789 research outputs found

    Iron-Based Heavy Quasiparticles in SrFe4_{4}Sb12_{12}: An Infrared Spectroscopic Study

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    Temperature-dependent infrared reflectivity spectra of SrFe4_{4}Sb12_{12} has been measured. A renormalized Drude peak with a heavy effective mass and a pronounced pseudogap of 10 meV develops in the optical conductivity spectra at low temperatures. As the temperature decreases below 100 K, the effective mass (mm^{*}) rapidly increases, and the scattering rate (1/τ1/\tau) is quenched. The temperature dependence of mm^{*} and 1/τ1/\tau indicates that the hybridization between the Fe 3d spins and the charge carriers plays an important role in determining the physical properties of SrFe4_{4}Sb12_{12} at low temperatures. This result is the clear evidence of the iron-based heavy quasiparticles.Comment: 5 pages, 5 figure

    Biochemical analyses of lipids deposited on silicone hydrogel lenses

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    AbstractPurposeThis study was performed to determine the levels of lipids deposited on in vivo worn silicone hydrogel lenses.MethodsThree silicone hydrogel materials, galyfilcon A, senofilcon A, and asmofilcon A, were worn for 2 weeks by 35 normal subjects. Total lipid deposition was determined by the sulfo-phospho-vanillin reaction. Cholesterol was estimated by a colorimetric probe through enzymatic oxidation. Phospholipid level was estimated by determining phosphorus with ammonium molybdate through enzymatic digestion.ResultsThe total lipid content recovered from galyfilcon A, senofilcon A, and asmofilcon A was 32.9 ± 33.8, 42.1 ± 14.0, and 36.6 ± 31.9 μg/lens, respectively. The cholesterol content recovered from galyfilcon A, senofilcon A, and asmofilcon A was 26.2 ± 26.9, 28.6 ± 19.4, and 31.1 ± 21.1 μg/lens, respectively. There were no statistically significant differences in total lipids and cholesterol among the contact lens types. However, the quantity of phospholipid recovered from the asmofilcon A (7.0 ± 5.5 μg/lens) lenses was significantly higher than from galyfilcon A (1.1 ± 0.8 μg/lens) and senofilcon A (2.4 ± 0.8 mg/lens) lenses (p < 0.05, Mann-Whitney test).ConclusionsThe quantity of total lipid and cholesterol deposited on the 3 silicone hydrogel lenses tested did not differ. However, there were significant differences in the amounts of phospholipid deposited among the 3 silicone hydrogel lenses, of which clinical significance should be explored in the future study

    Resolving Marker Pose Ambiguity by Robust Rotation Averaging with Clique Constraints

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    Planar markers are useful in robotics and computer vision for mapping and localisation. Given a detected marker in an image, a frequent task is to estimate the 6DOF pose of the marker relative to the camera, which is an instance of planar pose estimation (PPE). Although there are mature techniques, PPE suffers from a fundamental ambiguity problem, in that there can be more than one plausible pose solutions for a PPE instance. Especially when localisation of the marker corners is noisy, it is often difficult to disambiguate the pose solutions based on reprojection error alone. Previous methods choose between the possible solutions using a heuristic criteria, or simply ignore ambiguous markers. We propose to resolve the ambiguities by examining the consistencies of a set of markers across multiple views. Our specific contributions include a novel rotation averaging formulation that incorporates long-range dependencies between possible marker orientation solutions that arise from PPE ambiguities. We analyse the combinatorial complexity of the problem, and develop a novel lifted algorithm to effectively resolve marker pose ambiguities, without discarding any marker observations. Results on real and synthetic data show that our method is able to handle highly ambiguous inputs, and provides more accurate and/or complete marker-based mapping and localisation.Comment: 7 pages, 4 figures, 4 table

    Japanese Orthopaedic Association Back Pain Evaluation Questionnaire. Part 3. Validity study and establishment of the measurement scale: Subcommittee on Low Back Pain and Cervical Myelopathy Evaluation of the Clinical Outcome Committee of the Japanese Orthopaedic Association, Japan

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    AbstractBackgroundThe Japanese Orthopaedic Association decided to revise the JOA score for low back pain and to develop a new outcome measure. In February 2002, the first survey was performed with a preliminary questionnaire consisting of 60 evaluation items. Based on findings of that survey, 25 items were selected for a draft of the JOA Back Pain Evaluation Questionnaire (JOABPEQ). The second survey was performed to confirm the reliability of the draft questionnaire. This article further evaluates the validity of this questionnaire and establishes a measurement scale.MethodsThe subjects of this study consisted of 355 patients with low back disorders of any type (201 men, 154 women; mean age 50.7 years). Each patient was asked to fill in a self-administered questionnaire. Superficial validity was checked in terms of the completion rate for filling out the entire questionnaire. Factor analysis was then performed to evaluate the validity of the questionnaire and establish a measurement scale.ResultsAs a result of the factor analysis, 25 items were categorized into five factors. The factors were named based on the commonality of the items: social function, mental health, lumbar function, walking ability, and low back pain. To establish a measurement scale for each factor, we determined the coefficient for each item so the difference between the maximum factor scores and minimum factor scores was approximately 100. We adjusted the formula so the maximum for each factor score was 100 and the minimum was 0.ConclusionsWe confirmed the validity of the JOA Back Pain Evaluation Questionnaire and est ablished a measurement scale

    Magnetic Field Amplification Associated with the Richtmyer-Meshkov Instability

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    The amplification of a magnetic field due to the Richtmyer-Meshkov instability (RMI) is investigated by two-dimensional MHD simulations. Single-mode analysis is adopted to reveal definite relation between the nonlinear evolution of RMI and the field enhancement. It is found that an ambient magnetic field is stretched by fluid motions associated with the RMI, and the strength is amplified significantly by more than two orders of magnitude. The saturation level of the field is determined by a balance between the amplified magnetic pressure and the thermal pressure after shock passage. This effective amplification can be achieved in a wide range of the conditions for the RMI such as the Mach number of an incident shock and the density ratio at a contact discontinuity. The results suggest that the RMI could be a robust mechanism of the amplification of interstellar magnetic fields and cause the origin of localized strong fields observed at the shock of supernova remnants.Comment: 16 pages, 9 figures, accepted for publication in Ap

    Postoperative Electroencephalogram for Follow up of Pediatric Moyamoya Disease

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    It is well known that the electroencephalographic finding in patients with moyamoya disease demonstrates the characteristic "re-build up" phenomenon a few minutes after hyperventilation. To evaluate the usefulness of an electroencephalogram (EEG) in the postoperative management of children with moyamoya disease, we studied the presence or absence of improvement in the clinical, single photon emission computed tomography (SPECT) and EEG findings, before and after surgery. Twenty-two patients, who underwent indirect revascularization surgery for moyamoya disease, were included in our study. Clinical improvement was assessed as the disappearance or decrease of a transient ischemic attack or headache. The findings on the EEG and SPECT were considered improved when the re-build up phenomenon was absent and when there was improvement in the cerebrovascular reserve as a result of the acetazolamide challenge test. The statistical correlation analysis for both clinical and EEG improvement were consistent (kappa value=0.409, p<0.05). However, the result from the clinical and SPECT improvement as well as that from EEG and SPECT improvement were not statistically significant. Our results suggest that EEG can be used as a noninvasive and simple follow-up test for moyamoya disease after indirect revascularization surgery if the hyperventilation procedure is effectively performed during EEG recording

    Selective labeling of a single organelle by using two-photon conversion of a photoconvertible fluorescent protein

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    SPIE BiOS, 2008, San Jose, California, United StatesWataru Watanabe, Tomoko Shimada, Sachihiro Matsunaga, Daisuke Kurihara, Shin-ichi Arimura, Nobuhiro Tsutsumi, Kiichi Fukui, Kazuyoshi Itoh, "Selective labeling of a single organelle by using two-photon conversion of a photoconvertible fluorescent protein," Proc. SPIE 6860, Multiphoton Microscopy in the Biomedical Sciences VIII, 68601B (15 February 2008); https://doi.org/10.1117/12.768745
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