• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 6
  • 3
  • 1
  • 1
  • Tagged with
  • 11
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Avenços en la fisiopatologia de la Leucoencefalopatia Megalencefàlica amb Quists subcorticals

Duarri Piqué, Anna 28 May 2010 (has links)
La Leucoencefalopatia Megalencefàlica amb quists subcorticals (MLC) és un tipus de leucodistròfia espongiforme d'herència autosòmica recessiva. Està considerada una malaltia rara que es caracteritza per macrocefàlia els primers anys de vida, deteriorament de les funcions motores, atàxia i espasticitat, lleuger retràs mental i en alguns casos atacs epilèptics. El diagnòstic es fa per ressonància magnètica d'imatge ja que els pacients presenten la substància blanca anormalment difusa i quists subcorticals a la regió anterio-temporal i fronto-parietal. Es va descriure el primer gen causant de la malaltia, MLC1 mapat al cromosoma 22qtel, del qual s'han descrit més de 60 mutacions diferents. Però existeix un 20% dels pacients de MLC que no presenten mutacions en aquest gen, suggerint més d'un gen implicat a la malaltia. En l'actualitat encara no es coneix la funció de la proteïna MLC1. L'expressió de MLC1 és bàsicament en el sistema nerviós en ratolí, a astròcits i neurones. En la present tesi s'han generat tres anticossos contra la proteïna humana MLC1 per tal de caracteritzar l'expressió i localització de MLC1 en humans. MLC1 s'expressa a sistema nerviós central i perifèric en adult, principalment a astròcits perivasculars i concretament en la membrana en contacte entre els astròcits, amb petites diferències en l'etapa fetal on és predominantment expressió neuronal. Trobem una sobreexpressió de MLC1 en la zona de penombra en condicions d'infart cerebral. S'ha desenvolupat dos models cel·lulars per estudiar la fisiopatologia de MLC1. En el model primari d'astròcits, MLC1 es localitza als processos astrocitaris entre astròcits en unions complexes, formades per proteïnes d'unions tight, gap i adherents, colocalitzant i co¬immunoprecipitant amb ZO-1 i GlialCAM. La seva localització depèn dels microfilaments d'actina. En el model primari de neurones, MLC1 està localitzat al tracte axonal. L'estudi de les mutacions de MLC1 en el model astrocitari provoquen un defecte de plegament amb la retenció de la proteïna a reticle endoplasmàtic, sense poder arribar a membrana. MLC1 s'expressa a monòcits de sang perifèrica, una nova eina pel diagnòstic dels pacients. L'estudi de pacients de MLC amb diferents mutacions revelen una manca total de la proteïna MLC1. El model astrocitari knock-down de MLC1, utilitzant la tecnologia de RNA d'interferència i adenovirus, presenta canvis morfològics en els astròcits. La manca de MLC1 provoca una reducció de la mida cel·lular i l'aparició de vacuoles intracel·lulars. La seva expressió i localització es veu alterada per condicions hipoosmòtiques del medi. La sobreexpressió de MLC1 provoca un augment en la permeabilitat de l'aigua en els astròcits i una disminució de la capacitat de recuperar el volum cel·lular RVD (regulatory colume decrese) en condicions hipoosmòtiques, i en condicions fisiològiques, produeix una major sortida d'aspartat dels astròcits degut a l'activació dels VRACs (volume.regulated anion channels). La nostre hipòtesi és que MLC1 podria actuar com un canal d'aigua, un canal/transporador de Cl-o K+, o un VRAC. / Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a type of spongiform leukodystrophy with an autosomal recessive inheritance. It is considered a rare disease characterized by early life macrocephaly, impaired motor functions, ataxia and spasticity, slight mental delay and some cases of seizures. Magnetic resonance imaging is used as diagnostic of patients and shows abnormally diffuse white matter and subcortical cysts in the anterio-temporal and fronto-parietal regions. We describe the first gene causing the disease; MLC1 is mapped to chromosome 22qtel, which have been described more than 60 different mutations. But there is 20% of MLC patients who have no mutations in this gene, suggesting more than one gene involved in disease. The function of MLC1 protein is unknown. The expression of MLC1 is basically in the nervous system in mice, in neurons and astrocytes. In this thesis, we have generated three antibodies against MLC1 human protein to characterize the expression and localization of human MLC1. MLC1 is expressed in central and peripheral nervous system in adults, mainly in perivasculars astrocytes and specifically in the membrane contact between cells, with small differences in the fetal stage where it is predominantly neuronal expression. We found an overexpression of MLC1 in the penumbra zone of a cerebral stroke. We have developed two cell models to study the pathophysiology of MLC1. In the primary astrocytes model, MLC1 is localized in the astrocytic processes between astrocytes, in a complex junctions formed by proteins of tight, gap and adherent junctions, interacting with ZO-1 and GlialCAM. Its location depends on the actin microfilaments. In the model of primary neurons, MLC1 is located in axonal tracts. In the astrocytes model, mutations in MLC1 cause protein folding defects and an endoplasmic reticulum retention, unable to reach membrane. MLC1 is expressed in peripheral blood monocytes, a tool for the diagnosis of patients. Studies of different MLC1 mutations in patients with MLC reveal a total lack of MLC1 protein. The astrocyte knock-down model of MLC1, using RNA interference and adenovirus technology, produces cell morphological changes. The lack of MLC1 causes a reduction in cell size and the appearance of intracellular vacuoles. The expression and localization is altered by hypoosmotical extracellular conditions. In this conditions, the overexpression of MLC1 causes an increase in the permeability of water in astrocytes and a reduced ability to recover the cellular volume RVD (regulatory volume decrease), and under physiological conditions, it triggers a greater efflux of aspartate due to the activation of VRACs (volume-regulated anions channels). Our hypothesis is that MLC1 could act as a water channel, a channel or transporter of Cl-or K+, or a VRAC.
2

Dinámica de los componentes de la ingesta energética en las diferentes etapas de la vida

Capdevila Muñoz, Francesca 03 April 2006 (has links)
DE LA TESI TITULADA: DINÀMICA DELS COMPONENTS DE LA INGESTA ENERGÈTICA EN LES DIFERENTS ETAPES DE LA VIDA.Francesca Capdevila MuñozObjectius: Descriure quins són els canvis en la ingesta energètica, la densitat energètica i el volum alimentari que es donen en una població sana, en funció de l'edat i el sexe, i determinar el paper relatiu de la densitat energètica i del volum alimentari en la consecució de la ingesta energètica necessària en cada etapa de la vida. També es pretén veure si la dinàmica que s'estableix entre aquests factors és comparable entre dues poblacions de característiques genètiques, socials i culturals diferents, com són els nens de Reus (Espanya) i els de Guadalajara (Mèxic). Material i mètodes: Projecte que consta de tres estudis observacionals, transversals i prospectius. A) Estudi de la ingesta alimentària i nutricional en un grup de 120 nens en l'etapa de diversificació alimentària (4 a 12 mesos). B) Estudi nutricional en una mostra de la població de Reus d'entre 1 i 98 anys. C) Comparació de la ingesta alimentària i nutricional d'una mostra de nens mexicans de 1 a 4 anys amb una mostra de la població de Reus d'aquestes mateixes edats. En els tres casos, a partir de les dades recollides mitjançant recordatoris de 24 hores, es va obtenir la ingesta mitjana dels diferents grups d'aliments i es van quantificar els valors d'ingesta energètica diària (kcal/dia) i de macronutrients (g/dia de proteïnes, lípids i hidrats de carboni). Es va realitzar el càlcul del volum alimentari, de la densitat energètica de la dieta, del percentatge de l'energia total aportat pels macronutrients, de la ingesta d'energia per kg de pes corporal i del volum alimentari per kg de pes corporal.Resultats i conclusions: La ingesta energètica, el volum alimentari i la densitat energètica de la dieta augmenten progressivament al llarg de la infància i fins al final de la pubertat. A la pubertat comencen a fer-se patents diferències significatives entre sexes en les variables analitzades. Durant l'edat adulta s'observa una tendència significativa (p<0.001 als dos sexes) al descens de la ingesta energètica i de la densitat energètica de la dieta. El volum alimentari mostra un progressiu augment des del segon any de vida fins al final de la pubertat; però en l'edat adulta aquesta variable no mostra una tendència significativa a la disminució amb l'edat a les dones, i als homes el descens del volum alimentari es dóna a partir dels 45 anys i és molt menys marcat que el que s'observa a la densitat energètica. Al comparar la població infantil de Reus amb la mostra de nens mexicans s'observa que les diferències existents en la dieta d'ambdós països condicionen una densitat energètica diferent, que fa que els nens mexicans ingereixin un volum d'aliments major per tal d'obtenir la ingesta energètica necessària, a partir d'una dieta menys densa des del punt de vista energètic. El percentatge de l'energia total aportat per proteïnes i lípids és superior a les recomanacions en gairebé tots els grups d'edat, mentre que el percentatge aportat pels hidrats de carboni en molt pocs casos arriba al 50%.De l'anàlisi dels tres estudis es desprèn que, al llarg de les diferents etapes de la vida, la variació de la ingesta energètica en resposta a canvis fisiològics en les necessitats s'aconsegueix bàsicament mitjançant variacions en la densitat energètica de la dieta, tot i que en diferents moments en les quals les necessitats energètiques s'incrementen puntualment o bé la dieta presenta una baixa densitat, s'observa també un augment del volum d'aliments ingerit. En canvi, amb l'edat, quan les necessitats es van fent menors, no es constata una reducció del volum alimentari paral.lela a l'observada en la ingesta energètica i la densitat energètica. / OF THE THESIS ENTITLED: DYNAMICS OF THE COMPONENTS OF THE ENERGY INTAKE ALONG THE DIFFERENT STAGES OF LIFE. Francesca Capdevila Muñoz Objectives: To describe which are the changes in energy intake, energy density and food volume that take place in a healthy population, according to age and sex, and to determine the relative role of energy density and food volume in the achievement of the energy intake which is necessary in each stage of life. We also try to see whether the dynamics established between these two factors is comparable between two populations of different genetic, social and cultural characteristics, like the children from Reus (Spain) and the ones from Guadalajara (Mexico).Material and methods: Project that consists of three observational, cross-sectional and prospective studies. A) Study of the food and nutritional intake in a group of 120 children during the dietary diversification age (4 to 12 months old). B) Study of the food and nutritional intake in a sample of the Reus population, aged from 1 to 98 years old. C) Comparison of the food and nutritional intake of a sample of 1 to 4 year-old Mexican children with a sample of the Reus population of the same ages. In the three studies, from the data obtained by means of 24-hour recalls, the mean intakes of the different food groups were calculated and the values of daily energy intake (kcal/day) and macronutrients (g/day of proteins, lipids and carbohydrates) were quantified.We also calculated the food volume, the dietary energy density, the percentage of total energy provided by each macronutrient, the energy intake per kg of body weight and the food volume per kg of body weight. Results and conclusions: From infancy to the end of puberty there is a progressive increase of the energy intake, the food volume and the energy density of the diet. At the pubertal age significant differences between sexes are established in the variables analysed. During adulthood there is a significant tendency (p<0.001 in both sexes) towards a decrease in the energy intake and in the energy density of the diet. The food volume shows a progressive increase from the second year of life onwards; however, in adulthood this variable does not show a significant tendency towards a decrease in women and, in men, the descent of the food volume begins from the age of 45 and it is much less pronounced than that observed in the energy density.When we compare the children from Reus with the sample of Mexican children, we observe that the existing differences between the diets of both countries determine a different energy density, so the Mexican children eat a greater food volume in order to obtain the necessary energy intake from a less dense diet.The percentage of total energy intake that is provided by proteins and lipids exceeds the recommendations in nearly all the age groups, whereas the percentage provided by carbohydrates rarely achieves a 50%.From the analysis of these three studies we can see that, along the different life stages, the variation in the energy intake &#9472;due to physiological changes in the energy requirements&#9472; is achieved basically by means of variations in the energy density of the diet, although in certain moments, when the energy requirements increase momentarily or the diet has a low energy density, we also observe an increase in the volume of foods consumed. Whereas, with age, as the requirements tend to decrease, we don't find a decrease of the food volume parallel to the one observed both in the energy intake and in the energy density.
3

Factores estéricos en reacciones de substitución con complejos aminados de metales de transición.

Rodríguez Frías, Elisa 21 May 2001 (has links)
En este trabajo se realiza un estudio cinético de las reacciones de acuatización de diversos complejos pentaaminados con diferente impedimento estérico y ligandos neutros. También se estudia la relación entre el ácido arsénico y diferentes aqualcomplejos y varios ligandos macrocíclicos pentadentados. Todas las reacciones se han seguido mediante el registro de valores de absorbancia. Por último, se describe también la síntesis de 43 complejos, 11 de los cuales han sido sintetizados y caracterizados por primera vez.
4

Multidestination travel: a critical theoretical approach and empirical evidence for the case of Brazil

de Oliveira Santos, Glauber Eduardo 16 November 2012 (has links)
Los viajes de turismo a multidestinos (MTTs) pueden ser definidos como un viaje en que se visita más de un destino. La presente tesis estudia tres omisiones principales de la literatura académica sobre MTTs. En primer lugar, en esta tesis se desarrolla un modelo teórico alternativo de las elecciones de los turistas en el paradigma de MTTs y con base en la teoría económica tradicional. En segundo lugar, a pesar de que la literatura teórica sobre los determinantes del consumo de MTTs es relativamente extensa, pocos estudios examinaron ese tema desde una perspectiva empírica. El turismo receptivo internacional de Brasil es estudiado empíricamente. En tercer lugar, se estudia el tiempo de estancia de los turistas en diferentes localidades en viajes de multidestino.
5

A Markerless Augmented Reality Environment for On-Patient Medical Data Visualization

Macedo, Marcio Cerqueira de Farias 17 November 2014 (has links)
Submitted by Santos Davilene (davilenes@ufba.br) on 2016-05-25T15:56:18Z No. of bitstreams: 1 MasterDissertation2013-2014.pdf: 12146553 bytes, checksum: 4e7f58dc645b0bebb4885cdbc0adf8f5 (MD5) / Made available in DSpace on 2016-05-25T15:56:18Z (GMT). No. of bitstreams: 1 MasterDissertation2013-2014.pdf: 12146553 bytes, checksum: 4e7f58dc645b0bebb4885cdbc0adf8f5 (MD5) / Visualiza c~ao de dados m edicos no paciente e desej avel em muitas situa cões, como planejamento cir urgico e treinamento m edico. Atualmente, esta visualiza c~ao e possí vel com o uso da realidade aumentada, uma tecnologia que habilita a visualiza c~ao da anatomia virtual do paciente na localiza c~ao da anatomia real em um display convencional. Nesta disserta c~ao, e apresentado um ambiente de realidade aumentada sem marcadores para visualiza c~ao de dados m edicos no paciente com suporte ao fotorrealismo, a m etodos so sticados para composi ção de dados reais e virtuais e a caracter ísticas adicionais como oclusão. A partir de uma avalia ção do ambiente proposto, os resultados obtidos mostram que o ambiente executa em tempo real e provê boa qualidade visual da cena aumentada.
6

Envolvimento dos núcleos da rafe nas respostas adaptativas a alterações de volume sangüineo em ratos, estudo através da expressão de Fos / Role of the raphe nuclei in the homeostatic responses to blood volume alteration : an immunohistochemical study of Fos expression in rats

Frazão, Renata 03 September 2004 (has links)
Estudos prévios demonstram projeções dos núcleos da rafe para áreas clássicas relacionadas ao controle do sistema cardiovascular, como locus coeruleus, núcleo do trato solitário, coluna intermédio lateral da medula espinal, núcleos motor dorsal do vago e ambíguo. Baseado nesta informação este estudo investigou a participação dos núcleos da rafe nas respostas adaptativas a estímulos de hipervolemia e hipovolemia. Foram utilizados ratos machos (Wistar), adultos, mantidos em biotério sob condições controladas, divididos em cinco grupos: hipovolemia (Hipo, submetidos à punção cardíaca com remoção sangüínea), controle da hipovolemia (C hipo, submetidos à punção cardíaca sem remoção sangüínea), hipervolemia (Hiper, submetidos à cirurgia para canulação da veia jugular externa e adição de solução salina no sexto dia pós-cirúrgico), controle da hipervolemia (C hiper, submetidos à cirurgia para canulação da veia jugular externa sem adição de solução salina) e basal (BS). Após 90 minutos do estímulo, os animais foram profundamente anestesiados e perfundidos transcardiacamente com salina seguida de fixador Paraformaldeído + Bórax 4%, 4ºC, pH 9,5. Os encéfalos foram removidos pós-fixados, crioprotegidos e seccionados em cortes coronais de 40 µm e processados com técnicas de imunohistoquímica contra Fos e 5-HT. Os estímulos de hipo e hipervolemia não causaram aumento significativo dos neurônios Fos-imunoreativos ou 5HT/Fos-imunoreativos. Nos núcleos Li, DR, MnR, RMg e ROb o grupo C hipo apresentou maior número de neurônios Fos-IR e 5HT/Fos-IR em relação ao grupo C hiper. Os resultados sugerem que os núcleos da rafe não participam nas repostas adaptativas aos estímulos aplicados. Entretanto, os mesmos parecem estar envolvidos em processos de nocicepção, seja através da 5-HT ou de outras substâncias neuroativas, presentes nestes núcleos. / Previous studies presented projections from the raphe nuclei to areas related to the cardiovascular control, like the locus coeruleus, nucleus of the solitary tract, spinal cord intermedium lateral column, dorsal motor vagus and ambiguus nuclei. Based in this information, the present work analyzed the participation of the raphe nuclei in the adaptative responses to hypovolaemia and hypervolaemia. Were used wistar rats, kept in controlled conditions, divided in 5 groups: hypovolaemia (Hypo, cardiac puncture and blood extraction), hypovolaemia control (C Hypo, cardiac puncture without blood extraction), hypervolaemia (Hyper, external jugular vein canulation surgery and saline addition), hypervolaemia control (C Hyper, external jugular vein canulation surgery and no saline addition) and basal condition (BS). Ninety minutes after the stimulus, the animals were anesthetized and perfused with saline followed by 4% paraformaldehyde plus borax, pH 9.5 at 4ºC. The brains were removed, pos-fixated, cryoprotected, sectioned in 40µm thickness coronal slices and proceeded with double-labeling immunohistochemistry techniques against Fos protein and serotonin. The Hypo and Hyper stimuli presented no significant increase of Fos-IR and double-labeled neurons. The C Hypo group presented higher number of labeled neurons in the Li, DR, MnR, RMg and ROb nuclei in comparison to the group C Hyper. These results suggest that the raphe nuclei have no participation in the adaptative responses to the volemy stimuli. However, this nuclei seems to be related to the nociception no modulated just by the serotonin but by others neurotransmitters too.
7

Retención de medicación en los equipos de sueroterapia: repercusión clínica y acciones de mejora

García Matarin, Adellna 27 January 2012 (has links)
El text del capítol 4 ha estat retirat seguint instruccions de l’autorai, en existir participació d’empreses, existir conveni de confidencialidad o existeix la possibilitat de generar patents / El texto del capítulo 4 ha sido retirado siguiendo instrucciones de la autora, al existir participación de empresas, convenio de confidencialidad o la posibilidad de generar patentes. / The text of chapter 4 has been withdrawn on the instructions of the author, as there is participation of undertakings, confidentiality agreement or the ability to generate patent / OBJETIVO: Conocer el método de administración intermitente de un fármaco endovenoso en un servicio de urgencias (SU) y si la retención de fármaco en el equipo de sueroterapia, una vez finalizada la perfusión, repercute sobre la respuesta clínica. MÉTODO: Estudio prospectivo, observacional y descriptivo en una primera fase. En una segunda fase ha sido intervencionista y analítico. Fase 1: análisis de la técnica de perfusión y su repercusión en la respuesta terapéutica sobre el paciente. Fase 2: análisis de la técnica de perfusión intermitente tras acción docente de mejora dirigida al personal de enfermería y su repercusión en la respuesta terapéutica sobre el paciente. Fármaco analizado: Paracetamol 1 g/ev. Variables: edad, sexo, peso, minutos de perfusión, volumen residual post-perfusión en los equipos, escala de dolor y/o temperatura basal (15’, 60’ y 4 horas), concentración plasmática de paracetamol a las 4 horas. Población de estudio: Individuos de ambos sexos mayores de 15 años de edad que acuden al SU y que se les prescribe paracetamol 1 g/ev. RESULTADOS: Se incluye 119 pacientes, 60 durante la 1ª fase y 59 en la 2ª fase. Ninguna perfusión considerada administrada en su totalidad había sido purgada durante la fase 1. El tiempo de administración de la perfusión fue de 25,7 ± 10,9 minutos. La omisión de purga conllevó un volumen residual medio retenido en el sistema de perfusión de 12,6 ± 2,9 ml, alcanzándo una concentración plasmática media de paracetamol de 4,3 ± 5,0 μg/ml, frente a los 5,27 ± 4,42 μg/ml en los casos en los que sí se realizó purga (fase 2). La relación entre concentración de fármaco y la mejoría del dolor se mostró estadísticamente significativa en la medición del mismo a las 4 horas (p = 0,05). El efecto antitérmico no estuvo relacionado con el volumen residual obtenido. CONCLUSIONES: El volumen residual es considerable en los equipos de perfusión y puede tener una repercusión en la respuesta clínica y terapéutica. Consideramos que la práctica de una purga del equipo de sueroterapia es una medida necesaria y debe considerarse su implantación y realización rutinaria. / OBJECTIVES: To determine whether acetaminophen is retained inside intravenous infusion bottles and lives after intermittent administration of fluids in the emergency department and whether such retention has an effect on outcomes. METHODS: Prospective, observational study in the first phase, followed by a second phase to analyze the effect of technical instruction and intervention. In the first phase, the completeness of intravenous administration of medication and the patient’s response to therapy were recorded. In the second phase, after instruction to improve the staff’s technical performance of intravenous infusion of medication, completeness of administration and patient response were again recorded. The medication studied was acetaminophen (1 g) infused through an intravenous line. Variables recorded were age, sex, weight, duration of infusion, residual volume left in the intravenous infusion equipment, score on a pain scale and/or temperature (at 15 minutes, 1 hour, and 4 hours), and plasma concentration of acetaminophen at 4 hours. The study population consisted of male and female emergency department patients aged 15 years or older who were prescribed 1 g of intravenous Acetaminophen. RESULTS: A total of 119 patients were enrolled; 60 were studied in the first phase and 59 in the second. In the first phase, the infusion equipment failed to draim completely in all cases. Intravenous administration took a mean (SD) of 25.7 (10.9) minutes during this phase and omission of a flush maneuver at the end led to leaving a mean residual volume of 12.65 (2.95) mL in the system. The mean plasma concentration of acetaminophen in the first phase (no instruction to flush the line) was 4.28 (5.04) micrograms/mL; in the second phase, after the staff had been instructed to flush the system, the mean plasma concentration was 5,27 (4,42) micrograms/mL. We observed a statistically significant relation between drug plasma concentration and pain relief at 4 hours (P=.05), but no correlation between temperature and residual volume in the equipment. CONCLUSIONS: Considerable volume is left inside intravenous infusion systems, and loss of infusion may affect clinical response and therapy. We believe routine flusing of intravenous infusion system is essential.
8

Segmenta??o fuzzy de objetos tridimensionais com propriedades texturais / Segmentation of three-dimensional objects with textural propertie

Silva Neto, Jos? Francisco da 25 September 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T17:46:31Z No. of bitstreams: 1 JoseFranciscoDaSilvaNeto_DISSERT.pdf: 5950864 bytes, checksum: 5306cd9802b9aa1c09288d75c32ccbe2 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-28T18:00:31Z (GMT) No. of bitstreams: 1 JoseFranciscoDaSilvaNeto_DISSERT.pdf: 5950864 bytes, checksum: 5306cd9802b9aa1c09288d75c32ccbe2 (MD5) / Made available in DSpace on 2016-01-28T18:00:31Z (GMT). No. of bitstreams: 1 JoseFranciscoDaSilvaNeto_DISSERT.pdf: 5950864 bytes, checksum: 5306cd9802b9aa1c09288d75c32ccbe2 (MD5) Previous issue date: 2014-09-25 / Segmenta??o digital de imagens ? o processo de atribuir r?tulos distintos a diferentes objetos em uma imagem digital, e o algoritmo de segmenta??o fuzzy tem sido utilizado com sucesso na segmenta??o de imagens de diversas modalidades. Contudo, o algoritmo tradicional de segmenta??o fuzzy falha ao segmentar objetos que s?o caracterizados por texturas cujos padr?es n?o podem ser descritos adequadamente por simples estat?sticas computadas sobre uma ?rea restrita. Neste trabalho apresentamos uma extens?o do algoritmo de segmenta??o fuzzy que realiza segmenta??o de texturas empregando fun??es de afinidade adaptativas e o estendemos a imagens tridimensionais. Fun??es de afinidade adaptativas mudam o tamanho da ?rea em que s?o calculados os descritores da textura de acordo com as caracter?sticas da textura processada, enquanto imagens tridimensionais podem ser descritas como um conjunto finito de imagens bidimensionais. O algoritmo ent?o segmenta o volume com uma ?rea apropriada calculada para cada textura, tornando poss?vel obter boas estimativas dos volumes reais das estruturas alvo do processo de segmenta??o. Experimentos ser?o realizados com dados sint?ticos e reais obtidos no estudo de segmenta??o de tumores cerebrais em imagens m?dicas adquiridas atrav?s de exames de Resson?ncia Magn?tica / Digital image segmentation is the process of assigning distinct labels to different objects in a digital image, and the fuzzy segmentation algorithm has been used successfully in the segmentation of images from several modalities. However, the traditional fuzzy segmentation algorithm fails to segment objects that are characterized by textures whose patterns cannot be successfully described by simple statistics computed over a very restricted area. In this paper we present an extension of the fuzzy segmentation algorithm that achieves the segmentation of textures by employing adaptive affinity functions as long as we extend the algorithm to tridimensional images. The adaptive affinity functions change the size of the area where they compute the texture descriptors, according to the characteristics of the texture being processed, while three dimensional images can be described as a finite set of two-dimensional images. The algorithm then segments the volume image with an appropriate calculation area for each texture, making it possible to produce good estimates of actual volumes of the target structures of the segmentation process. We will perform experiments with synthetic and real data in applications such as segmentation of medical imaging obtained from magnetic rosonance
9

Envolvimento dos núcleos da rafe nas respostas adaptativas a alterações de volume sangüineo em ratos, estudo através da expressão de Fos / Role of the raphe nuclei in the homeostatic responses to blood volume alteration : an immunohistochemical study of Fos expression in rats

Renata Frazão 03 September 2004 (has links)
Estudos prévios demonstram projeções dos núcleos da rafe para áreas clássicas relacionadas ao controle do sistema cardiovascular, como locus coeruleus, núcleo do trato solitário, coluna intermédio lateral da medula espinal, núcleos motor dorsal do vago e ambíguo. Baseado nesta informação este estudo investigou a participação dos núcleos da rafe nas respostas adaptativas a estímulos de hipervolemia e hipovolemia. Foram utilizados ratos machos (Wistar), adultos, mantidos em biotério sob condições controladas, divididos em cinco grupos: hipovolemia (Hipo, submetidos à punção cardíaca com remoção sangüínea), controle da hipovolemia (C hipo, submetidos à punção cardíaca sem remoção sangüínea), hipervolemia (Hiper, submetidos à cirurgia para canulação da veia jugular externa e adição de solução salina no sexto dia pós-cirúrgico), controle da hipervolemia (C hiper, submetidos à cirurgia para canulação da veia jugular externa sem adição de solução salina) e basal (BS). Após 90 minutos do estímulo, os animais foram profundamente anestesiados e perfundidos transcardiacamente com salina seguida de fixador Paraformaldeído + Bórax 4%, 4ºC, pH 9,5. Os encéfalos foram removidos pós-fixados, crioprotegidos e seccionados em cortes coronais de 40 µm e processados com técnicas de imunohistoquímica contra Fos e 5-HT. Os estímulos de hipo e hipervolemia não causaram aumento significativo dos neurônios Fos-imunoreativos ou 5HT/Fos-imunoreativos. Nos núcleos Li, DR, MnR, RMg e ROb o grupo C hipo apresentou maior número de neurônios Fos-IR e 5HT/Fos-IR em relação ao grupo C hiper. Os resultados sugerem que os núcleos da rafe não participam nas repostas adaptativas aos estímulos aplicados. Entretanto, os mesmos parecem estar envolvidos em processos de nocicepção, seja através da 5-HT ou de outras substâncias neuroativas, presentes nestes núcleos. / Previous studies presented projections from the raphe nuclei to areas related to the cardiovascular control, like the locus coeruleus, nucleus of the solitary tract, spinal cord intermedium lateral column, dorsal motor vagus and ambiguus nuclei. Based in this information, the present work analyzed the participation of the raphe nuclei in the adaptative responses to hypovolaemia and hypervolaemia. Were used wistar rats, kept in controlled conditions, divided in 5 groups: hypovolaemia (Hypo, cardiac puncture and blood extraction), hypovolaemia control (C Hypo, cardiac puncture without blood extraction), hypervolaemia (Hyper, external jugular vein canulation surgery and saline addition), hypervolaemia control (C Hyper, external jugular vein canulation surgery and no saline addition) and basal condition (BS). Ninety minutes after the stimulus, the animals were anesthetized and perfused with saline followed by 4% paraformaldehyde plus borax, pH 9.5 at 4ºC. The brains were removed, pos-fixated, cryoprotected, sectioned in 40µm thickness coronal slices and proceeded with double-labeling immunohistochemistry techniques against Fos protein and serotonin. The Hypo and Hyper stimuli presented no significant increase of Fos-IR and double-labeled neurons. The C Hypo group presented higher number of labeled neurons in the Li, DR, MnR, RMg and ROb nuclei in comparison to the group C Hyper. These results suggest that the raphe nuclei have no participation in the adaptative responses to the volemy stimuli. However, this nuclei seems to be related to the nociception no modulated just by the serotonin but by others neurotransmitters too.
10

RR3D: Uma solu??o para renderiza??o remota de imagens m?dicas tridimensionais

Papaiz, Fabiano 05 April 2013 (has links)
Made available in DSpace on 2014-12-17T15:48:05Z (GMT). No. of bitstreams: 1 FabianoP_DISSERT.pdf: 3905877 bytes, checksum: 0721827c114aec9f61c1c690dc27dd1d (MD5) Previous issue date: 2013-04-05 / The visualization of three-dimensional(3D)images is increasigly being sed in the area of medicine, helping physicians diagnose desease. the advances achived in scaners esed for acquisition of these 3d exames, such as computerized tumography(CT) and Magnetic Resonance imaging (MRI), enable the generation of images with higher resolutions, thus, generating files with much larger sizes. Currently, the images of computationally expensive one, and demanding the use of a righ and computer for such task. The direct remote acess of these images thruogh the internet is not efficient also, since all images have to be trasferred to the user?s equipment before the 3D visualization process ca start. with these problems in mind, this work proposes and analyses a solution for the remote redering of 3D medical images, called Remote Rendering (RR3D). In RR3D, the whole hedering process is pefomed a server or a cluster of servers, with high computational power, and only the resulting image is tranferred to the client, still allowing the client to peform operations such as rotations, zoom, etc. the solution was developed using web services written in java and an architecture that uses the scientific visualization packcage paraview, the framework paraviewWeb and the PACS server DCM4CHEE.The solution was tested with two scenarios where the rendering process was performed by a sever with graphics hadwere (GPU) and by a server without GPUs. In the scenarios without GPUs, the soluction was executed in parallel with several number of cores (processing units)dedicated to it. In order to compare our solution to order medical visualization application, a third scenario was esed in the rendering process, was done locally. In all tree scenarios, the solution was tested for different network speeds. The solution solved satisfactorily the problem with the delay in the transfer of the DICOM files, while alowing the use of low and computers as client for visualizing the exams even, tablets and smart phones / A visualiza??o de imagens tridimensionais (3D) est? cada vez mais presente na ?rea da medicina, auxiliando os m?dicos no diagn?stico de doen?as e na emiss?o de laudos. Com o avan?o dos equipamentos que geram imagens tomogr?ficas dos pacientes, como os de Tomografia Computadorizada (TC), est?o sendo geradas imagens cada vez mais n?tidas e, portanto, com resolu??es e tamanhos maiores. Atualmente, as imagens contidas em um exame de TC geralmente ocupam o tamanho de dezenas e centenas de megabytes, tornando o processo de visualiza??o 3D cada vez mais pesado - exigindo do usu?rio um equipamento com bom poder computacional. O acesso remoto ? estas imagens, via internet por exemplo, tamb?m n?o ? muito eficiente, pois todas as imagens precisam ser transferidas para o equipamento do usu?rio antes que o processo de visualiza??o 3D seja iniciado. Diante destes problemas (tamanho das imagens e acesso remoto), este trabalho envolve a cria??o e an?lise de um servi?o web para renderiza??o remota de imagens m?dicas 3D, denominado RR3D. Nele, todo o processo de renderiza??o volum?trica ser? realizado por um servidor, ou cluster de servidores, com alto poder computacional e somente a imagem 3D resultante ser? enviada ao cliente, permitindo que este ainda possa fazer opera??es como rota??o, zoom etc. O servi?o web ser? desenvolvido utilizando a linguagem Java e na arquitetura do projeto ser?o utilizados o programa de visualiza??o cient?fica Paraview, o framework ParaviewWeb e o servidor DCM4CHEE

Page generated in 0.0364 seconds