84 research outputs found

    Trimming of a Migrated Biliary Nitinol Stent Using Argon Plasma

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    Metallic stent migration is a well-known complication which cannot always be managed by removal or repositioning, especially in case of uncovered stent. We report a patient who developed obstructive jaundice due to migration of an expandable metallic stent (EMS) inserted in the lower bile duct. Trimming of the EMS using argon plasma was performed, with the power setting of 60 W and 2.0 l/min of argon flow. The distal part of the EMS was removed and mechanical cleaning using balloon catheter was performed for remnant EMS. Without additional stent insertion, jaundice was relieved in a few days. No complication was recognized during the procedure and no recurrence of jaundice in the rest of his life

    Diffuse radio source candidate in CIZA J1358.9-4750

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    We report on results of our upgraded Giant Metrewave Radio Telescope (uGMRT) observations for an early-stage merging galaxy cluster, CIZA J1358.9-4750 (CIZA1359), in Band-3 (300--500 MHz). We achieved the image dynamic range of 38,000\sim 38,000 using the direction dependent calibration and found a candidate of diffuse radio emission at 4~σrms\sigma_{rms} significance. The flux density of the candidate at 400~MHz, 24.04±2.4824.04 \pm 2.48~mJy, is significantly positive compared to noise, where its radio power, 2.40×10242.40 \times 10^{24}~W~Hz1^{-1}, is consistent with those of typical diffuse radio sources of galaxy clusters. The candidate is associated with a part of the X-ray shock front at which the Mach number reaches its maximum value of M1.7\mathcal{M}\sim 1.7. The spectral index (FνναF_\nu \propto \nu^{\alpha}) of the candidate, α=1.22±0.33\alpha = - 1.22 \pm 0.33, is in agreement with an expected value derived from the standard diffusive shock acceleration (DSA) model. But such a low Mach number with a short acceleration time would require seed cosmic-rays supplied from active galactic nucleus (AGN) activities of member galaxies, as suggested in some other clusters. Indeed, we found seven AGN candidates inside the diffuse source candidate. Assuming the energy equipartition between magnetic fields and cosmic-rays, the magnetic field strength of the candidate was estimated to be 2.1 μ2.1~\muG. We also find head-tail galaxies and radio phoenixes or fossils near the CIZA1359.Comment: 17 pages, 9 figures, Accepted to PAS

    Fabrication of high-concentration Cu-doped deuterated targets for fast ignition experiments

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    In high-energy-density physics, including inertial fusion energy using high-power lasers, doping tracer atoms and deuteration of target materials play an important role in diagnosis. For example, a low-concentration Cu dopant acts as an x-ray source for electron temperature detection while a deuterium dopant acts as a neutron source for fusion reaction detection. However, the simultaneous achievement of Cu doping, a deuterated polymer, mechanical toughness and chemical robustness during the fabrication process is not so simple. In this study, we report the successful fabrication of a Cu-doped deuterated target. The obtained samples were characterized by inductively coupled plasma optical emission spectrometry, differential scanning calorimetry and Fourier transform infrared spectroscopy. Simultaneous measurements of Cu K-shell x-ray emission and beam fusion neutrons were demonstrated using a petawatt laser at Osaka University.Ikeda T., Kaneyasu Y., Hosokawa H., et al. Fabrication of high-concentration Cu-doped deuterated targets for fast ignition experiments. Nuclear Fusion 63, 016010 (2023); https://doi.org/10.1088/1741-4326/aca2ba

    Demonstration of a spherical plasma mirror for the counter-propagating kilojoule-class petawatt LFEX laser system

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    A counter-propagating laser-beam platform using a spherical plasma mirror was developed for the kilojoule-class petawatt LFEX laser. The temporal and spatial overlaps of the incoming and redirected beams were measured with an optical interferometer and an x-ray pinhole camera. The plasma mirror performance was evaluated by measuring fast electrons, ions, and neutrons generated in the counter-propagating laser interaction with a Cu-doped deuterated film on both sides. The reflectivity and peak intensity were estimated as ∼50% and ∼5 × 1018 W/cm2, respectively. The platform could enable studies of counter-streaming charged particles in high-energy-density plasmas for fundamental and inertial confinement fusion research.Kojima S., Abe Y., Miura E., et al. Demonstration of a spherical plasma mirror for the counter-propagating kilojoule-class petawatt LFEX laser system. Optics Express 30, 43491 (2022); https://doi.org/10.1364/oe.475945

    Field Effect of Alcohol, Cigarette Smoking, and Their Cessation on the Development of Multiple Dysplastic Lesions and Squamous Cell Carcinoma: A Long-term Multicenter Cohort Study

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    [Background and Aims] Multiple developments of squamous dysplasia and squamous cell carcinoma (SCC) in the upper aerodigestive tract have been explained by field cancerization phenomenon and were associated with alcohol and cigarette use. Second primary SCC development after curative treatment impairs patients’ quality of life and survival; however, how these consumption and cessation affect field cancerization is still unknown. [Methods] This is a multicenter cohort study including 331 patients with superficial esophageal SCC (ESCC) treated endoscopically and pooled data from 1022 healthy subjects for comparison. Physiological condition in the background esophageal mucosa was classified into 3 groups based on the number of Lugol-voiding lesions (LVLs) per endoscopic view: grade A, 0; grade B, 1–9; or grade C, ≥10 LVLs. Lifestyle surveys were conducted using a self-administered questionnaire. Patients were counseled on the need for alcohol and smoking cessation by physicians and were endoscopically surveyed every 6 months. [Results] LVL grades were positively associated with alcohol drinking intensity, flushing reactions, smoking, and high-temperature food and were negatively associated with eating green and yellow vegetables and fruit. Second primary ESCC and head/neck SCC were significantly more prevalent in the grade C LVL (cumulative 5-y incidences 47.1%, 95% confidence interval [CI] = 38.0–57.2 and 13.3%, 95% CI = 8.1–21.5, respectively). Alcohol and smoking cessation significantly reduced the development of second primary ESCC (adjusted hazard ratios 0.47, 95% = CI 0.26–0.85 and 0.49, 95% CI = 0.26–0.91, respectively). [Conclusion] Alcohol drinking, smoking, flushing reaction, and high-temperature food were closely associated with field cancerization, and cessation of alcohol and smoking significantly reduced the risk of development of second primary cancer. UMIN Clinical Trials Registry ID:UMIN000001676

    Association between Catechol-O-Methyltrasferase Val108/158Met Genotype and Prefrontal Hemodynamic Response in Schizophrenia

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    BACKGROUND:"Imaging genetics" studies have shown that brain function by neuroimaging is a sensitive intermediate phenotype that bridges the gap between genes and psychiatric conditions. Although the evidence of association between functional val108/158met polymorphism of the catechol-O-methyltransferase gene (COMT) and increasing risk for developing schizophrenia from genetic association studies remains to be elucidated, one of the most topical findings from imaging genetics studies is the association between COMT genotype and prefrontal function in schizophrenia. The next important step in the translational approach is to establish a useful neuroimaging tool in clinical settings that is sensitive to COMT variation, so that the clinician could use the index to predict clinical response such as improvement in cognitive dysfunction by medication. Here, we investigated spatiotemporal characteristics of the association between prefrontal hemodynamic activation and the COMT genotype using a noninvasive neuroimaging technique, near-infrared spectroscopy (NIRS). METHODOLOGY/PRINCIPAL FINDINGS:Study participants included 45 patients with schizophrenia and 60 healthy controls matched for age and gender. Signals that are assumed to reflect regional cerebral blood volume were monitored over prefrontal regions from 52-channel NIRS and compared between two COMT genotype subgroups (Met carriers and Val/Val individuals) matched for age, gender, premorbid IQ, and task performance. The [oxy-Hb] increase in the Met carriers during the verbal fluency task was significantly greater than that in the Val/Val individuals in the frontopolar prefrontal cortex of patients with schizophrenia, although neither medication nor clinical symptoms differed significantly between the two subgroups. These differences were not found to be significant in healthy controls. CONCLUSIONS/SIGNIFICANCE:These data suggest that the prefrontal NIRS signals can noninvasively detect the impact of COMT variation in patients with schizophrenia. NIRS may be a promising candidate translational approach in psychiatric neuroimaging

    Fabrication of high-concentration Cu-doped deuterated targets for fast ignition experiments

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    先端科学・社会共創推進機構In high-energy-density physics, including inertial fusion energy using high-power lasers, doping tracer atoms and deuteration of target materials play an important role in diagnosis. For example, a low-concentration Cu dopant acts as an x-ray source for electron temperature detection while a deuterium dopant acts as a neutron source for fusion reaction detection. However, the simultaneous achievement of Cu doping, a deuterated polymer, mechanical toughness and chemical robustness during the fabrication process is not so simple. In this study, we report the successful fabrication of a Cu-doped deuterated target. The obtained samples were characterized by inductively coupled plasma optical emission spectrometry, differential scanning calorimetry and Fourier transform infrared spectroscopy. Simultaneous measurements of Cu K-shell x-ray emission and beam fusion neutrons were demonstrated using a petawatt laser at Osaka University

    Cold snare polypectomy and underwater endoscopic mucosal resection for superficial nonampullary duodenal epithelial tumors

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    Although the diagnostic and therapeutic opportunities for superficial nonampullary duodenal epithelial tumors (SNADETs) have been increasing, the natural history and treatment outcomes remain unclear. Due to the anatomical characteristics of the duodenum, clinicians should be more sensitive to the occurrence of complications for tumors in the duodenum compared to other gastrointestinal tumors. Recently, with the expectation of minimally invasive treatment, cold snare polypectomy (CSP) and underwater endoscopic mucosal resection (UEMR) have been accepted as simple and safe endoscopic treatments for SNADETs. In our institution, CSP achieved good treatment outcomes: a median procedure time of 3 (range, 1-23) min, an en bloc resection rate of 96.9%, an R0 resection rate of 50.0%, and a low incidence of adverse events (no delayed bleeding and no intra- and postoperative perforation). Moreover, UEMR also achieved good treatment outcomes: a median procedure time of 5 (range, 1-104) min, an en bloc resection rate of 82.9%, an R0 resection rate of 52.0%, and a low incidence of adverse events (delayed bleeding occurred in 2.6% of cases, and there were no incidences of no intra- and postoperative perforation). Residual recurrences occurred in two lesions (4.1%) that were treated with CSP and three lesions (4.8%) that were treated with UEMR, but these recurrences could be treated by re-endoscopic resection. Although there are limited data on these treatments for SNADETs, some previous reports and our data suggest that CSP could be indicated for adenomas sized 10 mm or less and that UEMR could be indicated for adenomas sized 10-20 mm and for intramucosal carcinomas. However, at present, the number of cases evaluated is still insufficient, and further studies are needed to evaluate long-term outcomes with enough cases

    Transfer of Light Helicity to Nanostructures

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    We discovered that chiral nanoneedles fabricated by vortex laser ablation can be used to visualize the helicity of an optical vortex. The orbital angular momentum of light determines the chirality of the nanoneedles, since it is transferred from the optical vortex to the metal. Only the spin angular momentum of the optical vortex can reinforce the helical structure of the created chiral nanoneedles. We also found that optical vortices with the same total angular momentum (defined as the sum of the orbital and spin angular momenta) are degenerate, and they generate nanoneedles with the same chirality and spiral frequency
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