3,454 research outputs found

    Evaluation of group work in the Chemistry and Biotechnology laboratory: Case study

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    Trabalho apresentado em CISPEE 2018, 27-29 de junho de 2018, Aveiro, PortugalN/

    Export and innovation in SMEs and large firms : the main determinants

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    O presente estudo faz a análise dos principais factores explicativos das exportações e da despesa em investigação e desenvolvimento (I&D) das PME´s e das grandes empresas a operar em Portugal, para o período 2004-2008. A partir de uma amostra constituída por 200 PME´s e por 30 grandes empresas exportadoras o estudo utiliza dados de painel e os estimadores de efeitos fixos e efeitos aleatórios para estimar os efeitos sobre as exportações e sobre a despesa em I&D. Em relação às exportações, o estudo conclui pelo efeito positivo do aumento da produtividade e da despesa em I&D tanto nas PME´s como nas grandes empresas e que as PME´s estrangeiras exportam mais que as PME´s nacionais. Quanto às determinantes da despesa em I&D o estudo conclui que o aumento dos capitais próprios e dos resultados líquidos tem um efeito positivo sobre as despesas em I&D nas grandes empresas ao passo que nas PME´s é o aumento das exportações que leva ao aumento das despesas em I&D, tendo o aumento dos resultados líquidos um efeito negativo

    Can growth of nannochloropsis oculata under modulated stress enhance its lipid-associated biological properties?

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    Nannochloropsis oculata is well-recognized as a potential microalgal source of valuable compounds such as polyunsaturated fatty acids, particularly, eicosapentaenoic acid (EPA). The content and profile of these lipids is highly dependent on the growth conditions and can, therefore, be tailored through modulation of the growth parameters, specifically, temperature. Moreover, biological activities are composition dependent. In the present work, lipid extracts obtained from N. oculata, grown under constant temperature and under modulated temperature stress (to increase EPA content; Str) were characterized by GC-FID and several bioactivities were evaluated, namely, antioxidant (L-ORACFL), cytotoxic (MTT), adipolytic, anti-hepatic lipid accumulation (steatosis), and anti-inflammatory properties. Both extracts exhibited antioxidant activity (c.a. 49 µmol Troloxequivalent/mgextract) and the absence of toxicity (up to 800 µg/mL) toward colon and hepatic cells, adipocytes, and macrophages. They also induced adipolysis and the inhibition of triglycerides hepatic accumulation, with a higher impact from Str. In addition, anti-inflammatory activity was observed in the lipopolysaccharide-induced inflammation of macrophages in the presence of either extract, since lower levels of pro-inflammatory interleukin-6 and interferon-β were obtained, specifically by Str. The results presented herein revealed that modulated temperature stress may enhance the health effects of N. oculata lipid extracts, which may be safely utilized to formulate novel food products.info:eu-repo/semantics/publishedVersio

    New garment proposal for prevention of spreading Gram-negative bacteria resistant to carbapenem antibiotic class under hospital settings

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    Sensitive skin diseases, including atopic dermatitis, skin inflammation and bedsores, leave patients vulnerable under hospital setting. It is important for the development of a hospital gown with ‘‘soft hand’’ properties and at the same time as a protector against nosocomial infections. Klebsiella pneumoniae has developed resistance to antibiotics in the carbapenem antibiotic class, known as carbapenem-resistant K. pneumoniae (CRKP). CRKP is resistant to nearly all antibiotics and can kill up to 50% of infected patients. This work consisted in the development of a washable recycled silk fibroin-based gown covalently linked with an amino acid L-Cysteine(L-Cys), focused on prevention of K. pneumoniae establishment, proliferation and spreading to community, for use under hospital settings. With the growing problem of resistance to antibiotics and few new therapies on the horizon, gowns adsorbed with L-Cys show to function as a barrier to the establishment and proliferation of microorganisms, providing user protection from infectious disease. This gown was knitted at a rectilinear needle loom with a Jersey knit structure. Then it was cross-linked with L-Cys, subjected to laundry, and subsequently characterized by energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, contact angle, free energy of adhesion, scanning electron microscopy and transmission electron microscopy. Results presented a bactericidal effect against K. pneumoniae of 94.92% after three rinses and 88.88% after five washing cycles, with the few adhered bacteria with an altered and compromised morphology.info:eu-repo/semantics/publishedVersio

    Analysis of the Cytisetea scopario-striati scrubs in the south-west-centre of the Iberian Peninsula

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    The statistical and phytosociological study of 255 relevés taken in the south-west of the Iberian Peninsula and made up of our own samples and previous publications reveals how close these relevés, previously ascribed to different syntaxa, really are. Our re-arrangement of the data leads us to propose for the territory the 15 associations already published and three new ones, namely: Genisto floridae-Adenocarpetum argyrophylli ass. nova hoc loco, Cytisetum bourgaei- eriocarpi nova, Lavandulo viridis-Cytisetum striati ass. nova hoc. loco. We also suggest a name correction, Adenocarpo anisochili-Cytisetum scoparii J.C. Costa et al. 2000 corr., and a status change, namely, Ulici latebracteati- Cytisetum striati (Costa et al. 2000) status novo

    Formulações micelares proteicas e respectivo método de produção

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    The present invention describes micellar protein formulations for the controlled release of active ingredients, and method for preparing the same. The invention describes a new micelle composition for use in pharmaceuticals, cosmetics and detergents. In particular, it describes micelle formation formulations that comprise: an aqueous phase containing a protein or a natural or synthetic peptide; a lipophilic phase containing a hydrophobic compound; an adjuvant dissolved in the aqueous phase to regulate the size and stability of the micelles; the size of the micelles varying from 30 to 5000 nm, preferably from 30 to 100 nm, wherein the micelles can be obtained by two different methods, namely using ultrasound or a high-pressure homogeniser. The preparation method involves two distinct phases: an aqueous phase and a lipophilic phase. The aqueous phase can be water or any buffer that is best suitable for a given use, such as an aqueous solution of bovine serum albumen (BSA); human serum albumen (HSA); silk fibroin or a polypeptide fibroin.A presente invenção descreve em formulações micelares proteicas para libertação controlada de agentes e respetivo método de produção. A invenção descreve numa nova composição de micelas para aplicações farmacêuticas, cosméticas e 0 o0 detergência. Nomeadamente, formulações para a formação de micelas que compreendem: · uma fase aquosa contendo uma proteína ou um péptido natural ou sintético; · uma fase lipofílica que compreende um composto hidrofóbico; · um agente adjuvante dissolvido na fase aquosa que regula o tamanho e estabilidade das micelas; em que os tamanhos das referidas micelas varia entre 30 a 5000 nm, de preferência de 30-100 nm, as referidas micelas podem ser obtidas a partir de duas metodologias diferentes, nomeadamente ultra-sons ou homogeneizador de alta pressão. O método de preparação envolve duas fases distintas: fase aquosa e fase lipofílica. A fase aquosa pode ser água ou qualquer tampão que mais se adeque para uma determinada aplicação, como por exemplo uma solução aquosa de albumina sérica bovina (BSA); albumina sérica humana (HSA); fibroína da seda ou de um polipéptido.Universidade do Minh

    Populational analysis of Saccharomyces cerevisiae strains from different appellations of origin and grape varieties by microsatellite analysis.

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    The objective of the present study was to evaluate populational relationships among Saccharomyces cerevisiae strains isolated from some of the Portuguese most important grapevine varieties in different appellations of origin, using polymorphic microsatellites. 
One hundred ninety two grape samples were collected during the 2006 and 2007 harvest season in the Vinho Verde (grape varieties: Arinto, Alvarinho, Avesso, Loureiro, Touriga Nacional) Bairrada (grape varieties: Arinto, Baga, Castelão Francês, Maria Gomes, Touriga Nacional) Alentejo (grape varieties, Aragonês, Trincadeira, Touriga Nacional), Terras do Sado (grape variety Castelão) Bucelas (grape variety Arinto) and Estremadura (grape varieties: Arinto, Aragonês, Castelão, Trincadeira, Touriga Nacional) appellations of origin. From the final stage of spontaneous fermentations, 2820 yeast isolates were obtained, mainly belonging to the species S. cerevisiae. An initial genetic screen, based on mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) and/or interdelta sequence analysis was followed by microsatellite analysis of strains with unique genetic profiles, using 10 highly polymorphic microsatellites. Our results showed that microsatellite analysis revealed a high resolution populational screen, showing that genetic differences and populational structures among S. cerevisiae populations derived from both “diagnostic” vineyard-, specific alleles and the accumulation of small allele-frequency differences across ten microsatellite loci. Heterozygosity was three to four times lower than the expected value, confirming the strong populational substructuring. The presented large-scale approach shows that each vineyard contains differentiated S. cerevisiae populations, showing the occurrence of specific native strains that can be associated with a terroir. 

Financially supported by the programs POCI 2010 (FEDER/FCT, POCTI/AGR/56102/2004) and AGRO (ENOSAFE, Nº 762).
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