224 research outputs found

    Brain tumors induced in rats by human adenovirus type 12

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    Oncogenesis of human adenovirus type 12 in the brain of rats was examined. Newborn rats of Sprague-Dawley and Donryu&#12288;strains were injected intracranially with human adenovirus type 12.&#12288;The incidence of intracranial tumors was 91% (30/33) in SpragueDawley&#12288;and 56% (14/25) in Donryu rats. Except for one tumor nodule&#12288;located in the parietal cortex of a Sprague.Dawley rat, all tumors&#12288;developed in the paraventricular areas or in the meninges. Tumors were quite similar histologically to those induced in hamsters and&#12288;mice resembling the undifferentiated human brain tumors such as medulloblastoma,&#12288;ependymoblastoma and embryonic gliomas. From&#12288;the histological features and primary sites of tumor development, it is&#12288;suggested that the tumors in the brain of rats induced by adenovirus type 12 originate from the embryonic cells in the&#12288;paraventricular area&#12288;and also from the undifferentiated supporting cells of the peripheral&#12288;nerves in the&#12288;leptomeninges.</p

    Radiographic Prediction of the Results of Long-term Treatment with the Pavlik Harness for Developmental Dislocation of the Hip

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    In 1957, Pavlik introduced the Pavlik harness as a useful treatment for developmental dislocation of the hip (DDH), and subsequent studies have documented favorable outcomes among patients treated with this device. However, there are only a few articles reporting how early radiographic measurements can be used to determine the prognosis after treatment with the Pavlik harness. In this study, 217 hips from 192 patients whose DDH treatment with the Pavlik harness was initiated before they were 6 months old and whose follow-up lasted at least 14 years (rate, 63.8%) were analyzed using measurements from radiographs taken immediately before and after harness treatment, and at 1, 2, and 3 years of age. Severin's classification at the final follow-up was I or II in 71.9% and III or IV in 28.1% of the hips, respectively. Avascular necrosis of the femoral head (AVN) was seen in 10% of the hips. Stepwise multiple regression analysis was performed to retrospectively determine whether any radiographic factors were related to the final classification as Severin I/II or III/IV. Receiver opera-ting characteristic (ROC) curves were drawn for these factors, and a Wiberg OE angle (Point O was the middle point of the proximal metaphyseal border of the femur) of 2 degrees on the 3-year radiographs was found to be the most useful screening value for judging the acetabular development of DDH cases after treatment with a Pavlik harness, with a sensitivity of 71% a specificity of 93%, and a likelihood ratio of 10.1.</p

    Weighing matrices and spherical codes

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    Mutually unbiased weighing matrices (MUWM) are closely related to an antipodal spherical code with 4 angles. In the present paper, we clarify the relationship between MUWM and the spherical sets, and give the complete solution about the maximum size of a set of MUWM of weight 4 for any order. Moreover we describe some natural generalization of a set of MUWM from the viewpoint of spherical codes, and determine several maximum sizes of the generalized sets. They include an affirmative answer of the problem of Best, Kharaghani, and Ramp.Comment: Title is changed from "Association schemes related to weighing matrices

    Numerical simulation of immiscible two-fluid flows by flux-free finite element method

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    The purpose of this paper is to present a numerical model for immiscible incompressible two-fluid flows, which preserves the discrete mass of the fluid more highly. This method is derived from the variational formulation including the flux-free constraint for the Navier-Stokes equations by the Lagrange multiplier technique and is implemented by the level set of the pseudo-density function, so that we aldo solve the transport equation by the finite element method. Finally we give some numerical results to validate our proposed method

    Traumatic reactions in train disasters

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    Objective : The purpose of this study was to examine the relationship between peritraumatic reactions, posttraumatic stress disorder (PTSD) symptoms, and pain in people injured in train disasters. Methods : The participants were injured in a train crash in Japan that left more than 100 dead. There were 218 participants in the analysis, with a mean age of 37.50 ± 14.67 years. Peritraumatic reactions were assessed using the Peritraumatic Distress Inventory. PTSD symptoms were evaluated using the Impact of Event Scale-Revised Japanese-language version. Pain was measured using the Visual Analog Scale. Results : Peritraumatic reactions did not directly affect PTSD symptoms but were found to be associated via latent variables. Regarding pain and PTSD symptoms, intrusive memories were more associated with pain than other symptoms were. There was an associative path from intrusion to pain, but no such path from pain to intrusion. Conclusions : Our results suggest that a therapeutic approach to intrusion may be effective in ameliorating the pain caused by injury. Future research should examine integrated treatment approaches for both PTSD and pain, rather than just for aspects of PTSD

    Fabrication of Electroluminesecent Thin Films Doped with Rare-Earth Ions by Evaporation Method

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    The fabrication conditions of the electroluminescent ZnS:TbF₃, ZnS:ErF₃, and ZnS;NdF₃ thin films have been investigated. The effects of pre-heating upon the electroluminescent properties, and the relationship between crucible temperature and deposition rate, have been studied. The optimum fabrication conditions of the strong electroluminescent films have been found to be as fol1ows; crucible temperature for ZnS of 760~780℃, crucible temperature for rare-earth fluorides of 780~820℃, and the deposition rate of 300Å/min. These conditions were independent of the rare-earth ions doped. The EL emission spectra of the films have been related to known energy level schemes of doped rare-earth ions. The external power efficiency of 5×10⁶ have been obtained
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