26 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)

    Hand osteoarthritis: clinical phenotypes, molecular mechanisms and disease management

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    Osteoarthritis (OA) is a highly prevalent condition and the hand is the most commonly affected site. Patients with hand OA frequently report symptoms of pain, functional limitations, and frustration in undertaking everyday activities. The condition presents clinically with changes to the bone, ligaments, cartilage and synovial tissue, which can be observed using radiography, ultrasonography or MRI. Hand OA is a heterogeneous disorder and is considered to be multifactorial in aetiology. This review provides an overview of the epidemiology, presentation and burden of hand OA, including an update on hand OA imaging (including the development of novel techniques), disease mechanisms and management. In particular, areas for which new evidence has substantially changed the way we understand, consider and treat hand OA are highlighted. For example, genetic studies, clinical trials and careful prospective imaging studies from the past 5 years are beginning to provide insights into the pathogenesis of hand OA that might uncover new therapeutic targets in disease

    Short- and long-term effects of mud-bath treatment on hand osteoarthritis: a randomized clinical trial.

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    The aim of this study was to evaluate both the short-term and the long-term effectiveness of spa therapy in patients with primary hand osteoarthritis (OA). This was a prospective randomized, single blind controlled trial. Sixty outpatients with primary bilateral hand OA were included in the study and randomized to one of two groups. One group (n = 30) was treated with 12 daily local mud packs and generalized thermal baths with a sulfate-calcium-magnesium-fluorides mineral water added to usual treatment. The control group (n = 30) continued regular outpatient care routine (exercise, NSAIDs and/or analgesics). Each patient was examined at baseline, after 2 weeks, and after 3, 6, 9 and 12 months. Primary outcome measures were global spontaneous hand pain on a visual analogue scale (VAS) and the functional index for hand osteoarthritis (FIHOA) score; secondary outcomes were health assessment questionnaire (HAQ), duration of morning stiffness, medical outcomes study 36-item short form (SF-36) and symptomatic drugs consumption. Our results demonstrated that the efficacy of spa therapy was significant in all the assessed parameters, both at the end of therapy and after 3 months; the values of FIHOA, HAQ and drugs consumption continued to be significantly better after 6 months in comparison with baseline. There were no significant modifications of the parameters throughout the follow-up in the control group. Differences between the two groups were significant for all parameters at the 15th day and at 3 months follow-up; regarding FIHOA, HAQ, and symptomatic drugs consumption, the difference between the two groups persisted and was significant at 6month follow-up. Tolerability of spa therapy seemed to be good. In conclusion, our results confirm that the beneficial effects of spa therapy in patients with hand OA last over time

    The Big Meaning of Small Messages : The Use of WhatsApp in Intergenerational Family Communication

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    This study explores the use of WhatsApp instant messenger in extended families in two countries, Finland and Italy, that represent different family and communication cultures. Qualitative research material was collected in 2014/2015 from families consisting of three or more generations and living either in the same or different households. A directed approach to qualitative content analysis was applied in the analysis of the research data. The results of the study show that WhatsApp is considered to facilitate family interaction across generations. The success of WhatsApp in the family context accounts for two main factors: first, for the possibility to reach the whole family at once; and secondly, for its capacity to promote “phatic communion” via small messages. While utilizing various communicative modalities of WhatsApp (text and voice messages, photos, videos), family members take into account others’ preferences and communication skills.peerReviewe

    Impact of coated calcium carbonate nanofillers and annealing treatments on the microstructure and gas barrier properties of poly(lactide) based nanocomposite films

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    International audienceAmorphous poly(lactide) (PLA) and nanocomposite films were prepared from melt-blending with precipitated calcium carbonate nanofillers (PCC). Nanocomposites based on uncoated PCC (PCC-UT), stearic acid coated PCC (PCC-S), and poly(epsilon-caprolactone) coated PCC (PCC-P) were investigated for an inorganic content fixed to 8 wt %. Using coated nanofillers allowed preserving both PLA average molar mass and thermal stability while enhancing the nanofiller dispersion state. Poly(epsilon-caprolactone) was identified as the best coating for optimized morphology and thermal properties. Maxwell law accurately described the increase in oxygen barrier properties observed for the nanocomposites based on PCC-S. A modified Maxwell law was proposed to take account of the additional increase in barrier properties evidenced for the PLA/PCC-P nanocomposites and assigned to the particularly strong compatibility between PCL and PLA. Different annealing conditions were investigated to respectively study the impact of physical ageing and PLA crystallization on gas permeability. Different extents of physical ageing did not significantly modify the oxygen transport properties. However, a high permeability decrease was observed for the semicrystalline nanocomposites with respect to the amorphous reference PLA film. Finally, the gain in barrier properties was shown to result from both contribution of the nanofillers and the crystalline phase
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