Time filter

Source Type

Lisbon, Portugal

Martins R.B.,Piaget Institute | Martins R.B.,Piaget Alimentar Unipessoal Lda | Hogg T.,Catholic University of Portugal | Otero J.G.,University of Santiago de Compostela
Food Control | Year: 2012

The aim of this study was to assess the food hygiene knowledge of professional food handlers from an institutional catering company which manufactures and distributes meals to the canteens of schools, kindergartens and nursing homes in Portugal. A total of 101 food handlers from 18 geographically distributed business units were assessed. Data collection employed a previously used, multiple-choice questionnaire, aimed at exploring the food safety knowledge and practices of individual respondents. The average score of questions answered correctly was 13 out of 23 (56.5%) with a standard deviation (SD) of 3.22. However, the percentage of correct answers varies with the issues questioned, being significantly lower on issues such as temperature control (p < 0.001) and sources of contamination/high-risk foods (p < 0.001). The level of knowledge was influenced by the level of formal education (p = 0.025) of respondents. The results reinforce the importance of conducting a preliminary assessment of training needs and evaluating the effectiveness of training. © 2011 Elsevier Ltd. Source

Alves M.M.,Piaget Institute
Clinical hemorheology and microcirculation | Year: 2013

The aim of this work was to investigate the rheological behaviour of human blood, in a controlled stress rheometer, using different cone-plate and parallel plate geometries. Steady-shear (flow curves and kinetics) and oscillatory (strain, frequency and time sweeps) tests were performed at 37°C. The results demonstrated that rheological data are significantly influenced by the measuring geometry and the rheological parameters obtained from rheological models must be analysed with great caution. The Cross model provided a better fit of the flow curves and the Power Law model gave a better concordance between the rheological parameters obtained with the different measuring systems. The oscillatory measurements demonstrated a linear viscoelastic behaviour below a critical frequency and the Friedrich-Braun model described well the frequency sweeps experimental data in that region. The correlation between steady-shear and oscillatory properties (Cox-Merz rule) suggests that the two methods can be complementary and may give important information on red blood cells aggregation and deformability. Results from oscillatory time sweeps confirm a blood aggregation process in two steps. Source

Rocha-Santos T.,University of Aveiro | Rocha-Santos T.,Piaget Institute | Duarte A.C.,University of Aveiro
TrAC - Trends in Analytical Chemistry | Year: 2015

Plastics can be found in food packaging, shopping bags, and household items, such as toothbrushes and pens, and facial cleansers. Due to the high disposability and low recovery of discharged materials, plastics materials have become debris accumulating in the environment. Microplastics have a dimension <5 mm and possess physico-chemical properties (e.g., size, density, color and chemical composition) that are key contributors to their bioavailability to organisms. This review addresses the analytical approaches to characterization and quantification of microplastics in the environment and discusses recent studies on their occurrence, fate, and behavior. This critical overview includes a general assessment of sampling and sample handling, and compares methods for morphological and physical classification, and methodologies for chemical characterization and quantification of the microplastics. Finally, this review addresses the advantages and the disadvantages of these techniques, and comments on future applications and potential research interest within this field. © 2014 Elsevier B.V. Source

Justino C.I.L.,University of Aveiro | Rocha-Santos T.A.P.,University of Aveiro | Rocha-Santos T.A.P.,Piaget Institute | Duarte A.C.,University of Aveiro
TrAC - Trends in Analytical Chemistry | Year: 2013

Healthcare is the combination of diagnosis, treatment, and prevention of any disease in humans, which is being constantly improved with efficient, rapid, useful point-of-care (POC) technologies as molecular diagnostic devices. In this way, biosensors based on carbon nanotubes (CNTs) have been developed and used in recent years, due to their high sensitivity, specificity, rapidity in analysis, low cost, and ease of use. This review provides an up-to-date overview of the analytical performance of emerging technologies in the form of POC biosensors based on CNTs, which can be implemented in the clinical area, mainly for the detection of cancer biomarkers and glucose (analytes associated with two of the most common diseases in developed world, cancer and diabetes).This review also addresses the synthesis, the properties and the areas of application of CNTs and the characteristics and the clinical importance of POC testing. © 2013 Elsevier Ltd. Source

Justino C.I.L.,University of Aveiro | Rocha-Santos T.A.,University of Aveiro | Rocha-Santos T.A.,Piaget Institute | Duarte A.C.,University of Aveiro
TrAC - Trends in Analytical Chemistry | Year: 2011

Efficient sampling and characterization of nanoparticles have been challenging tasks in environmental research due to the limitations of regular analytical techniques (e.g., dynamic light scattering, and nuclear magnetic resonance and UV-Vis spectroscopies) - especially the difficulties in their application to in situ and real-time monitoring, which are intrinsically related to the nanometer-size range.This critical overview aims at characterizing recent instrumental techniques (e.g., hygroscopic tandem-differential mobility analysis, thermal desorption-gas chromatography-mass spectrometry, and time-of-flight secondary ion mass spectrometry) for sampling and characterization of individual nanoaerosols in terms of their general operation principles, analytical parameters, advantages and limitations. We also discuss classification of this instrumentation based on off-line and/or in situ methods, and on physical and chemical characterization of nanoaerosols. Further, we summarize recent air-quality studies aimed at understanding the physical and chemical behavior of aerosols in different environments. © 2011 Elsevier Ltd. Source

Discover hidden collaborations