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1.
Nat Mater ; 23(5): 627-632, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38321239

RESUMO

When excited, the magnetization in a magnet precesses around the field in an anticlockwise manner on a timescale governed by viscous magnetization damping, after which any information carried by the initial actuation seems to be lost. This damping appears to be a fundamental bottleneck for the use of magnets in information processing. However, here we demonstrate the recall of the magnetization-precession phase after times that exceed the damping timescale by two orders of magnitude using dedicated two-colour microwave pump-probe experiments for a Y3Fe5O12 microstructured film. Time-resolved magnetization state tomography confirms the persistent magnetic coherence by revealing a double-exponential decay of magnetization correlation. We attribute persistent magnetic coherence to a feedback effect, that is, coherent coupling of the uniform precession with long-lived excitations at the minima of the spin-wave dispersion relation. Our finding liberates magnetic systems from the strong damping in nanostructures that has limited their use in coherent information storage and processing.

2.
Phys Rev Lett ; 131(25): 253003, 2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38181354

RESUMO

Muonic helium atom hyperfine structure (HFS) measurements are a sensitive tool to test the three-body atomic system and bound-state quantum electrodynamics theory, and determine fundamental constants of the negative muon magnetic moment and mass. The world's most intense pulsed negative muon beam at the Muon Science Facility of the Japan Proton Accelerator Research Complex allows improvement of previous measurements and testing further CPT invariance by comparing the magnetic moments and masses of positive and negative muons (second-generation leptons). We report new ground-state HFS measurements of muonic helium-4 atoms at a near-zero magnetic field, performed for the first time using a small admixture of CH_{4} as an electron donor to form neutral muonic helium atoms efficiently. Our analysis gives Δν=4464.980(20) MHz (4.5 ppm), which is more precise than both previous measurements at weak and high fields. The muonium ground-state HFS was also measured under the same conditions to investigate the isotopic effect on the frequency shift due to the gas density dependence in He with CH_{4} admixture and compared with previous studies. Muonium and muonic helium can be regarded as light and heavy hydrogen isotopes with an isotopic mass ratio of 36. No isotopic effect was observed within the current experimental precision.

3.
Nat Commun ; 13(1): 7193, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36424384

RESUMO

The dynamics of a nuclear open quantum system could be revealed in the correlations between the breakup fragments of halo nuclei. The breakup mechanism of a proton halo nuclear system is of particular interest as the Coulomb polarization may play an important role, which, however, remains an open question. Here we use a highly efficient silicon detector array and measure the correlations between the breakup fragments of 8B incident on 120Sn at near-barrier energies. The energy and angular correlations can be explained by a fully quantum mechanical method based on the state-of-the-art continuum discretized coupled channel calculations. The results indicate that, compared to the neutron halo nucleus 6He, 8B presents distinctive reaction dynamics: the dominance of the elastic breakup. This breakup occurs mainly via the short-lived continuum states, almost exhausts the 7Be yield, indicating the effect of Coulomb polarization on the proton halo state. The correlation information reveals that the prompt breakup mechanism dominates, occurring predominantly on the outgoing trajectory. We also show that, as a large environment, the continuum of 8B breakup may not significantly influence elastic scattering and complete fusion.

4.
Pharmazie ; 77(6): 202-206, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35751159

RESUMO

Patients experiencing severe side effects when taking high-risk drugs may have a significantly reduced health-related quality of life (QOL); therefore, it is important to identify changes in the health-related QOL in these patients. This study aimed to determine the health-related QOL in community pharmacy outpatients taking high-risk drugs. This prospective observational study was conducted in 29 community pharmacies with 71 pharmacists in 12 regions and cities in Japan from October to December 2020 and 760 patients were enrolled. Using descriptive questionnaires of EuroQOL-5-dimensions-5-levels (EQ-5D-5L), community pharmacists obtained health-related QOL data from outpatients taking high-risk drugs. The mean health-related QOL of all outpatients was 0.869. The health-related QOL decreased with increasing age. The outpatient health-related QOL was 0.700, 0.763, 0.785, and 0.817 when taking antiepileptic, antidepressant, digitalis, and antiarrhythmic drugs, respectively, which was lower than the average health-related QOL of all outpatients. Mobility and pain/ discomfort accounted for a large proportion of the decline in the health-related QOL with increasing age. There were no significant differences in personal care with increasing age; however, the number of outpatients with mobility, normal activity, and pain challenges decreased with age. In contrast, outpatients aged <65 years with anxiety/depression showed a lower than overall average health-related QOL. To the best of our knowledge, this is the first study in Japan to report an investigation by community pharmacists regarding health-related QOL assessment in outpatients taking high-risk drugs.


Assuntos
Pacientes Ambulatoriais , Qualidade de Vida , Humanos , Dor , Farmacêuticos , Inquéritos e Questionários
5.
Phys Rev Lett ; 127(17): 172701, 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34739292

RESUMO

We report the first (in)elastic scattering measurement of ^{25}Al+p with the capability to select and measure in a broad energy range the proton resonances in ^{26}Si contributing to the ^{22}Mg(α,p) reaction at type I x-ray burst energies. We measured spin-parities of four resonances above the α threshold of ^{26}Si that are found to strongly impact the ^{22}Mg(α,p) rate. The new rate advances a state-of-the-art model to remarkably reproduce light curves of the GS 1826-24 clocked burster with mean deviation <9% and permits us to discover a strong correlation between the He abundance in the accreting envelope of the photospheric radius expansion burster and the dominance of ^{22}Mg(α,p) branch.

6.
Pharmazie ; 76(9): 450-454, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34481537

RESUMO

Objective: The efficacy of docetaxel, cisplatin, and 5-fluorouracil (DCF) therapy in treating esophageal cancer has been reported. However, febrile neutropenia (FN) is a potentially serious adverse event of DCF therapy with an incidence of 10 to 40%. Pegfilgrastim, a granulocyte colony-stimulating factor (G-CSF), has been shown to have a primary prophylactic role in FN. However, it has been suggested that excessive use of expensive G-CSF should be avoided. Therefore, we performed a cost-utility analysis of primary prophylaxis with pegfilgrastim. Design: Cost-effectiveness analysis using decision tree modelling. Methods: We used a decision tree analysis model based on the report of primary prophylaxis with pegfilgrastim. Based on a previous study, the FN incidence rate was set at 40.0% (95% confidence interval (CI): 11.9-68.1) for the pegfilgrastim group and 43.5% (95%CI: 21.6-65.4) for the no pegfilgrastim group. The FN treatment cost was US$726.63, and the duration of FN was 3.65±1.20 days. The utility value of patients who received DCF therapy was 0.643, and the change in utility value at FN onset was -0.15. Expected cost, quality-adjusted life year (QALY), and incremental cost-effectiveness ratio (ICER) were calculated, and cost-utility analysis was performed. Results: The ICER of pegfilgrastim was 184,976.75 USD/QALY. As a result of sensitivity analysis, the utility of FN had the greatest impact on the cost-effectiveness analysis, followed by the drug cost of pegfilgrastim. Conclusion: Primary prophylaxis of FN with pegfilgrastim might not be cost-effectiveness. In determining whether to administer pegfilgrastim it is necessary to consider patient factors, not just the incidence of FN.


Assuntos
Neoplasias Esofágicas , Neutropenia Febril , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Cisplatino , Análise Custo-Benefício , Docetaxel , Neoplasias Esofágicas/tratamento farmacológico , Neutropenia Febril/induzido quimicamente , Neutropenia Febril/tratamento farmacológico , Neutropenia Febril/prevenção & controle , Filgrastim , Fluoruracila , Humanos , Polietilenoglicóis , Proteínas Recombinantes/uso terapêutico
7.
J Dent Res ; 100(13): 1475-1481, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33978514

RESUMO

Polymer-infiltrated ceramic network (PICN) composites are mechanically compatible with human enamel, and are therefore promising dental restorative materials. Fabrication technology for PICN composites used in tooth restorative material has been established through computer-aided design/computer-aided manufacturing (CAD/CAM) milling, however, to date, has not been successfully developed using 3-dimensional (3D) printing. This study aimed to develop a 3D-printable PICN composite as a restorative material. The PICN composite was fabricated using a specific method based on 3D printing. A 3D-printable precursor slurry containing a high concentration of silica nanoparticles was produced and 3D-printed using stereolithography (SLA). The 3D-printed object was sintered to obtain a nano-porous object, and subsequently infiltrated and polymerized with resin monomer. Three different fabrication condition combinations were used to produce the 3D-printed PICN composites, which were characterized based on microstructure, mechanical properties, inorganic content, physicochemical properties, and overall shrinkage. The 3D-printed PICN composites were also compared to 2 commercially available CAD/CAM composite blocks, namely a PICN composite and a dispersed-filler composite. The 3D-printed PICN composites exhibited a nano-sized dual-network structure comprising a silica skeleton with infiltrated resin. The 3D-printed PICN composite exhibited a similar Vickers hardness to enamel, and a similar elastic modulus to dentin. The 3D-printed PICN composite exhibited comparable flexural strength (>100 MPa) to the CAD/CAM block, and acceptable water sorption and solubility for practical use. Further, the 3D-printed model-crown underwent isotropic shrinkage during sintering without fatal deformation. Overall, the potential of this 3D-printable PICN composite as a restorative material with similar mechanical properties to human teeth was successfully demonstrated.


Assuntos
Cerâmica , Polímeros , Desenho Assistido por Computador , Resistência à Flexão , Humanos , Teste de Materiais , Propriedades de Superfície
10.
Vet Anim Sci ; 10: 100134, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32775764

RESUMO

Cranial rib fractures during dystocia and the ensuing callus formations in calves often cause tracheal stenosis. Rib fractures may affect the lung since ribs tend to fracture above the costochondral junction during delivery. Considering that calving assistance rates for dystocia are high, calves with fractured ribs may develop respiratory disease which results in economic loss. The objective of this study was to elucidate the contribution of rib fractures to economic loss through respiratory disease in calves. Of 163 sick calves delivered from Holstein-Friesian dams included in this study, a total of 18 rib fractured calves was found, giving an incidence of rib fracture in sick calves of 11.0%. There were significant differences in incidence by the rib involved, indicating the 2nd to 7th ribs tend to break. Many of the rib fractured calves showed dyspnea and pyrexia. In this study, four of five scanned or necropsied calves had pneumonia lesions despite the fact that these four calves did not have tracheal stenosis. Rib fractured calves sold at below market value with a median difference from average sale price of minus 64,861 yen. Survival analysis indicated an overall association between rib fracture and time to death. In this study, we demonstrated that rib fractures happened most frequently in the 2nd to 7th ribs, and these cases tended to cause pneumonia, which decreased sale prices and longevity. Farmers should work to reduce risks and rates of dystocia so as to lessen economic loss and poor welfare in calves due to rib fractures.

11.
Phys Rev Lett ; 124(20): 202501, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32501086

RESUMO

We measured missing mass spectrum of the ^{12}C(γ,p) reaction for the first time in coincidence with potential decay products from η^{'} bound nuclei. We tagged an (η+p) pair associated with the η^{'}N→ηN process in a nucleus. After applying kinematical selections to reduce backgrounds, no signal events were observed in the bound-state region. An upper limit of the signal cross section in the opening angle cosθ_{lab}^{ηp}<-0.9 was obtained to be 2.2 nb/sr at the 90% confidence level. It is compared with theoretical cross sections, whose normalization ambiguity is suppressed by measuring a quasifree η^{'} production rate. Our results indicate a small branching fraction of the η^{'}N→ηN process and/or a shallow η^{'}-nucleus potential.

14.
Rev Sci Instrum ; 91(3): 033318, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32259963

RESUMO

For the purpose of future visualization of the flow field in superfluid helium-4, clusters of the triplet state excimer 4He2 * are generated along the micro-scale recoil tracks of the neutron-absorption reaction n + 3He → 3T + p. This reaction is induced by neutron irradiation of the 3He fraction contained in natural isotopic abundance liquid helium with neutron beams either from the Japan Proton Accelerator Research Complex, Materials and Life Science Experimental Facility (JPARC)/Materials and Life Science Experimental Facility or from the Kyoto University Institute for Integrated Radiation and Nuclear Science. These 4He2 * clusters are expected to be ideal tracers of the normal-fluid component in superfluid helium with several advantageous properties. Evidence of the excimer generation is inferred by detection of laser induced fluorescence emitted from the 4He2 * clusters excited by a purpose-built short pulse gain-switched titanium:sapphire (Ti:sa) laser operating at a wavelength of 905 nm. The setup and performance characteristics of the laser system including the Ti:sa and two continuous wave re-pumping lasers are described. Detection at the fluorescence wavelength of 640 nm is performed by using optical bandpass filtered photomultiplier tubes (PMT). Electrical noise in the PMT acquisition traces could successfully be suppressed by post-processing with a simple algorithm. Despite other laser-related backgrounds, the excimer was clearly identified by its fluorescence decay characteristics. Production of the excimer was found to be proportional to the neutron flux, adjusted via insertion of different collimators into the neutron beam. These observations suggest that the apparatus we constructed does function in the expected manner and, therefore, has the potential for groundbreaking turbulence research with superfluid helium.

18.
Radiat Prot Dosimetry ; 188(1): 65-72, 2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31836891

RESUMO

The aim of this study was to develop a head-chest phantom that could mimic the physique of a Japanese 0.5-year-old child and to investigate the current status of exposure dose in infant head computed tomography examinations in Japan. The phantom was produced by machine processing, and radiophotoluminescence glass dosemeters were installed in the phantom for dose measurement. Organ doses were measured for seven different head scan protocols routinely used in three hospitals. In this study, the average dose of the brain and lens within the scan region was equivalent to that measured using infant phantoms in previous studies. In contrast, the doses of both salivary glands and thyroid glands adjacent to the scan region were 1.4-1.8 times higher than those in previous studies. Expansion of the scan area accompanied by a transition of the scan mode from non-helical to helical may have resulted in the differences in organ doses.


Assuntos
Cabeça/efeitos da radiação , Imagens de Fantasmas , Doses de Radiação , Dosimetria Termoluminescente , Tórax/efeitos da radiação , Tomografia Computadorizada por Raios X , Carga Corporal (Radioterapia) , Desenho de Equipamento , Cabeça/diagnóstico por imagem , Humanos , Lactente , Japão , Tórax/diagnóstico por imagem
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