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1.
ACS Nano ; 17(17): 16879-16885, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37642321

RESUMO

Engineering nontrivial spin textures in magnetic van der Waals materials is highly desirable for spintronic applications based on hybrid heterostructures. The recent observation of labyrinth and bubble domains in the near room-temperature ferromagnet Fe5-xGeTe2 down to a bilayer thickness was thus a significant advancement toward van der Waals-based many-body physics. However, the physical mechanism responsible for stabilizing these domains remains unclear and requires further investigation. Here, we combine cryogenic scanning diamond quantum magnetometry and field reversal techniques to elucidate the high-field propagation and nucleation of bubble domains in trilayer Fe5-xGeTe2. We provide evidence of pinning-induced nucleation of magnetic bubbles and further show an unexpectedly high layer-dependent coercive field. These measurements can be easily extended to a wide range of magnetic materials to provide valuable nanoscale insight into domain processes critical for spintronic applications.

2.
Nanotechnology ; 34(27)2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-36947871

RESUMO

The topological surface states (TSSs) in topological insulators (TIs) offer exciting prospects for dissipationless spin transport. Common spin-based devices, such as spin valves, rely on trilayer structures in which a non-magnetic layer is sandwiched between two ferromagnetic (FM) layers. The major disadvantage of using high-quality single-crystalline TI films in this context is that a single pair of spin-momentum locked channels spans across the entire film, meaning that only a very small spin current can be pumped from one FM to the other, along the side walls of the film. On the other hand, using nanocrystalline TI films, in which the grains are large enough to avoid hybridization of the TSSs, will effectively increase the number of spin channels available for spin pumping. Here, we used an element-selective, x-ray based ferromagnetic resonance technique to demonstrate spin pumping from a FM layer at resonance through the TI layer and into the FM spin sink.

3.
ACS Nano ; 16(7): 10545-10553, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35802911

RESUMO

Magnetic domain formation in two-dimensional (2D) materials gives perspectives into the fundamental origins of 2D magnetism and also motivates the development of advanced spintronics devices. However, the characterization of magnetic domains in atomically thin van der Waals (vdW) flakes remains challenging. Here, we employ X-ray photoemission electron microscopy (XPEEM) to perform layer-resolved imaging of the domain structures in the itinerant vdW ferromagnet Fe5GeTe2 which shows near room temperature bulk ferromagnetism and a weak perpendicular magnetic anisotropy (PMA). In the bulk limit, we observe the well-known labyrinth-type domains. Thinner flakes, on the other hand, are characterized by increasingly fragmented domains. While PMA is a characteristic property of Fe5GeTe2, we observe a spin-reorientation transition with the spins canting in-plane for flakes thinner than six layers. Notably, a bubble phase emerges in four-layer flakes. This thickness dependence, which clearly deviates from the single-domain behavior observed in other 2D magnetic materials, demonstrates the exciting prospect of stabilizing complex spin textures in 2D vdW magnets at relatively high temperatures.

4.
J Infect Chemother ; 28(1): 1-5, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34580009

RESUMO

The Urogenital Sub-committee and the Surveillance Committee of the Japanese Society of Chemotherapy, The Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology conducted the second nationwide surveillance of the antimicrobial susceptibility of Chlamydia trachomatis. In this second surveillance study, clinical urethral discharge specimens were collected from patients with urethritis in 26 hospitals and clinics from May 2016 to July 2017. Based on serial cultures, the minimum inhibitory concentration (MIC) could be determined for 41 isolates; the MICs (MIC90) of ciprofloxacin, levofloxacin, tosufloxacin, sitafloxacin, doxycycline, minocycline, erythromycin, clarithromycin, azithromycin and solithromycin were 2 µg/ml (2 µg/ml), 1 µg/ml (0.5 µg/ml), 0.25 µg/ml (0.25 µg/ml), 0.125 µg/ml (0.063 µg/ml), 0.125 µg/ml (0.125 µg/ml), 0.25 µg/ml (0.25 µg/ml), 0.031 µg/ml (0.031 µg/ml), 0.25 µg/ml (0.125 µg/ml), and 0.016 µg/ml (0.008 µg/ml), respectively. In summary, this surveillance project did not identify any strains resistant to fluoroquinolone, tetracycline, or macrolide agents in Japan. In addition, the MIC of solithromycin was favorable and lower than that of other antimicrobial agents. However, the MIC of azithromycin had a slightly higher value than that reported in the first surveillance report, though this might be within the acceptable margin of error. Therefore, the susceptibility of azithromycin, especially, should be monitored henceforth.


Assuntos
Chlamydia trachomatis , Uretrite , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Azitromicina/farmacologia , Farmacorresistência Bacteriana , Humanos , Japão/epidemiologia , Masculino , Testes de Sensibilidade Microbiana , Uretrite/tratamento farmacológico , Uretrite/epidemiologia
5.
ACS Appl Mater Interfaces ; 12(41): 46854-46861, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-32955239

RESUMO

Heterostructures of two-dimensional (2D) van der Waals semiconductor materials offer a diverse playground for exploring fundamental physics and potential device applications. In InSe/GaSe heterostructures formed by sequential mechanical exfoliation and stacking of 2D monochalcogenides InSe and GaSe, we observe charge transfer between InSe and GaSe because of the 2D van der Waals interface formation and a strong hysteresis effect in the electron transport through the InSe layer when a gate voltage is applied through the GaSe layer. A gate voltage-dependent conductance decay rate is also observed. We relate these observations to the gate voltage-dependent dynamical charge transfer between InSe and GaSe layers.

6.
Int J Clin Oncol ; 18(2): 306-13, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22350099

RESUMO

BACKGROUND: There are few reports of long-term treatment with docetaxel in castration-resistant prostate cancer (CRPC) because of the limit of a maximum of ten cycles of treatment in TAX327 showing a survival benefit. Therefore, this study, ARD6563, was conducted to evaluate the safety of more than ten cycles of docetaxel in metastatic CRPC. METHODS: We enrolled patients who had received ten cycles of docetaxel in the preceding study, ARD6562. For ARD6563, patients received docetaxel every 3 weeks, at the last dose (70, 60, or 50 mg/m(2)) received for cycle 10 in ARD6562, with prednisolone 5 mg orally twice daily. RESULTS: The safety analysis set comprised 15 patients (median age, 64 years; performance status, 0 in 87%) out of 43 patients treated in ARD6562. The median initial dose of docetaxel was 60 mg/m(2), and the median number of additional cycles administered was 8 (range, 1-42). The relative dose intensity was 78.0% for docetaxel and 98.0% for prednisolone. Dose reduction was needed in 3 cycles because of grade 3 infection, febrile neutropenia, and grade 2 neuropathy. Administration delay was necessitated in 6 cycles because of grade 1-2 nonhematological toxicities. The major grade 3-4 toxicities were myelosuppression. Five patients who had an observed partial response or stable disease in ARD6562 maintained their clinical response in ARD6563. The study treatment was discontinued in 10 patients because of disease progression and in 4 patients for serious toxicities. There were no treatment-related deaths. CONCLUSIONS: Long-term docetaxel with prednisolone is feasible in selected Japanese patients with CRPC.


Assuntos
Metástase Neoplásica/tratamento farmacológico , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Prednisolona/administração & dosagem , Neoplasias da Próstata/tratamento farmacológico , Taxoides/administração & dosagem , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Docetaxel , Esquema de Medicação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/induzido quimicamente , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/classificação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica/patologia , Neoplasias Hormônio-Dependentes/patologia , Orquiectomia , Neoplasias da Próstata/patologia , Taxoides/efeitos adversos , Resultado do Tratamento
7.
J Biomech Eng ; 129(6): 890-97, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18067393

RESUMO

In this study, the effect of hyperactivity of the lateral pterygoid muscle (LPM) on the temporomandibular joint (TMJ) disk during prolonged clenching was examined with a mathematical model. Finite element models of the TMJ were constructed based on magnetic resonance images from two subjects with or without internal derangement of the TMJ. For each model, muscle forces were used as a loading condition for stress analysis for 10 min clenching. Furthermore, an intermittent increase of the LPM force with intervals of 1 min was applied. In the asymptomatic model, large stresses were found in the central and lateral part of the disk at the onset of clenching. In the retrodiscal tissue, stress relaxation occurred during the first 2 min of clenching. When the force of the LPM increased temporarily, the disk moved anteriorly and returned to its original position afterward. In the symptomatic model, large stresses were observed in both the posterior region of the disk and the retrodiscal tissue throughout clenching. Upon temporary increase of the LPM force, the disk was elongated anteriorly, which appeared to be irreversible. These results indicate that hyperactivity of the LPM may be involved in the progression of disk displacement.


Assuntos
Músculos Pterigoides/fisiopatologia , Disco da Articulação Temporomandibular/fisiopatologia , Transtornos da Articulação Temporomandibular/fisiopatologia , Adulto , Força de Mordida , Bruxismo/fisiopatologia , Força Compressiva/fisiologia , Simulação por Computador , Feminino , Análise de Elementos Finitos , Humanos , Imageamento Tridimensional , Luxações Articulares/etiologia , Imageamento por Ressonância Magnética , Modelos Biológicos , Estresse Mecânico , Disco da Articulação Temporomandibular/lesões , Transtornos da Articulação Temporomandibular/etiologia , Fatores de Tempo
8.
Urology ; 69(3): 457-61, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17382144

RESUMO

OBJECTIVES: To determine the oncologic safety of laparoscopic nephroureterectomy (LNU), we compared the long-term oncologic outcome of LNU versus open nephroureterectomy (ONU) in patients with upper tract transitional cell carcinoma. METHODS: A total of 367 nephroureterectomy procedures were performed at our institutes for upper tract transitional cell carcinoma without distant metastases. Of 224 patients without concomitant or previous bladder cancer, 58 underwent LNU with open intact specimen retrieval plus open distal ureter and bladder cuff removal and 166 underwent ONU. Their data were reviewed and analyzed retrospectively. The mean follow-up was 13.6 months (range 14 to 34) for the LNU group and 28.0 months (range 14 to 36) for the ONU group. RESULTS: Bladder recurrence was recognized in 19 patients (32.8%) after LNU at a median follow-up of 5.6 months compared with 63 patients (38.0%) after ONU. Local recurrence only developed in 2 patients (1.1%) after ONU. One port site metastasis occurred in a patient who had undergone LNU. Distant metastases developed in 10 patients (17.2 %) after LNU and 33 patients (19.9%) after ONU. The frequency of bladder recurrence, local recurrence, and distant metastases did not differ significantly between the two groups. The actual disease-free 2-year survival rates were similar (75.6% versus 81.7%). In all patients, the risk of metastases and death increased with advanced tumor stage and grade, but not by surgical procedure. CONCLUSIONS: In the surgical management of upper tract transitional cell carcinoma, LNU does not negatively affect long-term oncologic control and can be considered an alternative modality. Tumor stage and grade are, however, important prognostic factors in the incidence of metastases and cancer-specific mortality.


Assuntos
Carcinoma de Células de Transição/cirurgia , Nefrectomia/métodos , Ureter/cirurgia , Neoplasias da Bexiga Urinária/cirurgia , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células de Transição/mortalidade , Cistoscopia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/epidemiologia , Inoculação de Neoplasia , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento , Neoplasias da Bexiga Urinária/mortalidade
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