Josephson junction in cobalt-doped BaFe2As2 epitaxial thin films on (La, Sr)(Al, Ta)O3 bicrystal substrates

Josephson junctions were fabricated in epitaxial films of cobalt-doped BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 bicrystal substrates. 10m-wide microbridges spanning a 30-degrees-tilted bicrystal grain boundary (BGB bridge) exhibited resistively-shunted-junction (RSJ)-like current-voltage characteristics up to 17 K, and the critical current was suppressed remarkably by a magnetic field. Microbridges without a BGB did not show the RSJ-like behavior, and their critical current densities were 20 times larger than those of BGB bridges, confirming BGB bridges display a Josephson effect originating from weakly-linked BGB

Biaxially textured cobalt-doped BaFe2As2 films with high critical current density over 1 MA/cm2 on MgO-buffered metal-tape flexible substrates

High critical current densities (Jc) > 1 MA/cm2 were realized in cobalt-doped BaFe2As2 (BaFe2As2:Co) films on flexible metal substrates with biaxially-textured MgO base-layers fabricated by an ion-beam assisted deposition technique. The BaFe2As2:Co films showed small in-plane crystalline misorientations (delta fai BaFe2As2:Co) of ~3o regardless of doubly larger misorientaions of the MgO base-layers (delta fai MgO = 7.3o), and exhibited high self-field Jc up to 3.5 MA/cm2 at 2 K. These values are comparable to that on MgO single crystals and the highest Jc among iron pnictide superconducting tapes and wires ever reported. High in-field Jc suggests the existence of c-axis correlated vortex pinning centers.Comment: Published in Appl. Phys. Let

Evaluation of Asthenopia Caused by Game Consoles

A visual function test and a questionnaire survey on asthenopia were performed before and after the use of a game console and compared to clarify the influence of the use of a game console on the visual function and asthenopia of healthy young people. The subjects were 20 healthy young persons aged 20.0 ± 0.5 years (17 females and 3 males). The near point, the rate of high frequency component (HFC) of accommodative microfluctuation, and lacrimal secretion were measured and an original questionnaire survey on asthenopia was performed before and after carrying out a task using a game console. The task was continuous playing of an action race game,‘MARIOKART 8’ (Nintendo) using Wii U (Nintendo), for 2 hours at a visual distance of 170 cm. The near point was 11.86D before the task and it significantly extended to 10.98D after the task (p < 0.05). The rates of HFC of the dominant eye before and after the task were 13.3 and 8.6%, respectively. Those of the non-dominant eye were 8.4 and 8.2%, respectively. And the lacrimal secretions were 21.2 and 21.0 mm, respectively. All the tasks showed no significant changes after each task in any parameter. The score of the subjective questionnaire survey was 14.6 before the task and it significantly increased to 34.8 after the task (p < 0.05). The task of continuous 2-hour operation of the game console significantly extended the near point and caused subjective fatigue

Exploration of new superconductors and functional materials and fabrication of superconducting tapes and wires of iron pnictides

This paper reviews the highlights of a 4-years-long research project supported by the Japanese Government to explore new superconducting materials and relevant functional materials. The project found several tens of new superconductors by examining ~1000 materials, each of which was chosen by Japanese team member experts with a background in solid state chemistry. This review summarizes the major achievements of the project in newly found superconducting materials, and the wire and tape fabrication of iron-based superconductors. It is a unique feature of this review to incorporate a list of ~700 unsuccessful materials examined for superconductivity in the project. In addition, described are new functional materials and functionalities discovered during the project.Comment: 141 pages, 127 Figures, 14 Tables, 535 Refrence

Ameliorated Outcome of Subarachnoid Hemorrhage Patients Treated with Reduced Form Glutathione

This study was designed to investigate the effects of glutathione (GSH) on delayed vasospasm and the outcome of subarachnoid hemorrhage (SAH) patients. Seventy-seven SAH patients who were admitted to 4 hospitals and operated on within 72 h after SAH, were injected intravenously with GSH (2.4 g/day) every 6 h for 14 days. Seventy SAH patients who were not treated with GSH in the same period were selected as the control group. Patient background, the outcome at 3 months after SAH according to the Glasgow Outcome Scale and the occurrence of symptomatic vasospasm were investigated. There were no statistically significant differences in patient backgrounds between the 2 groups. Regarding patient outcome, 57 patients (74%) showed good recovery, 8 (10%) were moderately disabled, 9 (12%) were severely disabled, 2 (3%) were in vegetative survival and 1 (1%) died in the GSH group, versus 39 (56%), 9 (13%), 15 (21%), 3 (4%) and 4 (6%) in the control group, respectively. These overall outcomes in the GSH group were significantly better than those in the control group (P < 0.05). In the GSH group, 31 patients (40%) showed symptomatic vasospasm, significantly lower than 46 (66%) in the control group (P < 0.01). Administration of GSH could be a good treatment for SAH patients

Ischemic and Bleeding Risk After Percutaneous Coronary Intervention in Patients With Prior Ischemic and Hemorrhagic Stroke

Background: Prior stroke is regarded as risk factor for bleeding after percutaneous coronary intervention (PCI). However, there is a paucity of data on detailed bleeding risk of patients with prior hemorrhagic and ischemic strokes after PCI. Methods and Results: In a pooled cohort of 19 475 patients from 3 Japanese PCI studies, we assessed the influence of prior hemorrhagic (n=285) or ischemic stroke (n=1773) relative to no-prior stroke (n=17 417) on ischemic and bleeding outcomes after PCI. Cumulative 3-year incidences of the co-primary bleeding end points of intracranial hemorrhage, non-intracranial global utilization of streptokinase and tissue plasminogen activator for occluded coronary arteries (GUSTO) moderate/severe bleeding, and the primary ischemic end point of ischemic stroke/myocardial infarction were higher in the prior hemorrhagic and ischemic stroke groups than in the no-prior stroke group (6.8%, 2.5%, and 1.3%, P<0.0001, 8.8%, 8.0%, and 6.0%, P=0.001, and 12.7%, 13.4%, and 7.5%, P<0.0001). After adjusting confounders, the excess risks of both prior hemorrhagic and ischemic strokes relative to no-prior stroke remained significant for intracranial hemorrhage (hazard ratio (HR) 4.44, 95% CI 2.64-7.01, P<0.0001, and HR 1.52, 95% CI 1.06-2.12, P=0.02), but not for non-intracranial bleeding (HR 1.18, 95% CI 0.76-1.73, P=0.44, and HR 0.94, 95% CI 0.78-1.13, P=0.53). The excess risks of both prior hemorrhagic and ischemic strokes relative to no-prior stroke remained significant for ischemic events mainly driven by the higher risk for ischemic stroke (HR 1.46, 95% CI 1.02-2.01, P=0.04, and HR 1.49, 95% CI 1.29-1.72, P<0.0001). Conclusions: Patients with prior hemorrhagic or ischemic stroke as compared with those with no-prior stroke had higher risk for intracranial hemorrhage and ischemic events, but not for non-intracranial bleeding after PCI

DC superconducting quantum interference devices fabricated using bicrystal grain boundary junctions in Co-doped BaFe2As2 epitaxial films

DC superconducting quantum interference devices (dc-SQUIDs) were fabricated in Co-doped BaFe2As2 epitaxial films on (La, Sr)(Al, Ta)O3 bicrystal substrates with 30deg misorientation angles. The 18 x 8 micro-meter^2 SQUID loop with an estimated inductance of 13 pH contained two 3 micro-meter wide grain boundary junctions. The voltage-flux characteristics clearly exhibited periodic modulations with deltaV = 1.4 micro-volt at 14 K, while the intrinsic flux noise of dc-SQUIDs was 7.8 x 10^-5 fai0/Hz^1/2 above 20 Hz. The rather high flux noise is mainly attributed to the small voltage modulation depth which results from the superconductor-normal metal-superconductor junction nature of the bicrystal grain boundary

Spectral evolution of GRB 060904A observed with Swift and Suzaku -- Possibility of Inefficient Electron Acceleration

We observed an X-ray afterglow of GRB 060904A with the Swift and Suzaku satellites. We found rapid spectral softening during both the prompt tail phase and the decline phase of an X-ray flare in the BAT and XRT data. The observed spectra were fit by power-law photon indices which rapidly changed from $\Gamma = 1.51^{+0.04}_{-0.03}$ to $\Gamma = 5.30^{+0.69}_{-0.59}$ within a few hundred seconds in the prompt tail. This is one of the steepest X-ray spectra ever observed, making it quite difficult to explain by simple electron acceleration and synchrotron radiation. Then, we applied an alternative spectral fitting using a broken power-law with exponential cutoff (BPEC) model. It is valid to consider the situation that the cutoff energy is equivalent to the synchrotron frequency of the maximum energy electrons in their energy distribution. Since the spectral cutoff appears in the soft X-ray band, we conclude the electron acceleration has been inefficient in the internal shocks of GRB 060904A. These cutoff spectra suddenly disappeared at the transition time from the prompt tail phase to the shallow decay one. After that, typical afterglow spectra with the photon indices of 2.0 are continuously and preciously monitored by both XRT and Suzaku/XIS up to 1 day since the burst trigger time. We could successfully trace the temporal history of two characteristic break energies (peak energy and cutoff energy) and they show the time dependence of $\propto t^{-3} \sim t^{-4}$ while the following afterglow spectra are quite stable. This fact indicates that the emitting material of prompt tail is due to completely different dynamics from the shallow decay component. Therefore we conclude the emission sites of two distinct phenomena obviously differ from each other.Comment: 19 pages, 9 figures, accepted for publication in PASJ (Suzaku 2nd Special Issue