Este trabalho diz respeito ao desenvolvimento de uma nova estratégia de Sensoriamento adaptada ao imageamento de escoamento bifásico por tomografia de impedância elétrica. Sua motivação básica vem do fato que a maioria dos algoritmos de reconstrução numérica foram desenvolvidos para campos de sensoriamento do tipo \'\'duro\", isto é, eles têm a hipótese subjacente de que o campo de sensoriamento é bidimensional e paralelo. Quando usam campos de sensoriamento do tipo \"mole\", tais como em tomografia capacitiva elétrica de escoamentos bifásicos, estas condições são marginalmente satisfeitas, a menos na situação de um menor contraste entre as propriedades elétricas do escoamento bifásico, para o qual a natureza mal condicionada do problema será de qualquer modo muito mais crítica. O desenvolvimento de um método menos restritivo pode ser alcançado pelo refinamento da qualidade da imagem produzida por uma sonda de imagem direta, por meio da minimização de um convenientemente definido erro funcional refletindo as diferenças entre valores experimentais e numéricos calculados na fronteira do volume de sensibilidade. De qualquer modo, é requerido que estes valores de fronteira sejam suficientemente sensíveis às mudanças na distribuição das propriedades elétricas do escoamento. Este trabalho apresenta a análise da sensibilidade de diferentes estratégias de excitação e sua aplicabilidade no algoritmo de reconstrução tomográfica descrito acima. Dois perfis de excitação clássica são comparados a fim de propor um no qual observa-se a sensibilidade dos resultados do perfil medido na fronteira às mudanças nas posições das inclusões no volume de sensibilidade. Os resultados confirmam que a estratégia clássica é prejudicada devido a falta de sensibilidade e que novas possibilidades devem ser desenvolvidas baseadas na otimização do perfil de excitação ou sob técnicas multi-sensitivas. / This work concerns the development of a new sensing strategy adapted to two-phase flow imaging by electrical impedance tomography. Its basic motivation comes from the fact that most of the numerical reconstruction algorithms were developed for hard sensing fields, i.e. they have the underlying assumptions that the sensing field is two-dimensional and parallel. When using soft sensing fields, such as in electrical capacitance tomography of two-phase flows, these conditions are barely satisfied, unless in the situation of a poor contrast between the electrical properties of the flowing phases, for which the ill-conditioned nature of the problem will be much more critical anyway. The development of a less restrictive method can be achieved by refining the qualitative images produced by a direct imaging probe, by means of the minimization of a conveniently defined error functional reflecting the difference between experimental and numerical values calculated at the boundary of the sensing volume. However, in order to do this, it is required that these boundary values be sufficiently sensitive to changes in the distribution of the electrical properties of the flow. This work presents a sensitivity analysis of different excitation strategies and their applicability in a tomographic reconstruction algorithm such as described above. Two classical excitation profiles are compared to a proposed one in what regards the sensitivity of the resulting measured profile at the boundary to changes in the positions of inclusions in the sensing volume. The results confirm that classical strategies suffer from a major lack of sensitivity and that new ones must be developed possibly based optimization of the excitation profiles or on multi-sensing techniques.

Parents’ capacity to represent and sensitively respond to their children as individuals, is a particularly pertinent ability during infancy. This thesis contributes to theoretical understanding of the nature of parental sensitivity during infancy. In particular, it examined whether parental mind-mindedness and coherence, dimensions theoretically related to sensitivity, are (i) measurable during pregnancy, (ii) conceptually distinct, and (iii) meaningfully associated with observed sensitivity. Results from two studies are presented. The first, a prospective longitudinal study, involved interviews with and observations of 201 first-time parents during late pregnancy and at 4 and 14 months postpartum. Drawing on this data, I established that both expectant mothers and fathers can construct mind-minded and coherent descriptions of their unborn infants during pregnancy. However, there was no evidence that these prenatal constructs had a direct or indirect effect on parents’ sensitivity during infancy. These results were added to the second meta-analytic study that showed expectant mothers’ (but not fathers’) thoughts and feelings about their unborn infant were related to their observed parenting in the postnatal period. In line with the gendered meta-analytic results, further differences emerged between mothers’ and fathers’ talk and behaviour within the prospective longitudinal study. Specifically, mind-mindedness was more stable than sensitivity for mothers whilst the reverse was evident for fathers. Compared with mothers, fathers’ talk and behaviour was more susceptible to influence from other members of the family system. Couple relationship quality influenced both fathers’ prenatal coherence and gains in their mind-mindedness over time. Infant affective responses were also important for fathers’ mind-mindedness, whilst maternal parental efficacy alongside infants’ receptive vocabulary were associated with fathers’ sensitivity. Unexpectedly, infant gender was an important influence on parents’ behaviour: mothers’ sensitivity at 4 months appeared to stimulate fathers’ sensitivity towards their daughters at 14 months. By following both mothers and fathers and in line with family systems theory, assessing whether partners contribute to the emergence of their co-parents’ sensitivity, this thesis provides a rich portrayal of the transition to parenthood in the 21st century.

This study considers the usefulness of the Intercultural Development Inventory in measuring the intercultural sensitivity of a sample of teachers at an established international school in Thailand. In this study, the Intercultural Development Inventory (IDI) was used to measure participants’ levels of intercultural sensitivity (ICS), based on Bennett’s Developmental Model of Intercultural Sensitivity (DMIS). To crosscheck the IDI findings and to provide additional insights, qualitative research using interviews of a sample of teacher participants was undertaken. Comparisons were also made with previous studies using the IDI to measure teacher levels of ICS. The aims of the study were to provide additional data about ICS among teachers at an established international school and to look for correlates relating to demographic factors. Specifically, the study aimed to assess the usefulness of the IDI to international schools looking to enhance ICS among students and teachers. The study concludes that the IDI is applicable to an international school context in measuring the intercultural sensitivity of teachers. The results showed that teachers in international schools involved in this study have higher levels of ICS than their counterparts in national schools who took part in previous studies. With respect to the participants in this study, 67.9% were operating in Bennett’s Minimization stage in the DMIS. Levels of ICS were positively correlated with years living in another culture, professional development related to ICS and knowledge of a foreign language. The findings provide insights into and opportunities for further study. Other studies may find similarities with respect to professional development for teachers with respect to ICS, teacher recruitment, gender differences, and levels of ICS among faculties at both national and international schools.

The Hygiene Hypothesis and Old Friends Hypothesis focus attention on the coevolutionary relationship between humans and pathogens, positing that reduced pathogen exposure in economically developed nations is responsible for immune dysregulation and associated increases in chronic inflammation, allergy, and autoimmunity. Despite progress in testing these ideas, few studies have examined these relationships among populations undergoing the transition from traditional to more market-based lifestyles. The present study tests relationships between economic development and social change, altered infectious disease exposure, and immune function among the Shuar forager-horticulturalists of Amazonian Ecuador, a population undergoing rapid economic change associated with increased market participation. Using stool samples to assess soil-transmitted helminth (STHs; parasitic intestinal worms) burden, dried blood spot measurement of the inflammatory marker C-reactive protein (CRP), and interviews to evaluate level of market integration (MI; the suite of social and cultural changes associated with rapid economic development) and disgust sensitivity, this dissertation tests the Hygiene and Old Friends Hypotheses. The first study tests relationships between STH exposure and MI, using geographic location in relation to the regional market center as a proxy for MI. This study documents lower rates of STHs in people living in more market integrated regions. The second study tests the coevolutionary role that STHs and other pathogens have played in shaping human psychology and behavior. Findings suggest that pathogen exposure has acted as a selective pressure, resulting in evolved disgust sensitivity toward pathogen related stimuli. This study provides evidence that disgust sensitivity is calibrated to local environments, acting to decrease STH exposure. The third study tests the role of STHs in immune function. CRP was positively related to age in uninfected individuals. No relationships existed for more traditionally living or infected individuals. These findings suggest that STH exposure may decrease the risk of developing chronic inflammation and associated diseases with advancing age. These studies provide support for the idea that STHs provide stimuli that decrease chronic inflammation, suggesting that altered intestinal microflora in developed nations may be partially responsible for the development of chronic inflammatory disorders like allergy and autoimmunity. This dissertation includes previously published and unpublished coauthored material.

Magister Scientiae Dentium - MSc(Dent) / Introduction: Dental caries has one the highest incidences in children and the host’s diet may be a major factor in determining susceptibility to the disease. A proposed tool to screen and identify high risk individuals uses a bitter compound 6-n-propylthiouracil (PROP). The goal of this screening tool is to identify mothers and children who are Non-tasters (those who cannot taste PROP) and to educate them about their possible affinity towards sugar substances and its harmful effects on oral and general health. It is suggested that Non-taster children could be prioritized when providing preventative dental treatment. Aim: To validate the use of PROP as a screening tool for determining high caries risk individuals by identifying the taster status of mothers and children, their preference towards sugar, and its impact on their caries status. Methodology: 75 mother/ child pairs were recruited to participate in this study. Caries experience, sugar preference and taster status were determined for all the subjects. Comparisons were made between mothers and their children to find a possible association. Results: Caries experience was greater in individuals who were Non-tasters when compared to Super-tasters. A significant association between taster status and DMFT score was established (p<0.000). A significant association between taster status and sugar preference was established (p<0.000). A positive correlation with regard to taster status, sugar preference and caries experience was observed in mother/child pairs. Conclusion: Similarities in the mother's and child’s PROP taster status and its association with sugar preference allows such a screening test to identify individuals who are at high risk of developing dental caries. Early identification of mothers who are Non-tasters may allow the introduction of early intervention strategies and assist in the early detection of potentially high-risk children, especially in environments where resources are limited.

O clareamento dentário é a maneira mais conservadora e barata de melhorar a satisfação dos pacientes com o seu sorriso. Entretanto existem poucos estudos que correlacionam a eficácia clareadora com a satisfação dos pacientes e a maneira como eles percebem a mudança das cores. OBJETIVO: Investigar a relação entre mudança de cor e satisfação e a percepção da mudança de cor pelos pacientes e operador treinado comparado a um método instrumental. MATERIAIS E MÉTODOS: Uma pesquisa clínica randomizada duplo-cega foi conduzida com 100 pacientes que atendiam os critérios de inclusão e exclusão. Eles foram divididos em 5 grupos randomizados: Peróxido de hidrogênio 4%, peróxido de carbamida 15%, peróxido de carbamida 16%, Peróxido de carbamida 16% experimental e placebo. Foi tomada a cor base dos dentes através de tomadas objetivas com Vita Easyshade e subjetivas com a escala Vita BleachGuide 3D. Eles foram submetidos à terapia clareadora recebendo uma seringa de gel clareador por semana durante 3 semanas e preencheram avaliação sobre sua sensibilidade e avaliações sobre satisfação e percepção de mudança de cor. Foi um total de 11 visitas por paciente: entrevista inicial e triagem, moldagem e profilaxia, tomada de cor e entrega de clareador, controles de 7, 14, 21, 30, 60, 90, 120 e 180 dias. Nos retornos todas as etapas de tomada e controle de cor pelo paciente e pelo mesmo operador treinado, objetiva e subjetiva foram repetidas. RESULTADOS maiores valores de ?E* na sem 1, ANOVA mostrou que eles foram diferentes entre si (P=0.001), valor que não se repete a partir da segunda semana na análise entre os grupo (P=0.275). Maiores ?E* foram os géis à base de peróxido de carbamida (PC15, PC16 e PC16EX). ?E* Final foi maior no grupo PC15, PC16 e PC16EX e esses 3 grupos foram estatísticamente semelhantes. Os menores valores foram para o grupo placebo que não foi semelhante a nenhum outro grupo e nem entre os tempos. A análise de variância entre os 5 grupos mostrou diferenças para percepção cega (p=0.001), percepção orientada (p=0.001), e expectativa (p=0.603. Fica claro que a satisfação do paciente é crescente em todos os grupos da primeira a terceira semana de terapia. A ordem de satisfação dos pacientes foi PC15, PC16EX, PC16, PH4 e PLAC. No último período representado, terceira semana ao fim do acompanhamento de 6 meses, verificamos que a satisfação diminui no período pós-terapia, principalmente para o grupo PLAC e para o grupo PC16EX. Mesmo o grupo PLAC (que representa o placebo) também teve satisfação crescente. No arco inferior os maiores resultados para sensibilidade ficaram também com PH4, PC15 e PC16..CONCLUSÕES: Os clareadores baseados em peróxido de carbamida tiverem as maiores variações de cor, sendo os mais efetivos. Em comparação ao paciente, o operador treinado tem uma capacidade de avaliação de cor mais próxima dos valores aferidos instrumentalmente. A satisfação do paciente aumenta com todos os grupos, inclusive o placebo, porém declina no período pós terapia. Os pacientes tendem a enxergar os dentes mais escuros do que realmente são e criam expectativas por cores mais claras. Todos os grupos causaram sensibilidade, inclusive o placebo, semelhantes para maxila e mandíbula. / Tooth whitening is the most conservative and inexpensive way to improve patient satisfaction with your smile. However there are few studies that correlate the whitening efficacy with patient satisfaction and how they perceive the change of colors. To investigate the relationship between color change and satisfaction and perception of color change by patients and trained operator compared to an instrumental method. MATERIALS AND METHODS: A double-blind randomized clinical trial was conducted with 100 patients who met the inclusion and exclusion criteria. They were divided into five randomized groups: Hydrogen peroxide 4%, 15% carbamide peroxide, 16% carbamide peroxide, 16% carbamide experimental and placebo. It was made the base color of the teeth through objective taken with Vita Easyshade and subjective with the Vita BleachGuide 3D scale. They underwent therapy Clarifying getting a whitening gel syringe per week for 3 weeks and completed evaluation of its sensitivity and reviews of satisfaction and perception of color change. There were a total of 11 visits per patient: initial interview and sorting, forming and prophylaxis, making color and delivery bleaching 7 controls 14, 21, 30, 60, 90, 120 and 180 days. In returns all steps taken and color control by the patient and by the same trained operator, objective and subjective were repeated. RESULTS larger ?E * values in no 1, ANOVA showed that they were different (P = 0.001), a figure that is not repeated from the second week on the analysis of the group (P = 0.275). Larger ?E * the gels were carbamide peroxide-based (PC15, PC16 and PC16EX). ?E * Final was higher in the group PC15, PC16 and PC16EX and these 3 groups were statistically similar. The lowest values were for the placebo group was not similar to any other group or between the times. Analysis of variance among the five groups showed differences to blind perception (p = 0.001), oriented perception (p = 0.001) and expectation (p = 0.603. It is clear that patient satisfaction is increasing in all of the first groups third week of therapy. the order of patient satisfaction was PC15, PC16EX, PC16, PH4 and PLAC. in the latter represented period, the third week after the 6-month follow-up, we found that satisfaction decreases in the post therapy period, mainly for PLAC group and the group PC16EX Even the PLAC group (representing placebo) also had increasing satisfaction in the lower arch greater results for sensitivity were also PH4, PC15 and PC16..CONCLUSÕES: carbamide peroxide have the greater color variations, the most effective being. compared to the patient, the trained operator has a capacity assessment of the closest color of the measured values instrumentally. patient satisfaction increases with all the groups, including the placebo, but declines in the period post therapy. Patients tend to see the darker teeth than they really are and create expectations for lighter colors. All groups sensitivity caused, including placebo, similar to maxilla and mandible.

Esta dissertação apresenta um estudo sobre a utilização de tomografia acústica para reconstruir a distribuição interna de temperaturas de um corpo ou escoamento. Para tanto, o problema inverso foi modelado matematicamente a partir da equação de propagação acústica e de um funcional de erro quantificando a sensibilidade dos perfis de pressão acústica externa relativamente a variações na distribuição interna de impedância acústica. Simulações numéricas foram realizadas em um modelo de um problema real, tendo sido testadas duas técnicas de excitação, a clássica tipo Dirac e uma estratégia otimizada segundo um perfil triangular. / This work presents a study about the utilization of acoustic tomography to reconstruct the internal temperature distribution of a body or a flow. To do this, the inverse problem was mathematically modeled from the acoustic propagation equation and a error functional quantifying the sensitivity of external acoustic pressure profile according to changes in the internal acoustic impedance distribution. Numerical simulations were done in a real problem model, two excitation techniques were tested, the classical Dirac type and a optimized strategy with a triangular profile.

Os tratamentos que visam a remissão dos sintomas provocados pela hipersensibilidade dentinária são baseados na obliteração física dos túbulos dentinários com o objetivo de reduzir a condutibilidade hidráulica da dentina. Nesse contexto, diversos tratamentos têm sido avaliados, entre eles, a irradiação da superfície dentinária com laser. O objetivo do presente estudo foi avaliar a condutibilidade hidráulica da dentina radicular bovina, após irradiação com um laser de diodo (980nm), associado ou não com um verniz fluoretado. Sessenta espécimes de dentina radicular bovina com dimensões 5,5 X 5,5 X 1mm foram divididos em 6 grupos (n=10): Grupos 1, 3 e 5 (laser de diodo com 0,5; 0,7 e 1W respectivamente); Grupos 2, 4 e 6 (associação entre verniz fluoretado e laser de diodo com 0,5; 0,7 e 1W). A condutibilidade hidráulica da dentina, avaliada em FLODEC, foi analisada em 4 momentos: após criação da smear layer (permeabilidade mínima), após condicionamento com gel de ácido fosfórico a 37% (permeabilidade máxima), após os tratamentos propostos e após o desafio ácido com ácido cítrico a 6%. Os dados obtidos foram avaliados pela ANOVA a 2 critérios e teste de Tukey para comparação entre os diferentes grupos e ANOVA 1 critério de medidas repetidas e teste de Tukey para comparação entre as diferentes leituras dentro de cada grupo, sempre com p<0,05%. As análises demonstraram um melhor resultado conforme o aumento da potência de irradiação, principalmente se esta for associada à aplicação do verniz fluoretado, garantindo uma melhor estabilidade dos tratamentos, mesmo após o desafio ácido. Após essa última etapa, os espécimes foram avaliados quanto à composição mineral em EDX, apresentando como principais alterações nos grupos irradiados com laser, um aumento na proporção de ions Cálcio e Fósforo, associada à redução dos íons Carbono e Oxigênio. Dessa forma, a irradiação da dentina exposta com laser de diodo promoveu redução significante na condutibilidade hidráulica, principalmente com densidades de energia mais elevadas e quando associado ao verniz fluoretado. / The dentin hypersensitivity treatments are based on the physical obliteration of dentinal tubules in order to reduce the dentin hydraulic conductance. Hence, many treatments have been evaluated, such as the dentin surface laser irradiation. The aim of the present study was to evaluate the bovine root dentin hydraulic conductance after 980nm diode laser irradiation, associated or not with a fluoride varnish. Sixty bovine root dentin specimens were divided into six groups (n=10): Groups 1, 3 and 5 (0.5, 0.7 and 1W diode laser respectively); Groups 2, 4 and 6 (association between fluoride varnish application and 0.5, 0.7 and 1W diode laser irradiation). The dentin hydraulic conductance was evaluated at 4 moments, with FLODEC: after smear layer (minimum permeability), after 37% phosphoric acid gel etching (maximum permeability), after the treatments and after 6% citric acid challenge. The analysis demonstrated a better result with increased irradiation power, especially if the diode laser irradiation was associated with the application of a fluoride varnish, ensuring a greater treatment stability, even after acid challenge. After the citric acid challenge, the specimens were evaluated for mineral composition in EDX. The irradiated groups showed, as major changes after laser irradiation, an increase in the proportion of calcium and phosphorus ions, associated with the reduction of carbon and oxygen ions. In conclusion, the laser irradiation of the exposed dentin promoted a significant reduction in hydraulic conductance, mainly with higher energy densities and when combined with a fluoride varnish.

A Hanseníase é uma doença de evolução crônica e lenta causada pelo bacilo Mycobacterium leprae, com inflamação especifica, que acomete o sistema nervoso periférico. A detecção da perda de sensibilidade protetora é importante para identificar pacientes que apresentam neuropatia periférica. O método mais utilizado para medir a sensibilidade das fibras de adaptação lenta é o de estesiometria por monofilamentos de Semmes-Weinstein (SW). Um dos fatores etiológicos da úlcera plantar neuropática é a alta pressão em determinado local na região plantar. O Baropodômetro é um aparelho eficiente para avaliar a pressão plantar tanto na postura estática como na dinâmica. Este estudo teve como objetivo descrever clinico-epidemiologicamente pacientes com hanseníase em tratamento no CRNDS do HCFMRP - USP, correlacionando os respectivos resultados dos testes baropodométricos na postura estática e dinâmica com teste de sensibilidade pelos monofilamentos SW. Foram avaliados 51 pacientes com hanseníase, com idade entre 18 e 60 anos, 30 classificados operacionalmente em multibacilares (MB) e 15 em paucibacilares (PB). 20 sujeitos sem neuropatia foram selecionados para o Grupo Controle (GC). Somente os pacientes com hanseníase foram submetidos à estesiometria. Os resultados demonstraram estatisticamente que o paciente MB e PB apresentaram maiores picos de pressão plantar e maior taxa de alteração de sensibilidade na região do calcanhar. Pacientes MB apresentaram maiores picos de pressão plantar na estática, e o GC na dinâmica. Tanto o grupo PB quanto o MB apresentaram úlceras ou calosidades plantares, sendo que no MB estas ocorreram nas áreas de sensibilidade alterada, enquanto no PB as lesões apresentaram-se em áreas coincidentes de alteração de sensibilidade e picos máximos de pressão. Assim, os resultados evidenciaram que a baropodometria contribui para o melhor entendimento da biomecânica do processo de ulceração plantar, além de ser um método prático e não invasivo para o diagnóstico funcional dos pacientes com neuropatia hansênica em relação à distribuição pressórica plantar. / Leprosy is a disease of chronic evolution that causes specific and slow inflammatory reaction, damaging the peripheral neural system. The detection of the sensibility loss is important to identify patients with peripheral neuropathy, and the standard method for it is the Semmes-Weinstein\'s monofilament sensibility test. One of the etiologic factors of the plantar ulcers on neuropathic feet is the high pressure on determined plantar spot. The Podometry is effective to evaluate the plantar pressure during standing position and gait. The aim of this study was to describe epidemically and clinically leprosy\'s patients through podometric evaluations during gait and static posture, and compare these data with Semmes-Weinstein monofilaments sensitivity tests. Methods: 51 leprosy subjects, 18 to 60 years old, already on treatment at the CRNDS of HCFMRP - USP were evaluated and classified as multibacillary (MB) and paucibacillary (PB). Also, 20 normal subjects performed the podometric test and have their data taken as a control group (GC). The statistical analysis of the data showed that leprosy patients have both greater sensitivity loss and plantar peak pressure on the heel area. The MB group showed higher plantar peak pressures during standing position, as well as GC on gait analysis. Both MB and PB presented plantar callus and ulcer; MB skin damage was found within the areas of sensory loss, and PB\'s within the areas of sensitivity loss plus higher peak pressures. The results showed that podometry offers an important contribution to understanding plantar ulcer\'s biomechanics; besides, it is a practical and non-invasive method to functionally diagnose leprosys neuropathy related to plantar pressure distribution.

Esta tese de doutorado aborda o desenvolvimento de sistemas microfluídicos eletroquímicos ultrassensíveis mediante a integração de eletrodos i) concêntricos e ii) nanoestruturados seletivos à detecção condutométrica sem contato acoplada capacitivamente (capacitively coupled contactless conductivity detection, C4D) e à amperometria, respectivamente. O uso dos eletrodos concêntricos, uma configuração inédita em microdispositivos na qual o filme fino metálico circunda todo o microcanal, se mostrou efetivo na melhora da detectabilidade da C4D para análises em fluxo de soluções padrão de LiClO4. O limite de detecção (LD) para esse sal foi igual a 343 pmol L-1, um valor aproximadamente quatro ordens de grandeza inferior àquele obtido com eletrodos planares. O microchip amperométrico nanoestruturado, por sua vez, consistiu de filmes de Au modificados com nanotubos de carbono de parede única (single-walled carbon nanotubes, SWCNTs) verticalmente alinhados e foi aplicado a padrões do neurotransmissor serotonina. A melhora na detectabilidade do método foi novamente apreciável; os valores de LD foram de 11,8 (Au liso) e 0,2 nmol L-1 (Au modificado com os SWCNTs verticalmente alinhados). Esse último é menor frente à grande maioria dos valores descritos na literatura, para os quais técnicas diversas foram empregadas, incluindo: i) potenciometria com eletrodos modificados (1,0 a 500 nmol L-1), ii) HPLC-MS (18,2 nmol L-1), iii) eletroforese capilar combinada com etapas de extração, empilhamento e préconcentração do analito (7,9 nmol L-1) e iv) sensor químico (200 nmol L-1). Finalmente, objetivando a fabricação de microchips de vidro, condutométricos e amperométricos, incorporando eletrodos concêntricos nanoestrurados, uma nova técnica de selagem foi desenvolvida. Essa técnica, designada como selagem adesiva de sacrifício, baseia-se no uso do resiste negativo SU-8 como camada intermediária de modo a permitir a vedação entre duas lâminas de vidro. Numa etapa posterior, a remoção seletiva do SU-8 sob o microcanal é realizada. Logo, canais microfluídicos com propriedades de superfície similares às do vidro foram obtidos. O protocolo experimental adotado é i) simples, ii) rápido, iii) não envolve níveis de pressão e temperatura elevados e iv) prescinde o uso de salas \"limpas\". Vedações com forças de adesão satisfatórias foram alcançadas, suportando pressões superiores a 4 MPa. / This PhD thesis reports the development of ultrasensitive electrochemical microfluidic systems by integrating concentric and nanostructured electrodes selective to capacitively coupled contactless conductivity detection (C4D) and amperometry, respectively. The use of the concentric electrodes, a new assembly in microdevices with thin films wrapping around the microchannel, showed to be effective towards improvement of the detectability in pressure-driven flow platforms incorporating C4D. The limit-of-detection (LOD) in flow analysis of LiClO4 solutions was 343 pmol L-1, ca. four orders of magnitude lower than to the levels obtained with planar electrodes alone. The nanostructured amperometric microchip, in turn, is related to integration of vertically aligned singlewalled carbon nanotubes (SWCNTs) over Au film. Such platform was applied to determination of serotonin standards. The nanomaterial influenced remarkably the sensitivity and detectability. Our system achieved a LOD of 0.2 nmol L-1, to the best of our knowledge one of the lowest values reported in the literature. Finally, in order to fabricate glass microdevices, conductometric and amperometric, with nanostructured concentric electrodes, we developed a new bonding method. This technique, called as sacrificial adhesive bonding, is based on SU-8 negative resist like intermediate layer so to allow the sealing between two glass slides. Next, the selective removal of the SU-8 under the microchannel is carried out. Thus, microfluidic channels presenting glass-like surface properties were achieved. The experimental protocol is simple and fast. In addition, neither high-pressure and elevated-temperature nor the use of \"clean\" rooms were not required. Bondings with satisfactory adhesion forces were obtained, supporting pressures above 4 MPa.