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Previous research studies confirmed that both resveratrol (RES) and β-hydroxy-β-methyl butyric acid (HMB) improved growth performance by altering intestinal microbiota. However, the mechanism underlying of RES and HMB on intestinal function remains unclear in ruminant. In this study, supplements of RES and HMB alone or in combination were evaluated as promoters of antioxidant capacity, immune response and barrier function, and modulators of the microbiota and metabolite profiles in the jejunum of Tibetan sheep. A total of 120 two-month-old Tibetan rams were randomly divided into four treatments (n = 30 per treatment), which were supplemented with a basal diet with 1.5 g RES/d (RES group), 1.25 g HMB/d (HMB group), 1.5 g RES/d plus 1.25 g HMB/d (RES-HMB group), and without additions (Control group). The results showed that RES and HMB improved the antioxidant capacity (CAT, GSH-Px, SOD, and T-AOC), immunity (IgA, IgG, and IgM), and digestive enzyme activity (α-amylase, lipase, and chymotrypsin) of the experimental lambs (p < 0.05). Additionally, jejunal morphology including villus width, villus height, and muscle layer thickness exhibited a significant difference when rams were fed diets supplemented with RES and HMB (p < 0.05). Furthermore, the determination of fermentation parameters showed that the butyrate concentration in the RES-HMB group was greater than those in the C and RES groups (p < 0.05). When compared to the C group, barrier-related gene expression (MUC-2, ZO-1, and IL-10) was significantly increased in the RES-HMB group (p < 0.05). Dietary RES and (or) HMB supplementation significantly increased the abundance of Methanobrevibacter, Actinobacteriota and Bacillus (p < 0.05). The abundance of differential bacteria was positively associated with butyrate concentration (p < 0.05). Metabolome analysis revealed that alpha ketoglutarate, succinic semialdehyde, and diacetyl as well as butanoate metabolism pathways connected to the improvements in butyrate concentration by RES and (or) HMB supplementation. Collectively, our results suggested that RES and (or) HMB supplementation improved butyrate concentration via regulating the microbial community (Methanobrevibacter, Actinobacteriota and Bacillus) and metabolism (alpha ketoglutarate, succinic semialdehyde, and diacetyl), thus contributing to jejunal morphology, antioxidant capacity, immune response, digestive enzyme activity, and barrier function. [ABSTRACT FROM AUTHOR]

Topological semimetals with nontrivial band crossing points have attracted widespread interest in recent years. Here, we propose that AB2 (A = Cr, Mo; B = Si, Ge) compounds are topological semimetals that feature a pair of triple points (TPs) on high-symmetry paths in the absence of spin–orbital coupling (SOC). In particular, the existence of this kind of TP is accompanied by a quadratic nodal line (QNL). In addition, we discover that these TPs are movable. Under a triaxial strain, we can change their positions on high-symmetry paths. When considering SOC, TPs transform into two pairs of type-II Dirac points along the high-symmetry path. Akin to TPs without SOC, each pair of Dirac points can also shift their positions on the high-symmetry paths under a triaxial strain. To characterize this property of TPs and Dirac points, we construct an effective model around the TPs and Dirac points, finding that there indeed exists a parameter that could characterize the movable properties for the TPs and Dirac points. According to the bulk-surface correspondence, we also discover that the length of the Fermi arcs that correspond to the nontrivial band crossings are also altered when changing their positions. Meanwhile, the shapes of Fermi arcs are also changed. Therefore, our work provides a platform to study the band crossings that are movable. The controllable fermions are beneficial to utilize the topological materials in nano-devices. [ABSTRACT FROM AUTHOR]

Novel spintronic materials combining both magnetism and nontrivial topological electronic structures have attracted increasing attention recently. Here, we systematically studied the doping effects, magnetism, half-metallicity, and topological properties in the family of Fe2−xVxPO5 (x = 0, 0.5, 1, 1.5, 2) compounds. Our results show that Fe2PO5 takes an antiferromagnetic (AFM) ordering with a zero total magnetic moment. Meanwhile, the material hosts a Dirac nodal line and a Weyl nodal line near the Fermi level. V2PO5 is a ferromagnetic (FM) nodal line half-metal with a 100% spin-polarized Weyl nodal line. After doping, we find that Fe1.5V0.5PO5, Fe1V1PO5 and Fe0.5V1.5PO5 all take ferrimagnetic (FiM) ordering, with the Fe and V atoms taking opposite spin directions. Both Fe1.5V0.5PO5 and Fe0.5V1.5PO5 are FiM half-metals. Meanwhile, they show several pairs of fully spin-polarized Weyl points near the Fermi level. Fe1V1PO5 is a FiM semiconductor with different sizes of band gaps in different spin channels. These Fe2−xVxPO5 materials not only provide a good research platform to study the novel properties combining magnetism and nontrivial band topology, but also have promising applications in spintronic applications. [ABSTRACT FROM AUTHOR]

Topological aspects of electronic structures have received intensive research interest in recent years. Here, we systematically investigate the electronic structure, doping effect and topological signature in a family of realistic compounds Li3−xNaxM (x = 3, 2, 1, 0; M = N, P, As, Sb, Bi). Without considering SOC, their electronic band structures show a doubly degenerate nodal line (NL) near the Fermi level in the Γ–A path. In addition, some compounds including Li2NaN, LiNa2N, Na3N and Na3Bi also exhibit one (or two) pair(s) of triply-degenerate nodal points (TDNPs) in the Γ–A path, locating at both sides of the Γ point. When SOC is taken into account, the band degeneracy of the NLs splits, and the scale of band splitting follows a positive correlation with the atomic weight of the M elements. Due to the band splitting by SOC, most of the Li3−xNaxM compounds show a pair of Dirac points (DPs) near the Fermi level. Very interestingly, we find that these DPs possess different types of band dispersions, namely type-I, type-II and the critical-type. The Fermi arcs from the DPs are identified. Our results indicate that Li3−xNaxM compounds are good candidates to study the novel properties of NLs, TDNPs, and DPs with different slopes of band dispersions. [ABSTRACT FROM AUTHOR]

Topological metals/semimetals, as novel topological states of matter, have been well investigated in nonmagnetic and ferromagnetic materials. Here, by performing band structure calculations, we report the discovery of rich topological states in an antiferromagnetic metal β-Fe2PO5. When spin–orbit coupling (SOC) is not considered, it hosts a Weyl nodal line, Dirac point, and Dirac nodal line near the Fermi level. In particular, the Weyl nodal line in β-Fe2PO5 is formed by the crossing bands from a single spin channel. Such a fully spin-polarized Weyl nodal line has not been identified in realistic AFM materials before. The Dirac point and Dirac nodal line in β-Fe2PO5 occur in a specific high-symmetry path, and are formed by the crossing bands from both spin channels, showing different signatures with the Weyl nodal line. When SOC is taken into account, the Weyl nodal line is retained, and the Dirac nodal point and nodal line degenerate into their Weyl counterparts. The existence of rich fermionic states in antiferromagnetic β-Fe2PO5 not only provides an excellent platform to study the entanglement between magnetism and topological states, but also shows great potential in topological antiferromagnetic spintronics applications. [ABSTRACT FROM AUTHOR]

This study investigated the effects of dietary resveratrol (RES) and β-Hydroxy-β-methyl butyric acid (HMB) on immune, oxidative, and morphological changes in the livers of Tibetan sheep using transcriptomics and metabolomics. One hundred and twenty male Tibetan lambs of a similar initial weight (15.5 ± 0.14 kg) were randomly divided into four groups with thirty lambs per treatment: (1) H group (basal diet without RES or HMB); (2) H-RES group (1.5 g/day of RES); (3) H-HMB group (1250 mg/day of HMB); (4) H-RES-HMB group (1.5 g/day of RES and 1250 mg/day of HMB). The experiment was conducted for 100 days, including a pre-test period of 10 days and a formal period of 90 days. The results showed significantly increased concentrations of glutathione peroxidase, superoxide dismutase, and IgM in the H-RES-HMB group ( p < 0.05), while the malondialdehyde levels were significantly decreased ( p < 0.05). The glycolytic indices including creatinine kinase (CK), malate dehydrogenase (MDH), and succinate dehydrogenase (SDH) were significantly increased in the H-RES-HMB group compared with the others ( p < 0.05). A histological analysis showed that the hepatic plate tissue in the H-RES-HMB group appeared normal with multiple cells. The transcriptomic analysis showed that the expression of genes associated with the calcium signaling pathway ( MYLK2 , CYSLTR2 , ADCY1 , HRH1 , ATP2B2 , NOS2 , HRC , ITPR1 , and CAMK2B ) and the NF-κB signaling pathway ( BCL2 and CARD14 ) in the H-RES-HMB group were upregulated. The key differential metabolites (d-pyroglutamic acid, DL-serine, DL-threonine, fumarate, and glyceric acid) were enriched in the pathways associated with D-amino acid metabolism, the citrate cycle (TCA cycle), and carbon metabolism. The combined transcriptomic and non-targeted metabolomic analyses showed the co-enrichment of differential genes ( NOS2 and GLUD1 ) and metabolites (fumarate) in arginine biosynthesis-regulated glycolytic activity, whereas the differential genes ( ME1 , SCD5 , FABP2 , RXRG , and CPT1B ) and metabolites (Leukotriene b4) co-enriched in the PPAR signaling pathway affected the immune response by regulating the PI3K/AKT and cGMP/PKG signaling. In conclusion, the dietary RES and HMB affected the hepatic antioxidant capacity, immune response, and glycolytic activity through modulating the transcriptome ( BCL2 , CAMK2B , ITPR1 , and IL1R1 ) and metabolome (DL-serine, DL-threonine, fumaric acid, and glycolic acid).

Topological semimetals with nontrivial band crossing points have attracted widespread interest in recent years. Here, we propose that AB 2 (A = Cr, Mo; B = Si, Ge) compounds are topological semimetals that feature a pair of triple points (TPs) on high-symmetry paths in the absence of spin-orbital coupling (SOC). In particular, the existence of this kind of TP is accompanied by a quadratic nodal line (QNL). In addition, we discover that these TPs are movable. Under a triaxial strain, we can change their positions on high-symmetry paths. When considering SOC, TPs transform into two pairs of type-II Dirac points along the high-symmetry path. Akin to TPs without SOC, each pair of Dirac points can also shift their positions on the high-symmetry paths under a triaxial strain. To characterize this property of TPs and Dirac points, we construct an effective model around the TPs and Dirac points, finding that there indeed exists a parameter that could characterize the movable properties for the TPs and Dirac points. According to the bulk-surface correspondence, we also discover that the length of the Fermi arcs that correspond to the nontrivial band crossings are also altered when changing their positions. Meanwhile, the shapes of Fermi arcs are also changed. Therefore, our work provides a platform to study the band crossings that are movable. The controllable fermions are beneficial to utilize the topological materials in nano-devices.

Novel spintronic materials combining both magnetism and nontrivial topological electronic structures have attracted increasing attention recently. Here, we systematically studied the doping effects, magnetism, half-metallicity, and topological properties in the family of Fe 2-x V x PO 5 (x = 0, 0.5, 1, 1.5, 2) compounds. Our results show that Fe 2 PO 5 takes an antiferromagnetic (AFM) ordering with a zero total magnetic moment. Meanwhile, the material hosts a Dirac nodal line and a Weyl nodal line near the Fermi level. V 2 PO 5 is a ferromagnetic (FM) nodal line half-metal with a 100% spin-polarized Weyl nodal line. After doping, we find that Fe 1.5 V 0.5 PO 5 , Fe 1 V 1 PO 5 and Fe 0.5 V 1.5 PO 5 all take ferrimagnetic (FiM) ordering, with the Fe and V atoms taking opposite spin directions. Both Fe 1.5 V 0.5 PO 5 and Fe 0.5 V 1.5 PO 5 are FiM half-metals. Meanwhile, they show several pairs of fully spin-polarized Weyl points near the Fermi level. Fe 1 V 1 PO 5 is a FiM semiconductor with different sizes of band gaps in different spin channels. These Fe 2-x V x PO 5 materials not only provide a good research platform to study the novel properties combining magnetism and nontrivial band topology, but also have promising applications in spintronic applications.

Topological aspects of electronic structures have received intensive research interest in recent years. Here, we systematically investigate the electronic structure, doping effect and topological signature in a family of realistic compounds Li 3-x Na x M (x = 3, 2, 1, 0; M = N, P, As, Sb, Bi). Without considering SOC, their electronic band structures show a doubly degenerate nodal line (NL) near the Fermi level in the Γ-A path. In addition, some compounds including Li 2 NaN, LiNa 2 N, Na 3 N and Na 3 Bi also exhibit one (or two) pair(s) of triply-degenerate nodal points (TDNPs) in the Γ-A path, locating at both sides of the Γ point. When SOC is taken into account, the band degeneracy of the NLs splits, and the scale of band splitting follows a positive correlation with the atomic weight of the M elements. Due to the band splitting by SOC, most of the Li 3-x Na x M compounds show a pair of Dirac points (DPs) near the Fermi level. Very interestingly, we find that these DPs possess different types of band dispersions, namely type-I, type-II and the critical-type. The Fermi arcs from the DPs are identified. Our results indicate that Li 3-x Na x M compounds are good candidates to study the novel properties of NLs, TDNPs, and DPs with different slopes of band dispersions.