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Sample records for elemental selenium nanoparticles

  1. Extracellular Polymeric Substances Govern the Surface Charge of Biogenic Elemental Selenium Nanoparticles

    KAUST Repository

    Jain, Rohan

    2015-02-03

    © 2014 American Chemical Society. The origin of the organic layer covering colloidal biogenic elemental selenium nanoparticles (BioSeNPs) is not known, particularly in the case when they are synthesized by complex microbial communities. This study investigated the presence of extracellular polymeric substances (EPS) on BioSeNPs. The role of EPS in capping the extracellularly available BioSeNPs was also examined. Fourier transform infrared (FT-IR) spectroscopy and colorimetric measurements confirmed the presence of functional groups characteristic of proteins and carbohydrates on the BioSeNPs, suggesting the presence of EPS. Chemical synthesis of elemental selenium nanoparticles in the presence of EPS, extracted from selenite fed anaerobic granular sludge, yielded stable colloidal spherical selenium nanoparticles. Furthermore, extracted EPS, BioSeNPs, and chemically synthesized EPS-capped selenium nanoparticles had similar surface properties, as shown by ζ-potential versus pH profiles and isoelectric point measurements. This study shows that the EPS of anaerobic granular sludge form the organic layer present on the BioSeNPs synthesized by these granules. The EPS also govern the surface charge of these BioSeNPs, thereby contributing to their colloidal properties, hence affecting their fate in the environment and the efficiency of bioremediation technologies.

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

    Science.gov (United States)

    Loeschner, Katrin; Hadrup, Niels; Hansen, Marianne; Pereira, Sonia A; Gammelgaard, Bente; Møller, Laura Hyrup; Mortensen, Alicja; Lam, Henrik Rye; Larsen, Erik H

    2014-02-01

    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(-1) bw per day (low dose) or at 0.5 mg kg(-1) bw per day (high dose) as Se to female rats. Prior to administration, the size distribution of the Se nanoparticles was characterized by dynamic light scattering and transmission electron microscopy, which showed that the particles' mean diameter was 19 nm and ranged in size from 10 to 80 nm. Following administration of the high dose of Se nanoparticles or selenite the concentration of Se was determined by ICP-MS in the liver, kidney, urine, feces, stomach, lungs, and plasma at the μg g(-1) level and in brain and muscle tissue at the sub-μg g(-1) level. In order to test if any elemental Se was present in the liver, kidney or feces, an in situ derivatization selective to elemental Se was performed by treatment with sulfite, which resulted in formation of the selenosulfate anion. This Se species was selectively and quantitatively determined by anion exchange HPLC and ICP-MS detection. The results showed that elemental Se was present in the livers, kidneys and feces of animals exposed to low and high doses of elemental Se nanoparticles or to selenite, and was also detected in the same samples from control animals. The fraction of Se present as elemental Se in livers and kidneys from the high dose animals was significantly larger than the similar fraction in samples from the low dose animals or from the controls. This suggested that the natural metabolic pathways of Se were exhausted when given the high dose of elemental Se or selenite resulting in a non-metabolized pool of elemental Se. Both dosage forms of Se were bioavailable as demonstrated by the blood biomarker selenoprotein P, which was equally up-regulated in the high-dose animals for both dosage forms of Se. Finally, the excretion of Se in urine and its occurrence as Se

  3. Preparation and antioxidant capacity of element selenium nanoparticles sol-gel compounds.

    Science.gov (United States)

    Bai, Yan; Qin, Biyin; Zhou, Yanhui; Wang, Yudong; Wang, Zi; Zheng, Wenjie

    2011-06-01

    This paper reported the preparation and antioxidant capacities of element selenium nanoparticles (nanoSe(0))-ascorbic acid (Vc) sol and nanSe(0)/Vc/selenocystine (SeCys) sol-gel compounds. NanoSe(0)-Vc sol was prepared by reduction of selenious dioxide (SeO2) with Vc. In the nanoSe(0)-Vc sol, highly concentrated Vc was also used as a modifier to modulate the diameter of Se(0) nanoparticles in the liquid phase. Then excellent nanoSe(0) sol-gel compounds were obtained by adding SeCys into the nanoSe(0)-Vc sol. The structure of the nanoSe(0)/Vc/SeCys sol-gel compounds was defined, which was constructed via C-Se, Se-H and O=C-Se valences and by interaction between SeCys and Vc via peptide bonds, esterification and dehydration. The antioxidant capacities of the nanoSe(0)-Vc sol and the nanoSe(0)Vc/SeCys sol-gel compounds were estimated by oxygen radical absorption capacity (ORAC) assay. The nanoSe(0)/Vc/SeCys sol-gel compounds possessed a strong antioxidant capacity due to forming the perfect three-dimensional (3D) frameworks structure. The results suggested that the nanoSe(0)-Vc sol and the nanoSe(0)Vc/SeCys sol-gel compounds might be potential medicine, especially antioxidant.

  4. A study of selenium nanoparticles as charge storage element for flexible semi-transparent memory devices

    Science.gov (United States)

    Alotaibi, Sattam; Nama Manjunatha, Krishna; Paul, Shashi

    2017-12-01

    Flexible Semi-Transparent electronic memory would be useful in coming years for integrated flexible transparent electronic devices. However, attaining such flexibility and semi-transparency leads to the boundaries in material composition. Thus, impeding processing speed and device performance. In this work, we present the use of inorganic stable selenium nanoparticles (Se-NPs) as a storage element and hydrogenated amorphous carbon (a-C:H) as an insulating layer in two terminal non-volatile physically flexible and semi-transparent capacitive memory devices (2T-NMDs). Furthermore, a-C:H films can be deposited at very low temperature (memory on a flexible substrate. Moreover, the memory behaviour of the Se-NPs was found to be more distinct than those of the semiconductor and metal nanostructures due to higher work function compared to the commonly used semiconductor and metal species. The memory behaviour was observed from the hysteresis of current-voltage (I-V) measurements while the two distinguishable electrical conductivity states (;0; and "1") were studied by current-time (I-t) measurements.

  5. 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 (SeO3(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 SeO3(2-) to Se° when cultured aerobically in liquid medium at 27°C, while B. fungorum 95 can reduce more than 1mM SeO3(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

  6. Selenium: Element of Contrasts

    Science.gov (United States)

    Goldsmith, Robert H.; And Others

    1978-01-01

    Reports on recent findings concerning the impact of selenium on human and animal health. In its various oxidation states, different concentrations of selenium may be helpful or detrimental to human health. (CP)

  7. Selenium nanoparticles as a nutritional supplement.

    Science.gov (United States)

    Skalickova, Sylvie; Milosavljevic, Vedran; Cihalova, Kristyna; Horky, Pavel; Richtera, Lukas; Adam, Vojtech

    2017-01-01

    Selenium is an essential trace element in the diet, required for maintenance of health and growth; however, its toxicity could cause serious damage depending on dose and chemical form. Selenium nanoparticles (SeNPs) represent what we believe to be a novel prospect for nutritional supplementation because of their lower toxicity and ability to gradually release selenium after ingestion. In this review, we discuss various forms and types of SeNPs, as well as the way they are synthesized. We also discuss absorption and bioavailability of nanoparticles within the organism. SeNPs demonstrate anticancer and antimicrobial properties that may contribute to human health, not only as dietary supplements, but also as therapeutic agents. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. 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

    the controls. This suggested that the natural metabolic pathways of Se were exhausted when given the high dose of elemental Se or selenite resulting in a non-metabolized pool of elemental Se. Both dosage forms of Se were bioavailable as demonstrated by the blood biomarker selenoprotein P, which was equally up......-regulated in the high-dose animals for both dosage forms of Se. Finally, the excretion of Se in urine and its occurrence as Se-methylseleno-N-Acetyl-galactosamine and trimethylselenonium-ion demonstrated that both dosage forms were metabolized and excreted. The results of the study showed that both forms of Se were...

  9. Low cytotoxic trace element selenium nanoparticles and their differential antimicrobial properties against S. aureus and E. coli

    Science.gov (United States)

    Tran, Phong A.; O'Brien-Simpson, Neil; Reynolds, Eric C.; Pantarat, Namfon; Biswas, Dhee P.; O'Connor, Andrea J.

    2016-01-01

    Antimicrobial agents that have no or low cytotoxicity and high specificity are desirable to have no or minimal side effects. We report here the low cytotoxicity of polyvinyl alcohol-stabilized selenium (Se) nanoparticles and their differential effects on growth of S. aureus, a gram-positive bacterium and E. coli, a gram-negative bacterium. The nanoparticles were synthesised through redox reactions in an aqueous environment at room temperature and were characterised using UV visible spectrophotometry, transmission electron microscopy, dynamic light scattering and x-ray photoelectron spectroscopy. The nanoparticles showed low toxicity toward fibroblasts which remained more than 70% viable at Se concentrations as high as 128 ppm. The nanoparticles also exhibited very low haemolysis with only 18% of maximal lysis observed at a Se concentration of 128 ppm. Importantly, the nanoparticles showed strong growth inhibition toward S. aureus at a concentration as low as 1 ppm. Interestingly, growth of E. coli was unaffected at all concentrations tested. This study therefore strongly suggests that these nanoparticles should be investigated further to understand this differential effect as well as for potential advanced antimicrobial applications such as S. aureus infection—resisting, non-cytotoxic coatings for medical devices.

  10. Biosynthesis of selenium nanoparticles using Klebsiella pneumoniae and their recovery by a simple sterilization process

    Directory of Open Access Journals (Sweden)

    Parisa Jafari Fesharaki

    2010-06-01

    Full Text Available The use of biologically derived metal nanoparticles for various proposes is going to be an issue of considerable importance; thus, appropriate methods should be developed and tested for the biological synthesis and recovery of these nanoparticles from bacterial cells. In this research study, a strain of Klebsiella pneumoniae was tested for its ability to synthesize elemental selenium nanoparticles from selenium chloride. A broth of Klebsiella pneumoniae culture containing selenium nanoparticles was subjected to sterilization at 121ºC and 17 psi for 20 minutes. Released selenium nanoparticles ranged in size from 100 to 550 nm, with an average size of 245 nm. Our study also showed that no chemical changes occurred in selenium nanoparticles during the wet heat sterilization process. Therefore, the wet heat sterilization process can be used successfully to recover elemental selenium from bacterial cells.

  11. Selenium nanoparticles: potential in cancer gene and drug delivery.

    Science.gov (United States)

    Maiyo, Fiona; Singh, Moganavelli

    2017-05-01

    In recent decades, colloidal selenium nanoparticles have emerged as exceptional selenium species with reported chemopreventative and therapeutic properties. This has sparked widespread interest in their use as a carrier of therapeutic agents with results displaying synergistic effects of selenium with its therapeutic cargo and improved anticancer activity. Functionalization remains a critical step in selenium nanoparticles' development for application in gene or drug delivery. In this review, we highlight recent developments in the synthesis and functionalization strategies of selenium nanoparticles used in cancer drug and gene delivery systems. We also provide an update of recent preclinical studies utilizing selenium nanoparticles in cancer therapeutics.

  12. Biogenesis of Selenium Nanoparticles Using Green Chemistry.

    Science.gov (United States)

    Shoeibi, Sara; Mozdziak, Paul; Golkar-Narenji, Afsaneh

    2017-11-09

    Selenium binds some enzymes such as glutathione peroxidase and thioredoxin reductase, which may be activated in biological infections and oxidative stress. Chemical and physical methods for synthesizing nanoparticles, apart from being expensive, have their own particular risks. However, nanoparticle synthesis through green chemistry is a safe procedure that different biological sources such as bacteria, fungi, yeasts, algae and plants can be the catalyst bed for processing. Synthesis of selenium nanoparticles (SeNPs) by macro/microorganisms causes variation in morphology and shape of the particles is due to diversity of reduction enzymes in organisms. Reducing enzymes of microorganisms by changing the status of redox convert metal ions (Se 2- ) to SeNPs without charge (Se 0 ). Biological activity of SeNPs includes their protective role against DNA oxidation. Because of the biological and industrial properties, SeNPs have wide applications in the fields of medicine, microelectronic, agriculture and animal husbandry. SeNPs can show strong antimicrobial effects on the growth and proliferation of microorganisms in a dose-dependent manner. The objective of this review is to consider SeNPs applications to various organisms.

  13. Shedding Light on Selenium Biomineralization: Proteins Associated with Bionanominerals

    NARCIS (Netherlands)

    Lenz, M.; Kolvenbach, B.; Gygax, B.; Moes, S.; Corvini, P.F.X.

    2011-01-01

    Selenium reducing microorganisms produce elemental selenium nanoparticles with particular physico-chemical properties being due to an associated organic fraction. This study identified high affinity proteins being associated with such bionanominerals and with non-biogenic elemental selenium.

  14. Selenium

    Science.gov (United States)

    Stillings, Lisa L.; Schulz, Klaus J.; DeYoung, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    Selenium (Se) was discovered in 1817 in pyrite from copper mines in Sweden. It is a trace element in Earth’s crust, with an abundance of three to seven orders of magnitude less than the major rock-forming elements. Commercial use of selenium began in the United States in 1910, when it was used as a pigment for paints, ceramic glazes, and red glass. Since that time, it has had many other economic uses—notably, in the 1930s and 1940s, when it was used in rectifiers (which change alternating current to direct current), and in the 1960s, when it began to be used in the liner of photocopier drums. In the 21st century, other compounds have replaced selenium in these older products; modern uses for selenium include energy-efficient windows that limit heat transfer and thin-film photovoltaic cells that convert solar energy into electricity.In Earth’s crust, selenium is found as selenide minerals, selenate and selenite salts, and as substitution for sulfur in sulfide minerals. It is the sulfide minerals, most commonly those in porphyry copper deposits, that provide the bulk of the selenium produced for the international commodity market. Selenium is obtained as a byproduct of copper refining and recovered from the anode slimes generated in electrolytic production of copper. Because of this, the countries that have the largest resources and (or) reserves of copper also have the largest resources and (or) reserves of selenium.Because selenium occurs naturally in Earth’s crust, its presence in air, water, and soil results from both geologic reactions and human activity. Selenium is found concentrated naturally in soils that overlie bedrock with high selenium concentrations. Selenium mining, processing, use in industrial and agricultural applications, and disposal may all contribute selenium to the environment. A well-known case of selenium contamination from agricultural practices was discovered in 1983 in the Kesterson National Wildlife Refuge in California. There

  15. Bioavailable nanoparticles obtained in laser ablation of a selenium target in water

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmin, P G; Shafeev, Georgii A; Voronov, Valerii V; Raspopov, R V; Arianova, E A; Trushina, E N; Gmoshinskii, I V; Khotimchenko, S A

    2012-11-30

    The process of producing colloidal solutions of selenium nanoparticles in water using the laser ablation method is described. The prospects of using nanoparticles of elementary selenium as a nutrition source of this microelement are discussed. (nanoparticles)

  16. Bioavailable nanoparticles obtained in laser ablation of a selenium target in water

    Science.gov (United States)

    Kuzmin, P. G.; Shafeev, Georgii A.; Voronov, Valerii V.; Raspopov, R. V.; Arianova, E. A.; Trushina, E. N.; Gmoshinskii, I. V.; Khotimchenko, S. A.

    2012-11-01

    The process of producing colloidal solutions of selenium nanoparticles in water using the laser ablation method is described. The prospects of using nanoparticles of elementary selenium as a nutrition source of this microelement are discussed.

  17. Biomimetic synthesis of selenium nanoparticles by Pseudomonas aeruginosa ATCC 27853: An approach for conversion of selenite.

    Science.gov (United States)

    Kora, Aruna Jyothi; Rastogi, Lori

    2016-10-01

    A facile and green method for the reduction of selenite was developed using a Gram-negative bacterial strain Pseudomonas aeruginosa, under aerobic conditions. During the process of bacterial conversion, the elemental selenium nanoparticles were produced. These nanoparticles were systematically characterized using various analytical techniques including UV-visible spectroscopy, XRD, Raman spectroscopy, SEM, DLS, TEM and FTIR spectroscopy techniques. The generation of selenium nanoparticles was confirmed from the appearance of red colour in the culture broth and broad absorption peaks in the UV-vis. The synthesized nanoparticles were spherical, polydisperse, ranged from 47 to 165 nm and the average particle size was about 95.9 nm. The selected-area electron diffraction, XRD patterns; and Raman spectroscopy established the amorphous nature of the fabricated nanoparticles. The IR data demonstrated the bacterial protein mediated selenite reduction and capping of the produced nanoparticles. The selenium removal was assessed at different selenite concentrations using ICP-OES and the results showed that the tested bacterial strain exhibited significant selenite reduction activity. The results demonstrate the possible application of P. aeruginosa for bioremediation of waters polluted with toxic and soluble selenite. Moreover, the potential metal reduction capability of the bacterial strain can function as green method for aerobic generation of selenium nanospheres. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. The antimicrobial effects of selenium nanoparticle-enriched probiotics and their fermented broth against Candida albicans.

    Science.gov (United States)

    Kheradmand, Erfan; Rafii, Fatemeh; Yazdi, Mohammad Hossien; Sepahi, Abas Akhavan; Shahverdi, Ahmad Reza; Oveisi, Mohammad Reza

    2014-06-06

    Lactic acid bacteria are considered important probiotics for prevention of some infections. The aim of this work was to investigate the effect of selenium dioxide on the antifungal activity of Lactobacillus plantarum and L. johnsonii against Candida albicans. Lactobacillus plantarum and L. johnsonii cells, grown in the presence and absence of selenium dioxide, and their cell-free spent culture media were tested for antifungal activity against C. albicans ATCC 14053 by a hole-plate diffusion method and a time-kill assay. Both L. plantarum and L. johnsonii reduced selenium dioxide to cell-associated elemental selenium nanoparticles. The cell-free spent culture media, from both Lactobacillus species that had been grown with selenium dioxide for 48 h, showed enhanced antifungal activity against C. albicans. Enhanced antifungal activity of cell biomass against C. albicans was also observed in cultures grown with selenium dioxide. Selenium dioxide-treated Lactobacillus spp. or their cell-free spent broth inhibited the growth of C. albicans and should be investigated for possible use in anti-Candida probiotic formulations in future.

  19. Selenium uptake and assessment of the biochemical changes in Arthrospira (Spirulina) platensis biomass during the synthesis of selenium nanoparticles.

    Science.gov (United States)

    Zinicovscaia, I; Chiriac, T; Cepoi, L; Rudi, L; Culicov, O; Frontasyeva, M; Rudic, V

    2017-01-01

    The process of selenium uptake by biomass of the cyanobacterium Arthrospira (Spirulina) platensis was investigated by neutron activation analysis at different selenium concentrations in solution and at different contact times. Experimental data showed good fit with the Freundlich adsorption isotherm model, with a regression coefficient value of 0.99. In terms of absorption dependence on time, the maximal selenium content was adsorbed in the first 5 min of interaction without significant further changes. It was also found that A. platensis biomass forms spherical selenium nanoparticles. Biochemical analysis was used to assess the changes in the main components of spirulina biomass (proteins, lipids, carbohydrates, and phycobilin) during nanoparticle formation.

  20. 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.

  1. Preparation and antioxidant properties of selenium nanoparticles-loaded chitosan microspheres.

    Science.gov (United States)

    Bai, Kaikai; Hong, Bihong; He, Jianlin; Hong, Zhuan; Tan, Ran

    2017-01-01

    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.

  2. Green synthesis of selenium nanoparticles by excimer pulsed laser ablation in water

    Directory of Open Access Journals (Sweden)

    O. Van Overschelde

    2013-10-01

    Full Text Available Pure selenium nanoparticles were successfully synthesized by Liquid Phase - Pulsed Laser Ablation (LP-PLA in de-ionized water. Excimer laser (248 nm operating at low fluence (F ∼ 1 J/cm2 was used to generate colloidal solutions of selenium nanoparticles. The obtained selenium nanoparticles were characterized by UV-visible spectroscopy, Raman spectroscopy, Dynamic Light Scattering, and Transmission Electron Microscopy. We describe the multi-modal size distributions generated and use the centrifugation method to isolate the smallest nanoparticles (∼60 nm in diameter.

  3. Cyclic Peptide?Selenium Nanoparticles as Drug Transporters

    OpenAIRE

    Nasrolahi Shirazi, Amir; Tiwari, Rakesh K.; Oh, Donghoon; Sullivan, Brian; Kumar, Anil; Beni, Yousef A.; Parang, Keykavous

    2014-01-01

    A cyclic peptide composed of five tryptophan, four arginine, and one cysteine [W5R4C] was synthesized. The peptide was evaluated for generating cyclic peptide-capped selenium nanoparticles (CP?SeNPs) in situ. A physical mixing of the cyclic peptide with SeO3 ?2 solution in water generated [W5R4C]?SeNPs via the combination of reducing and capping properties of amino acids in the peptide structure. Transmission electron microscopy (TEM) images showed that [W5R4C]?SeNPs were in the size range of...

  4. Evaluation of selenium in dietary supplements using elemental speciation.

    Science.gov (United States)

    Kubachka, Kevin M; Hanley, Traci; Mantha, Madhavi; Wilson, Robert A; Falconer, Travis M; Kassa, Zena; Oliveira, Aline; Landero, Julio; Caruso, Joseph

    2017-03-01

    Selenium-enriched dietary supplements containing various selenium compounds are readily available to consumers. To ensure proper selenium intake and consumer confidence, these dietary supplements must be safe and have accurate label claims. Varying properties among selenium species requires information beyond total selenium concentration to fully evaluate health risk/benefits A LC-ICP-MS method was developed and multiple extraction methods were implemented for targeted analysis of common "seleno-amino acids" and related oxidation products, selenate, selenite, and other species relatable to the quality and/or accuracy of the labeled selenium ingredients. Ultimately, a heated water extraction was applied to recover selenium species from non-selenized yeast supplements in capsule, tablet, and liquid forms. For selenized yeast supplements, inorganic selenium was monitored as a means of assessing selenium yeast quality. A variety of commercially available selenium supplements were evaluated and discrepancies between labeled ingredients and detected species were noted. Published by Elsevier Ltd.

  5. Multispecies Biofilms Transform Selenium Oxyanions into Elemental Selenium Particles: Studies Using Combined Synchrotron X-ray Fluorescence Imaging and Scanning Transmission X-ray Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Soo In; George, Graham N.; Lawrence, John R.; Kaminskyj, Susan G. W.; Dynes, James J.; Lai, Barry; Pickering, Ingrid J.

    2016-10-04

    Selenium (Se) is an element of growing environmental concern, because low aqueous concentrations can lead to biomagnification through the aquatic food web. Biofilms, naturally occurring microbial consortia, play numerous important roles in the environment, especially in biogeochemical cycling of toxic elements in aquatic systems. The complexity of naturally forming multispecies biofilms presents challenges for characterization because conventional microscopic techniques require chemical and physical modifications of the sample. Here, multispecies biofilms biotransforming selenium oxyanions were characterized using X-ray fluorescence imaging (XFI) and scanning transmission X-ray microscopy (STXM). These complementary synchrotron techniques required minimal sample preparation and were applied correlatively to the same biofilm areas. Sub-micrometer XFI showed distributions of Se and endogenous metals, while Se K-edge X-ray absorption spectroscopy indicated the presence of elemental Se (Se0). Nanoscale carbon K-edge STXM revealed the distributions of microbial cells, extracellular polymeric substances (EPS), and lipids using the protein, saccharide, and lipid signatures, respectively, together with highly localized Se0 using the Se LIII edge. Transmission electron microscopy showed the electron-dense particle diameter to be 50–700 nm, suggesting Se0 nanoparticles. The intimate association of Se0 particles with protein and polysaccharide biofilm components has implications for the bioavailability of selenium in the environment.

  6. Biocompatibility selenium nanoparticles with an intrinsic oxidase-like activity

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Leilei; Huang, Kaixun; Liu, Hongmei, E-mail: hmliu2004@126.com [Huazhong University of Science and Technology, School of Chemistry and Chemical Engineering (China)

    2016-03-15

    Selenium nanoparticles (SeNPs) are considered to be the new selenium supplement forms with high biological activity and low toxicity; however, the molecular mechanism by which SeNPs exert the biological function is unclear. Here, we reported that biocompatibility SeNPs possessed intrinsic oxidase-like activity. Using Na{sub 2}SeO{sub 3} as a precursor and glutathione as a reductant, biocompatibility SeNPs were synthesized by the wet chemical reduction method in the presence of bovine serum albumin (BSA). The results of structure characterization revealed that synthesized SeNPs were amorphous red elementary selenium with spherical morphology, and ranged in size from 25 to 70 nm size with a narrow distribution (41.4 ± 6.7 nm). The oxidase-like activity of the as-synthesized SeNPs was tested with 3,3′,5,5′-tetramethylbenzidine (TMB) as a substrate. The results indicated that SeNPs could catalyze the oxidization of TMB by dissolved oxygen. These SeNPs showed an optimum catalytic activity at pH 4 and 30 °C, and the oxidase-like activity was higher as the concentration of SeNPs increased and the size of SeNPs decreased. The Michaelis constant (K{sub m}) values and maximal reaction velocity (V{sub max}) of the SeNPs for TMB oxidation were 0.0083 mol/L and 3.042 μmol/L min, respectively.

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

    Science.gov (United States)

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

    2012-11-01

    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.

  9. Biosynthesis of selenium nanoparticles using Enterococcus faecalis and evaluation of their antibacterial activities.

    Science.gov (United States)

    Shoeibi, Sara; Mashreghi, Mohammad

    2017-01-01

    Microorganisms are capable of synthesizing metal nanoparticles, and specifically Enterococcus faecalis bacteria were tested for its ability to synthesize selenium nanoparticles (Se-NPs) from sodium selenite. The biosynthesized Se-NPs were spherical in shape with the size range of 29-195nm. Also, the TEM microscopy showed the accumulation of nano-structures as extracellular deposits. The ability of the bacteria to tolerate high levels of toxic selenite was studied by changing with different concentrations of sodium selenite (0.19mM-2.97mM). Also, the effect of Se-NPs was studied on the growth profile of number of pathogenic Gram-positive and -negative bacteria. High concentrations of sodium selenite in the medium led to the production of small amounts of selenium nanostructures by bacteria. In addition, Se-NPs can be used as an anti-staphylococcal element to effectively prevent and treat S. aureus infections. Copyright © 2016 Elsevier GmbH. All rights reserved.

  10. Role of proteins in controlling selenium nanoparticle size

    Energy Technology Data Exchange (ETDEWEB)

    Dobias, J; Suvorova, E I; Bernier-Latmani, R, E-mail: rizlan.bernier-latmani@epfl.ch [Environmental Microbiology Laboratory, EPFL, Station 6, 1015 Lausanne (Switzerland)

    2011-05-13

    This work investigates the potential for harnessing the association of bacterial proteins to biogenic selenium nanoparticles (SeNPs) to control the size distribution and the morphology of the resultant SeNPs. We conducted a proteomic study and compared proteins associated with biogenic SeNPs produced by E. coli to chemically synthesized SeNPs as well as magnetite nanoparticles. We identified four proteins (AdhP, Idh, OmpC, AceA) that bound specifically to SeNPs and observed a narrower size distribution as well as more spherical morphology when the particles were synthesized chemically in the presence of proteins. A more detailed study of AdhP (alcohol dehydrogenase propanol-preferring) confirmed the strong affinity of this protein for the SeNP surface and revealed that this protein controlled the size distribution of the SeNPs and yielded a narrow size distribution with a three-fold decrease in the median size. These results support the assertion that protein may become an important tool in the industrial-scale synthesis of SeNPs of uniform size and properties.

  11. Lead, mercury, selenium, and other trace elements in tissues of golden eagles from southwestern Montana, USA

    National Research Council Canada - National Science Library

    Harmata, Alan R; Restani, Marco

    2013-01-01

    .... We captured and sampled 74 Golden Eagles (Aquila chrysaetos) in southwestern Montana, USA, from 2008 to 2010 to evaluate levels of lead, mercury, selenium, and 13 other trace elements in blood and feathers...

  12. Bacteriogenic synthesis of selenium nanoparticles by Escherichia coli ATCC 35218 and its structural characterisation.

    Science.gov (United States)

    Kora, Aruna Jyothi; Rastogi, Lori

    2017-03-01

    A biosynthetic method for the production of selenium nanoparticles under ambient temperature and pressure from sodium selenite was developed using Gram-negative bacterial strain Escherichia coli ATCC 35218. Bacteriogenic nanoparticles were methodologically characterized employing UV-vis, XRD, Raman spectroscopy, SEM, TEM, DLS and FTIR techniques. Generation of nanoparticles was visualized from the appearance of red colour in the selenite supplemented culture medium and broad absorption bands in the UV-vis. Biofabricated nanoparticles were spherical, polydisperse, ranged from 100-183 nm and the average particle size was about 155 nm. Based on selected-area electron diffraction, XRD patterns; and Raman spectroscopy the nanospheres were found to be amorphous. IR spectrum revealed the involvement of bacterial proteins in the reduction of selenite and stabilization of nanoparticles. Used bacterial strain demonstrated efficient selenite reduction capability which was evident from 89.2% of selenium removal within 72 h at a concentration of 1 mM. Observation noted in the current study highlight the importance of bacterial reduction in selenium nanoparticle generation which can be scaled up for commercial production. Also, the bacteriogenic, amorphous nanoparticles can also be used as nutritional supplements for humans since selenium nanoparticles of 5-200 nm are bioavailable and known to induce seleno enzymes involved in antioxidant defence.

  13. Toxicity of selenium and other elements in food organisms to razorback sucker larvae

    Science.gov (United States)

    Hamilton, Steven J.; Holley, Kathy M.; Buhl, Kevin J.; Bullard, Fern A.; Weston, L. Ken; McDonald, Susan F.

    2002-01-01

    Elevated selenium concentrations documented in water, sediment, and biota in irrigation drain water studies by U.S. Department of the Interior agencies and academia have raised concerns that selenium may be adversely affecting endangered fish in the upper Colorado River basin. The objective of the study was to determine the effects on endangered razorback sucker (Xyrauchen texanus) larvae from exposure to selenium and other trace elements in water and zooplankton collected from sites adjacent to the Colorado River near Grand Junction, CO. A 30-day study was initiated with 5-day-old larvae exposed in a 4×4 factor experiment with four food and four water treatments, and the biological endpoints measured were survival, growth, development, and whole-body residues of selenium. Mean selenium concentration in reference water (24-Road) was brine shrimp) was 3.2 μg/g, at Horsethief was 1.6 μg/l in water and 6.0 μg/g in zooplankton, at Adobe Creek was 3.4 μg/l in water and 32 μg/g in zooplankton, and at Walter Walker was 13 μg/l in water and 52 μg/g in zooplankton. Although there were differences in concentrations of inorganic elements in water and biota among the three sites, selenium was apparently the only element elevated to concentrations of concern. Effects on survival were more prominent from dietary exposure compared to waterborne exposure. Selenium concentrations of ≥4.6 μg/g in food organisms adversely affected the survival of razorback sucker larvae. The onset of mortality in larvae exposed to food and water from Walter Walker seemed delayed compared to mortality in larvae exposed to food and water from Horsethief, which has been observed in two other studies. Elevated arsenic in one food source seemed to interact with selenium to reduce the toxic effects of selenium.

  14. The effect of selenium supplementation on elements distribution in liver of rats subject to strenuous swimming.

    Science.gov (United States)

    Sivrikaya, A; Akil, M; Bicer, M; Kilic, M; Baltaci, A K; Mogulkoc, R

    2013-01-01

    The present study aims to explore how selenium supplementation affects the element distribution in the liver tissue of rats subjected to strenuous swimming exercise. Thirty-two Spraque-Dawley male rats were equally divided into the four groups: Group 1, normal control group. Group 2, selenium-supplemented, non-swimming (0.6 mg/kg/day sodium selenite) group. Group 3, swimming, no supplementation group. Group 4, swimming, selenium-supplemented (0.6 mg/kg/day sodium selenite) group. After one month, the animals were decapitated and liver tissue samples were collected to determine the levels of lead, cobalt, boron, molybdenum, chromium, sulfur, magnesium, sodium, potassium, phosphorus, copper, iron, zinc and selenium. The chromium, molybdenum, iron, sodium and potassium values were higher in the swimming groups, relative to controls. Group 3 had significantly lower lead levels (pselenium and zinc values were obtained in the Group 2 and those of the Group 4 were higher than in the Groups 1 and 3. Group 1 had higher selenium and zinc levels than the Group 3. The results of the present study demonstrated that selenium-supplemented rats subjected to strenuous swimming exercise had distinct elements distribution in liver tissue. Also, selenium supplementation offsets the decrease in zinc levels in rats subjected to vigorous swimming (Tab. 3, Ref. 20).

  15. Nanoparticles as potential clinical therapeutic agents in Alzheimer's disease: focus on selenium nanoparticles.

    Science.gov (United States)

    Nazıroğlu, Mustafa; Muhamad, Salina; Pecze, Laszlo

    2017-07-01

    In etiology of Alzheimer's disease (AD), involvement of amyloid β (Aβ) plaque accumulation and oxidative stress in the brain have important roles. Several nanoparticles such as titanium dioxide, silica dioxide, silver and zinc oxide have been experimentally using for treatment of neurological disease. In the last decade, there has been a great interest on combination of antioxidant bioactive compounds such as selenium (Se) and flavonoids with the oxidant nanoparticles in AD. We evaluated the most current data available on the physiological effects of oxidant and antioxidant nanoparticles. Areas covered: Oxidative nanoparticles decreased the activities of reactive oxygen species (ROS) scavenging enzymes such as glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase in the brain of rats and mice. However, Se-rich nanoparticles in small size (5-15 nm) depleted Aβ formation through decreasing ROS production. Reports on low levels of Se in blood and tissue samples and the low activities of GSH-Px, catalase and SOD enzymes in AD patients and animal models support the proposed crucial role of oxidative stress in the pathogenesis of AD. Expert commentary: In conclusion, present literature suggests that Se-rich nanoparticles appeared to be a potential therapeutic compound for the treatment of AD.

  16. Pre-Clinical Study for the Antidiabetic Potential of Selenium Nanoparticles.

    Science.gov (United States)

    Ahmed, Hanaa H; Abd El-Maksoud, Mohamed Diaa; Abdel Moneim, Ahmed E; Aglan, Hadeer A

    2017-06-01

    This research was delineated to explore the efficacy of selenium nanoparticles delivered in liposomes (L-Se) in the mitigation of type-2 diabetes mellitus. Adult female Wistar rats were assigned into four groups: group I, the normal control group in which the rats received normal saline solution orally; group II, the diabetic control group in which the rats were injected intraperitoneally with a single dose of streptozotocin (STZ) for induction of diabetes; group III, the metformin (Met)-treated group in which the diabetic rats were treated orally with Met; and group IV, the L-Se-treated group in which the diabetic rats were treated orally with L-Se. All treatments were delivered for 21 days. Blood and pancreas tissue samples were obtained for biochemical analysis, immunohistochemical examinations, and histopathological investigation. The L-Se-treated group showed significant drop in serum glucose and pancreatic malondialdehyde (MDA), nitric oxide (NO), tumor necrosis factor-α (TNF-α), and prostaglandin F2α (PGF2α) levels associated with significant rise in serum insulin and pancreatic glutathione, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) values, in addition to significant improvement in the immunohistochemical indices (insulin and glucagon). Aforementioned results are appreciated by the histopathological findings of pancreatic tissue. In conclusion, our data have brought about compelling evidence favoring the antidiabetic potency of elemental selenium nanoparticles delivered in liposomes through preservation of pancreatic β cell integrity with consequent increment of insulin secretion and in turn glucose depletion, repression of oxidative stress, potentiation of the antioxidant defense system, and inhibition of pancreatic inflammation.

  17. Selenium Nanoparticles for Stress-Resilient Fish and Livestock

    Science.gov (United States)

    Sarkar, Biplab; Bhattacharjee, Surajit; Daware, Akshay; Tribedi, Prosun; Krishnani, K. K.; Minhas, P. S.

    2015-09-01

    The fisheries and livestock sectors capture the highest share of protein-rich animal food and demonstrate accelerated growth as an agriculture subsidiary. Environmental pollution, climate change, as well as pathogenic invasions exert increasing stress impacts that lead the productivity momentum at a crossroads. Oxidative stress is the most common form of stress phenomenon responsible for the retardation of productivity in fisheries and livestock. Essential micronutrients play a determinant role in combating oxidative stress. Selenium, one of the essential micronutrients, appears as a potent antioxidant with reduced toxicity in its nanoscale form. In the present review, different methods of synthesis and characterization of nanoscale selenium have been discussed. The functional characterization of nano-selenium in terms of its effect on growth patterns, feed digestibility, and reproductive system has been discussed to elucidate the mechanism of action. Moreover, its anti-carcinogenic and antioxidant potentiality, antimicrobial and immunomodulatory efficacy, and fatty acid reduction in liver have been deciphered as the new phenomena of nano-selenium application. Biologically synthesized nano-selenium raises hope for pharmacologically enriched, naturally stable nanoscale selenium with high ecological viability. Hence, nano-selenium can be administered with commercial feeds for improvising stress resilience and productivity of fish and livestock.

  18. Facile microwave synthesis, characterization, and solar cell application of selenium nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Panahi-Kalamuei, Mokhtar [Institute of Nano Science and Nano Technology, University of Kashan, P.O. Box. 87317-51167, Kashan (Iran, Islamic Republic of); Salavati-Niasari, Masoud, E-mail: salavati@kashanu.ac.ir [Institute of Nano Science and Nano Technology, University of Kashan, P.O. Box. 87317-51167, Kashan (Iran, Islamic Republic of); Hosseinpour-Mashkani, S. Mostafa [Young Researchers and Elites Club, Kashan Branch, Islamic Azad University, Kashan (Iran, Islamic Republic of)

    2014-12-25

    Highlights: • Selenium (Se) nanoparticles were synthesized via a simple microwave method. • The effects of preparation parameters were investigated. • A preliminary study on the possibility of developing a solar cell having FTO/TiO{sub 2}/Se/Pt-FTO. - Abstract: In the current study, selenium (Se) nanoparticles with hexagonal phase were synthesized by applying microwave irradiation using selenium tetrachloride as a starting reagent in distilled water at various conditions. Se nanoparticles were formed using hydrazine in short reaction time (4 min). The effects of reaction time, irradiation power, and types of surfactant including sodium dodecyl sulfate (SDS), polyethylene glycol 600 (PEG 600), and cetyltrimethylammonium bromide (CTAB) on the particle size of the product were investigated. To fabricate a FTO/TiO{sub 2}/Se/Pt-FTO and FTO/Se/CdS/Pt-FTO solar cell, selenium film was directly deposited on top of the TiO{sub 2} and FTO glass prepared by Doctor’s blade method, respectively. Solar cell results indicate that an inexpensive solar cell could be developed by synthesis of Se nanoparticles through microwave method.

  19. Dose-response relationship study of selenium nanoparticles as an immunostimulatory agent in cancer-bearing mice.

    Science.gov (United States)

    Faghfuri, Elnaz; Yazdi, Mohamad Hossein; Mahdavi, Mehdi; Sepehrizadeh, Zargham; Faramarzi, Mohammad Ali; Mavandadnejad, Faranak; Shahverdi, Ahmad Reza

    2015-01-01

    Oral administration of selenium nanoparticles has an immunomodulatory effect on individuals with cancer. In the present study we aimed to compare the cancer preventive effect via administration of different doses of selenium nanoparticles in mice with cancer. Forty 6- to 8-week-old inbred female BALB/c mice were used and divided into four test and control groups; each group contained ten mice. Group 1 (administered PBS) was used as the control and the test groups 2, 3, and 4 were daily administered 50, 100, and 200 μg of selenium nanoparticles, respectively, for 60 days. After 60 days, tumor induction was carried out and 10 days later serum samples were collected to measure the cytokines. Tumor growth and life span of the mice were also monitored during the study. The results showed a significant increase in serum IFN-γ and the ratio of IFN-γ/IL-4 in all administered doses compared to control. In addition, in mice that received higher doses of selenium nanoparticles (200 μg/day), lower tumor volume and extended life span were observed compared to control. Administration of selenium nanoparticles in normal mice without tumor challenge caused a nonsignificant increase in cytokine production, indicating that selenium supplementation has no effect on the immune response in the absence of tumor challenge. The 200-μg dose of selenium nanoparticles can induce more efficient responses against breast tumors. Copyright © 2015 IMSS. Published by Elsevier Inc. All rights reserved.

  20. A novel one-pot green synthesis of selenium nanoparticles and evaluation of its toxicity in zebrafish embryos.

    Science.gov (United States)

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

    2016-01-01

    Over the last 50 years, compelling evidence has accumulated on the beneficial role of selenium in human health. In the present study, different proteins were evaluated as reducing agents for the eco-friendly synthesis of selenium nanoparticles from an aqueous solution of sodium selenite. This method is a simple, low cost green synthesis alternative to chemical synthesis. The high conversion of selenium ions to selenium nanoparticles (SeNPs) was achieved by a reaction mixture of 0.1 g bovine serum albumin and 0.1 g sodium selenite at a reaction temperature of 121°C for 20 min duration. The selenium nanoparticles were characterized by fourier transform infrared (FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy. The FTIR spectral bands were sharp with strong absorption peaks at 1649 and 1551 cm(-1). SEM analysis of the synthesized selenium nanoparticles clearly showed the spherical shape with an average size ranging from 500 to 600 nm. The toxicity of SeNPs was evaluated using zebrafish embryos as a model system. SeNPs induced malformations in zebrafish embryos in a concentration-dependent manner. Selenium nanoparticles at 15-25 μg/ml concentration caused pericardial edema, tail malformation and decrease in heart rate in zebrafish embryos. Treatments with lower concentrations did not alter the heart rate or display any heart abnormalities. This study underlines the importance of identifying optimal SeNP concentration that could have potential therapeutic applications.

  1. Antitumor activity of hyaluronic acid-selenium nanoparticles in Heps tumor mice models.

    Science.gov (United States)

    Ren, Yuena; Zhao, Ting; Mao, Guanghua; Zhang, Min; Li, Fang; Zou, Ye; Yang, Liuqing; Wu, Xiangyang

    2013-06-01

    In this study, hyaluronic acid-selenium (HA-Se) nanoparticles as novel complexes were synthesized and their antitumor activities in vivo were investigated. The mice inoculated with Heps tumor were orally administered with HA-Se nanoparticles at 86.45 mg/kg (H) and 4.32 mg/kg (L) body weights as high and low doses respectively (2.20% selenium content in the HA-Se nanoparticles samples by ICP-AES) for 10 days. The transmission electron microscopy (TEM) results indicated that the HA-Se nanoparticles were spherical with mean size of 50-70 nm. The HA-Se nanoparticles could significantly reduce tumor weights at the tumor inhibition ratios of 46.92% (H) and 49.12% (L) respectively. However, in the 5-fluorouracil positive group (25 mg/kg), the tumor inhibition ratio was 61.71%. From the study, the HA-Se nanoparticles (4.32 mg/kg) significantly increased thymus and spleen relative weights, enhanced the activities of superoxide dismutase (SOD), reduced the formation of malondialdehyde (MDA) and the activities of aspartate transaminase, alanine transaminase and crea in Heps tumor mice. The results of the study indicated that the HA-Se nanoparticles are potential antitumor candidate for cancer treatment. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Reduction of selenite to red elemental selenium by Rhodopseudomonas palustris strain N.

    Directory of Open Access Journals (Sweden)

    Baozhen Li

    Full Text Available The trace metal selenium is in demand for health supplements to human and animal nutrition. We studied the reduction of selenite (SeO₃⁻² to red elemental selenium by Rhodopseudomonas palustris strain N. This strain was cultured in a medium containing SeO₃⁻² and the particles obtained from cultures were analyzed using transmission electron microscopy (TEM, energy dispersive microanalysis (EDX and X ray diffraction analysis (XRD. Our results showed the strain N could reduce SeO₃⁻² to red elemental selenium. The diameters of particles were 80-200 nm. The bacteria exhibited significant tolerance to SeO₃⁻² up to 8.0 m mol/L concentration with an EC₅₀ value of 2.4 m mol/L. After 9 d of cultivation, the presence of SeO₃²⁻ up to 1.0 m mol/L resulted in 99.9% reduction of selenite, whereas 82.0% (p<0.05, 31.7% (p<0.05 and 2.4% (p<0.05 reduction of SeO₃⁻² was observed at 2.0, 4.0 and 8.0 m mol/L SeO₃²⁻ concentrations, respectively. This study indicated that red elemental selenium was synthesized by green technology using Rhodopseudomonas palustris strain N. This strain also indicated a high tolerance to SeO₃⁻². The finding of this work will contribute to the application of selenium to human health.

  3. In-situ phase formation study of copper indium diselenide absorber layers from CuIn nanoparticles and evaporated selenium

    Energy Technology Data Exchange (ETDEWEB)

    Möckel, Stefan A., E-mail: Stefan.Moeckel@ww.uni-erlangen.de [Department of Materials Science, Chair of Materials for Electronics and Energy Technology, Friedrich-Alexander-University Erlangen-Nürnberg, Martensstr. 7, 91058 Erlangen (Germany); Hölzing, Astrid; Hock, Rainer [Chair for Crystallography and Structural Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Staudtstr. 3, 91058 Erlangen (Germany); Wellmann, Peter J. [Department of Materials Science, Chair of Materials for Electronics and Energy Technology, Friedrich-Alexander-University Erlangen-Nürnberg, Martensstr. 7, 91058 Erlangen (Germany)

    2013-05-01

    In this work CuInSe{sub 2} (CISe) thin films were fabricated by rapid thermal processing of printed CuIn nanoparticles and thermally evaporated selenium as precursor layer. Research is focused on real-time investigations such as in-situ X-ray diffraction and dynamic scanning calorimetry. These measurements show CISe formation starting at 300 °C. Significant amount of intermediate phases as reported for state-of-the-art rapid thermal processing of stacked elemental layer was not observed. The morphology of the nanoparticulate layers was examined by field emission scanning electron microscopy. Grain size developed from nanosized binary CuIn nanoparticles to microsized CISe grains. Porosity decreases in the temperature range from 340 °C to 540 °C. - Highlights: ► Synthesis and characterisation of CuIn nanoparticles ► Preparation of precursor layers for CuInSe2 from nanoparticles ► Characterisation by dynamic scanning calorimetry and in-situ X-ray diffraction ► CuInSe{sub 2} formation from 300 °C although high amount of sodium included.

  4. Biogenic synthesis of selenium nanoparticles and their effect on As(III)-induced toxicity on human lymphocytes.

    Science.gov (United States)

    Prasad, Kumar Suranjit; Selvaraj, Kaliaperumal

    2014-03-01

    A bioreductive capacity of a plant, Terminalia arjuna leaf extract, was utilized for preparation of selenium nanoparticles. The leaf extract worked as good capping as well as stabilizing agent and facilitated the formation of stable colloidal nanoparticles. Resulting nanoparticles were characterized using UV-Vis spectrophotometer, transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction analysis (XRD), respectively. The colloidal solution showed the absorption maximum at 390 nm while TEM and selected area electron diffraction (SAED) indicated the formation of polydispersed, crystalline selenium nanoparticles of size raging from 10 to 80 nm. FT-IR analysis suggested the involvement of O-H, N-H, C=O, and C-O functional group of the leaf extract in particle formation while EDAX analysis indicated the presence of selenium in synthesized nanoparticles. The effect of nanoparticles on human lymphocytes treated with arsenite, As(III), has been studied. Studies on cell viability using MTT assay and DNA damage using comet assay revealed that synthesized selenium nanoparticles showed protective effect against As(III)-induced cell death and DNA damage. Chronic ingestion of arsenic infested groundwater, and prevalence of arsenicosis is a serious public health issue. The synthesized benign nanoselenium can be a promising agent to check the chronic toxicity caused due to arsenic exposure.

  5. Plants and microbes assisted selenium nanoparticles: characterization and application

    National Research Council Canada - National Science Library

    Husen, Azamal; Siddiqi, Khwaja Salahuddin

    2014-01-01

    .... 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...

  6. 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.

  7. Selenium nanoparticle-enriched biomass of Yarrowia lipolytica enhances growth and survival of Artemia salina.

    Science.gov (United States)

    Hamza, Faseela; Vaidya, Amogh; Apte, Mugdha; Kumar, Ameeta Ravi; Zinjarde, Smita

    2017-11-01

    Controlling disease outbreaks is a major challenge in aquaculture farms and conventional methods are often ineffective. Nutritional supplementation and probiotic preparations help in reducing severity of such infections. The generally regarded as safe yeast (Yarrowia lipolytica) was used in the current study. A marine strain of Y. lipolytica exhibited tolerance towards sodium selenite and formed cell associated selenium nanoparticles (SeNPs). The synthesized nanoparticles were characterized by UV-vis spectroscopy, X-ray diffraction (XRD) and Field Emission Scanning Electron Microscope (FE-SEM) observations. Fourier transform infra-red (FTIR) spectroscopy indicated the role of carboxylic and amine groups in the synthesis of nanoparticles. This SeNP-enriched biomass was used as feed for the model aquaculture system, Artemia salina and compared with normal feed, baker's yeast (Saccharomyces cerevisiae). A. salina fed with SeNP-enriched biomass, showed increased survival rates (96.66%) as compared to those fed with S. cerevisiae (60.0%). The size of the larvae fed with SeNP-enriched biomass of Y. lipolytica was also found to be larger. Additionally, larval groups fed with SeNP-enriched biomass were better protected (70.0% survival) against V. harveyi infection when compared with groups fed with S. cerevisiae (24.44%). This combination of selenium in the nanoparticle form associated with the biomass of Y. lipolytica has potential application in improving health of aquaculture species in farms. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Colloidally stable selenium@copper selenide core@shell nanoparticles as selenium source for manufacturing of copper-indium-selenide solar cells.

    Science.gov (United States)

    Dong, Hailong; Quintilla, Aina; Cemernjak, Marco; Popescu, Radian; Gerthsen, Dagmar; Ahlswede, Erik; Feldmann, Claus

    2014-02-01

    Selenium nanoparticles with diameters of 100-400nm are prepared via hydrazine-driven reduction of selenious acid. The as-prepared amorphous, red selenium (a-Se) particles were neither a stable phase nor were they colloidally stable. Due to phase transition to crystalline (trigonal), grey selenium (t-Se) at or even below room temperature, the particles merged rapidly and recrystallized as micronsized crystal needles. As a consequence, such Se particles were not suited for layer deposition and as a precursor to manufacture thin-film CIS (copper indium selenide/CuInSe2) solar cells. To overcome this restriction, Se@CuSe core@shell particles are presented here. For these Se@CuSe core@shell nanoparticles, the phase transition a-Se→t-Se is shifted to temperatures higher than 100°C. Moreover, a spherical shape of the particles is retained even after phase transition. Composition and structure of the Se@CuSe core@shell nanostructure are evidenced by electron microscopy (SEM/STEM), DLS, XRD, FT-IR and line-scan EDXS. As a conceptual study, the newly formed Se@CuSe core@shell nanostructures with CuSe acting as a protecting layer to increase the phase-transition temperature and to improve the colloidal stability were used as a selenium precursor for manufacturing of thin-film CIS solar cells and already lead to conversion efficiencies up to 3%. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Two-dimensional finite elements model for selenium transport in saturated and unsaturated zones.

    Science.gov (United States)

    Tayfur, Gokmen; Tanji, Kenneth K; Baba, Alper

    2010-10-01

    A two-dimensional finite element model was developed to simulate species of selenium transport in two dimensions in both saturated and unsaturated soil zones. The model considers water, selenate, selenite, and selenomethionine uptake by plants. It also considers adsorption and desorption, oxidation and reduction, volatilization, and chemical and biological transformations of selenate, selenite, and selenomethionine. In addition to simulating water flow, selenate, selenite, and selenomethionine transport, the model also simulates organic and gaseous selenium transport. The developed model was applied to simulate two different observed field data. The simulation of the observed data was satisfactory, with mean absolute error of 48.5 microg/l and mean relative error of 8.9%.

  10. Layer-by-Layer Nanoassembly of Copper Indium Gallium Selenium Nanoparticle Films for Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    A. Hemati

    2012-01-01

    Full Text Available Thin films of CIGS nanoparticles interdigited with polymers have been fabricated through a cost-effective nonvacuum film deposition process called layer-by-layer (LbL nanoassembly. CIGS nanoparticles synthesized by heating copper chloride, indium chloride, gallium chloride, and selenium in oleylamine were dispersed in water, and desired surface charges were obtained through pH regulation and by coating the particles with polystyrene sulfonate (PSS. Raising the pH of the nanoparticle dispersion reduced the zeta-potential from +61 mV at pH 7 to −51 mV at pH 10.5. Coating the CIGS nanoparticles with PSS (CIGS-PSS produced a stable dispersion in water with −56.9 mV zeta-potential. Thin films of oppositely charged CIGS nanoparticles (CIGS/CIGS, CIGS nanoparticles and PSS (CIGS/PSS, and PSS-coated CIGS nanoparticles and polyethylenimine (CIGS-PSS/PEI were constructed through the LbL nanoassembly. Film thickness and resistivity of each bilayer of the films were measured, and photoelectric properties of the films were studied for solar cell applications. Solar cell devices fabricated with a 219 nm CIGS film, when illuminated by 50 W light-source, produced 0.7 V open circuit voltage and 0.3 mA/cm2 short circuit current density.

  11. Biogenic selenium nanoparticles induce ROS-mediated necroptosis in PC-3 cancer cells through TNF activation.

    Science.gov (United States)

    Sonkusre, Praveen; Cameotra, Swaranjit Singh

    2017-06-07

    Selenium is well documented to inhibit cancer at higher doses; however, the mechanism behind this inhibition varies widely depending on the cell type and selenium species. Previously, we have demonstrated that Bacillus licheniformis JS2 derived biogenic selenium nanoparticles (SeNPs) induce non-apoptotic cell death in prostate adenocarcinoma cell line, PC-3, at a minimal concentration of 2 µg Se/ml, without causing toxicity to the primary cells. However, the mechanism behind its anticancer activity was elusive. Our results have shown that these SeNPs at a concentration of 2 µg Se/ml were able to induce reactive oxygen species (ROS) mediated necroptosis in PC-3 cells by gaining cellular internalization. Real-time qPCR analysis showed increased expression of necroptosis associated tumor necrotic factor (TNF) and interferon regulatory factor 1 (IRF1). An increased expression of RIP1 protein was also observed at the translational level upon SeNP treatment. Moreover, the cell viability was significantly increased in the presence of necroptosis inhibitor, Necrostatin-1. Data suggest that our biogenic SeNPs induce cell death in PC-3 cells by the ROS-mediated activation of necroptosis, independent to RIP3 and MLKL, regulated by a RIP1 kinase.

  12. Hazard assessment of selenium and other trace elements in wild larval razorback sucker from the Green River, Utah

    Science.gov (United States)

    Hamilton, S.J.; Muth, R.T.; Waddell, B.; May, T.W.

    2000-01-01

    Contaminant investigations of the Green River in northeastern Utah have documented selenium contamination at sites receiving irrigation drainage. The Green River provides critical habitat for four endangered fishes including the largest extant riverine population of endangered razorback sucker. Although 2175 larval razorback suckers were collected from the river between 1992 and 1996, very few juveniles have been captured within recent decades. Selenium concentrations were measured in larval razorback suckers collected from five sites in the Green River (Cliff Creek, Stewart Lake Drain, Sportsman's Drain, Greasewood Corral, and Old Charlie Wash) to assess the potential for adverse effects on recruitment of larvae to the juvenile stage and the adult population. Larvae from all sites contained mean selenium concentrations ranging from 4.3 to 5.8 ??g/g. These values were at or above the proposed toxic threshold of 4 ??g/g for adverse biological effects in fish, which was derived from several laboratory and field studies with a wide range of fish species. At two sites, Cliff Creek and Stewart Lake Drain, selenium concentrations in larvae increased over time as fish grew, whereas selenium concentrations decreased as fish grew at Sportsman's Drain. Evaluation of a 279-larvae composite analyzed for 61 elements demonstrated that selenium and, to a lesser extent, vanadium were elevated to concentrations reported to be toxic to a wide range of fish species. Elevated selenium concentrations in larval razorback suckers from the five sites suggest that selenium contamination may be widespread in the Green River, and that survival and recruitment of larvae to the juvenile stage may be limited due to adverse biological effects. Selenium contamination may be adversely affecting the reproductive success and recruitment of endangered razorback sucker.

  13. Selenium bioaccumulation in shiitake mushrooms: a nutritional alternative source of this element.

    Science.gov (United States)

    Nunes, Regiane Gonçalves Feitosa Leal; da Luz, Jose Maria R; Freitas, Rodrigo de B; Higuchi, Angela; Kasuya, Maria Catarina M; Vanetti, Maria Cristina D

    2012-09-01

    Mushrooms have effective mechanisms to absorb and accumulate trace elements from substrates and, therefore could be used as a strategy to produce mineral-enriched food and nutritional supplements. This study aimed to enrich shiitake mushrooms with selenium (Se), an important dietary element in human health. Strains of Lentinula edodes (Berk.) were grown on artificial logs composed of eucalyptus sawdust, and were subjected to cold shock in water containing sodium selenite (Na(2)SeO(3) ) at concentrations of up to 1.28 mM. The content of Se in the mushrooms increased linearly with increasing amounts of Na(2)SeO(3) added to the cold water although above 0.96 mM, mushroom formation was inhibited. Concentrations greater than 17 mg Se 100/g of dried mushrooms were observed after treatment with 0.64 mM Na(2)SeO(3). Shiitake mushroom had a demonstrate potential to offer an effective and economical way to produce Se-enriched products and, the strategy of adding selenite in cold water, used in this study, showed promising once it does not interfere with mycelial growth. Selenium is an essential trace element for both human and animals and is required for the 21st amino acid, selenocysteine, which is used for the synthesis of about a dozen selenoenzymes. In this study, it is demonstrated that shiitake mushroom is a good Se accumulator and only one step during fructification was necessary to obtained enriched mushroom. Se enriched shiitake mushroom can be considered to be an excellent source of this element and used to consumption in different ways. © 2012 Institute of Food Technologists®

  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. High-throughput bioaccumulation, biotransformation, and production of silver and selenium nanoparticles using genetically engineered Pichia pastoris.

    Science.gov (United States)

    Elahian, Fatemeh; Reiisi, Somayeh; Shahidi, Arman; Mirzaei, Seyed Abbas

    2017-04-01

    A genetically modified Pichia pastoris strain overexpressing a metal-resistant variant of cytochrome b5 reductase enzyme was developed for silver and selenium biosorption and for nanoparticle production. The maximum recombinant enzyme expression level was approximately 31 IU/ml in the intercellular fluid after 24 h of incubation, and the capacity of the recombinant biomass for the biosorption of silver and selenium in aqueous batch models were measured as 163.90 and 63.71 mg/g, respectively. The ions were reduced in the presence of enzyme, leading to the formation of stable 70-180 nm metal nanoparticles. Various instrumental analyses confirmed the well-dispersed and crystalline nature of the spherical nanometals. The purified silver and selenium nanoparticles exhibited at least 10-fold less cytotoxicity toward HDF, EPG85-257, and T47D cells than silver nitrate and selenium dioxide. These results revealed that the engineered Pichia strain is an eco-friendly, rapid, high-throughput, and versatile reduction system for nanometal production. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Anti-inflammatory effect of selenium nanoparticles on the inflammation induced in irradiated rats.

    Science.gov (United States)

    El-Ghazaly, M A; Fadel, N; Rashed, E; El-Batal, A; Kenawy, S A

    2017-02-01

    Selenium (Se) has been reported to possess anti-inflammatory properties, but its bioavailability and toxicity are considerable limiting factors. The present study aimed to investigate the possible anti-inflammatory and analgesic effects of selenium nanoparticles (Nano-Se) on inflammation induced in irradiated rats. Paw volume and nociceptive threshold were measured in carrageenan-induced paw edema and hyperalgesia model. Leukocytic count, tumor necrosis factor-α (TNF-α), prostaglandin E2 (PGE2), thiobarbituric acid reactive substances (TBAR), and total nitrate/nitrite (NOx) were estimated in the exudate collected from 6 day old air pouch model. Irradiated rats were exposed to 6 Gy gamma (γ)-irradiation. Nano-Se were administered orally in a dose of 2.55 mg/kg once before carrageenan injection in the first model and twice in the second model. The paw volume but not the nociceptive response produced by carrageenan in irradiated rats was higher than that induced in non-irradiated rats. Nano-Se were effective in reducing the paw volume in non-irradiated and irradiated rats but it did not alter the nociceptive threshold. The inflammation induced in irradiated rats increased all the estimated parameters in the exudate whereas; Nano-Se decreased their elevation in non-irradiated and irradiated rats. Nano-Se possess a potential anti-inflammatory activity on inflammation induced in irradiated rats.

  17. Speeding up bioproduction of selenium nanoparticles by using Vibrio natriegens as microbial factory.

    Science.gov (United States)

    Fernández-Llamosas, Helga; Castro, Laura; Blázquez, María Luisa; Díaz, Eduardo; Carmona, Manuel

    2017-11-22

    Selenium and selenium nanoparticles (SeNPs) are extensively used in biomedicine, electronics and some other industrial applications. The bioproduction of SeNPs is gaining interest as a green method to manufacture these biotechnologically relevant products. Several microorganisms have been used for the production of SeNPs either under aerobic or anaerobic conditions. Vibrio natriegens is a non-pathogenic fast-growing bacterium, easily cultured in different carbon sources and that has recently been engineered for easy genetic manipulation in the laboratory. Here we report that V. natriegens was able to perfectly grow aerobically in the presence of selenite concentrations up to 15 mM with a significant survival still observed at concentrations as high as 100 mM selenite. Electron microscopy and X-ray spectroscopy analyses demonstrate that V. natriegens cells growing aerobically in selenite-containing LB medium at 30 °C produced spherical electron-dense SeNPs whose size ranged from 100-400 nm. Selenite reduction just started at the beginning of the exponential growth phase and the release of SeNPs was observed after cell lysis. Remarkably, V. natriegens produced SeNPs faster than other described microorganisms that were proposed as model bioreactors for SeNPs production. Thus, the fast-growing V. natriegens bacterium becomes a suitable biocatalyst for bioremediation of selenite and for speeding-up the eco-friendly synthesis of SeNPs.

  18. Selenium nanoparticles induce suppressed function of tumor associated macrophages and inhibit Dalton's lymphoma proliferation

    Directory of Open Access Journals (Sweden)

    Pramod Kumar Gautam

    2017-12-01

    Full Text Available Selenium Nanoparticle (SeNPs is reported that it enhances and maintains optimal immune during infection and malignancies. To this end, we examined the role of selenium on TAMS whose anti-tumor function suppressed which favor tumor progression. BALB/c (H2d strain of mice non-Hodgkin type of Dalton's cell line was used to check the role of carboxlic group induced, synthesized SeNPs on TAMs. Screening of IC50 value was done primarily trypen blue exclusion assay and 50% proliferation of DL cells inhibited 40 ng/ml to 50 ng/. Treatment also decreases ΔΨm, fragmentation of DNA of DL cells and arrest cells cycle in G1/G0 phage. Untreated TAMs cells showing suppressed expression of ROS, adhesion, phagocytosis, fusion and receptor profiling such as ICAM-1, CD47, CD172α. Which was induced more as compare to untreated group. SeNPs have potential to induce the anti-tumor function of TAMs whose anti-tumor function down-regulated pliable shifted towards tumor progression. It decreased the proliferation of DL cell by inducing apoptosis. Therefore, the synthesized SeNPs could be used for imaging diagnosis and cancer therapy which must be cost effective with negligible side effects shifted towards tumor progression. It decreased the proliferation of DL cell by inducing apoptosis.

  19. Toxicological implications of selenium nanoparticles with different coatings along with Se(4+) 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.

  20. Alleviating anastrozole induced bone toxicity by selenium nanoparticles in SD rats

    Energy Technology Data Exchange (ETDEWEB)

    Vekariya, Kiritkumar K.; Kaur, Jasmine; Tikoo, Kulbhushan, E-mail: tikoo.k@gmail.com

    2013-04-15

    Aromatase inhibitors like anastrozole play an undisputed key role in the treatment of breast cancer, but on the other hand, various side effects like osteoporosis and increased risk of bone fracture accompany the chronic administration of these drugs. Here we show for the first time that selenium nanoparticles, when given in conjugation to anastrozole, lower the bone toxicity caused by anastrozole and thus reduce the probable damage to the bone. Selenium nanoparticles at a dose of 5 μg/ml significantly reduced the cell death caused by anastrozole (1 μM) in HOS (human osteoblast) cells. In addition, our results also highlighted that in female SD rat model, SeNPs (0.25, 0.5, 1 mg/kg/day) significantly prevented the decrease in bone density and increase in biochemical markers of bone resorption induced by anastrozole (0.2 mg/kg/day) treatment. Histopathological examination of the femurs of SeNP treated group revealed ossification, mineralization, calcified cartilaginous deposits and a marginal osteoclastic activity, all of which indicate a marked restorative action, suggesting the protective action of the SeNPs. Interestingly, SeNPs (1 mg/kg/day) also exhibited protective effect in ovariectomized rat model, by preventing osteoporosis, which signifies that bone loss due to estrogen deficiency can be effectively overcome by using SeNPs. - Highlights: ► SeNPs significantly reduce bone toxicity in anastrozole treated rats. ► SeNPs successfully prevented osteoporosis in ovariectomized rats. ► SeNP treatment lowered the levels of TRAP and increased the levels of ALKP.

  1. Characterization, antioxidant property and cytoprotection of exopolysaccharide-capped elemental selenium particles synthesized by Bacillus paralicheniformis SR14.

    Science.gov (United States)

    Cheng, Yuanzhi; Xiao, Xiao; Li, Xiaoxiao; Song, Deguang; Lu, Zeqing; Wang, Fengqin; Wang, Yizhen

    2017-12-15

    Instead of using existing methods to chemically synthesize elemental selenium particles (CheSePs), which first require separating and purifying polysaccharides or proteins and adding extra reducing agent, this study applied a novel method to directly assemble exopolysaccharide-capped biogenic elemental selenium particles (EPS-BioSePs) by Bacillus paralicheniformis SR14 during the metabolic process. Characterization by energy dispersive X-ray spectrometry (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), size measurement and chemical composition analysis verified that EPS-BioSePs exhibited a monodispersed and homogeneous spherical structure 293.73±4.03nm in size. Compared to a widely used form of CheSePs stabilized and coated by bovine serum albumin, EPS-BioSePs exhibited better antioxidant properties on scavenging DPPH, superoxide and ABTS free radicals, but not hydroxyl radical. In vitro experiments with porcine jejunum epithelial (IPEC-J2) cells also indicated a significant cytoprotection of EPS-BioSePs against hydrogen peroxide-induced oxidative stress, as exhibited by cell viability reduction and suppression of ROS generation. These results suggested that this new form of selenium possessed great antioxidant property and cytoprotection and exopolysaccharide-producing bacteria could gradually become an appropriate choice to synthesize biogenic elemental selenium particles with potential applications as antioxidants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Fecal selenium excretion is regulated by dietary selenium intake1

    OpenAIRE

    Pedrosa,Lucia Fatima Campos; Motley, Amy K.; Stevenson, Teri D.; Hill, Kristina E.; Burk, Raymond F.

    2012-01-01

    Whole-body selenium is regulated by excretion of the element. Reports of studies carried out using isotopic tracers have led to the conclusion that urinary selenium excretion is regulated by selenium intake but that fecal excretion is not. Because of the limitations of tracer studies, we measured urinary and fecal selenium excretion by mice with selenium intakes ranging from deficient to almost toxic. Tissue and whole-body selenium concentrations increased sharply between deficient and adequa...

  3. Effects on diameter and morphology of polycaprolactone nanofibers infused with various concentrations of selenium nanoparticles

    Science.gov (United States)

    Kamaruzaman, Nurul Asyikin; Yusoff, Abdull Rahim Mohd; Buang, Nor Aziah; Salleh, Nik Ghazali Nik

    2017-12-01

    Electrospinning is one of the techniques used in the fabrication of nanofibers. Polycaprolactone (PCL), is a biodegradable polymer which was commonly electrospun without the presence of nanoparticles as additives and/or filler in the applications such as tissue engineering, biosensors, filtration, wound dressings, drug delivery and enzyme immobilization. In this study, via FESEM analyses, the effects on the diameter and morphology of PCL nanofibers was investigated with respect to various concentration of selenium nanoparticles (SeNP). Increasing the concentration of SeNP from 0.2 to 1.0% (w/v) resulted in increased of fiber diameter as well as the density of the nanofiber networking. Consequently, the formation of beads have also increased with the increment of the concentration of SeNP. The images from FESEM micrographs showed the formation of "aligned fibers" with the average size of less than 550 nm. The optimized concentration of SeNP obtained was 0.4 % w/v for the formation of aligned fibers with a uniform diameter in size and the least formation of beads in the matrices. Aligned nanofibers are biocompatible and can be used in tissue engineering and wound dressing applications. Meanwhile, nanofibers with beads are suitable for filtration design in water and gaseous applications.

  4. Selenium and Human Health

    Directory of Open Access Journals (Sweden)

    M Abedi

    2013-04-01

    Full Text Available Introduction: Selenium is an essential element for human health and it is toxic at high concentrations. Selenium is a constituent component of selenoproteins that have enzymatic and structural roles in human biochemistry. Selenium is a best antioxidant and catalyst for production of thyroid hormone. This element has the key role in the immune function; prevention of AIDS progression and the deactivity of toxins. Furthermore, selenium is essential for sperm motility and can reduce abortions. Selenium deficiency was also associated with adverse mood states. The findings regarding cardiovascular disease risk related to selenium deficiency is unclear, though other conditions such as vascular inflammation, oxidative stress and selenium deficiency can cause this disease too. Moreover, consuming of 60 mg of selenium per day may be associated with reduction of cancer risk. In this study, a review of studies has been performed on the biochemical function of selenium toxicity, and its effects on human health. Furthermore, certain identified cancers associated with selenium have been discussed to absorb more attention to the status of this element and also as a guide for further studies. Selenium plays the dual character (useful and harmful in human health, and then it is necessary to determine the concentration of this element in body fluids and tissues. An appropriate method for routine measurement of selenium in clinical laboratories is electro thermal atomic absorption spectrometry (ETAAS with very low detection limit and good precision.

  5. Selenium Nanoparticle-Enriched Lactobacillus Brevis Causes More Efficient Immune Responses In Vivo And Reduces The Liver Metastasis In Metastatic Form Of Mouse Breast Cancer

    Directory of Open Access Journals (Sweden)

    Mohammad Esfandyar

    2013-04-01

    Full Text Available Background and the purpose of the study:Selenium enriched Lactobacillus has been reported as an immunostimulatory agent which can be used to increase the life span of cancer bearing animals. Lactic acid bacteria can reduce selenium ions to elemental selenium nanoparticles (SeNPs and deposit them in intracellular spaces. In this strategy two known immunostimulators, lactic acid bacteria (LAB and SeNPs, are concomitantly administered for enhancing of immune responses in cancer bearing mice.Methods:Forty five female inbred BALB/c mice were divided into three groups of tests and control, each containing 15 mice. Test mice were orally administered with SeNP-enriched Lactobacillus brevis or Lactobacillus brevis alone for 3 weeks before tumor induction. After that the administration was followed in three cycles of seven days on/three days off. Control group received phosphate buffer saline (PBS at same condition. During the study the tumor growth was monitored using caliper method. At the end of study the spleen cell culture was carried out for both NK cytotoxicity assay and cytokines measurement. Delayed type hypersensitivity (DTH responses were also assayed after 72h of tumor antigen recall. Serum lactate dehydrogenase (LDH and alkaline phosphatase (ALP levels were measured, the livers of mice were removed and prepared for histopathological analysis.Results:High level of IFN-γ and IL-17 besides the significant raised in NK cytotoxicity and DTH responses were observed in SeNP-enriched L. brevis administered mice and the extended life span and decrease in the tumor metastasis to liver were also recorded in this group compared to the control mice or L.brevis alone administered mice.Conclusion:Our results suggested that the better prognosis could be achieved by oral administration of SeNP-enriched L. brevis in highly metastatic breast cancer mice model.

  6. Longitudinal association between toenail selenium levels and measures of subclinical atherosclerosis: the CARDIA trace element study

    Science.gov (United States)

    Xun, Pengcheng; Liu, Kiang; Morris, J Steven; Daviglus, Martha L; He, Ka

    2010-01-01

    Objectives To examine the longitudinal association between toenail selenium levels and sub-clinical atherosclerosis over an 18-year period. Methods Toenail selenium concentrations were examined among 3112 Americans age 20–32 years in 1987 and measured by instrumental neutron-activation analysis. Subclinical atherosclerosis, including common, bulb and internal carotid intima-media thickness (CIMT), was measured in 2005 and coronary artery calcium (CAC) score in 2000 and 2005. General linear regression was developed examining the relation between toenail selenium levels and CIMTs, and logistic regression for repeated outcomes was employed estimating the risk of having CAC>0. Results After adjustment for potential confounders, no associations were observed between toenail selenium levels and CIMTs as well as CAC score. Comparing participants in the highest with the lowest quintile of selenium, the CIMT was 0.005mm (SE=0.008mm, Ptrend=0.39), 0.018mm (SE=0.019mm, Ptrend=0.49), and 0.017mm (SE=0.014mm, Ptrend=0.21) thicker measured in common, bulb and internal carotid, respectively. The adjusted odds ratio of having CAC>0 was 0.95 (95%CI: 0.67–1.35; Ptrend=0.999). Conclusions No associations were observed between toenail selenium and measures of subclinical atherosclerosis among American young adults. This study does not support an atherosclerotic mechanism of selenium for risk reduction of cardiovascular disease. PMID:20138620

  7. Effects of selenium hyperaccumulation on plant-plant interactions: evidence for elemental allelopathy?

    Science.gov (United States)

    El Mehdawi, Ali F; Quinn, Colin F; Pilon-Smits, Elizabeth A H

    2011-07-01

    • Few studies have investigated plant-plant interactions involving hyperaccumulator plants. Here, we investigated the effect of selenium (Se) hyperaccumulation on neighboring plants. • Soil and litter Se concentrations were determined around the hyperaccumulators Astragalus bisulcatus and Stanleya pinnata and around the nonhyperaccumulators Medicago sativa and Helianthus pumilus. We also compared surrounding vegetative cover, species composition and Se concentration in two plant species (Artemisia ludoviciana and Symphyotrichum ericoides) growing either close to or far from Se hyperaccumulators. Then, Arabidopsis thaliana germination and growth were compared on soils collected next to the hyperaccumulators and the nonhyperaccumulators. • Soil collected around hyperaccumulators contained more Se (up to 266 mg Se kg(-1) ) than soil collected around nonhyperaccumulators. Vegetative ground cover was 10% lower around Se hyperaccumulators compared with nonhyperaccumulators. The Se concentration was higher in neighboring species A. ludoviciana and S. ericoides when growing close to, compared with far from, Se hyperaccumulators. A. thaliana showed reduced germination and growth, and higher Se accumulation, when grown on soil collected around Se hyperaccumulators compared with soil collected around nonaccumulators. • In conclusion, Se hyperaccumulators may increase the surrounding soil Se concentration (phytoenrichment). The enhanced soil Se contents around hyperaccumulators can impair the growth of Se-sensitive plant species, pointing to a possible role of Se hyperaccumulation in elemental allelopathy. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  8. 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

    2018-03-05

    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 160-250nm; their zeta potential was measured to be minus 18.5mV. 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 500cm-1 down to 150cm-1) showed a single very strong band with a maximum at 250cm-1 which, in line with its increased width (ca. 30cm-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. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. 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.

  10. Efficacy of biogenic selenium nanoparticles against Leishmania major: in vitro and in vivo studies.

    Science.gov (United States)

    Beheshti, Nasibeh; Soflaei, Saied; Shakibaie, Mojtaba; Yazdi, Mohammad Hossein; Ghaffarifar, Fatemeh; Dalimi, Abdolhossein; Shahverdi, Ahmad Reza

    2013-07-01

    This study investigated the in vitro and in vivo effectiveness of biogenic selenium nanoparticles (Se NPs), biosynthesized by Bacillus sp. MSh-1, against Leishmania major (MRHO/IR/75/ER). The 3-(4,5-dimethylthiozol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay was used to evaluate the cytotoxicity effects of the biogenic Se NPs against both promastigote and amastigote forms of L. major. In a separate in vivo experiment, we also determined the preventive and therapeutic effects of biogenic Se NPs in BALB/c mice following subcutaneous infected with L. major. The MTT assays showed that the highest toxicity occurred after 72 h against both promastigote and amastigote forms of L. major. The cytotoxicity of Se NPs was higher at all incubation times (24, 48, and 72 h) against the promastigote than the amastigote form (pdoses of biogenic Se NPs delayed the development of localized cutaneous lesions. Moreover, daily administration of Se NPs (5 or 10 mg kg(-1) day(-1)) in similarly infected BALB/c mice that had not received prophylactic doses of Se NPs also abolished the localized lesions after 14 days. Based on these in vitro and in vivo studies, biogenic Se NPs can be considered as a novel therapeutic agent for treatment of the localized lesions typical of cutaneous leishmaniasis. Copyright © 2012 Elsevier GmbH. All rights reserved.

  11. Toxicity of selenium nanoparticles in male Sprague-Dawley rats at supranutritional and nonlethal levels.

    Science.gov (United States)

    He, Yudan; Chen, Siyi; Liu, Zixun; Cheng, Chu; Li, Hui; Wang, Minqi

    2014-10-12

    We synthesized selenium nanoparticles (SeNPs) and examined their toxicity in male rats at supranutritional and nonlethal doses. The SeNPs were administered daily by gavage at doses of 0.0, 0.2, 0.4, 0.8, 2.0, 4.0, or 8.0 mg Se/kg-body weight (bw) in 2 mL of 0.9% saline for 14 consecutive days. Body weight, viscera index and blood biochemical parameters were measured. Histopathological examination was performed on selected tissues, and liver tissue was examined for apoptotic cells. Body weight decreased considerably in the groups given doses of 2.0, 4.0, and 8.0 mg Se/kg-bw, but increased in the groups given doses of 0.2 and 0.4 mg Se/kg-bw. The viscera index and some biochemical parameters in the 8.0 mg Se/kg-bw group differed from the control group. Lesions in the liver, kidneys, lungs, and thymus, and apoptotic liver cells were observed in the 4.0 and 8.0 mg Se/kg-bw groups. From this study, we conclude that supranutritional levels of SeNPs had no obvious toxic effects in rats, and could be used as potential candidates for cancer chemoprevention, although doses greater than 2.0 mg Se/kg-bw induced chronic toxicity. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Review on Nano SeleniumProduced by Bacteria

    OpenAIRE

    LI Ji-xiang; Wu, Wen-Liang; GUO Yan-bin

    2014-01-01

    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 ...

  13. 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.

  14. Inhibition of various gram-positive and gram-negative bacteria growth on selenium nanoparticle coated paper towels.

    Science.gov (United States)

    Wang, Qi; Larese-Casanova, Philip; Webster, Thomas J

    2015-01-01

    There are wide spread bacterial contamination issues on various paper products, such as paper towels hanging in sink splash zones or those used to clean surfaces, filter papers used in water and air purifying systems, and wrappings used in the food industry; such contamination may lead to the potential spread of bacteria and consequent severe health concerns. In this study, selenium nanoparticles were coated on normal paper towel surfaces through a quick precipitation method, introducing antibacterial properties to the paper towels in a healthy way. Their effectiveness at preventing biofilm formation was tested in bacterial assays involving Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus epidermidis. The results showed significant and continuous bacteria inhibition with about a 90% reduction from 24 to 72 hours for gram-positive bacteria including S. aureus and S. epidermidis. The selenium coated paper towels also showed significant inhibition of gram-negative bacteria like P. aeruginosa and E. coli growth at about 57% and 84%, respectively, after 72 hours of treatment. Therefore, this study established a promising selenium-based antibacterial strategy to prevent bacterial growth on paper products, which may lead to the avoidance of bacteria spreading and consequent severe health concerns.

  15. Protection of cisplatin-induced spermatotoxicity, DNA damage and chromatin abnormality by selenium nano-particles

    Energy Technology Data Exchange (ETDEWEB)

    Rezvanfar, Mohammad Amin; Rezvanfar, Mohammad Ali [Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences (TUMS), Tehran (Iran, Islamic Republic of); Shahverdi, Ahmad Reza [Department of Pharmaceutical Biotechnology and Biotechnology Research Centre, Faculty of Pharmacy, TUMS, Tehran (Iran, Islamic Republic of); Ahmadi, Abbas [Department of Histology and Embryology, Faculty of Veterinary Medicine, Urmia University, Urmia (Iran, Islamic Republic of); Baeeri, Maryam; Mohammadirad, Azadeh [Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences (TUMS), Tehran (Iran, Islamic Republic of); Abdollahi, Mohammad, E-mail: mohammad.abdollahi@utoronto.ca [Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences (TUMS), Tehran (Iran, Islamic Republic of)

    2013-02-01

    Cisplatin (CIS), an anticancer alkylating agent, induces DNA adducts and effectively cross links the DNA strands and so affects spermatozoa as a male reproductive toxicant. The present study investigated the cellular/biochemical mechanisms underlying possible protective effect of selenium nano-particles (Nano-Se) as an established strong antioxidant with more bioavailability and less toxicity, on reproductive toxicity of CIS by assessment of sperm characteristics, sperm DNA integrity, chromatin quality and spermatogenic disorders. To determine the role of oxidative stress (OS) in the pathogenesis of CIS gonadotoxicity, the level of lipid peroxidation (LPO), antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) and peroxynitrite (ONOO) as a marker of nitrosative stress (NS) and testosterone (T) concentration as a biomarker of testicular function were measured in the blood and testes. Thirty-two male Wistar rats were equally divided into four groups. A single IP dose of CIS (7 mg/kg) and protective dose of Nano-Se (2 mg/kg/day) were administered alone or in combination. The CIS-exposed rats showed a significant increase in testicular and serum LPO and ONOO level, along with a significant decrease in enzymatic antioxidants levels, diminished serum T concentration and abnormal histologic findings with impaired sperm quality associated with increased DNA damage and decreased chromatin quality. Coadministration of Nano-Se significantly improved the serum T, sperm quality, and spermatogenesis and reduced CIS-induced free radical toxic stress and spermatic DNA damage. In conclusion, the current study demonstrated that Nano-Se may be useful to prevent CIS-induced gonadotoxicity through its antioxidant potential. Highlights: ► Cisplatin (CIS) affects spermatozoa as a male reproductive toxicant. ► Effect of Nano-Se on CIS-induced spermatotoxicity was investigated. ► CIS-exposure induces oxidative sperm DNA damage

  16. Quantification of pharmaceutical peptides using selenium as an elemental detection label

    DEFF Research Database (Denmark)

    Møller, Laura Hyrup; Gabel-Jensen, Charlotte; Franzyk, Henrik

    2014-01-01

    analysis of cell samples by LC-ICP-MS showed mainly uptake of the intact peptides, while the amount of intact peptides in cell lysates was semi-quantitatively determined. The selenium-containing penetratin analogues were to some extent degraded in pure cell medium, while an extensive degradation...... studies. Most pharmaceutical peptides, including penetratin, are synthetic analogues of endogenous peptides, and incorporation of selenium may improve the critical assessment of the native drug or drug delivery candidate early in the drug development process....

  17. 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

    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....

  18. Exploratory studies of element substitutions in synthetic tetrahedrite. Part II. Selenium and tellurium as anions in Zn-Fe tetrahedrites

    DEFF Research Database (Denmark)

    Karup-Møller, Sven; Makovicky, E.

    1999-01-01

    Composition limits of iron and/or zinc-bearing selenium tetrahedrite were explored by means of dry syntheses from pure elements at 450oC. Only the substituted compositions Cu10Zn2Sb4Se13 (a 10.833 Å) and Cu10Fe1.8Sb4Se13 (a 10.823 Å) are stable. All partly substituted and unsubstituted (i.e. Zn...... holes created in the anionic band in this process, such reducible (i.e. partly substituted) compositions are absent or their extend is very limited....

  19. Targeted sulphur and selenium speciation in yeast by parallel elemental and molecular mass spectrometry

    DEFF Research Database (Denmark)

    Hillestrøm, Peter René; Mapelli, Valeria; Olsson, Lisbeth

    Selenium supplement, often selenized yeast, are currently the subject of intense study owing to their potential preventive effects against cancer. However, fundamental knowledge of the yeast’s metabolism is required for metabolic engineering biosynthetic production of potent Se-species. A method...

  20. Study of trace elements remobilization from a contaminated soil: influence of soil organic compounds ageing on the selenium remobilization; Etude de la remobilisation d'elements traces a partir d'un sol de surface contamine: influence du vieillissement de la matiere organique du sol sur la remobilisation du selenium

    Energy Technology Data Exchange (ETDEWEB)

    Chabroullet, Ch

    2007-03-15

    {sup 79}Se is a high-life fission product presents in high-activity nuclear wastes. Selenium is often taking into account for health and environmental risk assessments as it is usually considered as a mobile and a toxic element. The terrestrial ecosystems are thought to be a potential reservoir of selenium. In this study, we specially studied how the associations between selenium and soil organic matter and/or microorganisms modify soils selenium mobility and partition (solid, liquid and gaseous). A particular attention was paid to the temporal evolution of the retention parameters, which remains one of the weak points of modeling especially for long term simulations (several tens-hundreds of thousand years). Methodology developed consists on a regular characterization of 3 soils samples pre-contaminated at a very week selenium concentration (2.2*10{sup -9} g Se.g{sup -1} soil) and incubated during 1.5 year in controlled conditions. The evolution of the organic status of the soil samples was established and well modeled (Roth C.). Alternatively, the selenium-OM associations did not present any significant modification with time affecting selenium mobility. The detailed study of selenium mobility showed that selenium sorption processes was poorly reversible (sorption Kd: 20-50 L.kg{sup -1}; desorption Kd: 100-500 L.kg{sup -1}), whatever the soil organic status. In addition, numerous transitory phenomenons were able to disturb the 'basic' behavior of selenium by increasing the amount of soluble selenium. We specially established that: (i) the use of phosphate fertilizers constituted the most important way of selenium remobilization leading to the release of 30-40 % of sorbed selenium in some extreme cases; (ii) the week selenium volatilization ({approx} 0.2 % for 1.5 year of incubation) may constitute a significant biotic way of {sup 79}Se dispersion as soon as very long time scales are considered; (iii) the colloidal transport due to the soil

  1. Levels of trace elements in green turtle eggs collected from Hong Kong: Evidence of risks due to selenium and nickel

    Energy Technology Data Exchange (ETDEWEB)

    Lam, James C.W. [Center for Coastal Pollution and Conservation, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong (China); Tanabe, Shinsuke [Center for Marine Environmental Studies, Ehime University, Tarumi 3-5-7, Matsuyama 790-8556 (Japan); Chan, Simon K.F. [Agriculture, Fisheries and Conservation Department, Hong Kong SAR Government, Hong Kong, (China); Lam, Michael H.W. [Center for Coastal Pollution and Conservation, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong (China); Martin, Michael [Center for Coastal Pollution and Conservation, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong (China); Lam, Paul K.S. [Center for Coastal Pollution and Conservation, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong (China)]. E-mail: bhpksl@cityu.edu.hk

    2006-12-15

    Concentrations of 22 trace elements were determined in green turtle (Chelonia mydas) eggs collected from Hong Kong. Concentrations of selenium, lead and nickel in these eggs were generally higher than those reported in other studies. The predicted no effect concentrations (PNEC; ng/g wet weight) of Pb (1000), Se (340 and 6000 for the worst-case and best-case scenarios, respectively) and Ni (17) in the green turtle eggs were estimated. Hazard quotients (HQs) estimate that Se (HQs: 0.2-24.5) and Ni (HQs: 4.0-26.4) may pose some risks to the turtles. Our study also found that concentrations of Ag, Se, Zn, Hg and Pb in the shell of the turtle eggs were significantly correlated with levels in the whole egg contents (yolk + albumen). Once the precise relationships of specific elements are established, egg-shell concentrations may be used as a non-lethal, non-invasive, surrogate for predicting whole egg burden of certain contaminants in marine turtles. - Concentrations of selenium and nickel in green turtle eggs from Hong Kong might pose some risks to the turtles.

  2. Biodegradation of an organoselenium compound to elemental selenium by Lentinula edodes (shiitake) mushroom.

    Science.gov (United States)

    Tsivileva, Olga M; Loshchinina, Ekaterina A; Pankratov, Alexei N; Burashnikova, Marina M; Yurasov, Nikolay A; Bylinkina, Nina N; Kazarinov, Ivan A; Nikitina, Valentina E

    2012-10-01

    The present paper reports for the first time the transformation of an organic selenium compound into red selenium (Se), which causes the intense red pigmentation of Lentinula edodes (shiitake mushroom) mycelia. The biotransformation of 1,5-diphenyl-3-selenopentanedione-1,5 (diacetophenonyl selenide, preparation DAPS-25) was studied in liquid- and solid-phase cultures of L. edodes. In liquid culture medium, a red color develops in the mycelium at initial DAPS-25 concentrations equal to or higher than 0.1 mmol/l. The intensity and initiation time of coloration is Se concentration-dependent. Semiquantitative data obtained by physicochemical methods on the extent of Se and acetophenone production suggest that L. edodes is able to absorb and/or destruct this organic Se xenobiotic.

  3. Ameliorative Effects of Dietary Selenium Against Cadmium Toxicity Is Related to Changes in Trace Elements in Chicken Kidneys.

    Science.gov (United States)

    Zhang, Runxiang; Wang, Yanan; Wang, Chao; Zhao, Peng; Liu, Huo; Li, Jianhong; Bao, Jun

    2017-04-01

    The ameliorative effects of selenium (Se) against cadmium (Cd)-induced toxicity have been reported extensively. However, few studies have assessed the effects of multiple ions simultaneously on the variations of elements. In this study, the changes in Se, Cd, and 26 other element concentrations were investigated in chicken kidneys. One hundred and twenty-eight 31-week-old laying hens were fed a diet supplemented with either Se, Cd, or both Se and Cd for 90 days. The ion content was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). We found that the Se, Cd, and combined Se and Cd treatments significantly affected the trace elements in the chicken kidneys. The Cd supplement caused ion profile disorders, including reduced concentrations of V, Cr, Mn, Mo, As, Ba, Hg, Ti, and Pb and increased Si, Cu, Li, Cd, and Sb. The Se supplement reduced the contents of Co, Mo, and Pb and increased the contents of Cr, Fe, and Se. Moreover, Se also increased the concentrations of Cr, Mn, Zn, and Se and decreased those of Li and Pb, which in contrast were induced by Cd. Complex interactions between elements were analyzed, and both positive and negative correlations among these elements are presented. The present study indicated that Se can help against the negative effects of Cd and may be related to the homeostasis of the trace elements in chicken kidneys.

  4. Mixed Surfactant Template Method for Preparation of Nanometer Selenium

    Directory of Open Access Journals (Sweden)

    Zhi-Lin Li

    2009-01-01

    Full Text Available Selenium nanoparticles have been synthesized in an aqueous solution by using sodium dodecyl sulfate and polyvinyl alcohol as a soft template. The factors on synthesis, such as reaction time, concentration of reactants and ultrasonic irradiation were studied. The uniform stable selenium nanospheres were obstained in the conditions of 1.0 (mass fraction sodium dodecyl sulfate, 1.0 (mass fraction polyvinyl alcohol, n(Vc:n(H2SeO3=7:1 and 7 minutes after the initiation of the reaction at room temperature. The average particle size of selenium is about 30 nm. The product was characterized by UV and TEM. Finally the applications of the red element nanometer selenium in anti-older cosmetics are presented.

  5. Differential protein expression of Caco-2 cells treated with selenium nanoparticles compared with sodium selenite and selenomethionine

    Science.gov (United States)

    Fu, Linglin; Yan, Xuxia; Ruan, Xinming; Lin, Junda; Wang, Yanbo

    2014-10-01

    The study was designed to determine the differential protein expression of Caco-2 cells treated with different forms of selenium including sodium selenite, selenomethionine (Se-Met), and selenium nanoparticles (nano-Se). Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS) were used to identify the differentially expressed proteins. The results indicated that seven protein spots, ubiquitin-conjugating enzyme E2 (E2), glutathione synthetases (GS), triosephosphate isomerase (TSP), T-complex protein 1 subunit zeta (TCPZ), lamin-B1, heterogeneous nuclear ribonucleoprotein F (hnRNP F), and superoxide dismutase [Cu-Zn] (Cu, Zn-SOD) were significantly different among all the groups. According to the order of control, sodium selenite, Se-Met, and Nano-Se, the expression levels of two proteins (E2 and GS) increased and the other differential proteins were reverse. Except for E2, there were no significant differences in other protein expressions between the groups treated with nano-Se and Se-Met.

  6. 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,

  7. Methods of Selenium Supplementation: Bioavailability and Determination of Selenium Compounds.

    Science.gov (United States)

    Bodnar, Malgorzata; Szczyglowska, Marzena; Konieczka, Piotr; Namiesnik, Jacek

    2016-01-01

    Selenium, a "dual-surface" element, maintains a very thin line between a level of necessity and harmfulness. Because of this, a deficiency or excess of this element in an organism is dangerous and causes health-related problems, both physically and mentally. The main source of selenium is a balanced diet, with a proper selection of meat and plant products. Meanwhile, the proper assimilation of selenium into these products depends on their bioavailability, bioaccessibility, and/or bioactivity of a given selenium compound. From the time when it was discovered that selenium and its compounds have a significant influence on metabolic processes and in many countries throughout the world, a low quantity of selenium was found in different parts of the environment, pressure was put upon an effective and fast method of supplementing the environment with the help of selenium. This work describes supplementation methods applied with the use of selenium, as well as new ideas for increasing the level of this element in various organisms. Based on the fact that selenium appears in the environment at trace levels, the determination of total amount of selenium or selenium speciation in a given sample demands the selection of appropriate measurement methods. These methods are most often comprised of a sample preparation technique and/or a separation technique as well as a detection system. The work presents information on the subject of analytical methods used for determining selenium and its compounds as well as examples in literature of their application.

  8. Marine Primary Productivity as a Potential Indirect Source of Selenium and Other Trace Elements in Atmospheric Deposition.

    Science.gov (United States)

    Blazina, Tim; Läderach, Alexander; Jones, Gerrad D; Sodemann, Harald; Wernli, Heini; Kirchner, James W; Winkel, Lenny H E

    2017-01-03

    Atmospheric processes play an important role in the supply of the trace element selenium (Se) as well as other essential trace elements to terrestrial environments, mainly via wet deposition. Here we investigate whether the marine biosphere can be identified as a source of Se and of other trace elements in precipitation samples. We used artificial neural network (ANN) modeling and other statistical methods to analyze relationships between a high-resolution atmospheric deposition chemistry time series (March 2007-January 2009) from Plynlimon (UK) and exposure of air masses to marine chlorophyll a and to other source proxies. Using ANN sensitivity analyses, we found that higher air mass exposure to marine productivity leads to higher concentrations of dissolved organic carbon (DOC) in rainfall. Furthermore, marine productivity was found to be an important but indirect factor in controlling Se as well as vanadium (V), cobalt (Co), nickel (Ni), zinc (Zn), and aluminum (Al) concentrations in atmospheric deposition, likely via scavenging by organic compounds derived from marine organisms. Marine organisms may thus play an indirect but important role in the delivery of trace elements to terrestrial environments and food chains.

  9. Circulating Immune Complexes and trace elements (Copper, Iron and Selenium as markers in oral precancer and cancer : a randomised, controlled clinical trial

    Directory of Open Access Journals (Sweden)

    Karjodkar Freny R

    2006-10-01

    Full Text Available Abstract Aim To evaluate the levels of circulating immune complexes, trace elements (copper, iron and selenium in serum of patients with oral submucous fibrosis (OSMF, oral leukoplakia (L, and oral squamous cell carcinoma (SCC, analyze the alteration and identify the best predictors amongst these parameters for disease occurrence and progression. Methods Circulating immune complexes (CIC were estimated using 37.5% Polyethylene Glycol 6000(PEG serum precipitation. Serum estimation of copper (Cu, Iron (Fe and selenium (Se was done using the Oxalyl Dihydrazide method, Colorimetric Dipyridyl method and the Differential Pulse Cathodic Stripping Voltametry respectively. Results The data analysis revealed increased circulating immune complex levels in the precancer and cancer patients. Serum copper levels showed gradual increase from precancer to cancer patients. However, serum iron levels were decreased significantly in the cancer group. Selenium levels showed marked decrease in the cancer group. Among CIC, serum, copper, iron and selenium the best predictors for the occurrence of lesions were age, serum iron, CIC, serum selenium in the decreasing order. Conclusion The present study shows that these immunological and biological markers may be associated with the pathogenesis of oral premalignant and malignant lesions and their progressions. Concerted efforts would, therefore, help in early detection, management, and monitoring the efficacy of treatment.

  10. Selenium and the thyroid.

    Science.gov (United States)

    Köhrle, Josef

    2015-10-01

    This article provides an update on the role of the essential trace element selenium and its interaction with the other trace elements iodine and iron that together contribute to adequate thyroid hormone status. Synthesis, secretion, metabolism and action of thyroid hormone in target tissues depend on a balanced nutritional availability or supplementation of these elements. Selenium status is altered in benign and malignant thyroid diseases and various selenium compounds have been used to prevent or treat widespread diseases such as goiter, autoimmune thyroid disease or thyroid cancer. Several studies, most with still too low numbers of cases, indicate that selenium administration in both autoimmune thyroiditis (Hashimoto thyroiditis) and mild Graves' disease improves clinical scores and well-being of patients and reduces thyroperoxidase antibody titers. However, published results are still conflicting depending on basal selenium status, dose, time and form of selenium used for intervention. Evidence for sex-specific selenium action, lack of beneficial effects in pregnancy and contribution of genetic polymorphisms (selenoprotein S) has been presented. Adequate nutritional supply of selenium that saturates expression of circulating selenoprotein P, together with optimal iodine and iron intake, is required for a healthy and functional thyroid during development, adolescence, adulthood and aging.

  11. Selenium Sulfide

    Science.gov (United States)

    Selenium sulfide, an anti-infective agent, relieves itching and flaking of the scalp and removes the dry, ... Selenium sulfide comes in a lotion and is usually applied as a shampoo. As a shampoo, selenium ...

  12. Effect of supplementation of different levels of selenium as nanoparticles/sodium selenite on blood biochemical profile and humoral immunity in male Wistar rats

    Directory of Open Access Journals (Sweden)

    S. J. Bunglavan

    2014-12-01

    Full Text Available Aim: To study the effect of supplementation of different levels of selenium as nanoparticles/sodium selenite on blood biochemical profile and humoral immunity in male Wistar rats. Materials and Methods: The experimental research was conducted at Division of Animal Nutrition, Indian Veterinary Research Institute, Izatnagar. 63 male Wistar rats were divided into 9 equal groups on the basis of their mean body weight (BW (124.3±3.1 g BW following completely randomized design. Experimental feeding was similar in all the groups except for the source and level of selenium (Se in the diet. While Group 1 (control was fed a basal diet with no Se supplementation, in Groups 2 and 3, 150 ppb Se was supplemented either as sodium selenite or Se nanoparticles, respectively. In Groups 4, 5, 6 and 7, Se was supplemented as its nanoparticles at 50%, 25%, 12.5% and 6.25% levels respectively i.e. at 75 ppb, 37.5 ppb, 18.75 ppb and 9.375 ppb levels respectively. In Groups 8 and 9, 300 ppb Se was supplemented either as Se nanoparticles or sodium selenite, respectively. Experimental feeding was conducted for a period of 91 days. At the end of the experimental trial, blood samples were collected to analyze the blood serum biochemical profile (serum glucose, serum total protein (TP, serum albumin, serum globulin, serum albumin: globulin ratio [A:G ratio], serum total cholesterol and humoral immunity. Results: The levels of serum glucose, serum TP and serum albumin were comparable (p>0.05 among the nine groups of male Wistar rats. The mean serum total cholesterol was significantly (p<0.001 lowered in all the Se supplemented Wistar rats compared to the control group. The mean serum globulin level was significantly (p<0.05 higher and A:G ratio was significantly (p<0.05 lowered in Group 3 (supplemented with 150 ppb selenium nanoparticles followed by Groups 2, 4, 5, 6, 8, and 9 as compared to the control group. The mean serum antibody titer was significantly (p<0.001 higher

  13. Genome-wide association study of serum selenium concentrations

    DEFF Research Database (Denmark)

    Gong, Jian; Hsu, Li; Harrison, Tabitha

    2013-01-01

    Selenium is an essential trace element and circulating selenium concentrations have been associated with a wide range of diseases. Candidate gene studies suggest that circulating selenium concentrations may be impacted by genetic variation; however, no study has comprehensively investigated this ...

  14. 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.

  15. Boundary element method for surface nonlinear optics of nanoparticles.

    Science.gov (United States)

    Mäkitalo, Jouni; Suuriniemi, Saku; Kauranen, Martti

    2011-11-07

    We present the frequency-domain boundary element formulation for solving surface second-harmonic generation from nanoparticles of virtually arbitrary shape and material. We use the Rao-Wilton-Glisson basis functions and Galerkin's testing, which leads to very accurate solutions for both near and far fields. This is verified by a comparison to a solution obtained via multipole expansion for the case of a spherical particle. The frequency-domain formulation allows the use of experimentally measured linear and nonlinear material parameters or the use of parameters obtained using ab-initio principles. As an example, the method is applied to a non-centrosymmetric L-shaped gold nanoparticle to illustrate the formation of surface nonlinear polarization and the second-harmonic radiation properties of the particle. This method provides a theoretically well-founded approach for modelling nonlinear optical phenomena in nanoparticles.

  16. Selenium, selenoproteins and vision.

    Science.gov (United States)

    Flohé, Leopold

    2005-01-01

    Selenium biochemistry is reviewed in respect to its presumed relevance to age-related ocular diseases. Selenium is an essential trace element that exerts its physiological role as selenocysteine residue in at least 25 distinct selenoenzymes in mammals. Lack of GPx-1 due to alimentary selenium deprivation has been inferred to induce cataract in rats and was demonstrated to cause cataracts in mice by targeted gene disruption. The role of other selenoproteins in the eye remains to be worked out. Selenium in excess of the tiny amounts required for selenoprotein synthesis is toxic in general and causes cataracts in experimental animals. Clinical evidence for a protective role of selenium in the development of cataract, macula degeneration, retinitis pigmentosa or any other ocular disease is not available, likely because suboptimum selenium intake, as it may result from unbalanced diet, does not cause any pathologically relevant selenium deficiency in the eye. At present, there is neither theoretical nor an empirical basis to expect beneficial effects of selenium supplementation beyond the dietary reference intakes of 55 microg/day in the context of ocular diseases.

  17. Selenium in reproductive health.

    Science.gov (United States)

    Mistry, Hiten D; Broughton Pipkin, Fiona; Redman, Christopher W G; Poston, Lucilla

    2012-01-01

    Selenium is an essential trace element of importance to human biology and health. Increasing evidence suggests that this mineral plays an important role in normal growth and reproduction in animals and humans, and selenium supplementation is now recommended as part of public health policy in geographical areas with severe selenium deficiency in soil. This review addresses the biological functions of selenium followed by a detailed review of associations between selenium status and reproductive health. In many countries, selenium dietary intake falls below the recommended nutrient intakes and is inadequate to support maximal expression of the selenoenzymes. Numerous reports implicate selenium deficiency in several reproductive and obstetric complications including male and female infertility, miscarriage, preeclampsia, fetal growth restriction, preterm labor, gestational diabetes, and obstetric cholestasis. Currently, there is inadequate information from the available small intervention studies to inform public health strategies. Larger intervention trials are required to reinforce or refute a beneficial role of selenium supplementation in disorders of reproductive health. Copyright © 2012 Mosby, Inc. All rights reserved.

  18. PLANT RESOURCES BASED SELENIUM SUPPLEMENTATION IN DAILY NUTRITION

    OpenAIRE

    Vida Škrabanja

    2017-01-01

    Selenium is one of the essential elements that has a direct effect on human health and disease. Environmental conditions and agricultural practice have a profound influence on the selenium content in plants. Cultivation of plants enriched with the selenium has an effective potential for selenium supplementation in diets for population which is exposed to selenium deficiency. Bioavailability of selenium compounds from food is in strong correlation with the source and its chemical form. The sel...

  19. Meaning and resource of selenium in human nutrition

    OpenAIRE

    KRATOCHVÍLOVÁ, Zuzana

    2014-01-01

    Bachelor's thesis concentrates on functions of selenium in human nutrition. Selenium is an essential trace element of importance to human health. Its availability depends on the concentration of selenium in the soil. The average income of selenium in the Czech population are usually 36 g/day per individuals. Excess or insufficient selenium intakes can result in adverse effects on human health. The most important sources of selenium in the diets of most people are meat, fish, eggs, milk, cerea...

  20. Biomedical potential of actinobacterially synthesized selenium nanoparticles with special reference to anti-biofilm, anti-oxidant, wound healing, cytotoxic and anti-viral activities.

    Science.gov (United States)

    Ramya, Suseenthar; Shanmugasundaram, Thangavel; Balagurunathan, Ramasamy

    2015-10-01

    Currently, there is an ever-increasing need to develop environmentally benign processes in place of synthetic protocols. As a result, researchers in the field of nanoparticle synthesis are focusing their attention on microbes from rare biological ecosystems. One potential actinobacterium, Streptomyces minutiscleroticus M10A62 isolated from a magnesite mine had the ability to synthesize selenium nanoparticles (SeNPs), extracellularly. Actinobacteria mediated SeNP synthesis were characterized by UV-visible, Fourier transform infrared (FT-IR), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and high resolution transmission electron microscopy (HR-TEM) analysis. The UV-spectral analysis of SeNPs indicated the maximum absorption at 510nm, FT-IR spectral analysis confirms the presence of capping protein, peptide, amine and amide groups. The selenium signals confirm the presence of SeNPs. All the diffraction peaks in the XRD pattern and HR-TEM confirm the size of SeNPs in the range of 10-250nm. Further, the anti-biofilm and antioxidant activity of the SeNPs increased proportionally with rise in concentration, and the test strains reduced to 75% at concentration of 3.2μg. Selenium showed significant anti-proliferative activity against HeLa and HepG2 cell lines. The wound healing activity of SeNPs reveals that 5% selenium oinment heals the excision wound of Wistar rats up to 85% within 18 days compared to the standard ointment. The biosynthesized SeNPs exhibited good antiviral activity against Dengue virus. The present study concludes that extremophilic actinobacterial strain was a novel source for SeNPs with versatile biomedical applications and larger studies are needed to quantify these observed effects of SeNPs. Copyright © 2015 Elsevier GmbH. All rights reserved.

  1. The influence of selenium and zinc addition in food on concentration of these elements in blood and milk, on somatic cells number and histological characteristics of cows udders

    Directory of Open Access Journals (Sweden)

    Davidov Ivana

    2014-01-01

    Full Text Available The experiment included 30 cows of Holstein-Friesian breed, out of which 15 were receiving selenium and zinc in optimal doses before calving, while the others had never been supplemented with these micronutrients. There was analysed the concentration of selenium and zinc in blood and milk serum as well as the average number of somatic cells in corresponding lactation. After the cows exclusion from production, histological characteristics of cows udders were examined. The results of the investigation have shown that addition of selenium and zinc before calving has a positive effect on the values of these microelements in the blood and milk during the period of early lactation, that is, the concentration of these elements was significantly higher in the blood and milk of the cows that obtained selenium and zinc supplements. Also, in these cows there was significantly lower number of somatic cells during the following lacation period. In the parenchyma of the udder there was found less pronounced infiltration of leukocytes, notably thicker keratin layer of ductus papillaris and less expressed repairing processes that indicate a chronic inflammation of the udder in the samples after exclusion of the cows from production. There was a significant positive correlation between selenium in blood and milk, while there was not observed such a correlation for zinc. On the other hand, there was a significant negative correlation between the concentration of selenium in the blood and milk with the average number of somatic cells and the degree of infiltration of leukocytes, while its influence on the keratin layer of ductus papillarus was not shown. Zinc from blood and udder had a negative correlation with the number of somatic cells, had a positive correlation with the thickness of ductus papillaris keratin layer and had no influence on the level of leukocyte infiltration of udder parenchyma. Zinc demonstrates a positive influence on the formation of ductus

  2. Interaction of engineered nanoparticles with toxic and essential elements

    Science.gov (United States)

    Shumakova, A. A.; Gmoshinski, I. V.; Khotimchenko, S. A.; Trushina, E. N.

    2015-11-01

    Interaction of engineered nanoparticles with toxic and essential trace elements must be taken into consideration when estimating risks of NPs presented in the natural environment. The purpose of this work was to study the possible influence of silica, titanium dioxide (rutile) and fullerenol NPs on the toxicity of cadmium and to research the status of some trace elements and related indices of immune function in experiments on laboratory animals. Young male Wistar rats received cadmium salt (1 mg/kg b.w. Cd) orally for 28 days separately or in conjunction with the said kinds of NPs in different doses. A number of effects was observed as a result of combined action of Cd together with NPs, increase in bioaccumulation of this toxic trace element in the liver was most evident. The observed effects didn't show simple dose- dependence in respect to nanomaterials that should be taken into consideration when assessing the possible risks of joint action of nanoparticles and toxic elements existing in the environment in extremely low doses. Violation of microelement homeostasis caused by the combined action of Cd and NPs can have various adverse effects, such as inhibition of T-cell immunity induced by co-administration of Cd with rutile NPs.

  3. Biological significance of selenium

    Energy Technology Data Exchange (ETDEWEB)

    Duerre, P.; Andreesen, J.R.

    1986-02-01

    Until a few years ago, selenium was exclusively thought of as a toxic substance which was applied mainly in the optical and electrical industries. By now, many biological reactions have been detected which cannot take place without the catalytic effect of selenium. The majority of these processes was found and clarified in microorganisms; however, the anticarcinogenic properties of this trace element may well have some significance for man in future.

  4. Level of trace elements (copper, zinc, magnesium and selenium) and toxic elements (lead and mercury) in the hair and nail of children with autism.

    Science.gov (United States)

    Lakshmi Priya, Malarveni Damodaran; Geetha, Arumugam

    2011-08-01

    Autism is a multi-factorial pathology observed in children with altered levels of essential and elevated levels of toxic elements. There are also studies reporting a decrease in nutritional trace elements in the hair and nail of autistic children with healthy controls; moreover, bioelements have been shown to play an important role in the central nervous system. Therefore, the purpose of the present study was to assess the levels of trace elements like copper (Cu), zinc (Zn), magnesium (Mg), and selenium (Se) and toxic elements like mercury (Hg), and lead (Pb) in the hair and nail samples of autistic children and to evaluate whether the level of these elements could be correlated with the severity of autism. The subjects of the study were 45 autistic children with different grades of severity (low (LFA), medium (MFA), and high (HFA) functioning autism) according to Childhood Autism Rating Scale, n = 15 children in each group and 50 healthy children (age and sex matched). The boys and girls ratio involved in this study was 4:1, and they were 4-12 years of age. The study observed a valid indication of Cu body burden in the autistic children. The children with different grades of autism showed high significance (p autism). The study showed a significant elevation (p < 0.001) in the levels of toxic metals Pb and Hg in both hair and nail samples of autistic children when compared to healthy control group. The elevation was much pronounced in LFA group subjects when compared among autistic groups MFA and HFA. The levels of trace elements Mg and Se were significantly decreased (p < 0.001) in autistic children when compared to control. The trace element Zn showed significant variation in both hair and nails of LFA group children when compared to control group and other study groups. The significant elevation in the concentration of Cu, Pb, and Hg and significant decrease in the concentration of Mg and Se observed in the hair and nail samples of autistic subjects could be

  5. Rhizobium selenitireducens proteins involved in the reduction of selenite to elemental selenium

    Science.gov (United States)

    Microbial based bioremediation barriers can remove the metalloid selenite (SeO3–2) from flowing groundwater. The organisms associated with the process include microorganisms from within the bacterial and archaeal domains that can reduce soluble SeO3–2 to the insoluble and reddish-colored elemental ...

  6. Mineral Commodity Profiles: Selenium

    Science.gov (United States)

    Butterman, W.C.; Brown, R.D.

    2004-01-01

    Overview -- Selenium, which is one of the chalcogen elements in group 16 (or 6A) of the periodic table, is a semiconductor that is chemically similar to sulfur for which it substitutes in many minerals and synthetic compounds. It is a byproduct of copper refining and, to a much lesser extent, lead refining. It is used in many applications, the major ones being a decolorizer for glass, a metallurgical additive to free-machining varieties of ferrous and nonferrous alloys, a constituent in cadmium sulfoselenide pigments, a photoreceptor in xerographic copiers, and a semiconductor in electrical rectifiers and photocells. Refined selenium amounting to more than 1,800 metric tons (t) was produced by 14 countries in 2000. Japan, Canada, the United States, and Belgium, which were the four largest producers, accounted for nearly 85 percent of world production. An estimated 250 t of the world total is secondary selenium, which is recovered from scrapped xerographic copier drums and selenium rectifiers; the selenium in nearly all other uses is dissipated (not recoverable as waste or scrap). The present selenium reserve bases for the United States and the world (including the United States), which are associated with copper deposits, are expected to be able to satisfy demand for selenium for several decades without difficulty.

  7. 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

  8. Phytoremediation of selenium using transgenic plants.

    Science.gov (United States)

    Pilon-Smits, Elizabeth A H; LeDuc, Danika L

    2009-04-01

    Selenium (Se) is a micronutrient for many organisms but also toxic at higher concentrations. Both selenium deficiency and toxicity are serious problems worldwide. Owing to the similarity of selenium to sulfur, plants readily take up and assimilate selenate via sulfur transporters and enzymes and can even volatilize selenium. Selenium accumulating or volatilizing plants may be used for phytoremediation of selenium pollution and as fortified foods. Several transgenic approaches have been used successfully to further enhance plant selenium accumulation, tolerance, and volatilization: upregulation of genes involved in sulfur/selenium assimilation and volatilization, methylation of selenocysteine, and conversion of selenocysteine to elemental Se. Lab and field trials with different transgenic plants have yielded promising results, showing up to ninefold higher levels of selenium accumulation and up to threefold faster volatilization rates.

  9. Selenium for preventing cancer

    Directory of Open Access Journals (Sweden)

    Gabriele Dennert

    Full Text Available BACKGROUND: Selenium is a trace element essential to humans. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancers. OBJECTIVE: Two research questions were addressed in this review: What is the evidence for: 1. an aetiological relationship between selenium exposure and cancer risk in women and men?; 2. the efficacy of selenium supplementation for cancer prevention in women and men? SEARCH STRATEGY: We searched electronic databases and bibliographies of reviews and included publications. SELECTION CRITERIA: We included prospective observational studies to answer research question (a and randomised controlled trials (RCTs to answer research question (b. DATA COLLECTION AND ANALYSIS: We conducted random effects meta-analyses of epidemiological data when five or more studies were retrieved for a specific outcome. We made a narrative summary of data from RCTs. MAIN RESULTS: We included 49 prospective observational studies and six RCTs. In epidemiologic data, we found a reduced cancer incidence (summary odds ratio, OR, 0.69; 95% confidence interval, CI, 0.53 to 0.91 and mortality (OR 0.55, 95% CI 0.36 to 0.83 with higher selenium exposure. Cancer risk was more pronouncedly reduced in men (incidence: OR 0.66, 95% CI 0.42 to 1.05 than in women (incidence: OR 0.90, 95% CI 0.45 to 1.77. These findings have potential limitations due to study design, quality and heterogeneity of the data, which complicated the interpretation of the summary statistics. The RCTs found no protective efficacy of selenium yeast supplementation against non-melanoma skin cancer or L-selenomethionine supplementation against prostate cancer. Study results for the prevention of liver cancer with selenium supplements were inconsistent and studies had an unclear risk of bias. The results of the Nutritional Prevention of Cancer Trial (NPCT and SELECT raised concerns about possible harmful effects of selenium supplements. AUTHORS

  10. 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.

  11. High throughput microencapsulation of Bacillus subtilis in semi-permeable biodegradable polymersomes for selenium remediation.

    Science.gov (United States)

    Barlow, Jacob; Gozzi, Kevin; Kelley, Chase P; Geilich, Benjamin M; Webster, Thomas J; Chai, Yunrong; Sridhar, Srinivas; van de Ven, Anne L

    2017-01-01

    Encapsulating bacteria within constrained microenvironments can promote the manifestation of specialized behaviors. Using double-emulsion droplet-generating microfluidic synthesis, live Bacillus subtilis bacteria were encapsulated in a semi-permeable membrane composed of poly(ethylene glycol)-b-poly(D,L-lactic acid) (mPEG-PDLLA). This polymer membrane was sufficiently permeable to permit exponential bacterial growth, metabolite-induced gene expression, and rapid biofilm growth. The biodegradable microparticles retained structural integrity for several days and could be successfully degraded with time or sustained bacterial activity. Microencapsulated B. subtilis successfully captured and contained sodium selenite added outside the polymersomes, converting the selenite into elemental selenium nanoparticles that were selectively retained inside the polymer membrane. This remediation of selenium using polymersomes has high potential for reducing the toxicity of environmental selenium contamination, as well as allowing selenium to be harvested from areas not amenable to conventional waste or water treatment.

  12. Comparison of biological activities of selenium and silver nanoparticles attached with bioactive phytoconstituents: green synthesized using Spermacoce hispida extract

    Science.gov (United States)

    Vennila, Krishnan; Chitra, Loganathan; Balagurunathan, Rama; Palvannan, Thayumanavan

    2018-03-01

    Selenium and silver nanoparticles (NPs) were synthesized using Spermacoce hispida aqueous leaf extract (Sh-ALE). The optimum condition required for the synthesis of Sh-SeNPs was found to be 30 mM selenious acid solution to Sh-ALE at the ratio of 4:46, pH 9, incubated at 40 °C for 10 min. On the other hand, for Sh-AgNPs the optimum condition was found to be 1 mM AgNO3 to the Sh-ALE solution at the ratio of 4:46, pH 8, incubated at 40 °C for 10 min. SEM analysis revealed that both the Sh-AgNPs and Sh-SeNPs are predominantly rod-shaped. Sh-SeNPs and Sh-AgNPs were found to possess concentration-dependent antioxidant activity. However, Sh-SeNPs showed potent anti-inflammatory property, antibacterial property and anticancer activity against human cervical cancer cell in comparison to Sh-AgNPs. Phytochemical analysis, FTIR and GC-MS analysis showed that various flavonoids, saponins and phenolic compounds present in Sh-ALE catalysed the formation of NPs. Also, GC-MS analysis revealed that Sh-SeNPs are capped by synaptogenin B and derivatives of apigenin, quinoline and quinazoline. The advantage of attachment of such phytoconstituents on Sh-SeNPs for its potent biological activity in comparison to Sh-AgNPs is evident in in vitro conditions.

  13. Alkaline Earth Element Adsorption onto PAA-Coated Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Qing Wang

    2017-02-01

    Full Text Available In this paper, we present a study on the adsorption of calcium (Ca2+ onto polyacrylic acid-functionalized iron-oxide magnetic nanoparticles (PAA-MNPs to gain an insight into the adsorption behavior of alkaline earth elements at conditions typical of produced water from hydraulic fracturing. An aqueous co-precipitation method was employed to fabricate iron oxide magnetic nanoparticles, whose surface was first coated with amine and then by PAA. To evaluate the Ca2+ adsorption capacity by PAA-MNPs, the Ca2+ adsorption isotherm was measured in batch as a function of pH and sodium chlorite (electrolyte concentration. A surface complexation model accounting for the coulombic forces in the diffuse double layer was developed to describe the competitive adsorption of protons (H+ and Ca2+ onto the anionic carboxyl ligands of the PAA-MNPs. Measurements show that Ca2+ adsorption is significant above pH 5 and decreases with the electrolyte concentration. Upon adsorption, the nanoparticle suspension destabilizes and creates large clusters, which favor an efficient magnetic separation of the PAA-MNPs, therefore, helping their recovery and recycle. The model agrees well with the experiments and predicts that the maximum adsorption capacity can be achieved within the pH range of the produced water, although that maximum declines with the electrolyte concentration.

  14. Selenium: a micronutrient essential for maintaining human health

    OpenAIRE

    GONCA, Süheyla

    2014-01-01

    Selenium is an fundamental importance to human health. It is an essential trace element for major metabolic pathways, since selenium is an essential component of Glutathione peroxidase enzyme. Diet is the main source of selenium. Selenoproteins in mammalian cells indicated that essential role of selenium in the bodys antioxidant defense system.

  15. Epigallocatechin-3-gallate (EGCG)-stabilized selenium nanoparticles coated with Tet-1 peptide to reduce amyloid-β aggregation and cytotoxicity.

    Science.gov (United States)

    Zhang, Jingnan; Zhou, Xianbo; Yu, Qianqian; Yang, Licong; Sun, Dongdong; Zhou, Yanhui; Liu, Jie

    2014-06-11

    Alzheimer's disease (AD), the most common neurodegenerative disease, is caused by an accumulation of amyloid-β (Aβ) plaque deposits in the brains. Evidence is increasingly showing that epigallocatechin-3-gallate (EGCG) can partly protect cells from Aβ-mediated neurotoxicity by inhibiting Aβ aggregation. In order to better understand the process of Aβ aggregation and amyloid fibril disaggregation and reduce the cytotoxicity of EGCG at high doses, we attached EGCG onto the surface of selenium nanoparticles (EGCG@Se). Given the low delivery efficiency of EGCG@Se to the targeted cells and the involvement of selenoprotein in antioxidation and neuroprotection, which are the key factors for preventing the onset and progression of AD, we synthesized EGCG-stabilized selenium nanoparticles coated with Tet-1 peptide (Tet-1-EGCG@Se, a synthetic selenoprotein analogue), considering the affinity of Tet-1 peptide to neurons. We revealed that Tet-1-EGCG@Se can effectively inhibit Aβ fibrillation and disaggregate preformed Aβ fibrils into nontoxic aggregates. In addition, we found that both EGCG@Se and Tet-1-EGCG@Se can label Aβ fibrils with a high affinity, and Tet-1 peptides can significantly enhance the cellular uptake of Tet-1-EGCG@Se in PC12 cells rather than in NIH/3T3 cells.

  16. Oral administration of synthetic selenium nanoparticles induced robust Th1 cytokine pattern after HBs antigen vaccination in mouse model.

    Science.gov (United States)

    Mahdavi, Mehdi; Mavandadnejad, Faranak; Yazdi, Mohammad H; Faghfuri, Elnaz; Hashemi, Hura; Homayouni-Oreh, Somayeh; Farhoudi, Ramin; Shahverdi, Ahmad R

    Hepatitis B virus (HBV) infection is known as a life-threatening liver infection and leads to chronic liver disease if left untreated. Nevertheless, the prevalence of HBV infection has been reduced by an approved vaccination approach using recombinant Hepatitis B surface Antigen (HBsAg) and Alum, known as the HBV vaccine. Alum can be used as an adjuvant to increase HBsAg immunogenicity as a strong Th2 stimulator. There is a vital need to stimulate Th1 immunity by HBsAg vaccination; however, the present vaccine does not induce a prophylactic immune response in some groups. The main aim of the present study was to induce a Th1 cytokine pattern and stimulate an immune response after HBsAg vaccination. Experimental mice were fed selenium nanoparticles (SeNPs) and were later immunized with 5μg of Hepatitis B Vaccine. After a period of 30 days, the experimental animals were given two booster doses of SeNPs during their vaccination course. Group one, i.e., the control vaccine group, was only administered the HBsAg vaccine. The two treated groups, Groups 2 and 3, were daily fed different doses of SeNPs (100μg and 200μg, respectively) via gavage. Group four was considered the control group and was only given phosphate buffered saline (PBS). Lymphocyte proliferation, IFN-γ and IL-4 levels, total antibody and the isotypes of IgG1, IgG2a, IgG2b, and IgM were measured by Enzyme Linked Immunosorbent Assay (ELISA). The administration of SeNPs and the HBs antigen vaccine affected the lymphocyte proliferation; moreover, the total antibody responses also increased the IFN-γ level and induced a Th1 response. The present study proposed that the administration of SeNPs with a conventional HBs antigen vaccine induces a better immune response with a Th1 bias. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  17. Effects of an inorganic and two new organic compounds of selenium on morphologic blood elements and antioxidant status in mice.

    Science.gov (United States)

    Musik, Irena; Kozioł-Montewka, Maria; Pasternak, Kazimierz; Toś-Luty, Sabina; Tokarska, Małgorzata

    2003-01-01

    Two organic compounds, 4-(o-tolilo-)-selenosemicarbazide of p-chlorobenzoic acid and 3-(p-chlorobenzoylamino-)-2-(o-tolylimino-)-4-phenyl-4-selenazoline were compared to the effects of the supplementation with inorganic Na2SeO3. Studies were carried out in four groups consisting of 10 female mice each of SWISS strain. Three of them were supplemented with different selenium formula at the dose of 10(-3) mg Se per g over the period of 10 day. The blood samples were collected to heparinized test tubes; the red blood and white blood count, hematocrit and haemoglobin concentration were studied. The influence of selenium compounds on phagocytosis and NBT test was determined.

  18. 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.

  19. Biomarkers of selenium status

    Science.gov (United States)

    The essential trace element selenium (Se) has multiple biological activities, which depend on the level of Se intake. Relatively low Se intakes determine the expression of selenoenzymes in which it serves as an essential constituent. Higher intakes have been shown to have anti-tumorigenic potentia...

  20. Selenium essentials

    CERN Document Server

    Sams, Prashanth

    2015-01-01

    If you are a developer who wants to migrate from Selenium RC or any other automation tool to Selenium WebDriver, then this book is for you. Knowledge of automation tools is necessary to follow the examples in this book.

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

    NARCIS (Netherlands)

    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, Elizabeth A H

    2015-01-01

    Aims: To identify bacteria with high selenium tolerance and reduction capacity for bioremediation of wastewater and nanoselenium particle production. Methods and Results: A bacterial endophyte was isolated from the selenium hyperaccumulator Stanleya pinnata (Brassicaceae) growing on seleniferous

  2. Multi-elements (aluminium, copper, magnesium, manganese, selenium and zinc) determination in serum by dynamic reaction cell-inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Wah Fong, Bonnie Mei; Siu, Tak Shing; Kit Lee, Joseph Sai; Tam, Sidney

    2009-01-01

    Trace element determination in laboratory medicine is widely carried out by atomic absorption or emission spectroscopy. In the last decade, there has been a rapid growth in the use of inductively coupled plasma-mass spectrometry because of its strong detection power, and the possibility of multi-elements analysis in a single run. Having the advantages of smaller sample volume and better detection limit, we developed a method for the simultaneous determinations of six trace elements by using 100 microL serum, and the assay can be accomplished within 3 min. The method developed gave recovery of the six elements ranging from 97% to 117%. The method covered a wide dynamic range with manganese in the range of nmol/L, while magnesium was in the range of mmol/L. The detection limits were 0.001 mmol/L, 0.05 micromol/L, 2.0 nmol/L, 0.2 micromol/L, 0.05 micromol/L, and 0.01 micromol/L for magnesium, aluminium, manganese, copper, zinc, and selenium, respectively. All the six elements had intra-assay imprecision of less than 5%, and inter-assay imprecision of less than 8%. This fast and robust method is suitable for use in the clinical laboratory where short turnaround time is needed for managing patients with trace element deficiency or toxicity.

  3. 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.

  4. Chemical form of selenium in naturally selenium-rich lentils (Lens culinaris L.) from Saskatchewan.

    Science.gov (United States)

    Thavarajah, Dil; Vandenberg, Albert; George, Graham N; Pickering, Ingrid J

    2007-09-05

    Lentils (Lens culinaris L.) are a source of many essential dietary components and trace elements for human health. In this study we show that lentils grown in the Canadian prairies are additionally enriched in selenium, an essential micronutrient needed for general well-being, including a healthy immune system and protection against cancer. Selenium K near-edge X-ray absorption spectroscopy (XAS) has been used to examine the selenium biochemistry of two lentil cultivars grown in various locations in Saskatchewan, Canada. We observe significant variations in total selenium concentration with geographic location and cultivar; however, almost all the selenium (86-95%) in these field-grown lentils is present as organic selenium modeled as selenomethionine with a small component (5-14%) as selenate. As the toxicities of certain forms of arsenic and selenium are antagonistic, selenium-rich lentils may have a pivotal role to play in alleviating the chronic arsenic poisoning in Bangladesh.

  5. Chemical Form of Selenium in Naturally Selenium-Rich Lentils (Lens Culinaris L.) From Saskatchewan

    Energy Technology Data Exchange (ETDEWEB)

    Thavarajah, D.; Vandenberg, A.; George, G.N.; Pickering, I.J.

    2009-06-04

    Lentils (Lens culinaris L.) are a source of many essential dietary components and trace elements for human health. In this study we show that lentils grown in the Canadian prairies are additionally enriched in selenium, an essential micronutrient needed for general well-being, including a healthy immune system and protection against cancer. Selenium K near-edge X-ray absorption spectroscopy (XAS) has been used to examine the selenium biochemistry of two lentil cultivars grown in various locations in Saskatchewan, Canada. We observe significant variations in total selenium concentration with geographic location and cultivar; however, almost all the selenium (86--95%) in these field-grown lentils is present as organic selenium modeled as selenomethionine with a small component (5--14%) as selenate. As the toxicities of certain forms of arsenic and selenium are antagonistic, selenium-rich lentils may have a pivotal role to play in alleviating the chronic arsenic poisoning in Bangladesh.

  6. PLANT RESOURCES BASED SELENIUM SUPPLEMENTATION IN DAILY NUTRITION

    Directory of Open Access Journals (Sweden)

    Vida Škrabanja

    2017-01-01

    Full Text Available Selenium is one of the essential elements that has a direct effect on human health and disease. Environmental conditions and agricultural practice have a profound influence on the selenium content in plants. Cultivation of plants enriched with the selenium has an effective potential for selenium supplementation in diets for population which is exposed to selenium deficiency. Bioavailability of selenium compounds from food is in strong correlation with the source and its chemical form. The selenium of different sources and forms can become a part of human consumption when entering the food chain, wherein the inorganic forms of selenium are metabolized and converted to more available organic forms. Numerous results of systematic research of the selenium content in individual plant species as well as various techniques for producing selenium enriched foodstuffs is reviewed. The soil in Slovenia is selenium-poor and may concern a part of population which is potentially sensitive to selenium status. The merits of selenium effect, either alone or in combination with different environmental changes on plant production published by Slovenian authors are thus closely considered. Controversies continue to prevail regarding adequate amounts for selenium for health and disease prevention. Thus, general and individualized recommendations for selenium intake and supplementation in the future need to be cautiously followed and the reference values continually revised.

  7. Selenium: environmental significance, pollution, and biological treatment technologies.

    Science.gov (United States)

    Tan, Lea Chua; Nancharaiah, Yarlagadda V; van Hullebusch, Eric D; Lens, Piet N L

    2016-01-01

    Selenium is an essential trace element needed for all living organisms. Despite its essentiality, selenium is a potential toxic element to natural ecosystems due to its bioaccumulation potential. Though selenium is found naturally in the earth's crust, especially in carbonate rocks and volcanic and sedimentary soils, about 40% of the selenium emissions to atmospheric and aquatic environments are caused by various industrial activities such as mining-related operations. In recent years, advances in water quality and pollution monitoring have shown that selenium is a contaminant of potential environmental concern. This has practical implications on industry to achieve the stringent selenium regulatory discharge limit of 5μgSeL(-1) for selenium containing wastewaters set by the United States Environmental Protection Agency. Over the last few decades, various technologies have been developed for the treatment of selenium-containing wastewaters. Biological selenium reduction has emerged as the leading technology for removing selenium from wastewaters since it offers a cheaper alternative compared to physico-chemical treatments and is suitable for treating dilute and variable selenium-laden wastewaters. Moreover, biological treatment has the advantage of forming elemental selenium nanospheres which exhibit unique optical and spectral properties for various industrial applications, i.e. medical, electrical, and manufacturing processes. However, despite the advances in biotechnology employing selenium reduction, there are still several challenges, particularly in achieving stringent discharge limits, the long-term stability of biogenic selenium and predicting the fate of bioreduced selenium in the environment. This review highlights the significance of selenium in the environment, health, and industry and biotechnological advances made in the treatment of selenium contaminated wastewaters. The challenges and future perspectives are overviewed considering recent

  8. Selenium in Oncology: From Chemistry to Clinics

    OpenAIRE

    Oliver Micke; Lutz Schomburg; Jens Buentzel; Klaus Kisters; Ralph Muecke

    2009-01-01

    The essential trace element selenium, which is a crucial cofactor in the most important endogenous antioxidative systems of the human body, is attracting more and more the attention of both laypersons and expert groups. The interest of oncologists mainly focuses in the following clinical aspects: radioprotection of normal tissues, radiosensitizing in malignant tumors, antiedematous effect, prognostic impact of selenium, and effects in primary and secondary cancer prevention. Selenium is a con...

  9. Selenium nanoparticles synthesized in aqueous extract of Allium sativum perturbs the structural integrity of Calf thymus DNA through intercalation and groove binding.

    Science.gov (United States)

    Ezhuthupurakkal, Preedia Babu; Polaki, Lokeswara Rao; Suyavaran, Arumugam; Subastri, Ariraman; Sujatha, Venugopal; Thirunavukkarasu, Chinnasamy

    2017-05-01

    Biomedical application of selenium nanoparticles (SeNPs) demands the eco-friendly composite for synthesis of SeNPs. The present study reports an aqueous extract of Allium sativum (AqEAS) plug-up the current need. Modern spectroscopic, microscopic and gravimetric techniques were employed to characterize the synthesized nanoparticles. Characterization studies revealed the formation of crystalline spherical shaped SeNPs. FTIR spectrum brings out the presence of different functional groups in AqEAS, which influence the SeNPs formation and stabilization. Furthermore the different aspects of the interaction between SeNPs and CT-DNA were scrutinized by various spectroscopic and cyclic voltametric studies. The results reveals the intercalation and groove binding mode of interaction of SeNPs with stacked base pair of CT-DNA. The Stern-Volmer quenching constant (KSV) were found to be 7.02×10(6)M-(1) (ethidium bromide), 4.22×10(6) M-(1) (acridine orange) and 7.6×10(6)M-(1) (Hoechst) indicating strong binding of SeNPs with CT-DNA. The SeNPs - CT-DNA interactions were directly visualized by atomic force microscopy. The present study unveils the cost effective, innocuous, highly stable SeNPs intricate mechanism of DNA interaction, which will be a milestone in DNA targeted chemotherapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Phycocyanin-Functionalized Selenium Nanoparticles Reverse Palmitic Acid-Induced Pancreatic β Cell Apoptosis by Enhancing Cellular Uptake and Blocking Reactive Oxygen Species (ROS)-Mediated Mitochondria Dysfunction.

    Science.gov (United States)

    Liu, Chang; Fu, Yuanting; Li, Chang-E; Chen, Tianfeng; Li, Xiaoling

    2017-06-07

    Accumulation of palmitic acid (PA) in human bodies could cause damage to pancreatic β cells and lead to chronic diseases by generation of reactive oxygen species (ROS). Therefore, it is of great significance to search for nutrition-available agents with antioxidant activity to protect pancreatic islet cells against PA-induced damage. Phycocyanin (PC) and selenium (Se) have been reported to have excellent antioxidant activity. In this study, PC-functionalized selenium nanoparticles (PC-SeNPs) were synthesized to investigate the in vitro protective effects on INS-1E rat insulinoma β cells against PA-induced cell death. A potent protective effect was achieved by regulation of particle size and PC content. Among three PC-SeNPs (165, 235, and 371 nm), PC-SeNPs-235 nm showed the highest cellular uptake and the best protective activities. For cell cycle analysis, PC-SeNPs showed a better protective effect on PA-induced INS-1E cell apoptosis than PC or SeNPs, and PC-SeNPs-235 nm exhibited the best effect. Further mechanistic studies demonstrated that PA induced overproduction of intracellular ROS, mitochondria fragmentation, activation of caspase-3, -8, and -9, and cleavage of PARP. However, pretreatment of the cells with PC-SeNPs effectively blocked these intracellular events, which suggests that PC-SeNPs could protect INS-1E cells against PA-induced cell apoptosis via attenuating oxidative stress and downstream signaling pathways. This finding provides a great promising nutritional approach for protection against diseases related to islet damage.

  11. 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.

  12. Metabolic interrelationships between arsenic and selenium.

    Science.gov (United States)

    Levander, O A

    1977-08-01

    In 1938, Moxon discovered that arsenic protected against selenium toxicity. Since that time it has been shown that this protective effect of arsenic against selenium poisoning can be demonstrated in many different animal species under a wide variety of conditions. Antagonistic effects between arsenic and selenium have also been noted in teratologic experiments. Early metabolic studies showed that arsenic inhibited the expiration of volatile selenium compounds by rats injected with acutely toxic doses of both elements. This was puzzling since pulmonary excretion had long been regarded as a means by which animals could rid themselves of excess selenium. However, later work demonstrated that arsenic increased the biliary excretion of selenium. Not only did arsenic stimulate the excretion of selenium in the bile, but selenium also stimulated the excretion of arsenic in the bile. This increased biliary excretion of selenium caused by arsenic provides a reasonable rationale for the ability of arsenic to counteract the toxicity of selenium, although the chemical mechanism by which arsenic does this is not certain. The most satisfactory explanation is that these two elements react in the liver to form a detoxication conjugate which is then excreted into the bile. This is consistent with the fact that both arsenic and selenium each increase the biliary excretion of the other. Several other metabolic interactions between arsenic and selenium have been demonstrated in vitro, but their physiological significance is not clear. Although arsenic decreased selenium toxicity under most conditions, there is a pronounced synergistic toxicity between arsenic and two methylated selenium metabolites, trimethylselenonium ion or dimethyl selenide. The ecological consequences of these synergisms are largely unexplored, although it is likely that selenium methylation occurs in the environment. All attempts to promote or prevent selenium deficiency diseases in animals by feeding arsenic have

  13. 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

  14. Selenium deficiency, reversible cardiomyopathy and short-term intravenous feeding.

    OpenAIRE

    Levy, J. B.; Jones, H. W.; Gordon, A. C.

    1994-01-01

    We report the case of a patient with Crohn's disease receiving short-term postoperative parenteral nutrition supplemented with trace elements who nevertheless became selenium deficient with evidence of a cardiomyopathy. This was fully reversible with oral selenium supplementation. Current parenteral feeding regimes may not contain enough selenium for malnourished patients.

  15. Environmental Selenium Research: From Microscopic Processes to Global Understanding

    NARCIS (Netherlands)

    Winkel, L.H.E.; Johnson, C.A.; Lenz, M.; Grundl, T.; Leupin, O.X.; Amini, M.; Charlet, L.

    2012-01-01

    Selenium is a natural trace element that is of fundamental importance to human health. The extreme geographical variation in selenium concentrations in soils and food crops has resulted in significant health problems related to deficient or excess levels of selenium in the environment. To deal with

  16. Characterization of Selenium Species in the Shijimi Clam.

    Science.gov (United States)

    Yoshida, Sakura; Koga, Kaori; Iwataka, Miho; Fuchigami, Takeshi; Haratake, Mamoru; Nakayama, Morio

    2017-01-01

    Selenium is an essential trace element for humans and animals. Fish and shellfish are known to be rich in selenium and suppose to be an effective selenium source. In this study, we characterized the selenium species in the Shijimi clam (Corbicula japonica), which is a typical clam eaten in Japan. The Shijimi clam contains a relatively high concentration of selenium (3.5 µg-selenium/g-dry Shijimi). Approximately 30% of the total selenium in the Shijimi clam meat was extractable with water, while selenium in the Shijimi clam was hardly extracted with ethanol, chloroform and hexane. Based on an ultrafiltration study, the molecular mass of the major selenium species in the Shijimi water-extract was estimated to be less than 5000. Because amphoteric selenium species were contained in the Shijimi water-extract, which was indicated by ion-exchange chromatographic separation, an ion-pair reagent was utilized to extract the ionic selenium species into an organic solvent. A matrix assisted laser desorption ionization (MALDI) time of flight (TOF)-mass spectrometric analysis revealed the selenium isotopic pattern involving one selenium atom in a molecule with the 80Se molecular ion peak at m/z 534. This selenium species was mainly found in the visceral part of the Shijimi clam by imaging mass spectrometry.

  17. Vapor-liquid-solid (VLS) synthesis of alpha-monoclinic selenium and antimony selenide nanowires and sonication synthesis of blue photoluminescent zero-dimensional nanoparticles

    Science.gov (United States)

    Farfan Mendoza, Willinton

    Semiconducting nanostructures such as nanowires and 0-D nanoparticles have received great interest due to their improved properties in comparison with macroscopic materials. Therefore, these nanostructures have attracted considerable attention for optoelectronics and biological applications, among others. In this way, this thesis reports the synthesis of alpha-monoclinic selenium and antimony selenide (Sb2Se3) semiconducting nanowires using a physical vapor-liquid-solid (VLS) process for the first time. In addition, synthesis of naturally dispersed Sb2Se 3 0-D nanoparticles using a sonication process is also reported here for the first time. Crystalline alpha-monoclinic selenium nanowires with diameters in the range between 20 nm and 1im and lengths up to 30 mum were synthesized. The majority of these VLS synthesized nanowires have a diameter of ~50 nm. As-obtained nanowires grew perpendicular to the (053) plane and exhibit an energy band-gap of 2.20 +/- 0.05 eV, showing a blue shift of 0.18 eV relative to the bulk than is attributed to quantum confinement from the most abundant produced nanowires (~50 nm). Crystalline Sb2Se3 nanowires with diameters in the range between 20 nm and 2mum and lengths up to 30 mum were synthesized. The diameter of the most abundant produced nanowires is ~800 nm. Our nanowires are oriented along the [010] crystallographic direction. Growth along this orientation is being reported for the first time. Due to the anisotropy of the lattice, [010] oriented nanowires have properties different to the ones produced by the other methods that are [001] oriented. This thesis also analyses the controversial band gap energy results reported in the literature and conclude that is due to incorrect interpretation of experimental measurements. Photoluminescence (PL) measurements of powdered crystalline bulk Sb2Se3 at room temperature and under UV excitation are reported here for the first time. The PL spectra show that Sb2Se3 crystalline exhibits high

  18. Cardioprotective Effect of Aloe vera Biomacromolecules Conjugated with Selenium Trace Element on Myocardial Ischemia-Reperfusion Injury in Rats.

    Science.gov (United States)

    Yang, Yang; Yang, Ming; Ai, Fen; Huang, Congxin

    2017-06-01

    The present study was undertaken to evaluate the cardioprotection potential and underlying molecular mechanism afforded by a selenium (Se) polysaccharide (Se-AVP) from Aloe vera in the ischemia-reperfusion (I/R) model of rats in vivo. Myocardial I/R injury was induced by occluding the left anterior descending coronary artery (LAD) for 30 min followed by 2-h continuous reperfusion. Pretreatment with Se-AVP (100, 200, and 400 mg/kg) attenuated myocardial damage, as evidenced by reduction of the infarct sizes, increase in serum and myocardial endogenous antioxidants (superoxide dismutase (SOD), glutathione peroxidase (GSH), and catalase (CAT)), and decrease in the malondialdehyde (MDA) level in the rats suffering I/R injury. This cardioprotective activity afforded by Se-AVP is further supported by the decreased levels of cardiac marker enzymes creatine kinase (CK) and lactate dehydrogenase (LDH), as well as the rise of myocardial Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities in I/R rats. Additionally, cardiomyocytic apoptosis was measured by terminal-deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) staining and the result showed that the percent of TUNEL-positive cells in myocardium of Se-AVP-treated groups was lower than I/R rats. In conclusion, we clearly demonstrated that Se-AVP had a protective effect against myocardial I/R injury in rats by augmenting endogenous antioxidants and protecting rat hearts from oxidative stress-induced myocardial apoptosis.

  19. Effect of selenium nanoparticles with different sizes in primary cultured intestinal epithelial cells of crucian carp, Carassius auratus gibelio.

    Science.gov (United States)

    Wang, Yanbo; Yan, Xuxia; Fu, Linglin

    2013-01-01

    Nano-selenium (Se), with its high bioavailability and low toxicity, has attracted wide attention for its potential application in the prevention of oxidative damage in animal tissues. However, the effect of nano-Se of different sizes on the intestinal epithelial cells of the crucian carp (Carassius auratus gibelio) is poorly understood. Our study showed that different sizes and doses of nano-Se have varied effects on the cellular protein contents and the enzyme activities of secreted lactate dehydrogenase, intracellular sodium potassium adenosine triphosphatase, glutathione peroxidase, and superoxide dismutase. It was also indicated that nano-Se had a size-dependent effect on the primary intestinal epithelial cells of the crucian carp. Thus, these findings may bring us a step closer to understanding the size effect and the bioavailability of nano-Se on the intestinal tract of the crucian carp.

  20. Selenium biofortification

    Science.gov (United States)

    Plant foods are the major dietary sources of selenium (Se) in most countries around the world, followed by meats and seafood. For this reason, it is vital to increase Se uptake by plants and to produce crops with higher Se concentrations and bioavailability in their edible tissues. One of the most p...

  1. Blockage of both the extrinsic and intrinsic pathways of diazinon-induced apoptosis in PaTu cells by magnesium oxide and selenium nanoparticles.

    Science.gov (United States)

    Shiri, Mahdi; Navaei-Nigjeh, Mona; Baeeri, Maryam; Rahimifard, Mahban; Mahboudi, Hossein; Shahverdi, Ahmad Reza; Kebriaeezadeh, Abbas; Abdollahi, Mohammad

    Diazinon (DZ) is an organophosphorus insecticide that acts as an acetylcholinesterase inhibitor. It is important to note that it can induce oxidative stress, lipid peroxidation, diabetic disorders, and cytotoxicity. Magnesium oxide (MgO) and selenium nanoparticles (Se NPs) showed promising protection against oxidative stress, lipid peroxidation, cytotoxicity, and diabetic disorders. Therefore, this study was conducted to explore the possible protective mechanisms of MgO and Se NPs against DZ-induced cytotoxicity in PaTu cell line. Cytotoxicity of DZ, in the presence or absence of effective doses of MgO and Se NPs, was determined in human pancreatic cancer cell line (PaTu cells) after 24 hours of exposure by using mitochondrial activity and mitochondrial membrane potential assays. Then, the insulin, proinsulin, and C-peptide release; caspase-3 and -9 activities; and total thiol molecule levels were assessed. Determination of cell viability, including apoptotic and necrotic cells, was assessed via acridine orange/ethidium bromide double staining. Furthermore, expression of 15 genes associated with cell death/apoptosis in various phenomena was examined after 24 hours of contact with DZ and NPs by using real-time polymerase chain reaction. Compared to the individual cases, the group receiving the combination of MgO and Se NPs showed more beneficial effects in reducing the toxicity of DZ. Cotreatment of PaTu cell lines with MgO and Se NPs counteracts the toxicity of DZ on insulin-producing cells.

  2. Nanoparticle size detection limits by single particle ICP-MS for 40 elements.

    Science.gov (United States)

    Lee, Sungyun; Bi, Xiangyu; Reed, Robert B; Ranville, James F; Herckes, Pierre; Westerhoff, Paul

    2014-09-02

    The quantification and characterization of natural, engineered, and incidental nano- to micro-size particles are beneficial to assessing a nanomaterial's performance in manufacturing, their fate and transport in the environment, and their potential risk to human health. Single particle inductively coupled plasma mass spectrometry (spICP-MS) can sensitively quantify the amount and size distribution of metallic nanoparticles suspended in aqueous matrices. To accurately obtain the nanoparticle size distribution, it is critical to have knowledge of the size detection limit (denoted as Dmin) using spICP-MS for a wide range of elements (other than a few available assessed ones) that have been or will be synthesized into engineered nanoparticles. Herein is described a method to estimate the size detection limit using spICP-MS and then apply it to nanoparticles composed of 40 different elements. The calculated Dmin values correspond well for a few of the elements with their detectable sizes that are available in the literature. Assuming each nanoparticle sample is composed of one element, Dmin values vary substantially among the 40 elements: Ta, U, Ir, Rh, Th, Ce, and Hf showed the lowest Dmin values, ≤10 nm; Bi, W, In, Pb, Pt, Ag, Au, Tl, Pd, Y, Ru, Cd, and Sb had Dmin in the range of 11-20 nm; Dmin values of Co, Sr, Sn, Zr, Ba, Te, Mo, Ni, V, Cu, Cr, Mg, Zn, Fe, Al, Li, and Ti were located at 21-80 nm; and Se, Ca, and Si showed high Dmin values, greater than 200 nm. A range of parameters that influence the Dmin, such as instrument sensitivity, nanoparticle density, and background noise, is demonstrated. It is observed that, when the background noise is low, the instrument sensitivity and nanoparticle density dominate the Dmin significantly. Approaches for reducing the Dmin, e.g., collision cell technology (CCT) and analyte isotope selection, are also discussed. To validate the Dmin estimation approach, size distributions for three engineered nanoparticle samples were

  3. The risk assessment of selenium exposure from food in the Slovak Republic

    OpenAIRE

    Ursinyova, Monika

    2012-01-01

    Selenium is a ubiquitous essential trace element originated from natural and anthropogenic sources.  Effects of selenium on human health are ranging from protective to toxic (acute or chronic selenosis). Toxicity depends on the form of selenium in a compound and its bioavailability. Selenium occurs naturally in food and is worldwide approved as an additive into food and food supplements. The existing studies point out that the levels of selenium in food and the status of Slovak population are...

  4. Selenium deficiency and toxicity in the environment

    OpenAIRE

    Fordyce, Fiona

    2005-01-01

    Selenium (Se) is a naturally occurring metalloid element, which is essential to human and other animal health in trace amounts but is harmful in excess. Of all the elements, selenium has one of the narrowest ranges between dietary deficiency (40 gday1) and toxic levels (400gday1) (WHO, 1996), which makes it necessary to carefully control intakes by humans and other animals, hence, the importance of understanding the relationships between environmental exposure and health. Geology exerts...

  5. ENHANCED ANAEROBIC DIGESTION OF FOOD WASTE BY SUPPLEMENTING TRACE ELEMENTS: ROLE OF SELENIUM (VI AND IRON (II

    Directory of Open Access Journals (Sweden)

    Javkhlan eAriunbaatar

    2016-02-01

    Full Text Available This paper discusses the potential to enhance the anaerobic digestion of food waste FW by supplementing trace elements (Fe, Co, Ni, Zn, Mn, Cu, Se, and Mo individually as well as in cocktails. A series of batch experiments on the biomethane potential of synthetic food waste were performed with low (FW-A and high (FW-B trace element background concentrations prepared in, respectively, Delft (The Netherlands and Tampa (Florida, USA. The most effective trace elements for FW-A were Fe with an increase of 39.2 (± 0.6 % of biomethane production, followed by Se (34.1 ± 5.6 % increase, Ni (26.4 ± 0.2 % increase and Co (23.8 ± 0.2 % increase. For FW-B supplementing these trace elements did not result in enhancement of the biomethane production, except for Se. FW-B had a Se concentration of 1.3 (± 0. 5 µg/gTS, while it was below the detection limit for FW-A. Regardless of the FW source, Se resulted in 30 – 35% increase of biomethane production at a concentration range of 25-50 µg/L (0.32 – 0.63 µM. Volatile fatty acids analysis revealed that TE supplementation enhances their consumption, thus yielding a higher biomethane production. Moreover, additional experiments on sulfide inhibition showed the enhancing effects of trace elements on the anaerobic digestion of food waste were not related with sulfide toxicity, but with the enzymatic reactions and/or microbial biomass aggregation.

  6. Selenium and selenocysteine: roles in cancer, health, and development.

    Science.gov (United States)

    Hatfield, Dolph L; Tsuji, Petra A; Carlson, Bradley A; Gladyshev, Vadim N

    2014-03-01

    The many biological and biomedical effects of selenium are relatively unknown outside the selenium field. This fascinating element, initially described as a toxin, was subsequently shown to be essential for health and development. By the mid-1990s selenium emerged as one of the most promising cancer chemopreventive agents, but subsequent human clinical trials yielded contradictory results. However, basic research on selenium continued to move at a rapid pace, elucidating its many roles in health, development, and in cancer prevention and promotion. Dietary selenium acts principally through selenoproteins, most of which are oxidoreductases involved in diverse cellular functions. Published by Elsevier Ltd.

  7. The use of pH-sensitive functional selenium nanoparticles shows enhanced in vivo VEGF-siRNA silencing and fluorescence imaging

    Science.gov (United States)

    Yu, Qianqian; Liu, Yanan; Cao, Chengwen; Le, Fangling; Qin, Xiuying; Sun, Dongdong; Liu, Jie

    2014-07-01

    The utility of small interfering RNAs (siRNAs) has shown great promise in treating a variety of diseases including many types of cancer. While their ability to silence a wide range of target genes underlies their effectiveness, the application of therapies remains hindered by a lack of an effective delivery system. In this study, we sought to develop an siRNA-delivery system for VEGF, a known signaling molecule involved in cancer, that consists of two selenium nanoparticles SeNPs and G2/PAH-Cit/SeNPs. A G2/PAH-Cit/SeNP is a pH-sensitive delivery system that is capable of enhancing siRNA loading, thus increasing siRNA release efficiency and subsequent target gene silencing both in vitro and in vivo. In vivo experiments using G2/PAH-Cit/SeNPs@siRNA led to significantly higher accumulation of siRNA within the tumor itself, VEGF gene silencing, and reduced angiogenesis in the tumor. Furthermore, the G2/PAH-Cit/SeNP delivery system not only enhanced anti-tumor effects on tumor-bearing nude mice as compared to SeNPs@siRNA, but also resulted in weak occurrence of lesions in major target organs. In sum, this study provides a new class of siRNA delivery system, thereby providing an alternative therapeutic route for cancer treatment.The utility of small interfering RNAs (siRNAs) has shown great promise in treating a variety of diseases including many types of cancer. While their ability to silence a wide range of target genes underlies their effectiveness, the application of therapies remains hindered by a lack of an effective delivery system. In this study, we sought to develop an siRNA-delivery system for VEGF, a known signaling molecule involved in cancer, that consists of two selenium nanoparticles SeNPs and G2/PAH-Cit/SeNPs. A G2/PAH-Cit/SeNP is a pH-sensitive delivery system that is capable of enhancing siRNA loading, thus increasing siRNA release efficiency and subsequent target gene silencing both in vitro and in vivo. In vivo experiments using G2/PAH

  8. Acute treatment with bis selenide, an organic compound containing the trace element selenium, prevents memory deficits induced by reserpine in rats.

    Science.gov (United States)

    Bortolatto, Cristiani Folharini; Guerra Souza, Ana Cristina; Wilhelm, Ethel Antunes; Nogueira, Cristina Wayne

    2013-01-01

    Taking into account the promising pharmacological actions of (Z)-2,3-bis(4-chlorophenylselanyl) prop-2-en-1-ol) (bis selenide), an organic compound containing the trace element selenium, and the constant search for drugs that improve the cognitive performance, the objective of the present study was to investigate whether bis selenide treatment ameliorates memory deficits induced by reserpine in rats. For this aim, male adult rats received a single subcutaneous injection of reserpine (1 mg/kg), a biogenic amine-depleting agent used to induce memory deficit. After 24 h, bis selenide at doses of 25 and 50 mg/kg was administered to rats by intragastric route, and 1 h later, the animals were submitted to behavior tasks. The effects of acute administration of bis selenide on memory were evaluated by social recognition, step-down passive avoidance, and object recognition paradigms. Exploratory and locomotor activities of rats were determined using the open-field test. Analysis of data revealed that the social memory disruption caused by reserpine was reversed by bis selenide at both doses. In addition, bis selenide, at the highest dose, prevented the memory deficit resulting from reserpine administration to rats in step-down passive avoidance and object recognition tasks. No significant alterations in locomotor and exploratory behaviors were found in animals treated with reserpine and/or bis selenide. Results obtained from distinct memory behavioral paradigms revealed that an acute treatment with bis selenide attenuated memory deficits induced by reserpine in rats.

  9. Transformation of Selenium-Containing Phases in Copper Anode Slimes During Leaching

    Science.gov (United States)

    Li, Xue Jiao; Yang, Hong Ying; Jin, Zhe Nan; Chen, Guo Bao; Tong, Lin Lin

    2017-10-01

    The transformation of selenium-containing phases in copper anode slimes during the leaching process was investigated based on the Eh-pH diagram, leaching efficiencies of metals, and characterization of the residues produced during leaching. The leaching efficiency of selenium increases slowly to 17.7% in the first 50 min and then more rapidly to 98.3% in the next 110 min. The Eh-pH diagram indicates that elemental selenium is an intermediate product of the oxidation of selenide to selenite. The x-ray powder diffraction data and scanning electron microscopy-energy-dispersive x-ray spectroscopy data demonstrate that selenium leaching can be divided into three stages. Ag-Cu selenide first transforms into silver selenide and then converts to elemental selenium. Finally, elemental selenium is dissolved as selenite. The intermediate product, elemental selenium, is the main reason for the slow initial leaching rate of selenium.

  10. Assimilation and retention of selenium and other trace elements from crustacean food by juvenile striped bass (Morone saxatilis)

    Science.gov (United States)

    Baines, Stephen B.; Fisher, Nicholas S.; Stewart, Robin

    2002-01-01

     Estimates of the assimilation and retention of trace elements from food by fish are useful for linking toxicity with the biogeochemical cycling of these elements through aquatic food webs. Here we use pulse-chase radiotracer techniques to estimate the assimilation and retention of Se and four trace metals, Ag, Am, Zn, and Cd, by 43- and 88-d-old juvenile striped bass, Morone saxatilis, from crustacean food. Brine shrimp nauplii, Artemia franciscana, or adult copepods,Acartia tonsa, were fed radiolabeled diatoms and then fed to juvenile striped bass. Assimilation efficiencies (AEs ± SD) for 43-d-old fish were 18 ± 2%, 6 ± 1%, 23 ± 4%, 33 ± 3%, and 23 ± 2% for Ag, Am, Cd, Se, and Zn, respectively. For 88-d-old fish, the AEs were 28 ± 1%, 42 ± 5%, and 40 ± 5% for Cd, Se, and Zn, respectively. The higher AEs in the older fish may result from longer gut passage times for larger fish. The 44-d-old fish excreted 5 ± 0.8%, 4 ± 2.0%, 7 ± 0.3%, 9 ± 0.4%, and 1.3 ± 0.9% of the Ag, Am, Cd, Se, and Zn, respectively, they ingested from food per day, whereas the 88-d-old fish excreted 3 ± 1.0%, 8 ± 0.5%, and 3 ± 0.5% of the assimilated Cd, Se, and Zn per day, respectively. Predictions of steady state Se concentrations in juvenile striped bass tissues made using a biokinetic model and the measured AE and efflux rates ranged from 1.8 to 3.0 mg Se g-1dry wt for muscle tissue and 6.8 to 11.6 mg Se g-1 dry wt for gut tissue. These predictions agreed well with average values of 2.1 and 13 mg Se g-1 dry wt measured independently in North San Francisco Bay, where elevated Se concentrations are of concern. The model results imply that the planktonic food web, including juvenile striped bass, does not transfer Se as efficiently to top consumers as does the benthic food web.

  11. [The role of selenium in endocrine system diseases].

    Science.gov (United States)

    Balázs, Csaba; Rácz, Károly

    2013-10-13

    Oxygen derived free radicals, generated by a number of cellular reactions, include superoxide anion, hydrogen peroxide and hydroxyl radicals. They exert their cytotoxic effects mainly via peroxidation of the cell membrane resulting in the loss of membrane integrity. The essential trace element, selenium exerts complex effects on the endocrine systems, partly due to its antioxidant capacity. Well-characterized selenoproteins include iodothyronine deiodinases, glutathione peroxidases and thioredoxin reductases involved in thyroid hormone metabolism and protection from oxidative damage. The value of selenium supplementation in autoimmune thyroid disorders has been investigated and most studies confirmed the beneficial effect of selenium supplementation in Hashimoto's and Graves's diseases. Recently, selenium proved to be effective in mild inflammatory orbitopathy. There are a number of reports about the effect of selenium in diabetes mellitus, but the data are controversial as both insulin-like and diabetes-inducing effects of selenium have been described. Selenium was successfully used in both female and male infertility of autoimmune origin.

  12. Combined effect of aerobic interval training and selenium nanoparticles on expression of IL-15 and IL-10/TNF-α ratio in skeletal muscle of 4T1 breast cancer mice with cachexia.

    Science.gov (United States)

    Molanouri Shamsi, M; Chekachak, S; Soudi, S; Quinn, L S; Ranjbar, K; Chenari, J; Yazdi, M H; Mahdavi, M

    2017-02-01

    Cancer cachexia is characterized by inflammation, loss of skeletal muscle and adipose tissue mass, and functional impairment. Oxidative stress and inflammation are believed to regulate pathways controlling skeletal muscle wasting. The aim of this study was to determine the effects of aerobic interval training and the purported antioxidant treatment, selenium nanoparticle supplementation, on expression of IL-15 and inflammatory cytokines in 4T1 breast cancer-bearing mice with cachexia. Selenium nanoparticle supplementation accelerated cachexia symptoms in tumor-bearing mice, while exercise training prevented muscle wasting in tumor-bearing mice. Also, aerobic interval training enhanced the anti-inflammatory indices IL-10/TNF-α ratio and IL-15 expression in skeletal muscle in tumor-bearing mice. However, combining exercise training and antioxidant supplementation prevented cachexia and muscle wasting and additionally decreased tumor volume in 4T1 breast cancer mice. These finding suggested that combining exercise training and antioxidant supplementation could be a strategy for managing tumor volume and preventing cachexia in breast cancer. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Atomic Data for Neutron-capture Elements I. Photoionization and Recombination Properties of Low-charge Selenium Ions

    Science.gov (United States)

    Sterling, N. C.; Witthoeft, Michael

    2011-01-01

    We present multi-configuration Breit-Pauli AUTOSTRUCTURE calculations of distorted-wave photoionization (PI) cross sections. and total and partial final-state resolved radiative recombination (RR) and dielectronic recombination (DR) rate coefficients for the first six ions of the trans-iron element Se. These calculations were motivated by the recent detection of Se emission lines in a large number of planetary nebulae. Se is a potentially useful tracer of neutron-capture nucleosynthesis. but accurate determinations of its abundance in photoionized nebulae have been hindered by the lack of atomic data governing its ionization balance. Our calculations were carried out in intermediate coupling with semi re1ativistic radial wavefunctions. PI and recombination data were determined for levels within the ground configuration of each ion, and experimental PI cross-section measurements were used to benchmark our results. For DR, we allowed (Delta)n = 0 core excitations, which are important at photoionized plasma temperatures. We find that DR is the dominant recombination process for each of these Se ions at temperatures representative of photoionized nebulae (approx.10(exp 4) K). In order to estimate the uncertainties of these data, we compared results from three different configuration-interaction expansions for each ion, and also tested the sensitivity of the results to the radial scaling factors in the structure calculations. We find that the internal uncertainties are typically 30-50% for the direct PI cross sections and approx.10% for the computed RR rate coefficients, while those for low-temperature DR can be considerably larger (from 15-30% up to two orders of magnitude) due to the unknown energies of near-threshold autoionization resonances. These data are available at the CDS, and fitting coefficients to the total RR and DR rate coefficients are presented. The results are suitable for incorporation into photoionization codes used to numerically simulate

  14. Selenium levels of Estonians.

    Science.gov (United States)

    Rauhamaa, P; Kantola, M; Viitak, A; Kaasik, T; Mussalo-Rauhamaa, H

    2008-09-01

    The objective of this study is to sum up the dietary selenium intake of the Estonian people according to the serum selenium concentrations. This research compiles the information published in the literature about the levels of selenium in the serum of the Estonian people. We compare these results with the findings obtained from the analyses of serum samples gathered by us in the 1990s in Estonia. The selenium concentration in sera of 404 Estonians ranged from 26 to 116 microg/l; the mean was 75 microg/l. The selenium contents of Estonians were at a similar level as reported for Finns before the selenium supplementation of fertilizers carried out in Finland in 1984. In view of the selenium concentration in the sera, we suggest that the dietary selenium intake among the Estonian people might be scarce, and Estonian authorities should consider in their nutrition policies the possible low intake of selenium of Estonians.

  15. Ecological Importance of Insects in Selenium Biogenic Cycling

    Directory of Open Access Journals (Sweden)

    Nadezhda Golubkina

    2014-01-01

    Full Text Available Selenium is an essential trace element for animal and human beings. Despite the importance of insects in most ecosystems and their significant contribution to the biological cycling of trace elements due to high abundance, population productivity, and diverse ecosystem functions, surprisingly little information is available on selenium bioaccumulation by these arthropods. This review considers selenium essentiality and toxicity to insects as well as insects’ contribution to selenium trophic transfer through the food chains. Data on Se accumulation by insects of the Dniester River Valley with no anthropogenic Se loading reveal typically low Se content in necrophagous insects compared to predators and herbivores and seasonal variations in Se accumulation.

  16. Bioaccumulation and distribution of selenium in Enterococcus durans.

    Science.gov (United States)

    Pieniz, Simone; Andreazza, Robson; Mann, Michele Bertoni; Camargo, Flávio; Brandelli, Adriano

    2017-03-01

    Selenium is an essential nutrient for all living organisms. Under appropriate conditions lactic acid bacteria (LAB) are capable for accumulating large amounts of trace elements, such as selenium, and incorporating them into organic compounds. In this study, the capacity of selenium bioaccumulation by Enterococcus durans LAB18s was evaluated. The distribution of organic selenium in selenium-enriched E. durans LAB18s biomass was analyzed, and the highest percentage of organic selenium was found in the fraction of total protein, followed by the fractions of polysaccharides and nucleic acids. When the protein fraction was obtained by different extractions (water, NaCl, ethanol and NaOH) it was demonstrated that alkali-soluble protein showed the higher Selenium content. Analysis of protein fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that selenium was present in the proteins ranging from 23 to 100kDa. The cells were analyzed by scanning electron microscopy (SEM); scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) and transmission electron microscopy (TEM). SEM, TEM and SEM/EDS showed the morphology, the selenium particles bioaccumulated into and on the cells and the amounts of selenium present into the cells, respectively. Thus, the isolate E. durans LAB18s can be a promising probiotic to be used as selenium-enriched biomass in feed trials. Copyright © 2016 Elsevier GmbH. All rights reserved.

  17. Spectrophotometric Determination of Selenium Through Triiodide Anion.

    Science.gov (United States)

    Bizerea-Spiridon, Otilia; Nartita, Radu; Rogobete, Alexandru F; Negrea, Adina; Stroescu, Ramona; Bizerea, Teofana O; Ilie, Constantin; Marginean, Otilia

    2017-05-01

    Selenium is a chemical element found in the human body that plays a crucial role in its regulation. Depending on the concentration, it may have beneficial or have toxic effects. Selenium is incorporated as selenocysteine amino acid residue in selenoproteins which play an important role in many biological functions: anti-oxidant defense, regulation of the immune function and of the inflammatory response, metabolism of thyroid hormones, functioning of the central nervous system, biosynthesis of DNA and RNA, fertility, and reproduction. Excess selenium, altough less common than selenium deficiency, has equally important negative effects. Given the importance of selenium quantification in various samples, the study proposes a simple and direct spectrophotometric determination of selenium using triiodide anions. The method is based on the oxidation of iodide in acidic medium by selenium (IV) contained in the sample, to form elemental iodine which, in turn, reacts with the excess iodide to form the triiodide anions, the most stable soluble species in aqueous solution. Triiodide is colored from yellow to brown, depending on the concentration. The coloured compound has maximum absorbance at specific wavelengths and thus, the stage of interaction with a chromogenic agent is eliminated. Due to the sensitivity of the reaction, the detection limit of triiodide, and therefore selenium, is extended toward lower values. The optimal conditions for the measurements were established: λ = 290 nm, pH = 1.0 - 1.5, reaction time = 15 minutes. Two areas of selenium detection were determined from the samples: 0.025 - 0.100 ppm, and 0.1 - 4.0 ppm. The detection limit of selenium was lowered at 0.100 ppm and even at 0.025 ppm, which significantly improves the sensitivity of the determination. Types of samples were specified which are suitable for analysis using the proposed method and explained why, in case of biological fluids, it must be used only accompanied by an adequate digestion

  18. Toxicological risk assessment of elemental gold following oral exposure to sheets and nanoparticles – A review

    DEFF Research Database (Denmark)

    Hadrup, Niels; Sharma, Anoop Kumar; Poulsen, Morten

    2015-01-01

    of gold ions from its surface. Elemental gold, or the released ions, is, to some extent, absorbed in the gastrointestinal tract. Gold is distributed to organs such as the liver, heart, kidneys and lungs. The main excretion route of absorbed gold is through urine. Data on the oral toxicity of elemental...... gold is limited. The acute toxicity of elemental gold seems to be low, as rats were unaffected by a single dose of 2000mg nanoparticles/kg of body weight. Information on repeated dose toxicity is very limited. Skin rashes have been reported in humans following the ingestion of liquors containing gold...... melanogaster; however, genotoxicity studies in mammals are lacking. Overall, based on the literature and taking low human exposure into account, elemental gold via the oral route is not considered to pose a health concern to humans in general....

  19. 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.

  20. Selenium: Poison and Preventive.

    Science.gov (United States)

    Marmion Howe, Sister

    1978-01-01

    Selenium is an essential nutrient to the human body, but it can reach toxic levels causing a disease called selenosis. This article discusses selenium, its geographical distribution, toxicity, nutritional role, and carcinogenicity. (MA)

  1. Selenium in diet

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002414.htm Selenium in diet To use the sharing features on this page, please enable JavaScript. Selenium is an essential trace mineral. This means your ...

  2. Aquatic Life Criterion - Selenium

    Science.gov (United States)

    Documents pertaining to the 2016 Acute and Chronic Ambient Aquatic Life Water Quality Criteria for Selenium (Freshwater). These documents include what the safe levels of Selenium are in water for the majority of species.

  3. Selenium in oncology: from chemistry to clinics.

    Science.gov (United States)

    Micke, Oliver; Schomburg, Lutz; Buentzel, Jens; Kisters, Klaus; Muecke, Ralph

    2009-10-12

    The essential trace element selenium, which is a crucial cofactor in the most important endogenous antioxidative systems of the human body, is attracting more and more the attention of both laypersons and expert groups. The interest of oncologists mainly focuses in the following clinical aspects: radioprotection of normal tissues, radiosensitizing in malignant tumors, antiedematous effect, prognostic impact of selenium, and effects in primary and secondary cancer prevention. Selenium is a constituent of the small group of selenocysteine-containing selenoproteins and elicits important structural and enzymatic functions. Selenium deficiency has been linked to increased infection risk and adverse mood states. It has been shown to possess cancer-preventive and cytoprotective activities in both animal models and humans. It is well established that Se has a key role in redox regulation and antioxidant function, and hence in membrane integrity, energy metabolism and protection against DNA damage. Recent clinical trials have shown the importance of selenium in clinical oncology. Our own clinical study involving 48 patients suggest that selenium has a positive effect on radiation-associated secondary lymphedema in patients with limb edemas, as well as in the head and neck region, including endolaryngeal edema. Another randomized phase III study of our group was performed to examine the cytoprotective properties of selenium in radiation oncology. The aim was to evaluate whether sodium selenite is able to compensate a preexisting selenium deficiency and to prevent radiation induced diarrhea in adjuvant radiotherapy for pelvic gynecologic malignancies. Through this study, the significant benefits of sodium selenite supplementation with regards to selenium deficiency and radiotherapy induced diarrhea in patients with cervical and uterine cancer has been shown for the first time in a prospective randomized trial. Survival data imply that supplementation with selenium does not

  4. Selenium in Oncology: From Chemistry to Clinics

    Directory of Open Access Journals (Sweden)

    Oliver Micke

    2009-10-01

    Full Text Available The essential trace element selenium, which is a crucial cofactor in the most important endogenous antioxidative systems of the human body, is attracting more and more the attention of both laypersons and expert groups. The interest of oncologists mainly focuses in the following clinical aspects: radioprotection of normal tissues, radiosensitizing in malignant tumors, antiedematous effect, prognostic impact of selenium, and effects in primary and secondary cancer prevention. Selenium is a constituent of the small group of selenocysteine-containing selenoproteins and elicits important structural and enzymatic functions. Selenium deficiency has been linked to increased infection risk and adverse mood states. It has been shown to possess cancer-preventive and cytoprotective activities in both animal models and humans. It is well established that Se has a key role in redox regulation and antioxidant function, and hence in membrane integrity, energy metabolism and protection against DNA damage. Recent clinical trials have shown the importance of selenium in clinical oncology. Our own clinical study involving 48 patients suggest that selenium has a positive effect on radiation-associated secondary lymphedema in patients with limb edemas, as well as in the head and neck region, including endolaryngeal edema. Another randomized phase III study of our group was performed to examine the cytoprotective properties of selenium in radiation oncology. The aim was to evaluate whether sodium selenite is able to compensate a preexisting selenium deficiency and to prevent radiation induced diarrhea in adjuvant radiotherapy for pelvic gynecologic malignancies. Through this study, the significant benefits of sodium selenite supplementation with regards to selenium deficiency and radiotherapy induced diarrhea in patients with cervical and uterine cancer has been shown for the first time in a prospective randomized trial. Survival data imply that supplementation with

  5. Selenium and thyroid autoimmunity

    Directory of Open Access Journals (Sweden)

    Roberto Negro

    2008-06-01

    Full Text Available Roberto NegroDepartment of Endocrinology, “V. Fazzi” Hospital, Lecce, ItalyAbstract: The trace element selenium (Se occurs in the form of the amino acid selenocysteine in selenoproteins. Selenoproteins exerts multiple physiological effects in human health, many of which are related with regulation of reduction-oxidation processes. In fact, the selenoenzyme families of glutathione peroxidase (GPx and thioredoxin reductase (TRx display the ability to act as antioxidants, protecting cells from oxidative damage. Furthermore, another class of selenoproteins are the iodothyronine deiodinase enzymes (DIO, which catalyze the conversion of thyroxine (T4 in triiodothyronine (T3, then exerting a fine tuned control on thyroid hormones metabolism. Several studies have investigated the potential positive effects of Se supplementation in thyroid diseases, characterized by increased levels of hydrogen peroxide and free radicals, like autoimmune chronic thyroiditis. These studies have supplied evidences indicating that Se supplementation, maximizing the antioxidant enzymes activity, may reduce the thyroid inflammatory status. Then, it may be postulated that Se could play a therapeutical role in thyroid autoimmune diseases. Despite the fact that recent studies seem to be concordant about Se beneficial effects in decreasing thyroid peroxidase antibodies (TPOAb titers and ameliorating the ultrasound echogenicity pattern, several doubts have to be still clarified, before advising Se supplementation in chronic autoimmune thyroiditis.Keywords: selenium, thyroid, autoimmunity

  6. Selenium speciation in radix puerariae using ultrasonic assisted extraction combined with reversed phase high performance liquid chromatography-inductively coupled plasma-mass spectrometry after magnetic solid-phase extraction with 5-sulfosalicylic acid functionalized magnetic nanoparticles

    Science.gov (United States)

    Cao, Yupin; Yan, Lizhen; Huang, Hongli; Deng, Biyang

    2016-08-01

    A new method for determination of selenium species in radix puerariae was described. The method consists of sample enrichment with 5-sulfosalicylic acid (SSA)-functionalized silica-coated magnetic nanoparticles (SMNPs), high performance liquid chromatography (HPLC) separation, and online detection using inductively coupled plasma mass spectrometry (ICP-MS). The selenium species were extracted using ultrasonic extraction system with a mixture of protease K and lipase. The SSA-SMNPs were used to enrich trace amounts of selenite [Se(IV)], selenate [Se(VI)], selenomethionine (SeMet), and selenocystine (SeCys2) from lower selenium containing samples. Under the optimal conditions, the limits of detection (3σ) for SeCys2, Se(IV), SeMet and Se(VI) were observed as 0.0023, 0.0015, 0.0043, and 0.0016 ng mL- 1, respectively. The RSD values (n = 6) of method for intraday were observed between 0.5% and 0.9%. The RSD values of method for interday were less than 1.3%. The linear concentration ranges for SeCys2, Se(IV), SeMet and Se(VI) were 0.008-1000, 0.005-200, 0.015-500 and 0.006-200 ng mL- 1, respectively. The detection limits of this method were improved by 10 times due to the enrichment with the SSA-SMNP extraction. The contents of SeCys2, Se(IV), SeMet, and Se(VI) in radix puerariae were determined as 0.0140, 0.171, 0.0178, and 0.0344 μg g- 1, respectively. The recoveries were in the range of 95.6%-99.4% and the RSDs (n = 6) of recoveries were less than 1.5%.

  7. Selenium, selenoproteins and neurodegenerative diseases.

    Science.gov (United States)

    Cardoso, Bárbara Rita; Roberts, Blaine R; Bush, Ashley I; Hare, Dominic J

    2015-08-01

    It is unsurprising that our understanding of the role of selenium in neurological function is somewhat immature, considering its relatively recent discovery as an essential element to human health. Selenocysteine, the 21st amino acid, is the defining feature of the 25 selenoprotein-encoding genes so far discovered within the human genome. The low abundance of these proteins in the brain belies the integral role they play in normal neurological function, from well-characterised antioxidant activity in the periphery to poorly understood mechanisms that modulate mitochondrial function and response to brain pathology. Selenium has been identified as playing a role in several neurodegenerative disorders, including Alzheimer's and Parkinson's disease, though its function as a 'cause or effect' of disease process remains unclear. This review discusses selenium metabolism in detail, specifically with regard to the role it plays within the central nervous system, and examines the most current literature investigating how selenium may be involved in chronic diseases of the central nervous system.

  8. Review - Selenium - Its metabolism and relation to exercise.

    Science.gov (United States)

    Baltaci, Abdulkerim Kasim; Mogulkoc, Rasim; Akil, Mustafa; Bicer, Mursel

    2016-09-01

    Selenium (Se), which is commonly found in nature, is one of the essential trace elements necessary for the normal development of human and animal organisms. Selenium was first defined in 1818 by the Swedish chemist Berzelius in sulfuric acid residues. At the end of 1960s, the role of selenium in human health began to attract attention and human diseases that resembled animal diseases responding to selenium was started to be investigated. Selenium, which is highly important for human health, is necessary for a variety of metabolic processes, including thyroid hormone metabolism, protection against oxidative stress and immunity functions. Selenium is a molecule that activates glutathione peroxidase, and thus, it is involved in the antioxidant mechanisms that prevent oxidant damage. Exhaustive physical exercise is known to cause oxidant damage, probably by promoting free radical production in many tissues, including muscle, liver, heart and lungs in animals. The increase in oxidative stress during exercise and recognition of selenium's stimulation of antioxidant activity inevitably suggest a relation between selenium and exercise. The present review aims to provide information on selenium metabolism and the relation between selenium and exercise.

  9. Nanoparticle-Functionalized Porous Polymer Monolith Detection Elements for Surface-Enhanced Raman Scattering

    Science.gov (United States)

    Liu, Jikun; White, Ian; DeVoe, Don L.

    2011-01-01

    The use of porous polymer monoliths functionalized with silver nanoparticles is introduced in this work for high-sensitivity surface-enhanced Raman scattering (SERS) detection. Preparation of the SERS detection elements is a simple process comprising the synthesis of a discrete polymer monolith section within a silica capillary, followed by physically trapping silver nanoparticle aggregates within the monolith matrix. A SERS detection limit of 220 fmol for Rhodamine 6G (R6G) is demonstrated, with excellent signal stability over a 24 h period. The capability of the SERS-active monolith for label-free detection of biomolecules was demonstrated by measurements of bradykinin and cyctochrome c. The SERS-active monoliths can be readily integrated into miniaturized micro-total-analysis systems for on-line and label-free detection for a variety of biosensing, bioanalytical, and biomedical applications. PMID:21322579

  10. [Cadmium and selenium interaction in mammals].

    Science.gov (United States)

    Lazarus, Maja

    2010-09-01

    Cadmium occurs in the environment naturally and as a pollutant. Its exposure is inevitable and may produce toxic effects in many organs and organ systems through binding to biological structures, accumulation in internal organs or induction of free radical production. Another important aspect of Cd toxicity is its interaction, often anthagonistic, with essential elements. Vice versa, additional intake of the essential elements may have beneficial influence on distribution and toxic effects of cadmium. Selenium is an essential microelement and a constituent of many selenoproteins with antioxidant properties that bind cadmium (and other toxic elements such as mercury or arsenic). This review summarizes results, to date, of cadmium toxicokinetics and toxicodinamics, selenium biokinetics and biodinamics, as well as mechanisms of cadmium-selenium interaction and their impact on the oxidative status derived from the studies based upon mainly on animal experiments and on limited number of human studies. The wide variety of different doses, dose ratios, element administration modes and exposure lenghts of cadmium and selenium often yielded contradictory results. Future studies should be focused on assessment of effects of cadmium and selenium interaction in sensitive population groups and mechanisms of that interaction. Regarding animal studies, doses and exposure should be adjusted to long-term low exposure levels that are usually found in human population.

  11. Selenium redox biochemistry of zinc–sulfur coordination sites in proteins and enzymes

    OpenAIRE

    Jacob, Claus; Maret, Wolfgang; Vallee, Bert L.

    1999-01-01

    Selenium has been increasingly recognized as an essential element in biology and medicine. Its biochemistry resembles that of sulfur, yet differs from it by virtue of both redox potentials and stabilities of its oxidation states. Selenium can substitute for the more ubiquitous sulfur of cysteine and as such plays an important role in more than a dozen selenoproteins. We have chosen to examine zinc–sulfur centers as possible targets of selenium redox biochemistry. Selenium compounds release zi...

  12. Accurate determination of selenium and iron in erythrocytes from ...

    African Journals Online (AJOL)

    Accurate determination of selenium and iron in erythrocytes from Nigeria subjects using INAA. JO Ojo, Jan Kucera. Abstract. Levels of two essential elements playing crucial roles in erythrocyte's structure and functions, iron and selenium, have been carefully determined in 36 erythrocyte samples drawn from two healthy ...

  13. Relationship between soil contents and plasma levels of selenium ...

    African Journals Online (AJOL)

    The soil contents of trace elements selenium, chromium and manganese were measured to determine their impact on the plasma levels of 160 healthy adult Nigerians in five different experimental locations in Cross River and Akwa Ibom States, South - South Nigeria. The mean (±SD) soil selenium, chromium and ...

  14. Importance of selenium status in patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Nicole Ebner

    2015-02-01

    Full Text Available Overactivity of the immune system may be a worthwhile therapeutic target for implementing prognostic improvements. Therefore the impact of lipopolysaccharide (LPS desensitization on survival may help in the development of novel therapies. An understanding of the pathophysiology of the trace element selenium may complement such approaches, as recent data suggest that inflammatory responses are selenium-dependent.

  15. Selenium and Human Health: Witnessing a Copernican Revolution?

    Science.gov (United States)

    Jablonska, Ewa; Vinceti, Marco

    2015-01-01

    In humans, selenium was hypothesized to lower the risk of several chronic diseases, mainly due to the antioxidant activity of selenium-containing proteins. Recent epidemiologic and laboratory studies, however, are changing our perception of the biological effects of this nutritionally essential trace element. We reviewed the most recent epidemiologic and biochemical literature on selenium, synthesizing the findings from these studies into a unifying view. Randomized trials have shown that selenium did not protect against cancer and other chronic diseases, but even increased the risk of specific neoplasms such as advanced prostate cancer and skin cancer, in addition to type 2 diabetes. Biochemical studies indicate that selenium may exert a broad pattern of toxic effects at unexpectedly low concentrations. Furthermore, its upregulation of antioxidant proteins (selenium-dependent and selenium-independent) may be a manifestation of self-induced oxidative stress. In conclusion, toxic effects of selenium species occur at lower concentrations than previously believed. Those effects may include a large range of proteomic changes and adverse health effects in humans. Since the effects of environmental exposure to this element on human health still remain partially unknown, but are potentially serious, the toxicity of selenium exposure should be further investigated and considered as a public health priority.

  16. Elemental composition of natural nanoparticles and fine colloids in European forest stream waters and their role as phosphorus carriers

    DEFF Research Database (Denmark)

    Gottselig, N.; Amelung, W.; Kirchner, J. W.

    2017-01-01

    Biogeochemical cycling of elements largely occurs in dissolved state, but many elements may also be bound to natural nanoparticles (NNP, 1–100 nm) and fine colloids (100-450 nm). We examined the hypothesis that the size and composition of stream water NNP and colloids vary systematically across...

  17. Bio-transformation of selenium in Se-enriched bacterial strains of Lactobacillus casei.

    Science.gov (United States)

    Kurek, Eliza; Ruszczyńska, Anna; Wojciechowski, Marcin; Łuciuk, Anna; Michalska-Kacymirow, Magdalena; Motyl, Ilona; Bulska, Ewa

    Selenium is an element of very great importance for the proper functioning of the human body, mainly due to its antioxidant properties. Selenium exhibits a preventive effect in the case of cardiovascular disease, the immune system, male infertility and inhibits the toxic action of other agents. Selenium is important for Hashimoto's disease. Intake of selenium in the diet slows the aging process. The biological and toxicological effects of selenium strongly depend on its chemical form. Some organisms for example: plant, yeast, are capable of metabolizing low bioavailable selenium compounds (inorganic selenium) into its high bioavailable forms (organic selenium). The aim of this study was to investigate the bio-transformation of selenium by Lactobacillus bacteria towards the characterisation of selenium metabolites. The speciation of selenium was evaluated by high performance liquid chromatography with inductively coupled plasma mass spectrometry detector. The extraction of selenium species from lyophilized bacteria was executed with water, the mixture of lipase and protease, as well as lisozyme and sodium dodecyl sulphate. All investigated bacteria strains cultivated in the presence of Na2SeO3 effectively uptake selenium. Surprisingly, none of the applied extraction media exhibited a strong power to release the majority of the uptaken selenium compounds. Thus a maximum of 10% of the selenium was extracted from bacteria exposed to the enzymes. However, it was found that Lactobacillus bacteria are able to metabolize inorganic ions of selenium (IV) into Se-methionine, Se-methyloselenocysteine and other unidentified forms. The study confirmed the ability of probiotic bacteria to biotransform inorganic selenium into its organic derivatives. Therefore, Se-enriched bacteria can be considered as an addition to the functional food. selenium speciation, extraction procedure, Lactobacillus casei bacteria, Lactic acid bacteria (LAB), HPLC ICP-MS, functional food.

  18. Biomonitoring Equivalents for selenium.

    Science.gov (United States)

    Hays, Sean M; Macey, Kristin; Nong, Andy; Aylward, Lesa L

    2014-10-01

    Selenium is an essential nutrient for human health with a narrow range between essentiality and toxicity. Selenium is incorporated into several proteins that perform important functions in the body. With insufficient selenium intake, the most notable effect is Keshan disease, an endemic cardiomyopathy in children. Conversely, excessive selenium intake can result in selenosis, manifested as brittle nails and hair and gastro-intestinal disorders. As such, guidance values have been established to protect against both insufficient and excessive selenium exposures. Dietary Reference Intakes (DRIs) have been established as standard reference values for nutritional adequacy in North America. To protect against selenosis resulting from exposure to excessive amounts of selenium, several government and non-governmental agencies have established a range of guidance values. Exposure to selenium is primarily through the diet, but monitoring selenium intake is difficult. Biomonitoring is a useful means of assessing and monitoring selenium status for both insufficient and excessive exposures. However, to be able to interpret selenium biomonitoring data, levels associated with both DRIs and toxicity guidance values are required. Biomonitoring Equivalents (BEs) were developed for selenium in whole blood, plasma and urine. The BEs associated with assuring adequate selenium intake (Estimated Average Requirements - EAR) are 100, 80 and 10μg/L in whole blood, plasma and urine, respectively. The BEs associated with protection against selenosis range from 400 to 480μg/L in whole blood, 180-230μg/L in plasma, and 90-110μg/L in urine. These BE values can be used by both regulatory agencies and public health officials to interpret selenium biomonitoring data in a health risk context. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Realizing the therapeutic potential of rare earth elements in designing nanoparticles to target and treat glioblastoma.

    Science.gov (United States)

    Lu, Victor M; McDonald, Kerrie L; Townley, Helen E

    2017-10-01

    The prognosis of brain cancer glioblastoma (GBM) is poor, and despite intense research, there have been no significant improvements within the last decade. This stasis implicates the need for more novel therapeutic investigation. One such option is the use of nanoparticles (NPs), which can be beneficial due to their ability to penetrate the brain, overcome the blood-brain barrier and take advantage of the enhanced permeation and retention effect of GBM to improve specificity. Rare earth elements possess a number of interesting natural properties due to their unique electronic configuration, which may prove therapeutically advantageous in an NP formulation. The underexplored exciting potential for rare earth elements to augment the therapeutic potential of NPs in GBM treatment is discussed in this review.

  20. Application of the boundary-element method to the interaction of light with single and coupled metallic nanoparticles

    OpenAIRE

    Rockstuhl, Carsten; Salt, Martin Guy; Herzig, Hans-Peter

    2008-01-01

    The boundary-element method is applied to the interaction of light with resonant metallic nanoparticles. At a certain wavelength, excitation of a surface plasmon takes place, which leads to a resonantly enhanced near-field amplitude and a large scattering cross section. The resonance wavelength for different scatterer geometries is determined. Alteration of the scattering properties in the presence of other metallic nanoparticles is discussed. To treat this problem, a novel formulation of the...

  1. Conceptual Model for Selenium Cycling in the Great Salt Lake

    Science.gov (United States)

    Johnson, W. P.; Conover, M. R.; Wurtsbaugh, W. A.; Adams, J.

    2006-12-01

    The conceptual model for Selenium cycling in the Great Salt Lake was developed to guide investigations in support of determining an open water selenium standard for the Great Salt Lake. The motivation to determine this particular selenium standard derives from public concern for a plan to allow disposal of reverse osmosis (RO) concentrate in the GSL, which would contain elevated concentrations of major and trace elements, including selenium. The development of an open water standard for selenium requires a working knowledge of the biological significance of existing selenium concentrations in the Great Salt Lake, as well as a working understanding of the likely changes of these concentrations over time given existing and proposed loads to the system. This working knowledge" is being represented in a conceptual model that accounts for selenium in various stocks" in the system (e.g. water, sediment, biota) and the flow" of selenium between stocks (e.g., precipitation and settling, volatilization, bioconcentration). It illustrates the critical pathway of selenium in the Great Salt Lake from water, to microorganisms, to brine shrimp and brine flies, to birds, and to their eggs. It also addresses the complexity of the GSL system: a) Spatially diverse, being comprised by four distinct bays and two layers, with major differences in salinity among their waters. b) Temporally dynamic, due to seasonal and inter-annual variations in runoff. The conceptual model is presently descriptive, but will serve as the basis for a semi-quantitative model that will be fed by data accumulated during subsequent investigations.

  2. Selenium Administration Attenuates 5-Flurouracil-Induced Intestinal Mucositis.

    Science.gov (United States)

    Lee, Jae Min; Chun, Hoon Jai; Choi, Hyuk Soon; Kim, Eun Sun; Seo, Yeon Seok; Jeen, Yoon Tae; Lee, Hong Sik; Um, Soon Ho; Kim, Chul Hwan; Sul, Donggeun

    2017-01-01

    Chemotherapy-induced mucositis is mediated by the release of proinflammatory cytokines and reactive oxygen species. Selenium has several metabolic functions, including the protection of membrane lipids and macromolecules against oxidative damage. However, to date, there is little evidence on the effect of trace elements on intestinal mucositis after chemotherapy. This study investigated the protective effect of selenium against chemotherapy-induced mucositis in rats. Twenty-four 9-wk-old female Wistar rats were randomized to 4 groups: control, selenium, 5-fluorouracil (5-FU), and 5-FU plus selenium. Mucositis was induced by a single dose of 5-FU (400 mg/kg BW) via intraperitoneal injection, and selenium was administered by a single intraperitoneal dose of sodium selenite (0.2 mg/kg BW). Diarrhea and weight loss after 5-FU administration were attenuated by selenium treatment. The mean villus height in the 5-FU plus selenium group was significantly taller than rats administered with 5-FU alone, but not significantly different compared to the control group. Interleukin (IL)-1β and tumor necrosis factor (TNF)-α mRNA expression were significantly lower in the 5-FU plus selenium group than in the 5-FU only group (IL-1β, P selenium protects the mucosa during chemotherapy via its anti-inflammatory effects and its suppression of cytotoxic cytokine production.

  3. Selenium and pseudoexfoliation syndrome.

    Science.gov (United States)

    Yilmaz, Ayça; Ayaz, Lokman; Tamer, Lülüfer

    2011-02-01

    To investigate the levels of selenium (Se), an essential trace element, in aqueous humor, conjunctival specimens, and serum of patients with pseudoexfoliation (PEX) syndrome and control subjects; and to determine the role of Se in the development and pathogenesis of PEX syndrome. A prospective case-control study. Twenty-seven cataract patients with PEX syndrome and 20 age-matched cataract patients without PEX syndrome were enrolled in this institutional study. Patients with ophthalmic conditions other than PEX and conditions that may influence Se levels were excluded. During cataract surgeries, aqueous humor, conjunctival specimens, and serum were collected in both groups. Selenium levels of all samples were measured by using atomic absorption spectrophotometer. The mean Se levels in aqueous humor of patients with PEX syndrome (50.96 ± 23.79 μg/L) were significantly lower than the control group (77.85 ± 19.21 μg/L) (P < .001). The mean Se levels in conjunctival specimens of patients with PEX syndrome (4.04 ± 1.44 μg/mg) were significantly lower than the control group (7.19 ± 2.00 μg/mg) (P < .001), as well. The mean Se levels in serum of patients with PEX syndrome (115.25 ± 25.20 μg/L) were lower than the control group (124.25 ± 14.40 μg/L), but this was not statistically significant (P = .325). Reduced levels of Se in aqueous humor, conjunctival specimens, and serum of patients with PEX may support the role of impairment in antioxidant defense system in the pathogenesis of PEX syndrome. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Selenium and human health.

    Science.gov (United States)

    Rayman, Margaret P

    2012-03-31

    Selenium is incorporated into selenoproteins that have a wide range of pleiotropic effects, ranging from antioxidant and anti-inflammatory effects to the production of active thyroid hormone. In the past 10 years, the discovery of disease-associated polymorphisms in selenoprotein genes has drawn attention to the relevance of selenoproteins to health. Low selenium status has been associated with increased risk of mortality, poor immune function, and cognitive decline. Higher selenium status or selenium supplementation has antiviral effects, is essential for successful male and female reproduction, and reduces the risk of autoimmune thyroid disease. Prospective studies have generally shown some benefit of higher selenium status on the risk of prostate, lung, colorectal, and bladder cancers, but findings from trials have been mixed, which probably emphasises the fact that supplementation will confer benefit only if intake of a nutrient is inadequate. Supplementation of people who already have adequate intake with additional selenium might increase their risk of type-2 diabetes. The crucial factor that needs to be emphasised with regard to the health effects of selenium is the inextricable U-shaped link with status; whereas additional selenium intake may benefit people with low status, those with adequate-to-high status might be affected adversely and should not take selenium supplements. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Selenium fertilization on lentil (Lens culinaris Medikus) grain yield, seed selenium concentration, and antioxidant activity

    Science.gov (United States)

    Selenium (Se) is an essential element for mammals but has not been considered as an essential element for higher plants. Lentil (Lens culinaris Medik.) is a cool season food legume rich in protein and a range of micronutrients including minerals (iron and zinc), folates, and carotenoids. The objecti...

  6. Direct synthesis of antimicrobial coatings based on tailored bi-elemental nanoparticles

    Directory of Open Access Journals (Sweden)

    Giulio Benetti

    2017-03-01

    Full Text Available Ultrathin coatings based on bi-elemental nanoparticles (NPs are very promising to limit the surface-related spread of bacterial pathogens, particularly in nosocomial environments. However, tailoring the synthesis, composition, adhesion to substrate, and antimicrobial spectrum of the coating is an open challenge. Herein, we report on a radically new nanostructured coating, obtained by a one-step gas-phase deposition technique, and composed of bi-elemental Janus type Ag/Ti NPs. The NPs are characterized by a cluster-in-cluster mixing phase with metallic Ag nano-crystals embedded in amorphous TiO2 and present a promising antimicrobial activity including also multidrug resistant strains. We demonstrate the flexibility of the method to tune the embedded Ag nano-crystals dimension, the total relative composition of the coating, and the substrate type, opening the possibility of tailoring the dimension, composition, antimicrobial spectrum, and other physical/chemical properties of such multi-elemental systems. This work is expected to significantly spread the range of applications of NPs coatings, not only as an effective tool in the prevention of healthcare-associated infections but also in other technologically relevant fields like sensors or nano-/micro joining.

  7. Direct synthesis of antimicrobial coatings based on tailored bi-elemental nanoparticles

    Science.gov (United States)

    Benetti, Giulio; Cavaliere, Emanuele; Canteri, Adalberto; Landini, Giulia; Rossolini, Gian Maria; Pallecchi, Lucia; Chiodi, Mirco; Van Bael, Margriet J.; Winckelmans, Naomi; Bals, Sara; Gavioli, Luca

    2017-03-01

    Ultrathin coatings based on bi-elemental nanoparticles (NPs) are very promising to limit the surface-related spread of bacterial pathogens, particularly in nosocomial environments. However, tailoring the synthesis, composition, adhesion to substrate, and antimicrobial spectrum of the coating is an open challenge. Herein, we report on a radically new nanostructured coating, obtained by a one-step gas-phase deposition technique, and composed of bi-elemental Janus type Ag/Ti NPs. The NPs are characterized by a cluster-in-cluster mixing phase with metallic Ag nano-crystals embedded in amorphous TiO2 and present a promising antimicrobial activity including also multidrug resistant strains. We demonstrate the flexibility of the method to tune the embedded Ag nano-crystals dimension, the total relative composition of the coating, and the substrate type, opening the possibility of tailoring the dimension, composition, antimicrobial spectrum, and other physical/chemical properties of such multi-elemental systems. This work is expected to significantly spread the range of applications of NPs coatings, not only as an effective tool in the prevention of healthcare-associated infections but also in other technologically relevant fields like sensors or nano-/micro joining.

  8. Beneficial Effects of Selenium on Some Morphological and Physiological Trait of Hot Pepper (Capsicum anuum)

    OpenAIRE

    Shekari, L.; m.m Kamelmanesh; M. Mozafarian; F Sadeghi

    2016-01-01

    Introduction: Aluminum (Al), cobalt (Co), sodium (Na), selenium (Se), and silicon (Si) are considered as beneficial elements for plants. They are not required for all plants but they can improve the growth and development of some plant species. Selenium is an essential element for human with antioxidant and antivirus functions but is not considered essential for higher plants. Selenium is reported to be protective against cancer and more than 40 types of diseases are associated with Se defici...

  9. Speciation of Selenium in Stream Insects Using X-Ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Andrahennadi, R.; Wayland, M.; Pickering, I.J.

    2009-05-28

    Selenium contamination in the environment is a widespread problem affecting insects and other wildlife. Insects occupy a critical middle link and aid in trophic transfer of selenium in many terrestrial and freshwater food chains, but the mechanisms of selenium uptake through the food chain are poorly understood. In particular, biotransformation of selenium by insects into different chemical forms will greatly influence how toxic or benign the selenium is to that organism or to its predators. We have used X-ray absorption spectroscopy (XAS) to identify the chemical form of selenium in insects inhabiting selenium contaminated streams near Hinton, Alberta (Canada). Selenium K near-edge spectra indicate a variability of selenium speciation among the insects that included mayflies (Ephemeroptera), stoneflies (Plecoptera), caddisflies (Trichoptera), and craneflies (Diptera). Higher percentages of inorganic selenium were observed in primary consumers, detritivores, and filter feeders than in predatory insects. Among the organic forms of selenium, organic selenides constituted a major fraction in most organisms. A species modeled as trimethylselenonium was observed during the pupal stage of caddisflies. These results provide insights into how the insects cope with their toxic cargo, including how the selenium is biotransformed into less toxic forms and how it can be eliminated from the insects. More broadly, this study demonstrates the strengths of XAS to probe the effects of heavy elements at trace levels in insects from the field.

  10. Selenium accumulation by plants.

    Science.gov (United States)

    White, Philip J

    2016-02-01

    Selenium (Se) is an essential mineral element for animals and humans, which they acquire largely from plants. The Se concentration in edible plants is determined by the Se phytoavailability in soils. Selenium is not an essential element for plants, but excessive Se can be toxic. Thus, soil Se phytoavailability determines the ecology of plants. Most plants cannot grow on seleniferous soils. Most plants that grow on seleniferous soils accumulate plant species have evolved tolerance to Se, and commonly accumulate tissue Se concentrations >100 mg Se kg(-1) dry matter. These plants are considered to be Se accumulators. Some species can even accumulate Se concentrations of 1000-15 000 mg Se kg(-1 )dry matter and are called Se hyperaccumulators. This article provides an overview of Se uptake, translocation and metabolism in plants and highlights the possible genetic basis of differences in these between and within plant species. The review focuses initially on adaptations allowing plants to tolerate large Se concentrations in their tissues and the evolutionary origin of species that hyperaccumulate Se. It then describes the variation in tissue Se concentrations between and within angiosperm species and identifies genes encoding enzymes limiting the rates of incorporation of Se into organic compounds and chromosomal loci that might enable the development of crops with greater Se concentrations in their edible portions. Finally, it discusses transgenic approaches enabling plants to tolerate greater Se concentrations in the rhizosphere and in their tissues. The trait of Se hyperaccumulation has evolved several times in separate angiosperm clades. The ability to tolerate large tissue Se concentrations is primarily related to the ability to divert Se away from the accumulation of selenocysteine and selenomethionine, which might be incorporated into non-functional proteins, through the synthesis of less toxic Se metabilites. There is potential to breed or select crops

  11. Synthesis of Tungsten Diselenide Nanoparticles by Chemical Vapor Condensation Method

    Directory of Open Access Journals (Sweden)

    Oleg V. Tolochko

    2015-09-01

    Full Text Available Crystalline tungsten diselenide (WSe2 nanoparticles have been synthesized by a gas phase reaction using tungsten hexacarbonyl and elemental selenium as precursors. The WSe2 nanoparticle morphology varies from the spherical shape to flake-like layered structures. Mean size in smaller dimension are less than 5 nm and the number of layers decreased linearly with decreasing of reaction time and concentration of carbonyl in the gas phase. The mean value of interlayer distance in <0001> direction is comparable with the microscopic values. The selenium-to-tungsten atomic ratios of 2.07, 2.19 and 2.19 were determined respectively, approach to the stoichiometric ratio of 2:1. Main impurities are oxygen and carbon and strongly interrelated with carbonyl concentration in the gas phase.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7356

  12. Biochemical discrimination between selenium and sulfur 1: a single residue provides selenium specificity to human selenocysteine lyase.

    Directory of Open Access Journals (Sweden)

    Ruairi Collins

    Full Text Available Selenium and sulfur are two closely related basic elements utilized in nature for a vast array of biochemical reactions. While toxic at higher concentrations, selenium is an essential trace element incorporated into selenoproteins as selenocysteine (Sec, the selenium analogue of cysteine (Cys. Sec lyases (SCLs and Cys desulfurases (CDs catalyze the removal of selenium or sulfur from Sec or Cys and generally act on both substrates. In contrast, human SCL (hSCL is specific for Sec although the only difference between Sec and Cys is the identity of a single atom. The chemical basis of this selenium-over-sulfur discrimination is not understood. Here we describe the X-ray crystal structure of hSCL and identify Asp146 as the key residue that provides the Sec specificity. A D146K variant resulted in loss of Sec specificity and appearance of CD activity. A dynamic active site segment also provides the structural prerequisites for direct product delivery of selenide produced by Sec cleavage, thus avoiding release of reactive selenide species into the cell. We thus here define a molecular determinant for enzymatic specificity discrimination between a single selenium versus sulfur atom, elements with very similar chemical properties. Our findings thus provide molecular insights into a key level of control in human selenium and selenoprotein turnover and metabolism.

  13. Acute selenium toxicity associated with a dietary supplement.

    Science.gov (United States)

    MacFarquhar, Jennifer K; Broussard, Danielle L; Melstrom, Paul; Hutchinson, Richard; Wolkin, Amy; Martin, Colleen; Burk, Raymond F; Dunn, John R; Green, Alice L; Hammond, Roberta; Schaffner, William; Jones, Timothy F

    2010-02-08

    Selenium is an element necessary for normal cellular function, but it can have toxic effects at high doses. We investigated an outbreak of acute selenium poisoning. A case was defined as the onset of symptoms of selenium toxicity in a person within 2 weeks after ingesting a dietary supplement manufactured by "Company A," purchased after January 1, 2008. We conducted case finding, administered initial and 90-day follow-up questionnaires to affected persons, and obtained laboratory data where available. The source of the outbreak was identified as a liquid dietary supplement that contained 200 times the labeled concentration of selenium. Of 201 cases identified in 10 states, 1 person was hospitalized. The median estimated dose of selenium consumed was 41 749 microg/d (recommended dietary allowance is 55 microg/d). Frequently reported symptoms included diarrhea (78%), fatigue (75%), hair loss (72%), joint pain (70%), nail discoloration or brittleness (61%), and nausea (58%). Symptoms persisting 90 days or longer included fingernail discoloration and loss (52%), fatigue (35%), and hair loss (29%). The mean initial serum selenium concentration of 8 patients was 751 microg/L (reference range, selenium concentration of 7 patients was 166 microg/24 h (reference range, selenium in a liquid dietary supplement resulted in a widespread outbreak. Had the manufacturers been held to standards used in the pharmaceutical industry, it may have been prevented.

  14. Erythrocyte selenium concentration as a marker of selenium status.

    Science.gov (United States)

    Stefanowicz, Fiona A; Talwar, Dinesh; O'Reilly, Denis S J; Dickinson, Natalie; Atkinson, John; Hursthouse, Andrew S; Rankin, Jean; Duncan, Andrew

    2013-10-01

    Plasma selenium concentration and glutathione peroxidase (GPx) activity are commonly used as markers of selenium nutritional status. However, plasma selenium concentrations fall independently of selenium status during the acute phase response and GPx is analytically problematic. The assay for erythrocyte selenium is robust and concentrations are unaffected by the systemic inflammatory response. This study was performed to investigate the validity of erythrocyte selenium measurement in assessing selenium status. C-reactive protein (CRP), plasma and erythrocyte selenium concentrations and GPx activity were measured in 96 women from two regions of Malawi with low and high selenium dietary intakes. CRP and plasma and erythrocyte selenium was measured in 91 critically ill patients with a systemic inflammatory response. The median CRP value of all subjects from Malawi was 4.2 mg/L indicating no inflammation. The median CRP value for the critically ill patients was 126 mg/L indicating this group was inflamed. In the non-inflamed population there was a strong positive correlation (r = 0.95) between erythrocyte and plasma selenium and a strong positive correlation (r = 0.77) between erythrocyte selenium and erythrocyte GPx up to 6.10 nmol/g Hb after which maximal activity was reached. In the inflamed population, plasma selenium was low, erythrocyte selenium was normal and there was a weak correlation (r = 0.30) between selenium concentrations in plasma and erythrocytes. This demonstrates that plasma selenium is affected by the inflammatory response while erythrocyte selenium concentration is unaffected and can be used to reliably assess selenium status across a wide range of selenium intakes. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  15. Nanoparticle-labeled DNA capture elements for detection and identification of biological agents

    Science.gov (United States)

    Kiel, Johnathan L.; Holwitt, Eric A.; Parker, Jill E.; Vivekananda, Jeevalatha; Franz, Veronica

    2004-12-01

    Aptamers, synthetic DNA capture elements (DCEs), can be made chemically or in genetically engineered bacteria. DNA capture elements are artificial DNA sequences, from a random pool of sequences, selected for their specific binding to potential biological warfare or terrorism agents. These sequences were selected by an affinity method using filters to which the target agent was attached and the DNA isolated and amplified by polymerase chain reaction (PCR) in an iterative, increasingly stringent, process. The probes can then be conjugated to Quantum Dots and super paramagnetic nanoparticles. The former provide intense, bleach-resistant fluorescent detection of bioagent and the latter provide a means to collect the bioagents with a magnet. The fluorescence can be detected in a flow cytometer, in a fluorescence plate reader, or with a fluorescence microscope. To date, we have made DCEs to Bacillus anthracis spores, Shiga toxin, Venezuelan Equine Encephalitis (VEE) virus, and Francisella tularensis. DCEs can easily distinguish Bacillus anthracis from its nearest relatives, Bacillus cereus and Bacillus thuringiensis. Development of a high through-put process is currently being investigated.

  16. Method for fabrication and verification of conjugated nanoparticle-antibody tuning elements for multiplexed electrochemical biosensors.

    Science.gov (United States)

    La Belle, Jeffrey T; Fairchild, Aaron; Demirok, Ugur K; Verma, Aman

    2013-05-15

    There is a critical need for more accurate, highly sensitive and specific assay for disease diagnosis and management. A novel, multiplexed, single sensor using rapid and label free electrochemical impedance spectroscopy tuning method has been developed. The key challenges while monitoring multiple targets is frequency overlap. Here we describe the methods to circumvent the overlap, tune by use of nanoparticle (NP) and discuss the various fabrication and characterization methods to develop this technique. First sensors were fabricated using printed circuit board (PCB) technology and nickel and gold layers were electrodeposited onto the PCB sensors. An off-chip conjugation of gold NP's to molecular recognition elements (with verification technique) is described as well. A standard covalent immobilization of the molecular recognition elements is also discussed with quality control techniques. Finally use and verification of sensitivity and specificity is also presented. By use of gold NP's of various sizes, we have demonstrated the possibility and shown little loss of sensitivity and specificity in the molecular recognition of inflammatory markers as "model" targets for our tuning system. By selection of other sized NP's or NP's of various materials, the tuning effect can be further exploited. The novel platform technology developed could be utilized in critical care, clinical management and at home health and disease management. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Biomarkers of Selenium Status

    Science.gov (United States)

    Combs, Gerald F.

    2015-01-01

    The essential trace element, selenium (Se), has multiple biological activities, which depend on the level of Se intake. Relatively low Se intakes determine the expression of selenoenzymes in which it serves as an essential constituent. Higher intakes have been shown to have anti-tumorigenic potential; and very high Se intakes can produce adverse effects. This hierarchy of biological activities calls for biomarkers informative at different levels of Se exposure. Some Se-biomarkers, such as the selenoproteins and particularly GPX3 and SEPP1, provide information about function directly and are of value in identifying nutritional Se deficiency and tracking responses of deficient individuals to Se-treatment. They are useful under conditions of Se intake within the range of regulated selenoprotein expression, e.g., for humans health considerations. This would include determining whether supranutritional intakes of Se may be required for maximal selenoprotein expression in immune surveillance cells. It would also include developing methods to determine low molecular weight Se-metabolites, i.e., selenoamino acids and methylated Se-metabolites, which to date have not been detectable in biological specimens. Recent analytical advances using tandem liquid chromatography-mass spectrometry suggest prospects for detecting these metabolites. PMID:25835046

  18. The role of selenium in human conception and pregnancy.

    Science.gov (United States)

    Pieczyńska, Joanna; Grajeta, Halina

    2015-01-01

    Selenium (Se) is a trace element essential for the appropriate course of vital processes in the human body. It is also a constituent of the active center of glutathione peroxidase that protects cellular membranes against the adverse effects of H2O2 lipid peroxides. Epidemiological surveys have demonstrated that selenium deficiency in the body may contribute to an increased risk for certain neoplasmic diseases (including colonic carcinoma, gastric carcinoma, pulmonary carcinoma and prostate carcinoma), as well as diseases of the cardiovascular, osseous and nervous systems. Apart from its cancer prevention and antioxidative activities, selenium protects the body against detrimental effects of heavy metals and determines the proper functioning of the immunological system. Furthermore, selenium plays a significant role in the undisturbed functioning of the reproductive system. Many studies have addressed correlations between its intake and fertility as well as disorders of procreation processes. Selenium deficiencies may lead to gestational complications, miscarriages and the damaging of the nervous and immune systems of the fetus. A low concentration of selenium in blood serum in the early stage of pregnancy has been proved to be a predictor of low birth weight of a newborn. A deficiency of this element may also cause infertility in men by causing a deterioration in the quality of semen and in sperm motility. For this reason, supplementation in the case of selenium deficiencies in the procreation period of both women and men is of utmost significance. Copyright © 2014 Elsevier GmbH. All rights reserved.

  19. Selenium and Its Supplementation in Cardiovascular Disease—What do We Know?

    Directory of Open Access Journals (Sweden)

    Carina Benstoem

    2015-04-01

    Full Text Available The trace element selenium is of high importance for many of the body’s regulatory and metabolic functions. Balanced selenium levels are essential, whereas dysregulation can cause harm. A rapidly increasing number of studies characterizes the wide range of selenium dependent functions in the human body and elucidates the complex and multiple physiological and pathophysiological interactions of selenium and selenoproteins. For the majority of selenium dependent enzymes, several biological functions have already been identified, like regulation of the inflammatory response, antioxidant properties and the proliferation/differentiation of immune cells. Although the potential role of selenium in the development and progression of cardiovascular disease has been investigated for decades, both observational and interventional studies of selenium supplementation remain inconclusive and are considered in this review. This review covers current knowledge of the role of selenium and selenoproteins in the human body and its functional role in the cardiovascular system. The relationships between selenium intake/status and various health outcomes, in particular cardiomyopathy, myocardial ischemia/infarction and reperfusion injury are reviewed. We describe, in depth, selenium as a biomarker in coronary heart disease and highlight the significance of selenium supplementation for patients undergoing cardiac surgery.

  20. Selenium and Its Supplementation in Cardiovascular Disease—What do We Know?

    Science.gov (United States)

    Benstoem, Carina; Goetzenich, Andreas; Kraemer, Sandra; Borosch, Sebastian; Manzanares, William; Hardy, Gil; Stoppe, Christian

    2015-01-01

    The trace element selenium is of high importance for many of the body’s regulatory and metabolic functions. Balanced selenium levels are essential, whereas dysregulation can cause harm. A rapidly increasing number of studies characterizes the wide range of selenium dependent functions in the human body and elucidates the complex and multiple physiological and pathophysiological interactions of selenium and selenoproteins. For the majority of selenium dependent enzymes, several biological functions have already been identified, like regulation of the inflammatory response, antioxidant properties and the proliferation/differentiation of immune cells. Although the potential role of selenium in the development and progression of cardiovascular disease has been investigated for decades, both observational and interventional studies of selenium supplementation remain inconclusive and are considered in this review. This review covers current knowledge of the role of selenium and selenoproteins in the human body and its functional role in the cardiovascular system. The relationships between selenium intake/status and various health outcomes, in particular cardiomyopathy, myocardial ischemia/infarction and reperfusion injury are reviewed. We describe, in depth, selenium as a biomarker in coronary heart disease and highlight the significance of selenium supplementation for patients undergoing cardiac surgery. PMID:25923656

  1. Selenium and its supplementation in cardiovascular disease--what do we know?

    Science.gov (United States)

    Benstoem, Carina; Goetzenich, Andreas; Kraemer, Sandra; Borosch, Sebastian; Manzanares, William; Hardy, Gil; Stoppe, Christian

    2015-04-27

    The trace element selenium is of high importance for many of the body's regulatory and metabolic functions. Balanced selenium levels are essential, whereas dysregulation can cause harm. A rapidly increasing number of studies characterizes the wide range of selenium dependent functions in the human body and elucidates the complex and multiple physiological and pathophysiological interactions of selenium and selenoproteins. For the majority of selenium dependent enzymes, several biological functions have already been identified, like regulation of the inflammatory response, antioxidant properties and the proliferation/differentiation of immune cells. Although the potential role of selenium in the development and progression of cardiovascular disease has been investigated for decades, both observational and interventional studies of selenium supplementation remain inconclusive and are considered in this review. This review covers current knowledge of the role of selenium and selenoproteins in the human body and its functional role in the cardiovascular system. The relationships between selenium intake/status and various health outcomes, in particular cardiomyopathy, myocardial ischemia/infarction and reperfusion injury are reviewed. We describe, in depth, selenium as a biomarker in coronary heart disease and highlight the significance of selenium supplementation for patients undergoing cardiac surgery.

  2. Selenium in Graves' disease

    Directory of Open Access Journals (Sweden)

    Jadwiga Kryczyk

    2013-05-01

    Full Text Available The aim of this study was to present the current state of knowledge of the role of selenium in Graves’ disease. Recently, in the pathogenesis and course of this autoimmune disease, more attention has been paid to the relationship between oxidative stress and the antioxidant system, where selenium compounds play an important role. The thyroid is the organ with the highest selenium concentration in the human body. Selenium compounds, having antioxidant properties, protect thyrocytes against the destructive effects of reactive oxygen species (ROS, which are generated during the synthesis of thyroid hormones. Therefore, strengthening the body’s defense mechanisms, which protect against the formation and activity of ROS during medical treatment of Graves’ disease patients, may be an effective adjuvant in commonly used methods of therapy.

  3. The radiative decays of excited states of transition elements located inside and near core-shell nanoparticles

    Science.gov (United States)

    Pukhov, Konstantin K.

    2017-12-01

    Here we discuss the radiative decays of excited states of transition elements located inside and outside of the subwavelength core-shell nanoparticles embedded in dielectric medium. Based on the quantum mechanics and quantum electrodynamics, the general analytical expressions are derived for the probability of the spontaneous transitions in the luminescent centers (emitter) inside and outside the subwavelength core-shell nanoparticle. Obtained expressions holds for arbitrary orientation of the dipole moment and the principal axes of the quadrupole moment of the emitter with respect to the radius-vector r connecting the center of the emitter with the center of the nanoparticle. They have simple form and show how the spontaneous emission in core-shell NPs can be controlled and engineered due to the dependence of the emission rates on core-shell sizes, radius-vector r and permittivities of the surrounding medium, shell, and core.

  4. Plasma-assisted synthesis and high-resolution characterization of anisotropic elemental and bimetallic core–shell magnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    M. Hennes

    2014-04-01

    Full Text Available Magnetically anisotropic as well as magnetic core–shell nanoparticles (CS-NPs with controllable properties are highly desirable in a broad range of applications. With this background, a setup for the synthesis of heterostructured magnetic core–shell nanoparticles, which relies on (optionally pulsed DC plasma gas condensation has been developed. We demonstrate the synthesis of elemental nickel nanoparticles with highly tunable sizes and shapes and Ni@Cu CS-NPs with an average shell thickness of 10 nm as determined with scanning electron microscopy, high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy measurements. An analytical model that relies on classical kinetic gas theory is used to describe the deposition of Cu shell atoms on top of existing Ni cores. Its predictive power and possible implications for the growth of heterostructured NP in gas condensation processes are discussed.

  5. Effects of selenium biofortification on crop nutritional quality

    OpenAIRE

    Mario eMalagoli; Michela eSchiavon; Stefano eDall'Acqua; Pilon-Smits, Elizabeth A. H.

    2015-01-01

    Selenium (Se) at very low doses has crucial functions in humans and animals. Since plants represent the main dietary source of this element, Se-containing crops may be used as a means to deliver Se to consumers (biofortification). Several strategies have been exploited to increase plant Se content. Selenium assimilation in plants affects both sulfur (S) and nitrogen (N) metabolic pathways, which is why recent research has also focused on the effect of Se fertilization on the production of S- ...

  6. Colloidal properties of nanoparticular biogenic selenium govern environmental fate and bioremediation effectiveness

    NARCIS (Netherlands)

    Buchs, B.; Evangelou, M.H.W.; Winkel, L.; Lenz, M.

    2013-01-01

    Microbial selenium (Se) bioremediation is based on conversion of water soluble, toxic Se oxyanions to water insoluble, elemental Se. Formed biogenic elemental Se is of nanometer size, hampering straightforward separation from the aqueous phase. This study represents the first systematic

  7. Nuclear-based methods for the study of selenium

    Energy Technology Data Exchange (ETDEWEB)

    Spyrou, N.M.; Akanle, O.A.; Dhani, A. (Univ. of Surrey (England))

    1988-01-01

    The essentiality of selenium to the human being and in particular its deficiency state, associated with prolonged inadequate dietary intake, have received considerable attention. In addition, the possible relationship between selenium and cancer and the claim that selenium may possess cancer-prevention properties have focused research effort. It has been observed in a number of studies on laboratory animals that selenium supplementation protects the animals against carcinogen-induced neoplastic growth in various organ sites, reduces the incidence of spontaneous mammary tumors, and suppresses the growth of transplanted tumor cells. In these research programs on the relationship between trace element levels and senile dementia and depression and the elemental changes in blood associated with selenium supplementation in a normal group of volunteers, it became obvious that in addition to establishing normal levels of elements in the population of interest, there was a more fundamental requirement for methods to be developed that would allow the study of the distribution of selenium in the body and its binding sites. The authors propose emission tomography and perturbed angular correlation as techniques worth exploring.

  8. Selenium concentrations of selected medicinal and aromatic plants in Turkey.

    Science.gov (United States)

    Ozkutlu, Faruk; Sekeroglu, Nazim; Koca, Ufuk; Yazici, Gizem

    2011-10-01

    Recent scientific studies have proven the importance of trace elements on human health. The main food supplies are plants and animals, which are significant sources of these minerals. Studies on determining mineral compositions of herbs, spices and some other crops have increased all over the world. Published works revealed that spices, herbs and medicinal plants should be consumed to obtain beneficial trace elements. Selenium (Se), one of the most vital trace elements, has a significant role in human diet acting as a preventative agent against some serious illnesses. Despite numerous scientific works on mineral compositions of medicinal and aromatic plants, investigations of selenium content in these foods could not be successfully studied until recently due to the lack of suitable analytical methods for selenium analysis. Thus, publications on selenium concentrations of foods are recent. In this regard, selenium contents of some medicinal and aromatic plants commonly used as spices, herbal teas and traditional medicines in Turkey were studied in the present research. Selenium contents of the most used parts of these plants were analyzed by ICP-OES (Varian Vista-Pro, Australia). Of the analyzed 26 medicinal and aromatic plants, the highest Se concentration (1133 microg kg-1) was found in sweet basil (Ocimum basilicum L.) and the lowest in sumac (Rhus coriaria L.) fruits (11 microg kg(-1)).

  9. The possibility of modifying the elements of the bearing assembly with nanoparticles in order to reduce the friction coefficient

    Science.gov (United States)

    Stankevich, P.; Mironovs, V.; Vasilyeva, E.; Breki, A.; Tolochko, O.

    2017-10-01

    Recent study considers the tribological characteristics of the sintered bushings used in the connecting nodes brake lever system of railway cars. Particular attention is paid sleeves low content of alloying elements. Bushings had been prepared by powder metallurgy route by using low alloyed powders of Fe-Cu-C system. Porosity after sintering was about 20%. Generally, before using material was impregnated by industrial mineral oil in order to improve friction condition. In the recent study we use new lubricating compositions for impregnating in sintered bodies. Such compositions consist of basic mineral oil with addition of 4 wt.% of layered tungsten dichalcogenides (WS2 and WSe2) nanoparticles, which were ultrasonically dispersed. Tungsten disulphide nanoparticles have spherical shape with the diameter of 30-50 nm, and diselenide nanoparticles have a flat shape with the mean dimensions of 5x70 nm. Tribological testing of the product was provided. Sintered bushings impregnated with commercial oil and suspension of nanoparticles were tested in the spinning friction conditions in the couple with bearing steel at the load of 210 N and spinning rate of 200 rpm. The friction test in couple with steel exhibited the value of friction moment to be about 2 times less as compared with commercial oil. The additions of tungsten disulphide nanoparticles also significantly decrease oscillations the friction torque.

  10. Distribution of toenail selenium levels in young adult Caucasians and African Americans in the United States: The CARDIA Trace Element Study

    Energy Technology Data Exchange (ETDEWEB)

    Xun, Pengcheng; Bujnowski, Deborah [Department of Nutrition, Gillings School of Global Public Health and School of Medicine, University of North Carolina at Chapel Hill, 2221 McGavran-Greenberg, Campus Box: 7461, Chapel Hill, NC (United States); Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States); Liu, Kiang [Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL (United States); Steve Morris, J. [Research Reactor Center, University of Missouri-Columbia, Columbia, MO (United States); Guo, Zhongqin [Department of Epidemiology and Biostatistics, School of Public Health, Ningxia Medical University, Ningxia (China); Department of Nutrition, Gillings School of Global Public Health and School of Medicine, University of North Carolina at Chapel Hill, 2221 McGavran-Greenberg, Campus Box: 7461, Chapel Hill, NC (United States); He, Ka, E-mail: kahe@unc.edu [Department of Nutrition, Gillings School of Global Public Health and School of Medicine, University of North Carolina at Chapel Hill, 2221 McGavran-Greenberg, Campus Box: 7461, Chapel Hill, NC (United States); Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States)

    2011-05-15

    Background: Data on selenium (Se) levels in American young adults, especially in African Americans, are lacking. Objective: This study presented toenail Se distributions in American young adults of both genders, including both Caucasians and African Americans; and explored potential predictors of toenail Se levels. Data and methods: Data from the Coronary Artery Risk Development in Young Adults study among 4252 American young adults, aged 20-32 in 1987 was used to examine toenail Se levels by instrumental neutron-activation analysis. The distribution of Se levels was described and multivariable linear regression was used to examine potential modifiers of toenail Se concentration within ethnicity-gender subgroups. Results: The geometric mean of toenail Se in this cohort was 0.844 {mu}g/g (95% CI, 0.840-0.849 {mu}g/g) and the median was 0.837 {mu}g/g (95% CI, 0.833-0.844 {mu}g/g). Median levels from lowest to highest quintile were 0.691, 0.774, 0.838, 0.913 and 1.037 {mu}g/g. Se levels varied geographically, and were generally in accordance with its concentrations in local soil. Males, African Americans, current smokers, heavy drinkers and less educated participants were more likely to have low Se levels. Conclusion: This study suggests that toenail Se levels vary geographically depending on soil Se concentrations. In addition to gender, ethnicity and education level, smoking status and alcohol consumption are two important indicators of Se status since they are modifiable lifestyle factors. Findings from this study might aid public health professionals in identifying people at relatively high or low Se levels, so that chronic disease prevention efforts can be directed toward these subgroups. - Research highlights: {yields} Average of toenail Se levels in this cohort was 0.844 {mu}g/g (95% CI, 0.840-0.849 {mu}g/g). {yields} Toenail Se levels vary geographically depending on soil Se concentrations. {yields} Males, African Americans and less educated participants have

  11. Selenium in Cattle: A Review

    Directory of Open Access Journals (Sweden)

    Youcef Mehdi

    2016-04-01

    Full Text Available This review article examines the role of selenium (Se and the effects of Se supplementation especially in the bovine species. Selenium is an important trace element in cattle. Some of its roles include the participation in the antioxidant defense the cattle farms. The nutritional requirements of Se in cattle are estimated at 100 μg/kg DM (dry matter for beef cattle and at 300 μg/kg DM for dairy cows. The rations high in fermentable carbohydrates, nitrates, sulfates, calcium or hydrogen cyanide negatively influence the organism’s use of the selenium contained in the diet. The Se supplementation may reduce the incidence of metritis and ovarian cysts during the postpartum period. The increase in fertility when adding Se is attributed to the reduction of the embryonic death during the first month of gestation. A use of organic Se in feed would provide a better transfer of Se in calves relative to mineral Se supplementation. The addition of Se yeasts in the foodstuffs of cows significantly increases the Se content and the percentage of polyunsaturated fatty acids (PUFA in milk compared to the addition of sodium selenite. The enzyme 5-iodothyronine deiodinase is a seleno-dependent selenoprotein. It is one of the last proteins to be affected in the event of Se deficiency. This delay in response could explain the fact that several studies did not show the effect of Se supplementation on growth and weight gain of calves. Enrichment of Se in the diet did not significantly affect the slaughter weight and carcass yield of bulls. The impact and results of Se supplementation in cattle depend on physiological stage, Se status of animals, type and content of Se and types of Se administration. Further studies in Se supplementation should investigate the speciation of Se in food and yeasts, as well as understanding their metabolism and absorption. This constitute a path to exploit in order to explain certain different effects of Se.

  12. Selenium in Cattle: A Review.

    Science.gov (United States)

    Mehdi, Youcef; Dufrasne, Isabelle

    2016-04-23

    This review article examines the role of selenium (Se) and the effects of Se supplementation especially in the bovine species. Selenium is an important trace element in cattle. Some of its roles include the participation in the antioxidant defense the cattle farms. The nutritional requirements of Se in cattle are estimated at 100 μg/kg DM (dry matter) for beef cattle and at 300 μg/kg DM for dairy cows. The rations high in fermentable carbohydrates, nitrates, sulfates, calcium or hydrogen cyanide negatively influence the organism's use of the selenium contained in the diet. The Se supplementation may reduce the incidence of metritis and ovarian cysts during the postpartum period. The increase in fertility when adding Se is attributed to the reduction of the embryonic death during the first month of gestation. A use of organic Se in feed would provide a better transfer of Se in calves relative to mineral Se supplementation. The addition of Se yeasts in the foodstuffs of cows significantly increases the Se content and the percentage of polyunsaturated fatty acids (PUFA) in milk compared to the addition of sodium selenite. The enzyme 5-iodothyronine deiodinase is a seleno-dependent selenoprotein. It is one of the last proteins to be affected in the event of Se deficiency. This delay in response could explain the fact that several studies did not show the effect of Se supplementation on growth and weight gain of calves. Enrichment of Se in the diet did not significantly affect the slaughter weight and carcass yield of bulls. The impact and results of Se supplementation in cattle depend on physiological stage, Se status of animals, type and content of Se and types of Se administration. Further studies in Se supplementation should investigate the speciation of Se in food and yeasts, as well as understanding their metabolism and absorption. This constitute a path to exploit in order to explain certain different effects of Se.

  13. Aquatic Life Criterion - Selenium Documents

    Science.gov (United States)

    Documents pertaining to the 2016 Acute and Chronic Ambient Aquatic Life Water Quality Criteria for Selenium (Freshwater). These documents include what the safe levels of Selenium are in water for the majority of species.

  14. Genome-Wide Association Study of Serum Selenium Concentrations

    Directory of Open Access Journals (Sweden)

    Ulrike Peters

    2013-05-01

    Full Text Available Selenium is an essential trace element and circulating selenium concentrations have been associated with a wide range of diseases. Candidate gene studies suggest that circulating selenium concentrations may be impacted by genetic variation; however, no study has comprehensively investigated this hypothesis. Therefore, we conducted a two-stage genome-wide association study to identify genetic variants associated with serum selenium concentrations in 1203 European descents from two cohorts: the Prostate, Lung, Colorectal, and Ovarian (PLCO Cancer Screening and the Women’s Health Initiative (WHI. We tested association between 2,474,333 single nucleotide polymorphisms (SNPs and serum selenium concentrations using linear regression models. In the first stage (PLCO 41 SNPs clustered in 15 regions had p < 1 × 10−5. None of these 41 SNPs reached the significant threshold (p = 0.05/15 regions = 0.003 in the second stage (WHI. Three SNPs had p < 0.05 in the second stage (rs1395479 and rs1506807 in 4q34.3/AGA-NEIL3; and rs891684 in 17q24.3/SLC39A11 and had p between 2.62 × 10−7 and 4.04 × 10−7 in the combined analysis (PLCO + WHI. Additional studies are needed to replicate these findings. Identification of genetic variation that impacts selenium concentrations may contribute to a better understanding of which genes regulate circulating selenium concentrations.

  15. Biomarkers of Selenium Status

    Directory of Open Access Journals (Sweden)

    Gerald F. Combs, Jr.

    2015-03-01

    Full Text Available The essential trace element, selenium (Se, has multiple biological activities, which depend on the level of Se intake. Relatively low Se intakes determine the expression of selenoenzymes in which it serves as an essential constituent. Higher intakes have been shown to have anti-tumorigenic potential; and very high Se intakes can produce adverse effects. This hierarchy of biological activities calls for biomarkers informative at different levels of Se exposure. Some Se-biomarkers, such as the selenoproteins and particularly GPX3 and SEPP1, provide information about function directly and are of value in identifying nutritional Se deficiency and tracking responses of deficient individuals to Se-treatment. They are useful under conditions of Se intake within the range of regulated selenoprotein expression, e.g., for humans <55 μg/day and for animals <20 μg/kg diet. Other Se-biomarkers provide information indirectly through inferences based on Se levels of foods, tissues, urine or feces. They can indicate the likelihood of deficiency or adverse effects, but they do not provide direct evidence of either condition. Their value is in providing information about Se status over a wide range of Se intake, particularly from food forms. There is need for additional Se biomarkers particularly for assessing Se status in non-deficient individuals for whom the prospects of cancer risk reduction and adverse effects risk are the primary health considerations. This would include determining whether supranutritional intakes of Se may be required for maximal selenoprotein expression in immune surveillance cells. It would also include developing methods to determine low molecular weight Se-metabolites, i.e., selenoamino acids and methylated Se-metabolites, which to date have not been detectable in biological specimens. Recent analytical advances using tandem liquid chromatography-mass spectrometry suggest prospects for detecting these metabolites.

  16. Nanosized Selenium: A Novel Platform Technology to Prevent Bacterial Infections

    Science.gov (United States)

    Wang, Qi

    As an important category of bacterial infections, healthcare-associated infections (HAIs) are considered an increasing threat to the safety and health of patients worldwide. HAIs lead to extended hospital stays, contribute to increased medical costs, and are a significant cause of morbidity and mortality. In the United States, infections encountered in the hospital or a health care facility affect more than 1.7 million patients, cost 35.7 billion to 45 billion, and contribute to 88,000 deaths in hospitals annually. The most conventional and widely accepted method to fight against bacterial infections is using antibiotics. However, because of the widespread and sometimes inappropriate use of antibiotics, many strains of bacteria have rapidly developed antibiotic resistance. Those new, stronger bacteria pose serious, worldwide threats to public health and welfare. In 2014, the World Health Organization (WHO) reported antibiotic resistance as a global serious threat that is no longer a prediction for the future but is now reality. It has the potential to affect anyone, of any age, in any country. The most effective strategy to prevent antibiotic resistance is minimizing the use of antibiotics. In recent years, nanomaterials have been investigated as one of the potential substitutes of antibiotics. As a result of their vastly increased ratio of surface area to volume, nanomaterials will likely exert a stronger interaction with bacteria which may affect bacterial growth and propagation. A major concern of most existing antibacterial nanomaterials, like silver nanoparticles, is their potential toxicity. But selenium is a non-metallic material and a required nutrition for the human body, which is recommended by the FDA at a 53 to 60 μg daily intake. Nanosized selenium is considered to be healthier and less toxic compared with many metal-based nanomaterials due to the generation of reactive oxygen species from metals, especially heavy metals. Therefore, the objectives of

  17. Optimising Selenium for Modulation of Cancer Treatments.

    Science.gov (United States)

    Evans, Stephen Owen; Khairuddin, Puteri Farisa; Jameson, Michael B

    2017-12-01

    Selenium is an essential trace element involved in many biological processes that are mediated through, at least, 25 selenoproteins expressed in humans. Extensive study of selenium compounds has demonstrated growth inhibition of malignant cells in a vast array of experimental models. Moreover combining selenium with conventional cancer therapy has yielded promising results in both preclinical studies and a cohort of human trials. The aim of this review is to highlight the current research evaluating the role of selenium compounds in combination with chemotherapy and radiation. Pharmacodymanic mechanisms responsible for the differential effects of the commonly studied compounds on healthy and malignant cells are presented and the pertinent in vitro and in vivo data summarised. The clinical utility of this approach is discussed both in terms of anti-tumour efficacy and toxicity prevention. Finally a case is made for novel trial designs to facilitate rapid progression into pivotal studies. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  18. Selenium and redox signaling.

    Science.gov (United States)

    Brigelius-Flohé, Regina; Flohé, Leopold

    2017-03-01

    Selenium compounds that contain selenol functions or can be metabolized to selenols are toxic via superoxide and H2O2 generation, when ingested at dosages beyond requirement. At supra-nutritional dosages various forms of programmed cell death are observed. At physiological intakes, selenium exerts its function as constituent of selenoproteins, which overwhelmingly are oxidoreductases. Out of those, the glutathione peroxidases counteract hydroperoxide-stimulated signaling cascades comprising inflammation triggered by cytokines or lipid mediators, insulin signaling and different forms of programmed cell death. Similar events are exerted by peroxiredoxins, which functionally depend on the selenoproteins of the thioredoxin reductase family. The thiol peroxidases of both families can, however, also act as sensors for hydroperoxides, thereby initiating signaling cascades. Although the interaction of selenoproteins with signaling events has been established by genetic techniques, the in vivo relevance of these findings is still hard to delineate for several reasons: The biosynthesis of individual selenoproteins responds differently to variations of selenium intakes; selenium is preferentially delivered to privileged tissues via inter-organ trafficking and receptor-mediated uptake, and only half of the selenoproteins known by sequence have been functionally characterized. The fragmentary insights do not allow any uncritical use of selenium for optimizing human health. Copyright © 2016. Published by Elsevier Inc.

  19. Selenium and cancer: biomarkers of selenium status and molecular action of selenium supplements.

    OpenAIRE

    Gromadzinska, Jolanta; Reszka, Edyta; Bruzelius, Katharina; Wasowicz, Wojciech; Akesson, Bjorn

    2008-01-01

    BACKGROUND: The relationship between selenium and cancer involves many different aspects. These include the forms of selenium present in the diet and in the body, their functions and mechanisms of action, and methods employed in assessing an individual's selenium nutritional status-both in general, and in epidemiological studies of the risk of cancer in relation to diet, as well as in connection with long-term trials for investigating the disease-preventive potential of selenium supplementati...

  20. Establishing the Structural Integrity of Core-Shell Nanoparticles against Elemental Migration using Luminescent Lanthanide Probes.

    Science.gov (United States)

    Chen, Bing; Peng, Dengfeng; Chen, Xian; Qiao, Xvsheng; Fan, Xianping; Wang, Feng

    2015-10-19

    Core-shell structured nanoparticles are increasingly used to host luminescent lanthanide ions but the structural integrity of these nanoparticles still lacks sufficient understanding. Herein, we present a new approach to detect the diffusion of dopant ions in core-shell nanostructures using luminescent lanthanide probes whose emission profile and luminescence lifetime are sensitive to the chemical environment. We show that dopant ions in solution-synthesized core-shell nanoparticles are firmly confined in the designed locations. However, annealing at certain temperatures (greater than circa 350 °C) promotes diffusion of the dopant ions and leads to degradation of the integrity of the nanoparticles. These insights into core-shell nanostructures should enhance our ability to understand and use lanthanide-doped luminescent nanoparticles. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Selenium for preventing cancer

    Science.gov (United States)

    Vinceti, Marco; Dennert, Gabriele; Crespi, Catherine M; Zwahlen, Marcel; Brinkman, Maree; Zeegers, Maurice PA; Horneber, Markus; D'Amico, Roberto; Del Giovane, Cinzia

    2015-01-01

    Background This review is an update of the first Cochrane publication on selenium for preventing cancer (Dennert 2011). Selenium is a metalloid with both nutritional and toxicological properties. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancers. Objectives Two research questions were addressed in this review: What is the evidence for: an aetiological relation between selenium exposure and cancer risk in humans? andthe efficacy of selenium supplementation for cancer prevention in humans? Search methods We conducted electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL, 2013, Issue 1), MEDLINE (Ovid, 1966 to February 2013 week 1), EMBASE (1980 to 2013 week 6), CancerLit (February 2004) and CCMed (February 2011). As MEDLINE now includes the journals indexed in CancerLit, no further searches were conducted in this database after 2004. Selection criteria We included prospective observational studies (cohort studies including sub-cohort controlled studies and nested case-control studies) and randomised controlled trials (RCTs) with healthy adult participants (18 years of age and older). Data collection and analysis For observational studies, we conducted random effects meta-analyses when five or more studies were retrieved for a specific outcome. For RCTs, we performed random effects meta-analyses when two or more studies were available. The risk of bias in observational studies was assessed using forms adapted from the Newcastle-Ottawa Quality Assessment Scale for cohort and case-control studies; the criteria specified in the Cochrane Handbook for Systematic Reviews of Interventions were used to evaluate the risk of bias in RCTs. Main results We included 55 prospective observational studies (including more than 1,100,000 participants) and eight RCTs (with a total of 44,743 participants). For the observational studies, we found lower cancer incidence (summary odds ratio (OR) 0

  2. Selenium Metabolism in Cancer Cells: The Combined Application of XAS and XFM Techniques to the Problem of Selenium Speciation in Biological Systems

    Directory of Open Access Journals (Sweden)

    Hugh H. Harris

    2013-05-01

    Full Text Available Determining the speciation of selenium in vivo is crucial to understanding the biological activity of this essential element, which is a popular dietary supplement due to its anti-cancer properties. Hyphenated techniques that combine separation and detection methods are traditionally and effectively used in selenium speciation analysis, but require extensive sample preparation that may affect speciation. Synchrotron-based X-ray absorption and fluorescence techniques offer an alternative approach to selenium speciation analysis that requires minimal sample preparation. We present a brief summary of some key HPLC-ICP-MS and ESI-MS/MS studies of the speciation of selenium in cells and rat tissues. We review the results of a top-down approach to selenium speciation in human lung cancer cells that aims to link the speciation and distribution of selenium to its biological activity using a combination of X-ray absorption spectroscopy (XAS and X-ray fluorescence microscopy (XFM. The results of this approach highlight the distinct fates of selenomethionine, methylselenocysteine and selenite in terms of their speciation and distribution within cells: organic selenium metabolites were widely distributed throughout the cells, whereas inorganic selenium metabolites were compartmentalized and associated with copper. New data from the XFM mapping of electrophoretically-separated cell lysates show the distribution of selenium in the proteins of selenomethionine-treated cells. Future applications of this top-down approach are discussed.

  3. Current Knowledge on the Importance of Selenium in Food for Living Organisms: A Review.

    Science.gov (United States)

    Kieliszek, Marek; Błażejak, Stanisław

    2016-05-10

    Selenium is one of the elements classified within the group of micronutrients which are necessary in trace amounts for the proper functioning of organisms. Selenium participates in the protection of cells against excess H₂O₂, in heavy metal detoxification, and regulation of the immune and reproductive systems as well. It also ensures the proper functioning of the thyroid gland. Selenium induces the occurrence of the selenoprotein synthesis process involved in the antioxidant defense mechanism of the organism. Recent years have brought much success in the studies on selenium. Anticarcinogenic properties of selenium against some cancers have been reported. Supplementation is increasingly becoming a solution to this problem. A large number of different supplementation methods are promoting studies in this area. Slight differences in the selenium content can result in excess or deficiency, therefore supplementation has to be done carefully and cautiously.

  4. Current Knowledge on the Importance of Selenium in Food for Living Organisms: A Review

    Directory of Open Access Journals (Sweden)

    Marek Kieliszek

    2016-05-01

    Full Text Available Selenium is one of the elements classified within the group of micronutrients which are necessary in trace amounts for the proper functioning of organisms. Selenium participates in the protection of cells against excess H2O2, in heavy metal detoxification, and regulation of the immune and reproductive systems as well. It also ensures the proper functioning of the thyroid gland. Selenium induces the occurrence of the selenoprotein synthesis process involved in the antioxidant defense mechanism of the organism. Recent years have brought much success in the studies on selenium. Anticarcinogenic properties of selenium against some cancers have been reported. Supplementation is increasingly becoming a solution to this problem. A large number of different supplementation methods are promoting studies in this area. Slight differences in the selenium content can result in excess or deficiency, therefore supplementation has to be done carefully and cautiously.

  5. Selenium Supplementation Does Not Improve Vascular Responsiveness in Healthy North American Men

    Science.gov (United States)

    Selenium is an essential trace element that is an integral part of many selenoproteins, such as glutathione peroxidase and thioredoxin reductase, which may be important in inflammation and cardiovascular disease. In animal studies, selenium deficiency is associated with cardiomyopathy and sudden dea...

  6. Selenium in human mammary carcinogenesis

    DEFF Research Database (Denmark)

    Overvad, Kim; Grøn, P.; Langhoff, Otto

    1991-01-01

    In a case-referent study on the possible role of selenium in human mammary carcinogenesis, serum selenium was found to be 79 +/- 12 micrograms/l in 66 cases and 81 +/- 12 micrograms/l in 93 referents. An internal trend in serum selenium was observed among cases (TNM stage I 81 +/- 11 micrograms....../l and TNM stage II 76 +/- 13 micrograms selenium/l), indicating disease-mediated changes. The evaluation of selenium as a risk indicator in human breast cancer was therefore restricted to TNM stage I patients (n = 36). Multiple logistic regression analyses including variables associated with selenium levels...... revealed no association between selenium levels and breast cancer risk....

  7. [Selenium content in human in Sakha Republic].

    Science.gov (United States)

    Golubkina, N A; Senkevich, O A; Kekina, E G

    2009-01-01

    Sakha Republic is considered to be endemic selenium deficient and poorly investigated region. Analysis of selenium in human sera, hair and nails revealed strongly decreased values. Low selenium concentrations were registered also in meat of domestic animals, fresh-water fish, mushrooms weight, agaricus campester. The possibility of the human selenium content improvement is discussed via import of grain with high selenium concentration.

  8. Dietary Selenium and Human Health

    Directory of Open Access Journals (Sweden)

    Lutz Schomburg

    2016-12-01

    Full Text Available Next year (2017, the micronutrient Selenium (Se is celebrating its birthday—i.e., 200 years after first being identified by the Swedish chemist Jöns Jakob Berzelius. Despite its impressive age, research into the functions of this essential trace element is very alive and reaching out for new horizons. This special issue presents some recent fascinating, exciting, and promising developments in Se research in the form of eight original contributions and seven review articles. Collectively, aspects of Se supply, biochemical, physiological, and chemotherapeutic effects, and geobiological interactions are covered by leading scientists in the areas of nutritional, basic, and clinical research. It is obvious from the contributions that the bicentennial anniversary will celebrate a micronutrient still in its infancy with respect to being understood in terms of its biomedical importance.

  9. Dietary Selenium and Human Health.

    Science.gov (United States)

    Schomburg, Lutz

    2016-12-30

    Next year (2017), the micronutrient Selenium (Se) is celebrating its birthday-i.e., 200 years after first being identified by the Swedish chemist Jöns Jakob Berzelius. Despite its impressive age, research into the functions of this essential trace element is very alive and reaching out for new horizons. This special issue presents some recent fascinating, exciting, and promising developments in Se research in the form of eight original contributions and seven review articles. Collectively, aspects of Se supply, biochemical, physiological, and chemotherapeutic effects, and geobiological interactions are covered by leading scientists in the areas of nutritional, basic, and clinical research. It is obvious from the contributions that the bicentennial anniversary will celebrate a micronutrient still in its infancy with respect to being understood in terms of its biomedical importance.

  10. Influence of selenium amount on the structural and electronic properties of Cu(In,Ga)Se{sub 2} thin films and solar cells formed by the stacked elemental layer process

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, B.J., E-mail: bjm.mueller@web.de [Institute of Micro- and Nanomaterials, University of Ulm, D-89081 Ulm (Germany); Corporate Research, Robert Bosch GmbH, D-71272 Renningen (Germany); Opasanont, B.; Haug, V. [Corporate Research, Robert Bosch GmbH, D-71272 Renningen (Germany); Hergert, F. [Bosch Solar CISTech GmbH, D-14772 Brandenburg (Germany); Zweigart, S. [Corporate Research, Robert Bosch GmbH, D-71272 Renningen (Germany); Herr, U., E-mail: ulrich.herr@uni-ulm.de [Institute of Micro- and Nanomaterials, University of Ulm, D-89081 Ulm (Germany)

    2016-06-01

    In the following article the influence of selenium supply on the stacked elemental layer process during the final annealing step is investigated. We find that the Se supply strongly influences the phase formation in the Cu(In,Ga)Se {sub 2} resulting in a modified Ga/In distribution. The effects of Se supply on the structural and electronic properties of the films are reported. The solar cell performance has been investigated in detail using current voltage and external quantum efficiency measurements. We find that the chalcopyrite crystal formation is strongly influenced by the Se supply during the growth process. Furthermore the interdiffusion of Ga and In is accelerated with increasing Se amount. This has direct consequences on band gap and series resistance, which leads to changes in the values of short-circuit current density, open-circuit voltage and fill factor. The open-circuit voltage increases with increasing band gap of the Cu(In,Ga)Se {sub 2}, whereas the short-circuit current density decreases with increasing band gap. The fill factor is affected by the formation of MoSe {sub 2} at the back contact. The experimental findings are compared with the theoretical efficiency limits calculated from the Shockley–Queisser model, and also with numerical 1D SCAPS simulations. - Highlights: • Adjustment of the Ga/In distribution by the Se supply • Enhanced Ga incorporation near-surface • Interdiffusion coefficients of Ga/In are investigated. • Shockley–Queisser modeling and 1D SCAPS simulations • Fill factor is strongly coupled on the MoSe2/Mo ratio.

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

    Directory of Open Access Journals (Sweden)

    Azadeh SAFFARYAZDI

    2012-11-01

    Full Text Available 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 shoot and root fresh weight, shoot and root dry weight, total dry weight, shoot and root length increased by 17, 15, 38, 19, 18 and 34 percent in response to the lowest concentration of Se (1 mg L-1, respectively over control. However, application of higher Se concentrations reduced these parameters as compared to control. Selenium up to 1 mg L-1 enhanced the levels of chlorophyll a and chlorophyll b by 87 and 165 percent, respectively, while higher levels of Se exert toxic effects. Total phenolic compounds in leaves increased directly by increasing the level of Se and plants treated with 10 mg. L-1 Se had the highest values. Selenium, sodium and calcium content increased, while potassium content decreased, by increasing selenium treatments. The highest amounts of Se in shoots (3.89 mg g-1 DW and roots (4.27 mg g-1 DW were obtained for the highest concentration of Se (10 mg L-1. The present results suggested the beneficial effects of Se on spinach growth and also its contribute ion to improving the nutritional value of spinach for livestock and human nutrition.

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

    Directory of Open Access Journals (Sweden)

    Azadeh SAFFARYAZDI

    2012-11-01

    Full Text Available 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 shoot and root fresh weight, shoot and root dry weight, total dry weight, shoot and root length increased by 17, 15, 38, 19, 18 and 34 percent in response to the lowest concentration of Se (1 mg L-1, respectively over control. However, application of higher Se concentrations reduced these parameters as compared to control. Selenium up to 1 mg L-1 enhanced the levels of chlorophyll a and chlorophyll b by 87 and 165 percent, respectively, while higher levels of Se exert toxic effects. Total phenolic compounds in leaves increased directly by increasing the level of Se and plants treated with 10 mg. L-1 Se had the highest values. Selenium, sodium and calcium content increased, while potassium content decreased, by increasing selenium treatments. The highest amounts of Se in shoots (3.89 mg g-1 DW and roots (4.27 mg g-1 DW were obtained for the highest concentration of Se (10 mg L-1. The present results suggested the beneficial effects of Se on spinach growth and also its contribute ion to improving the nutritional value of spinach for livestock and human nutrition.

  13. Elemental Composition of Natural Nanoparticles and Fine Colloids in European Forest Stream Waters and Their Role as Phosphorus Carriers

    Science.gov (United States)

    Gottselig, N.; Amelung, W.; Kirchner, J. W.; Bol, R.; Eugster, W.; Granger, S. J.; Hernández-Crespo, C.; Herrmann, F.; Keizer, J. J.; Korkiakoski, M.; Laudon, H.; Lehner, I.; Löfgren, S.; Lohila, A.; Macleod, C. J. A.; Mölder, M.; Müller, C.; Nasta, P.; Nischwitz, V.; Paul-Limoges, E.; Pierret, M. C.; Pilegaard, K.; Romano, N.; Sebastià, M. T.; Stähli, M.; Voltz, M.; Vereecken, H.; Siemens, J.; Klumpp, E.

    2017-10-01

    Biogeochemical cycling of elements largely occurs in dissolved state, but many elements may also be bound to natural nanoparticles (NNP, 1-100 nm) and fine colloids (100-450 nm). We examined the hypothesis that the size and composition of stream water NNP and colloids vary systematically across Europe. To test this hypothesis, 96 stream water samples were simultaneously collected in 26 forested headwater catchments along two transects across Europe. Three size fractions ( 1-20 nm, >20-60 nm, and >60 nm) of NNP and fine colloids were identified with Field Flow Fractionation coupled to inductively coupled plasma mass spectrometry and an organic carbon detector. The results showed that NNP and fine colloids constituted between 2 ± 5% (Si) and 53 ± 21% (Fe; mean ± SD) of total element concentrations, indicating a substantial contribution of particles to element transport in these European streams, especially for P and Fe. The particulate contents of Fe, Al, and organic C were correlated to their total element concentrations, but those of particulate Si, Mn, P, and Ca were not. The fine colloidal fractions >60 nm were dominated by clay minerals across all sites. The resulting element patterns of NNP <60 nm changed from North to South Europe from Fe- to Ca-dominated particles, along with associated changes in acidity, forest type, and dominant lithology.

  14. Synthetic Smectite Colloids: Characterization of Nanoparticles after Co-Precipitation in the Presence of Lanthanides and Tetravalent Elements (Zr, Th

    Directory of Open Access Journals (Sweden)

    Muriel Bouby

    2015-09-01

    Full Text Available The magnesian smectite hectorite is a corrosion product frequently detected in nuclear waste glass alteration experiments. The structural incorporation of a single trivalent lanthanide was previously demonstrated. Hectorite was presently synthesized, for the first time, in the presence of several lanthanides (La, Eu, Yb following a multi-step synthesis protocol. The smallest-sized particles (nanoparticles, NPs were isolated by centrifugation and analyzed by asymmetrical flow field-flow fractionation (AsFlFFF coupled to ICP-MS, in order to obtain information on the elemental composition and distribution as a function of the size. Nanoparticles can be separated from the bulk smectite phase. The particles are able to accommodate even the larger-sized lanthanides such as La, however, with lower efficiency. We, therefore, assume that the incorporation proceeds by substitution for octahedral Mg accompanied by a concomitant lattice strain that increases with the size of the lanthanides. The presence of a mixture does not seem to affect the incorporation extent of any specific element. Furthermore, syntheses were performed where in addition the tetravalent zirconium or thorium elements were admixed, as this oxidation state may prevail for many actinide ions in a nuclear waste repository. The results show that they can be incorporated as well.

  15. 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...

  16. 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.

  17. Selenium biochemistry and its role for human health.

    Science.gov (United States)

    Roman, Marco; Jitaru, Petru; Barbante, Carlo

    2014-01-01

    Despite its very low level in humans, selenium plays an important and unique role among the (semi)metal trace essential elements because it is the only one for which incorporation into proteins is genetically encoded, as the constitutive part of the 21st amino acid, selenocysteine. Twenty-five selenoproteins have been identified so far in the human proteome. The biological functions of some of them are still unknown, whereas for others there is evidence for a role in antioxidant defence, redox state regulation and a wide variety of specific metabolic pathways. In relation to these functions, the selenoproteins emerged in recent years as possible biomarkers of several diseases such as diabetes and several forms of cancer. Comprehension of the selenium biochemical pathways under normal physiological conditions is therefore an important requisite to elucidate its preventing/therapeutic effect for human diseases. This review summarizes the most recent findings on the biochemistry of active selenium species in humans, and addresses the latest evidence on the link between selenium intake, selenoproteins functionality and beneficial health effects. Primary emphasis is given to the interpretation of biochemical mechanisms rather than epidemiological/observational data. In this context, the review includes the following sections: (1) brief introduction; (2) general nutritional aspects of selenium; (3) global view of selenium metabolic routes; (4) detailed characterization of all human selenoproteins; (5) detailed discussion of the relation between selenoproteins and a variety of human diseases.

  18. Optimization of LC-DRC-ICP-MS for the speciation of selenotrisulfides with simultaneous detection of sulfur and selenium as oxides combined with determination of elemental and isotope ratios

    DEFF Research Database (Denmark)

    Sturup, S.; Bendahl, L.; Gammelgaard, B.

    2006-01-01

    . The selenotrisulfides were separated applying a 30 rnin gradient liquid chromatographic (LC) method with a formic acid/methanol eluent. The detection limits for sulfur (as (SO+)-S-32-O-16) and selenium (as (SeO+)-Se-80-O-16) in the chromatographic system were 4.0 and 0.2 mu g L-1 (100 and 5 ng in absolute mass units......A LC-DRC-ICP-MS method for the simultaneous detection of selenium and Sulfur in the selenotrisulfides selenocysteineglutathione (Cys-Se-SG) and selenodiglutathione (GS-Se-SG) is described. Both sulfur and selenium are reacted with oxygen in the dynamic reaction cell (DRC) and detected as oxides...

  19. 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.

  20. In vivo synthesis of nano-selenium by Tetrahymena thermophila SB210.

    Science.gov (United States)

    Cui, Yin-Hua; Li, Ling-Li; Zhou, Nan-Qing; Liu, Jing-Hua; Huang, Qing; Wang, Hui-Juan; Tian, Jie; Yu, Han-Qing

    2016-12-01

    Nano-selenium has a great potential to be used in chemical, biological, medical and environmental fields. Biological methods for nano-selenium synthesis have attracted wide interests, because they can be operated at ambient temperature and pressure without complicated equipments. In this work, a protozoa, Tetrahymena thermophila (T. thermophila) SB210, was used to in vivo synthesize nano-selenium. The biosynthesized nano-selenium was characterized using transmission electron microscopy, energy dispersive X-ray spectroscopy and Raman spectroscopy. The synthesized amorphous spherical selenium nanoparticles had diameters of 50-500nm with the coexistence of irregular nano-selenium. The expressions of glutathione (GSH) synthesis related gene glutathione synthase, cysteine-rich protein metallothionein related gene metallothionein-1 and [2Fe-2S] cluster-binding protein related gene were up-regulated in the nano-selenium producing group. Also, the subsequent GSH detection and in vitro synthesis experimental results suggest the three proteins were likely to be involved in the nano-selenium synthesis process. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Selenium and ocular health in New Zealand.

    Science.gov (United States)

    Sheck, Leo; Davies, Jo; Wilson, Graham

    2010-06-11

    Selenium is an essential mineral and severe selenium deficiency is known to cause significant health problems. It has been well documented that New Zealand soil is low in selenium. Recent studies have addressed the roles of selenoproteins in the eyes, with evidence suggesting that selenium supplementation may have a role in preventing cataract formation and age-related maculopathy. This paper summarises the role of selenium in ocular and general health and discusses selenium supplementation in a New Zealand specific context.

  2. Monodisperse selenium-substituted hydroxyapatite: Controllable synthesis and biocompatibility.

    Science.gov (United States)

    Sun, Jianpeng; Zheng, Xiaoyan; Li, Hui; Fan, Daidi; Song, Zhanping; Ma, Haixia; Hua, Xiufu; Hui, Junfeng

    2017-04-01

    Hydroxyapatite (HA) is the major inorganic component of natural bone tissue. As an essential trace element, selenium involves in antioxidation and anticancer of human body. So far, ion-doped hydroxyapatites (HAs) are widely investigated owing to their great applications in field of biomaterial, biological labeling. In this paper, series of monodisperse HA doped with SeO32- (SeHA) was successfully synthesized based on the liquid-solid-solution (LSS) strategy. The obtained samples were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and energy-dispersive spectrometer (EDS). The results indicated that the SeO32- doping level of the Se/(P+Se) molar ratio of 0-0.4 can be requisitely controlled, and the morphology of SeHA nanoparticles varied from nanorods to nanoneedles with increasing Se/(P+Se) molar ratio. Significantly, the as-synthesized SeHA nanocrystals exhibit a low cytotoxicity for osteoblastic cells, showing exciting potentials for application in artificial scaffold materials inhibiting of tumor growth in bone. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Interaction between nanoparticles generated by zinc chloride treatment and oxidative responses in rat liver.

    Science.gov (United States)

    Azzouz, Inès; Trabelsi, Hamdi; Hanini, Amel; Ferchichi, Soumaya; Tebourbi, Olfa; Sakly, Mohsen; Abdelmelek, Hafedh

    2014-01-01

    The aim of the present study was to investigate the interaction of zinc chloride (3 mg/kg, intraperitoneally [ip]) in rat liver in terms of the biosynthesis of nanoparticles. Zinc treatment increased zinc content in rat liver. Analysis of fluorescence revealed the presence of red fluorescence in the liver following zinc treatment. Interestingly, the co-exposure to zinc (3 mg/kg, ip) and selenium (0.20 mg/L, per os [by mouth]) led to a higher intensity of red fluorescence compared to zinc-treated rats. In addition, X-ray diffraction measurements carried out on liver fractions of zinc-treated rats point to the biosynthesis of zinc sulfide and/or selenide nanocomplexes at nearly 51.60 nm in size. Moreover, co-exposure led to nanocomplexes of about 72.60 nm in size. The interaction of zinc with other mineral elements (S, Se) generates several nanocomplexes, such as ZnS and/or ZnSe. The nanocomplex ZnX could interact directly with enzyme activity or indirectly by the disruption of mineral elements' bioavailability in cells. Subacute zinc or selenium treatment decreased malondialdehyde levels, indicating a drop in lipid peroxidation. In addition, antioxidant enzyme assays showed that treatment with zinc or co-treatment with zinc and selenium increased the activities of glutathione peroxidase, catalase, and superoxide dismutase. Consequently, zinc complexation with sulfur and/or selenium at nanoscale level could enhance antioxidative responses, which is correlated to the ratio of number of ZnX nanoparticles (X=sulfur or X=selenium) to malondialdehyde level in rat liver.

  4. Synthesis and characterization of CdSe nanoparticles via thermal treatment technique

    Directory of Open Access Journals (Sweden)

    Aeshah Salem

    Full Text Available The synthesis of CdSe nanoparticles was undertaken via the thermal treatment method at varying calcination temperatures from 450 to 700 °C in alternate oxygen and nitrogen environment. Selenium powder was dissolved in ethylenediamine at 200 °C for 2 h before mixing with the metal precursor, cadmium nitrate and the capping agent polyvinylpyrrolidone to materialize the CdSe nanoparticles upon calcination. A series of measurements were employed to analyze the structural, elemental and optical properties of the attained nanoparticles at room temperatures using FTIR, XRD, EDX, SEM and TEM spectroscopies. XRD patterns and FTIR spectra revealed of the fact that, prior to calcination, an amorphous phase of the unheated material has taken shape, which after calcination achieved the crystalline structure of CdSe nanoparticles. The CdSe nanoparticle samples confirmed to be pure cadmium and selenium through EDX and FTIR analyses. The TEM images showed that as the calcination temperature raised from 450 to 700 °C the average particle size increased from 11 to 32 nm and the optical band gap energy decreased from 2.36 to 1.80 eV. Keywords: Cadmium selenide nanoparticles, Thermal treatment method, Structural and optical properties

  5. Comparison of selenium distribution in mice organs after the supplementation with inorganic and organic selenium compound selenosemicarbazide.

    Science.gov (United States)

    Musik, Irena; Kozioł-Montewka, Maria; Toś-Luty, Sabina; Donica, Helena; Pasternak, Kazimierz; Wawrzycki, Sławomir

    2002-01-01

    Studies on selenium organ content and its function in living organisms just like studies on other elements provide interesting results although their interpretation is not always clear. The aim of our study was to determine the concentration and distribution of selenium in several organs and tissues in mice after supplementation with our newly synthesized organic compound of selenium selenosemicarbazide (4-o-tolyl-selenosemicarbazide of o-chlorobenzoic acid) as compared to the effects of the supplementation with inorganic compounds. SWISS mice were fed with both types of compounds at the dose of 10(-3) g Se per kg for the period of 10 days. The concentrations of selenium in brains of mice treated with selenocarbazide and sodium selenite were higher than in controls (38.04 micrograms g-1 and 32.00 micrograms g-1 vs. 26.18 micrograms g-1). There was a statistically significant increase in the selenium contents in lungs after supplementation with selenosemicarbazide and sodium selenite (11.81 micrograms g-1 and 6.79 micrograms g-1 vs. 1.75 micrograms g-1 in controls). We found a statistically insignificant increase in selenium contents in intercostal muscles after supplementation with inorganic selenium compounds and a statistically significant increase after the supplementation with selenosemicarbazide (10.13 micrograms g-1; 14.21 micrograms g-1 and 28.84 micrograms g-1, respectively). Our investigations lead to a conclusion that 4-o-tolyl-seleno-semicarbazide of o-chlorobenzoic acid, an organic selenium compound may be more easily absorbed than inorganic sodium IV selenite.

  6. Dietary Selenium in Adjuvant Therapy of Viral and Bacterial Infections12

    Science.gov (United States)

    Steinbrenner, Holger; Al-Quraishy, Saleh; Dkhil, Mohamed A; Wunderlich, Frank; Sies, Helmut

    2015-01-01

    Viral and bacterial infections are often associated with deficiencies in macronutrients and micronutrients, including the essential trace element selenium. In selenium deficiency, benign strains of Coxsackie and influenza viruses can mutate to highly pathogenic strains. Dietary supplementation to provide adequate or supranutritional selenium supply has been proposed to confer health benefits for patients suffering from some viral diseases, most notably with respect to HIV and influenza A virus (IAV) infections. In addition, selenium-containing multimicronutrient supplements improved several clinical and lifestyle variables in patients coinfected with HIV and Mycobacterium tuberculosis. Selenium status may affect the function of cells of both adaptive and innate immunity. Supranutritional selenium promotes proliferation and favors differentiation of naive CD4-positive T lymphocytes toward T helper 1 cells, thus supporting the acute cellular immune response, whereas excessive activation of the immune system and ensuing host tissue damage are counteracted through directing macrophages toward the M2 phenotype. This review provides an up-to-date overview on selenium in infectious diseases caused by viruses (e.g., HIV, IAV, hepatitis C virus, poliovirus, West Nile virus) and bacteria (e.g., M. tuberculosis, Helicobacter pylori). Data from epidemiologic studies and intervention trials, with selenium alone or in combination with other micronutrients, and animal experiments are discussed against the background of dietary selenium requirements to alter immune functions. PMID:25593145

  7. Selenium dynamics in boreal streams: the role of wetlands and changing groundwater tables.

    Science.gov (United States)

    Lidman, Fredrik; Mörth, Carl-Magnus; Björkvald, Louise; Laudon, Hjalmar

    2011-04-01

    The concentrations of selenium in 10 catchments of a stream network in northern Sweden were monitored over two years, yielding almost 350 observations of selenium concentrations in streamwater. The export of selenium was found to be systematically greater from forests than from mires. Accounting for atmospheric deposition, which was monitored over four years, there was a net accumulation of selenium in mires, while the export from forest soils was approximately equal to the atmospheric deposition. In forest dominated catchments the concentrations of selenium oscillated rapidly back and forth from high to low levels during spring floods. High selenium concentrations coincided with rising groundwater tables in the riparian forest soils, while low selenium concentrations were associated with receding groundwater. Thermodynamic modeling indicated that precipitation of elemental selenium would occur under reducing conditions in the riparian soils. Since changes in the redox conditions are likely to occur near the transition from the unsaturated to the saturated zone, it is hypothesized that the transport of selenium from forest soils to streams is controlled by redox reactions in riparian soils.

  8. Optimised selenium enrichment of Artemia sp. feed to improve red drum (Sciaenops ocellatus) larvae rearing.

    Science.gov (United States)

    Juhász, Péter; Lengyel, Szvetlana; Udvari, Zsolt; Sándor, Alex Nagy; Stündl, László

    2017-09-01

    Selenium is an essential microelement for the normal functioning of life processes. Moreover, it is a component of enzymes with antioxidant effects. However, it has the smallest window of any micronutrient between requirement and toxicity. Selenium is a regularly used element in fish feeds; moreover, enriching zooplankton with selenium to rear larvae is also a well-known technology. It is accepted that the most common starter foods of fish larvae, natural rotifers contain the smallest dosage of selenium, but providing selenium enriched Artemia sp. instead could increase survival and growth rate of fish. However, no such references are available for the red drum (Sciaenops ocellatus) larvae. Therefore, in this study, Artemia sp. was enriched with nano-selenium of verified low toxicity and easy availability in 5 treatments (1, 5, 10, 50, 100 mg/l Se), and then, fish larvae were fed with four of these enriched Artemia stocks (1, 5, 10, 50 mg/l Se) and a control group. At the end of the 9-day-long experiment, survival rate (S) and growth parameters (SL, W, K-factor, SGR) of fish larvae were calculated as well as their selenium retention and glutathione peroxidase enzyme activity were analysed. It was revealed that a moderate level of selenium enrichment (~4 mg/kg dry matter) of Artemia sp. positively influences the rearing efficiency (i.e. survival and growth) of fish larvae, but higher dosages of selenium could cause adverse effects.

  9. Applied investigation on the interaction of hazardous elements binding on ultrafine and nanoparticles in Chinese anthracite-derived fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luis F.O., E-mail: lfsoliveira@univates.br [Centro Universitario Univates, Programa de Pos Graduacao Ambiente e Desenvolvimento, Rua Avelino Tallini, 171, Universitario, 95900-000 Lajeado, RS (Brazil); Environmental Science and Nanotechnology Department, Catarinense Institute of Environmental Research and Human Development - IPADHC, Capivari de Baixo, Santa Catarina (Brazil); Jasper, Andre [Centro Universitario Univates, Programa de Pos Graduacao Ambiente e Desenvolvimento, Rua Avelino Tallini, 171, Universitario, 95900-000 Lajeado, RS (Brazil); Andrade, Maria L. [Department of Plant Biology and Soil Science, University of Vigo, 36310 Vigo (Spain); Sampaio, Carlos H. [Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Goncalves, 9500, Bairro Agronomia, CEP: 91501-970, Porto Alegre, RS (Brazil); Dai, Shifeng; Li, Xiao; Li, Tian; Chen, Weimei; Wang, Xibo; Liu, Huidong; Zhao, Lixin [China University of Mining and Technology, Beijing (China); Hopps, Shelley G.; Jewell, Robert F. [University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (United States); Hower, James C., E-mail: james.hower@uky.edu [University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (United States)

    2012-03-01

    A multifaceted instrumental approach was employed to determine the chemistry and mineralogy of pulverized-coal-combustion fly ashes from two Chinese power plants. Techniques included traditional optical microscopy, X-ray diffraction, and chemical analysis along with a variety of electron beam methods. The aim is to demonstrate and bring together the wide variety of procedures dealing with F as the key element of concern, and determining its location in the mineral nanoparticles. The Hg content of the Anwen (Songzao coalfield) fly ashes is higher than that of the Diandong (East Yunnan) fly ashes, possibly owing to the greater C and Cl in the Anwen fly ashes. Both fly ash sources contain a variety of amorphous and nano-crystalline trace-element-bearing particles, both associated with multi-walled carbon nanotubes and as particles independent of carbons.

  10. Synthesis and characterization of MnS and MnSe nanoparticles: Morphology, optical and magnetic properties

    Science.gov (United States)

    Moloto, N.; Moloto, M. J.; Kalenga, M.; Govindraju, S.; Airo, M.

    2013-11-01

    Herein, we report on the synthesis of manganese chalcogenide nanoparticles using mild synthetic methods. The MnS nanoparticles were synthesised using a single-source precursor method with tetramethylthiuram disulfide as a ligand, whilst the MnSe nanoparticles were synthesised by reacting reduced elemental selenium with manganese. These synthetic methods resulted in crystalline MnS nanoparticles with wire-like morphology with high aspect ratio and MnSe nanorods that were nearly mono-dispersed. The absorption band-edges of both MnS and MnSe were blue-shifted from the reported bulk band-edges indicative of quantum confinement effects seen in nanoparticles. Furthermore, both MnS and MnSe showed paramagnetic characteristics with the ESR spectra showing broad single resonance peaks with g-values of 2.0064 and 2.0068 respectively.

  11. Selenium in food and health

    National Research Council Canada - National Science Library

    Reilly, Conor

    2006-01-01

    ...) to be a carcinogen and banned as an additive in food. Selenium is considered by some to be a serious hazard to the environment and to animal health. Selenium-contaminated water has brought deformity and death to wildlife in nature reserves in western USA. There is even concern that because of selenium contamination of soil, crops supplied to the great cities of California could become unfit for human consumption. In large areas of China, endemic selenium toxicity is a hazard for locals who depend on cr...

  12. The Association between Selenium and Other Micronutrients and Thyroid Cancer Incidence in the NIH-AARP Diet and Health Study

    OpenAIRE

    Thomas J O'Grady; Kitahara, Cari M.; A Gregory DiRienzo; Gates, Margaret A

    2014-01-01

    BACKGROUND: Selenium is an essential trace element that is important for thyroid hormone metabolism and has antioxidant properties which protect the thyroid gland from oxidative stress. The association of selenium, as well as intake of other micronutrients, with thyroid cancer is unclear. METHODS: We evaluated associations of dietary selenium, beta-carotene, calcium, vitamin D, vitamin C, vitamin E, folate, magnesium, and zinc intake with thyroid cancer risk in the National Institutes of Heal...

  13. [Assessment of efficiency of use of the developed supplement containing selenium on laboratory animals].

    Science.gov (United States)

    Bazhenova, B A; Aslaliev, A D; Danilov, M B; Badmaeva, T M; Vtorushina, I A

    2015-01-01

    The article presents the results of a study of the effectiveness of wheat flour containing selenium in organic form. The organic form of trace element was achieved by transformation of selenium in selenium-methionine (Se-Met) at germination of wheat grains, moistened with a solution of sodium selenite. To determine the effectiveness of selenium- containing supplements experimental investigations were carried out on Long white rats with initial body weight 50 ± 2 g. The duration of the experiment was 30 days. The research model included four groups of animals: control group--animals were fed a complete vivarium diet; group 1--a model of selenium deficiency, which was achieved by feeding selenium-deficient food (grain growh in the Chita region of the Trans-Baikal Territory Zabaikalsky Krai); group 2--animals were administered selenium supplement in the form of enriched flour (0.025 µg Se per 50 g body weight of the animal) on the background of selenium-deficient diet; group 3--animals were treated with a high dose of selenium in the form of a solution of sodium selenite intragastrically through a tube (0.15 µg Se per 50 g body weight). Selenium-containing additive on the background of selenium-deficient diet had a positive impact on the appearance and behavior of animals, the body weight gain per head after 10 days in group 2 amounted to 47.9 g that was 4 fold larger than in rats of group 1. The study of selenium content showed that in the blood, liver, lungs and heart of rats treated with the additive on the background of selenium-deficient diet (group 2), selenium level did not differ from those in the control group and was within physiological norms. The experiment showed that selenium deficiency and rich in selenium rich diet has a significantly different effect on the studied parameters of oxidative-antioxidative status. The activity of blood glutathione peroxidase in animals of group 2 (did not differ from that in group 3) was almost 2 fold higher than in

  14. The properties, functions, and use of selenium compounds in living organisms.

    Science.gov (United States)

    Bodnar, Malgorzata; Konieczka, Piotr; Namiesnik, Jacek

    2012-01-01

    Selenium occurs in the environment in inorganic and organic compounds. For many years it was regarded as a toxic element, causing numerous illnesses and diseases. But research in the past 50 years has revealed a "bright side" to this element, especially as a component of selenoproteins, selenium makes a significant contribution to the health of humans and animals. The selenium content in an organism depends on its concentration and bioavailability in the soil, and the differences between its deficiency, appropriate intake, and excess are very slight. This article gathers information from the literature on: • the consequences of a deficiency and an excess of selenium in the body, as well as the health-promoting mechanisms of selenium, including the functions of selenoproteins • the uptake and transformation of selenium compounds by plants, because of the fact that selenium is better assimilated from plant food and also the classification of plants with respect to their ability to take up selenium from the soil and to accumulate it.

  15. How Certain Trace Elements Behave.

    Science.gov (United States)

    Zingaro, Ralph A.

    1979-01-01

    Fluorine, selenium, tin, and arsenic are among the trace elements occurring in the environment which are considered. Emphasis is given to developing a qualitative survey of the extent and kinds of metal transformations and their resultant effects. (CS)

  16. Binary mixtures of mercury/ selenium, and lead/selenium

    African Journals Online (AJOL)

    Physiologically-based biokinetic models have been developed for predicting simultaneously the Absorption, Distribution, Metabolism and Elimination (ADME) properties of lead (Pb) and selenium (Se), and mercury (Hg) and selenium in a number of target tissues of humans. This was done for three population groups, ...

  17. 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

  18. Biofortification and phytoremediation of selenium in China.

    Science.gov (United States)

    Wu, Zhilin; Bañuelos, Gary S; Lin, Zhi-Qing; Liu, Ying; Yuan, Linxi; Yin, Xuebin; Li, Miao

    2015-01-01

    Selenium (Se) is an essential trace element for humans and animals but at high concentrations, Se becomes toxic to organisms due to Se replacing sulfur in proteins. Selenium biofortification is an agricultural process that increases the accumulation of Se in crops, through plant breeding, genetic engineering, or use of Se fertilizers. Selenium phytoremediation is a green biotechnology to clean up Se-contaminated environments, primarily through phytoextraction and phytovolatilization. By integrating Se phytoremediation and biofortification technologies, Se-enriched plant materials harvested from Se phytoremediation can be used as Se-enriched green manures or other supplementary sources of Se for producing Se-biofortified agricultural products. Earlier studies primarily aimed at enhancing efficacy of phytoremediation and biofortification of Se based on natural variation in progenitor or identification of unique plant species. In this review, we discuss promising approaches to improve biofortification and phytoremediation of Se using knowledge acquired from model crops. We also explored the feasibility of applying biotechnologies such as inoculation of microbial strains for improving the efficiency of biofortification and phytoremediation of Se. The key research and practical challenges that remain in improving biofortification and phytoremediation of Se have been highlighted, and the future development and uses of Se-biofortified agricultural products in China has also been discussed.

  19. Addition of Selenium to Carica papaya Linn Pulp Extract Enhances ...

    African Journals Online (AJOL)

    Methods: Phosphate-buffered saline (PBS) and water extracts of unripe Carica papaya. papaya were analyzed for mineral element composition (Ca, calcium; Mg, magnesium; Na, sodium; Fe, iron; Mn, manganese; Zn, zinc; Ag, silver; and Se, selenium) using a microwave-assisted digestion procedure. Atomic absorption ...

  20. Serum Levels of Selenium, Zinc, Copper and Magnesium in ...

    African Journals Online (AJOL)

    Background: Free radicals have harmful effects on cells and tissues and are thought to be responsible for the pathogenesis of many diseases including bronchial asthma. Selenium (Se), Zinc (Zn), copper (Cu), and magnesium (Mg) are trace elements required for the antioxidant enzymes and hence the optimal functions of ...

  1. Biogeochemistry of selenium isotopes: processes, cycling and paleoenvironmental applications

    NARCIS (Netherlands)

    Mitchell, K.A.

    2012-01-01

    Selenium (Se) is an essential trace element, which, with multiple oxidation states and six stable isotopes, has been suggested as a potentially powerful environmental tracer and paleoenvironmental proxy. Chapter 1 provides a literature review of the Se cycle. While the Se cycle shares some

  2. Decreased reproductive rates in sheep fed a high selenium diet

    Science.gov (United States)

    High Se-containing forages grow on seleniferous soils in many parts of the United States and throughout the world. Selenium is an essential trace element that is required for many physiological processes but can also be either acutely or chronically toxic to livestock. Anecdotal reports of decrease...

  3. Selenium affects biosilica formation in the demosponge Suberites domuncula

    NARCIS (Netherlands)

    Mueller, W.E.G.; Borejko, A.; Brandt, D.; Osinga, R.; Ushijima, H.; Hamer, B.; Krasko, A.; Xupeng, C.; Mueller, I.M.; Schroeder, H.C.

    2005-01-01

    Selenium is a trace element found in freshwater and the marine environment. We show that it plays a major role in spicule formation in the demosponge Suberites domuncula. If added to primmorphs, an in vitro sponge cell culture system, it stimulates the formation of siliceous spicules. Using

  4. Selenium as an Essential Micronutrient: Roles in Cell Cycle and Apoptosis

    Directory of Open Access Journals (Sweden)

    Huawei Zeng

    2009-03-01

    Full Text Available Selenium is an essential trace element for humans and animals, and selenium deficiency is associated with several disease conditions such as immune impairment. In addition, selenium intakes that are greater than the recommended daily allowance (RDA appear to protect against certain types of cancers. In humans and animals, cell proliferation and death must be regulated to maintain tissue homeostasis, and it has been well documented that numerous human diseases are directly related to the control of cell cycle progression and apoptosis. Thus, the elucidation of the mechanisms by which selenium regulates the cell cycle and apoptosis can lead to a better understanding of the nature of selenium’s essentiality and its role in disease prevention. This article reviews the status of knowledge concerning the effect of selenium on cell cycle and apoptosis

  5. Selenium speciation in different organs of African catfish (Clarias gariepinus) enriched through a selenium-enriched garlic based diet

    NARCIS (Netherlands)

    Pedrero, Z.; Murillo, S.; Camara, C.; Schram, E.; Luten, J.B.; Feldmann, I.; Jakubowski, N.; Madrid, Y.

    2011-01-01

    Speciation of Se in fish is needed to elucidate the metabolism of this element in living organisms in the marine environment. In this paper, selenium concentration and its species distribution in several organs and tissues (liver, gills, kidney, muscle and gastrointestinal tract) of African catfish

  6. Dietary Selenium Levels Affect Selenoprotein Expression and Support the Interferon-γ and IL-6 Immune Response Pathways in Mice.

    Science.gov (United States)

    Tsuji, Petra A; Carlson, Bradley A; Anderson, Christine B; Seifried, Harold E; Hatfield, Dolph L; Howard, Michael T

    2015-08-06

    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.

  7. 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.

  8. The occurrence of hazardous volatile elements and nanoparticles in Bulgarian coal fly ashes and the effect on human health exposure

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luis F.O., E-mail: lfsoliveira@univates.br [Centro Universitario Univates, Pro Reitoria de Pesquisa Estensao e Pos Graduacao, Programa de Pos Graduacao Ambiente e Desenvolvimento (Brazil); Environmental Science and Nanotechnology Department, Catarinense Institute of Environmental Research and Human Development - IPADHC, Capivari de Baixo, Santa Catarina (Brazil); DaBoit, Katia [Department of Environmental Medicine, Catarinense Institute of Environmental Research and Human Development - IPADHC, Capivari de Baixo, Santa Catarina (Brazil); Sampaio, Carlos H. [Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Goncalves, 9500, Bairro Agronomia, CEP: 91501-970, Porto Alegre - RS (Brazil); Jasper, Andre [Centro Universitario Univates, Pro Reitoria de Pesquisa Estensao e Pos Graduacao, Programa de Pos Graduacao Ambiente e Desenvolvimento (Brazil); Andrade, Maria L. [Department of Plant Biology and Soil Science, University of Vigo, 36310 Vigo (Spain); Kostova, Irena J. [Sofia University ' St. Kliment Ohridski' , Department of Geology, Paleontology and Fossil Fuels, 15, Tzar Osvoboditel Blvd., 1000 Sofia (Bulgaria); and others

    2012-02-01

    Low-rank, high-mineral matter Bulgarian coals were studied using a variety of chemical, optical, and electron beam methods. The larger fly ash carbon phases include charred carbons in contrast to coked carbons present in the fly ashes of bituminous-coal-derived fly ashes. Nanoscale carbons include multi-walled carbon nanotubes (MWCNTs) encapsulating Hg, Se, and As, among other elements. In addition to the glass which dominates the fly ash, relatively coarse 'rock fragments', consisting of an unmelted to partially melted core surrounded by a glassy rim, are present in the fly ash. Nano-scale minerals can contain hazardous elements and, along with metal-bearing multiwalled nanotubes, can be a path for the entry of hazardous particles into the lungs and other organs. Highlights: Black-Right-Pointing-Pointer We model Bulgarian power plants which have regulated minerals nanoparticles can contain hazardous elements. Black-Right-Pointing-Pointer We study changes in the level of information about nanominerals importance and the effect on human health exposure. Black-Right-Pointing-Pointer Increasing information will increase quality if power plants procedures are similar.

  9. Elemental Mass Size Distribution for Characterization, Quantification and Identification of Trace Nanoparticles in Serum and Environmental Waters.

    Science.gov (United States)

    Zhou, Xiao-Xia; Liu, Jing-Fu; Jiang, Gui-Bin

    2017-04-04

    Accurate characterization, quantification, and identification of nanoparticles (NPs) are essential to fully understand the environmental processes and effects of NPs. Herein, the elemental mass size distribution (EMSD), which measures particle size, mass, and composition, is proposed for the direct size characterization, mass quantification, and composition identification of trace NPs in complex matrixes. A one-step method for the rapid measurement of EMSDs in 8 min was developed through the online coupling of size-exclusion chromatography (SEC) with inductively coupled plasma mass spectrometry (ICP-MS). The use of a mobile phase with a relatively high ionic strength (a mixture of 2% FL-70 and 2 mM Na2S2O3) ensured the complete elution of different-sized NPs from the column and, therefore, a size-independent response. After application of a correction for instrumental broadening by a method developed in this study, the size distribution of NPs by EMSD determination agreed closely with that obtained from transmission electron microscopy (TEM) analysis. Compared with TEM, EMSD allows a more rapid determination with a higher mass sensitivity (1 pg for gold and silver NPs) and comparable size discrimination (0.27 nm). The proposed EMSD-based method was capable of identifying trace Ag2S NPs and core-shell nanocomposite Au@Ag, as well as quantitatively tracking the dissolution and size transformation of silver nanoparticles in serum and environmental waters.

  10. Modification of the internal surface of photonic crystal fibers with Ag and Au nanoparticles for application as sensor elements

    Science.gov (United States)

    Pidenko, Pavel S.; Borzov, Victor M.; Savenko, Olga A.; Skaptsov, Alexander A.; Skibina, Yulia S.; Goryacheva, Irina Yu.; Rusanova, Tatiana Yu.

    2017-03-01

    Photonic crystal fibers (PCFs) are one of the most promising materials for biosensors construction due to their unique optical properties. The modification of PCF by noble metal nanoparticles (NPs) provides the SPR and SERS signal detection where as the application amino group-containing compounds allows efficient binding of biomolecules. In this work the internal surface of glass hollow core photonic crystal fibers (HC-PCFs) has been modified Ag and Au nanoparticles using three different approaches. PCFs were treated by: 1) mixture of NPs and precursors for silanization (tetraethoxysilane (TEOS) and (3-aminopropyl)triethoxysilane (APTES)); 2) alternately deposition of polyelectrolytes and NPs, 3) mixture of chitosan with NPs. The shift of local maxima in the HC-PCF transmission spectrum has been selected as a signal for estimating the amount of NPs on the HC-PCF inner surface. The most efficient techniques were the chitosan application for Ag NPs and silanization for Au NPs. The obtaining PCFs could be useful for creating biosensitive elements.

  11. Bacteria versus selenium: A view from the inside out

    Science.gov (United States)

    Staicu, Lucian; Oremland, Ronald S.; Tobe, Ryuta; Mihara, Hisaaki

    2017-01-01

    Bacteria and selenium (Se) are closely interlinked as the element serves both essential nutrient requirements and energy generation functions. However, Se can also behave as a powerful toxicant for bacterial homeostasis. Conversely, bacteria play a tremendous role in the cycling of Se between different environmental compartments, and bacterial metabolism has been shown to participate to all valence state transformations undergone by Se in nature. Bacteria possess an extensive molecular repertoire for Se metabolism. At the end of the 1980s, a novel mode of anaerobic respiration based on Se oxyanions was experimentally documented for the first time. Following this discovery, specific enzymes capable of reducing Se oxyanions and harvesting energy were found in a number of anaerobic bacteria. The genes involved in the expression of these enzymes have later been identified and cloned. This iterative approach undertaken outside-in led to the understanding of the molecular mechanisms of Se transformations in bacteria. Based on the extensive knowledge accumulated over the years, we now have a full(er) view from the inside out, from DNA-encoding genes to enzymes and thermodynamics. Bacterial transformations of Se for assimilatory purposes have been the object of numerous studies predating the investigation of Se respiration. Remarkable contributions related to the understating of the molecular picture underlying seleno-amino acid biosynthesis are reviewed herein. Under certain circumstances, Se is a toxicant for bacterial metabolism and bacteria have evolved strategies to counteract this toxicity, most notably by the formation of elemental Se (nano)particles. Several biotechnological applications, such as the production of functional materials and the biofortification of crop species using Se-utilizing bacteria, are presented in this chapter.

  12. Dietary supplements based on selenium containing culture of lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    N. Tregub

    2017-06-01

    Full Text Available The article describes the role of selenium in the humankind being. The analysis based on the published data shows that the biological synthesis is a perspective way to obtain an organic form of selenium, which can be used in dietary supplements. The ability of lactic acid bacteria (Lactobacillus acidophilus 412/307to accumulate inorganic forms of selenium (selenites, selenates, turning them into organic forms, with purposeful trace element enrichment of culture medium is described in the article. The main organic forms of selenium, which are being used in the process of biotransformation from its inorganic forms by microorganisms, have been reorganized. The relationship between the increasing of concentrations of sodium selenite in the culture medium and the growth of biomass of lactic acid bacteria was established. It was found the depressing effect of increasing concentrations of sodium selenite on optical density rate. It was estabilished the optimal conditions for the maximum accumulation of selenium containing culture of lactic acid bacteria. The influence of selenium concentration on the lactic acid bacteria biomass accumulation was determined also by changing the values of optical density. Due to the obtained data, the selenium containing dietary supplement «Selenolakt» was created. The main microbiological indicators that characterize the quality of the obtained product are given. The content of organic form of selenium in products reaches –195 ± 1 mkg/g.

  13. Selenium Ecotoxicology in Freshwater Lakes Receiving Coal Combustion Residual Effluents: A North Carolina Example.

    Science.gov (United States)

    Brandt, Jessica E; Bernhardt, Emily S; Dwyer, Gary S; Di Giulio, Richard T

    2017-02-21

    Anthropogenic activities resulting in releases of selenium-laden waste streams threaten freshwater ecosystems. Lake ecosystems demand special consideration because they are characterized by prolonged retention of selenium and continuous cycling of the element through the food chain, through which it becomes available to toxicologically susceptible egg-laying vertebrates. This study documents the current selenium burden of lakes in North Carolina (NC) with historic selenium inputs from nearby coal-fired power plants. We measured selenium concentrations in surface waters, sediment pore waters, and resident fish species from coal combustion residual (CCR)-impacted lakes and paired reference lakes. The data are related to levels of recent selenium inputs and analyzed in the context of recently updated federal criteria for the protection of aquatic life. We show that the Se content of fish from lakes with the highest selenium inputs regularly exceed these criteria and are comparable to those measured during historic fish extirpation events in the United States. Large legacy depositions of CCRs within reservoir sediments are likely to sustain Se toxicity for many years despite recent laws to limit CCR discharge into surface waters in NC. Importantly, the widespread use of high-selenium coals for electricity generation extends the potential risk for aquatic ecosystem impacts beyond U.S. borders.

  14. Arsenic and Selenium

    Science.gov (United States)

    Plant, J. A.; Kinniburgh, D. G.; Smedley, P. L.; Fordyce, F. M.; Klinck, B. A.

    2003-12-01

    Arsenic (As) and selenium (Se) have become increasingly important in environmental geochemistry because of their significance to human health. Their concentrations vary markedly in the environment, partly in relation to geology and partly as a result of human activity. Some of the contamination evident today probably dates back to the first settled civilizations which used metals.Arsenic is in group 15 of the periodic table (Table 1) and is usually described as a metalloid. It has only one stable isotope, 75As. It can exist in the -III, -I, 0, III, and V oxidation states (Table 2).

  15. Response surface design for accumulation of selenium by different lactic acid bacteria.

    Science.gov (United States)

    Yang, Jingpeng; Li, Yao; Zhang, Li; Fan, Mingtao; Wei, Xinyuan

    2017-05-01

    The accumulation of selenium (Se) by Lactobacillus delbrueckii ssp. bulgaricus (Lb) and Streptococcus thermophilus (St) at the different cultivation conditions, including initial pH, inoculum dose (%), and temperature (°C), was investigated in this work. Se enrichment efficiency was optimized using the Design-Expert software for response surface methodology on a basis of single-factor experiment. The antioxidant activities of Se-enriched Lactic acid bacteria (LAB) were also investigated. The qualitative analysis of Se-enriched LAB was performed by FT-IR spectra. The cell morphology and chemical element components were measured by a scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscopy. The results indicated that the optimum initial pH, inoculum doses, and temperatures of Lb and St were 5.96, 6.73%, 33.24 °C, and 6.37, 6%, 40 °C, respectively. Under the optimal conditions, the ratios of Se enrichment reached 94.34% for Lb and 97.05% for St. Furthermore, Se-enriched LAB enhanced scavenging rates on DPPH, ABTS free radical, and also heightened reducing activity. The FT-IR results showed that the two Se-enriched strains had similar characteristic absorption peaks, which were further demonstrated that both Se biomasses had the same carbonyl, carboxyl, and hydroxyl groups. Elemental selenium nanoparticles were verified around cell surfaces of Se-enriched LAB, which implied that both strains had detoxification ability when grown in liquid media containing selenite.

  16. Effect of Selenium, Molybdenum and Zinc on Seedling Growth and Frequency of Grain Weevil (Sitophilus granarius in Triticale Grain

    Directory of Open Access Journals (Sweden)

    Rudolf Kastori

    2009-01-01

    Full Text Available The effects of different doses (0, 90, 270, 810 kg/ha of selenium, molybdenum and zinc microelements on their translocation and accumulation in grains, seedling growth and grain infestation were examined under field conditions on a calcareous chernozem soil.Thirteen years after the application of selenium, molybdenum and zinc, significant translocation and accumulation of these elements in the grain were established, indicating a long-term effect of these microelements on triticale plants. The highest degree of accumulation in grains and seedling shoots was found for selenium, then molybdenum, while the detected amounts of zinc were significantly lower. The degree of accumulation of all threemicroelements in the grain and seedling shoot increased as doses increased. Translocation index from shoot to grain at the grain-filling phase was the highest when zinc was used, then selenium, and the lowest when molybdenum was applied. The highest translocationindex from the grain during germination into seedling shoots was obtained with zinc, then molybdenum and selenium. Translocation indexes of the investigated elements significantly decreased as the doses of elements increased. Dry weight of seedling shoots decreasedas molybdenum and zinc in grain increased. High selenium concentration moderately stimulated seedling development, pointing out a high tolerance of triticale to higher concentration of this microelement at initial development stages. Infestatation with grain weevil was provoked by high concentrations of these microelements in the grain. High concentrations of zinc and selenium, in particular, significantly decreased the percentage of damaged grains, while molybdenum moderately increased their numbers. The effect of zincand molybdenum may be attributed to their chemical effect, while selenium effect may also be referred to a negative effect of the volatile selenium compound. The effect of selenium, molybdenum and zinc contamination of grains

  17. Comparison of 3D Adaptive Remeshing Strategies for Finite Element Simulations of Electromagnetic Heating of Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Fadhil Mezghani

    2015-01-01

    Full Text Available The optical properties of metallic nanoparticles are well known, but the study of their thermal behavior is in its infancy. However the local heating of surrounding medium, induced by illuminated nanostructures, opens the way to new sensors and devices. Consequently the accurate calculation of the electromagnetically induced heating of nanostructures is of interest. The proposed multiphysics problem cannot be directly solved with the classical refinement method of Comsol Multiphysics and a 3D adaptive remeshing process based on an a posteriori error estimator is used. In this paper the efficiency of three remeshing strategies for solving the multiphysics problem is compared. The first strategy uses independent remeshing for each physical quantity to reach a given accuracy. The second strategy only controls the accuracy on temperature. The third strategy uses a linear combination of the two normalized targets (the electric field intensity and the temperature. The analysis of the performance of each strategy is based on the convergence of the remeshing process in terms of number of elements. The efficiency of each strategy is also characterized by the number of computation iterations, the number of elements, the CPU time, and the RAM required to achieve a given target accuracy.

  18. Synthesis and thermal stability of selenium-doped hydroxyapatite with different substitutions

    Science.gov (United States)

    Liu, Yonghui; Ma, Jun; Zhang, Shengmin

    2015-12-01

    Selenium (Se) plays a specific role in human health, especially for its antitumor effect. Incorporation of selenium into biocompatible hydroxyapatite (HAP) may endow the materials with novel characteristics. In the current work, a series of seleniumdoped hydroxyapatite (Se-HAP) nanoparticles with different Se/P ratios were synthesized by a modified chemical precipitation. It was revealed that the powders with/without heattreatment were nano-sized needle-like HAP while the heat-treated samples have high crystallinity. The addition of selenium decreases the crystallinity of the synthesized apatite, and also takes a negative effect on the thermal stability of the as-prepared powders. The Se-HAP nanoparticles with Se/P molar ratio not more than 5% sintered at 900°C can achieve good crystallinity and thermal stability.

  19. Production of porous filter elements from PEUAPM nanocomposites and silver nanoparticles; Producao de elementos filtrantes porosos a partir de nanocompositos de PEUAPM e nanoparticulas de prata

    Energy Technology Data Exchange (ETDEWEB)

    Bizzo, M.A.; Hui, W.S., E-mail: mbizzo@usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Departamento de Engenharia Metalurgica e de Materiais

    2014-07-01

    The production of filter elements for water based in polymers is widespread in the market, but has an undesirable characteristic: they are not efficient and able to retain or eliminate microorganisms at all times. This paper proposes to produce nanocomposite filters with biocidal properties composed of ultra-high molecular weight polyethylene(UHMWPE) and silver nanoparticles, the UHMWPE is responsible for the uniform porous structure of the filters and the silver nanoparticles incorporated on the polymer are responsible for the biocide action. Particulate polymer that presents a different particle size curve was used for sintering the filters. Samples of filter elements obtained in this work were characterized by the techniques of X-ray diffraction, scanning electron microscopy and EDS microanalysis. The results indicated a porosity of approximately 49% in the filter, and the formation of the nanocomposite. key-words: nanocomposites, silver, UHMWPE, filter elements. (author)

  20. Molten-droplet synthesis of composite CdSe hollow nanoparticles

    KAUST Repository

    Gullapalli, Sravani

    2012-11-16

    Many colloidal synthesis routes are not scalable to high production rates, especially for nanoparticles of complex shape or composition, due to precursor expense and hazards, low yields, and the large number of processing steps. The present work describes a strategy to synthesize hollow nanoparticles (HNPs) out of metal chalcogenides, based on the slow heating of a low-melting-point metal salt, an elemental chalcogen, and an alkylammonium surfactant in octadecene solvent. The synthesis and characterization of CdSe HNPs with an outer diameter of 15.6 ± 3.5 nm and a shell thickness of 5.4 ± 0.9 nm are specifically detailed here. The HNP synthesis is proposed to proceed with the formation of alkylammonium-stabilized nano-sized droplets of molten cadmium salt, which then come into contact with dissolved selenium species to form a CdSe shell at the droplet surface. In a reaction-diffusion mechanism similar to the nanoscale Kirkendall effect it is speculated that the cadmium migrates outwardly through this shell to react with more selenium, causing the CdSe shell to thicken. The proposed CdSe HNP structure comprises a polycrystalline CdSe shell coated with a thin layer of amorphous selenium. Photovoltaic device characterization indicates that HNPs have improved electron transport characteristics compared to standard CdSe quantum dots, possibly due to this selenium layer. The HNPs are colloidally stable in organic solvents even though carboxylate, phosphine, and amine ligands are absent; stability is attributed to octadecene-selenide species bound to the particle surface. This scalable synthesis method presents opportunities to generate hollow nanoparticles with increased structural and compositional variety. © 2012 IOP Publishing Ltd.

  1. VO2 thin films and nanoparticles for energy-saving applications in architectural elements

    OpenAIRE

    Garcia, Ivan Aristides Ferreira

    2015-01-01

    Vanadium dioxide (VO2) is a promising material with large interest in construction industry and architecture, due to its thermochromic properties. This material may be used to create "smart" coatings that result in improvements in the buildings energy efficiency, by reducing heat exchanges and, consequently, the need for acclimatization. In this work, VO2 thin films and coatings were produced and tested in laboratory, to apply in architectural elements, such as glass, rooftop tiles and exteri...

  2. Au nanoparticles attached carbon nanotubes as a high performance active element in field effect transistor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myeongsoon; Kim, Don, E-mail: donkim@pknu.ac.kr

    2016-08-15

    The Au nanoparticles attached carbon nanotubes (Au-CNTs), diameter ranged from 40 to 250 nm, were prepared and discussed their chemical and electrical properties. The shape and crystallinity of the carbon nanotubes (CNTs) phase depended main2ly on the diameter of CNTs (r{sub Au-CNT}). Highly crystalline, straight CNTs were observed when the r{sub Au-CNT} exceeded 80 nm, and less crystalline noodle-shaped CNTs were observed when the r{sub Au-CNT} was smaller than 80 nm. The crystallinity of the CNT phase was confirmed by analyzing the G and D bands in their Raman spectra and the electrical conductivities of the Au-CNTs. The electrical conductivity of the highly crystalline carbon phase of Au-CNTs (r{sub Au-CNT} = 250 nm) was ∼10{sup 4} S/cm. The back-gated field effect transistors (FETs) based on the Au-CNTs, which were assembled on a SiO{sub 2}/Si wafer using the dielectrophoresis technique, showed that the Au-CNTs would be a good functional electronic material for future electronic and sensing applications. The transconductance and hole mobility of the FETs, which were assembled with the highly crystalline Au-CNTs (r{sub Au-CNT} = 250 nm), reached to 3.6 × 10{sup −4} A/V and 3.1 × 10{sup 4} cm{sup 2}/V s, respectively. These values are in the middle of those of reported for single walled carbon nanotubes and graphene. However, we could not find any field effect in a CNTFET, which assembled without Au nanoparticles, through the same process. - Highlights: • The shape and crystallinity of the CNTs depended mainly on the diameter of CNTs. • The electrical conductivity of the highly crystalline Au-CNTs was ∼10{sup 4} S/cm. • The Au-CNT FET shows typical p-channel gate effect with the on/off ratio of ∼10{sup 4}. • The Au-CNT FET shows very high transconductance (g{sub m}) and carrier mobility (μ{sub h}).

  3. Selenium uptake, tolerance and reduction in Flammulina velutipes supplied with selenite

    Directory of Open Access Journals (Sweden)

    Jipeng Wang

    2016-05-01

    Full Text Available Recently, selenium (Se enriched mushrooms have been exploited as dietary Se supplements, but our knowledge of the metabolic process during the Se enrichment process is far from complete. In this study, the uptake, tolerance and reduction of selenite in a widely cultivated mushroom, Flammulina velutipes, was investigated. The results showed that pH variation (from 5.5–7.5, metabolic inhibitor (0.1 mM 2,4-DNP and P or S starvation led to 11–26% decreases in the selenite uptake rate of F. velutipes. This indicates that a minor portion of the selenite uptake was metabolism dependent, whereas a carrier-facilitated passive transport may be crucial. Growth inhibition of F. velutipes initiated at 0.1 mM selenite (11% decrease in the growth rate and complete growth inhibition occurred at 3 mM selenite. A selenite concentration of 0.03–0.1 mM was recommended to maintain the balance between mycelium production and Se enrichment. F. velutipes was capable of reducing selenite to elemental Se [Se(0] including Se(0 nanoparticles, possibly as a detoxification mechanism. This process depended on both selenite concentration and metabolism activity. Overall, the data obtained provided some basic information for the cultivation of the selenized F. velutipes, and highlighted the opportunity of using mushrooms for the production of Se(0 nanoparticles.

  4. Mercury and selenium relationship in a tropical estuarine fish

    Directory of Open Access Journals (Sweden)

    Ana Carolina Pizzochero

    2015-11-01

    Full Text Available Aquatic systems have been considered as final sinks for persistent and bioaccumulative toxicants (PBTs, such as metals and organohalogen compounds. Among the trace elements, non-essential metals deserve special attention due to their toxicity. In this context, mercury (Hg should be highlighted due to its toxic effects, which comprise neurotoxicity, nephrotoxicity, hepatotoxicity, genotoxicity, among others. Several studies have highlighted the selenium-mediated methylmercury detoxification process, via mercury selenide formation in tissues of marine vertebrates. Despite being an essential element, selenium may also be toxic in high concentrations. This study focused on Guanabara Bay (GB, a heavily polluted urban estuary in Rio de Janeiro state (Brazil, where the whitemouth croaker (Micropogonias furnieri provides a valuable fishery resource. Therefore, hepatic (Hg and Se and muscular (Hg concentrations of these elements were determined in GB whitemouth croakers. Mercury and selenium measurements were performed by cold vapor atomic absorption spectrometry (CV-AAS and electrothermal AAS (ET-AAS, respectively. Total mercury (THg concentrations in muscle (n=19 ranged from 184.9 to 858.6 (ng/g, while in liver they varied from 11.05 to 1188 (ng/g. Hepatic selenium concentrations ranged from 7820 to 40085 (ng/g. The hepatic Se:THg molar ratio ranged from 40,8 to 3102,5. The results showed a significant correlation between hepatic mercury and selenium levels, but the molar ratio suggests the absence of mercury selenide formation. Some of the Se concentrations found were above the threshold level for freshwater fish (12000 ng/g; however, it is not yet clear if these concentrations are toxic for marine fish as well. More studies are necessary for evaluating the impact of such exposure in fish from Guanabara Bay.

  5. Selenium. Role of the essential metalloid in health.

    Science.gov (United States)

    Kurokawa, Suguru; Berry, Marla J

    2013-01-01

    Selenium is an essential micronutrient in mammals, but is also recognized as toxic in excess. It is a non-metal with properties that are intermediate between the chalcogen elements sulfur and tellurium. Selenium exerts its biological functions through selenoproteins. Selenoproteins contain selenium in the form of the 21st amino acid, selenocysteine (Sec), which is an analog of cysteine with the sulfur-containing side chain replaced by a Se-containing side chain. Sec is encoded by the codon UGA, which is one of three termination codons for mRNA translation in non-selenoprotein genes. Recognition of the UGA codon as a Sec insertion site instead of stop requires a Sec insertion sequence (SECIS) element in selenoprotein mRNAs and a unique selenocysteyl-tRNA, both of which are recognized by specialized protein factors. Unlike the 20 standard amino acids, Sec is biosynthesized from serine on its tRNA. Twenty-five selenoproteins are encoded in the human genome. Most of the selenoprotein genes were discovered by bioinformatics approaches, searching for SECIS elements downstream of in-frame UGA codons. Sec has been described as having stronger nucleophilic and electrophilic properties than cysteine, and Sec is present in the catalytic site of all selenoenzymes. Most selenoproteins, whose functions are known, are involved in redox systems and signaling pathways. However, several selenoproteins are not well characterized in terms of their function. The selenium field has grown dramatically in the last few decades, and research on selenium biology is providing extensive new information regarding its importance for human health.

  6. Selenium. Role of the Essential Metalloid in Health

    Science.gov (United States)

    Kurokawa, Suguru; Berry, Marla J.

    2015-01-01

    Selenium is an essential micronutrient in mammals, but is also recognized as toxic in excess. It is a non-metal with properties that are intermediate between the chalcogen elements sulfur and tellurium. Selenium exerts its biological functions through selenoproteins. Selenoproteins contain selenium in the form of the 21st amino acid, selenocysteine (Sec), which is an analog of cysteine with the sulfur-containing side chain replaced by a Se-containing side chain. Sec is encoded by the codon UGA, which is one of three termination codons for mRNA translation in non-selenoprotein genes. Recognition of the UGA codon as a Sec insertion site instead of stop requires a Sec insertion sequence (SECIS) element in selenoprotein mRNAs and a unique selenocysteyl-tRNA, both of which are recognized by specialized protein factors. Unlike the 20 standard amino acids, Sec is biosynthesized from serine on its tRNA. Twenty-five selenoproteins are encoded in the human genome. Most of the selenoprotein genes were discovered by bioinformatics approaches, searching for SECIS elements downstream of in-frame UGA codons. Sec has been described as having stronger nucleophilic and electrophilic properties than cysteine, and Sec is present in the catalytic site of all selenoenzymes. Most selenoproteins, whose functions are known, are involved in redox systems and signaling pathways. However, several selenoproteins are not well characterized in terms of their function. The selenium field has grown dramatically in the last few decades, and research on selenium biology is providing extensive new information regarding its importance for human health. PMID:24470102

  7. The response of duckweed (Lemna minor L.) to different concentrations and compounds of selenium

    OpenAIRE

    Brudar, Nina

    2017-01-01

    Selenium is a trace element and an essential microelement for humans, animals and microorganisms, whereas this has not been established for plants yet. It is widespread in the earth's crust and occurs in soil, seawater and freshwater as well as minerals and sediments. Climatic conditions, geological composition of the soil and numerous anthropogenic factors affect the presence of selenium in the environment. It can exist in four oxidation states. Selenite is the most important form of seleniu...

  8. The role of selenium and iodine in controlling some egg minerals

    Directory of Open Access Journals (Sweden)

    A. Mordenti

    2010-01-01

    Full Text Available Selenium (Se is recognised as an essential trace element for animal and human health. It acts by improving immunity, decreasing free radicals, and providing protection against some diseases, such as thyroid dysfunctions and cancer. In some regions the presence of Se in the food chain is declining, so various strategies should be undertaken to increase its intake: for example, selenium can be concentrated in eggs by transfer from the diet fed to hens.

  9. The association between dietary selenium intake and diabetes: a cross-sectional study among middle-aged and older adults.

    Science.gov (United States)

    Wei, Jie; Zeng, Chao; Gong, Qian-yi; Yang, Hao-bin; Li, Xiao-xiao; Lei, Guang-hua; Yang, Tu-bao

    2015-02-18

    Selenium is an important trace element for human health. Although numerous epidemiological and interventional studies have examined the association between selenium and diabetes, their findings have been inconclusive. Moreover, no research has specifically focused on the association between dietary selenium and diabetes in the Asian population. The objective of this study was to evaluate the relationship between dietary selenium and diabetes in middle-aged and elderly Chinese adults. A cross-sectional study including 5,423 subjects was carried out. The basic characteristics, biochemical test results, and dietary intake were collected from each subject for analysis. The adjusted odds ratio (OR) and the corresponding 95% confidence interval (CI) were used to determine the relationship between dietary selenium intake and diabetes through logistic regression. The prevalence of diabetes in the study population was 9.7%, and the average level of dietary selenium intake was 43.51 μg/day. The multivariate adjusted OR was 1.52 (95% CI: 1.01 to 2.28, P = 0.04) for the highest quartile of dietary selenium intake in comparison with the lowest quartile. There was a significant positive association between dietary selenium intake and diabetes (P for trend = 0.03). There was a significant positive correlation between dietary selenium intake and the prevalence of diabetes.

  10. Generalized Langevin dynamics of a nanoparticle using a finite element approach: thermostating with correlated noise.

    Science.gov (United States)

    Uma, B; Swaminathan, T N; Ayyaswamy, P S; Eckmann, D M; Radhakrishnan, R

    2011-09-21

    A direct numerical simulation (DNS) procedure is employed to study the thermal motion of a nanoparticle in an incompressible Newtonian stationary fluid medium with the generalized Langevin approach. We consider both the Markovian (white noise) and non-Markovian (Ornstein-Uhlenbeck noise and Mittag-Leffler noise) processes. Initial locations of the particle are at various distances from the bounding wall to delineate wall effects. At thermal equilibrium, the numerical results are validated by comparing the calculated translational and rotational temperatures of the particle with those obtained from the equipartition theorem. The nature of the hydrodynamic interactions is verified by comparing the velocity autocorrelation functions and mean square displacements with analytical results. Numerical predictions of wall interactions with the particle in terms of mean square displacements are compared with analytical results. In the non-Markovian Langevin approach, an appropriate choice of colored noise is required to satisfy the power-law decay in the velocity autocorrelation function at long times. The results obtained by using non-Markovian Mittag-Leffler noise simultaneously satisfy the equipartition theorem and the long-time behavior of the hydrodynamic correlations for a range of memory correlation times. The Ornstein-Uhlenbeck process does not provide the appropriate hydrodynamic correlations. Comparing our DNS results to the solution of an one-dimensional generalized Langevin equation, it is observed that where the thermostat adheres to the equipartition theorem, the characteristic memory time in the noise is consistent with the inherent time scale of the memory kernel. The performance of the thermostat with respect to equilibrium and dynamic properties for various noise schemes is discussed.

  11. Removal of Trace Elements by Cupric Oxide Nanoparticles from Uranium In Situ Recovery Bleed Water and Its Effect on Cell Viability.

    Science.gov (United States)

    Schilz, Jodi R; Reddy, K J; Nair, Sreejayan; Johnson, Thomas E; Tjalkens, Ronald B; Krueger, Kem P; Clark, Suzanne

    2015-06-21

    In situ recovery (ISR) is the predominant method of uranium extraction in the United States. During ISR, uranium is leached from an ore body and extracted through ion exchange. The resultant production bleed water (PBW) contains contaminants such as arsenic and other heavy metals. Samples of PBW from an active ISR uranium facility were treated with cupric oxide nanoparticles (CuO-NPs). CuO-NP treatment of PBW reduced priority contaminants, including arsenic, selenium, uranium, and vanadium. Untreated and CuO-NP treated PBW was used as the liquid component of the cell growth media and changes in viability were determined by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay in human embryonic kidney (HEK 293) and human hepatocellular carcinoma (Hep G2) cells. CuO-NP treatment was associated with improved HEK and HEP cell viability. Limitations of this method include dilution of the PBW by growth media components and during osmolality adjustment as well as necessary pH adjustment. This method is limited in its wider context due to dilution effects and changes in the pH of the PBW which is traditionally slightly acidic however; this method could have a broader use assessing CuO-NP treatment in more neutral waters.

  12. Fast preconcentration of trace rare earth elements from environmental samples by di(2-ethylhexyl)phosphoric acid grafted magnetic nanoparticles followed by inductively coupled plasma mass spectrometry detection

    Science.gov (United States)

    Yan, Ping; He, Man; Chen, Beibei; Hu, Bin

    2017-10-01

    In this work, di(2-ethylhexyl)phosphoric acid (P204) grafted magnetic nanoparticles were synthesized by fabricating P204 onto Fe3O4@TiO2 nanoparticles based on Lewis acid-base interaction between Ti and phosphate group under weakly acidic condition. The prepared Fe3O4@TiO2@P204 nanoparticles exhibited excellent selectivity for rare earth elements, and good anti-interference ability. Based on it, a method of magnetic solid phase extraction (MSPE) combined with inductively coupled plasma mass spectrometry (ICP-MS) was developed for fast preconcentration and determination of trace rare earth elements in environmental samples. Under the optimal conditions, the detection limits of rare earth elements were in the range of 0.01 (Tm)-0.12 (Nd) ng L- 1 with an enrichment factor of 100-fold, and the relative standard deviations ranged from 4.9 (Pr) to 10.7% (Er). The proposed method was successfully applied to the determination of rare earth elements in environmental samples, including river water, lake water, seawater and sediment.

  13. A novel one-pot route for the synthesis of water-soluble cadmium selenide nanoparticles

    Science.gov (United States)

    Oluwafemi, S. O.; Revaprasadu, N.; Ramirez, A. J.

    2008-06-01

    A novel, facile one-pot synthetic route to highly water dispersible and potentially biocompatible CdSe nanoparticles is reported. The monodispersed CdSe particles are passivated by cysteine, with water being the solvent. This route involves the reaction of selenium powder with sodium borohydride to produce selenide ions, followed by the addition of a cadmium salt and L-cysteine ethyl ester hydrochloride. The nanoparticles formed show quantum confinement fluorescing in the blue region. Fourier transform infrared spectroscopy study shows that CdSe nanoparticles are capped through mercapto group of the amino acid cysteine whilst its free amino and carboxylate groups make it amenable to bioconjugation establishing the possibility of using these as fluorescent biomarkers. High-resolution transmission electron spectroscopy images of these materials show well-defined, crystalline nanosized particles. Energy dispersive spectroscopy spectra confirm the presence of the corresponding elements.

  14. Selenium protects reproductive system and foetus development in a rat model of gestational lead exposure.

    Science.gov (United States)

    Shen, W; Chen, J; Yin, J; Wang, S-L

    2016-01-01

    Lead is a common environmental contaminant. Lead accumulation in the body is especially dangerous for pregnant women and newborns. Selenium is a trace element which may rectify the damaging effects of lead. Here we tested potential protective effects of selenium against gestational lead exposure. Pregnant SD rats were exposed to 200 mg/L of lead acetate (given with water), with or without sodium selenite supplementation (2-8 mg/kg/day via intragastric administration). Pregnant rats not exposed to lead or selenium served as control animals. The outcomes in pregnant rats were serum lead and selenium levels, reproductive hormone (follicle-stimulating hormone, luteinizing hormone, prolactin, oestradiol, progesterone) levels, and uterine and ovarian morphological changes. The outcomes in the offspring were sex differentiation, survival rates (day 21 after birth), weight (days 0-35 after birth), weight of reproductive organs, and puberty onset (foreskin separation or vaginal opening). Selenium supplementation dose-dependently decreased serum lead levels, rectified reproductive hormone levels, and attenuated reproductive morphological changes caused by lead exposure. Lead exposure did not affect sex differentiation, but significantly (p lead exposure delayed the onset of puberty. These pathological changes were dose-dependently rectified or attenuated by selenium supplementation. Gestational lead exposure causes damages to the reproductive system of pregnant rats, and negatively modulates growth and reproductive system development of the offspring. These adverse effects are rectified or attenuated by selenium supplementation.

  15. Biological effects of selenium compounds with a particular attention to the ontogenetic development.

    Science.gov (United States)

    Ošt'ádalová, I

    2012-01-01

    Selenium is a trace element that is essential for living organism. Its beneficial effect is, however, expressed in a very narrow dosage range: the high and low doses of selenium are connected with pathological manifestations. The toxicity depends on the chemical form of selenium, state of organism, interactions with heavy metals and on the stage of ontogenetic development. Whereas one dose of sodium selenite (20 micromol/kg b.w.) is lethal in adult rats, suckling rats are entirely resistant. However, within one week after administration of the same dose, cataract of eye lens developed. The highest incidence of cataract was observed in 10-day-old animals and it decreased until day 20. From postnatal day 20 to day 40 the rats were resistant to both the lethal and cataractogenic effects of selenium. The incidence of cataract may be suppressed by premature weaning, lower hydration of suckling, change of water soluble/water insoluble lens protein ratio, thyroxine treatment, and by interaction with mercury. By means of its oxidative and reduction properties, selenium is involved in the maintenance of the cell redox homeostasis. Typical example is its possible cardioprotective effect: selenium decreased number of arrhythmias, reduced infarct size and improved the contractile recovery after ischemia/reperfusion injury. Selenium supplementation may thus increase cardiac tolerance to ischemic damage.

  16. Inter-individual variation of selenium in maternal plasma, cord plasma and placenta

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Anne M.; Huel, Guy; Godin, Jean; Hellier, Georgette; Sahuquillo, Josiane; Moreau, Thierry [Epidemiological Research Unit, National Institute of Health and Medical Research, Villejuif (France); Blot, Phillipe [Clinique obstetricale Baudelocque, Paris (France)

    1994-12-09

    Selenium (Se) in high doses has been known to cause injury to the fetus and newborn. The major difficulty in assessing the effects of selenium on human reproduction stems from the need for a suitable means of estimating maternal and fetal exposure. The present investigation, therefore, examines the respective reliability of maternal plasma, cord plasma and placenta as epidemiological indicators as well as inter-individual variation of this trace element. An unselected population of 128 pregnancies was studied. Obstetrical characteristics were noted. Selenium concentrations were determined for maternal plasma, cord plasma, and placental tissue by fluorometric analysis. Maternal plasma selenium concentrations (Se-Bm) were significantly greater than fetal concentrations (Se-Bc). Placental selenium (Se-Pl) levels were four times that of fetal levels. Variability of Se-Bc is best explained by placental concentrations. Maternal weight and ethnic origin are significantly correlated with Se-Bc. Female newborn have higher selenium levels than male newborn. The present study demonstrates the significance of the placenta as an indicator of fetal selenium exposure.

  17. Association between Toenail Mercury and Metabolic Syndrome Is Modified by Selenium

    Directory of Open Access Journals (Sweden)

    Kyong Park

    2016-07-01

    Full Text Available Background: Although Asian populations consume relatively large amounts of fish and seafood and have a high prevalence of metabolic diseases, few studies have investigated the association between chronic mercury exposure and metabolic syndrome and its effect modification by selenium. Methods: We analyzed baseline data from the Trace Element Study of Korean Adults in the Yeungnam area. Participants included 232 men and 269 women, aged 35 years or older, who had complete data regarding demographic, lifestyle, diet, toenail mercury and selenium levels, and health. Toenail mercury and selenium concentrations were measured using instrumental neutron-activation analysis. The metabolic biomarker levels were obtained through biannual medical checkups. Results: Higher toenail mercury levels were associated with habitual consumption of whale and shark meats, older age, obesity, smoking, alcohol drinking, and higher household income. Multivariable analysis showed a positive association between toenail mercury exposure and metabolic syndrome. In addition, this association was significantly stronger at lower selenium levels and was weaker at higher selenium levels. Conclusion: The possible harmful effects of mercury on metabolic syndrome may be attenuated by high levels of selenium. Future studies are needed to suggest optimal dietary guidelines regarding fish and selenium intakes, particularly for Asians with high levels of fish intake.

  18. Role of Selenium from Different Sources in Prevention of Pulmonary Arterial Hypertension Syndrome in Broiler Chickens.

    Science.gov (United States)

    Zamani Moghaddam, A K; Mehraei Hamzekolaei, M H; Khajali, F; Hassanpour, H

    2017-11-01

    Pulmonary arterial hypertension (PAH) syndrome in broilers is associated with hypoxia, which prevails at high altitude. Oxidative stress is the pathogenic mechanism underlying PAH. Because selenium is key element in the structure of antioxidant enzymes, we evaluated pulmonary hypertensive responses in broiler chickens fed with diets supplemented with organic or nano-selenium. One hundred forty-four broilers (starting at 5 days old) were fed with (i) control group: birds received a standard diet; (ii) nano-selenium group: birds were fed with basal diet supplemented with nano-selenium at 0.3 mg/kg; and (iii) organic selenium group: birds received basal diet supplemented with organic selenium at 0.3 mg/kg. We assessed growth performance, carcass characteristics, antioxidant variables, blood parameters, and small intestine morphology. Although Se supplementation did not affect growth performance, carcass traits, and organ weight (P > 0.05), the right to total ventricular weight ratio (RV:TV), malondialdehyde concentration in the liver, and heterophil to lymphocyte ratio were significantly lower in the nano-selenium group relative to the control (P right ventricular hypertrophy as reflected by reduced RV:TV, reduced levels of lipid peroxidation in the liver, and improved gut function.

  19. Selenium content of vegetal foodstuffs in the Federal Republic of Germany

    Energy Technology Data Exchange (ETDEWEB)

    Hofsommer, H.J.; Bielig, H.J.

    1982-02-01

    We are quoting selenium contents in foodstuffs as cited in literature and are discussing them. The survey of published selenium contents in vegetal foodstuffs over the last 20 years reveals that diverging values must mainly be attributed to the site involved. Results of investigations on approximately 800 samples of different fruits and vegetables in the Federal Republic of Germany have shown that fruit does not contain any selenium and vegetables but very minor quantities. Contents differ widely with the individual types of vegetables. Regional variances could not be determined. It can therefore be assumed that the Federal Republic of Germany must be counted among the earth's low-selenium areas. If and how far there is possibly already an undersupply prevailing in this essential trace element - particularly in infant and toddler feeding - will require further supporting data and physiological investigations. Technological factors in the industrial manufacture of fruit and vegetable products are not affecting the selenium content. A specific strain on the environment through selenium cannot be determined at the moment and is not expected for the next few years either, since even sites in heavily endangered environments do not exhibit selenium contents deviating from the average in the individual fruits and vegetables.

  20. Gas-Phase Synthesis of Bimetallic Oxide Nanoparticles with Designed Elemental Compositions for Controlling the Explosive Reactivity of Nanoenergetic Materials

    Directory of Open Access Journals (Sweden)

    Ji Young Ahn

    2011-01-01

    Full Text Available We demonstrate a simple and viable method for controlling the energy release rate and pressurization rate of nanoenergetic materials by controlling the relative elemental compositions of oxidizers. First, bimetallic oxide nanoparticles (NPs with a homogeneous distribution of two different oxidizer components (CuO and Fe2O3 were generated by a conventional spray pyrolysis method. Next, the Al NPs employed as a fuel were mixed with CuO-Fe2O3 bimetallic oxide NPs by an ultrasonication process in ethanol solution. Finally, after the removal of ethanol by a drying process, the NPs were converted into energetic materials (EMs. The effects of the mass fraction of CuO in the CuO-Fe2O3 bimetallic oxide NPs on the explosive reactivity of the resulting EMs were examined by using a differential scanning calorimeter and pressure cell tester (PCT systems. The results clearly indicate that the energy release rate and pressurization rate of EMs increased linearly as the mass fraction of CuO in the CuO-Fe2O3 bimetallic oxide NPs increased. This suggests that the precise control of the stoichiometric proportions of the strong oxidizer (CuO and mild oxidizer (Fe2O3 components in the bimetallic oxide NPs is a key factor in tuning the explosive reactivity of EMs.

  1. Detection of mercury ions using silver telluride nanoparticles as a substrate and recognition element through surface-enhanced Raman scattering

    Directory of Open Access Journals (Sweden)

    Chia-Wei eWang

    2013-10-01

    Full Text Available In this paper we unveil a new sensing strategy for sensitive and selective detection of Hg2+ through surface-enhanced Raman scattering (SERS using Ag2Te nanoparticles (NPs as a substrate and recognition element and rhodamine 6G (R6G as a reporter. Ag2Te NPs prepared from tellurium dioxide and silver nitrate and hydrazine in aqueous solution containing sodium dodecyl sulfate at 90ºC with an average size of 26.8 ± 4.1 nm (100 counts have strong SERS activity. The Ag2Te substrate provides strong SERS signals of R6G with an enhancement factor of 3.6 × 105 at 1360 cm-1, which is comparable to Ag NPs. After interaction of Ag2Te NPs with Hg2+, some HgTe NPs are formed, leading to decreases in the SERS signal of R6G, mainly because HgTe NPs relative to Ag2Te NPs have weaker SERS activity. Under optimum conditions, this SERS approach using Ag2Te as substrates is selective for the detection of Hg2+, with a limit of detection of 3 nM and linearity over 10-150 nM. The practicality of this approach has been validated for the determination of the concentrations of spiked Hg2+ in a pond water sample.

  2. Multi-elemental nanoparticle exposure after tantalum component failure in hip arthroplasty: In-depth analysis of a single case.

    Science.gov (United States)

    Schoon, Janosch; Geißler, Sven; Traeger, Juliane; Luch, Andreas; Tentschert, Jutta; Perino, Giorgio; Schulze, Frank; Duda, Georg N; Perka, Carsten; Rakow, Anastasia

    2017-11-01

    Porous tantalum components are widely used for complex acetabular reconstructions in revision hip arthroplasty. Multiple other metal alloys such as titanium-aluminum-vanadium or cobalt-chromium-molybdenum are principally used in artificial joint setups. We report a case of tantalum component failure being both cause and effect of a multiple metal exposure. Our aims were to assess and to characterize associated particle exposure and biological consequences. Metal level quantification revealed substantial in vivo exposure to particulate and dissociated tantalum, zirconium, chromium, cobalt, molybdenum, titanium, aluminum and vanadium in periprosthetic compartments. Aside from micron-sized particles, nanoparticles of a broad size range and elemental composition were obtained. Histological exams verified a spectrum of necrotic changes in the periprosthetic tissues. In the presented case tantalum release was accompanied by concomitance of particles originating from other utilized metals. We conclude that an overall in vivo exposure assessment is mandatory for realistic appraisal of metal toxicity and associated risks. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Baseline selenium status and effects of selenium and vitamin e supplementation on prostate cancer risk.

    Science.gov (United States)

    Kristal, Alan R; Darke, Amy K; Morris, J Steven; Tangen, Catherine M; Goodman, Phyllis J; Thompson, Ian M; Meyskens, Frank L; Goodman, Gary E; Minasian, Lori M; Parnes, Howard L; Lippman, Scott M; Klein, Eric A

    2014-03-01

    The Selenium and Vitamin E Cancer Prevention Trial found no effect of selenium supplementation on prostate cancer (PCa) risk but a 17% increased risk from vitamin E supplementation. This case-cohort study investigates effects of selenium and vitamin E supplementation conditional upon baseline selenium status. There were 1739 total and 489 high-grade (Gleason 7-10) PCa cases and 3117 men in the randomly selected cohort. Proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for effects of supplementation within quintiles of baseline toenail selenium. Cox proportional hazards models were used to estimate hazard ratios, and all statistical tests are two-sided. Toenail selenium, in the absence of supplementation, was not associated with PCa risk. Selenium supplementation (combined selenium only and selenium + vitamin E arms) had no effect among men with low selenium status (selenium) but increased the risk of high-grade PCa among men with higher selenium status by 91% (P = .007). Vitamin E supplementation (alone) had no effect among men with high selenium status (≥40th percentile of toenail selenium) but increased the risks of total, low-grade, and high-grade PCa among men with lower selenium status (63%, P = .02; 46%, P = .09; 111%, P = .008, respectively). Selenium supplementation did not benefit men with low selenium status but increased the risk of high-grade PCa among men with high selenium status. Vitamin E increased the risk of PCa among men with low selenium status. Men should avoid selenium or vitamin E supplementation at doses that exceed recommended dietary intakes.

  4. Selenium enrichment of table eggs.

    Science.gov (United States)

    Bennett, D C; Cheng, K M

    2010-10-01

    Selenium is an essential trace element with a recommended dietary allowance for human adults of 55 μg/d. However, there is evidence that greater dietary intakes may have possible health benefits, including a reduction in the risk of cancer. Several studies have shown the feasibility of enriching eggs using organic Se and that Se-enriched eggs are an effective way to supplement human diets. However, few studies have examined the response of egg Se concentration to high (>1 μg/g) dietary organic Se intake by the laying hens. The objective of the current study is to examine the effect of higher dietary organic Se levels on production, egg mass, and egg Se levels. These were assessed by feeding 3 breeds of laying hens (Barred Plymouth Rock, Lohmann Brown, Lohmann White) a basal diet containing 0.3 μg of Se/g of diet as Na2SeO3. Into this diet, Se yeast (SelenoSource AF 600), an organic source of Se, was added at 1.0, 2.4, or 5.1 μg of Se/g of diet for 4 wk. Feed consumption, egg production, and egg mass were not affected by the dietary Se concentration in all 3 breeds. Within the range of Se levels employed in the laying hens' diet, egg Se content increased linearly as dietary levels of Se increased. The results of this study indicate that feeding up to 5.1 µg/g of Se will not affect egg production and the welfare of the laying hen and is a practical way of producing Se-enriched eggs for the consumers.

  5. Bioaccumulation and toxicity of selenium compounds in the green alga Scenedesmus quadricauda

    Science.gov (United States)

    Umysová, Dáša; Vítová, Milada; Doušková, Irena; Bišová, Kateřina; Hlavová, Monika; Čížková, Mária; Machát, Jiří; Doucha, Jiří; Zachleder, Vilém

    2009-01-01

    Background Selenium is a trace element performing important biological functions in many organisms including humans. It usually affects organisms in a strictly dosage-dependent manner being essential at low and toxic at higher concentrations. The impact of selenium on mammalian and land plant cells has been quite extensively studied. Information about algal cells is rare despite of the fact that they could produce selenium enriched biomass for biotechnology purposes. Results We studied the impact of selenium compounds on the green chlorococcal alga Scenedesmus quadricauda. Both the dose and chemical forms of Se were critical factors in the cellular response. Se toxicity increased in cultures grown under sulfur deficient conditions. We selected three strains of Scenedesmus quadricauda specifically resistant to high concentrations of inorganic selenium added as selenite (Na2SeO3) – strain SeIV, selenate (Na2SeO4) – strain SeVI or both – strain SeIV+VI. The total amount of Se and selenomethionine in biomass increased with increasing concentration of Se in the culturing media. The selenomethionine made up 30–40% of the total Se in biomass. In both the wild type and Se-resistant strains, the activity of thioredoxin reductase, increased rapidly in the presence of the form of selenium for which the given algal strain was not resistant. Conclusion The selenium effect on the green alga Scenedesmus quadricauda was not only dose dependent, but the chemical form of the element was also crucial. With sulfur deficiency, the selenium toxicity increases, indicating interference of Se with sulfur metabolism. The amount of selenium and SeMet in algal biomass was dependent on both the type of compound and its dose. The activity of thioredoxin reductase was affected by selenium treatment in dose-dependent and toxic-dependent manner. The findings implied that the increase in TR activity in algal cells was a stress response to selenium cytotoxicity. Our study provides a new

  6. Bioaccumulation and toxicity of selenium compounds in the green alga Scenedesmus quadricauda

    Directory of Open Access Journals (Sweden)

    Doucha Jiří

    2009-05-01

    Full Text Available Abstract Background Selenium is a trace element performing important biological functions in many organisms including humans. It usually affects organisms in a strictly dosage-dependent manner being essential at low and toxic at higher concentrations. The impact of selenium on mammalian and land plant cells has been quite extensively studied. Information about algal cells is rare despite of the fact that they could produce selenium enriched biomass for biotechnology purposes. Results We studied the impact of selenium compounds on the green chlorococcal alga Scenedesmus quadricauda. Both the dose and chemical forms of Se were critical factors in the cellular response. Se toxicity increased in cultures grown under sulfur deficient conditions. We selected three strains of Scenedesmus quadricauda specifically resistant to high concentrations of inorganic selenium added as selenite (Na2SeO3 – strain SeIV, selenate (Na2SeO4 – strain SeVI or both – strain SeIV+VI. The total amount of Se and selenomethionine in biomass increased with increasing concentration of Se in the culturing media. The selenomethionine made up 30–40% of the total Se in biomass. In both the wild type and Se-resistant strains, the activity of thioredoxin reductase, increased rapidly in the presence of the form of selenium for which the given algal strain was not resistant. Conclusion The selenium effect on the green alga Scenedesmus quadricauda was not only dose dependent, but the chemical form of the element was also crucial. With sulfur deficiency, the selenium toxicity increases, indicating interference of Se with sulfur metabolism. The amount of selenium and SeMet in algal biomass was dependent on both the type of compound and its dose. The activity of thioredoxin reductase was affected by selenium treatment in dose-dependent and toxic-dependent manner. The findings implied that the increase in TR activity in algal cells was a stress response to selenium cytotoxicity

  7. Degradation of gaseous formaldehyde via visible light photocatalysis using multi-element doped titania nanoparticles.

    Science.gov (United States)

    Laciste, Maricris T; de Luna, Mark Daniel G; Tolosa, Nolan C; Lu, Ming-Chun

    2017-09-01

    This study developed a modified titanium dioxide photocatalyst doped with multi-element synthesized via sol-gel process to productize a novel photocatalyst. The study includes degradation of gaseous formaldehyde under visible light using the synthesized novel titanium dioxide photocatalyst. Varying molar ratios from 0 to 2 percent (% mole in titanium dioxide) of ammonium fluoride, silver nitrate and sodium tungstate as dopant precursors for nitrogen, fluorine, silver and tungsten were used. Photodegradation of gaseous formaldehyde was examined on glass tubular reactors illuminated with blue light emitting diodes (LEDs) using immobilized photocatalyst. The photocatalytic yield is analyzed based on the photocatalyst surface chemical properties via X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared (FTIR) Spectrophotometry, Brunauer-Emmett-Teller (BET) and X-ray Diffraction (XRD) characterization results. The applied modifications enhanced the visible light capability of the catalyst in comparison to the undoped catalyst and commercially available Degussa P-25, such that it photocatalytically degrades 88.1% of formaldehyde in 120 min. Synthesized titanium dioxide photocatalyst exhibits a unique spin orbital at 532.07 eV and 533.27 eV that came from the hybridization of unoccupied Ti d(t 2g ) levels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Geiten krijgen meestal te veel selenium

    NARCIS (Netherlands)

    Smolders, E.A.A.; Govaerts, W.; Eekeren, van N.J.M.

    2010-01-01

    Geiten gaan efficiënt om met selenium. Mede daardoor zijn de bloedwaardes voor selenium bij geiten vaak hoog, en soms te hoog, zo bleek na bloedonderzoek op dertien biologische geitenbedrijven binnen het project Biogeit. Te veel selenium is schadelijk voor geiten.

  9. 21 CFR 573.920 - Selenium.

    Science.gov (United States)

    2010-04-01

    ... months.” (h) Selenium yeast is a dried, non-viable yeast (Saccharomyces cerevisiae) cultivated in a fed... additive; (4) selenium at such levels does not achieve its intended effect of promoting normal growth and... which minimizes the detrimental effects of selenium salts on the growth rate of the yeast and allows for...

  10. Biofortification and phytoremediation of selenium in China

    Directory of Open Access Journals (Sweden)

    Zhilin eWu

    2015-03-01

    Full Text Available Selenium (Se is an essential trace element for humans and animals but at high concentrations, Se becomes toxic to organisms due to Se replacing sulfur in proteins. Selenium biofortification is an agricultural process that increases the accumulation of Se in crops, through plant breeding, genetic engineering, or use of Se fertilizers. While Se phytoremediation is a green biotechnology to clean up Se-contaminated environments, primarily through phytoextraction and phytovolatilization. By integrating Se phytoremediation and biofortification technologies, Se-enriched plant materials harvested from Se phytoremediation can be used as Se-enriched green manures or other supplementary sources of Se for producing Se-biofortified agricultural products. Earlier studies primarily aimed at enhancing efficacy of phytoremediation and biofortification of Se based on natural variation in progenitor or identification of unique plant species. In this review, we discuss promising approaches to improve biofortification and phytoremediation of Se using knowledge acquired from model crops. We also explored the feasibility of applying biotechnologies such as inoculation of microbial strains for improving the efficiency of biofortification and phytoremediation of Se. The key research and practical challenges that remain in improving biofortification and phytoremediation of Se have been highlighted, and the future development and uses of Se-biofortified agricultural products in China has also been discussed.

  11. Effects of selenium biofortification on crop nutritional quality

    Directory of Open Access Journals (Sweden)

    Mario eMalagoli

    2015-04-01

    Full Text Available Selenium (Se at very low doses has crucial functions in humans and animals. Since plants represent the main dietary source of this element, Se-containing crops may be used as a means to deliver Se to consumers (biofortification. Several strategies have been exploited to increase plant Se content. Selenium assimilation in plants affects both sulphur (S and nitrogen (N metabolic pathways, which is why recent research has also focused on the effect of Se fertilization on the production of S- and N- secondary metabolites with putative health benefits. In this review we discuss the function of Se in plant and human nutrition and the progress in the genetic engineering of Se metabolism to increase the levels and bioavailability of this element in food crops. Particular attention is paid to Se biofortification and the synthesis of compounds with beneficial effects on health.

  12. Effects of selenium biofortification on crop nutritional quality.

    Science.gov (United States)

    Malagoli, Mario; Schiavon, Michela; dall'Acqua, Stefano; Pilon-Smits, Elizabeth A H

    2015-01-01

    Selenium (Se) at very low doses has crucial functions in humans and animals. Since plants represent the main dietary source of this element, Se-containing crops may be used as a means to deliver Se to consumers (biofortification). Several strategies have been exploited to increase plant Se content. Selenium assimilation in plants affects both sulfur (S) and nitrogen (N) metabolic pathways, which is why recent research has also focused on the effect of Se fertilization on the production of S- and N- secondary metabolites with putative health benefits. In this review we discuss the function of Se in plant and human nutrition and the progress in the genetic engineering of Se metabolism to increase the levels and bioavailability of this element in food crops. Particular attention is paid to Se biofortification and the synthesis of compounds with beneficial effects on health.

  13. Modeling the impact of soil aggregate size on selenium immobilization

    Directory of Open Access Journals (Sweden)

    M. F. Kausch

    2013-03-01

    Full Text Available Soil aggregates are mm- to cm-sized microporous structures separated by macropores. Whereas fast advective transport prevails in macropores, advection is inhibited by the low permeability of intra-aggregate micropores. This can lead to mass transfer limitations and the formation of aggregate scale concentration gradients affecting the distribution and transport of redox sensitive elements. Selenium (Se mobilized through irrigation of seleniferous soils has emerged as a major aquatic contaminant. In the absence of oxygen, the bioavailable oxyanions selenate, Se(VI, and selenite, Se(IV, can be microbially reduced to solid, elemental Se, Se(0, and anoxic microzones within soil aggregates are thought to promote this process in otherwise well-aerated soils. To evaluate the impact of soil aggregate size on selenium retention, we developed a dynamic 2-D reactive transport model of selenium cycling in a single idealized aggregate surrounded by a macropore. The model was developed based on flow-through-reactor experiments involving artificial soil aggregates (diameter: 2.5 cm made of sand and containing Enterobacter cloacae SLD1a-1 that reduces Se(VI via Se(IV to Se(0. Aggregates were surrounded by a constant flow providing Se(VI and pyruvate under oxic or anoxic conditions. In the model, reactions were implemented with double-Monod rate equations coupled to the transport of pyruvate, O2, and Se species. The spatial and temporal dynamics of the model were validated with data from experiments, and predictive simulations were performed covering aggregate sizes 1–2.5 cm in diameter. Simulations predict that selenium retention scales with aggregate size. Depending on O2, Se(VI, and pyruvate concentrations, selenium retention was 4–23 times higher in 2.5 cm aggregates compared to 1 cm aggregates. Under oxic conditions, aggregate size and pyruvate concentrations were found to have a positive synergistic effect on selenium retention. Promoting soil

  14. Modeling the impact of soil aggregate size on selenium immobilization

    Science.gov (United States)

    Kausch, M. F.; Pallud, C. E.

    2013-03-01

    Soil aggregates are mm- to cm-sized microporous structures separated by macropores. Whereas fast advective transport prevails in macropores, advection is inhibited by the low permeability of intra-aggregate micropores. This can lead to mass transfer limitations and the formation of aggregate scale concentration gradients affecting the distribution and transport of redox sensitive elements. Selenium (Se) mobilized through irrigation of seleniferous soils has emerged as a major aquatic contaminant. In the absence of oxygen, the bioavailable oxyanions selenate, Se(VI), and selenite, Se(IV), can be microbially reduced to solid, elemental Se, Se(0), and anoxic microzones within soil aggregates are thought to promote this process in otherwise well-aerated soils. To evaluate the impact of soil aggregate size on selenium retention, we developed a dynamic 2-D reactive transport model of selenium cycling in a single idealized aggregate surrounded by a macropore. The model was developed based on flow-through-reactor experiments involving artificial soil aggregates (diameter: 2.5 cm) made of sand and containing Enterobacter cloacae SLD1a-1 that reduces Se(VI) via Se(IV) to Se(0). Aggregates were surrounded by a constant flow providing Se(VI) and pyruvate under oxic or anoxic conditions. In the model, reactions were implemented with double-Monod rate equations coupled to the transport of pyruvate, O2, and Se species. The spatial and temporal dynamics of the model were validated with data from experiments, and predictive simulations were performed covering aggregate sizes 1-2.5 cm in diameter. Simulations predict that selenium retention scales with aggregate size. Depending on O2, Se(VI), and pyruvate concentrations, selenium retention was 4-23 times higher in 2.5 cm aggregates compared to 1 cm aggregates. Under oxic conditions, aggregate size and pyruvate concentrations were found to have a positive synergistic effect on selenium retention. Promoting soil aggregation on

  15. Selenium Bioaccessibility and Speciation in Selenium-Enriched Lettuce: Investigation of the Selenocompounds Liberated after in Vitro Simulated Human Digestion Using Two-Dimensional HPLC-ICP-MS.

    Science.gov (United States)

    do Nascimento da Silva, Emanueli; Aureli, Federica; D'Amato, Marilena; Raggi, Andrea; Cadore, Solange; Cubadda, Francesco

    2017-03-31

    The evaluation of selenium-enriched vegetables as potential dietary sources of selenium, an essential element for humans, requires an assessment of the plant's accumulation ability as well as of the bioaccessibility and speciation of the accumulated selenium, which influence its biological effects in humans. Lettuce hydroponically grown at three selenite (SeVI)/selenate (SeIV) amendment levels was characterized accordingly. Selenium accumulation in lettuce leaves was greatest with Se(VI) amendment, whereas bioaccessibility was 70% on average in both cases. Selenium speciation in gastrointestinal hydrolysates, characterized by anion and cation exchange HPLC-ICP-MS, showed that Se(IV) was largely biotransformed into organoselenium metabolites, with selenomethionine accounting for 1/3 of the total detected species, whereas Se(VI) was incorporated as such in the edible portion of the plant, with only a small fraction (∼20%) converted into organic species. Taking into account both nutritional quality and safety, the Se(IV)-enriched lettuce appeared more favorable as a potential selenium source for human consumption.

  16. Selenium and inflammatory bowel disease.

    Science.gov (United States)

    Kudva, Avinash K; Shay, Ashley E; Prabhu, K Sandeep

    2015-07-15

    Dietary intake of the micronutrient selenium is essential for normal immune functions. Selenium is cotranslationally incorporated as the 21st amino acid, selenocysteine, into selenoproteins that function to modulate pathways involved in inflammation. Epidemiological studies have suggested an inverse association between selenium levels and inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis that can potentially progress to colon cancer. However, the underlying mechanisms are not well understood. Here we summarize the current literature on the pathophysiology of IBD, which is multifactorial in origin with unknown etiology. We have focused on a few selenoproteins that mediate gastrointestinal inflammation and activate the host immune response, wherein macrophages play a pivotal role. Changes in cellular oxidative state coupled with altered expression of selenoproteins in macrophages drive the switch from a proinflammatory phenotype to an anti-inflammatory phenotype to efficiently resolve inflammation in the gut and restore epithelial barrier integrity. Such a phenotypic plasticity is accompanied by changes in cytokines, chemokines, and bioactive metabolites, including eicosanoids that not only mitigate inflammation but also partake in restoring gut homeostasis through diverse pathways involving differential regulation of transcription factors such as nuclear factor-κB and peroxisome proliferator-activated receptor-γ. The role of the intestinal microbiome in modulating inflammation and aiding in selenium-dependent resolution of gut injury is highlighted to provide novel insights into the beneficial effects of selenium in IBD. Copyright © 2015 the American Physiological Society.

  17. Influence of selenite and fourteen trace elements on cataractogenesis in the rat.

    Science.gov (United States)

    Shearer, T R; Anderson, R S; Britton, J L

    1983-04-01

    The purposes of these experiments were to measure the influence of 14 trace elements on cataractogenesis and to test if these trace elements could prevent cataracts induced by selenium. On days 5-9 postpartum, suckling white rats received daily subcutaneous injections of either selenium (0.15 mumoles Se, as Na2SeO3, per pup) or selenium plus one of 14 other trace elements (separate subcutaneous injection) at one to five times the molar concentration of selenium. The frequency and severity of cataracts at three locations in the lens were assessed by slit-lamp examination on day 26-28 postpartum. Seven ions were found to be effective in preventing selenium-induced cataracts (% protection): mercuric (100%), silver (80%), cyanide (75%), arsenite (75%), cadmium (60%), and cupric (44%). Tellurite ion offered only 20% protection, while ferrous, zinc, lead, chromic, molybdate, tungstate, and vanadate ions provided no protection against selenium-induced cataract. No significant differences were found between the concentration of selenium in the lenses of control and cataractous lenses when measured approximately three weeks after selenium injection. Except for selenium, none of the trace minerals alone caused cataracts under our experimental conditions. In addition to subcutaneous injection of selenium, oral administration of this element was also found to cause cataract. It was concluded that among the ions studied, selenite was a powerful and rapid promoter of nuclear cataract formation, and that the protection ions may serve as useful probes for elucidating the mechanism of selenium-induced cataracts.

  18. Forecasting Selenium Discharges to the San Francisco Bay-Delta Estuary: Ecological Effects of A Proposed San Luis Drain Extension

    Science.gov (United States)

    Presser, Theresa S.; Luoma, Samuel N.

    2006-01-01

    Selenium discharges to the San Francisco Bay-Delta Estuary (Bay-Delta) could change significantly if federal and state agencies (1) approve an extension of the San Luis Drain to convey agricultural drainage from the western San Joaquin Valley to the North Bay (Suisun Bay, Carquinez Strait, and San Pablo Bay); (2) allow changes in flow patterns of the lower San Joaquin River and Bay-Delta while using an existing portion of the San Luis Drain to convey agricultural drainage to a tributary of the San Joaquin River; or (3) revise selenium criteria for the protection of aquatic life or issue criteria for the protection of wildlife. Understanding the biotransfer of selenium is essential to evaluating effects of selenium on Bay-Delta ecosystems. Confusion about selenium threats to fish and wildlife stem from (1) monitoring programs that do not address specific protocols necessary for an element that bioaccumulates; and (2) failure to consider the full complexity of the processes that result in selenium toxicity. Past studies show that predators are more at risk from selenium contamination than their prey, making it difficult to use traditional methods to predict risk from environmental concentrations alone. This report presents an approach to conceptualize and model the fate and effects of selenium under various load scenarios from the San Joaquin Valley. For each potential load, progressive forecasts show resulting (1) water-column concentration; (2) speciation; (3) transformation to particulate form; (4) particulate concentration; (5) bioaccumulation by invertebrates; (6) trophic transfer to predators; and (7) effects on those predators. Enough is known to establish a first-order understanding of relevant conditions, biological response, and ecological risks should selenium be discharged directly into the North Bay through a conveyance such as a proposed extension of the San Luis Drain. The approach presented here, the Bay-Delta selenium model, determines the mass, fate

  19. Cadmium, lead, arsenic and selenium levels in patients with type 2 ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the level of toxic elements: lead (Pb), cadmium (Cd) and arsenic (As) levels in whole blood and selenium (Se) (an antioxidant element) in serum of patients with type 2 diabetes mellitus. Fifty diabetic patients and 40 apparently healthy non-diabetic individuals were recruited into this ...

  20. Long-term selenium supplementation of humans: selenium status and relationships between selenium concentrations in skeletal muscle and indicator materials.

    Science.gov (United States)

    Behne, Dietrich; Alber, Dorothea; Kyriakopoulos, Antonios

    2010-04-01

    Supplementation with elevated doses of l-selenomethionine (SeM) or selenium-enriched yeast that contains SeM as the main selenium species is frequently used as a protective or therapeutic measure. Information on the effects of long-term selenium supplementation on the body selenium status is, however, rather scarce. We therefore investigated fifteen male test persons who had taken selenium yeast and/or SeM supplements in medium doses of 62.5-125 microg Se/day or high doses of 200-262.5 microg Se/day for periods ranging from 1 year to 24 years. Seven non-supplemented men served as controls. As skeletal muscle is the main selenium pool, thigh muscle biopsy samples were taken. The selenium concentrations in these biopsies and in samples of the indicator materials blood, blood plasma, blood cells, head hair and toenails were determined by neutron activation analysis. Compared with the controls, the muscle selenium level was raised with additional selenium supplementation, but the relative increase in the mean muscle selenium concentration (by factors of about 1.6 and 2 for the medium and high doses, respectively) was lower than that in the selenium intake. Highly significant correlations found between the selenium concentrations in muscle and whole blood (R=0.90), red blood cells (R=0.91), blood plasma (R=0.87), head hair (R=0.89) and toenails (R=0.85) show that in humans supplemented in this way the selenium status can be assessed in a relatively easy way by analysis of the selenium retention in these indicator materials. 2009 Elsevier GmbH. All rights reserved.

  1. Selenium Content in Seafood in Japan

    Directory of Open Access Journals (Sweden)

    Haruka Iida

    2013-01-01

    Full Text Available Selenium is an essential micronutrient for humans, and seafood is one of the major selenium sources, as well as red meat, grains, eggs, chicken, liver and garlic. A substantial proportion of the total amount of selenium is present as selenium containing imidazole compound, selenoneine, in the muscles of ocean fish. In order to characterize the selenium content in seafood, the total selenium levels were measured in the edible portions of commercially important fish and shellfish species. Among the tested edible portions, alfonsino muscle had the highest selenium levels (concentration of 1.27 mg/kg tissue. High levels of selenium (1.20–1.07 mg/kg were also found in the salted ovary products of mullet and Pacific herring. In other fish muscles, the selenium levels ranged between 0.12 and 0.77 mg/kg tissue. The selenium levels were closely correlated with the mercury levels in the white and red muscles in alfonsino. The selenium content in spleen, blood, hepatopancreas, heart, red muscle, white muscle, brain, ovary and testis ranged between 1.10 and 24.8 mg/kg tissue in alfonsino.

  2. Does selenium supplementation affect thyroid function?

    DEFF Research Database (Denmark)

    Winther, Kristian Hillert; Bonnema, Steen Joop; Cold, Frederik

    2015-01-01

    OBJECTIVE: Selenium is present in the active site of proteins important for thyroid hormone synthesis and metabolism. The objective of this study is to investigate the effect of selenium supplementation in different doses on thyroid function, under conditions of suboptimal dietary selenium intake......=0.015), respectively, per 100 μg/day increase, with insignificant differences between 6 months and 5 years. No significant effects were found for FT3 and FT3:FT4 ratio. CONCLUSIONS: In euthyroid subjects, selenium supplementation minutely and dose-dependently affects thyroid function, when compared...... with placebo, by decreasing serum TSH and FT4 concentrations. Based on these findings, selenium supplementation is not warranted under conditions of marginal selenium deficiency. However, a role for selenium supplementation in the treatment of autoimmune thyroid diseases is still unresolved....

  3. Recovery of palladium, cesium, and selenium from heavy metal alkali borosilicate glass by combination of heat treatment and leaching processes

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhanglian; Okada, Takashi, E-mail: t-okada@u-fukui.ac.jp; Nishimura, Fumihiro; Yonezawa, Susumu

    2017-06-05

    Highlights: • A separation technique of both noble and less noble metal from glass is studied. • Via reductive heat treatment, 80% of palladium is extracted in liquid bismuth. • Sodium–potassium-rich materials with cesium and selenium are phase separated. • From the materials, over 80% of cesium and selenium are extracted in water. - Abstract: Reductive heat-treatment and leaching process were applied to a simulated lead or bismuth soda-potash-borosilicate glass with palladium, cesium, and selenium to separate these elements. In the reductive heat treatment, palladium is extracted in liquid heavy metal phase generated by the reduction of the heavy metal oxides, whereas cesium and selenium are concentrated in phase separated Na–K-rich materials on the glass surface. From the materials, cesium and selenium can be extracted in water, and the selenium extraction was higher in the treatment of the bismuth containing glass. The chemical forms of palladium in the glass affected the extraction efficiencies of cesium and selenium. Among the examined conditions, in the bismuth glass treatment, the cesium and selenium extraction efficiencies in water were over 80%, and that of palladium in liquid bismuth was over 80%.

  4. Soil Redox Chemistry Limitation of Selenium Concentration in Carex Species Sedges

    Energy Technology Data Exchange (ETDEWEB)

    Bruce J. Mincher; John Mionczynski; Patrick A. Hnilicka

    2007-09-01

    The trace element selenium (Se) is required in the production of enzymes that protect mammalian cells from oxidative damage due to the byproducts of aerobic respiration. Its deficiency in livestock results in the nutritional muscular dystrophy called white muscle disease. This especially affects juveniles in the preweaning period. Symptoms have also been reported in wild herbivores on low-Se forage, and their appearance may be episodic, suggesting temporal variations in Se uptake by plants. Here, we report variations in selenium concentrations in Carex spp. sedges used as forage by bighorn sheep (Ovis canadensis) on summer range in the Wyoming, Wind River Mountains, and correlate those variations with soil conditions that affect the bioavailability of selenium. Variations in available Se are explained based upon the known oxidation/reduction chemistry of the element. It is concluded that water-saturated, alpine soils provide conditions suitable for the reduction of Se to the unavailable, elemental form, limiting its concentration in forage plants.

  5. Biosynthesis of nanoparticles of metals and metalloids by basidiomycetes. Preparation of gold nanoparticles by using purified fungal phenol oxidases.

    Science.gov (United States)

    Vetchinkina, Elena P; Loshchinina, Ekaterina A; Vodolazov, Ilya R; Kursky, Viktor F; Dykman, Lev A; Nikitina, Valentina E

    2017-02-01

    The work shows the ability of cultured Basidiomycetes of different taxonomic groups-Lentinus edodes, Pleurotus ostreatus, Ganoderma lucidum, and Grifola frondosa-to recover gold, silver, selenium, and silicon, to elemental state with nanoparticles formation. It examines the effect of these metal and metalloid compounds on the parameters of growth and accumulation of biomass; the optimal cultivation conditions and concentrations of the studied ion-containing compounds for recovery of nanoparticles have been identified. Using the techniques of transmission electron microscopy, dynamic light scattering, X-ray fluorescence and X-ray phase analysis, the degrees of oxidation of the bioreduced elements, the ζ-potential of colloidal solutions uniformity, size, shape, and location of the nanoparticles in the culture fluid, as well as on the surface and the inside of filamentous hyphae have been determined. The study has found the part played by homogeneous chromatographically pure fungal phenol-oxidizing enzymes (laccases, tyrosinases, and Mn-peroxidases) in the recovery mechanism with formation of electrostatically stabilized colloidal solutions. A hypothetical mechanism of gold(III) reduction from HAuCl4 to gold(0) by phenol oxidases with gold nanoparticles formation of different shapes and sizes has been introduced.

  6. Radioprotection by metals: Selenium

    Science.gov (United States)

    Weiss, J. F.; Srinivasan, V.; Kumar, K. S.; Landauer, M. R.

    The need exists for compounds that will protect individuals from high-dose acute radiation exposure in space and for agents that might be less protective but less toxic and longer acting. Metals and metal derivatives provide a small degree of radioprotection (dose reduction factor animal survival after whole-body irradiation). Emphasis is placed here on the radioprotective potential of selenium (Se). Both the inorganic salt, sodium selenite, and the organic Se compound, selenomethionine, enhance the survival of irradiated mice (60Co, 0.2 Gy/min) when injected IP either before (-24 hr and -1 hr) or shortly after (+15 min) radiation exposure. When administered at equitoxic doses (one-fourth LD10; selenomethionine = 4.0 mg/kg Se, sodium selenite = 0.8 mg/kg Se), both drugs enhanced the 30-day survival of mice irradiated at 9 Gy. Survival after 10-Gy exposure was significantly increased only after selenomethionine treatment. An advantage of selenomethionine is lower lethal and behavioral toxicity (locomotor activity depression) compared to sodium selenite, when they are administered at equivalent doses of Se. Sodium selenite administered in combination with WR-2721, S-2-(3-aminopropylamino)ethylphosphorothioic acid, enhances the radioprotective effect and reduces the lethal toxicity, but not the behavioral toxicity, of WR-2721. Other studies on radioprotection and protection against chemical carcinogens by different forms of Se are reviewed. As additional animal data and results from human chemoprevention trials become available, consideration also can be given to prolonged administration of Se compounds for protection against long-term radiation effects in space.

  7. Nutrigenetics, nutrigenomics and selenium

    Directory of Open Access Journals (Sweden)

    Lynnette Robiin Ferguson

    2011-04-01

    Full Text Available Selenium (Se is an important micronutrient that, as a component of selenoproteins, influences oxidative and inflammatory processes. Its’ levels vary considerably, with different ethnic and geographic population groups showing varied conditions, ranging from frank Se deficiencies to toxic effects. An optimum Se level is essential for the maintenance of homeostasis, and this optimum may vary according to life stage, general state of health and genotype. Nutrigenetic studies of different Se levels, in the presence of genetic variants in selenoproteins, suggest that an effective dietary Se intake for one individual may be very different from that for others. However, we are just starting to learn the significance of various genes in selenoprotein pathways, functional variants in these, and how to combine such data from genes into pathways, alongside dietary intake or serum levels of Se. Advances in systems biology, genetics and genomics technologies, including genetic/genomic, epigenetic/epigenomic, transcriptomic, proteomic and metabolomic information, start to make it feasible to assess a comprehensive spectrum of the biological activity of Se. Such nutrigenomic approaches may prove very sensitive biomarkers of optimal Se status at the individual or population level. The premature cessation of a major human Se intervention trial has led to considerable controversy as to the value of Se supplementation at the population level. New websites provide convenient links to current information on methodologies available for nutrigenetics and nutrigenomics. These new technologies will increasingly become an essential tool in optimising the level of Se and other micronutrients for optimal health, in individuals and in population groups. However, definitive proof of such effects will require very large collaborative studies, international agreement on study design and innovative approaches to data analysis.

  8. 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

    rapidly than it sorbs to ferric solids. Though it was not possible to demonstrate a decrease in selenium concentrations to levels below the project'ale testing were evident at the pilot scale. Specifically, reducing oxidation air rate and ORP tends to either retain selenium as selenite in the liquor or shift selenium phase partitioning to the solid phase. Oxidation air flow rate control may be one option for managing selenium behavior in FGD scrubbers. Units that cycle load widely may find it more difficult to impact ORP conditions with oxidation air flow rate control alone. Because decreasing oxidation air rates to the reaction tank showed that all new selenium reported to the solids, the addition of ferric chloride to the pilot scrubber could not show further improvements in selenium behavior. Ferric chloride addition did shift mercury to the slurry solids, specifically to the fine particles. Several competing pathways may govern the reporting of selenium to the slurry solids: co-precipitation with gypsum into the bulk solids and sorption or co-precipitation with iron into the fine particles. Simultaneous measurement of selenium and mercury behavior suggests a holistic management strategy is best to optimize the fate of both of these elements in FGD waters. Work conducted under this project evaluated sample handling and analytical methods for selenium speciation in FGD waters. Three analytical techniques and several preservation methods were employed. Measurements of selenium speciation over time indicated that for accurate selenium speciation, it is best to conduct measurements on unpreserved, filtered samples as soon after sampling as possible. The capital and operating costs for two selenium management strategies were considered: ferric chloride addition and oxidation air flow rate control. For ferric chloride addition, as might be expected the reagent makeup costs dominate the overall costs, and range from 0.22 to 0.29 mills/kWh. For oxidation air flow rate

  9. Memory effect of low-temperature processed ZnO thin-film transistors having metallic nanoparticles as charge trapping elements.

    Science.gov (United States)

    Park, Young-Su; Kim, Soo-Jin; Lyu, Si-Hoon; Lee, Byoung Hoon; Sung, Myung Mo; Lee, Jaegab; Lee, Jang-Sik

    2012-02-01

    In this study, non-volatile memory effect was characterized using the single-transistor-based memory devices based on self-assembled gold nanoparticles (AuNP) as the charge trapping elements and atomic-layer deposited ZnO as the channel layer. The fabricated memory devices showed controllable and reliable threshold voltage shifts according to the program/erase operations that resulted from the charging/discharging of charge carriers in the charge trapping elements. Reliable non-volatile memory properties were also confirmed by the endurance and data retention measurements. The low temperature processes of the key device elements, i.e., AuNP charge trapping layer and ZnO channel layer, enable the use of this device structure to the transparent/flexible non-volatile memory applications in the near future.

  10. Aspects of a Distinct Cytotoxicity of Selenium Salts and Organic Selenides in Living Cells with Possible Implications for Drug Design

    Directory of Open Access Journals (Sweden)

    Ethiene Castellucci Estevam

    2015-07-01

    Full Text Available Selenium is traditionally considered as an antioxidant element and selenium compounds are often discussed in the context of chemoprevention and therapy. Recent studies, however, have revealed a rather more colorful and diverse biological action of selenium-based compounds, including the modulation of the intracellular redox homeostasis and an often selective interference with regulatory cellular pathways. Our basic activity and mode of action studies with simple selenium and tellurium salts in different strains of Staphylococcus aureus (MRSA and Saccharomyces cerevisiae indicate that such compounds are sometimes not particularly toxic on their own, yet enhance the antibacterial potential of known antibiotics, possibly via the bioreductive formation of insoluble elemental deposits. Whilst the selenium and tellurium compounds tested do not necessarily act via the generation of Reactive Oxygen Species (ROS, they seem to interfere with various cellular pathways, including a possible inhibition of the proteasome and hindrance of DNA repair. Here, organic selenides are considerably more active compared to simple salts. The interference of selenium (and tellurium compounds with multiple targets could provide new avenues for the development of effective antibiotic and anticancer agents which may go well beyond the traditional notion of selenium as a simple antioxidant.

  11. Serum selenium concentration in Mashhad prisoners, Iran.

    Science.gov (United States)

    Ehteshamfar, Seyed-Morteza; Shapouri-Moghaddam, Abbas; Safarian, Mohammad; Nematy, Mohsen; Bahrami-Taghanaki, Hamidreza; Azizi, Hoda

    2012-08-01

    To determine the serum selenium concentration among prisoners in the central jail of Mashhad, Northeast of Iran. In a cross-section study, a sample of 435 prisoners (387 men [34.5±10 years] and 48 women [36.4±11 years]) recruited during May 2008 to June 2008 from Mashhad Central Prison, Mashhad, Iran, using multistage sampling method, proportionate to gender, age groups and kind of crime. Serum level of selenium was assessed using atomic absorption spectrophotometer. The mean of serum selenium concentration was 121±20 ug/l. Prevalence of selenium deficiency was 9.7% in selected sample. The selenium deficiency was more prevalent in women than men (25.5% versus 7.8%, p=0.00). Age distribution of serum selenium level had a different pattern among men and women. While in men serum selenium level on average was least in those aged 50 and over, in women, serum selenium did not change with age. Body mass index (BMI) and weight change had no relations. Results of this study suggest that selenium status of the prisoners in Mashhad central prison is of concern. Women may be at higher risk for selenium deficiency. These results have implications for officials in charge with prisoners and health policy makers.

  12. In vitro evaluation of selenium genotoxic, cytotoxic, and protective effects: a review

    Energy Technology Data Exchange (ETDEWEB)

    Valdiglesias, Vanessa [University of A Coruna, Toxicology Unit, Department of Psychobiology, A Coruna (Spain); University of A Coruna, Department of Cell and Molecular Biology, Faculty of Sciences, A Coruna (Spain); Pasaro, Eduardo; Laffon, Blanca [University of A Coruna, Toxicology Unit, Department of Psychobiology, A Coruna (Spain); Mendez, Josefina [University of A Coruna, Department of Cell and Molecular Biology, Faculty of Sciences, A Coruna (Spain)

    2010-05-15

    Selenium is an oligoelement with essential biological functions. Diet is the most important selenium source, and intake of this element depends on its concentration in food and amount of food consumed. Among the essential human micronutrients, selenium is peculiar due to its beneficial physiological activity and toxicity. It may have anticarcinogenic effects at low concentrations, whereas at concentrations higher than those necessary for nutrition, it can be genotoxic and carcinogenic. Because of that, selenium is probably the most widely investigated of all the oligonutrients. In the last decades, there has been increasing interest in several nutritional Se compounds because of their environmental, biological, and toxicological properties, particularly for their cancer- and disease-preventing activities. This article gives an overview of the results of in vitro studies on mutagenicity, genotoxicity, cytotoxicity, and DNA repair conducted within the last decades with different organic and inorganic selenium compounds. Results from these studies provide a better knowledge on the selenium activity and help to elucidate the reasons underlying its duality in order to regulate its correct use in nutrition and clinic. (orig.)

  13. Omega-3 fatty acids, mercury, and selenium in fish and the risk of cardiovascular diseases.

    Science.gov (United States)

    Park, Kyong; Mozaffarian, Dariush

    2010-11-01

    Fish consumption is associated with lower risk of cardiovascular disease. Some fish species also contain methylmercury, which may increase cardiovascular risk, as well as selenium, a trace element that could counter the effects of methylmercury or have beneficial effects itself. These potentially conflicting effects have created public confusion about the risks and benefits of fish consumption in adults. We examined the evidence for cardiovascular effects of fish consumption, particularly effects of marine omega-3 fatty acids, methylmercury, and selenium. Compelling evidence indicates that modest fish consumption substantially reduces cardiovascular risk, in particular cardiac mortality, related at least partly to benefits of omega-3 fatty acids. In contrast, observational studies and (for selenium) clinical trials demonstrate mixed and inconclusive results for cardiovascular effects of methylmercury and selenium. Net health benefits of overall fish consumption in adults are clear. Quantitative risk-benefit analyses of cardiovascular effects of consuming specific fish species, based on joint contents of fatty acids, methylmercury, and selenium, cannot currently be performed until the cardiovascular effects of methylmercury and selenium are established.

  14. nanoparticles

    Science.gov (United States)

    Olive-Méndez, Sion F.; Santillán-Rodríguez, Carlos R.; González-Valenzuela, Ricardo A.; Espinosa-Magaña, Francisco; Matutes-Aquino, José A.

    2014-04-01

    In this work, we present the role of vanadium ions (V+5 and V+3), oxygen vacancies (VO), and interstitial zinc (Zni) to the contribution of specific magnetization for a mixture of ZnO-V2O5 nanoparticles (NPs). Samples were obtained by mechanical milling of dry powders and ethanol-assisted milling for 1 h with a fixed atomic ratio V/Zn?=?5% at. For comparison, pure ZnO samples were also prepared. All samples exhibit a room temperature magnetization ranging from 1.18?×?10-3 to 3.5?×?10-3 emu/gr. Pure ZnO powders (1.34?×?10-3 emu/gr) milled with ethanol exhibit slight increase in magnetization attributed to formation of Zni, while dry milled ZnO powders exhibit a decrease of magnetization due to a reduction of VO concentration. For the ZnO-V2O5 system, dry milled and thermally treated samples under reducing atmosphere exhibit a large paramagnetic component associated to the formation of V2O3 and secondary phases containing V+3 ions; at the same time, an increase of VO is observed with an abrupt fall of magnetization to σ?~?0.7?×?10-3 emu/gr due to segregation of V oxides and formation of secondary phases. As mechanical milling is an aggressive synthesis method, high disorder is induced at the surface of the ZnO NPs, including VO and Zni depending on the chemical environment. Thermal treatment restores partially structural order at the surface of the NPs, thus reducing the amount of Zni at the same time that V2O5 NPs segregate reducing the direct contact with the surface of ZnO NPs. Additional samples were milled for longer time up to 24 h to study the effect of milling on the magnetization; 1-h milled samples have the highest magnetizations. Structural characterization was carried out using X-ray diffraction and transmission electron microscopy. Identification of VO and Zni was carried out with Raman spectra, and energy-dispersive X-ray spectroscopy was used to verify that V did not diffuse into ZnO NPs as well to quantify O/Zn ratios.

  15. Blood selenium levels and contribution of food groups to selenium intake in adolescent girls in Iceland

    National Research Council Canada - National Science Library

    Gudmundsdottir, Edda Y; Gunnarsdottir, Ingibjorg; Thorlacius, Arngrimur; Reykdal, Olafur; Gunnlaugsdottir, Helga; Thorsdottir, Inga; Steingrimsdottir, Laufey

    2012-01-01

    .... The aim of this study was to assess selenium in the diet and whole blood of adolescent girls, as well as define the most important foods contributing to intake and blood concentrations of selenium...

  16. 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.

  17. Selenium exposure by food sources. impact into human health due selenium deficiency as well as selenium excess

    OpenAIRE

    Ivanov Iliev, Angel

    2012-01-01

    Selenium is important micronutrient with great impact into human health. In mammal metabolism it is included as coenzyme in several key enzymes. There are 35 selenoproteins identified, which role is not fully clarified yet. Selenium is well known both with its high toxicity and presence of several important diseases impacted by its deficiency. Selenium dosage is also a problem. Minimal daily required dose differs less than an order from maximum allowed daily intake. Northern Balkans is territ...

  18. The influence of selenium supplementation of animal feed on human selenium intake in Serbia

    OpenAIRE

    Pavlović Z.; Miletić I.; Jokić Ž.; Stevanović J.; Šobajić S.; Bulat Z.

    2013-01-01

    The use of selenium as animal feed supplement in Serbia was approved in 1989 for some categories of pigs, sheep and poultry. From 2000 selenium in animal feed became a requirement for all categories of farm animals. The aim of this study was to determine the consumption of selenium by Serbian livestock and in poultry production between 1990-1991 and 2000-2008 and to analyze the selenium content of meat, milk and eggs sold on Serbian markets to gain insight ...

  19. Baseline Selenium Status and Effects of Selenium and Vitamin E Supplementation on Prostate Cancer Risk

    OpenAIRE

    Kristal, AR; Darke, AK; Morris, JS; Tangen, CM; Goodman, PJ; Thompson, IM; Meyskens, FL; Goodman, Ge; Minasian, LM; Parnes, HL; Lippman, SM; Klein, EA

    2014-01-01

    Background The Selenium and Vitamin E Cancer Prevention Trial found no effect of selenium supplementation on prostate cancer (PCa) risk but a 17% increased risk from vitamin E supplementation. This case-cohort study investigates effects of selenium and vitamin E supplementation conditional upon baseline selenium status. Methods There were 1739 total and 489 high-grade (Gleason 7-10) PCa cases and 3117 men in the randomly selected cohort. Proportional hazards models estimated hazard ratios (HR...

  20. Effect of temperature on selenium removal from wastewater by UASB reactors.

    Science.gov (United States)

    Dessì, Paolo; Jain, Rohan; Singh, Satyendra; Seder-Colomina, Marina; van Hullebusch, Eric D; Rene, Eldon R; Ahammad, Shaikh Ziauddin; Carucci, Alessandra; Lens, Piet N L

    2016-05-01

    The effect of temperature on selenium (Se) removal by upflow anaerobic sludge blanket (UASB) reactors treating selenate and nitrate containing wastewater was investigated by comparing the performance of a thermophilic (55 °C) versus a mesophilic (30 °C) UASB reactor. When only selenate (50 μM) was fed to the UASB reactors (pH 7.3; hydraulic retention time 8 h) with excess electron donor (lactate at 1.38 mM corresponding to an organic loading rate of 0.5 g COD L(-1) d(-1)), the thermophilic UASB reactor achieved a higher total Se removal efficiency (94.4 ± 2.4%) than the mesophilic UASB reactor (82.0 ± 3.8%). When 5000 μM nitrate was further added to the influent, total Se removal was again better under thermophilic (70.1 ± 6.6%) when compared to mesophilic (43.6 ± 8.8%) conditions. The higher total effluent Se concentration in the mesophilic UASB reactor was due to the higher concentrations of biogenic elemental Se nanoparticles (BioSeNPs). The shape of the BioSeNPs observed in both UASB reactors was different: nanospheres and nanorods, respectively, in the mesophilic and thermophilic UASB reactors. Microbial community analysis showed the presence of selenate respirers as well as denitrifying microorganisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Mercury-selenium interactions in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Saroff, L. [Department of Energy, Washington, DC (United States); Lipfert, W.; Moskowitz, P.D. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science

    1996-02-01

    The Clean Air Act Amendments of 1990 require the U.S. Environmental Protection Agency (EPA) to consider the need to control emissions of trace elements and compounds emitted from coal combustion, including coal-fired power plants. Concern has been expressed about emissions of mercury and arsenic, for example, since health effects may be associated with exposure to some of these compounds. By and large, effects of trace element emissions have been considered individually, without regard for possible interactions. To the extent that the relevant environmental pathways and health endpoints differ, this mode of analysis is appropriate. For example, arsenic is considered a carcinogen and mercury affects the brain. However, there may be compelling reasons to consider emissions of mercury (Hg) and selenium (Se) together: (1) Both Se and Hg are emitted from power plants primarily as vapors. (2) Hg and Se are both found in fish, which is the primary pathway for Hg health effects. (3) Se has been shown to suppress Hg methylation in aqueous systems, which is a necessary step for Hg health effects at current environmental concentrations. (4) Se is a trace element that is essential for health but that can also be toxic at high concentrations; it can thus have both beneficial and adverse health effects, depending on the dosage. This paper reviews some of the salient characteristics and interactions of the Hg-Se system, to consider the hypothesis that the effects of emissions of these compounds should be considered jointly.

  2. Survivin gene silencing sensitizes prostate cancer cells to selenium growth inhibition

    Directory of Open Access Journals (Sweden)

    Liu Xichun

    2010-08-01

    Full Text Available Abstract Background Prostate cancer is a leading cause of cancer-related death in men worldwide. Survivin is a member of the inhibitor of apoptosis (IAP protein family that is expressed in the majority of human tumors including prostate cancer, but is barely detectable in terminally differentiated normal cells. Downregulation of survivin could sensitize prostate cancer cells to chemotherapeutic agents in vitro and in vivo. Selenium is an essential trace element. Several studies have shown that selenium compounds inhibit the growth of prostate cancer cells. The objective of this study is to investigate whether survivin gene silencing in conjunction with selenium treatment could enhance the therapeutic efficacy for prostate cancer and to elucidate the underlying mechanisms. Methods Expression of survivin was analyzed in a collection of normal and malignant prostatic tissues by immunohistochemical staining. In vitro studies were conducted in PC-3M, C4-2B, and 22Rv1 prostate cancer cells. The effect of selenium on survivin expression was analyzed by Western blotting and semi-quantitative RT-PCR. Survivin gene knockdown was carried out by transfecting cells with a short hairpin RNA (shRNA designed against survivin. Cell proliferation was quantitated by the 3-(4,5-Dimethylthiazol-2-yl- 2,5-Diphenyltetrazolium Bromide (MTT assay and apoptosis by propidium iodide staining followed by flow cytometry analysis. Finally, in vivo tumor growth assay was performed by establishing PC-3M xenograft in nude mice and monitoring tumor growth following transfection and treatment. Results We found that survivin was undetectable in normal prostatic tissues but was highly expressed in prostate cancers. Survivin knockdown or selenium treatment inhibited the growth of prostate cancer cells, but the selenium effect was modest. In contrast to what have been observed in other cell lines, selenium treatment had little or no effect on survivin expression in several androgen

  3. Toxicology evaluation of selenium protein powder

    Directory of Open Access Journals (Sweden)

    Qin Shunyi

    2017-01-01

    Full Text Available The experiment was conducted to evaluate the safety of selenium protein powder, a novel organic selenium nutritional supplement, and reported corresponding data and results based on a series of toxicological tests. It was examined to evaluate oral acute toxicity by median lethal dose test and mutagenic potential by bone marrow cell micronucleus test and sperm abnormality test using Kun-Ming mice. The results showed that the oral LD50 of selenium protein powder exceeded 31.25 g/kg body weight in mice. No mutagenicity was found by mouse bone marrow cell micronucleus test and mouse sperm abnormality test. The results suggested greater safety of selenium protein powder as a nutritional selenium supplement, and selenium protein powder has the potential for development and application in food systems or functional foods.

  4. Contrasting impact of organic and inorganic nanoparticles and colloids on the behavior of particle-reactive elements in tropical estuaries: An experimental study

    Science.gov (United States)

    Merschel, Gila; Bau, Michael; Dantas, Elton Luiz

    2017-01-01

    Estuarine processes may affect the flux of dissolved organic carbon (DOC), iron and other particle-reactive elements such as the rare earth elements and yttrium (REY), into the ocean via salt-induced coagulation and subsequent removal of river-borne (nano-)particles and colloids. We experimentally assessed the impact of the admixture of seawater on DOC, Fe and REY associated with inorganic and organic nanoparticles and colloids (NPCs) present in tropical rivers, using Rio Solimões and Rio Negro, which are particularly rich in inorganic and organic NPCs, respectively, as river water endmembers. Similar to the conservative elements Sr, Rb and U, DOC behaves conservatively in all mixing experiments, whereas strong removal of Fe and REY (and preferential removal of light over heavy REY and of Ce relative to La and Pr) is confined to experiments with inorganic NPC-rich Rio Solimões water. This removal already occurs at very low salinity and is due to the aggregation of the inorganic NPCs. However, REY removal efficiency increases gradually with increasing salinity, which is in marked contrast to DOC-poor Arctic river waters from which REY removal at lowest salinity is significantly stronger. This suggests that the DOC concentrations in the water have a profound impact on the estuarine mixing behavior of particle-reactive elements. In marked contrast to the Rio Solimões mixing experiment, Fe and the REY in experiments with Rio Negro water behave similarly to DOC and mix conservatively with seawater, indicating that the organic NPCs, most of which are humic and fulvic acids, and their associated trace elements are much less susceptible to coagulation and estuarine removal than inorganic ones. Even at higher salinities, estuarine REY removal from inorganic NPC-rich Rio Solimões water significantly exceeds REY removal from organic NPC-rich Rio Negro water. Hence, the combination of higher element concentrations in and of less estuarine removal from organic NPC

  5. Development of filter element from nanocomposites of ultra high molar mass polyethylene having silver nanoparticles; Desenvolvimento de elemento filtrante a partir de nanocompositos de polietileno de ultra-alta massa molar contendo nanoparticulas de prata

    Energy Technology Data Exchange (ETDEWEB)

    Bizzo, Maurizio A.; Wang, S. Hui, E-mail: mbizzo@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Escola Politecnica de Engenharia Metalurgica e de Materiais

    2015-07-01

    The production of polymer based filter elements for water is widespread in the market but has an undesirable characteristic, they are not always efficient and capable of retaining or eliminating microorganisms. This paper proposes the production of filters with biocidal activity, comprised by nanocomposites of ultra-high molar mass polyethylene (UHMMPE) containing silver nanoparticles. The polymer is responsible for the uniform porous structure of the filter element and the Ag nanoparticles for its biocidal action. The filter elements were produced from two kinds of UHMMPE particles with different particle size distributions, one in the range of 150 to 200μm and the other of 300 to 400μm. Samples were collected from the obtained filter elements and characterized by X-ray diffractometry, scanning electron microscopy and microanalysis. The results indicated the formation of nanocomposite containing silver nanoparticles. (author)

  6. A randomized, placebo-controlled trial of selenium supplementation in patients with type 2 diabetes: effects on glucose homeostasis, oxidative stress, and lipid profile.

    Science.gov (United States)

    Faghihi, Toktam; Radfar, Mania; Barmal, Maedeh; Amini, Peyvand; Qorbani, Mostafa; Abdollahi, Mohammad; Larijani, Bagher

    2014-01-01

    Selenium is an antioxidant trace element. Patients with diabetes are shown to have increased oxidative stress together with decreased selenium concentrations. Whether raising serum selenium will improve blood glucose management in diabetes is largely unknown. In this randomized, double-blind placebo-controlled trial, we assessed the effects of selenium on blood glucose, lipid profile, and oxidative stress in 60 patients with type 2 diabetes. Selenium 200 µg/d or placebo was administered orally for 3 months. Serum concentrations of fasting plasma glucose, glycosylated hemoglobin A1c (HbA1c), insulin, and lipid profile, as well as ferric-reducing ability of plasma and thiobarbituric acid-reactive substances were determined in the fasting state at baseline and after 3 months. Mean (SD) serum selenium at baseline was 42.69 (29.47) µg/L and 47.11 (42.86) µg/L in selenium and placebo groups, respectively. At endpoint, selenium concentration reached to 71.98 (45.08) µg/L in selenium recipients compared with 45.38 (46.45) µg/L in placebo recipients (Pselenium recipient arm. Other endpoints changes during the course of trial were not statistically different across the 2 treatment arms. This study suggests that selenium supplementation in patients with type 2 diabetes may be associated with adverse effects on blood glucose homeostasis, even when plasma selenium concentration is raised from deficient status to the optimal concentration of antioxidant activity. Until results of further studies become available, indiscriminate use of selenium supplements in patients with type 2 diabetes warrants caution.

  7. How to use the world's scarce selenium resources efficiently to increase the selenium concentration in food.

    Science.gov (United States)

    Haug, Anna; Graham, Robin D; Christophersen, Olav A; Lyons, Graham H

    2007-12-01

    The world's rare selenium resources need to be managed carefully. Selenium is extracted as a by-product of copper mining and there are no deposits that can be mined for selenium alone. Selenium has unique properties as a semi-conductor, making it of special value to industry, but it is also an essential nutrient for humans and animals and may promote plant growth and quality. Selenium deficiency is regarded as a major health problem for 0.5 to 1 billion people worldwide, while an even larger number may consume less selenium than required for optimal protection against cancer, cardiovascular diseases and severe infectious diseases including HIV disease. Efficient recycling of selenium is difficult. Selenium is added in some commercial fertilizers, but only a small proportion is taken up by plants and much of the remainder is lost for future utilization. Large biofortification programmes with selenium added to commercial fertilizers may therefore be a fortification method that is too wasteful to be applied to large areas of our planet. Direct addition of selenium compounds to food (process fortification) can be undertaken by the food industry. If selenomethionine is added directly to food, however, oxidation due to heat processing needs to be avoided. New ways to biofortify food products are needed, and it is generally observed that there is less wastage if selenium is added late in the production chain rather than early. On these bases we have proposed adding selenium-enriched, sprouted cereal grain during food processing as an efficient way to introduce this nutrient into deficient diets. Selenium is a non-renewable resource. There is now an enormous wastage of selenium associated with large-scale mining and industrial processing. We recommend that this must be changed and that much of the selenium that is extracted should be stockpiled for use as a nutrient by future generations.

  8. Determination of Selenium in infant formula by differential pulse cathodic stripping voltammetry

    Directory of Open Access Journals (Sweden)

    "Oveisi MR

    2002-07-01

    Full Text Available Selenium as a nonmetallic chemical element has received high attention of biologists because of its dual role as an essential trace nutrient and a toxic element. This interest has created a need for reliable analytical methods for determination of selenium. In this investigation determination of selenium by differential pulse cathodic stripping voltammetry and the influence of various parameters such as deposition potentials, deposition time. Cu concentration pH, etc. on selenium peak in voltammogram are described. Determination of selenium was accomplished in mixture of acetic acid, hydrochloric acid and sodium chloride buffer (pH=1 with a scan rate of 60 mv/s and a pulse height of 100 my by hanging mercury drop electrode (HMDE as working electrode. The solution was stirred during pre-electrolysis at - 350 mv (vs SCE for 30 s and the potential was scanned between - 350 mv and - 800 mv. The determination limit of the method was 0.005 mg/kg for the sample. The calibration curves were linear in the range of 0-30 μg/L (R2=0.996, p<0.001. Repeatability of the method at concentrations of 30 and 0.5 μg/L were 2.5 and 10.5% respectively.

  9. Determination of Selenium and Nickel in Asphaltite from Milli (Sirnak) Deposit in SE Anatolia of Turkey

    Science.gov (United States)

    Aydin, Isil; Fidan, Celal; Kavak, Orhan; Erek, Figen; Aydin, Firat

    2017-12-01

    Asphaltite is one of the naturally occurring black, solid bitumen’s, which are soluble at heating in carbon disulphide band fuse. Asphaltite is also a solidified hydro carbon compound derived from petroleum [1]. According to the World Energy Council, Turkish National Committee (1998), the total reserve of the asphaltic substances that are found in south eastern Turkey is about 82 million tons, with Silopi and Sirnak reserves to get her comprising the major part of the Asphaltite deposits. Selenium and Nickel are very important elements both environmental and health. Selenium plays an important role in the formation of the enzyme antioxidant effect in the cell. The need for Selenium increases in situations such as pregnancy, menopause, grow than development, air pollution. Nickel is used for preventing iron-poor blood, increasing iron absorption, and treating weak bones. In this study, asphaltites were taken from Milli vein from Sirnak deposit in SE Anatolia of Turkey. A total of 6.500.000 tons of Asphaltite reserves have been identified as asphaltites in Milli (Sirnak). The sample preparation method was developed in Asphaltite by spectroanalytical techniques, wet acid digestion. MW-AD followed by ICP-OES were used for the determination of Selenium and Nickel in Asphaltite. Proximate analysis of Asphaltite fly ash samples was made. It also, Selenium and Nickel element analysis in Asphaltite were made.

  10. Nanoscale dose deposition in cell structures under X-ray irradiation treatment assisted with nanoparticles of a set of elements: an analytical approach to cell survival

    Energy Technology Data Exchange (ETDEWEB)

    Melo B, W.; Barboza F, M. [Universidad de Sonora, Departamento de Investigacion en Fisica, 83000 Hermosillo, Sonora (Mexico); Chernov, G., E-mail: g.chernovch@gmail.com [Universidad de Sonora, Departamento de Fisica, 83000 Hermosillo, Sonora (Mexico)

    2016-10-15

    The goal of combining nanoparticles (Nps) with radiation therapy is to increase the differential effect between healthy and tumor tissues. Only some elements have been investigated to be used as radiosensitizers and no systematic experimental or theoretical comparisons between different materials have been developed. MacMahon, et al. (Nano scale, 2016, 8, 581) presents the first systematic computational study of the impact of elemental composition on nanoparticle radiation interaction for kilo voltage and megavoltage X-ray exposure, for a range of elements (Z = 14 - 80). In this study we present and analytical model to assess the cell survival modification responses of cell cultures under irradiation treatments with keV X-rays assisted with Nps of different materials as platinum, hafnium, gadolinium, gold, germanium, iodine and iron. This model starts from the data of radial dose deposition around a single 20 nm diameter Np irradiated with photons of an energy 20 keV higher than the element K-shell binding energy to the nano scale probability of dose distribution inside cell structures with embedded Nps (the assessment of the average dose and the average squared dose in cell structure). Also based on the Local Effect Model we estimate potential biological effects, as is the case of the Relative Biological Effectiveness (RBE). Nano scale dose deposition exhibits a complex dependence on atomic number, as a consequence of the variations in secondary Auger electron spectra, this is manifested in significant variations in RBE. Upon in vitro experiments RBE varies from 1 to 1.6. Values representative of a high radiosensitization were observed for lower energies, ones that are well reproduced by our analytical analysis for cell cultures with a homogeneous distribution of different material Nps. (Author)

  11. Synthesizing A Phase Changing Bistable Electroactive Polymer And Silver Nanoparticles Coated Fabric As A Resistive Heating Element

    Science.gov (United States)

    Ren, Zhi

    that decreases to several MPa at above 70°C after a rigid-to-rubbery transition via glass transition. The rubbery BSEP possesses a stable storage modulus regardless of temperature fluctuations, which is beneficial to stable electrical actuation performances under an electric field. The bimodal structure creates a framework involving both long chain crosslinkers and small molecular crosslinkers. Due to the limited chain extensibility of this bimodal framework, the rubbery BSEP can self-stiffen at modest strains to suppress electromechanical instability, which is responsible for the premature electrical breakdown of the previous BSEP materials in their rubbery states. A BSEP actuator with a braille dot size exhibits steadily increased actuation height with increasing electric field at 70 °C. A stable actuation with a cycle lifetime of over 2000 cycles at a raised dot height of 0.4 mm was demonstrated. A fabrication process for a page-size braille paper using the BSEP has been developed. A selective heating strategy has been investigated based on a 2-cell device to provide a selective actuation strategy of BSEP braille dots. Wearable thermal management strategy has presented itself recently as a new challenge to offer an optimal thermal experience for the occupant as well as to reduce building energy usage for heating, ventilation and air conditioning (HVAC). Joule heating based on silver nanoparticles (AgNPs) coated non-woven fabric can provide a wearable localized heating element.A sheet resistance of bonding between oxygen groups on the fabrics' surface and AgNPs. As a result, the bonding between the AgNPs layer and the polyester fabrics is strong enough to resist sonication damage. The resistance only increased slightly after an 80minutes of sonication and therefore the AgNPs-polyester fabrics composite are regarded as washable. The AgNPs coated polyester fabrics was employed as a heating element. A voltage as low as 1volt is adequate to heat up the Ag

  12. Selenium Enrichment of Horticultural Crops

    Directory of Open Access Journals (Sweden)

    Martina Puccinelli

    2017-06-01

    Full Text Available The ability of some crops to accumulate selenium (Se is crucial for human nutrition and health. Selenium has been identified as a cofactor of the enzyme glutathione peroxidase, which is a catalyzer in the reduction of peroxides that can damage cells and tissues, and can act as an antioxidant. Plants are the first link in the food chain, which ends with humans. Increasing the Se quantity in plant products, including leafy and fruity vegetables, and fruit crops, without exceeding the toxic threshold, is thus a good way to increase animal and human Se intake, with positive effects on long-term health. In many Se-enriched plants, most Se is in its major organic form. Given that this form is more available to humans and more efficient in increasing the selenium content than inorganic forms, the consumption of Se-enriched plants appears to be beneficial. An antioxidant effect of Se has been detected in Se-enriched vegetables and fruit crops due to an improved antioxidative status and to a reduced biosynthesis of ethylene, which is the hormone with a primary role in plant senescence and fruit ripening. This thus highlights the possible positive effect of Se in preserving a longer shelf-life and longer-lasting quality.

  13. Selenium Enrichment of Horticultural Crops.

    Science.gov (United States)

    Puccinelli, Martina; Malorgio, Fernando; Pezzarossa, Beatrice

    2017-06-04

    The ability of some crops to accumulate selenium (Se) is crucial for human nutrition and health. Selenium has been identified as a cofactor of the enzyme glutathione peroxidase, which is a catalyzer in the reduction of peroxides that can damage cells and tissues, and can act as an antioxidant. Plants are the first link in the food chain, which ends with humans. Increasing the Se quantity in plant products, including leafy and fruity vegetables, and fruit crops, without exceeding the toxic threshold, is thus a good way to increase animal and human Se intake, with positive effects on long-term health. In many Se-enriched plants, most Se is in its major organic form. Given that this form is more available to humans and more efficient in increasing the selenium content than inorganic forms, the consumption of Se-enriched plants appears to be beneficial. An antioxidant effect of Se has been detected in Se-enriched vegetables and fruit crops due to an improved antioxidative status and to a reduced biosynthesis of ethylene, which is the hormone with a primary role in plant senescence and fruit ripening. This thus highlights the possible positive effect of Se in preserving a longer shelf-life and longer-lasting quality.

  14. Impact of application of zinc oxide nanoparticles on callus induction, plant regeneration, element content and antioxidant enzyme activity in tomato (Solanum lycopersicum Mill. under salt stress

    Directory of Open Access Journals (Sweden)

    Alharby Hesham F.

    2016-01-01

    Full Text Available The properties of nanomaterials and their potential applications have been given considerable attention by researchers in various fields, especially agricultural biotechnology. However, not much has been done to evaluate the role or effect of zinc oxide nanoparticles (ZnO-NP in regulating physiological and biochemical processes in response to salt-induced stress. For this purpose, some callus growth traits, plant regeneration rate, mineral element (sodium, potassium, phosphorous and nitrogen contents and changes in the activity of superoxide dismutase (SOD and glutathione peroxidase (GPX in tissues of five tomato cultivars were investigated in a callus culture exposed to elevated concentrations of salt (3.0 and 6.0 g L-1NaCl, and in the presence of zinc oxide nanoparticles (15 and 30 mg L-1. The relative callus growth rate was inhibited by 3.0 g L-1 NaCl; this was increased dramatically at 6.0 g L-1. Increasing exposure to NaCl was associated with a significantly higher sodium content and SOD and GPX activities. Zinc oxide nanoparticles mitigated the effects of NaCl, and in this application of lower concentrations (15 mg L-1 was more effective than a higher concentration (30 mg L-1. This finding indicates that zinc oxide nanoparticles should be investigated further as a potential anti-stress agent in crop production. Different tomato cultivars showed different degrees of tolerance to salinity in the presence of ZnO-NP. The cultivars Edkawy, followed by Sandpoint, were less affected by salt stress than the cultivar Anna Aasa.

  15. Upconversion nanoparticle as elemental tag for the determination of alpha-fetoprotein in human serum by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Liu, Zhengru; Yang, Bin; Chen, Beibei; He, Man; Hu, Bin

    2016-12-19

    Upconversion nanoparticles (UCNPs) have received increasing attention due to their unique optical properties. Recognizing that UCNPs are lanthanide-doped nanoparticles, we incorporated UCNPs into an immunoassay with inductively coupled plasma mass spectrometry (ICP-MS) detection for the determination of specific proteins, e.g., alpha-fetoprotein (AFP). The sensitivity of the assay was enhanced because of the ICP-MS detection of UCNPs that contained large numbers of lanthanide elemental tags. Conjugates of UCNPs and antibodies were prepared and the morphology of the conjugates was characterized by transmission electron microscopy. After a sandwich immunoreaction, the AFP was determined by the ICP-MS analysis of UCNPs. Under the optimized conditions, a limit of detection (3σ) of 0.31 ng mL-1 based on 89Y signal and 0.22 ng mL-1 based on 174Yb signal was obtained for AFP, with a dynamic range of 0.5-35 ng mL-1 and a relative standard deviation of 4.8% (c = 5 ng mL-1, n = 9). The developed method was applied to the determination of AFP in human serum and the recovery for the spiked sample was in the range of 98.6-123%. The proposed method is simple, rapid, selective and sensitive, and has a good tolerance for the complex biological matrix, indicating great potential for the application of UCNP in biological research as an elemental tag.

  16. Assessment of requirements for selenium and adequacy of selenium status: a review.

    Science.gov (United States)

    Thomson, C D

    2004-03-01

    The intent of this review is to evaluate the scientific evidence for the assessment of adequacy of selenium status and of the requirements for selenium. From this evidence, attempts have been made to define levels of plasma selenium and dietary selenium intake, which could be used for the assessment of deficiency or adequacy of selenium status. The first section briefly reviews the methods for assessment of selenium status. The second section outlines the requirements for selenium based on a number of criteria, and how these have been translated into recommended intakes of selenium. In the final section, levels of plasma selenium and dietary intake based on different criteria of adequacy have been proposed. The minimum requirement for selenium is that which prevents the deficiency disease, Keshan disease. The recommended intakes of selenium have been calculated from the requirement for optimum plasma glutathione peroxidase (GPx) activity that must, because of the hierarchy of selenoproteins, also take account of the amounts needed for normal levels of other biologically necessary selenium compounds. Whether optimal health depends upon maximization of GPx or other selenoproteins, however, has yet to be resolved, and the consequences of less-than-maximal GPx activities or mRNA levels need investigation. Intakes, higher than recommended intakes, and plasma selenium concentrations that might be protective for cancer or result in other additional health benefits have been proposed. There is an urgent need for more large-scale trials to assess any such beneficial effects and to provide further data on which to base more reliable estimates for intakes and plasma selenium levels that are protective.

  17. Estimation of selenium bioavailability from human, cow's, goat and sheep milk by an in vitro method

    NARCIS (Netherlands)

    Shen, L.; Dael, van P.; Luten, J.; Deelstra, H.

    1996-01-01

    The trace element selenium (Se) has been recognized to be essential for human health. The dependence of infants on milk as their principal food source, generally low in Se content, makes them more vulnerable to inadequate Se intake. The present study compared the Se availability as estimated by a

  18. Selenium cycling across soil-plant atmosphere interfaces: a critical review

    Science.gov (United States)

    Selenium (Se) is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass, and in the atmosphere. Low Se levels in certain terrestrial environments ha...

  19. Germanium, Arsenic, and Selenium Abundances in Metal-poor Stars

    Science.gov (United States)

    Roederer, Ian U.

    2012-09-01

    The elements germanium (Ge, Z = 32), arsenic (As, Z = 33), and selenium (Se, Z = 34) span the transition from charged-particle or explosive synthesis of the iron-group elements to neutron-capture synthesis of heavier elements. Among these three elements, only the chemical evolution of germanium has been studied previously. Here we use archive observations made with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope and observations from several ground-based facilities to study the chemical enrichment histories of seven stars with metallicities -2.6 Administration. These data are associated with Programs H2aH, H6aH, and H39aH (PI: Boesgaard), N01H (PI: Latham), and U11H (PI: Prochaska).This paper includes data taken at The McDonald Observatory of The University of Texas at Austin.

  20. Sponge-supported synthesis of colloidal selenium nanospheres

    Science.gov (United States)

    Ahmed, Snober; Brockgreitens, John; Xu, Ke; Abbas, Abdennour

    2016-11-01

    With increasing biomedical and engineering applications of selenium nanospheres (SeNS), new efficient methods are needed for the synthesis and long-term preservation of these nanomaterials. Currently, SeNS are mostly produced through the biosynthesis route using microorganisms or by using wet chemical reduction, both of which have several limitations in terms of nanoparticle size, yield, production time and long-term stability of the nanoparticles. Here, we introduce a novel approach for rapid synthesis and long-term preservation of SeNS on a solid microporous support by combining a mild hydrothermal process with chemical reduction. By using a natural sponge as a solid three-dimensional matrix for nanoparticle growth, we have synthesized highly monodisperse spherical nanoparticles with a wide size range (10-1000 nm) and extremely high yield in a relatively short period of time (1 h). Additionally, the synthesized SeNS can be stored and retrieved whenever needed by simply washing the sponge in water. Keeping the nanospheres in the support offers remarkable long-term stability as particles left on the sponge preserve their morphological and colloidal characteristics even after eight months of storage. Furthermore, this work reveals that SeNS can be used for efficient mercury capture from contaminated waters with a record-breaking mercury removal capacity of 1900 mg g-1.

  1. Effects of SiC nanoparticles orally administered in a rat model: Biodistribution, toxicity and elemental composition changes in feces and organs

    Energy Technology Data Exchange (ETDEWEB)

    Lozano, Omar, E-mail: omar.lozanogarcia@fundp.ac.be [Namur Nanosafety Center (NNC), NAmur Research Institute for LIfe Sciences (NARILIS), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000 Namur (Belgium); Research Centre for the Physics of Matter and Radiation (PMR-LARN), University of Namur (FUNDP), Rue de Bruxelles 61, B-5000 Namur (Belgium); Laloy, Julie; Alpan, Lütfiye [Namur Nanosafety Center (NNC), NAmur Research Institute for LIfe Sciences (NARILIS), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000 Namur (Belgium); Department of Pharmacy, NAMEDIC, Namur Thrombosis and Hemostasis Center (NTHC), University of Namur (FUNDP), Rue de Bruxelles 61, B-5000 Namur (Belgium); Mejia, Jorge [Namur Nanosafety Center (NNC), NAmur Research Institute for LIfe Sciences (NARILIS), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000 Namur (Belgium); Research Centre for the Physics of Matter and Radiation (PMR-LARN), University of Namur (FUNDP), Rue de Bruxelles 61, B-5000 Namur (Belgium); Rolin, Stéphanie [Namur Nanosafety Center (NNC), NAmur Research Institute for LIfe Sciences (NARILIS), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000 Namur (Belgium); Department of Pharmacy, NAMEDIC, Namur Thrombosis and Hemostasis Center (NTHC), University of Namur (FUNDP), Rue de Bruxelles 61, B-5000 Namur (Belgium); Toussaint, Olivier [Namur Nanosafety Center (NNC), NAmur Research Institute for LIfe Sciences (NARILIS), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000 Namur (Belgium); Laboratory of Biochemistry and Cellular Biology (URBC), University of Namur (FUNDP), Rue de Bruxelles 61, B-5000 Namur (Belgium); Dogné, Jean-Michel [Namur Nanosafety Center (NNC), NAmur Research Institute for LIfe Sciences (NARILIS), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000 Namur (Belgium); Department of Pharmacy, NAMEDIC, Namur Thrombosis and Hemostasis Center (NTHC), University of Namur (FUNDP), Rue de Bruxelles 61, B-5000 Namur (Belgium); and others

    2012-10-15

    Background: Silicon carbide (SiC) presents noteworthy properties as a material such as high hardness, thermal stability, and photoluminescent properties as a nanocrystal. However, there are very few studies in regard to the toxicological potential of SiC NPs. Objectives: To study the toxicity and biodistribution of silicon carbide (SiC) nanoparticles in an in vivo rat model after acute (24 h) and subacute (28 days) oral administrations. The acute doses were 0.5, 5, 50, 300 and 600 mg·kg{sup −1}, while the subacute doses were 0.5 and 50 mg·kg{sup −1}. Results: SiC biodistribution and elemental composition of feces and organs (liver, kidneys, and spleen) have been studied by Particle-Induced X-ray Emission (PIXE). SiC and other elements in feces excretion increased by the end of the subacute assessment. SiC did not accumulate in organs but some elemental composition modifications were observed after the acute assessment. Histopathological sections from organs (stomach, intestines, liver, and kidneys) indicate the absence of damage at all applied doses, in both assessments. A decrease in the concentration of urea in blood was found in the 50 mg·kg{sup −1} group from the subacute assessment. No alterations in the urine parameters (sodium, potassium, osmolarity) were found. Conclusion: This is the first study that assesses the toxicity, biodistribution, and composition changes in feces and organs of SiC nanoparticles in an in vivo rat model. SiC was excreted mostly in feces and low traces were retrieved in urine, indicating that SiC can cross the intestinal barrier. No sign of toxicity was however found after oral administration. -- Highlights: ► SiC nanoparticles were orally administered to rats in acute and subacute doses. ► SiC was found in low traces in urine. It is mostly excreted in feces within 5 days. ► SiC excretion rate, feces and organ elemental composition change with time. ► No morphological alteration were found on GI tract, liver, kidneys

  2. The effect of dietary selenium level on lead toxicity in the Japanese quail.

    Science.gov (United States)

    Stone, C L; Soares, J H

    1976-01-01

    Previous studies (Parizek et al., 1969) have shown significant interactions between selenium and certain heavy metals, particularly mercury and cadmium. Since these elements have an affinity for sulfhydryl groups, it was proposed that a similar interaction might exist with lead. In an initial experiment, adult quail hens were given diets supplemented with 0 and 1 p.p.m. selenium and 0, 500 and 1000 p.p.m. lead in a 2 X 3 factorial arrangement. After 32 days of feeding, body weight, liver weight and egg production decreased in birds fed lead while kidney weights increased. Highly significant decreases in red blood cell delta-aminolevulinic acid dehydratase (RBC-ALAD) activity occurred when lead was added to the diet. Control RBC-ALAD activity was 1337 versus 105, 91, 156 and 110 nmol. porphobilogen produced per ml. of erythrocyte per hour (nmol. PBG/ml. RBC/hr.) for the 500, 1000, 500 plus selenium and 1000 plus groups, respectively. After 85 days of feeding lead to male birds in a second study, selenium appeared to have variable effects on the concentration of lead in liver, kidney and tibia. Selenium supplementation to lead diets resulted in significantly increased levels of lead in kidney tissue while little or no effects were observed on liver or tibia lead levels. RBC-ALAD activity was significantly reduced with lead supplementation and no effect of selenium addition was observed. Electrophoretic gels of serum from birds fed lead containing diets showed increased protein bands in the transferrin and globulin regions regardless of the presence of 1 p.p.m. selenium. A third study was conducted to determine the effects of supplementing an isolated soy protein diet with 0 and 1 p.p.m. selenium and 0 and 3000 p.p.m. lead. Selenium supplementation improved body weights over controls while lead additions caused reduced egg production and ALAD activity. Lead feeding increased tibia/body weight ratios and lead concentrations in liver, kidney and tibia. No significant

  3. Evaluation of flushing of a high-selenium backwater channel in the Colorado River

    Science.gov (United States)

    Hamilton, S.J.; Holley, K.M.; Buhl, K.J.; Bullard, F.A.; Weston, L.K.; McDonald, S.F.

    2004-01-01

    Concern has been raised that selenium contamination may be adversely affecting endangered fish in the upper Colorado River basin. The objective of the study was to determine if operation of a water control structure (opened in December 1996) that allowed the Colorado River to flow through a channel area at Walter Walker State Wildlife Area (WWSWA) would reduce selenium and other inorganic elements in water, sediment, aquatic invertebrates, and forage fish. Endangered Colorado pikeminnow were collected and muscle plug samples taken for selenium analysis. Selenium concentrations in filtered water were 21.0 ??g/L in 1995, 23.5 ??g/L in 1996, 2.1 ??g/L in 1997, and 2.1 ??g/L in 1998. Selenium concentrations in sediment cores and sediment traps were 8.5 ??/g in 1995, 8.2 ??g/g in 1996, 4.8 ??g/g in 1997, and 1.1 ??g/g in 1998. Selenium concentrations in aquatic invertebrates were 27.4 ??g/g in 1996, 15.5 ??g/g in 1997, and 4.9 ??g/g in 1998. Selenium concentrations in forage fish were 27.2 ??g/g in 1996, 20.2 ??g/g in 1997, and 8.6 ??g/g in 1998. Selenium concentrations in muscle plugs of Colorado pikeminnow were 9.8 ??g/g in 1995, 9.5 ??g/g in 1996, 9.0 ??g/g in 1997, and 10.3 ??g/g in 1998. Although selenium concentrations in water, sediment, aquatic invertebrates, and forage fish decreased substantially after operation of the water control structure, a corresponding change in Colorado pikeminnow did not seem to occur. Selenium concentrations in muscle plugs decreased with increasing fish total length and weight, did not change between repeat sampling in the same year or recapture in subsequent years, and seemed to be most closely associated with the mean monthly river flow for the March-July period. ?? 2004 Wiley Periodicals, Inc.

  4. Learning selenium testing tools with Python

    CERN Document Server

    Gundecha, Unmesh

    2014-01-01

    If you are a quality testing professional, or a software or web application developer looking to create automation test scripts for your web applications, with an interest in Python, then this is the perfect guide for you. Python developers who need to do Selenium testing need not learn Java, as they can directly use Selenium for testing with this book.

  5. DIETARY SELENIUM AND COPPER INTAKE BY RESIDENT ...

    African Journals Online (AJOL)

    hi-tech

    2004-01-01

    Jan 1, 2004 ... Ph.D., Senior Research Fellow and Head, Nutrition Unit, Noguchi Memorial Institute for Medical Research, University of Ghana and P. Amankwa, ... Objectives: To determine and evaluate dietary intake of selenium and copper by resident undergraduate ... number of Selenium-dependent enzymes known as.

  6. Immunomodulatory effect of dietary selenium supplementation on ...

    African Journals Online (AJOL)

    Effect of selenium supplementation on the immune response of Trypanosoma brucei brucei infected rats was investigated. Twenty five (25) adult male albino rats divided into five groups of five rats each were used for this study. Groups A, B and C were fed 4, 8 and 16 part per million (ppm) selenium in their feed, respectively ...

  7. Understanding selenium biogeochemistry in engineered ecosystems

    NARCIS (Netherlands)

    Jain, Rohan; Hullebusch, Van Eric D.; Lenz, Markus; Farges, François

    2017-01-01

    Selenium is used extensively in many industries, and it is necessary for human nutrition. On the other hand, it is also toxic at slightly elevated concentrations. With the advent of industrialisation, selenium concentrations in the environment due to anthropogenic activities have increased.

  8. Changing selenium nutritional status of Chinese residents

    Science.gov (United States)

    China has been designated as one of 40 countries deficient in selenium (Se) according to the World Health Organization. Selenium concentrations in hair are commonly used to evaluate the Se level of the human body. Moreover, hair Se concentrations are significantly correlated with Se concentrations ...

  9. The Role of Selenium in Human Immunity | Chisenga | Medical ...

    African Journals Online (AJOL)

    ... including selenium deficiency, so it has been postulated that selenium has a role in immune function. Immune dysfunction, susceptibility to viral infections and increased mortality are some of the outcomes associated with selenium deficiency. Key Words: Selenium; Human; Cell-mediated immunity; Innate immunity; HIV; ...

  10. Advanced prostate cancer risk in relation to toenail selenium levels

    NARCIS (Netherlands)

    Geybels, M.S.; Verhage, B.A.J.; Schooten, F.J. van; Goldbohm, A.; Brandt, P.A. van den

    2013-01-01

    BACKGROUND: Selenium may prevent advanced prostate cancer (PCa), but most studies on this topic were conducted in populations with moderate to high selenium status. We investigated the association of toenail selenium, reflecting long-term selenium exposure, and advanced PCa risk in a population from

  11. Carbon-enhanced inductively coupled plasma mass spectrometric detection of arsenic and selenium and its application to arsenic speciation

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Sturup, Stefan

    1994-01-01

    Addition of carbon as methanol or ammonium carbonate to the aqueous analyte solutions in combination with increased plasma power input enhanced the inductively coupled plasma mass spectrometry (ICP-MS) signal intensities of arsenic and selenium. In the presence of the optimum 3% v/v methanol...... concentration the signal intensities achieved were about 4500-5000 counts s-1 per ng ml-1 of arsenic and about 700-1100 counts s-1 per ng ml-1 of selenium (Se-82), corresponding to enhancement factors of 3.5-4.5 compared with aqueous solution for the two elements. Differences in sensitivity (calculated...... on the basis of analyte atom) were observed between the individual arsenic species and between the selenium species in aqueous as well as in carbon-added solutions. The presence of 3% v/v methanol in the analyte solutions doubled the level of the background signal for arsenic and selenium, but its fluctuation...

  12. Structural and electrical properties of selenium nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Prajna, E-mail: prajna111@gmail.com [Department of Physics, Visva-Bharati, Santiniketan, 731235 (India); Department of Physics, Bolpur College, Bolpur, 731204 (India); Konar, Shyamal [Department of Physics, Visva-Bharati, Santiniketan, 731235 (India); Gupta, Bikash C., E-mail: bikashc.gupta@visva-bharati.ac.in [Department of Physics, Visva-Bharati, Santiniketan, 731235 (India)

    2016-01-08

    The electronic structure calculations are systematically carried out within the density functional formalism for understanding the structural and electronic properties of a number of selenium nanotubes. In particular, single walled selenium nanotubes (achiral) are studied in this work. Our investigations reveal that the lower diameter nanotubes are unstable. Beyond certain diameter, the tubes retain their tubular structure and they show metallic property. Furthermore, work-functions of these tubes are found to depend on their diameters and differ from that of the bulk selenium surface. - Highlights: • The selenium tubes become stable and retain tubular shape beyond certain diameter. • In contrary to bulk selenium, the tubular structures show metallic property. • The work-functions of tubes vary with diameter. The amount of variation is 1.2 eV.

  13. Selenium supplementation induces mitochondrial biogenesis in trophoblasts.

    Science.gov (United States)

    Khera, Alisha; Dong, Lan-Feng; Holland, Olivia; Vanderlelie, Jessica; Pasdar, Elham A; Neuzil, Jiri; Perkins, Anthony V

    2015-08-01

    Placental oxidative stress has been implicated in pregnancy complications and previous work has shown that selenium can protect trophoblast mitochondria from oxidative stress. This report examines mitochondrial function and content in trophoblasts supplemented with selenium. Swan-71, JEG-3 and BeWo cells and placental tissue were incubated with sodium selenite or selenomethionine. Mitochondrial function was examined in a respirometer. Mitochondrial content was determined using RT-PCR. The levels of the mitochondrial biogenesis markers selenoprotein H, PGC-1α and NRF-1 was examined by western blotting. Mitochondrial respiration was significantly enhanced post selenium supplementation in cells and tissues. Selenium supplementation increased mitochondrial content and up-regulated mitochondrial biogenesis mediators in cells. These results emphasise the importance of selenium in mitochondrial regeneration in trophoblasts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California

    Science.gov (United States)

    Saiki, Michael K.; Martin, Barbara A.; May, Thomas W.

    2012-01-01

    Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 μg/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98–58.0 μg Se/g; midge larvae, 12.7–50.6 μg Se/g; mosquitofish, 13.2–20.2 μg Se/g; and mollies, 12.8–30.4 μg Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish.

  15. Acute and subchronic toxicity studies on Sel-Plex, a standardized, registered high-selenium yeast.

    Science.gov (United States)

    Griffiths, James C; Matulka, Ray A; Power, Ronan

    2006-01-01

    Selenium has been recognized as an essential nutrient for human health; however, its bioavailability is primarily dependent upon the type of selenium, elemental versus organic. In geographic areas low in selenium, there is the potential for animals (including humans) to become selenium deficient and this potential deficiency can be remedied by consumption of exogenous selenium, including selenium-enriched yeast (Saccharomyces cerevisiae) that contains high levels of organic selenium (e.g., selenized yeast). The present studies were conducted to investigate potential oral toxicity of a unique selenized yeast preparation (Sel-Plex) when administered to (1) adult female CHS Swiss mice ICo:OFI (IOPS Caw); (2) adult female CHS Sprague-Dawley rats; and (3) adult male and female Sprague-Dawley CD rats. For the 28- and 90-day toxicity studies, (1) adult male and female Sprague-Dawley CRL:CD(R)(SD) IGS BR strain rats and (2) adult male and female 6- to 7-month-old Beagle dogs were used. The LD50 for mice was >or=2000 mg Sel-Plex/kg (>or=4.06 mg Se/kg) and for rats, was greater than >or=2000 mg Sel-Plex/kg (>or=4.06 mg Se/kg). In the two 28-day studies, for rats, the no observed adverse effects level (NOAEL) was 50 mg Sel-Plex/kg/day (0.1 mg Se/kg/day), and for the dogs, the NOAEL was 22.5 mg Sel-Plex/kg/day (0.045 mg Se/kg/day). For the two 90-day studies, for rats the NOAEL for Sel-Plex was 114 mg/kg/day (0.23 mg Se/kg/day), and for dogs, the NOAEL was 30 mg Sel-Plex/kg/day (0.06 mg Se/kg/day): the latter being the NOAEL in the most sensitive species.

  16. Survival of the hermit crab, Clibanarius vittatus, exposed to selenium and other environmental factors

    Energy Technology Data Exchange (ETDEWEB)

    1986-09-01

    Recent investigations of water quality criteria have frequently examined the effects of a pollutant; however, a more realistic investigation would consider effects of multiple environmental factors and their interactions with the pollutant. Awareness of selenium as a pollutant is increasing. The growing sulfur and petroleum industries are only two of the potential sources of the element on the Texas coast. This study examined the toxicity of selenium to hermit crab Clibanarius vittatus (Bosc) under twelve different combinations of temperature and salinity. Additionally, the impact of the organisms' original environment was considered as an environmental factor.

  17. Medical geology of arsenic, selenium and thallium in China.

    Science.gov (United States)

    Li, Shehong; Xiao, Tangfu; Zheng, Baoshan

    2012-04-01

    Arsenic (As), selenium (Se) and thallium (Tl) are three trace metals (metalloids) of high concern in China because deficiency or excess expose can cause a range of endemic diseases, such as endemic arsenism, selenosis, Keshan disease (KD), Kashin-Beck disease (KBD) and thallotoxicosis. These specific endemic diseases were attributable for overabundance or deficiency (mainly referring to selenium) of these three elements in the local environment as a result of natural geochemical processes and/or anthropologic activities. The geochemistry and human health impacts of these three trace elements have been intensively studied since the 1970s in China, in terms of geochemical sources, distribution, transportation, health impact pathways, and prevention/remediation measures. Endemic arsenism in China are induced from the exposures of high As in either drinking water or domestic combustion of As-rich coals. Both endemic selenium deficiency and selenosis occurred in China. The KD and KBD were related to the deficiency of Se in the low-Se geological belt with Se contents in soil less than 0.125mg/kg stretching from northeast to southwest of China. Endemic selenosis occurred in areas with high Se concentrations in soils derived from the Se-enriched black carbonaceous siliceous rocks, carbonaceous shale and slate. Endemic Tl poisoning occurred in southwestern China due to Tl contamination in local drinking water and vegetables surrounding the Tl-rich sulfide mineralized areas. Some measures have been taken to control and remedy the endemic diseases with significant effects in reducing health risk and damage of As, Se and Tl. However, the states of the endemic diseases of As, Se and Tl in China are still serious in some areas, and substantial research efforts regarding the health impacts of these elements are further required. This paper reviews the progress of medical geology of As, Se and Tl in China, and provides with some outlooks for future research directions. Copyright

  18. (lead) and essential elements in whole blood from 1

    African Journals Online (AJOL)

    Towards bio monitoring of toxic (lead) and essential elements in whole blood from ... as zinc, copper, selenium, calcium, and magnesium are essential for normal human development ..... are exposed to it through environmental dust and paint,.

  19. Study of Optical and Structural Characteristics of Ceria Nanoparticles Doped with Negative and Positive Association Lanthanide Elements

    Directory of Open Access Journals (Sweden)

    N. Shehata

    2014-01-01

    Full Text Available This paper studies the effect of adding lanthanides with negative association energy, such as holmium and erbium, to ceria nanoparticles doped with positive association energy lanthanides, such as neodymium and samarium. That is what we called mixed doped ceria nanoparticles (MDC NPs. In MDC NPs of grain size range around 6 nm, it is proved qualitatively that the conversion rate from Ce4+ to Ce3+ is reduced, compared to ceria doped only with positive association energy lanthanides. There are many pieces of evidence which confirm the obtained conclusion. These indications are an increase in the allowed direct band gap which is calculated from the absorbance dispersion measurements, a decrease in the emitted fluorescence intensity, and an increase in the size of nanoparticles, which is measured using both techniques: transmission electron microscope (TEM and X-ray diffractometer (XRD. That gives a novel conclusion that there are some trivalent dopants, such as holmium and erbium, which can suppress Ce3+ ionization states in ceria and consequently act as scavengers for active O-vacancies in MDC. This promising concept can develop applications which depend on the defects in ceria such as biomedicine, electronic devices, and gas sensors.

  20. Distribution of selenium in zebrafish larvae after exposure to organic and inorganic selenium forms.

    Science.gov (United States)

    Dolgova, N V; Hackett, M J; MacDonald, T C; Nehzati, S; James, A K; Krone, P H; George, G N; Pickering, I J

    2016-03-01

    Selenium is an essential micronutrient for many organisms, and in vertebrates has a variety of roles associated with protection from reactive oxygen species. Over the past two decades there have been conflicting reports upon human health benefits and detriments arising from consumption of selenium dietary supplements. Thus, early studies report a decrease in the incidence of certain types of cancer, whereas subsequent studies did not observe any anti-cancer effect, and adverse effects such as increased risks for type 2 diabetes have been reported. A possible contributing factor may be that different chemical forms of selenium were used in different studies. Using larval stage zebrafish (Danio rerio) as a model organism, we report a comparison of the toxicities and tissue selenium distributions of four different chemical forms of selenium. We find that the organic forms of selenium tested (Se-methyl-l-selenocysteine and l-selenomethionine) show considerably more toxicity than inorganic forms (selenite and selenate), and that this appears to be correlated with the level of bioaccumulation. Despite differences in concentrations, the tissue specific pattern of selenium accumulation was similar for the chemical forms tested; selenium was found to be highly concentrated in pigment (melanin) containing tissues especially for the organic selenium treatments, with lower concentrations in eye lens, yolk sac and heart. These results suggest that pigmented tissues might serve as a storage reservoir for selenium.

  1. Blood selenium levels and contribution of food groups to selenium intake in adolescent girls in Iceland

    Directory of Open Access Journals (Sweden)

    Ingibjorg Gunnarsdottir

    2012-08-01

    Full Text Available Background/objectives: Significant changes have been reported in dietary habits and food availability in Iceland that would be expected to compromise selenium intake and status, especially among young people. These include substantial decreases in the consumption of fish and milk, as well as the selenium content of imported wheat. The aim of this study was to assess selenium in the diet and whole blood of adolescent girls, as well as define the most important foods contributing to intake and blood concentrations of selenium. Design: The subjects were 96 randomly selected girls, aged 16–20, who answered a validated food frequency questionnaire (FFQ for dietary assessment. Selenium intake from each food group was calculated in µg/day. Blood samples were collected for measurement of whole blood selenium. Results: Mean dietary selenium was 51±25 µg/day. Milk/dairy products, including cheese, contributed 36±14% of total dietary selenium; fish 18±12%; and bread/cereal products 13±6%. Mean whole blood selenium was 117±12 µg/l (range 90–208; nearly 90% of subjects were above the optimal level of 100 µg/l. Fish and bread/cereal products were the only foods significantly correlated with selenium in blood (r=0.32; P = 0.002 and r=0.22; P = 0.04, respectively while no correlation was found with milk and dairy products in spite of their greater contribution to total selenium intake. Conclusion: In this population of Icelandic adolescent girls, selenium intake and status seem acceptable. Judging from associations between intake and blood levels, fish and cereals may be the most important contributors to blood selenium.

  2. Selenium status alters tumour differentiation but not incidence or latency of pancreatic adenocarcinomas in Ela-TGF-alpha p53+/ mice.

    Science.gov (United States)

    Aichler, Michaela; Algül, Hana; Behne, Dietrich; Hölzlwimmer, Gabriele; Michalke, Bernhard; Quintanilla-Martinez, Leticia; Schmidt, Jörg; Schmid, Roland M; Brielmeier, Markus

    2007-09-01

    Genetic predisposition and environmental factors act in concert in the pathogenesis of multi-factorial diseases. Selenoproteins represent fundamental antioxidative systems for the maintenance of cellular redox homeostasis, which is altered in various disease processes. Optimal function of selenoproteins requires availability of sufficient amounts of the essential trace element selenium, but in many countries the nutritive selenium supply is regarded insufficient. Supplemental selenium has been shown to have cancer-protective effects in a variety of experimental settings and clinical studies. Pancreatic carcinoma has so far not been tested as an end-point in such studies. We thus investigated the influence of supplemental nutritive selenium on pancreatic carcinogenesis in selenium-deficient animals by use of a genetically defined disease model. Over a period of 800 days, all animals (n = 131) in the study developed tumours. Within this time, the mean total tumour latency was not influenced by the selenium status (471 versus 472 days). Also, the mean latency of pancreatic carcinomas (n = 83) was not influenced (464 versus 466 days). In contrast, the percentage of pancreatic tumors within all tumours was lower in the selenium-deficient group (55 versus 70%). A highly significant difference in the differentiation grade of the pancreatic tumours was evident between the two groups: selenium-deficient mice (n = 33) developed predominantly undifferentiated anaplastic carcinomas (26 anaplastic versus 7 differentiated), whereas in the selenium-supplemented group (n = 50) mainly well-differentiated carcinomas were detected (20 anaplastic versus 30 differentiated). These data point at a new role of the trace element selenium in carcinogenesis.

  3. Problem of Combined Selenium and Iodine Deficiency in the Development of Thyroid Pathology

    Directory of Open Access Journals (Sweden)

    V.I. Pankiv

    2014-09-01

    Full Text Available The article organizes data on the role of iodine and selenium deficiency in the functioning of the thyroid gland (TG, its importance in the development of thyropathies. Markers needed to determine the provision of the organism with iodine and selenium are given, as well as deficiency conditions associated with these trace elements, and their physiological daily doses are recommended. It was concluded that the use of selenium compounds (average dose 75 μg/day and iodine (average dose 150 μg/day with the purpose of prevention or treatment in physiological doses is safe, can reduce the severity or inhibit pathological processes in TG, including improving the course of autoimmune diseases.

  4. Selenium speciation in the Fountain Creek Watershed and its effects on fish diversity.

    Science.gov (United States)

    Carsella, James; Melnykov, Igor; Bonetti, Sandra; Sánchez-Lombardo, Irma; Crans, Debbie C

    2017-07-01

    Se is an environmental concern as it can be toxic if present in high concentrations even though it is a dietary requirement for all animals. Se levels are a special concern in the Fountain Creek Watershed located in southeastern Colorado whose geological source is the Se-rich Pierre Shale. Segments of Fountain Creek have Se water levels that exceed the current EPA limit of 5 µg/l. In the studies described here, the effects of river water containing selenium were examined on fish populations at different sites along the Fountain Creek Watershed. Based on the hypothesis that high levels of Se present in the Creek and resident bryophytes should be an indicator of diversity in the river fish we explored the possibility that the low toxicity of the selenium could be due to speciation. A speciation analysis was conducted to determine the selenium(IV) and selenium(VI). Our results show that sites with higher ratios of the more toxic Se(IV) relative to total selenium exhibit lower fish diversity and number of fish. Our results indicate that factors, other than total Se, such as Se speciation may be involved in controlling the bioavailability and toxicity of this element to aquatic organisms in Fountain Creek.

  5. 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.

  6. Selenium contaminated waters: An overview of analytical methods, treatment options and recent advances in sorption methods.

    Science.gov (United States)

    Santos, Sílvia; Ungureanu, Gabriela; Boaventura, Rui; Botelho, Cidália

    2015-07-15

    Selenium is an essential trace element for many organisms, including humans, but it is bioaccumulative and toxic at higher than homeostatic levels. Both selenium deficiency and toxicity are problems around the world. Mines, coal-fired power plants, oil refineries and agriculture are important examples of anthropogenic sources, generating contaminated waters and wastewaters. For reasons of human health and ecotoxicity, selenium concentration has to be controlled in drinking-water and in wastewater, as it is a potential pollutant of water bodies. This review article provides firstly a general overview about selenium distribution, sources, chemistry, toxicity and environmental impact. Analytical techniques used for Se determination and speciation and water and wastewater treatment options are reviewed. In particular, published works on adsorption as a treatment method for Se removal from aqueous solutions are critically analyzed. Recent published literature has given particular attention to the development and search for effective adsorbents, including low-cost alternative materials. Published works mostly consist in exploratory findings and laboratory-scale experiments. Binary metal oxides and LDHs (layered double hydroxides) have presented excellent adsorption capacities for selenium species. Unconventional sorbents (algae, agricultural wastes and other biomaterials), in raw or modified forms, have also led to very interesting results with the advantage of their availability and low-cost. Some directions to be considered in future works are also suggested. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Effect of Selenium Deficiency on Phosphorylation of the AMPK Pathway in Rats.

    Science.gov (United States)

    He, Shulan; Guo, Xiong; Tan, Wuhong; Su, Xiaohui; Li, Jiangping; Pan, Wang; Qiu, Hongyan

    2016-02-01

    Selenium is an important trace element for human health. Previous studies have raised concern that dietary selenium intake may change energy metabolism. AMP-activated protein kinase (AMPK) is a sensor of energy status that controls cellular energy homeostasis. We aimed to determine the effect of selenium on the phosphorylation of AMPK pathway between Se-deficient and normal Sprague-Dawley rats. Twenty-four weaning rats were fed either a Se-deficient diet (0.02 mg Se/kg) or a standard diet (0.18 mg Se/kg). After 109 days, total serum levels of non-esterified fatty acid and total amino acids were significantly higher and the serum insulin concentration was significantly lower in Se-deficient rats than in healthy controls. Selenium concentration and the activity of glutathione peroxidase (GPx) in myocardial tissue were significantly lower in Se-deficient rats. Importantly, mRNA levels of acetyl-CoA carboxylase beta (ACACB), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), and protein levels of p-AMPKα were increased in the Se-deficient group compared to normal controls (p selenium deficiency induces changes in metabolic and molecular parameters involved in energy metabolism in the AMPK pathway.

  8. Nutritional status and serum zinc and selenium levels in Iranian HIV infected individuals

    Directory of Open Access Journals (Sweden)

    Saeedi AA

    2008-12-01

    Full Text Available Abstract Background Human immunodeficiency virus infected individuals are prone to malnutrition due to increased energy requirements, enteropathy and increased catabolism. Trace elements such as zinc and selenium have major role in maintaining a healthy immune system. This study was designed to evaluate the nutritional status of Iranian subjects who were newly diagnosed with human immunodeficiency virus infection and to compare serum level of zinc and selenium in these patients with those of the sex and aged match healthy subjects. Methods After an interview and physical examination, nutritional assessment was done based on clinical and anthropometric parameters. Body mass index (normal range 18.5–27 kg/m2 based on age of less than 16, 16–16.9 and 17–18.4 kg/m2 were considered as severe, moderate and mild malnutrition respectively. Serum level of zinc and selenium were measured by graphite furnace atomic absorption. Results Severe, moderate and mild malnutrition were detected in 15%, 38% and 24% of human immunodeficiency virus infected individuals respectively. Compared with the healthy control group, serum level of zinc and selenium in the human immunodeficiency virus infected subjects were significantly lower (P = 0.01 and P = 0.02 respectively. Conclusion Malnutrition found to be prevalent in Iranian human immunodeficiency virus infected individuals and low serum zinc and selenium levels are common in this population.

  9. Nutritional status and serum zinc and selenium levels in Iranian HIV infected individuals.

    Science.gov (United States)

    Khalili, H; Soudbakhsh, A; Hajiabdolbaghi, M; Dashti-Khavidaki, S; Poorzare, A; Saeedi, A A; Sharififar, R

    2008-12-09

    Human immunodeficiency virus infected individuals are prone to malnutrition due to increased energy requirements, enteropathy and increased catabolism. Trace elements such as zinc and selenium have major role in maintaining a healthy immune system. This study was designed to evaluate the nutritional status of Iranian subjects who were newly diagnosed with human immunodeficiency virus infection and to compare serum level of zinc and selenium in these patients with those of the sex and aged match healthy subjects. After an interview and physical examination, nutritional assessment was done based on clinical and anthropometric parameters. Body mass index (normal range 18.5-27 kg/m2 based on age) of less than 16, 16-16.9 and 17-18.4 kg/m2 were considered as severe, moderate and mild malnutrition respectively. Serum level of zinc and selenium were measured by graphite furnace atomic absorption. Severe, moderate and mild malnutrition were detected in 15%, 38% and 24% of human immunodeficiency virus infected individuals respectively. Compared with the healthy control group, serum level of zinc and selenium in the human immunodeficiency virus infected subjects were significantly lower (P = 0.01 and P = 0.02 respectively). Malnutrition found to be prevalent in Iranian human immunodeficiency virus infected individuals and low serum zinc and selenium levels are common in this population.

  10. The protective influence of selenium on oxidant disturbances in brain of rats exposed to lithium.

    Science.gov (United States)

    Kiełczykowska, M; Kocot, J; Lewandowska, A; Żelazowska, R; Musik, I

    2015-01-01

    For more than sixty years lithium carbonate has been used in medicine. However, during its administration different side effects including oxidative stress can occur. Selenium belongs to essential elements possessing antioxidant properties. This study aimed at evaluating if selenium could be used as a protective adjuvant in lithium therapy. The experiment was performed on four groups of Wistar rats: I (control), II (Li), III (Se), IV (Li + Se) treated with saline, lithium carbonate (2.7 mg Li/kg b.w.), sodium selenite (0.5 mg Se/kg b.w.) and lithium carbonate (2.7 mg Li/kg b.w.) + sodium selenite (0.5 mg Se/kg b.w.), respectively. All substances were administered as water solutions by stomach tube for 3 or 6 weeks. Catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) as well as malonyldialdehyde (MDA) were determined in brain homogenates. Lithium slightly enhanced MDA and depressed CAT and SOD after 6 weeks as well as GPx after 3 weeks. Selenium co-administration showed tendency to restore the disturbed parameters. Selenium alone and given with lithium significantly increased GPx vs. Li-treated group after 3 weeks. Having regarded the outcomes of this study, the research on application of selenium during lithium treatment seems to be worth continuation.

  11. Analytical determination of selenium in medical samples, staple food and dietary supplements by means of total reflection X-ray fluorescence spectroscopy

    Science.gov (United States)

    Stosnach, Hagen

    2010-09-01

    Selenium is essential for many aspects of human health and, thus, the object of intensive medical research. This demands the use of analytical techniques capable of analysing selenium at low concentrations with high accuracy in widespread matrices and sometimes smallest sample amounts. In connection with the increasing importance of selenium, there is a need for rapid and simple on-site (or near-to-site) selenium analysis in food basics like wheat at processing and production sites, as well as for the analysis of this element in dietary supplements. Common analytical techniques like electrothermal atomic absorption spectroscopy (ETAAS) and inductively-coupled plasma mass spectrometry (ICP-MS) are capable of analysing selenium in medical samples with detection limits in the range from 0.02 to 0.7 μg/l. Since in many cases less complicated and expensive analytical techniques are required, TXRF has been tested regarding its suitability for selenium analysis in different medical, food basics and dietary supplement samples applying most simple sample preparation techniques. The reported results indicate that the accurate analysis of selenium in all sample types is possible. The detection limits of TXRF are in the range from 7 to 12 μg/l for medical samples and 0.1 to 0.2 mg/kg for food basics and dietary supplements. Although this sensitivity is low compared to established techniques, it is sufficient for the physiological concentrations of selenium in the investigated samples.

  12. Monitoring of selenium in oral cavity argyria - a clinical and microscopic study.

    Science.gov (United States)

    Venclíková, Zora; Benada, Oldřich; Joska, Luděk

    2011-01-01

    Argyria is generally classified as localized or generalized condition. Distinct pigmentation of the oral mucosa in the vicinity of amalgam fillings is often referred to as amalgam tattoos. Pigmented areas can also be associated with silver-containing corrosion products of dental alloys used for prosthetic restorations. Silver-containing electron dense particles (Ag-EDPs) are frequently found in pigmented areas. We attempted to correlate results of the elemental composition of Ag-EDPs with excerpts from health profiles of our study paticipants. Eight patients with diagnosed signs of localized argyria were investigated in this study. Biopsies from distinctly pigmented gingival areas were subjected to histological examination, electron microscopy and x-ray microanalysis. Elemental composition of Ag-EDPs determined by x-ray microanalysis showed mainly silver in combination with sulfur or selenium or a combination of both chalcogens. Elemental analyzes results of Ag-EDPs were analyzed along with excerpts from the patient's clinical records. Two patients with low or undetectable selenium in the Ag-EDPs suffered from autoimmune thyroiditis, Parkinson's disease, bronchial asthma, and allergies to molds, pollen and dust. We suggest that selenium in Ag-EDPs is a product of the detoxification process for Ag(+) ions in gingival tissue and that it may reflect the availability of endogenous selenium for physiological processes in the human body. Its presence or absence might thus be used as another marker of a patient's health status.

  13. Fracture Phenomena in Amorphous Selenium

    DEFF Research Database (Denmark)

    Lindegaard-Andersen, Asger; Dahle, Birgit

    1966-01-01

    Fracture surfaces of amorphous selenium broken in flexure at room temperature have been studied. The fracture velocity was found to vary in different regions of the fracture surface. Peculiar features were observed in a transition zone between fast and slower fracture. In this zone cleavage steps...... with a nearly constant spacing of approximately 1 µ were found. Occasionally long cleavage whiskers—up to some millimeters long—were observed. Within certain regions the cleavage steps were crossed and interrupted by two line systems. The maximum fracture velocity has been measured to 350 m/sec. Further...

  14. Using Cytochrome c{sub 3} to Make Selenium Nanowires

    Energy Technology Data Exchange (ETDEWEB)

    ABDELOUAS,A.; FRANCO,R.; GONG,W.L.; LUTZE,W.; MOURA,I.; SHELNUTT,JOHN A.

    1999-11-24

    We report on a new method to make nanostructures, in this case selenium nanowires, in aqueous solution at room temperature. We used the protein cytochrome c{sub 3} to reduce selenate (SeO{sub 4}{sup 2{minus}}) to selenium (Se{sup 0}). Cytochrome c{sub 3} is known for its ability to catalyze reduction of metals including U{sup VI} {yields} U{sup IV}, Cr{sup VI} {yields} Cr{sup III}, Mo{sup VI} {yields} Mo{sup IV}, Cu{sup II} {yields} Cu{sup 0}, Pb{sup II} {yields} Pb{sup 0}, Hg{sup II} {yields} Hg{sup 0}. Nanoparticles of Se{sup 0} precipitated from an aqueous solution at room temperature, followed by spontaneous self-assembling into nanowires. Cytochrome c{sub 3} was extracted from the sulfate-reducing bacteria Desulfovibrio vulgaris (strain Holdenborough) and isolated by the procedure of DerVartanian and Legall.

  15. 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.

  16. Role of selenium toxicity and oxidative stress in aquatic birds

    Science.gov (United States)

    Hoffman, D.J.

    2002-01-01

    hepatic GSH peroxidase, depletion of hepatic protein bound thiols and total thiols, but a small increase in GSH. Diving ducks in the San Francisco Bay area exhibited a positive correlation between hepatic Se concentration and GSH peroxidase activity (r=0.63, Pother elements and dietary protein, should also be taken into consideration. Further studies are needed to examine the relationship between different forms of environmentally occurring selenium, arsenic and mercury on reproduction, hepatotoxicity and immune function of aquatic birds. Further selenium nutritional interaction studies may also help to illucidate the mechanism of selenium induced teratogenesis, by optimizing GSH and other antioxidant defense mechanisms in a manner that would stabilize or raise the cell's threshold for susceptibility to toxic attack from excess selenium. It is concluded that Se-related manifestations of oxidative stress may serve as useful bioindicators of Se exposure and toxicity in wild aquatic birds.

  17. Selenium deficiency associated porcine and human cardiomyopathies.

    Science.gov (United States)

    Oropeza-Moe, Marianne; Wisløff, Helene; Bernhoft, Aksel

    2015-01-01

    Selenium (Se) is a trace element playing an important role in animal and human physiological homeostasis. It is a key component in selenoproteins (SeP) exerting multiple actions on endocrine, immune, inflammatory and reproductive processes. The SeP family of glutathione peroxidases (GSH-Px) inactivates peroxides and thereby maintains physiological muscle function in humans and animals. Animals with high feed conversion efficiency and substantial muscle mass have shown susceptibility to Se deficiency related diseases since nutritional requirements of the organism may not be covered. Mulberry Heart Disease (MHD) in pigs is an important manifestation of Se deficiency often implicating acute heart failure and sudden death without prior clinical signs. Post-mortem findings include hemorrhagic and pale myocardial areas accompanied by fluid accumulation in the pericardial sac and pleural cavity. Challenges in MHD are emerging in various parts of the world. Se is of fundamental importance also to human health. In the 1930s the Se deficiency associated cardiomyopathy named Keshan Disease (KD) was described for the first time in China. Various manifestations, such as cardiogenic shock, enlarged heart, congestive heart failure, and cardiac arrhythmias are common. Multifocal necrosis and fibrous replacement of myocardium are characteristic findings. Pathological findings in MD and KD show striking similarities. Copyright © 2014 Elsevier GmbH. All rights reserved.

  18. Genetic polymorphisms that affect selenium status and response to selenium supplementation in United Kingdom pregnant women.

    Science.gov (United States)

    Mao, Jinyuan; Vanderlelie, Jessica J; Perkins, Anthony V; Redman, Christopher W G; Ahmadi, Kourosh R; Rayman, Margaret P

    2016-01-01

    Low selenium status in pregnancy has been associated with a number of adverse conditions. In nonpregnant populations, the selenium status or response to supplementation has been associated with polymorphisms in dimethylglycine dehydrogenase (DMGDH), selenoprotein P (SEPP1) and the glutathione peroxidases [cytosolic glutathione peroxidase (GPx1) and phospholipid glutathione peroxidase (GPx4)]. We hypothesized that, in pregnant women, these candidate polymorphisms would be associated with selenium status in early pregnancy, its longitudinal change, and the interindividual response to selenium supplementation at 60 μg/d. With the use of stored samples and data from the United Kingdom Selenium in Pregnancy Intervention (SPRINT) study in 227 pregnant women, we carried out genetic-association studies, testing for associations between selenium status, its longitudinal change, and response to supplementation and common genetic variation in DMGDH (rs921943), SEPP1 (rs3877899 and rs7579), GPx1 (rs1050450) and GPx4 (rs713041). Selenium status was represented by the concentration of whole-blood selenium at 12 and 35 wk of gestation, the concentration of toenail selenium at 16 wk of gestation, and plasma glutathione peroxidase (GPx3) activity at 12 and 35 wk of gestation. Our results showed that DMGDH rs921943 was significantly associated with the whole-blood selenium concentration at 12 wk of gestation (P = 0.032), which explained ≤2.0% of the variance. This association was replicated with the use of toenail selenium (P = 0.043). In unsupplemented women, SEPP1 rs3877899 was significantly associated with the percentage change in whole-blood selenium from 12 to 35 wk of gestation (P = 0.005), which explained 8% of the variance. In supplemented women, SEPP1 rs3877899 was significantly associated with the percentage change in GPx3 activity from 12 to 35 wk of gestation (P = 0.01), which explained 5.3% of the variance. Selenium status was not associated with GPx1, GPx4, or SEPP1

  19. Changes in selenium, zinc, copper and cadmium contents in human milk during the time when selenium has been supplemented to fertilizers in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Kantola, M. [Dept. of Chemistry, Univ. of Kuopio, Kuopio (Finland); Vartiainen, T. [Div. of Environmental Health, National Public Health Inst., Kuopio (Finland); Univ. of Kuopio, Dept. of Environmental Sciences, Kuopio (Finland)

    2001-07-01

    Sodium selenate has been supplemented to all agricultural fertilizers used in Finland since 1984. We followed the changes in selenium, cadmium, zinc and copper content in Finnish human milk between the years 1987 and 1993-1995. A total of 257 milk samples was collected, four weeks after delivery, in two areas: In Helsinki, an urban area, and in Kuopio, a rural area, where elevated copper concentrations have been found in the bedrock. Direct atomic absorption spectrophotometric methods without digestion were used for the analyses. The dependence of trace element content on study time, living area, smoking habits, fish eating frequency, and parity of mothers was studied by analysis of covariance. Inter-element correlations and correlations with mother's age and fat content in milk were studied by partial correlation. Significant increases were observed in mean selenium (16.4 {mu}g/l and 18.9 {mu}g/l, p < 0.001) and in fat contents (3.4% and 4.0%, p < 0.001), whereas significant decreases were seen in mean zinc (3.00 mg/l and 1.47 mg/l, p < 0.001), copper (0.52 mg/l and 0.43 mg/l, p < 0.001) and cadmium contents (0.095 {mu}g/l and 0.062 {mu}g/l, p < 0.01). In 1987, zinc had a positive correlation with copper and fat. Copper correlated inversely with the mothers' age. In 1993-1995, selenium correlated positively with copper, and zinc correlated inversely with mothers' age. Mothers living area had an effect on copper content in milk. Our results confirm that selenium supplementation to fertilizers in Finland has increased the selenium level in human maternal milk and most likely it also has an effect on the zinc and copper concentrations in maternal milk. (orig.)

  20. EFFECT OF SELENIUM ON THE DISTRIBUTION OF HEAVY METALS IN TISSUES OF FALLOW DEER (Dama dama L.

    Directory of Open Access Journals (Sweden)

    Neška Vukšić

    2016-06-01

    Full Text Available The aim of this study was to determine the concentration of heavy metals (Cd, Pb, Hg and As and essential elements (Fe and Se in fallow deer tissues (muscle, kidney, liver, adipose tissue and spleen before the addition of selenium in the food and after that to determine the interaction of selenium with heavy metals in the tissues and the influence of selenium on immunohaematological (CBC and WBC, biochemistry (glucose, urea, CRE, ALB, TGC, KOL, HLD, LDL, Fe, TP, GLOB, IgG indicators and indicators of oxidative stress (SOD, GPx, GSH and vitamin E. The research was conducted on 40 fallow deer that were shot in the hunting season during the two year research. Analysis of habitat included analyses of soil, tree leaves, grasses and fodders. Supplemental nutrition with the addition of selenium (0.5 mg/kg was carried out for 60 days in the second year of the research. During the first year of the experiment there were increased concentrations of Cd and Pb in the tissues of fallow deer whereas concentration of Se was low. After supplementary feeding with the addition of selenium, concentration of heavy metals in the tissues was lower and antioxidant protection was improved. Addition of selenium had no negative impact on other tested parameters.

  1. A Summary of New Findings on the Biological Effects of Selenium in Selected Animal Species—A Critical Review

    Directory of Open Access Journals (Sweden)

    Bozena Hosnedlova

    2017-10-01

    Full Text Available Selenium is an essential trace element important for many physiological processes, especially for the functions of immune and reproductive systems, metabolism of thyroid hormones, as well as antioxidant defense. Selenium deficiency is usually manifested by an increased incidence of retention of placenta, metritis, mastitis, aborts, lowering fertility and increased susceptibility to infections. In calves, lambs and kids, the selenium deficiency demonstrates by WMD (white muscle disease, in foals and donkey foals, it is associated with incidence of WMD and yellow fat disease, and in pigs it causes VESD (vitamin E/selenium deficiency syndrome. The prevention of these health disorders can be achieved by an adequate selenium supplementation to the diet. The review summarizes the survey of knowledge on selenium, its biological significance in the organism, the impact of its deficiency in mammalian livestock (comparison of ruminants vs. non-ruminants, herbivore vs. omnivore and possibilities of its peroral administration. The databases employed were as follows: Web of Science, PubMed, MEDLINE and Google Scholar.

  2. Does a role for selenium in DNA damage repair explain apparent controversies in its use in chemoprevention?

    Science.gov (United States)

    Diamond, Alan M.

    2013-01-01

    The trace element selenium is an essential micronutrient that has received considerable attention for its potential use in the prevention of cancer. In spite of this interest, the mechanism(s) by which selenium might function as a chemopreventive remain to be determined. Considerable experimental evidence indicates that one possible mechanism by which selenium supplementation may exert its benefits is by enhancing the DNA damage repair response, and this includes data obtained using cultured cells, animal models as well as in human clinical studies. In these studies, selenium supplementation has been shown to be beneficial in reducing the frequency of DNA adducts and chromosome breaks, consequentially reducing the likelihood of detrimental mutations that ultimately contribute to carcinogenesis. The benefits of selenium can be envisioned as being due, at least in part, to it being a critical constituent of selenoproteins such as glutathione peroxidases and thioredoxin reductases, proteins that play important roles in antioxidant defence and maintaining the cellular reducing environment. Selenium, therefore, may be protective by preventing DNA damage from occurring as well as by increasing the activity of repair enzymes such as DNA glycosylases and DNA damage repair pathways that involve p53, BRCA1 and Gadd45. An improved understanding of the mechanism of selenium’s impact on DNA repair processes may help to resolve the apparently contradicting data obtained from decades of animal work, human epidemiology and more recently, clinical supplementation studies. PMID:23204505

  3. Enhanced Adsorption of Selenium Ions from Aqueous Solution Using Iron Oxide Impregnated Carbon Nanotubes.

    Science.gov (United States)

    Bakather, Omer Y; Kayvani Fard, Ahmad; Ihsanullah; Khraisheh, Majeda; Nasser, Mustafa S; Atieh, Muataz Ali

    2017-01-01

    The aim of this research was to investigate the potential of raw and iron oxide impregnated carbon nanotubes (CNTs) as adsorbents for the removal of selenium (Se) ions from wastewater. The original and modified CNTs with different loadings of Fe2O3 nanoparticles were characterized using high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray diffractometer (XRD), Brunauer, Emmett, and Teller (BET) surface area analyzer, thermogravimetric analysis (TGA), zeta potential, and energy dispersive X-ray spectroscopy (EDS). The adsorption parameters of the selenium ions from water using raw CNTs and iron oxide impregnated carbon nanotubes (CNT-Fe2O3) were optimized. Total removal of 1 ppm Se ions from water was achieved when 25 mg of CNTs impregnated with 20 wt.% of iron oxide nanoparticles is used. Freundlich and Langmuir isotherm models were used to study the nature of the adsorption process. Pseudo-first and pseudo-second-order models were employed to study the kinetics of selenium ions adsorption onto the surface of iron oxide impregnated CNTs. Maximum adsorption capacity of the Fe2O3 impregnated CNTs, predicted by Langmuir isotherm model, was found to be 111 mg/g. This new finding might revolutionize the adsorption treatment process and application by introducing a new type of nanoadsorbent that has super adsorption capacity towards Se ions.

  4. Scaffold of Selenium Nanovectors and Honey Phytochemicals for Inhibition of Pseudomonas aeruginosa Quorum Sensing and Biofilm Formation.

    Science.gov (United States)

    Prateeksha; Singh, Braj R; Shoeb, M; Sharma, S; Naqvi, A H; Gupta, Vijai K; Singh, Brahma N

    2017-01-01

    Honey is an excellent source of polyphenolic compounds that are effective in attenuating quorum sensing (QS), a chemical process of cell-to-cell communication system used by the opportunistic pathogen Pseudomonas aeruginosa to regulate virulence and biofilm formation. However, lower water solubility and inadequate bioavailability remains major concerns of these therapeutic polyphenols. Its therapeutic index can be improved by using nano-carrier systems to target QS signaling potently. In the present study, we fabricated a unique drug delivery system comprising selenium nanoparticles (SeNPs; non-viral vectors) and polyphenols of honey (HP) for enhancement of anti-QS activity of HP against P. aeruginosa PAO1. The developed selenium nano-scaffold showed superior anti-QS activity, anti-biofilm efficacy, and anti-virulence potential in both in-vitro and in-vivo over its individual components, SeNPs and HP. LasR is inhibited by selenium nano-scaffold in-vitro. Using computational molecular docking studies, we have also demonstrated that the anti-virulence activity of selenium nano-scaffold is reliant on molecular binding that occurs between HP and the QS receptor LasR through hydrogen bonding and hydrophobic interactions. Our preliminary investigations with selenium-based nano-carriers hold significant promise to improve anti-virulence effectiveness of phytochemicals by enhancing effective intracellular delivery.

  5. Scaffold of Selenium Nanovectors and Honey Phytochemicals for Inhibition of Pseudomonas aeruginosa Quorum Sensing and Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Prateeksha

    2017-03-01

    Full Text Available Honey is an excellent source of polyphenolic compounds that are effective in attenuating quorum sensing (QS, a chemical process of cell-to-cell communication system used by the opportunistic pathogen Pseudomonas aeruginosa to regulate virulence and biofilm formation. However, lower water solubility and inadequate bioavailability remains major concerns of these therapeutic polyphenols. Its therapeutic index can be improved by using nano-carrier systems to target QS signaling potently. In the present study, we fabricated a unique drug delivery system comprising selenium nanoparticles (SeNPs; non-viral vectors and polyphenols of honey (HP for enhancement of anti-QS activity of HP against P. aeruginosa PAO1. The developed selenium nano-scaffold showed superior anti-QS activity, anti-biofilm efficacy, and anti-virulence potential in both in-vitro and in-vivo over its individual components, SeNPs and HP. LasR is inhibited by selenium nano-scaffold in-vitro. Using computational molecular docking studies, we have also demonstrated that the anti-virulence activity of selenium nano-scaffold is reliant on molecular binding that occurs between HP and the QS receptor LasR through hydrogen bonding and hydrophobic interactions. Our preliminary investigations with selenium-based nano-carriers hold significant promise to improve anti-virulence effectiveness of phytochemicals by enhancing effective intracellular delivery.

  6. Selenium and Sulfur to Produce Allium Functional Crops.

    Science.gov (United States)

    González-Morales, Susana; Pérez-Labrada, Fabián; García-Enciso, Ema Laura; Leija-Martínez, Paola; Medrano-Macías, Julia; Dávila-Rangel, Irma Esther; Juárez-Maldonado, Antonio; Rivas-Martínez, Erika Nohemí; Benavides-Mendoza, Adalberto

    2017-03-30

    Selenium is an element that must be considered in the nutrition of certain crops since its use allows the obtaining of biofortified crops with a positive impact on human health. The objective of this review is to present the information on the use of Se and S in the cultivation of plants of the genus Allium. The main proposal is to use Allium as specialist plants for biofortification with Se and S, considering the natural ability to accumulate both elements in different phytochemicals, which promotes the functional value of Allium. In spite of this, in the agricultural production of these species, the addition of sulfur is not realized to obtain functional foods and plants more resistant; it is only sought to cover the necessary requirements for growth. On the other hand, selenium does not appear in the agronomic management plans of most of the producers. Including S and Se fertilization as part of agronomic management can substantially improve Allium crop production. Allium species may be suitable to carry out biofortification with Se; this practice can be combined with the intensive use of S to obtain crops with higher production and sensory, nutritional, and functional quality.

  7. Reproductive impacts of elevated selenium levels

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objectives of this study were to: 1. Evaluate selenium levels in Neotropical migrants and riparian obligate birds on Imperial National Wildlife Refuge. 2....

  8. Copper, iron, and selenium dietary deficiencies negatively impact skeletal integrity: A review.

    Science.gov (United States)

    Medeiros, Denis M

    2016-06-01

    Nutrients have been known to have a significant role in maintaining the health of the skeleton, both bone and cartilage. The nutrients that have received the majority of the attention are Vitamin D and calcium. However, limited attention has been directed toward three trace elements that may have mechanistic impact upon the skeletal tissues and could compromise skeletal health resulting from inadequate intakes of copper, iron, and selenium. The role of copper and selenium has been known, but the role of iron has only received recent attention. Copper deficiency is thought to impact bone health by a decrease in lysyl oxidase, a copper-containing enzyme, which facilitates collagen fibril crosslinking. Iron deficiency impact upon bone has only recently been discovered but the exact mechanism on how the deficient states enhance bone pathology is speculative. Selenium deficiency has an impact on cartilage thereby having an indirect impact on bone. However, several studies suggest that a mycotoxin when consumed by humans is the culprit in some cartilage disorders and the presence of selenium could attenuate the pathology. This review summarizes the current knowledge base with respect to skeletal integrity when each of these three trace elements are inadequate in diets of both animals and humans. © 2016 by the Society for Experimental Biology and Medicine.

  9. Fate and Transport of Elemental Copper (Cu0) Nanoparticles through Saturated Porous Media in the Presence of Organic Materials

    Science.gov (United States)

    Column experiments were performed to assess the fate and transport of nanoscale elemental copper (Cu0) particles in saturated quartz sands. Both effluent concentrations and retention profiles were measured over a broad range of physicochemical conditions, which included pH, ionic...

  10. Is selenium supplementation in autoimmune thyroid diseases justified?

    DEFF Research Database (Denmark)

    Winther, Kristian H.; Bonnema, Steen; Hegedüs, Laszlo

    2017-01-01

    PURPOSE OF REVIEW: This review provides an appraisal of recent evidence for or against selenium supplementation in patients with autoimmune thyroid diseases, and discusses possible effect mechanisms. RECENT FINDINGS: Epidemiological data suggest an increased prevalence of autoimmune thyroid...... diseases under conditions of low dietary selenium intake. Two systematic reviews have evaluated controlled trials among patients with autoimmune thyroiditis and report that selenium supplementation decreases circulating thyroid autoantibodies. The immunomodulatory effects of selenium might involve reducing...... proinflammatory cytokine release. However, clinically relevant effects of selenium supplementation, including improvement in quality of life, are more elusive. In Graves’ disease, some, but not all, trials indicate that adjuvant selenium supplementation enhances the restoration of biochemical euthyroidism...

  11. Selenium supplementation for patients with Graves’ hyperthyroidism (the GRASS trial)

    DEFF Research Database (Denmark)

    Watt, Torquil; Cramon, Per; Bjorner, Jakob Bue

    2013-01-01

    Graves' hyperthyroidism is an autoimmune disease causing hyperfunction of the thyroid gland. The concentration of selenium is high in the thyroid gland and two important groups of enzymes within the thyroid are selenoproteins, that is, they depend on selenium. Selenium may have beneficial effects...... on autoimmune hypothyroidism and on Graves' orbitopathy, but the effects of selenium on Graves' hyperthyroidism is unknown.We hypothesize that adjuvant selenium may be beneficial in the treatment of Graves' hyperthyroidism. The objective is to investigate if selenium supplementation plus standard treatment......, anti-thyroid drug treatment success), and improved quality of life in patients with Graves' hyperthyroidism....

  12. Enteral yeast-selenium supplementation in preterm infants

    OpenAIRE

    Bogye, G.; Alfthan, G.; Machay, T.; Zubovics, L.

    1998-01-01

    AIM—To study the bioavailability of selenium enriched yeast in preterm infants living in a low selenium area (Hungary).
METHODS—Thirty six preterm infants were randomly assigned to two groups at birth with respect to selenium supplementation. In the supplemented group (n=18) infants received 4.8 mg of selenium enriched yeast containing 5 µg selenium daily.
RESULTS—In the supplemented group the serum selenium concentration increased from 36.1(±12.8) µg/l to 43.5 (7.9) µg/l and in t...

  13. A simplified method for determining titanium from TiO2 nanoparticles in fish tissue with a concomitant multi-element analysis.

    Science.gov (United States)

    Shaw, Benjamin J; Ramsden, Christopher S; Turner, Andrew; Handy, Richard D

    2013-08-01

    The reliable detection of nanoparticles (NPs) in fish tissue is required to support ecotoxicological research and food safety investigations. Therefore the current work aimed to develop a simple method to determine Ti from TiO2 NPs in fish tissue whilst simultaneously measuring other elements in the sample. Spike recovery tests showed no differences when digestion was conducted in glass or plastic vials, there was stirring or sonication of the samples, or when sodium dodecyl sulfate was added. However, the addition of 2% Triton X-100 and sonicating and then vortexing of samples immediately prior to analysis did improve recovery (approximately 20% to >90% in trout gill and muscle samples). Method precision and accuracy were good with coefficients of variation recovery results showed that the method is also suitable for multi-element analysis in the same samples. This improved method is simple with high throughput and represents a marked improvement for routine determination Ti from TiO2 NPs in fish tissues. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Accidental death from acute selenium poisoning.

    Science.gov (United States)

    See, Katharine A; Lavercombe, Peter S; Dillon, Jasmine; Ginsberg, Riesa

    2006-10-02

    We report a fatal case of acute selenium poisoning in a 75-year-old man. After reading on the Internet about a possible role of selenium in prostate cancer, the patient ingested 10 g of sodium selenite. Despite intensive care treatment, he suffered a cardiac arrest and died 6 hours after ingestion. This case illustrates the risks of failing to critically evaluate Internet information and exposes the myth that natural therapies are inherently safe.

  15. Biomarkers of selenium status in dogs

    OpenAIRE

    Van Zelst, Marielle; Hesta, Myriam; Gray, Kerry; Staunton, Ruth; Du Laing, Gijs; Janssens, Geert

    2016-01-01

    Background: Inadequate dietary selenium (Se) intake in humans and animals can lead to long term health problems, such as cancer. In view of the owner's desire for healthy longevity of companion animals, the impact of dietary Se provision on long term health effects warrants investigation. Little is currently known regards biomarkers, and rate of change of such biomarkers in relation to dietary selenium intake in dogs. In this study, selected biomarkers were assessed for their suitability to d...

  16. Pathology of selenium poisoning in fish

    Science.gov (United States)

    A. Dennis Lemly

    1998-01-01

    Selenium presents an interesting paradox in the field of aquatic toxicology because it is both a nutrient and a poison. As a nutrient, it is required in the diet of fish at concentrations of about 0. 1 to 0. 5 Fg/g dry weight. Selenium is necessary for proper formation and functioning of glutathione peroxidase, which is a major cellular antioxidant enzyme. This enzyme...

  17. The role of selenium in predicting preeclampsia

    Directory of Open Access Journals (Sweden)

    Z Ghaemi

    2013-10-01

    Full Text Available Introduction: Preeclampsia is a common disorder that is a leading cause of perinatal and maternal morbidity and mortality; however its specific etiology has still remained obscure.The first step in preventing preeclampsia is early detection of women at risk. Since there is no valid and reliable screening test, appropriate diagnostic and screening tests are necessary, which are inexpensive, non-invasive and beneficial for pregnant women. Therefore, regarding the role of selenium as an antioxidant in the prevention preeclampsia, this study was designed which aimed to determine the prognostic value of plasma selenium levels in the diagnosis of preeclampsia in primigravida women Methods: In a nested case control design, a sample of 650 normal primigravida women of 24-28 weeks participated in the study. Subjects who involved the case group were followed up for 3 months and 38 were affected by preeclampsia. Blood samples were obtained from these 38patients as well as from 38 subjects as their matched controls. Moreover, the amount of selenium was measured by atomic absorption spectrometry. Results: The mean level of selenium in blood plasma of the cases was significantly lower than in their matched controls. The present study findings revealed that pregnant women with serum Se < 66.1 μg/L had a significantly increased risk of preeclampsia. Conclusion: Lower plasma selenium level in women destines to suffering from preeclampsia which confirms the destructive effect of selenium deficiency as an antioxidant in etiopathology of preeclampsia. Measurement of plasma selenium can improve the prediction of preeclampsia; thus, it seems that plasma selenium level test owns an acceptable sensitivity and specificity for predicting preeclampsia.

  18. A natural analogue of high-pH cement pore waters from the Maqarin area of northern Jordan: Comparison of predicted and observed trace-element chemistry of uranium and selenium

    Science.gov (United States)

    Linklater, C. M.; Albinsson, Y.; Alexander, W. R.; Casas, I.; McKinley, I. G.; Sellin, P.

    1996-02-01

    Current design concepts for low-/intermediate-level radioactive waste disposal in many countries involve emplacement underground in a cementitious repository. The highly alkaline groundwaters at Maqarin, Jordan, are a good analogue for the cementitious pore waters that will be present within such a repository. A geochemical modelling study of these groundwaters has been carried out in order to test the applicability of equilibrium models in geochemical programs and their associated thermodynamic databases in such hyperalkaline conditions. This was achieved by comparison of elemental solubilities and speciations predicted by the programs with observations in the natural system. Five organisations took part in the study: AEA Technology, U.K.; Chalmers University of Technology, Sweden; MBT Tecnología Ambiental, Spain; Nagra, Switzerland; and SKB, Sweden. The modelling study was coordinated by the University of Berne. The results of the study showed good agreement between the predictions of the programs employed. Comparison of the observed solids with those predicted by the models has allowed limited validation of the databases. The results for U and Se are presented here.

  19. Selenium in human health and disease.

    Science.gov (United States)

    Fairweather-Tait, Susan J; Bao, Yongping; Broadley, Martin R; Collings, Rachel; Ford, Dianne; Hesketh, John E; Hurst, Rachel

    2011-04-01

    This review covers current knowledge of selenium in the environment, dietary intakes, metabolism and status, functions in the body, thyroid hormone metabolism, antioxidant defense systems and oxidative metabolism, and the immune system. Selenium toxicity and links between deficiency and Keshan disease and Kashin-Beck disease are described. The relationships between selenium intake/status and various health outcomes, in particular gastrointestinal and prostate cancer, cardiovascular disease, diabetes, and male fertility, are reviewed, and recent developments in genetics of selenoproteins are outlined. The rationale behind current dietary reference intakes of selenium is explained, and examples of differences between countries and/or expert bodies are given. Throughout the review, gaps in knowledge and research requirements are identified. More research is needed to improve our understanding of selenium metabolism and requirements for optimal health. Functions of the majority of the selenoproteins await characterization, the mechanism of absorption has yet to be identified, measures of status need to be developed, and effects of genotype on metabolism require further investigation. The relationships between selenium intake/status and health, or risk of disease, are complex but require elucidation to inform clinical practice, to refine dietary recommendations, and to develop effective public health policies.

  20. Biological activity of selenium: Revisited.

    Science.gov (United States)

    Wrobel, Jagoda K; Power, Ronan; Toborek, Michal

    2016-02-01

    Selenium (Se) is an essential micronutrient that exerts multiple and complex effects on human health. Se is essential for human well-being largely due to its potent antioxidant, anti-inflammatory, and antiviral properties. The physiological functions of Se are carried out by selenoproteins, in which Se is specifically incorporated as the amino acid, selenocysteine. Importantly, both beneficial and toxic effects of Se have been reported suggesting that the mode of action of Se is strictly chemical form and concentration dependent. Additionally, there is a relatively narrow window between Se deficiency and toxicity and growing evidence suggests that Se health effects depend greatly on the baseline level of this micronutrient. Thus, Se supplementation is not an easy task and requires an individualized approach. It is essential that we continue to explore and better characterize Se containing compounds and mechanisms of action, which could be crucial for disease prevention and treatment. © 2015 International Union of Biochemistry and Molecular Biology.

  1. Thin film solar cells by selenization sulfurization using diethyl selenium as a selenium precursor

    Science.gov (United States)

    Dhere, Neelkanth G.; Kadam, Ankur A.

    2009-12-15

    A method of forming a CIGSS absorber layer includes the steps of providing a metal precursor, and selenizing the metal precursor using diethyl selenium to form a selenized metal precursor layer (CIGSS absorber layer). A high efficiency solar cell includes a CIGSS absorber layer formed by a process including selenizing a metal precursor using diethyl selenium to form the CIGSS absorber layer.

  2. [Selenium levels in human bodies and environment in Qinghai province].

    Science.gov (United States)

    Shu, S; Yuan, J; Yan, H

    1996-07-01

    To study selenium level, its distribution in human bodies and environment and its effects on health, 3,035 specimens of human hair, blood, urine, and environmetal water, soil, food were collected from 91 sampling spots in 23 cities and counties of Qinghai Province and determined for selenium levels with fluorescence analysis. Results showed overall biological selenium level of human bodies in Qinghai Province was low and blood selenium level was lower than the normal reference value in 84.73% of the population, same as that in selenium-poor nations. Environmental selenium was poor or in a deficient status in Qinghai Province, 69.57% of the areas in the Province was in low, poor, or severely deficient selenium. Selenium level in vegetable food correlated closely with that in human blood, which indicated low selenium level in environment caused human selenium deficient in their internal environment via food chain. There were difference in biological selenium levels of human bodies in seven districts and six ethnic nationalities, which suggests selenium levels in human bodies correlate closely with economic development, selenium intake, geographical environment, living habits and customs, etc., and are nothing to do with the altitude above sea level.

  3. Updates on clinical studies of selenium supplementation in radiotherapy.

    Science.gov (United States)

    Puspitasari, Irma M; Abdulah, Rizky; Yamazaki, Chiho; Kameo, Satomi; Nakano, Takashi; Koyama, Hiroshi

    2014-05-29

    To establish guidelines for the selenium supplementation in radiotherapy we assessed the benefits and risks of selenium supplementation in radiotherapy. Clinical studies on the use of selenium in radiotherapy were searched in the PubMed electronic database in January 2013. Sixteen clinical studies were identified among the 167 articles selected in the initial search. Ten articles were observational studies, and the other 6 articles reported studies on the effects of selenium supplementation in patients with cancer who underwent radiotherapy. The studies were conducted worldwide including European, American and Asian countries between 1987 and 2012. Plasma, serum or whole blood selenium levels were common parameters used to assess the effects of radiotherapy and the selenium supplementation status. Selenium supplementation improved the general conditions of the patients, improved their quality of life and reduced the side effects of radiotherapy. At the dose of selenium used in these studies (200-500 μg/day), selenium supplementation did not reduce the effectiveness of radiotherapy, and no toxicities were reported. Selenium supplementation may offer specific benefits for several types of cancer patients who undergo radiotherapy. Because high-dose selenium and long-term supplementation may be unsafe due to selenium toxicity, more evidence-based information and additional research are needed to ensure the therapeutic benefits of selenium supplementation.

  4. Updates on clinical studies of selenium supplementation in radiotherapy

    Science.gov (United States)

    2014-01-01

    To establish guidelines for the selenium supplementation in radiotherapy we assessed the benefits and risks of selenium supplementation in radiotherapy. Clinical studies on the use of selenium in radiotherapy were searched in the PubMed electronic database in January 2013. Sixteen clinical studies were identified among the 167 articles selected in the initial search. Ten articles were observational studies, and the other 6 articles reported studies on the effects of selenium supplementation in patients with cancer who underwent radiotherapy. The studies were conducted worldwide including European, American and Asian countries between 1987 and 2012. Plasma, serum or whole blood selenium levels were common parameters used to assess the effects of radiotherapy and the selenium supplementation status. Selenium supplementation improved the general conditions of the patients, improved their quality of life and reduced the side effects of radiotherapy. At the dose of selenium used in these studies (200–500 μg/day), selenium supplementation did not reduce the effectiveness of radiotherapy, and no toxicities were reported. Selenium supplementation may offer specific benefits for several types of cancer patients who undergo radiotherapy. Because high-dose selenium and long-term supplementation may be unsafe due to selenium toxicity, more evidence-based information and additional research are needed to ensure the therapeutic benefits of selenium supplementation. PMID:24885670

  5. Organic selenium supplementation increased selenium concentrations in ewe and newborn lamb blood and in slaughter lamb meat compared to inorganic selenium supplementation

    OpenAIRE

    Steen Arvid; Strøm Turid; Bernhoft Aksel

    2008-01-01

    Abstract Background Selenium is part of the antioxidant defence system in animals and humans. The available selenium concentration in soil is low in many regions of the world. The purpose of this study was to evaluate the effect of organic versus inorganic selenium supplementation on selenium status of ewes, their lambs, and slaughter lambs. Methods Ewes on four organic farms were allocated five or six to 18 pens. The ewes were given either 20 mg/kg inorganic selenium as sodium selenite or or...

  6. SELENIUM MOBILITY IN SOME SOILS OF ROMANIA

    Directory of Open Access Journals (Sweden)

    Mihaela Lungu

    2013-12-01

    Full Text Available Selenium mobility in soil depends on a multitude of physical and chemical factors. The present paper highlights the selenium solubilization degree out of the total soil content in relation with its agrochemical properties. Soils samples were considered collected from different agricultural areas of the Country, with or without certain natural handicaps, from soils under industrial impact and long term agrochemical experiments. The selenium solubilization percentages out of the soil total content ranged between 3.57 and 8.15%. No solubilization percentage was calculated for Central and Southern Dobrudja and the South-Eastern Romanian Plane, because the total selenium quantities in these areas are lower and mobile selenium values are very low. The statistical analysis of the calculated percentage values highlighted homogeneous areas and areas with a higher scattering degree. Thus, in agricultural land, in acknowledged agrarian areas and in long term agricultural experiments, the percentage values are better grouped, showing (expectable soil homogeneousness, on one hand, and a significant soil selenium supply and its adequate solubilization for plant nutrition, on the other. The most scattered values occurred in the Călmăţui and Buzău valleys area in halomorphic soils, and in the Făgăraş Depression which is under the industrial polluting influence of chemical works. Among the causes for these differences is the uniformity or non-uniformity of the terrains, induced by land use and the existence or not of a handicap (polluting impact or halomorphic soils, for example. In general, there are no significant differences between the selenium mobility values and their grouping or scattering degree in the soil depth. A single exception stands out, namely in the Făgăraş Depression, where the selenium solubilization degree tends to increase with soil depth, as well as the scattering degree. In the Danube Delta diked areas Sireasa and Pardina very

  7. EURRECA-Estimating selenium requirements for deriving dietary reference values.

    Science.gov (United States)

    Hurst, Rachel; Collings, Rachel; Harvey, Linda J; King, Maria; Hooper, Lee; Bouwman, Jildau; Gurinovic, Mirjana; Fairweather-Tait, Susan J

    2013-01-01

    Current reference values for selenium, an essential micronutrient, are based on the intake of selenium that is required to achieve maximal glutathione peroxidase activity in plasma or erythrocytes. In order to assess the evidence of relevance to setting dietary reference values for selenium, the EURRECA Network of Excellence focused on systematic searches, review, and evaluation of (i) selenium status biomarkers and evidence for relationships between intake and status biomarkers, (ii) selenium and health (including the effect of intake and/or status biomarkers on cancer risk, immune function, HIV, cognition, and fertility), (iii) bioavailability of selenium from the diet, and (iv) impact of genotype/single nucleotide polymorphisms on status or health outcomes associated with selenium. The main research outputs for selenium and future research priorities are discussed further in this review.

  8. Optimization of selenoprotein P and other plasma selenium biomarkers for the assessment of the selenium nutritional requirement: a placebo-controlled, double-blind study of selenomethionine supplementation in selenium-deficient Chinese subjects1234

    OpenAIRE

    Xia, YiMing; Hill, Kristina E.; Li, Ping; Xu, Jiayuan; Zhou, Dingyou; Motley, Amy K.; WANG, LI; Byrne, Daniel W.; Burk, Raymond F.

    2010-01-01

    Background: The intake of selenium needed for optimal health has not been established. Selenoproteins perform the functions of selenium, and the selenium intake needed for their full expression is not known.

  9. Glutathione peroxidase response in tissues of rats fed diets containing fish protein concentrate prepared from shark flesh of known mercury and selenium contents

    Energy Technology Data Exchange (ETDEWEB)

    Thrower, S.J. (Commonwealth Scientific and Industrial Research Organization, Hobart, Australia); Andrewartha, K.A.

    1981-01-01

    Studies have been reported using experimental animals and synthetic diets containing selenium and mercury compounds to demonstrate detoxification of mercury by selenium. The mechanism of detoxification remains obscure. Most experiments have involved the use of high levels of both elements and relied on the observation of gross symptoms. The measurement of enzyme systems may be useful in detecting effects of mercury at a lower, subclinical level and in elucidating the biochemistry of mercury/selenium interactions. The activity of the selenoenzyme glutathione peroxidase (GSH-Px) in rats is dependent on dietary selenium and attempts have been made to use this enzyme as an indicator of mercury/selenium interactions. The research described in this paper was designed to investigate the effect of mercury, in the form and amounts which occur naturally in seafood, on the availability of selenium at levels approximating the nutritional requirement. In anticipation of mercury lowering the GSH-Px response a range of selenium concentrations was used, from nutritional deficiency to three times the nutritional requirement.

  10. Role of copper, zinc, and selenium in uterine cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Sarita, P.; Naga Raju, G.J. [Department of Physics, Institute of Technology, GITAM University, Visakhapatnam (India); Bhuloka Reddy, S. [Swami Jnanananda Laboratories for Nuclear Research, Andhra Universily, Visakahpatnam (India)

    2013-07-01

    Full text: The objective of this study was to evaluate the levels of trace elements in blood sera of uterine cervix cancer patients, analyze their alteration with respect to healthy controls, ascertain the role played by them in the initiation, promotion and inhibition of cancer, and identify the best predictors amongst these for disease occurrence and progression. Moreover, the variation of trace elemental content in the sera of cervix cancer patients with the clinical stage of disease and with therapy was also studied. Particle induced X-ray emission (PIXE), a well established method for elemental analysis, was used in this work to identify and quantify trace elements in the blood sera of uterine cervix cancer subjects and healthy control subjects. The PIXE measurements were carried out using 2.5 MeV collimated proton beam from the 3 MV Tandem Pelletron Accelerator at lon Beam Laboratory, Institute of Physics, Bhubaneswar, India. Among all the trace elements identified in this work, statistically significant alterations in serum levels of copper, zinc, and selenium were observed among the various studied groups. The observed alterations are discussed with respect to the possible mechanisms by which these elements might influence the carcinogenic process. (author)

  11. Updates on clinical studies of selenium supplementation in radiotherapy

    OpenAIRE

    Puspitasari, Irma M.; Abdulah, Rizky; Yamazaki, Chiho; KAMEO, Satomi; Nakano, Takashi; Koyama, Hiroshi

    2014-01-01

    To establish guidelines for the selenium supplementation in radiotherapy we assessed the benefits and risks of selenium supplementation in radiotherapy. Clinical studies on the use of selenium in radiotherapy were searched in the PubMed electronic database in January 2013. Sixteen clinical studies were identified among the 167 articles selected in the initial search. Ten articles were observational studies, and the other 6 articles reported studies on the effects of selenium supplementation i...

  12. Low blood selenium: A probable factor in essential hypertension ...

    African Journals Online (AJOL)

    The possible association between selenium and essential hypertension was investigated in this study. Blood selenium (BSe) and plasma glutathione peroxidase (plGSH-Px) activity were measured as biochemical markers of selenium status of 103 hypertensive patients (44 males and 59 females) and 88 apparently healthy ...

  13. Reduced Maternal Selenium levels in Pregnant and Lactating ...

    African Journals Online (AJOL)

    Reduced Maternal Selenium levels in Pregnant and Lactating Nigerian women: Should Routine Selenium Supplementation be advocated? ... However, there was a non significant increase immediately after birth. In the breast milk, selenium concentration significantly decreased (P<0.0001) as lactation progressed.

  14. Selenium deficiency and the effects of supplementation on preterm infants

    Science.gov (United States)

    Freitas, Renata Germano B. O. N.; Nogueira, Roberto José N.; Antonio, Maria Ângela R. G. M.; Barros-Filho, Antonio de Azevedo; Hessel, Gabriel

    2014-01-01

    Objective: This study aimed to review the literature about blood concentrations of selenium associated with gestational age, feeding, supplementation and related clinical features in preterm infants. Data sources: Systematic review in the following databases: MEDLINE, PubMed, Google academics, SciELO. org, ScienceDirect (Elsevier) and CINAHL-Plus with Full Text (EBSCO). Articles published up to January 2013 with the keywords "selenium deficiency", "selenium supplementation", "neonates", "infants", "newborn" and "preterm infants" were selected. Data synthesis: The studies reported that low blood selenium levels are associated with increased risk of respiratory diseases. Preterm infants, especially with low birth weight, presented lower selenium levels. Selenium deficiency has also been associated with the use of oral infant formula, enteral and parenteral nutrition (with or without selenium addition). The optimal dose and length of selenium supplementation is not well-established, since they are based only on age group and selenium ingestion by breastfed children. Furthermore, the clinical status of the infant affected by conditions that may increase oxidative stress, and consequently, selenium requirements is not taken into account. Conclusions: Prematurity and low birth weight can contribute to low blood selenium in premature infants. Selenium supplementation seems to minimize or prevent clinical complications caused by prematurity. PMID:24676200

  15. Evaluation Of Selenium Supplementation Alone, A Combination Of ...

    African Journals Online (AJOL)

    The effect of selenium supplementation alone and a combination of selenium and Vitamin E or low dose diminazene aceturate (berenil) was investigated in Trypanosoma brucei brucei infected rats. The effect of the selenium supplementation and its combinations were assessed using the parasitaemia, changes in body ...

  16. NAIL KERATIN AS MONITOR-TISSUE FOR SELENIUM EXPOSURE

    NARCIS (Netherlands)

    VANNOORD, PAH; MAAS, MJ; DEBRUIN, M

    1992-01-01

    Nail clippings might provide a way to monitor exposure to selenium in the recent past of an individual, since a clipping collected from a toe would reflect exposures months before actual clipping date. The relation between levels of exogenous selenium exposure and selenium levels in nail keratin was

  17. Selenistasis: Epistatic Effects of Selenium on Cardiovascular Phenotype

    Science.gov (United States)

    Joseph, Jacob; Loscalzo, Joseph

    2013-01-01

    Although selenium metabolism is intricately linked to cardiovascular biology and function, and deficiency of selenium is associated with cardiac pathology, utilization of selenium in the prevention and treatment of cardiovascular disease remains an elusive goal. From a reductionist standpoint, the major function of selenium in vivo is antioxidant defense via its incorporation as selenocysteine into enzyme families such as glutathione peroxidases and thioredoxin reductases. In addition, selenium compounds are heterogeneous and have complex metabolic fates resulting in effects that are not entirely dependent on selenoprotein expression. This complex biology of selenium in vivo may underlie the fact that beneficial effects of selenium supplementation demonstrated in preclinical studies using models of oxidant stress-induced cardiovascular dysfunction, such as ischemia-reperfusion injury and myocardial infarction, have not been consistently observed in clinical trials. In fact, recent studies have yielded data that suggest that unselective supplementation of selenium may, indeed, be harmful. Interesting biologic actions of selenium are its simultaneous effects on redox balance and methylation status, a combination that may influence gene expression. These combined actions may explain some of the biphasic effects seen with low and high doses of selenium, the potentially harmful effects seen in normal individuals, and the beneficial effects noted in preclinical studies of disease. Given the complexity of selenium biology, systems biology approaches may be necessary to reach the goal of optimization of selenium status to promote health and prevent disease. PMID:23434902

  18. Selenium deficiency and the effects of supplementation on preterm infants.

    Science.gov (United States)

    Freitas, Renata Germano B O N; Nogueira, Roberto Jose N; Antonio, Maria Angela R G M; Barros-Filho, Antonio de Azevedo; Hessel, Gabriel

    2014-03-01

    This study aimed to review the literature about blood concentrations of selenium associated with gestational age, feeding, supplementation and related clinical features in preterm infants. Systematic review in the following databases: MEDLINE, PubMed, Google academics, SciELO. org, ScienceDirect (Elsevier) and CINAHL-Plus with Full Text (EBSCO). Articles published up to January 2013 with the keywords "selenium deficiency", "selenium supplementation", "neonates", "infants", "newborn" and "preterm infants" were selected. The studies reported that low blood selenium levels are associated with increased risk of respiratory diseases. Preterm infants, especially with low birth weight, presented lower selenium levels. Selenium deficiency has also been associated with the use of oral infant formula, enteral and parenteral nutrition (with or without selenium addition). The optimal dose and length of selenium supplementation is not well-established, since they are based only on age group and selenium ingestion by breastfed children. Furthermore, the clinical status of the infant affected by conditions that may increase oxidative stress, and consequently, selenium requirements is not taken into account. Prematurity and low birth weight can contribute to low blood selenium in premature infants. Selenium supplementation seems to minimize or prevent clinical complications caused by prematurity.

  19. Selenistasis: epistatic effects of selenium on cardiovascular phenotype.

    Science.gov (United States)

    Joseph, Jacob; Loscalzo, Joseph

    2013-01-31

    Although selenium metabolism is intricately linked to cardiovascular biology and function, and deficiency of selenium is associated with cardiac pathology, utilization of selenium in the prevention and treatment of cardiovascular disease remains an elusive goal. From a reductionist standpoint, the major function of selenium in vivo is antioxidant defense via its incorporation as selenocysteine into enzyme families such as glutathione peroxidases and thioredoxin reductases. In addition, selenium compounds are heterogeneous and have complex metabolic fates resulting in effects that are not entirely dependent on selenoprotein expression. This complex biology of selenium in vivo may underlie the fact that beneficial effects of selenium supplementation demonstrated in preclinical studies using models of oxidant stress-induced cardiovascular dysfunction, such as ischemia-reperfusion injury and myocardial infarction, have not been consistently observed in clinical trials. In fact, recent studies have yielded data that suggest that unselective supplementation of selenium may, indeed, be harmful. Interesting biologic actions of selenium are its simultaneous effects on redox balance and methylation status, a combination that may influence gene expression. These combined actions may explain some of the biphasic effects seen with low and high doses of selenium, the potentially harmful effects seen in normal individuals, and the beneficial effects noted in preclinical studies of disease. Given the complexity of selenium biology, systems biology approaches may be necessary to reach the goal of optimization of selenium status to promote health and prevent disease.

  20. EURRECA—Estimating Selenium Requirements for Deriving Dietary Reference Values

    NARCIS (Netherlands)

    Hurst, R.; Collings, R.; Harvey, L.J.; King, M.; Hooper, L.; Bouwman, J.; Gurinovic, M.; Fairweather-Tait, S.J.

    2013-01-01

    Current reference values for selenium, an essential micronutrient, are based on the intake of selenium that is required to achieve maximal glutathione peroxidase activity in plasma or erythrocytes. In order to assess the evidence of relevance to setting dietary reference values for selenium, the

  1. Selenium deficiency and the effects of supplementation on preterm infants

    Directory of Open Access Journals (Sweden)

    Renata Germano B. O. N. Freitas

    2014-03-01

    Full Text Available Objective: This study aimed to review the literature about blood concentrations of selenium associated with gestational age, feeding, supplementation and related clinical features in preterm infants. Data sources: Systematic review in the following databases: MEDLINE, PubMed, Google academics, SciELO. org, ScienceDirect (Elsevier and CINAHL-Plus with Full Text (EBSCO. Articles published up to January 2013 with the keywords "selenium deficiency", "selenium supplementation", "neonates", "infants", "newborn" and "preterm infants" were selected. Data synthesis: The studies reported that low blood selenium levels are associated with increased risk of respiratory diseases. Preterm infants, especially with low birth weight, presented lower selenium levels. Selenium deficiency has also been associated with the use of oral infant formula, enteral and parenteral nutrition (with or without selenium addition. The optimal dose and length of selenium supplementation is not well-established, since they are based only on age group and selenium ingestion by breastfed children. Furthermore, the clinical status of the infant affected by conditions that may increase oxidative stress, and consequently, selenium requirements is not taken into account. Conclusions: Prematurity and low birth weight can contribute to low blood selenium in premature infants. Selenium supplementation seems to minimize or prevent clinical complications caused by prematurity.

  2. Selenistasis: Epistatic Effects of Selenium on Cardiovascular Phenotype

    Directory of Open Access Journals (Sweden)

    Joseph Loscalzo

    2013-01-01

    Full Text Available Although selenium metabolism is intricately linked to cardiovascular biology and function, and deficiency of selenium is associated with cardiac pathology, utilization of selenium in the prevention and treatment of cardiovascular disease remains an elusive goal. From a reductionist standpoint, the major function of selenium in vivo is antioxidant defense via its incorporation as selenocysteine into enzyme families such as glutathione peroxidases and thioredoxin reductases. In addition, selenium compounds are heterogeneous and have complex metabolic fates resulting in effects that are not entirely dependent on selenoprotein expression. This complex biology of selenium in vivo may underlie the fact that beneficial effects of selenium supplementation demonstrated in preclinical studies using models of oxidant stress-induced cardiovascular dysfunction, such as ischemia-reperfusion injury and myocardial infarction, have not been consistently observed in clinical trials. In fact, recent studies have yielded data that suggest that unselective supplementation of selenium may, indeed, be harmful. Interesting biologic actions of selenium are its simultaneous effects on redox balance and methylation status, a combination that may influence gene expression. These combined actions may explain some of the biphasic effects seen with low and high doses of selenium, the potentially harmful effects seen in normal individuals, and the beneficial effects noted in preclinical studies of disease. Given the complexity of selenium biology, systems biology approaches may be necessary to reach the goal of optimization of selenium status to promote health and prevent disease.

  3. Toxicity of organic and inorganic selenium to mallard ducklings

    Science.gov (United States)

    Heinz, G.H.; Hoffman, D.J.; Gold, L.G.

    1988-01-01

    The toxicity of selenomethionine and sodium selenite to mallard ducklings (Anas platyrhynchos) was measured by feeding each form from hatching to six weeks of age at dietary concentrations of 0, 10, 20, 40, and 80 ppm selenium. At 80 ppm selenium, sodium selenite caused 97.5% mortality by six weeks and selenomethionine caused 100% mortality. At 40 ppm, these two forms of selenium caused 25 and 12.5% mortality. No mortality occurred at 10 or 20 ppm. Diets containing 20, 40, or 80 ppm selenium in both forms caused decreases in food consumption and growth. The only statistically significant effect of 10 ppm selenium was with sodium selenite, which resulted in larger livers than controls. Selenomethionine was more readily stored in the liver than sodium selenite at levels above 10 ppm selenium in the diet. Based on comparisons of residues of selenium in livers of surviving and dead ducklings, concentrations in the liver were not diagnostic of death due to selenium poisoning. Because both forms of selenium resulted in severe reductions in food consumption, selenium-induced starvation may have been related to duckling mortality. It was not clear whether either form of selenium at 10 ppm in the diet resulted in a leveling off of selenium concentrations in the liver within six weeks.

  4. Technical issues affecting the implementation of US environmental protection agency's proposed fish tissue-based aquatic criterion for selenium

    Science.gov (United States)

    A. Dennis Lemly; Joseph P. Skorupa

    2007-01-01

    The US Environmental Protection Agency is developing a national water quality criterion for selenium that is based on concentrations of the element in fish tissue. Although this approach offers advantages over the current water-based regulations, it also presents new challenges with respect to implementation. A comprehensive protocol that answers the ‘‘what, where, and...

  5. Selenium supplementation in radiotherapy patients: do we need to measure selenium levels in serum or blood regularly prior radiotherapy?

    OpenAIRE

    Mücke, Ralph; Micke, Oliver; Schomburg, Lutz; Kisters, Klaus; Büntzel, Jens; Hübner, Jutta; Kriz, Jan

    2014-01-01

    Considering the review by Puspitasari and colleagues, an additional discussion of the endpoints of the Se supplementation studies described would be helpful. In our view, selenium can safely be given to selenium-deficient cancer patients prior to and during radiotherapy. Therefore, in order to help the radiation oncologist in decision making, we strongly advocate to determine the selenium status prior to and during a potential adjuvant selenium supplementation, e.g. when trying to ease the si...

  6. Selenium and Vitamin E for Prostate Cancer: Post-SELECT (Selenium and Vitamin E Cancer Prevention Trial) Status

    OpenAIRE

    Ledesma, Mark C; Jung-Hynes, Brittney; Schmit, Travis L; Kumar,Raj; Mukhtar, Hasan; Ahmad, Nihal

    2010-01-01

    Various formulations of selenium and vitamin E, both essential human dietary components, have been shown to possess a therapeutic and preventive effect against prostate cancer. Fortuitous results of clinical trials also implied a risk-reduction effect of selenium and vitamin E supplements. The Selenium and Vitamin E Cancer Prevention Trial (SELECT), using oral selenium and vitamin E supplementation in disease-free volunteers, was designed to test a prostate cancer chemoprevention hypothesis. ...

  7. Toenail mercury and dyslipidemia: Interaction with selenium.

    Science.gov (United States)

    Park, Kyong; Seo, Eunmin

    2017-01-01

    Although compelling evidences from in vivo and in vitro studies exist, limited studies have examined the association between chronic mercury exposure and dyslipidemia. Particularly, data are sparse regarding the influence of selenium on this association of mercury with dyslipidemia in humans. The purpose of the current study was to examine the associations of toenail mercury with dyslipidemia and its components, and to examine whether selenium in toenails modifies these associations. We performed cross-sectional analyses using baseline data from a cohort in the Yeungnam area in South Korea, including 232 men and 269 women. Toenail mercury and selenium concentrations were quantified using neutron activation analysis, and fasting serum lipid measurements were obtained through the medical examination. Odds ratios of the prevalent hypercholesterolemia, hyper-LDL-cholesterolemia, hypo-HDL-cholesterolemia, hypertriglyceridemia, and dyslipidemia in correlation with mercury levels were calculated using multivariable logistic regression. The mean levels of toenail mercury were 0.47μg/g for men and 0.34μg/g for women. After adjustment for multiple confounding variables, participants in the highest tertile of toenail mercury levels had 4.08 (95% CI 1.09-15.32, p for trend=0.02) times higher risk of hyper-LDL-cholesterolemia, and 2.24 (95% CI 1.15-4.37, p for trend=0.004) times higher risk of dyslipidemia than those in the lowest tertile. Selenium is a significant effect-modifier for these associations; the highest tertile of toenail mercury were significantly associated with a higher risk of hypercholesterolemia (OR 5.25, 95% CI 1.04-26.38) and dyslipidemia (OR 2.98, 95% CI 1.16-7.66) compared to the lowest tertile at toenail selenium levels ≤0.685μg/g, while these associations became weak and non-significant, showing OR 0.98 and 95% CI 0.25-3.80 for hypercholesterolemia and OR 1.99 and 95% CI 0.73-5.45 for dyslipidemia at toenail selenium levels >0.685μg/g. We

  8. Investigation of Serum Levels of Selenium, Zinc, and Copper in Adolescents with Idiopathic Scoliosis

    Directory of Open Access Journals (Sweden)

    Zahide Yalaki

    2017-03-01

    Full Text Available Objective: The purpose of this study was to investigate the serum levels of selenium, zinc and copper on the etiology of idiopathic scoliosis in adolescents. Methods: Forty four idiopathic scoliosis patients between 10 and 17 years of age were considered in this study. The vertebra curvature degrees of the patients were between 28° and 82°. The idiopathic scoliosis patients were assigned to two groups based on their vertebra curvature degrees. Curvature degree of 45° and lower was labeled as group 1 and curvature of upper 45° was labeled as group 2. Total blood count, serum levels of selenium, zinc and copper were studied. Results: Thirty three of the idiopathic scoliosis patients (75% were female. There was no statistically significant difference in serum zinc and copper levels between idiopathic scoliosis patients and the control group (p> 0.05. Serum selenium levels in idiopathic scoliosis patients were lower than that of the control group and the difference was statistically significant (p 0.05. Conclusion: Among the measured trace elements, selenium was lower in the serum of the IS patients. This is the first study in Turkey that we know of about this subject and we think that further studies are needed.

  9. Selenium in pollen gathered by bees foraging on fly ash-grown plants

    Energy Technology Data Exchange (ETDEWEB)

    De Jong, D.; Morse, R.A.; Gutenmann, W.H.; Lisk, D.J.

    1977-10-01

    Fly ash is the material collected in the stacks of coal burning electric power-generating plants by electrostatic precipitators. About 26 million metric tons of fly ash was estimated to have been produced in 1975 (BRACKETT, 1970). Aside from a small percentage of the material which is used as a base material for roads and in concrete, the bulk of it is deposited in landfills. It was first reported by Gutenmann et al. (1976) that sweet clover, found voluntarily growing on a fly ash landfill site, contained up to 200 ppM of selenium. Fly ashes from 21 states were found to contain the element. Cabbage grown on each of these fly ashes added (7 percent w/w) to soil was shown to absorb selenium in proportion to its concentration in the particular ash (GUTENMANN et al., 1976). The percentage of fly ash in soil was also shown to dictate the extent of selenium absorption by a variety of plants (FURR et al., 1976). In the work reported, pollen collected by honey bees foraging on plants growing on a fly ash landfill was analyzed for selenium and compared with that collected by bees from the same plants growing on soil.

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

    Science.gov (United States)

    Kamble, P; Mohsin, N; Jha, A; Date, A; Upadhaya, A; Mohammad, E; Khalil, M; Pakkyara, A; Budruddin, M

    2009-01-01

    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 recovered 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.

  11. 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.

  12. Selenium and Prostate Cancer Prevention: Insights from the Selenium and Vitamin E Cancer Prevention Trial (SELECT

    Directory of Open Access Journals (Sweden)

    Holly L. Nicastro

    2013-04-01

    Full Text Available The Selenium and Vitamin E Cancer Prevention Trial (SELECT was conducted to assess the efficacy of selenium and vitamin E alone, and in combination, on the incidence of prostate cancer. This randomized, double-blind, placebo-controlled, 2 × 2 factorial design clinical trial found that neither selenium nor vitamin E reduced the incidence of prostate cancer after seven years and that vitamin E was associated with a 17% increased risk of prostate cancer compared to placebo. The null result was surprising given the strong preclinical and clinical evidence suggesting chemopreventive activity of selenium. Potential explanations for the null findings include the agent formulation and dose, the characteristics of the cohort, and the study design. It is likely that only specific subpopulations may benefit from selenium supplementation; therefore, future studies should consider the baseline selenium status of the participants, age of the cohort, and genotype of specific selenoproteins, among other characteristics, in order to determine the activity of selenium in cancer prevention.

  13. Selenium and Prostate Cancer Prevention: Insights from the Selenium and Vitamin E Cancer Prevention Trial (SELECT)

    Science.gov (United States)

    Nicastro, Holly L.; Dunn, Barbara K.

    2013-01-01

    The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was conducted to assess the efficacy of selenium and vitamin E alone, and in combination, on the incidence of prostate cancer. This randomized, double-blind, placebo-controlled, 2 × 2 factorial design clinical trial found that neither selenium nor vitamin E reduced the incidence of prostate cancer after seven years and that vitamin E was associated with a 17% increased risk of prostate cancer compared to placebo. The null result was surprising given the strong preclinical and clinical evidence suggesting chemopreventive activity of selenium. Potential explanations for the null findings include the agent formulation and dose, the characteristics of the cohort, and the study design. It is likely that only specific subpopulations may benefit from selenium supplementation; therefore, future studies should consider the baseline selenium status of the participants, age of the cohort, and genotype of specific selenoproteins, among other characteristics, in order to determine the activity of selenium in cancer prevention. PMID:23552052

  14. Speciation of selenium dietary supplements; formation of S-(methylseleno)cysteine and other selenium compounds

    Energy Technology Data Exchange (ETDEWEB)

    Amoako, Prince O. [Department of Chemistry, University of Massachusetts Amherst, 710 N. Pleasant St., Amherst, MA 01003-9336 (United States); Uden, Peter C., E-mail: pcuden@chem.umass.edu [Department of Chemistry, University of Massachusetts Amherst, 710 N. Pleasant St., Amherst, MA 01003-9336 (United States); Tyson, Julian F. [Department of Chemistry, University of Massachusetts Amherst, 710 N. Pleasant St., Amherst, MA 01003-9336 (United States)

    2009-10-12

    Speciation of selenium is of interest because it is both essential and toxic to humans, depending on the species and the amount ingested. Following indications that selenium supplementation could reduce the incidence of some cancers, selenium-enriched yeast and other materials have been commercialized as supplements. Most dramatically however, the SELECT trial that utilized L-selenomethionine as the active supplement was terminated in 2008 and there is much debate regarding both the planning and the results of efficacy studies. Further, since dietary supplements are not regulated as pharmaceuticals, there are concerns about the quality, storage conditions, stability and selenium content in selenium supplements. Enzymatic hydrolysis enabled selenium speciation profiles to be obtained by high performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and following derivatization gas chromatography with atomic emission detection (GC-AED). Coated fiber solid phase microextraction (SPME) was used to extract volatile selenium species for determination by GC-AED and GC-MS. Similar speciation patterns were observed between yeast-based supplements subject to extended storage and those heated briefly at elevated temperatures. All the yeast-based supplements and one yeast-free supplement formed S-(methylseleno)cysteine on heating. Evidence was obtained in support of the hypotheses that S-(methylseleno)cysteine is formed from a reaction between dimethyldiselenide and cysteine or cystine.

  15. Selenium in Camel – A Review

    Directory of Open Access Journals (Sweden)

    Bernard Faye

    2009-07-01

    Full Text Available Requirements for trace minerals in camels, particularly selenium, are not well-known. Selenium supplementation using a pharmaceutical form or commercial mineral mixture is common practice in camels to address the cardiomyopathy often attributed to selenium deficiency. This supplementation is often empirical and based on estimated needs for cattle. Nowadays the use of selenium in animal foodstuffs is commonplace and further investigation of its metabolism (ingestion, dynamic of storage-destocking, excretion in camels is warranted. The present review aimed to synthesize all the experimental research (comparative selenium status in cow and camel, response to different levels of supplementation at different physiological stages, excretion maternal transfer, experimental toxicosis and field observations (deficiency, supplementation practices undertaken in camels. The results underline the particularity of the unique metabolic profile of the camel and lead to practical recommendations for supplementation in camels, highlighting its relative sensitivity to excess Se intake at lower levels than in cattle. The maximal tolerable dose is 8 mg and the recommended doses range from 2 to 4 mg.

  16. Selenium deficiency occurs in some patients with moderate-to-severe cirrhosis and can be corrected by administration of selenate but not selenomethionine: a randomized controlled trial123

    Science.gov (United States)

    Burk, Raymond F; Hill, Kristina E; Motley, Amy K; Byrne, Daniel W; Norsworthy, Brooke K

    2015-01-01

    Background: Selenomethionine, which is the principal dietary form of selenium, is metabolized by the liver to selenide, which is the form of the element required for the synthesis of selenoproteins. The liver synthesizes selenium-rich selenoprotein P (SEPP1) and secretes it into the plasma to supply extrahepatic tissues with selenium. Objectives: We conducted a randomized controlled trial to determine whether cirrhosis is associated with functional selenium deficiency (the lack of selenium for the process of selenoprotein synthesis even though selenium intake is not limited) and, if it is, whether the deficiency is associated with impairment of selenomethionine metabolism. Design: Patients with Child-Pugh (C-P) classes A, B, and C (mild, moderate, and severe, respectively) cirrhosis were supplemented with a placebo or supranutritional amounts of selenium as selenate (200 or 400 μg/d) or as selenomethionine (200 μg/d) for 4 wk. Plasma SEPP1 concentration and glutathione peroxidase (GPX) activity, the latter due largely to the selenoprotein GPX3 secreted by the kidneys, were measured before and after supplementation. Results: GPX activity was increased more by both doses of selenate than by the placebo in C-P class B patients. The activity was not increased more by selenomethionine supplementation than by the placebo in C-P class B patients. Plasma selenium was increased more by 400 μg Se as selenate than by the placebo in C-P class C patients. Within the groups who responded to selenate, there was a considerable variation in responses. Conclusion: These results indicate that severe cirrhosis causes mild functional selenium deficiency in some patients that is associated with impaired metabolism of selenomethionine. This trial was registered at clinicaltrials.gov as NCT00271245. PMID:26468123

  17. Selenium deficiency occurs in some patients with moderate-to-severe cirrhosis and can be corrected by administration of selenate but not selenomethionine: a randomized controlled trial.

    Science.gov (United States)

    Burk, Raymond F; Hill, Kristina E; Motley, Amy K; Byrne, Daniel W; Norsworthy, Brooke K

    2015-11-01

    Selenomethionine, which is the principal dietary form of selenium, is metabolized by the liver to selenide, which is the form of the element required for the synthesis of selenoproteins. The liver synthesizes selenium-rich selenoprotein P (SEPP1) and secretes it into the plasma to supply extrahepatic tissues with selenium. We conducted a randomized controlled trial to determine whether cirrhosis is associated with functional selenium deficiency (the lack of selenium for the process of selenoprotein synthesis even though selenium intake is not limited) and, if it is, whether the deficiency is associated with impairment of selenomethionine metabolism. Patients with Child-Pugh (C-P) classes A, B, and C (mild, moderate, and severe, respectively) cirrhosis were supplemented with a placebo or supranutritional amounts of selenium as selenate (200 or 400 μg/d) or as selenomethionine (200 μg/d) for 4 wk. Plasma SEPP1 concentration and glutathione peroxidase (GPX) activity, the latter due largely to the selenoprotein GPX3 secreted by the kidneys, were measured before and after supplementation. GPX activity was increased more by both doses of selenate than by the placebo in C-P class B patients. The activity was not increased more by selenomethionine supplementation than by the placebo in C-P class B patients. Plasma selenium was increased more by 400 μg Se as selenate than by the placebo in C-P class C patients. Within the groups who responded to selenate, there was a considerable variation in responses. These results indicate that severe cirrhosis causes mild functional selenium deficiency in some patients that is associated with impaired metabolism of selenomethionine. This trial was registered at clinicaltrials.gov as NCT00271245. © 2015 American Society for Nutrition.

  18. Selenium and Arsenic - Nitrate-facilitated Pyrite Oxidation in an Urban Watershed

    Science.gov (United States)

    Sjolin, J.; Meixner, T.; Hibbs, B.; Amrhein, C.; Walker, J.

    2003-12-01

    A century of Orange County urbanization on the Newport Bay / San Diego Creek Watershed has had dramatic impacts on surface geomorphology. Draining of historic wetlands and subsequent channel incision has caused oxidation and mobilization of toxic trace elements accumulated in the former wetlands. Levels of selenium (maximum 270 \\x8Dg/L, median 28 \\x8Dg/L) and arsenic (maximum 40 \\x8Dg/L, median 5 \\x8Dg/L) released to surface waters are as much as 50 times the standard for wildlife toxicity. Additionally field evidence indicates that high levels of nitrate present in the soil (6 mg/kg) and ground water (maximum 55 mg/L, median 7 mg/L), originating in past agricultural activity in the watershed, enhances trace element mobilization via microbially mediated denitrification and pyrite oxidation. The spatial pattern of groundwater concentrations of nitrate, selenium and arsenic suggest an inverse relationship that is indicative of this redox reaction. Preliminary results from a batch study using local vadose zone soils demonstrates a trend for greater mobilization of arsenic by a 200 ppm nitrate solution than by control solution. A positive correlation between sulfate, selenium and arsenic in groundwater samples supports concurrent oxidation and mobilization; it also defines pyrite and related sulfur compounds as candidates for original sequestration in the historic wetland. Ratios of chloride to sulfate as well as sulfur isotopes in groundwater samples show sulfate enrichment indicative of oxidative dissolution processes, possibly of pyrite, as opposed to evaporative concentration or external loading. Elevated bicarbonate concentrations in regions of high selenium and arsenic also support this hypothesis, since acidity generated by pyrite oxidation facilitates calcite dissolution. A positive correlation between arsenic and molybdenum suggests a significant role for surface adsorption of oxidized arsenic and reduced selenium species in controlling trace element

  19. 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

  20. Loss of selenium-binding protein 1 decreases sensitivity to clastogens and intracellular selenium content in HeLa cells

    Science.gov (United States)

    Selenium-binding protein 1 (SBP1) is not a selenoprotein but structurally binds selenium. Loss of SBP1 during carcinogenesis usually predicts poor prognosis. Because genome instability is a hallmark of cancer, we hypothesized that loss of SBP1 modulates cellular selenium content and the response of ...

  1. Selenium deficiency in children and adolescents nourished by parenteral nutrition and/or selenium-deficient enteral formula.

    Science.gov (United States)

    Etani, Yuri; Nishimoto, Yukiko; Kawamoto, Kouji; Yamada, Hiroyuki; Shouji, Yasuko; Kawahara, Hisayoshi; Ida, Shinobu

    2014-10-01

    The authors analyzed serum selenium levels of 95 children and adolescents with intestinal dysfunction and/or neurological disabilities [age range: 7 months-20 years; mean±standard deviation (SD): 8.0±5.3 years] who received parenteral nutrition (PN) and/or enteral nutrition (EN) with either reduced or no selenium doses for more than 3 months. Twenty-eight patients (29%) showed serum selenium levels below 4.0μg/dL. Five patients whose serum selenium levels were below 2μg/dL presented various clinical manifestations, including hair browning (n=5), macrocythemia (n=4), nail whitening (n=3) and cardiac dysfunction (n=1). None of these 5 patients were nourished through ordinary diets. Three of these patients were nourished through selenium-free enteral nutritional products, 1 through selenium-deficient PN and 1 through PN and a formula with reduced selenium. After selenium supplement therapy for 1 year, all 5 patients exhibited improvement in their serum selenium levels and clinical features of selenium deficiency. It is important to be cautious about secondary selenium deficiency in children and adolescents nourished only through EN/PN without an adequate dose of selenium. Copyright © 2014 Elsevier GmbH. All rights reserved.

  2. Levels of selenium in blood and tissues associated with some selenium deficiency diseases in New Zealand sheep.

    Science.gov (United States)

    Sheppard, A D; Blom, L; Grant, A B

    1984-06-01

    Whole bloods from weaned lambs with severe selenium responsive unthriftiness usually contain <5 ng Se/ml. Mildly or moderately affected lambs have blood levels of 5-10 ng/ml. Selenium responsive infertility in ewes appears to be associated with whole blood selenium levels below 10 ng/ml.

  3. Selenium hyperaccumulation offers protection from cell disruptor herbivores

    Directory of Open Access Journals (Sweden)

    Quinn Colin F

    2010-08-01

    Full Text Available Abstract Background Hyperaccumulation, the rare capacity of certain plant species to accumulate toxic trace elements to levels several orders of magnitude higher than other species growing on the same site, is thought to be an elemental defense mechanism against herbivores and pathogens. Previous research has shown that selenium (Se hyperaccumulation protects plants from a variety of herbivores and pathogens. Selenium hyperaccumulating plants sequester Se in discrete locations in the leaf periphery, making them potentially more susceptible to some herbivore feeding modes than others. In this study we investigate the protective function of Se in the Se hyperaccumulators Stanleya pinnata and Astragalus bisulcatus against two cell disrupting herbivores, the western flower thrips (Frankliniella occidentalis and the two-spotted spider mite (Tetranychus urticae. Results Astragalus bisulcatus and S. pinnata with high Se concentrations (greater than 650 mg Se kg-1 were less subject to thrips herbivory than plants with low Se levels (less than 150 mg Se kg-1. Furthermore, in plants containing elevated Se levels, leaves with higher concentrations of Se suffered less herbivory than leaves with less Se. Spider mites also preferred to feed on low-Se A. bisulcatus and S. pinnata plants rather than high-Se plants. Spider mite populations on A. bisulcatus decreased after plants were given a higher concentration of Se. Interestingly, spider mites could colonize A. bisulcatus plants containing up to 200 mg Se kg-1 dry weight, concentrations which are toxic to many other herbivores. Selenium distribution and speciation studies using micro-focused X-ray fluorescence (μXRF mapping and Se K-edge X-ray absorption spectroscopy revealed that the spider mites accumulated primarily methylselenocysteine, the relatively non-toxic form of Se that is also the predominant form of Se in hyperaccumulators. Conclusions This is the first reported study investigating the

  4. INAA determination of selenium via sup(77m)Se in plasma, semen and hair samples from beef and dairy bulls

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J.S.; Smith, M.F.; Morrow, R.E.; Heimann, E.D.; Hancock, J.C.; Gall, T. (Missouri Univ., Columbia (USA))

    1982-01-01

    Interest in the element selenium with respect to its biological significance has been steadily increasing for the last ten years. Neutron activation analysis has long been used for the accurate determination of selenium in biological samples usually via /sup 75/Se. More recently activation analysts having access to high flux reactors with rapid delivery pneumatic tube facilities; have successfully employed sup(77m)Se. This approach, which is much faster, is particularly well suited to the Missouri University Research Reactor (MURR). The specific interest concerning bulls has to do with the involvement of selenium in the reproductive system. Selenium analysis methodology and data on plasma, semen and 22 tissues from both beef and dairy bulls are presented.

  5. Selenium and Mercury in the Brazilian Amazon: Opposing Influences on Age-Related Cataracts

    OpenAIRE

    Lemire, Melanie; Fillion, Myriam; FRENETTE, Benoit; Mayer, Annie; Philibert, Aline; PASSOS, Carlos Jose Sousa; GUIMARAES, Jean Remy Davee; Barbosa Jr., Fernando; Mergler, Donna

    2010-01-01

    BACKGROUND: Age-related cataracts (ARCs) are an important cause of blindness in developing countries. Although antioxidants may be part of the body's defense to prevent ARC, environmental contaminants may contribute to cataractogenesis. In fish-eating populations of the lower Tapajos region, elevated exposure to mercury (Hg) has been reported, and blood levels of selenium (Se) range from normal to very high (> 1,000 mu g/L). OBJECTIVES: We examined ARCs in relation to these elements among adu...

  6. Content of microelements in the rat pineal gland at different ages and the effects of selenium supplementation

    Directory of Open Access Journals (Sweden)

    Demajo M.

    2006-01-01

    Full Text Available The mammalian pineal gland regulates a number of important physiological processes. In this paper we report changes in the content of iron (Fe, zinc (Zn, copper (Cu, and selenium (Se in the male rat pineal glands at 4, 5, 8, and 12 months of age. The effect of Se supplementation in drinking water on the content of pineal gland microelements was also studied. Selenium (Se-dependent changes in pineal gland reported in this study suggest novel physicochemical and biochemical properties of Se, an important element essential in the antioxidative processes, yet known to influence a number of endocrine processes.

  7. Selenium supplementation for critically ill adults

    DEFF Research Database (Denmark)

    Allingstrup, Mikkel; Afshari, Arash

    2015-01-01

    was originally published in 2004 updated in 2007 and again 2015. OBJECTIVES: The primary objective was to examine the effect of nutrition supplemented with selenium or ebselen on mortality in critically ill patients.The secondary objective was to examine the relationship between selenium or ebselen...... supplementation and number of infections, duration of mechanical ventilation, length of intensive care unit stay and length of hospital stay. SEARCH METHODS: In this update, we searched the current issue of the Cochrane Central Register of Controlled Trials, the Cochrane Library (2014, Issue 5); MEDLINE (Ovid SP...... RESULTS: We included six new RCTs in this review update. In total we included 16 RCTs (2084 participants) in this review. Most trials were at high risk of bias. The availability of outcome data was limited and trials involving selenium supplementation were, with the exception of one trial, small regarding...

  8. A calibration method for proposed XRF measurements of arsenic and selenium in nail clippings.

    Science.gov (United States)

    Gherase, Mihai R; Fleming, David E B

    2011-10-21

    A calibration method for proposed x-ray fluorescence (XRF) measurements of arsenic and selenium in nail clippings is demonstrated. Phantom nail clippings were produced from a whole nail phantom (0.7 mm thickness, 25 × 25 mm(2) area) and contained equal concentrations of arsenic and selenium ranging from 0 to 20 µg g(-1) in increments of 5 µg g(-1). The phantom nail clippings were then grouped in samples of five different masses: 20, 40, 60, 80 and 100 mg for each concentration. Experimental x-ray spectra were acquired for each of the sample masses using a portable x-ray tube and a detector unit. Calibration lines (XRF signal in a number of counts versus stoichiometric elemental concentration) were produced for each of the two elements. A semi-empirical relationship between the mass of the nail phantoms (m) and the slope of the calibration line (s) was determined separately for arsenic and selenium. Using this calibration method, one can estimate elemental concentrations and their uncertainties from the XRF spectra of human nail clippings.

  9. Mercury, Lead, Cadmium, Arsenic, Chromium and Selenium in Feathers of Shorebirds during Migrating through Delaware Bay, New Jersey: Comparing the 1990s and 2011/2012

    Directory of Open Access Journals (Sweden)

    Joanna Burger

    2015-02-01

    Full Text Available Understanding temporal changes in contaminant levels in coastal environments requires comparing levels of contaminants from the same species from different time periods, particularly if species are declining. Several species of shorebirds migrating through Delaware Bay have declined from the 1980s to the present. To evaluate some contaminants as cause for the declines, we examine levels of mercury, lead, cadmium, arsenic, chromium and selenium in feathers of red knot (Calidris canutus, N = 46 individuals, semipalmated sandpiper (Calidris pusilla, N = 70 and sanderling (Calidris alba, N = 32 migrating through Delaware Bay, New Jersey, USA, from 1991 to 1992 (N = 40, 1995 (N = 28, and 2011–2012 (N = 80 to determine if levels have changed. We found: (1 arsenic, chromium, and lead increased in red knot and decreased in semipalmated sandpiper; (2 cadmium decreased in semipalmated sandpipers; (3 mercury decreased in red knot and sanderlings; (4 selenium decreased in red knot and increased in semipalmated sandpipers. In 2011/2012 there were significant interspecific differences for arsenic, mercury and selenium. Except for selenium, the element levels were well below levels reported for feathers of other species. The levels in feathers in red knots, sanderling, and semipalmated sandpipers from Delaware Bay in 2011/2012 were well below levels in feathers that are associated with effect levels, except for selenium. Selenium levels ranged from 3.0 µg·g−1 dry weight to 5.8 µg·g−1 (semipalmated sandpiper, within the range known to cause adverse effects, suggesting the need for further examination of selenium levels in birds. The levels of all elements were well below those reported for other marine species, except for selenium, which was near levels suggesting possible toxic effects.

  10. Mercury, Lead, Cadmium, Arsenic, Chromium and Selenium in Feathers of Shorebirds during Migrating through Delaware Bay, New Jersey: Comparing the 1990s and 2011/2012.

    Science.gov (United States)

    Burger, Joanna; Tsipoura, Nellie; Niles, Lawrence J; Gochfeld, Michael; Dey, Amanda; Mizrahi, David

    2015-02-06

    Understanding temporal changes in contaminant levels in coastal environments requires comparing levels of contaminants from the same species from different time periods, particularly if species are declining. Several species of shorebirds migrating through Delaware Bay have declined from the 1980s to the present. To evaluate some contaminants as cause for the declines, we examine levels of mercury, lead, cadmium, arsenic, chromium and selenium in feathers of red knot ( Calidris canutus , N = 46 individuals), semipalmated sandpiper ( Calidris pusilla , N = 70) and sanderling ( Calidris alba , N = 32) migrating through Delaware Bay, New Jersey, USA, from 1991 to 1992 ( N = 40), 1995 ( N = 28), and 2011-2012 ( N = 80) to determine if levels have changed. We found: (1) arsenic, chromium, and lead increased in red knot and decreased in semipalmated sandpiper; (2) cadmium decreased in semipalmated sandpipers; (3) mercury decreased in red knot and sanderlings; (4) selenium decreased in red knot and increased in semipalmated sandpipers. In 2011/2012 there were significant interspecific differences for arsenic, mercury and selenium. Except for selenium, the element levels were well below levels reported for feathers of other species. The levels in feathers in red knots, sanderling, and semipalmated sandpipers from Delaware Bay in 2011/2012 were well below levels in feathers that are associated with effect levels, except for selenium. Selenium levels ranged from 3.0 µg·g -1 dry weight to 5.8 µg·g -1 (semipalmated sandpiper), within the range known to cause adverse effects, suggesting the need for further examination of selenium levels in birds. The levels of all elements were well below those reported for other marine species, except for selenium, which was near levels suggesting possible toxic effects.

  11. Plasma Selenium Levels in Chronic Cocaine Abuse.

    Science.gov (United States)

    Petrova, Julia; Manolov, Victor; Kiryakova, Theodora; Vasilev, Vasil; Tzatchev, Kamen; Borislav, Marinov; Radoslava, Emilova

    2016-01-01

    Cocaine abuse is a significant health problem worldwide. We aim to evaluate the role of selenium in oxidative stress in patients with cocaine related cardio- and cerebrovascular diseases. Selenium is of fundamental importance to human health. It is an essential component of several major metabolic pathways. We included 26 patients with chronic cocaine abuse separated into two groups according to duration of intake--from six months up to one year and more than a year, with and without only vascular incidents (TIA, stroke, myocardial infarction), or presence of hypertension. All included groups were analyzed for laboratory parameters: CBC, CRP, AST, ALT, γ-GT, serum creatinine, urea, K, Na, and Ca. Main risk factors were evaluated: total cholesterol, LDL and HDL-cholesterol, triglycerides, glucose, and selenium. Our result shows that in the first group only 20% have cardiovascular problems. In the group with cocaine abuse more than a year, number of vascular incidents has increased (58.3%). Patients from the group cocaine abuse up to 1 year showed no changes in lipid profile, but cocaine abuse more than a year showed interesting changes in the lipid profile. We found a high positive correlation between the two cocaine groups for plasma selenium concentrations. This means that after the first six months oxidative stress has occured. It increases with duration of cocaine abuse. CRP correlated positively between these two groups, showing an endothelial function disorder. Development of oxidative stress increased with cocaine abuse, which leads to lower plasma selenium levels in patients with different duration of intake--less and more than a year. It is possible to supplement selenium during the early period of cocaine dependence to prevent hard vascular accidents, which are common after more than one year of cocaine abuse.

  12. Zinc, copper, and selenium tissue levels and their relation to subcutaneous abscess, minor surgery, and wound healing in humans

    DEFF Research Database (Denmark)

    Mirastschijski, Ursula; Martin Moreno, Alicia; Jorgensen, Lars N

    2013-01-01

    Trace element involvement in wounds left to heal by secondary intention needs clarification. We have previously reported faster healing of wounds following acute surgery compared with elective excision of pilonidal sinus disease. The effect of topical zinc on the closure of the excisional wounds...... was mediocre compared with placebo. In contrast, parenteral zinc, copper, and selenium combined appear effective for wound healing in humans. We have investigated zinc, copper, and selenium with respect to (a) impact of acute versus chronic pilonidal sinus and (b) regional concentrations within granulating...... wounds treated topically with placebo or zinc in 42 (33 males) pilonidal disease patients. Baseline serum and skin concentrations of copper correlated (r S = 0.351, p = 0.033, n = 37), but not of zinc or selenium. Patients with abscesses had elevated serum C-reactive protein (CRP) and copper levels (+29...

  13. THE INFLUENCE OF SELENIUM ON CONTENT OF TOTAL POLYPHENOLS AND ANTIOXIDANT ACTIVITY OF ONION (ALLIUM CEPA L.

    Directory of Open Access Journals (Sweden)

    Petra Kavalcová

    2014-02-01

    Full Text Available Selenium (Se is an essential element, which is located in soil and stones, accumulated in plants and input them the food chain. Selenium significantly influences the function nearly of all the components of the immune system. Is also protects the body from the toxic effects of some metals. The content of the total polyphenols was determined by using the Folin-Ciocalteu reagent (FCR. Antioxidant activity was measured using a compound DPPH˙ (2.2-diphenyl-1-picrylhydrazyl. The content of total polyphenols in samples onion moved in the range from 575.25±33.90 to 695.07±59.91. In this work was watched the influence of selenium on antioxidant activity, where values were in interval from 37.09±1.72 to 63.29±5.14.

  14. Distribution of Arsenic, Manganese, and Selenium in the Human Brain in Chronic Renal Insufficiency, Parkinsons Disease and Amyotrophic Lateral Sclerosis

    DEFF Research Database (Denmark)

    Larsen, N. A.; Pakkenberg, H.; Damsgaard, Else

    1981-01-01

    The concentrations of arsenic, manganese and selenium/g wet tissue weight were determined in samples from 24 areas of the human brain from 3 patients with chronic renal insufficiency, 2 with Parkinson's disease and 1 with amyotrophic lateral sclerosis. The concentrations of the 3 elements were...... determined for each sample by neutron activation analysis with radiochemical separation. Overall arsenic concentrations were about 2.5 times higher in patients with chronic renal failure than in controls, and lower than normal in the patients with Parkinson's disease and amyotrophic lateral sclerosis....... There were no obvious differences in the overall concentrations of manganese and selenium from one group to another. Even multivariate data analysis by the SIMCA method failed to reveal any significant difference in the distribution pattern of manganese and selenium in Parkinson's disease compared to normal...

  15. Selenium supplementation can slow the development of naphthalene cataract.

    Science.gov (United States)

    Zhu, Xiangjia; Lu, Yi

    2012-03-01

    To evaluate the effect of selenium supplementation on the progress of naphthalene cataract. Sprague-Dawley rats were randomly divided into five groups as follows: normal control, naphthalene control and selenium-supplemented groups (Selenium I, II and III, which were orally administrated with selenium at doses of 0.0104 mg/kg, 0.0208 mg/kg and 0.0416 mg/kg, respectively). All the intervention groups were orally administered with 10% naphthalene solution for 5 weeks. The lens density of each group was determined by photography. Moreover, glutathione peroxidase (GPx) activity in the lens, erythrocyte and plasma was investigated. In addition, lens glutathione (GSH), malondialdehyde (MDA) and hydroxyl radical levels were evaluated. Selenium level in aqueous humor was determined using atomic absorption spectrometry. The maximum, mean and minimum densities of lens opacities were lower in Selenium group II and III than those in naphthalene group. The maximum density of the lens increased more slowly in Selenium group I than that in naphthalene controls. In selenium-supplemented groups, blood and lens GPx activities as well as aqueous humor selenium level increased significantly. Selenium supplementation also significantly ameliorated the decrease in GSH level and increase in MDA and hydroxyl radical levels in the lens of naphthalene-treated rats. Selenium supplementation could slow the development of naphthalene cataract possibly by attenuating the oxidative stress in the lens.

  16. Nanoparticle standards

    Energy Technology Data Exchange (ETDEWEB)

    Havrilla, George Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-12-08

    We will purchase a COTS materials printer and adapt it for solution printing of known elemental concentration solutions. A methodology will be developed to create deposits of known mass in known locations on selected substrates. The deposits will be characterized for deposited mass, physical morphology, thickness and uniformity. Once an acceptable methodology has been developed and validated, we will create round robin samples to be characterized by LGSIMS instruments at LANL, PNNL and NIST. We will demonstrate the feasibility of depositing nanoparticles in known masses with the goal of creating separated nanoparticles in known locations.

  17. Environmental Risk Limits for Nine Trace Elements

    NARCIS (Netherlands)

    Vlaardingen PLA van; Posthumus R; Posthuma-Doodeman CJAM; SEC

    2005-01-01

    In this report, we present an update of environmental risk limits (ERLs), based on the literature, for nine trace elements, namely, beryllium (Be), vanadium (V), cobalt (Co), selenium (Se), molybdenum (Mo), tin (Sn), antimony (Sb), barium (Ba) and thallium (Tl). The updated ERLs, established for

  18. Selenium, copper, and zinc concentrations in the raw and processed meat of edible land snails harvested in Poland

    Directory of Open Access Journals (Sweden)

    Drozd Łukasz

    2017-09-01

    Full Text Available Introduction: The objective of the present research was to carry out a comparative assessment of copper, zinc, and selenium concentrations in the meat of edible land snails collected in Poland (Helix pomatia, Cornu aspersum maxima, and Cornu aspersum aspersum, as well as to determine the effect of preliminary processing of Roman snails (Helix pomatia on the content of the aforementioned elements. Material and Methods: In the first stage, determinations were made on unprocessed snail meat. In the second stage, the study focused on Roman snails and consisted in an additional evaluation of frozen meat after full processing. Zinc and copper contents were determined by flame atomic absorption spectrometry and the selenium content was established by graphite furnace atomic absorption spectrometry. Results: The selenium content differed significantly among all three species. The copper content in Roman snails differed significantly from that in farmed snails. No significant difference in the zinc level was noted among the three snail species. The selenium content in raw and processed meat of Roman snails did not show any significant difference while the copper and zinc level was significantly higher in processed meat samples. Conclusion: The present research on the meat of edible snails showed different levels of selenium, copper, and zinc, depending on the species, collection site, and subjection to processing.

  19. The association between selenium and other micronutrients and thyroid cancer incidence in the NIH-AARP Diet and Health Study.

    Science.gov (United States)

    O'Grady, Thomas J; Kitahara, Cari M; DiRienzo, A Gregory; Gates, Margaret A

    2014-01-01

    Selenium is an essential trace element that is important for thyroid hormone metabolism and has antioxidant properties which protect the thyroid gland from oxidative stress. The association of selenium, as well as intake of other micronutrients, with thyroid cancer is unclear. We evaluated associations of dietary selenium, beta-carotene, calcium, vitamin D, vitamin C, vitamin E, folate, magnesium, and zinc intake with thyroid cancer risk in the National Institutes of Health - American Association of Retired Persons Diet and Health Study, a large prospective cohort of 566,398 men and women aged 50-71 years in 1995-1996. Multivariable-adjusted Cox proportional hazards regression was used to examine associations between dietary intake of micronutrients, assessed using a food frequency questionnaire, and thyroid cancer cases, ascertained by linkage to state cancer registries and the National Death Index. With the exception of vitamin C, which was associated with an increased risk of thyroid cancer (HR(Q5 vs Q1), 1.34; 95% CI, 1.02-1.76; P(trend), thyroid cancer. Our study does not suggest strong evidence for an association between dietary intake of selenium or other micronutrients and thyroid cancer risk. More studies are needed to clarify the role of selenium and other micronutrients in thyroid carcinogenesis.

  20. Selenium supplementation in radiotherapy patients: do we need to measure selenium levels in serum or blood regularly prior radiotherapy?

    Science.gov (United States)

    Muecke, Ralph; Micke, Oliver; Schomburg, Lutz; Kisters, Klaus; Buentzel, Jens; Huebner, Jutta; Kriz, Jan

    2014-12-16

    Considering the review by Puspitasari and colleagues, an additional discussion of the endpoints of the Se supplementation studies described would be helpful. In our view, selenium can safely be given to selenium-deficient cancer patients prior to and during radiotherapy. Therefore, in order to help the radiation oncologist in decision making, we strongly advocate to determine the selenium status prior to and during a potential adjuvant selenium supplementation, e.g. when trying to ease the side-effects of radiation treatment or in the aftercare situation when the selenium status may become insufficient.

  1. Dissolution behavior of selenium from coal fly ash particles for the development of an acid-washing process.

    Science.gov (United States)

    Kashiwakura, Shunsuke; Ohno, Hajime; Kumagai, Yuichi; Kubo, Hiroshi; Matsubae, Kazuyo; Nagasaka, Tetsuya

    2011-10-01

    Coal fly ash emitted from coal-fired electric power stations generally contains environmentally regulated trace elements. In particular, boron, arsenic, and selenium have been recognized as troublesome trace elements because elutions from the fly ash contain them. In order to design an effective removal process for these trace elements, we have developed and investigated an acid-washing process. The dissolution behavior of selenium from coal fly ash particles was focused on for the improvement of the process, and was found to greatly depend on the pH of the acid solutions. The species of selenium in solutions with a pH of around 0-1 was determined to be H2SeO3. The dissolved H2SeO3 transformed into HSeO3- and adsorbed onto the surface of the ash particles in solution upon elevation of the pH. The re-elution of the absorbed HSeO3- as SeO3(2-) at a pH of 10 was also confirmed, and will cause the elution of the excess selenium from the acid-washed ash. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. In vivo and in vitro testing for selenium and selenium compounds bioavailability assessment in foodstuff.

    Science.gov (United States)

    Moreda-Piñeiro, Jorge; Moreda-Piñeiro, Antonio; Bermejo-Barrera, Pilar

    2017-03-04

    The assessment of selenium and selenium species bioavailability in foodstuff is of special concern on the context of human nutrition. In vivo (human and animal), and in vitro tests are important approaches for estimating the bioavailability of toxic and essential compounds to humans. An overview on in vivo and in vitro bioavailability assays for releasing selenium and selenium species in foodstuffs is summarized. Se and Se species content in a foodstuff critically influence Se bioavailability and bioactivity to humans and animals. Se bioavailability is affected by foodstuff-matrix major composition and minor components. Foodstuffs processing and/or treatments could enhancement or decrease Se bioavailability. Experimental conditions such as the selection of healthy status of examined people (in in vivo humans approaches), the selection of animal model (in vivo animals approaches), or the selection of GI conditions (in in vitro tests) could determines the results. Thus, international standardized protocol for in vivo and in vitro approaches assessment is mandatory.

  3. Selenium electrochemistry. Applications in the nuclear fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Maslennikov, A.; Peretroukhine, V. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Physical Chemistry; David, F. [Centre National de la Recherche Scientifique (CNRS), 91 - Orsay (France); Lecomte, M. [CEA Centre d' Etudes de la Valle du Rhone, 30 - Marcoule (France). Direction du Cycle du Combustible

    1999-07-01

    Modern state of selenium electrochemistry is reviewed in respect of the application of electrochemical methods for the study of the behavior of this element and its quantitative analysis in the solutions of nuclear fuel cycle. The review includes the data on the redox potentials of Se in aqueous solutions, and the data on Se redox reactions, occurring at mercury and solid electrodes. Analysis of the available literature data shows that the inverse stripping voltammetry technique for trace Se concentration and determination seems to be the most promising in application for the Se determination in PUREX solutions and in radioactive wastes. The adaptation of the ISV technique for the trace Se concentration and determination in the solutions of the nuclear fuel cycle is indicated as the most prospective goal of the future experimental study. (author)

  4. Homeostasis of chosen bioelements in organs of rats receiving lithium and/or selenium.

    Science.gov (United States)

    Kiełczykowska, Małgorzata; Musik, Irena; Żelazowska, Renata; Lewandowska, Anna; Kurzepa, Jacek; Kocot, Joanna

    2016-10-01

    Lithium is an essential trace element, widely used in medicine and its application is often long-term. Despite beneficial effects, its administration can lead to severe side effects including hyperparathyroidism, renal and thyroid disorders. The aim of the current study was to evaluate the influence of lithium and/or selenium treatment on magnesium, calcium and silicon levels in rats' organs as well as the possibility of using selenium as an adjuvant in lithium therapy. The study was performed on rats divided into four groups (six animals each): control-treated with saline; Li-treated with Li2CO3 (2.7 mg Li/kg b.w.); Se-treated with Na2SeO3·H2O (0.5 mg Se/kg b.w.); Se + Li-treated simultaneously with Li2CO3 and Na2SeO3·H2O (2.7 mg Li/kg b.w. and of 0.5 mg Se/kg b.w., respectively). The administration was performed in form of water solutions by stomach tube once a day for 3 weeks. In the organs (liver, kidney, brain, spleen, heart, lung and femoral muscle) the concentrations of magnesium, calcium and silicon were determined. Magnesium was increased in liver of Se and Se + Li given rats. Lithium decreased tissue Ca and co-administration of selenium reversed this effect. Silicon was not affected by any treatment. The beneficial effect of selenium on disturbances of calcium homeostasis let suggest that further research on selenium application as an adjuvant in lithium therapy is worth being performed.

  5. Changes in selenium speciation associated with increasing tissue concentrations of selenium in wheat grain.

    Science.gov (United States)

    Cubadda, Francesco; Aureli, Federica; Ciardullo, Silvia; D'Amato, Marilena; Raggi, Andrea; Acharya, Raghunath; Reddy, Ramana A V; Prakash, Nagaraja Tejo

    2010-02-24

    Wheat (Triticum aestivum) collected in the Nawanshahr-Hoshiarpur Region (Punjab, India) showed the highest selenium concentrations ever recorded in cereal grains (29-185 microg g(-1)). There was a strong positive relationship between the selenium content in shoots and that in kernels, showing that grain selenium concentration can be predicted from that in the vegetative tissues of the plant. The identity and content of the selenocompounds in the grain samples and in wheat-based reference materials were investigated by HPLC-ICP-dynamic reaction cell-MS. Reversed-phase, cation exchange, and anion exchange HPLC were used to separate the selenium species after ultrasound-assisted enzymatic extraction with an ultrasonic probe. Selenomethionine and selenate accounted for 72-85% and 2-6% of the sum of the selenium species, respectively. The proportion of organic Se species varied with increasing Se content; namely, SeMet showed a relative reduction whereas the other organoselenium compounds increased up to 18-22% of the total chromatographed selenium. Se-methyl-selenocysteine was detected as a minor compound (0.2-0.5%) in high-Se wheat by both reversed-phase and cation exchange HPLC using retention time matching with the standard substance spiked to the sample extracts. Regular consumption of locally produced wheat-based food items may lead the population of the study area to an excessive intake of selenium. On the other hand, the large predominance of selenomethionine shows that local wheat can be a promising raw material for naturally enriched products to be used to supplement human and animal diets in low selenium areas.

  6. Bioaccumulation of arsenic, cadmium, mercury, lead and selenium in the benthic and pelagic food chain of Lake Baikal

    OpenAIRE

    Leeves, Sara Ann

    2011-01-01

    Increased anthropogenic release of potentially toxic trace elements such as arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb) and selenium (Se) into freshwater ecosystems over the past century has caused much concern. These elements are well known toxicants in aquatic ecosystems and may exert toxic effects even if present at relatively low concentrations in organisms. In this study, bioaccumulation of As, Cd, Hg, Pb and Se in the pelagic and benthic food chain of Lake Baikal have been inves...

  7. The Relationship between Selenium and T3 in Selenium Supplemented and Nonsupplemented Ewes and Their Lambs

    Directory of Open Access Journals (Sweden)

    Abd Elghany Hefnawy

    2014-01-01

    Full Text Available Twenty pregnant ewes were selected and classified into two groups. The first group received subcutaneous selenium supplementation (0.1 mg of sodium selenite/kg BW at the 8th and 5th weeks before birth and 1st week after birth while the other was control group without selenium injection. Maternal plasma and serum samples were collected weekly from the 8th week before birth until the 8th week after birth and milk samples were taken from ewes weekly, while plasma and serum samples were collected at 48 hours, 1st, 2nd, 3rd, 5th, and 8th weeks after birth from the newborn lambs. Results demonstrated significant positive relationship between maternal plasma selenium and serum T3 in supplemented and control ewes (r=0.69 to 0.72, P<0.05. There was significant (P<0.001 increase in T3 in supplemented ewes and their lambs until the 8th week after birth. There was positive relationship between milk, selenium concentration, and serum T3 in the newborn lambs of the supplemented group (r=0.84, P<0.01, while the relationship was negative in the control one (r=-0.89, P<0.01. Muscular and thyroid pathological changes were independent of selenium supplementation. Selenium supplementation was important for maintaining T3 in ewes and newborn lambs until the 8th week after birth.

  8. Elemental copper nanoparticle toxicity to anaerobic ammonium oxidation and the influence of ethylene diamine-tetra acetic acid (EDTA) on copper toxicity.

    Science.gov (United States)

    Gonzalez-Estrella, Jorge; Li, Guangbin; Neely, Sarah E; Puyol, Daniel; Sierra-Alvarez, Reyes; Field, Jim A

    2017-10-01

    Soluble ions released by elemental copper nanoparticles (Cu(0) NP) are toxic to key microorganisms of wastewater treatment processes. However, their toxicity to anaerobic ammonium oxidation (anammox) has not yet been studied. Chelating agents occurring in wastewater may decrease copper ions (Cu(2+)) concentration and consequently, decrease copper toxicity. This study evaluated Cu(0) NP and CuCl2 toxicity to anammox and the influence of ethylene diamine-tetra acetic acid (EDTA) on copper toxicity. Bioassays were supplemented with Cu(0) NP or CuCl2 with and without EDTA. Anammox activities were used to calculate inhibition con