Microscopia electrónica de transmissão: diagnosticar com controlo de qualidade

INTRODUÇÃO: A Microscopia Electrónica de Transmissão, como meio complementar de diagnóstico, necessita de estabelecer métodos de controlo de qualidade para cumprir exigências dos processos de certificação e/ou acreditação dos Serviços de Anatomia Patológica, contribuindo para a melhoria contínua dos procedimentos. OBJECTIVOS: Apresentar um método de controlo de qualidade em Microscopia Electrónica em meio hospitalar, através da definição de critérios de avaliação aplicados ao processamento, corte e coloração/contraste de semi-finos e ultra-finos. MATERIAL E MÉTODOS: O controlo de qualidade foi aplicado por médicos e técnicos a 35 casos (Abril-Dezembro de 2011). Atribuíram-se valores de 1-3 que qualitativamente corresponderam a avaliações de “Não Satisfaz” a “Muito Bom”. As classificações obtiveram-se partindo do valor máximo (3) descontando sucessivamente valores definidos atribuídos a artefactos segundo o impacto que estes apresentavam no estudo dos casos. RESULTADOS: Observaram-se artefactos de processamento em 14,3% das amostras, sendo o critério mais registado a “extracção de componentes tecidulares” (83,3%). Os cortes semi-finos obtiveram classificação “Muito Bom” em 91,4% dos casos. Dos artefactos registados, 52,4% relacionaram-se com a coloração. Os cortes ultra-finos registaram 90,0% de classificação “Muito Bom”. Do total de artefactos identificados, 67,8% corresponderam a estrias e artefactos de contraste. CONCLUSÕES: Através da detecção/registo dos artefactos mais frequentes foram implementadas alterações e desenvolvidos novos protocolos, justificando também a aquisição de novos materiais e equipamentos.O controlo de qualidade desenvolvido foi usado como indicador de qualidade da área de Microscopia Electrónica cumprindo os requisitos dos processos de certificação/acreditação

Transmesocolic hernia with sigmoid colon strangulation without surgical history: a series of two case reports.

The incidence of internal hernias is rare (0.2-0.9%). The prevalence of intestinal obstruction for an internal hernia is low (0.5-5%), however if strangulation is present the overall mortality is higher than 50%. There are multiple places where an internal hernia may be localized, with transmesenteric: transmesocolic (8%) and transomental (1-4%) as the rarest. We report a series of two cases (men with 40 years-old and women with 92 years old) of volvulus of colon sigmoid in a strangulated transverse and descendent transmesocolic hernia, with one case associated also to a transomental hernia. Both patients were submitted to a Hartmann procedure and on follow-up remained free of complains. In conclusion, transmesenteric internal hernia should be included as diagnosis hypothesis for intestinal occlusion and if the diagnosis is made, the patient should be submitted to emergency surgery due to high rates of complications, high morbidity and mortality.info:eu-repo/semantics/publishedVersio

Simple camera calibration for light measurements

The availability and decreasing prices of digital photographic cameras using megapixel sensors could point to its use as high quality light measuring devices if simple and effective calibration procedures could be put to work.This paper proposes such a system, using a common digital camera combined with low cost reference color charts. The procedure to obtain the response function of the camera, the production of the color chart and its calibration is presented.In this way, it is possible to obtain light measurements otherwise only possible with sophisticated and expensive equipments.The research work is being conducted with partial funding from FCT (Portuguese Foundation for Science and Technology)

Calibration of camera for light quality measurements of low-power lamps

Environmental concerns and power efficiency point to increased use of power efficient lamps. Different manufacturers and price targets produce a wide range of light outputs, varying in intensity and spectral distribution. This type of apparatus also presents a non-linear load to the electric power supply, introducing some problems that should be taken in consideration and corrected as much as possible. To be able to measure light quality, we propose a technique that uses a conventional digital photographic camera and a set of colour-reference reflective cards. By analysis of the obtained images, a colour quality index can be computed and used to compare different type of lamps. The calibration of the set-up is crucial for the approach and some problems need to be solved for the reliability of the method.This work is being conducted at Algoritmi Research Centre, University of Minho and sponsored by FCT- Fundação para a Ciência e Tecnologia, Portugal

Modelling the role of ground-true riparian vegetation for providing regulating services in a Mediterranean watershed

Intensive agricultural and industrial activities are often considered major sources of water contamination. Currently, riparian vegetation (RV) is increasingly being promoted as a solution to balance the potentially adverse effects that agriculture may have on water quality. Nonetheless, existing RV is often overlook in recent modelling efforts, failing to capture the current amount of ecosystem services provide. Here, we used the Soil and Water Assessment Tool ecohydrological model to simulate the influence of ground-true RV on i) nutrient (nitrate and total phosphorus) and sediment exports from agricultural areas and ii) its effect for in-stream concentrations. These results are further compared against a set of hypothetical scenarios of different RV widths and different land-uses. Our results point to a great relevance of existing RV in controlling in-stream concentration of sediments and nutrients where pressure from agriculture is highest, preventing them to surpass limits set in the EU Water Framework Directive. On the other hand, in areas with industry discharges, the role of RV is limited and model results suggest that restoring RV would have limited impacts. We illustrate how existing RV may already provide strong but not acknowledged water quality regulation services, how these services can differ substantially between nearby streams, and that effective strategies to improve water quality using RV must acknowledge existing patterns of vegetation, land use and contamination sources.info:eu-repo/semantics/publishedVersio