120 research outputs found

    Two types of s-wave pairing due to magnetic and orbital fluctuations in the two-dimensional 16-band d-p model for iron-based superconductors

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    We study superconductivity in the two-dimensional 16-band d-p model extracted from a tight-binding fit to the band structure of LaFeAsO, using the random phase approximation. When the intraorbital repulsion U is larger than the interorbital one U', an extended s-wave (s+--wave) pairing with sign reversal of order parameter is mediated by antiferromagnetic spin fluctuations, while when U<U' another kind of s-wave (s++-wave) pairing without sign reversal is mediated by ferro-orbital fluctuations. The s++-wave pairing is enhanced due to the electron-phonon coupling and then can be expanded over the realistic parameter region with U>U'.Comment: 10 pages, 8 figures, added discussions and references, published in Phys. Rev.

    Selective and Mutual Separation of Palladium (II), Platinum (IV), and Rhodium (III) Using Aliphatic Primary Amines

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    The selective recovery of platinum-group metals (PGMs) remains a huge challenge. Although solvent extraction processes are generally used for PGM separation, the use of organic solvents is problematic because of their toxicity and environmental concerns. Here, we have developed a new PGM recovery method by precipitation from hydrochloric acid (HCl) solutions containing Pd(II), Pt(IV), and Rh(III) using aliphatic primary amines as precipitants. Pt(IV) was precipitated using the amines with alkyl chains longer than hexyl independent of HCl concentration. The precipitation of Pd(II) required longer alkyl amines than octyl, regardless of the HCl concentration. Rh(III) was recovered by precipitation at high HCl concentrations using the amines longer than hexyl. The mutual separation of Pt(IV), Rh(III), and Pd(II), in this order, was successfully achieved by changing the HCl concentrations and alkyl chain lengths of the amines. X-ray photoelectron spectroscopy and thermogravimetric analysis evidently showed that the metal-containing precipitates were ion-pair complexes composed of metal chloro-complex anions and ammonium cations

    Variation in bradyrhizobial NopP effector determines symbiotic incompatibility with Rj2-soybeans via effector-triggered immunity

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    The soybean Rj2 gene encodes a TIR-NBS-LRR protein that confers resistance to nodulation by certain rhizobial strains. Here, the authors show that T3SS effector NopP is an avirulence protein that is necessary for Bradyrhizobium diazoefficiens USDA 122 to trigger Rj2-dependent incompatibility

    Iroquois homeobox 3 regulates odontoblast proliferation and differentiation mediated by Wnt5a expression

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    Iroquois homeobox (Irx) genes are TALE-class homeobox genes that are evolutionarily conserved across species and have multiple critical cellular functions in fundamental tissue development processes. Previous studies have shown that Irxs genes are expressed during tooth development. However, the precise roles of genes in teeth remain unclear. Here, we demonstrated for the first time that Irx3 is an essential molecule for the proliferation and differentiation of odontoblasts. Using cDNA synthesized from postnatal day 1 (P1) tooth germs, we examined the expression of all Irx genes (Irx1-Irx6) by RT-PCR and found that all genes except Irx4 were expressed in the tooth tissue. Irx1-Irx3 a were expressed in the dental epithelial cell line M3H1 cells, while Irx3 and Irx5 were expressed in the dental mesenchymal cell line mDP cells. Only Irx3 was expressed in both undifferentiated cell lines. Immunostaining also revealed the presence of IRX3 in the dental epithelial cells and mesenchymal condensation. Inhibition of endogenous Irx3 by siRNA blocks the proliferation and differentiation of mDP cells. Wnt3a, Wnt5a, and Bmp4 are factors involved in odontoblast differentiation and were highly expressed in mDP cells by quantitative PCR analysis. Interestingly, the expression of Wnt5a (but not Wnt3a or Bmp4) was suppressed by Irx3 siRNA. These results suggest that Irx3 plays an essential role in part through the regulation of Wnt5a expression during odontoblast proliferation and differentiation

    The Early Arthroscopic Pullout Repair of Medial Meniscus Posterior Root Tear Is More Effective for Reducing Medial Meniscus Extrusion

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    Clinical studies have demonstrated that transtibial pullout repair led to favorable midterm outcomes in patients with medial meniscus posterior root tears (MMPRTs) although medial meniscal extrusion (MME) continued to be present. It has been unclear whether these residual postoperative MMEs existed after the pullout repair or had progressed at the very short-term evaluation after surgery. We sought to determine which characteristics of patients with MMPRTs influence the incidence of postoperative MME. The cases of 23 patients whose date of injury was known were analyzed. All patients underwent MMPRT pullout fixation. Preoperative and 3-month postoperative magnetic resonance imaging (MRI) examinations were performed. MME was retrospectively assessed on the mid-coronal plane of MRI scans. The preoperative and postoperative MME values were 4.2±1.2 mm and 4.3±1.5 mm, respectively (p=0.559). Pullout repair surgery was performed significantly earlier after the MMPRT-specific injury in patients whose postoperative MME improved compared to the patients whose MME did not improve (p<0.001). Our findings demonstrated that an early transtibial pullout repair of an MMPRT was more effective in reducing MME than a late repair. Surgeons should not miss the optimal timing for the pullout repair of an MMPRT, considering the period from the injury and the preoperative MME

    Candidate Brown-dwarf Microlensing Events with Very Short Timescales and Small Angular Einstein Radii

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    Short-timescale microlensing events are likely to be produced by substellar brown dwarfs (BDs), but it is difficult to securely identify BD lenses based on only event timescales t_E because short-timescale events can also be produced by stellar lenses with high relative lens-source proper motions. In this paper, we report three strong candidate BD-lens events found from the search for lensing events not only with short timescales (t_E ≲ 6 days) but also with very small angular Einstein radii (θ_E ≲ 0.05 mas) among the events that have been found in the 2016–2019 observing seasons. These events include MOA-2017-BLG-147, MOA-2017-BLG-241, and MOA-2019-BLG-256, in which the first two events are produced by single lenses and the last event is produced by a binary lens. From the Monte Carlo simulations of Galactic events conducted with the combined t_E and θ_E constraint, it is estimated that the lens masses of the individual events are 0.051^(+0.100)_(−0.027) M⊙, 0.044^(+0.090)_(−0.023) M⊙, and 0.046^(+0.067)_(−0.023) M⊙/0.038^(+0.056)_(−0.019) M⊙ and the probability of the lens mass smaller than the lower limit of stars is ~80% for all events. We point out that routine lens mass measurements of short-timescale lensing events require survey-mode space-based observations
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