51 resultados para Morphological control


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Doctoral dissertation for Ph.D. degree in Sustainable Chemistry

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Memoria presentada para optar al grado de Doctor en Higiene, Salud y Seguridade en el Trabajo

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RESUMO: A operação de Nissen, por laparoscopia, é considerada a cirurgia antirefluxo mais adequada por ser a que melhor replica a fisiologia normal da válvula gastresofágica na maioria dos doentes com sintomas típicos de doença do refluxo gastresofágico (DRGE). São critérios técnicos o encerramento seguro dos pilares do diafragma e a criação de fundoplicatura completa (360 graus), curta (inferior a dois centímetros), lassa e sem tensão – desiderando para o qual a laqueação proximal dos vasos curtos gástricos é crucial. Realizei a operação de Nissen, por laparoscopia, em sessenta mulheres e quarenta homens com DRGE, sem mortalidade operatória, no Serviço de Cirurgia 6 do Hospital dos Capuchos, CHLC, EPE. Os cem doentes apresentavam média etária de 46 anos e queixas, com tempo de evolução entre 1 e 43 anos, de pirose (90%), regurgitação (80%), azia (73%), epigastralgias (54%). A endoscopia alta revelou esofagite de grau Savary-Miller 0-I (62%), II (23%), III (8%), IV (7%); hérnia de deslizamento (71%), hérnia paraesofágica (8%), sem hérnia (21%); a pHmetria de 24h diagnosticou padrão misto (38%), levantado (20%), deitado (20%), inconclusiva (22%) e a manometria diagnosticou EEI hipotónico (35%), peristálise esofágica normal (88%), hipomotilidade ligeira (5%) e foi omissa (7%). Hérnia hiatal, esofagite grave, ineficácia do controlo sintomático com inibidor da bomba de protões e desejo de descontinuidade terapêutica constituíram as indicações para tratamento cirúrgico. Por celioscopia, efetuei laqueação dos vasos curtos gástricos (70%), cruroplastia e fundoplicatura total (seda 2/0), curta (dimensão média 1,5-2 cm), lassa, sem tensão e sem calibração intraoperatória do esófago. A fundoplicatura de Nissen laparoscópica mostrou-se segura e eficaz no tratamento da DRGE. A sua idoneidade foi ainda comprovada pela normalização da pHmetria de 24 horas e da manometria pós-operatórias, com significado estatístico, num grupo de catorze voluntários assintomáticos. Em catamnese com recuo médio 30,7 meses 94% dos indivíduos persistem assintomáticos. Interrogando-me acerca das repercussões desta operação sobre a microcirculação do fundo gástrico coloquei, como premissa, a possibilidade de na operação de Nissen a laqueação dos vasos curtos poder induzir modificação no diâmetro arteriolar da parede do fundo gástrico. Para pesquisar a influência da laqueação dos vasos curtos gástricos e da fundoplicatura total sobre o calibre arteriolar da parede do estômago no cárdia, no fundo e na região dos vasos curtos gástricos, idealizei um Projeto de investigação experimental em cobaias. O Projeto foi desenvolvido no Centro de Investigação do Departamento de Anatomia da FCM-UNL. Para a sua realização obtive autorização da Comissão Científica e Pedagógica da FCM-UNL, requeri a acreditação como investigador à Direção Geral de Veterinária e, por recorrer à utilização de animais, submeti-o à Comissão de Ética da FCM-UNL, que o aprovou por unanimidade. Para limitar o número de animais utilizados ao mínimo necessário, calculei, por método estatístico, a quantidade de cobaias necessárias. Subdividindo-as num grupo de ensaio (GE), onde realizei a operação de Nissen, e num grupo de controlo (GC), onde apenas procedi a tração gástrica, defini e apliquei protocolos de anestesia, de cirurgia e de eutanásia, segundo os princípios dos 3R – Replacement, Reduction, Refinement da técnica de experimentação humana de Russell e Burch (1959) – uma estrutura ética amplamente aceite para a realização de experimentação científica humanizada com animais. A utilização das técnicas de estudo angiomorfológico permitiu-me analisar e descrever a anatomia normal, a vascularização arterial macroscópica, a microangioarquitetura, por microscopia eletrónica de varrimento de moldes de corrosão vascular, e a histologia da parede do estômago da cobaia. Procedi, também, à definição dos critérios morfológicos que considerei suscetíveis de validação deste modelo animal para o estudo proposto. Por razões académicas, foi necessário abreviar o Projeto encurtando, em cerca de dois anos, o prazo disponível para conclusão do estudo. Apreciando-o com o Gabinete de Análise Epidemiológica e Estatística do Centro de Investigação do CHLC, EPE, optou-se, perante a escassez de elementos após já terem sido recrutados 46 animais, por uma amostra, suplementar, de dimensão de conveniência de oito cobaias (quatro em cada grupo), condicionada pelo limite temporal universitário e pelo respeito pela dignidade dos animais. Neste subgrupo procedi, por microscopia eletrónica de varrimento, à medição dos calibres arteriolares nos moldes vasculares do cárdia, do fundo e da zona dos vasos curtos gástricos tanto no GC como no GE efetuando 469 medições no primeiro e 461 no último. Os dados foram enviados ao Centro de Investigação do CHLC, EPE que procedeu à sua análise estatística (ANOVA). A referida análise revelou que as arteríolas do plexo mucoso e as do plexo submucoso do cárdia, do fundo e da região dos vasos curtos gástricos, mostraram aumento de calibre no GE. O aumento foi, estatisticamente, significativo por ser superior a 50% do calibre do GC. Nos vasos curtos, a diferença foi mais pequena, mas persistiu sendo, estatisticamente, significativa. Os vasos retos dilataram na base, na sua emergência do plexo seroso, apenas no fundo gástrico. Na cobaia a operação de Nissen – fundoplicatura total com laqueação dos vasos curtos gástricos –, provocou vasodilatação arteriolar do fundo gástrico. Considero que essa vasodilatação constituiu acomodação à modificação introduzida e infiro que o mesmo possa acontecer no ser humano. Admito, assim, que também ocorra vasodilatação no ser humano, na sequência da laqueação dos vasos curtos gástricos, pela analogia microvascular entre as duas espécies e que essa vasodilatação corresponda, igualmente, a um mecanismo de adaptação arteriolar visando, por exemplo, suprir a perda incorrida pela laqueação. A associação experimental entre laqueação dos vasos curtos gástricos e realização de fundoplicatura total, que exerce aumento inerente de pressão sobre a JEG, não só não provocou défice da microcirculação do esófago distal ou do estômago proximal como desencadeou um mecanismo de vasodilatação fúndica que reforça o conceito de segurança da operação de Nissen para tratamento da DRGE. -------------- ABSTRACT: The laparoscopic Nissen operation is considered to be the most appropriate antirefluxsurgery because it suitably replicates the standard physiology of the gastroesophageal valve in most patients with typical symptoms of gastroesophageal reflux disease (GERD). The technical criteria includes the safe shutdown of the diafragmatic crura(cruroplasty) and the creation of a complete fundoplication (360 degrees), short (lesser than two inches), floppy and without tension – a goal for which the proximal ligation of the gastric short vessels is crucial. The laparoscopic Nissen operation was performed in sixty women and forty men with GERD, without any operative mortality, at the Surgical Department of the Hospital dos Capuchos, CHLC, EPE. The one hundred patients, averaged 46 years old, complained of heartburn (90%), regurgitation (80%) and upper abdominal pain (54 %). The endoscopy process revealed Savary-Miller esophagitis of grade 0-I (62%), II (23%), III (8%), IV (7%), sliding hernia (71%), paraesophageal hernia (8%) or no herniation (21%). The pHmetry/24h diagnosed mixed pattern (38%), raised (20%), lying (20%) or inconclusive (22%). The manometry diagnosed hypotensive LES (35%), normal esophageal peristalsis (88%), mild hypomotility (5%) and was absent (7%). Hiatal hernia, severe esophagitis, ineffective symptomatic control with proton pump inhibitor and request for treatment discontinuation were the signs for surgical action. A laparoscopic ligation of short gastric vessels (70%), cruroplasty and fundoplication (silk 2/0), short (average size 1.5–2 cm) and floppy, without tension and without intraoperative calibration of the esophagus were thus performed. The laparoscopic Nissen fundoplication behaved safe and effective in treating GERD. In a group of 14 asymptomatic volunteers its reputation was confirmed with statistical significance by normalization of postoperative pHmetry/24h and manometry. 94% of the individuals remained asymptomatic up to 30.7 months (average) in the follow-up. Interrogating myself about the impact of this operation on the microcirculation of the gastric fundus I put premised on the possibility of the ligation of the short gastric vessels in the Nissen procedure can induce changes in the arteriolar diameter in the Wall of the gastric fundus. To explore the influence of ligation of the short gastric vessels and the fundoplication at the arteriolar caliber of the cardia, the fundus and the region of the short vessels of the gastric wall, I designed a project of experimental research in guinea pigs with two interdependent components: one veterinary and another technical where I applied angiomorphological studies. The project was developed at the Research Centre of the Department of Anatomy FCMUNL. For its accomplishment I got permission from the Scientific and Pedagogical Committee of the FCM-UNL, I requested for accreditation as a researcher at the General Directorate of Veterinary and, by resorting to the use of animals I submitted it to the Ethics Committee of the FCM-UNL, which approved it unanimously. The guinea pigs were divided into two experimental groups: an experimental group (EG), in which the Nissen procedure was performed and a control group (CG) in which only a gastric traction was done. Protocols of anesthesia, surgery and euthanasia were applied according to the 3Rs – Replacement, Reduction, Refinement of the technique of human experimentation of Burch and Russell (1959) – a widely accepted ethical framework for conducting scientific experiments using animals humanely. Using histological and angiomorphological techniques, I performed the analysis and the description of the normal, macro and microvascular, anatomy of the guinea pig stomach and I defined the morphological criteria that I considered susceptible for validation of this animal model for the proposed study. By means of scanning electron microscopy I measured the arteriolar calibers of the vascular casts of the cardia, of the fundus and of the short gastric vessels in both CG and EG, making 469 measurements in the former and 461 in the latter. The data were sent to the Research Center of the CHLC which conducted the statistical analysis (ANOVA). The data were sent to the Centre for Research of the CHLC, EPE which proceeded to statistical analysis (ANOVA). This analysis revealed that the arterioles plexus of the mucosal and submucosal plexus of the cardia, fundus and region of the short gastric vessels, showed increased caliber in EG. The increase was statistically significant for being greater than 50% CG gauge. In the short gastric vessels, the difference was smaller, but persisted and statistically significant. Straight vessels were dilated at the base, on its emergence of the plexus serous only in the fundus. In the guinea pig, the Nissen procedure - complete fundoplication with ligation of the short gastric vessels - caused arteriolar vasodilation on the gastric fundus. I believe that this vasodilation constituted some accommodation to the modification introduced and infer that the same might happen in humans. I admit therefore that vasodilation also occurs in humans following the ligation of the short gastric vessels by microvascular analogy between the two species and that this vasodilation corresponds also to na adaptation mechanism arteriolar, for example, to compensate the loss incurred by ligation. The association of experimental ligation of the short gastric vessels with conducting complete fundoplication, which exerts increased pressure on the EGJ, not only did not cause a microcirculation deficit of the distal esophagus or proximal stomach as triggered a mechanism of fundic vasodilation which reinforces the security concept of the Nissen procedure for treatment of GERD.

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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and Economics

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Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente Perfil de Engenharia de Sistemas Ambientais

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Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores

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Functional regeneration of organs upon injury is a key process for animals survival. Contrary to humans, some vertebrates are remarkably competent in regenerating after acute organ or appendage lesions. This advantageous skill allows overcoming limitations in repair even in adult stages, when tissues are fully developed, via a process of epimorphic regeneration. One such organism is the zebrafish, which can regenerate several organs, namely its heart, retina, spinal cord and fins. (...)

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The main objective of the research work developed in the framework of this PhD thesis was the preparation and development of novel photorheological fluids. This was pursued following two distinct strategies. The first one focused on the synthesis of tripodal compounds functionalized with photodimerizable moieties of cinnamic acid, coumarin and anthracene. Two sets of compounds were prepared, varying the central unit as well as spacers resulting in molecules with different solubilities and molecular weight. All compounds were characterized towards their photochemical properties and all exhibited photoreactivity upon irradiation with ultra-violet light. In particular, both coumarin derivatives exhibited the greatest photopolymerization reactivity, resulting in the formation of dendrimeric nanoparticles or in the increase of viscosity of organic solutions. The second strategy was focused on the careful design of photosensitive ionic liquids, based on the results of several quantitative structure-property relationship studies. Thus, photosensitive ionic liquids were synthesized bearing cinnamic acid or coumarin moieties in the organic cation. Upon irradiation, all compounds exhibited reactivity, which resulted in changes in their physical properties, such as melting point or viscosity. In addition, novel coumarin chromophores with different photophysical and photochemical properties were developed. It is expected that these compounds may find application in the preparation of new photosensitive ionic liquids.

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Changes in development impact the final form of organisms and compose the natural variation that is the raw material for evolution. Development is hierarchically structured in progressive series of cell fate determination and differentiation. How does variation in different stages of development contribute to morphological diversification?

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Digital Microfluidics (DMF) is a second generation technique, derived from the conventional microfluidics that instead of using continuous liquid fluxes, it uses only individual droplets driven by external electric signals. In this thesis a new DMF control/sensing system for visualization, droplet control (movement, dispensing, merging and splitting) and real time impedance measurement have been developed. The software for the proposed system was implemented in MATLAB with a graphical user interface. An Arduino was used as control board and dedicated circuits for voltage switching and contacts were designed and implemented in printed circuit boards. A high resolution camera was integrated for visualization. In our new approach, the DMF chips are driven by a dual-tone signal where the sum of two independent ac signals (one for droplet operations and the other for impedance sensing) is applied to the electrodes, and afterwards independently evaluated by a lock-in amplifier. With this new approach we were able to choose the appropriated amplitudes and frequencies for the different proposes (actuation and sensing). The measurements made were used to evaluate the real time droplet impedance enabling the knowledge of its position and velocity. This new approach opens new possibilities for impedance sensing and feedback control in DMF devices.

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With the continuum growth of Internet connected devices, the scalability of the protocols used for communication between them is facing a new set of challenges. In robotics these communications protocols are an essential element, and must be able to accomplish with the desired communication. In a context of a multi-­‐‑agent platform, the main types of Internet communication protocols used in robotics, mission planning and task allocation problems will be revised. It will be defined how to represent a message and how to cope with their transport between devices in a distributed environment, reviewing all the layers of the messaging process. A review of the ROS platform is also presented with the intent of integrating the already existing communication protocols with the ServRobot, a mobile autonomous robot, and the DVA, a distributed autonomous surveillance system. This is done with the objective of assigning missions to ServRobot in a security context.

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RESUMO: Introdução: Uma meta-análise recente demonstrou que uso adjuvante de ácido zoledrónico (AZ) em mulheres pós-menopáusicas com cancro da mama precoce (CM) conduz a redução do risco de morte por CM em 17%. Investigámos o efeito do estado hormonal (pré [PrM] vs pós-menopausa tardia [PoM]) na remodelação óssea e controlo de doença em mulheres com CM e metástases ósseas (MO) tratadas com AZ e quimioterapia (QT). Métodos: Neste estudo de coorte retrospetivo, colhemos variáveis clinico-patológicas e quantificámos o telopéptido N-terminal (NTX) urinário e marcadores tumorais (MT) séricos em mulheres com CM e MO tratadas com QT e AZ. As doentes foram divididas em PrM (<45 anos) e PoM (>60 anos). Endpoints do estudo: variação do NTX, CA15.3 e CEA nos meses 3, 6 e 9, tempo até falência de QT de primeira-linha e sobrevivência. Quando apropriado foram usados os testes de Wilcoxon rank-sum, modelo de efeitos lineares mistos, teste log-rank e modelo de Cox. Resultados: Quarenta doentes foram elegíveis para análise (8 PrM e 32 PoM). Depois da introdução de AZ e QT, os níveis de NTX e MT caíram no coorte global. O perfil de resposta não diferiu entre grupos no mês 3 ou em tempos posteriores (valor-p para interação tempo-estado hormonal no mês 3=0.957). Ademais, o perfil de resposta dos MT também não diferiu entre grupos. O tempo mediano até falência de primeira-linha de QT em PrM e PoM foi de 15.2 e 17.4 meses, respetivamente. Não foi identificada diferença significativa entre grupos, quer em análise univariada quer após controlo para envolvimento visceral (p=0.399 e 0.469, respetivamente). Igualmente, não houve diferenças em termos de sobrevivência. Conclusões: Neste coorte, não foram identificadas diferenças no controlo de NTX ou MT em função do estado menopausico. Igualmente, não foi identificada diferença no tempo até falência de primeira-linha de CT ou sobrevivência.----------- ABSTRACT: Background: A recent meta-analysis showed that the adjuvant use of zoledronic acid (ZA) in postmenopausal women with early breast cancer (BC) leads to a reduction in the risk of breast cancer death by 17%. We investigated the effect of the hormonal status (pre [PrM] vs late post menopause [PoM]) on bone turnover and disease control among women with BC and boné metastases (BM) treated with ZA and chemotherapy (CT). Methods: In this retrospective cohort study, we collected clinicopathologic variables, urinary Nterminal telopeptide (NTX) and serum tumor marker levels from women with BC and BM treated with CT and ZA. Patients were divided in PrM (<45 years) and PoM (>60 years). Study endpoints were NTX, CA15.3 and CEA variation at 3, 6 and 9 months, and time to first-line CT failure and survival. We performed multilevel mixed-effects linear regression models to assess the variation of repeated measures and cox regression models for time to event outcomes. Results: Forty patients were eligible for analysis (8 PrM and 32 PoM). After introduction of ZA and CT, NTX and tumor markers declined in the overall cohort. Response profile was similar between menopausal groups at month 3 and at later time points (p-value for time-hormonal status interaction at month 3=0.957). Furthermore, tumor markers response profile was also equal between groups. Median time to first-line CT failure in PrM and PoM women was 15.2 and 17.4 months, respectively. No significant difference between groups was found, either using a univariate analysis or after controlling for visceral disease involvement (p=0.399 and 0.469, respectively). Likewise, no differences in survival were found. Conclusions: In this cohort, no differences were found in terms of NTX or tumor markers control according to menopausal status. Similarly, no difference in time to first-line CT failure or survival was found.

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The capacity to use geologic materials (soil and rock) that are available in the surrounding environment is inherent to the human civilization and has contributed to the evolution of societies throughout the course of history. The use of these materials in the construction of structures such as houses, roads, railways or dams, stirred the improvement of socioeconomic and environmental conditions. Several reports of structural problems on embankments can be found throughout history. A considerable number of those registers can be linked to inadequate compaction, demonstrating the importance of guaranteeing a suitable quality of soil compaction. Various methodologies and specifications of compaction quality control on site of earthworks, based on the fill moisture content and dry unit weight, were developed during the 20th century. Two widely known methodologies are the conventional and nuclear techniques. The conventional methods are based on the use of the field sand cone test (or similar) and sampling of material for laboratory-based testing to evaluate the fill dry unit weight and water content. The nuclear techniques measure both parameters in the field using a nuclear density gauge. A topic under discussion in the geotechnical community, namely in Portugal, is the comparison between the accuracy of the nuclear gauge and sand cone test results for assessing the compaction and density ratio of earth fills, particularly for dams. The main purpose of this dissertation is to compare both of them. The data used were acquired during the compaction quality control operations at the Coutada/Tamujais dam trial embankment and core construction. This is a 25 m high earth dam located in Vila Velha de Rodão, Portugal. To analyse the spatial distribution of the compaction parameters (water content and compaction ratio), a 3D model was also developed. The main results achieved are discussed and finally some considerations are put forward on the suitability of both techniques to ensure fill compaction quality and on additional research to complement the conclusions obtained.

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Um dos maiores desafios da neurofisiologia é o de compreender a forma como a informação é transmitida através do sistema nervoso. O estudo do sistema nervoso tem várias aplicações, tanto na neurologia, permitindo avanços ao nível clínico, como noutras áreas, e.g., nos sistemas de processamento de informação baseados em redes neuronais. A transmissão de informação entre neurónios é feita por via de sinais elétricos. A compreensão deste fenómeno é ainda incompleta e há projectos a nível europeu e mundial com o objetivo de modular o sistema nervoso no seu todo de forma a melhor o compreender. Uma das teses que se desenvolve hoje em dia é a de que a transmissão de sinais elétricos no sistema nervoso é influenciada por fenómenos de sincronia. O objetivo desta dissertação é o de otimizar um protocolo de aquisição e análise de dados reais de eletroencefalograma e eletromiograma com o propósito de observar fenómenos de sincronia, baseando-se num algoritmo (análise por referência de fase, ou RPA, do inglês reference phase analysis) que deteta sincronias de fase entre os sinais de eletroencefalograma (EEG) e um sinal de referência, que é, no caso presente, o eletromiograma (EMG). A otimização deste protocolo e sua validação indicaram a existência de fenómenos significativos de sincronia no sinal elétrico, transmitido entre os músculos da mão e o córtex motor, no decorrer da ação motora.

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White Color tuning is an attractive feature that Organic Light Emitting Diodes (OLEDs) offer. Up until now, there hasn’t been any report that mix both color tuning abilities with device stability. In this work, White OLEDs (W-OLEDs) based on a single RGB blend composed of a blue emitting N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) doped with a green emitting Coumarin-153 and a red emitting 4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM1) dyes were produced. The final device structure was ITO/Blend/Bathocuproine (BCP)/ Tris(8-hydroxyquinolinato)aluminium (Alq3)/Al with an emission area of 0.25 cm2. The effects of the changing in DCM1’s concentration (from 0.5% to 1% wt.) allowed a tuning in the final white color resulting in devices capable of emitting a wide range of tunes – from cool to warm – while also keeping a low device complexity and a high stabilitty. Moreover, an explanation on the optoelectrical behavior of the device is presented. The best electroluminescense (EL) points toward 160 cd/m2 of brightness and 1.1 cd/A of efficiency, both prompted to being enhanced. An Impedance Spectroscopy (IS) analysis allowed to study both the effects of BCP as a Hole Blocking Layer and as an aging probe of the device. Finally, as a proof of concept, the emission was increased 9 and 64 times proving this structure can be effectively applied for general lighting.