Browse Articles

First-principles assisted design of high-entropy thermoelectric materials based on half-Heusler alloys

The deformation potential theory and semi-classical Boltzmann theory were combined to predict the thermoelectric performances of half-Heusler NaCuTe alloy and Li0.5Na0.5CuSe0.5Te0.5 high-entropy half-Heusler alloy through first-principles calculations. The former was constructed via the congener substitution method from LiCuSe alloy, while the latter was designed by the high-entropy engineering concept. The phonon spectrum and ab initio molecular dynamics simulations indicated that the three alloys display stable intermetallic compounds at ambient temperature. The electrical and thermal transport properties of p-type LiCuSe, NaCuTe, and Li0.5Na0.5CuSe0.5Te0.5 alloys were computed as a function of temperature and carrier concentration. The thermoelectric figure of merit for p-type Li0.5Na0.5CuSe0.5Te0.5 alloy was 1.005 and 3.443 at room temperature and 800 K, whereas that of p-type NaCuTe alloy achieved 2.488 at 800 K, which is obviously superior to most of the recently reported p-type half-Heusler thermoelectric materials. A comprehensive analysis of the phonon lifetime, Grüneisen parameters, phonon group velocities, and primitive cell phonon spectrum revealed that high-entropy engineering could introduce non-equivalent atoms and thus enhance phonon scattering, resulting in the reduction of lattice thermal conductivity. Furthermore, numerical simulations demonstrated that high-entropy engineering could improve the thermoelectric performances of half-Heusler alloys effectively, which provides a unique approach for the optimized design of novel thermoelectric materials.

Tuning into urban birdsong: enhancing nature connectedness with an AI-powered wearable

Author Correction: Uncovering functional lncRNAs by scRNA-seq with ELATUS

Creation of hyperoxia superconducting phase in La2CuO4 by applying shear strain under high-pressure compression

We successfully stabilized the hyperoxia superconducting phase of La2CuO4, the parent insulating compound of La-based cuprate superconductors, by applying compression under high pressure and successive shear strains via the process of high-pressure torsion (HPT). Superconducting phases in the La2CuO4 system are created via the hole doping by replacing the La-sites with alkali-earth metals or by overdoping oxygen. However, the present study demonstrates that the HPT processing induces structural strain, and subsequent annealing stabilizes the hyperoxia phase, i.e., the superoxide phase. The superconducting transition temperature Tc systematically varies as a function of the revolution number N in HPT processing under compression of 6 GPa, and Tc has the maximum value of approximately 40 K for N≤1. Stabilized superconducting states intrinsically have a large critical field at the 20 T level. This approach proposes a high-pressure material synthesis method that is useful for mechanically tuning carriers in insulating La2CuO4.

SRADHO: statistical reduction approach with deep hyper optimization for disease classification using artificial intelligence

Defluorinative functionalization approach led by difluoromethyl anion chemistry

Modulation of flux-closure polar state for enhanced storage unit and thermal conductivity via dual-probe excitation

Ferroelectric topological structures have broad application prospects for high-density information storage for long-term data retention via topological protection. However, the high-density memory component might generate tremendous power consumption, causing the failure of ferroelectric devices due to the severe thermal effect. There remains an emergent issue on the synchronous achievement of high-density data storage with the decreasing influences of the thermal effects in ferroelectric topological domain structures. Here, we introduce dual-probe excitation to control the symmetry of the electric field and integrate the phase field simulation for modulating the flux-closure ferroelectric domain configuration to simultaneously improve the memory storage unit and thermal conductivity at the nanoscale in PbTiO3 thin film under a piezoresponse force microscopy experiment. It is found that the grown flux-closure polar state in both in-plane directions encourages us to enhance the storage density during dual-probe excitation in topological ferroelectric memory devices. Moreover, the increased number of flux-closure polar states and the decreased density of the domain walls can be obtained by using dual-probe excitation. Finally, we figured out that both the double-staircase-like and paddle-like domain configurations exhibit large storage units and effective thermal conductivity simultaneously under dual-probe excitation. Our study gives a guideline to synchronously improve storage performance and thermal conductivity through multiple-probe excitations in topological ferroelectric materials and devices.

Surgical glove perforation during intramedullary nailing of intertrochanteric fractures

Structural insights into the activation mechanism of the human zinc-activated channel

Monte Carlo and micromagnetic study on constructing biskyrmion-like spin textures in bilayer magnetic films

Biskyrmion, a novel topological magnetic structure, has its unique physical properties and potential application value. In this study, we proposed a mechanism for constructing biskyrmions in a bilayer centrosymmetric magnetic thin film with the broken inversion symmetry for each layer. By using Monte Carlo and micromagnetic simulation methods, we found that biskyrmion-like spin textures can be stabilized under the opposite Dzyaloshinskii–Moriya interactions and finite magnetic fields applied. In addition, we also provided insights into the dynamic property of a biskyrmion with the spin polarized current applied to the system. After the current density reaches a certain threshold, the biskyrmion moves forward in a bound state and exhibits a behavior similar to the skyrmion Hall effect. Our findings have provided a theoretical basis for the application of biskyrmions in spintronics.

Identification of key elements in MRI reporting of intracranial meningiomas based on a nationwide survey of clinical experts in Germany

AbstractWhile MRI has become the imaging modality of choice for intracranial meningiomas, no radiologic reporting guidance exists to date that relies on a systematic collection of information relevant to the core medical disciplines involved in the management of these patients. To address this issue, a nationwide expert survey was conducted in Germany. A literature-based catalog of potential reporting elements for MRI examinations of meningioma patients was developed interdisciplinarily. Subsequently, all board-certified members of the German Societies of Neuroradiology, Neurosurgery and Radiation Oncology with expertise in managing meningioma patients were invited to vote on the relevance of the suggested items via online survey. A total of 150 experts participated in the study (104 neurosurgeons/radiation oncologists, 46 neuroradiologists). The reporting elements of tumor location, extent, growth pattern, contrast uptake, associated cysts, and impact on adjacent anatomic structures received widespread approval (> 75.0% of all participants). In addition, a vast majority (> 75.0%) supported reference to perifocal edema, signs of mass effect, and hydrocephalus. Postoperative imaging is particularly requested to describe the extent of resection (94.0%) and treatment-related changes (89.3%). Advanced methods (diffusion, perfusion, proton spectroscopy) and meningioma-specific classifications (Nauta, Zee, Sindou) were judged to be less relevant (< 50.0% agreement) to MRI reporting. To serve as a vital clinical communication tool and enable an optimal contribution to the care of meningioma patients, the radiological report should focus on the fundamental information requirements of the neuro-oncology treatment team encompassing primarily tumor location, extent, tissue imaging characteristics, and potential impairment of neighboring anatomical structures.

NPC1 controls TGFBR1 stability in a cholesterol transport-independent manner and promotes hepatocellular carcinoma progression

AbstractNiemann-Pick disease type C protein 1 (NPC1), classically associated with cholesterol transport and viral entry, has an emerging role in cancer biology. Here, we demonstrate that knockout of Npc1 in hepatocytes attenuates hepatocellular carcinoma (HCC) progression in both DEN (diethylnitrosamine)-CCl4 induced and MYC-driven HCC mouse models. Mechanistically, NPC1 significantly promotes HCC progression by modulating the TGF-β pathway, independent of its traditional role in cholesterol transport. We identify that the 692-854 amino acid region of NPC1’s transmembrane domain is critical for its interaction with TGF-β receptor type-1 (TGFBR1). This interaction prevents the binding of SMAD7 and SMAD ubiquitylation regulatory factors (SMURFs) to TGFBR1, reducing TGFBR1 ubiquitylation and degradation, thus enhancing its stability. Notably, the NPC1 (P691S) mutant, which is defective in cholesterol transport, still binds TGFBR1, underscoring a cholesterol-independent mechanism. These findings highlight a cholesterol transport-independent mechanism by which NPC1 contributes to the stability of TGFBR1 in HCC and suggest potential therapeutic strategies targeting NPC1 for HCC treatment.

Modulating the resonance transport of edge states in topological insulator junction

This work investigates how the width (Ny) of zigzag silicene-like nanoribbons, along with defect size and position, affect the resonance transmission of a topological insulator junction with anisotropic chiral and helical edge states. Despite changes in the resonance peak with Ny below the critical value, neither a proportional nor inverse formula can adequately express the relationship between the resonance period (T) and Ny. The energy band calculations indicate that the change mechanism is attributed to the size effect on the band structure. We also examine the influence of the defect size and position on resonance and provide a detailed explanation by calculating the local bond current. It is found that specific defect size and position greatly impact the resonance peak, indicating the potential of modulating resonance using these two variables. These findings provide theoretical insights for controlling resonance.

Bacillus velezensis A-27 as a potential biocontrol agent against Meloidogyne incognita and effects on rhizosphere communities of celery in field

Two-dimensional anion-rich NaCl2 crystal under ambient conditions

Strain-controllable electronic, magnetic properties, and magnetic anisotropy energy in a 2D ferromagnetic half-metallic MGT monolayer

The investigation of two-dimensional (2D) intrinsic ferromagnetic material is important in the field of spintronics. In this study, the Mn2Ge2Te6 monolayer (ML) with intrinsic ferromagnetism was fabricated by using the density functional theory (DFT). The Mn2Ge2Te6 ML is a half metal (HM) with a spin-β bandgap of 1.462 eV. Biaxial strain could be applied to tune the electronic and magnetic properties of Mn2Ge2Te6. The magnetic moment (MM), magnetic exchange parameter (J), band structures, and magnetic anisotropy energy (MAE) could be effectively controlled by the biaxial strains (ε). This modulation originates that the states near the Fermi level mainly come from the contribution of in-plane atomic orbitals. The MM of Mn monotonously increases as the tensile strains increase. The energy difference between different magnetic orders (ΔE) and J also change with the strains. The antiferromagnetic-stripy order always has the lowest energy under the strains. As the strains change, ΔE and J monotonously change as the direct exchange and super-exchange interactions between Mn atoms vary. As the tensile strain decreases and compressive strain increases (−2.1%<ε<8%), the gap of spin-β electrons monotonously decreases. The Mn2Ge2Te6 ML changes from a HM to a normal spin-unpolarized metal under larger compressive strains (ε>−2.1%). When the tensile strains are applied, the MAE monotonously increases to the largest value of −22.3 meV (ε=12%). As the compressive strains increase, the MAE monotonously decreases. Last, the Mn2Ge2Te6 ML changes from an in-plane magnetic anisotropy into a perpendicular magnetic anisotropy under a larger compressive strain (−11%). The change of MAE direction origins that the contribution of hybridization between Te's py and pz orbitals is changed when the strain changes. Our results offer crucial insights into the potential of strain modulation in a 2D Mn2Ge2Te6 ML, paving the way for future advancements in this field.

Examining the effect of personality on user acceptance of conditionally automated vehicles

AbstractAutomated vehicle acceptance (AVA) research has grown substantially in the past few years. There is a paucity of research on the role of the big five personality traits on attitudes towards automated vehicles (AVs) and AVA. This is a critical shortcoming given that personality is considered a critical factor explaining technology adoption. Our major theoretical contribution is the integration of the most popular personality measure – the big five – and one of the most influential technology acceptance models – Unified Theory of Acceptance and Use of Technology (UTAUT2). A questionnaire was administered to 9,339 respondents from nine countries to predict the behavioral intention to use conditionally automated vehicles (CondAVs). The original UTAUT2 was extended by trust and driver engagement and the big five personality traits openness, conscientiousness, extraversion, agreeableness, and neuroticism. Structural equation modeling was applied to examine the direct effects of these constructs on behavioral intention and the indirect effects of the personality traits on the independent constructs of the extended UTAUT2. The results have shown positive effects of social influence, trust, and performance expectancy on the behavioral intention to use CondAVs. Most of the hypotheses pertaining to the role of the personality traits on the UTAUT2 constructs were supported, but the effects were relatively small (< 0.25). Our findings support the usefulness of UTAUT2 in evaluating the success of AVs, providing crucial insights into the factors driving the acceptance of CondAVs. The cross-country analysis provides further insights into the role of an individual’s personality for AVA. Our study yields important implications for practitioners. Given the small effect sizes of personality, designing CondAVs around the personalities of their customers during development and commercialization may be ineffective to promote trust and acceptance.

Mitochondria- and ER-associated actin are required for mitochondrial fusion

Effective demagnetizing tensor incorporating finite width effect for magnetic nanowire design in racetrack devices

Structural engineering is a promising approach to enhance the performance of racetrack devices in term of power consumption for domain wall dynamics and shift errors via the control of the in-plane shape anisotropy in magnetic nanowires. Because the in-plane shape anisotropy is determined by the nanowire width, it is essential to incorporate the width effect into the demagnetizing tensor to design racetrack devices through a structural approach; however, a quantitative evaluation of the width effect on the demagnetizing tensor is still lacking. In this work, we have derived the formula for the effective demagnetizing tensor in nanowires with finite width. We also analytically revealed that the special width, at which intrinsic pining potential vanishes, is proportional to the domain wall width. The derived formulas were in good agreement with the two-dimensional micromagnetic simulation results at various nanowire widths, demonstrating their validity. Our results provide a guideline for designing racetrack devices with low power consumption and minimal shift errors via structural engineering.

Author Correction: Optimal power generation of proton exchange membrane fuel cell using ANFIS based MPPT algorithm