1,191 research outputs found

    Advances in extraction methods to recover added-value compounds from seaweeds: sustainability and functionality

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    Seaweeds are a renewable natural source of valuable macro and micronutrients that have attracted the attention of the scientists in the last years. Their medicinal properties were already recognized in the ancient traditional Chinese medicine, but only recently there has been a considerable increase in the study of these organisms in attempts to demonstrate their health benefits. The extraction process and conditions to be used for the obtention of value-added compounds from seaweeds depends mainly on the desired final product. Thermochemical conversion of seaweeds, using high temperatures and solvents (including water), to obtain high-value products with more potential applications continues to be an industrial practice, frequently with adverse impact on the environment and productsâ functionality. However more recently, alternative methods and approaches have been suggested, searching not only to improve the process performance, but also to be less harmful for the environment. A biorefinery approach display a valuable idea of solving economic and environmental drawbacks, enabling less residues production close to the much recommended zero waste system. The aim of this work is to report about the new developed methods of seaweeds extractions and the potential application of the components extracted.This work was funded by the Portuguese Foundation for Science and Technology (FCT) un der the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte. The work was also supported by the Euro pean Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant (MSCA-RISE; FODIAC; 778388). Gabriela Matos is recipient of a PhD fellowship supported by a doctoral advanced training (call NORTE-69-2015-15), funded by the European Social Fund under the scope of Norte2020—Programa Operacional Regional do Norte (NORTE-08-5369-FSE-000036). Sara Pereira and Zlatina Genisheva are supported by the project OH2O (POCI-01-0145-FEDER 029145) funded by FCT and Fundo Europeu de Desenvolvimento Regional (FEDER) under the scope of Programa Operacional de Competividade e Internacionalização (POCI)-COMPETE 2020 and Portugal 2020.info:eu-repo/semantics/publishedVersio

    Evaluation of T tube trial as a strategy of weaning from mechanical ventilation

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    BACKGROUND AND OBJECTIVES: Weaning from mechanical ventilation (MV) is an important strategy to reduce morbidity and mortality in critical care patients. In this setting, this study aimed at evaluation of T-tube trial (TT) in weaning from MV. METHODS: Patient admitted in the ICU were included if they present the following inclusion criteria: MV > 24 hours, no neuromuscular disorders, PaO2/FiO2 ratio >200, hemodynamic stability, reversion of the cause of respiratory failure, adequate respiratory drive. All were submitted to TT. Failure was defined by the presence of one of these symptoms: RR > 30 ipm, hypoxemia, tachycardia, arrhythmia, hypertension or hypotension. After two hours of TT, patients without failure criteria were extubated. After 48 hours of adequate spontaneous respiration the patient was considered successful weaned. Results were considered significant if p 24 horas, ausência de doença neuromuscular, relação PaO2/FiO2 > 200, estabilidade hemodinâmica, reversão da causa da intubação traqueal e drive respiratório adequado. Todos foram submetidos ao teste de tubo T. Considerou-se falha a ocorrência de FR > 30 irpm, hipoxemia, taquicardia, disritmias cardíacas, hipertensão ou hipotensão arterial. Após 2 horas de teste TT sem critérios de falha, os pacientes foram extubados. Considerou-se como sucesso na retirada da VM a manutenção por 48 horas de autonomia ventilatória. RESULTADOS: Foram incluídos 49 pacientes com idade média de 51,8 ± 21,7 anos. As incidências de SDRA e choque séptico foram 26,5% e 32,7% e o tempo médio de VM foi 11,9 ± 13 dias. A retirada da VM ocorreu em 79,2%, re-intubação em 31,6%, com tempo médio 13 ± 8,7 horas, sendo 75% devido à falência respiratória. Não houve correlação entre extubação e níveis de hemoglobina, PaO2/FiO2, idade, sexo, SDRA ou choque séptico prévios. O sucesso da retirada da VM (48 horas de autonomia) não se correlacionou com nenhuma das variáveis descritas. Os resultados foram considerados significativos se p < 0,05. CONCLUSÕES: O tubo T mostrou ser método adequado para a retirada da VM na maioria dos pacientes. Entretanto, a taxa de re-intubação foi elevada, podendo ser conseqüência do longo tempo do TT, da ventilação mecânica prévia ou da falha dos critérios de indicação de extubação traqueal.UNIFESP-EPM Unidade de Terapia Intensiva da Disciplina de Anestesiologia, Dor e Terapia IntensivaUNIFESP-EPMUNIFESP, EPM, Unidade de Terapia Intensiva da Disciplina de Anestesiologia, Dor e Terapia IntensivaUNIFESP, EPMSciEL

    CIANOBACTÉRIAS E CIANOTOXINAS EM RESERVATÓRIOS DOESTADO DORIOGRANDEDONORTEE O POTENCIAL CONTROLE DAS FLORAÇÕES PELA TILÁPIA DO NILO (OREOCHROMIS NILOTICUS)

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    Cyanobacteria blooms in reservoirs result in loss of water quality and negative effects to human health. To reduce these impacts the monitoring of the cyanobacteria and cyanotoxin occurrence as well as the application of measures to counteract the cyanobacteria blooms are made necessary. The manipulation of filter-feeding omnivorous fish stock, as Nile tilapia, has been proposed as an strategy for cyanobacteria bloom control. The present work aimed to evaluate: I) the presence of cyanobacteria (composition, density and biovolume by sedimentation technique) and cianotoxins (mouse bioassay) in five reservoirs located at the semi-arid region of Rio Grande do Norte state, in five sampling campaigns between September 2002 and March 2004; II) the per capita consumption rates of filamentous cyanobacteria by Nile tilapia through laboratory experiments using a natural population of cyanobacteria (experiment I) and a culture of Cylindrospermopsis raciborskii (experiment II), after the juveniles tilapias being exposed to a gradient of cyanobacteria biomass. The phytoplankton of the investigated reservoirs were dominated by cyanobacteria, including various toxigenic species (C. raciborskii, Microcystis spp., Aphanizomenon e Anabaena circinalis). Cianotoxins were present in three out of five reservoirs. The consumption rate of cyanobacteria (?g chlorophyll-a.fish-1.day-1) by the tilapia was 0,29 in the experiment I and 0,5 in the experiment II. The human populations that use the studied reservoirs as drinking water supply are being potentially exposed to the negative effects of the cyanobacteria. The present research suggests that the stock of Nile tilapia to control cyanobacteria blooms is viable. Nevertheless, factors such as the ichthyo-eutrophication and the accumulation of cyanotoxins in the fish biomass should be taken into account before implementing a biomanipulation program.Florações de cianobactérias em reservatórios resultam na perda da qualidade da água e em efeitos negativos para a saúde humana. Faz-se, portanto, necessário o monitoramento da ocorrência de cianobactérias e cianotoxinas, bem como a aplicação de medidas de controle das florações. Uma estratégia viável para esse controle é a manipulação dos estoques de peixes onívoros filtradores, como a tilápia do Nilo. Neste trabalho foram avaliados: i) a presença de cianobactérias (composição, densidade e biovolume, pelo método da sedimentação) e cianotoxinas (bioensaios com camundongos) em cinco reservatórios do semi-árido do estado do Rio Grande do Norte, em cinco campanhas de coletas, entre setembro de 2002 e março de 2004; e ii) as taxas de consumo per capita de cianobactérias filamentosas pela tilápia, através de dois experimentos em laboratório, utilizando populações naturais de cianobactérias (experimento I) e uma cultura de Cylindrospermopsis raciborskii (experimento II), após a exposição de indivíduos jovens de tilápia a um gradiente de biomassa de cianobactérias. O fitoplâncton nos reservatórios estudados apresentou dominância de cianobactérias, incluindo várias espécies toxigênicas (C. raciborskii, Microcystis spp., Aphanizomenon e Anabaena circinalis). Cianotoxinas foram evidenciadas em três dos cinco reservatórios. O consumo de cianobactérias (?g clorofila-a.peixe-1.dia-1) foi de 0,29 no experimento Ie de 0,5 no experimento II. Populações abastecidas pelos reservatórios investigados estão potencialmente expostas aos efeitos negativos das cianotoxinas. Esta pesquisa sugere que é viável a estocagem da tilápia do Nilo no controle de florações de cianobactérias. Entretanto, fatores como a ictioeutrofização e o acúmulo de cianotoxinas na biomassa dos peixes devem ser levados em consideração antes que um programa de biomanipulação possa ser implementado

    Avaliação de espécies leguminosas na formação de cafezais no segmento da agricultura familiar no Acre.

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    Leguminosas quando consorciadas com o café e usadas como adubação verde podem contribuir fornecendo nitrogênio e proteção ao solo pela adição de matéria orgânica. O trabalho foi conduzido com o objetivo de avaliar o efeito do uso de leguminosas no sistema de produção de café, no segmento de agricultura familiar, visando promover a implantação e a manutenção dos cafezais de forma técnica e economicamente sustentável. O experimento foi conduzido no período de novembro de 2000 a abril de 2003, em delineamento experimental de blocos ao acaso em esquema de parcelas subdivididas, com quatro repetições. Os tratamentos utilizados nas parcelas foram as leguminosas (Stizolobium atterrimum, Cajanus cajan, Canavalia endiformis e Flemingia congesta) e a testemunha (sem leguminosa) e, nas subparcelas, duas doses de N (0 e 22 g de N por cova). A Flemingia congesta e a Mucuna aterrima foram as leguminosas que mais influenciaram positivamente a produtividade dos cafeeiros, independente da adubação nitrogenada. Em relação à testemunha, o aumento em produção foi de 109% quando utilizou-se a Flemingia congesta e 52% com a Mucuna aterrima. A Flemingia congesta foi também a leguminosa que melhor controlou as invasoras, dado o volume de fitomassa produzida e a possibilidade de 2 cortes durante um período de doze meses, evidenciando o potencial desta leguminosa na formação de novos cafezais no Acre. Por outro lado, a Canavalia ensiformis, leguminosa que é normalmente utilizada nas entrelinhas dos cafeeiros pelos cafeicultores, do Acre e de outras regiões produtoras, neste trabalho influenciou negativamente a altura das plantas, diâmetro da copa e crescimento dos cafeeiros

    DESENVOLVIMENTO DE TECNOLOGIAS ASSISTIVAS, DE BAIXO CUSTO, PARA MOBILIDADE AUTONOMA DE PESSOAS CEGAS

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    This work presents two proposals for assistive technologies,with low cost of implantation and use, that aim to allowthe circulation of the blind in large urban centers, with lowcost of implantation and operation. The first one, presentsa sensory cane, for the detection of obstacles by pedestrianproposals. The following proposal describes a bus detectionsystem based on Bluetooth low energy (BLE) technology,with the objective of facilitating the boarding of blind people,or people with low vision, on buses. A given system wasbuilt and field tested at 91.5%, indicating the feasibility ofthe proposal.DOI: 10.36558/rsc.v12i2.770

    Extending the ecological distribution of Desmonostoc genus: proposal of Desmonostoc salinum sp. nov., a novel Cyanobacteria from a saline–alkaline lake

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    Cyanobacteria is an ancient phylum of oxygenic photosynthetic microorganisms found in almost all environments of Earth. In recent years, the taxonomic placement of some cyanobacterial strains, including those belonging to the genus Nostoc sensu lato, have been reevaluated by means of a polyphasic approach. Thus, 16S rRNA gene phylogeny and 16S–23S internal transcribed spacer (ITS) secondary structures coupled with morphological, ecological and physiological data are considered powerful tools for a better taxonomic and systematics resolution, leading to the description of novel genera and species. Additionally, underexplored and harsh environments, such as saline–alkaline lakes, have received special attention given they can be a source of novel cyanobacterial taxa. Here, a filamentous heterocytous strain, Nostocaceae CCM-UFV059, isolated from Laguna Amarga, Chile, was characterized applying the polyphasic approach; its fatty acid profile and physiological responses to salt (NaCl) were also determined. Morphologically, this strain was related to morphotypes of the Nostoc sensu lato group, being phylogenetically placed into the typical cluster of the genus Desmonostoc. CCM-UFV059 showed identity of the 16S rRNA gene as well as 16S–23S secondary structures that did not match those from known described species of the genus Desmonostoc, as well as distinct ecological and physiological traits. Taken together, these data allowed the description of the first strain of a member of the genus Desmonostoc from a saline–alkaline lake, named Desmonostoc salinum sp. nov., under the provisions of the International Code of Nomenclature for algae, fungi and plants. This finding extends the ecological coverage of the genus Desmonostoc, contributing to a better understanding of cyanobacterial diversity and systematics
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