1,326 research outputs found

    Exploring the micro-to-macro response of granular soils with real particle shapes via \u1d741\u1d46a\u1d47b-aided DEM analyses

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    This contribution provides high fidelity images of real granular materials with the aid of X-ray micro computed tomography (μCT ), and employs a multi-sphere approximation to reconstruct non-spherical particles. Through the discrete element method (DEM) simulations on granular samples composed of these non-spherical clumps, the effect of particle shape on the macroscopic mechanical response and microscopic soil fabric evolution is examined for sheared soil assemblies under triaxial loading conditions. Simulation results indicate that materials with more irregular particles tend to show higher shear resistance in both peak and critical stresses, while more sphere-like materials tend to exhibit lower void ratio and mean coordination number values under isotropic loading conditions and in the critical state. The proposed critical state parameters for describing the sensitivity of the mean coordination number to confining pressures are larger as particles become more irregular. At a microscopic level of observation, more irregular materials appear to exhibit higher fabric anisotropy in terms of contact normal and particle orientation in the critical state. The critical stress ratio determined through experimental and simulation results are found to be linearly linked to the shape-weighted fabric anisotropy index

    Validation of the Japanese version of the Dementia Screening Questionnaire for Individuals with Intellectual Disabilities

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    Background, Dementia in people with intellectual disabilities (IDs) is difficult to detect because of preexisting cognitive deficits. An effective screening method is required. The Dementia Screening Questionnaire for Individuals with Intellectual Disabilities (DSQIID) was developed as an observer rating tool to screen dementia in people with ID. The aim of this study was to verify the screening accuracy of the DSQIID for Japanese people with ID. Methods Four‐hundred ninety‐three subjects with ID participated in this study. Caregivers who had observed the participants for more than 2 years scored the Japanese version of the DSQIID (DSQIID‐J) of the participants. Three doctors examined participants directly and diagnosed dementia using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria. To identify the key screening items that predict dementia, the specificities of a single and pairs of items with 100% sensitivity were evaluated relative to the dementia diagnosis. Results Of 493 participants, 34 were people with Down syndrome (DS), and 459 were people without DS. Seventeen participants were diagnosed with dementia. The suitable cut‐off score of the DSQIID‐J was 10/11 (sensitivity 100% and specificity 96.8%) for screening dementia. The inter‐rater reliability, test–retest reliability and internal consistency of the DSQIID‐J were excellent. Regarding key items, there was no single item with 100% sensitivity, and the best two‐item combination was the pair of ‘Cannot dress without help’ and ‘Walks slower’ (sensitivity 100% and specificity 93.5%). Conclusions We identified several important question items of the DSQIID‐J related to the diagnosis of dementia in people with ID. The DSQIID‐J is a useful screening tool for dementia in adults with ID

    p53 expression in squamous dysplasia associated with carcinoma of the oesophagus: evidence for field carcinogenesis

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    Squamous epithelial dysplasia is often observed multifocally in the cancerous oesophagus and is presumably considered to be a pre-cancerous lesion. A mutation of the p53 tumour suppressor gene is commonly identified in oesophageal cancer and dysplasia. p53 mutations can be anticipated immunohistochemically. In order to confirm the biological and clinical significance of p53 expressions in oesophageal field carcinogenesis, immunostaining for p53 in cancerous and multifocal precancerous lesions from resected human oesophagus was systematically investigated, while paying special attention to the contiguity of these lesions. Lesions expressing p53 were detected in 46.5% (20 of 43 lesions) of the invasive carcinoma, and in 51.0% (46 of 90 lesions) of the carcinoma in situ, and in 51.4% (92 of 179 lesions) of the dysplasia. Next, the p53 expression in dysplasia was compared with that in carcinoma for the same case. 37 of 39 (94.8%) dysplasias contiguous to p53-positive carcinomas also expressed p53 (P < 0.0001). On the other hand, the isolated dysplasias without contiguity to p53-positive carcinomas, only expressed p53 protein in 44.0% (11 of 25 lesions). No significant correlations were found between the p53 staining and either the clinicopathological features or prognosis. Discordant p53 alterations, such as those seen in cancerous and isolated precancerous lesions, may thus demonstrate further evidence for a multicentric or field carcinogenesis of the human oesophagus. © 2000 Cancer Research Campaig

    Prognostic factors in patients with submucosal carcinoma of the oesophagus

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    To clarify the prognostic factors in patients with submucosal carcinoma of the oesophagus, we examined the results of surgical treatment for 78 cases over the last decade. The clinicopathological factors including age, sex, location of the tumour, length of the tumour, histological differentiation, subclassification of depth, lymphatic or blood vessel invasion, intramural metastasis and lymph node metastasis were all analysed. Then the correlation between these factors and prognosis was investigated. As a result, significant differences were observed in the survival rates between the groups regarding lymphatic vessel invasion (P = 0.0003), intramural metastasis (P = 0.0051) and lymph node metastasis (P = 0.0026). According to a multivariate analysis, intramural metastasis (P = 0.0038, relative risk 9.17), vessel invasion (P = 0.0033, relative risk 6.25) and lymph node metastasis (P = 0.0187, relative risk 3.62) were found to be independent prognostic factors. The prognosis of the patients with at least one of these factors was significantly poorer than that without. The five-year survival rate of the patients without these factors was as good as that with mucosal carcinoma of the oesophagus. Based on our findings, vessel invasion, intramural metastasis and lymph node metastasis are thus considered to be significant prognostic factors in patients with submucosal carcinoma of the oesophagus. © 2000 Cancer Research Campaig
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