Browsing by Issue Date, starting with "2023-09-18"
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- As incapacidades do trabalhador vítima de acidente de trabalhoPublication . Pereira, Margarida Gonçalves; Gomes, Júlio Manuel VieiraOs acidentes de trabalho podem ter um grande impacto na vida dos trabalhadores. Dependendo da gravidade do acidente, o trabalhador pode sofrer lesões físicas que limitam e, por vezes, até impossibilitam, a sua capacidade de realizar as mesmas tarefas que realizava antes do acidente. As consequências do acidente de trabalho e a reparação dos danos causados por este dependerão de vários fatores, sempre considerando a incapacidade que o trabalhador passa a suportar e a sua nova realidade. A matéria das incapacidades levanta imensas questões - umas teóricas, outras práticas -, com imensa relevância, e este será o meu contributo para tentar encontrar as suas respostas.
- Da sucessão nas sociedades comerciais : a definição unilateral e o repúdio dos instrumentos sucessórios em favor de mecanismos societáriosPublication . Rosa, Paulo Jorge Esteves; Oliveira, Ana da Paz Ferreira da Câmara Perestrelo deNum país onde grande parte do tecido empresarial é composto por empresas de base familiar, a transmissão das mesmas para a geração seguinte mostra-se cada vez mais como uma fonte de problemas e ineficiências que carecem de ser acauteladas a priori. Essa sucessão mostra-se especialmente complexa num sistema sucessório como o português, que deixa muito pouca margem à vontade do testador, impondo-lhe um vasto leque de regras no que toca à sucessão legítima, sendo assim necessário estabelecer formas de, não violando as normas imperativas do Direito das Sucessões, garantir que a empresa não entrará em colapso com o falecimento do seu fundador e assegurar uma passagem tranquila de geração em geração. Desta forma, a questão terá de ser obrigatoriamente resolvida com recurso ao Direito das Sociedades, criando mecanismos aptos a garantir que a empresa não será abalada por possíveis conflitos familiares, e dando uma relevância superior à vontade do empresário. Para tal, optamos por elencar uma multiplicidade de cláusulas que deverão ser inseridas no contrato de sociedade antes de se dar o fenómeno sucessório, e que permitirão uma transição suave de uma geração para a outra, impedindo que a mesma seja destrutiva para a sociedade.
- Sentir-se abandonado : pessoas com mais de 80 anosPublication . Marques, Gina Maria Da Silva; Amendoeira, José Joaquim PenedosA presente investigação centra-se nas experiências subjetivas das pessoas com mais de 80 anos, grupo populacional que atualmente mais cresce no mundo, cuja longevidade representa uma conquista civilizacional. Contracorrente o valor da vida humana das pessoas mais velhas, surge cada vez mais menorizado pelas sociedades. Tornou pertinente desenvolver um estudo acerca do vivido pelas pessoas com mais de 80 anos, com o objetivo de compreender o significado de Sentir-se Abandonado. E como finalidade: contribuir para o desenvolvimento do conhecimento de enfermagem pela proposta de uma prototeoria compreensiva de cuidado de enfermagem existencial às pessoas com mais de 80 anos. Metodologia – abordagem fenomenológica hermenêutica para compreensão do significado das experiências vividas pelos participantes, pessoas entre os 80 e os 97 anos, obtidas através de entrevistas fenomenológicas no seu domicílio. Discussão e resultados – O significado das experiências vividas revelam que depois dos 80 anos, o Homem para sentir a sua existência significativa, necessita de afetar e se sentir afetado pelos afetos, pelos valores, partilhados nas relações de pertença construídas durante a sua existência. Tais achados, revelam que a longevidade vista do ponto de vista do estritamente biológico compreende uma dimensão subjetiva de abandono de existência humana. O significado de sentir-se abandonado – pessoa com mais de 80 anos, constitui-se em torno de três temas: Bem-estar Existencial, Ausência de bem-estar existencial e Cuidado de enfermagem existencial. O estado de sentir-se abandonado, resulta da perceção de que a relação matricial da pessoa ao seu lócus ou relação de pertença, que ela própria define, se definhou ou extinguiu, com base no sentimento da diminuição ou ausência de valor atribuído à sua existência humana, ao seu estatuto de ser, que a impede do usufruto de uma vida significativa. Conclusão – a população idosa aumenta, e as suas necessidades individuais subjetivas, complexas crescem proporcionalmente, a compreensão do significado de sentir-se abandonado, aponta para que as pessoas para se sentirem permanentemente ligadas à vida, percecionem a sua vida como significativa, para si, para os outros, e para o mundo. Concomitantemente, necessitam de uma matriz de cuidado de enfermagem existencial, que se operacionaliza em presença terapêutica de enfermagem, centrado na pessoa, nos seus significados e necessidade subjetiva de se sentir humanamente valorizada enquanto ser-no-mundo independentemente da sua idade cronológica e das suas capacidades funcionais. Por se basear nas suas expectativas face ao cuidado de enfermagem, pode dar suporte a cuidados individualizados, sensíveis e de elevada competência humana, reconhecida e necessária no cuidado de enfermagem às pessoas com mais de 80 anos.
- Assigning patients to healthcare centers using dispatching rulesPublication . Teymourifar, Aydin; Trindade, Maria A. M.This study proposes a model for the balanced assignment of patients to healthcare centers in a region. In the suggested model, it is supposed that patients want to go to the nearest center, which causes an imbalance in the workloads of resources between centers. This disproportion is undesirable not only for the centers but also for the patients. Thus, balancing assignments is targeted. This goal is expressed in a model with a multi-objective function. Since balancing is one of the main goals of the sectorization concept, we characterize the model based on it. Unlike studies in the literature, we do sectorization employing dispatching rules. This diminishes the problem's complexity and makes it suitable for solving actual, large, and dynamic problems. We simulated the system using the Rockwell Arena software. We consider the effect of different seasons, days, and hours on the system. The dispatching rule used for sectorization is optimized using the OptQuest software. The numerical results demonstrate that by optimizing the dispatching rule, it is possible to enhance the objective function significantly.
- Acorn starch extraction and modification by emerging technologiesPublication . Castro, Luís Manuel Gomes de; Pintado, Maria Manuela Estevez; Saraiva, Jorge Manuel Alexandre; Alexandre, Elisabete Maria da CruzNative to the Northern Hemisphere, the trees of the genus Quercus spp. are found between the temperate and tropical latitudes of the Americas, Asia, Europe, and North Africa. These oaks are evergreen, semi-deciduous, or deciduous trees and produce small fruits called acorns. According to the National Institute of Statistics, these trees represent 35% of the forest area in mainland Portugal, where 85% of cork oaks and 92% of holm oaks are found in the Alentejo, while 94% of the remaining species are concentrated in the North and Center regions. For this reason, large quantities of acorns are produced, and it is estimated that the annual production is 401,585 tons. Despite being a fruit rich in polyphenols and gluten-free (resistant) starch, about 55% of the acorns produced are underused. Currently, as starch has multiple applications in the food and non-food industry, the exploitation of acorns as a source of starch would be advantageous. According to the literature, alkaline extraction is the methodology that allows obtaining the highest extraction yields in starch with the highest purity and with the most relevant properties. However, these starches cannot be used as food additives in the European Union due to a lack of approval. Thus, the main objective of this thesis was to value acorns within the scope of the principle of sustainable development through the creation of high-added value and zero-waste ingredients. Different species of acorns (Q. pyrenaica, Q. robur, and Q. ilex) were collected to study the effect of different dehulling methods on their nutritional and phytochemical composition. Each specie was dehulled separately by three different methods: manual, thermal (by thermal shock), and drying. It was found that the carbohydrate content was not significantly affected, but there was a loss of resistant starch of 76, 42 and 62% after thermal dehulling and a loss of 35, 27 and 25% after dehulling by drying compared to manual dehulling for Q. pyrenaica, Q. robur, and Q. ilex, respectively. As Q. robur was the specie with the highest resistant starch/total starch ratio (0.89), as well as the highest phenolic contents (19.3±1.3 mg GA Eq./g DF), hydrolyzable and condensable tannins (73.2±4.6 mg TA Eq./g DF and 0.103±0.01 mg TA Eq./g DF, respectively) comparatively to Q. pyrenaica and Q. ilex, the manually dehulled acorn of the Q. robur specie was selected in the following tests. Then, the optimization of the starch extraction was conducted at room temperature using water as extraction solvent by high hydrostatic pressure (HP) (pressure levels between 0.1 and 500 MPa and extraction times between 5 and 20 min) and pulsed electric field (PEF) (field strengths between 0.1 and 20 kV/cm and times between 35 and 85 μs) technologies. Due to the presence of large tannin content, which are anti-nutritional compounds of great importance in leather production, their extraction was also optimized, as well as other phenolic compounds, to obtain antioxidant extracts with high added value. Regarding the HP extraction, the optimal extraction condition was found at 333 MPa for 17.4 min with a desirability of 79.5%. The starch yield was 35.4±1.1% (w/w DF) and the extracts had a phenolic and hydrolyzable tannin content of 23.1±0.3 mg GA Eq./g DF and 54.1±0.1 mg TA Eq./g DF, respectively, and an antioxidant activity measured by ABTS of 53.6±0.6 mg TX Eq./g DF. As for the PEF extraction, the optimal extraction condition was obtained at 0.1 kV/cm for 63.3 μs with a desirability of 86.5%. The starch yield was 34.5±0.4% (m/m DF) and the extracts had a phenolic and hydrolyzable tannin content of 27.0±1.2 mg GA Eq./g DF and 56.7±0.6 mg TA Eq./g DF, respectively with antioxidant activity of 59.1±1.9 mg TX Eq./g DF. Condensed tannins were not detected in any of the extracts. Compared to alkaline extraction, the results observed under optimal conditions represent an increase in phenolic yields, tannins, and antioxidant activity by 2, 900, and 4% by HP and an increase by 24, 1012, and 15% by PEF, respectively. Thus, these technologies make it possible to obtain aqueous extracts with a higher tannin content than alkaline extraction, thus valuing these compounds. However, it was the PEF extraction technology that made it possible to obtain extracts with a higher content of polyphenols (phenolics and tannins) and with greater antioxidant activity than HP. Concerning starch, although the extraction yields obtained by HP and PEF under optimal conditions were lower than those verified in the respective alkaline extractions (49.7±0.5 and 48.9±1.2% w/w DF for HP and PEF, respectively), these starches are clean-label and can be used more safely as an additive and/or ingredient in human food than alkaline starches. As the extraction yields under optimal conditions were like each other, the impact of technologies on starch properties was studied and the properties were compared to commercial corn starch to try to identify the most advantageous extraction technology. Regarding the starch obtained by HP under optimal conditions, pressurization preserved the type of polymorphism of the acorn starch and did not significantly alter the relative crystallinity and the onset gelatinization temperatures (i.e., it preserved the hydrogen bonds). However, the significant increase in the amylose/amylopectin ratio by 97%, motivated by the cleavage of the amylopectin chains, led to changes in the properties of starches. Pressurization led to a decrease in the solubility and swelling power of the starches relative to the control and led to an increase in the resistance of the gels to deformation. However, no differences were observed in the in-vitro digestibility, pseudo-plastic behavior, or resistance to flow after pressurization. Regarding the starch obtained by PEF under optimal conditions, the amylose and amylopectin contents were not altered, as well as the onset gelatinization temperatures (hydrogen bonds). Although the type of polymorphism was not changed, there was a decrease in relative crystallinity of 17%. PEF treatment did not alter the starch properties concerning the control starch (solubility, swelling power, in-vitro digestibility, and rheology). Compared to commercial corn starch, acorn starches showed lower gelatinization temperatures and enthalpies, better pseudo-plastic behavior, lower in-vitro digestibility, greater resistance to complex flow, and lower resistance to deformation. Overall, acorn starches also showed higher solubility and swelling power up to 80 °C than commercial starch, which encourages the use of acorn starch as an additive in fermented yogurt and dairy products. As extraction by HP and PEF led to obtaining acorn starches with different properties, a dairy product was developed to try to identify the most suitable starch for this purpose. The effect of replacing commercial corn starch with acorn starch extracted by HP and PEF under optimal conditions on the nutritional composition, functional and sensory properties, and shelf-life of chocolate puddings was studied. Acorn starch improved the rheological properties of puddings without negatively affecting their nutritional composition, internal structure, or in-vitro digestibility. The sensory analysis revealed that 61% of tasters preferred the puddings made with acorn starch over commercial corn starch (control). As for the shelf life, acorn starch led to color stabilization and improved texture of the puddings after 28 days of storage at 4°C compared to the control without compromising the microbiological safety. Of the acorn starches used, PEF-extracted acorn starch led to the greatest improvement in pudding texture. In addition, the chocolate pudding made with PEF-extracted acorn starch also had a higher acceptability index than the HP-extracted starch. Thus, PEF-extracted acorn starch seems to be the most suitable for pudding production. In its entirety, the work described in this Doctoral thesis marks important steps in the valorization of acorns in Portugal, that is, in the valorization of its polyphenols and starch. This work will also contribute to the sustainability and transformation of the acorn in a circular economy context, as it demonstrates the potential of using PEF technology, as a sustainable alternative to alkaline extractions, in obtaining products with high added value and of great economic interest.
- Investigation of Trypanosoma-induced vascular damage sheds insights into Trypanosoma vivax sequestrationPublication . Pereira, Sara Silva; Brás, Daniela; Porqueddu, Teresa; Nascimento, Ana M.; Niz, Mariana DeMultiple blood-borne pathogens infecting mammals establish close interactions with the host vascular endothelium as part of their life cycles. In this work, we investigate differences in the interactions of three Trypanosoma species: T. brucei, T. congolense and T. vivax with the blood vasculature. Infection with these species results in vastly different pathologies, including different effects on vascular homeostasis, such as changes in vascular permeability and microhemorrhages. While all three species are extracellular parasites, T. congolense is strictly intravascular, while T. brucei is capable of surviving both extra- and intravascularly. Our knowledge regarding T. vivax tropism and its capacity of migration across the vascular endothelium is unknown. In this work, we show for the first time that T. vivax parasites sequester to the vascular endothelium of most organs, and that, like T. congolense, T. vivax Y486 is largely incapable of extravasation. Infection with this parasite species results in a unique effect on vascular endothelium receptors including general downregulation of ICAM1 and ESAM, and upregulation of VCAM1, CD36 and E-selectin. Our findings on the differences between the two sequestering species (T. congolense and T. vivax) and the non-sequestering, but extravasating, T. brucei raise important questions on the relevance of sequestration to the parasite’s survival in the mammalian host, and the evolutionary relevance of both sequestration and extravasation.