Increase In Selenium Concentration Research Articles

Study on the selenium accumulation of peach seedlings

An experiment was conducted to study the effect of peach seedlings (Prunus davidiana) grown in nutrient solution with different selenium concentration. The results showed that selenium concentration were 0.05 and 0.10 mg/L which caused a marked increase of roots and shoorts biomass, and the root/shoot ratio were relatively low (0.180 and 0.170) compared with control, and other selenium treatments decreased significantly the biomass. Consequently, 0.05 and 0.10 mg/L selenium treatments were conducive to peach seedlings growth, while the peach seedlings was inhibited significantly by the increasing concentration of selenium (≥ 0.10 mg/L). Selenium content of peach seedlings increased remarkably with the increase of selenium concentration that indicated the accumulation of selenium in peach seedlings had a linear relation with the dose of selenium. Above all, when selenium concentration in the range of 0-0.10 mg/ L, which not only promotes peach seedlings growth, but also increases peach seedlings selenium content.

Selenium Attenuates Staphylococcus aureus Mastitis in Mice by Inhibiting the Activation of the NALP3 Inflammasome and NF-κB/MAPK Pathway.

Mastitis is one of the most important diseases affecting the dairy industry in the world, and it also poses a great threat to human food safety. In this study, we explored whether selenium can inhibit the activation of the NALP3 inflammasome and NF-κB/MAPK pathway to achieve anti-inflammatory effects. Sixty BALB/c female mice were randomly divided into three groups according to diets of different selenium concentrations (high, normal, and low). After 90days, mice fed the same selenium concentration were randomly divided into two smaller groups, one of which was inoculated with Staphylococcus aureus and the other injected with saline as a control. Through histopathologic examination staining, western blot, qPCR, and ELISA, the results showed that with increasing selenium concentrations, the expression levels of IL-1β, TNF-α, NALP3, caspase-1, and ASC were decreased in mouse mammary tissue. Therefore, this study revealed that selenium can attenuate S. aureus mastitis by inhibiting the activation of the NALP3 inflammasome and NF-κB/MAPK pathway.

Selenium Accumulation Characteristics of Solanum alatum

To study the effects of different concentrations of selenium on the selenium accumulation characteristics of Solanum alatum, we used the pot experiment to study effects of different selenium concentrations (0, 5, 10, 25, 50, 75, 100 mg/kg) on the biomass and selenium content of S. alatum. The results showed that all concentrations of selenium reduced the biomass of S. alatum. The biomass of S. alatum decreased with the increase of selenium concentration. In addition, with the increase of Se concentration, the Se content of S. alatum roots and stems increased. The Se content of S. alatum leaves and shoots increased first and then decreased with the increase of Se concentration. The selenium accumulation of each part of S. alatum increased first and then decreased with the increase of selenium concentration. Selenium accumulation in S. alaum shoots and whole plants were in the ranges of 0.503-13.915 μg/plant and 1.089-18.319 μg/plant respectively under the selenium stress. In all treatments, when the concentration of selenium was 10 mg/kg, the selenium accumulation of each part of S. alatum was the highest. Therefore S. alatum is most suitable for planting at a selenium concentration of 10 mg/kg.

Study on Selenium Accumulation Characteristics of Solanum nigrum

In order to study the effects of different concentrations of selenium on the selenium accumulation characteristics of Solanum nigrum, we used the pot experiment to study the effects of different selenium concentrations (0, 5, 10, 25, 50, 75, 100 mg/kg) on the biomass and selenium content of S. nigrum. The results showed that all concentrations of selenium inhibited the biomass of S. nigrum and high concentrations of selenium inhibited the growth of S. nigrum more significantly. In addition, the biomass and selenium content of S. nigrum decreased with the increase of selenium concentration. Selenium content in S. nigrum roots, stems and leaves were in the ranges of 1.75-59.83 mg/kg, 0.91-47.83 mg/kg, and 0.38-44.50 mg/kg respectively under the selenium stress. The selenium accumulation of each part of S. nigrum increased first and then decreased with the increase of selenium concentration. In all treatments, when the concentration of selenium was 10 mg/kg, the selenium accumulation of each part of S. nigrum was the highest and the selenium accumulation of S. nigrum in shoots and whole plants reached 7.888 μg/plant and 12.893 μg/plant respectively. In a word, S. nigrum is most suitable for planting at a selenium concentration of 10 mg/kg.

Study on Selenium Accumulation Characteristics of Radish

In order to study the effects of different concentrations of selenium on the selenium accumulation characteristics of radish, we used the pot experiment to study effects of different selenium concentrations (0, 5, 10, 25, 50, 75, and 100 mg/kg) on the biomass and selenium content of radish. The results showed that selenium stress inhibited the biomass of radish and the higher the concentration of selenium and the stronger the inhibition of radish growth. In addition, the selenium content of radish increased with the increase of selenium concentration. Selenium content in radish roots, tubers and leaves were in the ranges of 21.71-346.64 mg/kg, 11.05-251.38 mg/kg, and 8.34-210.91 mg/kg respectively under the selenium stress. Compared with the selenium concentration of 0 mg/kg, all treatments significantly increased the tubers, leaves, shoots and whole plants of radish selenium accumulation. In all treatments, when the concentration of selenium was 25 mg/kg, the selenium accumulation of each part of radish reached the maximum and the selenium accumulation of radish in shoots and whole plants reached 111.96 μg/plant and 119.21 μg/plant respectively. In a word, radish has the strongest accumulation ability of selenium in soil when the concentration of selenium is 25 mg/kg, which can be considered as the best selenium concentration to increase the selenium content of radish.

Selenium Enrichment Ability of Capsella bursa-pastoris

Pot experiment was conducted to investigate the dry weight, selenium extraction and accumulation of roots, stems, leaves and shoots of Capsella bursa-pastoris under the conditions of 0, 5, 10, 25, 50, 75 and 100 mg/kg. The results showed that selenium at the concentrations of 5, 10 and 25 mg/kg could promote the growth of C. bursa-pastoris, and the selenium content of each part of C. bursa-pastoris increased with the increase of selenium concentration. The transfer factor increased at first and then decreased, the maximum was 0.474. The accumulation of selenium increased at first and then decreased with the concentration increasing, and reached the maximum at 25 mg/kg.

Selenate reduction rates and kinetics across depth in littoral sediment of the Salton Sea, California

To predict selenium cycling in sediments, it is crucial to identify and quantify the processes leading to selenium sequestration in sediments. More specifically, it is essential to obtain environmentally-relevant kinetic parameters for selenium reduction and information on how they spatially vary in sediments. The Salton Sea (California, USA) is an ideal model system to examine selenium processes in sediments due to its semi-enclosed conditions and increasing selenium concentration over the last century. Selenium enters the Salton Sea mainly as selenate and might be sequestered in the sediment through microbial reduction. To determine the potential selenium sequestration of Salton Sea littoral sediments and which sediment properties are controlling selenate reduction kinetics, we determined the centimeter-scale vertical distribution of potential selenate reduction rates and apparent kinetic parameters (maximum selenate reduction rates, Vmax, and selenate half-saturation concentration, Km) using flow-through reactor (FTR) experiments. We compared sediments from two littoral sites (South and North) and four depth intervals (0–2, 2–4, 4–6 and 6–8 cm). Furthermore, we characterized the selenium fractions in the sediment recovered from the FTR experiments to identify the processes leading to the sequestration of selenium. Our results reveal higher potential for selenium reduction and sequestration in the topmost sediment (0–2 cm) suggesting that microorganisms inhabiting surface sediment are well adapted to reduce selenate entering the Salton Sea. As apparent Km values (103–2144 µM) exceed the average selenium concentration in the overlying water (6–25 nM), in situ selenate reduction is limited by the low availability of selenate and the resident selenate-reducing microorganisms operate well below their Vmax (11 and 43 nmol cm−3 h−1). Selenium speciation after FTR experiments confirms the primary sequestration of reduced biomass-associated and elemental selenium (68–99% of total selenium) in the sediment. Further, the absence of correlation between the tested sediment physical (porosity, bulk density, clay content), chemical (Corg, Ntot, total selenium content) and biological characteristics (abundance of culturable selenate-reducers) with the kinetic parameters of selenate reduction indicates that these sediment characteristics cannot be used as predictors of apparent Vmax or Km. Conclusively, microbial selenate reduction is an important, if not the primary process, leading to the sequestration of reduced selenium in the Salton Sea sediments and making the surficial Salton Sea sediments an important selenium sink.

Analyses of Selenotranscriptomes and Selenium Concentrations in Response to Dietary Selenium Deficiency and Age Reveal Common and Distinct Patterns by Tissue and Sex in Telomere-Dysfunctional Mice

Background: The hierarchies of tissue selenium distribution and selenotranscriptomes are thought to critically affect healthspan and longevity.Objective: We determined selenium status and selenotranscriptomes in response to long-term dietary selenium deficiency and age in tissues of male and female mice.Methods: Weanling telomerase RNA component knockout C57BL/6 mice were fed a selenium-deficient (0.03 mg Se/kg) Torula yeast-based AIN-93G diet or a diet supplemented with sodium selenate (0.15 mg Se/kg) until age 18 or 24 mo. Plasma, hearts, kidneys, livers, and testes were collected to assay for selenotranscriptomes, selected selenoproteins, and tissue selenium concentrations. Data were analyzed with the use of 2-factor ANOVA (diet × age) in both sexes.Results: Dietary selenium deficiency decreased (P ≤ 0.05) selenium concentrations (65-72%) and glutathione peroxidase (GPX) 3 (82-94%) and selenoprotein P (SELENOP) (17-41%) levels in the plasma of both sexes of mice and mRNA levels (9-68%) of 4, 4, and 12 selenoproteins in the heart, kidney, and liver of males, respectively, and 5, 16, and 14 selenoproteins, respectively, in females. Age increased selenium concentrations and SELENOP levels (27% and 30%, respectively; P ≤ 0.05) in the plasma of males only but decreased (12-46%; P < 0.05) mRNA levels of 1, 5, and 13 selenoproteins in the heart, kidney, and liver of males, respectively, and 6, 5, and 0 selenoproteins, respectively, in females. Among these mRNAs, selenoprotein H (Selenoh), selenoprotein M (Selenom), selenoprotein W (Selenow), methionine-R-sulfoxide reductase 1 (MsrB1), Gpx1, Gpx3, thioredoxin reductase 1 (Txnrd1), Txnrd2, selenoprotein S (Selenos), selenoprotein F (Selenof), and selenoprotein O (Selenoo) responded in parallel to dietary selenium deficiency and age in ≥1 tissue or sex, or both. Dietary selenium deficiency upregulated (40-160%; P ≤ 0.05) iodothyronine deiodinase 2 (Dio2) and selenoprotein N (Selenon) in the kidneys of males. Age upregulated (11-44%; P < 0.05) Selenon in the kidneys of males, selenoprotein K (Selenok) and selenoprotein I (Selenoi) in the kidneys of females, and Selenof and Selenok in the testes.Conclusions: These results illustrate tissue-specific sexual dimorphisms of selenium status and selenotranscriptomes because of dietary selenium deficiency and age.

Simultaneous selenate reduction and denitrification by a consortium of enriched mine site bacteria

Increasing selenium concentrations in aquatic environments downstream of mine sites is of great concern due to selenium's bioaccumulation propensity and teratogenic toxicity. Removal of selenium from mine influenced water is complicated by the presence of nitrate, which is also elevated in mine influenced water due to the use of explosives in mining. In many biological treatment processes, nitrate as a thermodynamically more preferable electron acceptor inhibits selenate reduction. Here we report on an enrichment of a bacterial assemblage from a mine impacted natural marsh sediment that was capable of simultaneous selenate reduction and denitrification. Selenate reduction followed first order kinetics with respect to the concentration of total dissolved selenium. The kinetic rate constant was independent of initial nitrate concentration over the range 3–143 mg L−1-NO3−-N. The initial concentration of selenate inhibited selenate reduction kinetics over the range 1–24 mg-Se L−1.Dominant taxa that grew in selenate only medium were classified in the genera Pseudomonas, Lysinibacillus and Thauera. When nitrate was introduced in addition to selenate, previously rare taxa that became dominant were relatives of Exiguobacterium, Tissierella and Clostridium. Open reading frames (ORFs) associated with dissimilatory denitrification were identified for Pseudomonas, Thauera and Clostridium. In addition, ORFs were found that were homologous with known selenate reductase subunits (SerA and SerB). These findings suggest that native mine site bacteria can be used for removing selenate and nitrate from mine wastewater.

Responses and Histopathological Studies of &lt;i&gt;Clarias gariepinus&lt;/i&gt; Exposed to Selenium Toxicity

Various toxicants have been deposited into aquatic environment due to human activities, in light with this, 180 healthy Clarias gariepinus juveniles with mean weight of 7.4±0.64 g and length of 11.2±0.88 cm were exposed to different concentrations of selenium (a typical toxicant) to evaluate its behaviour and histopathological response. The fish were exposed to different concentrations (2, 3, 4, 5 and 6 mg/L) of selenium under a static bioassay for 96 hours after a range finding test and 96 hours LC 50 was determined using probit method. 10 fish per concentration was used for the bioassay in triplicates. The 96 hours lethal concentration (LC 50 ) was estimated to be 3.39 mg/L. The histological examination of the gill revealed hyperplasia and haemorrhage of the gill lamellar. The kidney showed vacuolation and blood stains while the skin demonstrated mucosal eruption. These alterations increase with increase in selenium concentration. Selenium at high concentration has shown to induce behavioural changes on fish and also alterations to organs of C gariepinus juvenile. It is therefore recommended that industries ensure the incorporation of effluents treatment plants to treat wastes before discharging into the environment.

The roles of selenium, insulin-like growth factor binding protein 2 and suppressor of cytokine signaling 3 in the pathogenesis of Kashin–Beck disease

We aimed to verify the levels of IGFBP2 and SOCS3 in cartilage and chondrocytes of Kashin–Beck disease (KBD) patients and the effects of different selenium concentrations on the protein expression levels. Chondrocytes were cultured with sodium selenite in vitro. Immunohistochemistry and western blotting were used to verify the protein expressions. IGFBP2 and SOCS3 were up-regulated in KBD chondrocytes and decreased with increasing selenium concentrations. IGFBP2 expressed highest in the middle zone of KBD cartilage, SOCS3 expressed higher in the middle and deep zone. IGFBP2 and SOCS3 may be the biomarkers for KBD diagnosis and evaluating the effect of selenium supplement.

Effect of selenite and selenium nanoparticles on lactic bacteria: A multi-analytical study

The effect of selenite and chitosan-modified SeNPs (CS-SeNPs) on Lactobacillus bulgaricus was evaluated through a multianalytical approach based on flow cytometry and transmission electron microscopy (TEM), and high performance liquid chromatography (HPLC) on line coupled to inductively coupled plasma mass spectrometry (ICP-MS) to investigate both lactic bacteria viability in presence of selenium compounds and transformation of selenium compounds once accumulated by the bacteria. For this purpose, L. bulgaricus were grown at 37°C for 24, 48 and 72h in presence of 1 and 10μg Se·mL−1 of selenium as CS-SeNPs and Na2SeO3. No significant differences in bacteria cell viability between selenium-enriched and control bacteria were observed when adding 1μg Se·mL−1 either as Se(IV) or CS-SeNPs. In contrast, bacteria viability decreases when increasing selenium concentration up to 10μg Se·mL−1 being this effect more accused when selenium was supplemented as selenite. Under these conditions SeNPs killed approximately 20% of Lactobacillus after 24h of exposure while the percentage increased up to 60% of bacteria when 10μg Se·mL−1 as selenite was applied. Transmission electron microscopy (TEM) images show that CS-SeNPs readily enter in the bacteria cells preserving membrane integrity and therefore causing no cellular damage. Results from HPLC-ICPMS indicate that most of the CS-SeNPs in the culture media were transformed by the bacteria to organo selenocompounds. A low transformation into organic forms was observed when L. bulgaricus were exposed to selenite, with Se(IV) being the major Se-specie identified. The fact that Lactobacillus was more efficient in transforming SeNPs than selenite could also explain the differences observed in viability.

Adsorption and Diffusion of Lithium on Monolayer Transition Metal Dichalcogenides (MoS2(1–x)Se2x) Alloys

On the basis of first-principles plane-wave calculations, we examine the adsorption and diffusion of lithium on the hexagonal MoS2(1–x)Se2x monolayers with variation of x for 0.00, 0.33, 0.50, 0.66, and 1.00. We find that the lowest energy adsorption positions of Li adatom is at the top site of Mo atom in both MoS2 and MoSe2 monolayers, while Li moves through the Mo—S bond for MoS2(1–x)Se2x. While bare MoS2(1–x)Se2x compounds are nonmagnetic semiconductor and its energy band gap varies with x, they can be metallized by Li adsorption. NEB calculation results show that their energy barriers make them suitable for using in electrode materials. The lithium adsorption energy is sensitive to the external strain, when we elongate the lattice constants, the adsorption energy decreases quickly. We also examine the penetration energy barrier for single lithium atom to pass through the MoS2(1–x)Se2x monolayers, this barrier is decreasing from ∼2.5 eV to ∼1.3 eV with increasing selenium concentration.

The bioavailability of selenium in Saccharomyces cerevisiae

Mineral selenium (Se) is an essential nutrient of great importance to biology of human. Cultivation of Saccharomyces cerevisiae cells in molasses medium with different concentrations of selenium showed that the contents of organic selenium in the cells, increased with the increase in selenium concentration up to 2μg/ml followed by a gradual decrease after 24h of incubation. No clear inhibition effect on growth or gassing power of cells was observed at all concentrations of selenium. The bioavailability of selenium (Se) in Se-yeast was evaluated by measuring Se accumulation and glutathione peroxidase (GSH-Pxe) activity. For 6weeks, Sprague-Dawley rats experiments were subjected to a Se-yeast with a graded levels (0.9, 1.8, 3.2 and 3.6μgSe/100gBW/day). The results did not show any influence on kidney function (CK), liver function (AST, ALT, ALK, protein and albumin) and glucose in serum as well as histopathology studies. Content of Se and glutathione peroxidase (GSH-Pxe) activity in erythrocytes increased gradually with increase in supplemented Se. It could be recommended to use the selenium yeast (high quality baker’s yeast containing selenium) in baking process to control the selenium level in the final product as a source of antioxidant substance for protection from different diseases instead of using selenium drugs.

Solubility constraints affecting the migration of selenium through the cementitious backfill of a geological disposal facility

This work presents the study of the solubility of selenium under cementitious conditions and its diffusion, as SeO32−, through monolithic cement samples. The solubility studies were carried out under alkaline conditions similar to those anticipated in the near-field of a cement-based repository for low- and intermediate-level radioactive waste. Experiments were conducted in NaOH solution, 95%-saturated Ca(OH)2, water equilibrated with a potential backfill material (Nirex reference vault backfill, NRVB) and in solutions containing cellulose degradation products, with and without reducing agents. The highest selenium concentrations were found in NaOH solution. In the calcium-containing solutions, analysis of the precipitates suggests that the solubility controlling phase is Ca2SeO3(OH)2·2H2O, which appears as euhedral rhombic crystals. The presence of cellulose degradation products caused an increase in selenium concentration, possibly due to competitive complexation, thereby, limiting the amount of calcium available for precipitation. Iron coupons had a minor effect on selenium solubility in contrast to Na2S2O4, suggesting that effective reduction of Se(IV) occurs only at Eh values below −300mV. Radial through-diffusion experiments on NRVB and in a fly ash cement showed no evidence of selenium breakthrough after one year. However, autoradiography of the exposed surfaces indicated that some migration had occurred and that selenium was more mobile in the higher porosity backfill than in the fly ash cement.

The Roles of the Interaction of BCL2-Antagonist/Killer 1, Apoptotic Peptidase Activating Factor 1 and Selenium in the Pathogenesis of Kashin-Beck Disease.

BCL2-antagonist/killer 1 (BAK1) and apoptotic peptidase activating factor 1 (APAF1) are significant genes in apoptosis signalling pathway of Kashin-Beck disease (KBD). We aimed to verify the protein expression levels of BAK1 and APAF1 in the cartilage and chondrocytes of patients with KBD. Additionally, we explored the relationship between the levels of these proteins and selenium concentration. Chondrocytes was cultured and treated with sodium selenite in vitro. Immunohistochemistry and Western blotting were used to verify the expression levels of BAK1 and APAF1. Compared with the control samples, APAF1 was upregulated and BAK1 was downregulated in the cartilage and chondrocytes of KBD patients. APAF1 expression was higher in the middle and deep zone in the KBD cartilage. APAF1 levels decreased gradually with the increasing selenium concentration (0.05, 0.10 and 0.25mg/L). BAK1 expression in the 0.25mg/L selenium group was lower than that of the control group. Different selenium concentrations had varying effects on BAK1 and APAF1 levels. APAF1 may play an important role in the pathogenesis of KBD. APAF1-related apoptosis was more pronounced in the middle and deep zones of the KBD cartilage. APAF may represent a potentially novel molecular target, which may be a biomarker of the role of selenium on the prevention and treatment of KBD. The role of BAK1 in the pathogenesis of KBD requires further study.

English

The present investigation explores the effect of selenium supplementation on radial growth and ultrastructural alterations in the hyphae and spores of Ganoderma lucidum. A concentration dependent decrease in radial growth was observed on culturing G. lucidum on sodium selenate supplemented mushroom minimal agar post 24 h. However, in comparison to control, selenium supplementation slightly increased diameter of radial growth till 10 ppm after 48 h. The Scanning Electron Microscopy (SEM) studies of radial growth showed selenium concentration dependent gradual decrease in hyphal diameter suggesting thinning and extensive branching of mycelia in response to increased Se supplementation. Moreover, SE micrographs also depict selenium concentration dependent decrease in number of spores and spore size. A significant decrease in spore diameter was recorded for mushroom minimal agar supplemented with 20 and 25 ppm (5.64 and 1.26 μm, respectively) as compared to control (10.04 μm). The spore were morphologically altered from spherical to oval or oblong and inflated to constrict deformed on increasing selenium concentration. SEM-energy dispersive X-ray spectroscopy (SEM-EDS) studies of intact mycelia showed no traces of selenium. However, crushed mycelia samples exhibited Se signals probably due to presence of selenium as integral component of cytosolic moieties like selenoproteins. Atomic absorption spectroscopy (AAS) of mycelia showed an increasing trend in the uptake of selenium with increased selenium supplementation. Percentage absorption was found to be in range of 7.2 - 9.9% with maximum absorption at concentrations of 15 and 25 ppm. Hence, sodium selenate supplementation at 10 ppm (with maximum 15 ppm) can be used for Se fortification as Ganoderma can grow rapidly without significant alteration in structure and morphology to enhance its biomedicinal properties. Key words: Ganoderma, scanning electron microscopy (SEM), SEM-energy dispersive X-ray spectroscopy (SEM-EDS), selenium, selenoproteins.

Room temperature magnetism and metal to semiconducting transition in dilute Fe doped Sb1−xSex semiconducting alloy thin films

The magnetism was observed in very dilute Fe doped alloy thin film Fe0.008Sb1−xSex, for x = 0.01 to 0.10. These thin films were grown on silicon substrate using thermal evaporation technique. Structural, electrical, optical, charge carrier concentration measurement, surface morphology and magnetic properties were observed using glancing incidence x-ray diffraction (GIXRD), four probe resistivity, photoluminescence, Hall measurement, atomic force microscopy (AFM) and magnetic force microscopy (MFM) techniques, respectively. No peaks of iron were seen in GIXRD. The resistivity results show that activation energy increases with increase in selenium (Se) concentration. The Arrhenius plot reveals metallic behavior below room temperature. The low temperature conduction is explained by variable range-hopping mechanism, which fits very well in the temperature range 150–300 K. The decrease in density of states has been observed with increasing selenium concentration (x = 0.01 to 0.10). There is a metal-to-semiconductor phase transition observed above room temperature. This transition temperature is Se concentration dependent. The particle size distribution ∼47–61 nm is evaluated using AFM images. These thin films exhibit ferromagnetic interactions at room temperature.

Increased plasma selenium is associated with better outcomes in children with systemic inflammation

ObjectiveThe aim of this study was to assess the effects of changes in plasma selenium on the outcome of critically ill children. MethodsPlasma selenium was prospectively measured in 99 children with acute systemic inflammation. The exposure variables were selenium level on admission and on day 5 of stay in the intensive care unit (ICU) and the difference in selenium concentrations between day 5 post-admission and the ICU admission (delta selenium). Selenium was given only as part of enteral diets. Age, malnutrition, red cell glutathione peroxidase-1 activity, serum C-reactive protein, Pediatric Index of Mortality 2, and Pediatric Logistic Organ Dysfunction scores were analyzed as covariates. The outcome variables were ventilator-free days, ICU-free days, and 28-d mortality. ResultsPlasma selenium concentrations increased from admission (median 23.4 μg/L, interquartile range 12.0–30.8) to day 5 (median 25.1 μg/L, interquartile range 16.0–39.0; P = 0.018). After adjustment for confounding factors, a delta selenium increase of 10 μg/L was associated with reductions in ventilator days (1.3 d; 95% confidence interval [CI], 0.2–2.3; P = 0.017) and ICU days (1.4 d; 95% CI, 0.5–2.3; P < 0.01). Delta selenium >0 was associated with decreased 28-d mortality on a univariate model (odds ratio, 0.67; 95% CI, 0.46–0.97; P = 0.036). The mean daily selenium intake (6.82 μg; range 0–48.66 μg) was correlated with the increase in selenium concentrations on day 5. ConclusionsAn increase in plasma selenium is independently associated with shorter times of ventilation and ICU stay in children with systemic inflammation. These findings raise the hypothesis that selenium supplementation could be beneficial in children with critical illnesses.

Selenium Effect on Rye Malt Quality

Abstract Rye (Secale cereale L.) is the most important cereal crop after wheat, rice and maize. A substantial part of the rye yield is used for bread making, especially in European countries. There have been numerous studies on grain enrichment with selenium (Se), as it is known that selenium is a fundamental trace element essential for human health and in the form of selenoproteins plays key structural and enzymic roles. The main aim of this study was to investigate the effect of different selenium concentrations on quality indices of rye malt - the content of malt extract, diastase activity, selenium and total phenol content in malt. Rye grain of 95% viability was soaked and germinated at temperature +6 ± 2 °C for three days +18 ± 2 °C, using sodium selenate Na2SeO4 solutions (Se concentration 3 mg l-1, 5 mg l-1, 10 mg l-1), and dried in an oven for 24 hours at temperature +70 - 112 °C. Germination of grain with deionised water served as a control. The obtained results showed that an increase of selenium concentration caused increase of malt extract concentration (from 74 to 80%), selenium concentration (from 0.0139 to 0.3251 mg kg-1) and total phenol concentration (from 3.13 to 3.63 mg GAE g-1 DW) in rye malt, while diastase activity decreased from 330 to 216.