Cross-seeding effects of amyloid β-protein and α-synuclein

Amyloid β-protein (Aβ) and α-synuclein (αS) are the primary components of amyloid plaques and Lewy bodies (LBs), respectively. Previous in vitro and in vivo studies have suggested that interactions between Aβ and αS are involved in the pathogenesis of Alzheimer\u27s disease and LB diseases. However, the seeding effects of their aggregates on their aggregation pathways are not completely clear. To investigate the cross-seeding effects of Aβ and αS, we examined how sonicated fibrils or cross-linked oligomers of Aβ40, Aβ42, and αS affected their aggregation pathways using thioflavin T(S) assay and electron microscopy. Fibrils and oligomers of Aβ40, Aβ42, and αS acted as seeds, and affected the aggregation pathways within and among species. The seeding effects of αS fibrils were higher than those of Aβ40 and Aβ42 fibrils in the Aβ40 and Aβ42 aggregation pathways, respectively. We showed that Aβ and αS acted as seeds and affected each other\u27s aggregation pathways in vitro, which may contribute to our understanding of the molecular mechanisms of interactions between Alzheimer\u27s disease and LB diseases pathologies. © 2012 The Authors

Growth of Functional FeTi Clusters Covered with Carbon Layer

FeTi clusters with a diameter of less than 10 nm and covered with a graphitic layer have been preferentially produced in an H2 gas atmosphere at pressures of 10 and 26.6 kPa by the simultaneous evaporation of Fe and Ti wires from a concave carbon boat. To compare this result with cluster formation in an inert gas atmosphere, the result for an Ar gas pressure of 10 kPa is also discussed. The formation of disordered FeNi clusters predominately took place in an H2 gas atmosphere

FUNDAMENTAL NUMERICAL ANALYSIS OF INSOLATION OF THE HUMAN BODY

ABSTRACT Uneven thermal environments often result from insolation or radiation in outdoor spaces and half outdoor spaces such as arcades and under open membrane roofs. Similar environments are observed in the perimeter spaces of office buildings in winter during the daytime. To estimate thermal environments in such spaces, detailed consideration must be given to the effects of both insolation and long-wavelength radiation on each part of the human body. This study conducted fundamental analysis of the calculations of insolation of a human body. The incident insolation to each part of a human body was evaluated. The results are reported herein

Demonstration of periodic nanostructure formation with less ablation by double-pulse laser irradiation on titanium

By pairing femtosecond laser pulses (duration ∼40 fs and central wavelength ∼810 nm) at an appropriate time interval, a laser-induced periodic surface structure (LIPSS) is formed with much less ablation than one formed with a single pulse. On a titanium plate, a pair of laser pulses with fluences of 70 and 140 mJ/cm² and a rather large time interval (>10 ps) creates a LIPSS with an interspace of 600 nm, the same as that formed by a single pulse of 210 mJ/cm², while the double pulse ablates only 4 nm, a quarter of the ablation depth of a single pulse

Determination of specific ion positions of Cr³⁺ and O²- in Cr₂O₃ thin films and their relationship to exchange anisotropy at Co/Cr₂O₃ interfaces

The structures of antiferromagnetic Cr₂O₃(0001) thin films with perpendicular exchange bias were investigated using reflection high-energy electron diffraction, X-ray reflectivity, and synchrotron X-ray diffraction. We mainly investigated the specific ion positions of Cr³⁺ and O²- in the corundum structure and discussed their relationship to the magnetic anisotropy of Cr₂O₃. The Cr₂O₃(0001) thin film grown on a Pt(111) buffer layer exhibited a perpendicular exchange anisotropy density of 0.42 mJ/m², in which the Cr³⁺ position is the primary factor in the enhancement of magnetic anisotropy due to dipolar-interaction. In contrast, the single-crystalline Cr₂O₃(0001) film grown on a α-Al₂O₃(0001) substrate featured a low exchange magnetic anisotropy of 0.098 mJ/m². In this film, the Cr³⁺ position parameter is an insignificant factor, leading to low magnetic anisotropy. The O²- ion position also differs between the two types of films, which can affect both the magnetic anisotropy energy originating from fine structures and the magneto-electric properties of Cr₂O₃.Yu Shiratsuchi, Yuuta Nakano, Nobuhito Inami, Tetsuro Ueno, Kanta Ono, Reiji Kumai, Ryoko Sagayama, and Ryoichi Nakatani, Journal of Applied Physics 123, 103903 (2018); https://doi.org/10.1063/1.5020620

Enhancement of perpendicular exchange bias by introducing twin boundary in Pt/Co/α-Cr₂O₃/α-V₂O₃ epitaxial film

Perpendicular exchange anisotropy at the Co/α-Cr₂O₃ interface was investigated using the two types of films: the film with the single crystalline α-Cr₂O₃ and that with the twinned a-Cr₂O₃. Exchange anisotropy energy density JK of the film with the single crystalline α-Cr₂O₃ was ~0.09 erg/cm² whereas JK of the film with the twinned α-Cr₂O₃ was ~0.43 erg/cm², more than 4-times enhancement. We discussed the mechanism of the enhancement of JK based on the exchange coupling at the twin boundary and that the spin frustration at the twin boundary can be the origin of the enhancement of JK.Y.Shiratsuchi, S.Yoshida, S.Onoue, et al. Enhancement of perpendicular exchange bias by introducing twin boundary in Pt/Co/a-Cr₂O₃/a-V₂O₃ epitaxial film. Materials Transactions 60, 2028 (2019); https://doi.org/10.2320/matertrans.MT-M2019102

Giant Anomalous Hall Conductivity at the Pt/Cr₂O₃ Interface

The interface between a magnetic material and a heavy metal that has a large spin-orbit interaction is at the root of various spin-related phenomena. In this paper, we address the peculiar spin-dependent transport at a Pt/Cr₂O₃ interface by exploring the origin of the nonlinear anomalous Hall effect (AHE) in Pt/Cr₂O₃ bilayers. X-ray magnetic circular dichroism (XMCD) measurements show no appreciable magnetic moment at the interface originating from Cr 3d and Pt 5d orbitals, which could be associated with the AHE response. A possible interfacial magnetic moment M at the Pt/Cr₂O₃ interface, assumed from the detection limit of the XMCD measurements, yields an anomalous Hall conductivity (σAHE) per unit net magnetic moment (M),-σAHE/M, of 0.57 V-1, which is extraordinary large compared with that for general magnetic materials. Together with first-principles calculations, the results suggest the possibility of an intrinsic AHE in the Pt/Cr₂O₃ interface that does not rely on the net magnetic moment.T.Moriyama, Y.Shiratsuchi, T.Iino, et al. Giant Anomalous Hall Conductivity at the Pt/Cr₂O₃ Interface. Physical Review Applied 13, 034052 (2020); https://doi.org/10.1103/PhysRevApplied.13.034052