Selenosugar, selenopolysaccharide, and putative selenoflavonoid in plants.

Selenium (Se) is a naturally occurring essential micronutrient that is required for human health. Selenium supports cellular antioxidant defense and possesses bioeffects such as anti-inflammation, anti-cancer, anti-diabetic, and cardiovascular and liver protective effects arising from Se-enhanced cellular antioxidant activity. Past studies on Se have focused on elucidating Se speciation in foods, biofortification strategies to produce Se-enriched foods to address Se deficiency in the population, and the biochemical activities of Se in health. The bioavailability and toxicity of Se are closely correlated to its chemical forms and may exhibit varying effects on body physiology. Selenium exists in inorganic and organic forms, in which inorganic Se such as sodium selenite and sodium selenate is more widely available. However, it is a challenge for safe and effective supplementation considering inorganic Se low bioavailability and high cytotoxicity. Organic Se, by contrast, exhibits higher bioavailability and lower toxicity and has a more diverse composition and structure. Organic Se exists as selenoamino acids and selenoproteins, but recent research has provided evidence that it also exists as selenosugars, selenopolysaccharides, and possibly as selenoflavonoids. Different food categories contain various Se compounds, and their Se profiles vary significantly. Therefore, it is necessary to delineate Se speciation in foods to understand their impact on health. This comprehensive review documents our knowledge of the recent uncovering of the existence of selenosugars and selenopolysaccharides and the putative evidence for selenoflavonoids. The bioavailability and bioactivities of these food-derived organic Se compounds are highlighted, in addition to their composition, structural features, and structure-activity relationships.

Catalytic modification of corn straw facilitates the remediation of Cd contaminated water and soil.

Turning postharvest residue into high-value-added products is crucial for agricultural waste management and environmental remediation. In this proof-of-concept study, nanosized Pt/TiO2 was used as a model catalyst to modify corn straw (CS) materials through a simple low-temperature oxidation process. This method was demonstrated to be self-sustainable, waste-free, and with high yields. At an optimal temperature of 220 °C, O2 treatment with 1 wt% Pt/TiO2 greatly changed ultra-micropore and mesopore structures, dissolved organic carbon, aromatic contents and surface oxygen (O)-containing functional groups in CS products. This treatment resulted in an approximately 5-fold increase of cadmium (Cd) adsorption from aqueous solution and immobilization rate of 43.1% at 7d for bioavailable Cd in soil. Spectroscopic and linear regression analysis demonstrated that both acidic and basic functional groups in CS contributed to Cd adsorption, suggesting chemical adsorption. According to the d-band theory, the unexpected role of catalysts in CS modification could be associated with dissociative adsorption of molecular O2 on the Pt surface. These results provide insights for the development of economic and sustainable technologies to reutilize agricultural waste biomass for water and soil remediation.

Selenoproteins in Health.

Selenium (Se) is a naturally occurring essential micronutrient that is required for human health. The existing form of Se includes inorganic and organic. In contrast to the inorganic Se, which has low bioavailability and high cytotoxicity, organic Se exhibits higher bioavailability, lower toxicity, and has a more diverse composition and structure. This review presents the nutritional benefits of Se by listing and linking selenoprotein (SeP) functions to evidence of health benefits. The research status of SeP from foods in recent years is introduced systematically, particularly the sources, biochemical transformation and speciation, and the bioactivities. These aspects are elaborated with references for further research and utilization of organic Se compounds in the field of health.

Probing the effect of Cu-SrO loading on catalyst supports (ZSM-5, Y-zeolite, activated carbon, Al2O3, and ZrO2) for aromatics production during catalytic co-pyrolysis of biomass and waste cooking oil.

In this work, Cu-SrO bimetallic catalyst was synthesised and examined for catalytic co-pyrolysis of ironbark (IB) and waste cooking oil (WCO) using Py-GC/MS. The effect of catalyst supports (ZSM-5, Y-zeolite, activated carbon, Al2O3, and ZrO2) on aromatic hydrocarbons yield was studied. The effect of catalyst support on the selectivity of gasoline (C8-C14), diesel (C15-C17), and heavy oil (>C20) components of bio-oil were studied. Non-catalytic co-pyrolysis of IB and WCO produced a heavy oil component of 58.7% (>C20). SrO initiated a ketonization reaction that converted carboxylic acids into new C-C bonds. The addition of Cu effectively promoted secondary cracking and aromatization reactions enhancing the hydrocarbon yield. Cu-SrO/ZSM-5 and Cu-SrO/Y-zeolite produced low acid content of 4.43% and 12.5%, respectively. Overall, the bimetallic catalyst Cu-SrO/ZSM-5 significantly increased the amount of C8-C14 compounds to 87.28% and reduced compounds over C20 to 1.19%.

The role of fingernail selenium in the association between arsenic, lead and mercury and child development in rural Vietnam: a cross-sectional analysis.

As, Pb and Hg are common environmental contaminants in low- and middle-income countries. We investigated the association between child toxicant exposure and growth and development and determined if this association was mitigated by Se concentration. Toxicant concentrations in fingernail samples, anthropometry and Bayley's Scales of Infant Development, 3rd edition domains were assessed in 36-month-old children whose mothers had been part of a randomised controlled trial in rural Vietnam. Multivariable regression analyses were performed to estimate the effect of toxicant exposure on clinical outcomes with adjustments for potential confounders and interaction with fingernail Se concentration. We analysed 658 children who had data for at least one physical or developmental outcome, and at least one toxicant measurement, and each of the covariates. Fingernail As concentration was negatively associated with language (estimate per 10 % increase in As: -0·19, 95 % CI: (-0·32, -0·05)). Pb was negatively associated with cognition (estimate per 10 % increase in Pb: -0·08 (-0·15, -0·02)), language (estimate per 10 % increase in Pb: -0·18 (-0·28, -0·10)) and motor skills (estimate per 10 % increase in Pb: -0·12 (-0·24, 0·00)). Hg was negatively associated with cognition (estimate per 10 % increase in Hg: -0·48, (-0·72, -0·23)) and language (estimate per 10 % increase in Hg -0·51, (-0·88, -0·13)) when Se concentration was set at zero in the model. As Se concentration increased, the negative associations between Hg and both cognition and language scores were attenuated. There was no association between toxicant concentration and growth. As, Pb and Hg concentrations in fingernails of 3-year-old children were associated with lower child development scores. The negative association between Hg and neurological development was reduced in magnitude with increasing Se concentration. Se status should be considered when assessing heavy metal toxicants in children and their impact on neurodevelopmental outcomes.

Reduced graphene oxide-silicon interface involving direct Si-O bonding as a conductive and mechanical stable ohmic contact.

Metal-semiconductor junctions are essential contacts for semiconductor devices, but high contact junction resistance is a limiting operational factor. Here, we establish an ohmic contact of low resistance of <4 × 10-6 Ω cm2 between platinum and n-type Si (111)-H surfaces. This involved Si-O covalent bonding a monolayer of graphene oxide (GO) to the Si surface followed by electrochemical reduction to form reduced graphene oxide (rGO). Current-voltage plots demonstrate that the GO/rGO transformation is associated with a change from a rectifying to an ohmic contact. The process is a viable method for constructing semiconductor-rGO interfaces and demonstrates that GO/rGO monolayers can be used as active components in tuning the contact resistance of metal-semiconductor junctions.

Volatile chemical emissions from fragranced baby products.

Fragranced consumer products have been associated with adverse effects on human health. Babies are exposed to a variety of fragranced consumer products, which can emit numerous volatile organic compounds (VOCs), some considered potentially hazardous. However, fragranced baby products are exempt from disclosure of all ingredients. Consequently, parents and the public have little information on product emissions. This study investigates VOCs emitted from a range of fragranced baby products, including baby hair shampoos, body washes, lotions, creams, ointments, oils, hair sprays, and fragrance. The products were analysed using gas chromatography/mass spectrometry (GC/MS) headspace analysis. Of the 42 baby products tested, 21 products made claims of green, organic, or all-natural. Results of the analysis found 684 VOCs emitted collectively from the 42 products, representing 228 different VOCs. Of these 684 VOCs, 207 are classified as potentially hazardous under federal regulations, representing 43 different VOCs. The most common VOCs emitted were limonene, acetaldehyde, ethanol, alpha-pinene, linalool, beta-myrcene, acetone, and beta-pinene. A comparison between ingredients emitted and ingredients listed reveals that only 5% of the 684 VOCs, including 12% of 207 potentially hazardous VOCs, were listed on the product label, safety data sheet, or website. More than 95% of both green and regular products emitted one or more potentially hazardous VOCs. Further, emissions of the most prevalent VOCs from green, organic, or all-natural products were not significantly different from regular products. Results from this study can help improve public awareness about emissions from baby products, with the aim to reduce pollutant exposure and potential adverse effects on babies.

Continuous flow synthesis of phosphate binding h-BN@magnetite hybrid material.

Hexagonal boron nitride (h-BN) is rendered magnetically responsive in aqueous media by binding superparamagnetic magnetite nanoparticles 8.5-18.5 nm in diameter on the surface. The composite material was generated under continuous flow in water in a dynamic thin film in a vortex fluidic device (VFD) with the source of iron generated by laser ablation of a pure iron metal target in the air above the liquid using a Nd:YAG pulsed laser operating at 1064 nm and 360 mJ. Optimum operating parameters of the VFD were a rotational speed of 7.5k rpm for the 20 mm OD (17.5 mm ID) borosilicate glass tube inclined at 45 degrees, with a h-BN concentration at 0.1 mg mL-1, delivered at 1.0 mL min-1 using a magnetically stirred syringe to keep the h-BN uniformly dispersed in water prior to injection into the base of the rapidly rotating tube. The resulting composite material, containing 5.75% weight of iron, exhibited high phosphate ion adsorption capacity, up to 171.2 mg PO4 3- per gram Fe, which was preserved on recycling the material five times.