146 research outputs found

    Fractal mechanism of basin of attraction in passive dynamic walking

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    Passive dynamic walking is a model that walks down a shallow slope without any control or input. This model has been widely used to investigate how humans walk with low energy consumption and provides design principles for energy-efficient biped robots. However, the basin of attraction is very small and thin and has a fractal-like complicated shape, which makes producing stable walking difficult. In our previous study, we used the simplest walking model and investigated the fractal-like basin of attraction based on dynamical systems theory by focusing on the hybrid dynamics of the model composed of the continuous dynamics with saddle hyperbolicity and the discontinuous dynamics caused by the impact upon foot contact. We clarified that the fractal-like basin of attraction is generated through iterative stretching and bending deformations of the domain of the Poincaré map by sequential inverse images. However, whether the fractal-like basin of attraction is actually fractal, i.e., whether infinitely many self-similar patterns are embedded in the basin of attraction, is dependent on the slope angle, and the mechanism remains unclear. In the present study, we improved our previous analysis in order to clarify this mechanism. In particular, we newly focused on the range of the Poincaré map and specified the regions that are stretched and bent by the sequential inverse images of the Poincaré map. Through the analysis of the specified regions, we clarified the conditions and mechanism required for the basin of attraction to be fractal

    子宮内膜症性嚢胞の悪性転化におけるHO-1発現マクロファージの特徴

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    Malignant transformation of endometriosis is a rare and still poorly understood event, but is associated with the distortion of the pro-oxidant and anti-oxidant balance. The aim of the present study was to quantify the numbers of macrophages polarized as M1 or M2 phenotypes and the expression of heme oxygenase (HO)-1 in tissue sections from patients with benign ovarian endometrioma (OE) and its malignant transformation (endometriosis-associated ovarian cancer, EAOC). We performed a retrospective study at the Department of Gynecology, Nara Medical University hospital from December 2012 to March 2015. This study included 53 patients with OE (n = 33) and EAOC (n = 20), and we evaluated polarized functional status of macrophages by immunohistochemical staining of CD68, CD11c, CD163 and HO-1. The number of the M1 phenotype (CD11c+, p = 0.001) and the M2 phenotype (CD163+, p = 0.009) was significantly lower in EAOC patients than in OE patients. Analyzing the correlations between the studied markers, the expression of CD68, CD11c, and CD163 proteins significantly correlated with each other (p < 0.001). The number of M2 phenotypes expressing HO-1 was significantly decreased in the EAOC group, compared with the OE group (P < 0.001), demonstrating sustained downregulation of an antioxidant marker, HO-1, in EAOC. In conclusion, reduced number of M2 macrophages expressing HO-1 may have an important role in promoting malignant transformation of OE.博士(医学)・乙第1434号・令和元年9月27日Copyright © 2018. Published by Elsevier GmbH

    Pancreatic insulin release in vitamin C-deficient senescence marker protein-30/gluconolactonase knockout mice

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    We recently identified senescence marker protein-30 as the lactone-hydrolyzing enzyme gluconolactonase, which is involved in vitamin C biosynthesis. In this study, we investigated the effects of vitamin C on insulin secretion from pancreatic β-cells using senescence marker protein-30/gluconolactonase knockout mice. In intraperitoneal glucose tolerance tests, vitamin C-deficient senescence marker protein-30/gluconolactonase knockout mice demonstrated impaired glucose tolerance with significantly lower blood insulin levels at 30 and 120 min post-challenge than in wild type mice (p<0.01–0.05). In contrast, vitamin C-sufficient senescence marker protein-30/gluconolactonase knockout mice demonstrated significantly higher blood glucose and lower insulin only at the 30 min post-challenge time point (p<0.05). Senescence marker protein-30/gluconolactonase knockout mice showed enhanced insulin sensitivity regardless of vitamin C status. Static incubation of islets revealed that 20 mM glucose-stimulated insulin secretion and islet ATP production were significantly decreased at 60 min only in vitamin C-deficient SMP30/GNL knockout mice relative to wild type mice (p<0.05). These results indicate that the site of vitamin C action lies between glycolysis and mitochondrial oxidative phosphorylation, while SMP30 deficiency itself impairs the distal portion of insulin secretion pathway

    Sudden change in fractality of basin boundary in passive dynamic walking

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    The 11th International Symposium on Adaptive Motion of Animals and Machines. Kobe University, Japan. 2023-06-06/09. Adaptive Motion of Animals and Machines Organizing Committee.Poster Session P7

    Randomized Controlled Trial of Two Forms of Self-Management Group Education in Japanese People with Impaired Glucose Tolerance

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    The aim of this study was to determine the effectiveness of education on diabetes prevention in subjects with impaired glucose tolerance. A total of 100 subjects of impaired glucose tolerance with hemoglobin A1c (HbA1c) levels ≥5.5 to <6.1% were assigned randomly to either support or control groups. All subjects received education in 8 sessions over a 6-month period. The support group consisted of 10 members collaborating with a dietitian or a nurse who learned coping skills by employing a participant-centered approach. Participants in the support group were required to keep a diary that monitored weight, food intake and blood glucose levels, while the control group attended several lectures. Subjects assigned to the support group had a reduction in mean HbA1c levels from 5.77 ± 0.36% at baseline to 5.39 ± 0.24% at the endpoint (p<0.01). Weight, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) levels also decreased (p<0.01) in the support group, whereas subjects in the control group had no observable reduction in these indices. After intervention, participants of the support group had improvements in their 2-h post-meal blood glucose levels. Support group education can be effective for improving glycemic control in participants when carried out in collaboration with educators and other team members

    Wind Tunnel Testing on Start/Unstart Characteristics of Finite Supersonic Biplane Wing

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    This study describes the start/unstart characteristics of a finite and rectangular supersonic biplane wing. Two wing models were tested in wind tunnels with aspect ratios of 0.75 (model A) and 2.5 (model B). The models were composed of a Busemann biplane section. The tests were carried out using supersonic and transonic wind tunnels over a Mach number range of 0.3≤M∞≤2.3 with angles of attack of 0°, 2°, and 4°. The Schlieren system was used to observe the flow characteristics around the models. The experimental results showed that these models had start/unstart characteristics that differed from those of the Busemann biplane (two dimensional) owing to three-dimensional effects. Models A and B started at lower Mach numbers than the Busemann biplane. The characteristics also varied with aspect ratio: model A (1.3<M∞<1.5) started at a lower Mach number than model B (1.6<M∞<1.8) owing to the lower aspect ratio. Model B was located in the double solution domain for the start/unstart characteristics at M∞=1.7, and model B was in either the start or unstart state at M∞=1.7. Once the state was determined, either state was stable

    A simplified PCR assay for fast and easy mycoplasma mastitis screening in dairy cattle

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    A simplified polymerase chain reaction (PCR) assay was developed for fast and easy screening of mycoplasma mastitis in dairy cattle. Species of major mycoplasma strains [Mycoplasma (M.) bovis, M. arginini, M. bovigenitalium, M. californicum, M. bovirhinis, M. alkalescens and M. canadense] in cultured milk samples were detected by this simplified PCR-based method as well as a standard PCR technique. The minimum concentration limit for detecting mycoplasma by the simplified PCR was estimated to be about 2.5 × 103 cfu/mL and was similar to that of the standard PCR. We compared the specificity and sensitivity of the simplified PCR to those of a culture method. Out of 1,685 milk samples cultured in mycoplasma broth, the simplified PCR detected Mycoplasma DNA in 152 that were also positive according to the culture assay. The sensitivity and specificity of the simplified PCR were 98.7% and 99.7%, respectively, for detecting mycoplasma in those cultures. The results obtained by the simplified PCR were consistent with ones from standard PCR. This newly developed simplified PCR, which does not require DNA purification, can analyze about 300 cultured samples within 3 h. The results from our study suggest that the simplified PCR can be used for mycoplasma mastitis screening in large-scale dairy farms

    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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