19 research outputs found

    EMPRESS. XII. Statistics on the Dynamics and Gas Mass Fraction of Extremely-Metal Poor Galaxies

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    We present demography of the dynamics and gas-mass fraction of 33 extremely metal-poor galaxies (EMPGs) with metallicities of 0.0150.195 Z0.015-0.195~Z_\odot and low stellar masses of 104108 M10^4-10^8~M_\odot in the local universe. We conduct deep optical integral-field spectroscopy (IFS) for the low-mass EMPGs with the medium high resolution (R=7500R=7500) grism of the 8m-Subaru FOCAS IFU instrument by the EMPRESS 3D survey, and investigate Hα\alpha emission of the EMPGs. Exploiting the resolution high enough for the low-mass galaxies, we derive gas dynamics with the Hα\alpha lines by the fitting of 3-dimensional disk models. We obtain an average maximum rotation velocity (vrotv_\mathrm{rot}) of 15±3 km s115\pm3~\mathrm{km~s^{-1}} and an average intrinsic velocity dispersion (σ0\sigma_0) of 27±10 km s127\pm10~\mathrm{km~s^{-1}} for 15 spatially resolved EMPGs out of the 33 EMPGs, and find that all of the 15 EMPGs have vrot/σ0<1v_\mathrm{rot}/\sigma_0<1 suggesting dispersion dominated systems. There is a clear decreasing trend of vrot/σ0v_\mathrm{rot}/\sigma_0 with the decreasing stellar mass and metallicity. We derive the gas mass fraction (fgasf_\mathrm{gas}) for all of the 33 EMPGs, and find no clear dependence on stellar mass and metallicity. These vrot/σ0v_\mathrm{rot}/\sigma_0 and fgasf_\mathrm{gas} trends should be compared with young high-zz galaxies observed by the forthcoming JWST IFS programs to understand the physical origins of the EMPGs in the local universe.Comment: 18 pages, 9 figures, accepted for publication in Ap

    EMPRESS. IX. Extremely Metal-Poor Galaxies are Very Gas-Rich Dispersion-Dominated Systems: Will JWST Witness Gaseous Turbulent High-z Primordial Galaxies?

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    We present kinematics of 6 local extremely metal-poor galaxies (EMPGs) with low metallicities (0.0160.098 Z0.016-0.098\ Z_{\odot}) and low stellar masses (104.7107.6M10^{4.7}-10^{7.6} M_{\odot}). Taking deep medium-high resolution (R7500R\sim7500) integral-field spectra with 8.2-m Subaru, we resolve the small inner velocity gradients and dispersions of the EMPGs with Hα\alpha emission. Carefully masking out sub-structures originated by inflow and/or outflow, we fit 3-dimensional disk models to the observed Hα\alpha flux, velocity, and velocity-dispersion maps. All the EMPGs show rotational velocities (vrotv_{\rm rot}) of 5--23 km s1^{-1} smaller than the velocity dispersions (σ0\sigma_{0}) of 17--31 km s1^{-1}, indicating dispersion-dominated (vrot/σ0=0.290.80<1v_{\rm rot}/\sigma_{0}=0.29-0.80<1) systems affected by inflow and/or outflow. Except for two EMPGs with large uncertainties, we find that the EMPGs have very large gas-mass fractions of fgas0.91.0f_{\rm gas}\simeq 0.9-1.0. Comparing our results with other Hα\alpha kinematics studies, we find that vrot/σ0v_{\rm rot}/\sigma_{0} decreases and fgasf_{\rm gas} increases with decreasing metallicity, decreasing stellar mass, and increasing specific star-formation rate. We also find that simulated high-zz (z7z\sim 7) forming galaxies have gas fractions and dynamics similar to the observed EMPGs. Our EMPG observations and the simulations suggest that primordial galaxies are gas-rich dispersion-dominated systems, which would be identified by the forthcoming James Webb Space Telescope (JWST) observations at z7z\sim 7.Comment: Submitted to ApJ; After revisio

    Delayed surgery for acute type A aortic dissection: a retrospective review of an alternative surgical strategy in the COVID-19 era

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    Abstract Background During the coronavirus disease (COVID-19) pandemic, medical resources have often been limited to emergency surgeries. This study aimed to evaluate our experience with delayed surgery for acute type A aortic dissections (ATAADs). Methods A retrospective study was conducted on 33 patients who underwent surgery for ATAADs between January 2020 and December 2021. The patients were divided into two groups: patients treated within 12 h of arrival (E group; N = 21) and those treated > 12 h after arrival (D group; N = 12) with strict antihypertensive therapy until surgery. Results The plasma fibrinogen levels on arrival were lower in the D group than in the E group (174.3 ± 109.1 vs 293.4 ± 165.4, p = 0.038). The time to surgery from symptom onset was longer in the D group than in the E group (4 ± 1 h vs. 86 ± 108 h, p < 0.001). There was one case (3%) of mortality and seven cases (21%) of cerebral infarctions in the E group. There was no significant difference in the intraoperative data and quantity of blood transfused between the two groups. Conclusion Thus, delayed surgery for ATAAD with appropriate preoperative management may be an alternative surgical strategy in the COVID-19 era

    Eshelby/Mori-Tanakaモデルを用いた塑性ひずみのX線解析法およびその適用例

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    金沢大学人間社会研究域人間科学系A new method is proposed in this paper for determining plastic strains in composite materials using the X-ray diffraction method. The present method was derived by using both Eshelby\u27s approach and the Mori-Tanaka theory to express the stress state in composite materials instead of the elasticity in single-phase materials which is used in the conventional method of X-ray stress measurement. It was found that the plastic strain can be determined from the slope of the linear relation between lattice strains measured by the X-ray diffraction technique and sin2 ψ using almost the same procedure as that for determining stresses by the conventional X-ray method. The results on ferritic and austenitic dual-phase stainless steel are shown. We discuss the effects of a uniaxial tensile load in a range of plastic deformation on the field of plastic strain as well as on residual macro-, micro-and phase stresses built up in the sample

    Upstream open reading frame-mediated upregulation of ANAC082 expression in response to nucleolar stress in Arabidopsis

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    Perturbations in ribosome biogenesis cause a type of cellular stress called nucleolar or ribosomal stress, which triggers adaptive responses in both animal and plant cells. The Arabidopsis ANAC082 transcription factor has been identified as a key mediator of the plant nucleolar stress response. The 5 '-untranslated region (5 '-UTR) of ANAC082 mRNA contains an upstream ORF (uORF) encoding an evolutionarily conserved amino acid sequence. Here, we report that this uORF mediates the upregulation of ANAC082 expression in response to nucleolar stress. When transgenic Arabidopsis plants containing a luciferase reporter gene under the control of the ANAC082 promoter and 5 '-UTR were treated with reagents that induced nucleolar stress, expression of the reporter gene was enhanced in a uORF sequence-dependent manner. Additionally, we examined the effect of an endoplasmic reticulum (ER) stress-inducing reagent on reporter gene expression because the closest homolog of ANAC082 in Arabidopsis, ANAC103, is involved in the ER stress response. However, the ANAC082 uORF did not respond to ER stress. Interestingly, although ANAC103 has a uORF with an amino acid sequence similar to that of the ANAC082 uORF, the C-terminal sequence critical for regulation is not well conserved among ANAC103 homologs in Brassicaceae. Transient expression assays revealed that unlike the ANAC082 uORF, the ANAC103 uORF does not exert a sequence-dependent repressive effect. Altogether, our findings suggest that the ANAC082 uORF is important for the nucleolar stress response but not for the ER stress response, and that for this reason, the uORF sequence-dependent regulation was lost in ANAC103 during evolution

    Significance of Urinary Full-Length Megalin in Patients with IgA Nephropathy

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    <div><p>Background and Objectives</p><p>Megalin is highly expressed at the apical membranes of proximal tubular epithelial cells. A urinary full-length megalin (C-megalin) assay is linked to the severity of diabetic nephropathy in type 2 diabetes. This study examined the relationship between levels of urinary C-megalin and histological findings in adult patients with IgA nephropathy (IgAN).</p><p>Design, Setting, Participants, & Measurements</p><p>Urine samples voided in the morning on the day of renal biopsy were obtained from 73 patients with IgAN (29 men and 44 women; mean age, 33 years) and 5 patients with membranous nephropathy (MN). Renal pathologic variables were analyzed using the Oxford classification of IgAN, the Shigematsu classification and the Clinical Guidelines of IgAN in Japan. The levels of urinary C-megalin were measured by sandwich ELISA.</p><p>Results</p><p>Histological analysis based on the Oxford classification revealed that the levels of urinary C-megalin were correlated with mesangial hypercellularity in IgAN patients (OR = 1.76, 95% CI: 1.04–3.27, P<0.05). There was a significant correlation between the levels of urinary C-megalin and the severity of chronic extracapillary abnormalities according to the Shigematsu classification in IgAN patients (β = 0.33, P = 0.008). The levels of urinary C-megalin were significantly higher in all risk levels of IgAN patients requiring dialysis using the Clinical Guidelines of IgAN in Japan than in the control group. The levels of urinary C-megalin were significantly higher in the high risk and very high risk grades than in the low risk grade (P<0.05). The levels of urinary C-megalin were significantly higher in MN patients compared to the control group.</p><p>Conclusions</p><p>The levels of urinary C-megalin are associated with histological abnormalities in adult IgAN patients. There is a possibility that urinary C-megalin is an independent predictor of disease progression of IgAN. In addition, our results suggest that urinary C-megalin is a marker of glomerular abnormalities in various glomerular diseases as well as IgAN.</p></div

    Rac1 in podocytes promotes glomerular repair and limits the formation of sclerosis

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    Rac1, a Rho family member, is ubiquitously expressed and participates in various biological processes. Rac1 expression is induced early in podocyte injury, but its role in repair is unclear. To investigate the role of Rac1 expression in podocytes under pathological conditions, we used podocyte-specific Rac1 conditional knock-out (cKO) mice administered adriamycin (ADR), which causes nephrosis and glomerulosclerosis. Larger areas of detached podocytes, more adhesion of the GBM to Bowman’s capsule, and a higher ratio of sclerotic glomeruli were observed in Rac1 cKO mice than in control mice, whereas no differences were observed in glomerular podocyte numbers in both groups after ADR treatment. The mammalian target of rapamycin (mTOR) pathway, which regulates the cell size, was more strongly suppressed in the podocytes of Rac1 cKO mice than in those of control mice under pathological conditions. In accordance with this result, the volumes of podocytes in Rac1 cKO mice were significantly reduced compared with those of control mice. Experiments using in vitro ADR-administered Rac1 knockdown podocytes also supported that a reduction in Rac1 suppressed mTOR activity in injured podocytes. Taken together, these data indicate that Rac1-associated mTOR activation in podocytes plays an important role in preventing the kidneys from developing glomerulosclerosis

    Stepwise multiple regression analysis of levels of urinary total protein excretion with relevant factors.

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    <p>C-megalin, full-length megalin; β<sub>2</sub>-MG, β<sub>2</sub>-microglobulin; α<sub>1</sub>-MG, α<sub>1</sub>-microglobulin; NAG, N-acetyl-b-D-glucosaminidase.</p><p>Stepwise multiple regression analysis of levels of urinary total protein excretion with relevant factors.</p
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