126 research outputs found
Superoxide reductase from Giardia intestinalis: structural characterization of the first sor from a eukaryotic organism shows an iron centre that is highly sensitive to photoreduction
Superoxide reductase (SOR), which is commonly found in prokaryotic organisms, affords protection from oxidative stress by reducing the superoxide anion to hydrogen peroxide. The reaction is catalyzed at the iron centre, which is highly conserved among the prokaryotic SORs structurally characterized to date. Reported here is the first structure of an SOR from a eukaryotic organism, the protozoan parasite Giardia intestinalis (GiSOR), which was solved at 2.0 Ã… resolution. By collecting several diffraction data sets at 100 K from the same flash-cooled protein crystal using synchrotron X-ray radiation, photoreduction of the iron centre was observed. Reduction was monitored using an online UV-visible microspectrophotometer, following the decay of the 647 nm absorption band characteristic of the iron site in the glutamate-bound, oxidized state. Similarly to other 1Fe-SORs structurally characterized to date, the enzyme displays a tetrameric quaternary-structure arrangement. As a distinctive feature, the N-terminal loop of the protein, containing the characteristic EKHxP motif, revealed an unusually high flexibility regardless of the iron redox state. At variance with previous evidence collected by X-ray crystallography and Fourier transform infrared spectroscopy of prokaryotic SORs, iron reduction did not lead to dissociation of glutamate from the catalytic metal or other structural changes; however, the glutamate ligand underwent X-ray-induced chemical changes, revealing high sensitivity of the GiSOR active site to X-ray radiation damage
Estudos multitemporais com dados de detecção remota sobre a fronteira da Guiné-Bissau
Este estudo incidiu sobre duas regiões muito importantes no que respeita à definição da fronteira na Guiné-Bissau, Cabo Roxo e Ponta Cajete e tem como objectivo desenvolver estudos multitemporais para definir a posição exacta dos marcos de fronteira, com base em informação geográfica e dados de detecção remota antiga e recente. Foram utilizadas imagens do satélite de alta resolução espacial (WorldView2) de 2013 e 2014. Para melhorar a resolução espacial das imagens e consequentemente beneficiar a interpretação do terreno, foram testados vários algoritmos de fusão das bandas multiespectrais com a pancromática.
O resultado da análise multitemporal permitiu detectar a localização exacta do marco de fronteiro nº 184 e algumas mudanças nas formas de relevo litorais nas duas regiões em estudo
Polymeric biomaterials for wound healing
Skin indicates a person’s state of health and is so important that it influences a person’s emotional and psychological behavior. In this context, the effective treatment of wounds is a major concern, since several conventional wound healing materials have not been able to provide adequate healing, often leading to scar formation. Hence, the development of innovative biomaterials for wound healing is essential. Natural and synthetic polymers are used extensively for wound dressings and scaffold production. Both natural and synthetic polymers have beneficial properties and limitations, so they are often used in combination to overcome overcome their individual limitations. The use of different polymers in the production of biomaterials has proven to be a promising alternative for the treatment of wounds, as their capacity to accelerate the healing process has been demonstrated in many studies. Thus, this work focuses on describing several currently commercially available solutions used for the management of skin wounds, such as polymeric biomaterials for skin substitutes. New directions, strategies, and innovative technologies for the design of polymeric biomaterials are also addressed, providing solutions for deep burns, personalized care and faster healing.This research was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, and by LABBELS—Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020. This study was also funded by program Marie Skłodowska-Curie grant (MSCA-RISE; FODIAC; 778388), and by the European Regional Development Fund (ERDF) through the Competitiveness factors Operational program—Norte 2020, COMPETE and by National Funds through the FCT—under the project AgriFood XXI (NORTE- 01-0145-FEDER-000041)
Tuning the Bioactive Properties of Dunaliella salina Water Extracts by Ultrasound-Assisted Extraction
(1) Background: Microalgae are promising feedstock for obtaining valuable bioactive
compounds. To facilitate the release of these important biomolecules from microalgae, effective cell
disruption is usually necessary, where the use of ultrasound has achieved considerable popularity as
an alternative to conventional methods. (2) Methods: This paper aims to evaluate the use of ultra-
sound technology in water medium as a green technology to recover high added-value compounds
from Dunaliella salina and improve its sensory profile towards a high level of incorporation into novel
food products. (3) Results: Among the variables, the solid concentration and extraction time have
the most significant impact on the process. For the extraction of protein, or fat, the most influential
factor is the extraction time. Total polyphenols are only significantly affected by the extraction time.
The antioxidant capacity is strongly affected by the solid to liquid ratio and, to a small extent, by the
extraction time. Ultrasound-assisted extraction improves the overall odor/aroma of D. salina with
good acceptability by the panelists. (4) Conclusions: The application of ultrasonic-assisted extraction
demonstrates a positive overall effect on enhancing the sensory profile, particularly the odor of
microalgal biomass, while the bioactive properties are preserved. Notably, the intense sea/fish odors
are reduced, while earthy and citrus notes become more prominent, resulting in an improved overall
sensory profile score. This is the first time, to our knowledge, that this innovative, green, and efficient
technology has been used to upgrade the aroma profile of microalgae.info:eu-repo/semantics/publishedVersio
A review of conventional and emerging technologies for hydrogels sterilization
Funding
This work was financially supported by Fundaçao ˜ para a Ciˆencia e
Tecnologia (FCT), Portugal, through the project STERILAEROGEL –
Green method to prepare sterilised biopolymer-based aerogel (POCI01–0145-FEDER-032625) and Strategic Projects FCT-MEC PEst-C/EQB/
UI0102/2019, UIDB/00102/2020 and Programmatic Project UIDP/
00102/2020 of the CIEPQPF, and UI/05704/2020 of the ciTechCare. C.
S. A. Bento acknowledges for PhD grant UI/BD/151008/2021 and M. C.
Gaspar acknowledges FCT for the financial support under Scientific
Employment Stimulus – Individual and Institutional Calls (CEECIND/
00527/2017 and CEECINST/00060/2021).Hydrogels are extensively used in the biomedical field, as drug delivery systems, wound dressings, contact lenses or as scaffolds for tissue engineering. Due to their polymeric nature and the presence of high amounts of water in their structure, hydrogels generally present high sensitivity to terminal sterilization. The establishment of an efficient sterilization protocol that does not compromise the functional properties of the hydrogels is one of the challenges faced by researchers when developing a hydrogel for a specific application. Yet, until very recently this aspect was largely ignored in the literature. The present paper reviews the state of literature concerning hydrogels sterilization, compiling the main findings. Conventional terminal sterilization methods (heat sterilization, radiation sterilization, and gas sterilization) as well as emerging sterilization techniques (ozone, supercritical carbon dioxide) are covered. Considerations about aseptic processing are also included. Additionally, and as a framework, hydrogels’ polymeric materials, types of networks, and main biomedical applications are summarily described.info:eu-repo/semantics/publishedVersio
Multiple-clone infections of Plasmodium vivax: definition of a panel of markers for molecular epidemiology
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Previous issue date: 2015Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilUniversidade Federal de Mato Grosso. Hospital Julio Muller. Cuiabá, MT, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilBACKGROUND: Plasmodium vivax infections commonly contain multiple genetically distinct parasite clones. The detection of multiple-clone infections depends on several factors, such as the accuracy of the genotyping method, and the type and number of the molecular markers analysed. Characterizing the multiplicity of infection has broad implications that range from population genetic studies of the parasite to malaria treatment and control. This study compared and evaluated the efficiency of neutral and non-neutral markers that are widely used in studies of molecular epidemiology to detect the multiplicity of P. vivax infection.
METHODS: The performance of six markers was evaluated using 11 mixtures of DNA with well-defined proportions of two different parasite genotypes for each marker. These mixtures were generated by mixing cloned PCR products or patient-derived genomic DNA. In addition, 51 samples of natural infections from the Brazil were genotyped for all markers. The PCR-capillary electrophoresis-based method was used to permit direct comparisons among the markers. The criteria for differentiating minor peaks from artifacts were also evaluated.
RESULTS: The analysis of DNA mixtures showed that the tandem repeat MN21 and the polymorphic blocks 2 (msp1B2) and 10 (msp1B10) of merozoite surface protein-1 allowed for the estimation of the expected ratio of both alleles in the majority of preparations. Nevertheless, msp1B2 was not able to detect the majority of multiple-clone infections in field samples; it identified only 6 % of these infections. The merozoite surface protein-3 alpha and microsatellites (PvMS6 and PvMS7) did not accurately estimate the relative clonal proportions in artificial mixtures, but the microsatellites performed well in detecting natural multiple-clone infections. Notably, the use of a less stringent criterion to score rare alleles significantly increased the sensitivity of the detection of multi-clonal infections.
CONCLUSIONS: Depending on the type of marker used, a considerable amplification bias was observed, which may have serious implications for the characterization of the complexity of a P. vivax infection. Based on the performance of markers in artificial mixtures of DNA and natural infections, a minimum panel of four genetic markers (PvMS6, PvMS7, MN21, and msp1B10) was defined, and these markers are highly informative regarding the genetic variability of P. vivax populations
House dust fungal communities’ characterization: a double take on the six by sixty by six (6 × 60 × 6) project
Fungi are a group of microbes that are found with
particular incidence in the indoor environment. Their direct
toxicity or capability of generating toxic compounds
has been associated with a large number of adverse health
effects, such as infectious diseases and allergies. Given
that in modern society people spend a large part of their
time indoors; fungal communities’ characterization of this
environmental compartment assumes paramount importance
in the comprehension of health effects. House dustThis work was supported by European Funds through
COMPETE and by National Funds through the Portuguese
Science Foundation (FCT) within project PEstOE/SAU/UI0709/2014.
Ana C. A. Sousa and Sónia D. Coelho
acknowledge FCT for the grants SFRH/BPD/65884/2009
and SFRH/
BD/78168/2011 (supported by funding from the Human
Potential Operational Programme POPH, inscribed in
the National Strategic Reference Framework and partially
subsidized by the European Social Fund).info:eu-repo/semantics/publishedVersio
Monitoring Inequalities in the Health Workforce: The Case Study of Brazil 1991–2005
Introduction: Both the quantity and the distribution of health workers in a country are fundamental for assuring equitable access to health services. Using the case of Brazil, we measure changes in inequalities in the distribution of the health workforce and account for the sources of inequalities at sub-national level to identify whether policies have been effectiv
In the matter of the request of Liberty Mutual Fire Insurance Company, a Massachusetts domestic stock insurance company, to redomesticate to the state of Wisconsin
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Previous issue date: 2018Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de VÃrus Respiratórios e do Sarampo. Rio de Janeiro, RJ, Brazil / Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de BioquÃmica e Imunologia. Laboratório de Imunofarmacologia. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de BioquÃmica e Imunologia. Laboratório de Imunofarmacologia. Belo Horizonte, MG, Brazil / Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Fisiologia e BiofÃsica. Laboratório de Imunologia e Mecânica Pulmonar. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de BioquÃmica e Imunologia. Laboratório de Imunofarmacologia. Belo Horizonte, MG, Brazil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de HansenÃase. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de HansenÃase. Rio de Janeiro, RJ, Brazil / UNIFRANZ. Coordinación Nacional de Investigación. La Paz, Bolivia.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Morfologia. Belo Horizonte, MG, BrazilUniversidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de BioquÃmica e Imunologia. Laboratório de Imunofarmacologia. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de BioquÃmica e Imunologia. Laboratório de Imunofarmacologia. Belo Horizonte, MG, Brazil / Universidade de São Paulo. Departamento de Farmacologia. Laboratório de Inflamação e Dor. Universidade de São Paulo. Ribeirão Preto, SP, Brazil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de VÃrus Respiratórios e do Sarampo. Rio de Janeiro, RJ, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de BioquÃmica e Imunologia. Laboratório de Imunofarmacologia. Belo Horizonte, MG, Brazil / Fundação Oswaldo Cruz. Instituto René Rachou. Laboratório de Imunologia de Doenças Virais. Belo Horizonte, MG, BrazilUniversidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de BioquÃmica e Imunologia. Laboratório de Imunofarmacologia. Belo Horizonte, MG, Brazil / Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Biologia Geral. Belo Horizonte, MG, Brazil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de HansenÃase. Rio de Janeiro, RJ, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de BioquÃmica e Imunologia. Laboratório de RNA de Interferência Belo Horizonte, MG, Brazil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de VÃrus Respiratórios e do Sarampo. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Instituto René Rachou. Laboratório de Imunologia de Doenças Virais. Belo Horizonte, MG, BrazilUniversidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de BioquÃmica e Imunologia. Laboratório de Imunofarmacologia. Belo Horizonte, MG, Brazil / Universidade Federal de Minas Gerais. Faculdade de Farmácia. Departamento de Análises ClÃnicas e Toxicológicas. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de BioquÃmica e Imunologia. Laboratório de Imunofarmacologia. Belo Horizonte, MG, Brazil / Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Fisiologia e BiofÃsica. Laboratório de Imunologia e Mecânica Pulmonar. Belo Horizonte, MG, Brazil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de BioquÃmica e Imunologia. Laboratório de Imunofarmacologia. Belo Horizonte, MG, Brazil.Influenza A virus (IAV) infection causes severe pulmonary disease characterized by intense leukocyte infiltration. Phosphoinositide-3 kinases (PI3Ks) are central signaling enzymes, involved in cell growth, survival, and migration. Class IB PI3K or phosphatidyl inositol 3 kinase-gamma (PI3Kγ), mainly expressed by leukocytes, is involved in cell migration during inflammation. Here, we investigated the contribution of PI3Kγ for the inflammatory and antiviral responses to IAV. PI3Kγ knockout (KO) mice were highly susceptible to lethality following infection with influenza A/WSN/33 H1N1. In the early time points of infection, infiltration of neutrophils was higher than WT mice whereas type-I and type-III IFN expression and p38 activation were reduced in PI3Kγ KO mice resulting in higher viral loads when compared with WT mice. Blockade of p38 in WT macrophages infected with IAV reduced levels of interferon-stimulated gene 15 protein to those induced in PI3Kγ KO macrophages, suggesting that p38 is downstream of antiviral responses mediated by PI3Kγ. PI3Kγ KO-derived fibroblasts or macrophages showed reduced type-I IFN transcription and altered pro-inflammatory cytokines suggesting a cell autonomous imbalance between inflammatory and antiviral responses. Seven days after IAV infection, there were reduced infiltration of natural killer cells and CD8+ T lymphocytes, increased concentration of inflammatory cytokines in bronchoalveolar fluid, reduced numbers of resolving macrophages, and IL-10 levels in PI3Kγ KO. This imbalanced environment in PI3Kγ KO-infected mice culminated in enhanced lung neutrophil infiltration, reactive oxygen species release, and lung damage that together with the increased viral loads, contributed to higher mortality in PI3Kγ KO mice compared with WT mice. In humans, we tested the genetic association of disease severity in influenza A/H1N1pdm09-infected patients with three potentially functional PIK3CG single-nucleotide polymorphisms (SNPs), rs1129293, rs17847825, and rs2230460. We observed that SNPs rs17847825 and rs2230460 (A and T alleles, respectively) were significantly associated with protection from severe disease using the recessive model in patients infected with influenza A(H1N1)pdm09. Altogether, our results suggest that PI3Kγ is crucial in balancing antiviral and inflammatory responses to IAV infection
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Personality and the creativity of frontline service employees: linear and curvilinear effects
Previous studies have investigated the relationship between the Five Factor model of personality and creativity. As this model has been criticised for providing a limited account of an individual’s personality, this study considers additional personality traits that have recently been investigated in the literature as determinants of employee behaviour. Moreover, we also contribute to the existing body of literature by conducting this study in a services setting, for which we predict personality traits will exert differentiated effects on creativity when compared to other settings. Finally, while past research has focused on linear effects, this study examines the existence of non-linear effects between personality and creativity. The results indicate that personality traits apart from the Five Factor model have an impact on creativity and that the effects of several personality traits on the creativity of frontline service employees differ from those obtained in other settings. Lastly, the findings also show that five of the personality traits have non-linear effects on creativity, and this may be a stimulus for a new stream of research in the human resources literature
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