Amounts Of Selenium Research Articles

Accumulation of trace elements in tea under different soil conditions and the biomechanics-related mechanism of their influence on plant antioxidant enzyme activities

China is an important tea-growing country, and top quality tea, specialty tea and other high-quality tea is more and more favored by the tea industry, so that the production demand is rising year by year. The formation of high quality tea requires suitable soil factors, and soil is one of the two key factors affecting the production of high quality tea. The physicochemical properties and nutrient content of different soils can significantly impact the intracellular processes within tea plants. The absorption and transportation of trace elements such as selenium in tea roots are mediated by specific transporter proteins. These proteins operate based on molecular mechanisms and biomechanical forces that drive the movement of ions across cell membranes. In this paper, we utilize GPS technology to design the distribution area of the test tea production area, and adopt the S-type method to collect the soil of tea differential land in different ecological environments, to explore the physicochemical properties, nutrient content, pH value and water management of different soil types. The whole trace elements and effective trace elements in tea were determined through experiments. The antioxidant enzyme activity of tea was measured by TBA and other methods. The results showed that after planting in different soils, the selenium content of autumn tea was 0.08%, 0.04%, 0.04% in loamy soil > sandy soil = clay soil, respectively. The amount of selenium carried out was sandy soil > loamy soil > clay soil, and the amount of selenium carried out increased by 142.37 kg and 94.97 kg after comparing two by two. Compared with the tea leaves with added trace elements, the T-AOC of the tea leaves without added decreased by 18.75%, 14.20%, 28.06%, and 35.14%. These findings highlight the importance of understanding the cellular and molecular processes in tea plants influenced by soil conditions and trace elements for optimizing tea quality and production.

Dietary Reference Intakes of Selenium for Chinese Residents.

The plasma selenoprotein P (SELENOP) concentration leveling out was thought to represent saturation of the functional selenium body pool and an appropriate supply of selenium to all tissues, indicating that the necessary amount of selenium had been supplied. Based on the selenium intake when SELENOP reaches saturation, the estimated average requirement (EAR) of selenium was set as 50 μg/d, and the recommended nutrient intake (RNI) was 60 μg/d for Chinese general population. According a recent study, "lactating Chinese women with the optimal daily selenium intake" was defined, and the adequate intake (AI) of 0‒6 months old infants was set as 15 μg/d, and 20 μg/d was calculated for 7‒12 months old infants. Considering the negative health effects of intake of excessive nutrient levels of selenium, we recommend reducing the tolerable upper intake level (UL) for adults from 400 μg/d to 255 μg/d based on the results of the Selenium and Vitamin E Cancer Prevention Trial (SELECT). The SELECT trial is a key basis for setting selenium's UL. It has a large sample size and long-term design. Rigorously measures selenium intake and monitors multiple health endpoints precisely. Also, with proper control groups, it effectively determines the threshold of adverse effects, enhancing the reliability of UL determination.

Volatilization and cleaning recovery of Pb, Se and Hg in acid sludge of copper smelting system during vacuum distillation

The high lead acid sludge, containing a small amount of selenium and mercury, is a hazardous waste product of the copper smelting system. Improper disposal of this waste can cause serious harm to the environment. In this study, the method of vacuum distillation was proposed for treating the high lead acid sludge. The study aimed to investigate the volatilization rule of selenium, mercury, and lead in the acid sludge during vacuum distillation, as well as to purify PbSe and metallic lead. The results indicated that under 5 Pa, Hg and Se commence volatilizing at 300 ℃, the content of Hg in volatile substances remains relatively constant after reaching 400 ℃, demonstrating nearly complete volatilization at this temperature with a ratio of 92.93 %. Similarly, selenium almost completely volatilizes at 800 ℃ with a ratio of 96.74 %, while lead does so at around 1000 ℃ with a ratio of approximately 99.27 %. Mercury at 400 ℃ can be recovered as mercury selenide. Lead selenide can be achieved at 800 ℃, while lead sulfate can be decomposed and purified at 1000 ℃ to obtain metallic lead with a purity higher than 99 %. The method can properly treat and recover mercury, selenium, lead and other elements in the acid sludge with short process and no pollution, which provides a new cleaning approach for high lead acid sludge.

The role of selenium in the functioning of immune system components and the incidence of allergies: a content analysis of recent literature

Selenium is an essential trace element. Adequate intake of selenium is necessary for optimal functioning of cellular and humoral processes in the body. Lack of selenium in the diet can lead to aggravation of infectious and allergic diseases and also increase the risk of tumor formation. This review article provides data on the metabolic pathways of selenium and its role in the immune system, as well as the occurrence of allergies and antitumor and antioxidant protection. In detail, the role of selenium is discussed in relation to the implementation of body antiviral defenses. Under conditions of selenium deficiency, numerous viral infections are linked to an unfavorable prognosis, and this article specifically considers the problem of myocarditis occurring during viral infections, summarizing data on the pathogenesis of the condition and possible connections with selenium deficiency. The results of content analysis demonstrate that selenium, participating in the synthesis of selenium-containing enzymes and selenoproteins, ensures the functioning and activity of innate and acquired immunity, antitumour and antioxidant defence, which indirectly affects the course of allergic diseases. Selenium deficiency increases the incidence of allergies, tumours and infections, especially viral infections. In case of viral infections, not only the course of immune reactions depends on sufficient amount of selenium in the organism, but also the possibility of increasing the virulence of the pathogen in case of selenium deficiency. In the case of a severe course of the disease, the main symptoms of infection may be joined by other, more serious manifestations, such as myocarditis. The antioxidant, immunostimulant and antiviral properties of selenium ensure its modifying role in the development of diseases and the percentage of fatalities. Rational consumption of selenium may be of great importance in the prevention, course and determination of outcomes of many diseases, including allergopathology.

Selenium-Rich Black Soldier Fly Supplementation Enriches Serum Indexes and Egg Selenium Content in Laying Hens.

A certain amount of selenium (Se) is usually added to the diet of laying hens to improve the quality and nutritional value of eggs. The present study was carried out to investigate the effect of selenium-rich black soldier fly (BSF) supplementation in diets on laying production performance, egg quality, serum indexes, and egg selenium content of Hy-line variety brown laying hens. A total of 288 at 49-week-old healthy laying hens were divided into 3 treatment groups with 6 replicates per group and 16 hens per replicate using a single-factor completely randomized design. Treatments consisted of (1) control (basal diet without supplemental Se), (2) 0.30mg/kg supplemental Se, (Se as sodium selenite, SS), and (3) 0.30mg/kg supplemental Se (Se as selenium-rich black soldier fly, SE-BSF). Laying performance was not affected by dietary Se. There was no effect of selenium-rich BSF on egg quality (P > 0.05). The contents of malonaldehyde (MDA) were significantly reduced (P < 0.05). On the contrary, dietary Se supplementation increased the activity of superoxide dismutase (SOD, P < 0.05) and catalase (CAT, P < 0.05) and increased the concentration of reduced glutathione (P < 0.05). In addition, selenium-rich BSF supplementation significantly increased the Se content of eggs (P < 0.05). These results indicate that Se supplementation did not affect laying production performance and egg quality of laying hens, but the supplementation could improve antioxidant capacity and increased the Se content of eggs.

Anti-breast cancer activity of biosynthesized selenium nanoparticles using Bacillus coagulans supernatant

BackgroundIn the present study, Selenium Nanoparticles (SeNPs) were prepared using Bacillus coagulans, which is a type of Lactic Acid Bacteria (LAB), and then they were applied to treat breast cancer cells. MethodsThe chemicophysical properties of the bioengineered SeNPs were investigated by Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), zeta potential, dynamic light scattering, Fourier Transform Infrared Spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction analysis (XRD). The cytotoxic potential of SeNPs was evaluated by MTT assay against MCF-7 breast cancer cell line. The expression levels of apoptotic genes including BAX, BCL2, VEGF, ERBB2, CASP3, CASP9, CCNE1, CCND1, MMP2 and MMP9 were determined by real-time PCR. The rate of apoptosis and necrosis of the cancer cells as well as the results of the cell cycle were evaluated by flow cytometry method. ResultsThe synthesized SeNPs had an average particle size of about 24–40 nm and a zeta potential of –16.1 mV, indicating the high stability of SeNPs. EDX results showed presence of SeNPs because amount of selenium in SeNPs was 86.6 % by weight. The cytotoxicity results showed a concentration-dependent effect against MCF-7 cells. The half-maximal inhibitory concentration (IC50) values of B. coagulans supernatant and SeNPs against breast cancer cells were 389.7 µg/mL and 17.56 µg/mL, respectively. In addition, SeNPs synthesized by the green process exhibited enhanced apoptotic potential in MCF-7 cancer cells compared with bacterial supernatants. Cancer cells treated with IC50 concentration of SeNPs induced 32 % apoptosis compared to untreated cells (3 % apoptosis). The gene expression levels of BAX, CASP3, and CASP9 were upregulated, while the expression levels of BCL2, CCNE1, CCND1, MMP2, MMP9, VEGF, and ERBB2 were downregulated after SeNPs treatment of cells. The potential of SeNPs to induce cell apoptosis was demonstrated by the increase in the expression level of BAX gene and the decrease in the expression level of BCL2 after treatment of cancer cells with SeNPs. ConclusionThe obtained results indicated that SeNPs had strong potential to induce significant cell apoptosis and are cytotoxic against the MCF-7 cancer cell line.

Thermodynamics of antimony—selenium alloys formation and evaporation

The thermodynamic functions of alloy formation and evaporation were considered for two particular systems — Sb – Sb2Se3 and Sb2Se3 – Se in connection with the presence of congruently melting compound Sb2Se3 in the antimony—selenium system. The calculations are based on the partial vapor pressure values of the components forming the particular systems. The thermodynamic activity of antimony selenide and selenium as the most volatile components in the systems was calculated based on the saturated vapor pressure values of antimony selenide over the Sb – Sb2Se3 and selenium melts over Sb2Se3 – Se liquid alloys determined by the boiling point method (isothermal variant). Similar functions of the low volatile components in the above systems: Sb in the first system and Sb2Se3 in the latter one was calculated by numerical integration of the Gibbs—Duhem equation using the substitution proposed by Darken. The partial pressures of antimony selenide and antimony over Sb – Sb2Se3 and Sb2Se3 – Se melts were approximated by temperature—concentration relationships. The system is distinguished with a positive deviation from ideality due to the presence of a delamination region in the first system. The partial and integral entropies and enthalpies of the formation of liquid alloys were calculated based on the values of component activities found as the ratio of the partial vapor pressure of an element or compound above the solution to the saturated vapor pressure of a pure element or compound. The partial and integral functions of alloy formation are presented in the form of graphical dependences on the selenium amount in the melt. The obtained thermodynamic constants will replenish the physical and chemical data base and will be used to calculate the boundaries of the vapor— liquid equilibrium fields on the diagram of state, allowing to determine the possibility and completeness of distillation separation of molten systems.

Molecular Precursor Approach to Sulfur-Free CuInSe2: Replacing Thiol Coordination in Soluble Metal Complexes.

Solution-processed CuInSe2 films have generally relied on sulfide or sulfoselenide precursor films that, during the grain growth process, hamper the growth of thicker films and lead to the formation of a fine-grain layer. However, recent research has indicated that sulfur reduction in the precursor film modifies the grain growth mechanism and may enable the fabrication of thicker absorbers that are free of any fine-grain layer. In this work, we pursue direct solution deposition of sulfur-free CuInSe2 films from the molecular precursor approach. To this end, we tune the amine-thiol reactive solvent system and study the changes to the resulting soluble complexes through a combination of analytical techniques. We show that by reactively dissolving indium(III) selenide and selenium in solutions of n-butylamine and 1,2-ethanedithiol, a metal thiolate species is formed, and that this metal thiolate can be modified by isolation from the thiol-containing solvent via precipitation. As the quantity of selenium in the ink increases, the thiol content in the complex decreases, eventually producing soluble [InSex]- species. Extending this method to be used with copper selenide as a copper source, molecular precursor inks can be made for solution-processed, sulfur-free CuInSe2 films. We then show that these CuInSe2 precursor films can be fully coarsened without a fine-grain layer formation, even at the desired thicknesses of 2 μm and greater.

Deep eutectic solvent based on thymol and menthol for microextraction and sensitive UV-Vis determination of total selenium in eggs and chicken tissue

A hydrophobic deep eutectic solvent-based liquid-phase microextraction combined with UV-Vis spectrophotometry was presented for the determination of selenium in eggs and chicken tissue for the first time. Selenium is commonly used in the poultry industry as an additive in broiler feed and its determination in chicken products is important analytical task. In this study, deep eutectic solvents based on terpenoids (thymol and menthol) and fatty acids were investigated as extraction solvents for the sensitive determination of trace selenium amounts by UV-Vis spectrophotometry. The procedure involved microwave digestion of food sample, formation of yellow compound of piazselenol in the presence of selenium (IV) and 3,3′-diaminobenzidine followed by piazselenol microextraction. The quantification of selenium in deep eutectic solvent phase was carried out in a flow cell of a portable UV-Vis spectrometer. The sensitivity was improved by about 300 folds when compared with the UV-Vis spectrophotometry without analyte preconcentration. Deep eutectic solvent based on thymol and menthol provided suitable conditions for analyte detection. The analytical parameters for the quantitative microextraction of analyte were investigated and optimized. Validation of the procedure was performed. The linearity range was 7–150 µg kg−1 (0.14–3 µg L−1) and the limit of detection and limit of quantification were 2 µg kg−1 (0.04 µg L−1) and 7 µg kg−1 (0.14 µg L−1). The proposed procedure was successfully applied to analysis of real eggs and chicken tissue samples. The procedure does not require sophisticated and expensive analytical instrumentation and can be found application in food quality control laboratories.

Effect of Enrichment of Laying Quail Diets with Organic Selenium on Performance and Fresh and Stored Egg Quality

Selenium, which is a good antioxidant, is an essential trace mineral and its organic forms are more available than inorganic forms. Dietary deficiency or excess of this trace mineral causes health problems in poultry, and therefore the amount of selenium in the diet is controversial. The current research was carried out to determine the effect of diets enriched with organic selenium on the performance, egg quality, and stored egg properties in laying quails. In the study, 120 laying quails were allocated to six treatment groups with 20 quails in each, with five subgroups. Quails were fed for 70 days with experimental diet containing 0.12 mg/kg selenium based on corn-soybean meal enriched with the addition of organic selenium (Sel-Plex) at 0.0, 0.2, 0.4, 0.6, 0.8, or 1.0 mg/kg. Body weight change decreased linearly with the addition of 0.6 mg/kg and further levels of organic selenium (P&lt;0.05). Feed intake quadratically increased with the supplementation of organic selenium up to 0.8 mg/kg, but it was minimum at 1.0 mg/kg (P&lt;0.05). The eggshell quality parameters were not affected by the administration of organic selenium to the diet (P&gt;0.05). Albumen pH linearly decreased with organic selenium supplementation up to the level of 0.60 mg/kg, but increased with the addition of higher levels of organic selenium (P&lt;0.05). With the addition of organic selenium to the diet, yolk L* and b* values quadratically and linearly decreased respectively, while a* value increased linearly (P&lt;0.01). Albumen pH value of stored eggs was linearly decreased by treatments (P&lt;0.01), but other parameters did not affect (P&gt;0.05). As a result, it was determined that laying quails can be fed with diets enriched with organic selenium up to 0.4 mg/kg and the eggs could maintain the freshness for a longer time in during storage.

Hair concentrations of selenium in the Moldovan population

BACKGROUND: There is a substantial body of evidence indicating that the ecosystems in the Republic of Moldova contain a significant amount of selenium. However, little is known regarding the levels of this essential element in the hair of the country's population.&#x0D; AIM: To assess hair concentrations of selenium in the population of the Republic of Moldova.&#x0D; METHODS: A cross-sectional study. Hair samples were collected from 301 participants aged 194 years. The data were presented and analyzed by gender and across the following age-groups: under 18, 1844, 4559 and 60+ years old. Determination of hair selenium concentration was carried out by fluorimetric method using Fluorat 02-5M fluorimeter (Lumex, Russia). Hair sample GBW 09101b was used as a reference standard. The statistical software package SPSS 23.0 was used for data processing. Normal distribution of the continuous variables was tested using KolmogorovSmirnov tests with Lilliefors significance correction. MannWhitney tests were used for comparing selenium concentrations while Kruska-Wallis tests were used for selenium concentrations across age-groups.&#x0D; RESULTS: Selenium concentrations in the hair of the population of Moldova ranged between 148 and 5000 g/kg with arithmetic mean (М)=697 g/kg, 95% confidence interval CI: 636758 g/kg, standard deviation (SD)=538 g/kg, geometric mean (G)=598 g/kg, median (Me)=584 g/kg. The average values of selenium concentration in the hair of the women (M=659 g/kg, G=565 g/kg) were significantly lower than those among the men (M=769 g/kg, G=666 g/kg), p=0.004. Geometric means of selenium concentrations increased with age (540585601741 g/kg), p = 0.026.&#x0D; CONCLUSION: This is the first study providing the evidence on hair concentration of selenium among the residents of Moldova. The results are congruent with earlier findings from the neighboring Odesa region of Ukraine with similar biogeochemical conditions. Significant gender differences in the concentration of selenium were observed. Moreover, hair concentration of selenium increased with age.

Synergistic effect of Fe3C quantum dots, N-doped carbon and selenium on high conductive stable host for lithium sulfur batteries

Lithium-sulfur batteries are considered as one of the most promising energy storage devices. However, their development is still hindered by significant obstacles, particularly the well-known "shuttle effect". To overcome the issues, a three-dimensional porous biochar composite GC(Fe3C)x with Fe3C quantum dots/ C heterostructure is prepared by a simple one-stage chemical activation method as a sulfur host. A small amount of selenium is also added to form GC/Fe3C@SSe and improved electrochemical performances are obtained. The influence of Fe3C content on the structure and properties of the composites is investigated. It has been observed that an increase in Fe3C content leads to a reduction in specific surface area, thereby enhancing chemical adsorption while simultaneously weakening physical adsorption. When the Fe3C content reached 2.7%, the composite achieved a specific surface area of 1150.0 m² g−1. The synergistic effect of Fe3C quantum dots, N-doped carbon, and selenium resulted in outstanding electrochemical properties exhibited by the composite. At 1 C, GC/(Fe3C)2.7@SSe provides an initial specific discharge capacity of 803.7 mAh g−1. After 1000 long cycles, the specific discharge capacity is maintained at 363.1 mAh g−1, and the per-cycle capacity loss rate is 0.055%. Even at the current density of 5 C, the initial discharge capacity is 424.5 mAh g−1, and the capacity after 500 cycles is 322.9 mAh g−1, with a single cycle capacity decay rate of 0.048%. This work provides guidance for the design of lithium-sulfur battery cathode materials with synergetic physisorption and chemisorption for inhibiting shuttle effect.

The Problem of Selenium for Human Health—Removal of Selenium from Water and Wastewater

Selenium is a trace element that can be poisonous in small quantities. The aim of this study was to analyze the change in the content of selenium in drinking water, raw water, as well as treated and raw wastewater in an annual cycle in the city of Szczecin. The concentration of Se in samples was determined using the spectrofluorometric method at a 518 nm emission wavelength and a 378 nm excitation wavelength. The amount of selenium in drinking water ranged from &lt;LOD to 0.007 μg/mL, in raw water, from 0.001 to 0.006 μg/mL, in raw wastewater, from 0.001 to 0.008 μg/mL, and in treated wastewater, from 0.001 to 0.009 μg/mL. The selenium content did not exceed the maximum allowable concentration (MAC), 0.010 μg/mL, in any of the water samples tested.

72 A survey of North American horse diets: What are we missing?

Balanced nutrition is critical for the health and well-being of horses. To date, there is limited information on the composition of North American equine diets. Here, we describe an analysis of 200 equine diets and how they compare with NRC requirements. Owners from the US and Canada submitted their diets for review by a nutritionist. They were asked to provide information on their horses’ age, weight, exercise level, diet composition, and health concerns. They were also asked to classify their horses' body condition as underweight (UW), slightly underweight (SU), normal weight (NW), slightly overweight (SO), overweight (OW), or obese (OB). Our sample population includes mature horses of various breeds and exercise levels. Diet nutrient composition was based on guaranteed analyses provided by manufacturers and an average hay analysis corrected for variations in regional soil mineral contents, or the hay analysis submitted by the horse owner where available. Nutrient intakes were compared with each horse's requirements based on their exercise level and body weight, obtained from the NRC, to calculate nutrient intake as a percentage of requirements. Wilcoxon Signed Rank Tests and descriptive statistics were used to analyze the data in Prism. Data are presented asmean intakes as a percentage of requirements ± SEM. Our results revealed that diets were providing an adequate amount of selenium (113 ± 8%) and vitamin E (106 ± 7%). Diets were slightly over-supplying energy (118 ± 1%; P < 0.0001), zinc (125 ± 5%; P = 0.0002), copper (151 ± 6%; P < 0.0001), manganese (132 ± 5%; P < 0.0001), and vitamin A (138 ± 8%; P = 0.001). Protein (191 ± 3%), lysine (203 ± 4%), iron (352 ± 6%), phosphorus (192 ± 4%), calcium (292 ± 7%), magnesium (264 ± 4%), and potassium (680 ± 9%) were appreciably over-supplied (P < 0.0001), and sodium was under-supplied (65 ± 5%; P < 0.0001). Interestingly, all horses except those classified as obese were over-consuming energy (P < 0.004), with average intakes for UW horses being the highest (145 ± 8%), followed by SU (127 ± 5%), OW (122 ± 4%), SO (118 ± 3%), and NW horses (116 ± 2%). Understanding the degree to which horses are meeting or exceeding their nutritional requirements is fundamental for formulating recommendations to support performance, longevity, and overall health. This may inform future avenues of research and outreach to improve the health and well-being of the North American equine population.

Gas Chromatographic Determination of Fatty and Organic Acid Composition in Selenium-Protein Dietary Supplement

Topicality. The use of selenium-protein dietary supplements (SPDS) is relevant from a medical and economic point of view, as it can provide consumers with the required amount of selenium, and increase the value and attractiveness of food products. The diet of a modern person is very diverse in the composition of fatty ingredients. Of all natural fats, dairy is the most complex and unique one in its chemical composition. SPDS “Syvoselen Plus” contains up to 10% fat in its composition, therefore, studies of its composition are of certain scientific interest in view of the above. In many scientific studies, gas chromatography is used to determine the composition of not only the fat fraction of additives containing vegetable oils and animal fats, but also organic acids. The study of the fat fraction and the fraction of organic acids of additives by this method allows determining and predicting the composition of similar fractions in the final product from SPDS. This, in turn, allows for comprehensive control of the quality and composition of such final products. The aim of the article is to determine the quantitative and qualitative composition of fatty and organic acids in the SPDS “Syvoselen Plus” by the gas chromatography method, and to compare the results of the determination with the indicators of a hypothetical ideal fat. When writing the article, statistical and physico-chemical research methods were used, namely, the gas chromatography method, with the help of which the following problems are solved: the composition of the fat fraction of SPDS is determined quantitatively and qualitatively; the degree of correspondence of the main indicators of the fat “Syvoselen Plus” to the hypothetical ideal is established; the composition of organic acids in the additive is determined. Results. The fatty acid composition of milk fat, milk whey and SPDS was studied. Dietary supplement “Syvoselen Plus” contains a significant amount of palmitic (3117.71 mg/kg), stearic (1618.61 mg/kg), oleic (1397.95 mg/kg) and meristic (1296.69) mg/kg) fatty acids, which is confirmed by chromatograms of fat fractions of milk fat and SPDS. The main indicators of hypothetically ideal, milk, whey fats and DDBS were presented. As a result, it was established that the composition of fat, which is most similar to the ideal one, among the objects of the study, has SPDS “Syvoselen Plus” (the indicator of the ratio of the sum of oleic and linoleic acids to the sum of pentadecanoic and stearic acids coincides with the indicator of ideal fat, and the indicators of the ratio of linoleic to linolenic acids and linoleic to oleic acids are close to the values of the indicators of ideal fat). The study of the composition of organic acids of SPDS was carried out. Fractions of succinic, azelaic, and levulinic organic acids are predominant, which may be due to the type of dairy products from which the serum was obtained, the storage conditions of dairy products and the serum itself, the type of microorganisms that carry out the fermentation process and can produce various organic acids, and the production process of dairy products and their composition. Conclusions and discussion. The analysis of the fatty acid composition and the quality content of organic acids in “Syvoselen Plus” dietary supplement confirmed the feasibility of using a dietary supplement in health food technologies, since the latter contains enough polyfunctional fatty and organic acids.

Se‐Induced Fibrous Nano Red P with Superior Conductivity for Sodium Batteries

AbstractRed phosphorus shows great promise as a high‐capacity anode material for Na batteries. Such electrodes that suffered from the fracturing impact of volume change during cycling can be effectively improved by 1D nanomaterials. However, the synthesis of 1D red phosphorus has rarely been studied and employed in sodium batteries. Here, a simple selenium‐induced method to generate fibrous nano red phosphorus is presented. It turns out that a small amount of selenium can not only induce high‐quality fibrous nano red phosphorus from commercial red phosphorus, but also benefit qualitatively to the sodium ionic conductivity. Interestingly, the selenium dopant can also manipulate the chemical state of phosphorus leading to valence tunability which is able to tolerate structural stability under the Na‐rich or Na‐poor condition. As a result, the optimal fibrous nano red phosphorus used as anode outperforms over the traditional red phosphorus ≈6 and ≈10 times in terms of rate performance and cycle stability, respectively. Furthermore, as employed for sodium metal anode protection, the symmetrical cell cycling maintains long stable at a low polarization voltage for over 1000 h. The full cell performs excellent cycling stability of 1500 cycles at 3 C and high‐rate performance up to 30 C.

Humic acid chelated selenium is suitable for wheat biofortification.

Selenium rich bread is a good carrier of selenium, but the inorganic selenium used in the actual production process is toxic. It is necessary to develop a new green bread production technology. The extraction and utilization of humic acid chelated selenium from selenium-rich soil is beneficial for reducing resource waste and pollution without destroying the soil ecosystem in selenium-deficient areas. Sodium selenite and nanoselenium were selected as controls because they are commonly used as selenium agronomic enhancers in production. Humic acid chelated selenium can be absorbed and accumulated by wheat leaves, and humic acid chelated selenium had no significant effect on wheat yield, which was also shown in the treatments with nanoselenium and sodium selenite. Excessive accumulation of selenium in wheat grains can lead to a deterioration of processing quality. Among them, the use of excessive nanoselenium at the filling stage inhibited the accumulation of wheat grain protein, whereas humic acid chelated selenium is beneficial to grain protein accumulation and has the least negative effect on the processing quality. The accumulation of excessive selenium in wheat seeds had a negative effect on seed germination and growth; specifically, the seed vigor of wheat treated with humic acid chelated selenium was higher than that of untreated wheat. Humic acid chelated selenium is particularly suitable for the whole process of Se-enriched bread wheat production. The seed vigour of wheat treated with humic acid chelated selenium, which supplied a moderate amount of selenium, was higher than that of untreated wheat. Conversely, the accumulation of excessive selenium in wheat seeds reduced germination and seedling growth. © 2023 Society of Chemical Industry.

Selenium and thyroid diseases.

Selenium, a non-metallic element, is a micronutrient essential for the biosynthesis of selenoproteins containing selenocysteine. In adults, the thyroid contains the highest amount of selenium per gram of tissue. Most known selenoproteins, such as glutathione peroxidase, are expressed in the thyroid and are involved in thyroid hormone metabolism, redox state regulation, and maintenance of cellular homeostasis. Some clinical studies have shown that lack of selenium will increase the prevalence of several kinds of thyroid diseases. Selenium treatment in patients with Graves' orbitopathy has been shown to delay disease progression and improve the quality of life. Selenium supplementation in Hashimoto's thyroiditis was associated with the decreased levels of anti-thyroid peroxidase antibody and improved thyroid ultrasound structure. In thyroid cancer, various selenium supplements have shown variable anticancer activity. However, published results remain the conflicting and more clinical evidence is still needed to determine the clinical significance of selenium. This article reviews the strong association between selenium and thyroid disease and provides new ideas for the clinical management of selenium in thyroid disease.

Isolation of novel chemical components and their plant target proteins under selenium stress.

Selenium is recognized as a beneficial nutrient in living organisms. Excessive amounts of selenium, however, can have a significant negative impact on organisms. Screening of novel chemical compounds that regulate and/or moderate selenium in plants was conducted. The present chapter discusses (1) the design of a chemical screening strategy, (2) methods used to identify and select candidate chemicals, and (3) the identification of chemical-binding target proteins. We identified a novel chemical compound, C9H8N2OS2, in our screening program that enhances selenate accumulation and stress tolerance. The target protein, beta-glucosidase 23, in Arabidopsis was found to regulate selenium accumulation, as well as plant response to selenate stress.

Thermal neutrons effect on improvement of electrical properties at CIGS thin film derived by sol-gel dip coating technique

The thermal neutron effect on the copper indium gallium (di)selenide thin film synthesized by the sol-gel dip-coating technique has explained the novel use of this film under extreme conditions (such as neutron irradiation fields). The thin film samples were treated by using the reactor neutrons to obtain the optimum neutron treatment for the determination of the variations in the structural characteristics. The gamma filter system has provided the evaluation of the high thermal neutron flux effect on the thin film samples by using the tangential beam tube of ITU TRIGA Mark–II reactor. The influence of the neutron effect on the electrical and optical features was explained by the rise of selenium amount in the thin film. The neutron-treated thin film samples (at 50 at. % Se) had a significant effect on the lowest electrical resistivity depending on the increase of the film density. The equivalent gamma dose of the neutron-treated thin film was determined as a 0.024 Gy dose level for neutron irradiation. The neutron treatment was significant to evaluate the decrease in the sheet resistivity of the thin film at this dose level. The neutron dose has led to a slight decrease in the optical band gap as the result of the thermal and epithermal neutrons' effects on the thin film.