20 research outputs found

    Approaches in biotechnological applications of natural polymers

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    Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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    The depuration dynamics of oysters (Crassostrea gigas) artificially contaminated with hepatitis A virus and human adenovirus

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    Within the country of Brazil, Santa Catarina is a major shellfish producer. Detection of viral contamination is an important step to ensure production quality and consumer safety during this process. In this study, we used a depuration system and ultraviolet (UV) disinfection to eliminate viral pathogens from artificially infected oysters and analysed the results. Specifically, the oysters were contaminated with hepatitis A virus (HAV) or human adenovirus type 5 (HAdV5). After viral infection, the oysters were placed into a depuration tank and harvested after 48, 72 and 96 h. After sampling, various oyster tissues were dissected and homogenised and the viruses were eluted with alkaline conditions and precipitated with polyethylene glycol. The oyster samples were evaluated by cell culture methods, as well as polymerase chain reaction (PCR) and quantitative-PCR. Moreover, at the end of the depuration period, the disinfected seawater was collected and analysed by PCR. The molecular assays showed that the HAdV5 genome was present in all of the depuration time samples, while the HAV genome was undetectable after 72 h of depuration. However, viral viability tests (integrated cell culture-PCR and immunofluorescence assay) indicated that both viruses were inactivated with 96 h of seawater recirculation. In conclusion, after 96 h of UV treatment, the depuration system studied in this work purified oysters that were artificially contaminated with HAdV5 and HAV

    Colecistectomia videolaparoscópica experimental em cadáver humano: 70 casos

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    OBJETIVO: Apresentar, descrever e propor como método de treinamento e/ou aperfeiçoamento em colecistectomia videolaparoscópica, um modelo desenvolvido em cadáver de feto humano. MÉTODO: No Departamento de Morfologia da Faculdade de Medicina da Universidade Federal do Ceará foram utilizados 70 cadáveres de fetos humanos, de ambos sexos, frescos-congelados, com tamanhos entre 39 e 54 centímetros (média = 49cm) e pesos entre 1.210 e 3.900 gramas (média = 2.900g). Foi empregado, ainda, todo o arsenal de equipamentos e instrumentais de cirurgia videolaparoscópica. Cada feto foi submetido à videocolecistectomia experimental e os dados referentes aos aspectos técnicos e anatômicos registrados em fitas de vídeo e em protocolo para análise posterior. A técnica cirúrgica utilizada seguiu todos as etapas operatórias da videocolecistectomia in vivo. RESULTADOS: Foi possível manter um pneumoperitônio eficiente, em torno de 18mmHg, em todos os casos. A adequada clipagem do ducto cístico foi possível em 66 dos 68 casos operados, e da artéria cística em 62 casos. A vesícula foi extirpada satisfatoriamente em 67 fetos. O tempo cirúrgico médio foi de 70 minutos. Observou-se que o método proposto permite ao cirurgião adquirir, a partir de um treinamento adequado, habilidades técnicas, bem como segurança na execução de manobras necessárias para a prática desta modalidade cirúrgica. CONCLUSÃO: A videocolecistectomia em cadáver de feto humano representa um método factível, de grande importância, que pode ser aplicado no treinamento e/ou aperfeiçoamento de cirurgiões videolaparoscópicos
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