84 research outputs found

    Investigation of combustion noise generated by an open lean-premixed H₂/air low-swirl flame using the hybrid LES/APE-RF framework

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    An open lean-premixed hydrogen/air low-swirl (LPHALS) turbulent flame exhibiting a pronounced peak in its combustion noise spectra, is investigated numerically using a hybrid Computational Fluid Dynamics/Computational Aero-Acoustics (CFD/CAA) framework. Under this framework, the reacting flow-field of the flame is computed via Large-Eddy Simulation (LES), while the direct combustion noise it produces is captured by solving the Acoustic Perturbation Equations for Reacting Flows (APE-RF). Flame configuration and simulation conditions correspond to those of an experimental study on an open lean-premixed H₂/air flame stabilized using a Low-Swirl Burner (LSB). LES results are validated against experimental data. The CAA simulation is able to predict a pronounced sharp peak in the computed combustion noise spectra, similar to one of the two characteristic peaks observed in the measured combustion noise spectra. Frequency of this spectral peak predicted by the CAA simulation is 840 Hz, which is close to that of the higher frequency secondary spectral peak at 940 Hz measured in the experiment. Upon examining the hybrid LES/APE-RF results, the noise generation mechanism at 840 Hz is found to be the intense local heat release rate fluctuations, caused by strong interaction between the flame and the periodically generated vortical flow structures in the shear layers, downstream of the LSB exit. Additionally, analysis of the spectral content and directivity of the noise generated by different acoustic source terms is performed, in order to investigate their impact on the radiated acoustic field, and hence the characteristics of direct combustion noise produced by the open LPHALS flame

    烏口突起骨端線離開の新分類:自験例9例と過去の論分のレビューから

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    Objectives and Design. Epiphyseal separation of the coracoid process (CP) rarely occurs in adolescents. In this retrospective case series, we reviewed the data of nine patients treated at our center and those of 28 patients reported in the literature. This injury can be classified into three types according to the injured area: Type I, base including the area above the glenoid; Type II, center including the coracoclavicular ligament (CCL); and Type III, tip with the short head of the biceps and coracobrachialis, as well as the pectoralis minor. Patients/Participants. A total of 37 patients were included in the analysis. Data on sex, age, cause and mechanism of injury, separation type, concomitant injury around the shoulder girdle, treatment, and functional outcomes were obtained. Main Outcome Measurements and Results. Type I is the most common type. The cause of injury and associated injury around the shoulder girdle were significantly different between Type I, II, and III fractures. The associated acromioclavicular (AC) dislocation and treatment were significantly different between Type I and III fractures. Our new classification system reflects the clinical features, imaging findings, and surgical management of epiphyseal separation of the CP. Type I and II fractures are mostly associated with AC dislocation and have an associated injury around the shoulder girdle. Type III fractures are typically caused by forceful resisted flexion of the arm and elbow. Although the latter are best managed surgically, whether conservative or surgical management is optimal for Type I and II fractures remains controversial. Conclusions. We noted some differences in the clinical characteristics depending on the location of injury; therefore, we aimed to examine these differences to develop a new system for classifying epiphyseal separation of the CP. This would increase the clinicians' awareness regarding this injury and lead to the development of an appropriate treatment.博士(医学)・甲第783号・令和3年3月15日Copyright © 2020 Takamitsu Mondori et al. This is an open access article distributed under the Creative Commons Attribution License(https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

    Effects of medical education on attitudes towards mental illness among medical students: a five-year follow-up study.

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    In order to clarify the effects of medical education on attitudes towards mental illness among medical students, a follow-up study was conducted. All 100 students entering Kochi Medical School in 1988 were subjects. The initial questionnaire survey was conducted in 1988, and followed up in 1993. Response rate was 69% in the initial survey, and 83% in the follow-up study. By the time of the follow-up, all of the students had completed their medical education, including courses in psychiatry and mental health. Results were as follows: At the follow-up study, 1) a significantly higher percentage of students replied that they accepted the mentally ill as co-workers; 2) significantly favorable changes were observed in attitudes towards psychiatric services; 3) optimism about the effectiveness of treatment for mental illness at an early stage and prevention of mental illness had decreased; and 4) no change was observed in attitudes toward human rights of the mentally ill, except in the case of one item stating that the mentally ill should not have children in order to avoid hereditary handicaps, with which a lower percentage agreed. Conclusively, medical education can play an important role in attitudes towards mental illness. </p

    Not only Body Weight Perception but also Body Mass Index is Relevant to Suicidal Ideation and Self-Harming Behavior in Japanese Adolescents

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    Whether a low body mass index (BMI) is directly associated with a high risk of suicidal ideation or self-harming behavior in adolescents is still inconclusive. This study has, therefore, evaluated the relevance of BMI to suicidal ideation and self-harming behavior after controlling for body weight perception (BWP) and other potential confounding factors. BMI, BWP, suicidal ideation, and self-harming behavior were all assessed using a self-report questionnaire administered to 18,104 Japanese adolescents. Potential confounding factors were also evaluated. The data were then analyzed using bi-variate and multivariate logistic regression. Low BMI was associated with suicidal ideation and deliberate self-harm when controlling for sex, age, drug use, emotional distress, and BWP. Low BMI may be an independent risk factor for suicidal ideation and deliberate self-harming behavior in Japanese adolescents.ArticleJOURNAL OF NERVOUS AND MENTAL DISEASE. 200(4):305-309 (2012)journal articl

    肩鎖関節の安定性における肩鎖靭帯の役割 : 新鮮凍結屍体を用いた生体力学的研究

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    Background: Acromioclavicular (AC) joint dislocation is evaluated using the radiologically based Rockwood classification. The relationship between ligamentous injury and radiological assessment is still controversial. Purpose/hypothesis: To investigate how the AC ligament and trapezoid ligament biomechanically contribute to the stability of the AC joint using cadaveric specimens. The hypothesis was that isolated sectioning of the AC ligament would result in increased instability in the superior direction and that displacement >50% of the AC joint would occur. Study design: Controlled laboratory study. Methods: Six shoulders from 6 fresh-frozen cadavers were used in this study. Both the scapula and sternum were solidly fixed on a customized wooden jig with an external fixator. We simulated distal clavicular dislocation with sequential sectioning of the AC and coracoclavicular (CC) ligaments. Sectioning stages were defined as follows: stage 0, the AC ligament, CC ligament, and AC joint capsule were left intact; stage 1, the anteroinferior bundle of the AC ligament, joint capsule, and disk were sectioned; stage 2, the superoposterior bundle of the AC ligament was sectioned; and stage 3, the trapezoid ligament was sectioned. The distal clavicle was loaded with 70 N in the superior and posterior directions, and the magnitudes of displacement were measured. Results: The amounts of superior displacement averaged 3.7 mm (stage 0), 3.8 mm (stage 1), 8.3 mm (stage 2), and 9.5 mm (stage 3). Superior displacement >50% of the AC joint was observed in stage 2 (4/6; 67%) and stage 3 (6/6; 100%). The magnitudes of posterior displacement were 3.7 mm (stage 0), 3.7 mm (stage 1), 5.6 mm (stage 2), and 9.8 mm (stage 3). Posterior displacement >50% of the AC joint was observed in stage 3 (1/6; 17%). Conclusion: We found that the AC ligaments contribute significantly to AC joint stability, and superior displacement >50% of the AC joint can occur with AC ligament tears alone. Clinical relevance: The AC ligament plays an important role not only in horizontal stability but also in vertical stability of the AC joint.博士(医学)・甲第810号・令和4年3月15日© The Author(s) 2021. This open-access article is published and distributed under the Creative Commons Attribution - NonCommercial - No Derivatives License (https://creativecommons.org/ licenses/by-nc-nd/4.0/), which permits the noncommercial use, distribution, and reproduction of the article in any medium, provided the original author and source are credited. You may not alter, transform, or build upon this article without the permission of the Author(s). For article reuse guidelines, please visit SAGE’s website at http://www.sagepub.com/journals-permissions

    Predicting reliable H2_2 column density maps from molecular line data using machine learning

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    The total mass estimate of molecular clouds suffers from the uncertainty in the H2_2-CO conversion factor, the so-called XCOX_{\rm CO} factor, which is used to convert the 12^{12}CO (1--0) integrated intensity to the H2_2 column density. We demonstrate the machine learning's ability to predict the H2_2 column density from the 12^{12}CO, 13^{13}CO, and C18^{18}O (1--0) data set of four star-forming molecular clouds; Orion A, Orion B, Aquila, and M17. When the training is performed on a subset of each cloud, the overall distribution of the predicted column density is consistent with that of the Herschel column density. The total column density predicted and observed is consistent within 10\%, suggesting that the machine learning prediction provides a reasonable total mass estimate of each cloud. However, the distribution of the column density for values >2×1022> \sim 2 \times 10^{22} cm2^{-2}, which corresponds to the dense gas, could not be predicted well. This indicates that molecular line observations tracing the dense gas are required for the training. We also found a significant difference between the predicted and observed column density when we created the model after training the data on different clouds. This highlights the presence of different XCOX_{\rm CO} factors between the clouds, and further training in various clouds is required to correct for these variations. We also demonstrated that this method could predict the column density toward the area not observed by Herschel if the molecular line and column density maps are available for the small portion, and the molecular line data are available for the larger areas.Comment: Accepted for publication in MNRA

    Distance determination of molecular clouds in the 1st quadrant of the Galactic plane using deep learning : I. Method and Results

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    Machine learning has been successfully applied in varied field but whether it is a viable tool for determining the distance to molecular clouds in the Galaxy is an open question. In the Galaxy, the kinematic distance is commonly employed as the distance to a molecular cloud. However, there is a problem in that for the inner Galaxy, two different solutions, the ``Near'' solution, and the ``Far'' solution, can be derived simultaneously. We attempted to construct a two-class (``Near'' or ``Far'') inference model using a Convolutional Neural Network (CNN), a form of deep learning that can capture spatial features generally. In this study, we used the CO dataset toward the 1st quadrant of the Galactic plane obtained with the Nobeyama 45-m radio telescope (l = 62-10 degree, |b| < 1 degree). In the model, we applied the three-dimensional distribution (position-position-velocity) of the 12CO (J=1-0) emissions as the main input. The dataset with ``Near'' or ``Far'' annotation was made from the HII region catalog of the infrared astronomy satellite WISE to train the model. As a result, we could construct a CNN model with a 76% accuracy rate on the training dataset. By using the model, we determined the distance to molecular clouds identified by the CLUMPFIND algorithm. We found that the mass of the molecular clouds with a distance of < 8.15 kpc identified in the 12CO data follows a power-law distribution with an index of about -2.3 in the mass range of M >10^3 Msun. Also, the detailed molecular gas distribution of the Galaxy as seen from the Galactic North pole was determined.Comment: 29 pages, 12 figure

    Associations of carotid atherosclerosis and hyperuricemia with height in relation to drinking status of rural Japanese men: The Nagasaki Islands study.

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    Background; Several studies have identified a positive, independent association between uric acid and atherosclerosis whereas uric acid was once considered to be a major antioxidant in human plasma with possible beneficial anti-atherosclerotic effects. Several other studies have found an inverse association between height and stroke, while a previous study of ours detected a positive association between height and hyperuricemia. However, even though uric acid levels may be strongly affected by alcohol consumption and serum creatinine, no published study has examined the possible associations between hyperuricemia and carotid atherosclerosis while taking both height and drinking status into account.Methods; We conducted a cross-sectional study of 1,337 men aged 30-89 years undergoing a general health check-up to investigate the associations of hyperuricemia and carotid atherosclerosis with height in relation to drinking status.Results; Of the total study population, 312 men were diagnosed with carotid atherosclerosis (carotid intima-media thickness (CIMT)?1.1 mm) and 365 men with hyperuricemia (serum uric acid>7.0mg/dL). For shorter non-drinkers, a significantly positive association between these two abnormalities was detected, which was independent of classical cardiovascular risk factors except for serum creatinine. However, this association ceased to exist after further adjustment for serum creatinine. However, while the age-adjusted model showed no significant association for taller drinkers, adjustment for serum creatinine produced a significantly inverse association.Conclusion; Our study established that hyperuricemia is associated with carotid atherosclerosis for Japanese men, while body height, drinking status and serum creatinine are important determining factors for this association

    Randomized controlled trial of daily teriparatide, weekly high-dose teriparatide, or bisphosphonate in patients with postmenopausal osteoporosis: The TERABIT study

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    Purpose: The effects of daily teriparatide (20 μg) (D-PTH), weekly high-dose teriparatide (56.5 μg) (W-PTH), or bisphosphonates (BPs) on areal bone mineral density (aBMD), bone turnover markers (BTMs), volumetric BMD (vBMD), microarchitecture, and estimated strength were investigated in postmenopausal osteoporosis patients.Methods: The study participants were 131 women with a history of fragility fractures. They were randomized to receive D-PTH, W-PTH, or BPs (alendronate or risedronate) for 18 months. Dual-energy X-ray absorptiometry (DXA), BTMs, and high-resolution peripheral quantitative CT (HR-pQCT) parameters were evaluated at baseline and after 6 and 18 months of treatment. The primary endpoint was the change (%) in cortical thickness (Ct.Th) after 18 months\u27 treatment compared with baseline.Results: DXA showed that D-PTH, W-PTH, and BPs increased lumbar spine aBMD (+12.0%, +8.5%, and +6.8%) and total hip aBMD (+3.0%, +2.1%, and +3.0%), but D-PTH and W-PTH decreased 1/3 radius aBMD (− 4.1%, − 3.0%, − 1.4%) after 18 months. On HR-pQCT, D-PTH increased trabecular vBMD (Tb.vBMD) at the distal radius and tibia after 18 months (+6.4%, +3.7%) compared with the BPs group, decreased cortical volumetric tissue mineral density (Ct.vTMD) (− 1.8%, − 0.9%) compared with the other groups, increased Ct.Th (+1.3%, +3.9%), and increased failure load (FL) (+4.7%, +4.4%). W-PTH increased Tb.vBMD (+5.3%, +1.9%), maintained Ct.vTMD (− 0.7%, +0.2%) compared with D-PTH, increased Ct.Th (+0.6%, +3.6%), and increased FL (+4.9%, +4.5%). The BPs increased Tb.vBMD only in the radius (+2.0%, +0.2%), maintained Ct.vTMD (− 0.6%, +0.3%), increased Ct.Th (+0.5%, +3.4%), and increased FL (+3.9%, +2.8%).Conclusions: D-PTH and W-PTH comparably increased Ct.Th, the primary endpoint. D-PTH had a strong effect on trabecular bone. Although D-PTH decreased Ct.vTMD, it increased Ct.Th and total bone strength. W-PTH had a moderate effect on trabecular bone, maintained Ct.vTMD, and increased Ct.Th and total bone strength to the same extent as D-PTH
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