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1.
Nanotechnology ; 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38959868

RESUMEN

We present a spectroscopic study of the magnetic properties of Fe3-δGeTe2 single crystals with varying Fe content, achieved by tuning the stoichiometry of the crystals. We carried out x-ray absorption spectroscopy and analyzed the x-ray circular magnetic dichroism spectra using the sum rules, to determine the orbital and spin magnetic moments of the materials. We find a clear reduction of the spin and orbital magnetic moment with increasing Fe deficiency. Magnetic susceptibility measurements show that the reduction in magnetization is accompanied by a reduced Curie temperature. Multiplet calculations reveal that the Fe2+ state increasingly mixes with a higher valence state when the Fe deficiency is increased. This effect is correlated with the weakening of the magnetic moment. As single crystals are the base material for exfoliation processes, our results are relevant for the assembly of 2D magnetic heterostructures. .

2.
Nanotechnology ; 34(27)2023 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-36947871

RESUMEN

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.
J Infect Chemother ; 28(1): 1-5, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34580009

RESUMEN

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.


Asunto(s)
Chlamydia trachomatis , Uretritis , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Azitromicina/farmacología , Farmacorresistencia Bacteriana , Humanos , Japón/epidemiología , Masculino , Pruebas de Sensibilidad Microbiana , Uretritis/tratamiento farmacológico , Uretritis/epidemiología
4.
Int J Clin Oncol ; 18(2): 306-13, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22350099

RESUMEN

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.


Asunto(s)
Metástasis de la Neoplasia/tratamiento farmacológico , Neoplasias Hormono-Dependientes/tratamiento farmacológico , Prednisolona/administración & dosificación , Neoplasias de la Próstata/tratamiento farmacológico , Taxoides/administración & dosificación , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Docetaxel , Esquema de Medicación , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/inducido químicamente , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/clasificación , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/patología , Humanos , Japón , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia/patología , Neoplasias Hormono-Dependientes/patología , Orquiectomía , Neoplasias de la Próstata/patología , Taxoides/efectos adversos , Resultado del Tratamiento
5.
ACS Nano ; 17(17): 16879-16885, 2023 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-37642321

RESUMEN

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.

6.
ACS Nano ; 16(7): 10545-10553, 2022 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-35802911

RESUMEN

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.

7.
ACS Appl Mater Interfaces ; 12(41): 46854-46861, 2020 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-32955239

RESUMEN

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.

10.
Urology ; 69(3): 457-61, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17382144

RESUMEN

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.


Asunto(s)
Carcinoma de Células Transicionales/cirugía , Nefrectomía/métodos , Uréter/cirugía , Neoplasias de la Vejiga Urinaria/cirugía , Anciano , Anciano de 80 o más Años , Carcinoma de Células Transicionales/mortalidad , Cistoscopía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico , Recurrencia Local de Neoplasia/epidemiología , Siembra Neoplásica , Estudios Retrospectivos , Análisis de Supervivencia , Resultado del Tratamiento , Neoplasias de la Vejiga Urinaria/mortalidad
11.
J Biomech Eng ; 129(6): 890-97, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18067393

RESUMEN

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.


Asunto(s)
Músculos Pterigoideos/fisiopatología , Disco de la Articulación Temporomandibular/fisiopatología , Trastornos de la Articulación Temporomandibular/fisiopatología , Adulto , Fuerza de la Mordida , Bruxismo/fisiopatología , Fuerza Compresiva/fisiología , Simulación por Computador , Femenino , Análisis de Elementos Finitos , Humanos , Imagenología Tridimensional , Luxaciones Articulares/etiología , Imagen por Resonancia Magnética , Modelos Biológicos , Estrés Mecánico , Disco de la Articulación Temporomandibular/lesiones , Trastornos de la Articulación Temporomandibular/etiología , Factores de Tiempo
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