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This study was carried out to evaluate the effects of nano selenium (nano-Se) and conjugated linoleic acid (CLA) on performance, biometric and blood parameters and selenoprotein W1 (SEPW1) and lipid gene expression in male Moghani lambs. Thirty male Moghani lambs, 3-months-old and weighing 30 ± 0.25 kg, were used in completely randomized design in a 2 x 3 factorial arrangement with dietary supplemental the CLA (0 and 15 g/kg DM) and nano-Se (0, 1 and 2 mg/kg DM). The lambs were slaughtered on day 90 (end of experiment). Feeding a mixture of CLA and nano-Se tended to reduce the body weight of lambs comparing to the control group. The experimental diets had no impact on biometric parameters. Some blood parameters like high density lipoprotein (HDL), low density lipoprotein (LDL), thyroxine (T4), triiodothyronine (T3) and glutathione peroxidase (GPx) and glutathione peroxidase depended on dietary nano-Se supplementation (P<0.05); but glucose, triglycerides (TG), very low density lipoprotein (VLDL), total protein (TP) and cholesterol had no considerable effects. The results of qPCR analysis showed that nano-Se supplemental at highest level (2 mg/kg DM) increased gene expression of GPX1 and SEPW1 in liver (P<0.05). Dietary inclusion of CLA enhanced the peroxisome proliferator-activated receptor gamma expression and decreased stearoyl COA desaturase 1 genes in tail (P<0.01). In conclusion, nano-Se and CLA differently increased the gene expression in liver and tail and had good impacts on some blood parameters; suggesting that nano-Se and CLA have not synergism interaction in the above parameters. [ABSTRACT FROM AUTHOR]

The early interest in selenium (Se) focused on its toxicity, but since 1957 it has been recognized as an essential dietary element. The diet is the major Se source and approximately 80% of dietary Se is absorbed, depending on the type of food consumed. In several regions of the world, the content of Se in diets has been estimated as insufficient. The dietary requirement for Se for most species is about 0.3 ppm. Deficiencies of Se in animals have been confirmed under natural grazing conditions in many countries. Symptoms of deficiencies such as white muscle disease occur primarily in young calves or lambs born in low Se regions and thus we need to provide sufficient amounts in animal diets. Numerous studies have demonstrated that Se plays an important role in animal health. Therefore, this review gives a brief outline of the current information on the physical, chemical and metabolic properties of Se, oxidative stress, antioxidant defense, dietary requirement, deficiency, toxicity and effects of Se on fertility and performance. [ABSTRACT FROM AUTHOR]

The efforts to increase the active surface area of catalysts led to reduction of metal particle size, down to single metal atoms. This results in increasing importance of support-metal interactions. We demonstrate the mechanisms through which the support influences catalytic activity of nanoclusters: the support electronics, described by the O 2p energy level, and the support surface chemistry, determined by the density of Lewis base sites. Using Ru nanoclusters, our study shows that these parameters can be effectively captured within a single catalyst support descriptor (CSD). The apparent activation energy and turnover frequency (TOF) for the ammonia synthesis correlates strongly with CSD measured for the series Ru/MgO, Ru/Sc 2 O 3 , Ru/CeO 2 , Ru/La 2 O 3 , and Ru/Y 2 O 3 . Furthermore, the study demonstrates that CSD correlates linearly with the binding strength of N-Ru in nanocluster, thereby providing a direct link between the catalyst's surface chemistry and the nature of the support. The catalyst support descriptor developed in this study serves as a simple yet powerful tool for selecting the optimal support material to maximise the activity of metal nanoclusters without altering the metal itself., Competing Interests: The authors declare no competing interests., (This journal is © The Royal Society of Chemistry.)

Atomic-scale changes can significantly impact heterogeneous catalysis, yet their atomic mechanisms are challenging to establish using conventional analysis methods. By using identical location scanning transmission electron microscopy (IL-STEM), which provides quantitative information at the single-particle level, we investigated the mechanisms of atomic evolution of Ru nanoclusters during the ammonia decomposition reaction. Nanometre-sized disordered nanoclusters transform into truncated nano-pyramids with stepped edges, leading to increased hydrogen production from ammonia. IL-STEM imaging demonstrated coalescence and Ostwald ripening as mechanisms of nanocluster pyramidalization during the activation stage, with coalescence becoming the primary mechanism under the reaction conditions. Single Ru atoms, a co-product of the catalyst activation, become absorbed by the nano-pyramids, improving their atomic ordering. Ru nano-pyramids with a 2-3 nm 2 footprint consisting of 3-5 atomic layers, ensure the maximum concentration of active sites necessary for the rate-determining step. Importantly, the growth of truncated pyramids typically does not exceed a footprint of approximately 4 nm 2 even after 12 hours of the reaction, indicating their high stability and explaining ruthenium's superior activity on nanotextured graphitic carbon compared to other support materials. The structural evolution of nanometer-sized metal clusters with a large fraction of surface atoms is qualitatively different from traditional several-nm nanoparticles, where surface atoms are a minority, and it offers a blueprint for the design of active and sustainable catalysts necessary for hydrogen production from ammonia, which is becoming one of the critical reactions for net-zero technologies., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A key strategy for minimizing our reliance on precious metals is to increase the fraction of surface atoms and improve the metal-support interface. In this work, we employ a solvent/ligand/counterion-free method to deposit copper in the atomic form directly onto a nanotextured surface of graphitized carbon nanofibers (GNFs). Our results demonstrate that under these conditions, copper atoms coalesce into nanoparticles securely anchored to the graphitic step edges, limiting their growth to 2-5 nm. The resultant hybrid Cu/GNF material displays high selectivity in the CO 2 reduction reaction (CO 2 RR) for formate production with a faradaic efficiency of ~94% at -0.38 V vs RHE and a high turnover frequency of 2.78 × 10 6  h -1 . The Cu nanoparticles adhered to the graphitic step edges significantly enhance electron transfer to CO 2 . Long-term CO 2 RR tests coupled with atomic-scale elucidation of changes in Cu/GNF reveal nanoparticles coarsening, and a simultaneous increase in the fraction of single Cu atoms. These changes in the catalyst structure make the onset of the CO 2 reduction potential more negative, leading to less formate production at -0.38 V vs RHE, correlating with a less efficient competition of CO 2 with H 2 O for adsorption on single Cu atoms on the graphitic surfaces, revealed by density functional theory calculations., (© 2024. Crown.)

The production of atomically dispersed metal catalysts remains a significant challenge in the field of heterogeneous catalysis due to coexistence with continuously packed sites such as nanoclusters and nanoparticles. This work presents a comprehensive guidance on how to increase the degree of atomization through a selection of appropriate experimental conditions and supports. It is based on a rigorous macro-kinetic theory that captures relevant competing processes of nucleation and formation of single atoms stabilized by point defects. The effects of metal-support interactions and deposition parameters on the resulting single atom to nanocluster ratio as well as the role of metal centers formed on point defects in the kinetics of nucleation have been established, thus paving the way to guided synthesis of single atom catalysts. The predictions are supported by experimental results on sputter deposition of Pt on exfoliated hexagonal boron nitride, as imaged by aberration-corrected scanning transmission electron microscopy.

The characteristics of two-dimensional (2D) materials can be tuned by low-energy ion irradiation provided that the ion energy is correctly chosen. The optimum ion energy is related to E th ion , the minimum kinetic energy the ion should have to displace an atom from the material. E th ion can be assessed using the binary collision approximation (BCA) when the displacement threshold of the atom is known. However, for some ions the experimental data contradict the BCA results. Using density functional theory molecular dynamics (DFT-MD), we study the collisions of low-energy ions with graphene and hexagonal boron nitride and demonstrate that the BCA can strongly overestimate E th ion because energy transfer takes a finite time, and therefore, chemical interactions of the ion with the target are important. Finally, for all projectiles from H up to Ar, we calculate the values of E th ion required to displace an atom from graphene and h-BN, the archetypal 2D materials.

Unprecedented 2D metal chloride structures are grown between sheets of bilayer graphene through intercalation of metal and chlorine atoms. Numerous spatially confined 2D phases of AlCl 3 and CuCl 2 distinct from their typical bulk forms are found, and the transformations between these new phases under the electron beam are directly observed by in situ scanning transmission electron microscopy (STEM). The density functional theory calculations confirm the metastability of the atomic structures derived from the STEM experiments and provide insights into the electronic properties of the phases, which range from insulators to semimetals. Additionally, the co-intercalation of different metal chlorides is found to create completely new hybrid systems; in-plane quasi-1D AlCl 3 /CuCl 2 heterostructures are obtained. The existence of polymorphic phases hints at the unique possibilities for fabricating new types of 2D materials with diverse electronic properties confined between graphene sheets., (© 2021 Wiley-VCH GmbH.)

Controlled production of defects in hexagonal boron nitride (h-BN) through ion irradiation has recently been demonstrated to be an effective tool for adding new functionalities to this material, such as single-photon generation, and for developing optical quantum applications. Using analytical potential molecular dynamics, we study the mechanisms of vacancy creation in single- and multi-layer h-BN under low- and high-fluence ion irradiation. Our results quantify the densities of defects produced by noble gas ions in a wide range of ion energies and elucidate the types and distribution of defects in the target. The simulation data can directly be used to guide the experiment aimed at the creation of defects of particular types in h-BN targets for single-photon emission, spin-selective optical transitions and other applications by using beams of energetic ions.

Nowadays, the functionalization of food products using natural health-promoting additives is of great interest. Betalains are the natural pigments of red beets and are known for their health-promoting characteristics. The aim of this study was to evaluate gummy candies formulated with red beet extract (0.1 or 0.3%) as the coloring agent, Salix aegyptiaca distillate as the flavoring agent, and gellan gum (0.5 or 1.5%) as the gelling co-agent. The prepared gummy candy samples were assessed via texture profile analysis, DPPH assay, sensory evaluation, and color analysis. The results revealed that hardness (~ 60 N) improved and gumminess (~ 15 N) decreased with an increment in gellan gum content in the gummy candy formulation. Statistical analysis indicated that by addition of red beet extract, the radical scavenging capacity of the samples increased (50%) significantly ( p  < 0.05). Furthermore, gellan gum usage lead to the generation of a glossy red color and enhanced the lightness of the samples in comparison with gelatin-based gummy candies. About sensory evaluation, the panelists confirmed that usage of Salix aegyptiaca improved the sensory characteristics of the gummy candy (overall acceptance from 7.4 to 8.2; out of 9). Our findings suggest that gellan gum (as a highly transparent, acid-resistant, gel-forming gum), red beet extract (as an acid-stabilized natural color), and Salix aegyptiaca distillate have immense potential in the food industry for use as structuring, coloring, and flavoring agents, respectively., (© Association of Food Scientists & Technologists (India) 2020.)

Sheep keepers need suitable strategies to improve animal immunity and the quality of their products. This study was aimed to evaluate the effect of nano-selenium (nano-Se) and conjugated linoleic acid (CLA) on an antioxidant statue, trace minerals, and mRNA expression of glutathione peroxidase 1 (GPX1) and selenoprotein W1 (SEPW1) genes in the liver and peroxisome proliferator-activated receptor-gamma (PPARγ) and stearoyl COA desaturase 1 (SCD1) genes in fat- tail of male Moghani lambs. Thirty male Moghani lambs, three months old and average weight 30.00 ± 0.25 kg, were assigned to a completely randomized design in a 2×3 factorial arrangement with dietary supplementation of nano-Se (0, 1.00 and 2.00 mg kg -1 dry matter) and CLA (0.00 and 15.00 g kg -1 dry matter). The lambs were slaughtered at the end of the experiment, on day 90 of the experiment. Results showed that dietary inclusion of nano-Se significantly improved antioxidant enzymes glutathione peroxidase and superoxide dismutase in blood, however, did not show any differences in trace mineral treatments. The analysis of qPCR showed that nano-Se inclusion at the highest level (2.00 g kg -1 dry matter) enhanced gene expression of GPX1 (0.64 vs 0.34) and SEPW1 (0.72 vs 0.35) in the liver. Dietary inclusion of CLA increased the expression of PPARγ (0.63 vs 0.38) and decreased SCD1 (0.63 vs 0.33) genes in fat- tail. It could be concluded that selenium inclusion in the growing lamb's diet could improve antioxidant status, however, no synergistic interaction was observed along with CLA on the mentioned parameters., (© 2020 Urmia University. All rights reserved.)

Two-dimensional (2D) materials with nanometer-size holes are promising systems for DNA sequencing, water purification, and molecule selection/separation. However, controllable creation of holes with uniform sizes and shapes is still a challenge, especially when the 2D material consists of several atomic layers as, e.g., MoS 2 , the archetypical transition metal dichalcogenide. We use analytical potential molecular dynamics simulations to study the response of 2D MoS 2 to cluster irradiation. We model both freestanding and supported sheets and assess the amount of damage created in MoS 2 by the impacts of noble gas clusters in a wide range of cluster energies and incident angles. We show that cluster irradiation can be used to produce uniform holes in 2D MoS 2 with the diameter being dependent on cluster size and energy. Energetic clusters can also be used to displace sulfur atoms preferentially from either top or bottom layers of S atoms in MoS 2 and also clean the surface of MoS 2 sheets from adsorbents. Our results for MoS 2 , which should be relevant to other 2D transition metal dichalcogenides, suggest new routes toward cluster beam engineering of devices based on 2D inorganic materials.

The interpretation of helium ion microscopy (HIM) images of crystalline metal clusters requires microscopic understanding of the effects of He ion irradiation on the system, including energy deposition and associated heating, as well as channeling patterns. While channeling in bulk metals has been studied at length, there is no quantitative data for small clusters. We carry out molecular dynamics simulations to investigate the behavior of gold nanoparticles with diameters of 5-15 nm under 30 keV He ion irradiation. We show that impacts of the ions can give rise to substantial heating of the clusters through deposition of energy into electronic degrees of freedom, but it does not affect channeling, as clusters cool down between consecutive impact of the ions under typical imaging conditions. At the same time, high temperatures and small cluster sizes should give rise to fast annealing of defects so that the system remains crystalline. Our results show that ion-channeling occurs not only in the principal low-index, but also in the intermediate directions. The strengths of different channels are specified, and their correlations with sputtering-yield and damage production is discussed, along with size-dependence of these properties. The effects of planar defects, such as stacking faults on channeling were also investigated. Finally, we discuss the implications of our results for the analysis of HIM images of metal clusters.

Focused ion beams perfectly suit for patterning two-dimensional (2D) materials, but the optimization of irradiation parameters requires full microscopic understanding of defect production mechanisms. In contrast to freestanding 2D systems, the details of damage creation in supported 2D materials are not fully understood, whereas the majority of experiments have been carried out for 2D targets deposited on substrates. Here, we suggest a universal and computationally efficient scheme to model the irradiation of supported 2D materials, which combines analytical potential molecular dynamics with Monte Carlo simulations and makes it possible to independently assess the contributions to the damage from backscattered ions and atoms sputtered from the substrate. Using the scheme, we study the defect production in graphene and MoS 2 sheets, which are the two most important and wide-spread 2D materials, deposited on a SiO 2 substrate. For helium and neon ions with a wide range of initial ion energies including those used in a commercial helium ion microscope (HIM), we demonstrate that depending on the ion energy and mass, the defect production in 2D systems can be dominated by backscattered ions and sputtered substrate atoms rather than by the direct ion impacts and that the amount of damage in 2D materials heavily depends on whether a substrate is present or not. We also study the factors which limit the spatial resolution of the patterning process. Our results, which agree well with the available experimental data, provide not only insights into defect production but also quantitative information, which can be used for the minimization of damage during imaging in HIM or optimization of the patterning process.