Manipulating topological spin textures is a key for exploring unprecedented emergent electromagnetic phenomena. Whereas switching control of magnetic skyrmions, e.g., the transitions between a ...skyrmion-lattice phase and conventional magnetic orders, is intensively studied towards development of future memory device concepts, transitions among spin textures with different topological orders remain largely unexplored. Here we develop a series of chiral magnets MnSi
Ge
, serving as a platform for transitions among skyrmion- and hedgehog-lattice states. By neutron scattering, Lorentz transmission electron microscopy and high-field transport measurements, we observe three different topological spin textures with variation of the lattice constant controlled by Si/Ge substitution: two-dimensional skyrmion lattice in x = 0-0.25 and two distinct three-dimensional hedgehog lattices in x = 0.3-0.6 and x = 0.7-1. The emergence of various topological spin states in the chemical-pressure-controlled materials suggests a new route for direct manipulation of the spin-texture topology by facile mechanical methods.
The Lifshitz transition, a change in Fermi surface topology, is likely to greatly influence exotic correlated phenomena in solids, such as high-temperature superconductivity and complex magnetism. ...However, since the observation of Fermi surfaces is generally difficult in the strongly correlated systems, a direct link between the Lifshitz transition and quantum phenomena has been elusive so far. Here, we report a marked impact of the pressure-induced Lifshitz transition on thermoelectric performance for SnSe, a promising thermoelectric material without a strong electron correlation. By applying pressure up to 1.6 GPa, we have observed a large enhancement of the thermoelectric power factor by more than 100% over a wide temperature range (10-300 K). Furthermore, the high carrier mobility enables the detection of quantum oscillations of resistivity, revealing the emergence of new Fermi pockets at ∼0.86 GPa. The observed thermoelectric properties linked to the multivalley band structure are quantitatively reproduced by first-principles calculations, providing novel insight into designing the SnSe-related materials for potential valleytronic as well as thermoelectric applications.
Background
Recently, heterozygous RFX6 mutations including p.Arg377Ter were identified in individuals with maturity‐onset diabetes of the young (MODY). Clinical analysis of 36 individuals suggested ...that RFX6 mutation‐induced MODY is characterized by low penetrance and relatively late onset. However, given the small number of previous reports and the limited clinical information of each case, further studies are necessary to clarify the phenotypic characteristics of RFX6 mutations.
Case report
We identified a previously reported p.Arg377Ter variant of RFX6 in a three‐generation family with diabetes. The variant was detected through mutation screening for 30 diabetes‐associated genes. The variant was not found in public databases and was predicted to encode a truncated protein or undergo nonsense‐mediated mRNA decay. The proband showed glycosuria from 8 years of age and was diagnosed with MODY at 10 years of age, before the onset of puberty. She received basal and bolus insulin injection as initial therapy. The proband's mother exhibited glycosuria at 26 years of age when she conceived the first child. The mother was treated with insulin, oral hypoglycaemic drugs and diet. The proband and her mother were negative for islet cell autoantibodies. The maternal grandmother showed glycosuria around 50 years of age and was treated with oral hypoglycaemic drugs alone.
Conclusion
This study provides supporting evidence for the causal relationship between heterozygous RFX6 mutations and MODY. Furthermore, our results indicate that phenotypic consequences of RFX6 mutations are highly variable even within a single family, and possibly include childhood‐onset and pregnancy‐associated non‐autoimmune diabetes.
What's new?
Heterozygous protein‐truncating variants of RFX6 likely play a role in the development of diabetes in prepubertal children.
Phenotypic severities of RFX6 mutations are highly variable, even within a single family.
RFX6 mutations may also be associated with diabetes during pregnancy.
Quantum states characterized by nontrivial topology produce interesting electrodynamics and versatile electronic functionalities. One source for such remarkable phenomena is emergent electromagnetic ...field, which is the outcome of interplay between topological spin structures with scalar spin chirality and conduction electrons. However, it has scarcely been exploited for emergent function related to heat-electricity conversion. Here we report an unusually enhanced thermopower by application of magnetic field in MnGe hosting topological spin textures. By considering all conceivable origins through quantitative investigations of electronic structures and properties, a possible origin of large magneto-thermopower is assigned to the strong energy dependence of charge-transport lifetime caused by unconventional carrier scattering via the dynamics of emergent magnetic field. Furthermore, high-magnetic-field measurements corroborate the presence of residual magnetic fluctuations even in the nominally ferromagnetic region, leading to a subsisting behavior of field-enhanced thermopower. The present finding may pave a way for thermoelectric function of topological magnets.
•CL spectra were used to investigate observe nano-particles. The electron radiation damage to GFP was investigated by analyzing the change in CL intensity during electron beam irradiation.•The ...characteristic doses are independent of the dose rate.•The characteristic dose for a 20 kV electron beam is smaller than that for a 200 kV electron beam due to the larger cross section of the inelastic scattering
Green fluorescent protein (GFP) emits light when irradiated by not only light but also electrons. This electron-induced light emission called cathodoluminescence (CL) can be used to realize a high-resolution light emission microscopy based on the irradiation of a very narrow electron beam. To implement CL mapping in life sciences the investigation of the damage resistance of GFP to electron irradiation needs to be clarified. In this study, we investigated the electron radiation damage to GFP by analyzing the change in the CL intensity during electron beam irradiation. Since some of the CL spectra changed in shape during electron irradiation, the change in the intensity between 585 and 605 nm were measured. The characteristic doses at different electron current densities and electron energies were investigated. The characteristic dose of EGFP is much larger than that of coronene, which is one of the stable organic molecules against the electron beam irradiation.
A GEANT4 based simulation for pixelated X-ray hybrid detectors Marinho, F.; Akiba, K.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2015, Letnik:
772
Journal Article
Recenzirano
In this letter we present a detailed Monte Carlo approach to simulate pixelated detectors for X-ray applications. It allows us to fully characterize quantities such as interaction probability and ...reconstructed energy deposits according to beam energy as to evaluate energy and position resolution for comparisons with experimental results. The implementation and use of Monte Carlo truth information is also discussed.
•Energetic analyses of installing SOFC CGS with EV charging were performed.•Japanese cafeteria was selected as an installation target facility.•Merit of SOFC CGS is not optimal when it is backed up ...by gas water heater.•SOFC CGS with heat pump water heater provides much higher energy saving rate.•Nighttime-limited electric power supply for EV charging improves system efficiency.
Energetic feasibility analyses were conducted when an SOFC CGS with EV charging equipment is installed in a facility with a high hot-water demand and a high thermo-electric demand ratio. The university cafeteria located on the Hitachi Campus of Ibaraki University in Japan was selected as an installation target because its electric and hot-water demands fulfilled the intended criterion of a high thermo-electric demand ratio. It was made clear that the merits of a co-generation system are not optimal in the case a gas water heater is selected as the backup hot-water supply. To solve the problems contributing to this bad result and to improve the performance, the authors next selected a heat pump water heater as the backup hot-water supply. It was made clear that this system possesses sufficiently high energy savings performance. It was also shown that the coexistence and co-prosperity of the cafeteria and EV charging equipment are successfully achieved. These results reveal that an SOFC CGS with EV charging equipment can be a feasible candidate for a future energy supply system installed in Japanese cafeteria, which is a facility with a large hot-water demand and a high thermo-electric demand ratio, by adopting a heat pump water heater, instead of the usual gas water heater, as the backup hot-water supply.
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