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Hydrogen activation, storage properties and associated crystal structures of Ti 1- x Sc x Mn 1.6 V 0.4 (x = 0, 0.05, 0.1, 0.15, 0.2, 0.25) alloys are investigated by hydrogenation and XRD. The unit-cells of alloys and hydrides expand with Sc content and hydrogen concentration. Minor addition of Sc significantly improves hydrogen activation and storage properties. The plateau pressure decreases, whereas the sloping factor and relative partial molar enthalpy for hydrogenation increase with Sc content. The activation properties strongly depend on the particle sizes. The bulk samples can easily be activated by implementing a hydrogen-induced cracking mechanism, which avoids removal of protective oxide films and compensates the lack of metallic B-metal in catalysis of hydrogen dissociation. Samples with smaller particle sizes are difficult to activate. The unusual particle size effect is interpreted by activation kinetics, and attributed to the high oxygen binding ability of B-metals and their contribution to the surface oxide films. • Ti 1- x Sc x Mn 1.6 V 0.4 alloys and hydrides expand with Sc content and H concentration. • Minor addition of Sc in the alloy significantly improves hydrogen storage properties. • Hydrogen activation properties improve with increasing Sc content in the alloy. • Hydrogen activation properties of the alloys deteriorate with smaller particle sizes. • Unusual particle size effect is attribute of high oxygen binding ability of B-metals. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Phase transformation from 1:5H phase to 2:17 R phase was observed in anisotropic nanocrystalline SmCo 5 magnets. • Phase transformation results in much lower coercivity in the wet-milled anisotropic magnets when compared with the dry-milled isotropic magnets. • Phase transformation in wet-milled powder is much easier than that in dry-milled powder during heating. • Phase transformation originates from the oxidation of the nanoflakes with large specific surface area during sintering. Abstract SmCo 5 nanoflakes with excellent texture have great potential applications in high performance nanocomposite magnets, in which the phase structure of the hard magnetic phase is crucial for obtaining large coercivity. Phase transformation from 1:5H phase to 2:17 R phase is observed in anisotropic nanocrystalline SmCo 5 magnets when sintering the nanoflakes at 600–650 °C. The phase transformation is interesting because the 1:5H phase is relatively stable according to the thermodynamic and kinetic analysis. The phase transformation results in much lower coercivity of the wet-milled anisotropic magnets when compared with dry-milled isotropic magnets with 1:5H single phase. Analyses of differential scanning calorimetry, thermogravity and energy dispersive X-ray validate that the phase transformation originates from the oxidation of the nanoflakes with large specific surface area during sintering. The results suggest that controlling oxygen content strictly during sintering is necessary for maintaining 1:5H single phase in anisotropic nanocrystalline SmCo 5 magnets prepared by sintering the nanoflakes. [ABSTRACT FROM AUTHOR]

In order to understand the molecular mechanism of response to heat stress in largemouth bass (LMB) Micropterus salmoides , we performed transcriptome analysis of spleen tissue of LMB subjected to heat stress and challenged with A. veronii under heat stress. A total of 2162 DEGs were identified between the heat stressed (32 °C) and control groups (24 °C) after 7 d treatment. Gene Ontology (GO) annotation analysis revealed that these differentially expressed genes (DEGs) were mainly enriched on GO terms of biological regulation, membrane part, and binding. ELISA validation indicated that except major histocompatibility complex II (Mhc II), the protein levels of t-Sod, caspase 3 (Casp3), tumor necrosis factor-α (Tnf-α), and complement component 3 (C3) were consistent with RNA-seq results. In the experiment of A. veronii challenged under heat stress (32 °C), 2899 and 2663 DEGs were obtained from the heat stress-challenged group (H6 vs H0, H12 vs H0), while 1485 and 3501 DEGs from the control-challenged group (C6 vs C0, C12 vs C0). GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that immune-related categories and pathways were significantly enriched, such as immune system process, immune response and positive regulation of immune response in GO enrichment analysis, and cytokine-cytokine receptor interaction, human cytomegalovirus infection in KEGG signaling pathways. The expressions of f11 , c1q and c3 in complement and coagulation pathway, as well as that of proinflammatory genes tnf-α and il-8 , were deeply inhibited. Real-time quantitative PCR validation for nine DEGs showed that most of them had consistent expression trends with RNA-seq results. Our results indicated that heat stress affects the immunity and metabolism of LMB. In particular, it aggravates the inhibitory effects of A. veronii on the complement and coagulation systems while downregulating proinflammatory cytokine expression, thereby weakening the resistance of LMB to pathogen infection. Our results contribute to the elucidation of A. veronii infection pathogenic mechanisms in LMB under heat stress. [Display omitted] • Heat stress suppressed the immune response of largemouth bass to Aeromonas veronii. • Heat stress decreased complement and coagulation related gene expression. • Proinflammatory cytokine expression was also suppressed in response to heat stress. • High water temperatures contribute to infection related largemouth bass mortality. [ABSTRACT FROM AUTHOR]

Abstract: In activation of hydrogen storage alloys, the nickel-group metals, especially Pd, act as the catalysts to dissociate hydrogen and turn the alloys into successful hydrogen absorbers. The Laves phase Sc and Zr alloys with Cr–Mn as common components exhibit extraordinary hydrogen activation properties matching Pd. Through a cracking mechanism, the bulk samples of these alloys rapidly absorb hydrogen at sub-atmospheric pressures and room-temperature, achieve absorption performance of those Pd surface-modified alloys, meanwhile retaining good reversibility. Among them, the ScCrMn exhibits significantly higher absorption rate than Pd, whereas, the ZrCrMn shows similar absorption kinetics and reversibility to Pd. The shortest initial-activation-time, highest initial-activation-rate and lowest allowed-activation-pressure achieved by ScCrMn are 15 s, −16.6 kPa/s and 0.46 kPa, respectively, in comparison with those of 18 s, 3.2 kPa/s and 0.13 kPa for Pd powder measured under equivalent conditions. The findings and associated magnetization measurements indicate that Cr and Mn upon alloying with certain lower valence metals possess surface electronic structures highly beneficial to hydrogen dissociation. [Copyright &y& Elsevier]

The kisspeptin system, which lies upstream of the hypothalamic–pituitary–gonadal (HPG) axis, is believed to function as a regulator of reproduction in teleosts. In this study, we isolated and characterized kiss2 and its receptor kissr2 in largemouth bass (Micropterus salmoides). The complete coding sequences of kiss2 and kissr2 were 375 and 1134 bp long and encoded precursor proteins 124 and 377 amino acid long, respectively. Real-time PCR showed that kiss2 and kissr2 were primarily expressed in the HPG axis. The expression profile of kiss2 and kissr2 varied with gonadal development, with the highest and lowest expression levels being detected during the immature and final maturation stages, respectively. Intraperitoneal injection of exogenous Kiss2–10 peptide increased the transcript levels of gnrh3 , kissr2 , fshβ , lhβ , ar, and er2 within 24 h (p < 0.05), as well as plasma levels of 17 β -estradiol and testosterone. Histological analysis indicated that chronic administration of exogenous Kiss2–10 peptide accelerated vitellogenesis in females and spermatogenesis in males. Further, in situ hybridization revealed that kiss2 is expressed in the ooplasm and vitelline envelope of oocytes and the spermatocytes of testes. In addition, experiments using gonad tissue primary cell cultures indicated that exogenous Kiss2–10 peptide stimulates the expression of reproduction-related genes. Collectively, our findings indicate that the kiss2 / kissr2 system in largemouth bass is involved in regulating gonadal development through the HPG axis. [Display omitted] • Largemouth bass kiss2 / kissr2 was isolated and characterized. • The expression profile of kiss2 and kissr2 varied with gonadal development. • Kiss2-10 peptides increased HPG axis-related gene transcript levels, sex hormone levels, and accelerated puberty onset. • The gonad kisspeptin system stimulated the expression of reproduction-related genes. [ABSTRACT FROM AUTHOR]

In this study, Mo 0.9 Cr 0.1 AlB solid solution ceramic bulks were prepared from the element powder mixtures using hot pressing sintering method. Compared with MoAlB ceramics, the grains of as-prepared Mo 0.9 Cr 0.1 AlB were refined obviously. The lattice constants of Mo 0.9 Cr 0.1 AlB were confirmed to be a = 3.205 Å, b = 13.999 Å and c = 3.098 Å. The density of Mo 0.9 Cr 0.1 AlB was lower than that of MoAlB due to the incorporation of Cr element. In addition, the effect of doping Cr element on the comprehensive mechanical properties was studied as well. The hardness and compressive strength were improved significantly. In comparison with MoAlB ceramic, the improvement of mechanical properties could be attributed to solid solution strengthening and grain refinement. [ABSTRACT FROM AUTHOR]

Hydrogen storage properties, activation performance and thermodynamics of Ti 0.7 Zr 0.3 (Mn 1− x V x ) 2 ( x = 0.1, 0.2, 0.3, 0.4, 0.5) alloys and associated microstructures and surface chemical states were investigated by hydrogenation measurements and relevant structure and surface characterization methods. The results showed that the phase composition of the alloy changed from single C14 Laves phase ( x ≤ 0.2) to coexistent Laves phase and V-based BCC solid solution phase with increasing V content ( x ≥ 0.3). The V in the alloys catalyzed hydrogen dissociation and improved resistivity to oxygen poisoning, so that the alloys could be easily and quickly activated at 293 K even after being exposed in air for a long time. The hydrogen storage capacity of the alloy increased and the plateau pressure decreased with increasing V content. The x = 0.2 and 0.3 alloys exhibited the best reversible hydrogen storage capacities of above 1.8 wt% at 1 kPa–4 MPa and 293 K. The relative partial molar enthalpy | Δ H | increased but the relative partial molar entropy | Δ S | decreased with increasing V content, and deviated from the linear relationship for x = 0.4 and 0.5 alloys due to coexisted BCC phase in the alloys. [ABSTRACT FROM AUTHOR]