Browsing by Issue Date, starting with "2015-04"
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- 45Ti - Titanium: from cyclotron production to potential applications evaluationPublication . Costa, Pedro; Metello, Luís F.; Cunha, Lídia; Lass, Piotr; Currie, Geoff; Johnson, Richard R.; Gelbart, W.; Obermair, J.; Artner, Christoph; Alves, Francisco; Naia, M. DuarteIntroduction: Thousands of radioisotopes are known and virtually all may be artificially produced, however clinical applications of PET imaging are mainly based on 18F, 11C, 13N and 68Ga. This trend could change in the near future, since several groups worldwide are busy developing very promising new entities aiming to contribute for spreading the use and efficacy of clinical diagnostic using Nuclear Medicine imaging techniques. Our group is developing 45Ti-Titanium, assuming it as a potential candidate, since presenting interesting properties: physical half-life of 3.09h, together with relevant chemical properties, that enable radiolabelling with bifunctional chelates, ligands or could even be useful for studies concerning the distribution of new titanium-based chemotherapy drugs or titanium oxide nanoparticles. Considering that data characterizing excitation functions is necessary for radionuclide optimal production, this work aims to disseminate results regarding the determination of excitation function of 45Sc(p,n)45Ti reaction, studied as a potential route to produce 45Ti in low energy cyclotrons.
- Brazilian fruit pulps as functional foods and additives: Evaluation of bioactive compoundsPublication . Paz, Mário; Gúllon, Patricia; Barroso, M. Fátima; Carvalho, Ana P.; Domingues, Valentina F.; Gomes, Ana M.; Becker, Helena; Longhinotti, Elisane; Delerue-Matos, CristinaEight tropical fruit pulps from Brazil were simultaneously characterised in terms of their antioxidant and antimicrobial properties. Antioxidant activity was screened by DPPH radical scavenging activity (126–3987 mg TE/100 g DW) and ferric reduction activity power (368–20819 mg AAE/100 g DW), and complemented with total phenolic content (329–12466 mg GAE/100 g DW) and total flavonoid content measurements (46–672 mg EE /100 g DW), whereas antimicrobial activity was tested against the most frequently found food pathogens. Acerola and açaí presented the highest values for the antioxidant-related measurements. Direct correlations between these measurements could be observed for some of the fruits. Tamarind exhibited the broadest antimicrobial potential, having revealed growth inhibition of Pseudomonas aeruginosa. Escherichia coli, Listeria monocytogenes, Salmonella sp. and Staphylococcus aureus. Açaí and tamarind extracts presented an inverse relationship between antibacterial and antioxidant activities, and therefore, the antibacterial activity cannot be attributed (only) to phenolic compounds.
- Reliable link quality estimation in low-power wireless networks and its impact on tree-routingPublication . Baccour, Nouha; Koubâa, Anis; Youssef, Habib; Alves, MárioRadio link quality estimation is essential for protocols and mechanisms such as routing, mobility management and localization, particularly for low-power wireless networks such as wireless sensor networks. Commodity Link Quality Estimators (LQEs), e.g. PRR, RNP, ETX, four-bit and RSSI, can only provide a partial characterization of links as they ignore several link properties such as channel quality and stability. In this paper, we propose F-LQE (Fuzzy Link Quality Estimator, a holistic metric that estimates link quality on the basis of four link quality properties—packet delivery, asymmetry, stability, and channel quality—that are expressed and combined using Fuzzy Logic. We demonstrate through an extensive experimental analysis that F-LQE is more reliable than existing estimators (e.g., PRR, WMEWMA, ETX, RNP, and four-bit) as it provides a finer grain link classification. It is also more stable as it has lower coefficient of variation of link estimates. Importantly, we evaluate the impact of F-LQE on the performance of tree routing, specifically the CTP (Collection Tree Protocol). For this purpose, we adapted F-LQE to build a new routing metric for CTP, which we dubbed as F-LQE/RM. Extensive experimental results obtained with state-of-the-art widely used test-beds show that F-LQE/RM improves significantly CTP routing performance over four-bit (the default LQE of CTP) and ETX (another popular LQE). F-LQE/RM improves the end-to-end packet delivery by up to 16%, reduces the number of packet retransmissions by up to 32%, reduces the Hop count by up to 4%, and improves the topology stability by up to 47%.
- Inflammatory and Cardiometabolic Risk on Obesity: Role of Environmental XenoestrogensPublication . Teixeira, Diana; Pestana, Diogo; Santos, Cristina; Correia-Sá, Luísa; Marques, Cláudia; Norberto, Sónia; Meireles, Manuela; Faria, Ana; Silva, Ricardo; Faria, Gil; Sá, Carla; Freitas, Paula; Taveira-Gomes, António; Domingues, Valentina; Delerue-Matos, Cristina; Calhau, Conceição; Monteiro, RosárioContext: Some chemicals used in consumer products or manufacturing (eg, plastics, pesticides) have estrogenic activities; these xenoestrogens (XEs) may affect immune responses and have recently emerged as a new risk factors for obesity and cardiovascular disease. However, the extent and impact on health of chronic exposure of the general population to XEs are still unknown. Objective: The objective of the study was to investigate the levels of XEs in plasma and adipose tissue (AT) depots in a sample of pre- and postmenopausal obese women undergoing bariatric surgery and their cardiometabolic impact in an obese state. Design and Participants: We evaluated XE levels in plasma and visceral and subcutaneous AT samples of Portuguese obese (body mass index ≥ 35 kg/m2) women undergoing bariatric surgery. Association with metabolic parameters and 10-year cardiovascular disease risk was assessed, according to menopausal status (73 pre- and 48 postmenopausal). Levels of XEs were determined by gas chromatography with electron-capture detection. Anthropometric and biochemical data were collected prior to surgery. Adipocyte size was determined on tissue sections obtained during surgery. Results: Our data show that XEs are pervasive in this obese population. Distribution of individual and concentration of total XEs differed between plasma, visceral AT, and subcutaneous AT, and the pattern of accumulation was different between pre- and postmenopausal women. Significant associations between XE levels and metabolic and inflammatory parameters were found. In premenopausal women, XEs in plasma seem to be a predictor of 10-year cardiovascular disease risk. Conclusions: Our findings point toward a different distribution of XE between plasma and AT in pre- and postmenopausal women, and reveal the association between XEs on the development of metabolic abnormalities in obese premenopausal women
- The use of radiolabeled nanoparticles for biomedical imagingPublication . Costa, Pedro; Metello, Luís F.; Alves, Francisco; Naia, M. DuarteIntroduction: In the last years, the practice of medicine is being changing with a special emphasis on the application of technological innovations where medical imaging modalities play an important role. Between several imaging modalities, Molecular Imaging (that is essentially based on Nuclear Medicine) is one of the most interesting solutions. On the other hand, assuming that nanoparticles are being studied as drug delivery systems, its application as vectors for radionuclide-based imaging is in a clear growing.
- Analysis of Natural and Artificial Phenomena Using Signal Processing and Fractional CalculusPublication . Machado, J. A. Tenreiro; Lopes, António M.In this paper we study several natural and man-made complex phenomena in the perspective of dynamical systems. For each class of phenomena, the system outputs are time-series records obtained in identical conditions. The time-series are viewed as manifestations of the system behavior and are processed for analyzing the system dynamics. First, we use the Fourier transform to process the data and we approximate the amplitude spectra by means of power law functions. We interpret the power law parameters as a phenomenological signature of the system dynamics. Second, we adopt the techniques of non-hierarchical clustering and multidimensional scaling to visualize hidden relationships between the complex phenomena. Third, we propose a vector field based analogy to interpret the patterns unveiled by the PL parameters.
- Formar para a empatia: estudo transversal nas tecnologias da saúdePublication . Dores, Artemisa; Salgado, Ana; Magalhães, Andreia; Martins, Helena; Lopes, Paula; Carvalho, IreneA importância da empatia no contexto da saúde é amplamente aceite. Muita da investigação nesta área tem sido realizada na área da Medicina e os resultados são controversos. Alguns dos estudos concluem que a empatia tende a declinar durante a formação médica, enquanto outros, mais recentemente, sugerem que esta permanece igual ou chega mesmo a aumentar durante a formação. Contudo, pouco se sabe sobre a empatia em estudantes de Tecnologias da Saúde. O objetivo deste estudo transversal é comparar a empatia dos estudantes de diferentes anos e em diferentes cursos de Tecnologias da Saúde. Uma amostra de 140 estudantes, do 1.º e 3.º anos de Terapia da Fala.
- Physical therapy with drug treatment in bell palsy: a focused reviewPublication . Ferreira, M.; Marques, E. E.; Duarte, J. A; Santos, Paula ClaraThe physical therapy (PT) associated with standard drug treatment (SDT) in Bell palsy has never been investigated. Randomized controlled trials or quasirandomized controlled trials have compared facial PT (except treatments such as acupuncture and osteopathic) combined with SDT against a control group with SDT alone. Participants included those older than 15 yrs with a clinical diagnosis of Bell palsy, and the primary outcome measure was motor function recovery by the House-Brackmann scale. The methodologic quality of each study was also independently assessed by two reviewers using the PEDro scale. Four studies met the inclusion criteria. Three trials indicate that PT in association with SDT supports higher motor function recovery than SDT alone between 15 days and 1 yr of follow-up. On the other hand, one trial showed that electrical stimulation added to conventional PT with SDT did not influence treatment outcomes. The present review suggests that the current practice of Bell palsy treatment by PT associated with SDT seems to have a positive effect on grade and time recovery compared with SDT alone. However, there is very little quality evidence from randomized controlled trials, and such evidence is insufficient to decide whether combined treatment is beneficial in the management of Bell palsy.
- Effects of a home-based exercise program in body composition, abdominal fat and lipid profile in patients with coronary artery diseasePublication . Pinto, Joana; Noites, Andreia; Freitas, Carla Patrícia; Melo, Cristina; Albuquerque, Aníbal; Teixeira, MadalenaCoronary artery disease and aging seems to be associated with a sedentary lifestyle, contributing to increased abdominal fat and consequently metabolic complications. The exercise can break this cycle by stimulating lipolysis and the use of fatty acids. In Europe there is still a lack of cardiac rehabilitation programmes in hospitals, therefore, this study aims to demonstrate the advantages of implementing home-based exercise programmes, as well as, their effects on cardiovascular prevention. This study analyzed the effects of a home-based exercise programme, in patients with coronary artery disease (myocardial infarction for 1 year), in body composition, abdominal fat, lipid profile. An ongoing randomized controlled trial with a sample of 20 participants were randomly allocated to intervention (n = 10) and control groups (n = 10). Intervention group performed a specific exercise programme during 8 weeks, consisting of ten home based exercises taking into account flexibility, muscle endurance and strength as well as cardiovascular endurance. Skinfolds thickness were measure to calculate the percentage of total fat: Skinfolds used were suprailiac, abdominal horizontal and vertical. Body mass index calculation and blood tests for lipidic profile were performed. After eight weeks the intervention group decreased significantly the percentage of total fat (p < 0.05), the suprailiac skinfold (p < 0.05), the abdominal horizontal and vertical skinfold (p < 0.05) when compared with control group. In the intervention group it was observed after 8 weeks a significant decrease in body mass index, LDL-cholesterol and triglycerides. Home-based exercise programme influenced body composition, abdominal fat and lipid profile. These results highlight the importance of implementing home based exercises that are easy and cheap to implement in cardiac patients, in order to promote health and reduce cardiovascular risk factors.
- A potentiometric magnetic immunoassay for rapid detection of Salmonella typhimuriumPublication . Silva, Nádia F. D.; Magalhães, Júlia M. C. S.; Oliva-Teles, Teresa; Delerue-Matos, CristinaPotentiometric detection with homemade polymeric membrane microelectrodes was coupled to a magnetic sandwich immunoassay for Salmonella typhimurium determination. Cadmium and sodium ion selective electrodes were used respectively as indicator and pseudo-reference electrodes and were prepared in pipette tips to allow potentiometric measurements in microliter sample volumes. In the proposed method, the concentration of S. typhimurium was proportional to the amount of cadmium released upon dissolution of a CdS nanoparticle labeled to the secondary detection antibody. The limit of detection was 2 cells per 100 μL. The immunomagnetic assay with potentiometric detection is suitable for sensitive and rapid (average total time per assay of 75 minutes) detection of S. typhimurium in milk samples. The proposed method is easy to perform, safe, sensitive, and low cost and has potential for in situ analysis.