117 research outputs found

    Electronic structure modulation of graphene edges by chemical functionalization

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    Using the density functional theory with the effective screening medium method, we study the electronic properties of graphene nanoribbons with zigzag edges that are terminated by hydrogen and ketone, hydroxyl, carbonyl, and carboxyl functional groups. Our calculations showed that the work function and electronic structures of the edges of the nanoribbons are sensitive to the functional groups attached to the edges. The nearly free electron state emerges in the vacuum region outside the hydroxylated edges and crosses the Fermi level, indicating the possibility of negative electron affinity at the edges

    Energetics of edge oxidization of graphene nanoribbons

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    On the basis of the density functional theory, we studied the geometries and energetics of O atoms adsorbed on graphene edges for simulating the initial stage of the edge oxidization of graphene. Our calculations showed that oxygen atoms are preferentially adsorbed onto the graphene edges with the zigzag portion, resulting in a large adsorption energy of about 5 eV. On the other hand, the edges with armchair shape are rarely oxidized, or the oxidization causes substantial structural reconstructions, because of the stable covalent bond at the armchair edge with the triple bond nature. Furthermore, the energetics sensitively depends on the edge angles owing to the inhomogeneity of the charge density at the edge atomic sites

    Electronic structure and electric polarity of edge-functionalized graphene nanoribbons

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    On the basis of the density functional theory combined with the effective screening medium method, we studied the electronic structure of graphene nanoribbons with zigzag edges, which are terminated by functional groups. The work function of the nanoribbons is sensitive to the functional groups. The edge state inherent in the zigzag edges is robust against edge functionalization. OH termination causes the injection of electrons into the nearly free electron states situated alongside the nanoribbons, resulting in the formation of free electron channels outside the nanoribbons. We also demonstrated that the polarity of zigzag graphene nanoribbons is controllable by the asymmetrical functionalization of their edges

    In-Stent Yellow Plaque at 1 Year After Implantation Is Associated With Future Event of Very Late Stent Failure The DESNOTE Study (Detect the Event of Very late Stent Failure From the Drug-Eluting Stent Not Well Covered by Neointima Determined by Angioscopy)

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    AbstractObjectivesThis study examined whether coronary angioscopy-verified in-stent yellow plaque at 1 year after drug-eluting stent (DES) implantation is associated with future event of very late stent failure (VLSF).BackgroundAtherosclerosis detected as yellow plaque by angioscopy has been associated with future events of acute coronary syndrome. Development of in-stent neoatherosclerosis is a probable mechanism of VLSF.MethodsThis study included 360 consecutive patients who received successful angioscopic examination at 1 year after implantation of a DES. They were clinically followed up for VLSF defined as cardiac death, acute myocardial infarction or unstable angina, or need for revascularization associated with the stent site.ResultsThe follow-up interval was 1,558 ± 890 days (4.3 ± 2.4 years). The incidence of VLSF was significantly higher in the patients with yellow plaque than in those without (8.1% vs. 1.6%; log rank p = 0.02). Multivariable analysis revealed the presence of yellow plaque (hazard ratio [HR]: 5.38; p = 0.02) and absence of statin therapy (HR: 3.25; p = 0.02) as risks of VLSF.ConclusionsIn-stent atherosclerosis evaluated by yellow plaque at 1 year after the implantation of DES and the absence of statin therapy were risks of VLSF. The underlying mechanism of VLSF appeared to be the progression of atherosclerosis as demonstrated by the yellow plaque

    Factors affecting drug retention of Janus kinase inhibitors in patients with rheumatoid arthritis: the ANSWER cohort study

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    This multi-center, retrospective study aimed to clarify the factors affecting drug retention of the Janus kinase inhibitors (JAKi) including baricitinib (BAR) and tofacitinib (TOF) in patients with RA. Patients were as follows; females, 80.6%; age, 60.5 years; DAS28-ESR, 4.3; treated with either BAR (n = 166) or TOF (n = 185); bDMARDs- or JAKi-switched cases (76.6%). The reasons for drug discontinuation were classified into four major categories. The drug retention was evaluated at 24 months using the Kaplan–Meier method and multivariate Cox proportional hazards modelling adjusted by confounders. Discontinuation rates for the corresponding reasons were as follows; ineffectiveness (22.3%), toxic adverse events (13.3%), non-toxic reasons (7.2%) and remission (0.0%). Prior history of anti-interleukin-6 receptor antibody (aIL-6R) ineffectiveness significantly increased the risk of treatment discontinuation due to ineffectiveness (p = 0.020). Aging (≥ 75 years) (p = 0.028), usage of PSL ≥ 5 mg/day (p = 0.017) and female sex (p = 0.041) significantly increased the risk of treatment discontinuation due to toxic adverse events. Factors not associated with treatment discontinuation were: number of prior bDMARDs or JAKi, concomitant MTX usage, difference of JAKi, and prior use of TNF inhibitor, CTLA4-Ig or other JAKi.Ebina K., Hirano T., Maeda Y., et al. Factors affecting drug retention of Janus kinase inhibitors in patients with rheumatoid arthritis: the ANSWER cohort study. Scientific Reports 12, 134 (2022); https://doi.org/10.1038/s41598-021-04075-0

    Development of a Multifunctional Lightweight Membrane with a High Specific Power Generation Capacity

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    As a lighter power generation system, Japan Aerospace Exploration Agency (JAXA) and Sakase Adtech Corp. are developing a demonstrator component named “Harvesting Energy with Lightweight Integrated Origami Structure” (HELIOS), which is a deployable lightweight membrane structure. HELIOS has solar arrays on its surface and demonstrates the technology which enables higher specific power generation capacity compared to the conventional solar array panels. The membrane also has communication antennas, showing the potency of lightweight membrane’s multifunctionality such as large data transmitting by 5G antennas and high-resolution observation by interferometer antennas. This paper presents the component’s concept and design, and the expected achievements

    CKD患者の食事療法にむけた市販弁当の栄養価の検討について

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    In dialysis patients, it is essence to take nutrient amounts approximately such as energy, protein, salt, water, phosphorus, and potassium. However, since many dialysis patients are elderly and difficult to cook at home every day, they often utilize a commercially available lunch box. So, we aimed this study to estimate nutritional value from the nutritional label, and to measure total phosphorus content in 5 types of lunch box. We found that these lunch boxes contained almost within the recommended amount of potassium and phosphorous, while they contained excess energy, protein and salt amounts. So, when dialysis patients utilize commercially available lunch boxes, they should pay attention especially to a risk of excess dietary salt intake
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