87 research outputs found

    Influence of heat pipe operating temperature on exhaust heat thermoelectric generation

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    Increasingly stringent targets on energy efficiency and emissions, as well as growing vehicle electrification are making attractive the electric recovery of the energy normally wasted through the tailpipe of Internal Combustion Engines. Recent developments in thermoelectrics (TE) may soon make them a viable solution for such applications. This team has been exploring the potential of using TE modules in combination with variable conductance heat pipes for transferring the exhaust heat to the generator with very low thermal resistance and at a constant, prescribed temperature. This passive temperature control eliminates the need for by-pass systems in the event of temperature overshoots. The operating temperature of a generator should be as high as possible in order to maximize the Seebeck effect. However, currently available modules are temperature limited. Moreover, the higher the HP temperature the less the usable thermal power at the exhaust will be (heat can only be transferred to from a hotter to a colder body). The present work assesses both theoretically and experimentally the influence of the HP temperature in the electric output of a thermoelectric generator. A small diesel engine and a generator were tested and it was found that a high HP operating temperature is only limitative for performance in the cases where low exhaust temperature and low engine power are present. In those cases it is possible to estimate an optimal HP temperature in order to maximize power output. The combined use of Seebeck modules and heat pipes was found to be highly advantageous in various ways.Fundação para a Ciência e a Tecnologia (FCT), FEDER e POFC CompeteMIT Portugal EDAM, Project MOBI-MP

    Williams syndrome hypersociability: a neuropsychological study of the amygdala and prefrontal cortex hypotheses

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    Individuals with Williams syndrome display indiscriminate approach towards strangers. Neuroimaging studies conducted so far have linked this social profile to structural and/or functional abnormalities in WS amygdala and prefrontal cortex. In this study, the neuropsychological hypotheses of amygdala and prefrontal cortex involvement in WS hypersociability was explored using three behavioral tasks – facial emotional recognition task, a social approach task and a go no/go task. Thus, a group 15 individuals with Williams syndrome was compared to two groups of normal developing individuals – a group of 15 individuals matched for chronological age (CA) and 15 individualsmatched for mental age (MA), and sex. Individuals with WS present a specific impairment in recognizing negative facial expressions and do not display impairments in response inhibition when compared with typically developing groups. Although these findings partially support the amygdala contribution to WS hypersociability, we found that general cognitive functioning predicted this performance. Additionally, individuals with WS did not differ from both CA and MA groups in the recognition of angry facial expressions, a finding suggesting that they are actually able to identify stimuli associated with social threat. Overall, the results seem to indicate that this social profile must be understood within a developmental framework.Fundação para a Ciência e a Tecnologia (FCT) - bolsa PIC/IC/83290/200

    Autobiographical narratives in Williams Syndrome: structural, process and content dimensions

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    Williams syndrome (WS) is a neurodevelopmental disorder, with an intriguing cognitive phenotype. Previous studies found support for an atypical profile of fictional narrative production in WS (Gonçalves et al. The British Journal of Developmental Disabilities, 56(111), 89-109, 2010). This study aimed at testing if the same profile is observed when individuals with WS tell autobiographical narratives. Using a new scoring system, structural (coherence), process (complexity) and content (multiplicity) aspects of autobiographical narrative production were analyzed in WS. Results suggest that individuals with WS produce autobiographical narratives that are significantly less coherent and complex than typically developing controls, although similar to controls in terms of content diversity. These findings point out to deficits in autobiographical narrative production in WS, suggesting the relative preservation of the social dimension of narrative production. These results also support the hypothesis that fictional and autobiographical narrative production may rely on different neurocognitive mechanisms.Fundação para a Ciência e a Tecnologia (FCT) - bolsas SFRH/BD/35882/2007, PIC/IC/83290/200

    Optimization of injection blow molding: part I – defining part thickness profile

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    Manuscript DraftThis paper suggests a methodology based on a neuroevolutionary approach to optimize the use of material in blow molding applications. This approach aims at determining the optimal thickness distribution for a certain blow molded product as a function of its geometry. Multiobjective search is performed by neuroevolution to reflect the conflicting nature of the design problem and to capture some possible trade-offs. During the search, each design alternative is evaluated through a finite element analysis. The coordinates of mesh elements are the inputs to an artificial neural network that is evolved and whose output determines the thickness for the corresponding location. The proposed approach is applied to the design of an industrial bottle. The results reveal validity and usefulness of the proposed technique, which were able to distribute the material along mostcritical regions to adequate mechanical properties. The approach is general and can be applied to products with different geometries.Programa Operacional para a Competitividade e Internacionalização -COMPETE 2020, projectos POCI-01-0145-FEDER-007688 e POCI-01-0247-FEDER-00279

    Transcriptional responses of Candida glabrata biofilm cells to fluconazole are modulated by the carbon source

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    The datasets generated in this study are available at public repositories or from the corresponding author upon request. The raw RNA-seq data in fastq format, as well as the processed data have been deposited in NCBI’s Gene Expression Omnibus and are accessible through GEO Series accession number GSE121074.Candida glabrata is an important human fungal pathogen known to trigger serious infections in immune-compromised individuals. Its ability to form biofilms, which exhibit high tolerance to antifungal treatments, has been considered as an important virulence factor. However, the mechanisms involving antifungal resistance in biofilms and the impact of host niche environments on these processes are still poorly defined. In this study, we performed a whole-transcriptome analysis of C. glabrata biofilm cells exposed to different environmental conditions and constraints in order to identify the molecular pathways involved in fluconazole resistance and understand how acidic pH niches, associated with the presence of acetic acid, are able to modulate these responses. We show that fluconazole treatment induces gene expression reprogramming in a carbon source and pH-dependent manner. This is particularly relevant for a set of genes involved in DNA replication, ergosterol, and ubiquinone biosynthesis. We also provide additional evidence that the loss of mitochondrial function is associated with fluconazole resistance, independently of the growth condition. Lastly, we propose that C. glabrata Mge1, a cochaperone involved in iron metabolism and protein import into the mitochondria, is a key regulator of fluconazole susceptibility during carbon and pH adaptation by reducing the metabolic flux towards toxic sterol formation. These new findings suggest that different host microenvironments influence directly the physiology of C. glabrata, with implications on how this pathogen responds to antifungal treatment. Our analyses identify several pathways that can be targeted and will potentially prove to be useful for developing new antifungals to treat biofilm-based infections.This study was supported by the Portuguese National Funding Agency for Science, Research, and Technology FCT (grant PTDC/BIAMIC/5184/2014). R.A. received FCT Ph.D fellowship (PD/BD/113813/2015). We gratefully acknowledge Edinburgh Genomics for RNA-Seq library preparation and sequencing. The work on CBMA was supported by the strategic programs UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) and UID/BIA/04050/2019. The work on CEB was supported by PEst-OE/EQB/LA0023/2013, from FCT, “BioHealth-Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER and the project “Consolidating Research Expertize and Resources on Cellular and Molecular Biotechnology at CEB/IBB”, Ref. FCOMP-01-0124-FEDER-027462. The work in Aberdeen was also supported by the European Research Council through the advanced grant “STRIFE” (C-2009-AdG-249793), by the UK Medical Research Council (MR/M026663/1) and by the Medical Research Council Center for Medical Mycology and the University of Aberdeen (MR/N006364/1). The work at KU Leuven was supported by the Federation of European Biochemical Societies (FEBS) through a short-term fellowship awarded to R.A. and by the Fund for Scientific Research Flanders (FWO; WO.009.16N). We thank Beatriz Herrera-Malaver for technical assistance with the GC-MS analysis.info:eu-repo/semantics/publishedVersio

    Starch-based films doped with porphyrinoid photosensitizers for active skin wound healing

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    Starch is a biodegradable and biocompatible carbohydrate that, when combined with bioactive molecules, can be processed as biomimetic platforms with enhanced performance, allowing its use as active wound dressing materials. Porphyrinoid photosensitizers can tune the physicochemical/functional profile of biomacromolecules, allowing their use in anti-infective strategies. In this work, the feasibility of using the cationic 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin tetraiodide (TMPyP) to enhance the physicochemical, mechanical, antimicrobial performance, and wound healing ability of casted starch-based films was studied. TMPyP conferred a reddish coloration to the films, maintaining their pristine transparency. It increased by 87 % the films hydrophobicity and, depending on the TMPyP used, conferred mobility to the starch polymeric chains. Starch/TMPyP-based films effectively photoinactivated Escherichia coli (>99.99 %) and favored the wound healing process, even in the absence of light. Therefore, the incorporation of TMPyP into starch-based formulations revealed to be a promising strategy to tune the films compaction degree while giving rise to water tolerant and photosensitive biomaterials that can act as multitarget antimicrobial medical dressings and glycocarriers of active compounds relevant for effective skin wound healing.The authors thank to University of Aveiro and FCT/MCT for the financial support provided to CICECO (UIDB/50011/2020, UIDP/50011/2020, LA/P/0006/2020), LAQV-REQUIMTE (UIDB/50006/2020 and UIDP/50006/2020), CESAM (UIDP/50017/2020, UIDB/50017/2020, LA/P/0094/2020), CEB (UIDB/04469/2020), LABBELS (LA/P/0029/2020), and to projects PORP2PS (EXPL/QUI-QOR/0586/2021) and PREVINE (FCT-PTDC/ASP-PES/29576/2017), through national funds (OE) and where applicable co-financed by the FEDER - Operational Thematic Program for Competitiveness and Internationalization - COMPETE 2020, within the PT2020 Partnership Agreement. Thanks are also due to the Portuguese NMR and Mass Networks. FCT also funded ASMJ PhD grant (2021.06854.BD), Investigator FCT program (PF, IF/00300/2015), and the Scientific Employment Stimulus program (IG, CEECIND/00430/2017; AR, 2021.02803.CEECIND). NMMM thanks FCT for funding through program DL 57/2016 (CDL-CTTRI-048-88-ARH/2018). The authors also acknowledge to POTATOPLASTIC project (POCI-01-0247-FEDER-017938), financed by FEDER through POCI, to Isolago – Indústria de Plásticos, S. A., the project leader, and to A Saloinha, Lda. company for providing the starch-rich potato washing slurries.info:eu-repo/semantics/publishedVersio

    Colloidal nanomaterials for water quality improvement and monitoring

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    Water is the most important resource for all kind forms of live. It is a vital resource distributed unequally across different regions of the globe, with populations already living with water scarcity, a situation that is spreading due to the impact of climate change. The reversal of this tendency and the mitigation of its disastrous consequences is a global challenge posed to Humanity, with the scientific community assuming a major obligation for providing solutions based on scientific knowledge. This article reviews literature concerning the development of nanomaterials for water purification technologies, including collaborative scientific research carried out in our laboratory (nanoLAB@UA) framed by the general activities carried out at the CICECO-Aveiro Institute of Materials. Our research carried out in this specific context has been mainly focused on the synthesis and surface chemical modification of nanomaterials, typically of a colloidal nature, as well as on the evaluation of the relevant properties that arise from the envisaged applications of the materials. As such, the research reviewed here has been guided along three thematic lines: 1) magnetic nanosorbents for water treatment technologies, namely by using biocomposites and graphite-like nanoplatelets; 2) nanocomposites for photocatalysis (e.g., TiO2/Fe3O4 and POM supported graphene oxide photocatalysts; photoactive membranes) and 3) nanostructured substrates for contaminant detection using surface enhanced Raman scattering (SERS), namely polymers loaded with Ag/Au colloids and magneto-plasmonic nanostructures. This research is motivated by the firm believe that these nanomaterials have potential for contributing to the solution of environmental problems and, conversely, will not be part of the problem. Therefore, assessment of the impact of nanoengineered materials on eco-systems is important and research in this area has also been developed by collaborative projects involving experts in nanotoxicity. The above topics are reviewed here by presenting a brief conceptual framework together with illustrative case studies, in some cases with original research results, mainly focusing on the chemistry of the nanomaterials investigated for target applications. Finally, near-future developments in this research area are put in perspective, forecasting realistic solutions for the application of colloidal nanoparticles in water cleaning technologies.publishe

    Coronary computed tomography angiography-adapted Leaman score as a tool to noninvasively quantify total coronary atherosclerotic burden

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    To describe a coronary computed tomography angiography (CCTA)-adapted Leaman score (CT-LeSc) as a tool to quantify total coronary atherosclerotic burden with information regarding localization, type of plaque and degree of stenosis and to identify clinical predictors of a high coronary atherosclerotic burden as assessed by the CT-LeSc. Single center prospective registry including a total of 772 consecutive patients undergoing CCTA (Dual-source CT) from April 2011 to March 2012. For the purpose of this study, 581 stable patients referred for suspected coronary artery disease (CAD) without previous myocardial infarction or revascularization procedures were included. Pre-test CAD probability was determined using both the Diamond-Forrester extended CAD consortium method (DF-CAD consortium model) and the Morise score. Cardiovascular risk was assessed with the HeartScore. The cut-off for the 3rd tercile (CT-LeSc ≥8.3) was used to define a population with a high coronary atherosclerotic burden. The median CT-LeSc in this population (n = 581, 8,136 coronary segments evaluated; mean age 57.6 ± 11.1; 55.8 % males; 14.6 % with diabetes) was 2.2 (IQR 0-6.8). In patients with CAD (n = 341), the median CT-LeSc was 5.8 (IQR 3.2-9.6). Among patients with nonobstructive CAD, most were classified in the lowest terciles (T1, 43.0 %; T2, 36.1 %), but 20.9 % were in the highest tercile (T3). The majority of the patients with obstructive CAD were classified in T3 (78.2 %), but 21.8 % had a CT-LeSc in lower terciles (T1 or T2). The independent predictors of a high CT-LeSc were: Male sex (OR 1.73; 95 % CI 1.04-2.90) diabetes (OR 2.91; 95 % CI 1.61-5.23), hypertension (OR 2.54; 95 % CI 1.40-4.63), Morise score ≥16 (OR 1.97; 95 % CI 1.06-3.67) and HeartScore ≥5 (OR 2.42; 95 % CI 1.41-4.14). We described a cardiac CT adapted Leaman score as a tool to quantify total (obstructive and nonobstructive) coronary atherosclerotic burden, reflecting the comprehensive information about localization, degree of stenosis and type of plaque provided by CCTA. Male sex, hypertension, diabetes, a HeartScore ≥5 % and a Morise score ≥16 were associated with a high coronary atherosclerotic burden, as assessed by the CT-LeSc. About one fifth of the patients with nonobstructive CAD had a CT-LeSc in the highest tercile, and this could potentially lead to a reclass

    Setting performance indicators for coastal marine protected areas: An expert-based methodology

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    Marine Protected Areas (MPAs) require effective indicators to assess their performance, in compliance with the goals of relevant national and international commitments. Achieving and prioritizing shortlists of multidisciplinary indicators demands a significant effort from specialists to depict the multiple conservation and socioeconomic interests, and the large complexity of natural systems. The present paper describes a structured expert-based methodology (process and outputs) to co-define a list of multidisciplinary MPA performance indicators. This work was promoted by the management authority of coastal MPAs in mainland Portugal to gather a consensual and feasible list of indicators that would guide the design of a future national monitoring program. Hence, Portuguese coastal MPAs served as a case study to develop such a process between 2019 and 2020. In the end, participants (1) agreed on a shortlist of prioritized indicators (i.e., environmental, governance, and socioeconomic indicators) and (2) defined minimum monitoring frequencies for the indicators in this list, compatible with the potential replicability of the associated survey methods. The present approach recommends that management plans incorporate monitoring procedures and survey methods, with a validated list of indicators and associated monitoring periodicity, agreed among researchers, MPA managers and governance experts. The proposed methodology, and the lessons learned from it, can support future processes aiming to define and prioritize MPA performance indicatorsFundação para a Ciência e Tecnologia - FCT, European Maritime and Fisheries Fund (EMFF)info:eu-repo/semantics/publishedVersio

    Implications for Quality and Wine Production

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    UID/FIS/04559/2020Nowadays, there is a growing concern about micronutrient deficits in food products, with agronomic biofortification being considered a mitigation strategy. In this context, as Zn is essential for growth and maintenance of human health, a workflow for the biofortification of grapes from the Vitis vinifera variety Fernão Pires, which contains this nutrient, was carried out considering the soil properties of the vineyard. Additionally, Zn accumulation in the tissues of the grapes and the implications for some quality parameters and on winemaking were assessed. Vines were sprayed three times with ZnO and ZnSO4 at concentrations of 150, 450, and 900 g ha−1 during the production cycle. Physiological data were obtained through chlorophyll a fluorescence data, to access the potential symptoms of toxicity. At harvest, treated grapes revealed significant increases of Zn concentration relative to the control, being more pronounced for ZnO and ZnSO4 in the skin and seeds, respectively. After winemaking, an increase was also found regarding the control (i.e., 1.59-fold with ZnSO4-450 g ha−1). The contents of the sugars and fatty acids, as well as the colorimetric analyses, were also assessed, but significant variations were not found among treatments. In general, Zn biofortification increased with ZnO and ZnSO4, without significantly affecting the physicochemical characteristics of grapes.publishersversionpublishe
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