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Motivated by the recently discovered high- T c superconductor La 3 Ni 2 O 7 , we comprehensively study this system using density functional theory and random phase approximation calculations. At low pressures, the Amam phase is stable, containing the Y 2− mode distortion from the Fmmm phase, while the Fmmm phase is unstable. Because of small differences in enthalpy and a considerable Y 2− mode amplitude, the two phases may coexist in the range between 10.6 and 14 GPa, beyond which the Fmmm phase dominates. In addition, the magnetic stripe-type spin order with wavevector ( π , 0) was stable at the intermediate region. Pairing is induced in the s ± -wave channel due to partial nesting between the M  = ( π ,  π ) centered pockets and portions of the Fermi surface centered at the X  = ( π , 0) and Y  = (0,  π ) points. This resembles results for iron-based superconductors but has a fundamental difference with iron pnictides and selenides. Moreover, our present efforts also suggest La 3 Ni 2 O 7 is qualitatively different from infinite-layer nickelates and cuprate superconductors. Recently superconductivity with T c of about 80 K was discovered in a bilayer nickelate La 3 Ni 2 O 7 under high pressure. Here the authors report a density functional theory and random phase approximation study of structural and electronic properties as a function of pressure and discuss the pairing mechanism.

The anomalous Hall effect (AHE) is an intriguing transport phenomenon occurring typically in ferromagnets as a consequence of broken time reversal symmetry and spin-orbit interaction. It can be caused by two microscopically distinct mechanisms, namely, by skew or side-jump scattering due to chiral features of the disorder scattering, or by an intrinsic contribution directly linked to the topological properties of the Bloch states. Here we show that the AHE can be artificially engineered in materials in which it is originally absent by combining the effects of symmetry breaking, spin orbit interaction and proximity-induced magnetism. In particular, we find a strikingly large AHE that emerges at the interface between a ferromagnetic manganite (La 0.7 Sr 0.3 MnO 3 ) and a semimetallic iridate (SrIrO 3 ). It is intrinsic and originates in the proximity-induced magnetism present in the narrow bands of strong spin-orbit coupling material SrIrO 3 , which yields values of anomalous Hall conductivity and Hall angle as high as those observed in bulk transition-metal ferromagnets. These results demonstrate the interplay between correlated electron physics and topological phenomena at interfaces between 3 d ferromagnets and strong spin-orbit coupling 5 d oxides and trace an exciting path towards future topological spintronics at oxide interfaces. The anomalous Hall effect (AHE) occurs in ferromagnets caused by intrinsic and extrinsic mechanisms. Here, Yoo et al . report large anomalous Hall conductivity and Hall angle at the interface between a ferromagnet La 0.7 Sr 0.3 MnO 3 and a semimetallic SrIrO 3 , due to the interplay between correlated physics and topological phenomena.

We investigated 2 acute cases and 1 previous case of Seoul hantavirus infection in workers in a feeder rodent breeding farm in Taiwan. Prevalence of hantavirus IgG among the tested feeder rats was 37.5%. Appropriate prevention measures, including using disinfection protocols and personal protective equipment, are crucial to lowering risk.

The nodal-line semiconductor Mn 3 Si 2 Te 6 is generating enormous excitment due to the recent discovery of a field-driven insulator-to-metal transition and associated colossal magnetoresistance as well as evidence for a new type of quantum state involving chiral orbital currents. Strikingly, these qualities persist even in the absence of traditional Jahn-Teller distortions and double-exchange mechanisms, raising questions about exactly how and why magnetoresistance occurs along with conjecture as to the likely signatures of loop currents. Here, we measured the infrared response of Mn 3 Si 2 Te 6 across the magnetic ordering and field-induced insulator-to-metal transitions in order to explore colossal magnetoresistance in the absence of Jahn-Teller and double-exchange interactions. Rather than a traditional metal with screened phonons, the field-driven insulator-to-metal transition leads to a weakly metallic state with localized carriers. Our spectral data are fit by a percolation model, providing evidence for electronic inhomogeneity and phase separation. Modeling also reveals a frequency-dependent threshold field for carriers contributing to colossal magnetoresistance which we discuss in terms of polaron formation, chiral orbital currents, and short-range spin fluctuations. These findings enhance the understanding of insulator-to-metal transitions in new settings and open the door to the design of unconventional colossal magnetoresistant materials. Field-driven insulator-to-metal transition and associated colossal magnetoresistance have been reported in the magnetic nodal-line semiconductor Mn 3 Si 2 Te 6 . Gu et al. measure infrared response across magnetic ordering and the transition, revealing a weakly metallic state instead of a traditional metallic state.

The discovery of T c ~ 80 K superconductivity in pressurized La 3 Ni 2 O 7 has launched a new platform to study high-temperature superconductivity. Using non-perturbative dynamic cluster approximation quantum Monte Carlo calculations, we characterize the magnetic and superconducting pairing behavior of a realistic bilayer two-orbital Hubbard-Hund model of this system that describes the relevant Ni e g states with physically relevant interaction strengths. We find a leading s ± superconducting instability in this model at a temperature T ~ 100 K close to the experimentally observed T c . Analyzing the orbital and spatial structure of the effective pairing interaction giving rise to this state reveals that the interaction predominantly acts between local interlayer pairs of the d 3 z 2 - r 2 orbital. By correlating the strength of the interaction with that of the magnetic spin fluctuations we show that it is driven by strong interlayer spin-fluctuations arising from the d 3 z 2 - r 2 orbital. These results provide first-time non-perturbative evidence supporting the picture that a simple single-orbital bilayer Hubbard model for the Ni d 3 z 2 - r 2 orbital provides an excellent low-energy effective description of the superconducting behavior of La 3 Ni 2 O 7 .

The emergence of insulating ferromagnetic phase in iron oxychalcogenide chain system has been recently argued to be originated by interorbital hopping mechanism. However, the practical conditions for the stability of such mechanism still prevents the observation of ferromagnetic in many materials. Here, we study the stability range of such ferromagnetic phase under modifications in the crystal fields and electronic correlation strength, constructing a theoretical phase diagram. We find a rich emergence of phases, including a ferromagnetic Mott insulator, a ferromagnetic orbital-selective Mott phase, together with antiferromagnetic and ferromagnetic metallic states. We characterize the stability of the ferromagnetic regime in both the Mott insulator and the ferromagnetic orbital-selective Mott phase forms. We identify a large stability range in the phase diagram at both intermediate and strong electronic correlations, demonstrating the capability of the interorbital hopping mechanism in stabilizing ferromagnetic insulators. Our results may enable additional design strategies to expand the relatively small family of known ferromagnetic insulators. Ferromagnetic insulator (FM) materials are rare due to the challenge of stabilizing the ferromagnetic insulating phase. By exploiting the recently proposed interorbital-hopping mechanism, the authors show how such mechanism stabilizes FM insulators in broad classes of materials, largely extending the FM platforms to support spintronic applications.

The flaw of low dispersibility in the metal matrix brought on by graphene's full crystal structure can be improved by the application of ion beam radiation to the surface of the material. Copper atoms are uniformly dispersed on the modified graphene oxide (GO M ) surface after being irradiated to a copper ion beam, and during the sputtering modification, the valence state of copper is changed, resulting in the formation of a new CuO phase on the graphene oxide (GO) surface. Therefore, after copper ion beam irradiation of graphene, the interfacial adhesion between GO M and copper matrix is enhanced, and the wear resistance is significantly improved. When the GO M content is low, it can withstand most of the load during the friction and wear test, which reduces the wear of the copper matrix and the occurrence of fatigue cracks at the interface of the composite material.

This study examined the association between dietary patterns and the development of frailty during 4-, 8-, 12-year follow-up periods in the population-based Taiwan Study. We used the data of an elderly population aged 53 years and over (n = 3486) from four waves of the Taiwan Longitudinal Study on Aging. Frailty was identified by using the modified Fried criteria and the values were summed to derive a frailty score. We applied reduced rank regression to determine dietary patterns, which were divided into tertiles (healthy, general, and unhealthy dietary pattern). We used multinomial logistic regression models to assess the association between dietary patterns and the risk of frailty. The healthy dietary pattern was characterized by a higher intake of antioxidant drinks (tea), energy-rich foods (carbohydrates, e.g., rice, noodles), protein-rich foods (fish, meat, seafood, and eggs), and phytonutrient-rich foods (fruit and dark green vegetables). Compared with the healthy pattern, the unhealthy dietary pattern showed significant cross-sectional, short-term, medium-term, and long-term associations with a higher prevalence of frailty (odds ratios (OR) 2.74; 95% confidence interval (CI) 1.94–3.87, OR 2.55; 95% CI 1.67–3.88, OR 1.66; 95% CI 1.07–2.57, and OR 2.35; 95% CI 1.27–4.34, respectively). Our findings support recommendations to increase the intake of antioxidant drinks, energy-rich foods, protein-rich foods, and phytonutrient-rich foods, which were associated with a non-frail status. This healthy dietary pattern can help prevent frailty over time in elderly people.

Leptospirosis and hantavirus syndrome are two major rodent-borne diseases in Taiwan. Rocahepevirus ratii (RHEV), a virus closely related to hepatitis E virus (HEV, Paslahepevirus balayani), is emerging and has been reported to cause hepatitis in humans. We employed wastewater-based epidemiology to actively monitor rodent-borne pathogens, and the correlations with human cases were evaluated. Wastewater was collected using grab sampling at 11 sites along a sewer system including influents and effluents at a wastewater treatment plant in Tamsui, New Taipei City, Taiwan, monthly during June 2023 to May 2024. The presence of pathogens was examined by reverse transcription-polymerase chain reaction (RT-PCR). The result showed an overall positivity rate of 38.2% (50/131). Leptospira was detected most often (48/131, 36.6%), and RHEV and hantaviruses were found once each during the study period. Sequencing identified Leptospira interrogans close to isolates from rodents and human cases, while sequences of hantavirus and RHEV were most similar to isolates from rodents. No significant correlation was found with human cases or positive samples for rodent DNA. Here, we present an example of a One Health approach applying wastewater to environmental surveillance for the early detection and prevention of emerging diseases.

Purpose - The purpose of this paper is to investigate the sets of relationships, both physical and virtual, on which school technology coordinators (STCs) rely in exchanging problem-solving knowledge. Using prestige as an indicator of knowledge exchange across school boundaries, a model of relational variables was constructed from social networks to explain the characteristics of personal knowledge exchange in STC communities.Design methodology approach - The analytical model designed for this research was based on social network theory. Egocentric interviews were conducted to collect relational data on knowledge exchange among STCs. Path analysis was applied to examine associations among relational variables.Findings - Prestigious STCs engage more in contributing knowledge to online communities of related competency than to STCs at other schools. They do not expend as much effort helping other STCs and only reciprocate within a smaller group from whom they have received advice. Online knowledge contributions have mediation effects for STCs with limited personal networks in becoming prestigious.Originality value - Few studies have evaluated the sets of relationships on which teachers rely, to solve problems, and few empirical studies have focused on the features of personal knowledge exchange in a loosely coupled community of practice. This study uses prestige rather than job evaluations as an indicator for knowledge-intensive workers to examine the knowledge-exchange characteristics and demonstrate applicability to studies of communities of practice. The results also reveal deficiencies of knowledge dissemination in STC communities. These findings are relevant for studies of the information and communication technology practices of other professionals.