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The effects of selenite (0, 15, 30, 45 mg L-1) on physiological characteristics and medicinal components of Paeonia ostii were analyzed. The results showed that selenite application promoted the activity of superoxide dismutase and the contents of soluble sugar, proline, carotenoids, total flavonoids, and total polyphenols, and decreased the contents of reactive oxygen species, relative electrical conductivity, and malondialdehyde. In addition, selenite also increased chlorophyll content, improved electron transfer ability, PSI and PSII performance, and the coordination between PSI and PSII, which significantly improved photosynthetic capacity. Moreover, selenite treatment also greatly increased the contents of gallic acid, catechin, albiflorin, paeoniflorin, benzoic acid, and paeonol in Moutan cortex radicis (MCR). These results showed that selenite effectively protected the photosynthetic apparatus from photooxidative damage by enhancing antioxidant capacity, improving photosynthetic capacity, and increasing the content of the medicinal compounds in MCR.

Drug combination is considered to be an effective approach to improve the efficacy of cancer therapy and chemoprevention. Selenite, a representative of inorganic form of selenium, and butyrate, a major short-chain fatty acid, are two well-documented colon cancer dietary chemopreventive agents with distinct molecular mechanisms. We hypothesized that combination of selenite and butyrate might produce improved outcome against colon cancer. This hypothesis was tested using both HCT116 human colon cancer cells and its xenograft mouse model in the present study. The in vitro study showed a synergistically inhibitory effect on HCT116 colon cancer cells but not on NCM460 normal human colon mucosal epithelial cells. Consistent with the in vitro study, results of the xenograft mouse model further demonstrated that combination of selenite and butyrate led to improved efficacy in comparison with each agent alone. Mechanistically, the induction of alanine-serine-cysteine transporter 2 (ASCT2) by selenite repressed its inhibitory effect on colon cancer cells, which was reversed by its co-treatment with butyrate. The findings of the present study denote the likely potential for developing selenite/butyrate combination remedy to combat against colon cancer. [ABSTRACT FROM AUTHOR]

AbstractPurposeMethodsResultsConclusionsTo evaluate the protective role of Laurus Nobilis eye drops on selenite-induced cataracts in suckling rabbits.Fifteen male albino suckling rabbits with no signs of ocular inflammation were randomly assigned to three groups: controls (Group A), sodium-selenite group (Group B) and sodium-selenite plus Laurus Nobilis group (Group C). By selenite treatment, cataract formation was experimentally induced and then graded. The grade of oxidative stress was defined in the lens, measuring the concentration of malondialdehyde, alpha-tocopherol, oxidized glutathione, ascorbic acid and hydrogen peroxide, and in blood samples as levels of alpha-tocopherol and malondialdehyde.Mean lens concentrations of GSSG, H2O2, and MDA levels in group B were significantly higher than in both group C and control. Ascorbic acid and alpha-tocopherol concentrations were lower in group B than in both group C and A. As plasma oxidative status markers, the level of MDA was higher in group B respected group C and A. The mean alpha-tocopherol levels in group B were significantly lower than in both group A and group C.In animals treated with Laurus Nobilis-based eye drops, inflammation was inhibited, and lipid peroxidation was significantly reduced. Laurus nobilis leaves extract represents a good source of antioxidant components that may contrast sodium selenite-induced cataractogenesis in suckling rabbits. [ABSTRACT FROM AUTHOR]

• Selenite fertilization causes toxicity at lower doses than selenate fertilization. • Selenate fertilization favored the dry mass and Se accumulation in the radish and leaves. • Selenite fertilization with 1.8 mg Se dm−3 reduced radishes dry mass. • Se accumulation in radishes and leaves correlated positively and strongly with radishes dry mass. • Selenium fertilization caused changes in the anatomy and physiology of Raphanus sativus L. plants. Selenium (Se), in low doses, provides several beneficial effects, such as plant resistance to various abiotic stresses (e.g. drought stress and low/high temperatures). However, Se excess causes toxicity, with harmful impacts such as a decline in yield. Here, we studied the effects of fertilization with different Se sources and doses applied via soil on Se accumulation, toxicity, as well as on gas exchange, and anatomy of leaves and roots of radish plants. A randomized experimental design was adopted with three replications in a 2 × 3 + 1 factorial arrangement: two Se sources (sodium selenate – Na 2 SeO 4 and sodium selenite – Na 2 SeO 3 ·5H 2 O), three Se doses applied on soil (0.6, 1.2, and 1.8 mg dm−3), and one control treatment (without Se application). Each experimental unit consisted of one pot containing six radish plants. Selenate at 1.8 mg Se dm−3 increased the Se accumulation and radish dry matter. Selenite generally caused significant changes in the anatomical part, mainly in the conductive tissues of the leaves. In leaves with selenite fertilization, it was estimated that the maximum Se accumulation would be 5.9 µg plant−1 with a rate of 2.0 mg Se dm−3. However, it was impossible to estimate the maximum Se accumulation with selenate fertilization because as the dose increased, there were also increases in accumulation, thus presenting a linear regression. The maximum Se accumulation in radishes would be 10.7 µg Se plant −1 with 1.2 mg Se dm−3 by selenite and 45.8 µg Se plant−1 with 5.0 mg Se dm−3 by selenate. Although the highest dry mass production occurred with the 1.8 mg Se dm−3 through selenite, it is recommended to use smaller doses to provide adequate Se consumption selenate. The gas exchange and the anatomy of the plants changed due to Se fertilization through selenate and selenite. [ABSTRACT FROM AUTHOR]

Selenium (Se) enhances the resistance of plants exposed to metal stress and can be used to lessen the impacts of toxic elements and to enhance the effectiveness of the plants used to clean up polluted sites. There is no information available about the optimum dose and form of Se to stimulate the camelthorn (Alhagi maurorum Medik) plant, which is one of the plants used in the phytostabilization of toxic elements. The impacts of selenate (Se-VI) and selenite (Se-IV) on the phytoremediation of toxic metals from loamy soils by camelthorn were investigated in a pot experiment. Se-VI and Se-IV were added to the soil at doses of 0, 5, and 10 mg Se kg−1 soil, and each treatment was repeated five times. Se-VI and Se-IV, significantly increased plant growth and nutrient uptake. The addition of Se, either from Se-VI or Se-IV, significantly increased the superoxide dismutase (SOD) and peroxidase (POD) enzymes, and the non-enzymatic antioxidant compounds, i.e., proline and phenols, compared to the control. The addition of Se strengthened the defense against metal stress, and Se-VI outperformed Se-IV in boosting camelthorn's resistance to hazardous metal contamination. Selenium increased the accumulation of metal in the root of camelthorn and reduced root-shoot transfer. The best technique to boost camelthorn plants' capacity to clean up metal-contaminated soils is to supplement them with selenium in the form of selenate at a concentration of 10 mg Se kg−1 soil. [ABSTRACT FROM AUTHOR]

Selenium is a trace element which is an essential micronutrient for all organisms. Though it is essential, if taken in excess leads to toxicity. Hence have a detrimental effect on the health. Selenium exists in various oxidation states out of which selenite and selenate are toxic and forms the major part of the pollutant in the ecosystem. Therefore, there is an urgent need to address this issue in an eco‐friendly, efficient, and substantial way to protect the environment from further deterioration. In this regard, fungi have developed unique metabolic pathways to nullify the toxic effects of these pollutants and the process is known as mycoremediation. Mycoremediation is a cost‐effective, environmentally friendly, and efficient approach of environmental remediation that addresses organic, inorganic, and developing toxins (such as antibiotics and pharmaceuticals) by using fungus or their components. An alternative, environmentally friendly method for cleaning up contaminants in environmental matrices is provided by mycoremediation. This is due to the fact that most organic toxins are broken down rather than removed, which lowers the possibility of pollutants entering the food chain through bioaccumulation. Fungi possess robust morphology and various catabolic enzymes capable of using pollutant as a growth substrate. They transform the toxic selenium species via a series of biochemical reaction such as oxidation, reduction, methylation, and demethylation into nontoxic elemental selenium and selenium nanoparticles. Mycoremediation is a process subset that employs to fungi to degrade and restore contaminated Eco‐System. For this reason, a potential framework of "mycoremediation" was proposed to make it easier for this promising to report global environmental issues. [ABSTRACT FROM AUTHOR]

Selenium (Se) is a micronutrient known for its essential role in human health and plant metabolism. Waxy maize (Zea mays L. sinensis kulesh)—known for its high nutritional quality and distinctive flavor—holds significant consumer appeal. Therefore, this study aims to assess the effects of foliar Se spraying on the nutritional quality of waxy maize grains, with a focus on identifying varietal differences and determining optimal Se dosage levels for maximizing nutritional benefits. We employed a two-factor split-plot design to assess the nutritional quality, trace elements, and pigment content of jinnuo20 (J20) and caitiannuo1965 (C1965) at the milk stage after being subjected to varying Se doses sprayed on five leaves. Our findings indicate superior nutrient content in J20 compared to C1965, with both varieties exhibiting optimal quality under Se3 treatment, falling within the safe range of Se-enriched agricultural products. JS3 (0.793) demonstrated the highest overall quality, followed by JS2 (0.606), JS4 (0.411), and JS1 (0.265), while CS0 had the lowest (−0.894). These results underscore the potential of foliar biofortification to enhance the functional component contents of waxy maize grains. [ABSTRACT FROM AUTHOR]

The effects of selenite (0, 15, 30, 45 mg L–1) on physiological characteristics and medicinal components of Paeonia ostii were analyzed. The results showed that selenite application promoted the activity of superoxide dismutase and the contents of soluble sugar, proline, carotenoids, total flavonoids, and total polyphenols, and decreased the contents of reactive oxygen species, relative electrical conductivity, and malondialdehyde. In addition, selenite also increased chlorophyll content, improved electron transfer ability, PSI and PSII performance, and the coordination between PSI and PSII, which significantly improved photosynthetic capacity. Moreover, selenite treatment also greatly increased the contents of gallic acid, catechin, albiflorin, paeoniflorin, benzoic acid, and paeonol in Moutan cortex radicis (MCR). These results showed that selenite effectively protected the photosynthetic apparatus from photooxidative damage by enhancing antioxidant capacity, improving photosynthetic capacity, and increasing the content of the medicinal compounds in MCR. [ABSTRACT FROM AUTHOR]

Selenium (Se) is an essential trace element for humans and animals, but high-dose supplementation with Se compounds, most notably selenite, may exert cytotoxic and other adverse effects. On the other hand, bacteria, including Escherichia coli (E. coli), are capable of reducing selenite to red elemental Se that may serve as a safer Se source. Here, we examined how a diet of Se-enriched E. coli bacteria affected vital parameters and age-associated neurodegeneration in the model organism Caenorhabditis elegans (C. elegans). The growth of E. coli OP50 for 48 h in medium supplemented with 1 mM sodium selenite resulted in reddening of the bacterial culture, accompanied by Se accumulation in the bacteria. Compared to nematodes supplied with the standard E. coli OP50 diet, the worms fed on Se-enriched bacteria were smaller and slimmer, even though their food intake was not diminished. Nevertheless, given the choice, the nematodes preferred the standard diet. The fecundity of the worms was not affected by the Se-enriched bacteria, even though the production of progeny was somewhat delayed. The levels of the Se-binding protein SEMO-1, which serves as a Se buffer in C. elegans, were elevated in the group fed on Se-enriched bacteria. The occurrence of knots and ruptures within the axons of cholinergic neurons was lowered in aged nematodes provided with Se-enriched bacteria. In conclusion, C. elegans fed on Se-enriched E. coli showed less age-associated neurodegeneration, as compared to nematodes supplied with the standard diet. [ABSTRACT FROM AUTHOR]

Predictive subsurface transport of selenium oxyanions is important for the assessment of long-term nuclear waste repository performance, as well as monitoring compliance of selenium presence in groundwater once discharged from industry, agriculture or natural seleniferous minerals. The aim of the present study is to quantify the diffusion of selenite and selenate through water-saturated compacted clays of smectite and illite rich geochemistry. Diffusion coefficient (De) values for selenium oxyanions in argillaceous clay are ̴ 10–12 m2s−1 and are nearly an order of magnitude higher in the bentonite clay. Results indicate the role of clay geochemistry in controlling migration of selenium oxyanions through natural clay. [ABSTRACT FROM AUTHOR]

Selenium-yeast was mixed with the basal diet of treatment groups of birds at the dose rate of 0.15 mg/kg diet in treatment-I (T-I), 0.225 mg/kg in treatment-II (T-II) and 0.30 mg/kg in treatment-III (T-III) group. The body weight and weekly weight gain increased and, feed conversion ratio improved significantly (p

Selenite as an inorganic form of selenium can affect the redox state of mitochondria by modifying the thiol groups of cysteines. The F 1 F O -ATPase has been identified as a mitochondrial target of this compound. Indeed, the bifunctional mechanism of ATP turnover of F 1 F O -ATPase was differently modified by selenite. The activity of ATP hydrolysis was stimulated, whereas the ADP phosphorylation was inhibited. We ascertain that a possible new protein adduct identified as seleno-dithiol (-S-Se-S-) mercaptoethanol-sensitive caused the activation of F-ATPase activity and the oxidation of free –SH groups in mitochondria. Conversely, the inhibition of ATP synthesis by selenite might be irreversible. The kinetic analysis of the activation mechanism was an uncompetitive mixed type with respect to the ATP substrate. Selenite bound more selectively to the F 1 F O -ATPase loaded with the substrate by preferentially forming a tertiary (enzyme-ATP-selenite) complex. Otherwise, the selenite was a competitive mixed-type activator with respect to the Mg2+ cofactor. Thus, selenite more specifically bound to the free enzyme forming the complex enzyme-selenite. However, even if the selenite impaired the catalysis of F 1 F O -ATPase, the mitochondrial permeability transition pore phenomenon was unaffected. Therefore, the reversible energy transduction mechanism of F 1 F O -ATPase can be oppositely regulated by selenite. [Display omitted] • Selenite regulates oppositely the ATP hydrolysis and ATP synthesis of F 1 F O -ATPase. • Mercaptoethanol reverts the activation of ATPase activity of F 1 F O -ATPase. • Selenite can form a protein adduct identified as seleno-dithiol. • Toxic effect of selenite on mitochondrial bioenergetics does not stimulate the mPTP opening. [ABSTRACT FROM AUTHOR]

This study prepared a novel composite membrane coated with the cobalt-based metal–organic framework coated on multi-walled carbon nanotubes (Co-MOF@MWCNTs). The composite membrane can also be used as an electrocatalytic material after removing selenite acid from wastewater. This strategy offers the dual advantage of removing selenium from wastewater and resource upgrading. [Display omitted] • A novel Co-MOF@MWCNTs composite membrane was prepared via dip coating. • The composite membrane could be used for dynamic removal of contaminants. • The Co-MOF@MWCNTs-40 composite membrane had a filtration efficiency of 92.2 % for SeO 3 2−. • The used composite membrane could be recycled utilization as an OER electrocatalyst. The utilization of selenium as a novel functional material is rapidly expanding, and the retrieval of selenium from waste containing selenium is gaining recognition in the industry. This study prepared a novel composite membrane coated with the cobalt-based metal–organic framework coated on multi-walled carbon nanotubes (Co-MOF@MWCNTs). The MWCNTs served as the skeleton to support the active components of Co-MOF, which enabled efficient removal and resource utilization of liquid selenite (SeO 3 2−). The morphology, structure, and composition of the prepared membrane were characterized using field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), etc.. Applying a permeate flux of 67.08 L m−2 h−1, the SeO 3 2− removal efficiency of the composite membrane reached up to 92.2%. The composite membrane containing CoSeO 4 can be used as an electrocatalytic oxygen evolution catalyst. Density functional theory calculations and electrochemical analysis showed that the conversion from O* to OOH* was a rate-determining step. Under 1.0 M KOH conditions, the lowest overpotential for Co-MOF@MWCNTs-40 at 10 mA cm−2 was 360 mV. In this study, the process of selenium resource utilization and the mechanism of SeO 3 2− removal by Co-MOF@MWCNTs are revealed. It demonstrates that membrane-based sequestration of SeO 3 2− can provide a viable approach for SeO 3 2− removal and utilization in wastewater. [ABSTRACT FROM AUTHOR]

Abstract Jasmonic acid (JA) is an important and widely distributed plant hormone. However, the molecular and physiological mechanism of JA in improving drought tolerance in response to sodium selenite is limited. This work was performed to investigate the effects of exogenous sodium selenite application in promoting drought tolerance of cucumber. The drought tolerance of cucumber seedlings is enhanced under the application of selenite, positively influencing shoot fresh weight and chlorophyll relative content and altering the chloroplast ultrastructure. The contents of JA and JA-isoleucine (JA-ILE) increased significantly in response to selenite application under drought conditions. Furthermore, the expression of JA biosynthesis and regulatory genes, namely, LOX (Lipoxygenase), AOC (allene oxide cyclase), AOS (allene oxide synthase), and MYC2 (the basic helix-loop-helix (bHLH) protein) was upregulated to greater levels when selenite was added in combination with drought treatment. This study provides methods to mitigate drought stress and valuable theoretical support for further understanding the plant response to drought signals.

A new polymorphic form of sodium selenite pentahydrate is reported in this contribution. We determined its crystal structure from laboratory powder diffraction data recorded at room temperature. It crystallizes in the monoclinic system P 21/ n with Z = 4. The lattice parameters are a = 15.01473(16) Å, b = 7.03125(7) Å, c = 8.13336(10) Å, β = 98.4458(10)°, and V = 849.345(16) Å3. The crystal structure exhibits a layered structure with isolated 1D chains running along the b -axis. [ABSTRACT FROM AUTHOR]

Abstract Background Selenium, an essential trace element, has previously been investigated as a pro-apoptotic and DNA demethylation agent. It sensitizes the response to chemotherapy in patients who were refractory to cytotoxic agents. Meanwhile, ferroptosis is a novel approach to cancer treatment by triggering cell death and reversing drug resistance. The role of selenium in treating cancer cells harboring druggable oncogenic alterations and its underlying mechanism are largely unknown. Results We treated lung adenocarcinoma cell lines—EGFR-mutant H1975 (H1975 EGFR p.L858R and p.T790M) and KRAS-mutant H358 (H358 KRAS p.G12C), with sodium selenite to examine its effect on cell apoptosis, ferroptosis, and DNA methylation, as well as its interaction with existing targeted therapy, osimertinib, and adagrasib. We observed selenite to be a dual apoptotic and ferroptotic agent on lung cancer cells, associated with the activation of p38-ATF4-DDIT3 axis in the unfolded protein response. Ferroptosis induction was more remarkable in H1975 than H358. Selenite also altered cellular DNA methylation machinery through downregulating DNMT1 and upregulating TET1, though not as a major mechanism of its activity. Low-dose selenite synergized with osimertinib in EGFR-mutant H1975, and with adagrasib in KRAS-mutant H358, with stronger synergism observed in H1975. Conclusion These results suggest that selenite is a potential apoptotic and ferroptotic drug candidate for the treatment of especially EGFR- and potentially KRAS-mutant lung cancer.

Selenium (Se) is a micronutrient known for its essential role in human health and plant metabolism. Waxy maize (Zea mays L. sinensis kulesh)—known for its high nutritional quality and distinctive flavor—holds significant consumer appeal. Therefore, this study aims to assess the effects of foliar Se spraying on the nutritional quality of waxy maize grains, with a focus on identifying varietal differences and determining optimal Se dosage levels for maximizing nutritional benefits. We employed a two-factor split-plot design to assess the nutritional quality, trace elements, and pigment content of jinnuo20 (J20) and caitiannuo1965 (C1965) at the milk stage after being subjected to varying Se doses sprayed on five leaves. Our findings indicate superior nutrient content in J20 compared to C1965, with both varieties exhibiting optimal quality under Se3 treatment, falling within the safe range of Se-enriched agricultural products. JS3 (0.793) demonstrated the highest overall quality, followed by JS2 (0.606), JS4 (0.411), and JS1 (0.265), while CS0 had the lowest (−0.894). These results underscore the potential of foliar biofortification to enhance the functional component contents of waxy maize grains.

Selenium (Se) is an essential trace element for humans and animals, but high-dose supplementation with Se compounds, most notably selenite, may exert cytotoxic and other adverse effects. On the other hand, bacteria, including Escherichia coli (E. coli), are capable of reducing selenite to red elemental Se that may serve as a safer Se source. Here, we examined how a diet of Se-enriched E. coli bacteria affected vital parameters and age-associated neurodegeneration in the model organism Caenorhabditis elegans (C. elegans). The growth of E. coli OP50 for 48 h in medium supplemented with 1 mM sodium selenite resulted in reddening of the bacterial culture, accompanied by Se accumulation in the bacteria. Compared to nematodes supplied with the standard E. coli OP50 diet, the worms fed on Se-enriched bacteria were smaller and slimmer, even though their food intake was not diminished. Nevertheless, given the choice, the nematodes preferred the standard diet. The fecundity of the worms was not affected by the Se-enriched bacteria, even though the production of progeny was somewhat delayed. The levels of the Se-binding protein SEMO-1, which serves as a Se buffer in C. elegans, were elevated in the group fed on Se-enriched bacteria. The occurrence of knots and ruptures within the axons of cholinergic neurons was lowered in aged nematodes provided with Se-enriched bacteria. In conclusion, C. elegans fed on Se-enriched E. coli showed less age-associated neurodegeneration, as compared to nematodes supplied with the standard diet.

Temperature-swing solvent extraction (TSSE) is a cost-effective, simple, versatile, and industry-ready technology platform capable of desalinating hypersaline brines toward zero liquid discharge. In this work, we demonstrate the potential of TSSE in the effective removal of selenium oxyanions and traces of mercury with the coexistence of high contents of chloride and sulfate often encountered in flue gas desulfurization wastewater streams. We compare the rejection performance of the two common solvents broadly used for TSSE, decanoic acid (DA) and diisopropylamine (DPA), and correlate those with the solvent physicochemical properties (e.g., dielectric constant, polarity, molecular bulkiness, and hydrophobicity) and ionic properties (e.g., hydrated radii and H-bonding). The results show that TSSE can remove >99.5% of selenium oxyanions and 96%–99.6% of mercury traces coexisting with sulfate (at a sixfold Se concentration) and chloride (at a 400-fold Se concentration) in a synthetic wastewater stream. Compared to diisopropylamine, decanoic acid is more effective in rejecting ions for all cases, ranging from a simple binary system to more complex multicomponent systems with highly varied ionic concentrations. Furthermore, the H-bonding interaction with water and the hydrated radii of the oxyanions (i.e., selenate vs. selenite) along with the hindrance effects caused by the molecular bulkiness and hydrophobicity (or lipophilicity) of the solvents play important roles in the favorable rejection of TSSE. This study shows that TSSE might provide a technological solution with a high deionization potential for the industry in complying with the Environmental Protection Agency regulations for discharge streams from coal-fired power facilities.

Faba bean (Vicia faba L.) has spread worldwide as an excellent source of proteins. To evaluate the efficiency of Se biofortification, four cultivars of V. faba (Belorussian, Russian Black, Hangdown Grünkernig, and Dreifach Weiβe) were foliar treated with 1.27 mM solutions of nano-Se, sodium selenate, and sodium selenite. Yield, protein, and Se contents were greatly affected by genetic factors and chemical form of Se. Selenium biofortification levels were negatively correlated with Se concentration in control plants and increased according to the following sequence: nano-Se < sodium selenite < sodium selenate. Contrary to selenate and selenite, nano-Se showed a growth-stimulating effect, improving yield, seed weight, and pod number. Pod thickness decreased significantly as a result of nano-Se supply and increased by 1.5–2.3 times under selenate and selenite supply. The highest Se concentrations were recorded in the seeds of Se-fortified cv. Belorussian and the lowest one in those of Se-treated Hangdown Grünkernig. Protein accumulation was varietal dependent and decreased upon 1.27 mM selenate and selenite treatment in the cvs. Hangdown Grünkernig and Dreifach Weiβe. The results indicate the high prospects of nano-Se supply for the production of faba bean seeds with high levels of Se. [ABSTRACT FROM AUTHOR]

Selenium (Se) deficiency in human and animal nutrition is primarily due to low levels of Se in soils. It can be prevented by enriching crops, such as wheat, with Se through agronomic biofortification. Although Se is not essential for plants, it shows a dual effect on their metabolism depending on its concentration. This study aimed to elucidate the impact of five different concentrations (0.4, 4, 20, 40, and 400 mg/kg) of selenate and selenite on the oxidative status and antioxidative response of wheat (Triticum aestivum L., cv. Kraljica) shoots and roots. According to morpho-physiological analyses, selenite was found to have a lower toxicity threshold than selenate. The measurement of oxidative stress biomarkers showed that Se did not cause oxidative damage to wheat seedlings due to the activation of detoxification mechanisms at the biochemical level, which depended on the type of tissue, concentration, and form of applied Se. Treatment with 20 mg/kg of selenate can be recommended for wheat seedling biofortification due to a sufficient increase in Se accumulation in shoots without signs of toxicity. These results contribute to a better understanding of wheat seedlings' physiological and biochemical responses to Se and the development of more effective biofortification strategies. [ABSTRACT FROM AUTHOR]

Selenium (Se) is involved in the growth and development of plants. More importantly, Se from plant foods is a primary source of Se intake for humans and animals. Improving the Se content in vegetables through biofortification is an effective way to solve the hidden hunger induced by Se deficiency. This study demonstrated the effect of different exogenous Se application concentrations on the growth, antioxidative capacity, and nutritional quality of purple lettuce (Lactuca sativa var. crispa L. "Purple Rome") at the seedling stage. The low Se application concentration (≤8 μM) significantly promoted the lettuce seedling growth. Conversely, the high Se application concentration (16 μM) inhibited the seedling growth and overproduced the reactive oxygen species in lettuce root tips, which caused oxidative damage to membrane lipids and cell death. Furthermore, the enzyme activities and gene expression of the antioxidant enzymes, superoxide dismutase-peroxidase, and catalase, were significantly increased under exogenous Se application. The exogenous Se application significantly increased the accumulation of nutrients in purple lettuce at the seedling stage. Remarkably, the exogenous Se application concentrations were significantly positively related to the Se and anthocyanin contents. The gene expression levels of chalcone synthase were positively correlated with the anthocyanin contents under exogenous Se application. This study contributes to the role of Se in lettuce growth and provides a reference for producing high-quality purple lettuce rich in Se and anthocyanins. [ABSTRACT FROM AUTHOR]

Different aqueous selenium species including selenite, selenate, and selenocyanate, can be harmful to both humans and other life forms. Considering this, the present study investigated the application of Mg-Fe-LDH nanomaterial adsorbent for the removal of aqueous selenite, selenate, and selenocyanate species. The research examined the removal efficiency of selenite, selenate, and selenocyanate under a varying set of competitive conditions including Mg-Fe-LDH dosage (0.5–1.5) g/l, Mg-Fe-LDH calcination temperature (0–500 °C), and concentration of selenium species (2.5–7.5 ppm). The respective experimental results showed a higher removal for the selenite and selenate species as compared to the selenocyanate species. Also, the Freundlich isotherm provided a good fit both for selenite and selenocyanate uptake whereas for selenate the Langmuir isotherm provided a better fit. Furthermore, the study found that the removal of selenite and selenocyanate followed the pseudo-first-order and pseudo-second-order models, respectively, while both models fitted well with selenate. This work also employed response surface methodology (RSM) and back-propagation artificial neural network (BPANN) based modeling techniques to predict the removal efficiency of respective selenium species. The modeling results demonstrated that the BPANN method exhibited a higher accuracy in predicting selenium species removal as compared to the RSM technique. To that end, the BPANN-based models yielded R2 values of 0.9894, 0.9709, and 0.9568 for selenite, selenate, and selenocyanate, respectively. In contrast, the RSM methodology showed lower R2 values, i.e., 0.9464 for selenite, 0.9002 for selenate, and 0.8225 for selenocyanate. [ABSTRACT FROM AUTHOR]

Past chemopreventive human trials on dietary selenium supplements produced controversial outcomes. They largely employed selenomethionine (SeM)-based diets. SeM was less toxic than selenite or methylseleninic acid (MSeA) to lung cancer cells. We thus investigated the toxic action of these Se agents in two non-small cell lung cancer (NSCLC) cell lines and ex vivo organotypic cultures (OTC) of NSCLC patient lung tissues. Stable isotope-resolved metabolomics (SIRM) using 13C6-glucose and 13C5,15N2-glutamine tracers with gene knockdowns were employed to examine metabolic dysregulations associated with cell type- and treatment-dependent phenotypic changes. Inhibition of key anaplerotic processes, pyruvate carboxylation (PyC) and glutaminolysis were elicited by exposure to MSeA and selenite but not by SeM. They were accompanied by distinct anabolic dysregulation and reflected cell type-dependent changes in proliferation/death/cell cycle arrest. NSCLC OTC showed similar responses of PyC and/or glutaminolysis to the three agents, which correlated with tissue damages. Altogether, we found differential perturbations in anaplerosis-fueled anabolic pathways to underlie the distinct anti-cancer actions of the three Se agents, which could also explain the failure of SeM-based chemoprevention trials. [ABSTRACT FROM AUTHOR]

Three new copper-lead selenite bromides were synthesized by chemical vapor transport reactions. Pb5Cu+4(SeO3)4Br6 is monoclinic, space group C2/m, a = 17.7248(14), b = 5.5484(5), c = 12.7010(10) Å, β = 103.398(2)º, V = 1215.08(17) Å3, R1 = 0.024; Pb8Cu2+(SeO3)4Br10 is orthorhombic, space group I222, a = 9.5893(5), b = 12.4484(9), c = 12.7927(6) Å, V = 1527.08(15) Å3, R1 = 0.027; Pb5Cu2+(SeO3)4(Br,Cl)4 is monoclinic, C2/c, a = 24.590(6) Å, b = 5.5786(14) Å, c = 14.248(4) Å, β = 102.883(7)º, V = 1905.3(9) Å3, R1 = 0.026. The crystal structure of Pb5Cu+4(SeO3)4Br6 consists of two distinct parts: corner- and edge-sharing Cu+Br4 tetrahedra form infinite [Cu+4Br6]2- layers which alternate with [Pb5(SeO3)4]2+ layers. Pb8Cu2+(SeO3)4Br10 contains positively charged unique [Pb8Cu2+(SeO3)4]10+ rod-like chains with Cu2+ cations in the core. These chains are held together by Br- anions. Pb5Cu+4(SeO3)4Br6 and Pb8Cu2+(SeO3)4Br10 belong to new structure types. Pb5Cu2+(SeO3)4(Br,Cl)4 is a synthetic analogue of the mineral sarrabusite, Pb5Cu(SeO3)4Cl4, previously known from an electron diffraction study. The investigation of this synthetic equivalent of sarrabusite by conventional single-crystal X-ray diffraction provides a distinctly improved insight in this crystal structure. Cu atom has well-defined [2O+(2O+2X)] (X = halogen) distorted octahedral coordination. PbOn and SeO3 polyhedra interconnect via common oxygen atoms into [Pb5(SeO3)4]2+ layers parallel to (001). Cu2+ cations interconnect the layers into the framework with the large cavities filled by halide X anions. In all three new compounds described, a common feature is the formation of the selenophile substructure which is terminated by a 'lone-pair' shell that faces bromide complexes thus forming the surface of a halophile substructure. [ABSTRACT FROM AUTHOR]

The present study examined the biosynthesis and characterization of selenium nanoparticles (SeNPs) using two contrasting endophytic selenobacteria, one Gram-positive (Bacillus sp. E5 identified as Bacillus paranthracis) and one Gram-negative (Enterobacter sp. EC5.2 identified as Enterobacter ludwigi), for further use as biofortifying agents and/or for other biotechnological purposes. We demonstrated that, upon regulating culture conditions and selenite exposure time, both strains were suitable "cell factories" for producing SeNPs (B-SeNPs from B. paranthracis and E-SeNPs from E. ludwigii) with different properties. Briefly, dynamic light scattering (DLS), transmission electron microscopy (TEM), and atomic force microscopy (AFM) studies revealed that intracellular E-SeNPs (56.23 ± 4.85 nm) were smaller in diameter than B-SeNPs (83.44 ± 2.90 nm) and that both formulations were located in the surrounding medium or bound to the cell wall. AFM images indicated the absence of relevant variations in bacterial volume and shape and revealed the existence of layers of peptidoglycan surrounding the bacterial cell wall under the conditions of biosynthesis, particularly in the case of B. paranthracis. Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) showed that SeNPs were surrounded by the proteins, lipids, and polysaccharides of bacterial cells and that the numbers of the functional groups present in B-SeNPs were higher than in E-SeNPs. Thus, considering that these findings support the suitability of these two endophytic stains as potential biocatalysts to produce high-quality Se-based nanoparticles, our future efforts must be focused on the evaluation of their bioactivity, as well as on the determination of how the different features of each SeNP modulate their biological action and their stability. [ABSTRACT FROM AUTHOR]

Soybean (Glycine max L.) sprouts are a common vegetable with rich nutrients, such as protein, vitamin C and isoflavones. Soybean is also capable of accumulating selenium (Se). To study the effects of Se biofortification on the nutrient of this crop, soybean sprouts were treated with different concentrations of selenium nanoparticles (SeNPs) or selenite (i.e., 10 μM, 20 μM, 40 μM, 80 μM and 100 μM) in a hydroponic experiment. Results showed that SeNPs and selenite remarkably increased the total Se concentration in soybean sprouts. Five Se speciations, namely, selenocystine, selenomethionine, methyl selenocysteine, selenite and selenate were detected in soybean sprouts, but selenomethionine was found to be the dominant Se speciation. SeNPs and selenite increased the contents of chlorophyll, carotenoid, soluble sugar, soluble protein, vitamin C and isoflavones in soybean sprouts. SeNPs treatments led to less malondialdehyde content compared with selenite. SeNPs and selenite both enhanced the glutathione content. The modest dosage of exogenous Se stimulated the catalase activity, whereas the large amount reduced it. The peroxidase and ascorbate peroxidase activities were stimulated by SeNPs and selenite. SeNPs posed no significant influence on the superoxide dismutase activity. This study suggests that SeNPs are a good exogenous Se source for the production of Se-rich soybean sprouts.

Adolescence is a period during which body composition changes deeply. Selenium (Se) is an excellent antioxidant trace element related to cell growth and endocrine function. In adolescent rats, low Se supplementation affects adipocyte development differently depending on its form of administration (selenite or Se nanoparticles (SeNPs). Despite this effect being related to oxidative, insulin-signaling and autophagy processes, the whole mechanism is not elucidated. The microbiota–liver–bile salts secretion axis is related to lipid homeostasis and adipose tissue development. Therefore, the colonic microbiota and total bile salts homeostasis were explored in four experimental groups of male adolescent rats: control, low-sodium selenite supplementation, low SeNP supplementation and moderate SeNPs supplementation. SeNPs were obtained by reducing Se tetrachloride in the presence of ascorbic acid. Supplementation was received orally through water intake; low-Se rats received twice more Se than control animals and moderate-Se rats tenfold more. Supplementation with low doses of Se clearly affected anaerobic colonic microbiota profile and bile salts homeostasis. However, these effects were different depending on the Se administration form. Selenite supplementation primarily affected liver by decreasing farnesoid X receptor hepatic function, leading to the accumulation of hepatic bile salts together to increase in the ratio Firmicutes/Bacteroidetes and glucagon-like peptide-1 (GLP-1) secretion. In contrast, low SeNP levels mainly affected microbiota, moving them towards a more prominent Gram-negative profile in which the relative abundance of Akkermansia and Muribaculaceae was clearly enhanced and the Firmicutes/Bacteroidetes ratio decreased. This bacterial profile is directly related to lower adipose tissue mass. Moreover, low SeNP administration did not modify bile salts pool in serum circulation. In addition, specific gut microbiota was regulated upon administration of low levels of Se in the forms of selenite or SeNPs, which are properly discussed. On its side, moderate-SeNPs administration led to great dysbiosis and enhanced the abundance of pathogenic bacteria, being considered toxic. These results strongly correlate with the deep change in adipose mass previously found in these animals, indicating that the microbiota–liver–bile salts axis is also mechanistically involved in these changes. [ABSTRACT FROM AUTHOR]

It is a great challenge to develop UV nonlinear optical (NLO) material due to the demanding conditions of strong second harmonic generation (SHG) intensity and wide band gap. The first ultraviolet NLO selenite material, Y3F(SeO3)4, has been obtained by control of the fluorine content in a centrosymmetric CaYF(SeO3)2. The two new compounds represent similar 3D structures composed of 3D yttrium open frameworks strengthened by selenite groups. CaYF(SeO3)2 has a large birefringence (0.138@532 nm and 0.127@1064 nm) and a wide optical band gap (5.06 eV). The non‐centrosymmetric Y3F(SeO3)4 can exhibit strong SHG intensity (5.5×KDP@1064 nm), wide band gap (5.03 eV), short UV cut‐off edge (204 nm) and high thermal stability (690 °C). So, Y3F(SeO3)4 is a new UV NLO material with excellent comprehensive properties. Our work shows that it is an effective method to develop new UV NLO selenite material by fluorination control of the centrosymmetric compounds. [ABSTRACT FROM AUTHOR]

It is a great challenge to develop UV nonlinear optical (NLO) material due to the demanding conditions of strong second harmonic generation (SHG) intensity and wide band gap. The first ultraviolet NLO selenite material, Y3F(SeO3)4, has been obtained by control of the fluorine content in a centrosymmetric CaYF(SeO3)2. The two new compounds represent similar 3D structures composed of 3D yttrium open frameworks strengthened by selenite groups. CaYF(SeO3)2 has a large birefringence (0.138@532 nm and 0.127@1064 nm) and a wide optical band gap (5.06 eV). The non‐centrosymmetric Y3F(SeO3)4 can exhibit strong SHG intensity (5.5×KDP@1064 nm), wide band gap (5.03 eV), short UV cut‐off edge (204 nm) and high thermal stability (690 °C). So, Y3F(SeO3)4 is a new UV NLO material with excellent comprehensive properties. Our work shows that it is an effective method to develop new UV NLO selenite material by fluorination control of the centrosymmetric compounds. [ABSTRACT FROM AUTHOR]

It is a great challenge to develop UV nonlinear optical (NLO) material due to the demanding conditions of strong second harmonic generation (SHG) intensity and wide band gap. The first ultraviolet NLO selenite material, Y3F(SeO3)4, has been obtained by control of the fluorine content in a centrosymmetric CaYF(SeO3)2. The two new compounds represent similar 3D structures composed of 3D yttrium open frameworks strengthened by selenite groups. CaYF(SeO3)2 has a large birefringence (0.138@532 nm and 0.127@1064 nm) and a wide optical band gap (5.06 eV). The non‐centrosymmetric Y3F(SeO3)4 can exhibit strong SHG intensity (5.5×KDP@1064 nm), wide band gap (5.03 eV), short UV cut‐off edge (204 nm) and high thermal stability (690 °C). So, Y3F(SeO3)4 is a new UV NLO material with excellent comprehensive properties. Our work shows that it is an effective method to develop new UV NLO selenite material by fluorination control of the centrosymmetric compounds. [ABSTRACT FROM AUTHOR]

It is a great challenge to develop UV nonlinear optical (NLO) material due to the demanding conditions of strong second harmonic generation (SHG) intensity and wide band gap. The first ultraviolet NLO selenite material, Y3F(SeO3)4, has been obtained by control of the fluorine content in a centrosymmetric CaYF(SeO3)2. The two new compounds represent similar 3D structures composed of 3D yttrium open frameworks strengthened by selenite groups. CaYF(SeO3)2 has a large birefringence (0.138@532 nm and 0.127@1064 nm) and a wide optical band gap (5.06 eV). The non‐centrosymmetric Y3F(SeO3)4 can exhibit strong SHG intensity (5.5×KDP@1064 nm), wide band gap (5.03 eV), short UV cut‐off edge (204 nm) and high thermal stability (690 °C). So, Y3F(SeO3)4 is a new UV NLO material with excellent comprehensive properties. Our work shows that it is an effective method to develop new UV NLO selenite material by fluorination control of the centrosymmetric compounds. [ABSTRACT FROM AUTHOR]

In the present study, the ability of a modified CaCl2 zeolite (Ca-Z) to both increase Se(IV) availability and restrict Se(VI) mobility in soils is examined. As it was resulted from batch experiments and verified by X-ray absorption fine structure (XAFS) and X-ray fluorescence (XRF) spectroscopies, higher amounts of both Se species adsorbed on Ca-Z compared to natural zeolite (Z-N) forming outer-sphere complexes while the oxidation state did not alter during agitation of samples. Thereafter, Ca-Z was incorporated in six Greek soils, divided into acid and alkaline, at a 20% (w/w) rate and a series of equilibrium batch experiments were performed with soils alone and soils-Ca-Z mixtures to investigate sorption and desorption processes and mechanisms. The acid soils, either treated with Ca-Z or not, adsorbed higher amounts of Se(IV) than alkaline ones, whereas soils alone did not adsorb Se(VI) but impressively high adsorption of Se(VI) occurred in the Ca-Z-treated soils. Desorption of Se(IV) was higher from the Ca-Z-treated soils and especially from the acid soils. Higher distribution coefficients of desorption than the distribution coefficients of sorption were observed, clearly pointing to a hysteresis mechanism. The experimental data fitted with Langmuir and Freundlich isotherms. In the presence of Ca-Z, the Langmuir qm values increased indicating higher Se(IV) retention while Langmuir bL values decreased suggesting lower bonding strength and higher Se(IV) mobility. Overall, treating the soils with Ca-Z increased Se(IV) adsorption and mobility whereas it provided sites for Se(VI) adsorption that did not exist in the studied soils. [ABSTRACT FROM AUTHOR]

A manganese oxide-coated cylindrical graphite cathode with a zinc anode was developed to treat wastewater containing selenite in a dual-chambered microbial fuel cell. COD and selenite removal in the anodic chamber by Bacillus cereus with energy generation were evaluated in batch mode. A manganese dioxide-coated graphite cathode was tested for its surface morphology and chemical composition using scanning electron microscopy and dispersive energy analysis of X-rays. Compared to the non-coated graphite electrode, up to 69% enhancement was observed in the manganese dioxide-coated electrode voltage generation with 150 ppm selenite concentration. The fuel cell achieved a maximum power density of 1.29 W/m2 with 91% selenite reduction and up to 74% COD (initial COD of 120 mg/L) removal for an initial selenite concentration from 100 to 150 ppm. The current study demonstrated the possibility of a modified cathode in enhancing energy generation and the use of microbial fuel cell technology to treat wastewater containing selenite. [ABSTRACT FROM AUTHOR]

Introduction: Selenium (Se) is an essential trace element required for proper human and animal health. Methods: In this paper, we investigated the uptake and distribution characteristics of a new Se fertilizer, which comprises algal polysaccharides--selenium nanoparticles (APS-SeNPs), in rice plants in both hydroponic and pot experiments. Results: The results from the hydroponic experiments revealed that the rice root uptake of APS-SeNPs fitted the Michaelis--Menten equation, with a Vmax of 13.54 mg g-1 root dry weight (DW) per hour, which was 7.69 and 2.23 times those of selenite and selenate treatments, respectively. The root uptake of APSSeNPs was inhibited by AgNO3 (64.81%-79.09%) and carbonyl cyanide 3-chlorophenylhydrazone (CCCP; 19.83%-29.03%), indicating that the uptake of APS-SeNPs by rice roots is mainly via aquaporins and is also affected by metabolic activity. Moreover, sulfur deficiency caused rice roots to absorb more APS-SeNPs, but treatment with APS-SeNPs increased the expression of the sulfate transporter OsSULTR1;2 in the roots, suggesting that OsSULTR1;2 is probably involved in the uptake of APS-SeNPs. The application of APS-SeNPs significantly increased the Se content in rice plants and the apparent Se uptake efficiency compared with selenate and selenite treatments. Most of the Se in the roots of rice plants was distributed in the cell wall, while it was primarily located in the cytosol in the shoots when treated with APS-SeNPs. The results from the pot experiments indicated that the application of Se enhanced the Se content of each rice tissue. It is worth noting that the Se content in brown rice under APS-SeNP treatment was higher than that under selenite or selenate treatment and was mainly concentrated in the embryo end, with the Se in organic form. Discussion: Our findings provide important insights into the uptake mechanism and the distribution of APS-SeNPs in rice plants. [ABSTRACT FROM AUTHOR]

The partition of materials that react with soil between the solid and the solution phase, and how this changes with time, can often be described by a simple equation: S = a cb1tb2 where S is the amount sorbed, c is the solution concentration, t the time of contact, and a, b1 and b2 are parameters. However, when the range of values for sorption is large, it is apparent that both b1 and b2 increase with decreasing sorption. At low values for sorption, b1 approaches 1, and sorption plots are nearly linear. These observations are consistent with a mechanistic model in which it is postulated that the materials react with heterogenous sites. As the amount of sorption decreases, the heterogeneity of the occupied sites decreases. This is why b1 increases. Because there is heterogeneity of occupied sites, there is a range of rates for the subsequent reaction. This is why the rates are proportional to a fractional index of time. It is better to describe the effects of time this way than by using several first‐order equations. [ABSTRACT FROM AUTHOR]

In this research, 4-Vinyl pyridine grafted poly(ethylene terephthalate), (4VP-g-PET), fibers were synthesized using the radical polymerization method and used as a novel adsorbent for removing selenite (SeO32−) ions from aqueous solutions. SEM and FTIR spectroscopy were used to examine the structure of the synthesized fibers. Batch experiments were used to conducted the adsorption research. Parameters affecting the adsorption performance like pH, grafting yield, adsorption time, initial selenite concentration and temperature were investigated. The best removal of selenite ions was attained at pH 6. Interestingly, the fibers displayed significant adsorption potential at higher pHs even in highly alkaline environments. Within 3 h, adsorption equilibrium was established, and kinetically, the adsorption process was found to obey the pseudo-first-order kinetic model. Grafting yield increased the amount of selenium adsorption up to 47 percent. The synthesized fibers' maximum selenite adsorption ability was found to be 26.91 mg g−1. Thermodynamic parameters ΔH0, ΔS0 and ΔG0 of the adsorption were also calculated. The adsorption reaction was determined to be exothermic. The possible adsorption routes were proposed. The synthetic adsorbent, 4VP-g-PET fibers, may be a promising alternative adsorbent for removing selenite from aqueous media. [ABSTRACT FROM AUTHOR]

Background: Selenium, an essential trace element, has previously been investigated as a pro-apoptotic and DNA demethylation agent. It sensitizes the response to chemotherapy in patients who were refractory to cytotoxic agents. Meanwhile, ferroptosis is a novel approach to cancer treatment by triggering cell death and reversing drug resistance. The role of selenium in treating cancer cells harboring druggable oncogenic alterations and its underlying mechanism are largely unknown. Results: We treated lung adenocarcinoma cell lines—EGFR-mutant H1975 (H1975 EGFR p.L858R and p.T790M) and KRAS-mutant H358 (H358 KRAS p.G12C), with sodium selenite to examine its effect on cell apoptosis, ferroptosis, and DNA methylation, as well as its interaction with existing targeted therapy, osimertinib, and adagrasib. We observed selenite to be a dual apoptotic and ferroptotic agent on lung cancer cells, associated with the activation of p38-ATF4-DDIT3 axis in the unfolded protein response. Ferroptosis induction was more remarkable in H1975 than H358. Selenite also altered cellular DNA methylation machinery through downregulating DNMT1 and upregulating TET1, though not as a major mechanism of its activity. Low-dose selenite synergized with osimertinib in EGFR-mutant H1975, and with adagrasib in KRAS-mutant H358, with stronger synergism observed in H1975. Conclusion: These results suggest that selenite is a potential apoptotic and ferroptotic drug candidate for the treatment of especially EGFR- and potentially KRAS-mutant lung cancer. [ABSTRACT FROM AUTHOR]

Selenium (Se) is an important trace element in human and animal health. Approximately 0.5–1 billion people worldwide are facing Se deficiency which can result in various endemic diseases. Cabbage is one of the most popular vegetables and can accumulate Se through biofortification. Therefore, producing Se-enriched cabbage may be an effective method to alleviate Se deficiency. In this study, the effects of different concentrations of selenite application on the growth and nutritional quality of cabbage were investigated and the results showed that the growth of cabbage was promoted at low concentrations of selenite (0.1–0.4 mmol/L) but inhibited at high concentrations (0.8–1.6 mmol/L). Concentrations of 0.1–0.2 mmol/L of selenite induced the accumulation of primary metabolites (soluble proteins, soluble sugars, and free amino acids), representative secondary metabolites (ascorbic acid, glucosinolates, flavonoids, anthocyanins, and phenolic acids), and important antioxidant enzyme (glutathione peroxidase, catalase, and superoxide dismutase) activity to improve the nutritional quality of cabbages. In addition, a higher concentration (0.8–1.6 mmol/L) of selenite proved beneficial in the accumulation of total Se and representative organic Se in cabbages. The main organic Se species in cabbage were selenomethionine (SeMet), accounting for 12.10% of total Se, followed by selenocysteine (SeCys2), accounting for 2.96% of total Se. It is suggested that an appropriate dose of exogenous selenite could be selected for different production purposes in cabbage cultivation. These findings are helpful for us to deeply understand the effects of selenite on the growth and nutritional quality of cabbages and to provide reliable technical support for vegetable cultivation and Se biofortification. [ABSTRACT FROM AUTHOR]

In the present work, Fe3O4 nanoparticles were attached to the surface of UiO-66, a zirconium-based metal–organic framework material and the composite material formed was used to remove selenite (Se(IV)) in water. The Fe3O4/UiO-66 composite were assembled by a facile two-stage strategy. Benefiting from the ultra-high specific surface area of UiO-66, the Fe3O4/UiO-66 also had a large specific surface area, which made it easier to expose the active sites of Fe3O4 on the surface of UiO-66. The XPS and Mössbauer spectroscopy analysis indicated that there was charge transfer between Fe3O4 and UiO-66 in the Fe3O4/UiO-66, which made the Fe3O4 on the surface of UiO-66 had enhanced reductive activity. The mechanism of Fe3O4/UiO-66 to removed Se(IV) from the solution was further investigated by Zeta potential, FT-IR, SEM, TEM, and XPS spectra. The results indicated that the Fe3O4 nanoparticles on the surface of UiO-66 not only interacted with selenite through electrostatic action and inner-sphere complex but could also reduce a large amount of selenite to the insoluble Se0. The combination of these three actions finally strengthened the removal of selenite. This study cloud promote the practical application of MOF-based composites in removing heavy metal ions.

In this study, we focused on a member of the Ole e 1 domain-containing family, AtSAH7, in Arabidopsis thaliana. Our lab reports for the first time on this protein, AtSAH7, that was found to interact with Selenium-binding protein 1 (AtSBP1). We studied by GUS assisted promoter deletion analysis the expression pattern of AtSAH7 and determined that the sequence 1420 bp upstream of the transcription start can act as a minimal promoter inducing expression in vasculature tissues. Moreover, mRNA levels of AtSAH7 were acutely increased under selenite treatment in response to oxidative stress. We confirmed the aforementioned interaction in vivo, in silico and in planta. Following a bimolecular fluorescent complementation approach, we determined that the subcellular localization of the AtSAH7 and the AtSAH7/AtSBP1 interaction occur in the ER. Our results indicate the participation of AtSAH7 in a biochemical network regulated by selenite, possibly associated with responses to ROS production. [ABSTRACT FROM AUTHOR]

In this study, we conduct an investigation of the Sorbas Basin (Almería, Spain) on the Messinian gypsum unit using geophysical prospecting methods. Geophysical electrical resistivity tomography (ERT) methods were applied to study the subsurface of this gypsum unit, the exploitation of which could be of interest economically, with different commercial specifications for alabastrine and selenitic gypsums. For the interpretation of the different ERT images, the data for the surface geology, borehole cores, and seismic refraction conducted at a point within the ERT profiles were used. The results obtained from this investigation can be used as a reference for other similar studies in other regions. It was observed that selenitic gypsum is more resistive than alabastrine gypsum; therefore, the diagenetic processes of dehydration (anhydritization) and hydration (gypsification) increase the "percolation" phenomenon through possibly ensuring a greater connectivity of the shale matrix. Fracturing and moisture can be used to fully determine the resistivity of the purest and most resistive gypsum, to the point of considerably lowering the resistivity in an entire area affected by fracturing. The use of different tests with different lengths for the same profile can help one better understand the structure of the gypsum body in the subsurface, especially when there are shale intercalations or more- or less-pure levels of gypsum that do not reach a value of a few meters in thickness, because these thinner levels of a few meters are not defined in the ERT images when the test is performed at depths of up to 75 m. [ABSTRACT FROM AUTHOR]

Dunaliella salina is currently one of the most commercially valuable microalgae species in the world. In reponse to selenite, D. salina is a microalgae with a high selenium content, thereby increasing its value, which is crucial for increasing its economic value as a nutrional supplement. However, the effects of selenite on D. salina are still unclear, and its molecular mechanism of the response to selenite stress is also elusive. Here, in order to study the effects of selenite on D. salina and the corresponding regulatory mechanism, we characterized the physiological phenotypes of D. salina under different selenite concentrations and carried out a quantitative proteomic study. The results showed that the effective concentration for 50% growth inhibition (EC50) of the algae was 192.7 mg/L after 11 days of cultivation. When selenite concentration was lower than 100 mg/L, selenite did not hinder the growth of D. salina in the early stage, but shortened the cell growth cycle, although cell growth was significantly inhibited when the concentration of selenium was higher than 250 mg/L. Bioaccumulation experiments showed that the content of intracellular selenium in D. salina cells reached the highest level under the treatment with 50 mg/L selenite, and the contents of total selenium and organic selenium in D. salina cells were 499.77 μg/g and 303.01 μg/g (dry weight), respectively. Proteomic analysis revealed that a series of proteins related to stress responses, amino acid metabolism and energy production pathways were profoundly altered by the selenite treatment. Glutathione peroxidase (GPX7), a selenium-containing protein, was identified in the group given the selenium treatment. Moreover, proteins involved in photoreactions and oxidative phosphorylation were significantly upregulated, indicating that D. salina effectively balanced the energy demand and energy production under selenite stress. This study provides novel insights into the responses to selenite of D. salina, a microalgae candidate as a biological carrier of selenium and would be helpful for the development of industrial strains rich in selenium. [ABSTRACT FROM AUTHOR]

Cancer is one of the main causes of human death globally and novel chemotherapeutics are desperately required. As a simple selenium oxide, selenite is a very promising chemotherapeutic because of pronounced its dose-dependent tumor-specific cytotoxicity. We previously published a first-in-man systematic phase I clinical trial in patients with cancer (from IV to end-stage) (the SECAR trial) showing that selenite is safe and tolerable with an unexpectable high maximum tolerated dose (MTD) and short half-life. In the present study, we analyzed the selenium species in plasma samples, from the patients participating in the SECAR trial and from various time points and dose cohorts using LC-ICP-MS. In conclusion, selenite, selenosugars, and 1–2 unidentified peaks that did not correspond to any standard, herein denoted ui-selenium, were detected in the plasma. However, trimethylated selenium (trimethylselenonoium) was not detected. The unidentified ui-selenium was eluting close to the selenium-containing amino acids (selenomethionine and selenocysteine) but was not part of a protein fraction. Our data demonstrate that the major metabolite detected was selenosugar. Furthermore, the identification of selenite even long after the administration is remarkable and unexpected. The kinetic analysis did not support that dosing per the body surface area would reduce interindividual variability of the systemic exposure in terms of trough concentrations. [ABSTRACT FROM AUTHOR]

Based on the important feature of sulfur with excellent selectivity toward selenite in the presence of selenate, a simple and low-cost adsorbent of solid phase extraction known as sulfur loading activated carbon (SAC-6) was successfully prepared and applied for selenite (Se(IV)) analysis in water. Microstructure and morphological characteristics of SAC-6 had been identified by XRD, TEM, BET and FT-IR. In the static adsorption experiments, Se(IV) could be separated in a wide range of pH values (pH=3–11). The retention process of Se(IV) onto SAC-6 was characterized as spontaneous exothermic reaction. An obvious change of adsorption mechanism occurred in static and dynamic adsorption processes shown that the behaviors followed monolayer and hybrid adsorption. The theoretical maximum adsorption capacity of SAC-6 calculated by Langmuir-Freundlich was 13.48 mg/g. The microcolumn filled with SAC-6 was applied to extract Se(IV) in water solution. The detection limit of Se(IV) analytical procedure was confirmed as 0.27 μg/L within a linear range of 10–1000 μg/L. A good precision with relative standard deviation of 1.34 % (100 μg/L, n = 6) was achieved. The high adaptability and accuracy of SAC-6 microcolumn was validated by analyzing natural water samples and certified reference materials. Our work successfully excavated the application value of the sulfur selectivity, and also provided a new adsorbent for Se(IV) extraction and analysis. [Display omitted] • Sulfur-based functionalized activated carbon as SPE adsorbent can selectively extract Se(IV) in a wide range of pH (3-11). • Pressure-driven induced multilayer adsorption behavior to strengthen the interaction force between Se(IV) and adsorbent. • A procedure for on-site rapid speciation of Se(IV) was established with excellent analytical performances. [ABSTRACT FROM AUTHOR]

This study explored the application of magnesium precipitate (MP) obtained from seawater electrochlorination storage tanks as an innovative and sustainable adsorbent for Se(IV) and Se(VI) in water. Initially, the collected pristine MP mainly consisted of the low crystalline Mg(OH) 2 (brucite) phase. Subsequently, the MP underwent calcination (CMP), and analyses via scanning electron microscopy (SEM) and X-ray diffraction (XRD) confirmed an improved crystallinity, displaying a typical hexagonal plate structure in the aqueous phase. Notably, the CMP exhibited a significant adsorption capacity (q m : 85.0 mg/g) for Se(IV), while the adsorption capacity for Se(VI) was lower, determined as 3.0 mg/g using the Langmuir adsorption model. Se(IV) adsorption remained relatively consistent across a wide pH range and ionic strength in the presence of competing anions. In contrast, Se(VI) adsorption varied under the same conditions. This differing adsorption behavior of Se(IV) and Se(VI) on CMP could be ascribed to different mechanisms: inner-sphere predominant surface complexation for Se(IV) and outer-sphere complexation for Se(VI). These mechanisms were confirmed via X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), XRD, and SEM analyses, and surface complexation modeling (PHREEQC–PEST) of the batch experimental results. In conclusion, these findings underscored the potential utility of MP as an effective adsorbent for selenium, positioning it as an environmentally sustainable and significant novel material. Furthermore, the study offered mechanistic insights into the interaction between CMP, Se (IV), and Se(VI) in the aqueous phase. [Display omitted] • Study of rarely known magnesium precipitate (MP) from electrochlorination facility. • MP was calcined (CMP) to effectively adsorb Se(IV) and Se(VI) in water. • CMP showed 85.0 mg/g capacity for Se(IV) and 3.0 mg/g for Se(VI). • High selectivity for Se(IV) comparable to reported MgO adsorbent. • The surface complexation model revealed the selenium sorption mechanism onto CMP. [ABSTRACT FROM AUTHOR]