Browsing by Issue Date, starting with "2014-01"
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- STEAP1 is overexpressed in prostate cancer and prostatic intraepithelial neoplasia lesions, and it is positively associated with Gleason scorePublication . Gomes, Inês; Arinto, Patrícia; Lopes, Carlos; Santos, Cecilia; Baptista, CláudioSix transmembrane epithelial antigen of the prostate 1 (STEAP1) is a transmembrane protein of epithelial cells, mostly located at cell-cell junctions, and is overexpressed in several types of tumors, particularly prostate cancer. Several studies have pointed STEAP1 as a biomarker, but the clinical significance of its overexpression is not fully understood. Therefore, we aimed to establish the association of STEAP1 immunoreactivity with histologic diagnosis and clinical data of patients.
- Information technologies for pain managementPublication . Pombo, Nuno Gonçalo Coelho Costa; Araújo, Pedro José Guerra; Viana, Joaquim Manuel Vieira da SilvaMillions of people around the world suffer from pain, acute or chronic and this raises the importance of its screening, assessment and treatment. The importance of pain is attested by the fact that it is considered the fifth vital sign for indicating basic bodily functions, health and quality of life, together with the four other vital signs: blood pressure, body temperature, pulse rate and respiratory rate. However, while these four signals represent an objective physical parameter, the occurrence of pain expresses an emotional status that happens inside the mind of each individual and therefore, is highly subjective that makes difficult its management and evaluation. For this reason, the self-report of pain is considered the most accurate pain assessment method wherein patients should be asked to periodically rate their pain severity and related symptoms. Thus, in the last years computerised systems based on mobile and web technologies are becoming increasingly used to enable patients to report their pain which lead to the development of electronic pain diaries (ED). This approach may provide to health care professionals (HCP) and patients the ability to interact with the system anywhere and at anytime thoroughly changes the coordinates of time and place and offers invaluable opportunities to the healthcare delivery. However, most of these systems were designed to interact directly to patients without presence of a healthcare professional or without evidence of reliability and accuracy. In fact, the observation of the existing systems revealed lack of integration with mobile devices, limited use of web-based interfaces and reduced interaction with patients in terms of obtaining and viewing information. In addition, the reliability and accuracy of computerised systems for pain management are rarely proved or their effects on HCP and patients outcomes remain understudied. This thesis is focused on technology for pain management and aims to propose a monitoring system which includes ubiquitous interfaces specifically oriented to either patients or HCP using mobile devices and Internet so as to allow decisions based on the knowledge obtained from the analysis of the collected data. With the interoperability and cloud computing technologies in mind this system uses web services (WS) to manage data which are stored in a Personal Health Record (PHR). A Randomised Controlled Trial (RCT) was implemented so as to determine the effectiveness of the proposed computerised monitoring system. The six weeks RCT evidenced the advantages provided by the ubiquitous access to HCP and patients so as to they were able to interact with the system anywhere and at anytime using WS to send and receive data. In addition, the collected data were stored in a PHR which offers integrity and security as well as permanent on line accessibility to both patients and HCP. The study evidenced not only that the majority of participants recommend the system, but also that they recognize it suitability for pain management without the requirement of advanced skills or experienced users. Furthermore, the system enabled the definition and management of patient-oriented treatments with reduced therapist time. The study also revealed that the guidance of HCP at the beginning of the monitoring is crucial to patients' satisfaction and experience stemming from the usage of the system as evidenced by the high correlation between the recommendation of the application, and it suitability to improve pain management and to provide medical information. There were no significant differences regarding to improvements in the quality of pain treatment between intervention group and control group. Based on the data collected during the RCT a clinical decision support system (CDSS) was developed so as to offer capabilities of tailored alarms, reports, and clinical guidance. This CDSS, called Patient Oriented Method of Pain Evaluation System (POMPES), is based on the combination of several statistical models (one-way ANOVA, Kruskal-Wallis and Tukey-Kramer) with an imputation model based on linear regression. This system resulted in fully accuracy related to decisions suggested by the system compared with the medical diagnosis, and therefore, revealed it suitability to manage the pain. At last, based on the aerospace systems capability to deal with different complex data sources with varied complexities and accuracies, an innovative model was proposed. This model is characterized by a qualitative analysis stemming from the data fusion method combined with a quantitative model based on the comparison of the standard deviation together with the values of mathematical expectations. This model aimed to compare the effects of technological and pen-and-paper systems when applied to different dimension of pain, such as: pain intensity, anxiety, catastrophizing, depression, disability and interference. It was observed that pen-and-paper and technology produced equivalent effects in anxiety, depression, interference and pain intensity. On the contrary, technology evidenced favourable effects in terms of catastrophizing and disability. The proposed method revealed to be suitable, intelligible, easy to implement and low time and resources consuming. Further work is needed to evaluate the proposed system to follow up participants for longer periods of time which includes a complementary RCT encompassing patients with chronic pain symptoms. Finally, additional studies should be addressed to determine the economic effects not only to patients but also to the healthcare system.
- Innovative energy-efficient wireless sensor network applications and MAC sub-layer protocols employing RTS-CTS with packet concatenationPublication . Barroca, Norberto José Gil; Velez, Fernando José da Silvaof energy-efficiency as well as the number of available applications. As a consequence there are challenges that need to be tackled for the future generation of WSNs. The research work from this Ph.D. thesis has involved the actual development of innovative WSN applications contributing to different research projects. In the Smart-Clothing project contributions have been given in the development of a Wireless Body Area Network (WBAN) to monitor the foetal movements of a pregnant woman in the last four weeks of pregnancy. The creation of an automatic wireless measurement system for remotely monitoring concrete structures was an contribution for the INSYSM project. This was accomplished by using an IEEE 802.15.4 network enabling for remotely monitoring the temperature and humidity within civil engineering structures. In the framework of the PROENEGY-WSN project contributions have been given in the identification the spectrum opportunities for Radio Frequency (RF) energy harvesting through power density measurements from 350 MHz to 3 GHz. The design of the circuits to harvest RF energy and the requirements needed for creating a WBAN with electromagnetic energy harvesting and Cognitive Radio (CR) capabilities have also been addressed. A performance evaluation of the state-of-the art of the hardware WSN platforms has also been addressed. This is explained by the fact that, even by using optimized Medium Access Control (MAC) protocols, if the WSNs platforms do not allow for minimizing the energy consumption in the idle and sleeping states, energy efficiency and long network lifetime will not be achieved. The research also involved the development of new innovative mechanisms that tries and solves overhead, one of the fundamental reasons for the IEEE 802.15.4 standard MAC inefficiency. In particular, this Ph.D. thesis proposes an IEEE 802.15.4 MAC layer performance enhancement by employing RTS/CTS combined with packet concatenation. The results have shown that the use of the RTS/CTS mechanism improves channel efficiency by decreasing the deferral time before transmitting a data packet. In addition, the Sensor Block Acknowledgment MAC (SBACK-MAC) protocol has been proposed that allows the aggregation of several acknowledgment responses in one special Block Acknowledgment (BACK) Response packet. Two different solutions are considered. The first one considers the SBACK-MAC protocol in the presence of BACK Request (concatenation) while the second one considers the SBACK-MAC in the absence of BACK Request (piggyback). The proposed solutions address a distributed scenario with single-destination and single-rate frame aggregation. The throughput and delay performance is mathematically derived under both ideal conditions (a channel environment with no transmission errors) and non ideal conditions (a channel environment with transmission errors). An analytical model is proposed, capable of taking into account the retransmission delays and the maximum number of backoff stages. The simulation results successfully validate our analytical model. For more than 7 TX (aggregated packets) all the MAC sub-layer protocols employing RTS/CTS with packet concatenation allows for the optimization of channel use in WSNs, v8-48 % improvement in the maximum average throughput and minimum average delay, and decrease energy consumption.
- The diverse roles of calcium-binding protein regucalcin in cell biology: from tissue expression and signalling to diseasePublication . Marques, Ricardo; Baptista, Cláudio; Vaz, CV; Correia, Sara; Socorro, SílviaRegucalcin (RGN) is a calcium (Ca(2+))-binding protein widely expressed in vertebrate and invertebrate species, which is also known as senescence marker protein 30, due to its molecular weight (33 kDa) and a characteristically diminished expression with the aging process. RGN regulates intracellular Ca(2+) homeostasis and the activity of several proteins involved in intracellular signalling pathways, namely, kinases, phosphatases, phosphodiesterase, nitric oxide synthase and proteases, which highlights its importance in cell biology. In addition, RGN has cytoprotective effects reducing intracellular levels of oxidative stress, also playing a role in the control of cell survival and apoptosis. Multiple factors have been identified regulating the cell levels of RGN transcripts and protein, and an altered expression pattern of this interesting protein has been found in cases of reproductive disorders, neurodegenerative diseases and cancer. Moreover, RGN is a serum-secreted protein, and its levels have been correlated with the stage of disease, which strongly suggests the usefulness of this protein as a potential biomarker for monitoring disease onset and progression. The present review aims to discuss the available information concerning RGN expression and function in distinct cell types and tissues, integrating cellular and molecular mechanisms in the context of normal and pathological conditions. Insight into the cellular actions of RGN will be a key step towards deepening the knowledge of the biology of several human diseases.
- Nano revolução na arquitectura do amanhãPublication . Silva, Bruno Miguel Pereira da; Pinto, Luís Miguel de Barros MoreiraEsta investigação está dividida em três capítulos (Nanotecnologia, Arquitectura + Nanotecnologia, Rumo a um novo futuro), em que no primeiro capitulo é feita uma breve viagem ao mundo da Nanotecnologia, com o objectivo de se analisarem várias questões, nomeadamente o que é a Nanotecnologia e para que serve. No que diz respeito ao segundo capítulo, são abordados ainda alguns conceitos de Nanotecnologia, mas fundamentalmente tratará da sua aplicação na Arquitectura, ou seja, aos materiais de construção e seus benefícios. Também será também feito um levantamento de alguns produtos com base nesta tecnologia, já disponíveis no mercado. Por último o capítulo (Rumo a um novo futuro) terá características mais utópicas tendo como base alguns conceitos científicos (Montador Universal de Eric Drexler), de salientar também algumas propostas de alguns Arquitectos para um Arquitectura dinâmica. Como forma de conclusão deste capítulo são apresentados os resultados de um inquérito realizado a uma pequena amostra da sociedade, com o intuito de perceber as suas reacções aos três estilos arquitectónicos apresentados.
- A relação estética das artes plásticas na arquitetura de Miguel SaraivaPublication . Fidalgo, Ana Cristina Matos Lopes; Pinto, Luís Miguel de Barros MoreiraCom o presente trabalho, pretende-se defender a tese de que o arquiteto Miguel Saraiva, na primeira década da sua carreira, construiu uma arquitetura que foi beber inspiração aos pintores neoplasticistas, principalmente a Piet Mondrian, apresentando projetos que, após a sua edificação, se constituem como pinturas em três dimensões, jogando com a cor, a luz e o espaço, tomando como moldura o meio e a paisagem envolvente. Parte-se da abordagem de áreas científicas e artísticas diversas e complementares para compreender o contexto, a evolução histórica e os conceitos intrínsecos ao conhecimento da arquitetura e da pintura contemporânea, com o intuito de elaborar uma proposta de análise e a sua aplicabilidade num caso de estudo. Na primeira parte do trabalho, apresenta-se a relação estética das artes plásticas na Arquitetura, realçando a importância da estética no sujeito fruidor, a relação entre a obra de arte e o sujeito e a valorização de modelos de comportamento estéticos. Na segunda parte, estudam-se três temas, a cor, a luz e o espaço, fazendo referência a um determinado período de intervenções de alguns artistas plásticos que foram importantíssimos na forma como o fruidor olha, estuda, compreende e apreende a arte no seu todo e a influência do abstracionismo na arquitetura. Reserva-se a terceira parte da tese aos casos de estudo de uma seleção de obras dos primeiros anos de ateliê de Miguel Saraiva, fazendo um descritivo dessas obras e abordando o relacionamento entre o fruidor e a obra no que toca à perceção estética. Releva-se a cor, a importância da luminosidade e a materialização da luz no património construído. Na conclusão, aborda-se o papel preponderante do desenho na obra do arquiteto Miguel Saraiva, em que este nos apresenta cada projeto como a expressão da sua arte, como um todo em que o domínio do espaço ajuda a proporcionar um percurso unificado entre desenho, pintura e arquitetura, concluindo que o arquiteto pinta a natureza com a sua obra.
- Surface modification of polyurethane films by plasma and ultraviolet light to improve haemocompatibility for artificial heart valvesPublication . Alves, Patrícia; Cardoso, Rute; Correia, Tiago R.; Antunes, Bernardo Paiva; Correia, Ilídio Joaquim Sobreira; Ferreira, PaulaProsthetic cardiac valves implantation is a common procedure used to treat heart valve diseases. Although there are different prostheses already available in the market (either mechanical or bioprosthetic), their use presents several problems, specifically concerning thrombogenicity and structural failure. Recently, some progresses have been achieved in developing heart valves based on synthetic materials with special emphasis in polymers. Among them, polyurethanes are one of the most commonly used for the production of these devices. Herein, Elastollan®1180A50, a thermoplastic polyurethane (TPU), was used to formulate films whose surfaces were modified by grafting 2-hydroxyethylmethacrylate (HEMA) either by ultra-violet (UV) or by plasma treatment. All films were analyzed before and after grafting. X-ray photoelectron spectroscopy (XPS) measurements were used to evaluate TPU surfaces functionalization. HEMA grafting was confirmed by the increase of the hydroxyl (OH) groups’ concentration at the surface of the films. Atomic force microscopy (AFM) analysis was done to evaluate the surface topography of the biomaterials. Results showed that the roughness of the surface decreased when HEMA was grafted, especially for plasma treated samples. After grafting the films’ hydrophilicity was improved, as well as the polar component of the surface energy, by 15–30%. Hydrophobic recovery studies using milli Q water or PBS were also performed to characterize the stability of the modified surface, showing that the films maintained their surface properties along time. Furthermore, blood-contact tests were performed to evaluate haemolytic and thrombogenic potential. The results obtained for HEMA grafted surfaces, using plasma treatment, confirmed biomaterials biocompatibility and low thrombogenicity. Finally, the cytotoxicity and antibacterial activity of the materials was assessed through in vitro assays for both modified films. The obtained results showed enhanced bactericidal activity, especially for the films modified with plasma.
- Synthesis and characterization of micelles as carriers of non-steroidal anti-inflammatory drugs (NSAID) for application in breast cancer therapyPublication . Marques, João Filipe Gonçalves; Gaspar, Vítor Manuel Abreu; Costa, Elisabete C.; Paquete, Catarina; Correia, Ilídio Joaquim SobreiraNon-steroidal anti-inflammatory drugs (NSAIDS) are emerging as a particularly valuable class of drugs due to their recently reported anti-tumoral activity in colorectal cancer. However, despite this tremendous potential, their bioavailability at the tumor microenvironment remains rather limited. To overcome this issue, in this work we synthesized biocompatible micellar nanocarriers composed of amphiphilic chitosan to deliver ibuprofen into breast cancer cells and evaluate its anti-tumor activity, while avoiding side-effects. Our results reveal that the formulations produced herein self-assembly into spherical micelles with suitable sizes for tumor accumulation (108–252 nm). Furthermore, by using a vortex-sonication method, ibuprofen was successfully encapsulated with high efficiency. Cell uptake studies show that ibuprofen-loaded micelles are readily internalized by tumor cells and deliver their cargo in the intracellular compartment as demonstrated by confocal microscopy images. This fact led to a remarkable reduction in cancer cell viability (<13%), at a relatively low drug dosage, illustrating the anti-tumoral activity of ibuprofen when delivered to breast cancer cells. These findings demonstrate the promising potential of chitosan micelles as carriers of cost-effective NSAIDS for application in breast cancer therapy.
- Purification of pre-miR-29 by arginine-affinity chromatographyPublication . Pereira, Patrícia; Sousa, Ângela; Queiroz, João; Correia, Ilídio; Figueiras, Ana; Sousa, FaniRecently, differential expression of microRNAs, in patients with Alzheimer's disease (AD) suggests that they might have key regulatory roles in this neurodegenerative disease. Taking into account this fact, several studies demonstrated that the miR-29 is significantly decreased in AD patients, also displaying abnormally high levels of β-site APP-cleaving enzyme 1. Thus, RNA biochemical or structural studies often require a RNA sample that is chemically pure and biologically active. The present work describes a new affinity chromatography method using an arginine support to specifically purify pre-miR-29 from other Rhodovulum sulfidophilum small RNA species. Nevertheless, in order to achieve higher efficiency and selectivity, it is essential to characterize the behavior of pre-miR-29 binding/elution. Thus, three different strategies based on increased sodium chloride (280–500 mM), arginine (25 mM) or decreased ammonium sulfate (2–0.1 M) stepwise gradients are described to purify pre-miR-29. In this way, it was proved that well-defined binding/elution conditions are crucial to enhance the purification performance. As a matter of fact, by employing elution strategies using sodium chloride or arginine, an improvement in the final pre-miR-29 yields (96.5 and 56.7%, respectively) was obtained. Moreover, the quality control analysis revealed high integrity in pre-miR-29 preparations as well as high purity (90 and 98%, respectively), demonstrated by the scarce detection of proteins. This improved method takes advantage of its simplicity, significant cost reduction, due to the elimination of some complex operations, and speed for large-scale purification of pre-miRNAs suitable for biochemical and structural studies.
- Residência Universitária: definição de uma identidade tipológicaPublication . Neto, Filipe José Lacerda; Krenz, Jacek Tadeusz; Fernandes, Miguel João Mendes do Amaral SantiagoO projeto para a Residência de Estudantes localiza-se na freguesia da Ajuda (Lisboa), entre o Palácio Nacional da Ajuda, o Parque Florestal de Monsanto e a Tapada da Ajuda. Este projeto visa apoiar a população discente e docente no Campus do Pólo da Ajuda, promovendo a fixação de uma população residente na zona e propondo novas formas de articulação relacional entre os vários edifícios universitários e a envolvente construída, numa lógica de integração e interação. O projeto propõe uma aproximação a partir do quadro disciplinar do urbanismo e da arquitetura – Projeto de Arquitetura integrado na malha urbana real -, contribuindo para melhorar a coesão e dinâmica urbana através da gestão integrada do território e da adoção de medidas que melhorem a qualidade do espaço público e do espaço habitacional de curta duração. Pretendemos propor novas formas de habitar, rejeitando a ideia standard de espaços servidores e espaços servidos – zona de dia e zona de noite -, repensando os espaços concebidos como servidores e desvinculá-los da sua mera função de transição ou de serviços - utilizá-los com a mesma intensidade que o resto da habitação. Esta proposta tem em vista a articulação e potenciação da zona do Pólo da Ajuda através da revitalização do tecido urbano, promovendo uma relação coerente entre o edificado e o espaço público; refletindo sobre os espaços domésticos a partir das suas qualidades e do seu potencial, possibilitando a melhoria dos espaços que até agora têm sido ignorados e a introdução de mudanças no uso da habitação.