80 research outputs found

    Influencia da variaçao da constante solar na temperatura à superficie

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    Ponencia presentada en: XXX Jornadas Científicas de la AME y el IX Encuentro Hispano Luso de Meteorología celebrado en Zaragoza, del 5 al 7 de mayo de 2008

    Synthesis of 2,6-bis-(oxazolyl)pyridine ligands for luminescent Ln(III) complexes

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    Submitted to the European Journal of Organic ChemistryNew bis-(oxazolyl)pyridine ligands for Ln(III) ions were prepared using a expeditious methodology from threonine and dipicolinic acid chloride. The synthetic strategy includes a dehydration step to give a bis-dehydroaminobutyric acid derivative followed by bromination and cyclization with DBU. Photophysical studies of Eu(III) and Tb(III) complexes of these ligands showed that the 2,6-bis-(oxazolyl)pyridine moiety acts as an effective sensitizer for lanthanide luminescence and indicate the formation of 3:1 complexes [Ln-(bis-(oxazole)pyridine)3]3+.Fundação para a Ciência e Tecnologia (FCT), QREN, FEDER/E

    New eugenol derivatives with enhanced insecticidal activity

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    Eugenol, the generic name of 4-allyl-2-methoxyphenol, is the major component of clove essential oil, and has demonstrated relevant biological potential with well-known antimicrobial and antioxidant actions. New O-alkylated eugenol derivatives, bearing a propyl chain with terminals like hydrogen, hydroxyl, ester, chlorine, and carboxylic acid, were synthesized in the present work. These compounds were later subjected to epoxidation conditions to give the corresponding oxiranes. All derivatives were evaluated against their effect upon the viability of insect cell line Sf9 (Spodoptera frugiperda), demonstrating that structural changes elicit marked effects in terms of potency. In addition, the most promising molecules were evaluated for their impact in cell morphology, caspase-like activity, and potential toxicity towards human cells. Some molecules stood out in terms of toxicity towards insect cells, with morphological assessment of treated cells showing chromatin condensation and fragmentation, which are compatible with the occurrence of programmed cell death, later confirmed by evaluation of caspase-like activity. These findings point out the potential use of eugenol derivatives as semisynthetic insecticides from plant natural products.This research was funded by COMPETE 2020 program, co-financed by the FEDER and the European Union, PTDC/ASP-AGR/30154/2017 (POCI-01-0145-FEDER-030154). The authors also acknowledge the Foundation for Science and Technology (FCT; Portugal), and FEDER-COMPETE/QREN-EU for financial support to the research centers CQ/UM (UIDB/00686/2020), CF-UM-UP (UIDB/04650/2020) and REQUIMTE (UIDB/50006/2020). The NMR spectrometer Bruker Avance III 400 is part of the NationalNMRNetwork and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and the FCT. The authors would also like to thank RIAIDT-USC for the use of their analytical facilities

    The role of university teachers in providing support to their students with disabilities

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    University academic teachers have the responsibility to ensure the inclusion of students with intellectual disabilities in their classrooms. To this end, as has been confirmed in several studies, it is necessary to incorporate competences in the teaching CVs; specific training on disability, social, communicative and pedagogical skills among others... Also, university teaching staff must be supported by their institutions and be predisposed to be trained in such competences. The Universal Design for Learning (UDL) is responsible for facilitating flexible and inclusive educational practice; it aims to respond to the training needs of both students and teaching staff in all their diversity.This paper is result of the Erasmus + project “Training university teachers for the inclusion of people with intellectual disabilities” 2019-1-ES01-KA203-065823. The European Commission support for the production of this publication does not constitute an endorsement of the contents which reflects the views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained therein.info:eu-repo/semantics/publishedVersio

    Estudo de sensibilidade das previsoes de superficie em Portugal pelo WRF face à variaçao das parametrizaçoes físicas

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    Ponencia presentada en: XXX Jornadas Científicas de la AME y el IX Encuentro Hispano Luso de Meteorología celebrado en Zaragoza, del 5 al 7 de mayo de 2008

    Fluorescence properties of a potential antitumoral benzothieno[3,2-b]pyrrole in solution and lipid membranes

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    Fluorescence properties of the antitumoral methyl 3-(benzo[b]thien-2-yl)-benzothieno[3,2-b]pyrrole-2-carboxylate (BTP) were studied in solution and in lipid bilayers of dipalmitoyl phosphatidylcholine (DPPC), dioleoyl phosphatidylethanolamine (DOPE) and egg yolk phosphatidylcholine (Egg-PC). BTP presents good fluorescence quantum yields in all solvents studied (0.20 ≤ ΦF ≤ 0.32) and a bathochromic shift in polar solvents. The results indicate an ICT character of the excited state, with an estimated dipole moment of μe = 7.38 D. Fluorescence (steady-state) anisotropy measurements of BTP incorporated in lipid membranes of DPPC, DOPE and Egg-PC indicate that this compound is deeply located in the lipid bilayer, feeling the difference between the rigid gel phase and fluid phases. BTP inhibits the growth of three human tumour cell lines, MCF-7 (breast adenocarcinoma), SF-268 (glioma) and NCI-H460 (non-small cell lung cancer), being significantly more potent against the NCI-H460 tumour cells.European Communitarian Fund (FEDER)Fundação para a Ciência e a Tecnologia (FCT) – projecto SeARCH (ref. REEQ/443/EEI/2005), bolsa SFRH/BPD/24548/2005, projecto PTDC/QUI/81238/200

    Magnetic liposomes based on nickel ferrite and manganese ferrite nanoparticles for biomedical applications

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    In this work, nickel ferrite and manganese ferrite nanoparticles were synthesized and characterized. These nanoparticles were incorporated in liposomes for biomedical applications.Fundação para a Ciência e a Tecnologia (FCT

    Synthesis of fluorescent heteroaromatic compounds using dehydroamino acids as building blocks, studies of DNA and biomembranes interactions : evaluation of antiproliferative effects on tumor cell lines

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    Thanks are due to the Fundação para a Ciência e Tecnologia (FCT, Portugal) and FEDER to financial support through the research centres, the research project POCI/59407/2004 and pos-Doc grants attributed to A.S.Abreu (SFRH/BPD/24548/2005) and to L.V.-S. (SFRH/BPD/29112/2006)

    Liposomal formulations loaded with a eugenol derivative for application as insecticides: encapsulation studies and In silico identification of protein targets

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    Supplementary Materials can be downloaded at: https://www.mdpi.com/article/10.3390/nano12203583/s1,A recently synthesized new eugenol derivative, ethyl 4-(2-methoxy-4-(oxiran-2-ylmethyl)phenoxy)butanoate, with a high insecticidal activity against Sf9 (Spodoptera frugiperda) insect cells, was encapsulated in the liposomal formulations of egg-phosphatidylcholine/cholesterol (Egg-PC:Ch) 70:30 and 100% dioleoylphosphatidylglycerol (DOPG), aiming at the future application as insecticides. Compound-loaded DOPG liposomes have sizes of 274 ± 12 nm, while Egg-PC:Ch liposomes exhibit smaller hydrodynamic diameters (69.5 ± 7 nm), high encapsulation efficiency (88.8% ± 2.7%), higher stability, and a more efficient compound release, thus, they were chosen for assays in Sf9 insect cells. The compound elicited a loss of cell viability up to 80% after 72 h of incubation. Relevantly, nanoencapsulation maintained the toxicity of the compound toward insect cells while lowering the toxicity toward human cells, thus showing the selectivity of the system. Structure-based inverted virtual screening was used to predict the most likely targets and molecular dynamics simulations and free energy calculations were used to demonstrate that this molecule can form a stable complex with insect odorant binding proteins and/or acetylcholinesterase. The results are promising for the future application of compound-loaded nanoliposome formulations as crop insecticides.This research was funded by project PTDC/ASP-AGR/30154/2017 (POCI-01-0145-FEDER 030154) of the COMPETE2020 program, co-financed by the FEDER and the European Union. The authors also acknowledge the Foundation for Science and Technology (FCT, Portugal) and FEDERCOMPETE QREN-EU for financial support to the research centers CQUM (UID/QUI/00686/2021), CF-UM-UP (UIDB/04650/2020) and REQUIMTE (UIDB/50006/2020). Renato B. Pereira acknowledges PRIMA Foundation (H2020-PRIMA 2018—Section 2, Project MILKQUA) and FCT (PTDC/QUI-QFI/2870/2020) for additional funding. The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and FCT
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