2,779 research outputs found
"O ensino das Ciências no 1º ciclo centrado no tp" impacte de um programa de formação contínua de professores
Estudo da influência da temperatura sobre a evolução de ácidos orgânicos fixos durante a fermentação de mostos da região de vinhos verdes
RNA interference therapeutics in organ transplantation:The dawn of a new era
RNA interference (RNAi) is a natural process through which double-stranded RNA molecules can silence the gene carrying the same code as the particular RNA of interest. In 2006, the discovery of RNAi was awarded the Nobel Prize in Medicine and its success has accumulated since. Gene silencing through RNAi has been used successfully in a broad range of diseases, and, more recently, this technique has gained interest in the field of organ transplantation. Here, genes related to ischemia-reperfusion injury (IRI) or graft rejection may be silenced to improve organ quality after transplantation. Several strategies have been used to deliver siRNA, and pretransplant machine perfusion presents a unique opportunity to deliver siRNA to the target organ during ex situ preservation. In this review, the potential of RNAi in the field of organ transplantation will be discussed. A brief overview on the discovery of RNAi, its mechanism, and limitations are included. In addition, studies using RNAi to target genes related to IRI in liver, kidney, lung, and heart transplantation are discussed
Antimicrobial activity of phenolic extracts of Eucalyptus globulus and Juglans regia against dairy industry pathogens
Book of Abstracts of CEB Annual Meeting 2017[Excerpt] Bovine mastitis (BM) is the most expensive pathology for dairy industry and Staphylococcus aureus is amongst the most prevalent causative agents of this disease. Nowadays, it is known that S. aureus contaminated milk can enter the dairy production chain and be the origin of food contamination. Due to the poor efficacy of antibiotics and to the ability to form biofilms evidenced by this pathogen, BM has become increasingly difficult to control and to eradicate. Phenolic plant extracts are nowadays being evaluated since they are a rich source of bioactive molecules. Thus, in this work the antimicrobial activity of E. globulus and J. regia alone and in combination against S. aureus BM isolates was evaluated and compared with penicillin G (Pen G), an antibiotic commonly used in the treatment of this pathology. The evaluation of the cytotoxic potential of both extracts was also performed. [...]info:eu-repo/semantics/publishedVersio
Análise experimental e analítica de chapas metálicas enformadas a frio para coberturas e fachadas
Nesta comunicação apresenta-se um estudo desenvolvido para analisar o comportamento de chapas metálicas enformadas a frio com secção trapezoidal destinadas à utilização em coberturas e fachadas. Este estudo tem uma vertente analítica e uma vertente experimental. Numa primeira fase, procura-se analisar as características e a capacidade
resistente de várias chapas metálicas trapezoidais e desenvolver uma análise paramétrica de forma a identificar quais os parâmetros geométricos mais relevantes no seu comportamento.
Numa segunda fase, realizam-se ensaios experimentais sobre provetes executados a partir de dois modelos de chapas trapezoidais fornecidos pela firma O Feliz, Metalomecânica, S.A. e analisam-se os resultados obtidos
Avaliação estrutural do aço rápido M3/2 sinterizado através da tecnologia DMLS
O estudo da sinterização do pó de aço rápido M3/2 pela tecnologia DMLS baseou-se na utilização de diferentes parâmetros de processo e na optimização da respectiva distribuição granulométrica e densidade aparente. O material foi sinterizado em linha, área e volume utilizando uma distância entre linhas de varrimento constante (0.30mm), três velocidades de varrimento do laser (50, 150, 250mm/s) e duas potências de laser (154 and 180W). O aço rápido M3/2 foi utilizado tal qual e com diferentes adições de uma fracção fina do mesmo material de modo a aumentar a densidade aparente
Outdoor play and interaction skills in early childhood education : approaching for measuring using social network analysis
Over the last decade, researches show evidences that the free play and the outdoor activities have positive impact
on children, namely on social skills’ development as cooperation. However, the study of children interaction,
especially when we want to identify and study a particular type of interaction, like cooperative interaction,
requires a reflexion about the most efficient tolls and methods that can be used. With this article we intend to
present a first reflective review of mathematical techniques and methods that can be potentially useful in the
study of cooperative interactions with children in outdoor free play. Considering the characteristics of outdoor
learning environments, which are based on freedom and free play exploitation of nature, the methods used in
studies of this nature in indoor environment, tend to be more controlled by adults and more spatially limited,
may not be the most effective. We intend to demonstrate that it is necessary to create a combination of
mathematical techniques and methods based on the social network analysis, given the specificity of the
educational outdoor environment or the space level and the dynamics of activities that there are usually
generated.info:eu-repo/semantics/publishedVersio
Alternative pathways to a sustainable future lead to contrasting biodiversity responses
Land-use change is currently the main driver of biodiversity loss. Projections of land-use change are often used to estimate potential impacts on biodiversity of future pathways of human development. However, such analyses frequently neglect that species can persist in human-modified habitats. Our aim was to estimate changes in biodiversity, considering affinities for multiple habitats, for three different land-use scenarios. Two scenarios focused on more sustainable trajectories of land-use change, based on either technological improvements (Pathway A) or societal changes (Pathway B), and the third reflected the historical or business-as-usual trends (Pathway 0). Using Portugal as a case study, we produced spatially-explicit projections of land-use change based on these pathways, and then we assessed the resulting changes in bird species richness and composition projected to occur by 2050 in each of the scenarios. By 2050, alpha and gamma diversity were projected to decrease, relative to 2010, in Pathway 0 and increase in Pathways A and B. However, different pathways favored different species groups, and presented strong regional differences. In the technological improvement pathway, loss of extensive agricultural areas led to an increase in both natural and extensive forest areas. In this pathway, forest species increase at the expense of farmland species, while in the societal change pathway the reverse occurs, as extensive agricultural areas were projected to increase. We show that while multiple positive pathways (A and B) for biodiversity can be envisioned, they will lead to differential impacts on biodiversity depending on the transformational changes in place and the regional socio-economic context. Our results suggest that considering compositional aspects of biodiversity can be critical in choosing the appropriate regional land-use policies
Biodegradation of bioaccessible textile azo dyes by Phanerochaete chrysosporium
Azo dyes are important chemical pollutants of industrial origin. Textile azo dyes with bioaccessible groups for
lignin degrading fungi, such as 2-methoxyphenol (guaiacol) and 2,6-dimethoxyphenol (syringol), were synthesised
using different aminobenzoic and aminosulphonic acids as diazo components. The inocula of the best biodegradation
assays were obtained from a pre-growth medium (PAM), containing one of the synthesised dyes. The results of the
dye biodegradation assays were evaluated every 7 days, by the decrease of the absorbance at the maximum
wavelength of the dye, by the decrease of the sucrose concentration in the culture medium and by the increase of the
biomass during the 28 days of assay. It was observed that the extent of dye biodegradation depended on the sucrose
concentration, on the degraded dye structure and, on the dye present in the PAM medium.Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI/BD/15878/98, PRAXIS XXI/BD/9120/96.Instituto de Biotecnologia e Química Fina (IBQF)
A bacteriophage-based platform for early diagnosis of Alzheimers disease
Book of Abstracts of CEB Annual Meeting 2017[Excerpt] Alzheimer’s disease (AD) is the most common neurodegenerative disease affecting a large proportion of the human population worldwide. One hallmark of AD is the increased deposition of plaques, which consist of amyloid-beta (AB) peptide, a key molecule to cause AD onset and progression. However, it is not AB immobilized in plaques, but in the still-soluble oligomeric/fibrillar form that impairs synaptic function and memory encoding. It is therefore important to develop tools that selectively target AB in oligomeric/fibrillar form, to diagnose and neutralize these detrimental AB-clusters during the early stages of the disease. Homing peptides that selectively recognize AB-oligomers and fibrils have been described: AB30-39, reactive for AB fibrils and AB33-42, reactive to fibrils and oligomers [1]. However, these peptides are unable to cross the blood-brain barrier (BBB) by themselves. To overcome this limitation, viruses became a very interesting tool given their versatility to be modified through genetic or chemical manipulation. Bacteriophages (phages), are viruses that only infect bacteria (a major advantage in terms of safety when therapeutic use in humans is envisaged). M13KE is one of the most widely used phage which has been reported as capable to cross the BBB [2]. [...]info:eu-repo/semantics/publishedVersio
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