367 research outputs found

    Cyanobacteria-based bioprocess for cosmetic products—cyanobium sp. as a novel source of bioactive pigments

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    As a producer of pigments with known bioactive potential, cyanobacteria are a great source of active ingredients for cosmetics (i.e., carotenoids and phycobiliproteins). Multiple phases in the cyanobacteria-based bioprocess led to the obtention of these compounds. The marine Cyanobium sp. LEGE 06113 has been proposed as a promising source for pigments for cosmetic uses, and it has been optimized in the past few years in terms of production, extraction, and application of pigment extracts. This report aims at providing an overview of the cyanobacteria-based bioprocess, regarding optimization strategies, consolidating into a proposed bioprocess for this cyanobacterium. The optimization of Cyanobium sp. included strategies regarding its production (culture medium, light, temperature, pH and salinity) and extraction (successive solvent extraction and ohmic heating). After the optimization, the two pigment-rich extracts (carotenoids and phycobiliproteins) were assessed in terms of their cosmetic potential and compatibility as an ingredient. Finally, aiming a scale-up proposal, life cycle assessment (LCA) was used as tool for a sustainable process. Ultimately, the proposed process gives the possibility to obtain two stable cosmetic ingredients from the same biomass and applied as anti-agent agents, especially due to their high anti-hyaluronidase capacity. Moreover, there remain challenges and information regarding novel cosmetic ingredient regulations were also discussed.This work was co-supported by a PhD fellowship granted to author F.P. [SFRH/BD/136767/2018] funded by Foundation for Science and Technology (FCT, Portugal) under the auspices of Operational Program Human Capital (POCH), supported by the European Social Fund and Por tuguese funds (MECTES); as well as by the national funds through FCT, (UIDB/04423/2020 and UIDP/04423/2020) to CIIMAR and (UIDB/04469/2020) to CEB.info:eu-repo/semantics/publishedVersio

    Be(com)ing an excelent student: a qualitative study with engineering undergraduates

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    This study explores the factors affecting the development of academic excellence on a group of 33 high-achieving engineering students. Participants were interviewed individually to explore several personal and contextual aspects of their past and current academic pathways. The results obtained reflect three main contributions to the conceptualization and understanding of excellence in academic contexts: the need to adopt a multidimensional and dynamic view about the concept of excellence; the existence of a variety of possible pathways and environmental conditions to achieve excellence; and the understanding of excellence as a process undergoing continuous development, which thrives within the family context and school environment, and that seems to be continuously nurtured by individuals in interaction with their contexts

    Adaptação e validação do questionário de motivação para a prática deliberada em contexto académico: análise em alunos de engenharia com desempenho excelente

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    A diferenciação individual dos alunos tem sido cada vez mais importante e valorizada, tornando-se paralelamente importante a identificação e compreensão dos aspectos que distinguem os melhores alunos nos seus métodos de trabalho e nas suas características psicológicas. Um dos aspectos que tem merecido particular atenção na psicologia da educação diz respeito à motivação dos alunos face às suas tarefas, representando este um factor importante na compreensão do rendimento académico dos alunos. Nesta comunicação iremos apresentar os resultados preliminares da adaptação e validação do Questionário de Motivação para a Prática Deliberada em contexto académico, partindo da versão original desenvolvida por De Bruin, Rikers & Schmidt (2007). A análise factorial da escala adaptada para o contexto académico sugere a composição em dois factores: Mestria/ Aperfeiçoamento e Realização Pessoal. Foram igualmente obtidos níveis bastante aceitáveis de consistência interna nas duas subescalas e na escala total (.72, .70 e .76, respectivamente). Verificam-se, ainda, diferenças estatisticamente significativas a favor do grupo de alunos excelentes na subescala da Realização Pessoal, com o grupo de alunos excelentes a obter níveis mais elevados nesta dimensão motivacional

    Identifying key environmental indicators in the assessment of the proof-of-concept in pigment production from the marine Cyanobacterium cyanobium sp.

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    Cyanobacteria have long attracted market interest as a source of natural compounds such as pigments with proven bioactivity (carotenoid and phycobiliproteins). The cultivation and extraction processes for such compounds have been developed at different levels, from laboratory trials to photobioreactors on a demonstration scale. Based on this experience, it is possible to propose how the different stages of the process can be improved based on environmental performance indicators. The Life Cycle Assessment (LCA) methodology allows to identify the hotspots that represent the greatest environmental impacts and to propose strategies to focus on those stages that can be improved. The general environmental indicators have been identified and the results showed that cyanobacteria cultivation has the greatest influence on environmental impact for all scales considered (from 20 L to 100 m3), which is attributed to the energy requirements. The main changes proposed to reduce the impact should focus on the stages of reactor cleaning, culture medium sterilisation and biomass drying. The implementation of these improvement alternatives can reduce the impact of the production and extraction processes by 85%. This work demonstrates how technological development must go hand in hand with impact assessment to make the best decisions in the overall process.A PhD fellowship [SFRH/BD/136767/2018] for author F.P. was granted by Fundação para a Ciência e Tecnologia (FCT, Portugal) under the auspices of Programa Operacional Capital Humano (POCH), supported by the European Social Fund and Portuguese funds (MECTES). This work was financially co-supported by Galician Competitive Research Group (GRC ED431C 2017/29) and to the Cross-disciplinary Research in Environmental Technologies (CRETUS Research Center, ED431E 2018/01) and by the strategical funding from FCT (UIDB/04423/2020 and UIDP/04423/2020) to CIIMAR and (UIDB/04469/2020) to CEB.info:eu-repo/semantics/publishedVersio

    Pigments extraction from Cyanobium sp. a comparison between pressure-based and electric fields-based technologies

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    Pigments from cyanobacteria, in special carotenoids and phycobiliproteins, have been seen with considerable interest for industrial applications due to their bioactive properties and their natural product characteristics. The extraction of these compounds is focused on the methodologies of cell disruption and on the chemical solubility of the compounds. In this study, two different methods were optimised and evaluated in terms of pigments´ extraction from the marine cyanobacterium Cyanobium sp.: a continuous pressurized solvent extraction (CPSE) system, and an electric fields-assisted extraction system based in ohmic heating (OH). For each method, a Central Composite Design (23) was performed. Optimal conditions for each extraction method were then compared to determine the best method for the extraction of pigments from Cyanobium sp. In both optimisation and comparison steps, two extracts were obtained from the same biomass: an ethanolic extract (carotenoids-targeted) and a successive water extract (phycobiliproteins-targeted). The content and profile of carotenoids and phycobiliproteins and the respective antioxidant capacity of extracts were evaluated. OH provided the best ethanolic extract, with a carotenoids content of 41.6 ± 1.7 mg gDW-1, and total antioxidant capacity of 8.0 ± 0.3 mgTE gDW-1, representing an increase of 1.3-fold and 2.5-fold respectively, when compared to CPSE. Regarding the aqueous extract, both methods led to the same content of phycobiliprotein (135 ± 10.0 mg gDW-1), although OH led to an antioxidant capacity of this extract of 8.3 ± 0.3 mgTE gDW-1, 3.6-fold higher when compared to CPSE. In terms of profile, no major variation was found between extraction methods, being lutein, zeaxanthin, echinenone and -carotene the major carotenoids (>60 % of total carotenoids), and phycocyanin and allophycocyanin the only present phycobiliproteins (in a 1:2 ratio). In addition to the productivity and composition of the extracts, the design and applicability of the system must be considered. Once again, OH overtook the other methods due to the scalability and possible continuous operation. Overall, OH proved to be the best of the two methodologies for pigments co-extraction from Cyanobium sp..A PhD fellowship (reference SFRH/BD/136767/2018) for author Fernando Pagels was granted by Fundação para a Ciência e Tecnologia (FCT, Portugal) under the auspices of Programa Operacional Capital Humano (POCH), supported by the European Social Fund and Portuguese funds (MECTES). This work was financially co-supported by the strategical funding from FCT UIDB/04423/2020, UIDP/04423/2020 and UIDB/04469/2020; and the project ALGAVALOR – MicroALGAs: produção integrada e VALORização da biomassa e das suas diversas aplicações (POCI-01-0247-FEDER-035234), supported by the European Regional Development Fund 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.info:eu-repo/semantics/publishedVersio

    Yellow fever in Brazil: thoughts and hypotheses on the emergence in previously free areas

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    This article describes and discusses factors associated to the reemergence of yellow fever and its transmission dynamics in the states of São Paulo (Southeastern Brazil) and Rio Grande do Sul (Southern) during 2008 and 2009. The following factors have played a pivotal role for the reemergence of yellow fever in these areas: large susceptible human population; high prevalence of vectors and primary hosts (non-human primates); favorable climate conditions, especially increased rainfall; emergence of a new genetic lineage; and circulation of people and/or monkeys infected by virus. There is a need for an effective surveillance program to prevent the reemergence of yellow fever in other Brazilian states

    Remote ischemic preconditioning in myocardial protection in hemodialysis patients

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    Background: Remote ischemic preconditioning (RIPC) is a procedure that generates a brief period of ischemia followed by reperfusion. The role of RIPC in protecting myocardial ischemia during hemodialysis is not yet established. The aim of the study was to evaluate RIPC myocardial protection as evaluated by ultrasensitive I troponin in hemodialysis outpatients. Patients and methods: A double-blind randomized trial with two groups: intervention submitted to RIPC and control group without RIPC. Intervention group received RIPC in three consecutive hemodialysis sessions. Blood samples were taken before and after each session. Blood urea nitrogen for calculation of single-pool Kt/v and ultrasensitive I troponin were measured to evaluate dialysis adequacy and myocardial injury. Results: A total of 47 patients were randomized. About 60.8% were men and 54% were diabetic. The mean single-pool Kt/v was 1.51 in the intervention group and 1.49 in control. The ultrasensitive troponin I measured no significant change from the time of collection: before or after dialysis. Conclusion: The RIPC applied in three consecutive sessions did not demonstrate superiority to control, therefore another study tested RIPC in 12 consecutive sessions with a positive result in myocardial protection. In our study, more than half of the patients were diabetic. Diabetic patients have a trend to show a lower response to RIPC because of the greater presence of collateral coronary circulation. In summary, in this model there was no interference of RIPC in ultrasensitive troponin I values, but troponin had a high negative predictive value for myocardial infarction in all tested models.ABC, Fac Med, Dept Gen Practice, Av Principe Gales N 821, BR-09060650 Santo Andre, SP, BrazilABC, Fac Med, Dept Cardiol, Santo Andre, SP, BrazilABC, Fac Med, Clin Anal Lab, Santo Andre, SP, BrazilUniv Fed Sao Paulo, Dept Pharmaceut Sci, Diadema, SP, BrazilUniv Fed Sao Paulo, Dept Pharmaceut Sci, Diadema, SP, BrazilWeb of Scienc

    Entendendo a Pegada da VBR nos Estudos em Negócios Internacionais: os Últimos Vinte Anos de Pesquisa

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    International business (IB) research has evolved substantially over the past four decades incorporating new concerns and theoretical contributions. During the past two decades, the Resource-Based View (RBV) has gained the preference of many IB scholars and has gradually become one of the dominant theoretical perspectives for studying IB decisions and operations. The 1991 article “Firm resources and sustained competitive advantage” by Jay Barney is recognized as a fundamental contribution to the Resource-Based View (RBV). In this paper we assess the influence of the RBV, proxied by Jay Barney’s (1991) article, on IB research over the twenty years period, from 1991 to 2010. In this bibliometric study of the articles published in the leading journal for IB research – Journal of International Business Studies (JIBS) – we conduct citation and co-citation analyses, the networks of co-authorship, and delve into the analysis of the key research topics. Beyond understanding the extant research we also contribute to identifying future research avenues.A pesquisa em Negócios Internacionais (IB – International Business) evoluiu substancialmente ao longo das últimas quatro décadas, incorporando novas questões e contribuições teóricas. Durante as últimas duas décadas, a Visão Baseada em Recursos (RBV - Resource-Based View) conquistou a preferência de vários pesquisadores em negócios internacionais e se tornou gradualmente uma das perspectivas teóricas dominantes para estudar decisões e operações de IB. O artigo de 1991 “Firm resources and sustained competitive advantage” (“Recursos internos e vantagem competitiva sustentada” de Jay Barney é reconhecido como uma contribuição fundamental para a Visão Baseada em Recursos (RBV). Neste artigo avaliamos a influência da RBV, guiados pelo artigo de Jay Barney (1991), sobre pesquisa em negócios internacionais ao longo de um período de vinte anos, de 1991 a 2010. Neste estudo bibliométrico dos artigos publicados no periódico líder para a pesquisa em negócios internacionais – o Journal of International Business Studies (JIBS) – conduzimos análises de citações e de cocitações, das redes de coautoria e aprofundamos a análise dos tópicos-chave de pesquisa. Além de entender a pesquisa existente, também contribuímos para identificar perspectivas para pesquisa futura

    Human Hantavirus Infection, Brazilian Amazon

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    Tropical Medicine Foundation of Amazonas. Manaus, AM, Brasil / Amazonas State University. Manaus, AM, Brasil / Nilton Lins University Center. Manaus, AM, Brasil.Tropical Medicine Foundation of Amazonas. Manaus, AM, Brasil / Amazonas State University. Manaus, AM, Brasil / Nilton Lins University Center. Manaus, AM, Brasil / University of Brasília. Brasília, DF, Brasil.Tropical Medicine Foundation of Amazonas. Manaus, AM, Brasil.Tropical Medicine Foundation of Amazonas. Manaus, AM, Brasil / Amazonas State University. Manaus, AM, Brasil / Nilton Lins University Center. Manaus, AM, Brasil.Health Surveillance Foundation. Manaus, AM, Brasil.Ministry of Health. Brasília, DF, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Tropical Medicine Foundation of Amazonas. Manaus, AM, Brasil / Amazonas State University. Manaus, AM, Brasil / Nilton Lins University Center. Manaus, AM, Brasil / University of Brasília. Brasília, DF, Brasil
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