89 research outputs found

    Effect of the cation structure on the properties of homobaric imidazolium ionic liquids

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    In this work we investigate the structure-property relationships in a series of alkylimidazolium ionic liquids with almost identical molecular weight. Using a combination of theoretical calculations and experimental measurements, we have shown that re-arranging the alkyl side chain or adding functional groups results in quite distinct features in the resultant ILs. The synthesised ILs, although structurally very similar, cover a wide spectrum of properties ranging from highly fluid, glass forming liquids to high melting point crystalline salts. Theoretical ab initio calculations provide insight on minimum energy orientations for the cations, which then are compared to experimental X-ray crystallography measurements to extract information on hydrogen bonding and to verify our understanding of the studied structures. Molecular dynamics simulations of the simplest (core) ionic liquids are used in order to help us interpret our experimental results and understand better why methylation of C^{2} position of the imidazolium ring results in ILs with such different properties compared to their non-methylated analogues

    Apresentação clínica, achados histológicos e prognóstico em cadelas com neoplasias mamárias mistas

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    The aim of this study was to describe the clinical and morphological characteristics of mixed mammary neoplasms and verify what characteristics affect the prognosis of female dogs with carcinomas in mixed tumors and carcinosarcomas. This was a retrospective study of 67 female dogs that underwent mastectomies and were diagnosed with benign mixed tumors (n=13), carcinomas in mixed tumors (n=44) and carcinosarcomas (n=10). Data regarding the clinical and histological aspects of the neoplasms were collected and the relation with specific survival times, and hazard ratios (HR) in 24 months was calculated. In univariate analysis, the diagnosis of carcinosarcoma (HR 8.26, p=0.006), carcinomatous areas with micropapillary or solid patterns (HR 17.49; p=0. 001) and lymph node metastasis (HR 7.07;p=0.020) were associated with specific survival. In multivariable analysis, only micropapillary or solid pattern (HR=16.34; p=0.007) remained independent factor associated with lower specific survival. Micropapillary or solid carcinomatous patterns were associated with shorter specific survival time (p=0.002) among animals with carcinomas in mixed tumors. Among the carcinosarcomas, lymph node metastasis (p=0.010) was associated with a shorter specific survival time. In conclusion, carcinomas in mixed tumors and carcinosarcomas vary in prognosis depending on the carcinomatous proliferation patterns and spread of the disease.O objetivo deste estudo foi descrever as características clínicas e morfológicas das neoplasias mamárias mistas e verificar quais características interferem no prognóstico de cadelas com carcinomas em tumores mistos e carcinossarcomas. Este foi um estudo retrospectivo de 67 cadelas, que foram submetidas a mastectomias e diagnosticadas com tumores mistos benignos (n = 13), carcinomas em tumores mistos (n = 44) e carcinossarcomas (n = 10). Foram coletados dados sobre os aspectos clínicos e histológicos das neoplasias e a relação com o tempo de sobrevida específica e a razão de risco (OR) em 24 meses foram calculadas. Na análise univariada, o diagnóstico de carcinossarcoma (HR 8,26; p=0,006), as áreas carcinomatosas com padrão micropapilar e sólido (HR 17,49; p= 0,001) e metástase linfonodal (HR 7,07; p=0,020) foram associadas à menor sobrevida específica. Na análise multivariável, apenas o padrão micropapilar ou sólido (HR=16,34; p=0,007) permaneceu como fator independente associado à sobrevida. Proliferações carcinomatosas micropapilares ou sólidas (p = 0,002) foram associadas a tempos de sobrevida específica mais curtos entre os animais com carcinomas em tumor misto. Entre os pacientes com carcinossarcoma, metástases em linfonodos (p = 0,010) foram associadas a um menor tempo de sobrevida específica. Em conclusão, os resultados mostraram que os carcinomas em tumores mistos e os carcinossarcomas podem ter prognóstico variável, dependendo do padrão de proliferação carcinomatosa e da disseminação linfática da doença

    PU.1 controls fibroblast polarization and tissue fibrosis

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    Fibroblasts are polymorphic cells with pleiotropic roles in organ morphogenesis, tissue homeostasis and immune responses. In fibrotic diseases, fibroblasts synthesize abundant amounts of extracellular matrix, which induces scarring and organ failure. By contrast, a hallmark feature of fibroblasts in arthritis is degradation of the extracellular matrix because of the release of metalloproteinases and degrading enzymes, and subsequent tissue destruction. The mechanisms that drive these functionally opposing pro-fibrotic and pro-inflammatory phenotypes of fibroblasts remain unknown. Here we identify the transcription factor PU.1 as an essential regulator of the pro-fibrotic gene expression program. The interplay between transcriptional and post-transcriptional mechanisms that normally control the expression of PU.1 expression is perturbed in various fibrotic diseases, resulting in the upregulation of PU.1, induction of fibrosis-associated gene sets and a phenotypic switch in extracellular matrix-producing pro-fibrotic fibroblasts. By contrast, pharmacological and genetic inactivation of PU.1 disrupts the fibrotic network and enables reprogramming of fibrotic fibroblasts into resting fibroblasts, leading to regression of fibrosis in several organs

    Tactile perception, gesture and oral language in everyday instruments for children from 2 to 5 years of age: short report

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    Este estudo analisa a relação entre perceção tátil, simulação de uso de instrumento e palavra em crianças de 2 a 5 anos. Mostraram-se à criança 11 instrumentos do seu quotidiano, perguntou-se-lhe (i) o que era (palavra), (ii) que fingisse usá-los (gesto) e (iii) que os identificasse tatilmente. As crianças de 2 anos apresentaram mais desvios morfológicos. Com o avanço da idade, as crianças fizeram mais identificações táteis. Crianças com mais desvios por subextensão e morfológico realizaram menos gestos e fizeram menos identificações táteis. Crianças com mais identificações orais foram as com mais identificações táteis. Crianças com mais identificações táteis foram as com mais gestos do tipo “incorporação”. Ocorre uma transição abrupta dos 2 para os 3 anos em qualidade e quantidade de palavras. A identificação tátil e gestualização estão associadas a melhor dicção e maior léxico verbal. Ambas estão associadas, principalmente, com a gestualização de “incorporação”. Os resultados sustentam a hipótese de uma interação entre perceção tátil, gesto e aquisição da palavra.In this paper, we show an analyze the relationship between tactile perception, simulation of instrument use and word in children aged from 2 to 5 years. The child was shown 11 instruments from her/his daily live, asked (i) what they were (word), (ii) to pretend to use them (gesture), and (iii) to identify them tactically. The 2-year-old children had more morphological deviations. With age, children made more tactile identifications. Children with more subextension and morphological deviations performed fewer gestures and made fewer tactile identifications. Children with more oral identifications were the ones with more tactile identifications. Children with more tactile identifications were the ones with more gestures of the “incorporation” type. There is an abrupt transition from 2 to 3 years in terms of quality and quantity of words. Tactile identification and gestures are associated with better diction and greater verbal lexicon. Both are mainly associated with the gesture of “incorporation”. The results support the hypothesis of an interaction between tactile perception, gesture and word acquisition.info:eu-repo/semantics/publishedVersio

    An artificial intelligence algorithm is highly accurate for detecting endoscopic features of eosinophilic esophagitis

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    The endoscopic features associated with eosinophilic esophagitis (EoE) may be missed during routine endoscopy. We aimed to develop and evaluate an Artificial Intelligence (AI) algorithm for detecting and quantifying the endoscopic features of EoE in white light images, supplemented by the EoE Endoscopic Reference Score (EREFS). An AI algorithm (AI-EoE) was constructed and trained to differentiate between EoE and normal esophagus using endoscopic white light images extracted from the database of the University Hospital Augsburg. In addition to binary classification, a second algorithm was trained with specific auxiliary branches for each EREFS feature (AI-EoE-EREFS). The AI algorithms were evaluated on an external data set from the University of North Carolina, Chapel Hill (UNC), and compared with the performance of human endoscopists with varying levels of experience. The overall sensitivity, specificity, and accuracy of AI-EoE were 0.93 for all measures, while the AUC was 0.986. With additional auxiliary branches for the EREFS categories, the AI algorithm (AI-EoE-EREFS) performance improved to 0.96, 0.94, 0.95, and 0.992 for sensitivity, specificity, accuracy, and AUC, respectively. AI-EoE and AI-EoE-EREFS performed significantly better than endoscopy beginners and senior fellows on the same set of images. An AI algorithm can be trained to detect and quantify endoscopic features of EoE with excellent performance scores. The addition of the EREFS criteria improved the performance of the AI algorithm, which performed significantly better than endoscopists with a lower or medium experience level

    Detection of duodenal villous atrophy on endoscopic images using a deep learning algorithm

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    Background and aims Celiac disease with its endoscopic manifestation of villous atrophy is underdiagnosed worldwide. The application of artificial intelligence (AI) for the macroscopic detection of villous atrophy at routine esophagogastroduodenoscopy may improve diagnostic performance. Methods A dataset of 858 endoscopic images of 182 patients with villous atrophy and 846 images from 323 patients with normal duodenal mucosa was collected and used to train a ResNet 18 deep learning model to detect villous atrophy. An external data set was used to test the algorithm, in addition to six fellows and four board certified gastroenterologists. Fellows could consult the AI algorithm’s result during the test. From their consultation distribution, a stratification of test images into “easy” and “difficult” was performed and used for classified performance measurement. Results External validation of the AI algorithm yielded values of 90 %, 76 %, and 84 % for sensitivity, specificity, and accuracy, respectively. Fellows scored values of 63 %, 72 % and 67 %, while the corresponding values in experts were 72 %, 69 % and 71 %, respectively. AI consultation significantly improved all trainee performance statistics. While fellows and experts showed significantly lower performance for “difficult” images, the performance of the AI algorithm was stable. Conclusion In this study, an AI algorithm outperformed endoscopy fellows and experts in the detection of villous atrophy on endoscopic still images. AI decision support significantly improved the performance of non-expert endoscopists. The stable performance on “difficult” images suggests a further positive add-on effect in challenging cases
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