Energetic stability and magnetic moment of tri-, tetra-, and octa- ferromagnetic element nitrides predicted by first-principle calculations

Formation energies and magnetic moments of tri-, tetra-, and octa- ferromagnetic element nitrides have been calculated using spin-polarized Perdew–Wang generalized gradient approximations of the density functional theory. From the energetic point of view, Fe4N are more stable compared to Fe and N2 gas. Ni4N may be a metastable phase since mixture of Ni3N and Ni would be more energetically stable. Fe4N may be also a metastable from energetic point of view but effect of configurational entropy caused by N-vacancy and of disregarded random occupation of interstitial sites by N observed in Fe3N must be evaluated so as to make precise evaluation, which is beyond the scope of the present work. Co4N are not stable compared to Co metal with the hcp structure and N2 gas, but more stable in case Co metal with the fcc structure is used as a reference state. Only Fe8N with the α″-Fe16N2 type structure would be stable among octa-metal nitrides with the assumed structure of the α″-Fe16N2 type and the Ni32N4 type structure. All of Fe3N, Co3N, and Ni3N are stable, but Ni3N would be non-magnetic in contrast to ferromagnetism of other tri-metal nitrides

Relationship between the Hip Abductor Muscles and Abduction Strength in Patients with Hip Osteoarthritis

This study aimed to determine which muscle the gluteus maximus, gluteus medius, gluteus minimus (Gmin), or tensor fasciae latae (TFL) contributes most to hip abduction strength and to identify effective sites for cross-sectional area (CSA) Gmin and TFL measurement in hip osteoarthritis (OAhip) patients. Twenty-eight patients with OAhip were included. The muscle CSA and volume were determined using magnetic resonance imaging. Peak isometric strength was determined using hand-held dynamometry. Muscle volumes were normalized to the total muscle volume of hip abductors. Multiple regression analysis was performed. The difference between the CSA of Gmin and TFL was calculated, and correlations with volume and muscle strength were determined. Gmin volume was related to abductor muscle strength (p=0.042). The peak CSA of the Gmin correlated with muscle volume and strength. The CSA of the TFL correlated with volume, with no difference between the CSA of the most protruding part of the lesser trochanter and peak CSA. Gmin volume was strongly related to abductor muscle strength. Peak CSA is a useful parameter for assessing the CSA of the Gmin among patients with OAhip. The CSA of the TFL should be measured at the most protruding part of the lesser trochanter

Inhomogeneous superconductivity in thin crystals of FeSe1-xTex (x=1.0, 0.95, and 0.9)

We investigated the temperature dependence of resistivity in thin crystals of FeSe1-xTex (x = 1.0, 0.95, and 0.9), though bulk crystals with 1.0 x 0.9 are known to be non-superconducting. With decreasing thickness of the crystals, the resistivity of x = 0.95 and 0.9 decreases and reaches zero at a low temperature, which indicates a clear superconducting transition. The anomaly of resistivity related to the structural and magnetic transitions completely disappears in 55- to 155-nm-thick crystals of x = 0.9, resulting in metallic behavior in the normal state. Microbeam x-ray diffraction measurements were performed on bulk single crystals and thin crystals of FeSe1-xTex. A significant difference of the lattice constant, c, was observed in FeSe1-xTex, which varied with differing Te content (x), and even in crystals with the same x, which was mainly caused by inhomogeneity of the Se/Te distribution. It has been found that the characteristic temperatures causing the structural and magnetic transition (T-t), the superconducting transition (T-c), and the zero resistivity (T-c(zero)) are closely related to the value of c in thin crystals of FeSe1-xTex

Best Thermoelectric Efficiency of Ever-Explored Materials

A thermoelectric device is a heat engine that directly converts heat into electricity. Many materials with a high figure of merit ZT have been discovered in anticipation of a high thermoelectric efficiency. However, there has been a lack of investigations on efficiency-based material evaluation, and little is known about the achievable limit of thermoelectric efficiency. Here, we report the highest thermoelectric efficiency using 13,353 published materials. The thermoelectric device efficiencies of 808,610 configurations are calculated under various heat-source temperatures (T_h) when the cold-side temperature is 300 K, solving one-dimensional thermoelectric integral equations with temperature-dependent thermoelectric properties. For infinite-cascade devices, a thermoelectric efficiency larger than 33% (~1/3) is achievable when T_h exceeds 1400 K. For single-stage devices, the best efficiency of 17.1% (~1/6) is possible when T_h is 860 K. Leg segmentation can overcome this limit, delivering a very high efficiency of 24% (~1/4) when T_h is 1100 K.Comment: 32 pages (main+table+figure captions+figures), 7 additional pages for 6 high resolution figures, Supporting Data file is not public ye

Electronic structures and magnetic moments of Co3FeN thin films grown by molecular beam epitaxy

We evaluated electronic structures and magnetic moments in Co3FeN epitaxial films on SrTiO3(001). The experimentally obtained hard x-ray photoemission spectra of the Co3FeN film have a good agreement with those calculated. Site averaged spin magnetic moments deduced by x-ray magnetic circular dichroism were 1.52 μ B per Co atom and 2.08 μ B per Fe atom at 100 K. They are close to those of Co4N and Fe4N, respectively, implying that the Co and Fe atoms randomly occupy the corner and face-centered sites in the Co3FeN unit cell

Conditioned medium from stem cells derived from human exfoliated deciduous teeth ameliorates NASH via the Gut-Liver axis

Non-alcoholic steatohepatitis (NASH) occurrence has been increasing and is becoming a major cause of liver cirrhosis and liver cancer. However, effective treatments for NASH are still lacking. We examined the benefits of serum-free conditioned medium from stem cells derived from human exfoliated deciduous teeth (SHED-CM) on a murine non-alcoholic steatohepatitis (NASH) model induced by a combination of Western diet (WD) and repeated administration of low doses of carbon tetrachloride intraperitoneally, focusing on the gut-liver axis. We showed that repeated intravenous administration of SHED-CM significantly ameliorated histological liver fibrosis and inflammation in a murine NASH model. SHED-CM inhibited parenchymal cell apoptosis and reduced the activation of inflammatory macrophages. Gene expression of pro-inflammatory and pro-fibrotic mediators (such as Tnf-α, Tgf-β, and Ccl-2) in the liver was reduced in mice treated with SHED-CM. Furthermore, SHED-CM protected intestinal tight junctions and maintained intestinal barrier function, while suppressing gene expression of the receptor for endotoxin, Toll-like receptor 4, in the liver. SHED-CM promoted the recovery of Caco-2 monolayer dysfunction induced by IFN-γ and TNF-α in vitro. Our findings suggest that SHED-CM may inhibit NASH fibrosis via the gut-liver axis, in addition to its protective effect on hepatocytes and the induction of macrophages with unique anti-inflammatory phenotypes