Fabrication of Highly Reflective Bottom Electrodes for Inverted Top-emission OLED Applications

The demand for more air-stable and high resolution devices are opening the space for inverted top-emission OLEDs in the displays market. To realize these high-performance devices, a combination of a highly reflective bottom electrode with an efficient electron injection layer is essential to achieve high luminance efficiency and low driving voltage, respectively. The aim of this thesis was to develop a new highly reflective stack and a corresponding method for high resolution patterning to enable future top-emission iOLED applications. First, the deposition methods for a multilayer reflective stack were developed. Initially, a structure using silver as reflective thin film and ITZO as electron injection layer was used. Reflective and transmission measurements together with optical simulation were executed to optimize the thickness of each sputtered thin film in the final stack. During the development, the oxidation of Ag prevented the high reflectivity of the layer. To mitigate this issue, a new stack with an ITO interlayer between Ag and ITZO layers was created to prevent silver oxidation from the ITZO deposition process. Finally, optimized samples with a configuration of Ag(50 nm)/ITO(5 nm)/ITZO(80 nm) were demonstrated with a reflectivity > 78% in the visible range. To obtain high resolution feature sizes on the developed stack, the photolithography recipe to pattern the multilayer stacks with resolution down to 5um was also developed. During this project, different liquid etchants were tested to pattern the structure in two wet-etching steps. The quality of the etch were analysed by atomic force microscope and optical microscope images. Images of individual ITZO layers demonstrated the importance of using Ti Prime before photoresist spin-coating to improve the quality of the etch. At the end, cross-sections of the full stack showed that well-defined hills and valleys were achieved when samples were dipped in 10% mixed acid etchant for 30sec at RT followed by a dip in 75% PWES solution for 5 sec at 45C

Identificação de novos reguladores da fidelidade da síntese proteica

Doutoramento em BiomedicinaProtein synthesis is central to life and is being intensively studied at various levels. The exception is mRNA translational fidelity whose study has been hampered by technical difficulties in detecting amino acid misincorporations in proteins. Few genes have so far been associated to the control of protein synthesis fidelity and it is unclear how many genes control this biological process. We investigated the role of RNA modification by RNA modifying enzymes (RNAmods) in protein synthesis efficiency and accuracy. Our hypothesis was that RNAmods that modify tRNA nucleosides (tRNAmods) have a significant impact on protein synthesis through modulation of codonanticodon interactions. To address this issue, we focused our work on tRNAmods involved in the modification of tRNA anticodons. The biology of these enzymes is still poorly understood, but they are involved in RNA processing, stability and function and their deregulation is associated with cancer, neurodegenerative, metabolic and other diseases. We have set up a yeast genetic screen and used mass-spectrometry methods to determine the role of tRNAmods on proteome homeostasis. Our work identified a subgroup of yeast tRNAmods that play essential roles in protein synthesis fidelity and folding. The genes that encode insoluble proteins isolated from yeast cells lacking U34 modification were enriched in codon sites that are decoded by the hypomodified tRNAs. These aggregated proteins also participate in specific biological processes, suggesting that tRNAmods are linked to specific physiological pathways. Interestingly, we detected amino acid misincorporations at the codon sites decoded by the anticodons of the hypomodified tRNAs, demonstrating that tRNA U34 modifications control translational error rate.A síntese proteica é central para a vida e tem sido extensivamente estudada a vários níveis. Contudo, o estudo da fidelidade da tradução do mRNA tem progredido lentamente devido a dificuldades técnicas na deteção de incorporações incorretas de aminoácidos nas proteínas. Poucos genes têm sido associados com o controlo da fidelidade da síntese proteica e não é evidente quais os genes que controlam este processo biológico. Nesta tese investigámos o papel da modificação dos nucleósidos do RNA na eficiência e precisão da síntese proteica. A nossa hipótese é que as enzimas que modificam nucleósidos do tRNA (tRNAmods) têm um impacto significativo na síntese proteica através da modulação das interações codão-anticodão. A biologia das tRNAmods e das modificações do tRNA são ainda pouco conhecidas, mas estão envolvidas na estabilidade e função do RNA e mutações nos seus genes causam doenças neurodegenerativas, metabólicas, cancro, entre outras. Neste projeto realizámos um rastreio genético em levedura com o objetivo de identificar tRNAmods que asseguram a homeostase do proteoma (proteostase) e usámos espectrometria de massa para clarificar o papel das tRNAmods na fidelidade da síntese proteica. Os resultados do estudo genético mostram que um sub-grupo de tRNAmods envolvidas na modificação de nucleósidos do anticodão do tRNA são essenciais para manter a estabilidade do proteoma. Outras tRNAmods estudadas não produziram impactos visíveis na proteostase. Os genes de proteínas agregadas que isolámos a partir de células de levedura com tRNAs hipomodificados são enriquecidos em codões descodificados por estes tRNAs. Os nossos dados mostram também que tais proteínas participam em processos biológicos específicos e têm níveis de aminoácidos errados mais elevados que as células wild-type. Estes dados mostram que certas modificações do tRNA são essenciais para a fisiologia celular, estabilidade do proteoma e fidelidade da síntese proteica

Functional and structural studies of a mini-ferritin protein

Dissertação para obtenção do Grau de Mestre em BioquímicaDNA-binding protein from starved cells (Dps) are mini-ferritins mainly expressed in bacteria during severe environmental stress. These proteins with a highly conserved structure provide wide protection to cells and function as iron-storage proteins. Some Dps can also bind DNA and the N-terminus has been suggested to be involved in this interaction, due to its positively charged residues. This thesis focused on the functional and structural features of recombinant Dps protein from Pseudomonas nautica 617 (P. nautica). To investigate the iron incorporation mechanism, iron uptake assays using H2O2 and O2 as co-substrate for iron oxidation were performed with Dps WT and F46G variant, using UVVisible spectroscopy. The results showed that Phe46, located close to the ferroxidase center (FOC), does not influence the amount of iron stored. Nevertheless, this residue affectes the iron core formation when O2 was used as co-substrate. Structural characterization of the incorporation of Fe(II) and Cu(II) was performed with X-ray crystallography. High resolution crystal structures of Apo-Dps, Dps incubated with 12 Fe(II)/Dps (12Fe-Dps) and Dps incubated with 12 Cu(II)/Dps (12Cu-Dps) were obtained. It was possible to observe the binding of the metals to the FOCs with different coordination geometry as well as geometrically different FOCs. Additionally Fe(II) and Cu(II) atoms were assigned in a position where hydrophilic pores can be created and serve as entry routes for the metals. For the characterization of the Dps-DNA interaction, electrophoretic mobility shift assays (EMSAs) were carried out with Dps WT and Q14E variant. The results showed that this protein can bind DNA, but the affinity for DNA significantly decreases in the presence of the negative charge in the N-terminus. In this sense, mutations in the N-terminus that may increase the affinity for DNA binding were produced by site-directed mutagenesis

Caracterização de biótopos do intertidal rochoso e a sua aplicabilidade pedagógica

Dissertação de Mestrado em Cidadania Ambiental e Participação apresentada à Universidade AbertaA relação com o mar e com os ecossistemas marinhos é algo intrínseco a qualquer açoriano, e que advém desde cedo, pelo constante contacto com o oceano e a sua biodiversidade marinha, tornado assim as ilhas num laboratório vivo pronto a ser descoberto e estudado. Os estudos, porém recentes da zonação do intertidal, nomeadamente dos seus biótopos no arquipélago dos Açores, realçam a distância biológica destas ilhas e dos seus habitats em relação ao continente português. No entanto, esta especificidade biológica não é destacada no ensino básico, verificando-se assim a lacuna de associação do Currículo Regional do Ensino básico com os seus pilares – Açorianidade e Insularidade. A educação ambiental assume um papel principal na formação dos estudantes não só na conversação do ambiente, mas consciencializando-os para os impactes da ação antropogénica nos ecossistemas costeiros. Pela aplicabilidade do caderno de campo, desenvolvido tendo em conta os conteúdos pedagógicos do 8º ano do 3º ciclo do ensino básico e realidade da fauna /flora marinha e da riqueza geológica e paleontológica, verificou-se um aumento, em 95 %, na aquisição de conhecimentos por parte dos alunos que realizaram a saída de campo. Conclui-se assim que, recursos pedagógicos com especificidade local, associado a saída de campo da disciplina de Ciências Naturais são uma vantagem para o ensino e para o interesse dos alunos deste nível de escolaridade, no arquipélago dos Açores.The relationship with the sea and the marine ecosystems is something intrinsic to any Azorean citizen, and it becomes from an early age, by constant contact with the ocean an its marine biodiversity, thereby making the islands a living laboratory ready to be discovered and studied. Recent studies on the intertidal zonation, and particular in biotopes in the Azores archipelago, highlight the biological distant between these islands and their habitats in relation to the Portuguese mainland coast. However, this biological specific is not highlighted in elementary education; therefore this is a gap on the Regional Curriculum of Elementary Education, and with its pillars – Azoreanity and Insularity. Environmental Education plays a major role in the training in student’s education not only in environmental conservation, but it raises awareness to the impacts of anthropogenic action on coastal ecosystems. Through the sampling made in Praia Formosa, the Biotope set to Santa Maria’s mediolittoral it’s different, with high abundance of Halopteris scoparia. The applicability of the field book, that was prepared taking into account the pedagogical content of the 8th grade and the present marine fauna and flora, and also the geological and paleontological history, has measured an increase, in 95%, the knowledge acquisition by the students who participate on the field trip. In conclusion, learning resources with local specify associated to field trip in Natural Science discipline are an advantage to teaching and for student’s interests in this level of education., in the Azores

Secure Abstractions for Trusted Cloud Computation

Cloud computing is adopted by most organizations due to its characteristics, namely offering on-demand resources and services that can quickly be provisioned with minimal management effort and maintenance expenses for its users. However it still suffers from security incidents which have lead to many data security concerns and reluctance in further adherence. With the advent of these incidents, cryptographic technologies such as homomorphic and searchable encryption schemes were leveraged to provide solutions that mitigated data security concerns. The goal of this thesis is to provide a set of secure abstractions to serve as a tool for programmers to develop their own distributed applications. Furthermore, these abstractions can also be used to support trusted cloud computations in the context of NoSQL data stores. For this purpose we leveraged conflict-free replicated data types (CRDTs) as they provide a mechanism to ensure data consistency when replicated that has no need for synchronization, which aligns well with the distributed and replicated nature of the cloud, and the aforementioned cryptographic technologies to comply with the security requirements. The main challenge of this thesis consisted in combining the cryptographic technologies with the CRDTs in such way that it was possible to support all of the data structures functionalities over ciphertext while striving to attain the best security and performance possible. To evaluate our abstractions we conducted an experiment to compare each secure abstraction with their non secure counterpart performance wise. Additionally, we also analysed the security level provided by each of the structures in light of the cryptographic scheme used to support it. The results of our experiment shows that our abstractions provide the intended data security with an acceptable performance overhead, showing that it has potential to be used to build solutions for trusted cloud computation

Santini : a scoop of expansion

Santini has been a very well-­‐known artisanal brand of ice-­‐cream, famous for the quality of its products, based on a secret recipe. In 2009, the family ice-­‐cream company, Santini decided to open its capital to external investment. This started a new phase in the life of the company that allowed it to open new stores and a new protection plant. This dissertation provides a case study of this small Portuguese company which main objective is to keep its expansion process without damaging its brand image and its differentiation positioning. The Master Thesis also presents a Literature Review that seeks to provide theoretical tools for further analysis of the case. The Teaching Note includes an analysis of the case; it’s in this section that conclusions are drawn and the recommendations are suggested regarding the strategy that should be followed by the firm.Santini é uma conhecida marca de gelados artesanais, famosa pela qualidade dos seus produtos feitos com base numa receita secreta. Em 2009, a empresa de gelados familiar, Santini, abriu o seu capital a investimento externo. Isto desencadeou uma nova fase da vida da empresa que permitiram a abertura de mais lojas e de uma nova fábrica. Esta dissertação proporciona um Estudo de Caso da pequena empresa portuguesa cujo principal objective é continuar o processo de expansão sem prejudicar a imagem da marca e o seu posicionamento de diferenciação. A Tese de Mestrado apresenta também uma Revisão de Literatura que visa fornecer ferramentas teóricas para a posterior análise do caso. A Nota de Ensino contém a análise do caso, sendo nesta secção que são retiradas as conclusões e apresentadas as sugestões relativamente à estratégia que devem ser adoptada pela empresa

Isolamento de um diterpeno bioactivo a partir de plectranthus ornatus codd.

Orientação: Patrícia RijoA Tuberculose, infeta milhares de pessoas todos os anos sendo um problema grave de saúde pública mundial. O agente causador, Mycobacterium tuberculosis, é uma bactéria detentora de mecanismos de sobrevivência elaborados no hospedeiro. A descoberta de novos antibióticos é essencial para reduzir as mortes por TB e os produtos naturais oferecem um excelente ponto de partida para a descoberta destes compostos devido à sua diversidade estrutural e funcional. O género Plectranthus pertencente à família Lamiaceae, como a menta e a sálvia, e exibe uma ampla gama de usos etnobotânicos. A espécie P.ornatus tem propriedades: diurética, antipirética, analgésica, antibiótica e anti-inflamatória e é utilizada no alívio de perturbações estomacais e hepáticas. O diterpeno de esqueleto de halimano (ácido 11R*-acetoxi-halima-5,13E-dien- 15-óico) foi isolado pela primeira vez a partir de um extrato acetónico do P.ornatus. Este composto está descrito quanto à sua actividade antimicrobiana, nomeadamente antibacilar. Deste modo, neste trabalho foi-se isolar o composto em grande escala. Assim, foi realizada uma extração acetónica por ultra-sons (rendimento de extração de 7,082% (m/m)). Também foi realizado o isolamento cromatográfico de 5,3 mg de diterpeno puro, identificado por HPLC-DAD, por comparação com uma amostra autêntica. No futuro será possível o isolamento total do composto neste extrato permitindo novos estudos biológicos com potencial para o desenvolvimento de novos fármacos tuberculostáticos.Tuberculosis infects thousands of people every year and is a serious public health problem worldwide. The causative agent, Mycobacterium tuberculosis, is a bacterium that has elaborated survival mechanisms in the host. The discovery of new antibiotics is essential for reducing TB deaths and natural products offer an excellent starting point for the discovery of these compounds due to their structural and functional diversity. The genus Plectranthus belonging to the Lamiaceae family, such as mint and sage, exhibit a wide range of ethnobotanical uses. The P.ornatus species has diuretic, antipyretic, analgesic, antibiotic and anti-inflammatory properties and is used to relieve stomach and liver disorders. Haliman's backbone diterpene (11R*-acetoxy halima-5,13E-dien-15-oic acid) was isolated for the first time from an acetone extract of P.ornatus. This compound is described due to its antimicrobial, namely antitubercular activity. Thus, in this work the large-scale compound was isolated. Thus, acetonic ultrasound extraction was performed (extraction yield 7.082% (w / w)). Chromatographic isolation of 5.3 mg of pure diterpene, identified by HPLC-DAD, was also performed by comparison with an authentic sample. In the future it will be possible the total isolation of the compound in this extract allowing new biological studies with potential for the development of new tuberculostatic drugs

Delayed intramural duodenal hematoma after a simple diagnostic endoscopic ultrasonography fine-needle aspiration procedure

A 65-year-old man was evaluated for a difficult-to-characterize pancreatic head mass in the setting of idiopathic chronic pancreatitis. He had no other relevant medical history and was not taking any anticoagulant or antiplatelet treatment. Endoscopic ultrasonography fine-needle aspiration (EUS-FNA) failed to reveal neoplasm cells. A linear array echoendoscope (Olympus GF-UCT140, Center Valley, PA) was advanced up to the duodenal bulb, from which the head of the pancreas was visualized. After ensuring a vessel-free access to the pancreatic parenchyma, the FNA was performed using a 22G needle (Slimline 22G Handle Needle; Boston Scientific, Marlborough, MA) with a total of 3 passes (Figure 1). Three weeks after this procedure, the patient was admitted for hematemesis preceded by vomiting. On admission, his general physical examination was unremarkable except for jaundice. His blood tests showed no anemia; his platelet count, prothrombin time, amylase, and liver enzymes were within normal range, but his total bilirubin level was elevated (7.4 mg/dL). Upper gastrointestinal endoscopy showed Mallory-Weiss tears, an evident extrinsic compression of the knee, and the second portion of the duodenum, which could not be passed by the endoscope. The investigation by computed tomography and magnetic resonance cholangiopancreatography led to the diagnosis of an 11-cm intramural duodenal hematoma (IDH), leading to both gastric outlet and main biliary duct obstruction (Figure 2). The case was successfully managed with nasogastric decompression and exclusive parenteral feeding. Symptoms improved within 15 days, and cholestasis progressively disappeared.info:eu-repo/semantics/publishedVersio

Economic analysis of pharmaceutical water pollution abatement in nursing home effluents

Pharmaceuticals have been detected in surface and groundwater, and even in drinking water. Although concentrations are generally low, there are concerns about their impacts on aquatic organisms and human health. Risks are expected to increase due to rising pharmaceutical consumption and water reuse. From an economic point of view, pollution is an example of so-called market failure that can (and should) be corrected by means of government intervention, although pharmaceutical water pollution is a particularly difficult one to deal with in terms of regulation given that pharmaceutical consumption is critical to health outcomes. An alternative approach is to invest in end-of-pipe solutions which focus on reducing the impact of pharmaceutical consumption by removing harmful substances from wastewater before it is returned to the environment. This work summarize knowledge on pharmaceutical water pollution and provides a costbenefit analysis for two new kind of filters on a pilot scale, a solar pilot and a pilot combining a membrane bioreactor with photo-oxidation. The analysis is applied to nursing homes located in France, Spain and Portugal. The costs of both filters include investment costs (equipment and assembly) and operational costs (energy, chemicals, maintenance and equipment replacement) and the benefits based on shadow prices that differ depending on whether the residual water is discharged in a sensitive or non-sensitive destination. The net present value differs considerably across pilots, countries and the fact of the destination being sensitive or not.Os produtos farmacêuticos têm sido detetados em águas superficiais e subterrâneas, e mesmo até em água potável. Embora as concentrações detetadas sejam geralmente baixas, os impactos nos organismos aquáticos e na saúde humana constituem motivo de preocupação. Há uma tendência para estes riscos aumentarem devido ao uso crescente de medicamentos, assim como do reaproveitamento de água. De um ponto de vista económico, a poluição é um exemplo de uma falha de mercado que pode (e deve) ser corrigida através de intervenção governamental, contudo a poluição das águas com produtos farmacêuticos é particularmente difícil de regulamentar uma vez que o consumo de medicamentos é crucial em termos de saúde. Uma das alternativas é investir em soluções em que o foco é reduzir o impacto do consumo de medicamentos através da sua remoção das águas residuais antes da descarga no meio ambiente. Este trabalho sintetiza o conhecimento acerca da poluição das águas com produtos farmacêuticos e apresenta uma análise custo-benefício de dois novos tipos de filtros numa escala piloto, um solar e outro que combina um biorreator de membrana com foto-oxidação. A análise é aplicada a lares de idosos em França, Espanha e Portugal. Os custos incluem o investimento (equipamento e montagem) e custos operacionais (energia, químicos, manutenção e substituição de equipamento), os benefícios baseiam-se no preço sombra que difere consoante as águas residuais são descarregadas em áreas sensíveis ou não sensíveis. O valor atual líquido varia consideravelmente consoante o filtro piloto, o país e o destino das águas residuais