Search

The CALorimetric Electron Telescope (CALET) on the International Space Station consists of a high-energy cosmic-ray CALorimeter (CAL) and a lower-energy CALET Gamma-ray Burst Monitor (CGBM). CAL is sensitive to electrons up to 20 TeV, cosmic-ray nuclei from Z = 1 through Z ∼ 40, and gamma rays over the range 1 GeVâ€"10 TeV. CGBM observes gamma rays from 7 keV to 20 MeV. The combined CAL-CGBM instrument has conducted a search for gamma-ray bursts (GRBs) since 2015 October. We report here on the results of a search for X-ray/gamma-ray counterparts to gravitational-wave events reported during the LIGO/Virgo observing run O3. No events have been detected that pass all acceptance criteria. We describe the components, performance, and triggering algorithms of the CGBMâ€"the two Hard X-ray Monitors consisting of LaBr3(Ce) scintillators sensitive to 7 keVâ€"1 MeV gamma rays and a Soft Gamma-ray Monitor BGO scintillator sensitive to 40 keVâ€"20 MeVâ€"and the high-energy CAL consisting of a charge detection module, imaging calorimeter, and the fully active total absorption calorimeter. The analysis procedure is described and upper limits to the time-averaged fluxes are presented. [ABSTRACT FROM AUTHOR]

We have developed the FeCo nanocontact magnetoresistance (NCMR) with spin-valve structure [H. N. Fuke et al., IEEE Trans. Magn. 43, 2848 (2007)] which exhibits up to a MR ratio of 11%–12% at a resistance area (RA) of 0.3–0.55 Ω μm2. The nanocontact configurations were estimated at about 2 nm in in-plane diameter, 1.2 nm in thickness, and 0.55% in density for a RA∼0.5 Ω μm2 film based on in-plane current distribution by conductive atomic-force microscopy cross sectional transmission electron microscope images of the NCMR. The origin of the NCMR was discussed by comparing magnetic field dependence of resistance, with micromagnetics simulation based on the diffusive MR theory. It is found that our NCMR cannot be explained by diffusive domain wall theory or bulk scattering in free and pinned layers. It is likely that a theory on the basis of a ballistic MR consideration is needed to interpret our MR origin. [ABSTRACT FROM AUTHOR]

We have investigated the microwave oscillations due to a spin transfer effect induced by direct current in ferromagnetic nanocontact magnetoresistive (NCMR) elements with a current-perpendicular-to-plane spin-valve structure consisting of an FeCo/FeCo–AlOx nano-oxide layer/FeCo multilayer for the reference/spacer/free layers, respectively. Characteristic microwave oscillations were observed in the NCMR elements at different magnetization states induced by the application of a spin-polarized current, which are considered to be related to the introduction of a ferromagnetic NC to spacer layer (large interlayer coupling) and the resonance concerning the stability of the magnetization states of the free and reference layers around the NCs. A marvelously narrow full width at half maximum (FWHM) of l0–20 MHz is observed under a high applied magnetic field where the reference layer magnetization is slightly off axis relative to the pinned direction. By contrast, a wider FWHM of 80–600 MHz is observed at the magnetization state where the magnetization of the free layer just aligned to the antiparallel configuration against the magnetization of the reference layer. These characteristic results are discussed in terms of a spin dynamics mechanism induced by spin transfer torque in the free and reference layers around NCs. [ABSTRACT FROM AUTHOR]

LiteBIRD is a proposed CMB polarization satellite project to probe the inflationary B-mode signal. The satellite is designed to measure the tensor-to-scalar ratio with a 68 % confidence level uncertainty of $$\sigma _\mathrm{r}<10^{-3}$$ , including statistical, instrumental systematic, and foreground uncertainties. LiteBIRD will observe the full sky from the second Lagrange point for 3 years. We have a focal plane layout for observing frequency coverage that spans 40-402 GHz to characterize the galactic foregrounds. We have two detector candidates, transition-edge sensor bolometers and microwave kinetic inductance detectors. In both cases, a telecentric focal plane consists of approximately $$2\times 10^3$$ superconducting detectors. We will present the mission overview of LiteBIRD, the project status, and the TES focal plane layout. [ABSTRACT FROM AUTHOR]

LiteBIRD is a next-generation satellite mission to measure the polarization of the cosmic microwave background (CMB) radiation. On large angular scales the B-mode polarization of the CMB carries the imprint of primordial gravitational waves, and its precise measurement would provide a powerful probe of the epoch of inflation. The goal of LiteBIRD is to achieve a measurement of the characterizing tensor to scalar ratio $$r$$ to an uncertainty of $$\delta r=0.001$$ . In order to achieve this goal we will employ a kilo-pixel superconducting detector array on a cryogenically cooled sub-Kelvin focal plane with an optical system at a temperature of 4 K. We are currently considering two detector array options; transition edge sensor (TES) bolometers and microwave kinetic inductance detectors. In this paper we give an overview of LiteBIRD and describe a TES-based polarimeter designed to achieve the target sensitivity of 2 $$\upmu $$ K arcmin over the frequency range 50-320 GHz. [ABSTRACT FROM AUTHOR]

Background Radiofrequency ablation (RFA) therapy for hepatocellular carcinoma has enabled good local control to be possible. However, after successful local control, distant recurrences frequently occur in the remnant liver. Aim To identify the predictive factors for distant recurrence after RFA. Methods A total of 117 patients with initial non-advanced hepatocellular carcinoma with HCV who underwent RFA in our hospital were selected for this study. After transcatheter chemoembolization, RFA was performed under real-time computed tomography-fluoroscopic guidance. We studied survival rates, local (adjacent to treated tumour) and distant (intrahepatic site distant from the treated tumours) recurrence rates, as well as predictive factors for distant recurrence. Results After RFA, survival rates were 98.2% and 64.7% at 1 and 5 years, respectively. Child B patients had a significantly worse survival than Child A. Recurrence rates were 2.4% at 5 years for local, and 17.1% and 76.9% at 1 and 5 years, respectively, for distant. The Kaplan–Meier method revealed significantly high recurrence rates in cases with low albumin levels (Alb < 3.5 g/dL), high aspartate aminotransferase levels (AST > 60 IU/L), high alanine aminotransferase levels (ALT > 60 IU/L), low platelet counts (Plt < 10 × 104/μL), and high alpha-fetoprotein levels (AFP > 50 ng/mL). On multivariate analysis, low Alb levels and high AST levels were independent predictive factors for distant recurrence. Conclusions Although RFA enables good local control for initial hepatocellular carcinoma, distant recurrence is observed at high rates in HCV patients. Low albumin and high AST levels are predictive factors for distant recurrence. [ABSTRACT FROM AUTHOR]

Studies a two-GHz 12-pole superconducting microstrip line filter and a two-pole electrically tunable filter fabricated using interdigital electrodes and dielectric films. Changes in the dielectric constant of the films; Range of the center frequency modulation; Improvements in microwave frequency response.

When the surface energy of bottom layer is lower than top layer, the atoms of bottom layer should be pumped up at the triple point of the grain boundary. This phenomenon should be useful for the fabrication of well-defined nanobridge. To confirm the Atom Pumping-Up mechanism for metal/metal thin films, Ta(2 nm) on epitaxial MgO(001)IFe(001) films were prepared by the electron beam deposition method. The Pumping-Up mechanism was successfully confirmed by the Auger Electron Spectroscopy, the in situ Scanning Tunneling Microscopy, and the Transmission Electron Microscope observation after heat treatment of 400 ° C × 30 min. The size of the Fe bridges was 2-5 nm. Furthermore, the magnetic exchange coupling effect on the magnetization process through the ferromagnetic bridges between two Fe layers in MgO/Fe/Ta/Fe after Atom Pumping-Up shows a good agreement to the micromagnetics simulation result from the assumption of ferromagnetic bridges with the size of 1-4 nm. [ABSTRACT FROM AUTHOR]

Investigates the microstructure effect to improve the critical-current density properties for the YBCO crystal. Clarification of the pinning mechanism; Efficacy of the a- and c-axis grain as pinning centers; Composition of the film surface microstructures.

Presents a study on annealing time and temperature dependences of magnetoresistive (MR) ratio in CoFe/Cu spin-valves. Experimental procedures; Results; Conclusion.

The article presents a case study of a 32-year-old woman with focal nodular hyperplasia (FNH). Topics discussed include the magnetic resonance imaging (MRI) on FNH, the anti-mitochondrial antibody, and the levels of alpha fetoprotein. Also mentioned are the diagnosis for hepatic tumors, the liver biopsy, and the hepatitis C virus antibody.

The article presents a case study of a 50-year-old woman who was admitted to the hospital complaining abdominal pain, vomiting, and diarrhea. She was diagnosed with rupture of the pancreaticoduodenal artery aneurysms with segmental arterial mediolysis (SAM). The bleeding stopped, and the patient's symptoms disappeared when transcatheter coil embolization of the SAM was successfully performed.