68 research outputs found

    Numerical homogenization of dual-phase steel by nonlinear conjugate gradient method (Recent developments on inverse problems for partial differential equations and their applications)

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    A numerical method is proposed to solve a cell problem for numerical homogenization of composite material, all of whose phases are homogeneous isotropic and whose deformations follow the elastoplastic constitutive law of Hencky's total strain theory

    CIP methods for hyperbolic system with variable and discontinuous coefficient

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    We propose a multi-moment method for one-dimensional hyperbolic equations with smooth coefficient and piecewise constant coefficient. The method is entirely based on the backward characteristic method and uses the solution and its derivative as unknowns and cubic Hermite interpolation for each computational cell. The exact update formula for solution and its derivative is derived and used for an efficient time integration. At points of discontinuity of wave speed we define a piecewise cubic Hermite interpolation based on immersed interface method. The method is extended to the one-dimensional Maxwell's equations with variable material properties.Comment: 19 page

    Postprandial Hypotension due to a Lack of Sympathetic Compensation in Patients with Diabetes Mellitus.

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    Postprandial hypotension is an important hemodynamic abnormality in diabetes mellitus, but few reports are available on the relationship between autonomic dysfunction and postprandial hypotension. Ten diabetic patients and 10 healthy volunteers were recruited for this study. Postural blood pressure and heart rate changes were measured before lunch, and then the hemodynamic responses to a standardized meal were investigated. Holter electrocardiogram (ECG) monitoring was conducted for assessing spectral powers and time-domain parameters of RR variations. Postural changes from the supine to the upright position decreased the systolic blood pressure of the diabetics from 133(+-)16 to 107(+-)20 mmHg (p<0.01), but did not decrease the systolic blood pressure of the controls. The heart rate remained constant in the diabetics but was increased in the controls. Food ingestion decreased systolic blood pressure in the diabetics, with a maximum reduction of 25(+-)5 mmHg. This decrease was not associated with any changes in the ratio of low frequency to high frequency, and yet the heart rate remained almost constant. Indexes involving parasympathetic tone were not affected. Food ingestion did not affect blood pressure in the control group. These findings suggest that lack of compensatory sympathetic activation is a factor contributing to postprandial hypotension in diabetics, and that parasympathetic drive does not make a significant contribution to this condition

    Prognostic significance of right bundle branch block in patients with acute inferior myocardial infarction

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    There is little information available concerning the influence of right bundle branch block (RBBB) on the prognosis of patients with inferior myocardial infarction (MI). In this study we evaluated the influence of RBBB on the short-term prognosis of patients with inferior MI. Our study subjects were 1,265 hospitalized patients with Q wave MI. Patients were divided into 4 groups based on the presence or absence of RBBB and on the location of the infarction. RBBB was classified into 4 categories according to the timing of its appearance and its duration as new permanent, transient, old and age indeterminate. In-hospital death and pulmonary congestion were observed more frequently in patients with RBBB than in those without RBBB. Moreover, in inferior MI as in anterior MI, in-hospital death and pulmonary congestion occurred more frequently in new permanent RBBB patients than in patients with other types of RBBB. Multivariate regression analysis reveals that new permanent RBBB was a strong independent predictor for an adverse short-term prognosis in patients with inferior MI, as well as in patients with anterior MI. New permanent RBBB during inferior MI is a strong independent predictor for increased in-hospital mortality, regardless of the infarction location.</p

    Length-dependent recognition of double-stranded ribonucleic acids by retinoic acidā€“inducible gene-I and melanoma differentiationā€“associated gene 5

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    The ribonucleic acid (RNA) helicases retinoic acid-inducible gene-I (RIG-I) and melanoma differentiationā€“associated gene 5 (MDA5) recognize distinct viral and synthetic RNAs, leading to the production of interferons. Although 5ā€²-triphosphate single-stranded RNA is a RIG-I ligand, the role of RIG-I and MDA5 in double-stranded (ds) RNA recognition remains to be characterized. In this study, we show that the length of dsRNA is important for differential recognition by RIG-I and MDA5. The MDA5 ligand, polyinosinic-polycytidylic acid, was converted to a RIG-I ligand after shortening of the dsRNA length. In addition, viral dsRNAs differentially activated RIG-I and MDA5, depending on their length. Vesicular stomatitis virus infection generated dsRNA, which is responsible for RIG-Iā€“mediated recognition. Collectively, RIG-I detects dsRNAs without a 5ā€²-triphosphate end, and RIG-I and MDA5 selectively recognize short and long dsRNAs, respectively

    Malt1-Induced Cleavage of Regnase-1 in CD4+ Helper T Cells Regulates Immune Activation

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    SummaryRegnase-1 (also known as Zc3h12a and MCPIP1) is an RNase that destabilizes a set of mRNAs, including Il6 and Il12b, through cleavage of their 3ā€² UTRs. Although Regnase-1 inactivation leads to development of an autoimmune disease characterized by TĀ cell activation and hyperimmunoglobulinemia in mice, the mechanism of Regnase-1-mediated immune regulation has remained unclear. We show that Regnase-1 is essential for preventing aberrant effector CD4+ TĀ cell generation cell autonomously. Moreover, in TĀ cells, Regnase-1 regulates the mRNAs of a set of genes, including c-Rel, Ox40, and Il2, through cleavage of their 3ā€² UTRs. Interestingly, TĀ cell receptor (TCR) stimulation leads to cleavage of Regnase-1 at R111 by Malt1/paracaspase, freeing TĀ cells from Regnase-1-mediated suppression. Furthermore, Malt1 protease activity is critical for controlling the mRNA stability of TĀ cell effector genes. Collectively, these results indicate that dynamic control of Regnase-1 expression in TĀ cells is critical for controlling TĀ cell activation
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