17 research outputs found
Conceção, projeto e desenvolvimento de uma vitrina refrigerada de gelataria
O principal objetivo da vitrina refrigeradora para gelatarias é garantir a conservação dos
gelados, bem como mantê-los com a textura desejada. Este objetivo é garantido através da
imposição de um intervalo de temperaturas dentro do qual a vitrina se deve manter. A
norma portuguesa NP3293 de 2008 indica que os gelados devem ser mantidos a
temperaturas iguais ou inferiores a -18°C e nunca ultrapassar os -15°C, no entanto, as
vitrinas existentes apresentam na sua maioria problemas em manter este intervalo de
temperaturas em todo o seu volume útil.
Neste artigo é apresentado de forma detalhada o estudo e desenvolvimento de uma nova
vitrina de gelataria. Este equipamento deve garantir a qualidade dos gelados, mantendo-os
a uma temperatura de -18ºC. No intuito de otimizar a eficiência energética, foi analisado o
fluido refrigerante a utilizar, tendo-se optado pelo R507 apesar de ser diferente do habitual.
A minimização da carga térmica implicou uma cuidada seleção dos componentes e
isolamentos. Todo o controlo do sistema, garantido através de um PLC, foi concebido,
projetado e desenvolvido no sentido de permitir a melhor eficiência energética do
compressor e da ventoinha do condensador, de acordo com a temperatura lida no interior
da vitrina.The main objective of the shop ice cream refrigerator is to guarantee the conservation of ice
creams, as well as, to maintain them with the wanted texture. This objective is guaranteed
through the imposition of a temperature interval to the shop ice cream refrigerator. The
Portuguese norm NP3293 2008 indicates that the ice creams should be maintained to
temperatures same or inferior to -18°C and never to cross the -15°C, however, the existent
shop ice cream refrigerator present in its majority problems to maintain this temperature
interval.
This article present, in a detailed way, the study and development of a new shop ice cream
refrigerator. This equipment should guarantee the ice creams quality, maintaining them to a
temperature of -18ºC. To optimize the energy efficiency, the cooling fluid was analyzed,
having chosen the R507 in spite of being different from the usually used. In order to
minimize the thermal load it was realized a carefully selection of components and of thermal
and acoustic isolations. The control system, guaranteed through a PLC, it was designed
and developed with the purpose of allowing the best energy efficiency of compressor and
condenser fan, in agreement with the shop ice cream refrigerator temperature
Fine-scale survey of intertidal macroalgae reveals recent changes in a cold-water biogeographic stronghold
Global warming has been causing severe impacts on marine ecosystems, a notorious one being shifts in the geographical ranges of species. The north-western coast of the Iberian Peninsula is an especially interesting zone to study distributional shifts as it has a strong latitudinal thermal gradient, is influenced by the Canary upwelling system (which partially cancels coastal warming) and holds some of the most diverse macroalgae communities in Europe. Notably, it is within this region that many cold-water species, common in northern Europe, have their southernmost distribution refuge. Recent studies hypothesize that the environmental conditions may be nonetheless changing and already threatening this biodiversity hotspot. The main goal of this study was to carry out a fine-scale assessment of the distributional limits of several macroalgae in North-western Iberia, as well as identify possible population and range shifts using historical data (2001-2005) as reference. In addition, non-indigenous species were also surveyed. We also assessed if the regions of (i) Galicia, (ii) Northern Portugal, and (iii) Central Portugal displayed distinctive characters regarding macroalgae composition and abundance. We identified an increase in abundance of some non-indigenous macroalgae as well as a decrease in the abundance of some cold-water species. In the most severe cases, cold-water species were extirpated along hundreds of km. The compounded effect of the decrease in the abundance of cold-water species and the increase in the abundance of non-indigenous species is leading to the homogenization of macroalgae communities in north-western Iberia
Implementação de um dispositivo multivibracional para auxiliar à remoção de dentes e raízes
A corrente prática de extração dentária é realizada recorrendo a instrumentos rígidos num processo que implica elevadas forças mecânicas e, consequentemente, um pósoperatório doloroso para os pacientes. O presente trabalho apresenta as fases de conceção e desenvolvimento de um instrumento capaz de atuar na fase mais crítica do processo, com a indução de vibração a altas frequências, prevendo-se a diminuição da força necessária para efetuar a extração, bem como os danos provocados pelo procedimento atualmente realizado.info:eu-repo/semantics/publishedVersio
Implementation of a multivibrational medical device to assist the removal of teeth and roots
The current practice of tooth extraction is performed using rigid instruments in a process involving high mechanical strength and thus a painful postoperative for patients.
In this sense, this work presents the stages of design and development of an instrument capable of acting in the most critical stage of tooth extraction process, the luxation phase, with the induction of vibration at high frequencies, so it is expected to decrease the force required to perform the extraction as well as the damage caused by the currently used procedure.
The instrument used by the professional dentist in luxation phase is the dental elevator. So, it was selected and purchased a standard straight elevator to perform the operations necessary for the development of the vibrating elevator.
Vibration induction was performed by a system with a piezoelectric actuator. The placement of the whole vibration system was designed to reduce the number of operations to perform to the original instrument as well as maintain the most of his ergonomic shape. Thus, the system was placed inside of the instrument handle to fulfill the aims above.
The vibration system behavior was also study through simulation in COMSOL Multiphysics and a theoretical simulation. Through tests it was intended to provide an environment similar to a tooth extraction procedure, using a pig's head as model to which was perform the process of luxation and extraction of teeth of his jaw with the device developed and with or without its vibration system. During the tests, it was difficult to understand the influence of the vibration system in the process. However, tests had great difficulty once the model has significant anatomical differences comparing to Human teeth and roots.
However, it is estimated that this vibration can assist the depth penetration of the device between the tooth and the alveolar bone allowing the easier placement of the instrument and an easier lifting of the tooth. The oscillation in this region may also lead to its elevation. These facts indicate that the process is being facilitated, reducing the force applied and the duration of the process when using vibration.info:eu-repo/semantics/publishedVersio
A comprehensive assessment of the intertidal biodiversity along the Portuguese coast in the early 2000s
Background
The unprecedented rates of current biodiversity loss have motivated a renewed interest in environmental and biodiversity monitoring. The need for sustained monitoring strategies has prompted not only the establisment of new long-term monitoring programmes, but also the rescue of data from historical or otherwise archived sources. Amongst the most valuable datasets are those containing information on intertidal systems, as they are particularly well suited for studying the biological effects of climate change. The Portuguese rocky coast is quite interesting for studying the effects of climate change on the distribution of species due to its geographical orientation, latitudinal patterns in temperature, species richness, species' distribution patterns and availability of historical information. This work aims at providing a comprehensive picture of the distribution and abundance of intertidal macro-invertebrates and macro-algae along the Portuguese rocky coast in the early 2000s.
New information
This study provides a description of the rocky shore intertidal biodiversity of the mainland Portuguese coast in the early 2000s. The spatial distribution and semi-quantitative abundance of a total of 238 taxa were assessed at 49 wave-exposed locations. These data provide a comprehensive baseline against which biodiversity changes can be effectively and objectively evaluated.publishedVersio
O papel dos miRNAs na sobrevivência celular
Dissertação de Mestrado em Investigação Biomédica apresentada à Faculdade de MedicinaAs doenças cardiovasculares são a causa predominante de mortalidade, morbidade e custos associados com a saúde na Europa e nos Estados Unidos da América. Estão incluídas nas doenças cardiovasculares, patologias como enfarte do miocárdio, cardiomiopatias ou doenças cardíacas valvulares, que poderão culminar em insuficiência cardíaca. Doentes com esta condição apresentam um desempenho cardíaco reduzido sendo incapazes de suprimir as necessidades metabólicas do organismo. Para além do mais, o aumento da esperança média de vida, o estilo de vida sedentário e maus hábitos alimentares, assim como a maior taxa de sobrevivência após diagnóstico de uma doença cardíaca reforçam a necessidade do desenvolvimento de tratamentos eficazes para curar a insuficiência cardíaca. Nos últimos anos, o grande foco da pesquisa nesta área tem passado pelo desenvolvimento de estratégias que estimulem a proliferação dos cardiomiócitos. Contudo, os resultados obtidos têm ficado aquém das expectativas realçando a necessidade de uma mudança de direção. Recentemente, alguns autores demonstraram o papel importante do endotélio na regeneração cardíaca. Paralelamente, os “miRNAs” surgiram como moduladores versáteis dos processos intracelulares inclusive no contexto de doença cardíaca.O nosso grupo realizou uma experiência em larga escala para identificar “miRNAs” capazes de aumentar a sobrevivência celular endotelial. Brevemente, células endoteliais humanas foram transfectadas com 2080 “miRNA mimics” e expostas a condições de isquémia (0,1% O2 em meio basal sem soro ou fatores de crescimento). Quinze “miRNAs” foram identificados como capazes de aumentar a sobrevivência. Nesta tese, estudámos o papel de dois desses “miRNAs” (um previamente descrito na literatura como capaz de aumentar a sobrevivência e um nunca descrito). Na primeira parte do trabalho, desvendámos o mecanismo de acção o qual confere um efeito na sobrevivência celular. Na segunda parte, explorámos uma nanoformulação capaz de entregar os “miRNAs”.Os nossos resultados demonstram que ambos os “miRNAs” aumentaram a sobrevivência e a capacidade de migração das células endoteliais. Em seguida, validámos a interação directa dos dois “miRNAs” com a proteína PTEN levando a uma diminuição nos seus níveis de RNA mensageiro e proteicos. Ambos os “miRNAs” levaram à ativação de duas vias intracelulares relacionados com a sobrevivência: vias “Pi3K/Akt” e “MAPK”. Por fim, usámos nanopartículas poliméricas sensíveis à luz para entregar os “miRNAs” a células endoteliais e os nossos resultados preliminares apontaram para uma alta taxa de complexação e um forte potencial de entrega.O nosso trabalho apresenta estes “miRNAs” como fortes promotores da sobrevivência endotelial após condições isquémicas.Cardiovascular diseases are the leading cause of mortality, morbidity and health related costs in Europe and United States of America. They comprise different pathologies including myocardial infarction, cardiomyopathies and valvular heart disease all of them ultimately leading to heart failure (HF). HF is broadly characterized by and inability to efficiently fulfill the metabolic needs of the organism. The increase in life expectancy, the high prevalence of dietary and lifestyle risks factors, as well as the improved survival from cardiovascular events reinforces the need for efficient treatments to revert HF. During the last years, most of the research performed in that respect pertained to the discovery of molecules capable of enhancing cardiomyocyte proliferation. However, the results obtained with these approaches are far from ideal and a paradigm shift is necessary. Recently, several authors have demonstrated an important role of cardiac endothelium on cardiac regeneration. Moreover, miRNAs have appeared as versatile modulators of virtually all cell processes including in the cardiac context. Our group recently performed a high throughput screening experiment to identify miRNAs capable of enhancing endothelial cell survival. In brief, we transfected endothelial cells with a library of 2080 miRNA mimics and exposed the transfected cells to ischemia (0.1% O2 in endothelial basal medium without serum or growth factors). Fifteen miRNAs were identified as pro-survival miRNAs. In this thesis, we focused on the role of two of those miRNAs (a previously identified pro-survival miRNA and a miRNA never described in the literature). In the first part of the work we identified the mechanism of action governing the pro-survival effect of the selected miRNAs. In the second part, we explored a nanoparticle system capable of efficiently delivering the miRNAs to the cells both in vitro as well as in vivo. Our results showed that both miRNAs increased endothelial cell survival under ischemic conditions and increased the migration of human CD34+-derived endothelial cells. Then, we validated the direct interaction of both miRNAs with PTEN resulting in a decrease in its mRNA and protein levels. Furthermore, MAPK and PI3K/Akt pathways are activated by miR-C and miR-G both of which are well known mediators of the survival pathways. Finally, we used light-inducible polymeric nanoparticles to deliver miRNA to human derived endothelial cells with preliminary results showing their high complexation rate and strong delivery potential. Our work presents miR-C and miR-G as strong endothelial cell survival enhancers.FC
O desenvolvimento à luz de uma perspectiva multidimensional: uma aplicação aos munícipios
Economia e Gestão das CidadesMaster in Economics and Management of Citie
# 91. Anquiloses Múltiplas de dentes decíduos: A propósito de um caso clínico
Introdução: A anquilose dentoalveolar consiste na fusão anatómica anormal do cemento radicular com o tecido ósseo, sem interposição do ligamento periodontal. A prevalência, em dentição decídua, varia entre os 1,3% e os 38,5%. O tratamento consiste normalmente na extração das peças afetadas, mesmo sem a presença do dente sucessor, dado que na zona atingida o crescimento ósseo é inibido, o que poderá provocar perdas ósseas significativas. Com muita frequência estas extrações são difíceis., sendo indicada a realização de osteotomia e odontosecção. Caso clínico: Paciente do sexo masculino, com 13 anos, saudável, apresentou–se na consulta de Odontopediatria da Clínica Dentária Universitária da Universidade Católica Portuguesa devido à permanência de dentes decíduos na cavidade oral. O exame clínico revelou a permanência dos primeiros e segundos molares decíduos anquilosados com classificação grave, à exceção do dente 64. Revelou também uma oclusão completamente desajustada, havendo apenas contactos nos segundos molares permanentes em posição de intercuspidação máxima. O exame radiográfico confirmou a inexistência de ligamento periodontal dos dentes anquilosados e permitiu fazer o diagnóstico de agenesia dos segundos pré–molares permanentes. Atendendo à idade do paciente e à cronologia de erupção dentária, o plano de tratamento consistiu na exodontia dos dentes anquilosados e reencaminhamento do paciente para a consulta de Ortodontia. Pelo facto do menino ter 13 anos, não é necessário equacionar a colocação de mantenedores de espaço. Discussão e conclusões: O tratamento escolhido passou pela realização da exodontia dos dentes anquilosados devido ao facto dos primeiros pré–molares permanentes ainda não terem erupcionados e se encontrarem inclinados. Também se verificou perda do comprimento do arco dentário e, neste caso em particular, mordida aberta completa do 17 ao 27, sendo mais grave nos setores laterais. Após a consulta de controlo realizada um ano após as extrações, confirmou‐se que o tratamento escolhido foi o mais acertado, na medida que permitiu a erupção dos dentes 14, 34 e 44 e a desimpactação do 13.info:eu-repo/semantics/publishedVersio
A comprehensive assessment of the intertidal biodiversity along the Portuguese coast in the early 2000s
Background
The unprecedented rates of current biodiversity loss have motivated a renewed interest in environmental and biodiversity monitoring. The need for sustained monitoring strategies has prompted not only the establisment of new long-term monitoring programmes, but also the rescue of data from historical or otherwise archived sources. Amongst the most valuable datasets are those containing information on intertidal systems, as they are particularly well suited for studying the biological effects of climate change. The Portuguese rocky coast is quite interesting for studying the effects of climate change on the distribution of species due to its geographical orientation, latitudinal patterns in temperature, species richness, species' distribution patterns and availability of historical information. This work aims at providing a comprehensive picture of the distribution and abundance of intertidal macro-invertebrates and macro-algae along the Portuguese rocky coast in the early 2000s.
New information
This study provides a description of the rocky shore intertidal biodiversity of the mainland Portuguese coast in the early 2000s. The spatial distribution and semi-quantitative abundance of a total of 238 taxa were assessed at 49 wave-exposed locations. These data provide a comprehensive baseline against which biodiversity changes can be effectively and objectively evaluated