A emergência dos clusters no âmbito do QREN: análise dos clusters reconhecidos

O objetivo do presente trabalho é analisar os clusters reconhecidos pelo Programa Operacional Fatores de Competitividade (COMPETE) no âmbito do Quadro de Referência Estratégica Nacional (QREN), para o período 2007-13 enquanto sistemas que estimulam a interação e as sinergias entre os seus elementos, promovendo ganhos de produtividade e de competitividade. Pretende-se assim estudar os oito clusters reconhecidos pelo COMPETE, nomeadamente: o Cluster das Empresas do Mobiliário de Portugal, o Cluster Agro-Industrial do Centro, o Cluster das Indústrias Criativas da Região Norte, o Cluster do Habitat Sustentável, o Cluster do Conhecimento da Economia e do Mar, o Cluster da Pedra Natural, o Cluster Agro-Industrial do Ribatejo e, por último, o Cluster Dos Vinhos da Região Demarcada do Douro. Para a identificação dos clusters, a maioria dos estudos baseiam-se em análises de indicadores de concentração geográfica. Todavia, estas abordagens negligenciam aspetos fundamentais do conceito de cluster como a interação entre os agentes. Assim, neste estudo para analisar se os oito clusters funcionam e assumem as características de cluster, utilizaram-se por um lado os indicadores que constituem medidas de concentração geográfica e, simultaneamente, foi realizado um questionário aos clusters reconhecidos para se avaliar a densidade da rede e apoio das instituições ao desenvolvimento dos clusters, as ligações do cluster com as diversas atividades e por último a relação de cooperação e interação dos clusters com uma diversificada rede de instituições. Constatou-se através da aplicação metodológica que os resultados obtidos, apesar de assumirem valores que possam indicar um grau de especialização/concentração nas regiões em estudo, comparativamente a Portugal não são suficientemente significantes. Da análise dos indicadores de concentração geográfica conclui-se que apenas dois dos clusters reconhecidos apresentam resultados com maior concentração do que a média nacional, indiciando que se assumem como cluster. Da análise do questionário os resultados evidenciam também que apenas dois dos clusters reconhecidos apresentam ligações de interação/cooperação mais significativas relativamente aos outros clusters analisados. Conclui-se ainda, a partir das análises realizadas, que apenas um cluster está a funcionar na sua plenitude enquanto cluster, só este cumpre com as duas condições, ou seja, evidencia valores significantes na análise dos indicadores de concentração geográfica e evidencia ligações significativas de interação/cooperação. Assim, conclui-se que apenas um dos clusters reconhecidos se prefigura como cluster e atua como tal

Extrusion compounding of polyethylene with blowing agent

Cellular plastics are very attractive for the production of lightweight, structural and/or large dimension parts, e.g., boats, floaters, decks, etc. For their production, polymers and chemical blowing agents are either mixed or compounded prior to processing by injection or rotational moulding. It is essential to ensure good dispersion of the blowing agent in the polymeric matrix, and prevent its activation from occurring during compounding, i.e., an optimal processing window must be used. The aim of this work is to produce medium density polyethylene with Azodicarbonamide (MDPE/ADCA) masterbatches in pellet form for further processing by rotational moulding. For that purpose, a set of experimental procedures was conducted to evaluate the correct processing window without premature expansion during extrusion. Upon melt compounding of the masterbatch in pellets of different sizes, foamed parts were produced and characterized in terms of visual aspect, expansion ability and morphology.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska Curie grant agreement No. 734205 – H2020-MSCA-RISE-201

Quantitative studies on the enzymatic hydrolysis of milk proteins brought about by cardosins precipitated by ammonium sulfate

Hydrolysis of whey proteins may produce peptide mixtures with better functional properties than the original protein mixture, viz. higher solubilites and lower allergenic effects. Cynara cardunculus is a wild plant that possesses (aspartic) proteases in its flower cells; those enzymes exhibit general proteolytic and specific milk clotting activities, which are rather useful in traditional cheesemaking. This study was thus aimed at characterizing the enzymatic action of crude extracts of said plant after preliminary purification by salting out with ammonium sulfate at two different concentration levels, viz. 30% and 70% saturation. The coagulant activity on milk, and the proteolytic activity using casein and azocasein as substrates, of the crude extract and of each precipitated fraction were measured at 37°C and pH 5.2. The profile of hydrolysis of the major whey proteins, i.e. α-lactalbumin (α-La), β-lactoglobulin (β-Lg) and bovine serum albumin (BSA) was characterized by gel permeation chromatography and polyacrylamide gel electrophoresis (PAGE) in the presence of sodium dodecyl sulfate. The 30% and 70% saturation fractions exhibited lower coagulant and proteolytic specific activities than the crude extract. However, the relative ratio of coagulant to proteolytic activity, which is a useful indicator of appropriateness for cheesemaking, was higher for the partially purified fractions. The extents of hydrolysis of whey proteins brought about by the partially purified extracts were above those by their crude counterpart, but qualitative hydrolysis patterns were essentially identical to each other; by 24 h, α-La was substantially depleted, whereas β-Lg was very poorly hydrolyzed and BSA was only slightly hydrolyzed. The native proteins were converted to lower and lower molecular weight peptides

Identification and characterisation of xylanolytic yeasts isolated from decaying wood and sugarcane bagasse in Brazil

In this study, yeasts associated with lignocellulosic materials in Brazil, including decaying wood and sugarcane bagasse, were isolated, and their ability to produce xylanolytic enzymes was investigated. A total of 358 yeast isolates were obtained, with 198 strains isolated from decaying wood and 160 strains isolated from decaying sugarcane bagasse samples. Seventy-five isolates possessed xylanase activity in solid medium and were identified as belonging to nine species: Candida intermedia, C. tropicalis, Meyerozyma guilliermondii, Scheffersomyces shehatae, Sugiyamaella smithiae, Cryptococcus diffluens, Cr. heveanensis, Cr. laurentii and Trichosporon mycotoxinivorans. Twenty-one isolates were further screened for total xylanase activity in liquid medium with xylan, and five xylanolytic yeasts were selected for further characterization, which included quantitative analysis of growth in xylan and xylose and xylanase and ß-d-xylosidase activities. The yeasts showing the highest growth rate and cell density in xylan, Cr. laurentii UFMG-HB-48, Su. smithiae UFMG-HM-80.1 and Sc. shehatae UFMG-HM-9.1a, were, simultaneously, those exhibiting higher xylanase activity. Xylan induced the highest level of (extracellular) xylanase activity in Cr. laurentii UFMG-HB-48 and the highest level of (intracellular, extracellular and membrane-associated) ß-d-xylosidase activity in Su. smithiae UFMG-HM-80.1. Also, significant ß-d-xylosidase levels were detected in xylan-induced cultures of Cr. laurentii UFMG-HB-48 and Sc. shehatae UFMG-HM-9.1a, mainly in extracellular and intracellular spaces, respectively. Under xylose induction, Cr. laurentii UFMG-HB-48 showed the highest intracellular ß-d-xylosidase activity among all the yeast tested. C. tropicalis UFMG-HB 93a showed its higher (intracellular) ß-d-xylosidase activity under xylose induction and higher at 30 °C than at 50 °C. This study revealed different xylanolytic abilities and strategies in yeasts to metabolise xylan and/or its hydrolysis products (xylo-oligosaccharides and xylose). Xylanolytic yeasts are able to secrete xylanolytic enzymes mainly when induced by xylan and present different strategies (intra- and/or extracellular hydrolysis) for the metabolism of xylo-oligosaccharides. Some of the unique xylanolytic traits identified here should be further explored for their applicability in specific biotechnological processes

Bioactive properties of Mentha spicata L. infusions: a comparison between standard and reserve lots

Mentha spicata L., commonly known as spearmint and belonging to the Lamiaceae family, is widely used as infusion due to its exquisite and outstanding flavour [1]. This medicinal and aromatic plant is also known for its antioxidant properties due to naturally occurring active compounds, such as phenolic compounds including flavonoids. [2] Recently, with the increased consumption of herbal infusions, several novel products are emerging and different lots with distinct compositions of the same plant are available for herbal infusions preparation [3]. As an outstanding example, the standard lots have evolved to "reserve lots", which are prepared from the apical leaves of the plant, presenting different compositions and sensorial characteristics. In the present study, the aim was to evaluate and compare the antioxidant activity as well as the bioactive compounds (phenolics and flavonoids) content of M. spicatae infusions prepared from standard and reserve lots, in order to understand the potential differences between both batches. The antioxidant activity was assessed by different assays (free radicals scavenging activity, reducing power, and lipid peroxidation inhibition), whereas total phenolics and flavonoids were estimated by colorimetric assays. The best results of antioxidant activity were achieved with the reserve lot that presented the lowest EC50o values in all the assays performed (152 to 336 μg/mL) in comparison to the standard lot (173 to 546 μg/mL). Both the infusions revealed higher potential in lipid peroxidation inhibition, in concentrations of 173 (standard tot) and 152 μg/mL (reserve lot), followed by reducing power (301 and 198 μg/mL, respectively) and free radicals scavenging activity (546 and 336 μg/mL). As expected from the antioxidant assays results, the amounts of total phenolics and flavonoids were higher in the reserve lot (2. 86 and 0. 378 mg GAE/mL, respectively) when compared to the standard lot (1. 83 and 0.268 mg GAE/mL), which is in accordance with the well-known bioactivity of these compounds. Thus, in our perspective, this study represents a major contribution of scientific information, allowing the consumer to understand the increased benefits of these new emerging tea products

An Insight into the Release Kinetics

The authors acknowledge the financial support from Fundação para a Ciência e a Tecnologia (FCT-MEC), Portugal, through the dedicated project (PTDC/EDM-EDM/30828/2017) (BeLive) Publisher Copyright: © 2023 by the authors.This work explores the unique features of magnetic-responsive hydrogels to obtain liposomal hydrogel delivery platforms capable of precise magnetically modulated drug release based on the mechanical responses of these hydrogels when exposed to an external magnetic field. Magnetic-responsive liposomal hydrogel delivery systems were prepared by encapsulation of 1,2-dipalmitoyl-sn-glycero-3-phosphocoline (DPPC) multilayered vesicles (MLVs) loaded with ferulic acid (FA), i.e., DPPC:FA liposomes, into gelatin hydrogel membranes containing dispersed iron oxide nanoparticles (MNPs), i.e., magnetic-responsive gelatin. The FA release mechanisms and kinetics from magnetic-responsive liposomal gelatin were studied and compared with those obtained with conventional drug delivery systems, e.g., free liposomal suspensions and hydrogel matrices, to access the effect of liposome entrapment and magnetic field on FA delivery. FA release from liposomal gelatin membranes was well described by the Korsmeyer–Peppas model, indicating that FA release occurred under a controlled diffusional regime, with or without magnetic stimulation. DPPC:FA liposomal gelatin systems provided smoother controlled FA release, relative to that obtained with the liposome suspensions and with the hydrogel platforms, suggesting the promising application of liposomal hydrogel systems in longer-term therapeutics. The magnetic field, with low intensity (0.08 T), was found to stimulate the FA release from magnetic-responsive liposomal gelatin systems, increasing the release rates while shifting the FA release to a quasi-Fickian mechanism. The magnetic-responsive liposomal hydrogels developed in this work offer the possibility to magnetically activate drug release from these liposomal platforms based on a non-thermal related delivery strategy, paving the way for the development of novel and more efficient applications of MLVs and liposomal delivery systems in biomedicine.publishersversionpublishe

Psychosocial and psychopathological predictors of HIV-risk injecting behavior among drug users in Portugal

Abstract Despite the introduction of needle and syringe exchange programs (NSPs), sharing of syringes and other materials remains common among injection drug users (IDUs) worldwide. For this reason, IDUs are at high-risk of HIV transmission. This paper studies the psychosocial and psychopathological determinants of sharing among IDUs. Understanding the relationship between psychological morbidity, HIV knowledge, HIV risk perception, and sharing behaviors is important to developing campaigns to curb sharing among IDUs. We recruited 120 male (76.7%) and female (23.3%) IDUs at a public outpatient treatment service in northern Portugal whose age average was 34 (sd=7.56). They were characterized for sociodemographic, clinical, and behavioral variables, as well as for knowledge on HIV transmission and prevention, HIV risk perception, and psychopathological symptoms. Almost all patients (95.8%) were tested for HIV and 31.7% were HIV positive. Half of them had a chronic disease (50.8%) and declared to engage in sharing (51.7%). Most had accurate knowledge of HIV transmission and prevention. A great majority deemed HIV risk to be high in their communities (80.8%) but deemed their personal risk to be zero or low (72.5%). Statistical analysis showed that sociodemographic variables (female sex, lower education, living alone) and psychopathological symptoms (obsession-compulsion and somatization) predict sharing. We conclude that the development and implementation of campaigns to reduce sharing among IDUs should focus more on women, IDUs living alone, as well as early assessment and intervention on psychopathological disorders.   Keywords: HIV-risk injecting behavior, HIV knowledge, HIV risk perception, psychopathology, injection drug users (IDUs), Portuga

Evolutionary patterns and development prospects for e-government: a Delphi-based approach to perceptions of the administrative agent

Information technology is an open door for governments to service citizens in a more timely, cost-efficient and effective manner. Even considering citizen resistance, cultural adversity or changes in the economic agents’ relationship, few would contest that concern over the state of electronic government (e-government) has increased over the years. This concern has been responsible for the emergence of a wide range of new initiatives devoted to development of the information and knowledge society, which occupies a central place in government policies and planning strategies worldwide. In this paper, we aim to analyze the evolutionary patterns of e-government in Portugal and, based on an application of the Delphi technique, provide development prospects considering the perceptions of a panel of administrative agents. Despite the low use of e-government services, our study demonstrates that the administrative agent expresses overall satisfaction with its use. Additionally, the high level of modernization allows us to forecast the increased use of information and communication technologies in terms of e-government services

Escondido pelo cabelo - um caso de puberdade precoce

McCune-Albright syndrome (MAS) is one of the conditions causing precocious gonadotropin-independent puberty. It is a rare disease, characterized by two of the three following features: precocious puberty, polyostotic fibrous dysplasia (PFD), and café au lait (CAL) skin spots. Herein is presented the case of a girl with pubarche, acne, and transient thelarche since the age of three and menarche since the age of six years old. Besides transitory follicular cysts and advanced bone age, no other changes were found. Diagnosis was only established after brain magnetic resonance imaging showed fibrous dysplasia involving left craniofacial bones. The girl’s parents later mentioned that she had multiple café au lait skin spots on the scalp since birth, disclosing how the key diagnostic sign had been covered by the child’s hair. MAS is a rare disorder and diagnosis depends on a high index of suspicion. CAL skin spots are generally the first manifestation, but can easily go unnoticed. Additionally, PFD may only affect some bones, like craniofacial.info:eu-repo/semantics/publishedVersio