51 research outputs found

    Hybrid sol-gel coatings: smart and green materials for corrosion mitigation

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    Corrosion degradation of materials and metallic structures is one of the major issues that give rise to depreciation of assets, causing great financial outlays in their recovery and or prevention. Therefore, the development of active corrosion protection systems for metallic substrates is an issue of prime importance. The promising properties and wide application range of hybrid sol-gel-derived polymers have attracted significant attention over recent decades. The combination of organic polymers and inorganic materials in a single phase provides exceptional possibilities to tailor electrical, optical, anticorrosive, and mechanical properties for diverse applications. This unlimited design concept has led to the development of hybrid coatings for several applications, such as transparent plastics, glasses, and metals to prevent these substrates from permeation, mechanical abrasion, and corrosion, or even for decorative functions. Nevertheless, the development of new hybrid products requires a basic understanding of the fundamental chemistry, as well as of the parameters that influence the processing techniques, which will briefly be discussed. Additionally, this review will also summarize and discuss the most promising sol-gel coatings for corrosion protection of steel, aluminium, and their alloys conducted at an academic level.info:eu-repo/semantics/publishedVersio

    Gold nanoparticles for vectorization of nucleic acids for cancer therapeutics

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    This work was supported by the Applied Molecular Biosciences Unit-UCIBIO which is financed by national funds from FCT (Portuguese Foundation for Science and Technology) under the projects (UIDB/04378/2020), PTDC/NAN-MAT/31100/2017 and M-ERA-NET2/0008/2016-MagicCellGene (for DF).Cancer remains a complex medical challenge and one of the leading causes of death worldwide. Nanomedicines have been proposed as innovative platforms to tackle these complex diseases, where the combination of several treatment strategies might enhance therapy success. Among these nanomedicines, nanoparticle mediated delivery of nucleic acids has been put forward as key instrument to modulate gene expression, be it targeted gene silencing, interference RNA mechanisms and/or gene edition. These novel delivery systems have strongly relied on nanoparticles and, in particular, gold nanoparticles (AuNPs) have paved the way for efficient delivery systems due to the possibility to fine-tune their size, shape and surface properties, coupled to the ease of functionalization with different biomolecules. Herein, we shall address the different molecular tools for modulation of expression of oncogenes and tumor suppressor genes and discuss the state-of-the-art of AuNP functionalization for nucleic acid delivery both in vitro and in vivo models. Furthermore, we shall highlight the clinical applications of these spherical AuNP based conjugates for gene delivery, current challenges, and future perspectives in nanomedicine.publishersversionpublishe

    Dietary methionine improves the european seabass (dicentrarchus labrax) immune status, inflammatory response, and disease resistance

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    Methionine presents a pivotal role in the regulation of many cellular events with crucial impact on the immune system, such as in processes involved in the control of inflammation and polyamines synthesis. Accordingly, the present study aimed to assess the modulatory effects of dietary methionine on the European seabass (Dicentrarchus labrax) immune status, inflammatory response and disease resistance to Photobacterium damselae subsp. piscicida (Phdp). For this purpose, fish were randomly distributed in three independent groups (three replicates per group) and each was fed the corresponding diet: a control diet (CTRL) formulated to meet the established amino acid requirements for the species; a diet supplemented with methionine at 0.5% of feed weight relative to the CTRL diet (8.2% of methionine concentration above CTRL); and one supplemented with methionine at 1% of feed weight to the CTRL diet (11.8% of methionine concentration above CTRL). To evaluate the immune status of fish fed with each of the diets before being submitted to bacterial infection fish were sampled from each group at 2 and 4 weeks after the beginning of feeding. Non- sampled fish were injected intraperitoneally with Phdp (5 × 103 cfu/fish) at 4 weeks after initiation of feeding and the inflammatory response (at 4, 24, and 48 h post-infection) and survival (lasting 21 days post-infection) evaluated. Fish hematological profile, peripheral cell dynamics, plasma humoral immune parameters, leucocyte migration to the inflammatory focus and head-kidney gene expression were evaluated. Results show that methionine dietary supplementation improves seabass cellular immune status without evidence of activation of pro-inflammatory mechanisms. Additionally, the observed enhanced immune status provided by methionine supplementation translated into an improved immune response to infection, as higher cellular differentiation/proliferation and recruitment toThis work was partially supported by Projects ALISSA (reference ALG-01-0247-FEDER-3520) and F/00197/2015, financed by Portugal and the European Union through FEDER, COMPETE 2020 and CRESC Algarve 2020, in the framework of Portugal 2020, and through the COMPETE and Operational Human Potential Programmes and national funds through Fundação para a Ciência e a Tecnologia (FCT, Portugal). MM and BC were supported by FCT, Portugal (SFRH/BD/108243/2015 and IF/00197/2015, respectively). The authors also acknowledge Dr. Nuno Santos and Dr. Ana do Vale (i3S/IBMC) support during the study and for critically reviewing the manuscript

    Adenosine A(2A) receptor blockade reverts hippocampal stress-induced deficits and restores corticosterone circadian oscillation

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    Maternal separation (MS) is an early life stress model that induces permanent changes in the central nervous system, impairing hippocampal long-term potentiation (LTP) and spatial working memory. There are compelling evidences for a role of hippocampal adenosine A(2A) receptors in stress-induced modifications related to cognition, thus opening a potential window for therapeutic intervention. Here, we submitted rats to MS and evaluated the long-lasting molecular, electrophysiological and behavioral impairments in adulthood. We then assessed the therapeutic potential of KW6002, a blocker of A(2A) receptors, in stress-impaired animals. We report that the blockade of A(2A) receptors was efficient in reverting the behavior, electrophysiological and morphological impairments induced by MS. In addition, this effect is associated with restoration of the hypothalamic-pituitary-adrenal axis (HPA-axis) activity, as both the plasma corticosterone levels and hippocampal glucocorticoid receptor expression pattern returned to physiological-like status after the treatment. These results reveal the involvement of A(2A) receptors in the stress-associated impairments and directly in the stress response system by showing that the dysfunction of the HPA-axis as well as the long-lasting synaptic and behavioral effects of MS can be reverted by targeting adenosine A(2A) receptors. These findings provide a novel evidence for the use of adenosine A(2A) receptor antagonists as potential therapy against psychopathologiesWe acknowledge Alexandre de Mendonca, David Blum and Rodrigo Cunha for helpful discussions. VLB is thankful to Joao Baiao and Carla Batalha for technical assistance. VLB has been awarded a PhD fellowship from Fundacao para a Ciencia e Tecnologia (BD/63041/2009). LVL is funded by Fundacao para a Ciencia e Tecnologia (PTDC/SAU-NEU/099853/2008) and by EU programme Egide-Pessoa. YB and CEM were funded by the Ministry for Education and Research (BMBF, Grant number 01EW0911) in the frame of ERA-NET NEURON

    A biodiversidade terrestre e dulçaquícola dos arquipélagos da Madeira e das Selvagens

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    As ilhas atlânticas dos Açores, Madeira, Selvagens, Canárias e Cabo Verde constituem uma das regiões da Europa mais ricas em diversidade de fungos, plantas e animais. Desde 2004 que a inventariação detalhada da diversidade destas ilhas tem sido um dos principais objectivos dos projectos ATLÂNTICO e BIONATURA (incluídos no projecto EU INTERREG IIIB). Este livro é a mais recente contribuição destes projectos, apresentando uma lista de todos os fungos, flora e fauna terrestre conhecida, incluindo a dulçaquícola, para dois arquipélagos atlânticos (Madeira e Selvagens). A lista abrange o arquipélago da Madeira, constituído por duas ilhas de maiores dimensões (Madeira e Porto Santo) e três pequenas, cujo conjunto constitui as Desertas (Ilhéu Chão, Deserta Grande e Bugio), e ainda o arquipélago das Selvagens, formado por duas pequenas ilhas (Selvagem Grande e Selvagem Pequena) e um ilhéu (Ilhéu de Fora).ABSTRACT: The Azores, Madeira, Selvagens, Canary Islands and Cape Verde are among the richest regions in Fungi, plant and animal diversity in Europe. The main objectives of the EU INTERREG IIIB projects ATLÂNTICO and BIONATURA have been, since 2004, to carry out a detailed inventory of the terrestrial Fungi, Flora and Fauna of these archipelagos. This book, encompassing a checklist of all the known terrestrial and freshwater Fungi, Flora and Fauna of Madeira and Selvagens archipelagos is the latest contribution towards that goal. The geographic scope of this checklist includes the Madeira archipelago, composed of two large islands (Madeira and Porto Santo) and three small islands, which are globally named Desertas (Ilhéu Chão, Deserta Grande and Bugio), and the archipelago of Selvagens with two small islands (Selvagem Grande and Selvagem Pequena) and one islet (Ilhéu de Fora)

    A validação da distribuição de espécies através de modelos preditivos: casos de estudo para a ilha da madeira

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    Os modelos preditivos de distribuição de espécies são uma importante ferramenta para lidar com a falta de informação biogeográfica existente para a maior parte dos taxa. Com esta técnica, estabelece -se uma relação entre a variável dependente (presença/ausência de uma espécie) e um conjunto de variáveis potencialmente preditoras, e é criado um mapa com a probabilidade de presença da espécie para uma determinada área de interesse. Neste capítulo, é usado o programa Maxent para criar modelos de distribuição potencial de um conjunto seleccionado de espécies, e os resultados obtidos são discutidos com base no conhecimento de especialistas nessas espécies.ABSTRACT: Predictive models of species distribution emerge as a valuable tool for tackling the lack of distributional information on most taxa. A function between the dependente variable (presence/absence of the species) and a set of potential predictors is established, and a map is generated for the focus area, indicating the probability of presence of the species. In this chapter, we use Maxent to develop potential distribution models for a number of selected species and we discuss the results on the basis of expert knowledge

    AMP Affects Intracellular Ca2+ Signaling, Migration, Cytokine Secretion and T Cell Priming Capacity of Dendritic Cells

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    The nucleotide adenosine-5′-monophosphate (AMP) can be released by various cell types and has been shown to elicit different cellular responses. In the extracellular space AMP is dephosphorylated to the nucleoside adenosine which can then bind to adenosine receptors. However, it has been shown that AMP can also activate A1 and A2a receptors directly. Here we show that AMP is a potent modulator of mouse and human dendritic cell (DC) function. AMP increased intracellular Ca2+ concentration in a time and dose dependent manner. Furthermore, AMP stimulated actin-polymerization in human DCs and induced migration of immature human and bone marrow derived mouse DCs, both via direct activation of A1 receptors. AMP strongly inhibited secretion of TNF-α and IL-12p70, while it enhanced production of IL-10 both via activation of A2a receptors. Consequently, DCs matured in the presence of AMP and co-cultivated with naive CD4+CD45RA+ T cells inhibited IFN-γ production whereas secretion of IL-5 and IL-13 was up-regulated. An enhancement of Th2-driven immune response could also be observed when OVA-pulsed murine DCs were pretreated with AMP prior to co-culture with OVA-transgenic naïve OTII T cells. An effect due to the enzymatic degradation of AMP to adenosine could be ruled out, as AMP still elicited migration and changes in cytokine secretion in bone-marrow derived DCs generated from CD73-deficient animals and in human DCs pretreated with the ecto-nucleotidase inhibitor 5′-(alpha,beta-methylene) diphosphate (APCP). Finally, the influence of contaminating adenosine could be excluded, as AMP admixed with adenosine desaminase (ADA) was still able to influence DC function. In summary our data show that AMP when present during maturation is a potent regulator of dendritic cell function and point out the role for AMP in the pathogenesis of inflammatory disorders

    New national and regional bryophyte records, 52

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    Marchantia paleacea is a new species for the Umbria Region and is rare in central and southern Italy. This record is in a Site of Community Importance (SCI) IT5220017 and a Special Area of Conservation (SAC) of the Natura 2000 EU-wide network due to the presence of the 7220* ‘Petrifying springs with tufa formation (Cratoneurion)’ Annexe I priority habitat. The particular environment, with a gorge and waterfall, created a very special microclimate that allowed the establishment of interesting liverworts and mosses

    Corrosão da estátua de D. José I em Lisboa

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    Submitted by [email protected] ([email protected]) on 2009-09-28T14:27:57Z No. of bitstreams: 1 CPM_2008_2.pdf: 227437 bytes, checksum: 058c7f42b4c7da15ba4e639eb8adce14 (MD5)Approved for entry into archive by [email protected]([email protected]) on 2009-10-08T11:10:44Z (GMT) No. of bitstreams: 1 CPM_2008_2.pdf: 227437 bytes, checksum: 058c7f42b4c7da15ba4e639eb8adce14 (MD5)Made available in DSpace on 2009-10-08T11:10:50Z (GMT). No. of bitstreams: 1 CPM_2008_2.pdf: 227437 bytes, checksum: 058c7f42b4c7da15ba4e639eb8adce14 (MD5) Previous issue date: 2008Made available in DSpace on 2010-04-27T07:24:47Z (GMT). No. of bitstreams: 2 license.txt: 1837 bytes, checksum: a03a7a9a0a3a9a00df3dd051f9f125f0 (MD5) CPM_2008_2.pdf: 227437 bytes, checksum: 058c7f42b4c7da15ba4e639eb8adce14 (MD5) Previous issue date: 2008Made available in DSpace on 2014-10-20T16:32:12Z (GMT). No. of bitstreams: 2 CPM_2008_2.pdf: 227437 bytes, checksum: 058c7f42b4c7da15ba4e639eb8adce14 (MD5) license.txt: 1837 bytes, checksum: a03a7a9a0a3a9a00df3dd051f9f125f0 (MD5) Previous issue date: 2008Made available in DSpace on 2017-04-12T13:45:40Z (GMT). No. of bitstreams: 2 license.txt: 1837 bytes, checksum: a03a7a9a0a3a9a00df3dd051f9f125f0 (MD5) CPM_2008_2.pdf: 227437 bytes, checksum: 058c7f42b4c7da15ba4e639eb8adce14 (MD5) Previous issue date: 20082098-98Vol. 27 Nº
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