Para uma periodização da pré-história recente do norte de Portugal: da segunda metade do 4º milénio aos finais do 3º milénio AC

Tendo como base novas premissas e novos dados resultantes de projetos de investigação desenvolvidos para a Pré-história Recente, em diferente áreas do Norte de Portugal, as autoras revisitam as diferentes periodizações elaboradas para o período compreendido entre a segunda metade do 4º e os finais do 3º milénios AC (os chamados Neolítico Médio/Final, Calcolítico e Bronze Antigo ou Inicial). A uma ampla escala de análise, reflete-se sobre as bases duma futura periodização conjunta para a região, destacando-se, na longa duração, continuidades e mudanças culturais.Based on new premises and new data resulting from research projects developed for Late Prehistory in different areas of Northern Portugal, the authors review the different periodization’s elaborated for the period between the second half of the fourth and the end of the third millennia BC (the so-called Middle/Late Neolithic, Chalcolithic and Early Bronze Age). A broad scale of analysis reflects on the basis of a future joint periodization for the region, highlighting, in the long run, cultural continuities and changesinfo:eu-repo/semantics/acceptedVersio

Oxazole light triggered protecting groups: synthesis and photolysis of fused heteroaromatic conjugates

Fused oxazole derivatives were synthesized and evaluated as new light triggered protecting groups by using amino acids as model bifunctional molecules. The photosensitivity of ester conjugates was tested under irradiation at 254, 300, and 350 nm. Oxazole conjugates were readily photolyzed with complete release of the amino acid, the best results obtained for naphtho[2,3-d]oxazole at 254 and 300 nm, being the first reported application of this type of heterocycles as photocleavable protecting groups for carboxylic acids.Thanks are due to the Foundation for Science and Technology (Portugal) for financial support through project PTDC/QUI/69607/2006 (FCOMP-01-0124-FEDER-007449) and Centro de Quimica (Universidade do Minho). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased in the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005 with funds from POCI 2010 (FEDER) and FCT

Natação para bebés: a necessidade de uma acção conscientemente dirigida

A natação para bebés tem sido uma actividade aquática bastante procurada nos nossos dias.info:eu-repo/semantics/publishedVersio

The use of biomarkers to evaluate the toxicity of metaldehyde and methiocarb baits to the terrestrial isopod porcellionides pruinosus Brandt, 1833

Biochemical indicators (biomarkers) are known to provide early warning signs of environmental pollution or stress conditions to the organisms, by measuring cellular or molecular responses of the target organism to xenobiotic agents. In this study, the terrestrial isopod Porcellionides pruinosus was exposed to these two molluscicides and three different enzymes, glutathione Stransferase (GST), acetylcholinesterase (AChE) and catalase (CAT) were analyzed to evaluate the effects of the application of the two molluscicides in single exposures and binary mixtures tests. Results indicate that the carbamate methiocarb inhibited significantly AChE activity, but no effects were observed in CAT and GST levels. The exposure to the metaldehyde had no effects on AChE, but a decrease in the higher exposure period was observed in GST levels as well as a general increase in CAT activity. The combined exposure of the two molluscicides resulted in a general decrease in AChE and CAT activity, but no visible effects were observed in terms of GST. The use of several biomarkers was a suitable tool to understand the mode of action of these two molluscicides in this isopod species

Photoactivable oxobenzopyranoxazole esters of 5-aminolevulinic acid

Comunicação em painel P51 no 1st European Young Chemists Meeting/ 5th Portuguese Young Chemists Meeting, Guimarães, Portugal, 26-29 Abril 2016.In this communication we report the synthesis of new oxobenzopyranoxazoles 1a,b as photolabile protecting groups and their conjugation with 5-(N-butyloxycarbonyl)aminolevulinic acid 2 via an ester bond. The study of the photolytic behaviour of the resulting conjugates in different conditions was carried out in a photochemical reactor by irradiation at 254, 300, 350 and 419 nm, monitored by HPLC-UV and 1H NMR.Thanks are due to the Foundation for Science and Technology (Portugal) for financial support through project PEstC/QUI/UI0686/2013 (F-COMP-01-0124-FEDER-037302) FEDER-COMPETE, FCT-Portugal. A PhD grant to A.M.S.S. (SFRH/BD/80813/2011) is also acknowledged. The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased in the framework of the National Program for Scientific Reequipment, with funds from POCI 2010 (FEDER) and FCT.info:eu-repo/semantics/publishedVersio

Assessing the acute and chronic toxicity of exposure to naturally occurring oil sands deposits to aquatic organisms using Daphnia magna

In the Athabasca region, the oil sands are located at or near the surface making open-pit mining viable. In addition, the Athabasca River and its tributaries flow through these oil sands deposits, thereby receiving bitumen-associated contaminants through natural fluvial erosional and weathering processes. A key knowledge gap has been related to understanding both the magnitude and significance of the toxicological and ecological effects on aquatic organisms exposed to naturally occurring bitumen entering fluvial systems. Using the Daphnia magna model system, this study assessed the ecotoxicological effects of exposure to bitumen-elutriate treatments that simulated the early stages of fluvial/erosional exposure conditions. No significant among-site differences were observed in the survival of D. magna after 48 h exposure to elutriates produced from a 24 h extraction cycle, and chemical analysis indicated low concentration of a complex mixture of hydrocarbon and metal contaminants. In contrast, the same elutriates impaired reproduction and growth after a 21-day chronic exposure. F1 neonates from the chronic tests were tested for sensitivity to the reference substance potassium dichromate, revealing a decrease in their sensitivity. Inter-generational effects were also observed, with a significant decrease in subsequent neonate production, when daphnids were moved to a clean medium. Supplemental acute toxicity assays using 48 and 72 h bitumen extraction cycles progressively increased daphnid mortality after a 48-h exposure to the respective elutriates. This indicates that bitumen-associated contaminants are being liberated after initial input and fluvial washing (24 h), highlighting the need for future work to assess toxicity responses and associated elutriate water chemistry of a longer fluvial exposure time-series. This work contributes to our understanding of the possible effects of natural bitumen exposure on riverine aquatic ecosystems, providing new information to inform the delineation of baseline conditions to assess environmental change and the design of future regional effects-based monitoring programs.publishe

Photorelease of amino acids from novel thioxobenzo[f]benzopyran ester conjugates

Aiming at the enhancement of the performance of (9-methoxy-3-oxo-3H-benzo[f]benzopyran-1-yl) methyl ester as photocleavable protecting group for the carboxylic acid function at long-wavelengths, 9-methoxy-3-thioxo-3H-benzo[f]benzopyran-L-valine and L-phenylalanine model conjugates were prepared through a thionation reaction of the corresponding oxo-benzobenzopyrans. These thioxobenzobenzopyran derivatives were subjected to photocleavage reactions in the same conditions as the parent oxo-benzobenzopyrans at different wavelengths of irradiation, and photocleavage kinetic data was obtained. It was found that the exchange of the carbonyl by a thiocarbonyl group enhanced the performance of the heterocyclic protecting group at 419 nm by improving the photolysis rates, making it an appropriate group for practical applications at long wavelengths.Fundo Europeu de Desenvolvimento Regional (FEDER) - POCI 2010Fundação para a Ciência e a Tecnologia (FCT) - REDE/1517/RMN/200

Aportaciones desde la biomecánica de la natación de competición

A natação é uma modalidade individual, cíclica e fechada, pelo que, no respectivo quadro de factores determinantes do sucesso competitivo, a optimização do gesto técnico desempenha um papel determinante.info:eu-repo/semantics/publishedVersio

Gold nanoparticles as therapeutic agent for radiotherapy of PC3 prostate cancer cell line

Radiotherapy (RT) is a therapeutic modality that deliver a precise dose of ionizing radiation in a specific tumour volume, promoting the irradiation of tumor cells with as minimal damage as possible in surrounding normal tissues. Besides the evolution of equipment and technology, this therapy still has some problems related with radioresistance, which consequently increase the recurrence at 5 years. Over the years, gold nanoparticles (AuNP) have attracted a lot of interest in cancer therapies due their unique chemical, optical and physical properties. So, it was synthetized two different types of AuNPs spherical (AuNPsp) and rods (AuNPr) for treat human prostate cancer cell line (PC3) and it was observed cell behavior when treated cells were irradiated with three fractions of 2,5 Gy. AuNPs were characterized using UV-Vis and TEM to confirm their size and shape. After, cells were treated with different concentrations of AuNPs from 0 to 1.0 mM during 24h. The results showed that none of the forms of AuNPs show signals of cytotoxicity until 1.0 mM, with exception of 1mM of AuNPr, where cells exhibit cytotoxicity around ~10%. Taken all together, AuNPsp and AuNPr demonstrated be effective to reduce the cell viability when associated to RT. Comparing both structures, AuNPr demonstrated a higher dose-dependency with and without radiation and under irradiation the inhibition of cell growth is higher when compared to control (no treatment). These results demonstrate for the first time the possibility of different forms of AuNPs can be used as potential radiosensitizer for prostate cancer cells.Sílvia Soares is grateful for the financial support of Fundação para a Ciência e Tecnologia (grant reference SFRH/BD/138271/2018 and thanks the kind collaboration of all those involved in the radiotherapy service at Centro Hospitalar Universitário de São João for carrying out radiotherapy treatmentsinfo:eu-repo/semantics/publishedVersio

Nanotheranostics with gold nanoparticles applied to Radiotherapy

Sílvia Soares is grateful for the financial support of Fundação para a Ciência e Tecnologia (grant reference: SFRH/BD/138271/2018) and thanks the kind collaboration of all those involved in the radiotherapy service at Centro Hospitalar Universitário de São João for carrying out radiotherapy treatments.info:eu-repo/semantics/publishedVersio