Detection of ectopic gastric mucosa using scintigraphy in pediatric patients

Introdução: A cintigrafia é frequentemente usada na deteção de mucosa gástrica ectópica no Divertículo de Meckel (DM). Este estudo teve como objetivo avaliar a sua acuidade em crianças com suspeita de DM sintomático. Material e Métodos: Foram revistos os registos médicos dos pacientes submetidos a cintigrafia com pertecnetato de [99mTc] entre 2004 e 2018 num centro hospitalar terciário. Os critérios de exclusão foram: idade > 18 anos, registos médicos incompletos, indicação para cintigrafia pouco clara e óbito. Foram recolhidos os dados demográficos, as manifestações clínicas e achados histopatológicos. A cintigrafia foi realizada de acordo com as guidelines SNMMI / EANM. Os doentes foram divididos nos grupos A (hemorragia digestiva aguda) e B (outras manifestações). Resultados: Foram incluídos no estudo 131 exames (74% crianças do sexo masculino; idade 5 [2-10] anos). O grupo A incluiu 116 pacientes e o grupo B 15 (dor abdominal, n = 6; invaginação atípica, n = 9). O resultado foi positivo em 29 crianças. Em 5 doentes, apesar do resultado negativo, foi detetada mucosa gástrica ectópica. Os valores de sensibilidade, especificidade, VPP, VPN e acuidade foram de 84%, 97%, 90%, 95% e 94%, respetivamente. Não houve diferenças estatisticamente significativas entre os grupos relativamente aos resultados e à acuidade da cintigrafia. Discussão e conclusão: A cintigrafia com pertecnetato de [99mTc] apresenta uma acuidade elevada na deteção de mucosa gástrica ectópica em crianças com hemorragia digestiva aguda, bem como face a outras formas sintomáticas da DM.Background: [99mTc] Pertechnetate Scintigraphy is frequently used to detect ectopic gastric mucosa in Meckel's Diverticulum (MD). The present study aimed to assess its accuracy in paediatric patients suspected of symptomatic MD. Material and Methods: All the medical records of patients that underwent [99mTc] pertechnetate scintigraphy from 2004 to 2018 at a tertiary centre were reviewed. The exclusion criteria were: age above 18 years, incomplete medical records, unclear indication for scintigraphy and death. Demographic data, clinical manifestations, outcome, and histopathology findings were collected. The scans were performed according to SNMMI/EANM guidelines. Patients were divided into group A presenting acute digestive bleeding, and group B with other presentations. Results: 131 scans performed in children (74% males; age 5 [2-10] years) were included. Group A encompassed 116 patients, and group B 15 (abdominal pain, n=6; atypical intussusception, n=9). Overall, there were 29 positives scans. Ectopic gastric mucosa was found in an additional 5 patients with negative scans. The sensitivity, specificity, PPV, NPV and accuracy values were 84%, 97%, 90%, 95% and 94% respectively. There were no statistically significant differences between the groups concerning scan findings and accuracy. Discussion and conclusion: [99mTc] pertechnetate scintigraphy presents a high accuracy in detecting ectopic gastric mucosa in children with acute digestive bleeding as well as in front of suspicion of other symptomatic forms of MD

Significances of differences between slopes: An upgrade for replicated time series

In some ecology subjects the slope of the line fit between x and y variables is the focus of concern. Such is the case of self-thinning theory, developed for plant demography and later verified also occurring in algae and animals. Different slopes identify statistical populations subject to different conditions. Therefore, it is fundamental that a test is able to identify honestly significant differences between slopes. The most used tested for the overlap of the 95% confidence intervals of the bootstrapped slopes. However, Vieira and Creed (2013) demonstrated it to possess weak theoretical grounds having proposed a permutation methods alternative. Unfortunately, both were fallible upon small sample sizes and/or large data scatter. Data about self-thinning, as well as other subjects, often comes in replicated time series enabling upgrading the test algorithm to randomize sampling units only within the respective time frame. This was added to the previous software, increasing outstandingly the capacity of the permutation test in identifying both true and false differences between slopes

Estimating significances of differences between slopes: A new methodology and software

Determining the significance of slope differences is a common requirement in studies of self-thinning, ontogeny and sexual dimorphism, among others. This has long been carried out testing for the overlap of the bootstrapped 95% confidence intervals of the slopes. However, the numerical random re-sampling with repetition favours the occurrence of re-combinations yielding largely diverging slopes, widening the confidence intervals and thus increasing the chances of overlooking significant differences. To overcome this problem a permutation test simulating the null hypothesis of no differences between slopes is proposed. This new methodology, when applied both to artificial and factual data, showed an enhanced ability to differentiate slopes

Modelica como uma linguagem de engenharia: modelação de sistemas mecânicos/mecatrónicos

No presente artigo vão ser abordados alguns exemplos mecânicos/mecatrónicos básicos que podem ser encontrados nas bibliotecas do software Dymola 6.0 ou criados pelos autores, no sentido de serem verificadas as potencialidades do mesmo para a sua aplicação no projeto de sistemas/produtos.info:eu-repo/semantics/publishedVersio

Vinculação Amorosa, Ajustamento Diádico e Funcionamento Sexual na Violência nas Relações de Intimidade

A violência nas relações de intimidade tem sido alvo de muitos estudos e atualmente é vista como uma dimensão de grande impacto, podendo potenciar o desenvolvimento de consequências ao longo da vida. Este estudo teve como objetivo caracterizar os indivíduos ao nível da Vinculação Amorosa, do Ajustamento Diádico e do Funcionamento Sexual ao nível da Violência nas Relações de Intimidade.N/

Análise dinâmica da dependência e volatilidade dos preços spot das commodities

Mestrado em EconomiaNos últimos anos, os Mercados spot das commodities têm sofrido um processo de reestruturação em que se procura promover a competitividade. O aumento desta implica o surgimento de novas opções de negócio, surgindo diversos modelos de mercado, assentes em diferentes mecanismos de negociação. Novas regras ditam novos comportamentos de preços, obrigando as entidades dos mercados spot e dos mercados de Derivados de Commodities a um esforço de adaptação. A análise do preço no mercado spot, da sua evolução e da sua volatilidade, torna-se um factor chave nas tomadas de decisão de todos os stakeholders e shareholders que actuam nestes mercados. Este trabalho tem como objectivo geral tirar partido das potencialidades dos modelos dinâmicos de avaliação da volatilidade e dependência de preços no mercado spot das commodities na linha de continuidade dos estudos de L’H’égaret et al (2004) e Chemarin et al (2008). Utilizando os dados de preços do brent, gás, fuel e carvão relativos ao período compreendido entre Janeiro de 2002 e Dezembro de 2005 testa-se, com recurso a modelos econométricos, a causalidade e relações de equilíbrio entre os preços spot das commodities, tendo em conta a existência de possíveis repercussões cruzadas entre o mercado spot do brent, do carvão, do fuel e do gás natural. Os resultados permitiram validar as hipóteses que admitiam: a existência de uma relação de dependência directa entre os preços spot do brent e os preços spot do fuel, em que na relação de longo prazo são os preços do Brent que se movimentam para restabelecer o equilíbrio; a existência de uma relação de dependência directa entre os preços spot do brent e os preços spot do gás em que na relação de longo-prazo estabelecida entre os preços spot do brent e os preços do gás são os preços do gás que se movimentam para restabelecer o equilíbrio. Os mesmos resultados não permitiram, contudo, validar as hipóteses em que se admitia a existência de uma relação de causalidade e de cointegração entre o preço do brent e o preço do carvão e ainda entre o preço de electricidade Omel e o preço das commodities. ABSTRACT: In recent years, the commodities spot markets have experienced a restructuring process, which seeks to promote competitiveness. The competitiveness increase implies the emergence of new business options, and the emergence of several models of emerging market based on different mechanisms of negotiation. New rules dictate new price behavior, forcing the spot markets and Derivatives Commodities markets entities to an effort of adaptation. The analysis of spot market price, its development and its volatility, becomes a key factor in decision-making of all stakeholders and shareholders acting in these markets. This work aims to take advantage of the general potential of dynamic models for assessing the volatility and dependence on spot market prices of commodities at the continuation of studies of Hégaret et al (2004) and Chemarin et al (2008). Using data from the Brent, gas, fuel and coal prices for the period between January 2002 and December 2005, it was tested, using econometric models, the causal links and balance between the spot prices of commodities, taking in account the existence of possible cross-effects between the spot market of Brent, coal, fuel and natural gas. The results validate the assumptions that admitted: (1) the existence of a relationship of direct dependence between the spot prices of Brent and spot prices of fuel, where in the long-term relationship are the Brent prices which move to restore the balance, (2) the existence of a relationship of direct dependence between the Brent spot prices and gas spot prices which, in the long-term relationship between Brent spot prices and gas prices are the prices of gas which move to restore the balance. However, the same results did not validate the assumptions on which it is admitted the existence of a causal and cointegrating relationship between the price of Brent and the price of coal, and even, between the Spanish spot price of electricity and the commodities price

Biocides in food packaging: safety concerns and migration insights

Introduction: Context: Biocides such as BIT (1,2-Benzisothiazolin-3-one), CMIT (Chloromethylisothiazolinone), and MIT (Methylisothiazolinone) are commonly used in food packaging to preserve materials and ensure safety due to their antimicrobial properties. Problem: The potential migration of these biocides into food contact materials (FCMs) raises concerns, especially since their behavior under various conditions is not well understood. Objective: This study aims to characterize the extraction behavior of BIT, CMIT, and MIT from Kraft paper, focusing on its potential migration when used in food packaging. Results & Conclusions: The extraction of biocides from food packaging materials is influenced by the solvent type, temperature, and biocide properties (e.g., log Kow). BIT and CMIT showed higher solubility and extraction in ethanol, while MIT has a stronger affinity for water, reducing its extraction in ethanol. The complex interactions between temperature, solvent type, and the Kraft paper matrix affect biocide availability and migration patterns. Findings highlight the need for rigorous standards in food safety regarding biocide use in food packaging, emphasizing the need for further research of biocide behavior migration in various matrices.info:eu-repo/semantics/publishedVersio