Repositório RCAAP

The evaluation of encapsulation efficiency is a regulatory requirement for the characterization of drug delivery systems. However, the difficulties in efficiently separating nanomedicines from the free drug may compromise the achievement of accurate determinations. Herein, ultrafiltration was exploited as a separative strategy towards the evaluation of methotrexate (MTX) encapsulation efficiency in nanostructured lipid carriers and polymeric nanoparticles. The effect of experimental conditions such as pH and the amount of surfactant present in the ultrafiltration media was addressed aiming at the selection of suitable conditions for the effective purification of nanocarriers. MTX-loaded nanoparticles were then submitted to ultrafiltration and the portions remaining in the upper compartment of the filtering device and in the ultrafiltrate were collected and analyzed by HPLC-UV using a reversed-phase (C18) monolithic column. A short centrifugation time (5 min) was suitable for establishing the amount of encapsulated MTX in nanostructured lipid carriers, based on the assumption that the free MTX concentration was the same in the upper compartment and in the ultrafiltrate. The defined conditions allowed the efficient separation of nanocarriers from the free drug, with recoveries of >85% even when nanoparticles were present in cell culture media and in pig skin surrogate from permeation assays.

Recommendation systems are usually evaluated through accuracy and classification metrics. However, when these systems are supported by crowdsourced data, such metrics are unable to estimate data authenticity, leading to potential unreliability. Consequently, it is essential to ensure data authenticity and processing transparency in large crowdsourced recommendation systems. In this work, processing transparency is achieved by explaining recommendations and data authenticity is ensured via blockchain smart contracts. The proposed method models the pairwise trust and system-wide reputation of crowd contributors; stores the contributor models as smart contracts in a private Ethereum network; and implements a recommendation and explanation engine based on the stored contributor trust and reputation smart contracts. In terms of contributions, this paper explores trust and reputation smart contracts for explainable recommendations. The experiments, which were performed with a crowdsourced data set from Expedia, showed that the proposed method provides cost-free processing transparency and data authenticity at the cost of latency.

Given their therapeutic activity, natural products have been used in traditional medicines throughout the centuries. The growing interest of the scientific community in phytopharmaceuticals, and more recently in marine products, has resulted in a significant number of research efforts towards understanding their effect in the treatment of neurodegenerative diseases, such as Alzheimer's (AD), Parkinson (PD) and Huntington (HD). Several studies have shown that many of the primary and secondary metabolites of plants, marine organisms and others, have high affinities for various brain receptors and may play a crucial role in the treatment of diseases affecting the central nervous system (CNS) in mammalians. Actually, such compounds may act on the brain receptors either by agonism, antagonism, allosteric modulation or other type of activity aimed at enhancing a certain effect. The current manuscript comprehensively reviews the state of the art on the interactions between natural compounds and brain receptors. This information is of foremost importance when it is intended to investigate and develop cutting-edge drugs, more effective and with alternative mechanisms of action to the conventional drugs presently used for the treatment of neurodegenerative diseases. Thus, we reviewed the effect of 173 natural products on neurotransmitter receptors, diabetes related receptors, neurotrophic factor related receptors, immune system related receptors, oxidative stress related receptors, transcription factors regulating gene expression related receptors and blood-brain barrier receptors.

Although regular exercise improves overall well-being, increased physical activity results in enhanced breathing which consequently leads to elevated exposure to a variety of air pollutants producing adverse effects. It is well-known that one of these ambient air contaminants is ultrafine particles (UFP). Thus, this study aimed to (1) examine exposure to particle number concentrations (PNC) in size ranging from N20-1000 nm in different sport environments and (2) estimate the respective inhalation doses across varying activity scenarios based upon the World Health Organization recommendations for physical activity. PNC were continuously monitored (TSI P-Trak™ condensation particle counter) outdoors (Out1-Out2) and indoors (Ind1-Ind2; fitness clubs) over 4 weeks. Outdoor PNC (total median 12 563 # cm-3; means of 20 367 # cm-3 at Out1 and 7 122 # cm-3 at Out2) were approximately 1.6-fold higher than indoors (total median 7 653 # cm-3; means of 11 861 # cm-3 at Ind1 and 14 200 # cm-3 at Ind2). The lowest doses were inhaled during holistic group classes (7.91 × 107-1.87 × 108 # per kg body weight) whereas exercising with mixed cardio and strength training led to approximately 1.8-fold higher levels. In order to optimize the health benefit of exercises, environmental characteristics of the locations at which physical activities are conducted need to be considered.

A novel and disposable electrochemical biosensor for PCR-free and selective detection of Sola l 7, a non-specific lipid transfer protein (nsLTP) found in tomato seeds associated to severe symptoms of tomato-allergic patients, is reported in this work. The methodology involves the formation of DNA/RNA heterohybrids by sandwich hybridization of a specific fragment of the Sola l 7 allergen coding sequence with appropriate RNA probes designed and described for the first time in this work. Labeling was carried out with commercial antibodies specific to the heteroduplexes and secondary antibodies conjugated with HRP onto the surface of magnetic beads. Amperometric transduction was performed upon magnetic capture of the resulting magnetic bioconjugates on screen-printed electrodes using the system H2O2/HQ. A comparison of the sandwich hybridization format with a direct approach as well as between different labeling strategies was performed. The LOD value achieved was 0.2 pM (5 amol in 25 μL). The biosensor was successfully applied to the selective analysis of the targeted Sola l 7 specific region directly in just 100 ng of non-fragmented denatured genomic DNA extracted from tomato seeds.

Copper nanoparticles stabilized with cashew (CG-CuNPs) were synthesized by reduction reaction using ascorbic acid and sodium borohydride, using the cashew gum (CG) as a natural polymer stabilizer. Dynamic light scattering, atomic force microscopy, Fourier-transform infrared spectroscopy, UV-Vis spectrophotometry, and x-ray diffraction were used to characterize the nanoparticles (CG-CuNPs), and copper was quantified by electrochemical measurement. The UV-vis spectra of the CG-CuNPs confirmed the formation of nanoparticles by appearance of a surface plasmon band at 580 nm after 24 h of reaction. The Fourier-transform infrared spectrum of CG-CuNPs showed the peak at 1704 cm−1 from cashew gum, confirming the presence of the gum in the nanoparticles. The average size of CG-CuNPs by dynamic light scattering and atomic force microscopy was around 10 nm, indicating small, approximately spherical particles. Antimicrobial assays showed that CG-CuNPs had activity against Staphylococcus aureus ATCC 29213 with a minimal inhibitory concentration of 0.64 mM. The cytotoxicity assay on BALB/c murine macrophages showed lower cytotoxic effects for CG-CuNPs than CuSO4·5H2O. Viability cell assays for CG-CuNPs at (0.250 mM) inhibited by 70% the growth of 4T1 LUC (4T1 mouse mammary tumor cell line) and NIH 3T3 cells (murine fibroblast cells) over a 24-h period. Therefore, CG-CuNPs can be used as an antimicrobial agent with lower cytotoxic effects than the CuSO4·5H2O precursor.

Biomarkers are recognised sensitive early-warning tools of biological effects in aquatic organisms. In this scope, the main aim of this study was to investigate the potential usefulness of a battery of biomarkers, evaluated in different benthic macroinvertebrate taxa, to discriminate aquatic ecosystems with different levels of ecological status and to provide further clues supporting environmental management. The study took place during the autumn of 2013 and the spring and summer of 2014, and the study cases were two Mediterranean rivers (Âncora and Ferreira rivers), differing in their ecological status. The biomarkers determined are widely employed and comprise a large set of biochemical responses: the activity of enzymes (cholinesterases, glutathione S-transferases, catalase and lactate dehydrogenase) and the levels of lipid peroxidation. They were assessed seasonally and in different macroinvertebrate taxa. Thirteen water physico-chemical parameters were also seasonally determined, and the concentration of seven organophosphorus pesticides and the percentage of 32 trace metals in sediments were determined in the spring. This is particularly useful for water management. Based on this, authorities can take actions to prevent further damage in the ecological status. Multivariate analyses showed distinct patterns of biological response for the Calopteryx spp., Chironomidae and Baetis spp. taxa. Calopteryx spp. and Chironomidae, in particular, showed distinct response patterns for the two rivers, which were fairly stable across seasons. This study sets the foundations for future cost-effective biomonitoring campaigns in Mediterranean rivers, allowing to establish historical data important to understand ecosystem evolution, as well as baseline levels of diagnostic biomarkers in informative macroinvertebrate taxa.

This work aims to assess, individually and in mixtures, possible phytotoxic effects of three pharmaceuticals (paracetamol, ibuprofen and amoxicillin) on germination and early growth of Lactuca sativa seeds. Pharmaceuticals are an important group of emerging contaminants, whose presence has been described in several environmental compartments, including soils. However, knowledge on their possible impact in terrestrial organisms is still sparse and even more when mixtures are considered. Germination tests are important to evaluate the quality of soil and the toxic effects that contaminants can pose to plants. The acute effects of individual pharmaceuticals as well as binary and ternary mixtures were assessed using different endpoints, namely: percentage of seed germination, root elongation, shoot and leaf length, after an exposure time of five days. Overall, in the exposure of L. sativa seeds to individual pharmaceuticals there are indications of acute toxicity in the early plant growth. However, this inhibitory effect tends to be cancelled in the acute exposure to mixtures. This study shows the importance of evaluating the toxicity of mixtures of pharmaceuticals, since they might have distinct toxic effects when compared to the single compounds, and also because, probably, it is the closest scenario to the reality that can be found in the environment.

This study demonstrates the ability of an electrochemical sensor based on molecularly imprinted polymers (MIPs) to selectively quantify 3,4-methylenedioxymethamphetamine (MDMA), also known as ecstasy, in biological samples. The device was constructed using ortho-phenylenediamine (o-PD) as the MIP’s building monomer at the surface of a screen-printed carbon electrode (SPCE). The step-by-step construction of the SPCE-MIP sensor was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Density functional theory (DFT) calculations and modelling were performed not only to understand template-monomer interaction but also to comprehend which possible polymer structure - linear or ramified poly(o-PD) – indeed interacts with the analyte. The prepared sensor worked by directly measuring the MDMA oxidation signal through square-wave voltammetry (SWV) after an incubation period of 10 min. Several parameters were optimized, such as the monomer/template ratio, the number of electropolymerization scanning cycles, and the incubation period, to obtain the best sensing efficiency. Optimized sensors exhibited suitable selectivity, repeatability (2.6%), reproducibility (7.7%) and up to one month of stable response. A linear range up to 0.2 mmol L−1 was found with an r2 of 0.9990 and a limit of detection (LOD) and quantification (LOQ) of 0.79 and 2.6 μmol L−1 (0.15 and 0.51 μg mL−1), respectively. The proposed sensor was successfully applied to human blood serum and urine samples, showing its potential for application in medicine and in forensic sciences.

Pyrethroid insecticides are emerging contam-inants broadly used for insect pest control in agriculture,veterinary, and domestic applications. Limited informa-tion can be found in literature regarding pyrethroidpesticide soil contamination in playgrounds and agricul-tural areas. The focus of this study was on new findingsrelated to the spatial and seasonal occurrence of pyre-throid pesticide contamination in soils of northern Por-tugal. The soils were tested during summer and winterseasons. Pyrethroid pesticides were not found in the tenplaygrounds sampled during both seasons. For the 18agricultural soil samples tested, deltamethrin was theonly pyrethroid detected, just during the summer sea-son. For those, three of the samples taken were found tobe positive with concentrations between 15.7 and101.7 ng g−1. The results denote the need for monitoringand assessment of pyrethroid pesticide contamination inPortuguese soil. Further research is needed to access the ecological potential impact of pyrethroid pesticides onsoil.

The aim of this paper is to present an adaptation model for an Adaptive Educational Hypermedia System, PCMAT. The adaptation of the application is based on progressive self-assessment (exercises, tasks, and so on) and applies the constructivist learning theory and the learning styles theory. Our objective is the creation of a better, more adequate adaptation model that takes into account the complexities of different users.

The design of new advanced materials and technologies is essential for the development of smart windows for the next generation of energy‐efficient buildings. Here, it is demonstrated that the functionalization of glucose‐derived carbon dots with 1‐butyl‐3‐methylimidazolium chloride results in a self‐standing, water‐soluble, viscous, reusable nanofluid with self‐improving conductivity, thermotropy around 30–40 °C, and ultraviolet blocking ability. Its synthesis is straightforward, clean, fast, and cheap. At 36 °C (hot summer day), a sun‐actuated thermotropic (TT) device incorporating a 95% w/w nanofluid aqueous solution exhibits a transmittance variation (ΔT ) of 9% at 550/1000 nm, which is amplified to 47/31% via the surface plasmon resonance effect. An integrated self‐healing system enabling independent sun‐actuated TT and voltage‐actuated electrochromic (EC) operation is also produced. The low‐energy EC device offers bright hot and dark cold modes (ΔT = 68/64%), excellent cycling stability, unprecedented coloration efficiency values (−1.73 × 106/−1.67 × 106 cm2 C−1 (coloring) and +1.12 × 107/+1.08 × 107 cm2 C−1 (bleaching) at ±2.5 V), and impressive memory effect. The disruptive design and sustainable synthesis of the new nanofluid proposed here will foster the agile development of novel products with improved ecological footprint.

Actinidia deliciosa and A. arguta fruits (kiwifruit and kiwiberry, respectively) are an excellent source of bioactive compounds. The aim of this paper is to valorize the fruits that are not commercialized (e.g. due to inadequate size or physical damage) in infusions and decoctions. The antioxidant activity, the scavenging activity against reactive species, the phenolic profile and the intestinal effects of infusions and decoctions of dehydrated fruits were evaluated and compared. Decoctions presented the highest antioxidant activity and a good ability to capture HOCl and NO. The phenolic composition of A. arguta present quinic acid, cis-caftaric acid and its derivatives, caffeoyl hexoside, luteolin glucuronide, quercetin derivatives and myristin, while A. deliciosa extracts were characterized by the presence of quinic acid, caffeic acid and its derivatives and caffeoyl hexoside. No adverse effects were observed on Caco-2 and HT29-MTX cells. Kiwiberry decoctions showed to be the best option to keep the fruits benefits.

Specific monitoring of cystatin C (CysC) levels in biological fluids is critical for diagnosis, treatment and mechanistic understanding of a spectrum of diseases, particularly chronic kidney disease (CKD). Despite evidences that CysC correlates with the high risk and/or progression of CKD, its use in clinical practice is still scarce. In this context, we report the development of a simple and sensitive immunosensor for the detection of CysC. The biosensor combines the technology of cost-effective screen-printed electrodes with the high specificity of a sandwich immunoassay. Optimized conditions showed that the sensor operates in a linear range between 10 and 100 ng mL-1, with a detection limit and a sensitivity of 6.0 ng mL-1 and 6.4 ± 0.3 μA ng mL-1 cm-2, respectively. Moreover, the sensor provided precise results (RSD ≤ 6.2%) and the quantification of CysC in CKD serum samples revealed to be in agreement with the values obtained by a particle-enhanced nephelometric immunoassay. In this light, the proposed immunosensor qualifies for clinical application, constituting a step forward in the development of fast, sensitive and cost-effective diagnostic tools that can improve the current medical care settings of CKD patients.

The development of functional and nutraceutical foods comes from a greater awareness of the relationship between food and health by consumers. In recent years, the idea of purifying and encapsulating bioactive compounds through techniques such as spray drying has been well received by the food industry. The development and characterization of a grapefruit (Citrus paradisi) nutraceutical powder obtained by spray drying is of great interest owing to the different bioactive compounds and the potential health effects.

O avanço tecnológico e o aumento exponencial da utilização das redes sociais acarretou grandes mudanças ao nível da comunicação e do mercado de trabalho, que vieram trazer novas oportunidades mas também novos desafios aos profissionais. Em contexto de trabalho, ter uma presença digital profissional nos dias de hoje torna-se indispensável. A gestão estratégica e eficaz da marca pessoal no universo digital é uma forma de as pessoas mostrarem a sua promessa única de valor e de se destacarem num mercado tendencialmente mais concorrido. O LinkedIn é um dos meios digitais mais importantes para a gestão de marca pessoal e é considerado uma rede social para profissionais e uma ferramenta de gestão de marca pessoal e de carreira. Este estudo é um dos primeiros a explorar as estratégias de redes sociais no LinkedIn para a gestão de marca pessoal e o impacto na força da marca pessoal, através de um conjunto de métodos de pesquisa: observação não participante, questionário e análise de conteúdo. Os resultados deste estudo exploratório mostram que os participantes que gerem a sua marca pessoal no LinkedIn, através de estratégias eficazes de otimização do perfil, networking e produção de conteúdos, melhoram o posicionamento da sua marca pessoal e obtém maior notoriedade dentro do seu setor, o que resulta em mais oportunidades de negócios que ajudam na gestão eficaz da sua marca pessoal e na progressão de carreira.

Este relatório de estágio foi realizado no âmbito do plano de estudos do Mestrado em Finanças Empresariais no Instituto Superior de Contabilidade e Administração do Porto (ISCAP) e é o resultado de seis meses de aprendizagem na realização de consultoria financeira e de gestão na empresa Prime Century – Contabilidade e Consultoria de Gestão, Lda. Este estágio curricular teve inicio em novembro de 2018 e término em abril de 2019 e tem por objetivo a realização de um plano de negócios, visando a criação de uma empresa de cedência de instalações afetas à prestação de serviços de estética e bem-estar, entre os quais massagem, estética de corpo e rosto, psicologia, terapia da fala, nutrição, terapias alternativas entre outros serviços. Na primeira fase é apresentada a empresa de acolhimento e o enquadramento teórico. Seguidamente é descrita a ideia de negócio e realizada a análise económico-financeira, bem como utilizada a ferramenta de avaliação de projetos a do Instituto de Apoio às Pequenas e Médias Empresas e à Inovação (IAPMEI) como auxiliar à elaboração dos vários mapas e indicadores económico-financeiros de estudo de viabilidade do projeto.

Este livro foi produzido como parte das atividades que couberam à ABENGE no projeto VISIR+, que foi desenvolvido nos anos de 2016 e 2017 e que tem sua aplicação principal na área de Circuitos Elétricos e Eletrônicos com foco preponderante na Engenharia Elétrica e Eletrônica. Os capítulos seguintes, apresentam uma descrição mais detalhada do Projeto. O objetivo precípuo do projeto foi definir, desenvolver e avaliar um conjunto de módulos educacionais que envolvem experimentos práticos, virtuais e remotos, suportados pelo laboratório remoto denominado VISIR, que é um acrônimo para "Virtual Instrument Systems In Reality". O VISIR+ contou com financiamento da European Commission (DG EAC), Education, Audiovisual and Culture Executive Agency (EACEA) e National Erasmus+ Offices National Agencies EU Delegations. O coordenador do projeto foi o professor Gustavo Ribeiro Alves do Instituto Politécnico do Porto (IPP) e a equipe foi constituída por docentes das Instituições participantes do projeto.

Com a atualidade, a sociedade atravessa um dos momento mais desafiantes, e a indústria com maiores preocupações ambientais, como a produção elétrica e a automóvel, não são exceção. Ainda é muito cedo para sabermos quais são as consequências da pandemia, mas para já, são vários os países que defendem que a qualidade do ar melhorou. Não deveria ser uma surpresa: do dia para a noite tudo mudou. Os centros urbanos ficaram vazios e com o confinamento e consequentemente a indústria levou a que os níveis de poluição descessem bruscamente.

A globalização intensificou a competitividade e exigência do mercado, tornando a qualidade num importante foco para as empresas líderes nos setores onde atuam. Para que as empresas garantam a sua continuidade e evolução, é crucial que adotem uma estratégia competitiva, de longo e de curto prazo, capaz de incluir todos os níveis da organização, desde o nível de topo até ao nível mais operacional. Um método estratégico, originário do Japão, que emergiu da necessidade de aumentar o controlo de qualidade é o Hoshin Kanri. Atualmente este método é implementado nas organizações com objetivo de alinhar a estratégia da organização a todos os níveis hierárquicos, desde a gestão de topo a níveis operacionais, levando todos a agir na mesma direção. Mas será este o único propósito do Hoshin Kanri? O presente trabalho pretende responder a esta questão, apurando principalmente o impacto que a metodologia Hoshin Kanri tem ao nível dos Sistemas de Gestão de Qualidade e consequentemente na ISO 9001:2015, ao nível da filosofia Lean e ainda apurar a ligação deste método com a Melhoria Continua numa organização. As conclusões deste estudo são consideradas satisfatórias e são sustentadas pela opinião de colaboradores que acompanharam de perto a implementação do Hoshin Kanri numa organização e ainda, pela opinião de consultores experientes do Instituto Kaizen. Segundo estes, o Hoshin Kanri é muito mais do que um método de alinhamento da estratégia, é também um método com um impacto positivo nos Sistemas de Gestão de Qualidade e consequentemente na ISO 9001:2015, tem influência na eficácia do desempenho Lean e ainda acreditam que existe uma ligação deste método com a Melhoria Continua. O sucesso deste método estratégico é inegável, sendo adotado no Japão pela maior parte das empresas internacionais e por algumas grandes empresas ocidentais, nomeadamente Hewlett-Packard, Procter & Gamble, AT&T, Xerox Corporation, IBM, Florida Power & Light e Texas Instruments.