-range FT-IR spectroscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopic microanalysis. The synthesized apatites were found to be pure and nanocrystalline with a crystal size similar to that in bone mineral. The incorporation of selenium oxyanions into the crystal lattice was confirmed. The toxicity of hydroxyapatites containing selenite or selenate ions was evaluated with a protozoan assay and bacterial luminescence test. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Protective effect of selenium against ionizing radiation-induced malformations in mice

    Energy Technology Data Exchange (ETDEWEB)

    Cekan, E.; Tribukait, B.; Vokal-Borek, H.

    A single dose of sodium selenite (0.5 mg Se/kg b.w.) was injected intraperitoneally into mice on day 9 of pregnancy, either 30 min or 2 h before 1.75 Gy whole body irradiation. Administration of selenite 2 h but not 30 min before irradiation resulted in a significant decrease in the number of malformed foetuses (p < 0.005). The decrease in foetal malformations occurred proportionally for all the major malformations observed, i.e. short or kinked tail, rib and vertebral malformations, coloboma and deformation of retina and iris. In addition, selenium pretreatment also protected against radiation-induced retardation of the sternum of the foetus.

  12. Protective effect of selenium against ionizing radiation-induced malformations in mice

    International Nuclear Information System (INIS)

    Cekan, E.; Tribukait, B.; Vokal-Borek, H.; Stockholm Univ.

    1985-01-01

    A single dose of sodium selenite (0.5 mg Se/kg b.w.) was injected intraperitoneally into mice on day 9 of pregnancy, either 30 min or 2 h before 1.75 Gy whole body irradiation. Administration of selenite 2 h but not 30 min before irradiation resulted in a significant decrease in the number of malformed foetuses (p<0.005). The decrease in foetal malformations occurred proportionally for all the major malformations observed, i.e. short or kinked tail, rib and vertebral malformations, coloboma and deformation of retina and iris. In addition, selenium pretreatment also protected against radiation-induced retardation of the sternum of the foetus. (orig.)

  13. Autometallography: tissue metals demonstrated by a silver enhancement kit

    DEFF Research Database (Denmark)

    Danscher, G; Nørgaard, J O; Baatrup, E

    1987-01-01

    , primarily intended for the amplification of colloidal gold particles, has been used to demonstrate these catalytic tissue metals. Sections from animals exposed intravitally to aurothiomalatate, silver lactate, mercury chloride, sodium selenite or perfused with sodium sulphide were subjected to a commercial......In biological tissue, minute accumulations of gold, silver, mercury and zinc can be visualized by a technique whereby metallic silver is precipitated on tiny accumulations of the two noble metals, or on selenites or sulphides of all four metals. In the present study a silver enhancement kit...... silver enhancement kit (IntenSE, Janssen Pharmaceutica). It was found that the kit performs adequately to the silver lactate gum arabic developer and to the photographic emulsion technique. The kit can be used as a silver enhancement medium for the demonstration of zinc by the Neo-Timm and selenium...

  14. Simultaneous speciation of endogenous and exogenous elements by HPLC/ICP-MS with enriched stable isotopes

    International Nuclear Information System (INIS)

    Suzuki, K.T.

    1996-01-01

    High performance liquid chromatography (HPLC)/inductively coupled argon plasma-mass spectrometry (ICP-MS) was introduced to investigate the distributions of selenium (Se) in biological fluids. The method was to determine both the natural abundance of Se and an enriched stable isotope of Se used as a tracer. The distributions of Se in plasma and in urine specimens were determined in Wistar rats on various Se diets with and without an intravenous injection of 82 Se-selenite. Although the distribution of natural abundance Se (endogenous Se) in the plasma was affected little by the nutritional status of Se, that in the urine gave a Se peak depending on the nutritional status of Se, and the peak was identified as methylselenol. When 82 Se-selenite was injected in excess into rats given three different Se diets (Se-deficient, Se-adequate, Se-excessive), three Se peaks occurred in the HPLC chromatogram of the urine samples, corresponding to selenite, methylselenol and trimethylselenonium ion in the order of elution, and the intensities of the tracer peaks reflected the nutritional status. These results indicate that the HPLC/ICP-MS method is a powerful analytical tool for specifying Se-containing biological constituents, both natural abundance and enriched stable isotopes. Methylselenol in urine is proposed to be a sensitive and Se-specific biological indicator for diagnosing the nutritional status of Se. Furthermore, it was shown that an enriched stable isotope such as 82 Se-selenite was shown to be used for the same purpose, and that 82 Se-methylselenol and 82 Se-trimethylselenonium ion in urine were more sensitive indicators of the Se status of the rats. (author)

  15. Removal of selenium species from waters using various surface-modified natural particles and waste materials

    Energy Technology Data Exchange (ETDEWEB)

    Yigit, Nevzat O.; Tozum, Seda [Department of Environmental Engineering, Suleyman Demirel University, Isparta (Turkey)

    2012-07-15

    Waste red mud and natural pumice/volcanic slag particles were surface modified and their selenium adsorption from waters was investigated. Acid activation/heat treatment of original red mud (ORM) particles significantly increased their micropore and external surface area and cumulative volume of pores. Iron oxide coating of pumice/slags and acid activation of ORM decreased their pH{sub pzc} values and increased surface acidity. Selenite/selenate adsorption on iron oxide surfaces and acid activated red mud (AARM) was very fast with approximately first-order adsorption kinetics. Iron oxide coating of pumice/slag and acid activation of ORM particles significantly enhanced their selenite and selenate uptakes. Maximum Se adsorption capacities as high as 6.3 (mg Se/g adsorbent) were obtained by AARM. The extent of selenate uptakes by the surface modified particles was generally lower than those of selenite. Due to competition among Se species and other background water matrix for iron oxide adsorption sites, reduced selenite/selenate uptakes were found in natural water compared to single solute tests. Higher Se uptakes by iron oxide surfaces were found at pH 7.5 compared to pH 8.9, due to increased electrostatic repulsion among iron oxides and Se species at higher pH. The most effective adsorbents among the tested 17 different particles for Se uptake were AARM and iron oxide coated pumice. Se concentrations less than drinking water standards (5-10 {mu}g/L) can be achieved by these particles. These low-cost, natural, or recyclable waste particles appear to be promising adsorbents for Se removal after their surface modification. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Studies on Se-Cr interactions in mungbean using radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Shanker, Karuna; Mishra, Seema; Srivastava, Shalini; Srivastava, Rohit; Dass, Sahab; Prakash, Satya; Srivastava, M M [Dayalbagh Educational Institute, Agra (India). Dept. of Chemistry

    1995-09-01

    The paper describes a preliminary report of hydroponic experiment on the effect of selenium (selenite and selenate) treatments on the absorption of trivalent and hexavalent chromium by mung bean (Phaseolus mungo) plant. The studies are mainly confined to animal system and little attention has been paid on Se-metal interactions, particularly with those of different oxidation states of selenium and chromium in plant system. (author). 8 refs., 1 tab.

  17. Colorimetric determination of selenium in mineral premixes .

    Science.gov (United States)

    Hurlbut, J A; Burkepile, R G; Geisler, C A; Kijak, P J; Rummel, N G

    1997-01-01

    A method is described for determination of sodium selenite or sodium selenate in mineral-based premixes. It is based on the formation of intense-yellow piazselenol by Se(IV) and 3,3'-diaminobenzidine. Mineral premixes typically contain calcium carbonate as a base material and magnesium carbonate, silicon dioxide, and iron(III) oxide as minor components or additives. In this method, the premix is digested briefly in nitric acid, diluted with water, and filtered to remove any Iron(III) oxide. Ethylenediaminetetraacetic acid and HCl are added to the filtrate, which is heated to near boiling for 1 h to convert any selenate to selenite. After heating, the solution is buffered between pH 2 and 3 with NaOH and formic acid and treated with NH2OH and EDTA; any Se present forms a complex with 3,3'-diaminobenzidine at 60 degrees C. The solution is made basic with NH4OH, and the piazselenol is extracted into toluene. The absorbance of the complex in dried toluene is measured at 420 nm. The method was validated independently by 2 laboratories. Samples analyzed included calcium carbonate fortified with 100, 200, and 300 micrograms Se in the form of sodium selenite or sodium selenate, a calcium carbonate premix containing sodium selenite, a calcium carbonate premix containing sodium selenate, and a commercial premix; 5 replicates of each sample type were analyzed by each laboratory. Average recoveries ranged from 89 to 109% with coefficients of variation from 1.2 to 13.6%.

  18. Effects on the accumulation of calcium, magnesium, iron, manganese, copper and zinc of adding the two inorganic forms of selenium to solution cultures of Zea mays.

    Science.gov (United States)

    Longchamp, M; Angeli, N; Castrec-Rouelle, M

    2016-01-01

    The addition of selenate or selenite to common fertilizers for crop production could be an effective way of producing selenium-rich food and feed. However, this would be feasible only if the increase in plant selenium (Se) content did not negatively influence the uptake of other essential elements. We therefore need to understand the interactions between Se and other major and trace elements during uptake by the plant. This study aimed to evaluate the influence of inorganic forms of Se on the accumulation of selected macronutrients (Ca and Mg) and micronutrients (Fe, Zn, Mn and Cu). Those essential elements are involved in the oxidative balance of cells. Zea mays seedlings were grown hydroponically in growth chambers in nutrient solutions to which we added 10, 50 or 1000 μg.L(-1) of selenate and/or selenite. Cation accumulation was significantly affected by the addition of 50 μg.L(-1) or 1000 μg.L(-1) Se, but not by the presence of 10 μg.L(-1) of Se in the nutrient solution. The highest concentration (1000 μg.L(-1)) of Se in the nutrient solution affected the accumulation of essential cations in Zea mays: selenate tended to increase the accumulation of Mg, Zn and Mn, whereas a selenate/selenite mixture tended to decrease the accumulation of Ca, Mg, Zn and Mn. Only Fe accumulation was unaffected by Se whatever its form or concentration. Selenium may also affect the distribution of cations on Zea mays. For example, levels of Mg and Zn translocation to the shoots were lower in the presence of selenite. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  19. Selenium Uptake and Volatilization by Marine Algae

    Science.gov (United States)

    Luxem, Katja E.; Vriens, Bas; Wagner, Bettina; Behra, Renata; Winkel, Lenny H. E.

    2015-04-01

    Selenium (Se) is an essential trace nutrient for humans. An estimated one half to one billion people worldwide suffer from Se deficiency, which is due to low concentrations and bioavailability of Se in soils where crops are grown. It has been hypothesized that more than half of the atmospheric Se deposition to soils is derived from the marine system, where microorganisms methylate and volatilize Se. Based on model results from the late 1980s, the atmospheric flux of these biogenic volatile Se compounds is around 9 Gt/year, with two thirds coming from the marine biosphere. Algae, fungi, and bacteria are known to methylate Se. Although algal Se uptake, metabolism, and methylation influence the speciation and bioavailability of Se in the oceans, these processes have not been quantified under environmentally relevant conditions and are likely to differ among organisms. Therefore, we are investigating the uptake and methylation of the two main inorganic Se species (selenate and selenite) by three globally relevant microalgae: Phaeocystis globosa, the coccolithophorid Emiliania huxleyi, and the diatom Thalassiosira oceanica. Selenium uptake and methylation were quantified in a batch experiment, where parallel gas-tight microcosms in a climate chamber were coupled to a gas-trapping system. For E. huxleyi, selenite uptake was strongly dependent on aqueous phosphate concentrations, which agrees with prior evidence that selenite uptake by phosphate transporters is a significant Se source for marine algae. Selenate uptake was much lower than selenite uptake. The most important volatile Se compounds produced were dimethyl selenide, dimethyl diselenide, and dimethyl selenyl sulfide. Production rates of volatile Se species were larger with increasing intracellular Se concentration and in the decline phase of the alga. Similar experiments are being carried out with P. globosa and T. oceanica. Our results indicate that marine algae are important for the global cycling of Se

  20. Selenium content in the blood serum and urine of ewes receiving selenium-enriched unicellular alga Chlorella

    Czech Academy of Sciences Publication Activity Database

    Trávníček, J.; Písek, I.; Herzig, I.; Doucha, Jiří; Kvíčala, J.; Kroupová, V.; Rodinová, H.

    2007-01-01

    Roč. 52, - (2007), s. 42-48 ISSN 0375-8427 Grant - others:GA ČR(CZ) GD523/03/H076 Program:GD Institutional research plan: CEZ:AV0Z50200510 Source of funding: V - iné verejné zdroje Keywords : sodium selenite * organically bound selenium * ewes Subject RIV: EE - Microbiology, Virology Impact factor: 0.645, year: 2007

  1. Comparison of Selenium Treatments of Crops in the Field

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel

    1986-01-01

    Field experiments with spring and winter barley and ryegrass were carried out to compare the effect of fertilizers enriched with selenate or selenite with foliar application on the selenium (Se) concentrations in the crops. Application of about 20 g Se/ha given as selenate or about 100 g as selen...... not occur. The choice of method thus depends on the farming practice in the individual cases....

  2. Studies on Se-Cr interactions in mungbean using radiotracers

    International Nuclear Information System (INIS)

    Shanker, Karuna; Mishra, Seema; Srivastava, Shalini; Srivastava, Rohit; Dass, Sahab; Prakash, Satya; Srivastava, M.M.

    1995-01-01

    The paper describes a preliminary report of hydroponic experiment on the effect of selenium (selenite and selenate) treatments on the absorption of trivalent and hexavalent chromium by mung bean (Phaseolus mungo) plant. The studies are mainly confined to animal system and little attention has been paid on Se-metal interactions, particularly with those of different oxidation states of selenium and chromium in plant system. (author). 8 refs., 1 tab

  3. Efficacy of selenium from hydroponically produced selenium-enriched kale sprout (Brassica oleracea var. alboglabra L.) in broilers.

    Science.gov (United States)

    Chantiratikul, Anut; Pakmaruek, Pornpan; Chinrasri, Orawan; Aengwanich, Worapol; Chookhampaeng, Sumalee; Maneetong, Sarunya; Chantiratikul, Piyanete

    2015-05-01

    An experiment was conducted to determine the efficacy of Se from hydroponically produced Se-enriched kale sprout (HPSeKS) on performance, carcass characteristics, tissue Se concentration, and physiological responses of broilers in comparison to that of Se from Se-enriched yeast and sodium selenite. Three hundred and sixty male broilers, 10 days of age, were assigned to 6 groups, 4 replicates of 15 broilers each, according to the completely randomized design. The dietary treatments were the following: T1: control diet; T2: control diet plus 0.3 mg Se/kg from sodium selenite; T3: control diet plus 0.3 mg Se/kg from Se-enriched yeast; and T4, T5, and T6: control diet plus 0.3, 1.0, and 2.0 mg Se/kg from HPSeKS, respectively. The results found that dietary Se supplementation did not (p > 0.05) alter performance and carcass characteristics of broilers. Se supplementation increased (p < 0.05) Se concentrations in the liver and kidney of broilers. Heart tissue Se concentration of broilers fed Se from sodium selenite was lower (p < 0.05) than that of broilers fed Se from HPSeKS and Se-enriched yeast. Selenium from HPSeKS increased higher (p < 0.05) GSH-Px activity when compared to Se from sodium selenite and Se-enriched yeast. The results indicated that the efficacy of Se from HPSeKS was comparable in increasing tissue Se concentration, but higher in improving GSH-Px activity in Rbc when compared to those of Se from Se-enriched yeast.

  4. Acute selenium poisoning in lambs

    Energy Technology Data Exchange (ETDEWEB)

    Gabbedy, B J; Dickson, J

    1969-10-01

    An outbreak of sodium selenite poisoning is reported in which 180 of 190 six-weeks-old lambs died. The estimated dose rate of the selenium was 6.4 mg/kg body weight. Liver concentrations of selenium at the time of poisoning averaged 64 ppM and 15 days later liver and kidney concentrations of selenium averaged 26 ppM and 7.4 ppM respectively.

  5. Immobilization of selenium by biofilm of Shewanella putrefaciens with and without Fe(III)-citrate complex

    International Nuclear Information System (INIS)

    Suzuki, Yoshinori; Sakama, Yosuke; Saiki, Hiroshi; Kitamura, Akira; Yoshikawa, Hideki; Tanaka, Kazuya

    2014-01-01

    To investigate the effect of biofilms on selenium migration, we examined selenite reduction by biofilms of an iron-reducing bacterium, Shewanella putrefaciens, under anaerobic conditions. The biofilms were grown under static conditions on culture cover glasses coated with poly-L-lysine. Optical microscopic observation of the biofilms after staining with 0.1% crystal violet solution revealed that the cells were surrounded by filamentous extracellular polymer substances. Exposure of the biofilms to aqueous selenite resulted in the formation of red precipitates, which were assigned to nanoparticulate elemental selenium using X-ray absorption near-edge structure analysis. Micrographic observation showed that the precipitates immobilized at the biofilms. We also examined the selenite reduction in the presence of Fe(III)-citrate complex. In this case, a dark brown precipitate formed at the biofilms. X-ray absorption near-edge structure analysis revealed that the precipitate was a mixed compound with elemental selenium and iron selenide. These findings indicate that biofilms of iron-reducing bacteria in the environment can immobilize selenium by reducing Se(IV) to Se(0), and Fe(III)-citrate complex promotes the reduction of Se(0) to Se(-II). (author)

  6. Optimization of Selenium-enriched Candida utilis by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    ZHANG Fan

    2014-12-01

    Full Text Available The fermentation conditions of selenium enrichment by Candida utilis were studied. Based on the results of the single factor experiment, three factors including the concentration of sodium selenite, inital pH and incubation temperature were selected. The response surface method was used to optimize the various factors. The optimal conditions were obtained as follows: incubation time was 30 h, time of adding selenium was mid-logarithmic, the sodium selenite concentration was 35 mg·L-1 with inital pH of 6.6, incubation concentration of 10%, incubation temperature of 27 ℃, the medium volume of 150 mL/500 mL, respectively. Under the optimal condition, the biomass was 6.87 g·L-1. The total selenium content of Candida utilis was 12 639.7 μg·L-1, and the selenium content of the cells was 1 839.8 μg·g-1, in which sodium selenite conversion rate was 79.1% and the organic selenium was higher than 90%. The actual value of selenium content was substantially consistent with the theoretical value, and the response surface methodology was applicable for the fermentation conditions of selenium enriched by Candida utilis.

  7. Synthesis and biodistribution of 75Se-dinonyl-diselenide

    International Nuclear Information System (INIS)

    Liu, Y.F.; Qian, H.Q.; Zhang, Q.X.; Wang, X.Y.; Sun, J.G.; Li, B.Z.; Zhang, W.J.

    1985-01-01

    Selenium-75-labelled dinonyl-diselenide, C 9 H 19 75 SeSeC 9 H 19 , was synthesized and identified. It was injected into white rats in order to observe the selenium distribution in the tissues using inorganic 75 SeO 2 as the control agent. The sequence order of the 75 Se-dinonyl-diselenide uptake by tissues was: pancreas, muscles, stomach, liver, kidneys, spleen, blood, lungs, heart, brain, eyes. A very high accumulation of 75 Se-dinonyl-diselenide in the pancreas was observed, similar to that of the pancreatic imaging agent 75 Se-methionine. Furthermore, the enzymatic activity of glutathione peroxidase in the case of organic diselenide injection was higher than that measured for selenite. Selenium of dinonyl-diselenide was more effective and retainable in the process of converting itself to selenium-containing enzyme via the metabolic reactions. It may be advisable to replace inorganic sodium selenite by organic selenium compounds. Sodium selenite has been widely used in the prevention of the Keshan disease in China. (author)

  8. Biogenic selenium and tellurium nanoparticles synthesized by environmental microbial isolates efficaciously inhibit bacterial planktonic cultures and biofilms

    Directory of Open Access Journals (Sweden)

    Emanuele eZonaro

    2015-06-01

    Full Text Available The present study deals with Se0- and Te0-based nanoparticles bio-synthesized by two selenite- and tellurite-reducing bacterial strains, namely Stenotrophomonas maltophilia SeITE02 and Ochrobactrum sp. MPV1, isolated from polluted sites. We discovered that, by regulating culture conditions and exposure time to the selenite and tellurite oxyanions, differently sized zero-valent Se and Te nanoparticles were produced. The results revealed that these Se0 and Te0 nanoparticles possess antimicrobial and biofilm eradication activity against E. coli JM109, P. aeruginosa PAO1, and S. aureus ATCC 25923. In particular, Se0 nanoparticles exhibited antimicrobial activity at quite low concentrations, below that of selenite. Toxic effects of both Se0 and Te0 nanoparticles can be related to the production of reactive oxygen species upon exposure of the bacterial cultures. Evidence so far achieved suggests that the antimicrobial activity seems to be strictly linked to the dimensions of the nanoparticles: indeed, the highest activity was shown by nanoparticles of smaller sizes. In particular, it is worth noting how the bacteria tested in biofilm mode responded to the treatment by Se0 and Te0 nanoparticles with a susceptibility similar to that observed in planktonic cultures. This suggests a possible exploitation of both Se0 and Te0 nanoparticles as efficacious antimicrobial agents with a remarkable biofilm eradication capacity.

  9. Enriched selenium and its effects on growth and biochemical composition in Lactobacillus bulgaricus.

    Science.gov (United States)

    Xia, Shu Kai; Chen, Long; Liang, Jun Qing

    2007-03-21

    Se-enriched Lactobacillus bulgaricus (L. bulgaricus) was generated by administration of sodium selenite (0, 1, 4, 8, 16, 32, and 64 mg/L, respectively) in MRS medium and enriched selenium manifestation in L. bulgaricus was investigated using transmission electron microscopy and energy-dispersive X-ray spectrometry and alterations of essential elements and amino acids in the organism were evaluated. We demonstrate that administration of sodium selenite in the dosage of 1-16 mg/L is suitable for selenium enrichment in L. bulgaricus and can enhance nutritive value in the organism by elevating the contents of essential elements including P, Mg, Mn, Zn, Ca, and total amino acids as well as reducing selenite to insoluble elemental selenium, an electron-dense and amorphous Se (0) granule, thereby depositing it both in the cytoplasm and in the extracellular space of L. bulgaricus. Thus, Se-enriched Lactobacillus can provide a potential dietary source of nontoxic selenium and functional regulator used for food and medical industry.

  10. Selenium Accumulation in Unicellular Green Alga Chlorella vulgaris and Its Effects on Antioxidant Enzymes and Content of Photosynthetic Pigments

    Science.gov (United States)

    Sun, Xian; Zhong, Yu; Huang, Zhi; Yang, Yufeng

    2014-01-01

    The aim of the present study was to investigate selenite effects in the unicellular green algae Chlorella vulgaris as a primary producer and the relationship with intracellular bioaccumulation. The effects of selenite were evaluated by measuring the effect of different selenite concentrations on algal growth during a 144 h exposure period. It was found that lower Se concentrations (≤75 mg L−1) positively promoted C. vulgaris growth and acted as antioxidant by inhibiting lipid peroxidation (LPO) and intracellular reactive oxygen species (ROS). The antioxidative effect was associated with an increase in guaiacol peroxidase (GPX), catalase (CAT), superoxide dismutase (SOD) and photosynthetic pigments. Meanwhile, significant increase in the cell growth rate and organic Se content was also detected in the algae. In contrast, these changes were opposite in C. vulgaris exposed to Se higher than 100 mg L−1. The antioxidation and toxicity appeared to be correlated to Se bioaccumulation, which suggests the appropriate concentration of Se in the media accumulation of C. vulgaris should be 75 mg L−1. Taken together, C. vulgaris possesses tolerance to Se, and Se-Chlorella could be developed as antioxidative food for aquaculture and human health. PMID:25375113

  11. Toxicity of inorganic contaminants, individually and in environmental mixtures, to three endangered fishes (Colorado squawfish, bonytail, and razorback sucker)

    Science.gov (United States)

    Buhl, Kevin J.; Hamilton, S.J.

    1996-01-01

    Two life stages of three federally-listed endangered fishes, Colorado squawfish (Ptychocheilus lucius), bonytail (Gila elegans), and razorback sucker (Xyrauchen texanus) were exposed to copper, selenate, selenite, and zinc individually, and to mixtures of nine inorganics in a reconstituted water that simulated the water quality of the middle Green River, Utah. The mixtures simulated environmental ratios of arsenate, boron, copper, molybdenum, selenate, selenite, uranium, vanadium, and zinc in two tributaries, Ashley Creek and Stewart Lake outlet, of the middle Green River. The rank order of toxicity of the individual inorganics, from most to least toxic, was: copper > zinc > selenite > selenate. Colorado squawfish larvae were more sensitive to all four inorganics and the two mixtures than the juveniles, whereas there was no consistent response between the two life stages for the other two species. There was no consistent difference in sensitivity to the inorganics among the three endangered fishes. Both mixtures exhibited either additive or greater than additive toxicity to these fishes. The primary toxic components in the mixtures, based on toxic units, were copper and zinc. Acute toxicity values were compared to measured environmental concentrations in the two tributaries to derive margins of uncertainty. Margins of uncertainty were low for both mixtures (9–22 for the Stewart Lake outlet mixture, and 12–32 for the Ashley Creek mixture), indicating that mixtures of inorganics derived from irrigation activities may pose a hazard to endangered fishes in the Green River.

  12. Selenium speciation in acidic environmental samples: application to acid rain-soil interaction at Mount Etna volcano.

    Science.gov (United States)

    Floor, Geerke H; Iglesías, Mònica; Román-Ross, Gabriela; Corvini, Philippe F X; Lenz, Markus

    2011-09-01

    Speciation plays a crucial role in elemental mobility. However, trace level selenium (Se) speciation analyses in aqueous samples from acidic environments are hampered due to adsorption of the analytes (i.e. selenate, selenite) on precipitates. Such solid phases can form during pH adaptation up till now necessary for chromatographic separation. Thermodynamic calculations in this study predicted that a pHpH eluent that matches the natural sample pH of acid rain-soil interaction samples from Etna volcano was developed. With a mobile phase containing 20mM ammonium citrate at pH 3, selenate and selenite could be separated in different acidic media (spiked water, rain, soil leachates) in rain-soil interaction using synthetic rain based on H(2)SO(4) and soil samples collected at the flanks of Etna volcano demonstrated the dominance of selenate over selenite in leachates from samples collected close to the volcanic craters. This suggests that competitive behavior with sulfate present in acid rain might be a key factor in Se mobilization. The developed speciation method can significantly contribute to understand Se cycling in acidic, Al/Fe rich environments. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Selenium Supplementation does not Decrease Thyroid Peroxidase Antibody Concentration in Children and Adolescents with Autoimmune Thyroiditis

    Directory of Open Access Journals (Sweden)

    W. Bonfig

    2010-01-01

    Full Text Available In adults, selenium supplementation decreases thyroid peroxidase antibody (TPO Ab concentrations in patients with autoimmune thyroiditis (AIT. Our aim in this study was to investigate if selenium supplementation decreased TPO Ab and thyroglobulin antibody (Tg Ab concentrations in children with AIT. Forty-nine patients (33 females with newly diagnosed AIT and hypothyroidism were randomized to daily oral therapy with levothyroxine alone (group A, n = 18, levothyroxine plus 100 µg sodium-selenite (group B, n = 13, or levothyroxine plus 200 µg sodium-selenite (group C, n = 18. Mean age at diagnosis was 12.2 ± 2.2 years. All 49 patients needed a mean levothyroxine dose of 1.6 ± 0.5 µg/kg body weight to lower TSH to the treatment goal of 1–2 µU/ml, with no significant difference between groups. At study entry and after 12 months, TPO Ab concentrations were comparable in all three groups. Tg Ab concentrations decreased significantly after 12 months in group A and group C (p = 0.03 and p = 0.01, but not in group B (p = 0.06. It is our conclusion that selenium supplementation with sodium-selenite does not decrease TPO Ab concentrations in children and adolescents, neither given in the reduced dose of 100 µg daily nor given in the “adult” supplementation dose of 200 µg daily.

  14. Productivity and selenium concentrations in egg and tissue of laying quails fed selenium from hydroponically produced selenium-enriched kale sprout (Brassica oleracea var. alboglabra L.).

    Science.gov (United States)

    Chinrasri, Orawan; Chantiratikul, Piyanete; Maneetong, Sarunya; Chookhampaeng, Sumalee; Chantiratikul, Anut

    2013-12-01

    This study aimed to determine the effectiveness of Se from hydroponically produced Se-enriched kale sprout (HPSeKS) on productive performance, egg quality, and Se concentrations in egg and tissue of laying quails. Two-hundred quails, 63 days of age, were divided into four groups. Each group consisted of five replicates and each replicate had ten birds, according to a completely randomized design. The experiment lasted for 6 weeks. The dietary treatments were T1 (control diet), T2 (control diet plus 0.2 mg Se/kg from sodium selenite), T3 (control diet plus 0.2 mg Se/kg from Se-enriched yeast), T4 (control diet plus 0.2 mg Se/kg from HPSeKS). The findings revealed that productive performance and egg quality of quails were not altered (p > 0.05) by Se sources. Whole egg Se concentrations of quails fed Se from HPSeKS and Se-enriched yeast were higher (p  0.05), but higher (p < 0.05) than that of quails fed Se from sodium selenite. The results reveal that Se from HPSeKS did not change the performance and egg quality of quails. The effectiveness of Se from HPSeKS was comparable to that of Se-enriched yeast, which was higher than that of Se from sodium selenite.

  15. Responses of growing Japanese quails that received selenium from selenium enriched kale sprout (Brassica oleracea var. alboglabra L.).

    Science.gov (United States)

    Chantiratikul, Anut; Chinrasri, Orawan; Pakmaruek, Pornpan; Chantiratikul, Piyanete; Thosaikham, Withpol; Aengwanich, Worapol

    2011-12-01

    The objectives of this study were to determine the effect of selenium (Se) from Se-enriched kale sprout (Brassica oleracea var. alboglabra L.) on the performance and Se concentrations in tissues of growing Japanese quails. Two hundred quails were divided into five treatments. Each treatment consisted of four replicates and each replicate contained ten quails in a completely randomize design. The experiment was conducted for 5 weeks. The treatments were T1, control diet; T2, control diet plus 0.2 mg Se/kg from sodium selenite; T3, T4, and T5, control diet plus 0.2, 0.5, and 1.0 mg Se/kg from Se-enriched kale sprout. The results revealed that Se supplementation had no impact on feed intake, performance, and carcass characteristics of quails (p > 0.05). However, Se supplementation from both sodium selenite and Se-enriched kale sprout increased (p kale sprout. The results indicate that Se from Se-enriched kale sprout offers no advantage over Se from sodium selenite on tissue Se concentration.

  16. Chemical form of selenium affects its uptake, transport, and glutathione peroxidase activity in the human intestinal Caco-2 cell model.

    Science.gov (United States)

    Zeng, Huawei; Jackson, Matthew I; Cheng, Wen-Hsing; Combs, Gerald F

    2011-11-01

    Determining the effect of selenium (Se) chemical form on uptake, transport, and glutathione peroxidase activity in human intestinal cells is critical to assess Se bioavailability at nutritional doses. In this study, we found that two sources of L-selenomethionine (SeMet) and Se-enriched yeast each increased intracellular Se content more effectively than selenite or methylselenocysteine (SeMSC) in the human intestinal Caco-2 cell model. Interestingly, SeMSC, SeMet, and digested Se-enriched yeast were transported at comparable efficacy from the apical to basolateral sides, each being about 3-fold that of selenite. In addition, these forms of Se, whether before or after traversing from apical side to basolateral side, did not change the potential to support glutathione peroxidase (GPx) activity. Although selenoprotein P has been postulated to be a key Se transport protein, its intracellular expression did not differ when selenite, SeMSC, SeMet, or digested Se-enriched yeast was added to serum-contained media. Taken together, our data show, for the first time, that the chemical form of Se at nutritional doses can affect the absorptive (apical to basolateral side) efficacy and retention of Se by intestinal cells; but that, these effects are not directly correlated to the potential to support GPx activity.

  17. Assessment of the anticancer compounds Se-methylselenocysteine and glucosinolates in Se-biofortified broccoli (Brassica oleracea L. var. italica) sprouts and florets.

    Science.gov (United States)

    Ávila, Fabricio William; Faquin, Valdemar; Yang, Yong; Ramos, Silvio Junio; Guilherme, Luiz Roberto G; Thannhauser, Theodore W; Li, Li

    2013-07-03

    Broccoli (Brassica oleracea L. var. italica) is a rich source of chemopreventive compounds. Here, we evaluated and compared the effect of selenium (Se) treatment on the accumulation of anticancer compounds Se-methylselenocysteine (SeMSCys) and glucosinolates in broccoli sprouts and florets. Total Se and SeMSCys content in sprouts increased concomitantly with increasing Se doses. Selenate was superior to selenite in inducing total Se accumulation, but selenite is equally effective as selenate in promoting SeMSCys synthesis in sprouts. Increasing sulfur doses reduced total Se and SeMSCys content in sprouts treated with selenate, but not in those with selenite. Examination of five broccoli cultivars reveals that sprouts generally have better fractional ability than florets to convert inorganic Se into SeMSCys. Distinctive glucosinolate profiles between sprouts and florets were observed, and sprouts contained approximately 6-fold more glucoraphanin than florets. In contrast to florets, glucosinolate content was not affected by Se treatment in sprouts. Thus, Se-enriched broccoli sprouts are excellent for simultaneous accumulation of chemopreventive compounds SeMSCys and glucoraphanin.

  18. Comparison of Selenium Toxicity in Sunflower and Maize Seedlings Grown in Hydroponic Cultures.

    Science.gov (United States)

    Garousi, Farzaneh; Veres, Szilvia; Kovács, Béla

    2016-11-01

    Several studies have demonstrated that selenium (Se) at low concentrations is beneficial, whereas high Se concentrations can induce toxicity. Controlling Se uptake, metabolism, translocation and accumulation in plants is important to decrease potential health risks and helping to select proper biofortification methods to improve the nutritional content of plant-based foods. The uptake and distribution of Se, changes in Se content, and effects of various concentrations of Se in two forms (sodium selenite and sodium selenate) on sunflower and maize plants were measured in nutrient solution experiments. Results revealed the Se content in shoots and roots of both sunflower and maize plants significantly increased as the Se level increased. In this study, the highest exposure concentrations (30 and 90 mg/L, respectively) caused toxicity in both sunflower and maize. While both Se forms damaged and inhibited plant growth, each behaved differently, as toxicity due to selenite was observed more than in the selenate treatments. Sunflower demonstrated a high Se accumulation capacity, with higher translocation of selenate from roots to shoots compared with selenite. Since in seleniferous soils, a high change in plants' capability exists to uptake Se from these soils and also most of the cultivated crop plants have a bit tolerance to high Se levels, distinction of plants with different Se tolerance is important. This study has tried to discuss about it.

  19. Uptake of selenium by the unicellular green alga Chlamydomonas reinhardtii - effects induced by chronic exposure

    International Nuclear Information System (INIS)

    Morlon, H.; Fortin, C.; Pradines, C.; Floriani, M.; Grasset, G.; Adam, C.; Garnier-Laplace, J.

    2004-01-01

    79 Se is a long-lived radionuclide present in radioactive waste storages. The stable isotope selenium is an essential micro-nutrient that can act against oxidative damage. It is however well known for its bio-magnification potential and chemical toxicity to aquatic life. One of its particularity is to form oxyanions in freshwater ecosystems, which leads to specific behaviours towards biological membranes. Our study deals with the interactions between selenite -Se(IV)- and Chlamydomonas reinhardtii, a unicellular green alga representative of the freshwater phytoplankton community. Cells were exposed to selenite marked with Se 75 in well-known simple inorganic media. Short-term experiments (about one hour of exposure) were performed to better understand selenite transport (uptake kinetics and levels) and identify main factors influencing absorption (nutrients concentrations, pH). Long-term experiments (4 days of exposure) were performed (1) to evaluate the bioaccumulation considering environmentally relevant time scales, (2) to localize the intracellular selenium using EDAX-TEM and (3) to assess the toxicity of selenium as measured by growth impairment, ultrastructural changes, starch accumulation, and loss of pigment. Short-term experiments revealed a time-dependent linear absorption with an estimated absorbed flux of about 0.25 nmol.m -2 .nM -1 .h -1 . The absorption was proportional to ambient levels, except at very low concentrations (ca. 0.5 nM), were it was proportionally higher, suggesting that a specific but rapidly saturated transport could be used at those low concentrations. Selenite uptake was not dependent on phosphate nor carbonate concentrations. It was nevertheless inhibited by sulphate and nitrate, indicating that selenite could share common transporters with those nutrients. The accumulation was found to be maximum for intermediate pH around 7. EDAX-TEM analysis after long-term experiments revealed the presence of selenium in electron-dense granules

  20. Sensitivity and toxic mode of action of dietary organic and inorganic selenium in Atlantic salmon (Salmo salar).

    Science.gov (United States)

    Berntssen, M H G; Sundal, T K; Olsvik, P A; Amlund, H; Rasinger, J D; Sele, V; Hamre, K; Hillestad, M; Buttle, L; Ørnsrud, R

    2017-11-01

    Depending on its chemical form, selenium (Se) is a trace element with a narrow range between requirement and toxicity for most vertebrates. Traditional endpoints of Se toxicity include reduced growth, feed intake, and oxidative stress, while more recent finding describe disturbance in fatty acid synthesis as underlying toxic mechanism. To investigate overall metabolic mode of toxic action, with emphasis on lipid metabolism, a wide scope metabolomics pathway profiling was performed on Atlantic salmon (Salmo salar) (572±7g) that were fed organic and inorganic Se fortified diets. Atlantic salmon were fed a low natural background organic Se diet (0.35mg Se kg -1 , wet weight (WW)) fortified with inorganic sodium selenite or organic selenomethionine-yeast (SeMet-yeast) at two levels (∼1-2 or 15mgkg -1 , WW), in triplicate for 3 months. Apparent adverse effects were assessed by growth, feed intake, oxidative stress as production of thiobarbituric acid-reactive substances (TBARS) and levels of tocopherols, as well as an overall metabolomic pathway assessment. Fish fed 15mgkg -1 selenite, but not 15mgkg -1 SeMet-yeast, showed reduced feed intake, reduced growth, increased liver TBARS and reduced liver tocopherol. Main metabolic pathways significantly affected by 15mgkg -1 selenite, and to a lesser extent 15mgkg -1 SeMet-yeast, were lipid catabolism, endocannabinoids synthesis, and oxidant/glutathione metabolism. Disturbance in lipid metabolism was reflected by depressed levels of free fatty acids, monoacylglycerols and diacylglycerols as well as endocannabinoids. Specific for selenite was the significant reduction of metabolites in the S-Adenosylmethionine (SAM) pathway, indicating a use of methyl donors that could be allied with excess Se excretion. Dietary Se levels to respectively 1.1 and 2.1mgkg -1 selenite and SeMet-yeast did not affect any of the above mentioned parameters. Apparent toxic mechanisms at higher Se levels (15mgkg -1 ) included oxidative stress and

  1. Progress toward clonable inorganic nanoparticles

    Science.gov (United States)

    Ni, Thomas W.; Staicu, Lucian C.; Nemeth, Richard S.; Schwartz, Cindi L.; Crawford, David; Seligman, Jeffrey D.; Hunter, William J.; Pilon-Smits, Elizabeth A. H.; Ackerson, Christopher J.

    2015-10-01

    Pseudomonas moraviensis stanleyae was recently isolated from the roots of the selenium (Se) hyperaccumulator plant Stanleya pinnata. This bacterium tolerates normally lethal concentrations of SeO32- in liquid culture, where it also produces Se nanoparticles. Structure and cellular ultrastructure of the Se nanoparticles as determined by cellular electron tomography shows the nanoparticles as intracellular, of narrow dispersity, symmetrically irregular and without any observable membrane or structured protein shell. Protein mass spectrometry of a fractionated soluble cytosolic material with selenite reducing capability identified nitrite reductase and glutathione reductase homologues as NADPH dependent candidate enzymes for the reduction of selenite to zerovalent Se nanoparticles. In vitro experiments with commercially sourced glutathione reductase revealed that the enzyme can reduce SeO32- (selenite) to Se nanoparticles in an NADPH-dependent process. The disappearance of the enzyme as determined by protein assay during nanoparticle formation suggests that glutathione reductase is associated with or possibly entombed in the nanoparticles whose formation it catalyzes. Chemically dissolving the nanoparticles releases the enzyme. The size of the nanoparticles varies with SeO32- concentration, varying in size form 5 nm diameter when formed at 1.0 μM [SeO32-] to 50 nm maximum diameter when formed at 100 μM [SeO32-]. In aggregate, we suggest that glutathione reductase possesses the key attributes of a clonable nanoparticle system: ion reduction, nanoparticle retention and size control of the nanoparticle at the enzyme site.Pseudomonas moraviensis stanleyae was recently isolated from the roots of the selenium (Se) hyperaccumulator plant Stanleya pinnata. This bacterium tolerates normally lethal concentrations of SeO32- in liquid culture, where it also produces Se nanoparticles. Structure and cellular ultrastructure of the Se nanoparticles as determined by cellular

  2. Production of Se-methylselenocysteine in transgenic plants expressing selenocysteine methyltransferase

    Directory of Open Access Journals (Sweden)

    Harris Hugh

    2004-01-01

    Full Text Available Abstract Background It has become increasingly evident that dietary Se plays a significant role in reducing the incidence of lung, colorectal and prostate cancer in humans. Different forms of Se vary in their chemopreventative efficacy, with Se-methylselenocysteine being one of the most potent. Interestingly, the Se accumulating plant Astragalus bisulcatus (Two-grooved poison vetch contains up to 0.6% of its shoot dry weight as Se-methylselenocysteine. The ability of this Se accumulator to biosynthesize Se-methylselenocysteine provides a critical metabolic shunt that prevents selenocysteine and selenomethionine from entering the protein biosynthetic machinery. Such a metabolic shunt has been proposed to be vital for Se tolerance in A. bisulcatus. Utilization of this mechanism in other plants may provide a possible avenue for the genetic engineering of Se tolerance in plants ideally suited for the phytoremediation of Se contaminated land. Here, we describe the overexpression of a selenocysteine methyltransferase from A. bisulcatus to engineer Se-methylselenocysteine metabolism in the Se non-accumulator Arabidopsis thaliana (Thale cress. Results By over producing the A. bisulcatus enzyme selenocysteine methyltransferase in A. thaliana, we have introduced a novel biosynthetic ability that allows the non-accumulator to accumulate Se-methylselenocysteine and γ-glutamylmethylselenocysteine in shoots. The biosynthesis of Se-methylselenocysteine in A. thaliana also confers significantly increased selenite tolerance and foliar Se accumulation. Conclusion These results demonstrate the feasibility of developing transgenic plant-based production of Se-methylselenocysteine, as well as bioengineering selenite resistance in plants. Selenite resistance is the first step in engineering plants that are resistant to selenate, the predominant form of Se in the environment.

  3. Selenium transformation in coal mine spoils: Its environmental impact assessment. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Harness, J.; Atalay, A.; Koll, K.J.; Zhang, H.; Maggon, D.

    1991-12-31

    The objective of this program was to conduct an environmental impact assessment study for selenium from coal mine spoils. The use of in-situ lysimetry to predict selenium speciation, transformation, and mobility under natural conditions was evaluated. The scope of the study was to construct and test field-scale lysimeter and laboratory mini-column to assess mobility and speciation of selenium in coal mine overburden and soil systems; to conduct soil and groundwater sampling throughout the state of Oklahoma for an overall environmental impact assessment of selenium; and to conduct an in-depth literature review on the solubility, speciation, mobility, and toxicity of selenium from various sources. Groundwater and surface soil samples were also collected from each county in Oklahoma. Data collected from the lysimeter study indicated that selenium in the overburden of the abandoned mine site was mainly found in the selenite form. The amount of selenite found was too low and immobile to be of concern to the environment. The spoil had equilibrated long enough (over 50 years) that most of the soluble forms of selenium have already been lost. Examination of the overburden indicated the presence of pyrite crystals that precipitated over time. The laboratory mini-column study indicated that selenite is quite immobile and remained on the overburden material even after leaching with dilute acid. Data from groundwater samples indicated that based on the current permissible level for selenium in groundwater (0.01 mg Se/L), Oklahoma groundwater is widely contaminated with the element. However, according to the new regulation (0.05 mg Se/L), which is to be promulgated in 1992, only 9 of the 77 counties in the state exceed the limit.

  4. Selenium transformation in coal mine spoils: Its environmental impact assessment

    Energy Technology Data Exchange (ETDEWEB)

    Harness, J.; Atalay, A.; Koll, K.J.; Zhang, H.; Maggon, D.

    1991-12-31

    The objective of this program was to conduct an environmental impact assessment study for selenium from coal mine spoils. The use of in-situ lysimetry to predict selenium speciation, transformation, and mobility under natural conditions was evaluated. The scope of the study was to construct and test field-scale lysimeter and laboratory mini-column to assess mobility and speciation of selenium in coal mine overburden and soil systems; to conduct soil and groundwater sampling throughout the state of Oklahoma for an overall environmental impact assessment of selenium; and to conduct an in-depth literature review on the solubility, speciation, mobility, and toxicity of selenium from various sources. Groundwater and surface soil samples were also collected from each county in Oklahoma. Data collected from the lysimeter study indicated that selenium in the overburden of the abandoned mine site was mainly found in the selenite form. The amount of selenite found was too low and immobile to be of concern to the environment. The spoil had equilibrated long enough (over 50 years) that most of the soluble forms of selenium have already been lost. Examination of the overburden indicated the presence of pyrite crystals that precipitated over time. The laboratory mini-column study indicated that selenite is quite immobile and remained on the overburden material even after leaching with dilute acid. Data from groundwater samples indicated that based on the current permissible level for selenium in groundwater (0.01 mg Se/L), Oklahoma groundwater is widely contaminated with the element. However, according to the new regulation (0.05 mg Se/L), which is to be promulgated in 1992, only 9 of the 77 counties in the state exceed the limit.

  5. Biosynthesis of selenium nanoparticles by Pantoea agglomerans and their antioxidant activity

    International Nuclear Information System (INIS)

    Torres, S. K.; Campos, V. L.; León, C. G.; Rodríguez-Llamazares, S. M.; Rojas, S. M.; González, M.; Smith, C.; Mondaca, M. A.

    2012-01-01

    The bio-reduction of selenite (Se (IV)) generates nanoparticles with sizes ranging between 30 and 300 nm. Biologic properties of Se nanoparticles, e.g., antioxidant activity, are dependent on the nanoparticle size; smaller particles have greater activity. In this study, the bio-reduction of selenite by Pantoea agglomerans strain UC-32 under aerobic conditions and room temperature to produce bioactive Se nanoparticles smaller than 100 nm was demonstrated. Isolation and purification of the nanoparticles was performed by alkaline lysis. These purified nanoparticles were stabilized with l-cysteine (4 mM). The visualization and characterization of nanoparticles were performed by transmission electron microscopy, energy dispersive X-ray spectroscopy, and scanning electron microscopy. The antioxidant activity of nanoparticles was determined by production of reactive oxygen species using human umbilical vein endothelial cells. Transmission electron microscopy images showed the accumulation of spherical selenium nanoparticles as intracellular and extracellular deposits. The size of Se nanoparticles varied with incubation time. Amorphous Se nanoparticles with size in the order of 100 nm were obtained before 24 h of incubation; but, at 24 h of incubation, the size of the majority of the nanoparticles was in the desirable order of 100 nm and they were not aggregated. Energy dispersive spectroscopy spectra indicated that nanoparticles were composed entirely of selenium. Antioxidant activity of stabilized selenium nanoparticles demonstrated high antioxidant activity when compared to selenite and selenium nanoparticles without stabilization. Stabilized biologically synthetized selenium (0) nanoparticles with size less than 100 nm have a potential application as a food additive with antioxidant properties relevant to human health.

  6. Hazard evaluation of inorganics, singly and in mixtures, to Flannelmouth Sucker Catostomus latipinnis in the San Juan River, New Mexico

    Science.gov (United States)

    Hamilton, S.J.; Buhl, K.J.

    1997-01-01

    Larval flannelmouth sucker (Catostomus latipinnis) were exposed to arsenate, boron, copper, molybdenum, selenate, selenite, uranium, vanadium, and zinc singly, and to five mixtures of five to nine inorganics. The exposures were conducted in reconstituted water representative of the San Juan River near Shiprock, New Mexico. The mixtures simulated environmental ratios reported for sites along the San Juan River (San Juan River backwater, Fruitland marsh, Hogback East Drain, Mancos River, and McElmo Creek). The rank order of the individual inorganics, from most to least toxic, was: copper > zinc > vanadium > selenite > selenate > arsenate > uranium > boron > molybdenum. All five mixtures exhibited additive toxicity to flannelmouth sucker. In a limited number of tests, 44-day-old and 13-day-old larvae exhibited no difference in sensitivity to three mixtures. Copper was the major toxic component in four mixtures (San Juan backwater, Hogback East Drain, Mancos River, and McElmo Creek), whereas zinc was the major toxic component in the Fruitland marsh mixture, which did not contain copper. The Hogback East Drain was the most toxic mixture tested. Comparison of 96-h LC50values with reported environmental water concentrations from the San Juan River revealed low hazard ratios for arsenic, boron, molybdenum, selenate, selenite, uranium, and vanadium, moderate hazard ratios for zinc and the Fruitland marsh mixture, and high hazard ratios for copper at three sites and four environmental mixtures representing a San Juan backwater, Hogback East Drain, Mancos River, and McElmo Creek. The high hazard ratios suggest that inorganic contaminants could adversely affect larval flannelmouth sucker in the San Juan River at four sites receiving elevated inorganics.

  7. Biosynthesis of selenium nanoparticles by Pantoea agglomerans and their antioxidant activity

    Energy Technology Data Exchange (ETDEWEB)

    Torres, S. K.; Campos, V. L., E-mail: vcampos@udec.cl; Leon, C. G. [Universidad de Concepcion, Laboratorio de Microbiologia Ambiental, Departamento de Microbiologia (Chile); Rodriguez-Llamazares, S. M. [Centro de Investigacion de Polimeros Avanzados (CIPA) (Chile); Rojas, S. M.; Gonzalez, M. [Universidad de Concepcion, Laboratorio de Fisiologia Vascular, Departamento de Fisiologia (Chile); Smith, C. [Universidad de Concepcion, Departamento de Microbiologia (Chile); Mondaca, M. A. [Universidad de Concepcion, Laboratorio de Microbiologia Ambiental, Departamento de Microbiologia (Chile)

    2012-11-15

    The bio-reduction of selenite (Se (IV)) generates nanoparticles with sizes ranging between 30 and 300 nm. Biologic properties of Se nanoparticles, e.g., antioxidant activity, are dependent on the nanoparticle size; smaller particles have greater activity. In this study, the bio-reduction of selenite by Pantoea agglomerans strain UC-32 under aerobic conditions and room temperature to produce bioactive Se nanoparticles smaller than 100 nm was demonstrated. Isolation and purification of the nanoparticles was performed by alkaline lysis. These purified nanoparticles were stabilized with l-cysteine (4 mM). The visualization and characterization of nanoparticles were performed by transmission electron microscopy, energy dispersive X-ray spectroscopy, and scanning electron microscopy. The antioxidant activity of nanoparticles was determined by production of reactive oxygen species using human umbilical vein endothelial cells. Transmission electron microscopy images showed the accumulation of spherical selenium nanoparticles as intracellular and extracellular deposits. The size of Se nanoparticles varied with incubation time. Amorphous Se nanoparticles with size in the order of 100 nm were obtained before 24 h of incubation; but, at 24 h of incubation, the size of the majority of the nanoparticles was in the desirable order of 100 nm and they were not aggregated. Energy dispersive spectroscopy spectra indicated that nanoparticles were composed entirely of selenium. Antioxidant activity of stabilized selenium nanoparticles demonstrated high antioxidant activity when compared to selenite and selenium nanoparticles without stabilization. Stabilized biologically synthetized selenium (0) nanoparticles with size less than 100 nm have a potential application as a food additive with antioxidant properties relevant to human health.

  8. 79Se: geochemical and crystallo-chemical retardation mechanisms

    International Nuclear Information System (INIS)

    Chen, F.; Ewing, R.C.

    1999-01-01

    79 Se is a long-lived (1.1 x 10 6 yrs) fission product which is chemically and radiologically toxic. Under Eh-pH conditions typical of oxidative alteration of spent nuclear fuel, selenite, SeO 3 2- or HSeO 3 - or selenate, SeO 4 2- , are the dominant aqueous species of selenium. Because of the high solubility of metal-selenites and metal-selenates and the low adsorption of selenite and selenate aqueous species by geological materials under alkaline conditions, selenium may be highly mobile. However, 79 Se released from altered fuel may become immobilized by incorporation into secondary uranyl phases as low concentration impurities, and this may significantly reduce the mobility of selenium. Analysis and comparison of the known structures of uranyl phases indicate that (SeO 3 ) may substitute for (SiO 3 OH) in structures of α-uranophane and boltwoodite that are expected to be the dominant alteration products of UO 2 in Si-rich groundwater. The substitutions (SeO 3 ) (SiO 3 OH) in sklodowskite, Mg[(UO 2 )(SiO 3 OH)] 2 (H 2 O) 6 and (SeO 3 ) (PO 4 ) in phurcalite, Ca 2 [(UO 2 ) 3 (PO 4 ) 2 O 2 ](H 2 O) 7 , may occur with the eliminated apical anion being substituted for by an H 2 O group, but experimental investigation is required. The close similarity between the sheets in the structures of rutherfordine, [(UO 2 )(CO 3 )] and [(UO 2 )(SeO 3 )] implies that the substitution (SeO 3 ) (CO 3 ) can occur in rutherfordine, and possibly other uranyl carbonates. However, the substitutions: (SeO 3 ) (SiO 4 ) in soddyite and (SeO 3 ) (PO 4 ) in phosphuranylite may disrupt their structural connectivity and are, therefore, unlikely. (orig.)

  9. A selenium-deficient Caco-2 cell model for assessing differential incorporation of chemical or food selenium into glutathione peroxidase.

    Science.gov (United States)

    Zeng, Huawei; Botnen, James H; Johnson, Luann K

    2008-01-01

    Assessing the ability of a selenium (Se) sample to induce cellular glutathione peroxidase (GPx) activity in Se-deficient animals is the most commonly used method to determine Se bioavailability. Our goal is to establish a Se-deficient cell culture model with differential incorporation of Se chemical forms into GPx, which may complement the in vivo studies. In the present study, we developed a Se-deficient Caco-2 cell model with a serum gradual reduction method. It is well recognized that selenomethionine (SeMet) is the major nutritional source of Se; therefore, SeMet, selenite, or methylselenocysteine (SeMSC) was added to cell culture media with different concentrations and treatment time points. We found that selenite and SeMSC induced GPx more rapidly than SeMet. However, SeMet was better retained as it is incorporated into proteins in place of methionine; compared with 8-, 24-, or 48-h treatment, 72-h Se treatment was a more sensitive time point to measure the potential of GPx induction in all tested concentrations. Based on induction of GPx activity, the cellular bioavailability of Se from an extract of selenobroccoli after a simulated gastrointestinal digestion was comparable with that of SeMSC and SeMet. These in vitro data are, for the first time, consistent with previous published data regarding selenite and SeMet bioavailability in animal models and Se chemical speciation studies with broccoli. Thus, Se-deficient Caco-2 cell model with differential incorporation of chemical or food forms of Se into GPx provides a new tool to study the cellular mechanisms of Se bioavailability.

  10. Effect of chronic selenium exposure on the freshwater bivalve Corbicula fluminea

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, E.; Adam, C.; Massabuau, J.C.; Garnier-Laplace, J. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    Selenium is essential for most of living organisms. In oxic to moderately oxic fresh-waters, Se exists predominantly in the (+VI) and (+IV) oxidation states as selenate (SeO{sub 4}{sup 2-}) and selenite (SeO{sub 3}{sup 2-}) respectively, whereas in the biota it is incorporated as Se(-II) into seleno-proteins or amino-acids, or as elemental selenium Se(0). At low concentrations, it acts against oxidative damages mainly as the glutathione peroxidase seleno-dependant, but it may be toxic at higher levels (for example, by replacing sulphur in important biomolecules). In filter feeders, such as the freshwater bivalve Corbicula fluminea, selected as biological model, the ventilation activity is a primary limiting step that controls the water influx and therefore the delivery of contaminants. Consequently, a series of short-term experiments were performed to study the effects of different dissolved Se concentrations and forms (selenite; selenate; selenomethionine) on the ventilation activity of Corbicula fluminea and Se tissular distribution. The modification of the ventilation activity of the Se-exposed groups, in comparison to this of reference groups (not exposed to Se) varied greatly according to the form and the concentrations of the Se used. Se concentrations in tissues indicated that selenite was the less bioavailable form whereas selenomethionine displayed the opposite trend. On the basis of this set of experiments, a limited number of conditions have been selected to provide highly contrasting ventilation flow rates and selenium bioaccumulation levels, in order to study the effects of long term exposures, i) at the molecular level, by measuring bio-markers of oxidative stress (forms of glutathione, glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase, and bio-marker of genotoxicity (comet assay), ii) at the (sub)cellular level by analysing Se micro-localisation in target organs and iii) at the individual level by monitoring the variation

  11. Sodium selenosulfate at an innocuous dose markedly prevents cisplatin-induced gastrointestinal toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jun; Sun, Kang [School of Tea and Food Science, Anhui Agricultural University, Hefei 230036, Anhui (China); Ni, Lijuan; Wang, Xufang [School of Chemistry and Materials of Science, University of Science and Technology of China, Hefei 230052, Anhui (China); Wang, Dongxu [School of Tea and Food Science, Anhui Agricultural University, Hefei 230036, Anhui (China); Zhang, Jinsong, E-mail: zjs@ahau.edu.cn [School of Tea and Food Science, Anhui Agricultural University, Hefei 230036, Anhui (China)

    2012-02-01

    Our previous studies in mice revealed that two weeks short-term toxicity of sodium selenosulfate was significantly lower than that of sodium selenite, but selenium repletion efficacy of both compounds was equivalent. In addition, we showed that sodium selenosulfate reduced nephrotoxicity of cisplatin (CDDP) without compromising its anticancer activity, thus leading to a dramatic increase of cancer cure rate from 25% to 75%. Hydration has been used in clinical practice to reduce CDDP-induced nephrotoxicity, but it cannot mitigate CDDP-induced gastrointestinal toxicity. The present work investigated whether sodium selenosulfate is a potential preventive agent for the gastrointestinal toxicity. In tumor-bearing mice, sodium selenosulfate was administered at a dose of 9.5 μmol/kg daily for 11 days, CDDP alone resulted in diarrhea by 88% on day 12, whereas the co-administration of CDDP and sodium selenosulfate dramatically reduced diarrhea to 6% (p < 0.0001). Such a prominent protective effect promoted us to evaluate the safety potential of long-term sodium selenosulfate application. Mice were administered with sodium selenosulfate or sodium selenite for 55 days at the doses of 12.7 and 19 μmol/kg. The low-dose sodium selenite caused growth suppression and hepatotoxicity which were aggravated by the high-dose, leading to 40% mortality rate, but no toxic symptoms were observed in the two sodium selenosulfate groups. Altogether these results clearly show that sodium selenosulfate at an innocuous dose can markedly prevent CDDP-induced gastrointestinal toxicity. -- Highlights: ►Cisplatin resulted in diarrhea in mice by 88%. ►i.p. selenosulfate at 9.5 μmol/kg daily for 11 days reduced diarrhea to 6%. ►i.p. selenosulfate at 19 μmol/kg daily for 55 days was not toxic. ►i.p. selenite at 19 μmol/kg daily for 55 days was lethal. ►Innocuous dose of selenosulfate greatly prevents cisplatin-induced diarrhea.

  12. Sodium selenosulfate at an innocuous dose markedly prevents cisplatin-induced gastrointestinal toxicity

    International Nuclear Information System (INIS)

    Li, Jun; Sun, Kang; Ni, Lijuan; Wang, Xufang; Wang, Dongxu; Zhang, Jinsong

    2012-01-01

    Our previous studies in mice revealed that two weeks short-term toxicity of sodium selenosulfate was significantly lower than that of sodium selenite, but selenium repletion efficacy of both compounds was equivalent. In addition, we showed that sodium selenosulfate reduced nephrotoxicity of cisplatin (CDDP) without compromising its anticancer activity, thus leading to a dramatic increase of cancer cure rate from 25% to 75%. Hydration has been used in clinical practice to reduce CDDP-induced nephrotoxicity, but it cannot mitigate CDDP-induced gastrointestinal toxicity. The present work investigated whether sodium selenosulfate is a potential preventive agent for the gastrointestinal toxicity. In tumor-bearing mice, sodium selenosulfate was administered at a dose of 9.5 μmol/kg daily for 11 days, CDDP alone resulted in diarrhea by 88% on day 12, whereas the co-administration of CDDP and sodium selenosulfate dramatically reduced diarrhea to 6% (p < 0.0001). Such a prominent protective effect promoted us to evaluate the safety potential of long-term sodium selenosulfate application. Mice were administered with sodium selenosulfate or sodium selenite for 55 days at the doses of 12.7 and 19 μmol/kg. The low-dose sodium selenite caused growth suppression and hepatotoxicity which were aggravated by the high-dose, leading to 40% mortality rate, but no toxic symptoms were observed in the two sodium selenosulfate groups. Altogether these results clearly show that sodium selenosulfate at an innocuous dose can markedly prevent CDDP-induced gastrointestinal toxicity. -- Highlights: ►Cisplatin resulted in diarrhea in mice by 88%. ►i.p. selenosulfate at 9.5 μmol/kg daily for 11 days reduced diarrhea to 6%. ►i.p. selenosulfate at 19 μmol/kg daily for 55 days was not toxic. ►i.p. selenite at 19 μmol/kg daily for 55 days was lethal. ►Innocuous dose of selenosulfate greatly prevents cisplatin-induced diarrhea.

  13. The relationship between selenium and gastric cancer

    International Nuclear Information System (INIS)

    Shi Kuixiong; Ma Guansheng; Zhang Tingyu; Cheng Wufeng; Mao Dajuan; Pan Bixia; Xu Xiuxian

    1993-01-01

    Both sodium selenite and selenium yeast were chosen to block the MNNG mutagenesis. The inhibition rates were 66.5% and 37.9% respectively. The selenium levels in hair, serum and gastric juice, and the contents of nitrosamine in gastric juice were also determined. The results showed that the selenium levels were SG > CAG and Dys > GC (p CAG, Dyas and GC (p < 0.05). 19 cases of CAG patients treated with selenium yeast and 16 cases of the control were observed. After 10 weeks, the selenium levels in serum for the treated group were significantly increased. The symptoms of CAG patients seemed to be alleviated

  14. Cells structure peculiarities of posterity testicle epithelium, when posterity was developing after using selenium-containing preparation in chronic irradiation condition in early ontogenesis period

    International Nuclear Information System (INIS)

    Krasnova, I.A.; Gajdukevich, E.G.; Banetskaya, N.V.; Amvros'ev, A.P.

    2002-01-01

    Female rats 4 month old were receiving sodium selenite (0.15 mg/kg) and vitamin E (5 mg/kg) daily during 10 days. After coupling, pregnant animals were irradiated with dose 3.1*10 -7 Gy/s during all pregnancy period and 16 days after birth with posterity. Posterity 30-40 days old and 6 month old was decapitated and testicles were investigated. Results of morphological and cytogenetic analysis of posterity testicle epithelium cells testify to radiation modification peculiarities of selenium-containing preparation

  15. Migration of {sup 75}Se(IV) in crushed Beishan granite: Effects of the iron content

    Energy Technology Data Exchange (ETDEWEB)

    He, Jiangang; Ma, Bin; Kang, Mingliang; Wang, Chunli; Nie, Zhe; Liu, Chunli, E-mail: liucl@pku.edu.cn

    2017-02-15

    Highlights: • The diffusion of {sup 75}SeO{sub 3}{sup 2−} in crushed BsG was slowest at approximately pH 5. • The D{sub a} values under aerobic conditions were nearly one order of magnitude lower than those under anaerobic conditions. • Fe(II)-bearing mineralogical components can be responsible for the great difference in D{sub a} values. • Se{sup IV} can be reduced to Se{sup 0} by BsG under anaerobic conditions. - Abstract: The diffusion of selenite (labeled with {sup 75}Se) in compacted Beishan granite (BsG) was investigated using the in-diffusion capillary method at pH values from ∼2.0 to ∼11.0 under oxic and anoxic conditions. The results indicate that the apparent diffusion coefficient (D{sub a}) values of selenite in BsG always reached the minimum at approximately pH 5. Unexpectedly, the D{sub a} values under oxic conditions are nearly one order of magnitude lower than those under the anoxic conditions. Further characterization reveals the existence of redox-sensitive Fe(II)-containing components, which can be responsible for the great difference in D{sub a} values. Fe(2p) X-ray photoelectron spectroscopy (XPS) results show that more Fe(III)-oxyhydroxide coating is formed on the granite’s surface under aerobic conditions than is formed under anaerobic conditions. Correspondingly, Se(3d) spectra indicate that more selenium is sorbed under oxic conditions, and the sorbed amount always reached the maximum at pH values from ∼4 to ∼5. A linear combination fit of X-ray absorption near edge structure (XANES) spectroscopy data revealed that Se(0) was formed under anoxic condition and that selenite preferred to form inner-sphere complexes with Fe(III)-oxyhydroxide. Overall, this study indicates that natural Fe-bearing minerals can greatly attenuate selenite diffusion and the retardation would be enhanced under aerobic conditions.

  16. Selenium-induced autometallographic demonstration of endogenous zinc in organs of the rainbow trout, Salmo gairdneri

    DEFF Research Database (Denmark)

    Baatrup, E

    1989-01-01

    , the intestine, and the gills, whereas, no such grains were found in preparations from fish having received 1 ppm Se. The use of selenium for the histochemical demonstration of endogenous zinc versus exogenous metals is discussed. Also, consideration is given to the question of which part of the total tissue......Autometallographic (AMG) silver enhancement of endogenous zinc was studied in seven organs of the rainbow trout Salmo gairdneri. Groups of trout were injected intraperitoneally with sodium selenite in doses ranging from 0.08 to 25 ppm, administered 1 h before being killed. The concentration...

  17. Speciation of four selenium compounds using high performance liquid chromatography with on-line detection by inductively coupled plasma mass spectrometry or flame atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Pedersen, Gitte Alsing; Larsen, Erik Huusfeldt

    1997-01-01

    An analytical method for the speciation of selenomethionine, selenocystine, selenite and selenate by high performance liquid chromatography (HPLC) with atomic spectrometric detection is presented. An organic polymeric strong anion exchange column was used as the stationary phase in combination...... spectrometry (ICP-MS). The signal-to-noise ratio of the FAAS detector was optimized using a hydrogen-argon entrained-air flame and a slotted-tube atom trap (STAT) in the flame. The limit of detection (3 sigma) achieved by the HPLC-FAAS system was 1 mg L-1 of selenium (100 mu L injections) for each of the four...

  18. Metal-binding silica materials for wastewater cleanup

    Energy Technology Data Exchange (ETDEWEB)

    Kroh, F.O. [TPL, Inc., Albuquerque, NM (United States)

    1997-10-01

    In this Phase I Small Business Innovation Research program, TPL, Inc. is developing two series of high-efficiency covalently modified silica materials for removing heavy metal ions from wastewater. These materials have metal ion capacities greatly exceeding those of commercial ion exchange resins. One series, containing thiol groups, has high capacity for {open_quotes}soft{close_quotes} heavy metal ions such as Hg, Pb, Ag, and Cd; the other, containing quaternary ammonium groups, has high capacity for anionic metal ions such as pertechnetate, arsenate, selenite, and chromate. These materials have high selectivity for the contaminant metals and will function well in harsh systems that inactivate other systems.

  19. Impact of Selenium Supplementation on Growth and Selenium Accumulation on Spinach (Spinacia oleracea L.) Plants

    OpenAIRE

    Azadeh SAFFARYAZDI; Mehrdad LAHOUTI; Ali GANJEALI; Hassan BAYAT

    2012-01-01

    Selenium (Se) has been proved to be an essential element for humans and animals. However, less is known about its effects on plants. A hydroponic experiment was carried out to investigate the effects of selenium on growth, selenium accumulation and some physiological characteristics of spinach (Spinacia oleracea L. cv. �Missouri�) plants. Plants were grown in Hoagland nutrient solution amended with sodium selenite at 0 (control), 1, 2, 4, 6 and 10 mg.L-1 for 28 days. Growth parameters like sh...

  20. Effect of Organic Selenium from Se-enriched Alga (Chlorella spp. on Selenium Transfer from Sows to Their Progeny

    Directory of Open Access Journals (Sweden)

    Martin Svoboda

    2009-01-01

    Full Text Available The study was conducted to determine the efficacy of organic Se from Se-enriched alga Chlorella spp. in placental transfer to piglets. In group A (n = 8 the sows were fed during the gestation a diet supplemented with inorganic Se (sodium selenite, 0.3 mg/kg. In group B (n = 8 the diet of the sows was supplemented with organic Se from Se-enriched alga (0.3 mg/kg. The Se concentrations in the whole blood (P P Chlorella spp. in sows resulted in greater transfer of Se to their progeny.

  1. Soil ingestion may be an important route for the uptake of contaminants by some reptiles.

    Science.gov (United States)

    Rich, C Nelson; Talent, Larry G

    2009-02-01

    Some species of reptiles regularly ingest soil in the wild. Therefore, we evaluated the importance of soil ingestion as a route for the uptake of contaminants in lizards. We used sand as a substitute for soil during the present study. Different groups of leopard geckos (Eublepharis macularius) were provided with a control and five sodium selenite-spiked sand mixtures during a 28-d study. Twenty lizards were assigned to a control group and to each of five selenium-spiked sand mixtures that consisted of nominal selenium (Se) concentrations of 0.05, 0.46, 4.57, 11.41, and 22.83 mg Se/kg dry sand. Leopard geckos readily ingested the Se-spiked sand. We observed concentration-related effects in several endpoints. Overall growth in body mass was the most sensitive endpoint and was significantly (p leopard geckos appear to be as sensitive to sodium selenite as birds and mammals. The present study suggests that ingestion of soil could be an important potential route for the uptake of soil contaminants in some reptiles and should be evaluated in ecotoxicological studies and risk analyses of reptiles.

  2. Histological, histochemical and immunohistochemical assessment of the protective role of selenium against γ -radiation damage in rats salivary glands

    International Nuclear Information System (INIS)

    Ahmed, S.F.

    2008-01-01

    Ionizing radiation affects the biological tissues through either direct or indirect action. Both types of actions occur together when a charged particle passes through a cell and can cause cell damage by different mechanisms . Radiation protection is based on physical principles which aim at lowering the radiation exposure dose and subsequently the risk of radiation injury. As radiation injury to living cells is, to large extent, due to oxidative stresses, the present study was conducted in order to evaluate the radioprotective efficacy of selenium, a naturally occurring antoxidant nutrient, as a a free radical scavenger against γ- radiation damage in rats' salivary glands by histological, histochemical and immunohistochemical assessment. A total of 120 male albino rats were used in the present study. The rats were divided into 6 groups (20 rats each): Control group:- rats received neither radiation nor selenium. Group I :- rats were exposed to a single whole body γ -irradiation at dose of 4 gray(Gy). Group l l:- as group I, but with radiation dose of 6 Gy. Group lll:- rats were injected intraperitoneally by a daily dose of sodium selenite (15 μg./ kg.b.w. )for three weeks. Group IV:- rats were injected intraperitoneally by a daily dose of sodium selenite (15 μg./ kg.b.w.) for one week before exposure to gamma rays at dose of 4 Gy and two weeks after. Group V:- as group IV, but with radiation dose of 6 Gy.

  3. Cathodic electrodeposition of amorphous elemental selenium from an air- and water-stable ionic liquid.

    Science.gov (United States)

    Redman, Daniel W; Murugesan, Sankaran; Stevenson, Keith J

    2014-01-14

    Electrodeposition of selenium from 1-propyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide is reported. In situ UV-vis spectroelectrochemistry was used to investigate the reduction of diethyl selenite to form elemental selenium thin films from an ionic liquid-acetonitrile medium. Three reduction peaks of diethyl selenite were observed via cyclic voltammetry and are attributed to the stepwise reduction of the selenium precursor adsorbed on the electrode. The electrodeposition mechanism is influenced by both potential and time. Electrodeposition at -1.7 V vs Pt QRE resulted in the deposition of elemental selenium nanoparticles that with time coalesced to form a continuous film. At reduction potentials more negative than -1.7 V the morphology of the deposit changed significantly due to the reduction of elemental Se to Se(2-). In addition, p-type photoconductivity of the films was observed during the spectroelectrochemical measurements. X-ray diffraction and Raman spectroscopy confirmed that the deposited selenium films were amorphous. X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy confirm the films consisted of pure selenium with minor residual contamination from the precursor and ionic liquid.

  4. Respiration of arsenate and selenate by hyperthermophilic archaea.

    Science.gov (United States)

    Huber, R; Sacher, M; Vollmann, A; Huber, H; Rose, D

    2000-10-01

    A novel, strictly anaerobic, hyperthermophilic, facultative organotrophic archaeon was isolated from a hot spring at Pisciarelli Solfatara, Naples, Italy. The rod-shaped cells grew chemolithoautotrophically with carbon dioxide as carbon source, hydrogen as electron donor and arsenate, thiosulfate or elemental sulfur as electron acceptor. H2S was formed from sulfur or thiosulfate, arsenite from arsenate. Organotrophically, the new isolate grew optimally in the presence of an inorganic electron acceptor like sulfur, selenate or arsenate. Cultures, grown on arsenate and thiosulfate or arsenate and L-cysteine, precipitated realgar (As2S2). During growth on selenate, elemental selenium was produced. The G+C content of the DNA was 58.3 mol%. Due to 16S rRNA gene sequence analysis combined with physiological and morphological criteria, the new isolate belongs to the Thermoproteales order. It represents a new species within the genus Pyrobaculum, the type species of which we name Pyrobaculum arsenaticum (type strain PZ6*, DSM 13514, ATCC 700994). Comparative studies with different Pyrobaculum-species showed, that Pyrobaculum aerophilum was also able to grow organotrophically under anaerobic culture conditions in the presence of arsenate, selenate and selenite. During growth on selenite, elemental selenium was formed as final product. In contrast to P. arsenaticum, P. aerophilum could use selenate or arsenate for lithoautotrophic growth with carbon dioxide and hydrogen.

  5. Effect of peroral supplementation with selenium and vitamin e during late pregnancy on udder health and milk quality in dairy cows

    Directory of Open Access Journals (Sweden)

    Milan Vasiľ

    2017-01-01

    Full Text Available The aim of the experiment was to study selenium and vitamin E sources in the diet of dairy cows in late phase of pregnancy and their effects on udder health and milk quality during the first two weeks after calving. The experiment included 48 cows of Holstein breed divided into four equal groups (n = 12. The first experimental group (D1 was fed with addition of vitamin E in total dose of 1020 dl-a-tocopherol acetate Se/cow per day. The second group (D2 was added the selenium at a dose of 0.3 mg.kg-1 of DM in form of sodium selenite. The third group (D3 was supplemented with addition of vitamin E in combination with sodium selenite in total dose of 1020 dl-a-tocopherol acetate Se/cow per day and of 5.0 mg Se/cow per day, respectively. The control group (C was without the addition of selenium and vitamin E. In group (D2 with addition of selenium at a dose of 0.3 mg.kg-1 of DM and vitamin E a dose of 50 mg dl-a-tocopherol acetate/kg of DM in diet, increased the plasmatic concentration of selenium and vitamin E and reduced the incidence of mastitis by 13.3% and number of somatic cells during peripartal period in comparison with other groups.

  6. Optimization of selenizing conditions for Seleno-Lentinan and its characteristics.

    Science.gov (United States)

    Ren, Guangming; Li, Koukou; Hu, Yang; Yu, Min; Qu, Juanjuan; Xu, Xiuhong

    2015-11-01

    Lentinan was successfully modified with nitric acid-sodium selenite method based on L9(3(4)) orthogonal experiments. The optimum selenizing conditions were obtained according to selenium conversion rate as follows: Lentinan of 1.0g, pH of 4.5, temperature of 70°C and sodium selenite of 1.50g. The antioxidant activity assays in vitro (DPPH, reducing power, superoxide radicals and hydroxyl radicals) proved that Lentinan had stronger antioxidant activity after selenizing. The elevations of serum alanine aminotransferase and aspartate aminotransferase, as well as the abnormal hepatic architecture, verified that oral administration of Seleno-Lentinan (SL2-1) markedly alleviated oxidative damage in the liver of mice induced by D-gal. In addition, SL2-1 significantly increased total antioxidant capacity, activities and protein expressions of catalase and glutathione peroxidase and lowered malondialdehyde levels in serum and liver. Fourier transform infrared spectroscopy analysis indicated that selenium of SL2-1 was mostly existed as the formations of OSeO, SeO and SeOC. Scanning electron microscope coupled with energy dispersive X-ray spectroscopy analysis revealed that the surface structure and elemental components of Lentinan significantly changed after selenizing. The results are instructive for the development of organic selenium-supplement resource. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Synthesis and crystal structure of the solid solution Co3(SeO3)3-x(PO3OH)x(H2O) involving crystallographic split positions of Se4+ and P5+.

    Science.gov (United States)

    Zimmermann, Iwan; Johnsson, Mats

    2013-10-21

    Three new cobalt selenite hydroxo-phosphates laying in the solid solution Co3(SeO3)3-x(PO3OH)x(H2O), with x = 0.8, x = 1.0, and x = 1.2 are reported. Single crystals were obtained by hydrothermal synthesis and the crystal structure was determined by single crystal X-ray diffraction. The structure can be described as a 3D framework having selenite and hydroxo-phosphate groups protruding into channels in the crystal structure. Se(4+) and P(5+) share a split position in the structure so that either SeO3 groups having a stereochemically active lone pair or tetrahedrally coordinated PO3OH groups are present. The OH-group is thus only present when the split position is occupied by P(5+). The crystal water is coordinated to a cobalt atom and TG and IR measurements show that the water and hydroxyl groups leave the structure at unusually high temperatures (>450 °C). Magnetic susceptibility measurements show antiferromagnetic coupling below 16 K and a magnetic moment of 4.02(3) μB per Co atom was observed.

  8. Selenium Utilization Strategy by Microalgae

    Directory of Open Access Journals (Sweden)

    Hiroya Araie

    2009-11-01

    Full Text Available The diversity of selenoproteins raises the question of why so many life forms require selenium. Selenoproteins are found in bacteria, archaea, and many eukaryotes. In photosynthetic microorganisms, the essential requirement for selenium has been reported in 33 species belonging to six phyla, although its biochemical significance is still unclear. According to genome databases, 20 species are defined as selenoprotein-producing organisms, including five photosynthetic organisms. In a marine coccolithophorid, Emiliania huxleyi (Haptophyta, we recently found unique characteristics of selenium utilization and novel selenoproteins using 75Se-tracer experiments. In E. huxleyi, selenite, not selenate, is the main substrate used and its uptake is driven by an ATP-dependent highaffinity, active transport system. Selenite is immediately metabolized to low-molecular mass compounds and partly converted to at least six selenoproteins, named EhSEP1–6. The most (EhSEP2 and second-most abundant selenoproteins (EhSEP1 are disulfide isomerase (PDI homologous protein and thioredoxin reductase (TR 1, respectively. Involvement of selenium in PDI is unique in this organism, while TR1 is also found in other organisms. In this review, we summarize physiological, biochemical, and molecular aspects of selenium utilization by microalgae and discuss their strategy of selenium utilization.

  9. Toxicological implications of selenium nanoparticles with different coatings along with Se4+ on Lemna minor.

    Science.gov (United States)

    Tarrahi, Roshanak; Khataee, Alireza; Movafeghi, Ali; Rezanejad, Farkhondeh; Gohari, Gholamreza

    2017-08-01

    Nanoparticles have potential high risks for living organisms in the environment due to their specific qualities and their easy access. In the present study, selenium nanoparticles (Se NPs) with two different coatings (l-cysteine and tannic acid) were synthesized. The characteristics of particles were analyzed using XRD, FT-IR and SEM. The impact of the nanoparticles besides Se 4+ , on the aquatic higher plant Lemna minor was evaluated and compared. Entrance of l-cysteine and tannic acid capped Se NPs in the roots of Lemna minor was proved by TEM and fluorescence microscopy. Adverse effects of mentioned NPs and differences of these effects from those by sodium selenite as the ionic form were assessed by a range of biophysicochemical tests. Altogether, the results asserted that Lemna minor was notably poisoned by both capped Se NPs and Se 4+ . Thus, growth and photosynthetic pigments were decreased while lipid peroxidation along with total phenol and flavonoid contents were raised. Eventually some changes in enzymatic activities were presented. To sum up the consequences, it can be concluded that all changes occurred due to the plant defense system especially in order to remove reactive oxygen species (ROS) and possible phytotoxicity originated by l- cysteine and tannic acid capped Se NPs in addition to Se 4+ . The influence of tannic acid capped Se NPs after sodium selenite is stronger by the means of antioxidant enzymes activity in comparison with l-cysteine capped Se NPs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Copper and selenium supplementation in the diet of Brangus steers on the nutritional characteristics of meat

    Directory of Open Access Journals (Sweden)

    Arlindo Saran Netto

    2013-01-01

    Full Text Available Twenty-eight Brangus cattle were used to determine the effect of copper and selenium supplementation on the carcass characteristics, fatty acid composition of the longissimus dorsi muscle and on the copper and selenium concentrations in the liver. The treatments were: no supplementation of copper or selenium; 2 mg Se/kg DM as sodium selenite; 40 mg Cu/kg DM as copper sulfate; and 2 mg Se/kg DM as sodium selenite and 40 mg Cu/kg DM as copper sulfate. The fat thickness, rib eye area and fatty acid composition of the longissimus dorsi muscle were not affected by treatments. There was no effect on carcass yield and cooling loss with the supplementation of copper, selenium or selenium × copper in the levels studied. For the ether extract concentration in the longissimus dorsi muscle, no differences were found according to the treatments with selenium, copper or selenium × copper. The treatments with selenium and selenium × copper showed higher selenium concentrations in the liver than the control and copper treatments. For the copper concentration in the liver, the copper and selenium × copper treatments showed higher values than the control and selenium treatments. Despite the little effect on the meat composition, the results of this experiment demonstrate no interaction between selenium and copper in the levels studied.

  11. Deproteinization assessment using isotopically enriched compounds to trace the coprecipitation of low-molecular-weight selenium species with proteins.

    Science.gov (United States)

    Godin, Simon; Bouzas-Ramos, Diego; Fontagné-Dicharry, Stéphanie; Bouyssière, Brice; Bueno, Maïté

    2017-08-01

    Studies have shown that information related to the presence of low-molecular-weight metabolites is frequently lost after deproteinization of complex matrices, such as blood and plasma, during sample preparation. Therefore, the effect of several deproteinization reagents on low-molecular-weight selenium species has been compared by species-specific isotope labeling. Two isotopically enriched selenium tracers were used to mimic models of small inorganic anionic ( 77 Se-selenite) and organic zwitterionic ( 76 Se-selenomethionine) species. The results presented here show that the use of a methanol-acetonitrile-acetone (1:1:1 v/v/v) mixture provided approximately two times less tracer loss from plasma samples in comparison with the classic procedure using acetonitrile, which may not be optimal as it leads to important losses of low-molecular-weight selenium species. In addition, the possible interactions between selenium tracers and proteins were investigated, revealing that both coprecipitation phenomena and association with proteins were potentially responsible for selenite tracer losses during protein precipitation in blood samples. However, coprecipitation phenomena were found to be fully responsible for losses of both tracers observed in plasma samples and of the selenomethionine tracer in blood samples. This successfully applied strategy is anticipated to be useful for more extensive future studies in selenometabolomics. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Aerobic and anaerobic biosynthesis of nano-selenium for remediation of mercury contaminated soil.

    Science.gov (United States)

    Wang, Xiaonan; Zhang, Daoyong; Pan, Xiangliang; Lee, Duu-Jong; Al-Misned, Fahad A; Mortuza, M Golam; Gadd, Geoffrey Michael

    2017-03-01

    Selenium (Se) nanoparticles are often synthesized by anaerobes. However, anaerobic bacteria cannot be directly applied for bioremediation of contaminated top soil which is generally aerobic. In this study, a selenite-reducing bacterium, Citrobacter freundii Y9, demonstrated high selenite reducing power and produced elemental nano-selenium nanoparticles (nano-Se 0 ) under both aerobic and anaerobic conditions. The biogenic nano-Se 0 converted 45.8-57.1% and 39.1-48.6% of elemental mercury (Hg 0 ) in the contaminated soil to insoluble mercuric selenide (HgSe) under anaerobic and aerobic conditions, respectively. Addition of sodium dodecyl sulfonate enhanced Hg 0 remediation, probably owing to the release of intracellular nano-Se 0 from the bacterial cells for Hg fixation. The reaction product after remediation was identified as non-reactive HgSe that was formed by amalgamation of nano-Se 0 and Hg 0 . Biosynthesis of nano-Se 0 both aerobically and anaerobically therefore provides a versatile and cost-effective remediation approach for Hg 0 -contaminated surface and subsurface soils, where the redox potential often changes dramatically. Copyright © 2016. Published by Elsevier Ltd.

  13. Response of Agronomic Traits of Wheat and Barley to Sources and Different Rates of Selenium in Rainfed Condition

    Directory of Open Access Journals (Sweden)

    N. A Sajedi

    2017-10-01

    Full Text Available Introduction Environmental stresses affect growth, metabolism and crops yield. Drought is an important stress and it decreases crop productivity. Drought stress symptoms vary, depending on intensity and duration of drought and growth stage of the plant. The first response of plant to drought stress is producing the active oxygen species (ROS in cell that these cause injury to membranes and proteins. Selenium (Se application could have beneficial effect on growth and stress tolerance of plants by increasing their activity of antioxidants and reduce the reactive oxygen species over production. Selenium is essential for growth and activities of human and animals. Absorption and accumulation of selenium in plant depend on chemical compound and concentration of selenium in soil. Recent studies have demonstrated that Se increases resistance and antioxidant capacity of plants to various stress. It is reported that selenium application in barley plant no changes the amounts of malondialdehyde and hydrogen peroxide under water deficit stress. The current paper studies the response of agronomic traits of wheat and barley to sources and different rates of selenium in rain fed condition. Materials and Methods In order to investigate response of agronomic traits of wheat and barley to sources and different rates of selenium in rainfed condition, an experiment was carried out as factorial based on randomized complete block design with three replications at the Research Station of Islamic Azad University, Arak Branch, during 2014-2015. Experimental factors were included selenium sources at two levels, Sodium selenate and Selenite, Selenium rates at three levels of zero, 18 and 36 g ha-1 and two crop plants of wheat and barley. The wheat rain fed seed Azar 2 cultivar and Barley cultivar Abidar were hand planted at 15 cm spacing in 6 m rows, with one meter borders between the plots. Foliar application of Se was performed at rate of 18 and 36 g ha-1 at appearance

  14. Stabilization/solidification of selenium-impacted soils using Portland cement and cement kiln dust.

    Science.gov (United States)

    Moon, Deok Hyun; Grubb, Dennis G; Reilly, Trevor L

    2009-09-15

    Stabilization/solidification (S/S) processes were utilized to immobilize selenium (Se) as selenite (SeO(3)(2-)) and selenate (SeO(4)(2-)). Artificially contaminated soils were prepared by individually spiking kaolinite, montmorillonite and dredged material (DM; an organic silt) with 1000 mg/kg of each selenium compound. After mellowing for 7 days, the Se-impacted soils were each stabilized with 5, 10 and 15% Type I/II Portland cement (P) and cement kiln dust (C) and then were cured for 7 and 28 days. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effectiveness of the S/S treatments. At 28 days curing, P doses of 10 and 15% produced five out of six TCLP-Se(IV) concentrations below 10mg/L, whereas only the 15% C in DM had a TCLP-Se(IV) concentration soil-cement slurries aged for 30 days enabled the identification of Se precipitates by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX). XRD and SEM-EDX analyses of the Se(IV)- and Se(VI)-soil-cement slurries revealed that the key selenium bearing phases for all three soil-cement slurries were calcium selenite hydrate (CaSeO(3).H(2)O) and selenate substituted ettringite (Ca(6)Al(2)(SeO(4))(3)(OH)(12).26H(2)O), respectively.

  15. Selenium Speciation and Management in Wet FGD Systems

    Energy Technology Data Exchange (ETDEWEB)

    Searcy, K; Richardson, M; Blythe, G; Wallschlaeger, D; Chu, P; Dene, C

    2012-02-29

    This report discusses results from bench- and pilot-scale simulation tests conducted to determine the factors that impact selenium speciation and phase partitioning in wet FGD systems. The selenium chemistry in wet FGD systems is highly complex and not completely understood, thus extrapolation and scale-up of these results may be uncertain. Control of operating parameters and application of scrubber additives have successfully demonstrated the avoidance or decrease of selenite oxidation at the bench and pilot scale. Ongoing efforts to improve sample handling methods for selenium speciation measurements are also discussed. Bench-scale scrubber tests explored the impacts of oxidation air rate, trace metals, scrubber additives, and natural limestone on selenium speciation in synthetic and field-generated full-scale FGD liquors. The presence and concentration of redox-active chemical species as well as the oxidation air rate contribute to the oxidation-reduction potential (ORP) conditions in FGD scrubbers. Selenite oxidation to the undesirable selenate form increases with increasing ORP conditions, and decreases with decreasing ORP conditions. Solid-phase manganese [Mn(IV)] appeared to be the significant metal impacting the oxidation of selenite to selenate. Scrubber additives were tested for their ability to inhibit selenite oxidation. Although dibasic acid and other scrubber additives showed promise in early clear liquor (sodium based and without calcium solids) bench-scale tests, these additives did not show strong inhibition of selenite oxidation in tests with higher manganese concentrations and with slurries from full-scale wet FGD systems. In bench-tests with field liquors, addition of ferric chloride at a 250:1 iron-to-selenium mass ratio sorbed all incoming selenite to the solid phase, although addition of ferric salts had no impact on native selenate that already existed in the field slurry liquor sample. As ORP increases, selenite may oxidize to selenate more

  16. A High-Throughput Oxidative Stress Biosensor Based on Escherichia coli roGFP2 Cells Immobilized in a k-Carrageenan Matrix

    Directory of Open Access Journals (Sweden)

    Lia Ooi

    2015-01-01

    Full Text Available Biosensors fabricated with whole-cell bacteria appear to be suitable for detecting bioavailability and toxicity effects of the chemical(s of concern, but they are usually reported to have drawbacks like long response times (ranging from hours to days, narrow dynamic range and instability during long term storage. Our aim is to fabricate a sensitive whole-cell oxidative stress biosensor which has improved properties that address the mentioned weaknesses. In this paper, we report a novel high-throughput whole-cell biosensor fabricated by immobilizing roGFP2 expressing Escherichia coli cells in a k-carrageenan matrix, for the detection of oxidative stress challenged by metalloid compounds. The E. coli roGFP2 oxidative stress biosensor shows high sensitivity towards arsenite and selenite, with wide linear range and low detection limit (arsenite: 1.0 × 10−3–1.0 × 101 mg·L−1, LOD: 2.0 × 10−4 mg·L−1; selenite: 1.0 × 10−5–1.0 × 102 mg·L−1, LOD: 5.8 × 10−6 mg·L−1, short response times (0–9 min, high stability and reproducibility. This research is expected to provide a new direction in performing high-throughput environmental toxicity screening with living bacterial cells which is capable of measuring the bioavailability and toxicity of environmental stressors in a friction of a second.

  17. Nanocrystalline hydroxyapatite doped with selenium oxyanions: A new material for potential biomedical applications

    International Nuclear Information System (INIS)

    Kolmas, Joanna; Oledzka, Ewa; Sobczak, Marcin; Nałęcz-Jawecki, Grzegorz

    2014-01-01

    Selenium-substituted hydroxyapatites containing selenate SeO 4 2− or selenite SeO 3 2− ions were synthesized using a wet precipitation method. The selenium content was determined by atomic absorbance spectrometry. The raw, unsintered powders were also characterized using powder X-ray diffraction, middle-range FT-IR spectroscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopic microanalysis. The synthesized apatites were found to be pure and nanocrystalline with a crystal size similar to that in bone mineral. The incorporation of selenium oxyanions into the crystal lattice was confirmed. The toxicity of hydroxyapatites containing selenite or selenate ions was evaluated with a protozoan assay and bacterial luminescence test. - Highlights: • We synthesized and analyzed hydroxyapatites doped with selenium oxyanions. • We used various analytical methods, i.e. XRD, TEM, AAS and FT-IR. • We confirmed incorporation of SeO 3 2− and SeO 4 2− into the crystal lattice. • The toxicity of the materials was studied

  18. Nanocrystalline hydroxyapatite doped with selenium oxyanions: A new material for potential biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Kolmas, Joanna, E-mail: joanna.kolmas@wum.edu.pl [Medical University of Warsaw, Faculty of Pharmacy, Department of Inorganic and Analytical Chemistry, ul. Banacha 1, 02-097 Warsaw (Poland); Oledzka, Ewa; Sobczak, Marcin [Medical University of Warsaw, Faculty of Pharmacy, Department of Inorganic and Analytical Chemistry, ul. Banacha 1, 02-097 Warsaw (Poland); Nałęcz-Jawecki, Grzegorz [Medical University of Warsaw, Faculty of Pharmacy, Department of Environmental Health Sciences, ul. Banacha 1, 02-097 Warsaw (Poland)

    2014-06-01

    Selenium-substituted hydroxyapatites containing selenate SeO{sub 4}{sup 2−} or selenite SeO{sub 3}{sup 2−} ions were synthesized using a wet precipitation method. The selenium content was determined by atomic absorbance spectrometry. The raw, unsintered powders were also characterized using powder X-ray diffraction, middle-range FT-IR spectroscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopic microanalysis. The synthesized apatites were found to be pure and nanocrystalline with a crystal size similar to that in bone mineral. The incorporation of selenium oxyanions into the crystal lattice was confirmed. The toxicity of hydroxyapatites containing selenite or selenate ions was evaluated with a protozoan assay and bacterial luminescence test. - Highlights: • We synthesized and analyzed hydroxyapatites doped with selenium oxyanions. • We used various analytical methods, i.e. XRD, TEM, AAS and FT-IR. • We confirmed incorporation of SeO{sub 3}{sup 2−} and SeO{sub 4}{sup 2−} into the crystal lattice. • The toxicity of the materials was studied.

  19. Influence of Dietary Selenium Species on Selenoamino Acid Levels in Rainbow Trout.

    Science.gov (United States)

    Godin, Simon; Fontagné-Dicharry, Stéphanie; Bueno, Maïté; Tacon, Philippe; Prabhu, Philip Antony Jesu; Kaushik, Sachi; Médale, Françoise; Bouyssiere, Brice

    2015-07-22

    Two forms of selenium (Se) supplementation of fish feeds were compared in two different basal diets. A 12-week feeding trial was performed with rainbow trout fry using either a plant-based or a fish meal-based diet. Se yeast and selenite were used for Se supplementation. Total Se and Se speciation were determined in both diets and whole body of trout fry using inductively coupled plasma mass spectrometry (ICP MS) and high-performance liquid chromatography (HPLC). The two selenoamino acids, selenomethionine (SeMet) and selenocysteine (SeCys), were determined in whole body of fry after enzymatic digestion using protease type XIV with a prior derivatization step in the case of SeCys. The plant-based basal diet was found to have a much lower total Se than the fish meal-based basal diet with concentrations of 496 and 1222 μg(Se) kg(-1), respectively. Dietary Se yeast had a higher ability to raise whole body Se compared to selenite. SeMet concentration in the fry was increased only in the case of Se yeast supplementation, whereas SeCys levels were similar at the end of the feeding trial for both Se supplemented forms. The results show that the fate of dietary Se in fry is highly dependent on the form brought through supplementation and that a plant-based diet clearly benefits from Se supplementation.

  20. Effect of intraperitoneal selenium administration on liver glycogen levels in rats subjected to acute forced swimming.

    Science.gov (United States)

    Akil, Mustafa; Bicer, Mursel; Kilic, Mehmet; Avunduk, Mustafa Cihat; Mogulkoc, Rasim; Baltaci, Abdulkerim Kasim

    2011-03-01

    There are a few of studies examining how selenium, which is known to reduce oxidative damage in exercise, influences glucose metabolism and exhaustion in physical activity. The present study aims to examine how selenium administration affects liver glycogen levels in rats subjected to acute swimming exercise. The study included 32 Sprague-Dawley type male rats, which were equally allocated to four groups: Group 1, general control; Group 2; selenium-supplemented control (6 mg/kg/day sodium selenite); Group 3, swimming control; Group 4, selenium-supplemented swimming (6 mg/kg/day sodium selenite). Liver tissue samples collected from the animals at the end of the study were fixed in 95% ethyl alcohol. From the tissue samples buried into paraffin, 5-µm cross-sections were obtained using a microtome, put on a microscope slide, and stained with PAS. Stained preparations were assessed using a Nikon Eclipse E400 light microscope. All images obtained with the light microscope were transferred to a PC and evaluated using Clemex PE 3.5 image analysis software. The highest liver glycogen levels were found in groups 1 and 2 (p swimming exercise can be restored by selenium administration. It can be argued that physiological doses of selenium administration can contribute to performance.

  1. Speciation of Se and DOC in soil solution and their relation to Se bioavailability.

    Science.gov (United States)

    Weng, Liping; Vega, Flora Alonso; Supriatin, Supriatin; Bussink, Wim; Van Riemsdijk, Willem H

    2011-01-01

    A 0.01 M CaCl(2) extraction is often used to asses the bioavailability of plant nutrients in soils. However, almost no correlation was found between selenium (Se) in the soil extraction and Se content in grass. The recently developed anion Donnan membrane technique was used to analyze chemical speciation of Se in the 0.01 M CaCl(2) extractions of grassland soils and fractionation of DOC (dissolved organic carbon). The results show that most of Se (67-86%) in the extractions (15 samples) are colloidal-sized Se. Only 13-34% of extractable Se are selenate, selenite and small organic Se (<1 nm). Colloidal Se is, most likely, Se bound to or incorporated in colloidal-sized organic matter. The dominant form of small Se compounds (selenate, selenite/small organic compounds) depends on soil. A total of 47-85% of DOC is colloidal-sized and 15-53% are small organic molecules (<1 nm). In combination with soluble S (sulfur) and/or P (phosphor), concentration of small DOC can explain most of the variability of Se content in grass. The results indicate that mineralization of organic Se is the most important factor that controls Se availability in soils. Competition with sulfate and phosphate needs to be taken into account. Further research is needed to verify if concentration of small DOC is a good indicator of mineralization of soil organic matter.

  2. Physiological and biochemical responses of rainbow trout and brook trout exposed to elevated selenium from coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Miller, L.; Rasmussen, J.; Hontela, A. [Lethbridge Univ., Lethbridge, AB (Canada); Palace, V.; Carroll, L. [Fisheries and Oceans Canada, Winnipeg, MB (Canada); Wang, F. [Manitoba Univ., Winnipeg, MB (Canada)

    2009-07-01

    Since selenium (Se) is an element that bioaccumulates, anthropogenic activities in areas that already have high Se in parent rock can result in an increase in Se in aquatic systems. Se causes reproductive deformities in rainbow trout (RT), at lower concentrations than for brook trout (BT). This presentation reported on a study conducted at coal mines in northeastern Alberta in which juvenile hatchery-reared RT and BT were stocked into 2 reference and 2 Se contaminated end pit lakes. Fish were sampled at 0, 6, and 12 months after stocking, and will be sampled at 18 and 24 months. Water Se levels were found to be high in contaminated lakes. Selenite, the more toxic form of Se, was the highest in Pit C4. Liver glutathione levels were similar in the 2 fish species, and cellular damage in the fish was beginning to increase. At 6 months, liver glycogen levels were higher in the BT than in the RT, but no tangible site specific patterns emerged. At all sites except Pit C4, the RT were in better condition than BT. BT from Pit C4 also had a lower ability to secrete cortisol, suggesting that the elevated selenite levels may negatively affect fish. Se accumulation results from 28 fish sampled at 12 months were also discussed.

  3. Protective Effects of Combined Selenium and Punica granatum Treatment on Some Inflammatory and Oxidative Stress Markers in Arsenic-Induced Hepatotoxicity in Rats.

    Science.gov (United States)

    Shafik, Noha M; El Batsh, Maha M

    2016-01-01

    Oxidative stress is one of the major mechanisms implicated in inorganic arsenic poisoning. Punica granatum is known by its free radical scavenging properties. The aim of this study was to evaluate the protective role of combined selenium and P. granatum against arsenic-induced liver injury. Seventy-five female albino rats were divided into five groups (of 15 rats each). Toxicity was induced by oral sodium arsenite (5.5 mg/kg body weight (bw) daily) (group ІІ). Treatment of arsenic-intoxicated rats was induced by daily oral administration of sodium selenite (3 mg/kg bw) (group ІІІ), 100 mg of P. granatum ethanol extract per kilogram body weight dissolved in 300 mL distilled water in three divided doses (100 mL of this suspension every 8 h) (group IV), and combined daily oral treatment with both selenite and P. granatum ethanol extract (group V). After 3 weeks, serum and liver tissues were obtained from the decapitated rats for different estimations. Hepatotoxicity was demonstrated by significant elevation in liver weights and activities of liver enzymes, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and decrease in serum total proteins and albumin (p granatum and selenium. It was concluded that combined P. granatum and selenium treatment had a synergistic hepatoprotective effect against arsenic toxicity through activation of Nrf2 anti-oxidant pathway.

  4. Selenylation Modification of Degraded Polysaccharide from Enteromorpha prolifera and Its Biological Activities

    Science.gov (United States)

    Lv, Haitao; Duan, Ke; Shan, Hu

    2018-04-01

    Polysaccharide extracted from Enteromorpha prolifera possessed excellent biological activities, but its molecular weight was greatly high which influenced the activity. Organic Se had higher biological activities and was safer than inorganic Se species. In the present study, Enteromorpha polysaccharide was degraded to low molecular weight by free-radical degradation method of H2O2 and ascorbic acid. By single factor and orthogonal experiments, the optimal degradation conditions were reaction time of 2 h, reaction temperature of 50°C, H2O2/ascorbic acid (n/n=1:1) concentration of 15 mmol L-1, and solid-liquid ratio of 1:50 (g mL-1). Then, the degraded polysaccharide was chemically modified to obtain its selenide derivatives by nitric acid-sodium selenite method. The selenium content was 1137.29 μg g-1, while the content of sulfate radical had no change. IR spectra indicated that the selenite ester group was formed. Degraded polysaccharide selenide was characterized and evaluated for antioxidant, antifungal and antibacterial activities. The results showed that degraded polysaccharide selenide had strong capacity of scavenging DPPH and ·OH free radical. It had significant antibacterial properties for Escherichia coli, Bacillus subtilis and Salmonella spp., and it also had significant antifungal properties for Apple anthrax. The result ascertained degradation and selenylation modification did not change the main structure of polysaccharides. It was possible that free-radical degradation was an effective way for enhancing antioxidant activity to decrease molecular weight of polysaccharides.

  5. The effects of selenium on glutathione peroxidase activity and radioprotection in mammalian cells

    International Nuclear Information System (INIS)

    Diamond, A.M.; Murray, J.L.; Dale, P.; Tritz, R.; Grdina, D.J.

    1995-01-01

    The media of representative mammalian cell lines were supplemented with low levels of selenium in the form of sodium selenite in order to investigate the effects of selenium on mammalian cells. Following incubation in 30 nM sodium selenite, these cells were assayed for changes in glutathione peroxidase (GPx) activity. The cells examined included NIH 3T3 mouse fibroblasts, PC12 rat sympathetic precursor cells, SupT-1 human lymphocytes, MCF-7 adr human breast carcinoma cells and AA8 Chinese hamster ovary cells. Selenium supplementation resulted in a marginal increase in GPx activity for the NIH 3T3, MCF-7 adr and Supt-1 cells but stimulated GPx activity approximately 5-fold in PC12 and AA8 cells. AA8 cells were selected to evaluate whether selenium supplementation was radioprotective against 60 cobalt gamma irradiation. Protection against radiation-induced mutation was measured by evaluating mutation frequency at the hprt locus. In this assay, preincubation of AA8 CHO cells significantly protected these cells from exposure to 8 Gy

  6. Monodispersed spherical shaped selenium nanoparticles (SeNPs) synthesized by Bacillus subtilis and its toxicity evaluation in zebrafish embryos

    Science.gov (United States)

    Chandramohan, Subburaman; Sundar, Krishnan; Muthukumaran, Azhaguchamy

    2018-02-01

    Selenium is one of the essential elements involved in antioxidative and antiinflammatory effects in human body. By naturally, selenium ions are metabolised and converted into nano selenium. Now a days there is an increasing attention on applications of nanoparticles in therapeutic field. In the present study Bacillus subtilis was used to convert sodium selenite to SeNPs. The synthesized SeNPs were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X ray spectroscopy (EDX). The presence of SeNPs was confirmed by the formation of red colour. The bands were sharp with broad absorption peaks at 3562 cm-1 and 1678-1 cm in FTIR which showed that the bacterial proteins were responsible for the reduction of sodium selenite to SeNPs. The average size of the SeNPs was 334 nm and were spherical in shape with uniform distribution. The XRD data confirmed that SeNPs were of amorphous in nature. The zeta potential of SeNPs was negative in charge which indicated high stability. In the present study zebrafish embryos were used to study the toxicity of SeNPs and the results showed that the concentration beyond 10 μg ml-1 leads to toxic effects in embryos/hatchlings. The lesser concentration of SeNPs can be useful in various biomedical applications.

  7. Synthesis and structural, spectroscopic and magnetic studies of two new polymorphs of Mn(SeO3).H2O

    International Nuclear Information System (INIS)

    Larranaga, Aitor; Mesa, Jose L.; Pizarro, Jose L.; Pena, A.; Olazcuaga, Roger; Arriortua, Maria I.; Rojo, Teofilo

    2005-01-01

    Two new manganese(II) selenite polymorphs with formula Mn(SeO 3 ).H 2 O have been synthesized by slow evaporation from an aqueous solution. The crystal structure of both compounds (1) and (2) have been solved from X-ray diffraction data. The structure of (1) was determined from single-crystal X-ray diffraction techniques. The compound crystallizes in the Ama2 space group, with a=5.817(1), b=13.449(3), c=4.8765(9)A and Z=4. The structure of (2) has been solved from X-ray powder diffraction data. This phase crystallizes in the P2 1 /n space group with unit-cell parameters of a=4.921(3), b=13.121(7), c=5.816(1)A, β=90.03(2) o and Z=4. Both polymorphs exhibit a layered structure formed by isolated sheets of MnO 6 octahedra and (SeO 3 ) 2- trigonal pyramids in the (010) plane. These layers, which contain one manganese and selenium atom crystallographically independent, are formed by octahedra linked between them through the selenite oxoanions. The difference of both compounds consists in the stacking of the layers along the b-axis. The IR spectra show the characteristic bands of the selenite anion. Studies of luminescence performed at 6K and diffuse reflectance spectroscopy have been carried out for both phases. The Dq and Racah (B and C) parameters, from luminescence and diffuse reflectance spectroscopy, are Dq=705, B=750, C=3325cm -1 for (1) and Dq=720, B=745, C=3350cm -1 for (2). The ESR spectra of both compounds are isotropic with g-values of 1.99(1). Magnetic measurements indicate the presence of antiferromagnetic couplings in both phases. The J-exchange parameters have been estimated by fitting the experimental magnetic data to a model for square-planar lattice. The values obtained are J/k=-0.83, -0.91K and J ' /k=-0.97, -1.20K, for polymorphs (1) and (2), respectively

  8. Acrolein-induced activation of mitogen-activated protein kinase signaling is mediated by alkylation of thioredoxin reductase and thioredoxin 1.

    Science.gov (United States)

    Randall, Matthew J; Spiess, Page C; Hristova, Milena; Hondal, Robert J; van der Vliet, Albert

    2013-01-01

    Cigarette smoking remains a major health concern worldwide, and many of the adverse effects of cigarette smoke (CS) can be attributed to its abundant electrophilic aldehydes, such as acrolein (2-propenal). Previous studies indicate that acrolein readily reacts with thioredoxin reductase 1 (TrxR1), a critical enzyme involved in regulation of thioredoxin (Trx)-mediated redox signaling, by alkylation at its selenocysteine (Sec) residue. Because alkylation of Sec within TrxR1 has significant implications for its enzymatic function, we explored the potential importance of TrxR1 alkylation in acrolein-induced activation or injury of bronchial epithelial cells. Exposure of human bronchial epithelial HBE1 cells to acrolein (1-30 μM) resulted in dose-dependent loss of TrxR thioredoxin reductase activity, which coincided with its alkylation, as determined by biotin hydrazide labeling, and was independent of initial GSH status. To test the involvement of TrxR1 in acrolein responses in HBE1 cells, we suppressed TrxR1 using siRNA silencing or augmented TrxR1 by cell supplementation with sodium selenite. Acrolein exposure of HBE1 cells induced dose-dependent activation of the MAP kinases, extracellular regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38, and activation of JNK was markedly enhanced after selenite-mediated induction of TrxR1, and was associated with increased alkylation of TrxR1. Conversely, siRNA silencing of TrxR1 significantly suppressed the ability of acrolein to activate JNK, and also appeared to attenuate acrolein-dependent activation of ERK and p38. Alteration of initial TrxR1 levels by siRNA or selenite supplementation also affected initial Trx1 redox status and acrolein-mediated alkylation of Trx1, but did not significantly affect acrolein-mediated activation of HO-1 or cytotoxicity. Collectively, our findings indicate that alkylation of TrxR1 and/or Trx1 may contribute directly to acrolein-mediated activation of MAP kinases such as JNK, and

  9. Acrolein-induced activation of mitogen-activated protein kinase signaling is mediated by alkylation of thioredoxin reductase and thioredoxin 1

    Directory of Open Access Journals (Sweden)

    Matthew J. Randall

    2013-01-01

    Full Text Available Cigarette smoking remains a major health concern worldwide, and many of the adverse effects of cigarette smoke (CS can be attributed to its abundant electrophilic aldehydes, such as acrolein (2-propenal. Previous studies indicate that acrolein readily reacts with thioredoxin reductase 1 (TrxR1, a critical enzyme involved in regulation of thioredoxin (Trx-mediated redox signaling, by alkylation at its selenocysteine (Sec residue. Because alkylation of Sec within TrxR1 has significant implications for its enzymatic function, we explored the potential importance of TrxR1 alkylation in acrolein-induced activation or injury of bronchial epithelial cells. Exposure of human bronchial epithelial HBE1 cells to acrolein (1–30 μM resulted in dose-dependent loss of TrxR thioredoxin reductase activity, which coincided with its alkylation, as determined by biotin hydrazide labeling, and was independent of initial GSH status. To test the involvement of TrxR1 in acrolein responses in HBE1 cells, we suppressed TrxR1 using siRNA silencing or augmented TrxR1 by cell supplementation with sodium selenite. Acrolein exposure of HBE1 cells induced dose-dependent activation of the MAP kinases, extracellular regulated kinase (ERK, c-Jun N-terminal kinase (JNK, and p38, and activation of JNK was markedly enhanced after selenite-mediated induction of TrxR1, and was associated with increased alkylation of TrxR1. Conversely, siRNA silencing of TrxR1 significantly suppressed the ability of acrolein to activate JNK, and also appeared to attenuate acrolein-dependent activation of ERK and p38. Alteration of initial TrxR1 levels by siRNA or selenite supplementation also affected initial Trx1 redox status and acrolein-mediated alkylation of Trx1, but did not significantly affect acrolein-mediated activation of HO-1 or cytotoxicity. Collectively, our findings indicate that alkylation of TrxR1 and/or Trx1 may contribute directly to acrolein-mediated activation of MAP kinases

  10. Acrolein-induced activation of mitogen-activated protein kinase signaling is mediated by alkylation of thioredoxin reductase and thioredoxin 1☆☆☆

    Science.gov (United States)

    Randall, Matthew J.; Spiess, Page C.; Hristova, Milena; Hondal, Robert J.; van der Vliet, Albert

    2013-01-01

    Cigarette smoking remains a major health concern worldwide, and many of the adverse effects of cigarette smoke (CS) can be attributed to its abundant electrophilic aldehydes, such as acrolein (2-propenal). Previous studies indicate that acrolein readily reacts with thioredoxin reductase 1 (TrxR1), a critical enzyme involved in regulation of thioredoxin (Trx)-mediated redox signaling, by alkylation at its selenocysteine (Sec) residue. Because alkylation of Sec within TrxR1 has significant implications for its enzymatic function, we explored the potential importance of TrxR1 alkylation in acrolein-induced activation or injury of bronchial epithelial cells. Exposure of human bronchial epithelial HBE1 cells to acrolein (1–30 μM) resulted in dose-dependent loss of TrxR thioredoxin reductase activity, which coincided with its alkylation, as determined by biotin hydrazide labeling, and was independent of initial GSH status. To test the involvement of TrxR1 in acrolein responses in HBE1 cells, we suppressed TrxR1 using siRNA silencing or augmented TrxR1 by cell supplementation with sodium selenite. Acrolein exposure of HBE1 cells induced dose-dependent activation of the MAP kinases, extracellular regulated1 kinase (ERK), c-Jun N-terminal kinase (JNK), and p38, and activation of JNK was markedly enhanced after selenite-mediated induction of TrxR1, and was associated with increased alkylation of TrxR1. Conversely, siRNA silencing of TrxR1 significantly suppressed the ability of acrolein to activate JNK, and also appeared to attenuate acrolein-dependent activation of ERK and p38. Alteration of initial TrxR1 levels by siRNA or selenite supplementation also affected initial Trx1 redox status and acrolein-mediated alkylation of Trx1, but did not significantly affect acrolein-mediated activation of HO-1 or cytotoxicity. Collectively, our findings indicate that alkylation of TrxR1 and/or Trx1 may contribute directly to acrolein-mediated activation of MAP kinases such as JNK

  11. Imaging microbial metal metabolism in situ under conditions of the deep-sea hydrothermal vents

    Science.gov (United States)

    Oger, P. M.; Daniel, I.; Simionovici, A.; Picard, A.

    2006-12-01

    High-pressure biotopes are the most widely spread biotopes on Earth. They represent one possible location for the origin of life. They also share striking similarities with extraterrestrial biotopes such as those postulated for Europe or Mars. In absence of light, dissimilatory reduction of metals (DMR) is fueling the ecosystem. Monitoring the metabolism of the deep-sea hydrothermal vent microbial fauna under P, T and chemical conditions relevant to their isolation environment can be difficult because of the confinement and because most spectroscopic probes do not sense metallic ions in solution. We demonstrated the possibility to use Xray spectroscopy to monitor the speciation of metallic species in solution. Experiments were performed at The ESRF using Selenium (Se) detoxification by Agrobacterium tumefaciens as an analog of DMR. The reduction of Se from selenite to the metal was monitored by a combiantion of two Xray spectroscopic techniques (XANES and μXRF). Cells were incubated in the low pressure DAC in growth medium supplemented with 5mM Selenite and incubated under pressures up to 60 Mpa at 30°C for 24h. The evolution of the speciation can be easily monitored and the concentration of each Se species determined from the Xray spectra by linear combinations of standard spectra. Selenite is transformed by the bacterium into a mixture of metal Se and methylated Se after 24 hours. Se detoxification is observed in situ up to at least 25 MPa. The technique, developped for Se can be adapted to monitor other elements more relevant to DMR such as As, Fe or S, which should allow to monitor in situ under controlled pressure and temperature the metabolism of vent organisms. It is also amenable to the monitoring of toxic metals. Xray spectroscopy and the lpDAC are compatible with other spectroscopic techniques, such as Raman, UV or IR spectroscopies, allowing to probe other metabolic activities. Hence, enlarging the range of metabolic information that can be obtained in

  12. Redox-Active Selenium Compounds—From Toxicity and Cell Death to Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Sougat Misra

    2015-05-01

    Full Text Available Selenium is generally known as an antioxidant due to its presence in selenoproteins as selenocysteine, but it is also toxic. The toxic effects of selenium are, however, strictly concentration and chemical species dependent. One class of selenium compounds is a potent inhibitor of cell growth with remarkable tumor specificity. These redox active compounds are pro-oxidative and highly cytotoxic to tumor cells and are promising candidates to be used in chemotherapy against cancer. Herein we elaborate upon the major forms of dietary selenium compounds, their metabolic pathways, and their antioxidant and pro-oxidant potentials with emphasis on cytotoxic mechanisms. Relative cytotoxicity of inorganic selenite and organic selenocystine compounds to different cancer cells are presented as evidence to our perspective. Furthermore, new novel classes of selenium compounds specifically designed to target tumor cells are presented and the potential of selenium in modern oncology is extensively discussed.

  13. Complexation ion-exchange chromatography of some metal ions on papers impregnated with Ti(IV)-based inorganic ion exchangers.

    Science.gov (United States)

    Sharma, S D; Gupta, R

    2000-02-01

    The chromatographic behavior of 40 metal ions is studied on titanium (IV) arsenate, titanium (IV) phosphate-, titanium (IV) molybdate-, titanium(IV) tungstate-, and titanium(IV) selenite-impregnated papers in 0.1M oxalic, citric, and tartaric acid as mobile phases. Similar studies are carried out on Whatman No. 1 papers for comparison. The ion-exchange capacity of these papers is determined, and their selectivity for different cations is discussed. The mechanism of migration is explained in terms of ion-exchange, precipitation, and adsorption. The prediction of elution sequence from RF values is also checked. The average Ri is found to be almost linearly dependent on the charge of the metal ions. The effect of the pKa of complexing acids on average RF values of 3d series metal ions is explained. A number of binary and ternary separations are achieved.

  14. Plants and microbes assisted selenium nanoparticles: characterization and application.

    Science.gov (United States)

    Husen, Azamal; Siddiqi, Khwaja Salahuddin

    2014-08-16

    Selenium is an essential trace element and is an essential component of many enzymes without which they become inactive. The Se nanoparticles of varying shape and size may be synthesized from Se salts especially selenite and selenates in presence of reducing agents such as proteins, phenols, alcohols and amines. These biomolecules can be used to reduce Se salts in vitro but the byproducts released in the environment may be hazardous to flora and fauna. In this review, therefore, we analysed in depth, the biogenic synthesis of Se nanoparticles, their characterization and transformation into t- Se, m-Se, Se-nanoballs, Se-nanowires and Se-hollow spheres in an innocuous way preventing the environment from pollution. Their shape, size, FTIR, UV-vis, Raman spectra, SEM, TEM images and XRD pattern have been analysed. The weak forces involved in aggregation and transformation of one nano structure into the other have been carefully resolved.

  15. The Cultivation and SeleniumEnrichment of SeleniumEnriched Earthworm

    Directory of Open Access Journals (Sweden)

    SUN Xiao-fei

    2014-12-01

    Full Text Available As a bio-carrier, Eisenia fetida was fed with cow dung that added with sodium selenite in order to transfer inorganic selenium(Se into organic selenium. Targeting on survival rate and selenium content, the effects of five Se concentrations(0, 20, 40, 60, 80, 100 mg·kg-1 and four cultivation periods(15, 30, 45, 60 don earthworm growth and Se contents were investigated. The cultivation method with high survival rate, high Se content of earthworm and short breeding time would be screened out. The experimental results showed that the earthworm survival rate decreased and the Se content in earthworm increased with the increase of Se application and the extension of breeding time. The most optimummethod was screened out when the Se concentration was 80 mg·kg-1 and the cultivation period was 45 days, Se content in earthworm was up to 33.25 mg·kg-1.

  16. Comparação dos caldos selenito cistina, tetrationato Muller-Kauffmann e Rappaport-Vassiliadis no isolamento de Salmonella Typhimurium

    Directory of Open Access Journals (Sweden)

    L.G. Ávila

    2012-06-01

    Full Text Available Three selective enrichment broths - selenite cystine (SC, Muller-Kauffmann tetrathionate (MKT and Rappaport-Vassiliadis (RV - were compared, for Salmonella Typhimurium isolation from rectal swabs of a calf experimentally infected. The bacteriological procedure involved pre-enrichment in Hajna-GN broth (only for the samples inoculated in RV broth, selective enrichment (SC, MKT and RV broths, culture in modified brilliant green agar (BGA, presumptive biochemistry tests (using triple-sugar-iron agar and lysine-agar and slide agglutination test with poli-O and poli-H Salmonella antisera. SC and MKT broths were more efficient in the isolation of Salmonella Typhimurium (12 positive samples, whereas RV broth had a lower efficiency in the microbiological isolation (ten positive samples.

  17. Comparação da eficiência dos caldos de enriquecimento seletivo no isolamento de Salmonella Dublin Comparison of the efficiency of selective enrichment broths for Salmonella Dublin isolation

    Directory of Open Access Journals (Sweden)

    D.G. Silva

    2008-06-01

    Full Text Available The aim of this study was to compare three different selective enrichment broths: Rappaport-Vassiliadis (RV, selenite cystine (SC and Muller-Kauffmann tetrathionate (MKT for Salmonella Dublin isolation from faecal samples of calf experimentally infected. The bacteriological procedure involved pre-enrichment stages in Hajna-GN broth (only for the samples inoculated in RV broth, selective enrichment, culture in modified brilliant green agar (BGA, presumptive biochemistry tests (using triple-sugar-iron agar and lysine-agar and slide agglutination test with poli-O and poli-H Salmonella antiserum. The effects of enrichment temperatures using RV broth were also evaluated (37ºC and 42ºC. SC broth was significantly more efficient in the isolation of Salmonella Dublin (P<0,05, whereas RV broth incubated at 42ºC had a lower efficiency in the microbiological isolation.

  18. Acute selenium poisoning in cattle

    Energy Technology Data Exchange (ETDEWEB)

    Shortridge, E H; O' Hara, P J; Marshall, P M

    1971-01-01

    Three hundred and seventy-six (67%) of 557 calves of approximately 150-200 kg live-weight died following subcutaneous injection of a solution containing 100 mg selenium as sodium selenite. Eight per cent of the 254 heifer calves and 56% of the 303 steers died. The calves had endured the stress of being weaned twice and held in stockyards twice as well as encountering wet weather during the 4 days before receiving the selenium. The heifer calves were also vaccinated with Br. abortus strain 19 vaccine at the same time as receiving the selenium. The clinical signs and pathological findings of circulatory failure and myocardial damage were similar to those previously reported in acute selenium poisoning.

  19. Review on Nano SeleniumProduced by Bacteria

    Directory of Open Access Journals (Sweden)

    LI Ji-xiang

    2014-12-01

    Full Text Available Selenium (Se is a kind of essential trace element for people and animal, while ionic state of selenium is toxic with high concentrations and will cause the selenium pollution. Nano-selenium is stable, nontoxic with higher biological activity. Application of bacteria reducing selenite or selenate to biological nano-selenium has great potential in selenium pollution control and nano-selenium production. This review summarizes the research progress of the red elemental nano-selenium reduced by bacteria including characteristics and application of nano-selenium, effects of carbon and nitrogen source, oxygen, temperature and pH in bacteria nano-selenium production, and molecular mechanisms of nano-selenium reduced by bacteria.

  20. Investigation of the selenium metabolism in cancer cell lines

    DEFF Research Database (Denmark)

    Lunøe, Kristoffer; Gabel-Jensen, Charlotte; Stürup, Stefan

    2011-01-01

    The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line...... (Jurkat E6-1) were incubated with five selenium compounds representing inorganic as well as organic Se compounds in different oxidation states. Selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys), methylseleninic acid (MeSeA), selenite and selenate in the concentration range 5-100 mu M were...... incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size...

  1. New scientific challenges - the possibilities of using selenium in poultry nutrition and impact on meat quality

    Science.gov (United States)

    Marković, R.; Glišić, M.; Bošković, M.; Baltić, M. Ž.

    2017-09-01

    Physiological stress is one of many concerns facing modern broiler production. In conditions when birds are exposed to stress, supplementation of selenium, which is a crucial glutathione peroxidase enzymatic cofactor, increases the antioxidant capacity of the animals and decreases the harmful effects of free radicals. Dietary selenium improves production performance and health of animals, and positively affects the immune system, the quality, selenium content and fatty acid composition of meat and eggs. There are several different forms of selenium, the most common dietary supplements being an inorganic form (sodium selenite) and anorganic form (selenomethionine). However, in recent years, new forms of selenium, such as a 2-hydroxy-4-methylselenobutanoic acid (HMSeBA) and nanoselenium, which have more bioavailability, bioefficacy, and low toxicity have been designed. In this short comparative overview discusses the effects of inorganic, organic and nanoforms of selenium on production results, glutathione peroxidase activity, meat quality and level of toxicity in poultry.

  2. Selenium content of mushrooms.

    Science.gov (United States)

    Stijve, T

    1977-07-29

    The selenium contents of 83 species of wild mushrooms were determined by oxygen combustion of the sample, followed by conversion of selenite to bromopiazselenol and final estimation by electron capture gas-liquid chromatography. Selenium concentration were found to range from 0.012-20.0 mg/kg dry weight. Selenium content was species-dependent. High concentrations were found in Agaricaceae and in certain Boletaceae of the genus Tubiporus, whereas in Russulaceae, Amanitaceae and Cantharellaceae selenium-rich species were absent or rare. Ascomycetes and all mushrooms growing on wood had a very low selenium content. The highest selenium concentrations (up to 20 ppm) were found in Boletus (Tubiporus) edulis, a most popular edible mushroom. Analyses of various parts of carpophores of B. edulis, Suillus luteus and Amanita muscaria indicate that in all three species the stalk contains less selenium than the fleshy part of the cap. In Boletus and Suillus the highest selenium content was found in the tubes.

  3. Il laser scanning e CloudCUBE per le grotte di Naica

    Directory of Open Access Journals (Sweden)

    Erminio Paolo Canevese

    2008-03-01

    Full Text Available Laser scanning and CloudCube for Naica caves On May 2007, Virtualgeo, a geomatic software development and communication company, took part in the first official expedition to Mexico. The Project, coined "Naica", involves researchers from ten universities, four companies and several laboratories. Virtualgeo carried out the survey by applying laser scanning technology to hypogeal caves covered with selenite crystals. The data was processed using CloudCUBE, a proprietary software designed to manage and model 3D point clouds. The first results of the laser scanning survey of a spectacular “forest of crystals” are presented here.

  4. Il laser scanning e CloudCUBE per le grotte di Naica

    Directory of Open Access Journals (Sweden)

    Erminio Paolo Canevese

    2008-03-01

    Full Text Available Laser scanning and CloudCube for Naica cavesOn May 2007, Virtualgeo, a geomatic software development and communication company, took part in the first official expedition to Mexico. The Project, coined "Naica", involves researchers from ten universities, four companies and several laboratories. Virtualgeo carried out the survey by applying laser scanning technology to hypogeal caves covered with selenite crystals. The data was processed using CloudCUBE, a proprietary software designed to manage and model 3D point clouds. The first results of the laser scanning survey of a spectacular “forest of crystals” are presented here.

  5. Selenium recovery from kiln powder of cement manufacturing by chemical leaching and bioreduction.

    Science.gov (United States)

    Soda, S; Hasegawa, A; Kuroda, M; Hanada, A; Yamashita, M; Ike, M

    2015-01-01

    A novel process by using chemical leaching followed by bacterial reductive precipitation was proposed for selenium recovery from kiln powder as a byproduct of cement manufacturing. The kiln powder at a slurry concentration of 10 w/v% with 0.25 M Na2CO3 at 28°C produced wastewater containing about 30 mg-Se/L selenium. The wastewater was diluted four-fold and adjusted to pH 8.0 as preconditioning for bioreduction. A bacterial strain Pseudomonas stutzeri NT-I, capable of reducing selenate and selenite into insoluble elemental selenium, could recover about 90% selenium from the preconditioned wastewater containing selenium of 5 mg-Se/L when supplemented with lactate or glycerol. The selenium concentrations in the treated wastewater were low around the regulated effluent concentration of 0.1 mg-Se/L in Japan.

  6. Growth inhibitory factors in bovine faeces impairs detection of Salmonella Dublin by conventional culture procedure

    DEFF Research Database (Denmark)

    Baggesen, Dorte Lau; Nielsen, L.R.; Sørensen, Gitte

    2007-01-01

    Aims: To analyse the relative importance of different biological and technical factors on the analytical sensitivity of conventional culture methods for detection of Salmonella Dublin in cattle faeces. Methods and Results: Faeces samples collected from six adult bovines from different salmonella...... novobiocin, followed by combinations of culture media (three types) and selective media (two types). The sensitivity of each combination and sources of variation in detection were determined by a generalized linear mixed model using a split-plot design. Conclusions: Biological factors, such as faecal origin...... and S. Dublin strain influenced the sensitivity more than technical factors. Overall, the modified semisolid Rappaport Vassiliadis (MSRV)-culture medium had the most reliable detection capability, whereas detection with selenite cystine broth and Mueller Kauffman tetrathionate broth combinations varied...

  7. Serotyping, PCR, phage-typing and antibiotic sensitivity testing of Salmonella serovars isolated from urban drinking water supply systems of Nepal

    DEFF Research Database (Denmark)

    Bhatta, D.R.; Bangtrakulnonth, A.; Tishyadhigama, P.

    2007-01-01

    Aims: To study the occurrence and diversity of Salmonella serovars in urban water supply systems of Nepal. Methods and Results: Occurrence of Salmonella was detected in 42 out of 300 water samples by enrichment culture technique in selenite F broth followed by plating on Salmonella Shigella agar...... isolates of Salm. Enteritidis indicated the presence of one of the ESBL genes, blaSHV, whereas the genes blaTEM and blaCTX were absent. Conclusions: The microbiological quality of the urban water supply is poor and indicates possibility of fatal outbreaks of enteric fever and related infections in Nepal....... Significance and Impact of the Study: The present study will be useful in water borne disease control and prevention strategy formulation in Nepal and in the global context....

  8. Selenium and selenium species in feeds and muscle tissue of Atlantic salmon

    DEFF Research Database (Denmark)

    Sele, Veronika; Ørnsrud, Robin; Sloth, Jens Jørgen

    2018-01-01

    Selenium (Se) is an essential element for animals, including fish. Due to changes in feed composition for Atlantic salmon (Salmo salar), it may be necessary to supplement feeds with Se. In the present work, the transfer of Se and Se species from feed to muscle of Atlantic salmon fed Se supplemented...... diets was studied. Salmon were fed basal fish feed (0.35 mg Se/kg and 0.89 mg Se/kg feed), or feed supplemented either with selenised yeast or sodium selenite, at low (1–2 mg Se/kg feed) and high (15 mg Se/kg feed) levels, for 12 weeks. For the extraction of Se species from fish muscle, enzymatic...... cleavage with protease type XIV was applied. The extraction methods for Se species from fish feed were optimised, and two separate extraction procedures were applied, 1) enzymatic cleavage for organic Se supplemented feeds and 2) weak alkaline solvent for inorganic Se supplemented feeds, respectively...

  9. Mechanisms of Se(IV) Co-precipitation with Ferrihydrite at Acidic and Alkaline Conditions and Its Behavior during Aging

    DEFF Research Database (Denmark)

    Francisco, Paul Clarence M.; Sato, Tsutomu; Otake, Tsubasa

    2018-01-01

    in nanopore and defect structures. These results demonstrate a potential long-term immobilization pathway for Se(IV) even after phase transformation. This work presents one of the first direct insights on Se(IV) co-precipitation and its behavior in response to iron phase transformations.......Understanding the form of Se(IV) co-precipitated with ferrihydrite and its subsequent behavior during phase transformation is critical to predicting its long-term fate in a range of natural and engineered settings. In this work, Se(IV)-ferrihydrite co-precipitates formed at different pH were......, Se(IV) was removed dominantly as a ferric selenite-like phase intimately associated with ferrihydrite, while at pH 10, it was mostly present as a surface species on ferrihydrite. Similarly, the behavior of Se(IV) and the extent of its retention during phase transformation varied with pH. At pH 5, Se...

  10. Cs7Sm11[TeO3]12Cl16 and Rb7Nd11[TeO3]12Br16, the new tellurite halides of the tetragonal Rb6LiNd11[SeO3]12Cl16 structure type

    Science.gov (United States)

    Charkin, Dmitri O.; Black, Cameron; Downie, Lewis J.; Sklovsky, Dmitry E.; Berdonosov, Peter S.; Olenev, Andrei V.; Zhou, Wuzong; Lightfoot, Philip; Dolgikh, Valery A.

    2015-12-01

    Two new rare-earth - alkali - tellurium oxide halides were synthesized by a salt flux technique and characterized by single-crystal X-ray diffraction. The structures of the new compounds Cs7Sm11[TeO3]12Cl16 (I) and Rb7Nd11[TeO3]12Br16 (II) (both tetragonal, space group I4/mcm) correspond to the sequence of [MLn11(TeO3)12] and [M6X16] layers and bear very strong similarities to those of known selenite analogs. We discuss the trends in similarities and differences in compositions and structural details between the Se and Te compounds; more members of the family are predicted.

  11. Nano-Se Assimilation and Action in Poultry and Other Monogastric Animals: Is Gut Microbiota an Answer?

    Science.gov (United States)

    Surai, Peter F.; Kochish, Ivan I.; Velichko, Oksana A.

    2017-12-01

    Recently, a comprehensive review paper devoted to roles of nano-Se in livestock and fish nutrition has been published in the Nanoscale Research Letters. The authors described in great details an issue related to nano-Se production and its possible applications in animal industry and medicine. However, molecular mechanisms of nano-Se action were not described and the question of how nano-Se is converted into active selenoproteins is not resolved. It seems likely that the gut microbiota can convert nano-Se into selenite, H2Se or Se-phosphate with the following synthesis of selenoproteins. This possibility needs to be further studied in detail, and advantages and disadvantages of nano-Se as a source of Se in animal/poultry/fish nutrition await critical evaluations.

  12. Morphology and thermodynamic characteristics of selenium-containing nanostructures based on polymethacrylic acid

    Science.gov (United States)

    Valueva, S. V.; Borovikova, L. N.; Vylegzhanina, M. E.; Sukhanova, T. E.

    2010-09-01

    The morphology and thermodynamic characteristics of nanostructures formed as a result of the reduction of the selenium ion in a selenite-ascorbate redox system in water solutions of polymethacrylic acid were studied by molecular optics and atomic-force microscopy. The dependence of the morphology of the selenium-containing nanostructures on the mass selenium-to-polymer ratio (ν) in solution was determined. It was established that a large number of macromolecules (up to 4300) is adsorbed on the selenium nanoparticles, leading to the formation of nanostructures with super-high molecular mass and an almost spherical form. It was shown that the density of the nanostructures, as calculated on the basis of the experimental data on the size and molecular mass of the nanocomposite, depends substantially on the selenium concentrations in the solution. The thermodynamic state of the solutions of nanostructures is described.

  13. Immunomagnetic separation and conventional culture procedure for detection of naturally occurring Salmonella in raw pork sausages and chicken meat.

    Science.gov (United States)

    Ripabelli, G; Sammarco, M L; Ruberto, A; Iannitto, G; Grasso, G M

    1997-06-01

    The aim of the study was to compare immunomagnetic separation (IMS) and conventional selective enrichment procedures using selenite cystine broth (SC) and Rappaport-Vassiliadis broth (RV) in 137 naturally contaminated food samples (69 raw pork sausages and 68 chicken meat). The utilization of SC or IMS appeared to be the most appropriate enrichment procedure: 15 out of 18 Salmonella-positive samples (83.3%) were detected by SC and 12 (66.7%) by IMS; RV yielded only seven positive isolations (38.9%). However, RV yielded the highest count of Salmonella colonies per plate and the lowest interference by competing organisms. IMS could become a reliable alternative to standard enrichment procedures and a combined IMS and selective enrichment broth could increase the chance of Salmonella recovery.

  14. Selenium inhibits UV-light-induced skin carcinogenesis in hairless mice

    International Nuclear Information System (INIS)

    Overvad, Kim; Thorling, E.B.; Bjerring, Peter; Ebbesen, Peter

    1985-01-01

    Female hairless inbred hr/hr mice were exposed to UV-B irradiation from Philips TL 40W/13 fluorescent tubes. Fractionated irradiation, given as single daily doses 5 days a week, was gradually increased from 0.04 to 0.4 J/cm 2 over 2 weeks. Irradiation at 0.4 J/cm 2 was continued for 20 weeks. Selenium supplementation given as sodium selenite in the drinking water at 2, 4 and 8 mg/l began 3 weeks before UV-irradiation and continued thereafter. Development of skin tumors was followed by weekly examinations. Statistical analyses revealed significant dose-dependent selenium-mediated protection against UV-light-induced skin cancer. Leukemia developed in 5 of 150 UV-irradiated mice as opposed to none in a group of 60 unirradiated mice. (author)

  15. Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierra from California

    Science.gov (United States)

    Purvis, O.W.; Bennett, J.P.; Spratt, J.

    2011-01-01

    An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour.

  16. Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierrae from California

    Science.gov (United States)

    Purvis, O.W.; Bennett, J.P.; Spratt, J.

    2011-01-01

    An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour. Copyright ?? 2011 British Lichen Society.

  17. [Effect of selenium on serum TGAb, TMAb, FT3, FT4 and TSH of rats with excessive intake of iodine].

    Science.gov (United States)

    Chi, Haiyan; Zhou, Yuping; Li, Li

    2012-07-01

    To investigate the effect of selenium on the TGAb, TMAb, FT3, FT4 and TSH level of rats with excessive intake of iodine. Wistar rats were divided into three groups by random:normal control, high iodine group and high iodine plus selenium group. Rats in the high iodine plus selenium group were lavaged with sodium selenite for 10 weeks. The levels of serum TGAb, TMAb, FT3, FT4 and TSH were tested at different time of the experiment. There were no significant change on levels of FT3, FT4 and TSH (P > 0.05). The levels of TGAb and TMAb in the high iodine group were increased slowly (P iodine plus selenium group. Excessive intake of iodine might induce goiter, and selenium might have antagonistic effect on it.

  18. New challenge in the speciation of selenium. Measurement and production on nano selenium

    Energy Technology Data Exchange (ETDEWEB)

    Prokisch, J; Sztrik, A; Babka, B; Zommara, M; Daroczi, L [Debrecen University, Centre for Agricultural Sciences and Engineering, Debrecen (Hungary). Institute of Bio- and Environmental Energetics

    2009-07-01

    Complete text of publication follows. We have found that several species of probiotic bacteria also used in food industry for making yogurts is capable of producing spherical elemental selenium nanospheres having an average diameter in the range of 50-500 nm when 1-1000 mg/L selenium was added to the medium in the form of selenite ions. Elemental selenium produced thereby has a high degree of purity, is spherical, and its size and crystalline form depends on the bacterium species applied. We have found that some species of the probiotic yogurt bacteria (e.g. Bifidobacterium bifidum or Bifidobacterium longum) are capable of producing the grey crystalline form of elemental selenium which is so far unprecedented in the art for any bacteria capable of producing elemental selenium nanoparticles. Our finding, therefore, enables the first time the development of economical industrial bacterial fermentation based processes for the production of a high quality elemental selenium material comprising uniformly sized grey or red nanospheres having an average diameter in the range of 50-500 nm. The size and the crystalline form of the produced nanosized (50-500 nm) spherical particles is defined by the selected microorganism. This genetic pre-determination result in reproducible production of a material having individual characteristics which can be used in numerous fields of industry and research. The produced nano selenium could be a good raw material for a production of certified reference materials. The measurement of the produced elemental nanoselenium is a new challenge for the speciation analysis. A sample preparation and measurement method was developed and investigated for the analysis of different selenium forms by HPLC-AFS system. The atomic fluorescence (AFS) was a reliable and simple detection method for the elemental nano selenium. The elemental selenium can produce hydride in the system or can be converted to selenite with HCl/H{sub 2}O{sub 2} digestion.

  19. Performances of Water Management, Foliage Dressing, and Variation Screening in Controlling the Accumulation of As and Cd and Maintaining the Concentrations of Essential Elements in the Grains of Rice Plant

    Directory of Open Access Journals (Sweden)

    Lei Lei

    2018-03-01

    Full Text Available This study was conducted to understand why and how the technologies of variety screening, foliar dressing, and water management can reduce As/Cd accumulation and affect the concentrations of essential elements in different rice plants. In Trial I (variety screening, the grain As and Cd concentrations in Zhongguyou1361 variety (P3 were both lower than their individual National Food Hygiene Standard of China (NFHSC under insufficient field drying condition. The P3 also had a relatively high yield and high essential element contents among 15 selected rice varieties. In Trial II (foliar dressing, selenite foliar spray showed a better ability than silicate to reduce the grain As content in Guangliangyou1128 variety (P1. However, spraying Se and Si onto the Fengliangyou1 variety (P2 both showed a limited effect on the grain As and Cd contents, suggesting a different effect of Se on grain As content in various rice varieties. The insufficient field drying in Trial II resulted in the grain Cd content being lower but the grain As content being higher than their individual NFHSC in both P1 and Fengliangyou1 (P2 varieties. Se or Si did not affect the yields and the grain contents of most essential elements in P1 and P2. In Trial III (water management, increasing field drying time enhanced the Cd content but reduced the As content in the grains of P1, P2, and P3, and maintained their yields. Similar to the results of Trial II, the changes in soil pH, organic matter concentration and elemental available concentrations could hardly be used to explain why the contents of corresponding essential elements kept approximately constant in the grains of different rice varieties. Foliar dressing with selenite combined with water regulation can simultaneously reduce the As and Cd contents, and maintain the yields and the essential element contents in the grains of rice plants cultivated in As− and Cd− contaminated soil.

  20. Explorations of new phases in the Ga(III)/In(III)-Mo(VI)-Se(IV)/Te(IV)-O systems.

    Science.gov (United States)

    Kong, Fang; Hu, Chun-Li; Hu, Ting; Zhou, Yong; Mao, Jiang-Gao

    2009-07-07

    Systematic explorations of new phases in the Ga(III)/In(III)-Mo(VI)-Se(IV)/Te(IV)-O systems by hydrothermal syntheses or solid-state reactions at high-temperature led to four new quaternary compounds, namely, Ga(2)MoQ(2)O(10) (Q = Se, Te), In(2)Mo(2)Se(2)O(13)(H(2)O) and In(2)MoTe(2)O(10). Ga(2)MoQ(2)O(10) (Q = Se, Te) are isostructural and their structures feature a 3D network of gallium selenite/tellurite with 12-member ring tunnels along b-axis, the distorted MoO(6) octahedra are attached on the wall of the above tunnels. The structure of In(2)Mo(2)Se(2)O(13)(H(2)O) features a new pillared-layered architecture composed of 2D indium(III) selenite layers that are interconnected by Mo(2)O(10) dimers, forming 8-membered ring tunnels along the b-axis. The structure of In(2)MoTe(2)O(10) features a 2D indium oxide layer formed by corner- and edge-sharing InO(6) and InO(7) polyhedra with MoO(4) tetrahedra and TeO(n) (n = 4, 5) polyhedra hanging on both sides of the layer, there are weak interlayer Te-O bonds of 2.512 A. Results of optical diffuse reflectance spectrum measurements indicate that all four compounds are insulators, which are in agreement with results of band structure calculations based on DFT methods.

  1. Selenoprotein P Inhibits Radiation-Induced Late Reactive Oxygen Species Accumulation and Normal Cell Injury

    Energy Technology Data Exchange (ETDEWEB)

    Eckers, Jaimee C.; Kalen, Amanda L.; Xiao, Wusheng; Sarsour, Ehab H.; Goswami, Prabhat C., E-mail: prabhat-goswami@uiowa.edu

    2013-11-01

    Purpose: Radiation is a common mode of cancer therapy whose outcome is often limited because of normal tissue toxicity. We have shown previously that the accumulation of radiation-induced late reactive oxygen species (ROS) precedes cell death, suggesting that metabolic oxidative stress could regulate cellular radiation response. The purpose of this study was to investigate whether selenoprotein P (SEPP1), a major supplier of selenium to tissues and an antioxidant, regulates late ROS accumulation and toxicity in irradiated normal human fibroblasts (NHFs). Methods and Materials: Flow cytometry analysis of cell viability, cell cycle phase distribution, and dihydroethidium oxidation, along with clonogenic assays, were used to measure oxidative stress and toxicity. Human antioxidant mechanisms array and quantitative real-time polymerase chain reaction assays were used to measure gene expression during late ROS accumulation in irradiated NHFs. Sodium selenite addition and SEPP1 overexpression were used to determine the causality of SEPP1 regulating late ROS accumulation and toxicity in irradiated NHFs. Results: Irradiated NHFs showed late ROS accumulation (4.5-fold increase from control; P<.05) that occurs after activation of the cell cycle checkpoint pathways and precedes cell death. The mRNA levels of CuZn- and Mn-superoxide dismutase, catalase, peroxiredoxin 3, and thioredoxin reductase 1 increased approximately 2- to 3-fold, whereas mRNA levels of cold shock domain containing E1 and SEPP1 increased more than 6-fold (P<.05). The addition of sodium selenite before the radiation treatment suppressed toxicity (45%; P<.05). SEPP1 overexpression suppressed radiation-induced late ROS accumulation (35%; P<.05) and protected NHFs from radiation-induced toxicity (58%; P<.05). Conclusion: SEPP1 mitigates radiation-induced late ROS accumulation and normal cell injury.

  2. Reduction of chalcogen oxyanions and generation of nanoprecipitates by the photosynthetic bacterium Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Borghese, Roberto, E-mail: roberto.borghese@unibo.it [Department of Pharmacy and Biotechnology, University of Bologna (Italy); Baccolini, Chiara; Francia, Francesco [Department of Pharmacy and Biotechnology, University of Bologna (Italy); Sabatino, Piera [Department of Chemistry G. Ciamician, University of Bologna (Italy); Turner, Raymond J. [Department of Biological Sciences, University of Calgary, Calgary, Alberta (Canada); Zannoni, Davide, E-mail: davide.zannoni@unibo.it [Department of Pharmacy and Biotechnology, University of Bologna (Italy)

    2014-03-01

    Graphical abstract: - Highlights: • R. capsulatus cells produce extracellular chalcogens nanoprecipitates when lawsone is present. • Lawsone acts as a redox mediator from reducing equivalents to tellurite and selenite. • Nanoprecipitates production depends on carbon source and requires metabolically active cells. • Te{sup 0} and Se{sup 0} nanoprecipitates are identified by X-ray diffraction (XRD) spectroscopy. - Abstract: The facultative photosynthetic bacterium Rhodobacter capsulatus is characterized in its interaction with the toxic oxyanions tellurite (Te{sup IV}) and selenite (Se{sup IV}) by a highly variable level of resistance that is dependent on the growth mode making this bacterium an ideal organism for the study of the microbial interaction with chalcogens. As we have reported in the past, while the oxyanion tellurite is taken up by R. capsulatus cells via acetate permease and it is reduced to Te{sup 0} in the cytoplasm in the form of splinter-like black intracellular deposits no clear mechanism was described for Se{sup 0} precipitation. Here, we present the first report on the biotransformation of tellurium and selenium oxyanions into extracellular Te{sup 0} and Se{sup 0}nanoprecipitates (NPs) by anaerobic photosynthetically growing cultures of R. capsulatus as a function of exogenously added redox-mediator lawsone, i.e. 2-hydroxy-1,4-naphthoquinone. The NPs formation was dependent on the carbon source used for the bacterial growth and the rate of chalcogen reduction was constant at different lawsone concentrations, in line with a catalytic role for the redox mediator. X-ray diffraction (XRD) analysis demonstrated the Te{sup 0} and Se{sup 0} nature of the nanoparticles.

  3. Rationale and Design for the Peripartum Cardiomyopathy in Nigeria (PEACE Registry

    Directory of Open Access Journals (Sweden)

    Kamilu M Karaye

    2017-01-01

    Full Text Available Background Nigeria probably has the highest burden of Peripartum Cardiomyopathy (PPCM in the world. The primary objective of this study is to describe the burden, ventricular remodelling and survival of PPCM in Nigeria. In the sub-studies, we aim to describe the relationship between selenium deficiency, oxidative stress and PPCM, the impact of sodium selenite supplementation on left ventricular reverse remodelling, change in New York Heart Association functional class and survival in PPCM, and the prevalence of selenium deficiency and its relationship with cardiac function in apparently healthy pregnant women. Methods The main registry and the first sub-study are prospective longitudinal studies, while the second sub-study is an open-label randomised trial. 36 study centres across Nigeria have been registered and 14 of them are already recruiting subjects. Patients will be recruited from June to December 2017 and followed up till December 2018. Serum selenium and glutathione peroxidase will be assayed at recruitment for consecutive PPCM patients with LV ejection fraction (LVEF <45% at 6 months postpartum. 200 subjects with selenium deficiency will be randomised into treatment (Selenium Selenite 200μg tablets daily for 3 months and no-treatment arms. In the second sub-study, 120 apparently healthy pregnant women (Controls will be recruited at 28-38 weeks of gestation and reviewed at 6-8 weeks postpartum, and their serum selenium and GPO levels will be measured at recruitment. Conclusions This will be the largest systematic evaluation of PPCM in Nigeria, and it is hoped that the information will assist in understanding the disease better and developing locally applicable interventions for the disease. ClinicalTrials.gov Identifier: NCT03081949

  4. Preparation and antioxidant properties of selenium nanoparticles-loaded chitosan microspheres

    Directory of Open Access Journals (Sweden)

    Bai K

    2017-06-01

    Full Text Available Kaikai Bai,1,2 Bihong Hong,1,2 Jianlin He,1,2 Zhuan Hong,1,2 Ran Tan1,2 1Third Institute of Oceanography, 2Engineering Research Center of Marine Biological Resource, Comprehensive Utilization, State Oceanic Administration, Xiamen, People’s Republic of China Abstract: Selenium nanoparticles (SeNPs, as a special form of selenium (Se supplement, have attracted worldwide attention due to their favorable properties and unique bioactivities. Herein, an eco-friendly and economic way to prepare stable SeNPs is introduced. SeNPs were synthesized in aqueous chitosan (CTS and then embedded into CTS microspheres by spray-drying, forming selenium nanoparticles-loaded chitosan microspheres (SeNPs-M. The physicochemical properties including morphology, elemental state, size distribution and surface potential were investigated. Institute of Cancer Research mice were used as model animal to evaluate the bioactivities of SeNPs-M. Trigonal-phase SeNPs of ~35 nm were synthesized, and SeNPs-M physically embedding those SeNPs were successfully prepared. Amazingly, acute toxicity test indicated that SeNPs-M were much safer than selenite in terms of Se dose, with a LD50 of around 18-fold of that of selenite. In addition, SeNPs-M possessed powerful antioxidant activities, as evidenced by a dramatic increase of both Se retention and the levels of glutathione peroxidase, superoxide dismutase and catalase. The design of SeNPs-M can offer a new way for further development of SeNPs with a higher efficacy and better biosafety. Thus, SeNPs-M may be a potential candidate for further evaluation as an Se supplement with antioxidant properties and be used against Se deficiency in animals and human beings. Keywords: selenium, nano, microsphere, chitosan, antioxidant

  5. Epigenetic Regulation of Inflammatory Gene Expression in Macrophages by Selenium

    Science.gov (United States)

    Narayan, Vivek; Ravindra, Kodihalli C.; Liao, Chang; Kaushal, Naveen; Carlson, Bradley A.; Prabhu, K. Sandeep

    2014-01-01

    Acetylation of histone and non-histone proteins by histone acetyltransferases plays a pivotal role in the expression of pro-inflammatory genes. Given the importance of dietary selenium in mitigating inflammation, we hypothesized that selenium supplementation may regulate inflammatory gene expression at the epigenetic level. The effect of selenium towards histone acetylation was examined in both in vitro and in vivo models of inflammation by chromatin immunoprecipitation (ChIP) assays and immunoblotting. Our results indicated that selenium supplementation, as selenite, decreased acetylation of histone H4 at K12 and K16 in COX-2 and TNF promoters, and of the p65 subunit of the redox sensitive transcription factor NFκB in primary and immortalized macrophages. On the other hand, selenomethionine had a much weaker effect. Selenite treatment of HIV-1 infected human monocytes also significantly decreased the acetylation of H4 at K12 and K16 on the HIV-1 promoter, supporting the downregulation of proviral expression by selenium. A similar decrease in histone acetylation was also seen in the colonic extracts of mice treated with dextran sodium sulfate that correlated well with the levels of selenium in the diet. Bone marrow-derived macrophages from Trspfl/flCreLysM mice that lack expression of selenoproteins in macrophages confirmed the important role of selenoproteins in the inhibition of histone H4 acetylation. Our studies suggest that the ability of selenoproteins to skew the metabolism of arachidonic acid to contribute, in part, to their ability to inhibit histone acetylation. In summary, our studies suggest a new role for selenoproteins in the epigenetic modulation of pro-inflammatory genes. PMID:25458528

  6. An Australian experience with a constructed wetland to treat ash dam water

    Energy Technology Data Exchange (ETDEWEB)

    M.W. Jensen; K.W. Riley [Delta Electricity (Australia)

    2003-07-01

    In this paper, the effectiveness of a wetland system to treat water from a power station ash dam is discussed. The wetlands were constructed during 1996 and 1997. The length of the canals within the system is 1700 metres. There was a total planting of 35,000 tube stock of nine different species. In the summer of 1998, Typha orientalis colonised the system and is now the dominant species of emergent plant present. Water is introduced to the wetland from the return channel of the power station. The ash dam water is acidic (pH 4.5 5.5) and contains elevated levels of some trace elements including selenium, boron and fluorine. Of these three trace elements, selenium is regarded as the element of particular environmental concern. Since June 2000, there has been periodic sampling and analysis of both the inlet and outlet waters. The analytes include conductivity, pH, total organic carbon, Al, As, B, Ba, Ca, Cl, K, F, Fe, Mg, Mn, Na, selenite, total selenium, Si, Sr, sulfate and Zn. As well, plant material (stems and roots of the Typha) and sediments have been analysed for selenium. The results indicate boron and fluorine are not removed from the ash dam water by the processes occurring in the wetland. Selenium is partly removed. It appears that selenite is removed in preference to selenate. The development and operation of this experimental wetland is discussed in the context of a sustainable and ecologically sound system of minimising detrimental effects of the discharge of ash water. 26 refs., 4 tabs.

  7. Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria

    Directory of Open Access Journals (Sweden)

    Nelson L. Brock

    2013-05-01

    Full Text Available Members of the marine Roseobacter clade can degrade dimethylsulfoniopropionate (DMSP via competing pathways releasing either methanethiol (MeSH or dimethyl sulfide (DMS. Deuterium-labeled [2H6]DMSP and the synthetic DMSP analogue dimethyltelluriopropionate (DMTeP were used in feeding experiments with the Roseobacter clade members Phaeobacter gallaeciensis DSM 17395 and Ruegeria pomeroyi DSS-3, and their volatile metabolites were analyzed by closed-loop stripping and solid-phase microextraction coupled to GC–MS. Feeding experiments with [2H6]DMSP resulted in the incorporation of a deuterium label into MeSH and DMS. Knockout of relevant genes from the known DMSP demethylation pathway to MeSH showed in both species a residual production of [2H3]MeSH, suggesting that a second demethylation pathway is active. The role of DMSP degradation pathways for MeSH and DMS formation was further investigated by using the synthetic analogue DMTeP as a probe in feeding experiments with the wild-type strain and knockout mutants. Feeding of DMTeP to the R. pomeroyi knockout mutant resulted in a diminished, but not abolished production of demethylation pathway products. These results further corroborated the proposed second demethylation activity in R. pomeroyi. Isotopically labeled [2H3]methionine and 34SO42−, synthesized from elemental 34S8, were tested to identify alternative sulfur sources besides DMSP for the MeSH production in P. gallaeciensis. Methionine proved to be a viable sulfur source for the MeSH volatiles, whereas incorporation of labeling from sulfate was not observed. Moreover, the utilization of selenite and selenate salts by marine alphaproteobacteria for the production of methylated selenium volatiles was explored and resulted in the production of numerous methaneselenol-derived volatiles via reduction and methylation. The pathway of selenate/selenite reduction, however, proved to be strictly separated from sulfate reduction.

  8. Influence of microbial activity on the migration behaviour of redox-sensitive radionuclides (technetium and selenium) in loose rock

    International Nuclear Information System (INIS)

    Stroetmann, I.

    1995-01-01

    In closed cycle column tests under sterile conditions there was no or hardly any sorption of the two radionuclides. In closed cycle column tests with unsterile soils, however, the two radionuclides were extremely immobilised (80 % of the output activity of Tc-95m and 40 % of the output activity of Se-75). By inoculation of the sterile columns with mixed soil cultures an increase in sorption of 40 % of the output activity was achieved which is attributed to the microbial activity. The adsorbed radionuclides in unsterile columns could be remobilized by adding a bactericide. In columns with saline water the sorption of radionuclides was slightly lower. Soils with a 5 % organic carbon content showed extremely increased sorption of the two radionuclides. In comparison with closed cycle columns shake tests were carried out. During turbulent intermixing of water and solid, no sorption of technetium was observed in unsterile tests either, while Se-75 added as selenite was strongly adsorbed to the solid. When adding acetate as a C-source, the microbially conditioned reduction of the redox potential to -100 mV and, subsequently, a strong increase of sorption could be observed. A reduction of the pH value in the soils to pH 4, and simultaneous adding of acetate significally reduced the microbial activity and the sorption of technetium, while selenite sorption remained strong as before. Sorption tests with bacteria-pure and mixed cultures showed no sorption of the pertechnetate anion in the oxidation stage (VII). However, when reducing the pertechnetate by means of SnCl2, up to 40 % of the feed activity of killed and living biomass was immobilized. Between 20-30 % of the adsorbed technetium quantity was outside at the membrane, and 40% inside the cells. After a three-day incubation period in a technetium-containing solution, a factor of 15,5 was achieved as the maximum intracellular concentration factor for the isolate 143 (Xanthomas sp.). (orig./MG) [de

  9. A Bacterial Biosensor for Oxidative Stress Using the Constitutively Expressed Redox-Sensitive Protein roGFP2

    Directory of Open Access Journals (Sweden)

    Carlos R. Arias-Barreiro

    2010-06-01

    Full Text Available A highly specific, high throughput-amenable bacterial biosensor for chemically induced cellular oxidation was developed using constitutively expressed redox-sensitive green fluorescent protein roGFP2 in E. coli (E. coli-roGFP2. Disulfide formation between two key cysteine residues of roGFP2 was assessed using a double-wavelength ratiometric approach. This study demonstrates that only a few minutes were required to detect oxidation using E. coli-roGFP2, in contrast to conventional bacterial oxidative stress sensors. Cellular oxidation induced by hydrogen peroxide, menadione, sodium selenite, zinc pyrithione, triphenyltin and naphthalene became detectable after 10 seconds and reached the maxima between 80 to 210 seconds, contrary to Cd2+, Cu2+, Pb2+, Zn2+ and sodium arsenite, which induced the oxidation maximum immediately. The lowest observable effect concentrations (in ppm were determined as 1.0 x 10−7 (arsenite, 1.0 x 10−4 (naphthalene, 1.0 x 10−4 (Cu2+, 3.8 x 10−4 (H2O2, 1.0 x 10−3 (Cd2+, 1.0 x 10−3 (Zn2+, 1.0 x 10−2 (menadione, 1.0 (triphenyltin, 1.56 (zinc pyrithione, 3.1 (selenite and 6.3 (Pb2+, respectively. Heavy metal-induced oxidation showed unclear response patterns, whereas concentration-dependent sigmoid curves were observed for other compounds. In vivo GSH content and in vitro roGFP2 oxidation assays together with E. coli-roGFP2 results suggest that roGFP2 is sensitive to redox potential change and thiol modification induced by environmental stressors. Based on redox-sensitive technology, E. coli-roGFP2 provides a fast comprehensive detection system for toxicants that induce cellular oxidation.

  10. Dehydration-driven evolution of topological complexity in ethylamonium uranyl selenates

    Energy Technology Data Exchange (ETDEWEB)

    Gurzhiy, Vladislav V., E-mail: vladgeo17@mail.ru [Department of Crystallography, St. Petersburg State University, University Emb. 7/9, 199034 St. Petersburg (Russian Federation); Krivovichev, Sergey V. [Department of Crystallography, St. Petersburg State University, University Emb. 7/9, 199034 St. Petersburg (Russian Federation); Tananaev, Ivan G. [Far Eastern Federal University, Suhanova st. 8, 690950 Vladivostok (Russian Federation)

    2017-03-15

    Single crystals of four novel uranyl selenate and selenite-selenate oxysalts with protonated ethylamine molecules, (C{sub 2}H{sub 8}N){sub 2}[(UO{sub 2})(SeO{sub 4}){sub 2}(H{sub 2}O)](H{sub 2}O) (I), (C{sub 2}H{sub 8}N){sub 3}[(UO{sub 2})(SeO{sub 4}){sub 2}(HSeO{sub 4})] (II), (C{sub 2}H{sub 8}N)[(UO{sub 2})(SeO{sub 4})(HSeO{sub 3})] (III), and (C{sub 2}H{sub 8}N)(H{sub 3}O)[(UO{sub 2})(SeO{sub 4}){sub 2}(H{sub 2}O)] (IV) have been prepared by isothermal evaporation from aqueous solutions. Uranyl-containing 1D and 2D units have been investigated using topological approach and information-based complexity measurements that demonstrate the evolution of structural units and the increase of topological complexity with the decrease of H{sub 2}O content. - Graphical abstract: Single crystals of four novel uranyl selenate and selenite-selenate oxysalts with protonated ethylamine molecules have been prepared by isothermal evaporation from aqueous solutions. Structural analysis and information-based topological complexity calculations points to the possible sequence of crystalline phases formation, showing both topological and structural branches of evolution. - Highlights: • Single crystals of four novel uranyl oxysalts were prepared by evaporation method. • The graph theory was used for investigation of topologies of structural units. • Dehydration processes drives the evolution of topological complexity of 1D and 2D structural units.

  11. Thermal, spectroscopic and magnetic properties of the Co xNi1-x(SeO3).2H2O (x = 0, 0.4, 1) phases

    International Nuclear Information System (INIS)

    Larranaga, A.; Mesa, J.L.; Pizarro, J.L.; Pena, A.; Chapman, J.P.; Arriortua, M.I.; Rojo, T.

    2005-01-01

    The Co x Ni 1-x (SeO 3 ).2H 2 O (x = 0, 0.4, 1) family of compounds has been hydrothermally synthesized under autogeneous pressure and characterized by elemental analysis, infrared and UV-vis spectroscopies and thermogravimetric and thermodiffractometric techniques. The crystal structure of Co 0.4 Ni 0.6 (SeO 3 ).2H 2 O has been solved from single-crystal X-ray diffraction data. This phase is isostructural with the M(SeO 3 ).2H 2 O (M = Co and Ni) minerals and crystallizes in the P2 1 /n space group, with a 6.4681(7), b = 8.7816(7), c = 7.5668(7) A, β = 98.927(9) deg and Z = 4. The crystal structure of this series of compounds consists of a three-dimensional framework formed by (SeO 3 ) 2- selenite oxoanions and edge-sharing M 2 O 10 dimeric octahedra in which the metallic cations are coordinated by the oxygens belonging to both the selenite groups and water molecules. The diffuse reflectance spectra show the essential characteristics of Co(II) and Ni(II) cations in slightly distorted octahedral environments. The calculated values of the Dq and Racah (B and C) parameters are those habitually found for the 3d 7 and 3d 8 cations in octahedral coordination. The magnetic measurements indicate the existence of antiferromagnetic interactions in all the compounds. The magnetic exchange pathways involve the metal orbitals from edge-sharing dimeric octahedra and the (SeO 3 ) 2- anions which are linked to the M 2 O 10 polyhedra in three dimensions

  12. Antitumor activity and systemic effects of PVM/MA-shelled selol nanocapsules in lung adenocarcinoma-bearing mice

    International Nuclear Information System (INIS)

    De Souza, Ludmilla Regina; Muehlmann, Luis Alexandre; Matos, Lívia Carneiro; Lacava, Zulmira Guerreiro Marques; Báo, Sônia Nair; Azevedo, Ricardo Bentes; Simón-Vázquez, Rosana; González-Fernández, África; De-Paula, Alfredo Maurício Batista; Mosiniewicz-Szablewska, Ewa; Suchocki, Piotr; Morais, Paulo César

    2015-01-01

    Selol is a semi-synthetic compound containing selenite that is effective against cancerous cells and safer for clinical applications in comparison with other inorganic forms of selenite. Recently, we have developed a formulation of poly(methyl vinyl ether-co-maleic anhydride)-shelled selol nanocapsules (SPN), which reduced the proliferative activity of lung adenocarcinoma cells and presented little deleterious effects on normal cells in in vitro studies. In this study, we report on the antitumor activity and systemic effects induced by this formulation in chemically induced lung adenocarcinoma-bearing mice. The in vivo antitumor activity of the SPN was verified by macroscopic quantification, immunohistochemistry and morphological analyses. Toxicity analyses were performed by evaluations of the kidney, liver, and spleen; analyses of hemogram and plasma levels of alanine aminotransferase, aspartate transaminase, urea, and creatinine; and DNA fragmentation and cell cycle activity of the bone marrow cells. Furthermore, we investigated the potential of the SPN formulation to cause hemolysis, activate the complement system, provoke an inflammatory response and change the conformation of the plasma proteins. Our results showed that the SPN reduced the area of the surface tumor nodules but not the total number of tumor nodules. The biochemical and hematological findings were suggestive of the low systemic toxicity of the SPN formulation. The surface properties of the selol nanocapsules point to characteristics that are consistent with the treatment of the tumors in vivo: low hemolytic activity, weak inflammatory reaction with no activation of the complement system, and mild or absent conformational changes of the plasma proteins. In conclusion, this report suggests that the SPN formulation investigated herein exhibits anti-tumoral effects against lung adenocarcinoma in vivo and is associated with low systemic toxicity and high biocompatibility. (paper)

  13. Synthesis, Characterization, and Catalytic Performance of Sb2Se3 Nanorods

    Directory of Open Access Journals (Sweden)

    Ning Hu

    2017-01-01

    Full Text Available Antimony selenide has many potential applications in thermoelectric, photovoltaic, and phase-change memory devices. A novel method is described for the rapid and scalable preparation of antimony selenide (Sb2Se3 nanorods in the presence of hydrazine hydrate and/or permanganate at 40°C. Crystalline nanorods are obtained by the addition of hydrazine hydrate in a reaction mixture of antimony acetate and/or chloride and sodium selenite in neutral and basic media, while amorphous nanoparticles are formed by the addition of KMnO4 in a reaction mixture of antimony acetate/chloride and sodium selenite. The powder X-ray diffraction pattern confirms orthorhombic phase crystalline Sb2Se3 for the first and second reactions with lattice parameters a=1.120 nm, b=1.128 nm, and c=0.383 nm and amorphous Sb2Se3 for the third reaction. Scanning electron microscopy (SEM, transmission electron microscopy (TEM, and high-resolution TEM (HRTEM images show the diameter of nanorods for the first and second reactions to be in the order of 100 nm to 150 nm and about 20 nm particles for the third reaction. EDX and XPS suggest that the nanorods are pure Sb2Se3. The UV-vis analysis indicates a band gap of 4.14 and 4.97 eV for the crystalline and amorphous Sb2Se3, respectively, corresponding to a blue shift. The photocatalytic study shows that the decolorization of Rhodamine in solution by nanoparticles is slightly greater than nanorods.

  14. The Claim of Anti-Cataract Potential of Heliotropium indicum: A Myth or Reality?

    Science.gov (United States)

    Kyei, Samuel; Koffuor, George Asumeng; Ramkissoon, Paul; Afari, Clement; Asiamah, Emmanuel Akomanin

    2015-12-01

    Heliotropium indicum has several uses in traditional medicine attributable to its numerous bioactive compounds. It is used as a traditional remedy for cataracts in Ghana without any scientific verification. This study aimed at verifying the anti-cataract properties of an aqueous whole plant extract of H. indicum. The effect (cataract score) of 30, 100, and 300 mg kg(-1) extract (bid for 21 days, per os) on the development of 30 µmol kg(-1) sodium selenite-induced cataract in 10-day-old rat pups was investigated. Soluble lens proteins alpha A and alpha B crystallins, total lens protein, total lens glutathione, and aquaporin 0 in enucleated lens homogenates were determined spectrophotometrically using commercially available kits. Histopathological studies on the lenses were also performed. The 2,2-diphenyl-1-picrylhydrazyl scavenging effect and linoleic acid autoxidation (antioxidant properties) of the extract (0.1-3.0 mg ml(-1)), compared to n-propyl gallate, were ascertained using standard procedures. Cataract scores showed that the extract, at all dose levels, significantly alleviated selenite-induced cataracts (P ≤ 0.001). Markers of lens transparency (aquaporin 0, alpha A and B crystallins), as well as total lens proteins and lens glutathione levels, were significantly preserved (P ≤ 0.01-0.001). The extract exhibited activity relevant for scavenging free radicals and inhibition of lipid peroxidation. Epithelial and lens fiber integrity in the histopathological assessment were maintained with HIE treatment. The aqueous whole plant extract of H. indicum significantly inhibited the development of cataracts in rats via multiple mechanisms.

  15. High-calcium coal combustion by-products: Engineering properties, ettringite formation, and potential application in solidification and stabilization of selenium and boron

    Energy Technology Data Exchange (ETDEWEB)

    Solem-Tishmack, J.K.; McCarthy, G.J. [North Dakota State Univ., Fargo, ND (United States). Dept. of Chemistry; Docktor, B.; Eylands, K.E.; Thompson, J.S.; Hassett, D.J. [Univ. of North Dakota, Grand Forks, ND (United States). Energy and Environmental Research Center

    1995-04-01

    Four high-calcium coal combustion by-products (two pulverized coal fly ashes (PCFA), a flue gas desulfurization (FGD) residue, and an atmospheric fluidized bed combustion (AFBC) fly ash), were tested for engineering properties and ability to immobilize boron and selenium. These data are needed to explore high-volume utilization in engineered structure or in solidification/stabilization (S/S) technology. Strengths of cured pastes (91 days), varied from as much as 27 MPa (3,900 psi) for one of the PCFA specimens to 4.6 MPa (670 psi) for the FGD specimen. All of the coal by-product pastes developed more than the 0.34 MPa (50 psi) required for S/S applications. Ettringite formation is important to engineering properties and S/S mechanisms. XRD on plain specimens cured for 91 days indicated that the two PCFA pastes formed 5--6% ettringite, the FGD paste formed 22%, and the AFBC paste formed 32%. The hydrating PCFA pastes showed little expansion, the FGD paste contracted slightly, and the AFBC paste expanded by 2.9% over 91 days. Se and B were spiked into the mixing water as sodium selenite, selenate and borate, and for most pastes this had little effect on strength, workability, and expansion. Leaching of ground specimens (cured for 91 days) showed a generally positive correlation between the amount of ettringite formed and resistance to Se and B leaching. Se spiked as selenate was more readily leached than Se spiked as selenite. B showed a high level of fixation.

  16. Selenium Dynamics in the Blood of Beef Cows and Calves Fed Diets Supplemented with Organic and Inorganic Selenium Sources and the Effect on their Reproduction

    Directory of Open Access Journals (Sweden)

    P. Slavík

    2008-01-01

    Full Text Available The objective of this study was to compare the effects of feed supplementation with sodium selenite or selenized yeast on serum Se levels and reproduction indicators in cattle. In three beef herds young heifers, cows in late pregnancy, and their calves were randomly grouped by 6. In Herd 1, the mean Se serum levels were 51.01 μg l-1 in heifers, 32.12 μg l-1 in cows in late pregnancy, and 29.07 μg l-1 in their calves. In Herd 2, 27.42 μg l-1 (heifers, Z22.9 μg l-1 (late pregnancy, and 23.46 μg l-1 (calves. In Herd 3, 27.07 μg l-1 (heifers, 22 μg l-1 (late pregnant cows, and 31.05 μg l-1 (calves. Over a 6-month period, the animals in Herd 1 were given selenium yeast supplement; in Herd 2 sodium selenite, whereas Herd 3 served as a negative control. Afterwards, a second blood sample was taken. The mean Se serum levels were as follows: Herd 1 (selenium yeast: 90.73 μg l-1 in late pregnant cows ( p -1 in calves (p -1 (late pregnant cows p -1 (calves p -1 (late pregnant cows, 32.85 μg l-1 (calves. A significant difference was also observed in the second blood sample taken in both the late pregnant cows and the calves between the Herds 1 and 2 (late pregnant cows p p < 0.01. No significant differences were demonstrated between the groups. Herds 1 and 2 showed an improvement in their health status, as compared with the previous period, neither in reproduction indicators nor in the weight gain of the calves.

  17. The geochemical behaviour of selenium in the Boom Clay system - a XANES and EXAFS study

    International Nuclear Information System (INIS)

    2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Breynaert, Eric; 2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Dom, Dirk; 2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Vancluysen, Jacqueline; 2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Kirschhock, Christine E.A.; 2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Maes, Andre; Scheinost, Andreas C.

    2010-01-01

    Document available in extended abstract form only. In Belgium, the Boom Clay formation is studied as a reference host formation for the geological disposal of high-level and long-lived radioactive waste for more than 30 years. This formation mainly consists of mixed clay minerals (illite, inter-stratified illite-smectite), pyrite and immobile and dissolved natural organic matter. Since it provides good sorption capacities, very low permeability, and chemically reducing conditions due to the presence of pyrite (FeS 2 ), the Boom clay formation itself is considered to be the main barrier preventing radionuclide migration from the geological repository. Within this concept for geological storage Se 79 has been identified as one of the critical elements contributing to the final dose to man. Although the sorption and migration behaviour of Se in the Boom Clay system has been thoroughly studied, the speciation of Se in the Boom Clay system has never been identified spectroscopically. In all previous studies, the interpretation of the behaviour of Se in Boom Clay conditions has always been based on circumstantial evidence such as solubility measurements or comparison with the spectroscopically identified speciation of Se in model systems. Based on the XANES analysis, selenite is transformed into Se 0 confirming the previously proposed reduction of selenite in the Boom Clay system. Combination of the mass-balance for Se with the results from linear combination analysis of the XANES spectra provided new evidence for the sorption-reduction mechanism proposed to explain the interaction between Se(IV) and the BC solid phase. In addition, evidence was found that that the fate of Se(IV) in the BC system is completely dominated by its interaction with pyrite present in the Boom Clay. The combined EXAFS analysis of Se in Se 0 reference phases (hexagonal, monoclinic, Se-loaded pyrite) allowed to elucidate further details on the short-range structure of the reaction products formed

  18. Effects of Selenium Supplementation on the Diabetic Condition Depend on the Baseline Selenium Status in KKAy Mice.

    Science.gov (United States)

    Febiyanto, Novian; Yamazaki, Chiho; Kameo, Satomi; Sari, Dian K; Puspitasari, Irma M; Sunjaya, Deni K; Herawati, Dewi M D; Nugraha, Gaga I; Fukuda, Toshio; Koyama, Hiroshi

    2018-01-01

    Oxidative stress in obesity leads to insulin resistance in type 2 diabetes. Some selenoproteins possess antioxidant properties, suggesting that selenium (Se) may protect against type 2 diabetes; however, evidence from epidemiological studies is contradictory. We hypothesized that Se status before supplementation (baseline) contributes to the supplementation outcome. This study aimed to clarify the influence of baseline Se status on the effect of Se supplementation on the diabetic condition. Six-week-old KKAy mice were fed a diet without supplemental Se or with 0.1 ppm Se in the form of L-selenomethionine (SeM) for 2 weeks to create low-Se and sufficient-Se baseline statuses, respectively. For the next 4 weeks, low-Se mice were given a SeM (0.5 ppm Se)-supplemented diet, and sufficient-Se mice were given either a SeM (0.5 ppm Se)- or sodium selenite (0.5 ppm Se)-supplemented diet; control groups continued on baseline diets. Serum Se concentrations, glutathione peroxidase (GPx) activities, adiponectin levels, glucose tolerance, and insulin sensitivity were analyzed. All mice became diabetic during the 2-week baseline induction period. At the end of the supplementation period, Se-receiving groups demonstrated significantly higher Se concentrations and GPx activities than their respective controls. Sufficient-Se mice receiving SeM had lower blood glucose levels and better insulin sensitivity than control and sodium selenite-receiving mice, whereas low-Se mice receiving SeM showed no such improvements compared with their controls. Our results suggest that Se supplementation in the form of SeM may help prevent type 2 diabetes aggravation in people taking the 55 μg/day Se recommended dietary allowance.

  19. Syntheses, crystal structures and characterizations of BaZn(SeO3)2 and BaZn(TeO3)Cl2

    International Nuclear Information System (INIS)

    Jiang Hailong; Feng Meiling; Mao Jianggao

    2006-01-01

    Two new barium zinc selenite and tellurite, namely, BaZn(SeO 3 ) 2 and BaZn(TeO 3 )Cl 2 , have been synthesized by the solid state reaction. The structure of BaZn(SeO 3 ) 2 features double chains of [Zn(SeO 3 ) 2 ] 2- anions composed of four- and eight-member rings which are alternatively along a-axis. The double chains of [Zn 2 (TeO 3 ) 2 Cl 3 ] 3- anions in BaZn(TeO 3 )Cl 2 are formed by Zn 3 Te 3 rings in which each tellurite group connects with three ZnO 3 Cl tetrahedra. BaZn(SeO 3 ) 2 and BaZn(TeO 3 )Cl 2 are wide bandgap semiconductors based on optical diffuse reflectance spectrum measurements. -- Graphical abstract: Two new barium zinc selenite and tellurite, namely, BaZn(SeO 3 ) 2 and BaZn(TeO 3 )Cl 2 , have been synthesized by solid state reaction. The structure of BaZn(SeO 3 ) 2 features 1D double chains of [Zn(SeO 3 ) 2 ] 2- anions composed of four- and eight-member rings which are alternatively along a-axis. The 1D double chains of [Zn 2 (TeO 3 ) 2 Cl 3 ] 3- anions in BaZn(TeO 3 )Cl 2 are formed by Zn 3 Te 3 rings in which each tellurite group connects with one ZnO 3 Cl and two ZnO 2 Cl 2 tetrahedra. BaZn(SeO 3 ) 2 and BaZn(TeO 3 )Cl 2 are wide bandgap semiconductors based on optical diffuse reflectance spectrum measurements

  20. Characterisation of selenium compounds in rye seedling biomass using {sup 75}Se-labelling/SDS-PAGE separation/{gamma}-scintillation counting, and HPLC-ICP-MS analysis of a range of enzymatic digests

    Energy Technology Data Exchange (ETDEWEB)

    Bryszewska, Malgorzata A. [Technical University of Lodz (Poland). Institute of General Food Chemistry; Ambroziak, Wojciech [Technical University of Lodz (Poland). Institute of Fermentation Technology and Microbiology; Rudzinski, Juliusz [Technical University of Lodz (Poland). Institute of Applied Radiation Chemistry; Lewis, D. John [Central Science Laboratory, York (United Kingdom)

    2005-07-01

    In the present study, selenium-enriched plant biomass was investigated to evaluate the ability of rye seedlings to take up, and assimilate, inorganic selenium. Two different analytical approaches were used. Electrophoretic separation (SDS-PAGE) of proteins extracted from {sup 75}Se-labelled biomass was used to investigate the biotransformation of selenite into organic forms of the element. Ion-pair chromatography coupled with ICP-MS detection was chosen for the analysis of selenium species, enzymatically extracted from the plant biomass. The results of three enzymatic hydrolysis procedures and three sequential enzymatic extractions procedures are compared. The most effective single extraction was proteolysis (using protease type XIV), giving an overall extraction efficiency of 48%. However, for combinations of enzymes, the most effective was cellulase (Trichoderma viride) followed by sequential extraction of the solid pellet using protease type XIV, giving an extraction efficiency of 70%. The complementary data from the electrophoretic fractionation of proteins, and the HPLC separation of Se-species in the proteolytic digests, reveal the existence of large number of selenium-containing compounds in the rye seedling plant biomass. The results showed the complete biotransformation of inorganic selenium into organic forms during germination of the rye seedlings. HPLC-ICP-MS analysis of extracts from the plant biomass did not show the presence of selenate or selenite. At the time of this study, the lack of suitable organic-MS facilities meant that it was not possible to characterise them fully. However, the data does show that a combination of different enzymes, rather than just the commonly-used protease, should be considered when developing an extraction strategy for selenium in different food types to those already reported in the literature. (orig.)

  1. Selenium-mediated arsenic excretion in mammals: a synchrotron-based study of whole-body distribution and tissue-specific chemistry.

    Science.gov (United States)

    Ponomarenko, Olena; La Porte, Paul F; Singh, Satya P; Langan, George; Fleming, David E B; Spallholz, Julian E; Alauddin, Mohammad; Ahsan, Habibul; Ahmed, Selim; Gailer, Jürgen; George, Graham N; Pickering, Ingrid J

    2017-11-15

    Arsenicosis, a syndrome caused by ingestion of arsenic contaminated drinking water, currently affects millions of people in South-East Asia and elsewhere. Previous animal studies revealed that the toxicity of arsenite essentially can be abolished if selenium is co-administered as selenite. Although subsequent studies have provided some insight into the biomolecular basis of this striking antagonism, many details of the biochemical pathways that ultimately result in the detoxification and excretion of arsenic using selenium supplements have yet to be thoroughly studied. To this end and in conjunction with the recent Phase III clinical trial "Selenium in the Treatment of Arsenic Toxicity and Cancers", we have applied synchrotron X-ray techniques to elucidate the mechanisms of this arsenic-selenium antagonism at the tissue and organ levels using an animal model. X-ray fluorescence imaging (XFI) of cryo-dried whole-body sections of laboratory hamsters that had been injected with arsenite, selenite, or both chemical species, provided insight into the distribution of both metalloids 30 minutes after treatment. Co-treated animals showed strong co-localization of arsenic and selenium in the liver, gall bladder and small intestine. X-ray absorption spectroscopy (XAS) of freshly frozen organs of co-treated animals revealed the presence in liver tissues of the seleno bis-(S-glutathionyl) arsinium ion, which was rapidly excreted via bile into the intestinal tract. These results firmly support the previously postulated hepatobiliary excretion of the seleno bis-(S-glutathionyl) arsinium ion by providing the first data pertaining to organs of whole animals.

  2. Structural Changes of the Testis and Changes in Semen Quality Parameters Caused by Intraperitoneal and Peroral Administration of Selenium in Rats

    Directory of Open Access Journals (Sweden)

    Michal Cabaj

    2012-05-01

    Full Text Available The aim of this study was to find the structural changes in the testis and semen quality parameters of rat after a singleintraperitoneal and repeated peroral selenium administration. Rats were killed 36 hours following the intraperitonealadministration of selenium selenite (2 mg.kg-1 b.w.; 98% purity and after 90 days of the peroral repeatedadministration of selenium in drinking water (5 mg.l-1. Testis samples were evaluated by histological andmorphometrical methods in light microscopy. Evaluation of semen samples were examined with CASA method. 36hours after the selenium i.p. administration, damage of cellular associations, release of necrotised epithelial cells totubule lumen and fibrotisation and extension of interstitium were observed. Morphometry methods have shown thereduction of seminiferous epithelium volume (P<0.001, extension of interstitium (P<0.001 and increased area ofintraepithelial spaces (P<0.01. In p.o. group similar but more intense changes were noted; in addition, occasionalldegeneration of seminiferous tubuli and rarely total damage in histoarchitecture of seminiferous epithelium wereobserved. CASA analysis revealed significant decrease in all parameters except the concentration of spermatozoa.Additionally, we suppose that p.o. dose 5 mg.l-1 sodium selenite in drinking water is minimum lethal dose level foryoung rats. Selenium after i.p. and p.o. administration causes damage of seminiferous epithelium and interstitium. Itleads to changes in relative proportion of functional tissues of the testis. Reduced spermatogenesis and harmfuleffects in semen parameters are characteristic especially for peroral repeated (subchronic administration. Thesechanges are time- and dose-dependent. In both dosage methods subfertility or infertility can appear.

  3. Influence of the forms and levels of dietary selenium on antioxidant status and oxidative stress-related parameters in rainbow trout (Oncorhynchus mykiss) fry.

    Science.gov (United States)

    Fontagné-Dicharry, Stéphanie; Godin, Simon; Liu, Haokun; Antony Jesu Prabhu, Philip; Bouyssière, Brice; Bueno, Maïté; Tacon, Philippe; Médale, Françoise; Kaushik, Sadasivam J

    2015-06-28

    Se is an essential micronutrient required for normal growth, development and antioxidant defence. The objective of the present study was to assess the impact of dietary Se sources and levels on the antioxidant status of rainbow trout (Oncorhynchus mykiss) fry. First-feeding fry (initial body weight: 91 mg) were fed either a plant- or fishmeal-based diet containing 0·5 or 1·2 mg Se/kg diet supplemented or not with 0·3 mg Se/kg diet supplied as Se-enriched yeast or sodium selenite for 12 weeks at 17°C. Growth and survival of rainbow trout fry were not significantly affected by dietary Se sources and levels. Whole-body Se was raised by both Se sources and to a greater extent by Se-yeast. The reduced:oxidised glutathione ratio was raised by Se-yeast, whereas other lipid peroxidation markers were not affected by dietary Se. Whole-body Se-dependent glutathione peroxidase (GPX) activity was enhanced in fish fed Se-yeast compared to fish fed sodium selenite or non-supplemented diets. Activity and gene expression of this enzyme as well as gene expression of selenoprotein P (SelP) were reduced in fish fed the non-supplemented plant-based diet. Catalase, glutamate-cysteine ligase and nuclear factor-erythroid 2-related factor 2 (Nrf2) gene expressions were reduced by Se-yeast. These results suggest the necessity to supplement plant-based diets with Se for rainbow trout fry, and highlight the superiority of organic form of Se to fulfil the dietary Se requirement and sustain the antioxidant status of fish. GPX and SelP expression proved to be good markers of Se status in fish.

  4. Background electrolytes and pH effects on selenate adsorption using iron-impregnated granular activated carbon and surface binding mechanisms.

    Science.gov (United States)

    Zhang, Ning; Gang, Daniel Dianchen; McDonald, Louis; Lin, Lian-Shin

    2018-03-01

    Iron-impregnated granular activated carbon (Fe-GAC) has been shown effective for selenite adsorptive removal from aqueous solutions, but similar effectiveness was not observed with selenate. This study examined the effects of background electrolytes and pH on selenate adsorption on to Fe-GAC, and surface bindings to elucidate the selenate adsorption mechanisms. The decrease magnitude of selenate adsorption capacity under three background electrolytes followed the order: LiCl > NaCl > KCl, as ionic strength increased from 0.01 to 0.1 M. Larger adsorption capacity differences among the three electrolytes were observed under the higher ionic strengths (0.05 and 0.1 M) than those under 0.01 M. Multiplet peak fittings of high resolution X-ray photoelectron spectra for O1s and Fe2p 3/2 indicated the presence of iron (III) on adsorbent surface. pH variations during the adsorbent preparation within 3-8 in NaCl solutions did not cause appreciable changes in the iron redox state and composition. Raman spectra showed the formation of both monodentate and bidentate inner sphere complexes under pHs adsorption under alkaline conditions. Mechanisms for monodentate and bidentate formations and a stable six-member ring structure were proposed. Two strategies were recommended for modifying Fe-GAC preparation procedure to enhance the selenate adsorption: (1) mixed-metal oxide coatings to increase the point of zero charge (pH zpc ); and (2) ferrous iron coating to initially reduce selenate followed by selenite adsorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Effect of nitric acid for equal stabilization and sensitivity of different selenium species in electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Feyime [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey); Volkan, Muervet [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey); Ataman, O. Yavuz [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey)]. E-mail: ataman@metu.edu.tr

    2005-08-15

    Determination of selenium by electrothermal atomic absorption spectrometry (ETAAS) is complicated by the presence of different species of this analyte. The presence of different oxidation states (-II, IV and VI) may result in different sensitivities obtained for each species rendering impossible the use of a single species for calibration. These species also exhibit different behaviours regarding thermal stabilities; the temperature program must be provided to conform to this problem. Chemical modifiers are commonly used for thermal stabilization of selenium species. In this study, experiments were carried out to demonstrate the effect of nitric acid in the presence of chemical modifiers. Nickel and palladium + magnesium were selected as the most commonly used chemical modifiers. Using both aqueous and human serum solutions it has been demonstrated that although chemical modifiers provide thermal stabilization of species so that higher ashing temperatures can be used, equal sensitivities cannot be achieved unless nitric acid is also present. Selenite, selenate, selenomethionine and selenocystine were used in experiments. When equal sensitivities for all these species are achieved, determination of total selenium by ETAAS can be performed by using a single species as the standard; selenite was used in this study. Precision was 5.0% or better using peak height signals. There was no significant difference in detection limits (3s) when Ni or Pd + Mg(NO{sub 3}){sub 2} was used as chemical modifier; 37 and 35 pg of selenium were found to be the detection limits for Ni and Pd + Mg(NO{sub 3}){sub 2} chemical modifiers, respectively. For chemical modifications, either 5 {mu}g of Ni or 0.5 {mu}g of Pd and 5 {mu}g of Mg(NO{sub 3}){sub 2} were used; final solutions contained 2.5% HNO{sub 3}. In serum analyses, 10 {mu}g of Ni was used in presence of 2.5% HNO{sub 3}.

  6. The effect of dietary bacterial organic selenium on growth performance, antioxidant capacity, and Selenoproteins gene expression in broiler chickens.

    Science.gov (United States)

    Dalia, A M; Loh, T C; Sazili, A Q; Jahromi, M F; Samsudin, A A

    2017-08-18

    Selenium (Se) is an essential trace mineral in broilers, which has several important roles in biological processes. Organic forms of Se are more efficient than inorganic forms and can be produced biologically via Se microbial reduction. Hence, the possibility of using Se-enriched bacteria as feed supplement may provide an interesting source of organic Se, and benefit broiler antioxidant system and other biological processes. The objective of this study was to examine the impacts of inorganic Se and different bacterial organic Se sources on the performance, serum and tissues Se status, antioxidant capacity, and liver mRNA expression of selenoproteins in broilers. Results indicated that different Se sources did not significantly (P ≤ 0.05) affect broiler growth performance. However, bacterial organic Se of T5 (basal diet +0.3 mg /kg feed ADS18 Se), T4 (basal diet +0.3 mg /kg feed ADS2 Se), and T3 (basal diet +0.3 mg /kg feed ADS1 Se) exhibited significantly (P ≤ 0.05) highest Se concentration in serum, liver, and kidney respectively. Dietary inorganic Se and bacterial organic Se were observed to significantly affect broiler serum ALT, AST, LDH activities and serum creatinine level. ADS18 supplemented Se of (Stenotrophomonas maltophilia) bacterial strain showed the highest GSH-Px activity with the lowest MDA content in serum, and the highest GSH-Px and catalase activity in the kidney, while bacterial Se of ADS2 (Klebsiella pneumoniae) resulted in a higher level of GSH-Px1 and catalase in liver. Moreover, our study showed that in comparison with sodium selenite, only ADS18 bacterial Se showed a significantly higher mRNA level in GSH-Px1, GSH-Px4, DIO1, and TXNDR1, while both ADS18 and ADS2 showed high level of mRNA of DIO2 compared to sodium selenite. The supplementation of bacterial organic Se in broiler chicken, improved tissue Se deposition, antioxidant status, and selenoproteins gene expression, and can be considered as an effective alternative source of

  7. Contaminants from Cretaceous Black Shale Part 1: Natural weathering processes controlling contaminant cycling in Mancos Shale, southwestern United States, with emphasis on salinity and selenium

    Science.gov (United States)

    Tuttle, Michele L.W.; Fahy, Juli W.; Elliott, John G.; Grauch, Richard I.; Stillings, Lisa L.

    2013-01-01

    Soils derived from black shale can accumulate high concentrations of elements of environmental concern, especially in regions with semiarid to arid climates. One such region is the Colorado River basin in the southwestern United States where contaminants pose a threat to agriculture, municipal water supplies, endangered aquatic species, and water-quality commitments to Mexico. Exposures of Cretaceous Mancos Shale (MS) in the upper basin are a major contributor of salinity and selenium in the Colorado River. Here, we examine the roles of geology, climate, and alluviation on contaminant cycling (emphasis on salinity and Se) during weathering of MS in a Colorado River tributary watershed. Stage I (incipient weathering) began perhaps as long ago as 20 ka when lowering of groundwater resulted in oxidation of pyrite and organic matter. This process formed gypsum and soluble organic matter that persist in the unsaturated, weathered shale today. Enrichment of Se observed in laterally persistent ferric oxide layers likely is due to selenite adsorption onto the oxides that formed during fluctuating redox conditions at the water table. Stage II weathering (pedogenesis) is marked by a significant decrease in bulk density and increase in porosity as shale disaggregates to soil. Rainfall dissolves calcite and thenardite (Na2SO4) at the surface, infiltrates to about 1 m, and precipitates gypsum during evaporation. Gypsum formation (estimated 390 kg m−2) enriches soil moisture in Na and residual SO4. Transpiration of this moisture to the surface or exposure of subsurface soil (slumping) produces more thenardite. Most Se remains in the soil as selenite adsorbed to ferric oxides, however, some oxidizes to selenate and, during wetter conditions is transported with soil moisture to depths below 3 m. Coupled with little rainfall, relatively insoluble gypsum, and the translocation of soluble Se downward, MS landscapes will be a significant nonpoint source of salinity and Se to the

  8. New quaternary oxides with both families of second-order Jahn–Teller (SOJT) distortive cations: Solid-state synthesis, structure determination, and characterization of YNbTe{sub 2}O{sub 8} and YNbSe{sub 2}O{sub 8}

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeong Hun [Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756 (Korea, Republic of); Jeon, Beom-Yong; You, Tae-Soo [Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763 (Korea, Republic of); Ok, Kang Min, E-mail: kmok@cau.ac.kr [Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756 (Korea, Republic of)

    2015-07-15

    Graphical abstract: Ball-and-stick representation of YNbTe{sub 2}O{sub 8} composed of polyhedra of SOJT distortive cations, i.e., NbO{sub 6} and TeO{sub 3}, in the ac-plane. - Highlights: • Two novel tellurite and selenite (YNbQ{sub 2}O{sub 8}; Q = Te and Se) are synthesized. • YNbQ{sub 2}O{sub 8} possess both families of second-order Jahn–Teller distortive cations. • The distortive environments and bonding nature are supported by electronic structure calculations. - Abstract: Two novel quaternary mixed metal tellurite and selenite, YNbTe{sub 2}O{sub 8} and YNbSe{sub 2}O{sub 8}, respectively, have been synthesized through standard solid-state reactions using Y{sub 2}O{sub 3}, Nb{sub 2}O{sub 5}, TeO{sub 2} or SeO{sub 2} as reagents. Single crystal X-ray and powder neutron diffraction analyses have been utilized to determine the structures of the reported materials. YNbTe{sub 2}O{sub 8} and YNbSe{sub 2}O{sub 8} are isostructural to each other and crystallize in the monoclinic centrosymmetric space group, C2/m (No. 12). Due to the two families of constituent second-order Jahn–Teller (SOJT) distortive cations, i.e., Nb{sup 5+} and Te{sup 4+}/Se{sup 4+}, local asymmetric environments occur from the three-dimensional frameworks. Intra-octahedral distortions along the local C{sub 4} direction and asymmetric trigonal pyramidal coordination moieties generated by stereoactive lone pairs are observed from the NbO{sub 6} octahedra and TeO{sub 3} (or SeO{sub 3}) polyhedra, respectively. Thermogravimetric analysis, infrared and UV–vis diffuse reflectance spectroscopies, elemental analysis, out-of-center distortions, dipole moment calculations, and electronic structure calculations for the reported materials are presented.

  9. Nanoselenium prevents eimeriosis-induced inflammation and regulates mucin gene expression in mice jejunum

    Directory of Open Access Journals (Sweden)

    Alkhudhayri AA

    2018-04-01

    Full Text Available Abdulsalam A Alkhudhayri,1 Mohamed A Dkhil,1,2 Saleh Al-Quraishy1 1Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia; 2Department of Zoology and Entomology, Faculty of Science, Helwan University, Cairo, Egypt Background: Although elemental selenium has been found to be effective against Eimeria, no study has yet investigated the effects of selenium nanoparticles (SeNPs on the Eimeria parasite. The aim of this study, therefore, was to evaluate the ameliorative effect of SeNPs compared with elemental selenium on mice jejunum infected with sporulated oocysts of Eimeria papillata.Methods: The mice were divided into 4 groups, with the first being the non-infected, control group, and the second, third, and fourth groups being orally inoculated with 1,000 sporulated oocysts of E. papillata. The third and fourth groups also received, respectively, an oral dose of 0.1 mg/kg sodium selenite and 0.5 mg/kg SeNPs daily for 5 consecutive days.Results: The infection induced severe histopathological jejunal damage, reflected in the form of destroyed jejunal mucosa, increased jejunal oxidative damage, a reduction in the number of jejunal goblet cells, and increased production of pro-inflammatory cytokines, quantified by real-time polymerase chain reaction. Treatment of mice with SeNPs significantly decreased the oocyst output in the feces by ~80%. Furthermore, the number of parasitic stages counted in stained jejunal paraffin sections was significantly decreased after the mice were treated with SeNPs. In addition, the number of goblet cells increased from 42.6±7.3 to 95.3±8.5 cells/10 villus-crypt units after treatment. By day 5 post-infection with E. papillata, SeNPs could be seen to have significantly increased the activity of glutathione peroxidase from 263±10 to 402.4±9 mU/mL. Finally, SeNPs were able to regulate the gene expression of mucin 2, interleukin 1β, interleukin 6, interferon-γ, and tumor necrosis factor

  10. Identification of an S-adenosylmethionine (SAM) dependent arsenic methyltransferase in Danio rerio

    Energy Technology Data Exchange (ETDEWEB)

    Hamdi, Mohamad [Department of Biological Sciences, Oakland University, Rochester, MI 48309 (United States); Yoshinaga, Masafumi; Packianathan, Charles; Qin, Jie [Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, FL33199 (United States); Hallauer, Janell; McDermott, Joseph R. [Department of Biological Sciences, Oakland University, Rochester, MI 48309 (United States); Yang, Hung-Chi [Department of Medical Biotechnology and Laboratory Sciences, Chang-Gung University, Tao-Yuan, Kwei-San 333, Taiwan (China); Tsai, Kan-Jen [School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan (China); Liu, Zijuan, E-mail: liu2345@oakland.edu [Department of Biological Sciences, Oakland University, Rochester, MI 48309 (United States)

    2012-07-15

    Arsenic methylation is an important cellular metabolic process that modulates arsenic toxicity and carcinogenicity. Biomethylation of arsenic produces a series of mono-, di- and tri-methylated arsenic metabolites that can be detected in tissues and excretions. Here we report that zebrafish exposed to arsenite (As{sup III}) produces organic arsenicals, including MMA{sup III}, MMA{sup V} and DMA{sup V} with characteristic tissue ratios, demonstrating that an arsenic methylation pathway exists in zebrafish. In mammals, cellular inorganic arsenic is methylated by a SAM-dependent arsenic methyltransferase, AS3MT. A zebrafish arsenic methyltransferase homolog, As3mt, was identified by sequence alignment. Western blotting analysis showed that As3mt was universally expressed in zebrafish tissues. Prominent expression in liver and intestine correlated with methylated arsenic metabolites detected in those tissues. As3mt was expressed in and purified from Escherichia coli for in vitro functional studies. Our results demonstrated that As3mt methylated As{sup III} to DMA{sup V} as an end product and produced MMA{sup III} and MMA{sup V} as intermediates. The activity of As3mt was inhibited by elevated concentrations of the substrate As{sup III} as well as the metalloid selenite, which is a well-known antagonistic micronutrient of arsenic toxicity. The activity As3mt was abolished by substitution of either Cys160 or Cys210, which corresponds to conserved cysteine residues in AS3MT homologs, suggesting that they are involved in catalysis. Expression in zebrafish of an enzyme that has a similar function to human and rodent orthologs in catalyzing intracellular arsenic biomethylation validates the applicability of zebrafish as a valuable vertebrate model for understanding arsenic-associated diseases in humans. -- Highlights: ► Zebrafish methylated As{sup III} to MMA{sup III}, MMA{sup V} and DMA{sup V}. ► A zebrafish arsenic methyltransferase (As3mt) was purified in E. coli.

  11. Selenium speciation influences bioaccumulation in Limnodynastes peronii tadpoles

    Energy Technology Data Exchange (ETDEWEB)

    Lanctôt, C.M., E-mail: c.lanctot@griffith.edu.au [Central Queensland University, School of Medical and Applied Sciences, Gladstone, QLD 4680 (Australia); Australian Rivers Institute, School of Environment, Griffith University, Southport, QLD 4215 (Australia); Melvin, S.D., E-mail: s.melvin@griffith.edu.au [Australian Rivers Institute, School of Environment, Griffith University, Southport, QLD 4215 (Australia); Cresswell, T., E-mail: tom.cresswell@ansto.gov.au [Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia)

    2017-06-15

    Highlights: • Differences in SeIV and SeVI bioaccumulation and biodistribution were assessed. • Limnodynastes peronii tadpoles accumulated more selenite than selenate. • Selenium depuration kinetics was similar for both forms. • Tadpoles accumulated Se predominantly in the digestive and excretory organs. - Abstract: Despite being essential for animal health and fitness, Se has a relatively narrow range between deficiency and toxicity, and excess Se can cause a variety of adverse effects in aquatic organisms. Amphibians are particularly vulnerable to contaminants during larval aquatic life stage, because they can accumulate toxic ions through various routes including skin, gills, lungs and digestive tract. Few attempts have been made to understand the tissue-specific accumulation of trace elements, including the impacts of chemical speciation in developing amphibian larvae. We used radiolabelled {sup 75}Se to explore the biokinetics and tissue distributions of the two dominant forms occurring in surface waters, selenite (SeIV) and selenate (SeVI). Tadpoles of the native Australian frog Limnodynastes peronii were exposed to Se in both forms, and live-animal gamma spectroscopy was used to track accumulation and retention over time. Tissue biodistributions were also quantified at the end of the uptake and depuration phases. Results showed the bioconcentration of SeIV to be 3 times greater compared to SeVI, but rates of elimination were similar for both forms. This suggests a change of Se speciation within the organism prior to excretion. Depuration kinetics were best described by a one-phase exponential decay model, and tadpoles retained approximately 19% of the accumulated Se after 12 days of depuration in clean water. Selenium bioaccumulation was greatest in digestive and excretory organs, as well as the eye, which may directly relate to previously reported Se-induced impairments. Results demonstrate how the use of radiotracing techniques can significantly

  12. Toxicological effects of thiomersal and ethylmercury: Inhibition of the thioredoxin system and NADP+-dependent dehydrogenases of the pentose phosphate pathway

    International Nuclear Information System (INIS)

    Rodrigues, Juan; Branco, Vasco; Lu, Jun; Holmgren, Arne; Carvalho, Cristina

    2015-01-01

    Mercury (Hg) is a strong toxicant affecting mainly the central nervous, renal, cardiovascular and immune systems. Thiomersal (TM) is still in use in medical practice as a topical antiseptic and as a preservative in multiple dose vaccines, routinely given to young children in some developing countries, while other forms of mercury such as methylmercury represent an environmental and food hazard. The aim of the present study was to determine the effects of thiomersal (TM) and its breakdown product ethylmercury (EtHg) on the thioredoxin system and NADP + -dependent dehydrogenases of the pentose phosphate pathway. Results show that TM and EtHg inhibited the thioredoxin system enzymes in purified suspensions, being EtHg comparable to methylmercury (MeHg). Also, treatment of neuroblastoma and liver cells with TM or EtHg decreased cell viability (GI 50 : 1.5 to 20 μM) and caused a significant (p < 0.05) decrease in the overall activities of thioredoxin (Trx) and thioredoxin reductase (TrxR) in a concentration- and time-dependent manner in cell lysates. Compared to control, the activities of Trx and TrxR in neuroblastoma cells after EtHg incubation were reduced up to 60% and 80% respectively, whereas in hepatoma cells the reduction was almost 100%. In addition, the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were also significantly inhibited by all mercurials, with inhibition intensity of Hg 2+ > MeHg ≈ EtHg > TM (p < 0.05). Cell incubation with sodium selenite alleviated the inhibitory effects on TrxR and glucose-6-phosphate dehydrogenase. Thus, the molecular mechanism of toxicity of TM and especially of its metabolite EtHg encompasses the blockage of the electrons from NADPH via the thioredoxin system. - Highlights: • TM and EtHg inhibit Trx and TrxR both in purified suspensions and cell lysates. • TM and EtHg also inhibit the activities of G6PDH and 6PGDH in cell lysates, • Co-exposure to selenite alleviates the

  13. Salt lake Laguna de Fuente de Piedra (S-Spain) as Late Quaternary palaeoenvironmental archive

    Science.gov (United States)

    Höbig, Nicole; Melles, Martin; Reicherter, Klaus

    2014-05-01

    This study deals with Late Quaternary palaeoenvironmental variability in Iberia reconstructed from terrestrial archives. In southern Iberia, endorheic basins of the Betic Cordilleras are relatively common and contain salt or fresh-water lakes due to subsurface dissolution of Triassic evaporites. Such precipitation or ground-water fed lakes (called Lagunas in Spanish) are vulnerable to changes in hydrology, climate or anthropogenic modifications. The largest Spanish salt lake, Laguna de Fuente de Piedra (Antequera region, S-Spain), has been investigated and serves as a palaeoenvironmental archive for the Late Pleistocene to Holocene time interval. Several sediment cores taken during drilling campaigns in 2012 and 2013 have revealed sedimentary sequences (up to 14 m length) along the shoreline. A multi-proxy study, including sedimentology, geochemistry and physical properties (magnetic susceptibility) has been performed on the cores. The sedimentary history is highly variable: several decimetre thick silty variegated clay deposits, laminated evaporites, and even few-centimetre thick massive gypsum crystals (i.e., selenites). XRF analysis was focussed on valuable palaeoclimatic proxies (e.g., S, Zr, Ti, and element ratios) to identify the composition and provenance of the sediments and to delineate palaeoenvironmental conditions. First age control has been realized by AMS-radiocarbon dating. The records start with approximately 2-3 m Holocene deposits and reach back to the middle of MIS 3 (GS-3). The sequences contain changes in sedimentation rates as well as colour changes, which can be summarized as brownish-beige deposits at the top and more greenish-grey deposits below as well as highly variegated lamination and selenites below ca. 6 m depth. The Younger Dryas, Bølling/Allerød, and the so-called Mystery Interval/Last Glacial Maximum have presumably been identified in the sediment cores and aligned to other climate records. In general, the cores of the Laguna de

  14. Surface controlled dissolution rates of gypsum in aqueous solutions exhibit nonlinear dissolution kinetics

    Science.gov (United States)

    Jeschke, Alexander A.; Vosbeck, Katrin; Dreybrodt, Wolfgang

    2001-01-01

    The effective dissolution rates of gypsum are determined by mixed kinetics, where the rate constants of dissolution at the surface and the transport constant of molecular diffusion of dissolved material are similar. To obtain the surface reaction rate law it is necessary to know the transport constant. We have determined the surface rate law for monocrystalline selenite by using a rotating disc set-up, where the transport coefficients are well known. As a result, up to a calcium concentration of 0.6 · ceq, we find a nearly linear rate law Rs = ksl (1- cs/ ceq) n1, where cs is the total calcium concentration at the surface and ceq the equilibrium concentration with respect to gypsum, n1 = 1.2 ± 0.2, and ksl = 1.1 · 10 -4 mmol cm -2 s -1 ± 15%. We also employed batch-experiments for selenite, alabaster and gypsum rock samples. The result of these experiments were interpreted by using a transport constant determined by NaCl dissolution experiments under similar physical conditions. The batch experiments reveal a dissolution rate law Rs = ksl (1- cs/ ceq) n1, ksl = 1.3 · 10 -4 mmol · cm -2 s -1, n1 = 1.2 ± 0.2 for c ≤ 0.94 · ceq. Close to equilibrium a nonlinear rate law, Rs = ks2 (1- cs/ ceq) n2, is observed, where ks2 is in the order of 10 mmol · cm -2 s -1 and n2 ≈ 4.5. The experimentally observed gypsum dissolution rates from the batch experiments could be accurately fitted, with only minor variations of the surface reaction constant obtained from the rotating disk experiment and the transport coefficient from the NaCl dissolution batch experiment. Batch experiments on pure synthetic gypsum, reveal a linear rate law up to equilibrium. This indicates inhibition of dissolution in natural samples close to equilibrium, as is known also for calcite minerals.

  15. Selenium speciation using capillary electrophoresis coupled with modified electrothermal atomic absorption spectrometry after selective extraction with 5-sulfosalicylic acid functionalized magnetic nanoparticles.

    Science.gov (United States)

    Yan, Lizhen; Deng, Biyang; Shen, Caiying; Long, Chanjuan; Deng, Qiufen; Tao, Chunyao

    2015-05-22

    A new method for selenium speciation in fermented bean curd wastewater and juice was described. This method involved sample extraction with 5-sulfosalicylic acid (SSA)-functionalized silica-coated magnetic nanoparticles (SMNPs), capillary electrophoresis (CE) separation, and online detection with a modified electrothermal atomic absorption spectrometry (ETAAS) system. The modified interface for ETAAS allowed for the introduction of CE effluent directly through the end of the graphite tube. Elimination of the upper injection hole of the graphite tube reduced the loss of the anlayte and enhanced the detection sensitivity. The SSA-SMNPs were synthesized and used to extract trace amounts of selenite [Se(IV)], selenite [Se(VI)], selenomethionine (SeMet), and selenocystine (SeCys2) from dilute samples. The concentration enrichment factors for Se(VI), Se(IV), SeMet, and SeCys2 were 21, 29, 18, and 12, respectively, using the SSA-SMNPs extraction. The limits of detection for Se(VI), Se(IV), SeMet, and SeCys2 were 0.18, 0.17, 0.54, 0.49ngmL(-1), respectively. The RSD values (n=6) of method for intraday were observed between 0.7% and 2.9%. The RSD values of method for interday were less than 3.5%. The linear range of Se(VI) and Se(IV) were in the range of 0.5-200ngmL(-1), and the linear ranges of SeMet and SeCys2 were 2-500 and 2-1000ngmL(-1), respectively. The detection limits of this method were improved by 10 times due to the enrichment by the SSA-SMNP extraction. The contents of Se(VI) and Se(IV) in fermented bean curd wastewater were measured as 3.83 and 2.62ngmL(-1), respectively. The contents of Se(VI), Se(IV), SeMet, and SeCys2 in fermented bean curd juice were determined as 6.39, 4.08, 2.77, and 4.00ngmL(-1), respectively. The recoveries were in the range of 99.14-104.5% and the RSDs (n=6) of recoveries between 0.82% and 3.5%. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Antioxidant drugs to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis: What does evidence suggest?

    Science.gov (United States)

    Fuentes-Orozco, Clotilde; Dávalos-Cobián, Carlos; García-Correa, Jesús; Ambriz-González, Gabriela; Macías-Amezcua, Michel Dassaejv; García-Rentería, Jesús; Rendón-Félix, Jorge; Chávez-Tostado, Mariana; Cuesta-Márquez, Lizbeth Araceli; Alvarez-Villaseñor, Andrea Socorro; Cortés-Flores, Ana Olivia; González-Ojeda, Alejandro

    2015-06-07

    To determine whether or not the use of antioxidant supplementation aids in the prevention of post- endoscopic retrograde cholangiopancreatography pancreatitis. A systematic review of randomized controlled trials (RCTs) was made to evaluate the preventive effect of prophylactic antioxidant supplementation in post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP). The inclusion criteria included: acute post-endoscopic retrograde cholangiopancreatography pancreatitis in adults; randomized clinical trials with the use of any antioxidant as an intervention compared with placebo, to reduce PEP. The outcome measure was the incidence and severity of PEP. Twelve RCTs involving 3110 patients since 1999 were included. The antioxidants used were selenite, β-carotene, and pentoxifylline (each one in one trial), N-acetylcysteine (NAC) in three trials, and allopurinol in six trials. The group of patients treated with NAC received different doses; either oral or intravenous, and allopurinol-treated patients received five different oral doses in two different administration periods. The results are expressed with raw numbers, proportions, as well as mean and standard deviations. The incidence of pancreatitis between groups was analyzed with Pearson's χ(2) test or Fisher's exact test (F). The main outcome is expressed as relative risks and 95%CI. The incidence of pancreatitis in all antioxidant treatment groups was 8.6%, whereas it was 9.7% in the control group. The antioxidants used were selenite, β-carotene, and pentoxifylline (each one in one trial), NAC in three trials, and allopurinol in six trials. In allopurinol trials, three different dosifications were used; two trials reported a low dosage (of less than 400 mg), two trials reported a moderate dose (600 mg) and the remaining two employed higher doses (more than 900 mg). Supplementation was not associated with a significant reduction in the incidence of PEP [relative risk (RR) = 0.93; 95%CI: 0.82-1.06; P

  17. Toxicological effects of thiomersal and ethylmercury: Inhibition of the thioredoxin system and NADP{sup +}-dependent dehydrogenases of the pentose phosphate pathway

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Juan, E-mail: juanricardorodrigues@gmail.com [Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa (Portugal); Laboratory of Biochemistry, Faculty of Pharmacy, Central University of Venezuela (Venezuela, Bolivarian Republic of); Branco, Vasco [Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa (Portugal); Lu, Jun; Holmgren, Arne [Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet (Sweden); Carvalho, Cristina, E-mail: cristina.carvalho@ff.ulisboa.pt [Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa (Portugal)

    2015-08-01

    Mercury (Hg) is a strong toxicant affecting mainly the central nervous, renal, cardiovascular and immune systems. Thiomersal (TM) is still in use in medical practice as a topical antiseptic and as a preservative in multiple dose vaccines, routinely given to young children in some developing countries, while other forms of mercury such as methylmercury represent an environmental and food hazard. The aim of the present study was to determine the effects of thiomersal (TM) and its breakdown product ethylmercury (EtHg) on the thioredoxin system and NADP{sup +}-dependent dehydrogenases of the pentose phosphate pathway. Results show that TM and EtHg inhibited the thioredoxin system enzymes in purified suspensions, being EtHg comparable to methylmercury (MeHg). Also, treatment of neuroblastoma and liver cells with TM or EtHg decreased cell viability (GI{sub 50}: 1.5 to 20 μM) and caused a significant (p < 0.05) decrease in the overall activities of thioredoxin (Trx) and thioredoxin reductase (TrxR) in a concentration- and time-dependent manner in cell lysates. Compared to control, the activities of Trx and TrxR in neuroblastoma cells after EtHg incubation were reduced up to 60% and 80% respectively, whereas in hepatoma cells the reduction was almost 100%. In addition, the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were also significantly inhibited by all mercurials, with inhibition intensity of Hg{sup 2+} > MeHg ≈ EtHg > TM (p < 0.05). Cell incubation with sodium selenite alleviated the inhibitory effects on TrxR and glucose-6-phosphate dehydrogenase. Thus, the molecular mechanism of toxicity of TM and especially of its metabolite EtHg encompasses the blockage of the electrons from NADPH via the thioredoxin system. - Highlights: • TM and EtHg inhibit Trx and TrxR both in purified suspensions and cell lysates. • TM and EtHg also inhibit the activities of G6PDH and 6PGDH in cell lysates, • Co-exposure to selenite alleviates

  18. Effects of dietary supplementation with an organic source of selenium on characteristics of semen quality and in vitro fertility in boars.

    Science.gov (United States)

    Speight, S M; Estienne, M J; Harper, A F; Crawford, R J; Knight, J W; Whitaker, B D

    2012-03-01

    Semen characteristics in boars fed organic or inorganic sources of Se were assessed in 3 experiments. Crossbred boars were randomly assigned at weaning to 1 of 3 dietary treatments: I) basal diets with no supplemental Se (control), II) basal diets with 0.3 mg/kg of supplemental Se from an organic source (Sel-Plex, Alltech Inc., Nicholasville, KY), and III) basal diets supplemented with 0.3 mg/kg of supplemental Se from sodium selenite (Premium Selenium 270, North American Nutrition Co. Inc., Lewisburg, OH). For Exp. 1, semen was collected from boars (n = 10/dietary treatment) on 5 consecutive days at 15 mo of age. Effects of treatment × day were detected for the proportions of progressively motile (P = 0.02) and rapidly moving (P = 0.03) spermatozoa, and measures of sperm velocity, including path velocity of the smoothed cell path (P = 0.05) and average velocity measured in a straight line from the beginning to the end of the track (P = 0.05). Negative effects of day of semen collection on sperm motility were least pronounced in boars fed Sel-Plex. Experiment 2 was conducted when boars were 17 mo of age, and semen was collected (n = 10 boars/dietary treatment), diluted in commercially available extenders, and stored at 18°C for 9 d. Effects of treatment × day were detected for percentages of motile (P = 0.01) and static (P = 0.01) spermatozoa, amplitude of lateral head displacement (P = 0.02), frequency with which the sperm track crossed the sperm path (P = 0.04), straightness (P = 0.01), and average size of all sperm heads (P = 0.03). In general, sperm cells from boars fed Sel-Plex were better able to maintain motility during liquid storage compared with boars fed sodium selenite. For Exp. 3, semen was collected from boars (n = 6/dietary treatment) at 23 mo of age, and spermatozoa were evaluated at d 1 and 8 after semen collection using in vitro fertilization procedures. There was a tendency for an effect (P = 0.11) of dietary treatment on fertilization rate

  19. Evaluation of pharmacological activities and assessment of intraocular penetration of an ayurvedic polyherbal eye drop (Itone™ in experimental models

    Directory of Open Access Journals (Sweden)

    Velpandian Thirumurthy

    2013-01-01

    Full Text Available Abstract Background The polyherbal eye drop (Itone™ is a mixture of aqueous distillates of nineteen traditionally used ingredients that sum up to impart potency to the formulation and make it a useful adjunct in various ocular pathologies. However, as there have been no controlled experimental studies accounting to the above claim, therefore, the present study was designed to evaluate the polyherbal formulation (PHF for antiangiogenic, anti-inflammatory, anticataract, antioxidant and cytotoxicity in addition to the evaluation of intraocular penetration of PHF in rabbit eyes using LC-MS/MS. Materials and methods Antiangiogenic activity of the PHF was evaluated using in ovo chick chorio-allantoic membrane (CAM assay and in vivo cautery induced corneal neovascularization assay in rats. Anticataract potential was evaluated using steroid induced cataract in developing chick embryos, sodium selenite induced cataract in rat pups and galactose induced cataract in rats. The antioxidant activity was evaluated using di-phenyl picryl hydrazyl (DPPH radical scavenging assay. Anti-inflammatory activity was evaluated in vitro using inhibition of LTB4 formation in human WBCs and in vivo using carrageenan induced paw edema assay in rats. The cytotoxicity was evaluated against HeLa cancer cell lines using (3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Furthermore evaluation of the intraocular penetration of the PHF was carried out in rabbit eyes via aqueous humor paracentesis and further analysis using LC-MS/MS. Results PHF significantly inhibited VEGF induced proliferation of new blood vessels in CAM assay and inhibited the cautery induced corneal neovascularization in rats. Additionally, PHF showed noticeable delay in the progression of cataract in the selenite and galactose induced cataract models whereby the PHF treated lenses were graded for stages II and III respectively. However, the PHF did not show any anticataract activity in

  20. Effects of feeding pregnant beef cows selenium-enriched alfalfa hay on selenium status and antibody titers in their newborn calves.

    Science.gov (United States)

    Wallace, L G; Bobe, G; Vorachek, W R; Dolan, B P; Estill, C T; Pirelli, G J; Hall, J A

    2017-06-01

    In newborn dairy calves, it has been demonstrated that supranutritional maternal and colostral Se supplementation using Se yeast or sodium selenite, respectively, improves passive transfer of IgG. In beef cattle, agronomic biofortification with Se is a more practical alternative for Se supplementation, whereby the Se concentration of hay is increased through the use of Se-containing fertilizer amendments. It has been previously demonstrated that agronomic Se biofortification is an effective strategy to improve immunity and performance in Se-replete weaned beef calves. The objective of this experiment was to determine the effects of feeding beef cows Se-enriched alfalfa () hay during the last 8 to 12 wk of gestation on passive transfer of antibodies to calves. At 10 wk ± 16 d before calving, 45 cows were assigned to 1 of 3 treatment groups with 3 pens (5 cows/pen) per treatment: Control cows were fed non-Se-fortified alfalfa hay plus a mineral supplement containing 120 mg/kg Se from sodium selenite, Med-Se cows were fed alfalfa hay fertilized with 45.0 g Se/ha as sodium selenate, and High-Se cows were fed alfalfa hay fertilized with 89.9 g Se/ha as sodium selenate; both the Med-Se and the High-Se groups received mineral supplement without added Se. Colostrum and whole blood (WB) were collected from cows at calving, and WB was collected from calves within 2 h of calving and at 12, 24, 36, and 48 h of age. Concentrations of IgG1 and J-5 antibody in cow colostrum and calf serum were quantified using ELISA procedures. Selenium concentrations linearly increased in WB ( cows and in WB of newborn calves ( cows fed Se-biofortified alfalfa hay, but J-5 antibody ( = 0.43) concentrations were not. Calf serum IgG1 ( = 0.43) and J-5 antibody ( = 0.44) concentrations during the first 48 h of age were not affected by prior Se treatment of cows. These data suggest that feeding Se-biofortified alfalfa hay promotes the accumulation of Se and antibodies in colostrum but does not

  1. Toxicity of selenium (Na sub 2 SeO sub 3 ) and mercury (HgCl sub 2 ) on the planarian Dugesia gonocephala

    Energy Technology Data Exchange (ETDEWEB)

    Congiu, A.M.; Casu, S.; Ugazio, G. (Istituto di Genetica (Italy))

    1989-10-01

    The toxicity of selenium (Na{sub 2}SeO{sub 3}) and mercury (HgCl{sub 2}) was determined by using a freshwater planarian which is particularly sensitive to pollution, and belongs to a fissiparous breed of Dugesia gonocephala. The mortality and fissiparity frequency of the subjects were studied. They were exposed to intense treatments (48 hours) or for medium to long periods of time (21 days) to either the single compounds or a combination of both, and were fed or fasting. The lethal effect of sodium selenite is correlated to the food intake, whereas the toxicity of mercurous chloride is probably the result of a fixative effect which does not depend on feeding. The 21-day treatment with the first compound has a non-negligible lethal effect which is probably due to an accumulation phenomenon. At doses where an antioxidant effect prevails, fissiparity is stimulated. On the other hand, the second compound reduces reproduction frequency to half the base values. Compared to the Paracentrotus lividus, the Dugesia gonocephala offers various advantages concerning toxicological experiments; besides being easier to handle in the laboratory, it is available all year round and is not subject to seasonal cycles. It is also more susceptible to the toxic effect of mercury, which is a common and highly toxic pollutant, than the sea urchin.

  2. Isolasi karakterisasi dan pengelompokan strain Salmonella typhi asal Kabupaten Sumba Barat Daya Nusa Tenggara Timur berdasarkan sifat-sifat fenotip

    Directory of Open Access Journals (Sweden)

    Charis Amarantini

    2012-02-01

    Full Text Available Typhoid fever is highly endemic in the South-West Sumba Regency, East Nusa Tenggara. The incidence rate of the diseases is high estimated at 725/100,000. It is an acute systemic infection caused by Salmonella typhi. The clinical symptoms of the disease are extremely diverse, starting from the mild form to severe ones with the most feared complication being perforation within the small intestine. Therefore, it is important to perform isolation, characterization, and grouping of S. typhi strains from the blood culture in order to determined definitely diagnosis and the different phenotypic characteristics in the community. Isolation was done in selective and differential media: BacT/ALERT FA culture media, Selenite Cystine Broth, Chromocult Coliform Agar, MacConkey Agar, andSalmonella Shigella Agar. The typical colony of Salmonella was confirmed on Triple Sugar Iron Agar, Urea agar, and L-Lysinedecarboxylation media. Phenotypic characteristics of all isolates were identified using API 20E and API 50CHE diagnostics. Based on biochemical characteristics the result showed that 18 strains obtained from different geographical origins were diverse. Four strains have similarity value 100% while the remained strains have similarity value 86.3-98.4%. All of the strains were categorized in the species of S. typhi.

  3. Micro-X-ray absorption near edge structure as a suitable probe to monitor live organisms

    International Nuclear Information System (INIS)

    Oger, Phil M.; Daniel, I.; Simionovici, A.; Picard, A.

    2008-01-01

    X-ray spectroscopies are very powerful tools to determine the chemistry of complex dilute solutes in abiotic and biotic systems. We have assayed their suitability to monitor the chemistry of complex solutions in a live biotic system. The impact of the probe on cells was quantified for 4 different cellular organisms differing in their resistance level to environmental stresses. We show that none of the organisms tested can survive the radiation doses needed for the acquisition of meaningful spectroscopic data. Therefore, on one hand, X-ray spectroscopy cannot be applied to the monitoring of single cells, and cellular damages have to be taken into account in the interpretation of the evolution of such systems. On the other hand, due to the limited extension of X-ray induced cellular damages in the culture volume, it is possible to probe a population of live cells provided that the culture to beam probe ratio is large enough to minimize the impact of mortality on the evolution of the biological system. Our results suggest that it could be possible to probe the volume in the close vicinity of a cell without affecting its activity. Using this setup we could monitor the reduction of selenite by the X-ray sensitive bacterium, Agrobacterium tumefaciens strain C58, for 24 h. This method has a great potential to monitor the respiration of various metals, such as iron, manganese and arsenic, in situ under relevant environmental conditions by live microorganisms

  4. Influence of Some Micro nutrients Quenching the Effect of g-Radiation on Plasma Lipids and Vitamin E Contents in Rats

    International Nuclear Information System (INIS)

    Zahran, A.M.; Noaman, E.; Omran, M.F.

    2003-01-01

    The effects of ionizing radiation on some biological parameters in rats have been studied. Sublethal whole body g-irradiation dose on the plasma lipid fractions and susceptibility to oxidative stress were investigated. Male albino rats were intraperitoneally injected with a-tocopheryl acetate (200 mg/kg body weight), and/or sodium selenite (0.1 mg/kg body weight), daily for two weeks before exposure to 6.5 Gy of ionizing radiation. Exposed rats to ionizing radiation showed significant alterations in the assayed parameters indicating lipid metabolism disturbances. The combined administration of a-tocopherol and selenium greatly ameliorated the increase in total cholesterol, triacylglycerols, phospholipids, low-density lipoprotein- cholesterol concentration in plasma. Moreover, the data revealed an increased consumption of vitamin E concentration in plasma following g-rays exposure. Vitamin E/triacylglycerols ratio was greatly corrected by combined administration of vitamin E and Selenium. Cholesterol has a long scientific history being representing a major essential constituent for all animal cell membranes (Gurr and Harwood, 1992). Plasma lipid levels are affected by genetic and dietary factors, medication and certain primary disease states (Feldman and Kuske, 1989). Hyperlipemia may occur due to exposure to ionizing radiation resulting in accumulation of cholesterol,

  5. Selenium in edible mushrooms.

    Science.gov (United States)

    Falandysz, Jerzy

    2008-01-01

    Selenium is vital to human health. This article is a compendium of virtually all the published data on total selenium concentrations, its distribution in fruitbody, bioconcentration factors, and chemical forms in wild-grown, cultivated, and selenium-enriched mushrooms worldwide. Of the 190 species reviewed (belonging to 21 families and 56 genera), most are considered edible, and a few selected data relate to inedible mushrooms. Most of edible mushroom species examined until now are selenium-poor (cesarea, A. campestris, A. edulis, A. macrosporus, and A. silvaticus. A particularly rich source of selenium could be obtained from selenium-enriched mushrooms that are cultivated on a substrate fortified with selenium (as inorganic salt or selenized-yeast). The Se-enriched Champignon Mushroom could contain up to 30 or 110 microg Se/g dw, while the Varnished Polypore (Ganoderma lucidum) could contain up to 72 microg Se/g dw. An increasingly growing database on chemical forms of selenium of mushrooms indicates that the seleno-compounds identified in carpophore include selenocysteine, selenomethionine, Se-methylselenocysteine, selenite, and several unidentified seleno-compounds; their proportions vary widely. Some aspects of environmental selenium occurrence and human body pharmacokinetics and nutritional needs will also be briefly discussed in this review.

  6. Chromatin remodeling agent trichostatin A: a key-factor in the hepatic differentiation of human mesenchymal stem cells derived of adult bone marrow

    Directory of Open Access Journals (Sweden)

    Vinken Mathieu

    2007-04-01

    Full Text Available Abstract Background The capability of human mesenchymal stem cells (hMSC derived of adult bone marrow to undergo in vitro hepatic differentiation was investigated. Results Exposure of hMSC to a cocktail of hepatogenic factors [(fibroblast growth factor-4 (FGF-4, hepatocyte growth factor (HGF, insulin-transferrin-sodium-selenite (ITS and dexamethasone] failed to induce hepatic differentiation. Sequential exposure to these factors (FGF-4, followed by HGF, followed by HGF+ITS+dexamethasone, however, resembling the order of secretion during liver embryogenesis, induced both glycogen-storage and cytokeratin (CK18 expression. Additional exposure of the cells to trichostatin A (TSA considerably improved endodermal differentiation, as evidenced by acquisition of an epithelial morphology, chronological expression of hepatic proteins, including hepatocyte-nuclear factor (HNF-3β, alpha-fetoprotein (AFP, CK18, albumin (ALB, HNF1α, multidrug resistance-associated protein (MRP2 and CCAAT-enhancer binding protein (C/EBPα, and functional maturation, i.e. upregulated ALB secretion, urea production and inducible cytochrome P450 (CYP-dependent activity. Conclusion hMSC are able to undergo mesenchymal-to-epithelial transition. TSA is hereby essential to promote differentiation of hMSC towards functional hepatocyte-like cells.

  7. Variation of the distribution coefficient (Kd) of selenium in soils under various microbial states

    International Nuclear Information System (INIS)

    Fevrier, L.; Martin-Garin, A.; Leclerc, E.

    2007-01-01

    This study aimed to (i) evaluate whether the K d value of selenium is dependent upon the soil microbial activity and (ii) define the limitation of the use of the K d concept to describe selenium behaviour in soils when assessing the long-term radiological waste disposal risk. K d coefficients, as well as information on selenite speciation in the soil-solution, were derived from short- and long-term batch experiments with a calcareous silty clay soil in various microbial states. Soil microbial activity induced (i) an increase of the K d value from 16 l kg -1 in sterile conditions to 130 l kg -1 when the soil was amended with glucose and nitrate, and (ii) changes in selenium speciation both in the solution (presence of seleno-species other than free Se(IV)) and in the solid phase (Se linked to microorganisms). Although the K d coefficient adequately reflects the initial fractionation between soil-solid and soil-solution, it does not allow for speciation and microbial processes, which could affect reversibility, mobility and the long-term accumulation and uptake into crops

  8. Micro-X-ray absorption near edge structure as a suitable probe to monitor live organisms

    Energy Technology Data Exchange (ETDEWEB)

    Oger, Phil M. [Laboratoire de Sciences de la Terre, UMR CNRS 5570, Ecole Normale Superieure de Lyon-Universite Claude Bernard Lyon 1, Lyon, F-69364 (France)], E-mail: poger@ens-lyon.fr; Daniel, I.; Simionovici, A.; Picard, A. [Laboratoire de Sciences de la Terre, UMR CNRS 5570, Ecole Normale Superieure de Lyon-Universite Claude Bernard Lyon 1, Lyon, F-69364 (France)

    2008-04-15

    X-ray spectroscopies are very powerful tools to determine the chemistry of complex dilute solutes in abiotic and biotic systems. We have assayed their suitability to monitor the chemistry of complex solutions in a live biotic system. The impact of the probe on cells was quantified for 4 different cellular organisms differing in their resistance level to environmental stresses. We show that none of the organisms tested can survive the radiation doses needed for the acquisition of meaningful spectroscopic data. Therefore, on one hand, X-ray spectroscopy cannot be applied to the monitoring of single cells, and cellular damages have to be taken into account in the interpretation of the evolution of such systems. On the other hand, due to the limited extension of X-ray induced cellular damages in the culture volume, it is possible to probe a population of live cells provided that the culture to beam probe ratio is large enough to minimize the impact of mortality on the evolution of the biological system. Our results suggest that it could be possible to probe the volume in the close vicinity of a cell without affecting its activity. Using this setup we could monitor the reduction of selenite by the X-ray sensitive bacterium, Agrobacterium tumefaciens strain C58, for 24 h. This method has a great potential to monitor the respiration of various metals, such as iron, manganese and arsenic, in situ under relevant environmental conditions by live microorganisms.

  9. Selenium-substituted hydroxyapatite nanoparticles and their in vivo antitumor effect on hepatocellular carcinoma.

    Science.gov (United States)

    Yanhua, Wang; Hao, Hang; Li, Yan; Zhang, Shengmin

    2016-04-01

    Absence of curative treatment creates urgent need for new strategies for unresectable hepatoma. Novel selenium-substituted hydroxyapatite nanoparticles (SeHAN) were designed to serve as anticancer agent. The authors examined the nanoparticles by physicochemical techniques. The in vivo efficacy and toxicity of these nanoparticles were also investigated on a nude mice model of human hepatocellular carcinoma. The results showed that the selenite ions can be incorporated into the hydroxyapatite lattice facilely. They exhibited bundles of needles shape with a size of 160-200 nm. In the in vivo study, they showed better survival advantage. The overall survival rate of nude mice in the control, pure hydroxyapatite and SeHAN group were 50.00%, 76.92%, and 100.00% respectively. Blood biochemical studies showed that SeHAN group had significantly lower toxicities on the liver and kidney functions. Histopathological studies confirmed that massive tumor necrosis and calcium deposition were evident after SeHAN treatment. Moreover, immunohistochemistry and Western blot assay showed significantly reduced expression of the Ki-67, VEGF and MMP-9 protein in the SeHAN group. Taken together, these results suggest that the selenium-substituted hydroxyapatite nanoparticles could be a new type of promising anticancer agent to provide both survival advantage and lower toxicity. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Alternative syntheses of [73,75Se]selenoethers exemplified for homocysteine[73,75Se]selenolactone

    International Nuclear Information System (INIS)

    Ermert, J.; Blum, T.; Hamacher, K.; Coenen, H.H.

    2001-01-01

    The present work describes two radiosynthetic pathways to prepare homocysteine[ 75 Se]selenolactone 1 starting from n.c.a. [ 75 Se]selenite 2. It was achieved either by alkylation reaction of n.c.a. methyl[ 75 Se]selenide 4 or by hydrolysis of alkylated 1,3-dicyclohexyl[ 75 Se]selenourea 11. N.c.a. methyl[ 75 Se]selenide 4 is available using sulfur as non-isotopic carrier. However, the radiochemical yield of the substitution of 2-tert.-butoxycarbonylamino-4-bromobutyric acid ethylester 5 with n.c.a. methyl-[ 75 Se]selenide is only in the range of 15%-20%. Birch reduction of protected n.c.a. [ 75 Se]selenomethionine 6 formed leads to a RCY of 5%-10% homocysteine[ 75 Se]selenolactone 1. Alternatively, the synthesis of homocysteine[ 75 Se]selenolactone 1 is possible by hydrolysis of the corresponding [ 75 Se]selenouronium salt 11 available by addition of 2-tert.-butoxycarbonylamino-4-bromobutyric acid ethylester 5 to 1,3-dicyclohexyl[ 75 Se]selenourea 10. A method was developed for the synthesis of 1,3-dicyclohexyl[ 75 Se]selenourea 10 by addition of c.a. [ 75 Se]SeH 2 to 1,3-dicyclohexylcarbodiimide, which leads to 20%-30% RCY of c.a. homocysteine[ 75 Se]selenolactone 1. (orig.)

  11. Ocean floor sediment as a repository barrier: comparative diffusion data for selected radionuclides in sediments from the Atlantic and Pacific Oceans

    International Nuclear Information System (INIS)

    Schreiner, F.; Sabau, C.; Friedman, A.; Fried, S.

    1986-01-01

    Effective diffusion coefficients for selected radionuclides have been measured in ocean floor sediments to provide data for the assessment of barrier effectiveness in subseabed repositories for nuclear waste. The sediments tested include illite-rich and smectite-rich red clays from the mid plate gyre region of the Pacific Ocean, reducing sediment from the continental shelf of the northwest coast of North America, and Atlantic Ocean sediments from the Southern Nares Abyssal Plain and the Great Meteor East region. Results show extremely small effective diffusion coefficients with values less than 10 -14 m 2 s -1 for plutonium, americium, curium, thorium, and tin. Radionuclides with high diffusion coefficients of approximately 10 -10 m 2 s - include the anionic species pertechnetate, TcO 4 - , iodide, I - , and selenite, SO 3 -2 . Uranyl(VI) and neptunyl(V) ions, which are stable in solution, have diffusion coefficients around 10 -12 m 2 s -1 . The diffusion behavior of most radionuclides is similar in the oxygenated Pacific sediments and in the anoxic sediments from the Atlantic. An exception is neptunium, which is immobilized by Great Meteor East sediment, but has high mobility in Southern Nares Abyssal Plain sediment. Under stagnant conditions a 30 m thick sediment layer forms an effective geologic barrier isolating radionuclides in a subseabed repository from the biosphere

  12. Comparison of no gas and He/H2 cell modes used for reduction of isobaric interferences in selenium speciation by ion chromatography with inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Chen Zuliang; Wang Weihong; Mallavarapu, Megharaj; Naidu, Ravendra

    2008-01-01

    Inductively coupled plasma mass spectrometry (ICP-MS) used for the detection of most common selenium isotopes 78 Se (23.8%, abundance) and 80 Se (49.6%, abundance) is interfered in the presence of 38 Ar 40 Ar + and 40 Ar 40 Ar + in argon (Ar) gas. To address this issue, ICP-MS with an octopole reaction system (ORS) was explored for the detection of selenite and selenate, which was separated by anion-exchange chromatography. Results indicate that it was possible to detect 78 Se using no collusion gas, while to detect 80 Se a H 2 as the collusion/reaction gas was recommended since the background and noise were significantly reduced using H 2 as the gas. The selenium speciation interested was separated on a new column (G3154/101A, Agilent technologies) within 5 min using a mobile phase containing 10 mM NH 4 H 2 PO 4 and 20 mM NH 4 NO 3 at pH 6.5. Linear plots were obtained in a concentration range of 1-200 μg/L with detection limits less than of 0.4 μg/L for 80 Se (IV) and 0.6 μg/L for 80 Se (VI) using H 2 as the reaction gas. Finally, the proposed method was used in the determination of selenium in water and soil

  13. Preparation and characterization of a laboratory scale selenomethionine-enriched bread. Selenium bioaccessibility.

    Science.gov (United States)

    Sánchez-Martínez, María; Pérez-Corona, Teresa; Caímara, Carmen; Madrid, Yolanda

    2015-01-14

    This study focuses on the preparation at lab scale of selenomethionine-enriched white and wholemeal bread. Selenium was supplemented either by adding selenite directly to the dough or by using lab-made selenium-enriched yeast. The best results were obtained when using fresh selenium-enriched yeast. The optimum incubation time for selenomethionine-enriched yeast preparation, while keeping formation of selenium byproducts to a minimum, was 96 h. Selenium content measured by isotope dilution analysis (IDA)-ICP-MS in Se-white and Se-wholemeal bread was 1.28 ± 0.02 μg g–1 and 1.16 ± 0.02 μg g–1 (expressed as mean ± SE, 3 replicates), respectively. HPLC postcolumn IDA-ICP-MS measurements revealed that selenomethionine was the main Se species found in Se-enriched bread, which accounted for ca. 80% of total selenium. In vitro gastrointestinal digestion assay provided selenium bioaccessibility values of 100 ± 3% and 40 ± 1% for white and wholemeal Se-enriched bread, respectively, being selenomethionine the main bioaccessible Se species in white bread, while in wholemeal bread this compound was undetectable.

  14. Dietary Selenium Levels Affect Selenoprotein Expression and Support the Interferon-γ and IL-6 Immune Response Pathways in Mice

    Directory of Open Access Journals (Sweden)

    Petra A. Tsuji

    2015-08-01

    Full Text Available Selenium is an essential element that is required to support a number of cellular functions and biochemical pathways. The objective of this study was to examine the effects of reduced dietary selenium levels on gene expression to assess changes in expression of non-selenoprotein genes that may contribute to the physiological consequences of selenium deficiency. Mice were fed diets that were either deficient in selenium or supplemented with selenium in the form of sodium selenite for six weeks. Differences in liver mRNA expression and translation were measured using a combination of ribosome profiling, RNA-Seq, microarrays, and qPCR. Expression levels and translation of mRNAs encoding stress-related selenoproteins were shown to be up-regulated by increased selenium status, as were genes involved in inflammation and response to interferon-γ. Changes in serum cytokine levels were measured which confirmed that interferon-γ, as well as IL-6, were increased in selenium adequate mice. Finally, microarray and qPCR analysis of lung tissue demonstrated that the selenium effects on immune function are not limited to liver. These data are consistent with previous reports indicating that adequate selenium levels can support beneficial immune responses, and further identify the IL-6 and interferon-γ pathways as being responsive to dietary selenium intake.

  15. Effect of Vitamin E and Selenium Supplement on Paraoxonase-1 Activity, Oxidized Low Density Lipoprotein and Antioxidant Defense in Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Mohammad-Reza Rashidi

    2011-08-01

    Full Text Available Introduction: The aim of the present study was to assess the effects of vitamin E and selenium supplementation on serum paraoxonase (PON1 activity, lipid peroxidation and antioxidant defense in streptozotocin-induced diabetic rats. Methods: Thirty two female Sprague Dawley rats were divided into 3 groups: the control group (n=8 received a standard diet; streptozotocin (STZ-induced diabetic rats (n=12, received corn oil and physiological solution; and vitamin E and selenium supplemented diabetic rats (n=12 were treated with oral administration of vitamin E (300 mg/kg and sodium selenite (0.5 mg/kg once a day for 4 weeks. Results: Significantly lower total antioxidant status (TAS, PON1and erythrocyte SOD activities and a higher fasting plasma glucose level were observed in the diabetic rats compared to the control. A significant increase in SOD and GPX activities in vitamin E and selenium supplemented diabetic group was observed after 5 weeks of the experiment. Compared to the normal rats, malondialdehyde (MDA and oxidized LDL (Ox-LDL levels were higher in the diabetic animals; however, these values reduced significantly following vitamin E and selenium supplementation. Conclusion: Vitamin E and selenium supplementation in diabetic rats has hypolipidemic, hypoglycemic and antioxidative effects and may slow down the progression of diabetic complications through its protective effect on PON1 activity and lipoproteins oxidation.

  16. تاثیر کلیستین سولفات داخل دان بر روی کنترل آلودگی با سالمونلا انتریتیدیس در یک مزرعه پرورش مرغ گوشتی

    Directory of Open Access Journals (Sweden)

    محمدحسن بزرگمهری فرد

    2004-06-01

    Full Text Available The effect of colistin sulfate on reducing Salmonella enteritidis (S.enteritidis infection in broilers and contamination from broiler carcasses was evaluated. 40000 birds in two separate houses were considered. Colistin sulfate was added in to the feed of the test group as 100g containing 1,200,000IU/ton of feed for the whole period (56 days. To isolate S.enteritidis, samples were taken from different parts of the intestine and cultured in Selenite broth and then on SS agar plates. The suspected colonies were isolated and identified by biochemical and serological tests. It is conducted that the addition of the above mentioned amount of this antibiotic in to the broiler feed could decrease the rate of the infection of flocks and contamination of carcasses with S.enteritidis. The results also indicate that due to addition of colistin sulfate, the live weight gain increases by 14% and the feed conversion rate improves by 8% in this study.

  17. A reflectance flow-through thionine sol-gel sensor for the determination of Se(IV).

    Science.gov (United States)

    Carvalhido, Joana A E; Almeida, Agostinho A; Araújo, Alberto N; Montenegro, Maria C B S M

    2010-01-01

    In this work, a reversible sensor to assess the total Se(IV) content in samples is described. Pre-activated glass slides were spin-coated with 100 microL of a 20-h aged sol-gel mixture of 1 mL of tetramethoxysilane, 305 microL of 50 mmol L(-1) HCl and 2.0 mg of thionine. The flow-cell consisted of one of those slides as a window, and was filled with beads of a polystyrene anionic exchange resin to retain Se(IV) in the form of selenite ions. A reflectance transduction scheme at a wavelength of 596 nm was adopted. The cell was coupled to a multicommutation flow system where a programmed volume of a sample solution and 373 microL of 0.4 mmol L(-1) iodide in a 1.6 mol L(-1) HCl solution were sequentially inserted into the cell. The iodine produced from the reaction of retained Se(IV) with iodide bleached the blue color of thionine. Considering a sample volume of 2.30 mL, with which the preconcentration step was minimized, a linear dynamic working range between 1.5 to 20 microg mL(-1) and a detection limit of 0.29 microg mL(-1) were obtained. The sensor enabled us to perform approximately 200 assays, and provided results similar to those of electrothermal atomic absorption spectrometry.

  18. Selenoamino Acid-Enriched Green Pea as a Value-Added Plant Protein Source for Humans and Livestock.

    Science.gov (United States)

    Garousi, Farzaneh; Domokos-Szabolcsy, Éva; Jánószky, Mihály; Kovács, Andrea Balláné; Veres, Szilvia; Soós, Áron; Kovács, Béla

    2017-06-01

    Selenium deficiency in various degrees affects around 15% of the world's population, contributing to a variety of health problems. In this study, we examined the accumulation and biotransformation of soil applied Se-supplementation (sodium selenite and sodium selenate forms) at different concentrations, along with growth and yield formation of green pea, in a greenhouse experiment. Biotransformation of inorganic Se was evaluated using HPLC-ICP-MS for Se-species separation in the above ground parts of green pea. Results showed 3 mg kg -1 Se IV increased green pea growth biomarkers and also caused an increase in protein content in leaves by 17%. Selenomethionine represented 65% of the total selenium content in shoots, but was lower in pods and seeds (54 and 38%, respectively). Selenomethionine was the major species in all plant parts and the only organic selenium form in the lower Se IV concentration range. Elevating the dose of Se IV (≥30 mg kg -1 ) triggered detrimental effects on growth and protein content and caused higher accumulation of inorganic Se in forms of Se VI and Se IV . Selenocysteine, another organic form of proteinogenic amino acid, was determined when Se IV (≥10 mg kg -1 ) was applied in higher concentrations. Thus, agronomic biofortification using the appropriate chemical form and concentration of Se will have positive effects on green pea growth and its enriched shoots and seeds provide a value-added protein source for livestock and humans with significant increased selenomethionine.

  19. Selenium accumulation and metabolism in algae.

    Science.gov (United States)

    Schiavon, Michela; Ertani, Andrea; Parrasia, Sofia; Vecchia, Francesca Dalla

    2017-08-01

    Selenium (Se) is an intriguing element because it is metabolically required by a variety of organisms, but it may induce toxicity at high doses. Algae primarily absorb selenium in the form of selenate or selenite using mechanisms similar to those reported in plants. However, while Se is needed by several species of microalgae, the essentiality of this element for plants has not been established yet. The study of Se uptake and accumulation strategies in micro- and macro-algae is of pivotal importance, as they represent potential vectors for Se movement in aquatic environments and Se at high levels may affect their growth causing a reduction in primary production. Some microalgae exhibit the capacity of efficiently converting Se to less harmful volatile compounds as a strategy to cope with Se toxicity. Therefore, they play a crucial role in Se-cycling through the ecosystem. On the other side, micro- or macro-algae enriched in Se may be used in Se biofortification programs aimed to improve Se content in human diet via supplementation of valuable food. Indeed, some organic forms of selenium (selenomethionine and methylselenocysteine) are known to act as anticarcinogenic compounds and exert a broad spectrum of beneficial effects in humans and other mammals. Here, we want to give an overview of the developments in the current understanding of Se uptake, accumulation and metabolism in algae, discussing potential ecotoxicological implications and nutritional aspects. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Selenium Homeostasis and Clustering of Cardiovascular Risk Factors: A Systematic Review.

    Science.gov (United States)

    Gharipour, Mojgan; Sadeghi, Masoumeh; Behmanesh, Mehrdad; Salehi, Mansour; Nezafati, Pouya; Gharpour, Amin

    2017-10-23

      Selenium is a trace element required for a range of cellular functions. It is widely used for the biosynthesis of the unique amino acid selenocysteine [Sec], which is a structural element of selenoproteins. This systematic review focused on the possible relation between selenium and metabolic risk factors. The literature was searched via PubMed, Scopus, ISI Web of Science, and Google Scholar. Searches were not restricted by time or language. Relevant studies were selected in three phases. After an initial quality assessment, two reviewers extracted all the relevant data, whereas the third reviewer checked their extracted data. All evidence came from experimental and laboratory studies. Selenoprotein P is the best indicator for selenium nutritional levels. In addition, high levels of selenium may increase the risk of metabolic syndrome while the lack of sufficient selenium may also promote metabolic syndrome. selenium supplementation in subjects with sufficient serum selenium levels has a contrary effect on blood pressure, LDL, and total cholesterol. According to the bioavailability of different types of selenium supplementation such as selenomethionine, selenite and selenium-yeast, it seems that the best nutritional type of selenium is selenium-yeast. Regarding obtained results of longitudinal studies and randomized controlled trials, selenium supplementation should not be recommended for primary or secondary cardio-metabolic risk prevention in populations with adequate selenium status.

  1. Effect of selenium supplementation on pigeon reproductive performance, selenium concentration and antioxidant status.

    Science.gov (United States)

    Wang, Y; Yang, H M; Cao, W; Li, Y B

    2017-09-01

    The effects of dietary supplementation of sodium selenite (SS) on the reproductive performance and the concentration of selenium, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and malondialdehyde (MDA) were determined, and expression of glutathione peroxidase 4 (GPx4) and bone morphogenic protein 15 (BMP15) was evaluated. Paired pigeons (n = 864) were fed: T1 received no SS, while T2, T3, and T4 received 0.5, 1.0, and 1.5 mg of SS/kg of dry matter (DM), respectively. Treatments were performed in triplicate with 72 pairs in each replicate. The results showed that selenium supplementation significantly affected pigeon reproductive performance. Birds fed 1.0 mg of SS/kg displayed higher egg production (P > 0.05), higher birth rate, and lower dead sperm rate than the control group (P Selenium and biochemical analyses revealed a higher selenium concentration in the 1.5 mg of SS/kg group than in the control group (P  0.05); however, in plasma, MDA was lower in the control group (P  0.05), while in ovary, BMP15 was down-regulated in the 1.5 mg of SS/kg group (P selenium concentration, and 0.5 mg of SS/kg up-regulated GSH-Px activity. © 2017 Poultry Science Association Inc.

  2. Genotoxic and antigenotoxic properties of selenium compounds in the in vitro micronucleus assay with human whole blood lymphocytes and tk6 lymphoblastoid cells

    Directory of Open Access Journals (Sweden)

    Eduard Cemeli

    2006-01-01

    Full Text Available Selenium is known to possess both genotoxic and antigenotoxic properties. In the present study, we have evaluated the genotoxicity and antigenotoxicity of three selenium compounds (sodium selenate, sodium selenite and selenous acid by measuring in vitro micronucleus induction. Assays were conducted in whole blood lymphocytes and in the TK6 lymphoblastoid cell line, with and without co-treatment with potassium dichromate, a known genotoxic compound. In general, the compounds were more active in TK6 cells than they were in blood lymphocytes. Only 1 μM selenous acid increased the frequency of binucleated cells containing micronuclei (BNMN in blood lymphocytes, while all three selenium compounds increased BNMN in TK6 cells. In addition, combinations of selenous acid and potassium dichromate resulted in lower frequencies of BNMN than potassium dichromate alone in blood lymphocytes, while combinations of sodium selenate and potassium dichromate produced lower frequencies of BNMN than potassium dichromate alone in TK6 cells. The concentrations of selenium compounds that were used, in combination with the medium components and the biological physiology of the whole blood lymphocytes and TK6 cells, could have affected the redox potential of the compounds, switching the chemicals from a pro-oxidant to antioxidant status and vice-versa. The lower activities of the compounds in blood lymphocytes may be due to the protective effects of blood components. The results indicate that the genotoxic and antigenotoxic properties of selenium compounds are highly dependent upon the conditions under which they are evaluated.

  3. Characterization and Quantitation of Triterpenoid Saponins in Raw and Sprouted Chenopodium berlandieri spp. (Huauzontle) Grains Subjected to Germination with or without Selenium Stress Conditions.

    Science.gov (United States)

    Lazo-Vélez, Marco A; Guajardo-Flores, Daniel; Mata-Ramírez, Daniel; Gutiérrez-Uribe, Janet A; Serna-Saldivar, Sergio O

    2016-01-01

    Pseudocereal Chenopodium berlandieri spp. (huauzontle) was evaluated to determine saponin composition. Saponins were evaluated in raw and germinated grains subjected to chemical stress induced by sodium selenite. Analysis by liquid chromatography coupled with ELSD detector revealed the presence of 12 saponins, identified according to compounds previously assayed in Chenopodium quinoa. Saponins found at the highest concentrations in raw grains were derived from oleanolic and phytolaccagenic acids. Total saponin concentration significantly decreased in germinated compared to raw grains due to the significant loss of 90.1% and 95.7% of the phytolaccagenic acid without and with chemical selenium stress, respectively. The most abundant saponin in germinated sprouts decreased during normal germination. Interestingly, the concentration of this particular saponin significantly increased during the Se-induced stress germination. Chemical stress with selenium salts proved to change the saponin composition in geminated Chenopodium berlandieri spp. grains, therefore affecting their potential use as ingredient in the food industry. © 2015 Institute of Food Technologists®

  4. Selenium content of tissues in Finnish infants and adults with various diseases, and studies on the effects of selenium supplementation in neuronal ceroid lipofuscinosis patients

    International Nuclear Information System (INIS)

    Westermarck, T.

    1977-01-01

    A low blood selenium level has previously been observed in healthy inhabitants of Finland. In this study even lower blood selenium values were observed in patients with acrodermatitis enteropathica, dystrophia musculorum progressiva (Duchenne), infantile and juvenile type of neuronal ceroid lipofuscinosis (NCL), severe mental retardation caused by various factors, and myocardial infarction. The selenium content of the brain, heart, kidney and liver in patients of different ages was also determined. The highest selenium level was found in the kidney. The mean liver selenium concentrations in stillborn, premature and full-term neonates were 1.11 plus minus 0.23 (8), 1.21 plus minus 0.17 (12) and 0.93 plus minus 0.16 μg/g dry weight (12) respectively (the number of subjects in parentheses). The selenium values are considerably higher than those in infants of from one to nine months of age and adults, whose liver selenium values were 0.58 plus minus 0.21 (8) and 0.67 plus minus 0.08 μg/g dry weight (8) respectively. The vitamin E levels of serum in patients with NCL, as well as in subjects with severe mental retardation (controls), were low compared with values in healthy normal subjects. Sodium selenite supplementation in patients with NCL produced at least a transitory improvement without causing any toxic effects during one year of administration. (author)

  5. Effect of Selenium on Control of Postharvest Gray Mold of Tomato Fruit and the Possible Mechanisms Involved

    Science.gov (United States)

    Wu, Zhilin; Yin, Xuebin; Bañuelos, Gary S.; Lin, Zhi-Qing; Zhu, Zhu; Liu, Ying; Yuan, Linxi; Li, Miao

    2016-01-01

    Selenium (Se) has important benefits for crop growth and stress tolerance at low concentrations. However, there is very little information on antimicrobial effect of Se against the economically important fungus Botrytis cinerea. In the present study, using sodium selenite as Se source, we investigated the effect of Se salts on spore germination and mycelial growth of the fungal pathogen in vitro and gray mold control in harvested tomato fruit. Se treatment at 24 mg/L significantly inhibited spore germination of the fungal pathogen and effectively controlled gray mold in harvested tomato fruit. Se treatment at 24 mg/L seems to induce the generation of intracellular reactive oxygen species in the fungal spores. The membrane integrity damage was observed with fluorescence microscopy following staining with propidium iodide after treatment of the spores with Se. These results suggest that Se has the potential for controlling gray mold rot of tomato fruits and might be useful in integrated control against gray mold disease of postharvest fruits and vegetables caused by B. cinerea. The mechanisms by which Se decreased gray mold decay of tomato fruit may be directly related to the severe damage to the conidia plasma membrane and loss of cytoplasmic materials from the hyphae. PMID:26779128

  6. Overexpressing both ATP sulfurylase and selenocysteine methyltransferase enhances selenium phytoremediation traits in Indian mustard

    International Nuclear Information System (INIS)

    LeDuc, Danika L.; AbdelSamie, Manal; Montes-Bayon, Maria; Wu, Carol P.; Reisinger, Sarah J.; Terry, Norman

    2006-01-01

    A major goal of our selenium (Se) phytoremediation research is to use genetic engineering to develop fast-growing plants with an increased ability to tolerate, accumulate, and volatilize Se. To this end we incorporated a gene (encoding selenocysteine methyltransferase, SMT) from the Se hyperaccumulator, Astragalus bisulcatus, into Indian mustard (LeDuc, D.L., Tarun, A.S., Montes-Bayon, M., Meija, J., Malit, M.F., Wu, C.P., AbdelSamie, M., Chiang, C.-Y., Tagmount, A., deSouza, M., Neuhierl, B., Boeck, A., Caruso, J., Terry, N., 2004. Overexpression of selenocysteine methyltransferase in Arabidopsis and Indian mustard increases selenium tolerance and accumulation Plant Physiol. 135, 377-383.). The resulting transgenic plants successfully enhanced Se phytoremediation in that the plants tolerated and accumulated Se from selenite significantly better than wild type. However, the advantage conferred by the SMT enzyme was much less when Se was supplied as selenate. In order to enhance the phytoremediation of selenate, we developed double transgenic plants that overexpressed the gene encoding ATP sulfurylase (APS) in addition to SMT, i.e., APS x SMT. The results showed that there was a substantial improvement in Se accumulation from selenate (4 to 9 times increase) in transgenic plants overexpressing both APS and SMT. - Simultaneous overexpression of APS and SMT genes in Indian mustard greatly increases ability to accumulate selenate

  7. Intracellular Diagnostics: Hunting for the Mode of Action of Redox-Modulating Selenium Compounds in Selected Model Systems

    Directory of Open Access Journals (Sweden)

    Dominika Mániková

    2014-08-01

    Full Text Available Redox-modulating compounds derived from natural sources, such as redox active secondary metabolites, are currently of considerable interest in the field of chemoprevention, drug and phytoprotectant development. Unfortunately, the exact and occasionally even selective activity of such products, and the underlying (bio-chemical causes thereof, are often only poorly understood. A combination of the nematode- and yeast-based assays provides a powerful platform to investigate a possible biological activity of a new compound and also to explore the “redox link” which may exist between its activity on the one side and its chemistry on the other. Here, we will demonstrate the usefulness of this platform for screening several selenium and tellurium compounds for their activity and action. We will also show how the nematode-based assay can be used to obtain information on compound uptake and distribution inside a multicellular organism, whilst the yeast-based system can be employed to explore possible intracellular mechanisms via chemogenetic screening and intracellular diagnostics. Whilst none of these simple and easy-to-use assays can ultimately substitute for in-depth studies in human cells and animals, these methods nonetheless provide a first glimpse on the possible biological activities of new compounds and offer direction for more complicated future investigations. They may also uncover some rather unpleasant biochemical actions of certain compounds, such as the ability of the trace element supplement selenite to induce DNA strand breaks.

  8. Combination cancer treatment through photothermally controlled release of selenous acid from gold nanocages.

    Science.gov (United States)

    Cheng, Haoyan; Huo, Da; Zhu, Chunlei; Shen, Song; Wang, Wenxia; Li, Haoxuan; Zhu, Zhihong; Xia, Younan

    2018-04-03

    Selenite, one of the inorganic forms of selenium, is emerging as an attractive chemotherapeutic agent owing to its selectivity in eradicating cancer cells. Here we demonstrate a new formulation of nanomedicine based on selenous acid, which is mixed with lauric acid (a phase-change material with a melting point around 43 °C) and then loaded into the cavities of Au nanocages. The Au nanocages can serve as a carrier during cell endocytosis and then as a photothermal agent to melt the lauric acid upon the irradiation with a near-infrared laser, triggering the swift release of selenous acid. The photothermal and chemo therapies can also work synergistically, leading to enhanced destruction of cancer cells relative to normal cells. Our systematic study suggests that the impaired mitochondrial function arising from the ROS generated through combination treatment is responsible for the cell death. This study offers an appealing candidate that holds great promise for synergistic cancer treatment. Published by Elsevier Ltd.

  9. Absorption mechanisms for cationic and anionic mineral species on ferric iron polymer hydroxides and oxidation products of ferrous iron in aqueous media

    International Nuclear Information System (INIS)

    Gandon, Remi

    1982-01-01

    Adsorbents obtained by hydrolysing the Fe 3+ , 6H 2 O ion are made of polymers with aquo (H 2 O), hydroxo (-OH...) and oxo (...O...) ligands. Radioactive tracers reveal the importance of chemical mechanisms in adsorption phenomena on ferric oxide in aqueous media. Zn 2+ , Co 2+ and Mn 2+ cations are exchanged with hydrogen from hydroxo groups. CrO 4 2- , SeO 3 2- and Sb(OH) 6 - anions form covalent associations in place of iron ligands. The adsorption of hydrolyzed ions results in strong oxygen bridge bonds. In fresh water, Co and Mn participate alone in physical electrostatic adsorption. Iron II oxidation products generate chemical adsorptions. Zn 2+ and Sb(OH) 6 - associate with ferric hydroxides from oxidized Fe 2+ . 60 Co, 54 Mn and 51 Cr form covalent associations between unpaired 3d iron electrons and the adsorbed element. This process is not predominant with selenium IV or VI reduced to the metallic state or fixed on ferric hydroxide in the selenite form. These conclusions can be applied to pollutant analysis and to water purification and contribute to our understanding of the role of iron in the distribution of oligo-elements in aqueous media. (author) [fr

  10. The Caves of Naica: a decade of research; Las Cuevas de Naica: una decada de investigacion

    Energy Technology Data Exchange (ETDEWEB)

    Gazquez, F.; Calaforra, J. M.; Porti, P.; Badino, G.

    2016-07-01

    The caves of the Naica Mine have been the subject of study by scientists from up to seven counties over the past decade. Up to fifty research works have published to date, most relating to the origin of the giant selenite crystals of the Cueva de los Cristales. Nevertheless, a great deal of knowledge has been generated about other relevant aspects of the Naica system. This paper puts together the vast information available about the Naica caves, from the discovery of the Cueva de los Cristales in 2000 to the more recent investigations addressing mineralogy, microclimatology and the use of gypsum speleothems as a palaeo-environmental proxy. Special attention has been paid to novel research lines that have started to use the speleothems of Naica as a study case, particularly in fields such as Astrobiology and Planetary geology. Moreover, the conservation challenges which these caves will face in the near future as consequence of the end of mining activities have also been addressed in this article. (Author)

  11. Optical and structural properties of natural MnSeO{sub 4} mineral thin film

    Energy Technology Data Exchange (ETDEWEB)

    Kariper, Ishak Afsin, E-mail: akariper@gmail.com [Erciyes University, Education Faculty, Kayseri (Turkey)

    2017-05-15

    Manganese selenite (MnSeO{sub 4}) crystalline thin film has been produced with chemical bath deposition on substrates (commercial glass). Properties of the thin film, such as transmittance, absorption, and optical band gap and refraction index have been investigated via UV/VIS Spectrum. The structural properties of orthorhombic form have been observed in XRD. The structural and optical properties of MnSeO{sub 4} thin films, deposited at different pH levels were analyzed. Some properties of the films have been changed with the change of pH level, which has been deeply investigated. The grain size of MnSeO{sub 4} thin film has reached its highest value at pH 9. The refraction index and extinction coefficient of MnSeO{sub 4} thin films were measured to be 1.53, 2.86, 2.07, 1.53 (refraction index) and 0.005, 0.029, 0.014, 0.005 (extinction coefficient) for grain sizes 21, 13, 26, and 5 nm respectively. The band gaps (Eg) of the films were measured to be 2.06, 2.57, 2.04, and 2.76 eV for the grain sizes mentioned above. The value of dielectric constant at pH 10 was calculated as 1.575. (author)

  12. Stabilization/solidification of selenium-impacted soils using Portland cement and cement kiln dust

    International Nuclear Information System (INIS)

    Moon, Deok Hyun; Grubb, Dennis G.; Reilly, Trevor L.

    2009-01-01

    Stabilization/solidification (S/S) processes were utilized to immobilize selenium (Se) as selenite (SeO 3 2- ) and selenate (SeO 4 2- ). Artificially contaminated soils were prepared by individually spiking kaolinite, montmorillonite and dredged material (DM; an organic silt) with 1000 mg/kg of each selenium compound. After mellowing for 7 days, the Se-impacted soils were each stabilized with 5, 10 and 15% Type I/II Portland cement (P) and cement kiln dust (C) and then were cured for 7 and 28 days. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effectiveness of the S/S treatments. At 28 days curing, P doses of 10 and 15% produced five out of six TCLP-Se(IV) concentrations below 10 mg/L, whereas only the 15% C in DM had a TCLP-Se(IV) concentration 3 .H 2 O) and selenate substituted ettringite (Ca 6 Al 2 (SeO 4 ) 3 (OH) 12 .26H 2 O), respectively.

  13. The central role of selenium in the biochemistry and ecology of the harmful pelagophyte, Aureococcus anophagefferens

    Energy Technology Data Exchange (ETDEWEB)

    Gobler, Christopher J.; Lobanov, Alexei V.; Tang, Ying-Zhong; Turanov, Anton A.; Zhang, Yan; Doblin, Martina; Taylor, Gordon T.; Sañudo-Wilhelmy, Sergio A.; Grigoriev, Igor V.; Gladyshev, Vadim N.

    2013-03-07

    The trace element selenium (Se) is required for the biosynthesis of selenocysteine (Sec), the 21st amino acid in the genetic code, but its role in the ecology of harmful algal blooms (HABs) is unknown. Here, we examined the role of Se in the biology and ecology of the harmful pelagophyte, Aureococcus anophagefferens, through cell culture, genomic analyses, and ecosystem studies. This organism has the largest and the most diverse selenoproteome identified to date that consists of at least 59 selenoproteins, including known eukaryotic selenoproteins, selenoproteins previously only detected in bacteria, and novel selenoproteins. The A. anophagefferens selenoproteome was dominated by the thioredoxin fold proteins and oxidoreductase functions were assigned to the majority of detected selenoproteins. Insertion of Sec in these proteins was supported by a unique Sec insertion sequence. Se was required for the growth of A. anophagefferens as cultures grew maximally at nanomolar Se concentrations. In a coastal ecosystem, dissolved Se concentrations were elevated before and after A. anophagefferens blooms, but were reduced by >95percent during the peak of blooms to 0.05 nM. Consistent with this pattern, enrichment of seawater with selenite before and after a bloom did not affect the growth of A. anophagefferens, but enrichment during the peak of the bloom significantly increased population growth rates. These findings demonstrate that Se inventories, which can be anthropogenically enriched, can support proliferation of HABs, such as A. anophagefferens through its synthesis of a large arsenal of Se-dependent oxidoreductases that fine-tune cellular redox homeostasis.

  14. Screening of new substances for radiation protection and technology development of efficacy improvement

    International Nuclear Information System (INIS)

    Yoo, Byung Sun; Park, Sun Young; Jang, Eun Jung

    2005-03-01

    To evaluate the radioprotective efficacy of candidate compounds, we examined the effects of selenium compounds, melatonin, and propolis on the colony forming efficiency (CFE) of gamma-irradiated CHO cells. - Protective effects of selenium compounds against radiation-induced cytotoxicity Sodium selenite showed protective effects at low concentrations against radiation-induced toxicity in CHO cells, whereas its effects were weak at higher concentrations. Selenomethionine also reduced the radiation-induced cytotoxicity. Both of these compounds showed highest protective effects at the concentration of 1 uM. - Protective effects of melatonin against radiation-induced cytotoxicity Melatonin showed the protective effects against radiation-induced cytotoxicity, and the protection was highest at 1 mM concentration. - Protective effects of selenium compounds against hydrogen peroxide-induced cytotoxicity Propolis showed dose-dependent inhibition of hydrogen peroxide-induced cytotoxicity. In particular, the highest inhibition was observed when propolis were treated at 0.3 and 1 ng/ml 24h prior to the hydrogen peroxide treatment. The protective effects of propolis was observed only when it was pretreated at least 8 hours before hydrogen peroxide treatment

  15. Selenium regulates gene expression of selenoprotein W in chicken skeletal muscle system.

    Science.gov (United States)

    Ruan, Hongfeng; Zhang, Ziwei; Wu, Qiong; Yao, Haidong; Li, Jinlong; Li, Shu; Xu, Shiwen

    2012-01-01

    Selenoprotein W (SelW) is abundantly expressed in skeletal muscles of mammals and necessary for the metabolism of skeletal muscles. However, its expression pattern in skeletal muscle system of birds is still uncovered. Herein, to investigate the distribution of SelW mRNA in chicken skeletal muscle system and its response to different selenium (Se) status, 1-day-old chickens were exposed to various concentrations of Se as sodium selenite in the feed for 35 days. In addition, myoblasts were treated with different concentrations of Se in the medium for 72 h. Then the levels of SelW mRNA in skeletal muscles (wing muscle, pectoral muscle, thigh muscle) and myoblasts were determined on days 1, 15, 25, and 35 and at 0, 24, 48, and 72 h, respectively. The results showed that SelW was detected in all these muscle components and it increased both along with the growth of organism and the differentiation process of myoblasts. The thigh muscle is more responsive to Se intake than the other two skeletal muscle tissues while the optimal Se supplementation for SelW mRNA expression in chicken myoblasts was 10(-7) M. In summary, Se plays important roles in the development of chicken skeletal muscles. To effect optimal SelW gene expression, Se must be provided in the diet and the media in adequate amounts and neither at excessive nor deficient levels.

  16. Charge carrier transport and collection enhancement of copper indium diselenide photoactive nanoparticle-ink by laser crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Nian, Qiong; Cheng, Gary J., E-mail: gjcheng@purdue.edu [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47906 (United States); School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47906 (United States); Zhang, Martin Y. [School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47906 (United States); Wang, Yuefeng [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47906 (United States); School of Materials Engineering, Purdue University, West Lafayette, Indiana 47906 (United States); Das, Suprem R.; Bhat, Venkataprasad S. [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47906 (United States); Huang, Fuqiang [Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050 (China)

    2014-09-15

    There has been increasing needs for cost-effective and high performance thin film deposition techniques for photovoltaics. Among all deposition techniques, roll-to-roll printing of nanomaterials has been a promising method. However, the printed thin film contains many internal imperfections, which reduce the charge-collection performance. Here, direct pulse laser crystallization (DPLC) of photoactive nanoparticles-inks is studied to meet this challenge. In this study, copper indium selenite (CIS) nanoparticle-inks is applied as an example. Enhanced crystallinity, densified structure in the thin film is resulted after DLPC under optimal conditions. It is found that the decreased film internal imperfections after DPLC results in reducing scattering and multi-trapping effects. Both of them contribute to better charge-collection performance of CIS absorber material by increasing extended state mobility and carrier lifetime, when carrier transport and kinetics are coupled. Charge carrier transport was characterized after DPLC, showing mobility increased by 2 orders of magnitude. Photocurrent under AM1.5 illumination was measured and shown 10 times enhancement of integrated power density after DPLC, which may lead to higher efficiency in photo-electric energy conversion.

  17. Understanding reduced inorganic mercury accumulation in rice following selenium application: Selenium application routes, speciation and doses.

    Science.gov (United States)

    Tang, Wenli; Dang, Fei; Evans, Douglas; Zhong, Huan; Xiao, Lin

    2017-02-01

    Selenium (Se) has recently been demonstrated to reduce inorganic mercury (IHg) accumulation in rice plants, while its mechanism is far from clear. Here, we aimed at exploring the potential effects of Se application routes (soil or foliar application with Se), speciation (selenite and selenate), and doses on IHg-Se antagonistic interactions in soil-rice systems. Results of our pot experiments indicated that soil application but not foliar application could evidently reduce tissue IHg concentrations (root: 0-48%, straw: 15-58%, and brown rice: 26-74%), although both application routes resulted in comparable Se accumulation in aboveground tissues. Meanwhile, IHg distribution in root generally increased with amended Se doses in soil, suggesting antagonistic interactions between IHg and Se in root. These results provided initial evidence that IHg-Se interactions in the rhizosphere (i.e., soil or rice root), instead of those in the aboveground tissues, could probably be more responsible for the reduced IHg bioaccumulation following Se application. Furthermore, Se dose rather than Se speciation was found to be more important in controlling IHg accumulation in rice. Our findings regarding the importance of IHg-Se interactions in the rhizosphere, together with the systematic investigation of key factors affecting IHg-Se antagonism and IHg bioaccumulation, advance our understanding of Hg dynamics in soil-rice systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. On-line pre-reduction of Se(VI) by thiourea for selenium speciation by hydride generation

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Jianhua [Department of Chemistry and the MOE Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005 (China); Wang Qiuquan [Department of Chemistry and the MOE Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005 (China)]. E-mail: qqwang@xmu.edu.cn; Ma Yuning [Department of Chemistry and the MOE Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005 (China); Yang Limin [Department of Chemistry and the MOE Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005 (China); Huang Benli [Department of Chemistry and the MOE Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005 (China)

    2006-07-15

    In this study, thiourea (TU) was novelly developed as a reduction reagent for on-line pre-reduction of selenium(VI) before conventional hydride generation (HG) by KBH{sub 4}/NaOH-HCl. After TU on-line pre-reduction, the HG efficiency of Se(VI) has been greatly improved and because even higher than that of the same amount of Se(IV) obtained in the conventional HG system. The possible pre-reduction mechanism is discussed. The detection limit (DL) of selenate reaches 10 pg mL{sup -1} when using on-line TU pre-reduction followed by HG atomic fluorescence detection. When TU pre-reduction followed by HG is used as an interface between ion-pair high performance liquid chromatography and atomic fluorescence spectrometry, selenocystine, selenomethionine, selenite and selenate can be measured simultaneously and quantitatively. The DLs of these are 0.06, 0.08, 0.05 and 0.04 ng mL{sup -1}, respectively, and the relative standard deviations of 9 duplicate runs for all the 4 species are less than 5%. Furthermore, it was successfully applied to Se speciation analysis of cultured garlic samples, and validated by determination of total selenium and selenium species in certified reference material NIST 1946.

  19. Effects of selenylation modification on immune-enhancing activity of garlic polysaccharide.

    Directory of Open Access Journals (Sweden)

    Shulei Qiu

    Full Text Available The garlic polysaccharide was modified by HNO3-Na2SeO3 method according to orthogonal design L9(3(4 to obtain nine selenizing garlic polysaccharides, sGPS1-sGPS9. Their effects on chicken peripheral lymphocytes proliferation in vitro were compared by MTT assay. The results showed that sGPSs could significantly promote lymphocytes proliferation, sGPS3, sGPS5 and sGPS6 presented stronger efficacy. In vivo experiment, 14-day-old chickens were injected respectively with sGPS3, sGPS5 and sGPS6 when they were vaccinated with ND vaccine taking unmodified GPS as control. The results showed that three sGPSs could significantly promote lymphocyte proliferation, enhance serum antibody titer, IFN-γ and IL-2 contents. These results indicated that selenylation modification could significantly enhance the immune-enhancing activity of GPS, sGPS6 possessed the best efficacy and could be as a candidate drug of immunoenhancer. Its optimal modification conditions were 400 mg of sodium selenite for 500 mg of GPS, reaction temperature of 70°C and reaction time of 6 h.

  20. Electrochemical vapor generation of selenium species after online photolysis and reduction by UV-irradiation under nano TiO{sub 2} photocatalysis and its application to selenium speciation by HPLC coupled with atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Jing; Wang, Qiuquan; Huang, Benli [Xiamen University (China). Department of Chemistry; MOE Key Laboratory of Analytical Sciences, Xiamen (China)

    2005-01-01

    An online UV photolysis and UV/TiO{sub 2} photocatalysis reduction device (UV-UV/TiO{sub 2} PCRD) and an electrochemical vapor generation (ECVG) cell have been used for the first time as an interface between high-performance liquid chromatography (HPLC) and atomic fluorescence spectrometry (AFS) for selenium speciation. The newly designed ECVG cell of approximately 115 {mu}L dead volume consists of a carbon fiber cathode and a platinum loop anode; the atomic hydrogen generated on the cathode was used to reduce selenium to vapor species for AFS determination. The noise was greatly reduced compared with that obtained by use of the UV-UV/TiO{sub 2} PCRD-KBH{sub 4}-acid interface. The detection limits obtained for seleno-DL-cystine (SeCys), selenite (Se{sup IV}), seleno-DL-methionine (SeMet), and selenate (Se{sup VI}) were 2.1, 2.9, 4.3, and 3.5 ng mL{sup -1}, respectively. The proposed method was successfully applied to the speciation of selenium in water-soluble extracts of garlic shoots cultured with different selenium species. The results obtained suggested that UV-UV/TiO{sub 2} PCRD-ECVG should be an effective interface between HPLC and AFS for the speciation of elements amenable to vapor generation, and is superior to methods involving KBH{sub 4}. (orig.)

  1. Solid phase extraction for the speciation and preconcentration of inorganic selenium in water samples: a review.

    Science.gov (United States)

    Herrero Latorre, C; Barciela García, J; García Martín, S; Peña Crecente, R M

    2013-12-04

    Selenium is an essential element for the normal cellular function of living organisms. However, selenium is toxic at concentrations of only three to five times higher than the essential concentration. The inorganic forms (mainly selenite and selenate) present in environmental water generally exhibit higher toxicity (up to 40 times) than organic forms. Therefore, the determination of low levels of different inorganic selenium species in water is an analytical challenge. Solid-phase extraction has been used as a separation and/or preconcentration technique prior to the determination of selenium species due to the need for accurate measurements for Se species in water at extremely low levels. The present paper provides a critical review of the published methods for inorganic selenium speciation in water samples using solid phase extraction as a preconcentration procedure. On the basis of more than 75 references, the different speciation strategies used for this task have been highlighted and classified. The solid-phase extraction sorbents and the performance and analytical characteristics of the developed methods for Se speciation are also discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. The Gypsum: White gold of Rajasthan, introduction, uses and future prospective

    Science.gov (United States)

    Sharma, Gayatri

    2013-06-01

    Rajasthan is mineral based state and Bikaner and its surrounding district have been gifted with Gypsum. Mt of Gypsum is available in these districts. Gypsum has multiple uses including basic raw material for POP industry, addition in cement and a natural fertilizer. This mineral has changes the economic scenario in the remote areas of Bikaner, Nagaur, Hanumangarh, Sanchore, Shriganganagar etc. Gypsum and selenite are mined about 3.0 million tons per year. There is huge demand from cement industry as Gypsum is added for improving setting time of cement. Gypsum is a natural fertilizer for alkaline land and it role is vital in state like India where alkaline land is major role. Its high use as fertilizer has potential to change millions of poor farmer families and improving in crop production. Cement Industry has started importing Gypsum from Thailand, Bankong, Pakistan, Iran etc. The mining of gypsum of purity of 70% CaSO4.2H2O is cooperative effort between the land owners and Rajasthan State Mines and Minerals Limited. Gypsum fulfills the demand of POP and Cement industry in Rajasthan and powder gypsum used in agriculture for recon dining of alkaline soil. This paper deals with multiple uses, availability, and future prospective of Gypsum, a white gold of Rajasthan.

  3. Simultaneous detection of selenium by atomic fluorescence and sulfur by molecular emission by flow-injection hydride generation with on-line reduction for the determination of selenate, sulfate and sulfite

    Energy Technology Data Exchange (ETDEWEB)

    Tyson, J.F., E-mail: tyson@chem.umass.edu [Department of Chemistry, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States); Palmer, C.D. [Lead Poisoning Trace Elements Laboratory, Wadsworth Center, New York State Department of Health, P.O. Box 509, Empire State Plaza, Albany, NY 12201-0509 (United States)

    2009-10-12

    An inductively coupled plasma atomic fluorescence spectrometry (ICP-AFS) instrument, was modified so that it was capable of monitoring transient chromatographic or flow-injection profiles and that sulfur molecular emission and selenium atomic fluorescence could be monitored simultaneously in an argon-hydrogen diffusion flame on a glass burner. The analytes were introduced as hydrogen selenide and hydrogen sulfide, generated on a flow-injection manifold. Selenate was reduced to hydride-forming selenite by microwave-assisted on-line reaction with hydrochloric acid, and sulfate, or sulfite, was reduced to hydride-forming sulfide by a mixture of hydriodic acid, acetic acid and sodium hypophosphite. The effects of the nature of reducing agent, flow rate, microwave power and coil length were studied. The limit of detection (3 s) for selenium was 10 {mu}g L{sup -1}, and for sulfide was 70 {mu}g L{sup -1} (200-{mu}L injection volume). The calibration was linear for selenium up to 2 mg L{sup -1} and to 10 mg L{sup -1} for sulfide. The throughput was 180 h{sup -1}. The three sulfur species could be differentiated on the basis of reactivity at various microwave powers.

  4. Accumulation of heavy metals and trace elements in fluvial sediments received effluents from traditional and semiconductor industries.

    Science.gov (United States)

    Hsu, Liang-Ching; Huang, Ching-Yi; Chuang, Yen-Hsun; Chen, Ho-Wen; Chan, Ya-Ting; Teah, Heng Yi; Chen, Tsan-Yao; Chang, Chiung-Fen; Liu, Yu-Ting; Tzou, Yu-Min

    2016-09-29

    Metal accumulation in sediments threatens adjacent ecosystems due to the potential of metal mobilization and the subsequent uptake into food webs. Here, contents of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) and trace elements (Ga, In, Mo, and Se) were determined for river waters and bed sediments that received sewage discharged from traditional and semiconductor industries. We used principal component analysis (PCA) to determine the metal distribution in relation to environmental factors such as pH, EC, and organic matter (OM) contents in the river basin. While water PCA categorized discharged metals into three groups that implied potential origins of contamination, sediment PCA only indicated a correlation between metal accumulation and OM contents. Such discrepancy in metal distribution between river water and bed sediment highlighted the significance of physical-chemical properties of sediment, especially OM, in metal retention. Moreover, we used Se XANES as an example to test the species transformation during metal transportation from effluent outlets to bed sediments and found a portion of Se inventory shifted from less soluble elemental Se to the high soluble and toxic selenite and selenate. The consideration of environmental factors is required to develop pollution managements and assess environmental risks for bed sediments.

  5. Production of urinary selenium metabolites in the rat following 75SeO32- administration

    International Nuclear Information System (INIS)

    Kiker, K.W.; Burk, R.F.

    1974-01-01

    Urinary metabolites of 75 Se were studied in male Holtzmann rats fed a Torula yeast diet with either no selenium (basal) or 0.5 ppM selenium (selenium) added as sodium selenite. The animals were anesthetized, a ureter was cannulated, and 20 μCi of 75 SeO 3 2- were injected intraportally. Only a small fraction (1.3 percent) of the injected 75 Se was excreted in 6 h by animals fed the basal diet but 13.3 percent was excreted by animals fed the selenium diet. Paper chromatography showed that both groups excreted mostly inorganic 75 Se in the first 10 min. A decrease in 75 Se excretion followed, and then, 70 min after the collection was started, the selenium diet group had an increase in 75 Se excretion which persisted for the rest of the 6 h and consisted mainly of the organic metabolites trimethylselenonium ion and U-2. 75 Se excretion remained low in the basal diet group. Liver uptake and release of 75 Se in the 1 h following intraperitoneal 75 SeO 3 2- injection was much greater in the selenium diet rats than in the basal diet rats. These results suggest that the greater excretion of 75 Se by rats fed the selenium diet than that by rats fed the basal diet was due to increased production of organic urinary selenium metabolites by the liver. (U.S.)

  6. Effects of vitamin E and organic selenium on oxidative stability of omega-3 enriched dark chicken meat during cooking.

    Science.gov (United States)

    Perez, T I; Zuidhof, M J; Renema, R A; Curtis, J M; Ren, Y; Betti, M

    2010-03-01

    The influence of vitamin E and selenomethionine (SeMet) on lipid oxidation in frozen-raw and cooked omega-3 enriched dark chicken meat was evaluated. Feed was supplemented with 2 levels of vitamin E (250 and 50 IU/kg of feed) and selenium (0.1 mg of sodium selenite/kg of feed and 0.3 mg of SeMet/kg of feed). An extruded linseed product was used as the alpha-linolenic acid source. Fatty acid (FA) profile, oxysterols, and thiobarbituric reactive acid substances (TBARs) were analyzed in frozen-raw, boiled, pan-fried, and roasted meat. After 6 mo of storage, oxysterols in frozen-raw meat remained stable with either high or low levels of dietary antioxidants. During cooking, high levels of vitamin E reduced oxysterol formation, whereas high levels of SeMet were inconsistent and even increased oxysterols during roasting. TBARs in frozen-raw meat stored for 6 mo were inhibited by high levels of either antioxidant. Conversely, no protective effect during cooking was observed at this time of storage. After 12 mo at -30 degrees C no antioxidant protection was observed.

  7. Defined Conditions for the Isolation and Expansion of Basal Prostate Progenitor Cells of Mouse and Human Origin

    Directory of Open Access Journals (Sweden)

    Thomas Höfner

    2015-03-01

    Full Text Available Methods to isolate and culture primary prostate epithelial stem/progenitor cells (PESCs have proven difficult and ineffective. Here, we present a method to grow and expand both murine and human basal PESCs long term in serum- and feeder-free conditions. The method enriches for adherent mouse basal PESCs with a Lin−SCA-1+CD49f+TROP2high phenotype. Progesterone and sodium selenite are additionally required for the growth of human Lin−CD49f+TROP2high PESCs. The gene-expression profiles of expanded basal PESCs show similarities to ESCs, and NF-kB function is critical for epithelial differentiation of sphere-cultured PESCs. When transplanted in combination with urogenital sinus mesenchyme, expanded mouse and human PESCs generate ectopic prostatic tubules, demonstrating their stem cell activity in vivo. This novel method will facilitate the molecular, genomic, and functional characterization of normal and pathologic prostate glands of mouse and human origin.

  8. Effects of gestational stage and injection route on the corporeal distribution and placental transfer of selenium in pregnant mice

    Energy Technology Data Exchange (ETDEWEB)

    Nishikido, N.; Suzuki, T.

    1985-01-01

    Corporeal distribution and placental transfer of selenium after a single injection of sodium selenite (SS) were investigated over a period of 24 h with regard to the gestational stages of mice and the injection routes of SS. On day 16 of gestation, feto-placental accumulation of selenium was remarkably increased compared with that on day 12 following subcutaneous (sc) injection of SS. Selenium concentrations in the maternal liver, kidneys and lungs were higher on day 16 than on day 12. These results explain the occurrence of the enhanced abortion or maternal death due to SS injection (sc) on day 16 compared with that on day 12, in the previous study. Intravenous (iv) injection of SS caused increased selenium concentrations in most of the maternal organs and tissues but not in the placenta or the fetus compared with sc injection. This may explain the disappearance of the abortion-inducing effect of SS when iv injection is used. 12 references, 1 figure, 5 tables.

  9. The influence of a mineral-vitamin premix on the metabolism of pregnant horses with microelemetosis

    Directory of Open Access Journals (Sweden)

    A. R. Shcherbatyy

    2017-04-01

    Full Text Available The article presents data on research into the influence of a mineral-vitamin premix on the clinical condition, erythropoiesis and the metabolism (macro- and micro-elemental, vitaminic, proteinaceous, enzymic of Hucul breed mares in the last trimester of pregnancy. The Marmix premix contains: vitamins – А, D3, Е, В1, В2, В12, pantothenic and ascorbic acids, niacin, biotin; nonorganic compounds of microelements – sulphate of cobalt, copper, zinc, iron, manganese; potassium iodide, sodium selenite; amino acids – lysine, threonine, methionine.The usage of the mineral-vitaminic premix Marmix on pregnant mares during 60 days causes recovery of clinical status, erythropoiesis, raises the level of the cobalt (by 45.9% and copper (by 2.15 times, normalizes the calcium-phosphorus ratio, raises the phosphorus level in the blood (by 17.7%, raises vitamin А (by 2.5 times and tocopherol (by 2.02 times, total protein (by 27.7%, decreases the level of urea (by 42.2%, activity of AspAT [aspartate transaminase or aspartate aminotransferase] (by 42.9% and AlAT [alanine transaminase] (by 44.9% and alkaline phosphatase (by 43.7%. The research conducted contributes to improvements in the study of the pathogenesis of microelementosis of mares and develops an efficient way of treating and preventing the development of microelementosis among these animals.

  10. Immobilized poly-L-histidine for chelation of metal cations and metal oxyanions

    International Nuclear Information System (INIS)

    Malachowski, Lisa; Holcombe, James A.

    2003-01-01

    The biohomopolymer poly-L-histidine (PLHis) was immobilized onto controlled pore glass (CPG) and its metal binding capabilities evaluated through the use of a flow injection-flame atomic absorption system. The metal binding capability of PLHis-CPG was determined through the analysis of the generated breakthrough curves. The polymer likely coordinates cationic metals through the imidazole side chain (pK a ∼6) present on each histidine residue with both strong and weak binding sites for Cu 2+ , Cd 2+ , Co 2+ , and Ni 2+ . Weak to minimal binding was observed for Mn 2+ , Ca 2+ , Mg 2+ , Na + , and Cr 3+ . The bound metals are quantitatively released from the column with an acid strip. It has also been shown that the protonated imidazole side chain present in acidic solutions is capable of binding metal oxyanions such as chromates, arsenates, and selenites; although oxyanion binding currently exhibits interferences from competing anions in solution, such as sulfate and nitrate. The interference in oxyanion binding is less severe in the presence of chloride, phosphate, and acetate. PLHis-CPG exhibits a capacity of ∼30 μmol Cu 2+ /g CPG in neutral to basic conditions, and a capacity of ∼70 μmol Cr(VI)/g CPG, ∼4 μmol As(V)/g CPG, and ∼4 μmol Se(IV)/g CPG in acidic conditions

  11. Prevention of Graves' ophthalmopathy.

    Science.gov (United States)

    Bartalena, Luigi

    2012-06-01

    Smoking is the most important risk factor for the occurrence/progression of Graves' ophthalmopathy (GO), as well as for its lower/slower response to immunosuppression. Accordingly, refrain from smoking should be urged, both as primary prevention (removal of risk factors in Graves' patients without GO), secondary prevention (early detection and treatment of asymptomatic/very mild GO) and tertiary prevention (reduction of complications/disability of overt GO). A 6-month course of 200 μg/day sodium selenite can prevent progression of mild GO to more severe GO and is, therefore, a form of secondary prevention and, probably, primary prevention. Correction of thyroid dysfunction and stable maintenance of euthyroidism are important preventive measures. The optimal treatment for hyperthyroidism in patients with GO is uncertain, because evidence demonstrating the superiority of antithyroid drugs over thyroid ablation (radioiodine, thyroidectomy, or both) is lacking. If radioiodine is used, low-dose steroid prophylaxis is recommended, particularly in smokers, to prevent radioiodine-associated GO progression. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. In Situ Immobilization of Selenium in Sediment

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Robert C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stewart, Thomas Austin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    This project focused on the use of a sorbent, carbonated apatite, to immobilize selenium in the environment. It is know that apatite will sorb selenium and based on the mechanism of sorption it is theorized that carbonated apatite will be more effective that pure apatite. Immobilization of selenium in the environment is through the use of a sorbent in a permeable reactive barrier (PRB). A PRB can be constructed by trenching and backfill with the sorbent or in the case of apatite as the sorbent formed in situ using the apatite forming solution of Moore (2003, 2004). There is very little data on selenium sorption by carbonated apatite in the literature. Therefore, in this work, the basic sorptive properties of carbonated apatite were investigated. Carbonated apatite was synthesized by a precipitation method and characterized. Batch selenium kinetic and equilibrium experiments were performed. The results indicate the carbonated apatite contained 9.4% carbonate and uptake of selenium as selenite was rapid; 5 hours for complete uptake of selenium vs. more than 100 hours for pure hydroxyapatite reported in the literature. Additionally, the carbonated apatite exhibited significantly higher distribution coefficients in equilibrium experiments than pure apatite under similar experimental conditions. The next phase of this work will be to seek additional funds to continue the research with the goal of eventually demonstrating the technology in a field application.

  13. Isotope techniques in studies of selenium deficiency and toxicity syndromes in farm animals

    International Nuclear Information System (INIS)

    Giese, W.W.

    1984-01-01

    In a brief review of the Se deficiency syndrome in ruminants, studies using non-isotopic methods are applied to an introductory description of the disease. They include methods currently applied for determining Se deficiency status in feed and in ruminant animals. Detection of potential white muscle disease in lambs and calves is discussed. The application of 75 Se in studies on absorption, tissue distribution and excretion under feeding regimes with different Se levels and partly with addition of SO 4 ions or vitamin E is reviewed. In vitro studies with 75 Se include a description of the 75 Se uptake test with red blood cells, the metabolism of selenite, selenate and selenomethionine in rumen microorganisms, and the distribution of 75 Se in cow's and goat's milk. Methods of Se supplementation in Se-deficient areas are summarized and tests with 75 Se-labelled ruminal pellets in sheep and cattle are described. The Se toxicity syndrome is surveyed with respect to causative agents, symptomatology and gross pathology. Special reference is made to the blind staggers and the alkali disease types of selenosis. Isotope techniques are found to be less frequently applied in studies on Se toxicity than in Se deficiency studies. (author)

  14. Antagonistic Growth Effects of Mercury and Selenium in Caenorhabditis elegans Are Chemical-Species-Dependent and Do Not Depend on Internal Hg/Se Ratios.

    Science.gov (United States)

    Wyatt, Lauren H; Diringer, Sarah E; Rogers, Laura A; Hsu-Kim, Heileen; Pan, William K; Meyer, Joel N

    2016-03-15

    The relationship between mercury (Hg) and selenium (Se) toxicity is complex, with coexposure reported to reduce, increase, and have no effect on toxicity. Different interactions may be related to chemical compound, but this has not been systematically examined. Our goal was to assess the interactive effects between the two elements on growth in the nematode Caenorhabditis elegans, focusing on inorganic and organic Hg (HgCl2 and MeHgCl) and Se (selenomethionine, sodium selenite, and sodium selenate) compounds. We utilized aqueous Hg/Se dosing molar ratios that were either above, below, or equal to 1 and measured the internal nematode total Hg and Se concentrations for the highest concentrations of each Se compound. Observed interactions were complicated, differed between Se and Hg compounds, and included greater-than-additive, additive, and less-than-additive growth impacts. Biologically significant interactions were only observed when the dosing Se solution concentration was 100-25,000 times greater than the dosing Hg concentration. Mitigation of growth impacts was not predictable on the basis of internal Hg/Se molar ratio; improved growth was observed at some internal Hg/Se molar ratios both above and below 1. These findings suggest that future assessments of the Hg and Se relationship should incorporate chemical compound into the evaluation.

  15. Screening of new substances for radiation protection and technology development of efficacy improvement

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Byung Sun; Park, Sun Young; Jang, Eun Jung [Kyonggi University, Suwon (Korea, Republic of)

    2005-03-15

    To evaluate the radioprotective efficacy of candidate compounds, we examined the effects of selenium compounds, melatonin, and propolis on the colony forming efficiency (CFE) of gamma-irradiated CHO cells. - Protective effects of selenium compounds against radiation-induced cytotoxicity Sodium selenite showed protective effects at low concentrations against radiation-induced toxicity in CHO cells, whereas its effects were weak at higher concentrations. Selenomethionine also reduced the radiation-induced cytotoxicity. Both of these compounds showed highest protective effects at the concentration of 1 uM. - Protective effects of melatonin against radiation-induced cytotoxicity Melatonin showed the protective effects against radiation-induced cytotoxicity, and the protection was highest at 1 mM concentration. - Protective effects of selenium compounds against hydrogen peroxide-induced cytotoxicity Propolis showed dose-dependent inhibition of hydrogen peroxide-induced cytotoxicity. In particular, the highest inhibition was observed when propolis were treated at 0.3 and 1 ng/ml 24h prior to the hydrogen peroxide treatment. The protective effects of propolis was observed only when it was pretreated at least 8 hours before hydrogen peroxide treatment.

  16. Recycling of agricultural solid waste, coir pith: Removal of anions, heavy metals, organics and dyes from water by adsorption onto ZnCl2 activated coir pith carbon

    International Nuclear Information System (INIS)

    Namasivayam, C.; Sangeetha, D.

    2006-01-01

    The abundant lignocellulosic agricultural waste, coir pith is used to develop ZnCl 2 activated carbon and applied to the removal of toxic anions, heavy metals, organic compounds and dyes from water. Sorption of inorganic anions such as nitrate, thiocyanate, selenite, chromium(VI), vanadium(V), sulfate, molybdate, phosphate and heavy metals such as nickel(II) and mercury(II) has been studied. Removal of organics such as resorcinol, 4-nitrophenol, catechol, bisphenol A, 2-aminophenol, quinol, O-cresol, phenol and 2-chlorophenol has also been investigated. Uptake of acidic dyes such as acid brilliant blue, acid violet, basic dyes such as methylene blue, rhodamine B, direct dyes such as direct red 12B, congo red and reactive dyes such as procion red, procion orange were also examined to assess the possible use of the adsorbent for the treatment of contaminated ground water. Favorable conditions for maximum removal of all adsorbates at the adsorbate concentration of 20 mg/L were used. Results show that ZnCl 2 activated coir pith carbon is effective for the removal of toxic pollutants from water

  17. Effect of selenium on control of postharvest gray mould of tomato fruit and the possible mechanisms involved

    Directory of Open Access Journals (Sweden)

    Zhilin eWu

    2016-01-01

    Full Text Available Selenium (Se has important benefits for crop growth and stress tolerance at low concentrations. However, there is very little information on antimicrobial effect of selenium against the economically important fungus Botrytis cinerea. In the present study, using sodium selenite as Se source, we investigated the effect of Se salts on spore germination and mycelial growth of the fungal pathogen in vitro and gray mould control in harvested tomato fruit. Se treatment at 24 mg/L significantly inhibited spore germination of the fungal pathogen and effectively controlled gray mould in harvested tomato fruit. Se treatment at 24 mg/L seems to induce the generation of intracellular reactive oxygen species in the fungal spores. The membrane integrity damage was observed with fluorescence microscopy following staining with propidium iodide after treatment of the spores with Se. These results suggest that Se has the potential for controlling gray mould rot of tomato fruits and might be useful in integrated control against gray mould disease of postharvest fruits and vegetables caused by B. cinerea. The mechanisms by which Se decreased gray mould decay of tomato fruit may be directly related to the severe damage to the conidia plasma membrane and loss of cytoplasmic materials from the hyphae.

  18. Study on the protective role of selenium against cadmium toxicity in lactic acid bacteria: An advanced application of ICP-MS

    International Nuclear Information System (INIS)

    Caballero Arauz, Iris Liliana; Afton, Scott; Wrobel, Kazimierz; Caruso, Joseph A.; Gutierrez Corona, J. Felix; Wrobel, Katarzyna

    2008-01-01

    In this work, Lactobacillus casei rhamnosus were obtained from the commercial product of fermented milk and possible antagonistic effect of selenium (as sodium selenite) against cadmium toxicity was studied. The bacteria capability to incorporate Se was demonstrated: after 1 week exposure to Se(IV), its total concentration in the freeze-dried biomass was 405 ± 28 μg/g (7.4 ± 0.8 μg/g in control). In the presence of Se(IV) and Cd(II), the bacterial growth and cell viability were improved and lipid peroxidation less marked with respect to bacteria exposed to Cd(II) alone. The distribution of Se and Cd in molecular mass fractions of bacteria extracts was investigated by size exclusion chromatography with diode array and ICP-MS detection. The results obtained suggest that the antagonistic effect of Se is due to lower incorporation of cadmium at a high molecular mass (MM < 600 kDa). Slightly different distribution of elements in the fractions of MM < 40 kDa suggests the formation of new chemical species involving Cd and Se in bacteria exposed to Cd(II) + Se(IV) as compared to those exposed to Cd(II) alone. The study illustrates the high utility of atomic spectrometry to critically inform molecular questions that could be important in the industrial processes based on bacterial activity

  19. Study on the protective role of selenium against cadmium toxicity in lactic acid bacteria: An advanced application of ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Caballero Arauz, Iris Liliana [Instituto de Investigaciones Cientificas, Universidad de Guanajuato, L. de Retana No. 5, 36000 Guanajuato (Mexico); Afton, Scott [Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221-0172 (United States); Wrobel, Kazimierz [Instituto de Investigaciones Cientificas, Universidad de Guanajuato, L. de Retana No. 5, 36000 Guanajuato (Mexico); University of Cincinnati Metallomics Center of the Ameritas, University of Cincinnati, Cincinnati, OH 45221 (United States); Caruso, Joseph A. [Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221-0172 (United States); University of Cincinnati Metallomics Center of the Ameritas, University of Cincinnati, Cincinnati, OH 45221 (United States); Gutierrez Corona, J. Felix [Instituto de Investigacion en Biologia Experimental, Facultad de Quimica, Universidad de Guanajuato, L de Retana No. 5, 36000 Guanajuato (Mexico); Wrobel, Katarzyna [Instituto de Investigaciones Cientificas, Universidad de Guanajuato, L. de Retana No. 5, 36000 Guanajuato (Mexico); University of Cincinnati Metallomics Center of the Ameritas, University of Cincinnati, Cincinnati, OH 45221 (United States)], E-mail: katarzyn@quijote.ugto.mx

    2008-05-30

    In this work, Lactobacillus casei rhamnosus were obtained from the commercial product of fermented milk and possible antagonistic effect of selenium (as sodium selenite) against cadmium toxicity was studied. The bacteria capability to incorporate Se was demonstrated: after 1 week exposure to Se(IV), its total concentration in the freeze-dried biomass was 405 {+-} 28 {mu}g/g (7.4 {+-} 0.8 {mu}g/g in control). In the presence of Se(IV) and Cd(II), the bacterial growth and cell viability were improved and lipid peroxidation less marked with respect to bacteria exposed to Cd(II) alone. The distribution of Se and Cd in molecular mass fractions of bacteria extracts was investigated by size exclusion chromatography with diode array and ICP-MS detection. The results obtained suggest that the antagonistic effect of Se is due to lower incorporation of cadmium at a high molecular mass (MM < 600 kDa). Slightly different distribution of elements in the fractions of MM < 40 kDa suggests the formation of new chemical species involving Cd and Se in bacteria exposed to Cd(II) + Se(IV) as compared to those exposed to Cd(II) alone. The study illustrates the high utility of atomic spectrometry to critically inform molecular questions that could be important in the industrial processes based on bacterial activity.

  20. Toxicity and oxidative stress of different forms of organic selenium (Se) and dietary protein in mallard (Anas platyrhynchos) ducklings

    Science.gov (United States)

    Hoffman, D.; Heinz, G.; Eisemann, J.; Pendleton, G.

    1994-01-01

    High concentrations of Se have been found in aquatic food chains associated with irrigation drainwater and toxicity to fish and wildlife. Earlier studies have compared toxicities of Se as selenite and as seleno-DL-methionine (DL) in mallards. This study compares DL, seleno-L-methionine (L), selenized yeast (Y) and selenized wheat (W). Day-old mallard ducklings received an untreated diet (controls) containing 75% wheat (22% protein) or the same diet containing 15 or 30 ppm Se in the above forms. After 2 weeks blood and liver samples were collected for biochemical assays and Se analysis. All forms of selenium caused significant increases in plasma and hepatic glutathione peroxidase activities. Se as L was the most toxic, resulting in high mortality (64%) and impaired growth (>50%) and the greatest increase in ratio of oxidized to reduced glutathione with 30 ppm in the diet. Se as Y accumulated the least in liver. In a subsequent experiment with 30% dietary protein Se as L was less toxic.

  1. SeO2 adsorption on CaO surface: DFT study on the adsorption of a single SeO2 molecule

    Science.gov (United States)

    Fan, Yaming; Zhuo, Yuqun; Lou, Yu; Zhu, Zhenwu; Li, Liangliang

    2017-08-01

    Selenium is a hazardous element in coal. During coal combustion, most of the selenium will convert to SeO2 in the flue gas. Ca-based adsorbents, especially CaO, have been considered as a potential sorbent to adsorb SeO2 due to its low cost. In this paper, the adsorption mechanisms of single SeO2 on CaO surface were investigated by density functional theory (DFT) calculation. Both the physisorption and chemisorption structures were determined. It has been identified that the adsorption of SeO2 on CaO surface is primarily chemisorption, while physisorption takes effects at the initial stage of the process. Under O2 atmosphere, selenate is hard to form. Most of the adsorption products are selenite. Additionally, the electron density maps were obtained to reveal the surface active sites. The partial density of states (PDOS) was calculated for analyzing the electronic structural change of SeO2 and CaO surface during adsorption. The results provide fundamental information of the adsorption process, which could be meaningful for the development of new absorbents.

  2. FTIR and Raman spectroscopic studies of selenium nanoparticles synthesised by the bacterium Azospirillum thiophilum

    Science.gov (United States)

    Tugarova, Anna V.; Mamchenkova, Polina V.; Dyatlova, Yulia A.; Kamnev, Alexander A.

    2018-03-01

    Vibrational (Fourier transform infrared (FTIR) and Raman) spectroscopic techniques can provide unique molecular-level information on the structural and compositional characteristics of complicated biological objects. Thus, their applications in microbiology and related fields are steadily increasing. In this communication, biogenic selenium nanoparticles (Se NPs) were obtained via selenite (SeO32-) reduction by the bacterium Azospirillum thiophilum (strain VKM B-2513) for the first time, using an original methodology for obtaining extracellular NPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed the Se NPs to have average diameters within 160-250 nm; their zeta potential was measured to be minus 18.5 mV. Transmission FTIR spectra of the Se NPs separated from bacterial cells showed typical proteinacious, polysaccharide and lipid-related bands, in line with TEM data showing a thin layer covering the Se NPs surface. Raman spectra of dried Se NPs layer in the low-frequency region (under 500 cm-1 down to 150 cm-1) showed a single very strong band with a maximum at 250 cm-1 which, in line with its increased width (ca. 30 cm-1 at half intensity), can be attributed to amorphous elementary Se. Thus, a combination of FTIR and Raman spectroscopic approaches is highly informative in non-destructive analysis of structural and compositional properties of biogenic Se NPs.

  3. Biogenic SeNPs from Bacillus mycoides SelTE01 and Stenotrophomonas maltophilia SelTE02: Characterization with reference to their associated organic coating

    Science.gov (United States)

    Piacenza, Elena; Bulgarini, Alessandra; Lampis, Silvia; Vallini, Giovanni; Turner, Raymond J.

    2017-08-01

    The exploitation of biological systems (i.e. plants, fungi and bacteria) for the production of nanomaterials relies on their ability to bioconvert toxic metal(loid) ions into their less toxic and bioavailable elemental states forming mainly nanoparticles (NPs) or nanorods (NRs). Further, these methods of nanomaterial production are nowadays recognized as eco-friendly alternatives to the chemical synthesis processes. A common feature among the so-called biogenic nanomaterials is the presence of an organic layer surrounding them. However, we are just learning the existing relation between biogenic nanostructures and their organic material. Our work is focused on the study of bacterial strains for the production of selenium nanoparticles (SeNPs) as end product of selenite (SeO32 -) bioconversion. In this context, our previous reports described the ability of two bacteria, namely Bacillus mycoides SelTE01 and Stenotrophomonas maltophilia SelTE02, to generate SeNPs, which were surrounded by organic material. Here, the potential role of this organic material as stabilizing agent of SeNPs was investigated altering both the bacteria cells culturing and the SeNPs extraction procedure, in order to understand the interaction between these two elements in suspension. As a result, SeNPs produced by both bacterial strains showed the tendency to aggregate when subjected to the treatments tested, suggesting an involvement of the surrounding organic material in their stabilization in suspension.

  4. Facile Synthesis and Optical Properties of Small Selenium Nanocrystals and Nanorods

    Science.gov (United States)

    Jiang, Fengrui; Cai, Weiquan; Tan, Guolong

    2017-06-01

    Selenium is an important element for human's health, small size is very helpful for Se nanoparticles to be absorbed by human's body. Here, we present a facile approach to fabrication of small selenium nanoparticles (Nano-Se) as well as nanorods by dissolving sodium selenite (Na2SeO3) in glycerin and using glucose as the reduction agent. The as-prepared selenium nanoparticles have been characterized by X-ray diffraction (XRD), UV-Vis absorption spectroscopy and high resolution transmission electron microscope (HRTEM). The morphology of small Se nanoparticles and nanorods have been demonstrated in the TEM images. A small amount of 3-mercaptoproprionic acid (MPA) and glycerin play a key role on controlling the particle size and stabilize the dispersion of Nano-Se in the glycerin solution. In this way, we obtained very small and uniform Se nanoparticles; whose size ranges from 2 to 6 nm. This dimension is much smaller than the best value (>20 nm) ever reported in the literatures. Strong quantum confinement effect has been observed upon the size-dependent optical spectrum of these Se nanoparticles.

  5. Hydrothermal synthesis, structures and optical properties of A2Zn3(SeO3)4·XH2O (A=Li, Na, K; X=2 or 0)

    Science.gov (United States)

    Liu, Yunsheng; Mei, Dajiang; Xu, Jingli; Wu, Yuandong

    2015-12-01

    New alkali metal zinc selenites, A2Zn3(SeO3)4·XH2O (A=Li, Na, K; X=2 or 0) were prepared through hydrothermal reactions. Li2Zn3(SeO3)4·2H2O (1) crystallizes in the monoclinic space group P21/c with lattice parameters a=8.123(4), b=9.139(4), c=7.938(3) Å, β=112.838(9)°. Na2Zn3(SeO3)4·2H2O (2) crystallizes in the monoclinic space group C2/c with lattice parameters a=15.7940(18), b=6.5744(8), c=14.6787(17) Å, β=107.396(3)°. K2Zn3(SeO3)4 (3) crystallizes in the monoclinic space group C2/c with lattice parameters a=11.3584(12), b=8.6091(9), c=13.6816(14) Å, β=93.456(2)°. The anionic structures are composed of [Zn3O12]18- sheets, chains, and "isolated" units in compound 1, 2, 3, respectively, and trigonal pyramids SeO32-. The compounds were characterized by the solid state UV-vis-NIR diffuse reflectance spectroscopy, infrared spectra and thermogravimetric analysis.

  6. Study on induction of radioprotection using antioxidant combinations

    Energy Technology Data Exchange (ETDEWEB)

    Lim, J. S.; Choe, Y. K.; Lee, H. G.; Kim, K. D. [Korea Research Institute of Bioscience and Biotechnology, Taejeon (Korea)

    2000-04-01

    Antioxidants are applied in tumor patients during chemo- or radiotherapy due to its cytoprotective effects. Therefore, aim of our study was to evaluate the effect of exposure with a variety of antioxidants on primary bone marrow cells after {gamma}-irradiation. We studied the radiation-induced cell death in comparison to mouse bone marrow cells after single-dose irradiation with 1, 2, 3 or 6 Gy and controls without irradiation. Cells cultured in vitro had been exposed to different concentrations of antioxidants prior to {gamma}-irradiation. The effect was evaluated 6, 8, 17 or 24 h after radiation exposure by propium iodide staining. While sodium selenite and N-acetylcyseine could achieve significant inhibition of radiation-induced cell death, aminoguanidine and alpha-lipoic acid were not shown to inhibit it. Furthermore, the combination of N-acetylcysteine with some mild antioxidants such as BHA, propyl gallate, quercetin or trolox induced the significant inhibition of radiation-induced cell death. However, these effect was different depending on the duration of radiation exposure and the concentration of antioxidants added in culture. Although the radioprotective effect of antioxidants should be compared with the effect on tumor itself, our results indicate that the use of antioxidants in combination can efficiently modulate the radiation-induced cell damage like apoptosis and can be applied in tumor patients during radiotherapy. 26 refs., 7 figs., 7 tabs. (Author)

  7. On-line pre-reduction of Se(VI) by thiourea for selenium speciation by hydride generation

    International Nuclear Information System (INIS)

    Qiu Jianhua; Wang Qiuquan; Ma Yuning; Yang Limin; Huang Benli

    2006-01-01

    In this study, thiourea (TU) was novelly developed as a reduction reagent for on-line pre-reduction of selenium(VI) before conventional hydride generation (HG) by KBH 4 /NaOH-HCl. After TU on-line pre-reduction, the HG efficiency of Se(VI) has been greatly improved and because even higher than that of the same amount of Se(IV) obtained in the conventional HG system. The possible pre-reduction mechanism is discussed. The detection limit (DL) of selenate reaches 10 pg mL -1 when using on-line TU pre-reduction followed by HG atomic fluorescence detection. When TU pre-reduction followed by HG is used as an interface between ion-pair high performance liquid chromatography and atomic fluorescence spectrometry, selenocystine, selenomethionine, selenite and selenate can be measured simultaneously and quantitatively. The DLs of these are 0.06, 0.08, 0.05 and 0.04 ng mL -1 , respectively, and the relative standard deviations of 9 duplicate runs for all the 4 species are less than 5%. Furthermore, it was successfully applied to Se speciation analysis of cultured garlic samples, and validated by determination of total selenium and selenium species in certified reference material NIST 1946

  8. Effects of cyanide on selenium metabolism in rats

    International Nuclear Information System (INIS)

    Beilstein, M.A.; Whanger, P.D.

    1984-01-01

    Adult male rats were given drinking water containing either 0 or 150 ppm cyanide for 2 weeks. They were then injected with 5 microCi 75 Se-selenite, and excretion of radioactivity in urine and feces was determined. No difference in excretion of 75 Se occurred during the rapid phase, but the cyanide-treated rats (T1/2 28 days) excreted significantly more 75 Se in urine than control (T1/2 38 days) rats. Cyanide had no effect on excretion of 75 Se in feces or on the distribution of 75 Se in cytosolic proteins in liver, kidney, muscle or testes. In a second experiment weanling male rats were given water with either 0 or 150 ppm cyanide and were killed for glutathione peroxidase assay and selenium analysis in blood, kidney, liver, muscle and testes after 3, 6 or 9 weeks of treatment. Glutathione peroxidase activity and selenium concentrations were significantly reduced by cyanide in all tissues except testes

  9. The origin of native selenium microparticles during the oxidation of sideritic mudstones in the Veřovice Formation (Outer Western Carpathians

    Directory of Open Access Journals (Sweden)

    Matýsek Dalibor

    2015-08-01

    Full Text Available Microparticles of native selenium were detected in weathered sideritic mudstones of the Veřovice Formation (Aptian of the Silesian Unit (Outer Western Carpatians, NE part of the Czech Republic. This mineral forms small needle-like crystals with lengths of up to 20 μm, and is confined to fissures in sideritic mudstones covered by goethite or rarely also by hydrated Mn-oxide minerals. The oxidized sideritic mudstones show zonal structure and resemble the initial stage of the formation of the so-called rattle stones. From the superposition of phase diagrams of selenium and Fe-oxyhydroxides, Fe apparently occupies a large field in which Se(0 and FeOOH and/or Fe(OH3 can co-exist. The reduction of selenites or selenates by pyrite or by any other phase, capable of charge transfer, is likely to have been responsible for the formation of microparticles of native selenium. The crucial factor controlling the origin of these particles is the extremely low solubility of Se(0. The source of Se is not obvious. It can be released in trace concentrations during the weathering of pyrite. Sediments of the Veřovice Formation correspond to the anoxic event OAE1b and accumulation of siderophile elements in similar sediments is very probable. A probable mechanism for the origin of Se microcrystals is gradual crystallization from solution.

  10. Transport methods as complementary tools for speciation purposes

    International Nuclear Information System (INIS)

    Fourest, B.; Sladkov, V.

    2005-01-01

    Transport methods, and especially capillary electrophoresis, are shown to bring with a high simplicity and efficiently useful complementary data to solve some speciation problems. Their application in this aim is particularly interesting in the case of actinides or solutions resulting from the radioactive waste management. In the present article, three examples are proposed to illustrate this point. In the first one, the open-end capillary method is applied to point out the hydrolyzed species of Pa(V) over a wide pH range. The difficulties overcome in this case are related to the very low concentration and specific properties of the element under consideration. The second illustration concerns the complexation of uranyl by the anionic forms of some long-lived fission products (MO x n- , with M=I and Se). For the study of these systems, capillary electrophoresis appears to be a method particularly simple and efficient. The last example deals with the quantification of selenate and selenite ions in the presence of nitrate. Capillary electrophoresis is found to be especially appropriate to the simultaneous determination of these two anionic species in such media. (orig.)

  11. The isolation of salmonellas from British pork sausages and sausage meat.

    Science.gov (United States)

    Roberts, D; Boag, K; Hall, M L; Shipp, C R

    1975-10-01

    Between 1969 and 1974, 1467 packets (3309 samples) of pork sausages and sausage meat produced by two large and two medium sized manufacturers and several local butchers were examined for the presence of salmonellas. Of these, 435 packets (786 samples) were found to contain salmonellas, but there was a wide variation in the isolation rates according to the producer. The salmonella incidence in samples from several small and two medium sized producers was low (0-11%) while the results from the two large producers investigated showed a striking difference, the rate of salmonella contamination in the product of one was low (about 2%) and in that of the other consistently high (40-60%). A comparison of liquid enrichment media, incubation temperatures and selective agar media was also carried out to determine the most efficient combination for the isolation of salmonellas from minced meat products. The results showed that (a) incubation of enrichment cultures at 43 degrees C. yielded a consistently greater number of salmonella isolations that at 37 degrees C., regardless of plating medium, (b) tetrathionate broth A (Rolfe) was superior to selenite broth as en enrichment medium at both 37 and 43 degrees C. and (c) brilliant green agar gave better results than deoxycholate citrate sucrose agar and bismuth sulphite agar as a selective medium.

  12. SeO{sub 2} adsorption on CaO surface: DFT study on the adsorption of a single SeO{sub 2} molecule

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Yaming; Zhuo, Yuqun; Lou, Yu; Zhu, Zhenwu [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China); Li, Liangliang [Key Laboratory of Advanced Materials, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2017-08-15

    Highlights: • Adsorption mechanisms of SeO{sub 2} on CaO surface under O{sub 2} were firstly studied by DFT. • The adsorption energies, bond length and electron density maps were calculated. • The electronic structure changes upon adsorption were studied. - Abstract: Selenium is a hazardous element in coal. During coal combustion, most of the selenium will convert to SeO{sub 2} in the flue gas. Ca-based adsorbents, especially CaO, have been considered as a potential sorbent to adsorb SeO{sub 2} due to its low cost. In this paper, the adsorption mechanisms of single SeO{sub 2} on CaO surface were investigated by density functional theory (DFT) calculation. Both the physisorption and chemisorption structures were determined. It has been identified that the adsorption of SeO{sub 2} on CaO surface is primarily chemisorption, while physisorption takes effects at the initial stage of the process. Under O{sub 2} atmosphere, selenate is hard to form. Most of the adsorption products are selenite. Additionally, the electron density maps were obtained to reveal the surface active sites. The partial density of states (PDOS) was calculated for analyzing the electronic structural change of SeO{sub 2} and CaO surface during adsorption. The results provide fundamental information of the adsorption process, which could be meaningful for the development of new absorbents.

  13. Selenium is critical for cancer-signaling gene expression but not cell proliferation in human colon Caco-2 cells.

    Science.gov (United States)

    Zeng, Huawei; Botnen, James H

    2007-01-01

    Selenium (Se) is a potential anticarcinogenic nutrient, and the essential role of Se in cell growth is well recognized but certain cancer cells appear to have acquired a survival advantage under conditions of Se-deficiency. To understand the molecular basis of Se-anticancer effects at nutritional doses (nmol/L) for cultured cells, we generated Se-deficient colon Caco-2 cells by gradually reducing serum in media because serum contains a trace amount of Se. The glutathione peroxidase (GPx) activity of Se-deficient Caco-2 cells was 10.8 mU/mg protein compared to 133.6 approximately 146.3 mU/mg protein in Caco-2 cells supplemented with 500 nmol/L selenite, SeMSC or SeMet (three tested Se-chemical forms) after 7-d culture in serum free media. Interestingly, there were no detectable differences in cell growth, cell cycle progression between Se-deficient cells and cells supplemented with 500 nmol/L Se. To examine differential cancer signaling-gene expression between Se-deficient and Se-supplemented cells, we employed a cancer signal pathway-specific array assay coupled with the real time PCR analysis. Our data demonstrate that although Caco-2 cells are resistant to Se deprivation, Se may exert its anticancer property through increasing the expression of humoral defense gene (A2M) and tumor suppressor-related genes (IGFBP3, HHIP) while decreasing pro-inflammatory gene (CXC L9, HSPB2) expression.

  14. Determination of platinum in biological samples by NAA

    International Nuclear Information System (INIS)

    Okada, Yukiko; Hirai, Shoji; Sakurai, Hiromu; Haraguchi, Hiroki.

    1990-01-01

    Recently, a Pt compound, Cisplatin (cis-dichlorodiamine platinum) has been used therapeutically as an effective anti-malignant-cancer drug. However, since this drug has a harmful aftereffect on kidney, an urgent study of how to reduce its toxicity without influencing the therapeutic effect is needed. We have to understand the behavior of Pt in biological organs in order to elucidate the mechanism of its toxicity reduction. In this study, the analytical conditions for the determination of Pt in biological samples by neutron activation analysis, such as cooling time, counting time and sample weight, are optimized. Freeze-dried samples of the liver, kidney and whole blood of a rat treated with Cisplatin were prepared to evaluate the precision of the analysis and the lower limit of determination. 199 Au (t 1/2 = 3.15 d) produced from 199 Pt (n, γ, β - ) was selected as the analytical radionuclide. A concentration of ca. 1 ppm Pt was determinable under the optimal conditions: a cooling time of 5 d and a counting time of 1 h. Pt in the respective organs of the control rat was not detected under the same analytical conditions. The concentrations of Pt in the liver, kidney, spleen, pancreas and lung of a rat treated with both Cisplatin and sodium selenite were higher than those of a rat treated only with Cisplatin. (author)

  15. Identification of trace levels of selenomethionine and related organic selenium species in high-ionic-strength waters.

    Science.gov (United States)

    LeBlanc, Kelly L; Ruzicka, Josef; Wallschläger, Dirk

    2016-02-01

    A new anion-exchange chromatographic separation method was used for the simultaneous speciation analysis of selenoamino acids and the more ubiquitous inorganic selenium oxyanions, selenite and selenate. For quantification, this separation was coupled to inductively coupled plasma-mass spectrometry to achieve an instrumental detection limit of 5 ng Se L(-1) for all species. This chromatographic method was also coupled to electrospray tandem mass spectrometry to observe the negative ion mode fragmentation of selenomethionine and one of its oxidation products. Low detection limits were achieved, which were similar to those obtained using inductively coupled plasma-mass spectrometry. An extensive preconcentration and cleanup procedure using cation-exchange solid-phase extraction was developed for the identification and quantification of trace levels of selenomethionine in environmental samples. Preconcentration factors of up to five were observed for selenomethionine, which in addition to the removal of high concentrations of sulphate and chloride from industrial process waters, allowed for an unambiguous analysis that would have been impossible otherwise. Following these methods, selenomethionine was identified at an original concentration of 3.2 ng Se L(-1) in samples of effluent collected at a coal-fired power plant's biological remediation site. It is the first time that this species has been identified in the environment, outside of a biological entity. Additionally, oxidation products of selenomethionine were identified in river water and laboratory algal culture samples. High-resolution mass spectrometry was employed to postulate the chemical structures of these species.

  16. The application of Fe–Mn hydrous oxides based adsorbent for removing selenium species from water

    KAUST Repository

    Szlachta, Małgorzata

    2013-02-01

    In this study, the adsorptive removal of selenium(IV) and selenium(VI) from water by a newly developed ion exchange adsorbent, based on Fe(III) and Mn(III) hydrous oxides, was examined. This study was conducted to determine the influence of various operating parameters, such as initial anion concentration, contact time, adsorbent dose, pH, solution temperature, and the presence of competitive anions, on the treatment performance. The high Se(IV) adsorptive capacity of the adsorbent (up to 41.02. mg/g at pH 4) was due to its high affinity for selenite, as reflected in the fast rate of uptake (batch studies) and an efficient long-term removal (column experiments). Although adsorption of anions traditionally decreases as pH increases, the mixed adsorbent was capable of purifying large volumes of Se(IV)-containing water (at pH 7) to reach concentrations lower than 10 μg/L, which meets the European Commission standards. The presence of sulphate and carbonate did not influence Se(IV) adsorption. However, high phosphate and silicate concentrations may have decreased the removal efficiency of Se(IV). Data from the batch and column adsorption experiments were fitted with a number of approved models, which revealed the adsorption mechanism and allowed for a comparison of the results. © 2012 Elsevier B.V.

  17. Cataract: A major secondary complication of diabetes, its epidemiology and an overview on major medicinal plants screened for anticataract activity

    Directory of Open Access Journals (Sweden)

    Patel DK

    2011-12-01

    Full Text Available Cataract is a visual impairment caused due to opacification or optical dysfunction of crystallin lens affecting more than 17 million people around the world. Even though the incidences of cataract are increasing day by day among the elderly persons but, still except surgery no other ways of treatment have been successfully developed so far. Thus, the aim of writing the present review is to provide an insight over the pathophysiological and etiological aspects of cataract along with discussing the remedies available for the disorder. The review also describes different experimental models with their relevant mechanism and significance such as galactose-induced, naphthalene-induced and selenite-induced cataract models which are mainly used for evaluating the anticataract activity of a particular drug (mainly of natural origin. The review includes list of plants and their phytoconstituents which have been so far evaluated pharmacologicaly for the treatment of cataract. From the survey, it was confirmed that the antioxidant property of plants phytoconstituents are basically responsible for their effective anticataract activity. Thus, the valuable information provided in the present review will help researches in developing an alternative method rather than surgery for the treatment of cataract which will minimize the rate of blindness due to cataract thus, benefiting and extending protective aspects of eyes, an integral part of human body.

  18. Adsorption study of selenium ions from aqueous solutions using MgO nanosheets synthesized by ultrasonic method

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Wenwen; Li, Ping; Wang, Zheming; Zheng, Shili; Zhang, Yi

    2018-01-01

    tMgO nanosheets with thickness ranges of 3–10 molecule layers and high specific area (166.44 m2g-1)were successfully fabricated by an ultrasound-assisted exfoliation method and used as adsorbent forthe removal of both selenite (Se(IV)) and selenate (Se(VI)) from aqueous solutions. The resulting MgOnanosheets displayed high maximum adsorption capacities of 103.52 and 10.28 mg g-1for Se(IV) andSe(VI), respectively. ATR-FTIR and XPS spectroscopic results suggested that both Se(IV) and Se(VI) formedinner-sphere surface complexes on MgO nanosheets under the present experimental conditions. Fur-thermore, high adsorption capacity for Se(IV/VI) in the presence of coexistent anions (SO42-, PO43-, Cl-,and F-) and efficient regeneratability of adsorbent by NaOH solution were observed in the competitiveadsorption and regeneration steps. The simple one-step synthesis process of MgO nanosheets and highadsorption capacities offer a promising method for Se(IV/VI) removal in water treatment.

  19. Derivation of site-specific selenium criteria for a Kentucky stream receiving fly ash effluent

    International Nuclear Information System (INIS)

    Reash, R.J.; Van Hassel, J.H.

    1993-01-01

    Blaine Creek, a fifth-order tributary to the Big Sandy River in eastern Kentucky, receives fly ash effluent from Kentucky Power Company's Big Sandy Plant fly ash pond near the creek's mouth. Long-term biosurvey/physicochemical data and speciation studies were used to derive proposed site-specific selenium water quality criteria. Biosurvey results from 1982--1990 were consistent in showing no adverse effects of fly ash discharge, even during low flow conditions when the effluent comprised 75% of creek flow. Five macroinvertebrate parameters (taxa richness, total abundance, EPT taxa, number caddisflies and chironomids) were significantly correlated with % effluent, indicating enhanced communities at high instream waste concentrations. Several fish metrics similarly showed greater enhancement at high % effluent conditions. Selenium speciation studies indicated that selenite (Se 4+ ) represented 100% of total selenium in the effluent. Total selenium concentrations were low at fully mixed downstream reaches. US EPA's Recalculation Procedure was used to calculate site-specific selenium criteria based on Se 4+ toxicity data for resident species. These criteria are higher than statewide criteria which are based on selenium, effects at waterbodies having low turnover rates

  20. Part A. Neutron activation analysis of selenium and vanadium in biological matrices. Part B. Isomeric transition activation in aqueous solutions of alkyl bromides

    International Nuclear Information System (INIS)

    Ebrahim, A.

    1988-01-01

    Several procedures were evaluated for determination of selenium in biological fluids and vanadium in biological tissues by neutron activation analysis (NAA) employing 77m Se and 52 V isotopes, respectively. Procedures for determination of total selenium, trimethylselenonium (TMSe) ion and selenite (SeO 3 2- ) ion in urine and serum and for total selenoamino acids in urine were developed by utilizing anion exchange chromatography and molecular NAA. A pre-column derivatization of selenoamino acids with o-phthalaldehyde was necessary for their determination. Also an analytical approach was developed for determination of trace vanadium in liver samples from normal and diabetic rats as well as human and cow. Reactions of bromine-80 activated by radiative neutron capture and bromine-82 activated by isomeric transition were investigated in aqueous solutions of bromomethane and 1-bromobutane. Bromine-80 organic yields decreased with decreasing solute concentrations. The tendency for aggregation of the solute molecules diminished as the solute concentration approached zero where the probable state of the solute approached a monomolecular dispersion. Unlike reactions of 80 Br born by 79 Br(n,γ) 80 Br reaction, the total organic product yields resulting from the 82m Br(I.T.) 82 Br process showed no solute concentration dependence

  1. Evaluation of mice infected to Salmonella Spp in Poultry farms of Tehran Province

    Directory of Open Access Journals (Sweden)

    M Hadadian

    2012-08-01

    Full Text Available In this survey, 290 mice and rats fecal samples from commercial layer and broiler poultry houses were tested for Salmonella sp. presence. All samples were cultured on Selenite F broth media and passaged on SS agar and McConkey agar. The suspected colonies were cultured on Urea and TSI agars to be confirmed as Salmonella sp.. Finally, Salmonella isolates were identified genetically and biochemically by PCR and conventional methods, respectively. Serogrouping and Antibiotic resistance profiling were done for further differentiation of isolates. Twenty eight (9.65% Salmonellas were isolated from (out of 290 samples. Eight (28.6%, seven (25%, four (14.3%, and two (7.2% isolates were located in serogroups C, D, B and E, respectively. Seven isolates (25% belonged to Arizona subspecies and just one non-motile serogroup D Salmonella was isolated. All isolates were sensitive to enrofloxacin, difloxacin, norfloxacin, chloramphenicol and florfenicol, but they were resistant to sulfamethoxazole, trimethoprim and neomycin in decreasing order. In addition to former surveys, this study confirmed the role of mice and rats in spreading of Salmonella spp. in poultry farms. In conclusion it is essential to take appropriate measurements (measures for pest management in poultry houses to approach the prevention of some bacterial infection like  (such as salmonellosis.

  2. Selenate reduction to elemental selenium by anaerobic bacteria in sediments and culture: biogeochemical significance of a novel, sulfate-independent respiration

    Science.gov (United States)

    Oremland, Ronald S.; Hollibaugh, James T.; Maest, Ann S.; Presser, Theresa S.; Miller, Laurence G.; Culbertson, Charles W.

    1989-01-01

    Interstitial water profiles of SeO42−, SeO32−, SO42−, and Cl− in anoxic sediments indicated removal of the seleno-oxyanions by a near-surface process unrelated to sulfate reduction. In sediment slurry experiments, a complete reductive removal of SeO42− occurred under anaerobic conditions, was more rapid with H2 or acetate, and was inhibited by O2, NO3−, MnO2, or autoclaving but not by SO42− or FeOOH. Oxidation of acetate in sediments could be coupled to selenate but not to molybdate. Reduction of selenate to elemental selenium was determined to be the mechanism for loss from solution. Selenate reduction was inhibited by tungstate and chromate but not by molybdate. A small quantity of the elemental selenium precipitated into sediments from solution could be resolublized by oxidation with either nitrate or FeOOH, but not with MnO2. A bacterium isolated from estuarine sediments demonstrated selenate-dependent growth on acetate, forming elemental selenium and carbon dioxide as respiratory end products. These results indicate that dissimilatory selenate reduction to elemental selenium is the major sink for selenium oxyanions in anoxic sediments. In addition, they suggest application as a treatment process for removing selenium oxyanions from wastewaters and also offer an explanation for the presence of selenite in oxic waters.

  3. [Pharmaconutrition with parenteral selenium in sepsis].

    Science.gov (United States)

    Langlois, P L; de Oliveira Figliolino, L F; Hardy, G; Manzanares, W

    2014-04-01

    Critical illness is characterized by oxidative stress which leads to multiple organ failure, and sepsis-related organ dysfunction remains the most common cause of death in the intensive care unit. Over the last 2 decades, different antioxidant therapies have been developed to improve outcomes in septic patients. According to recent evidence, selenium therapy should be considered the cornerstone of the antioxidant strategies. Selenium given as selenious acid or sodium selenite should be considered as a drug or pharmaconutrient with prooxidant and cytotoxic effects when a loading dose in intravenous bolus form is administered, particularly in the early stage of severe sepsis/septic shock. To date, several phase ii trials have demonstrated that selenium therapy may be able to decrease mortality, improve organ dysfunction and reduce infections in critically ill septic patients. The effect of selenium therapy in sepsis syndrome must be confirmed by large, well designed phase iii clinical trials. The purpose of this review is to discuss current evidence on selenium pharmaconutrition in sepsis syndrome. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.

  4. Inhibition of serum cholesterol oxidation by dietary vitamin C and selenium intake in high fat fed rats.

    Science.gov (United States)

    Menéndez-Carreño, M; Ansorena, D; Milagro, F I; Campión, J; Martínez, J A; Astiasarán, I

    2008-04-01

    Cholesterol oxidation products (COPs) have been considered as specific in vivo markers of oxidative stress. In this study, an increased oxidative status was induced in Wistar rats by feeding them a high-fat diet (cafeteria diet). Another group of animals received the same diet supplemented with a combination of two different antioxidants, ascorbic acid (100 mg/kg rat/day) and sodium selenite (200 microg/kg rat/day) and a third group fed on a control diet. Total and individual COPs analysis of the different diets showed no differences among them. At the end of the experimental trial, rats were sacrificed and serum cholesterol, triglycerides and COPs were measured. None of the diets induced changes in rats body weight, total cholesterol and triglycerides levels. Serum total COPs in rats fed on the high-fat diet were 1.01 microg/ml, two times the amount of the control rats (0.47 microg/ml). When dietary antioxidant supplementation was given, serum total COPs concentration (0.44 microg/ml) showed the same levels than those of the rats on control diet. 7beta-hydroxycholesterol, formed non-enzymatically via cholesterol peroxidation in the presence of reactive oxygen species, showed slightly lower values in the antioxidant-supplemented animals compared to the control ones. This study confirms the importance of dietary antioxidants as protective factors against the formation of oxysterols.

  5. Ultrastructural changes in the mycelium of Hericium erinaceum (Bull.; Fr.) Pers. under selenium-induced oxidative stress.

    Science.gov (United States)

    Ślusarczyk, Joanna; Kuraś, Mieczysław; Malinowska, Eliza; Skalicka-Woźniak, Krystyna; Głowniak, Kazimierz

    2014-10-01

    In this study we examined the influence of various forms of selenium (organic and inorganic) on the vivacity of Hericium erinaceum mycelium and structural changes and ultrastructure occurring during its development in submerged culture. The mycelium was grown on sodium selenite (Na₂SeO₃), Selol (with 20 and 50 g kg⁻¹ Se, respectively) and a mixture of Na₂SeO₃ and Selol. Samples of the mycelium were collected on day 3 and day 24 of the incubation and viewed under an electron microscope. Selol at concentration 20 g kg⁻¹ did not cause any damage to the cell ultrastructure, but it contributed to the thickening of the cell wall, which implied an influence on polysaccharide production. In the other cases, degradation changes appeared in the protoplasm and the thickness of the cell wall did not increase. The nature of the effect exerted by various sources of selenium in the culture medium on the formation of polysaccharides probably results from the differences in their chemical composition and differences in the toxicity of these compounds towards the cells, but is also connected with the decomposition of the wall surrounding degraded fungal cells. © 2014 Society of Chemical Industry.

  6. Gene expression of endoplasmic reticulum resident selenoproteins correlates with apoptosis in various muscles of se-deficient chicks.

    Science.gov (United States)

    Yao, Hai-Dong; Wu, Qiong; Zhang, Zi-Wei; Zhang, Jiu-Li; Li, Shu; Huang, Jia-Qiang; Ren, Fa-Zheng; Xu, Shi-Wen; Wang, Xiao-Long; Lei, Xin Gen

    2013-05-01

    Dietary selenium (Se) deficiency causes muscular dystrophy in various species, but the molecular mechanism remains unclear. Our objectives were to investigate: 1) if dietary Se deficiency induced different amounts of oxidative stress, lipid peroxidation, and cell apoptosis in 3 skeletal muscles; and 2) if the distribution and expression of 4 endoplasmic reticulum (ER) resident selenoprotein genes (Sepn1, Selk, Sels, and Selt) were related to oxidative damages in these muscles. Two groups of day-old layer chicks (n = 60/group) were fed a corn-soy basal diet (33 μg Se/kg; produced in the Se-deficient area of Heilongjiang, China) or the diet supplemented with Se (as sodium selenite) at 0.15 mg/kg for 55 d. Dietary Se deficiency resulted in accelerated (P muscles. All these responses were stronger in the pectoral muscle than in the thigh and wing muscles (P muscles. Expression of Sepn1, Sels, and Selt in these muscles was correlated with (r > 0.72; P muscle demonstrated unique expression patterns of the ER resident selenoprotein genes and GPx activity, along with elevated susceptibility to oxidative cell death, compared with the other skeletal muscles. These features might help explain why it is a primary target of Se deficiency diseases in chicks.

  7. Comparison of ultra-violet and inductively coupled plasma-atomic emission spectrometry for the on-line quantification of selenium species after their separation by reversed-phase liquid chromatography</