Identification of novel biomarkers and candidate genes associated to lipid traits : improving the lipid metabolism knowledge base

FH, the most common monogenic dyslipidaemia, is characterised by increased circulating LDL-C levels leading to premature cardiovascular disease when undiagnosed or untreated. Current guidelines support genetic testing in patients fulfilling clinical diagnostic criteria and cascade screening of their family members. However, about half of clinical FH patients do not present pathogenic variants in the known disease genes (LDLR, APOB, PCSK9), and these most likely suffer from polygenic hypercholesterolaemia, which translates into a relatively low yield of genetic screening programs. This project aimed to identify new biomarkers able to improve the distinction between monogenic and polygenic profiles. Using a machine-learning approach in a paediatric dataset, tested for disease causative genes and investigated with an extended lipid profile, we developed new models that classify FH patients with higher specificity than currently used methods. The best performing models incorporated parameters absent from the common FH clinical criteria, which rely only on TC and LDL-C. A hierarchical clustering analysis of the same dataset showed that the study population can be clearly divided in three groups of dyslipidaemic individuals, showing the complexity of the dyslipidaemic biological context and the need of an integrative and multidisciplinary approach for biomarker selection. Both clustering and modelling analysis have revealed that the extended lipid profile contains important biomarkers. The exploration of lipid metabolic pathways associated with the identified biomarkers allowed us to identify a set of related genes. Using additional information from public databases, including gene expression data, associated GWAS and GO terms, we defined a universe of lipid-related genes and molecular interactions relevant for the dyslipidaemic context and future genetic studies. All this information was used to establish a new lipid knowledge base available online. The obtained results can be applied to improve the yield of genetic screening programs and decrease the associated costs, and also provide novel contributions to our understanding of dyslipidaemias

How virtuality impacts start-up employees performance through its influence on entrepreneurship passion

There is evidence that organizations have increased the use of virtual teams in recent years and combined with this there are many advantages. However, there is no certainty that these teams have a virtual positive effect on their performance. This study, through a questionnaire, examined how team's entrepreneurial passion mediated the relationship between Virtuality and Team Performance and how the Work Conflict moderated the Team's Entrepreneurial Passion effect on performance. A sample of 41 start-ups was analyzed using a moderate mediation model; and the results indicate that the Virtuality is positively related to Team Performance and that the Team's Entrepreneurial Passion also contributes to good performance. On the other hand, the relationship between Virtuality and Team Entrepreneurial Passion is less clear, and its positive impact depends on the informational value and the extent of use with which the team uses virtual tools to work. Practical implications of the results and possible questions for future research are discussed.Há evidências de que as organizações têm aumentado o uso de equipas virtuais nos últimos anos e aliado a isso existem muitas vantagens. Ainda assim, não há certeza de que estas equipas tenham um efeito positivo da virtualidade na sua performance. O presente estudo, através de um questionário, examinou como é que a paixão empreendedora da equipa mediou a relação entre virtualidade e performance e como o conflito de trabalho moderou o efeito da paixão empreendedora da equipa na performance. Uma amostra de 41 start-ups foi analisada por meio de um modelo de mediação moderada; e os resultados indicam que a virtualidade está positivamente relacionada com a performance e que também a paixão empreendedora da equipa contribui para uma boa performance. Por outro lado, a relação entre virtualidade e paixão empreendedora da equipa é menos clara, sendo que o seu positivo impacto depende do valor informacional e do grau de utilização com que a equipa recorre a ferramentas virtuais para trabalhar. São discutidas implicações práticas dos resultados e levantadas possíveis perguntas para futuras pesquisas

Desidratação no idoso

Trabalho final de mestrado integrado em Medicina , área cientifica de Geriatria, apresentado á Faculdade de Medicina da Universidade de CoimbraA desidratação é o distúrbio eletrolítico mais frequente no idoso. A população idosa é mais suscetível a desidratação, não só devido às alterações fisiológicas intrínsecas da idade mas também por causas patológicas, sociais, iatrogénicas e ambientais. O diagnóstico de desidratação não é fácil, já que a clínica e exames laboratoriais perdem especificidade nesta faixa etária e podem não ser conclusivos para um diagnóstico de desidratação. Por isso, é necessário cuidado redobrado na prática clínica para que a desidratação no idoso não passe despercebida, uma vez que o diagnóstico precoce e o tratamento adequado e atempado são indispensáveis para evitar complicações. Se não for tratada, a desidratação apresenta elevadas taxas de morbilidade e mortalidade no idoso. A prevenção da desidratação, no domicílio e em unidades de cuidados, toma assim uma importância indiscutível na sociedade envelhecida dos dias de hoje. Este artigo tem como objetivo fazer uma revisão da literatura mais recente acerca da temática “desidratação no idoso”, abordando os aspetos referidos anteriormente, bastante relevantes nesta populaçãoDehydration is the most common electrolyte disorder in the elderly. The elderly population is more vulnerable to dehydration, not only because of physiological changes related to the aging process but also due to pathological, social, iatrogenic and environmental causes. Diagnosing dehydration is not easy, since clinical signs and laboratory tests are less specific in this age group and may not be conclusive to a diagnosis. Therefore, in clinical practice, it is necessary to pay double attention so that dehydration does not go unnoticed, since early diagnosis and adequate treatment are essential to avoid complications. If left untreated, dehydration presents high morbidity and mortality rates in the elderly. Preventing dehydration, at home and in care units, is incontestably important nowadays in aged societies. The main purpose of this article is to review the recent literature on the subject “dehydration in the elderly”, concerning all aspects already referred which are so pertinent to this population

Ohmic-heating treatment as a new process for development of functional ingredients through valorisation of tomato and grape by-products

Tomato and wine production are the main agro-industrial sectors in Portugal. These activities produce and accumulate large amounts of waste, especially seeds, peels and pulp residues, with high economic and environmental concerns worldwide. These residues are typically rich in bioactive compounds (BC), such as proteins, sugars and lipids, and phenolic compounds (PC) and carotenoids. Therefore, they can be an economical source of high added value, with potential food, cosmetic, or pharmaceutical industry applications. However, current extraction methods (e.g. extraction with chemical solvents) and environmental hazards can also degrade BC and promote toxicity, reducing biological properties and health benefits, making it difficult to use as value-added products. The main objective of this thesis was to explore the value of grape and tomato bagasse to promote the principle of sustainable development, with the achievement of ingredients of added value and zero waste. Thus, an optimisation study of BC extraction from these by-products was carried out, using ohmic heating (OH) method and solvents used in the food industry, to ensure the maintenance of compositional integrity, functionality and safety of bioactive extracts obtained and compared with the traditional method in which it is used organic solvents (CONV). Initially, a group of grape by-products was used, namely stalk and bagasse samples from white and red wine and tomato bagasse, obtained from the processing industry. The compositional characterisation and phytochemical properties of the byproducts were carried out to verify the potential of the matrix to be used and to define the recovery strategy. Grape bagasse presented higher protein, carbohydrate, and BC content than stalks, mainly characterised by high fibre content. Concerning tomato bagasse, samples of the same Heinz tomato cultivar from two different industries were used, and the results were compared. Both samples presented protein contents between 16.3 and 19.4 g / 100 g DW; fibre content between 57.8 and 59.0 g / 100 g DW, mainly polyunsaturated, linoleic acid, oleic and palmitic acid. After complete characterisation, the grape and tomato bagasses were selected as the most promising byproducts and OH was applied to extract the BC and reduce the environmental impacts based on a circular economy strategy. As solvents, water was used alone or combined with ethanol to promote the extraction of more lipophilic compounds, such as carotenoids. In parallel, a CONV method was used to compare the results. After extraction, two different fractions were obtained: the liquid fraction (LF) rich in BC solubilised and the remnant, the solid fraction (SF) with relevant nutritional and functional potential. In the case of bagasse, LF did not present significant differences (p>0.05) between CONV and OH for total phenolic compounds (TPC), 2.84 ± 0.037 and 3.28 ± 0.46 mg / g DW equivalent of gallic acid, respectively. The same trend was found for antioxidant activity (AA), where CONV and OH presented values of 2.02 ± 0.007 g / 100 g and 2.34 ± 0.066 g / 100 g ascorbic acid equivalent, respectively. The main anthocyanins identified were malvidin-3-O-acetylglucoside, delphinidin-3-Oglucoside, petunidin-3-O-glucoside. These extracts exhibited antimicrobial potential against the microorganisms Yersinia enterocolitica, Pseudomonas aeruginosa, Salmonella Enteritidis, Methicillin-sensitive Staphylococcus aureus, methicillin-resistant S. aureus (MRSA) and Bacillus cereus. SFOH showed a composition with potential functional ingredients, showing higher proteins and BC bound to fibre than CONV. Regarding tomato bagasse, a LF rich in carotenoids, polyphenols, and sugars and a SF rich in fibres linked to polyphenols and carotenoids were obtained. Also, new molecules were identified by UPLC-qTOF-MS analysis, such as phene-di-hexane and N-acetyl-Dtryptophan. After first evaluating the feasibility of applying OH, an experimental design was made to obtain better yields. Different moderate electric fields (MEF) of different intensities (i.e., 4, 6 and 11 V.cm-1) were also used to identify non-thermal effects in the extraction process and their influence on the bioactive properties of the extracted compounds. BC extraction using OH was successfully optimised with the best extraction conditions corresponding to 70 ºC for 15 min using 70% ethanol as a solvent, which allowed a more significant recovery of rutin in 77% than the control samples. It allowed to recover up to 4.93 μg / g lycopene of tomato by-products without resorting to organic solvents, showing itself as a selective extraction method, depending on the compounds of interest. Since there are no studies on the impact of the extraction methodologies and the action of the gastrointestinal tract (GIT) on the bioaccessibility of BC obtained from tomato by-products, the GIT was simulated for each of the LF and SF obtained by the OH and CONV methods. In LF, the results showed that extraction significantly influences the bioaccessibility of the BC present, with OH demonstrating a positive impact on the preservation of BC and consequently on the associated biological properties such as antioxidant, antihypertensive, prebiotic and anti-inflammatory. The main BC identified by UPLC-qTOF-MS were p-cumáric acid (163 m/z), naringenin (271 m/z) and luteolin (285 m/z). In addition, extract obtained by OH after GIT simulation exhibited a prebiotic effect on different strains of Bifidobacterium and Lactobacillus. Regarding FS, the results showed that the OH treatment originated a flour (SFOH) with higher total fibre than the flours obtained with CONV (SFCONV), 62.47 ± 1.24 and 59.06 ± 0.67 g / 100 g DW, respectively. Both flours presented high resistant protein content, representing between 11 and 16% of the insoluble dietary fibre. The main carotenoids identified were lycopene, phytofluene and lutein, all known as health promoters. Despite the higher initial polyphenols and carotenoids in SFOH, BC were more bioaccessible and presented higher antioxidant capacity than those present in SFCONV, throughout the simulated GIT. Finally, and because there is scientific support on the positive effects of prebiotics on the intestinal microbiota, the fermentability of SFOH and SFCONV of tomato were evaluated. The results showed a higher growth of Bacteroidetes with SFOH and the highest values of Bacteroides with SFCONV. A correlation between the growth of microorganisms and short-chain fatty acids was also found. Therefore, the OH treatment allowed similar recovery yields with reduced treatment times and without the need for organic solvents (green extraction routes). In a sense, this work will contribute to the sustainability of the wine and tomato processing industries in the context of circular economy, as it presents an environmentally friendly, fast and economical process capable of recovering BC with high application potentials, such as functional ingredients for food, nutraceutical or cosmetic application.A produção de tomate e vinho são os principais sectores agroindustriais em Portugal. Estas atividades produzem e acumulam grandes quantidades de resíduos, sobretudo, sementes, cascas e restos de polpa, com elevada preocupação económica e ambiental em todo o mundo. Estes resíduos são tipicamente ricos em compostos bioactivos (CB), como por exemplo, proteínas, açúcares e lipídos, bem como compostos fenólicos (CF) e carotenoides. Assim sendo, podem constituir uma fonte económica, de elevado valor agregado, com potenciais aplicações na área alimentar, cosmética ou farmacêutica. No entanto, os métodos de extração atuais (por exemplo, extração com solventes químicos) além de serem um perigo ambiental, podem também degradar os CB e promover a sua toxicidade, reduzindo propriedades biológicas e benefícios à saúde, dificultando o seu uso como produtos de valor agregado. O principal objetivo desta tese foi explorar o valor de bagaço de uva e de tomate para promover o princípio do desenvolvimento sustentável, com a obtenção de ingredientes de valor acrescentado e resíduo zero. Assim, foi realizado um estudo de otimização da extração de CB a partir destes resíduos, utilizando o aquecimento óhmico (OH) e solventes utilizados na indústria alimentar, para garantir a manutenção da integridade composicional, funcionalidade e segurança dos extratos bioativos obtidos e comparar com o método tradicional o qual utiliza solventes orgânicos (CONV). Inicialmente foi utilizado um grupo alargado de subprodutos da uva, nomeadamente amostras de engaço e bagaço utilizadas na produção de vinho branco e tinto, assim como o bagaço de tomate, obtido da indústria de processamento. Procedeu-se à caracterização composicional e propriedades fitoquímicas dos subprodutos para verificar o potencial da matriz a ser utilizado e definir a estratégia de valorização. O bagaço de uva apresentou maior teor de proteína e de carboidratos e de CB do que o engaço, que se caracterizou principalmente por um alto teor de fibra. Relativamente ao bagaço do tomate, utilizaram-se amostras da mesma cultivar de tomate Heinz, de duas indústrias diferentes e compararam-se os resultados. Ambas as amostras apresentam teores de proteínas, entre 16,3 e 19,4 g / 100 g PS; teor de fibra entre 57,8 e 59,0 g / 100 g PS, além disso, são ricos em ácidos gordos 17,0 g / 100 g, principalmente, polinsaturados, ácido linoleico, oleico e o ácido palmítico. Após caraterização completa, selecionaram-se como mais promissores o bagaço de uva tinta e de tomate e aplicou-se OH para extrair os CB e reduzir os impactos ambientais com base numa estrategia de na economia circular. Como solventes foram usados a água isoladamente ou combinada com etanol, para promover a extração de compostos mais lipofílicos, como por exemplo os carotenos. Em paralelo procedeu-se a comparação dos resultados com o método CONV. Após a extração obtiveram-se duas frações diferentes, o extrato líquido (FL) rico em CB solubilizados e ainda, o remanescente, a fração sólida (FS) que também possui relevante potencial nutricional e funcional. No caso do bagaço, a FL, não apresentou diferenças significativas (p>0.05) entre o CONV e o OH para os compostos fenólicos totais (CFT), 2,84 ± 0,037 e 3,28 ± 0,46 mg / g PS equivalente de ácido gálico, respetivamente. A mesma tendência foi encontrada para a actividade antioxidante (AA), onde CONV e OH apresentaram valores de 2,02 ± 0,007 g / 100 g e 2,34 ± 0,066 g / 100 g equivalente de ácido ascórbico, respetivamente. As principais antocianinas identificadas foram malvidina-3-O-acetilglucosídeo, delfinidina-3-O-glucosídeo, petunidina-3-O-glucosídeo. Esses extratos exibiram potencial antimicrobiano contra os microrganismos Yersinia enterocolitica, Pseudomonas aeruginosa, Salmonella Enteritidis, Staphylococcus aureus sensível à meticilina, S. aureus resistente à meticilina (MRSA) e Bacillus cereus. A FS obtida por OH mostrou uma composição com potencial ingrediente funcional, tendo evidenciado maiores quantidades de proteínas e CF ligados à fibra do que o CONV. Relativamente ao bagaço de tomate, obteve-se uma FL rica em carotenoides, polifenóis, e açúcares e uma FS rica em fibras ligada a polifenóis e carotenoides. Também, novas moléculas foram identificadas pela análise LC-ESI-UHR-OqTOF-MS, como feno-di-hexano e N-acetil-D-triptofano. Após uma primeira avaliação da exequibilidade da aplicação do OH, fez-se um desenho experimental para obter melhores rendimentos. Foram utilizados também diferentes campos elétricos moderados (MEF) de diferentes intensidades (ou seja, 4, 6 e 11 V.cm-1) para identificar a presença de efeitos não térmicos no processo de extração e a sua influência nas propriedades bioativas dos compostos extraídos. A extração de CF usando OH foi otimizada com sucesso com as melhores condições de extração correspondendo a 70 ºC por 15 min usando etanol 70% como solvente, que permitiu uma maior recuperação de rutina em 77% do que as amostras controlo. Permitiu recuperar até 4,93 µg / g de licopeno dos subprodutos do tomate sem recorrer a solventes orgânicos, mostrando-se como método de extração seletivo, dependendo dos compostos de interesse. Como não existem estudos sobre o impacto das metodologias de extração e da ação do trato gastrointestinal (TGI) na bioacessibildiade de CB obtidos a partir de subprodutos do tomate, simulou-se o TGI para cada uma das FL e FS obtidas pelo métodos OH e CONV. Na FL os resultados mostraram que a extração influencia significativamente a bioacessibilidade dos CB presentes, com OH demonstrando um impacto positivo na preservação dos CF e consequentemente nas propriedades biológicas associadas, como propriedades antioxidante, anti-hipertensiva, prebiótica e anti-inflamatória. Os principais CB identificados por UPLC-qTOF-MS foram o ácido p-cumárico (163 m / z), naringenina (271 m / z) e luteolina (285 m / z). Além disso, o extrato obtido por OH após simulação do TGI exibiu efeito prébiótico sobre diferentes estirpes de Bifidobacterium e Lactobacillus. Relativamente à FS os resultados mostraram que o tratamento OH originou uma farinha (FSOH) com maior fibra total do que as farinhas obtidas com o CONV (FSCONV), 62,47 ± 1,24 e 59,06 ± 0,67 g / 100 g PS, respetivamente. Ambas as farinhas apresentaram alto teor de proteína resistente, representando entre 11 a 16% da fibra alimentar insolúvel. Os principais carotenoides identificados foram o licopeno, fitoflueno e luteína, todos conhecidos como promotores de saúde. Apesar dos valores iniciais maiores de polifenóis e carotenóides na FSCONV, os CB da FSOH foram mais bioacessíveis e apresentaram maior capacidade antioxidante do que os presentes no FSCONV, em todo o TGI. Finalmente, e porque existe um suporte científico sobre os efeitos positivos sobre a saúde funcional de prebióticos na microbiota intestinal avaliou-se a fermentabilidade das FSOH e FSCONV de tomate. Os resultados mostraram um maior crescimento de Bacteroidetes com FSOH e os maiores valores de Bacteroides para FSCONV. Uma correlação entre o crescimento de microrganismos e ácidos gordos de cadeia curta também foi encontrada. Assim sendo, o tratamento OH permitiu rendimentos de recuperação semelhantes com tempos de tratamento menores, e sem necessidade de solventes orgânicos (rotas de extração verdes). Em suma, este trabalho irá contribuir para a sustentabilidade das indústrias do vinho e do processamento do tomate num contexto de economia circular, na medida em que apresenta um processo amigo do ambiente, rápido e económico capaz de recuperar CB com elevado potencial de aplicação, gerando ingredientes funcionais para aplicação alimentar, nutracêutica ou cosmética

Understanding business relationships between SME service providers and electronic marketplaces

Mestrado Bolonha em Gestão e Estratégia IndustrialThe study seeks to analyze and understand the business relationship between SME service providers and Electronic Marketplaces. These platforms have increasingly stood out in the market, as the final consumers frequently use them to satisfy their needs. In this way, developing a business relationship with a Marketplace can be a good growth opportunity for SMEs. The study objective was pursued through a qualitative and multiple case study. Data collection included continuous participant observation over a 12-month internship on a company owing a Marketplace platform, through interviews with seven small and micro companies from different sectors that establish or have already established business relationships with these platforms, and secondary data. The interviewees in this study were the top managers and/or founders of the companies studied. The main conclusions are the perception of value is the decisive factor for companies to continue or break their business relationships. From the moment they no longer reflect a competitive advantage, it no longer makes sense to be partners. Furthermore, certain characteristics such as informal competition, customer perception of the service, customer ‘distrust, and the need to reach certain audiences lead SMEs to establish business relationships with Marketplace.O estudo apresentado procura analisar e compreender a relação de negócio entre PME prestadoras de serviço e Eletronic Marketplaces. Estas plataformas têm-se destacado cada vez mais no mercado, pois os consumidores finais utilizam-nas frequentemente para conseguir satisfazer as suas necessidades. Desta forma, o desenvolvimento de uma relação de negócio com um Marketplace pode ser uma boa oportunidade de crescimento para as PME. O objetivo do estudo foi concebido através de um estudo de caso qualitativo e de múltiplos casos de estudo. A recolha de dados incluiu observação participante contínua ao longo de um estágio de 12 meses na empresa detentora de uma plataforma Marketplace, através de entrevistas a sete pequenas e micro empresas de diferentes setores que estabelecem ou já estabeleceram relações co-merciais com estas plataformas, e dados secundários. Os entrevistados deste estudo foram os principais gestores e/ou fundadores das empresas estudadas. As principais conclusões são que a perceção de valor é o fator decisivo para as empresas continuarem ou romperam as suas relações de negócio. A partir do momento que não refletem mais uma vantagem competitiva, deixa de fazer sentido serem parceiros. Para além disso, certas caraterísticas como concorrência informal, a perceção do cliente sobre o serviço, a desconfiança do mesmo e a necessidade de chegar a determinados públicos leva as PME a estabelecerem relações de negócio com Marketplace.info:eu-repo/semantics/publishedVersio

Cannabis biosynthesis: reshaping traditional production with science

Fierce competition to gain market share is revolutionizing the cannabis industry and, as companies invest significant monetary resources to remain competitive in an evolving sector, a new era in cannabis production emerges. This report aims to explore the potential of cannabis biosynthesis and how it is reshaping traditional production, beginning with a brief description of what this new concept entails and the advantage it has. It also provides an analysis over the implications and opportunities that can be created, with an outlook of the investments and partnerships already made, ultimately reflecting on the impact it might generate

Promoting sustainability: Environmental education activities in a social institution

Environmental education should not only act in the context of formal education but can also be applied in informal contexts, allowing a multipurpose application, serving to raise awareness, and transmit knowledge, allowing individuals to develop attitudes and behaviors that go against a more eco-centric posture. Given this fact, we developed a series of activities within the spectrum of environmental education applied in a social IPSS (social solidarity private institution), Obra Social Padre Miguel in the City of Bragança in Portugal. In this work, we used a qualitative approach, specifically study of exploratory nature, since it involved users and employees of the entity in the developed action, subsequently, we collected statements through interviews. A short interview script was drawn up and validated by professionals. In the development of these actions, we collect some data, such as water saving, food waste, and testimonials from users and employees. In the development of this work, we can observe that there was a decrease in the ecological footprint of the institution, and these actions can serve as an example that can be replicated by other entities. Given the results of this work, we conclude that the application of these actions in environmental education in addition to helping those involved in environmental awareness, can help entities to reduce their ecological footprint.info:eu-repo/semantics/publishedVersio

Mesoscopic modelling of bipolar charge evolution in CN-PPV LEDs

Since various chances are possible in the molecular structure of the repeat unit, substituted poly(para-phenylenevinylene) (PPV) has ben used as active component in light-emitting diodes (LEDs) to obtain light emission in a wide range of colours.A major aspect determining device performance is the competition between current flow, trapping and recombination within the polymer layer. By suitable Monte Carlo calculations, we have performed computer experiments in which bipolar charge carriers are injected at constant rate in polymer networks made of cyano-substituted PPV chains with variable length and orientation. The intra-molecular electronic properties used in these simulations were calculated by a quantum molecular dynamics method. In order to assess the influence of cyano-substitution on the properties of single-layer PPV LEDs, we have focused our attention on bipolar charge evolution in time. Specifically addressed are the differences in electric field strength needed for intra-molecular charge mobility of electrons and holes and their consequences at mesoscopic scale. (C) 2004 Elsevier B.V. All rights reserved

Modelling the effect of nonplanarity on charge transport along conjugated polymer chains

Conjugated polymers show interesting properties that make them appropriated for nanoelectronics. Several studies of poly(p-phenylene vinylene) (PPV) have suggested that each polymer chain consists of several planar segments, with conjugation length of nanoscale dimension, linked by twists or kinks. A pronounced twist between two planar segments in a PPV chain not only causes loss of main-chain conjugation but it may also alter electron and hole mobility along the chain, which has further implications for the percolation of charge through the polymer film. We used self-consistent quantum molecular dynamics calculations to provide information on the electric field needed to move the injected charges (either electrons or holes) along the planar segments of PPV and to cross the twist between two planar segments perpendicular to each other. Field-dependent charge mobility was also estimated for conjugated segments of various lengths. Our results suggest that electrons can cross the twist between adjacent planar segments for lower applied electric fields than holes if there is no more than one electronic charge (electron or hole) on the PPV chain, otherwise similar fields are needed.Fundação para a Ciência e a Tecnologia FCT) Programa Operacional “Ciência , Tecnologia, Inovação” – POCTI/CTM/41574/2001, CONC-REEQ/443/EEI/2001 e SFRH/BD/11231/200

Multiresponsive supramolecular systems for information processing at the molecular level

Dissertação para obtenção do Grau de Doutor em Química SustentávelInformation processing at the molecular level requires systems able to move between several states under control of specific inputs. Flavylium salts (2-phenyl-1-benzopyrylium salts)analogues of naturally occurring anthocyanin dyes, are a versatile family of molecules that illustrates the multistate/multiresponsive concept. On the basis of the pH and light dependent network of chemical reactions of the flavylium network, different forms can be obtained by external stimuli exhibiting different properties. The research work developed in the framework of this PhD thesis aimed the synthesis and study of multiresponsive covalently linked supramolecular systems, based on a flavylium unit coupled redox-active and/or metal-complexing moieties. It is intended to increase the number of stimuli in the complex network of flavylium, including electrons and metal ions besides protons and photons (flavylium). In an initial study, two new benzopyrylium salts with directly attached metalcomplexing groups were synthesized and characterized (Chapter 2). The electrical stimulus was introduced with a viologen (Chapter 3) and finally redox- and photoactive units such as Ru(II)polypyridyl complexes (Chapter 4) are discussed. Regarding their possible applications as model compounds to optical memories, it is expected to achieve with these new systems a larger number of states, which allow increased functionality and versatility