Approaches in biotechnological applications of natural polymers

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)

Three adult cases of orbital hidrocystoma presenting with blepharoptosis

To report adult cases of superior orbital apocrine hidrocystoma. Retrospective case series of three patients with superior orbital apocrine hidrocystoma and blepharoptosis with review of the clinical aspects of each of the cases. All three cases presented with blepharoptosis. Two of the cases had occult hidrocystoma, and one was visibly subcutaneous at presentation. Although rare and more common along the eyelid margin, apocrine hidrocystomas may occur in the orbit leading to secondary blepharoptosis and should be included within the differential diagnosis of orbital cysts. Physicians should therefore be aware of this possibility

A Emenda Constitucional dos precatórios: histórico, incentivos e leilões de deságio

A questão dos precatórios se transformou em problema de magnitude nacional, comprometendo o bom funcionamento das instituições republicanas. Por um lado, estados e municípios se recusavam a pagá-los, argumentando insuficiência de verbas. Por outro lado, os credores exigiam o respeito a um direito legal. Uma nova legislação, a Emenda Constitucional nº 62, aprovada em 2009, estabeleceu um orçamento anual reservado ao pagamento de precatórios, bem como o uso de mecanismos de redução da dívida para ordenação de parte desse pagamento. Este artigo desenvolve uma análise econômica da Emenda Constitucional, que explica o apoio recebido pelos representantes dos estados e dos municípios no Congresso. Além disso, o artigo propõe e analisa uma forma específica para os leilões, baseando-se no formato dos leilões de Vickrey generalizados, que reduzem a dívida e o tempo necessário para seu pagamento