37 research outputs found
Zone-selection effect of photoelectron intensity distributions in a nonsymmorphic system RAlSi (R : Ce and Nd)
We investigate the electronic structures of noncentrosymmetric Weyl
semimetals RAlSi (R: Ce and Nd) using soft x-ray angle-resolved photoemission
spectroscopy. We find that the photoelectron intensity distribution observed in
the momentum-resolved electronic bands is highly sensitive to the covered
Brillouin zone (BZ) due to the zone-selection effect arising from the
nonsymmorphic crystal structure of RAlSi. Our data reconstruct the
photoelectron distributions varied according to the zone-selection effect, and
reveal comprehensive information about the electronic band structures
reproduced by band calculations. This detailed information enables us to
experimentally trace the Weyl-cone dispersion throughout three-dimensional
momentum space, providing valuable insights into the unique properties of
RAlSi
Multicentre multiobserver study of diffusion-weighted and fluid-attenuated inversion recovery MRI for the diagnosis of sporadic CreutzfeldtâJakob disease: a reliability and agreement study
Objectives: To assess the utility of the display standardisation of diffusion-weighted MRI (DWI) and to compare the effectiveness of DWI and fluid-attenuated inversion recovery (FLAIR) MRI for the diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD). Design: A reliability and agreement study. Setting: Thirteen MRI observers comprising eight neurologists and five radiologists at two universities in Japan. Participants: Data of 1.5-Tesla DWI and FLAIR were obtained from 29 patients with sCJD and 13 controls. Outcome measures: Standardisation of DWI display was performed utilising b0 imaging. The observers participated in standardised DWI, variable DWI (the display adjustment was observer dependent) and FLAIR sessions. The observers independently assessed each MRI for CJD-related lesions, that is, hyperintensity in the cerebral cortex or striatum, using a continuous rating scale. Performance was evaluated by the area under the receiver operating characteristics curve (AUC). Results: The mean AUC values were 0.84 (95% CI 0.81 to 0.87) for standardised DWI, 0.85 (95% CI 0.82 to 0.88) for variable DWI and 0.68 (95% CI 0.63 to 0.72) for FLAIR, demonstrating the superiority of DWI (p<0.05). There was a trend for higher intraclass correlations of standardised DWI (0.74, 95% CI 0.66 to 0.83) and variable DWI (0.72, 95% CI 0.62 to 0.81) than that of FLAIR (0.63, 95% CI 0.53 to 0.74), although the differences were not statistically significant. Conclusions: Standardised DWI is as reliable as variable DWI, and the two DWI displays are superior to FLAIR for the diagnosis of sCJD. The authors propose that hyperintensity in the cerebral cortex or striatum on 1.5-Tesla DWI but not FLAIR can be a reliable diagnostic marker for sCJD
Reliability of DWI and FLAIR for diagnosis of sporadic CJD
Objectives: To assess the utility of the display standardisation of diffusion-weighted MRI (DWI) and to compare the effectiveness of DWI and fluid-attenuated inversion recovery (FLAIR) MRI for the diagnosis of sporadic CreutzfeldteâJakob disease (sCJD).
Design: A reliability and agreement study.
Setting: Thirteen MRI observers comprising eight neurologists and five radiologists at two universities in Japan.
Participants: Data of 1.5-Tesla DWI and FLAIR were obtained from 29 patients with sCJD and 13 controls.
Outcome measures: Standardisation of DWI display was performed utilising b0 imaging. The observers participated in standardised DWI, variable DWI (the display adjustment was observer dependent) and FLAIR sessions. The observers independently assessed each MRI for CJD-related lesions, that is, hyperintensity in the cerebral cortex or striatum, using a continuous rating scale. Performance was evaluated by the area under the receiver operating characteristics curve (AUC).
Results: The mean AUC values were 0.84 (95% CI 0.81 to 0.87) for standardised DWI, 0.85 (95% CI 0.82 to 0.88) for variable DWI and 0.68 (95% CI 0.63 to 0.72) for FLAIR, demonstrating the superiority of DWI (p<0.05). There was a trend for higher intraclass correlations of standardised DWI (0.74, 95% CI 0.66 to 0.83) and variable DWI (0.72, 95% CI 0.62 to 0.81) than that of FLAIR (0.63, 95% CI 0.53 to 0.74), although the differences were not statistically significant.
Conclusions: Standardised DWI is as reliable as variable DWI, and the two DWI displays are superior to FLAIR for the diagnosis of sCJD. The authors propose that hyperintensity in the cerebral cortex or striatum on 1.5-Tesla DWI but not FLAIR can be a reliable diagnostic marker for sCJD
Early-type galaxies at z = 1.3. I. The Lynx supercluster: cluster and groups at z=1.3. Morphology and color-magnitude relation
We confirm the detection of 3 groups in the Lynx supercluster, at z~1.3, and
give their redshifts and masses. We study the properties of the group galaxies
as compared to the central clusters, RXJ0849+4452 and RXJ0848+4453, selecting
89 galaxies in the clusters and 74 galaxies in the groups. We morphologically
classify galaxies by visual inspection, noting that our early-type galaxy (ETG)
sample would have been contaminated at the 30% -40% level by simple automated
classification methods (e.g. based on Sersic index). In luminosity selected
samples, both clusters and groups show high fractions of Sa galaxies. The ETG
fractions never rise above ~50% in the clusters, which is low compared to the
fractions observed in clusters at z~1. However, ETG plus Sa fractions are
similar to those observed for ETGs in clusters at z~1. Bulge-dominated galaxies
visually classified as Sas might also be ETGs with tidal features or merger
remnants. They are mainly red and passive, and span a large range in
luminosity. Their star formation seems to have been quenched before
experiencing a morphological transformation. Because their fraction is smaller
at lower redshifts, they might be the spiral population that evolves into ETGs.
For mass-selected samples, the ETG fraction show no significant evolution with
respect to local clusters, suggesting that morphological transformations occur
at lower masses and densities. The ETG mass-size relation shows evolution
towards smaller sizes at higher redshift in both clusters and groups, while the
late-type mass-size relation matches that observed locally. The group ETG red
sequence shows lower zero points and larger scatters than in clusters, both
expected to be an indication of a younger galaxy population. The estimated age
difference is small when compared to the difference in age at different galaxy
masses.Comment: ApJ, submitted - referee report answered - iterating with the refere
The Hyper Suprime-Cam SSP survey: Overview and survey design
Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2-m Subaru telescope on the summit of Mauna Kea in Hawaii. A team of scientists from Japan, Taiwan, and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400âdeg2 in five broad bands (grizy), with a 5âÏ point-source depth of r â 26. The Deep layer covers a total of 26âdeg2 in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter still in two pointings of HSC (a total of 3.5âdeg2). Here we describe the instrument, the science goals of the survey, and the survey strategy and data processing. This paper serves as an introduction to a special issue of the Publications of the Astronomical Society of Japan, which includes a large number of technical and scientific papers describing results from the early phases of this survey
Development and Validation of an HPLC Method for Analysis of Topotecan in Human Cerebrospinal Fluid and Its Application in Elimination Evaluation of Topotecan after Intraventricular Injection
Intrathecal administration of anticancer drugs is an effective dosage strategy, but the elimination of intraventricular drugs is not uniform in all patients. For safety, a system to evaluate local pharmacokinetics in the ventricles after administration is desired. In this study, we developed a simple and reproducible method to measure topotecan concentration in the cerebrospinal fluid (CSF) and confirmed its clinical applicability. High-performance liquid chromatography (HPLC) analysis was performed using a C18 column to measure the total topotecan concentration in the CSF. Clinical CSF samples were obtained from a 1-year old child with poor CSF absorption and stagnation. The patient received topotecan via an intraventricular subcutaneous reservoir. The HPLC method complied with the validation criteria. The lower limit of quantitation of this method was 0.04 ”M. Using the developed method, we could determine the difference in topotecan CSF concentrations at 24 and 48 h after administration. The patientâs topotecan elimination rate was extremely low, and signs of adverse effects were observed at high CSF concentration of topotecan. The developed method could detect the delay in topotecan elimination after intrathecal injection. The findings of this study are valuable for the development of personalized treatments for the intrathecal administration of anticancer drugs