149 research outputs found

    An X-Ray Microlensing Test of AU-Scale Accretion Disk Structure in Q2237+0305

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    The innermost regions of quasars can be resolved by a gravitational-lens {\lq}telescope{\rq} on scales down to a few AU. For the purpose, X-ray observations are most preferable, because X-rays originating from the innermost regions, can be selectively amplified by microlensing due to the so-called `caustic crossing'. If detected, X-ray variations will constrain the size of the X-ray emitting region down to a few AU. The maximum attainable resolution depends mainly on the monitoring intervals of lens events, which should be much shorter than the crossing time. On the basis of this idea, we performe numerical simulations of microlensing of an optically-thick, standard-type disk as well as an optically-thin, advection-dominated accretion flow (ADAF). Calculated spectral variations and light curves show distinct behaviors, depending on the photon energy. X-ray radiation which is produced in optically thin region, exhibits intensity variation over a few tens of days. In contrast, optical-UV fluxes, which are likely to come from optically thick region, exhibit more gradual light changes, which is consistent with the microlensing events so far observed in Q2237+0305. Currently, Q2237+0305 is being monitored in the optical range at Apache Point Observatory. Simultaneous multi-wavelength observations by X-ray sattelites (e.g., ASCA, AXAF, XMM) as well as HST at the moment of a microlens event enable us to reveal an AU scale structure of the central accretion disk around black hole.Comment: 10 pages LaTeX, 3 figures, accepted to ApJ Letter. e-mail: [email protected]

    Importance of the ammonia assimilation by Penicillium purpurogenum in amino derivative Monascus pigment, PP-V, production

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    A fungal strain, Penicillium purpurogenum IAM 15392, produced the azaphilone Monascus pigment homolog when cultured in a medium composed of soluble starch, ammonium nitrate, yeast extract, and citrate buffer, pH 5.0. One of the typical features of violet pigment PP-V [(10Z)-12- carboxyl-monascorubramine] is that pyranoid oxygen is replaced with nitrogen. In this study, we found that glutamine synthetase (glnB) and glutamate dehydrogenase (gdh1) genes were expressed in the culture conditions conducive to PP-V production. Gln and Glu both support PP-V biosynthesis, but PP-V biosynthesis was much more efficient with Gln. We determined that synthesis of Gln by glutamine synthetase from ammonium is important for PP-V production

    Evaluation of automated measurement of left ventricular volume by novel real-time 3-dimensional echocardiographic system: Validation with cardiac magnetic resonance imaging and 2-dimensional echocardiography

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    AbstractBackgroundTraditional 3-dimensional echocardiography (3DE) with volumetric scanning technique requires several heart cycles for full-volume acquisition and complicated manual contouring of left ventricular (LV) endocardium. The new real-time 3DE (RT3DE) system allows acquisition of an instantaneous full-volume dataset in a single heart cycle and automated measurement of LV volume by the algorithm software. However, it has not been evaluated adequately whether automated measurement by RT3DE has better agreement with cardiac magnetic resonance imaging (CMR) than 2-dimensional echocardiography (2DE) with CMR.PurposeThis study aimed to evaluate the accuracy of automated measurement of LV volume using RT3DE compared with 2DE and CMR.Methods and resultsForty-four consecutive patients who underwent RT3DE, 2DE, and CMR were evaluated in this study. The feasibility of automated measurement by RT3DE was 93.2% and the mean operation time was 6min. LV volume and ejection fraction (EF) from semi-automated measurement [end-diastolic volume: r=0.96, limits of agreement (LOA) −30.5 to 39.3ml; end-systolic volume: r=0.97, LOA −22.6 to 32.7ml; EF: r=0.90, LOA −16.1 to 14.2%, respectively] had better agreement with CMR than those from 2DE (r=0.87, LOA −50.5 to 72.2ml; r=0.93, LOA −34.1 to 65.2ml; r=0.89, LOA −20.9 to 10.0%, respectively).ConclusionSemi-automated measurement by RT3DE has better agreement with CMR than 2DE in LV volume and EF. In addition, it is simple to operate and acceptable in feasibility for the clinical setting although there may be room for further learning required to incorporate small hypertrophic LV into the automated algorithm software

    Trends and characteristics of severe road traffic injuries in children: a nationwide cohort study in Japan

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    Purpose: The purpose of this study was to evaluate temporal trends of characteristics of severe road traffic injuries in children and identify factors associated with mortality using a nationwide database in Japan. Methods: We performed a retrospective analysis of Japan Trauma Data Bank (JTDB) from 2004 to 2018. We included patients with traffic injuries under the age of 18 who were hospitalized. The primary outcome was in-hospital mortality. We evaluated trends in characteristics and assessed factors associated with in-hospital mortality using a logistic regression analysis. Results: A total of 4706 patients were analyzed. The most common mechanism of injury was bicycle crash (34.4%), followed by pedestrian (28.3%), and motorcycle crash (21.3%). The overall in-hospital mortality was 11.2%. We found decreasing trends in motorcycle crash and in-hospital mortality and increasing trends in rear passenger seats in cars over the 15-year period. The following factors were associated with in-hospital mortality: car crash (aOR 1.69, 95%CI 1.18–2.40), pedestrian (aOR 1.50, 95%CI 1.13–1.99), motorcycle crash (aOR 1.42, 95%CI 1.03–1.95) [bicycle crash as a reference]; concomitant injuries to head/neck (aOR 5.06, 95%CI 3.81–6.79), thorax (aOR 2.34, 95%CI 1.92–2.87), abdomen (aOR 1.74, 95%CI 1.29–2.33), pelvis/lower-extremity (aOR 1.57, 95%CI 1.23–2.00), spine (aOR 3.01, 95%CI 2.02–4.43); and 5-year increase in time period (aOR 0.80, 95%CI 0.70–0.91). Conclusions: We found decreasing trends in motorcycle crash and in-hospital mortality, increasing trends in rear passenger seats in cars over the 15-year period, and factors associated with in-hospital mortality such as type of mechanisms and concomitant injuries. Strengthening child road safety measures, particularly for rear passenger seats in vehicles, is imperative to enhance our dedication to injury prevention.The version of record of this article, first published in European Journal of Trauma and Emergency Surgery, is available online at Publisher’s website: https://doi.org/10.1007/s00068-023-02372-

    Escape fraction of ionizing photons from high-redshift galaxies in cosmological SPH simulations

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    Combing the three-dimensional radiative transfer (RT) calculation and cosmological SPH simulations, we study the escape fraction of ionizing photons (f_esc) of high-redshift galaxies at z=3-6. Our simulations cover the halo mass range of M_h = 10^9 - 10^12 M_sun. We postprocess several hundred simulated galaxies with the Authentic Radiative Transfer (ART) code to study the halo mass dependence of f_esc. In this paper, we restrict ourselves to the transfer of stellar radiation from local stellar population in each dark matter halo. We find that the average f_esc steeply decreases as the halo mass increases, with a large scatter for the lower mass haloes. The low mass haloes with M_h ~ 10^9 M_sun have large values of f_esc (with an average of ~ 0.4), whereas the massive haloes with M_h ~ 10^11 M_sun show small values of f_esc (with an average of ~ 0.07). This is because in our simulations, the massive haloes show more clumpy structure in gas distribution, and star-forming regions are embedded inside these clumps, making it more difficult for the ionizing photons to escape. On the other hand, in low mass haloes, there are often conical regions of highly ionized gas due to the shifted location of young star clusters from the center of dark matter halo, which allows the ionizing photons to escape more easily than in the high-mass haloes. By counting the number of escaped ionizing photons, we show that the star-forming galaxies can ionize the intergalactic medium at z=3-6. The main contributor to the ionizing photons is the haloes with M_h < 10^10 M_sun owing to their high f_esc. The large dispersion in f_esc suggests that there may be various sizes of H{\sc ii} bubbles around the haloes even with the same mass in the early stages of reionization. We also examine the effect of UV background radiation field on f_esc using simple, four different treatment of UV background.Comment: 13 pages, 13 figures, accepted for publication in MNRAS, A full resolution version is available at http://www.ccs.tsukuba.ac.jp/Astro/Members/yajima/Yajima2010.pd

    Potential Impact of Rapid Blood Culture Testing for Gram-Positive Bacteremia in Japan with the Verigene Gram-Positive Blood Culture Test

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    Background. Early detection of Gram-positive bacteremia and timely appropriate antimicrobial therapy are required for decreasing patient mortality. The purpose of our study was to evaluate the performance of the Verigene Gram-positive blood culture assay (BC-GP) in two special healthcare settings and determine the potential impact of rapid blood culture testing for Gram-positive bacteremia within the Japanese healthcare delivery system. Furthermore, the study included simulated blood cultures, which included a library of well-characterized methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) isolates reflecting different geographical regions in Japan. Methods. A total 347 BC-GP assays were performed on clinical and simulated blood cultures. BC-GP results were compared to results obtained by reference methods for genus/species identification and detection of resistance genes using molecular and MALDI-TOF MS methodologies. Results. For identification and detection of resistance genes at two clinical sites and simulated blood cultures, overall concordance of BC-GP with reference methods was 327/347 (94%). The time for identification and antimicrobial resistance detection by BC-GP was significantly shorter compared to routine testing especially at the cardiology hospital, which does not offer clinical microbiology services on weekends and holidays. Conclusion. BC-GP generated accurate identification and detection of resistance markers compared with routine laboratory methods for Gram-positive organisms in specialized clinical settings providing more rapid results than current routine testing

    Effects of Concomitant Traumatic Spinal Cord and Brain Injury on In-Hospital Mortality: A Retrospective Analysis of a Nationwide Trauma Registry in Japan

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    Tachino J., Demetriades A.K., Peul W., et al. Effects of Concomitant Traumatic Spinal Cord and Brain Injury on In-Hospital Mortality: A Retrospective Analysis of a Nationwide Trauma Registry in Japan. Journal of Neurotrauma 41, 17 (2024); https://doi.org/10.1089/neu.2024.0168.Isolated traumatic spinal cord injury (t-SCI) and traumatic brain injury (TBI) represent significant public health concerns, resulting in long-term disabilities and necessitating sophisticated care, particularly when occurring concurrently. The impact of these combined injuries, while crucial in trauma management, on clinical, socioeconomic, and health care outcomes is largely unknown. To address this gap, our secondary retrospective cohort study used data from the Japan Trauma Data Bank, covering patients enrolled over a 13-year period (2006-2018), to elucidate the effects of concurrent t-SCI and TBI on in-hospital mortality. Data on patient demographics, injury characteristics, treatment modalities, and outcomes were analyzed. Multivariate logistic regression analysis was performed to examine prognostic variables associated with in-hospital mortality, including interaction terms between t-SCI severity and TBI presence. This study included 91,983 patients with neurotrauma, with a median age of 62 years (69.7% men). Among the patients, 9,018 (9.8%) died in the hospital. Concomitant t-SCI and TBI occurred in 2,954 (3.2%) patients. t-SCI only occurred in 9,590 (10.4%) patients, whereas TBI only occurred in the majority of these cases (79,439, 86.4%). Multivariate logistic regression analysis revealed age; sex; total number of comorbidities; systolic blood pressure at presentation; Glasgow coma scale score at presentation; and Abbreviated Injury Scale (AIS) scores for head, face, chest, abdomen, cervical-SCI, thoracic-SCI, and lumbar-SCI as significant independent factors for in-hospital mortality. The odds ratio of cervical-SCI × head AIS as an interaction term was 0.85 (95% confidence interval: 0.77-0.95), indicating a negative interaction. In conclusion, we identified 12 factors associated with in-hospital mortality in patients with t-SCI. In addition, the negative interaction between cervical t-SCI and TBI suggests that the presence of t-SCI in patients with TBI may be underestimated. This study highlights the importance of early recognition and comprehensive management of these complex trauma conditions while considering the possibility of concomitant t-SCI in patients with TBI

    Oral Clostridium butyricum on mice endometritis through uterine microbiome and metabolic alternations

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    Endometritis occurs frequently in humans and animals, which can negatively affect fertility and cause preterm parturition syndrome. Orally administered Clostridium butyricum, a butyrate-producing gram-positive anaerobe, exhibits anti-inflammatory effects. However, the precise mechanism by which Clostridium butyricum attenuates endometritis remains unclear. This in vivo study evaluated the anti-inflammatory effects of orally administered Clostridium butyricum on uterine tissues. In addition, we conducted uterine microbiome and lipid metabolome analyses to determine the underlying mechanisms. Female Balb/c mice were divided into the following four groups (n = 5–20): (1) mock group, (2) only operation group (mice only underwent operation to exposed uterine horns from the side), (3) control group (mice underwent the same operation with the operation group + perfusion of lipopolysaccharide solution from uterine horns), and (4) Clostridium butyricum administration group (mice underwent the same operation with the control group + oral Clostridium butyricum administration from days 0 to 9). Clostridium butyricum was administered via oral gavage. On day 10, we investigated protein expression, uterine microbiome, and lipid metabolism in uterine tissues. Consequently, orally administered Clostridium butyricum altered the uterine microbiome and induced proliferation of Lactobacillus and Limosilactobacillus species. The effects can contribute to show the anti-inflammatory effect through the interferon-β upregulation in uterine tissues. Additionally, oral Clostridium butyricum administration resulted in the upregulations of some lipid metabolites, such as ω-3 polyunsaturated fatty acid resolvin D5, in uterine tissues, and resolvin D5 showed anti-inflammatory effects. However, the orally administered Clostridium butyricum induced anti-inflammatory effect was attenuated with the deletion of G protein-coupled receptor 120 and 15-lipooxgenase inhibition. In conclusion, Clostridium butyricum in the gut has anti-inflammatory effects on uterine tissues through alterations in the uterine microbiome and lipid metabolism. This study revealed a gut-uterus axis mechanism and provided insights into the treatment and prophylaxis of endometritis

    Sonodynamic Therapy With Anticancer Micelles and High-Intensity Focused Ultrasound in Treatment of Canine Cancer

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    Sonodynamic therapy (SDT) is a minimally invasive anticancer therapy involving a chemical sonosensitizer and high-intensity focused ultrasound (HIFU). SDT enables the reduction of drug dose and HIFU irradiation power compared to those of conventional monotherapies. In our previous study, mouse models of colon and pancreatic cancer were used to confirm the effectiveness of SDT vs. drug-only or HIFU-only therapy. To validate its usefulness, we performed a clinical trial of SDT using an anticancer micelle (NC-6300) and our HIFU system in four pet dogs with spontaneous tumors, including chondrosarcoma, osteosarcoma, hepatocellular cancer, and prostate cancer. The fact that no adverse events were observed, suggests the usefulness of SDT
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