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1.
Proc Natl Acad Sci U S A ; 120(12): e2208968120, 2023 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-36917673

RESUMEN

Strong interactions between different degrees of freedom lead to exotic phases of matter with complex order parameters and emergent collective excitations. Conventional techniques, such as scattering and transport, probe the amplitudes of these excitations, but they are typically insensitive to phase. Therefore, novel methods with phase sensitivity are required to understand ground states with phase modulations and interactions that couple to the phase of collective modes. Here, by performing phase-resolved coherent phonon spectroscopy (CPS), we reveal a hidden spin-lattice coupling in a vdW antiferromagnet FePS3 that eluded other phase-insensitive conventional probes, such as Raman and X-ray scattering. With comparative analysis and analytical calculations, we directly show that the magnetic order in FePS3 selectively couples to the trigonal distortions through partially filled t2g orbitals. This magnetoelastic coupling is linear in magnetic order and lattice parameters, rendering these distortions inaccessible to inelastic scattering techniques. Our results not only capture the elusive spin-lattice coupling in FePS3 but also establish phase-resolved CPS as a tool to investigate hidden interactions.

2.
Acta Neuropathol ; 147(1): 84, 2024 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-38750212

RESUMEN

Amyotrophic Lateral Sclerosis/Parkinsonism-Dementia Complex (ALS/PDC), a rare and complex neurological disorder, is predominantly observed in the Western Pacific islands, including regions of Japan, Guam, and Papua. This enigmatic condition continues to capture medical attention due to affected patients displaying symptoms that parallel those seen in either classical amyotrophic lateral sclerosis (ALS) or Parkinson's disease (PD). Distinctly, postmortem examinations of the brains of affected individuals have shown the presence of α-synuclein aggregates and TDP-43, which are hallmarks of PD and classical ALS, respectively. These observations are further complicated by the detection of phosphorylated tau, accentuating the multifaceted proteinopathic nature of ALS/PDC. The etiological foundations of this disease remain undetermined, and genetic investigations have yet to provide conclusive answers. However, emerging evidence has implicated the contribution of astrocytes, pivotal cells for maintaining brain health, to neurodegenerative onset, and likely to play a significant role in the pathogenesis of ALS/PDC. Leveraging advanced induced pluripotent stem cell technology, our team cultivated multiple astrocyte lines to further investigate the Japanese variant of ALS/PDC (Kii ALS/PDC). CHCHD2 emerged as a significantly dysregulated gene when disease astrocytes were compared to healthy controls. Our analyses also revealed imbalances in the activation of specific pathways: those associated with astrocytic cilium dysfunction, known to be involved in neurodegeneration, and those related to major neurological disorders, including classical ALS and PD. Further in-depth examinations revealed abnormalities in the mitochondrial morphology and metabolic processes of the affected astrocytes. A particularly striking observation was the reduced expression of CHCHD2 in the spinal cord, motor cortex, and oculomotor nuclei of patients with Kii ALS/PDC. In summary, our findings suggest a potential reduction in the support Kii ALS/PDC astrocytes provide to neurons, emphasizing the need to explore the role of CHCHD2 in maintaining mitochondrial health and its implications for the disease.


Asunto(s)
Esclerosis Amiotrófica Lateral , Astrocitos , Proteínas de Unión al ADN , Proteínas Mitocondriales , Factores de Transcripción , Astrocitos/patología , Astrocitos/metabolismo , Esclerosis Amiotrófica Lateral/patología , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Humanos , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Mitocondrias/patología , Mitocondrias/metabolismo , Masculino , Femenino , Persona de Mediana Edad , Anciano
3.
Nano Lett ; 23(24): 11485-11492, 2023 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-38063397

RESUMEN

The spin Hall effect (SHE) can generate a pure spin current by an electric current, which is promisingly used to electrically control magnetization. To reduce the power consumption of this control, a giant spin Hall angle (SHA) in the SHE is desired in low-resistivity systems for practical applications. Here, critical spin fluctuation near the antiferromagnetic (AFM) phase transition in chromium (Cr) is proven to be an effective mechanism for creating an additional part of the SHE, named the fluctuation spin Hall effect. The SHA is significantly enhanced when the temperature approaches the Néel temperature (TN) of Cr and has a peak value of -0.36 near TN. This value is higher than the room-temperature value by 153% and leads to a low normalized power consumption among known spin-orbit torque materials. This study demonstrates the critical spin fluctuation as a prospective way to increase the SHA and enriches the AFM material candidates for spin-orbitronic devices.

4.
Phys Rev Lett ; 130(5): 059901, 2023 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-36800481

RESUMEN

This corrects the article DOI: 10.1103/PhysRevLett.129.167202.

6.
J Am Chem Soc ; 144(31): 14339-14350, 2022 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-35901238

RESUMEN

Exploring the relationship between intriguing physical properties and structural complexity is a central topic in studying modern functional materials. Co3Sn2S2, a newly discovered kagome-lattice magnetic Weyl semimetal, has triggered intense interest owing to the intimate coupling between topological semimetallic states and peculiar magnetic properties. However, the origins of the magnetic phase separation and spin glass state below TC in this ordered compound are two unresolved yet important puzzles in understanding its magnetism. Here, we report the discovery of local symmetry breaking surprisingly co-emerges with the onset of ferromagnetic order in Co3Sn2S2, by a combined use of neutron total scattering and half-polarized neutron diffraction. An anisotropic distortion of the cobalt kagome lattice at the atomic/nano level is also found, with distinct distortion directions among the two Co1 and four Co2 atoms. The mismatch of local and average symmetries occurs below TC, indicating that Co3Sn2S2 evolves to an intrinsically lattice disordered system when the ferromagnetic order is established. The local symmetry breaking with intrinsic lattice disorder provides new understanding of the puzzling magnetic properties. Our density functional theory (DFT) calculation indicates that the local symmetry breaking is expected to reorient local ferromagnetic moments, unveiling the existence of the ferromagnetic instability associated with the lattice instability. Furthermore, DFT calculation unveils that the local symmetry breaking could affect the Weyl property by breaking the mirror plane. Our findings highlight the fundamentally important role that the local symmetry breaking plays in advancing our understanding on the magnetic and topological properties in Co3Sn2S2, which may draw attention to explore the overlooked local symmetry breaking in Co3Sn2S2, its derivatives and more broadly in other topological Dirac/Weyl semimetals and kagome-lattice magnets.

7.
Phys Rev Lett ; 129(16): 167202, 2022 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-36306774

RESUMEN

We study the orbital angular momentum of magnons for collinear ferromagnet (FM) and antiferromagnetic (AF) systems with nontrivial networks of exchange interactions. The orbital angular momentum of magnons for AF and FM zigzag and honeycomb lattices becomes nonzero when the lattice contains two inequivalent sites and is largest at the avoided-crossing points or extremum of the frequency bands. Hence, the arrangement of exchange interactions may play a more important role at producing the orbital angular momentum of magnons than the spin-orbit coupling energy and the resulting noncollinear arrangement of spins.

8.
Plant Biotechnol J ; 19(10): 2040-2051, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34008333

RESUMEN

Potato (Solanum tuberosum L.) and sweetpotato (Ipomoea batatas L.), which are nutritionally and commercially important tuberous crops, possess a perplexing heredity because of their autopolyploid genomes. To reduce cross-breeding efforts for selecting superior cultivars from progenies with innumerable combinations of traits, DNA markers tightly linked to agronomical traits are required. To develop DNA markers, we developed a method for quantitative trait loci (QTL) mapping using whole-genome next-generation sequencing (NGS) in autopolyploid crops. To apply the NGS-based bulked segregant method, QTL-seq was modified. (1) Single parent-specific simplex (unique for one homologous chromosome) single-nucleotide polymorphisms (SNPs), which present a simple segregation ratio in the progenies, were exploited by filtering SNPs by SNP index (allele frequency). (2) Clusters of SNPs, which were inherited unevenly between bulked progenies with opposite phenotypes, especially those with an SNP index of 0 for the bulk that did not display the phenotypes of interest, were explored. These modifications allowed for separate tracking of alleles located on each of the multiple homologous chromosomes. By applying this method, clusters of SNPs linked to the potato cyst nematode resistance H1 gene and storage root anthocyanin (AN) content were identified in tetraploid potato and hexaploid sweetpotato, respectively, and completely linked DNA markers were developed at the site of the presented SNPs. Thus, polyploid QTL-seq is a versatile method that is free from specialized manipulation for sequencing and construction of elaborate linkage maps and facilitates rapid development of tightly linked DNA markers in autopolyploid crops, such as potato and sweetpotato.


Asunto(s)
Ipomoea batatas , Solanum tuberosum , Marcadores Genéticos , Ipomoea batatas/genética , Fitomejoramiento , Polimorfismo de Nucleótido Simple/genética , Poliploidía , Sitios de Carácter Cuantitativo/genética , Solanum tuberosum/genética
9.
Phys Rev Lett ; 127(11): 117201, 2021 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-34558925

RESUMEN

Understanding magnetism and its possible correlations to topological properties has emerged to the forefront as a difficult topic in studying magnetic Weyl semimetals. Co_{3}Sn_{2}S_{2} is a newly discovered magnetic Weyl semimetal with a kagome lattice of cobalt ions and has triggered intense interest for rich fantastic phenomena. Here, we report the magnetic exchange couplings of Co_{3}Sn_{2}S_{2} using inelastic neutron scattering and two density functional theory (DFT) based methods: constrained magnetism and multiple-scattering Green's function methods. Co_{3}Sn_{2}S_{2} exhibits highly anisotropic magnon dispersions and linewidths below T_{C}, and paramagnetic excitations above T_{C}. The spin-wave spectra in the ferromagnetic ground state is well described by the dominant third-neighbor "across-hexagon" J_{d} model. Our density functional theory calculations reveal that both the symmetry-allowed 120° antiferromagnetic orders support Weyl points in the intermediate temperature region, with distinct numbers and the locations of Weyl points. Our study highlights the important role Co_{3}Sn_{2}S_{2} can play in advancing our understanding of kagome physics and exploring the interplay between magnetism and band topology.

10.
Phys Rev Lett ; 127(3): 037201, 2021 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-34328778

RESUMEN

The lack of methods to experimentally detect and quantify entanglement in quantum matter impedes our ability to identify materials hosting highly entangled phases, such as quantum spin liquids. We thus investigate the feasibility of using inelastic neutron scattering (INS) to implement a model-independent measurement protocol for entanglement based on three entanglement witnesses: one-tangle, two-tangle, and quantum Fisher information (QFI). We perform high-resolution INS measurements on Cs_{2}CoCl_{4}, a close realization of the S=1/2 transverse-field XXZ spin chain, where we can control entanglement using the magnetic field, and compare with density-matrix renormalization group calculations for validation. The three witnesses allow us to infer entanglement properties and make deductions about the quantum state in the material. We find QFI to be a particularly robust experimental probe of entanglement, whereas the one and two-tangles require more careful analysis. Our results lay the foundation for a general entanglement detection protocol for quantum spin systems.

11.
Jpn J Clin Oncol ; 51(4): 584-589, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33388755

RESUMEN

OBJECTIVE: The present study aimed to clarify the occurrence rate of lymphedema and prognosis in patients with endometrial cancer according to sentinel lymph node biopsy alone with intraoperative histopathological examination. METHODS: The study included 45 consecutive patients with endometrial cancer treated at Tohoku University Hospital between October 2014 and August 2017. All patients had endometrial carcinoma with endometrioid histology Grade 1 or Grade 2 confirmed by biopsy and stage I on magnetic resonance imaging and/or computed tomography at their preoperative evaluation. Sentinel lymph node detection was performed by radioisotope and dye. Patients who were diagnosed intraoperatively as negative for sentinel lymph node metastasis did not undergo further systematic pelvic lymphadenectomy. The occurrence rate of lymphedema and prognosis was evaluated. RESULTS: Bilateral sentinel lymph nodes were detected in 44 of 45 patients (97%). Forty-three patients underwent sentinel lymph node biopsy alone, and only two patients underwent systematic lymphadenectomy. Sentinel lymph node metastases were detected in one patient intraoperatively and two patients postoperatively as ITCs. No patients experienced recurrence. New symptomatic lower-extremity lymphedema was identified in one of 43 patients (2.3%) who underwent sentinel lymph node biopsy alone. CONCLUSION: Sentinel lymph node biopsy alone with intraoperative histopathological diagnosis appears to be a safe and effective strategy to detect lymph node metastasis and to reduce the number of patients with lower-extremity lymphedema among patients with endometrial cancer.


Asunto(s)
Pueblo Asiatico , Neoplasias Endometriales/complicaciones , Neoplasias Endometriales/cirugía , Linfedema/etiología , Ganglio Linfático Centinela/cirugía , Adulto , Anciano , Quimioterapia Adyuvante , Neoplasias Endometriales/patología , Femenino , Estudios de Seguimiento , Humanos , Japón , Metástasis Linfática/patología , Linfedema/patología , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Pronóstico , Estudios Prospectivos , Factores de Riesgo , Ganglio Linfático Centinela/patología , Biopsia del Ganglio Linfático Centinela
12.
Breed Sci ; 71(3): 354-364, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34776742

RESUMEN

Occurrence of pale potato cyst nematode, Globodera pallida (Stone) Behrens, was first recorded in Japan in 2015. Among several control measures, cultivation of resistant potato (Solanum tuberosum L.) varieties is the most effective in cost and environmental impact. As no G. pallida-resistant varieties have yet been developed in Japan, great emphasis is being placed on screening of germplasm possessing the resistance and development of the resistant varieties. In this study, we first improved previously reported DNA markers linked to the G. pallida resistance loci (GpaIVs adg and Gpa5) and then used these to screen more than 1,000 germplasms to select several candidate germplasms with resistance. We performed inoculation testing on the selected candidates and identified several resistant germplasms to the Japanese G. pallida population. Furthermore, we developed a simultaneous detection method combining three DNA markers linked to G. pallida and Globodera rostochiensis (Wollenweber) Behrens resistance loci. We validated the ability of C237-I marker to select resistant allele of GpaIVs adg and predict the presence of resistance in a Japanese breeding population. Resistant germplasms identified in this study could potentially be used to develop G. pallida-resistant varieties. The marker evaluation methods developed in this study will contribute to the efficient development of resistant varieties.

13.
Sci Technol Adv Mater ; 22(1): 124-134, 2021 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-33628122

RESUMEN

Although coercivity is one of the fundamental properties of permanent magnets, it has not been well understood. In this paper, micromagnetics and thermal activation magnetization reversal theories are briefly reviewed, and then our recent macroscopic and microscopic experimental approaches for thermally activated magnetization reversal in advanced Nd-Fe-B hot-deformed magnets are explained. Our experimental results are well supported by the recent atomistic spin model calculations. Moreover, the systematic micromagnetics simulation study makes much clearer the physical picture of the thermally activated magnetization reversal process in permanent magnets.

14.
Phys Rev Lett ; 123(19): 196603, 2019 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-31765189

RESUMEN

We propose mechanisms for the spin Hall effect in metallic systems arising from the coupling between conduction electrons and local magnetic moments that are dynamically fluctuating. Both a side-jump-type mechanism and a skew-scattering-type mechanism are considered. In either case, dynamical spin fluctuation gives rise to a nontrivial temperature dependence in the spin Hall conductivity. This leads to the enhancement in the spin Hall conductivity at nonzero temperatures near the ferromagnetic instability. The proposed mechanisms could be observed in 4d or 5d metallic compounds.

15.
Phys Rev Lett ; 123(16): 167202, 2019 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-31702335

RESUMEN

We propose a new mechanism for the thermal Hall effect in exchange spin-wave systems, which is induced by the magnon-phonon interaction. Using symmetry arguments, we first show that this effect is quite general, and exists whenever the mirror symmetry in the direction of the magnetization is broken. We then demonstrate our result in a collinear ferromagnet on a square lattice, with perpendicular easy-axis anisotropy and Dzyaloshinskii-Moriya interaction from mirror symmetry breaking. We show that the thermal Hall conductivity is controlled by the resonant contribution from the anticrossing points between the magnon and phonon branches, and estimate its size to be comparable to that of the magnon-mediated thermal Hall effect.

16.
BMC Musculoskelet Disord ; 20(1): 92, 2019 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-30797234

RESUMEN

BACKGROUND: Gnathodiaphyseal dysplasia (GDD) is an extremely rare autosomal dominant disease characterized by cemento-osseous lesions in the jawbones, bone fragility, and diaphyseal sclerosis of the tubular bones. Patients with GDD are prone to sustain fractures by minor accidents. Although over 80 cases have been reported, detailed information about the orthopedic treatment of the fractures is limited. CASE PRESENTATION: A 9-year-old Japanese girl with a known history of GDD presented with pain and deformity in the left thigh after a minor fall. She had a displaced transverse fracture in the mid-shaft of the left femur and underwent a closed reduction and external fixation. In the 25th week after the initial surgery, she had another fracture in the left femur at one of the half-pin insertion sites. She underwent an external fixation again. After this operation, the patient sustained another refracture at the same fracture site and one supracondylar fracture at the distant site of the femur. The supracondylar fracture occurred without any triggering activity before beginning a weight-bearing exercise. The supracondylar fracture was successfully treated conservatively, but she sustained two more diaphyseal fractures at half-pin insertion sites one after another. She eventually underwent a revision surgery with a flexible intramedullary nail. At 3 months postoperatively, the fracture was healed and the patient maintained her ambulatory status without further refracture. CONCLUSIONS: Patients with GDD might have narrower safety ranges of biomechanical and physiological drawbacks, which are considered to be acceptable in ordinary cases. The choice of treatment should be aimed at minimizing these negative effects. We recommend intramedullary devise as the first-choice implant for the treatment of isolated femoral shaft fracture in GDD patients in this age group.


Asunto(s)
Fracturas del Fémur/diagnóstico por imagen , Fracturas del Fémur/cirugía , Fijación Interna de Fracturas/métodos , Osteogénesis Imperfecta/diagnóstico por imagen , Osteogénesis Imperfecta/cirugía , Niño , Femenino , Fracturas del Fémur/etiología , Fijación Interna de Fracturas/instrumentación , Humanos , Osteogénesis Imperfecta/complicaciones , Recurrencia
17.
Nano Lett ; 18(12): 7658-7664, 2018 12 12.
Artículo en Inglés | MEDLINE | ID: mdl-30408960

RESUMEN

We report the connection between the stacking order and magnetic properties of bilayer CrI3 using first-principles calculations. We show that the stacking order defines the magnetic ground state. By changing the interlayer stacking order, one can tune the interlayer exchange interaction between antiferromagnetic and ferromagnetic. To measure the predicted stacking-dependent magnetism, we propose using linear magnetoelectric effect. Our results not only gives a possible explanation for the observed antiferromagnetism in bilayer CrI3 but also have direct implications in heterostructures made of two-dimensional magnets.

18.
Nano Lett ; 18(6): 4023-4028, 2018 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-29719147

RESUMEN

Thin flakes of Cr1/3NbS2 are fabricated successfully via microexfoliation techniques. Temperature-dependent and field-dependent magnetizations of thin flakes with various thicknesses are investigated. When the thickness of the flake is around several hundred nanometers, the softening and eventual disappearance of the bulk soliton peak is accompanied by the appearance of other magnetic peaks at lower magnetic fields. The emergence and annihilation of the soliton peaks are explained and simulated theoretically by the change in spin spiral number inside the soliton lattice due to dimensional confinement. Compared to the conventional magnetic states in nanoscale materials, the stability and thickness tunability of quantified spin spirals make Cr1/3NbS2 a potential candidate for spintronics nanodevices beyond Moore's law.

19.
Int J Mol Sci ; 21(1)2019 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-31887985

RESUMEN

In this study, we reveal that liver organoid transplantation through the portal vein is a safe and effective method for the treatment of chronic liver damage. The liver organoids significantly reconstituted the hepatocytes; hence, the liver was significantly enlarged in this group, compared to the monolayer cell transplantation group in the retrorsine/partial hepatectomy (RS/PH) model. In the liver organoid transplantation group, the bile ducts were located in the donor area and connected to the recipient bile ducts. Thus, the rate of bile reconstruction in the liver was significantly higher compared to that in the monolayer group. By transplanting liver organoids, we saw a level of 70% replacement of the damaged liver. Consequently, in the transplantation group, diminished ductular reaction and a decrease of placental glutathione S-transferase (GST-p) precancerous lesions were observed. After trans-portal injection, the human induced pluripotent stem cell (hiPSC)-derived liver organoids revealed no translocation outside the liver; in contrast, the monolayer cells had spread to the lungs. The hiPSC-derived liver organoids were attached to the liver in the immunodeficient RS/PH rats. This study clearly demonstrates that liver organoid transplantation through the portal vein is a safe and effective method for the treatment of chronic liver damage in rats.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/terapia , Trasplante de Hígado/métodos , Organoides/citología , Vena Porta/cirugía , Alcaloides de Pirrolicidina/efectos adversos , Animales , Células Cultivadas , Femenino , Glutatión Transferasa/metabolismo , Hepatectomía , Humanos , Células Madre Pluripotentes Inducidas/citología , Regeneración Hepática , Técnicas de Cultivo de Órganos , Ratas , Resultado del Tratamiento
20.
Nano Lett ; 17(4): 2126-2130, 2017 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-28256840

RESUMEN

Charge transfer in superlattices consisting of SrIrO3 and SrMnO3 is investigated using density functional theory. Despite the nearly identical work function and nonpolar interfaces between SrIrO3 and SrMnO3, rather large charge transfer was experimentally reported at the interface between them. Here, we report a microscopic model that captures the mechanism behind this phenomenon, providing a qualitative understanding of the experimental observation. This leads to unique strain dependence of such charge transfer in iridate-manganite superlattices. The predicted behavior is consistently verified by experiment with soft X-ray and optical spectroscopy. Our work thus demonstrates a new route to control electronic states in nonpolar oxide heterostructures.

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