669 research outputs found
PKD2-dependent sensing mechanism in Kupffer’s vesicle: how it affects the left-right axis establishment in zebrafish
RESUMO: Estabelecimento do eixo Esquerda-Direita (ED) é um processo complexo que ocorre cedo
durante o desenvolvimento. Exige a integração de várias vias de sinalização, tais como TGF-
β, Notch, Wnt e Cálcio. Também envolve a coordenação de dinâmica de fluídos, difusão de
morfogénios e movimento ciliar. Tudo junto e coordenado no tempo leva à correta localização
dos órgãos internos. Problemas no estabelecimento deste eixo estão normalmente
associados a doenças crónicas. As primeiras decisões assimétricas acontecem numa
pequena e transiente estrutura chamada o Organizador Esquerda Direita, uma estrutura ciliar
que existe em vários vertebrados. Cílios móveis geram um fluxo de fluido assimétrico que se
traduz numa expressão génica assimétrica entre o lado esquerdo e o lado direito. Estes sinais
são depois transferidos à Mesoderme Lateral, o tecido que mais tarde dá origem ao coração
e influencia a endoderme que dá origem a órgãos como o fígado e o pâncreas.
No Capítulo 2, focámo-nos em tentar compreender como é que as vias de sinalização se
coordenavam para decidir entre um cílio móvel e imóvel no Organizador. Embora a expressão
de Foxj1a em todas as células do Organizador produza cílios com ultra-estrutura compatível
com motilidade, a decisão entre mover ou não é exclusiva da via de sinalização Notch. A
seguir, focámo-nos em caracterizar Pkd2, um canal de cálcio importante no estabelecimento
do eixo ED. Este canal está associado ao Pkd1l1, uma molécula com domínios capazes de
sentir fluido e responder com entrada de cálcio na célula. No Capítulo 3, questionámos se não
ter fluxo no Organizador tinha o mesmo impacto que não ter um mecanismo para sentir esse
fluxo através da ausência do Pkd2. A única manipulação que não afetou a arquitetura do
Organizador foi remover o Pkd2 apenas nas células do Organizador, o que não é muito
eficiente e tem impacto na velocidade do fluxo dentro do Organizador. Ainda assim, todas as
manipulações efetuadas deram o mesmo fenótipo: randomização da posição dos órgãos. No
Capítulo 4, fizemos um estudo de transcritómica usando apenas as células do Organizador em embriões normais ou injetados com morpholino contra o Pkd2. Embora não tenhamos
encontrado genes com expressão assimétrica à volta do Organizador, encontramos quatro
novos genes que influenciam o estabelecimento do eixo: cacybp, frzb, pvalb6 e ncl1. No
Capítulo 5, focámo-nos na ncl1, um gene nunca antes associado ao estabelecimento do eixo
e que atua como antagonista da via de sinalização TGF-β ao influenciar a secreção de Lefty
e influenciando a padronização da mesoderme-endoderme. Nós descobrimos que este gene
impactua no estabelecimento do eixo, provavelmente ao influenciar a secreção de algum
elemento da via de sinalização TGF-β. No Capítulo 6, focámo-nos em estabelecer o peixezebra
como um bom modelo para estudar toxicidade no rim em resposta a fármacos.
Em suma, os resultados apresentados nesta tese providenciam novas pistas para o
estabelecimento do eixo ED, desde o movimento do cílio a novos genes a jusante do Pkd2 e
do cálcio. Também reforçámos a ideia de que o peixe-zebra pode ser um bom modelo para
estudar doenças humanas.ABSTRACT: Left-Right (LR) axis establishment is a complex process that happens early in development. It requires the interplay of several genetic pathways like TGF-β, Notch, Wnt and Calcium signalling. It also involves the integration of fluid dynamics, morphogen diffusion and cilium biosynthesis to correctly position the internal organs in their final destinations. Problems in LR axis establishment are often associated with chronic diseases. The first asymmetric decision commonly happens in a small transient structure, the Left-Right Organizer (LRO), a ciliated structure present in many vertebrates. Motile cilia generate an asymmetric fluid flow that is perceived differently between the left and the right side, which generates a calcium response and asymmetric gene expression. These signals are then transferred to the Lateral Plate Mesoderm, the tissue that will later give rise to the heart and influence the endoderm derived organs such as the liver and pancreas. In Chapter 2, we focused in understand the pathways behind deciding between being a motile vs immotile cilium in the LRO. Although all cilia are made motile in terms of ultrastructure due to Foxj1a expression, the decision to move or not is dependent on Notch signalling alone. Then, we focused on further characterization of an important calcium channel, Pkd2, in the LR. This channel is thought to partner with Pkd1l1 and sense flow, an important feature in LR. In Chapter 3, we asked if having no flow had the same impact as having no Pkd2-mediated sensing. The only manipulation that did not affect the LRO architecture was to target Pkd2 on the LRO cells only, which still left visible Pkd2 protein and a slower flow. Still, all our manipulations had the same phenotype: randomization of organ situs. In Chapter 4, we performed a LRO-specific microarray between WT and pkd2 morphant embryos in order to find other asymmetric genes present in the LRO. Although we did not find any gene expressed asymmetrically between left and right side, we indeed find four new genes with minor roles in LR: cacybp, frzb, pvalb6 and ncl1. In Chapter 5, we further focused in manipulating ncl1, a new gene in LR that is known to act as a TGF-β antagonist by facilitating Lefty secretion and
impacting on mesendoderm patterning. Indeed, we found that it has an impact on LR, probably
by influencing the secretion of some TGF- β signalling player. In Chapter 6, we set to establish
zebrafish as a good model to study kidney toxicity when metabolizing drugs.
Together, the results presented in this thesis provide new clues for LR axis establishment, from
cilia motility to new downstream genes of Pkd2 and calcium. It also highlights the zebrafish as
a good model to study human disease
Can a lemon based Sagres product attract consumers that don't drink beer?
The purpose of this project is to understand if the brand Sagres is damaging the product Sagres Radler. The beer market in Portugal was studied and focus groups were used to perceive the impact of the brand in the product. The mother brand is bringing the beer association into a product designed to engage people that don’t like beer. With the insights, a new proposal was drawn and tested. Although it was not possible to prove that the new concept is better for the population, there are strong indications that the brand isn’t enabling the achievement of the proposed target
Development of a piezoelectric biosensor based on PVDF films
Dissertação para obtenção do Grau de Mestre em
Engenharia Química e BioquímicaThe core of this work is a piezoelectric biosensor in which acoustic waves are launched in very thin PVDF polymer films to produce an oscillatory resonant device. The essence of the device consists in a polymer film system made of a piezoelectric polymer, PVDF, responsible for the film oscillation and a porous membrane, Immobilon, a special type of porous PVDF with protein binding capacity which can act as a biosensitive area.
The possibility of using a film system composed only by PVDF was studied. Due to its strong hydrophobic nature, surface modification was aimed to be performed by coating a functional layer on the membrane surface, in order to improve the hydrophilicity and biocompatibility of PVDF. An immersion method was preformed and applied to porous and non-porous PVDF membranes. Three distinct coating solutions were studied, namely, polyethylene glycol (PEG), 3,4-Dihydroxy-DL-phenylalanine (DL-DOPA) and Gum Arabic solutions. Hydrophilicity improvements of the membranes were characterized by water contact angle measurements and its elemental composition was studied by elemental microanalysis. BSA protein marked with FITC fluorescein was used to perform quantitative and qualitative assays in order to study its adsorption to coated and uncoated PVDF membranes. Globally, the best results were obtained when a solution of PEG was utilized with 0.2 μm microporous membrane. The sensor response was tested with polyethylene glycol (PEG) and bovine serum albumin (BSA), using a film system composed by PVDF/0.2 μm Immobilon/PVDF, which was able to respond to the presence of both compounds in liquid medium
Banking crises in Europe: the importance of region - specific early warning models
Banking crises, albeit rare, can have nefarious consequences. As such, it is relevant
to understand not only what factors cause these crises, but what variables can be
used in their early detection. Economic integration still requires country speci cities
to be considered in macro-prudential monitoring. This project explores the dynamics
of banking crises, the role of economic and stock market growth as warning variables
for several European regions. Dynamic probit models are used in a panel dataset.
Results show that real GDP, stock market growth and house price growth are good
indicators of crisis, and separate models for regions within the Eurozone predict crisis
more accurately
Satisfação profissional: um estudo com enfermeiros especialistas em Enfermagem de Reabilitação
oai:ojs2.rper.aper.pt:article/7The goal of this study was to analyze the professional satisfaction of rehabilitation nurses, as well as to verify whetherthe practice of specialized care or the practice of general care influences your professional satisfaction.The study involved 306 rehabilitation nurses and their professional satisfaction was evaluated through their responsesto the “Satisfaction in Nurses’ Work Scale”. We used an analytics transverse methodology.For statistical evaluation, we used factorial analysis, Spearman’s correlation coefficient and parametric test t-studentfor independent samples.Our results show that the rehabilitation nurses are slightly dissatisfied.We found that Nurses who practice general care are more dissatisfied than those who practice specialty care.Este estudio pretendió analizar la satisfacción profesional de los enfermeros especialistas en Enfermería deRehabilitación y también averiguar si el ejercicio de cuidados de especialidad o el ejercicio de cuidados generalesinfluye en su satisfacción profesional.La satisfacción profesional fue evaluada a través de la aplicación de la “Escala de Evaluación de la Satisfacción en eltrabajo de los Enfermeros” a 306 profesionales de Enfermería, especialistas en Enfermería de Rehabilitación. Serealizó un estudio transverso analítico.Como instrumentos de análisis estadística de los datos, se recorrió al análisis factorial, al coeficiente de correlaciónde Spearman y a un teste paramétrico t-student para muestras independientes.Los resultados muestran que los enfermeros especialistas en Enfermería de Rehabilitación se encuentran ligeramenteinsatisfechos.Verificamos que los enfermeros que ejercen cuidados generales se encuentran más insatisfechos que los que trabajancomo especialistas.Este estudo pretendeu analisar a satisfação profissional dos Enfermeiros Especialistas em Enfermagem de Reabilitação (EEER) e também averiguar se o exercício de cuidados de especialidade ou o exercício de cuidados gerais influencia a sua satisfação profissional.A satisfação profissional foi avaliada através da aplicação da “Escala de Avaliação da Satisfação no Trabalho dos Enfermeiros” a 306 profissionais de Enfermagem, especialistas Enfermagem de Reabilitação. Foi realizado um estudo transversal analítico.Como instrumentos de análise estatística dos dados, recorreu-se à análise fatorial, ao coeficiente de correlação de Spearman e ao teste paramétrico t-student para amostras independentes. Os resultados mostram que os EEER se encontram ligeiramente insatisfeitos.Verificamos que os EEER que exercem cuidados gerais apresentam-se mais insatisfeitos do que os que exercem cuidados de especialidade
Ultrasound as a method for early diagnosis of breast pathology
Introduction: Ultrasound is a non-invasive, low-cost technique that does not use ionising radiation and provides a “real-time” image, and for these reasons, this method is ideal in several situations. Purpose: To demonstrate breast ultrasound evaluation as a first-line diagnostic method and to evaluate the variation of breast characteristics with age. Material and Methods: A total of 105 women with a mean age of 30 years participated and were divided into three age groups: 18–39, 40–59, and 60–79 years, excluding participants subject to mastectomy. After completing the informed consent, all participants answered personal and sociodemographic questions, such as personal and family history, menstrual cycle, pregnancy, ultrasound, and mammography, among others. They were then submitted to a bilateral breast ultrasound examination. Subsequently, all the images and their data were analysed, and a technical report of the examination was given to all the participants.
Results: A total of 105 women with a mean age of 30 years participated, 58 of whom underwent the
examination for the first time. In 31, changes (of which only 7 were known) were diagnosed. It was verified that, according to age group, the density of the breast stroma varied; older women have less breast density. Conclusions: Ultrasound is a good method for breast evaluation and can be considered important for the early evaluation of breast pathology and follow-up of the pathology.info:eu-repo/semantics/publishedVersio
Family care in advanced COPD: Perceived difficulties and expectations of support from services
Chronic Obstructive Pulmonary Disease (COPD) is an incapacitating, highly prevalent disease which often requires intensive support from patient's family members. However, knowledge about the difficulties experienced by family members in their caregiving role remains scarce. This study aimed to explore the difficulties experienced by family carers, and their expectations towards social and health support services.
A qualitative, cross-sectional study was conducted with 21 family carers of COPD outpatients at advanced grades (GOLD 3 and 4). Semi-structured interviews were performed to collect data. Participants were mostly female (n=20), with a mean age of 60.90±12.35 years old, spouses (n=12) and caring for more than 4 years (n=18). All interviews were audiorecorded, transcribed and submitted to content analysis by 2 independent judges.
The major difficulties reported are related to: i) provide support in basic [washing (n=6), dressing (n=2)], and in instrumental activities of daily living [preparing meals (n=4)]; ii) communication with patient (n=2); and iii) restrictions in social activities (n=2); Six carers did not identify any difficulty. Most of participants (n=12) could not identify how formal support services could help them. Only 3 participants reported the need of help to provide support in activities of daily living.
Carers reported several difficulties in their caregiving role. However, they were unable to identify how social and health services could support them. The lack of information about community resources might explain these results. Strategies towards effective flow of information must be addressed in order to prevent caregivers' burden.publishe
Teachers’ view of Language(s) in (CLIL) Science education: a case study in Portugal
The development of meaningful environments at school for the learning of Science as well as of foreign languages is an educational concern. CLIL (Content and Language Integrated Learning), aimed at the students’ acquisition of both the foreign Language and specific subject Content, is an approach that may promote the learning of English in use during subject classes and could result in the improvement of conditions and practices of Science education. Research, actually, reveals that teaching methodologies aware of language – such as CLIL – and other semiotic modes implied in Science are beneficial for the learning of Science. Studying a CLIL programme (“English Plus” project, EP), in which Science is taught/learnt with/in English, is thus relevant. A case study on the EP project and its participants (English and Science teachers, students involved in different school years) in one lower secondary state school in Portugal was carried out. In the present research, qualitative data collected through teacher interviews are presented and discussed, with the goal of understanding the role of Language(s) (verbal language in the mother tongue or English and other representation modalities) in the teaching of Science for EP teachers, both in conventional and project classes. A greater teacher awareness and use of Language(s), when an additional language (English, here) is also present for Science education, results from this work. This contributes to research on CLIL Science studies and teacher reflections on adopting a language-focused approach for Science education, also when the mother tongue is spoken.publishe
Virtual reality exposure therapy for armed forces veterans with post-traumatic stress disorder: A systematic review and focus group [artigo]
Virtual reality exposure therapy (VRET) is an emerging treatment for people diagnosed with Post-Traumatic Stress Disorder (PTSD) due to the limited accessibility of psychotherapies. This research aims to determine the guidelines for developing a Virtual Reality–War Scenario program for Armed Forces veterans with PTSD and encompasses two studies: Study 1, a systematic electronic database review; Study 2, a focus group of twenty-two Portuguese Armed Forces veterans. Results showed a positive impact of VRET on PTSD; however, there were no group differences in most of the studies. Further, according to veterans, new VRET programs should be combined with the traditional therapy and must consider as requirements the sense of presence, dynamic scenarios, realistic feeling, and multisensorial experience. Regardless, these findings suggest VRET as a co-creation process, which requires more controlled, personalized, and in-depth research on its clinical applicability.info:eu-repo/semantics/publishedVersio
"A forma prateada (Mente, Corpo, Coração, Câmara)".
Esta dissertação reflecte sobre uma matéria que esteve presente desde o início e que torna, para mim, a arquitectura na alegria de todos os dias. Falo aqui da oculta qualidade arquitectónica, poderia dizer, fala-se nesta dissertação acerca de vida.O presente trabalho tem como objectivo, pelo menos em parte, responder a uma questão que me persegue desde o primeiro ano: a procura por uma oculta qualidade arquitectural. Palavra ambígua, sem grande suporte físico, pouco científica até, a qualidade acaba por ser uma abstracção.Na abstracção reside todo o potencial, todas as matérias com as quais só se tem contacto através do tecido fino da empatia, e ao arquitecto na concepção, através da intuição. É vontade do arquitecto ouvir as vozes da matéria, prever todos os futuros quando concebe um projecto; o seu desejo é elaborar uma arquitectura que persista e que seja uma contribuição para o colectivo.Não existe uma forma de fazer, uma forma de agir por catálogo, o que deixa entregue ao arquitecto a responsabilidade de ouvir a sua própria voz, como parte do tecido do mundo. Pretendeu-se perceber de que matéria é feita essa voz na dificuldade encontrada na transposição de uma realidade interior a uma exterior.A Forma Prateada é o mote para revelar parte dessas matérias que constituem, para mim, o fio invisível da arquitectura. São uma declaração de intenções.This work's objective, or at least a part of it, is to answer a question that has followed me since the first grade: the search for a hidden architectural quality. An ambiguous word, without much of a physical existence, not even very scientific, quality is finally an abstraction (Francisco Alonso).In abstraction lies all potential, all matters with which contact can only be made through delicate empathy or, for the architect in conception, through intuition. The architects will is to listen to the voices of matter, predict all futures when conceiving a project; his desire to elaborate an architecture which persists and is a contribution the collective.There is not a manner of doing, not a frame for acting by the book, which leaves the architect to the responsibility of listening to his own voice as a part of the fabric of the world. It was sought to understand what matter that voice is made of, given the difficulty found on the transposition of an inner reality to an exterior one.A Forma Prateada (The Silvery Form) is the motif to reveal a part of those matters which, for me, compose the invisible thread of architecture. They are a statement of intent
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