Test of High Temperature Superconducting REBCO Coil Assembly for a Multi-Frequency ECR Ion Source

Chong T.H., Fukuda M., Yorita T., et al. Test of High Temperature Superconducting REBCO Coil Assembly for a Multi-Frequency ECR Ion Source. IEEE Transactions on Applied Superconductivity 34, 1 (2024); https://doi.org/10.1109/TASC.2024.3360935.High temperature superconducting REBCO tape has the characteristic of maintaining high critical current density under strong external magnetic field, which makes it an ideal material for the construction of air-core electromagnets of accelerator and electron cyclotron resonance (ECR) ion source. In Research Center for Nuclear Physics, Osaka University, a non-insulated air-cored REBCO coil assembly has been constructed. This coil assebmly consists of three circular REBCO solenoid and six racetrack REBCO coil. This coil assembly will be used as an electromagnet of a multi-frequency ECR ion source, and is also developed as a key technology development of an air-core cyclotron. The magnetic field of this ion source are designed, and 77 K performance tests of the assembly are carried out in order to examine the capability of REBCO coils of inducing magnetic field under external field. In this work, the test results and the magnetic field designed for the ECR ion source will be presented and discussed

Narrow safety range of intraoperative rectal irradiation exposure volume for avoiding bleeding after seed implant brachytherapy

<p>Abstract</p> <p>Background & Purpose</p> <p>Rectal toxicity is less common after ¹²⁵I seed implant brachytherapy for prostate cancer, and intraoperative rectal dose-volume constraints (the constraint) is still undetermined in pioneering studies. As our constraint failed to prevent grade 2 or 3 rectal bleeding (bled-pts) in 5.1% of patients, we retrospectively explored another constraint for the prevention of rectal bleeding.</p> <p>Materials and methods</p> <p>The study population consisted of 197 patients treated with the brachytherapy as monotherapy using real-time intraoperative transrectal ultrasound (US)-guided treatment at a prescribed dose of 145 Gy. Post-implant dosimetry was performed on Day 1 and Day 30 after implantation using computed tomography (CT) imaging. Rectal bleeding toxicity was classified by CTC-AE ver. 3.0 during a mean 29-month (range, 12-48 months) period after implantation. The differences in rV100s were compared among intraoperative, Day 1 and Day 30 dosimetry, and between that of patients with grade 2 or 3 rectal bleeding (the bled-pts) and of the others (the spared-pts). All patients were divided into groups based on provisional rV100s that were increased stepwise in 0.1-cc increments from 0 to 1.0 cc. The difference in the ratios of the bled-pts to the spared-pts was tested by chi-square tests, and their odds ratios were calculated (bled-OR). All statistical analyses were performed by <it>t</it>-tests.</p> <p>Results</p> <p>The mean values of rV100us, rV100CT_1, and rV100CT_30 were 0.31 ± 0.43, 0.22 ± 0.36, and 0.59 ± 0.68 cc, respectively. These values temporarily decreased (p = 0.020) on Day 1 and increased (p = 0.000) on Day 30. There was no significant difference in rV100s between the bled-pts and spared-pts at any time of dosimetry. The maximum bled-OR was identified among patients with an rV100us value above 0.1 cc (p = 0.025; OR = 7.8; 95% CI, 1.4-145.8); an rV100CT_1 value above 0.3 cc (p = 0.014; OR = 16.2; 95% CI, 3.9-110.7), and an rV100CT_30 value above 0.5 cc (p = 0.019; OR = 6.3; 95% CI, 1.5-42.3).</p> <p>Conclusion</p> <p>By retrospective analysis exploring rV100 as intraoperative rectal dose-volume thresholds in ¹²⁵I seed implant brachytherapy for prostate cancer, it is proved that rV100 should be less than 0.1 cc for preventing rectal bleeding.</p

Light Curves and Colors of the Ejecta from Dimorphos after the DART Impact

On 26 September 2022 the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, a satellite of the asteroid 65803 Didymos. Because it is a binary system, it is possible to determine how much the orbit of the satellite changed, as part of a test of what is necessary to deflect an asteroid that might threaten Earth with an impact. In nominal cases, pre-impact predictions of the orbital period reduction ranged from ~8.8 - 17.2 minutes. Here we report optical observations of Dimorphos before, during and after the impact, from a network of citizen science telescopes across the world. We find a maximum brightening of 2.29 $\pm$ 0.14 mag upon impact. Didymos fades back to its pre-impact brightness over the course of 23.7 $\pm$ 0.7 days. We estimate lower limits on the mass contained in the ejecta, which was 0.3 - 0.5% Dimorphos' mass depending on the dust size. We also observe a reddening of the ejecta upon impact.Comment: Accepted by Natur

High-resolution seismic reflection profiling across the Shiraiwa fault, eastern margin of the Yokote basin fault zone, northeast Japan : data acquisition and processing

The eastern margin of the Yokote basin fault zone extends about 56km at the western foot of the Ou Backbone Range, northeast Japan. The Rikuu earthquake (M=7.2) occurred in the Ou Backbone Range (Mahiru Range) on 31st August, 1896. Associated with this earthquake, four thrust faults-Obonai, Shiraiwa, Ota, and Senya fault3 appeared on the surface of the western foot of the Mahiru Range. These faults were highly sinuous with numerous gaps and en echelon steps. We conducted a high-resolution seismic reflection profiling survey across the Shiraiwa fault. The obtained seismic reflection data were processed by conventional common mid-point methods, post-stack migration, and depth conversion. The subsurface structure across the Shraiwa fault is characterized by branched low-angle reverse faults and conjugate back-thrust. The emergent thrust associated with the 1896 earthquake is regarded to be a subsidiary reverse fault

Noise pollution alters matrix permeability for dispersing anurans: Differential effects among land covers

Successful dispersal or movement between patches in fragmented landscapes is key for the survival and population persistence of wildlife. Despite the growing interest in the impacts of anthropogenic noise, how noise alters the permeability of different types of land cover to animal movement in fragmented landscapes is underappreciated. Here, we experimentally quantified the movement distances of a frog species in three types of land cover common to fragmented landscapes (lawns with or without canopy cover and artificial bare land) under two acoustic manipulations (traffic noise vs. a silent control). The results showed that the effects of noise on frog movements varied among land covers: with movement being impeded on bare land and unaffected on lawns with and without a closed canopy. These results suggest that anthropogenic noise and land cover types can interactively affect the functional connectivity of these anurans and increase our understanding of the complex ecological consequences of urbanization. Our finding emphasizes that the impacts of noise on animal movement in fragmented landscapes should be evaluated with consideration of land cover types. (C) 2018 The Authors. Published by Elsevier B.V

Parallel and four-step synthesis of natural-product-inspired scaffolds through modular assembly and divergent cyclization

By emulating the universal biosynthetic strategy, which employs modular assembly and divergent cyclizations, we have developed a four-step synthetic process to yield a collection of natural-product-inspired scaffolds. Modular assembly of building blocks onto a piperidine-based manifold 6, having a carboxylic acid group, was achieved through Ugi condensation, N-acetoacetylation and diazotransfer, leading to cyclization precursors. The rhodium-catalyzed tandem cyclization and divergent cycloaddition gave rise to tetracyclic and hexacyclic scaffolds by the appropriate choice of dipolarophiles installed at modules 3 and 4. A different piperidine-based manifold 15 bearing an amino group was successfully applied to demonstrate the flexibility and scope of the unified four-step process for the generation of structural diversity in the fused scaffolds. Evaluation of in vitro antitrypanosomal activities of the collections and preliminary structure-activity relationship (SAR) studies were also undertaken

Role of flood-control basins as summer habitat for wetland species : A multiple-taxon approach

In the era of global climate change, the risk of large-scale flood disasters has been increasing. Green infrastructure has gained increasing attention as one of the strategies for adaptation to mega-floods because it can concurrently enhance regional biodiversity and ecosystem services. Previous studies have assessed the efficacy of flood-control infrastructure in protecting biodiversity in urban areas. However, whether such infrastructure enhances biodiversity in other environments remains largely unknown. In this study, we assessed the function of flood-control basins constructed for flood risk management as summer habitat for wetland species in agricultural landscapes. We compared the species assemblages of four different taxa (fishes, aquatic insects, birds, and plants) among four water body types (flood-control basins, channelized watercourses, drainage pumping stations, and remnant ponds). We found that the flood-control basins had comparable or higher species richness and abundance of most taxa than the other water body types. We also found that the species compositions in the flood-control basins were characterized by pioneer species, which prefer shallow water or can adapt to fluctuations in water levels (e.g., herbivorous insects, shorebirds, and hygrophytes). These findings suggest that flood-control basins can provide summer habitat for wetland species, especially for species that inhabit environments with hydrological variation, and utilizing flood-control basins as green infrastructure is a reasonable option for conserving regional biodiversity in agricultural landscapes

Impact of home blood pressure variability on cardiovascular outcome in patients with arterial stiffness: Results of the J‐HOP study

Abstract This study sought to investigate whether the relation between increased blood pressure (BP) variability and increased arterial stiffness confers a risk for cardiovascular disease (CVD) events. We analyzed 2648 patients from a practitioner‐based population (mean ± SD age 64.9 ± 11.4 years: 75.8% taking antihypertensive medication) with at least one cardiovascular risk factor who underwent home BP monitoring in the Japan Morning Surge‐Home Blood Pressure Study. The standard deviation (SDSBP), coefficient of variation (CVSBP), and average real variability (ARVSBP) were assessed as indexes of day‐by‐day home systolic BP (SBP) variability. The authors assessed arterial stiffness by brachial‐ankle pulse wave velocity (baPWV) and divided patients into lower (< 1800 cm/s, n = 1837) and higher (≥1800 cm/s, n = 811) baPWV groups. During a mean follow‐up of 4.4 years, 95 cardiovascular events occurred (8.1 per 1000 person‐years). In Cox proportional hazard models adjusted for traditional cardiovascular risk factors including average home SBP, the highest quartiles of SDSBP (hazard ratio [HR], 2.30; 95% confidence interval [CI], 1.23‐4.32), CVSBP (HR, 2.89; 95%CI, 1.59‐5.26) and ARVSBP (HR, 2.55; 95%CI, 1.37‐4.75) were predictive of CVD events compared to the other quartiles in the higher baPWV group. Moreover, 1SD increases in SDSBP (HR, 1.44; 95%CI, 1.13‐1.82), CVSBP (HR, 1.49; 95%CI, 1.16‐1.90) and ARVSBP (HR, 1.37; 95%CI, 1.09‐1.73) were also predictive of CVD events. These associations remained even after N‐terminal pro‐brain natriuretic peptide was added to the models. However, these associations were not observed in the lower baPWV group. We conclude that arterial stiffness contributes to the association between home BP variability and CVD incidence