38 research outputs found

    Effective Stress Analysis by Shear Strain Controllable Model and its Application to Centrifuge Shaking Model Test

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    Effective stress FEM which is able to control the growth of shear strains is proposed. Its validity is firstly confirmed through the simulation of undrained cyclic torsional shear tests. Then, it is applied to simulation of centrifuge shaking model tests; the experimental model consists of a caisson type quay wall and reclamation laid on the sand layer. Development of shear strain is shown to be controlled arbitrary keeping the excess porewater pressure generation unchanged through the simulation of undrained cyclic torsional shear test, which indicates that proposed model can be applicable to variety of soils with different density and fines contents. Displacement is shown to be controlled keeping excess porewater pressure generation constant in the centrifugal model, too, and good agreement is obtained between test and analysis by controlling the parameter for shear strain development

    A novel clinical entity, IgG4-related disease (IgG4RD): general concept and details

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    IgG4-related disease (IgG4RD) is a novel clinical disease entity characterized by elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4-positive plasma cells. IgG4RD may be present in a certain proportion of patients with a wide variety of diseases, including Mikulicz’s disease, autoimmune pancreatitis, hypophysitis, Riedel thyroiditis, interstitial pneumonitis, interstitial nephritis, prostatitis, lymphadenopathy, retroperitoneal fibrosis, inflammatory aortic aneurysm, and inflammatory pseudotumor. Although IgG4RD forms a distinct, clinically independent disease category and is attracting strong attention as a new clinical entity, many questions and problems still remain to be elucidated, including its pathogenesis, the establishment of diagnostic criteria, and the role of IgG4. Here we describe the concept of IgG4RD and up-to-date information on this emerging disease entity

    Cutoff Values of Serum IgG4 and Histopathological IgG4+ Plasma Cells for Diagnosis of Patients with IgG4-Related Disease

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    IgG4-related disease is a new disease classification established in Japan in the 21st century. Patients with IgG4-related disease display hyper-IgG4-gammaglobulinemia, massive infiltration of IgG4+ plasma cells into tissue, and good response to glucocorticoids. Since IgG4 overexpression is also observed in other disorders, it is necessary to diagnose IgG4-related disease carefully and correctly. We therefore sought to determine cutoff values for serum IgG4 and IgG4/IgG and for IgG4+/IgG+ plasma cells in tissue diagnostic of IgG4-related disease. Patients and Methods. We retrospectively analyzed serum IgG4 concentrations and IgG4/IgG ratio and IgG4+/IgG+ plasma cell ratio in tissues of 132 patients with IgG4-related disease and 48 patients with other disorders. Result. Serum IgG4 >135  mg/dl demonstrated a sensitivity of 97.0% and a specificity of 79.6% in diagnosing IgG4-related disease, and serum IgG4/IgG ratios >8% had a sensitivity and specificity of 95.5% and 87.5%, respectively. IgG4+cell/IgG+ cell ratio in tissues >40% had a sensitivity and specificity of 94.4% and 85.7%, respectively. However, the number of IgG4+ cells was reduced in severely fibrotic parts of tissues. Conclusion. Although a recent unanimous consensus of all relevant researchers in Japan recently established the diagnostic criteria for IgG4-related disease, findings such as ours indicate that further discussion is needed

    Effect of different fuel NO models on the prediction of NO formation/reduction characteristics in a pulverized coal combustion field

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    To investigate the effects of fuel NO formation models on the prediction of NO concentrations in a coal combustion field, numerical simulations for a coal combustion field in a 760 kW test furnace were performed. Three models, those proposed by De Soete, Chen et al. and Mitchell et al. were employed to calculate fuel NO formation originating from volatile matter. The results show that the model proposed by Mitchell et al. reproduces the tendency of the experimental data better than the other two models. In addition, the difference between the NO conversion ratios of bituminous coal and sub-bituminous coal that contains a high level of moisture was examined in detail using simulation results from the model of Mitchell et al. It was found that the formation of a region with a low oxygen mole fraction immediately downstream of a region with a high NO production rate is essential to realize a low NO conversion ratio

    Prediction of soot formation characteristics in a pulverized-coal combustion field by large eddy simulations with the TDP model

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    In this study, the soot formation characteristics in a pulverized-coal combustion field formed by a 4 kW Central Research Institute of Electric Power Industry (CRIEPI) jet burner were predicted by large eddy simulation (LES) employing a tabulated-devolatilization-process model (TDP model) [N. Hashimoto et al., Combust. Flame 159 (2012) 353–366]. This model enables to take into account the effect of coal particle heating rate on coal pyrolysis. The coal-derived soot formation model proposed by Brown and Fletcher [A. L. Brown and T. H. Fletcher, Energy Fuels 12 (1998) 745–757] was employed in the LES. A comparison between the data predicted by LES and the soot volume fraction distribution data measured by laser induced incandescence confirmed that the soot formation characteristics in the coal combustion field of the CRIEPI burner can be accurately predicted by LES. A detailed analysis of the data predicted by LES showed that the soot particle distribution in this burner is narrow because the net soot formation rate is negative on both sides of the base of the soot volume fraction. At these positions, soot particles diffused from the peak position of soot volume fraction are oxidized due to a relatively high oxygen concentration. Finally, the effect of soot radiation on the predicted gas temperature distribution was examined by comparing the simulation results obtained with and without soot radiation. This comparison showed that the maximum gas temperature predicted by the simulation performed with soot radiation was over 100 K lower than that predicted by the simulation performed without soot radiation. From result strongly suggests the importance of considering a soot formation model for performing numerical simulations of a pulverized-coal combustion filed

    Intraorbital ancient pilocytic astrocytoma of the optic nerve in neurofibromatosis type 1 patient presenting with sudden ocular pain

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    Optic nerve pilocytic astrocytoma is an uncommon but well-known entity; however, intraorbital ancient pilocytic astrocytoma of the optic nerve is extremely rarely reported. To our knowledge, this is the first detailed description regarding the intraorbital ancient pilocytic astrocytoma, reported in available English literature, to date. We presented an extremely unusual neurofibromatosis type 1 case of a 17-year-old male’s sudden ocular pain secondary to intraorbital pilocytic astrocytoma of the optic nerve with markedly cystic degeneration, fluid production, and hemorrhage, due to ancient and possibly ruptured glioma. Future prospective studies are required to validate the significance of intraorbital ancient pilocytic astrocytoma arising from the optic nerve and the close correlation with ruptured cystic degeneration and ocular pain, after collecting and investigating a larger number of its cases examined
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