391 research outputs found

    Geometry-Driven Shift in the Tomonaga-Luttinger Exponent of Deformed Cylinders

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    We demonstrate the effects of geometric perturbation on the Tomonaga-Luttinger liquid (TLL) states in a long, thin, hollow cylinder whose radius varies periodically. The variation in the surface curvature inherent to the system gives rise to a significant increase in the power-law exponent of the single-particle density of states. The increase in the TLL exponent is caused by a curvature-induced potential that attracts low-energy electrons to region that has large curvature.Comment: 4 pages, 5 figure

    Thioredoxin Reductase 2 (Txnrd2) Regulates Mitochondrial Integrity in the Progression of Age-Related Heart Failure

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    A ging is a multifactorial process that is characterized bythe accumulation of damaged cellular components and that leads progressively to deterioration of biological func-tions.1 Recently, increased cellular production of reactive oxygen species (ROS) and decreased removal of oxidized proteins have been implicated in the aging process.2 During aging, ROS generation is amplified, leading to the accumula-tion of oxidative damage to cells. Such enhancements can result from the lack of proportional regulation of antioxidant systems in the body. Mitochondria are a central source of ROS under stressful energetic and redox conditions: They produce 85 % to 90 % of cellular ROS.3 Mitochondria are the energy-generating organelles that play crucial roles in the fundamental cellular processes, including supply of metabolic intermediates, calcium homeostasis, and apoptotic signaling. During mito

    Atomic scale localization of Kohn-Sham wavefunction at SiO2/4H-SiC interface under electric field, deviating from envelope function by effective mass approximation

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    To clarify the cause of the low channel conductivity at the SiO2/4H-SiC interface, the wavefunction at the SiC conduction band minimum was calculated using density functional theory under an applied electric field. We found that the wavefunction for a 4H-SiC (0001) slab tends to be localized at the cubic site closest to the interface. Importantly, because the conduction electrons are distributed closer to the interface (< 5 angstroms) than expected from the effective mass approximation (EMA), they are more frequently scattered by interface defects. This is expected to be the reason why the channel conductivity for the (0001) face is particularly low compared with that for other faces, such as (11-20). The breakdown of the EMA for the (0001) interface is related to the long structural periodicity along the [0001] direction in 4H-SiC crystals

    2,9,10-Trimeth­oxy­dibenzo[b,d]oxepin-7(6H)-one

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    The title compound, C17H16O5, was prepared through a cyclization reaction of 2-(3′,4′,5-trimeth­oxy­biphenyl-2-yl­oxy)acetyl chloride. The two benzene rings form a dihedral angle of 34.55 (5)°. The crystal structure does not feature any hydrogen bonds

    Soluble Siglec-9 suppresses arthritis in a collagen-induced arthritis mouse model and inhibits M1 activation of RAW264.7 macrophages

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    Background: The aim of this study was to assess the effects of soluble sialic acid-binding immunoglobulin-type lectin (sSiglec)-9 on joint inflammation and destruction in a murine collagen-induced arthritis (CIA) model and in monolayer cultures of murine macrophages (RAW264.7 cells and peritoneal macrophages) and fibroblast-like synoviocytes (FLS) derived from patients with rheumatoid arthritis. Methods: DBA/1J mice were immunized with type II collagen. Effects of sSiglec-9 were evaluated using a physiologic arthritis score, histological analysis, serum tumor necrosis factor (TNF)-α concentration, and the proportion of forkhead box P3 (Foxp3)-positive regulatory T (Treg) cells. In vivo biofluorescence imaging was used to assess the distribution of sSiglec-9. Levels of M1 (TNF-α, interleukin [IL]-6, and inducible nitric oxide synthase) and M2 (CD206, Arginase-1, and IL-10) macrophage markers and phosphorylation of intracellular signaling molecules were examined in macrophages, and levels of matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 were examined in FLS. Results: sSiglec-9 significantly suppressed the clinical and histological incidence and severity of arthritis. The proportion of Foxp3-positive Treg cells significantly improved and serum TNF-α concentration decreased in vivo. Although sSiglec-9 reduced the expression of M1 markers in macrophages, it did not affect the expression of M2 markers and MMPs in FLS. Nuclear factor (NF)-kB p65 phosphorylation was attenuated by sSiglec-9, and chemical blockade of the NF-kB pathway reduced M1 marker expression in RAW264.7 cells. Conclusions: In this study, we have demonstrated the therapeutic effects of sSiglec-9 in a murine CIA model. The mechanism underlying these effects involves the suppression of M1 proinflammatory macrophages by inhibiting the NF-kB pathway. sSiglec-9 may provide a novel therapeutic option for patients with rheumatoid arthritis refractory to currently available drugs

    Spherical-cap droplets of a photo-responsive bent liquid crystal dimer

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    The stays and research activities of J. Y. and F. A. in Hungary, and P. S. and A. B. in Japan are supported by the JSPS-HAS bilateral program. J. Y. was partially supported by JSPS KAKENHI Grant Number 15K17739. A. J. acknowledges financial support by NSF DMR: 1307674. Financial support from the grants NKFIH PD 121019 and FK 125134 are acknowledged.Peer reviewedPostprin

    Curvature effects on collective excitations in dumbbell-shaped hollow nanotubes

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    We investigate surface-curvature induced alteration in the Tomonaga-Luttinger liquid (TLL) states of a one-dimensional (1D) deformed hollow nanotube with a dumbbell-shape. Periodic variation of the surface curvature along the axial direction is found to enhance the TLL exponent significantly, which is attributed to an effective potential field that acts low-energy electrons moving on the curved surface. The present results accounts for the experimental observation of the TLL properties of 1D metallic peanut-shaped fullerene polymers whose enveloping surface is assumed to be a dumbbell-shaped hollow tube.Comment: 4 pages, 4 figure

    Thioredoxin-interacting protein regulates protein disulfide isomerases and endoplasmic reticulum stress

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    The endoplasmic reticulum (ER) is responsible for protein folding, modification, and trafficking. Accumulation of unfolded or misfolded proteins represents the condition of ER stress and triggers the unfolded protein response (UPR), a key mechanism linking supply of excess nutrients to insulin resistance and type 2 diabetes in obesity. The ER harbors proteins that participate in protein folding including protein disulfide isomerases (PDIs). Changes in PDI activity are associated with protein misfolding and ER stress. Here, we show that thioredoxin-interacting protein (Txnip), a member of the arrestin protein superfamily and one of the most strongly induced proteins in diabetic patients, regulates PDI activity and UPR signaling. We found that Txnip binds to PDIs and increases their enzymatic activity. Genetic deletion of Txnip in cells and mice led to increased protein ubiquitination and splicing of the UPR regulated transcription factor X-box-binding protein 1 (Xbp1s) at baseline as well as under ER stress. Our results reveal Txnip as a novel direct regulator of PDI activity and a feedback mechanism of UPR signaling to decrease ER stress

    新たに開発された高性能紫外線照射システムによる 医療機器表面の細菌制御に関する研究

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    患者や医療従事者が触れる機会の多い医療機器の表面消毒は非常に重要であり、医療機器表面の汚染の度合いによっては感染の危険性を生じる。しかし、環境表面の殺菌は、清掃スタッフにより手で行われているが、拭き残しの発生や薬剤耐性菌への効果が薄いことが課題とされている。そこで、本研究においては、キセノン紫外線消毒ロボット及び消毒ポッド(LS-DP システム)を導入し、用手清拭後、紫外線照射後の2つのタイミングで各種医療機器における表面採取、培養を行い、菌コロニーの検出数から評価を行った。その結果、全ての機器において、紫外線照射後のコロニー数は清拭後に比べて有意差を持って低かった。用手清拭後に多くの菌が培養、検出され、清掃スタッフにより手で行われる清掃には物理的に清拭できない部位があり、紫外線照射を用手清拭後に行うことで消毒効果が上乗せされ、医療機器を介する院内感染の防止に有用であると示唆された
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