Se Inclusion Research Articles

Selenized non-Saccharomyces yeasts and their potential use in fish feed.

Selenium (Se) is a vital trace element, essential for growth and other biological functions in fish. Its significance lies in its role as a fundamental component of selenoproteins, which are crucial for optimal functioning of the organism. The inclusion of Se in the diets of farmed animals, including fish, has proved invaluable in mitigating the challenges arising from elemental deficiencies experienced in captivity conditions due to limitations in the content of fishmeal. Supplementing diets with Se enhances physiological responses, particularly mitigates the effects of the continuous presence of environmental stress factors. Organic Se has been shown to have higher absorption rates and a greater impact on bioavailability and overall health than inorganic forms. A characteristic feature of yeasts is their rapid proliferation and growth, marked by efficient mineral assimilation. Most of the selenized yeasts currently available in the market, and used predominantly in animal production and aquaculture, are based on Saccharomyces cerevisiae, which contains selenomethionine (Se-Met). The object of this review is to highlight the importance of selenized yeasts. In addition, it presents metabolic and productive aspects of other yeast genera that are important potential sources of organic selenium. Some yeast strains discussed produce metabolites of interest such as lipids, pigments, and amino acids, which could have applications in aquaculture and further enrich their usefulness.

The effects of dietary organic selenium on growth, body composition and hematological parameters of common Carp (Cyprinus carpio) reared in recirculating aquaculture system.

A feeding trial was conducted to examine the effects of different levels of dietary organic selenium (Se) on the growth, body composition, and hematological indices of common carp. Se element was supplemented to the basal diet at the rates of 0.0, 0.5, 1 and 2 mgkg-1. Fish were randomly stocked at a rate of 25 fish into 500L tanks in the Recirculating Aquaculture System (RAS) system for 10 weeks. Weight gain, final body weight, and specific growth rate were significantly higher (p<0.05) in fish fed 0.5 mgkg-1 followed by 1 and 2 mgkg-1 treatment diets fish. The lowest growth rate values were detected in fish-fed basal diets. Feed consumption of fish fed Se was not significantly different (p>0.05), also the survival rate was similar among the treatment groups. Whole-body composition showed that fish fed 1 mgkg-1 had significantly higher (p<0.05) body moisture and protein as dry weight basis. The highest fiber content was in fish fed 2 mgkg-1, but ash was significantly higher in fish fed only 0.5 mgkg-1 and fat remained unaffected. Whole-body Se concentrations were significantly (p<0.05) increased with increasing Se levels in test diets. the red blood cells and hemoglobin were significantly higher (p<0.05) in fish fed only 0.5mgkg-1 and the basal diet. The white blood cells increased in fish fed the basal and 2 mgkg-1 diet, but the lymphocyte percentage was increased (p<0.05) in fish fed basal and 0.5 mgkg-1. The study concludes that dietary Se has an overall positive effect on common carp. Growth performance, protein content in fish body, selenium deposition and some hematological parameters were observed in fish fed dietary organic selenium specifically in fish fed 0.5 and 1 mgkg-1. Therefore, inclusion of Se in the diet from 0.5 to 1 mgkg-1 would be an optimal level for common carp feed.

PSXIV-8 Comparison of the Effects of Hydroxy-Selenomethionine and Selenium-Enriched Yeast Against Hydrogen Peroxide-Induced Oxidative Stress in Rat Intestinal Epithelial Cells

Abstract Superior bioavailability of organic selenium (Se) has been extensively studied. However, limited research has been conducted to evaluate the effect of organic forms on intestinal redox potential to support gut health and animal well-being. Two experiments (Exp) were conducted to compare the effect of either hydroxy-selenomethionine (OH-SeMet) or Se-enriched yeast (Se-yeast) on ameliorating hydrogen peroxide (H2O2)-induced oxidative stress in a rat intestinal epithelial cell line (IEC-6). A cell viability test was initially performed to validate the Se level (0.15, 0.3, 0.6 ug/mL) used for the reactive oxygen species (ROS) assay. In both studies, OH-SeMet or Se-yeast promoted cell viability and attenuated cell apoptosis indicating no negative impact on cell growth. However, the Se-yeast sources showed considerably greater effectiveness than OH-SeMet. To quantify redox potential, confluent cells were treated with DCFDA, an indicator of ROS production. Briefly, IEC-6 cells were seeded into 96-well plates (4 ×104 cells per well) with 3 replicates per treatment (Trt) and incubated with a fresh solution of DCFDA. The ROS production, in response to 30µM H2O2, was quantified by fluorescence emission at 485 nm. Data were analyzed with GLIMMIX procedure of SAS. In both Exp, Se inclusion in all Se-Trts was 0.3 ppm. In Exp 1, Trts included: Non treated (cells only), H2O2, H2O2 + 2mM Trolox (Vit. E analog), H2O2 + sodium selenite, H2O2 + OH-SeMet, H2O2 + Se-yeast product A, H2O2 + Se-yeast product B. Cells treated with H2O2 had 4.6-fold increase (P &amp;lt; 0.05) in ROS production relative to non-H2O2 treated cells. Trolox reduced ROS 7.6-fold (P &amp;lt; 0.05) relative to H2O2 only cells, OH-SeMet and sodium selenite did not ameliorate (P &amp;gt; 0.35) the negative impact of H2O2 on ROS production. However, cells treated with H2O2 + Se-yeast product A or B reduced ROS production by 15% (P = 0.07) and 32% (P &amp;lt; 0.01), respectively, compared with cells treated with H2O2 only. To validate the redox potential of OH-SeMet, Exp 2 included a pure form of selenomethionine. Treatments in Exp 2. were similar to Exp 1 with the inclusion of H2O2 + seleno-L-methionine. Selenomethionine, either as a pure source or the hydroxy analog, did not prevent (P &amp;gt; 0.40) H2O2-induced oxidative stress. However, Exp 2 confirmed the effectiveness of Se-Yeast products on reducing ROS production. More specifically, Se-Yeast product B (52% reduction, P = 0.04) was superior to product A (32% reduction, P = 0.17) in comparison to cells treated with H2O2 only. These findings suggest that the type of organic Se source differs in their ability to regulate intestinal redox potential, with Se-yeast sources being more effective than hydroxy analogs. Selenomethionine content in Se-yeast does not appear to be the main driver in reducing ROS in intestinal cells, suggesting that livestock fed Se-yeast can support better intestinal health during oxidative stress.

Metallomics analysis of metal exposure and cognitive function in older adults: A combined epidemiological and bioinformatics study

Dementia is a significant cause of elderly disability and Alzheimer's disease (AD) is the most prevalent form of dementia. As an early stage of AD, the mechanism related to mild cognitive impairment (MCI) and heavy metals is still unclear. This study utilized a cross-sectional design and enrolled 514 older adults in Bejing, China. Cognitive function was assessed by the Mini-Mental State Examination (MMSE) and fourteen blood metals were measured by inductively coupled plasma mass spectrometry (ICP-MS). In the adjusted single-metal models, we observed that copper [Cu, β (95% CI): 3.73 (−6.42, −1.03)] and lead [Pb, β (95% CI): 0.79 (−1.26, −0.32)] demonstrated negative associations with cognitive function, while selenium [Se, β (95% CI): 2.97 (1.23, 4.70)] was beneficial to cognition. Our findings were robust in secondary analysis using multi-metal models, which included generalized linear models (GLM), Bayesian kernel machine regression (BKMR), and quantile g-computation (qgcomp). Moreover, the toxic metal mixture (Cu and Pb) exhibited a significant negative association with MMSE scores and the inclusion of Se in the metal mixture attenuated the neurotoxicity of Cu–Pb mixture. The in silico analysis was used to examine the potential molecular mechanisms (genes, biological processes, pathways, and illnesses) of interaction among metal mixtures. We identified 20 cognition-related genes that are associated with both Cu–Pb and Se. Among these genes, eight (APOE, APP, BAX, BDNF, CASP3, HMOX1, TF, and TPP1) exhibited opposite effects on protein activity, mRNA expression, or protein expression in response to Se and Cu/Pb exposure, which could be the key genes accounting for the anti-neurotoxic effects of Se. Our findings support that Se can attenuate the neurotoxicity of exposure to single Cu or Pb, and Cu–Pb mixture. More research is needed to confirm our findings and gain knowledge about the molecular mechanisms of combined metal exposure on cognitive function.

Protective role of selenium and selenium-nanoparticles against multiple stresses in Pangasianodon hypophthalmus.

Pollution and climate change pose significant threats to aquatic ecosystems, with adverse impacts on aquatic animals, including fish. Climate change increases the toxicity of metal in aquatic ecosystems. To understand the severity of metal pollution and climate change, an experiment was conducted to delineate the mitigation potential of selenium (Se) and selenium nanoparticles (Se-NPs) against lead (Pb) and high temperature stress in Pangasianodon hypophthalmus.For the experiment, five isonitrogenous and isocaloric diets were prepared, varying in selenium supplementation as Se at 0, 1, and 2 mg kg-1 diet, and Se-NPs at 1 and 2 mg kg-1 diet. The fish in stressor groups were exposed to Pb (1/20th of LC50 concentration, 4 ppm) and high temperature (34 °C) throughout the experiment. The results demonstrated that dietary supplementation of Se at 1 and 2 mg kg-1 diet, as well as Se-NPs at 1 mg kg-1 diet, significantly reduced (p< 0.01) the levels of lactate dehydrogenase and malate dehydrogenase in both liver and muscle tissues. Additionally, the levels of alanine aminotransferase and aspartate aminotransferase in both gill and liver tissues were significantly decreased (p< 0.01) with the inclusion of Se and Se-NPs in the diets. Furthermore, the enzymes glucose-6-phosphate dehydrogenase in gill and liver tissues, fructose 1,6-bisphosphatase in liver and muscle tissues, and acid phosphatase in liver tissue were remarkably reduced (p< 0.01) due to the supplementation of Se and Se-NPs. Moreover, dietary supplementation of Se and Se-NPs significantly enhanced (p< 0.01) the activity of pyruvate kinase, glucokinase, hexokinase, alkaline phosphatase, ATPase, protease, amylase, lipase, and RNA/DNA ratio in the fish. Histopathological examination of gill and liver tissues also indicated that Se and Se-NPs protected against structural damage caused by lead and high-temperature stress. Moreover, the study examined the bioaccumulation of selenium and lead in muscle, water, and diets. The aim of the study revealed that Se and Se-NPs effectively protected the fish from lead toxicity and high-temperature stress, while also improving the function of cellular metabolic enzymes in P. hypophthalmus.

0136 Decreased Sleep Efficiency May Link Adverse Childhood Experiences with Increased Visceral Adiposity

Abstract Introduction Poor sleep has been shown to negatively impact cardiometabolic health. Adverse Childhood Experiences (ACEs), potentially traumatic events occurring within the first 18 years of life, have been linked to both poor sleep and cardiometabolic disease in adulthood. Evidence is needed to understand whether poor sleep plays a mechanistic role in the link between ACE exposure and cardiometabolic risk. The purpose of this study was to examine associations of ACE exposure with self-reported sleep efficiency (SE%) and waist circumference (WC). Methods In 25 young adults (21F/4M; mean±SD, age=25±5 y), we assessed ACE exposure using the 10-item ACE Questionnaire and SE% as the reported average sleep duration relative to time-in-bed from the Pittsburgh Sleep Quality Index. We measured WC, a known cardiometabolic risk factor, as a surrogate of visceral adiposity. We used multiple linear regression analyses to examine associations between ACE exposure, SE%, and WC adjusted for sex. We then utilized ANCOVA analyses to examine the possible mechanistic effect of SE% on the relationship between ACE exposure and WC. For these analyses, participants with 0-1 ACEs were categorized as low-ACE exposure (ACE-low) and participants with 2+ ACEs were categorized as moderate-to-high ACE exposure (ACE-mh). Results Following adjustment for sex, ACE score predicted SE% (β=-0.53, p=0.009) and WC (β=0.52, p=0.01), and SE% predicted WC (β=-0.44, p=0.03). Similarly, ANCOVA analyses indicated that ACE-mh was associated with greater WC than ACE-low, adjusted for sex (adjusted means ± 95% CI, 0.86 ± 0.07 m vs. 0.78±0.06 m; p=0.049). However, the effect of ACE group on WC was no longer significant following inclusion of SE% as a covariate (0.84 ± 0.07 m vs. 0.80 ± 0.07 m; p=0.29). Conclusion Both ACEs and sleep efficiency are associated with visceral adiposity. Further, SE% may serve as a mechanistic biobehavioral link between ACE exposure and increased visceral adiposity in young adults. These preliminary findings warrant further investigation with implications for sleep interventions as a possible preventative approach to reduce cardiometabolic risk in individuals exposed to ACEs. Support (if any) Research reported in this publication was partly supported by the NCATS of the NIH (UL1TR002537) and by the Injury Prevention Research Center through the CDC (R49 CE003095).

Milk yield, composition and immune status of dairy goats and respective goat kids fed diets with selenium and vitamin E supplementation

This study was carried out to examine the effects of including selenium (Se) and vitamin E (vitE) in diets for goats and their kids on milk yield and composition, and immune status. Twenty-one 1/2 Saanen x Pardo Alpine goat kids (average body weight of 3.70 ± 0.64 kg) were born from fifteen female Saanen goats (non-lactating and primiparous) with an average age of six years and an average initial live weight of 70 ± 10 kg, which had previously been synchronized with the OvSynch protocol. Animals were allocated at random to the treatments in a completely randomized experimental design, with five replicates per diet for goats and seven replicates, for goat kids. Animals were randomly assigned into three groups in the following diets: CON: control basal diet; Se: inclusion of 3.2 mg of Se/kg DM; SevitE: inclusion of 3.2 mg Se / kg DM and 1145 IU / day vitE/kg DM. Milk yield and composition of goats were evaluated only considering the average production of the period, whereas Se in serum, milk and total plasma antioxidant capacity and phagocytosis intensity data were evaluated by time repeated measures. Goats fed CON diet showed higher total dry extract levels in milk than those fed Se diet (P< 0.05). An interaction between diet and time was observed for serum Se concentration in goats (P < 0.01). The Se concentration in milk was higher for goats fed the Se and SevitE than animals fed the CON (P = 0.01). There was only a time effect (P = 0.04) for Se concentrations in milk, and vitE in serum (P < 0.01) and milk (P < 0.01) and TAS (P < 0.01). The concentrations of Se in the blood of goat kids fed the SevitE, and Se diets were higher than animals fed the CON diet (P < 0.01). Diets influenced the Se concentration and phagocytosis intensity, while a time effect was observed on phagocytosis intensity (P < 0.05). A week effect was observed for phagocytosis of E. coli in goats (P = 0.01). For goat kids, a diet effect was observed for phagocytosis of E. coli (P = 0.01) and only the percentage of polymorphonuclear leukocytes was not influenced by diets (P = 0.95). The inclusion of Se and vitE or their combination reduces oxidative stress without influencing oxidative stress in neonates fed with milk from goats supplemented with selenium and vitamin E in their diets.

Enhanced near-room temperature thermoelectric performance and mechanical strength of n-type BiTeSe materials incorporated with Ag2Se inclusions

Bi2Te3-based alloys are the best thermoelectric materials near room temperature.

Evaluation of dietary selenium methionine levels and their effects on growth performance, antioxidant status, and meat quality of intensively reared juvenile Hypophthalmichthys molitrix.

The objective of this study was to optimize the organic selenium (Se) requirements of intensively reared silver carp (Hypophthalmichthys molitrix). A total of n = 300 juveniles silver carp 11.40±0.52 cm long, and average weighing 25.28±0.18 grams were randomly assigned to 15 aquaria (20 fish/100L aquaria) and subjected to five different dietary Se levels in a completely randomized design. The diets were pelleted supplemented with exogenous Se methionine @ 0.0, 0.3, 0.6, 0.9 and 1.2 mg/kg of the diet. The fourteen days of aquaria acclimatization was given to fish and then an 84-day feeding trial was conducted. The group supplemented with 0.9 mg/kg Se had greater feed intake, gain in length, body weight %, and specific growth rate with a better feed conversion ratio as compared to those fed on the rest of the dietary levels or control (P<0.05). The deposition of Se was greater in the liver, and kidneys of the fishes fed on diets containing 0.9 and 1.2 mg Se levels than in the rest of the treatments (P<0.05). However, dietary Se levels had no effects on the bioaccumulation of Se in muscle tissues (P>0.05). The proximate analysis showed that dry matter, crude protein, and fat contents of meat were not changed (P>0.05) by dietary treatments. Similarly, values of TBARS, RBCs, Hb, and blood glucose contents were similar (P>0.05) across the treatments. However, the concentration of WBCs, HCT, and MCHC was greater in those groups fed on 0.9 and 1.2 Se levels than in those fed on 0.6, 0.3, and 0.0 Se levels respectively (P<0.05). The activities of ALT, AST, and ALP were lowered in the 0.9 mg Se supplemented fishes compared with the rest of the treatments (P<0.05). The SOD, catalases, and GPx levels for muscle, liver, and whole body were greater (P<0.05) in the Se-supplemented groups than in the control. These outcomes indicated that up to 0.9 mg/kg inclusion of methionine-based Se in the diet of juvenile silver carp improved the growth performance, feed conversion ratio, organs Se enrichment, and antioxidant status without any compromise on meat quality.

Effects of hydroxy-selenomethionine on performance, innate immune system and antioxidant defense of tambaqui (Colossoma macropomum) exposed to a physical stressor

Selenium (Se) is a mineral with natural antioxidant properties that constitutes a number of enzymes with a fundamental role in the immunity and antioxidant systems and may confer a protective role against oxidative stress in fish following exposure to physical stressors. Adopting an integrated approach, this study investigated simultaneously the role of hydroxy-selenomethionine (OH-SeMet) supplementation in performance, hematological parameters, innate immune, antioxidant capacity and tissue Se retention of tambaqui (Colossoma macropomum) and the possible protective role of dietary selenium when fish are exposed to a physical stressor (transport). Juvenile specimens (15.71 ± 1.90 g) were fed one of five diets: a basal unsupplemented diet (0.0 mg kg−1 Se) or diets supplemented with OH-SeMet to provide 0.3, 0.6, 0.9 and 1.2 mg kg−1 Se of diet for 75 days prior to subjection of fish to transport stress. Dietary supplementation with Se in the form of OH-SeMet for 75 days did not affect the production performance of juvenile tambaqui, but increased innate immunity parameters (oxidative burst) from the Se inclusion level of 0.6 mg kg−1 and induced the activation of the antioxidant defense system (GPX, GSH and GST) especially at the Se inclusion level of 0.9 mg kg−1. In addition, the Se content in the fillet rose significantly, as the OH-SeMet contents in the diet were increased. The stress caused by transport resulted in alterations in hematological parameters, blood protein profile and immune and enzymatic responses in the species. However, Se supplementation at 0.9 mg kg−1 had a positive effect, increasing innate immunity and activating antioxidant defenses (CAT and GPx, especially) after this physical stressor was applied. These results demonstrate that, when submitted to transport stress, juvenile tambaqui use Se stored in the muscle and dietary supplementation with OH-SeMet at 0.9 mg kg−1 improves the innate immunity and antioxidant system parameters of fish after transport. These findings reinforce the need for supplementing hydroxy-selenomethionine in commercial diets for tambaqui to ensure tissue Se reserves as a contingency in cases of stress.

Effects of organic Selenium- and Chromium-Enriched Diets on performance, carcass characteristics, lipid profile and fat quality of finishing pigs in different weight ranges.

An experiment was conducted to evaluate the fatty acid profile of subcutaneous fat from barrowS of same genetic lineage supplemented with organic chromium and selenium initiated in different weight ranges in the finishing phase using 24 carcasses. Three different diets were used that represent the time when supplementation starts: control - without the inclusion of organic Cr and Se; CrSe70 - control with 500 g ton-1 of organic Cr and Se of 70 to 130 kg in body weight; and CrSe100 - control with inclusion of 500 g ton-1 of organic Cr and Se from 100 kg to 130 kg body weight. Performance, carcass characteristics, and lipid profile were evaluated. The data were submitted to analysis of variance, and with significant differences (p<0.05), the means were compared using the Tukey test. From 70 to 100 kg, control and CrSe70 animals consumed less feed than CrSe100. From 100 kg body weight, it reduced the C20:5n3 and C24:1n9 acids and increased the activity of the Δ-6 desaturase, elongase, Δ-5 desaturase enzymes in the supplemented animals. The moment when supplementation starts of organic chromium and selenium does not improve the performance and carcass characteristics, does not change the fatty acid profile, and does not improve the quality of the fat.

Effects of selenium-chitosan on intestinal microflora, intestinal histomorphology, and immune response of broiler chickens

In a companion paper, the effects of Se-chitosan as organic Se, Na selenite, vitamin E, and their various combinations on growth performance, carcass traits, meat quality, and blood indices of broiler chickens have been reported. In this part of the paper, their effects on intestinal microflora, intestinal histomorphology, and immune response were investigated. A total of 480 one-day-old broiler chickens were randomly assigned to the Se source (inorganic and organic), Se inclusion (0.15 and 0.3 mg/kg), and vitamin E (0 and 80 IU/kg) in a 2 × 2 × 2 factorial arrangement of treatments with 5 pens per treatment and 12 broiler chickens per pen. Broiler chickens fed diets supplemented with Se-chitosan or 0.3 mg Se/kg had lower coliform counts and greater lactic acid bacteria/coliform ratios in ileum and cecum (P < 0.05). Dietary supplementation with Se-chitosan increased villus height/crypt depth ratio (VH/CD), villus surface area, and goblet cell density in ileum and jejunum (P < 0.05). Furthermore, broiler chickens fed diets supplemented by 0.3 mg Se/kg or vitamin E had greater villus height, VH/CD, villus surface area, and goblet cell density and lower crypt depth, and epithelial cell layer thickness in jejunum (P < 0.05). Dietary supplementation with Se-chitosan increased total antibody response to sheep red blood cells (SRBC), IgG, and antibody response to Newcastle disease virus (P < 0.05). Interaction between Se source and vitamin E content showed that broiler chickens fed Se-chitosan plus vitamin E had lower ileal coliform counts and greater jejunal villus height, VH/CD, and villus surface area and serum total antibody response to SRBC compared to broiler chickens fed Na selenite with or without vitamin E (P < 0.05). It could be concluded that, compared to the use of Na selenite alone or with vitamin E, the inclusion of Se-chitosan as a novel source of Se plus 80 IU vitamin E/kg could improve intestinal microflora, intestinal histomorphology, and immune response.

Quaternary Semiconductor Cd1−xZnxTe1−ySey for High-Resolution, Room-Temperature Gamma-Ray Detection

The application of Cd0.9Zn0.1Te (CZT) single crystals, the primary choice for high-resolution, room-temperature compact gamma-ray detectors in the field of medical imaging and homeland security for the past three decades, is limited by the high cost of production and maintenance due to low detector grade crystal growth yield. The recent advent of its quaternary successor, Cd0.9Zn0.1Te1−ySey (CZTS), has exhibited remarkable crystal growth yield above 90% compared to that of ~33% for CZT. The inclusion of Se in appropriate stoichiometry in the CZT matrix is responsible for reducing the concentration of sub-grain boundary (SGB) networks which greatly enhances the compositional homogeneity and growth yield. SGB networks also host defect centers responsible for charge trapping, hence their reduced concentration ensures minimized charge trapping. Indeed, CZTS single crystals have shown remarkable improvement in electron charge transport properties and energy resolution over CZT detectors. However, our studies have found that the overall charge transport in CZTS is still limited by the hole trapping. In this article, we systematically review the advances in the CZTS growth techniques, its performance as room-temperature radiation detector, and the role of defects and their passivation studies needed to improve the performance of CZTS detectors further.

Entrepreneurship in social: Brazilian university students toward a career with purpose

Purpose Social entrepreneurship (SE) presents specificities that the entrepreneur must address. Entrepreneurial intention (EI) and entrepreneurial orientation (EO) in SE should reflect specific characteristics of behavior. The purpose of this study is to identify the intention of Brazilian university students to undertake SE, having individual social EO (individual entrepreneurial orientation (IEO)-social) as their predictive behavior. Design/methodology/approach This paper collected study data from Brazilian university students. To test the study’s hypotheses, this paper used confirmatory factor analysis, structural equation model, partial least squares and generalized linear regression model. Findings The results indicate that Brazilian university students positively respond to their intention to become social entrepreneurs in the future, regardless of gender, courses or types of universities. In line with the literature, IEO-Social proved to be a strong predictor of EI-social. Research limitations/implications This study was limited to understanding EI-social from IEO-Social. Besides, its sample is non-probabilistic, therefore, the findings of this study cannot be generalized. Practical implications The results encourage the inclusion of SE in entrepreneurial education programs. They guide the involvement of students from different areas of knowledge in activities aimed at higher education. Social implications Evidence indicates that including the SE theme in entrepreneurial education programs proves to be valuable for opening purposeful career opportunities for students. Originality/value The study contributes to eliminating the gap in studies on EI-social in Brazilian university students. It also offers the IEO-social scale, theoretically constructed and with superior psychometric quality.

Effects of selenium-chitosan on growth performance, carcass traits, meat quality, and blood indices of broiler chickens

The current experiment was conducted to evaluate the effects of Se-chitosan as organic Se, Na selenite, vitamin E, and their various combinations on growth performance, carcass traits, meat quality, and blood indices of broiler chickens. A total of 480 one-d-old broiler chickens were randomly assigned to the Se source (inorganic and organic), Se inclusion (0.15 and 0.30 mg/kg), and vitamin E (0 and 80 IU/kg) in a 2 × 2 × 2 factorial arrangement of treatments with 5 pens per treatment and 12 broiler chickens per pen. Broiler chickens fed 0.30 mg Se/kg had a greater body weight gain and a lower feed conversion ratio at 11 to 24 d (P < 0.05). The relative weight of the liver was lower in broiler chickens fed diets supplemented with 0.30 mg Se/kg at 21 d (P < 0.05). Broiler chickens fed diets supplemented with Se-chitosan or 0.30 mg Se/kg had lower thiobarbituric acid reactive substances, drip loss, and cooking loss and greater water holding capacity (WHC) values in muscles (P < 0.05). The yellowness of the broiler chicken muscle fed diets supplemented by Se-chitosan was greater (P < 0.05). In addition, an interaction between Se inclusion rate and vitamin E was observed for WHC in breast and thigh meat, so that broiler chickens fed 0.30 mg Se/kg plus vitamin E had a greater WHC compared to other treatments (P < 0.05). The broiler chickens fed diets supplemented by 0.30 mg Se/kg had greater total protein and albumin concentrations and lower concentrations of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase (P < 0.05). In addition, alkaline phosphatase activity was lower for broiler chickens fed diets supplemented with vitamin E (P < 0.05). In addition, broiler chickens fed 0.30 mg Se/kg plus vitamin E had the greater total protein concentrations compared to other treatments, while greater concentrations of aspartate aminotransferase and alanine aminotransferase were observed in broiler chickens fed 0.15 mg Se/kg without vitamin E (P < 0.05). Dietary supplements did not affect concentrations of thyroid hormones. It could be concluded that Se-chitosan as a novel Se source is a simple and cost-effective approach to improve meat quality and the dietary inclusion of 0.30 mg Se/kg improved meat quality and blood indices of broiler chickens.

Effect of dietary microminerals in early weaning diets on growth, survival, mineral contents and gene expression in gilthead sea bream (Sparus aurata, L) larvae

In previous studies, combined inclusion of Zn, Mn and Se in early weaning diets improved larval growth, but suggested a potential toxicity by one of these elements. The present study aimed to determine the effect of the single inclusion of Zn, Mn, Se or Cu, their combination (Control+) or their absence (Control−) on larval diets. At the end of the trial, survival was significantly (p < .05) lowest in fish fed C+ diet (17.16 ± 7% mean ± SD), followed by that of larvae fed Mn diet (21.91 ± 7%). The highest survival was obtained by Cu diet (35.27 ± 15%), followed by C− diet (34.58 ± 9%). Cu and Se supplementation significantly improved total length and body weight, in comparison with the C− fish. On the contrary, fish fed Mn and C+ showed the lowest growth. Supplementation with Zn or Cu significantly increased CuZnsod, whereas gpx was significantly upregulated in fish fed Se and C+ diets. ARA/EPA level was significantly highest and DHA/EPA lowest in larvae fed the Cu diet in fish fed C+ diet. The results pointed out the importance of supplementation with Cu, as well as Se and Zn, on early weaning diets for gilthead sea bream, and the potential toxic effect of Mn.

Substrate temperature-dependent thermoelectric figure of merit of nanocrystalline Bi2Te3 and Bi2Te2.7Se0.3 prepared using pulsed laser deposition supported by DFT study

This work reports the pulsed laser deposition of n-type selenium (Se) doped bismuth telluride (Bi2Te2.7Se0.3) and n-type bismuth telluride (Bi2Te3) nanostructures under varying substrate temperatures. The influence of the substrate temperature during deposition on the structural, morphological and thermoelectric properties for each phase was investigated. Density functional theory (DFT) simulations were employed to study the electronic structures of the unit-cells of the compounds as well as their corresponding partial and total densities of states. Surface and structural characterization results revealed highly crystalline nanostructures with abundant grain boundaries. Systematic comparative analysis to determine the effect of Se inclusion into the Bi2Te3 matrix on the thermoelectric properties is highlighted. The dependence of the thermoelectric figure of merit (ZT) of the nanostructures on the substrate temperatures during deposition was demonstrated. The remarkable room temperature thermoelectric power factor (PF) of 2765 μW/mK2 and 3179 μW/mK2 for pure and Se-doped Bi2Te3 compounds respectively, signifies their potential of being useful in cooling and power generation purposes. The room temperature ZT values of the Se-doped Bi2Te3 was found to be 0.92, about 30% enhancement as compared with the pure phase, which evidently results from the suppressed thermal conductivity in the doped species caused by phonon scattering at the interfaces.

Effect of selenisation on the properties of antimony selenide thin films

Antimony Selenide (Sb2Se3) is an important photoconductive semiconductor and it has a band gap of 1.3 eV. It finds applications in solar selective and decorative coating, optical devices and thermoelectric cooling devices. In the present work, Sb2Se3 thin film is prepared by Chemical Bath Deposition (CBD) technique. This method is most suitable for large area samples and it is very simple. Antimony chloride and sodium selenosulfate are used as precursors for the preparation of antimony selenide thin films. It was observed from XPS analysis that antimony oxide was also present as an impurity phase along with antimony selenide. In this work, selenisation is carried out in order to increase the selenium content in the pristine antimony selenide thin films. Selenisation was also done by the method of CBD. These samples were annealed at various temperatures and characterized structurally, morphologically and optically. It was observed that the inclusion of Se has lead to exclusion of oxygen from the surface layers of Antimony Selenide films. Se inclusion has also changed the morphology of Antimony selenide films drastically.

Ammonia volatilization losses from urea coated with copper, boron, and selenium

Urea coated with copper and boron may be a vehicle for selenium fertilization in grazing systems to improve both forage and animal productivity, and consequently, the nutritional quality of milk and meat. Urea is the most often used form of N fertilizer in Brazil; however, it can experience high losses by volatilization, primarily in pastures with high amounts of senescent biomass. The goal of this study was to evaluate losses by ammonia volatilization from urea coated with Cu, B, and Se. The fertilizer was applied to the soil surface under forage straw residues in cylindric glass chambers under controlled laboratory conditions. The treatments were urea (UR), urea coated with boric acid and copper sulfate (UBC), urea coated with boric acid, copper sulfate, and selenium (UBCS), and ammonium sulfate (AS). Measurements were recorded at regular intervals after fertilizer application for 27 days. High losses occurred from ammonia volatilization of amidic-N sources in the initial days after fertilizer application. The total loss of N by ammonia volatilization according to fertilizer treatment was UR &gt; UBC = UBCS &gt; AS. Urea lost by ammonia volatilization accounted for up to 50% of the N applied, although losses from coated urea treatments UBC and UBCS were 11.45% lower than that of urea. The Cu and B in the coated urea reduced losses by ammonia volatilization and the inclusion of Se had no effect. It is suggested that Se may be added to the Cu and B coating of urea to reduce ammonia volatilization.

Dietary selenium required to achieve body homeostasis and attenuate pro-inflammatory responses in Atlantic salmon post-smolt exceeds the present EU legal limit

Selenium (Se) supplementation either as inorganic or organic form was evaluated in Atlantic salmon post-smolt in vivo and in vitro. The basal diet was formulated to be low in fish meal and contain 0.24 mg Se kg−1; six other diets with Se inclusion of 0.15, 0.4, 0.7 or 1.1 mg kg−1 as sodium selenite (SS) and 0.15 or 0.4 mg kg−1 as L-selenomethionine (SM) were formulated from the basal diet. The diets were fed to Atlantic salmon post-smolt (mean initial weight, 216 ± 27 g) in triplicate groups (35 fish tank−1) and reared in flow-through seawater (33 ppt) at 10–12 °C for 9 weeks. At the end of the feeding trial, whole fish and tissues were sampled for in vivo assessment; whereas, liver cells and head kidney leukocytes (HKL) were isolated and their primary cultures used for in vitro assessment following exposure to hydrogen peroxide (H2O2), lipopolysaccharide (LPS) or poly I:C (PIC). Growth, feed intake, feed conversion ratio, specific growth rate, hepato-somatic index, proximate composition and mineral concentration of the whole fish (except for Se) were unaffected by dietary Se (p > .05). Hematocrit was significantly higher in fish fed the 0.4 mg Se supplemented feeds, irrespective of the Se source (p = .02). The Se concentration in whole body, liver, muscle, plasma, kidney and liver/kidney Se ratio increased with increasing dietary Se concentration (p < .0001). Level of oxidised glutathione (GSSG) in liver and head kidney followed a quadratic function (p < .05) indicating that the concentrations were lower at intermediate SS supplementation of 0.4 and 0.65 mg Se kg−1 (total Se, 0.65 and 0.87 mg Se kg−1). Impact of Se sources on glutathione redox status was similar. Slope-ratio analysis revealed SM to be more efficient than SS in improving apparent availability, whole body or tissues Se status, Se retention and reducing Se loss to the environment. In vitro, the mRNA expression of p38mapk and aif, in liver cells were affected by the impact of dietary Se, but not by the treatment of H2O2 (p < .05). In the HKL, the LPS and PIC induced pro-inflamatory action of il-1β, cox2, nfkβ and viperin were attenuated by SM supplementation, but not by SS (p < .001). Dietary Se supplementation required to the basal diet containing 0.24 mg Se kg−1 was 0.41 mg Se as SS (total 0.65 mg kg−1) or 0.17 mg Se as SM (total 0.41 mg kg−1) based on body Se homeostasis or tissue Se status. SM inclusion at 0.4 mg kg−1 diet (total, 0.65 mg kg−1) attenuated LPS or PIC induced pro-inflammatory responses in vitro. Overall, Se requirement of Atlantic salmon post smolt was 0.27 mg kg−1 diet, on availale basis. Dietary Se level required to maintain body Se homeostasis and improved health status of Atlantic salmon fed plant-based diets (0.65 mg kg−1 diet) exceed the existing EU maximum limit of 0.5 mg Se kg−1 diet. SM as the Se source in salmon feeds has the potential to improve salmon health and reduce Se emissions from Norwegan salmon farming by 60 to 70%.