32 research outputs found

    Biocompatibility of a self-assembled glycol chitosan nanogel

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    The research of chitosan-based nanogel for biomedical applications has grown exponentially in the last years; however, its biocompatibility is still insufficiently reported. Hence, the present work provides a thorough study of the biocompatibility of a glycol chitosan (GC) nanogel. The obtained results showed that GC nanogel induced slight decrease on metabolic activity of RAW, 3T3 and HMEC cell cultures, although no effect on cell membrane integrity was verified. The nanogel does not promote cell death by apoptosis and/or necrosis, exception made for the HMEC cell line challenged with the higher GC nanogel concentration. Cell cycle arrest on G1 phase was observed only in the case of RAW cells. Remarkably, the nanogel is poorly internalized by bone marrow derived macrophages and does not trigger the activation of the complement system. GC nanogel blood compatibility was confirmed through haemolysis and whole blood clotting time assays. Overall, the results demonstrated the safety of the use of the GC nanogel as drug delivery system.Paula Pereira thanks FCT, the Ph.D. grant ref SFRH/BD/64977/2009. This work was also supported by a grant from the Spanish Ministry of Economy and Competitivity (SAF2011-30337-C02-02). We also acknowledge the European Union Seventh Framework Programme [FP7/REGPOT-2012-2013.1] under grant agreement BIOCAPS-316265. MP acknowledges fellowship from Spanish Ministry of Education (FPU predoctoral grant program)

    A social and ecological assessment of tropical land uses at multiple scales: the Sustainable amazon network

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    Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazônia Sustentável, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far

    DO YEASTS AND DROSOPHILA INTERACT JUST BY CHANCE?

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    The fruit fly Drosophila melanogaster and the baker’s yeast Saccharomyces cerevisiae are classic research model organisms that are also associated in nature, at least around vineyards. Sharing the same ephemeral fruit niche, winged Drosophila feed on immotile yeasts. That a yeast diet is essential for larvae development, and that saprophagous fruit flies are attracted to a suite of yeast volatiles, has been well established over the last century. Recently, research has focussed on the potential mutual benefit of this interaction hypothesising yeasts also benefit via dispersal from ephemeral fruits. It now appears that the concept of a co-evolved mutualism between yeasts and Drosophila has permeated the literature. However, until robust evidence regarding the evolution and maintenance of this yeast-fly association has been provided, we suggest there is no compelling evidence to reject the more simplistic null hypothesis that these interactions are due to exaptation, and not a mutualism driven by natural selection

    Contracepção hormonal e lesões cervicais pelo Papilomavírus Humano: uma revisão de literatura / Hormonal contraception and cervical injuries by Human Papillomavirus: a literature review

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    Introdução: A infecção pelo papilomavírus humano (HPV) é a doença sexualmente transmissível (DST) mais comum, afetando 50% da população mundial. Estima-se que entre 75 e 80% da de indivíduos sexualmente ativos adquirirão algum subtipo de HPV ao longo da vida. No Brasil, a taxa de prevalência de HPV varia de 13,7 a 54,3%, de acordo com a população e as regiões estudadas. Assim, este artigo tem como objetivo analisar a associação entre os hormônios contracepção e o aparecimento de lesões induzidas por HPV em o colo uterino. Metodologia: O presente estudo foi elaborado por meio de uma pesquisa bibliográfica, realizada eletronicamente, procurando registros sobre o desenvolvimento de lesões induzidas por HPV em colo uterino e hormônios de contracepção. Objetivando com isso identificar através da literatura a associação entre os hormônios de contracepção e o aparecimento de lesões induzidas por HPV em colo uterino. Para a realização do mesmo foram analisados artigos publicados em revistas científicas, utilizando as bases de dados da BVS (Biblioteca Virtual da Saúde), como: Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde) e Scielo (Scientific Electronic Library Online). Resultados: Após a seleção, restaram nove artigos para a discussão. Podemos observar os artigos escolhidos no quadro, composto pelos autores, título, metodologia, resultados e conclusão que cada um encontrou. Em seguida foi realizada uma discussão acerca destes artigos. Conclusão: Muitos estudos relataram que os mecanismos envolvidos na persistência e incidência de lesões de HPV estão longe de ser esclarecidas, e que novas estudos são necessários para elucidar melhores abordagens em relação ao tipo de contracepção, via de administração e doses hormonal que não estão associadas a lesões induzidas por HPV

    Turbine shutdown as an essential tool to prevent soaring bird fatalities at the Gulf of Suez

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    Climate change caused by high emissions of greenhouse gases to the atmosphere demands for worldwide reduction in fossil fuel energy production and increased use of wind energy as a clean alternative. However, there is a potential conflict between wildlife conservation and wind energy production. Bird mortalities may be high at windfarms installed along migratory flyways and bottlenecks, where a large number of species and large proportions of their global populations congregate during migration. The Rift Valley/Red Sea (RV-RS) flyway is the second most important flyway in the world for soaring birds, connecting the species’ breeding grounds in Eurasia and the wintering grounds in sub-Saharan Africa. Soaring birds depend on thermals for migration and thus congregate in large numbers at straits and land bridges to avoid long crosses over sea. The Gabel el Zayt in Egypt, classified as an important bird area is an integral part of the RV-RS flyway. It is located on the shores of the Red Sea, south of the Gulf of Suez land bridge, and its geographical configuration funnels the migratory birds through a narrow land strip framed by the Red Sea mountains and the coastline. Wind regimens in Gabel el Zayt are among the best for wind energy production and large windfarms are already operating in the area. To mitigate soaring bird mortalities at the 240 MW Gabel el Zayt windfarm, STRIX conducted radar assisted wind turbine shutdowns during spring migration from 2016 to 2020. STRIX also established a monitoring program to quantify the number of soaring birds migrating daily, further assess the international importance of the site, and evaluate the risk of mortality due to collisions. Fieldwork was conducted daily from early morning to late afternoon at vantage points located at the perimeter and centre of the windfarm. Observers followed all movements of birds within and outside the windfarm and recorded, among other data, time of observation, species, number of individuals, flight height and flight direction. Meteorological data was recorded hourly. Daily estimates of the number of migratory birds were produced by excluding movements recorded by more than one vantage point. STRIX’s monitoring of soaring birds in the Gabel el Zayt windfarm is to date the most comprehensive study in the region covering the entire spring migration. Forty soaring bird species were recorded between 2016 and 2020, including seven globally threatened and two near threatened species. The total number of soaring birds per year averaged 309,041 individuals and was highest in 2016 with 397,076 recorded soaring birds. Results also show that the site is of international importance for the conservation of 18 species, with numbers recorded per year surpassing 1% of the estimated flyway population. Noteworthy, numbers recorded for seven species surpassed 10% of the flyway population. Furthermore, the application of migrant collision risk Band models to evaluate the species’ vulnerability to mortality by collision, indicates that expected mortalities are not negligible for a large array of species, thus highlighting the importance of conducting radar assisted shutdown operations at windfarms in the region. CWW2022 4 - 8 April 2022 Egmond aan Zee, Netherlands Poster Presentations 96 Theme: 5. Wind and wildlife interaction in practice Turbine shutdown as an essential tool to prevent soaring bird mortality at the Gulf of Suez Alexandre Leitão, Pedro Moreira, Nadine Pires, Nuno C. Vieira, Filipe Canário, Miguel Repas Correspondence author: Alexandre Leitão, STRIX Email: [email protected] presentations and posters are typically about preliminary findings and are usually followed up by a detailed paper. This poster is based only on its abstract and may offer limited information. Please contact us for the detailed project brief, which may offer additional information that you can utilize for your research. This project was commissioned to STRIX by the developers of the Gabel el Zeyt Wind Farm NREA, supported by KfW, EIB and EU

    The Ideal Timing for Experimental Cleft Lip Creation

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    Cleft lip and palate (CLP) is the most common congenital defect of the face. Many animal models have been utilized to study embryogenesis and pathogenesis of CLP, including the development of secondary anomalies and consequent deformities. However, the ideal gestational age for surgical creation of lip or palate defects in rat models has never been determined. The aim of the present study is to improve the experimental model utilizing rat fetuses, defining the most appropriate timing for creation of the lip defect model. The study was composed of three groups of fetuses undergoing surgical creation of a lip defect at the left side of the superior lip at 17.5, 18.5, and 19.5 days of gestation. Fetuses were harvested at 21.5 days of gestation (term = 22 days) and underwent macroscopic and microscopic analyses. We found that the most appropriate moment for lip defect creation was at 19.5 days, given the presence of lip depression at the site of the defect and asymmetry and retraction associated with interruption of the lip and complete reepithelialization of the borders of the defect.Sao Paulo Research Foundation - FAPESP[08/50347-9

    Tyrosyl-tRNA synthetase has a noncanonical function in actin bundling

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    Dominant mutations in tyrosyl-tRNA synthetase (YARS1) and six other tRNA ligases cause Charcot-Marie-Tooth peripheral neuropathy (CMT). Loss of aminoacylation is not required for their pathogenicity, suggesting a gain-of-function disease mechanism. By an unbiased genetic screen in Drosophila, we link YARS1 dysfunction to actin cytoskeleton organization. Biochemical studies uncover yet unknown actin-bundling property of YARS1 to be enhanced by a CMT mutation, leading to actin disorganization in the Drosophila nervous system, human SH-SY5Y neuroblastoma cells, and patient-derived fibroblasts. Genetic modulation of F-actin organization improves hallmark electrophysiological and morphological features in neurons of flies expressing CMT-causing YARS1 mutations. Similar beneficial effects are observed in flies expressing a neuropathy-causing glycyl-tRNA synthetase. Hence, in this work, we show that YARS1 is an evolutionary-conserved F-actin organizer which links the actin cytoskeleton to tRNA-synthetase-induced neurodegeneration.Mutations in tRNA ligases, essential components of the translational machinery, are associated with Charcot-Marie-Tooth peripheral neuropathy, but the mechanistic details are not known. The authors report that the tyrosyl-tRNA synthetase is an evolutionary-conserved F-actin organizer, and dysregulation of this function is associated with the disorder.Peer reviewe

    Bioethanol from lignocelluloses: Status and perspectives in Brazil

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    The National Alcohol Program - ProAlcool, created by the government of Brazil in 1975 resulted less dependency on fossil fuels. The addition of 25% ethanol to gasoline reduced the import of 550 million barrels oil and also reduced the emission CO(2) by 110 million tons. Today, 44% of the Brazilian energy matrix is renewable and 13.5% is derived from sugarcane. Brazil has a land area of 851 million hectares, of which 54% are preserved, including the Amazon forest (350 million hectares). From the land available for agriculture (340 million hectares), only 0.9% is occupied by sugarcane as energy crop, showing a great expansion potential. Studies have shown that in the coming years, ethanol yield per hectare of sugarcane, which presently is 6000 L/ha, could reach 10,000 L/ha, if 50% of the produced bagasse would be converted to ethanol. This article describes the efforts of different Brazilian institutions and research groups on second generation bioethanol production, especially from sugarcane bagasse. (C) 2009 Elsevier Ltd. All rights reserved.MCIMCICNPqConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CAPESCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FINEPFinanciadora de Estudos e Projetos (FINEP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESPPetróleo Brasileiro S.A. (PETROBRAS)PETRO-BRA
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