205 research outputs found

    On Detection of Black Hole Quasi-Normal Ringdowns: Detection Efficiency and Waveform Parameter Determination in Matched Filtering

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    Gravitational radiation from a slightly distorted black hole with ringdown waveform is well understood in general relativity. It provides a probe for direct observation of black holes and determination of their physical parameters, masses and angular momenta (Kerr parameters). For ringdown searches using data of gravitational wave detectors, matched filtering technique is useful. In this paper, we describe studies on problems in matched filtering analysis in realistic gravitational wave searches using observational data. Above all, we focus on template constructions, matches or signal-to-noise ratios (SNRs), detection probabilities for Galactic events, and accuracies in evaluation of waveform parameters or black hole hairs. We have performed matched filtering analysis for artificial ringdown signals which are generated with Monte-Carlo technique and injected into the TAMA300 observational data. It is shown that with TAMA300 sensitivity, the detection probability for Galactic ringdown events is about 50% for black holes of masses greater than 20M20 M_{\odot} with SNR >10> 10. The accuracies in waveform parameter estimations are found to be consistent with the template spacings, and resolutions for black hole masses and the Kerr parameters are evaluated as a few % and 40\sim 40 %, respectively. They can be improved up to <0.9< 0.9 % and <24< 24 % for events of SNR10{\rm SNR} \ge 10 by using fine-meshed template bank in the hierarchical search strategy.Comment: 10 pages, 10 figure

    Plans for the LIGO-TAMA Joint Search for Gravitational Wave Bursts

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    We describe the plans for a joint search for unmodelled gravitational wave bursts being carried out by the LIGO and TAMA collaborations using data collected during February-April 2003. We take a conservative approach to detection, requiring candidate gravitational wave bursts to be seen in coincidence by all four interferometers. We focus on some of the complications of performing this coincidence analysis, in particular the effects of the different alignments and noise spectra of the interferometers.Comment: Proceedings of the 8th Gravitational Wave Data Analysis Workshop, Milwaukee, WI, USA. 10 pages, 3 figures, documentclass ``iopart'

    Coincidence analysis to search for inspiraling compact binaries using TAMA300 and LISM data

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    Japanese laser interferometric gravitational wave detectors, TAMA300 and LISM, performed a coincident observation during 2001. We perform a coincidence analysis to search for inspiraling compact binaries. The length of data used for the coincidence analysis is 275 hours when both TAMA300 and LISM detectors are operated simultaneously. TAMA300 and LISM data are analyzed by matched filtering, and candidates for gravitational wave events are obtained. If there is a true gravitational wave signal, it should appear in both data of detectors with consistent waveforms characterized by masses of stars, amplitude of the signal, the coalescence time and so on. We introduce a set of coincidence conditions of the parameters, and search for coincident events. This procedure reduces the number of fake events considerably, by a factor 104\sim 10^{-4} compared with the number of fake events in single detector analysis. We find that the number of events after imposing the coincidence conditions is consistent with the number of accidental coincidences produced purely by noise. We thus find no evidence of gravitational wave signals. We obtain an upper limit of 0.046 /hours (CL =90= 90 %) to the Galactic event rate within 1kpc from the Earth. The method used in this paper can be applied straightforwardly to the case of coincidence observations with more than two detectors with arbitrary arm directions.Comment: 28 pages, 17 figures, Replaced with the version to be published in Physical Review

    Images of colonic real-time tissue sonoelastography correlate with those of colonoscopy and may predict response to therapy in patients with ulcerative colitis

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    <p>Abstract</p> <p>Background</p> <p>Real-time tissue sonoelastography (EG) is a new non-invasive technique that visualizes differences in tissue strain. We evaluated the usefulness of EG in patients with ulcerative colitis (UC) by investigating the association between EG and colonoscopic findings and disease activity.</p> <p>Methods</p> <p>Thirty-seven UC patients undergoing EG and colonoscopy were invited to enroll. EG findings were classified as normal, homogeneous, random, or hard, and colonoscopic findings as normal, mucosal edema and erosion, punched-out ulcer, and extensive mucosal abrasion. Clinical findings were evaluated using clinical activity index (CAI) scores for each patient at colonoscopy.</p> <p>Results</p> <p>On EG, 10 cases were classified as normal, 11 as homogeneous, 6 as random, and 10 as hard. EG findings showed a significant correlation those of colonoscopy (<it>p </it>< 0.001). Seven of 10 (70%) normal-type patients were in the remission phase, while all 6 random-type patients were in the active phase. Among active-phase patients, 4 of 7 (57%) homogeneous-type patients responded to steroid or leukocytapheresis therapy, while 3 of 6 (50%) random-type patients required treatment with cyclosporine. Three of 10 (30%) hard-type patients required colectomy.</p> <p>Conclusions</p> <p>In this small series, EG findings reflected colonoscopic findings and correlated with disease activity among patients with UC.</p

    The incidence and risk factors of venous thromboembolism in Japanese inpatients with inflammatory bowel disease: a retrospective cohort study

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    Background/AimsVenous thromboembolism (VTE) is a major extraintestinal manifestation in inflammatory bowel disease (IBD), regarded as an independent risk factor for VTE according to reports from Western countries. However, the incidence and risk factors of VTE in Asian IBD patients are not fully understood. We aimed to reveal the incidence and risk factors of VTE in Japanese IBD inpatients.MethodsThe incidence of VTE in inpatients with IBD (n=340), gastrointestinal cancers (n=557), and other gastrointestinal diseases (n=569) treated at our hospital from 2009 to 2013 was retrospectively investigated. The characteristics and laboratory data of IBD inpatients with and without VTE were compared in univariate and multivariate analyses. Clinical courses of VTE in IBD were surveyed.ResultsVTE was detected in 7.1% of IBD inpatients, significantly higher than in gastrointestinal cancer inpatients (2.5%) and inpatients with other gastrointestinal diseases (0.88%). The incidence of VTE in ulcerative colitis (UC) patients (16.7%) was much higher than that in those with Crohn's disease (3.6%). In the univariate analysis, the risk factors were an older age, central venous catheter, prednisolone, surgery, low serum albumin, high serum C-reactive protein and D-dimer. According to a multivariate analysis, >50 years of age and surgery were the only risk factors. The in-hospital mortality rate of IBD inpatients with VTE was 4.2%.ConclusionsThe incidence of VTE with IBD, especially UC, was found to be high compared with other digestive disease, which was almost equivalent to that of Western countries. The efficacy of prophylaxis needs to be investigated in Asian IBD patients

    Risk factors for CAR-T cell manufacturing failure among DLBCL patients: A nationwide survey in Japan

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    CAR-T細胞製造を成功させるためのレシピ --アフェレーシス前の下ごしらえでの工夫--. 京都大学プレスリリース. 2023-04-27.For successful chimeric antigen receptor T (CAR-T) cell therapy, CAR-T cells must be manufactured without failure caused by suboptimal expansion. In order to determine risk factors for CAR-T cell manufacturing failure, we performed a nationwide cohort study in Japan and analysed patients with diffuse large B-cell lymphoma (DLBCL) who underwent tisagenlecleucel production. We compared clinical factors between 30 cases that failed (7.4%) with those that succeeded (n = 378). Among the failures, the proportion of patients previously treated with bendamustine (43.3% vs. 14.8%; p < 0.001) was significantly higher, and their platelet counts (12.0 vs. 17.0 × 10⁴/μL; p = 0.01) and CD4/CD8 T-cell ratio (0.30 vs. 0.56; p < 0.01) in peripheral blood at apheresis were significantly lower than in the successful group. Multivariate analysis revealed that repeated bendamustine use with short washout periods prior to apheresis (odds ratio [OR], 5.52; p = 0.013 for ≥6 cycles with washout period of 3–24 months; OR, 57.09; p = 0.005 for ≥3 cycles with washout period of <3 months), low platelet counts (OR, 0.495 per 105/μL; p = 0.022) or low CD4/CD8 ratios (<one third) (OR, 3.249; p = 0.011) in peripheral blood at apheresis increased the risk of manufacturing failure. Manufacturing failure remains an obstacle to CAR-T cell therapy for DLBCL patients. Avoiding risk factors, such as repeated bendamustine administration without sufficient washout, and risk-adapted strategies may help to optimize CAR-T cell therapy for DLBCL patients

    Results of the search for inspiraling compact star binaries from TAMA300's observation in 2000-2004

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    We analyze the data of TAMA300 detector to search for gravitational waves from inspiraling compact star binaries with masses of the component stars in the range 1-3Msolar. In this analysis, 2705 hours of data, taken during the years 2000-2004, are used for the event search. We combine the results of different observation runs, and obtained a single upper limit on the rate of the coalescence of compact binaries in our Galaxy of 20 per year at a 90% confidence level. In this upper limit, the effect of various systematic errors such like the uncertainty of the background estimation and the calibration of the detector's sensitivity are included.Comment: 8 pages, 4 Postscript figures, uses revtex4.sty The author list was correcte

    Clopidogrel Monotherapy After 1-Month DAPT in Patients With High Bleeding Risk or Complex PCI

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    BACKGROUND: High bleeding risk (HBR) and complex percutaneous coronary intervention (PCI) are major determinants for dual antiplatelet therapy (DAPT) duration. OBJECTIVES: The aim of this study was to evaluate the effects of HBR and complex PCI on short vs standard DAPT. METHODS: Subgroup analyses were conducted on the basis of Academic Research Consortium-defined HBR and complex PCI in the STOPDAPT-2 (Short and Optimal Duration of Dual Antiplatelet Therapy After Verulam's-Eluting Cobalt-Chromium Stent-2) Total Cohort, which randomly compared clopidogrel monotherapy after 1-month DAPT with 12-month DAPT with aspirin and clopidogrel after PCI. The primary endpoint was the composite of cardiovascular (cardiovascular death, myocardial infarction, definite stent thrombosis, or stroke) or bleeding (Thrombolysis In Myocardial Infarction [TIMI] major or minor) endpoints at 1 year. RESULTS: Regardless of HBR (n = 1, 893 [31.6%]) and complex PCI (n = 999 [16.7%]), the risk of 1-month DAPT relative to 12-month DAPT was not significant for the primary endpoint (HBR, 5.01% vs 5.14%; non-HBR, 1.90% vs 2.02%; P interaction = 0.95) (complex PCI, 3.15% vs 4.07%; noncomplex PCI, 2.78% vs 2.82%; P interaction = 0.48) and for the cardiovascular endpoint (HBR, 4.35% vs 3.52%; and non-HBR, 1.56% vs 1.22%; P interaction = 0.90) (complex PCI, 2.53% vs 2.52%; noncomplex PCI, 2.38% vs 1.86%; P interaction = 0.53), while it was lower for the bleeding endpoint (HBR, 0.66% vs 2.27%; non-HBR, 0.43% vs 0.85%; P interaction = 0.36) (complex PCI, 0.63% vs 1.75%; noncomplex PCI, 0.48% vs 1.22%; P interaction = 0.90). The absolute difference in the bleeding between 1- and 12-month DAPT was numerically greater in patients with HBR than in those without HBR (-1.61% vs -0.42%). CONCLUSIONS: The effects of 1-month DAPT relative to 12-month DAPT were consistent regardless of HBR and complex PCI. The absolute benefit of 1-month DAPT over 12-month DAPT in reducing major bleeding was numerically greater in patients with HBR than in those without HBR. Complex PCI might not be an appropriate determinant for DAPT durations after PCI. (Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2 [STOPDAPT-2], NCT02619760; Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2 for the Patients With ACS [STOPDAPT-2 ACS], NCT03462498)
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