Se Source Research Articles

Total Selenium Level and Its Distribution between Organs in Beef Cattle in Different Selenium Status.

The aim of this study was to determine the Se concentration in the main tissues of beef cattle and to evaluate the differences in tissue distribution between animals with different selenium status. Selenium concentration was determined in the serum, longissimus dorsi muscle, semitendinosus muscle, kidney, heart, liver, spleen and lungs of cows, heifers and beef bulls, using spectrofluorimetric method. Despite receiving supplementation, 55.6% animals demonstrated an optimal Se level, while 44.4% were deficient. The mean serum Se concentration was significantly higher (p < 0.05) in animals with a normal Se status than in Se-deficient animals. Differences in Se tissue distribution were observed between Se-deficient animals and those with normal Se status. The organs most susceptible to Se deficiency are the semitendinosus muscle, lungs, heart and liver. In both normal and Se-deficient animals, significantly higher Se concentrations were observed in the kidney than other organs (p < 0.05), and the lowest in the muscles. As Se deficiencies can be found among supplemented animals, the level of Se should be monitored in beef cattle in order to detect possible Se deficiencies, which may have negative health effects for animals and reduce the value of animal products as a source of Se in the human diet.

Effects of various selenium-enriched yeasts, selenomethionine, and nanoselenium on production performance, quality, and antioxidant capacity in laying hens

This study aimed to compare the effects of various selenium (Se) sources (2 mg/kg) on the performance, quality, and antioxidant capacity of laying hens as well as the Se content in their eggs and blood. We selected 720 34-wk-old Lohmann pink-shell laying hens were randomly assigned into 6 groups and fed a basal diet (control) or a basal diet supplemented with various Se sources (Se-enriched yeast, SY-A, SY-C, SY-N; selenomethionine SM, nano-Se SN) for 16 wk. There were 10 replicates of 120 hens per group. Dietary Se supplementation increased the egg production rate of all laying hens. Egg and serum Se deposition was highest in the SM group. Yolk color scores of SY-A and SY-N groups were significantly lower than those of other groups (P < 0.01). The protein height and Haugh unit were significantly lower in the SN group than in the other groups (P < 0.05). The yolk height was significantly higher in the SN and SY-N groups than in the SY-A group (P < 0.05). Dietary supplementation of selenium can improve the antioxidant capacity of laying hens. The SOD content of SM group was significantly lower than that of SY-A and SN group (P < 0.05). The malondialdehyde (MDA) content was significantly higher in the SM group than in the SY-A group (P < 0.05). The present work empirically demonstrated that the production performance of laying hens supplemented with 2 mg/kg Se was superior to that of the hens receiving only a basal diet. The SY-C group exhibited the best production performance, the SY-A group had the highest antioxidant capacity, and the SM group produced eggs with the highest level of Se enrichment.

Response of rumen fermentation and microbiota to dietary supplementation of sodium selenite and bio-nanostructured selenium in lactating Barki sheep

Dietary selenium (Se) sources affects the structure of the rumen microbial community and rumen fermentation. This study evaluated the effects of sodium selenite (SS) and bio-nanostructured selenium (SeNSM) on rumen fermentation and structure of rumen microbial community of lactating Barki ewes. Twenty one lactating Barki ewes were assigned into three groups based on their body weight and milk yield. The experiment lasted for 50 days, whenever, the control group was fed basal diet; group SS received basal diets plus sodium selenite as inorganic source of Se; and group SeNSM received basal diet plus organic selenium bio-nanostructured. Ruminal pH and volatile Fatty Acids (VFA) was lower (P < 0.05) in SeNSM group compared to control. Principle Coordinate Analysis separated the microbial communities into three clusters based on feeding treatment. The bacterial community was dominated by phylum Bacteroidetes and Firmicutes that were affected (P < 0.05) by Se sources. Specifically Bacteriodetes was higher (P < 0.05) in SS and SeNSM groups; and Firmicutes was higher (P < 0.05) in the control group. Moreover, the predominant bacterial genera were Prevotella, Rikenellaceae RC9 gut group, Unclassified_Bacteroidales, which were higher (P < 0.05) in SeNSM group. The methanogenic community belonged to phylum Euryarchaeota and was significantly decreased (P < 0.05) by Se supplementation. Principal component analysis based on rumen fermentation parameters, and relative abundances of bacteria and methanogens revealed three distinct clusters. These findings suggest that Se supplementation affected the relative abundances of dominant bacterial groups, declined rumen methanogens and SeNSM supplementation showed some positive impacts on some fibrolytic bacteria.

The Influence of Synthetic Parameters on HgSe QDs.

HgSe quantum dots (QDs) were synthesized by a thermal injection method. The effects of material ratio, growth time, and reaction temperature on the growth and spectral properties of the QDs have been studied. The experimental results show that the QDs had the highest yield of 53.04% when the molar ratio of Se source to Hg source was 1.5. Also, the excess source of SeS2 was reduced to Se. In addition, the critical radius and spectral red-shift rate of QDs can be increased with the reaction temperature. When the reaction temperature was increased to 100 °C, the spectrum reached far-infrared and the growth rate was increased to 10 times and reached 0.63 nm/min. Differing particle morphologies can be obtained by increasing the growth time to 40 min. Moreover, the growth rate reached the minimum at 30 min and the maximum at 80 min of the growth time. This study can provide guidance for the synthesis of long-wave infrared QD materials.

Effect of abscisic acid on selenium uptake and growth of Cyphomandra betacea Sendt. (Solanum betaceum Cav.) seedlings under selenium stress

Improvement of selenium (Se) uptake in fruit tree can improve the source of food Se for humans. In this study, the effect of various abscisic acid (ABA) concentrations on the Se uptake in Cyphomandra betacea Sendt. (Solanum betaceum Cav.) seedlings was studied under Se stress. Only the concentration of 20 μmol/L ABA promoted the growth of C. betacea seedlings by increasing the biomass and regulating the resistance physiology under Se stress. ABA also increased the Se content in C. betacea seedlings under Se stress. The concentration of ABA at 20 μmol/L got the maximum root Se and shoot Se contents, which increased by 76.64% and 55.83%, respectively, compared with the control. Correlation and grey relational analyses showed that the peroxidase activity and proline content had the first two closest relationship with the shoot Se content. This study shows that ABA can promote the Se uptake in C. betacea under Se stress, and the concentration of 20 μmol/L ABA is the optimum for Se uptake and growth of C. betacea.

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.

PSXIII-12 Effects of Dietary Mixed Sources of Selenium Supplementation on Immune Responses, Stress Parameter and Gut Microbiota of Weaned Pigs

Abstract Selenium (Se) is a micro-essential mineral, following the amount of Se can be appeared as selenosis or deficiency disease. Its representative role was the main compound of glutathione peroxidase as known antioxidant enzyme. This role closely relates to health of piglets. Popular form of Se was divided into organic Se (Ose) and inorganic Se (Ise) forms. Ose has greater bioavailability and costs and reduced toxicity than Ise. Mixed Se sources can save costs and improve bioavailability compared with single-source Se. This study was conducted to investigate the effects of dietary mixed Se supplementation on immune responses, stress parameter and gut microbiota of weaned pigs. Weaned pigs [n = 156; 7.85 ± 0.10 kg of initial body weight (BW)] were allotted to three dietary treatments (4 pigs/pen; 13 replicates/treatment) in a randomized complete block design (block: initial BW and sex) for 6 weeks. Dietary treatments were a corn-soybean based diet except for Se (CON), CON + 0.15 ppm Ose + 0.15 ppm Ise (A), and CON + 0.25 ppm Ose + 0.25 ppm Ise (B). On day 7, 14, and 42, blood samples were collected from randomly selected 6 pigs per treatment. The collected samples were used for immune responses and stress parameters like tumor necrosis factor-alpha, transforming growth factor beta1, interleukin-1beta, interleukin-6, and cortisol by using ELISA kits. On day 42, samples were collected to analyze microbial communities of pigs by 16s rRNA sequencing method. Microbial communities were analyzed using QIIME. The microbial alpha diversity indices such as number of OTUs, Chao1, Shannon, and Inverse Simpson were calculated to measure the within-sample diversity and richness at the species level. The microbial beta diversity was performed to inter-sample dissimilarities using weighted UniFrac distances based on principal coordinate analysis. Data were analyzed using PROC MIXED procedure of SAS. The experimental unit was a pen. The statistical model for immune responses, stress parameters and gut microbiota included dietary treatment as main effect and initial BW as a covariate. No differences were found on immune responses and stress parameters among dietary treatments. The number of OTUs, Chao1, Shannon, and Inverse Simpson were not different among dietary treatments. The Se increased (P &amp;lt; 0.05) relative abundance of phylum Bacteroidetes but decreased (P &amp;lt; 0.05) phylum Firmicutes. In addition, the Se increased (P &amp;lt; 0.05) relative abundance of genus Barnesiella but decreased (P &amp;lt; 0.05) genus Lactobacillus. In conclusion, addition of 0.3 and 0.5 ppm mixed Se can alter gut microbiota.

112 Effect of Selenium Sources on Sow Productive and Reproductive Performance and Their Progeny

Abstract Dietary selenium (Se) supplementation is a standard practice, using either an inorganic form, such as sodium selenite (SS) or organic forms, like SeYeasts (SY) or pure forms of selenomethionine (SeMet). Hydroxy-selenomethionine (OH-SeMet) is a chemically synthesized organic Se form and has been proven to be efficient in transferring Se from the diet to muscle compared with SS or SY products. The transfer of Se in tissues, in fact, leads to the buildup of a Se reserve as SeMet in the body that participates in maintaining effective antioxidant defenses and supports animal performance, particularly under challenging conditions. This trial aimed to determine the effects of different Se sources on the productive and reproductive performance of sows and on their progeny. Sows (n = 120) were allocated in individual cages in one of the three treatments according to the number of parities, number of piglets in previous parturition, body condition score and initial body weight. The experiment lasted 141 days (from the insemination of sows up to the weaning of the piglets at 21 days). A corn-soybean-based basal diet was formulated to meet the nutrient requirements of the sows during gestation and lactation. The Se supplementation was 0.35 ppm of Se either from SS, SY or OH-SeMet. The number of total piglets born showed a tendency (P = 0.06) for treatments fed organic Se sources (15.6 OH-SeMet; 15.4 SY vs 14 SS) with no differences on the litter weight at birth. However, sows fed OH-SeMet weaned more piglets (13.4) than the other treatments (12.5 SY and 12.2 SS, respectively, P &amp;lt; 0.01). The litter weight at weaning showed no differences among treatments (73.4, 70.4 and 75.9kg for SS, SY and OH-SeMet, respectively). The feed conversion of the sows during lactation was also affected by the Se source, in which OH-SeMet showed a significantly reduced FCR of 2.6 vs 3.0 and 3.1 for SS and SY, respectively (P &amp;lt; 0.01). Piglets fed organic sources showed a decreased diarrhea incidence (scores 2 and 3) compared with SS (P &amp;lt; 0.001), respectively, 5.68 vs 3.28 and 3.27%. The Se concentration of sows’ colostrum and milk of sows were numerically improved from SS to SY, but only significantly greater on OH-SeMet treatment. The same pattern of Se concentration in the milk was observed in the serum of piglets 48 h after birth (142, 122 and 228 μg/kg for SS, SY and OH-SeMet, respectively) and at weaning (85, 85 and 117 μg/kg for SS, SY and OH-SeMet, respectively). Feeding pure forms of organic Se, such as OH-SeMet supports the productive and reproductive performance of sows and improve the Se status of the progeny. Organic Se also reduces the diarrhea of piglets, compared with SS.

Biotransformation of se-methylselenocysteine into volatile selenocompounds by bacteria isolated from rat gut microflora

Selenium (Se) is an essential micronutrient that exists in various chemical forms in nature. Because of this property, animals must metabolize diverse Se species to utilize them as selenoproteins. Although gut microflora is suggested to play a role in Se metabolism in host animal, the biotransformation of Se by gut microflora in animal gut is not fully understood. In this study, we isolated Morganella morganii from rat feces under the condition that Se-methylseleno-L-cysteine (MeSeCys), one of the major Se sources in vegetables, was present in excess. Then, we examined the biotransformation of MeSeCys by M. morganii. Two volatile selenocompounds, dimethyldiselenide (DMDSe) and dimethylselenide (DMSe), were detected by GC–MS in the headspace of M. morganii culture. We speculate that M. morganii cleaved off the methylselenyl group from MeSeCys. Taken together, we conclude that gut microflora plays a role in the biotransformation of MeSeCys, and seems to support efficient metabolism in animals.

Different Dietary Sources of Selenium Alleviate Hepatic Lipid Metabolism Disorder of Heat-Stressed Broilers by Relieving Endoplasmic Reticulum Stress.

As global warming continues, the phenomenon of heat stress (HS) in broilers occurs frequently. The alleviating effect of different selenium (Se) sources on HS-induced hepatic lipid metabolism disorders in broilers remains unclear. This study compared the protective effects of four Se sources (sodium selenite; selenium yeast; selenomethionine; nano-Se) on HS-induced hepatic lipid metabolism disorder and the corresponding response of selenotranscriptome in the liver of broilers. The results showed that HS-induced liver injury and hepatic lipid metabolism disorder, which were reflected in the increased activity of serum alanine aminotransferase (ALT), the increased concentration of triacylglycerol (TG) and total cholesterol (TC), the increased activity of acetyl-CoA carboxylase (ACC), diacylglycerol O-acyltransferase (DGAT) and fatty acid synthase (FAS), and the decreased activity of hepatic lipase (HL) in the liver. The hepatic lipid metabolism disorder was accompanied by the increased mRNA expression of lipid synthesis related-genes, the decreased expression of lipidolysis-related genes, and the increased expression of endoplasmic reticulum (ER) stress biomarkers (PERK, IRE1, ATF6, GRP78). The dietary supplementation of four Se sources exhibited similar protective effects. Four Se sources increased liver Se concentration and promoted the expression of selenotranscriptome and several key selenoproteins, enhanced liver antioxidant capacity and alleviated HS-induced ER stress, and thus resisted the hepatic lipid metabolism disorders of broilers exposed to HS. In conclusion, dietary supplementation of four Se sources (0.3 mg/kg) exhibited similar protective effects on HS-induced hepatic lipid metabolism disorders of broilers, and the protective effect is connected to the relieving of ER stress.

Spatial bandgap tailoring via a novel injection chemical bath deposition enables highly efficient carbon-based Sb2(S,Se)3 thin film solar cells

In recent years, significant progress has been made in the fabrication of sulfoselenide Sb2(S,Se)3 solar cells using a widely adopted hydrothermal method. However, the record efficiency is still far behind the theoretical values partly due to an unfavorable spatial bandgap distribution, which is induced by the complicated chalcogenide growth kinetics of the hydrothermal synthesis. Herein, a novel solution growth method, called Injection Chemical Bath Deposition (ICBD), is developed to prepare Sb2(S,Se)3 alloys for the first time. With this open CBD process, the selenium (Se) source is facilely incorporated during intermediate stages of reaction, and then successfully constructing a V-shaped bandgap via carefully tailoring the vertical gradients in chemical constituents, which synergistically enhances light absorption and carrier separation in the Sb2(S,Se)3 absorber. As a result, the solar cell with a full-inorganic FTO/CdS/Sb2(S,Se)3/Carbon structure achieves an impressive conversion efficiency of 7.63 %, which is among the highest efficiency of carbon-based Sb2(S,Se)3 solar cells based on CBD method. This study demonstrates a flexible strategy for manipulating the gradient band gap for highly efficient Sb2(S,Se)3 solar cells.

Assessment of potential risks to human health associated with trace elements in three commercially important shark species captured in the Central Mexican Pacific.

Shark meat is a popular protein source worldwide. However, existing national control policies for ensuring the safety and quality of shark meat are minimal. There are concerns about the sustainability of shark populations, which bioaccumulate and biomagnify potentially toxic elements at higher rates than non-predatory fish, posing a risk to human health. In this study, the contributions of essential elements to the Recommended Dietary Allowance (RDA) and potentially toxic elements to the Reference Dose (RfD) linked to shark consumption (200g per week) were investigated for three shark species in the Central Mexican Pacific. We estimated risks and benefits for women, children, and men. Our results suggest that the three shark species are sources of Se, Co, Cr, Cu, Fe, and Zn, but poor sources of Mn for women and men aged 19-50years. A weekly ingestion of 200g of shark meat exceeded the RfD-As by 4-14 times and the RfD-Pb by 1.1-1.7 times for adults, indicating a potential risk to human health. The three shark species were also significant sources of potentially toxic elements for children, including Hg, Cd, Cr, and Pb. An excessive intake of Se was observed, with levels at 8.4-10.6 and 4.3-5.3 times the RDA for children aged 1-8 and 9-13years, respectively. Although shark meat can be a good source of essential nutrients, the lack of controls in the commercialization process indicates that it should be consumed in moderation due to the potential risks associated with excessive exposure to potentially toxic elements. This caution is particularly important for children and pregnant women, who are at higher risk of health complications from consuming contaminated food.

Comparative Evaluation of Yeast Selenium and Sodium selenite Supplementation on Fertility, Hatchability and Antioxidant Status in Dual Purpose Laying Hens

Selenium (Se) is an essential trace element, involved in many biological processes in animals, such as antioxidant status, reproduction, immunity, reproduction, and thyroid hormone metabolism. Dual purpose Giriraja (180) hens of 30 weeks of age were randomly distributed into 4 treatment groups having 5 replicates of 10 (1 male + 9 females) birds each. Treatment groups were divided based on additional selenium supplementation to the basal diet. Accordingly, the basal diet was T1, with further addition of sodium selenite, sodium selenite + selenium-enriched yeast and selenium enriched yeast @ 0.5, 0.3 + 0.2, and 0.5 mg Se/kg basal diet to form diets for T2, T3, and T4, respectively. The experimental period was for 8 weeks @ 150g feed/day/bird. Fertility, hatchability and antioxidant status viz., levels of Glutathione peroxidase, Superoxide dismutase and Catalase were assessed. The addition of different sources of Se alone and their combination did not show any significant difference in fertility and hatchability parameters at the end of 4th and 8th weeks of the study. Similarly, no significant improvement was seen in the antioxidant status of the birds at the end of the experiment. In conclusion, the requirement of selenium, in layer (0.05-0.08mg/kg diet) can be met with the amount of Se present in the feed raw material. Hence additional selenium supplementation may not be required under normal environment and production conditions.

Advances in selenium supplementation: From selenium-enriched yeast to potential selenium-enriched insects, and selenium nanoparticles.

Selenium (Se) is an essential micronutrient that plays an important role in animal and human development and physiological homoeostasis. This review surveys the role of Se in the environment, plants and animal bodies, and discusses data on Se biofortification with different sources of supplementation, from inorganic to organic forms, with special focus on Se-enriched yeast (Se-yeast). Although Se-yeast remains one of the main sources of organic Se, other emerging and innovative sources are reviewed, such as Se-enriched insects and Se-nanoparticles and their potential use in animal nutrition. Se-enriched insects are discussed as an option for supplying Se in organic form to livestock diets. Se-nanoparticles are also discussed, as they represent a more biocompatible and less toxic source of inorganic Se for animal organisms, compared to selenite and selenate. We also provide up to date information on the legal framework in the EU, USA, and Canada of Se that is contained in feed additives. From the scientific evidence available in the literature, it can be concluded that among the inorganic forms, sodium selenite is still one of the main options, whereas Se-yeast remains the primary organic form. However, other potential sources such as Se-enriched insects and Se-nanoparticles are being investigated as they could potentially combine a high bioavailability and reduced Se emissions in the environment.

Potential role of selenium in modifying the effect of maternal methylmercury exposure on child neurodevelopment – A review

Selenium (Se) is an essential trace element for normal neurodevelopment. It is incorporated into multiple selenoenzymes which have roles in the brain and neurological function, the synthesis of thyroid hormones, the antioxidant defense system, DNA synthesis, and reproduction. Fish is a source of both Se and neurotoxic methylmercury (MeHg). Selenium is known to ameliorate the effects of MeHg in experimental animals, but studies in children exposed to both Se and MeHg through prenatal fish consumption have been inconclusive. Research on Se's implications for pregnancy and child neurodevelopment is limited. The aims of this review are to summarize the literature on the biological roles of Se during pregnancy and the potential role in mitigating the effects of MeHg exposure from fish consumption on human health. This review has shown that Se concentrations among pregnant women globally appear insufficient, with the majority of pregnant women reporting Se concentrations below 70 µg/L during pregnancy. The role of Se in child development and its interactions with MeHg in children are inconclusive. Further investigation of the interaction between Se and MeHg in relation to child neurodevelopment in high fish-eating populations is required to fully elucidate effects.

Soil selenium enrichment in the Loess Plateau of China: Geogenic evidence, spatial distribution, and it's influence factors

The selenium (Se)-deficient soil belt in China has gained widespread attention. During large-scale soil surveys in China, Se-rich soils within low-Se belts have been identified. However, the sources of Se in those soils and the controlling factors for their enrichment remain unclear. Here we summarize Se concentrations and spatial distributions in the Yuanzhou district of the Loess Plateau. We evaluated Se variations in soil profiles, Se migration into water bodies, and considered soil indicators, topographic characteristics and the influence of land-use types on soil Se concentrations. The average Se concentration in the topsoil of the Yuanzhou district was 0.164 μg/g. High-Se soils (>0.222 μg/g) were found in the western valley plain and the southern red bed hilly area, as well as sporadically in higher elevation forestland and grassland areas in the east. Enrichment of Se in the topsoil in the eastern and southern areas was primarily due to Se adsorption and accumulation by soil organic matter as well as enrichment in gypsum, berlinite, and clay minerals during soil formation. Widespread enrichment in the southern area was linked to high Se concentrations in red Tertiary sedimentary rocks. In the western area, enrichment of Se in topsoil was found on both sides of the Qingshui River at low elevations with gentle slopes, with river water being the primary carrier of Se enrichment. These findings provide valuable insights into the epigenetic geochemical behavior of soil Se in China's low-Se belt that accounts for development of Se-rich soils in the region.

Synthesis of polymorphic CoSe2@MoSe2 microspheres with hollow and core-shell structures for electromagnetic wave absorption

Structure design and surface morphology control are effective strategies for preparing electromagnetic wave absorbing (EWA) materials with superior performance. In this work, Co microspheres with large diameters and rough surfaces were prepared by a simple solvothermal reaction. Then, through a one-pot hydrothermal reaction with Se and Mo sources, the Co was changed into polymorphic CoSe2 and loaded with a layer of MoSe2 nanosheets. Moreover, as the Co cations migrated outside to react with Se, free space was generated inside the spheres; thus, hollow and core-shell structures were achieved. The synthesized CoSe2@MoSe2 complex can cause dielectric and magnetic loss at the same time, achieving a minimum reflection loss of -45 dB and a maximum effective absorption bandwidth of 6 GHz. This work provides insight regarding the utility and massive synthesis of Co microspheres and advanced EWA materials with unique structures and diverse loss modes.

Novel Sb2S3-xSex photocathode decorated NiFe-LDH hole blocking layer with enhanced photoelectrochemical performance

The alloyed Sb2S3-xSex has attracted widespread attention as a promising light absorbing material in recent years because it has the advantages of both Sb2S3 and Sb2Se3, such as adjustable band gap in the range of 1.1–1.8 eV and good stability. However, expensive selenourea enormously increases its manufacturing cost. In this paper, using Se powder as Se source, high-quality and low-cost Sb2S3-xSex film photoelectrode is successfully prepared by one-step hydrothermal method, and applied to photoelectrochemical (PEC) water splitting. Furthermore, with the help of NiFe-layered double hydroxide (LDH) modification, an increase in photocurrent density from −0.22 mA cm−2 to −1.21 mA cm−2 at 0 VRHE is achieved, and the onset potential is positively shifted by 120 mV. NiFe-LDH significantly improve hydrogen evolution reaction (HER) performance. The relevant characterization can confirm that this is mainly due to the blocking effect of NiFe-LDH on photogenerated holes, promoting effect of Ni2+ on the kinetics of hydrogen evolution reactions, and the strengthening of bulk charge separation efficiency. Undoubtedly, this work opens up a simple and effective way for the development of low-cost, high-efficiency antimony chalcogenides photoelectrodes, and provides new ideas for its excellent application in the field of PEC water splitting.

Synthesis and Assembly of Core–Shell Nanorods with High Quantum Yield and Linear Polarization

AbstractThe seeded growth method offers an efficient way to design core–shell semiconductor nanocrystals in the liquid phase. The combination of seed and shell materials offers wide tunability of morphologies and photophysical properties. Also, semiconductor nanorods (NRs) exhibit unique polarized luminescence which can potentially break the theoretical limit of external quantum efficiency in light emitting diodes based on spherical quantum dots. Although rod‐in‐rod core–shell NRs present higher degree of polarization, most studies have focused on dot‐in‐rod core–shell NRs due to the difficulties in achieving uniform NR seeds. Here, this study prepares high‐quality uniform CdSe NRs by improving the reactivity of the Se source, using a secondary phosphine, namely diphenylphosphine, to dissolve the Se power, along with the conventional tertiary phosphine, namely trioctylphosphine. Starting from these high‐quality NR seeds, this study synthesizes CdSe/CdxZn1−xS/ZnS core–shell NRs with narrow emission bandwidth (29 nm at 620 nm), high PLQY (89%) and high linear polarization (p = 0.90). This study then assembles these core–shell NRs using the confined assembly method and fabricates long‐range‐ordered microarrays with programmable patterns and displaying highly polarized emission (p = 0.80). This study highlights the great potential of NRs for application in liquid crystal displays and full‐color light emitting diodes displays.

The effect of replacing sodium selenite with selenium-chitosan in laying hens on production performance, egg quality, egg selenium concentration, microbial population, immunological response, antioxidant enzymes, and fatty acid composition

The purpose of this study was to investigate into the effects of Se-chitosan and Na selenite supplementation on laying hen production performance, egg quality, egg Se concentration, microbial population, immunological response, antioxidant enzymes activity, and yolk fatty acid profile. Using a 2×2 factorial design, 168 27-wk-old laying hens were randomly divided into 4 treatment groups and 7 replications. Se source (Na selenite and Se-chitosan) and Se level (0.3 and 0.6 mg/kg) were used as treatments. Se-chitosan enhanced egg production percentage and egg mass (P < 0.05) when compared with Na selenite. There was an interaction, with 0.6 mg Se-chitosan/kg causing an increase in albumen height, Haugh unit, albumen index, and shell thickness of fresh eggs (P < 0.05). Se-chitosan increased yolk share, yolk color, and shape index of fresh eggs and shape index, albumen index, albumen height, Haugh unit, yolk color, shell thickness, and specific gravity of stored eggs (P < 0.05). The interaction showed that, 0.6 mg Se-chitosan/kg increased albumen Se concentration and decreased the level of malondialdehyde (MDA) in fresh egg yolk compared with 0.3 and 0.6 mg Na selenite/kg (P < 0.05). When compared with Na selenite, Se-chitosan increased the Se concentration in the yolk and decreased level of MDA in stored egg yolk (P < 0.01). When compared with Na selenite, Se-chitosan reduced coliforms (P < 0.01), increased lactic acid bacteria, and the lactic acid bacteria/coliform ratio (P < 0.05). Se-chitosan supplementation increased antibody response to sheep red blood cells and IgM titers and the activities of glutathione peroxidase and superoxide dismutase in plasma (P < 0.05). Furthermore, compared with Na selenite, supplementing diets with Se-chitosan decreased ∑ n-6 PUFA/∑ n-3 PUFA ratio (P < 0.01). In conclusion, Se-chitosan supplementation of laying hen feed improved production performance, egg quality, egg Se concentration, yolk lipid oxidation, microbial population, immune response, antioxidant enzymes activity, and yolk fatty acid profile, with 0.6 mg Se-chitosan/kg supplementation being optimal.