Pharmaceuticals in the environment : occurrence and exposure effects in non-target fish species

A contaminação por fármacos nas zonas costeiras constitui um problema ambiental emergente, onde os fármacos neuroativos são de particular importância porque bioacumulam em espécies não-alvo, afetando o sistema nervoso central e causando efeitos ao nível das populações. Os resultados demonstram, na literatura existente, os diversos efeitos adversos da exposição de fármacos neuroativos em peixes, apesar de incidir sobre poucos compostos e maioritariamente espécies de água-doce. A bioconcentração é também insuficientemente considerada e raramente estudada em combinação com outras respostas biológicas, dificultando a conjugação entre concentração interna e efeitos observados. A estimativa da bioconcentração dos fármacos neuroativos através da sua lipofilicidade não é direta e depende de múltiplos fatores experimentais, o que dificulta a previsão de risco. Contudo, concentrações ambientais de nove fármacos neuroativos excedem ou estão próximas de concentrações que causam efeitos deletérios em peixes. Dados ambientais, com a deteção de até 28 fármacos neuroativos em águas superficiais e peixes, evidenciam a ubiquidade e diversidade destes compostos em estuários, sendo que o padrão de bioacumulação em sete espécies de peixes foi independente da lipofilicidade dos compostos, do uso do habitat ou do nível-trófico das espécies, com maior frequência e concentrações observadas no cérebro, seguido do fígado e músculo. Experiências de curta e longa exposição a fármacos neuroativos com duas espécies estuarinas/marinhas demonstraram a toxicidade de fármacos com diferentes modos-de-ação, revelando maior acumulação e toxicidade do fármaco neuroativo, fluoxetina, em comparação com outros fármacos frequentemente detetados. As respostas sub-individuais revelaram efeitos em processos essenciais (e.g. mecanismos antioxidantes, biotransformação, metabolismo energético), enquanto efeitos individuais de relevância ecológica (e.g. crescimento, comportamentos alimentares e locomotores) ocorreram após exposição crónica, ou aguda a concentrações mais elevadas. Em suma, novos conhecimentos relativos à presença, acumulação e efeitos da exposição em peixes, demonstram a necessidade de priorizar a investigação e monitorização dos fármacos neuroativos em ecossistemas costeiros.Pharmaceutical contamination in coastal ecosystems is an emerging environmental issue, with neuroactive pharmaceuticals of particular concern as they bioaccumulate in non-target fish, affect the central nervous system and can trigger population-level effects. The presented outcomes disclose recent research efforts, revealing multiple adverse effects of exposure to neuroactive pharmaceuticals in fish, albeit skewed data concerning few neuroactive compounds and largely freshwater species exist. Moreover, bioconcentration is seldom considered and rarely determined in combination with other endpoints, hampering the link between internal dosage and effects. Also, estimating the bioconcentration of neuroactive pharmaceuticals through lipophilicity is not straightforward, depending on multiple experimental factors. Here, nine neuroactive compounds were signalled as potentially threatening in aquatic ecosystems due to environmental concentrations either exceeding or near thresholds known to significantly affect fish behaviour, growth and condition or reproduction. Up to 28 neuroactive pharmaceuticals were detected in estuarine surface waters and seven fish species demonstrating the diversity and pervasiveness of neuroactive compounds in both high and slightly impacted coastal ecosystems. Bioaccumulation among all species revealed no clear pattern linked to compounds lipophilicity, species habitat use or trophic level, with higher frequency and concentrations observed in the brain, followed by liver and muscle tissues. Acute and chronic exposure experiments with two estuarine/marine fish species evidenced the toxicity of three pharmaceuticals with different modes-of-action, highlighting higher uptake and toxicity of the neuroactive com-pound fluoxetine in comparison to other frequently detected compounds tested. Sub-individual measurements revealed effects on critical processes (e.g. antioxidant and biotransformation mechanisms, or energetic metabolism), whereas individual-level effects of higher ecological relevance (e.g. alterations to growth, feeding or activity behaviours) followed chronic exposure or acute exposure at higher concentrations. Overall, critical insights on environmental fate and exposure effects in fish are provided, highlighting the need for priority research and continuous monitoring of neuroactive pharmaceuticals in coastal ecosystems

The importance of low molecular weight protein tyrosine phosphatase in the progression of metastatic bone disease and therapeutic response

Tese de doutoramento, Ciências Biomédicas (Ciências Biopatológicas), Universidade de Lisboa, Faculdade de Medicina, 2013Bone metastases are the leading cause of morbidity and mortality among patients with breast cancer. Two different therapeutic approaches are used in patients with advanced metastatic bone disease: anti-tumor and anti-resorptive therapeutics such as bisphosphonates that block osteoclasts activity. Among patients treated with bisphosphonates, around 25% are non-responders. Our studies were based in LMW-PTP, codified by ACP1, a polymorphic enzyme with two main isoforms, called fast and slow. This protein has been largely associated with cancer, although with contradictory roles. Recently, LMW-PTP has been involved in bone metabolism. Our first results showed that the LMW-PTP slow isoform is more expressed in breast cancer cells compared to non-tumor cells. The fast isoform has the opposite pattern. However, both isoforms are involved in migration through a RhoA dependent mechanism, decreasing the migratory potential of cells, confirming previous studies suggesting the importance of GTP/GDP RhoA balance in the migratory potential and not its absolute activity. Suppression of the slow isoform in a breast tumor cell line decreased osteoclastogenesis, and this mechanism involved at least Src inactivation and decrease of IL8 production in the tumor cell line. Studies in surgical samples of normal, primary and metastatic breast cancer tissue, confirmed involvement of the slow isoform in tumor behavior and showed an increase in the fast isoform expression, suggesting that in metastatic tissue, where the vicious cycle of bone metastasis is well established, the fast isoform is being regulated by the microenvironment and this microenvironment has the ability to increase the expression of this isoform, possibly as an enhancement mechanism in response to the osteoclastogenic potential of the slow isoform. Regarding therapeutic response to bisphosphonates, there were no differences according to ACP1 genotypes. Taken together, our results showed that the two main LMW-PTP isoforms may have different roles depending on tumor stage, with the fast isoform being more dependent on the tumor microenvironment. Regarding the ACP1 polymorphism, and according to our results, it cannot be used either as a therapeutic response marker or as a prognostic marker.As metástases ósseas são a principal causa de morbilidade e mortalidade entre os pacientes com cancro da mama. São correntemente utilizadas duas abordagens terapêuticas diferentes em pacientes com doença metastática óssea avançada: terapêuticas anti-tumorais e terapêuticas anti-resorptivas, tais como bisfosfonatos, que inibem a actividade osteoclástica. Entre os pacientes tratados com bisfosfonatos, cerca de 25% não respondem à terapêutica. Os nossos estudos basearam-se na LMW-PTP, codificada pelo ACP1, um enzima polimórfico com duas isoformas principais, denominadas fast e slow. Esta proteína tem sido amplamente associada a diferentes tipos de cancro, embora o seu papel permaneça contraditório. Recentemente, a LMW-PTP foi associada ao metabolismo ósseo. Os nossos primeiros resultados mostraram que a isoforma slow da LMW-PTP é mais expressa em células de cancro da mama do que em células não tumorais. A isoforma fast apresentou padrão de expressão oposto. No entanto, ambas as isoformas estão envolvidas na migração através de um mecanismo dependente do RhoA, diminuindo o potencial migratório das células, e confirmando estudos prévios que sugerem a importância do equilíbrio GTP/GDP RhoA no potencial migratório e não a sua actividade absoluta. A supressão da isoforma slow numa linha celular tumoral da mama diminuiu a osteoclastogénese, e este mecanismo envolve, pelo menos, a inactivação da Src e a diminuição da produção de IL8 pela linha celular. Os estudos realizados em amostras cirúrgicas de tecido normal, primário e metastático de cancro da mama, confirmaram o envolvimento da isoforma slow no comportamento tumoral, e mostraram um aumento da expressão da isoforma fast, sugerindo que no tecido metastático, onde o ciclo vicioso de metastização óssea se encontra bem estabelecido, a isoforma fast está a ser regulada pelo microambiente e este microambiente tem a capacidade de aumentar a expressão desta isoforma, possivelmente como um mecanismo de potenciação em resposta ao potencial osteoclastogénico da isoforma slow. No que diz respeito à resposta terapêutica aos bisfosfonatos, não houve diferenças de acordo com os genótipos do ACP1. Globalmente, os nossos resultados mostraram que as duas isoformas principais da LMW-PTP podem ter diferentes funções, dependendo do estadio do tumor, com a isoforma fast a mostrar maior dependência do microambiente tumoral. Quanto ao polimorfismo do ACP1, e de acordo com os nossos resultados, este não pode ser usado como um marcador de resposta terapêutica nem como um marcador de prognóstico.Fundação para a Ciência e a Tecnologia (FCT, SFRH/BD/44716/2008

Comparative analysis of biomarker responses to environmental contamination in estuaries: a multi-taxa approach

Tese de mestrado, Ecologia Marinha, Universidade de Lisboa, Faculdade de Ciências, 2016Estuaries are highly productive areas of high ecological and economic importance, providing various benefits and services for mankind. The estuarine watershed is a preferential location for human settlement and associated anthropogenic activities, such as industrial and agricultural development, resource exploitation and shipping activities, which result in continuous pressures inevitably leading to environmental degradation. Biomarkers are considered early-warning signs able to provide a predictive perspective of the long-term effects of exposure to pollutants in organisms. Therefore, biomarkers are considered useful tools for environmental quality assessment that integrate biological responses and the degree of stressors, usually applied in a single taxa context. Exposure to xenobiotics compounds and their metabolites lead to enhanced oxidative stress and potentially to major molecular damages such as oxidation of proteins, DNA and peroxidation of unsaturated lipids in cell membranes. Hence, defence mechanisms play a major role in preventing damages and include several enzymes such as antioxidant enzymes superoxide dismutase enzymes (SOD) and catalase (CAT), as well as phase I ethoxyresorufin-O-deethylase (EROD) and phase II glutathione S-transferase (GST) biotransformation enzymes. Accordingly, these enzymes activities as well as both biomarkers of effects lipid peroxidation (LPO) and DNA damage (DNAd) were determined in the present study aiming at assessing overall contamination impacts on various organisms. In this context, the aim of this work is to quantify multiple biomarker responses in a multi-taxa approach, in order to assess the diversity in response patterns among species from two differently impacted estuarine systems. Two Portuguese estuaries, Tejo and Ria de Aveiro, were sampled in two months, June and September 2015, specifically in two sites in each estuary: Alcochete (ALC) and Vila Franca de Xira (VFX) in Tejo and Mira channel (AVSUL) and Murtosa (MUR) in Ria de Aveiro. Several species were selected based on their abundance and estuarine occurrence as well as on their prior use as bioindicator species. Two fish species were considered, the European sea bass Dicentrarchus labrax, a marine migrant species whose juveniles use estuarine areas as nursery areas; and the common goby Pomatoschistus microps a resident estuarine species. Four invertebrate species were also sampled, two common infaunal species, the bivalve Scrobicularia plana and the ragworm Hediste diversicolor and two epibenthic crustaceans, the brown shrimp Crangon crangon and the green shore crab Carcinus maenas. Overall, biomarker responses signaled environmental chemical exposure and some degree of deleterious effects for all species. Low variability among sites and months was observed in antioxidant enzymes responses for most species and no clear pattern was discernible amongst species. In fish species, induction of both biotransformation enzymes was observed with significant spatial variability, with lower variability of GST comparing to EROD activity, though with overall concordant higher levels in Tejo estuarine sites, especially in ALC. Less marked responses in biotransformation enzymes were observed in invertebrate species. A similar GST response pattern was observed for H. diversicolor, S. plana and C. maenas, identifying higher contamination levels in AVSUL, considered the least contaminated site in this study. Very low or even incipient spatial and temporal variability in EROD activity was observed in all invertebrates. Nevertheless, these species signaled mostly Tejo sites according to phase I enzyme responses, especially VFX, which is in agreement with previously reported environmental contamination levels. Concerning monthly variation in general all species showed higher enzyme activities and effects in September, which may reflect the effects of continuous exposure. Notwithstanding the significant activity of detoxification enzymes, deleterious effects were reported for all species, suggesting an overall contamination level above the capacity of the molecular defence mechanisms to limit exposure effects in these species. Biomarkers of effects response patterns differed amongst species, yet akin LPO variability patterns were observed among species, namely between C. crangon, C. maenas and P. microps, signalling VFX and for D. labrax, H. diversicolor and S. plana, signalling MUR. Most species also showed higher mean DNAd values in VFX, except for C. crangon and C. maenas that signalled MUR. A positive correlation between biomarkers of effects was observed for all invertebrate species (except for H. diversicolor), highlighting site-specific contamination. IBR indices also varied throughout sampled sites for all species studied, yet the major pattern observed was the opposed response pattern between a highly mobile fish species D. labrax and both infaunal invertebrate species (S. plana and H. diversicolor). Species-specific responses were evident from lack of concordance among species biomarker responses and IBR scores, most likely due to biological differences (in terms of physiology, vulnerability and overall capacity of defence mechanisms), but also to ecological differences such as differential habitat use, feeding habits, life-strategies and consequently differential contaminants exposure. Overall, Tejo sites were considered more impacted than Ria de Aveiro, yet significant responses were also found in the latter for all species studied. In conclusion, this multi-biomarker and multi-taxa approach provided important insights into the variability of species responses to contaminants exposure in estuaries. The complexity of biomarker response patterns for all species in this study evidenced species differential response and differential exposure to environmental contamination, on top of the complex environmental stimuli, such as pollutants’ mixtures and natural variability characteristic of the estuarine environment. This emphasizes the difficulties associated with effective multi-species ecological risk assessment, and application must carefully consider the potential added ecological value of a multispecific approach (similar to a multi-biomarker approach) versus more complex results interpretation and assessment of the environmental quality.Os estuários são sistemas de elevada importância ecológica onde, por exemplo, muitas espécies encontram as condições favoráveis à sobrevivência e rápido desenvolvimento, bem como de elevado potencial económico, constituindo uma fonte importante de recursos e serviços para o Homem. Consequentemente, estes sistemas tornam-se locais preferenciais para o desenvolvimento de centros urbanos, de que resultam inúmeras pressões associadas às atividades antropogénicas, desde a pesca, aquacultura, à indústria, agricultura e navegação, o que inevitavelmente conduz à degradação da qualidade ambiental. Os biomarcadores são frequentemente utilizados com o intuito de avaliar de que forma as pressões nestes sistemas afetam os organismos que os habitam. Constituem desta forma uma ferramenta útil em estudos de avaliação da qualidade ambiental, ao fornecerem uma perspetiva integrada da pressão existente e das respostas ao nível biológico. A exposição dos organismos a compostos xenobióticos resulta no aumento do stress oxidativo que propicia a ocorrência de danos ao nível da célula, nomeadamente a oxidação de proteínas e do DNA (DNAd) e peroxidação lipídica (LPO). Não obstante, os mecanismos de defesa das células desempenham um papel fundamental na prevenção desses efeitos, de que são exemplos: enzimas antioxidantes, como a catalase (CAT) e a superóxido dismutase (SOD), e de biotransformação, como a 7-etoxiresorufina-O-deetilase (EROD) e a glutationa-S-transferase (GST). O objetivo deste trabalho consiste no estudo comparativo das respostas biológicas de várias espécies às pressões antropogénicas a que estão sujeitas no seu ambiente natural, através da quantificação de diferentes biomarcadores, em estuários com níveis de pressões distintos, o estuário do Tejo e a Ria de Aveiro. A amostragem foi realizada em dois meses, em junho e em setembro de 2015, e em dois locais em cada estuário: Alcochete (ALC) e Vila Franca de Xira (VFX) no estuário do Tejo e o canal de Mira (AVSUL) e Murtosa (MUR) na Ria de Aveiro, cujo nível de contaminação, fontes de pressão, função de viveiro e abundância de espécies foi previamente descrito. Para tal, foram selecionadas várias espécies que utilizam ambos os estuários e consideradas, em trabalhos anteriores, bioindicadoras da qualidade ambiental, nomeadamente: duas espécies de peixes, o robalo-legítimo Dicentrarchus labrax e o caboz-comum Pomatoschistus microps, e quatro espécies de invertebrados, nomeadamente duas espécies endobentónicas, o poliqueta Hediste diversicolor e o bivalve Scrobicularia plana, e duas espécies de crustáceos epibentónicos, o camarão-mouro Crangon crangon e o caranguejo-verde Carcinus maenas. As atividades das enzimas SOD, CAT, EROD e GST bem como os níveis de LPO e DNAd foram analisados nos tecidos apropriados para cada uma das espécies consideradas. De um modo geral, as respostas dos biomarcadores evidenciaram a exposição a contaminantes no ambiente, passível de induzir alguns mecanismos de defesa e destoxificação e de produzir efeitos ao nível molecular em todas as espécies estudadas. A atividade das enzimas antioxidantes apresentou reduzida variabilidade entre locais e meses e não se observou nenhum padrão específico entre todas as espécies. As enzimas de biotransformação apresentaram maior variabilidade espacial e temporal que as antioxidantes, e maior nos peixes do que nos invertebrados. Os efeitos a nível molecular também foram evidentes, em todas as espécies, evidenciando um nível de contaminação global considerável que ultrapassa a capacidade de defesa e metabolização de xenobióticos destas espécies. Na generalidade, as respostas dos biomarcadores sinalizaram maiores níveis de contaminação nos locais do estuário do Tejo, assim como uma tendência de respostas mais elevadas em setembro, entre todas as espécies, quer para as enzimas antioxidantes e de biotransformação como para os biomarcadores de efeitos, possivelmente evidenciando um efeito de exposição continuada a stresses ambientais. De um modo geral, as respostas biológicas bem como os valores obtidos através do índice de IBR variaram bastante entre espécies e de acordo com os locais amostrados, tendo no entanto sido possível observar alguns padrões de resposta semelhantes entre espécies, particularmente no que diz respeito ao uso do habitat. Além disso, apesar dos locais do estuário do Tejo serem considerados mais impactados que os locais da Ria de Aveiro, nestes foram igualmente observados respostas significativas em várias espécies. A complexidade dos padrões de resposta dos vários biomarcadores analisados evidencia diferenças entre espécies em termos da sua fisiologia, vulnerabilidade aos contaminantes e capacidades dos mecanismos de defesa, bem como ao nível da ecologia, como o uso do habitat, e hábitos alimentares de que naturalmente decorrem diferentes níveis de exposição. A aplicação de uma abordagem multiespecífica e de vários biomarcadores pode constituir uma ferramenta útil para a compreensão de diferentes vias de exposição e para uma análise mais completa dos efeitos em diferentes componentes biológicos do ecossistema. No entanto, apesar de pertinente a nível ecológico, é evidente a complexidade de interpretação que lhe está associada, e para a qual a aplicação em programas de monitorização e de avaliação da qualidade ambiental requer maior planeamento. Além disso, a seleção das espécies deverá ser ponderada de acordo com o objetivo do estudo, sendo que diferentes espécies irão gerar avaliações de impacto diferentes para os mesmos locais

Labrys portucalensis F11 efficiently degrades Di-(2-ethylhexyl) Phthalate

info:eu-repo/semantics/publishedVersio

IFRS Adoption and Accounting Quality: A Review

Literature on IFRS adoption by countries concerning high quality, understandable and applicable IFRS in order to be worldwide accepted has generated a pertinent discussion, since the results presented in the literature are not unanimous on the adoption of IFRS and accounting quality. Soderstrom and Sun (2007) analyzed a research published in leading accounting journals selected from 1990’s on the consequences of IFRS adoption and found that the determinants of accounting quality after the adoption of these standards are articulated in: quality of the standards; political and judicial system in the country; financial reporting incentives. Based on Soderstrom and Sun (2007) study, this work aims to analyze literature on IFRS adoption and the accounting quality from 2006. In order to achieve this goal, a systematic search of the literature focused on a "Web of Science" database associated with a bibliometric analysis was done, aiming to understand the discussion on IFRS adoption and accounting quality in literature. As a result, it was found that the adoption of IFRS related to the accounting standard factors, political and judicial systems of the countries and the financial reporting incentives discussed by Soderstrom and Sun (2007) to determine the quality of accounting remains persistent. Overall, this analysis concludes that the quality of accounting cannot be evaluated only in terms of IFRS adoption, either on a voluntary or mandatory basis. The results of this study present at least two limitations: The studies on IFRS adoption researched, despite tackling institutional issues, do not show the real complexity of the reality, due to reduce the quality of the social context to the quality of economic rationality; and the alleged quality of standards based on principles is not enough to determine the quality of accounting

LipidTOX: A fatty acid-based index efficient for ecotoxicological studies with marine model diatoms exposed to legacy and emerging contaminants

Contaminants, when present above certain thresholds, can induce physiological constraints to organisms, namely diatoms, a model group representative of marine phytoplankton, triggering feedback mechanisms, such as changes in cell’s fatty acid profiles, that can be used as biomarkers towards xenobiotic exposure. Having this in mind and considering the ecological relevance of diatom fatty acid profiles as well as their recognized potential as biomarkers of contaminant exposure, the present work aims to develop and test the accuracy of an integrative multi-biomarker response index based on the fatty acid profiles of marine diatoms (using Phaeodactylum tricornutum as model diatom) exposed to several emerging contaminants. In terms of the impacts at the individual fatty acid level, it was possible to observe changes transversal to different contaminants, such as the reduction of C14:0 and C16:0 fatty acids, with increasing xenobiotic concentration, as observed, for example, under propranolol and fluoxetine exposure. Enhancement of C16:2n-7 and C16:3n-4 concentrations as well as complete disruption of the basal fatty acid profile was observed in diatoms exposed to copper nanoparticles. These individual diverse and intrinsically connected alterations in fatty acid concentrations depended on the type and dose of the xenobiotic applied, highlighting the need to address these profiles as a whole. The evaluation of the diatom cells’ fatty acids using a multivariate approach revealed a high degree of sensitivity of these biochemical traits to disclose the type of xenobiotic applied to the diatoms, as well as the exogenous concentration used. These biochemical profiles were later incorporated into a unifying numerical index (LipidTOX) using an integrated biomarker response approach. The LipidTOX index showed strong correlations with both the exogenous xenobiotic concentration applied as well as with the growth features assessed for the exposed cultures, revealing a very high efficiency in translating growth impairments imposed by each of the xenobiotics tested at the different test concentrations. The LipidTOX index proved to be an efficient tool for ecotoxicological assays with marine model diatoms and evidenced a high degree of reliability for classifying the exposure of the cells to emerging contaminants. The results and benefits of the LipidTOX index application can be easily communicated to non-expert audiences such as stakeholders, policymakers and environmental managers so that this approach can be used in future toxicological evaluations of the impacts of classical and emerging xenobiotics in marine primary producers.info:eu-repo/semantics/publishedVersio

LipidTOX: a fatty acid-based index efficient for ecotoxicological studies with marine model diatoms exposed to legacy and emerging contaminants

Contaminants, when present above certain thresholds, can induce physiological constraints to organisms, namely diatoms, a model group representative of marine phytoplankton, triggering feedback mechanisms, such as changes in cell’s fatty acid profiles, that can be used as biomarkers towards xenobiotic exposure. Having this in mind and considering the ecological relevance of diatom fatty acid profiles as well as their recognized potential as biomarkers of contaminant exposure, the present work aims to develop and test the accuracy of an integrative multi-biomarker response index based on the fatty acid profiles of marine diatoms (using Phaeodactylum tricornutum as model diatom) exposed to several emerging contaminants. In terms of the impacts at the individual fatty acid level, it was possible to observe changes transversal to different contaminants, such as the reduction of C14:0 and C16:0 fatty acids, with increasing xenobiotic concentration, as observed, for example, under propranolol and fluoxetine exposure. Enhancement of C16:2n-7 and C16:3n-4 concentrations as well as complete disruption of the basal fatty acid profile was observed in diatoms exposed to copper nanoparticles. These individual diverse and intrinsically connected alterations in fatty acid concentrations depended on the type and dose of the xenobiotic applied, highlighting the need to address these profiles as a whole. The evaluation of the diatom cells’ fatty acids using a multivariate approach revealed a high degree of sensitivity of these biochemical traits to disclose the type of xenobiotic applied to the diatoms, as well as the exogenous concentration used. These biochemical profiles were later incorporated into a unifying numerical index (LipidTOX) using an integrated biomarker response approach. The LipidTOX index showed strong correlations with both the exogenous xenobiotic concentration applied as well as with the growth features assessed for the exposed cultures, revealing a very high efficiency in translating growth impairments imposed by each of the xenobiotics tested at the different test concentrations. The LipidTOX index proved to be an efficient tool for ecotoxicological assays with marine model diatoms and evidenced a high degree of reliability for classifying the exposure of the cells to emerging contaminants. The results and benefits of the LipidTOX index application can be easily communicated to non-expert audiences such as stakeholders, policymakers and environmental managers so that this approach can be used in future toxicological evaluations of the impacts of classical and emerging xenobiotics in marine primary producers.info:eu-repo/semantics/publishedVersio

Ecoengineering Solutions for the Impairment of Spreading and Growth of Invasive Spartina patens in Mediterranean Salt Marshes

The invasion of natural communities by non-indigenous species represents one of the most serious threats to biodiversity. Understanding the ecophysiology of invasive species can provide insights into potential physiological handicaps relative to native species. By doing so, we can leverage the development of ecoengineering solutions for the removal of non-indigenous species, preferably using non-chemical methods. Spartina patens is a known invasive species of cordgrass aggressively proliferating in Mediterranean salt marshes, producing impenetrable monospecific stands. As its occurrence is delimited by the upper high tide water level, we hypothesized that S. patens is intolerant to waterlogging. Therefore, we developed a field experiment where strands of S. patens were kept waterlogged over the entire tidal cycle for 30 days. At the end of the experimental period, plants in the trial plots exhibited severe stress symptoms at different physiological levels compared with control plots (no intervention). At the photobiological level, intervened plants exhibited lower efficiency in producing chemical energy from light, whilst at the biochemical level waterlogging impaired the antioxidant system and increased lipid peroxidation products. Furthermore, the application of chlorophyll a pulse amplitude modulated (PAM) fluorometry, a non-invasive technique, allowed us to evaluate the effectiveness of the implemented measures, being the tool that provided the best separation between the control and intervened population. Considering the physiological traits observed here, ecoengineering solutions based on increased waterlogging of S. patens stands, can be a low-cost and efficient measure to reduce the spreading and growth of this invasive species in the Mediterranean and other salt marshes worldwide with little disturbance.info:eu-repo/semantics/publishedVersio

Preparation of macroporous alginate-based aerogels for biomedical applications

Aerogels are a special class of ultra-light porous materials with growing interest in biomedical applications due to their open pore structure and high surface area. However, they usually lack macroporosity, while mesoporosity is typically high. In this work, carbon dioxide induced gelation followed by expansion of the dissolved CO2 was performed to produce hybrid calcium-crosslinked alginate-starch hydrogels with dual meso- and macroporosity. The hydrogels were subjected to solvent exchange and supercritical drying to obtain aerogels. Significant increase in macroporosity from 2 to 25 % was achieved by increasing expansion rate from 0.1 to 30 bar/min with retaining mesoporosity (BET surface and BJH pore volume in the range 183 â 544 m2/g and 2.0 â 6.8 cm3/g, respectively). In vitro bioactivity studies showed that the alginate-starch aerogels are bioactive, i.e. they form hydroxyapatite crystals when immersed in a simulated body fluid solution. Bioactivity is attributed to the presence of calcium in the matrix. The assessment of the biological performance showed that the aerogels do not present a cytotoxic effect and the cells are able to colonize and grow on their surface. Results presented in this work provide a good indication of the potential of the alginate-starch aerogels in biomedical applications, particularly for bone regeneration. aerogels, alginate, starch, tissue engineering, supercritical fluids, CO2 induced gelation. (undefined

a cohort study based on data-linkage of national registries February-September 2021

Publisher Copyright: © 2022 Machado et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background Using data from electronic health registries, this study intended to estimate the COVID-19 vaccine effectiveness (VE) in the population aged 65 years and more, against symptomatic infection, COVID-19-related hospitalizations, and deaths, overall and by time since complete vaccination for the period February to September 2021 Methods We established a cohort of individuals aged 65 and more years old, resident in Portugal mainland, using the National Health Service User number to link eight electronic health registries. Outcomes included were symptomatic SARS-CoV-2 infections, COVID-19-related hospitalizations or deaths. The exposures of interest were the mRNA vaccines (Comirnaty or Spikevax) and the viral vector (Vaxzevria) vaccine. Complete schedule VE was estimated as one minus the confounder adjusted hazard ratio, for each outcome, estimated by time-dependent Cox regression with time-dependent vaccine exposure. Results For the cohort of individuals aged 65–79 years, complete scheme VE against symptomatic infection varied 43 (95%CI: 37–49) (Vaxzevria) and 65 (95%CI: 62–68) (mRNA vaccines). This estimate was slightly lower in the ≥80 years cohort (53, 95%CI: 45–60) for mRNA vaccines). VE against COVID-19 hospitalization varied between 89% (95%CI: 52–94) for Vaxzevria and 95% (95%CI: 93–97) for mRNA vaccines for the cohort aged 65–79 years and was 76% (95%CI: 67–83) for mRNA vaccines in the ≥80 years cohort. High VE against COVID-19-related deaths was estimated, for both vaccine types, 95% and 81 (95%CI:76–86) for the 65–79 years and the ≥80 years cohort, respectively. We observed a significant waning of VE against symptomatic infection, with VE estimates reaching approximately 34% for both vaccine types and cohorts. Significant waning was observed for the COVID-19 hospitalizations in the ≥80 years cohort (decay from 83% (95%CI:68 to 91) 14–41 days to 63% (95%CI:37 to 78) 124 days after mRNA second dose). No significant waning effect was observed for COVID-19-related deaths in the period of follow-up of either cohort. Conclusions In a population with a high risk of SARS-CoV-2 complications, we observed higher overall VE estimates against more severe outcomes for both age cohorts when compared to symptomatic infections. Considering the analysis of VE according to time since complete vaccination, the results showed a waning effect for both age cohorts in symptomatic infection and COVID-19 hospitalization for the 80 and more years cohort.publishersversionpublishe