778 research outputs found

    Grain deformability influence on the fracture behaviour of rock

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    It is known that the initially proposed circular/spherical rigid particle models are not able to match the ratio of the compressive strength to tensile strength that occurs in rock and the predicted macroscopic friction angle was much lower than the known hard rock experimental values. For this reason, several enhancements have been proposed to address these issues, namely the use of a clumped particle logic, the increase of the number of contacts per particle, the adoption of polygonal/polyhedral grain structures. A flexible 2D DEM based particle model that allows deformable particles to interact in a simplified away is presented. The flexible particle model is tested using biaxial tests and Brazilian tests. The results obtained are compared with those obtained with a rigid particle model with similar contact strength properties and with a flexible particle model, where the flexibility is due to the inner discretization of the grain with smaller particles. The results show that the proposed flexible particle model can predict a behaviour similar to a flexible particle model through inner particle discretization that is more computationally demanding. It is also shown that when compared with a rigid model, the flexible model predicts more reasonable indirect tensile strength to direct tensile strength ratio and requires a smaller value of contact fracture energy to give a good agreement with known experimental data

    Reduced salivary flow and colonization by mutans streptococci in children with Down syndrome

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    OBJECTIVES: Although individuals with Down syndrome have considerable oral disease, the prevalence of dental caries in this group is low. The present study aimed to compare known risk factors for dental caries development in children with Down syndrome and a matched population (siblings). In both populations, the number of acidogenic microorganisms, such as mutans streptococci, lactobacilli and Candida species, and the paraffin-stimulated pH, flow rate and IgA concentration in whole saliva were evaluated and compared. METHOD: Saliva was collected, and the caries index was evaluated in 45 sibling pairs aged between 6 and 18 years old. The salivary IgA concentration was determined by immunoturbidimetry. Salivary mutans streptococci, lactobacilli and Candida species were quantified on mitis salivarius agar containing bacitracin and 20% sucrose, rogosa agar supplemented with glacial acetic acid and sabouraud agar supplemented with chloramphenicol, respectively. RESULTS: Down syndrome children had a higher caries-free rate (p<0.05) and lower salivary mutans streptococci counts (p<0.03) compared to their siblings. Similar numbers of lactobacilli and Candida species were found in both groups. Salivary flow rates were 36% lower in Down syndrome children compared to their siblings (p<0.05). The salivary pH did not differ between Down syndrome children and controls. The Down syndrome children had an IgA secretion rate 29% lower than that of their siblings, but this difference was not statistically significant. CONCLUSIONS: In conclusion, the lower number of mutans streptococci in the saliva may be one of the factors contributing to the lower caries rate observed in Down syndrome children, despite evidence of hyposalivation

    Pressing issues for oral care quality improvement: findings from the EU DELIVER project

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    Background: While oral health often takes a backseat to other health domains, it silently affects nearly half of the Worldwide population. The DELIVER project, funded by the EU’s Horizon Europe program, seeks to develop a blueprint model for improving the quality of oral health care for everyone. Methods: Applying the Nominal Group Technique (NGT), 17 stakeholders from various backgrounds participated in identifying pressing issues for oral care quality improvement across practice, community, and policy levels. Results: The results revealed significant differences at the different levels, with accessibility emerging as a prominent issue, encompassing affordability, availability, and acceptability of oral healthcare services. Conclusions: These findings emphasizes the need for policy reforms, increased investments, and a shift towards preventive and patient-centered dental care practices. It highlights the importance of collaborative efforts with multi-stakeholders and prioritizing pressing issues on a multi-level to drive positive change in improving oral care quality. © The Author(s) 2024.The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This project has received funding from the European Union’s Horizon Europe research and innovation program under grant agreement 101057077: https://cordis.europa.eu/project/id/101057077

    Perfeccionismo no transtorno obsessivo-compulsivo e nos transtornos alimentares

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    OBJETIVO: Este estudo tem dois objetivos principais. Primeiro, avaliar as dimensões do perfeccionismo no transtorno obsessivo-compulsivo e nos transtornos alimentares em comparação com duas amostras controle: psiquiátrica (depressão/ansiedade) e não clínica. Segundo, avaliar se o perfeccionismo é um traço de personalidade especificamente relacionado com estas diferentes condições clínicas. MÉTODO: 39 pacientes com transtorno obsessivo-compulsivo, 24 com transtornos alimentares, 65 com um diagnóstico de depressão e/ou ansiedade (todos estes pacientes encontravam-se em regime de ambulatório) e 70 controles não clínicos completaram a versão portuguesa da Multidimensional Perfectionism Scale. RESULTADOS: Comparativamente à amostra não clínica, todas as amostras clínicas apresentaram níveis significativamente mais elevados na Multidimensional Perfectionism Scale total, no Perfeccionismo Auto-Orientado e no Perfeccionismo-Socialmente-Prescrito. Não houve diferenças estatisticamente significativas no Perfeccionismo-Auto-Orientado e na Multidimensional Perfectionism Scale total nas três amostras clínicas. No entanto, a amostra com transtornos alimentares apresentou níveis significativamente mais elevados de Perfeccionismo-Socialmente-Prescrito, comparativamente à transtornos alimentares e à amostra psiquiátrica (depressão/ansiedade). CONCLUSÃO: O perfeccionismo revelou estar associado a uma grande variedade de condições psicopatológicas. Contudo, as diferenças encontradas entre a amostra de transtornos alimentares, de transtorno obsessivo-compulsivo e a psiquiátrica no Perfeccionismo-Socialmente-Prescrito necessitam de investigação subsequente no sentido de clarificar a especificidade desta dimensão com os transtornos alimentares

    Arachnidism, scorpionism and ophidism in Ouro Preto Municipality, Minas Gerais State, Brazil

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    Abstract: INTRODUCTION This retrospective study shows the profile of arachnidism, ophidism, and scorpionism in the Ouro Preto Municipality, Brazil, from January 2007 to December 2013. METHODS The data were gathered from forms of the Epidemiological Surveillance Sector of the town's Health's Municipal Secretary. RESULTS Of the 412 envenomations, 308 were caused by spiders, 78 by scorpions, and 26 by snakes. The highest number of incidents involved people aged 20-34 years. Females were more affected than males. There were no reports of death. CONCLUSIONS The results show that envenomations caused by spiders, scorpions and snakes have decreased in recent years

    [Access to early breast cancer diagnosis in the Brazilian Unified National Health System: an analysis of data from the Health Information System].

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    The recent reduction in breast cancer mortality in high-income countries resulted from improvements in early detection and treatment. Breast cancer is the most common cancer in Brazilian women. Since 2004, the government has recommended annual clinical breast examination for women aged ≥ 40 years and biannual mammograms for those aged 50-69. This article investigates the degree of implementation of these guidelines using data from the Brazilian Unified National Health System for 2010 according to major geographic region and age group. The findings showed low national mammogram coverage in the target population (32% in the 50-59-year group; 25% from 60 to 69 years). The percentage of women with abnormal radiological findings who underwent biopsy was also low (27% for 50-59 years; 63% for 60-69 years). The number of breast cancer surgeries exceeded the number of cases detected by mammography but was well below the estimated number of incident breast cancer cases in 2010. There are striking regional inequalities in access to early detection and surgery, being the lowest access in the North Region and the highest in the South Region
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