• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 123
  • 97
  • 28
  • 26
  • 13
  • 10
  • 6
  • 5
  • 5
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 386
  • 62
  • 46
  • 31
  • 30
  • 24
  • 24
  • 22
  • 21
  • 17
  • 17
  • 16
  • 16
  • 15
  • 15
  • 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.
301

Efeitos do ômega-3 na parede arterial de coelhos albinos (Oryctolagus cuniculus) submetidos à aterosclerose experimental / Effects of omega-3 in the arterial wall of rabbits (Oryctolagus cuniculus) underwent experimental atherosclerosis

Martins, Josefa Sileda 17 June 2011 (has links)
The nutraceutical omega 3 fatty acid, which has been used to prevent cardiovascular disease; on the other hand, atherosclerosis is the leading cause of morbidity and mortality, becoming myocardial infarction and strokes the main consequences. Objective: This study aimed to verify the preventive effects of omega-3 in the formation of atherosclerosis, inducing hyperlipidemic diet in rabbits to quantify the atherosclerotic involvement of the arterial lumen and to evaluate serum lipid levels (total cholesterol, fractions, triglycerides and HDL). Methods: 21 male rabbits New Zealand white race were randomized into three groups with seven animals, namely: control group (G1) where the animals received food and water ad labium; group hyperlipidemic (G2) food and water ad labium, 20 ml of chicken egg yolk divided in two doses and treated group (G3) that in addition to 20 ml of yolk, ingested 221 mg / kg body weight of omega-3 as well as food and water ad labium. The blood was collected to determine serum and after 99 days of the experiment, animals were euthanized for removal of debris following: aortic arch, right common carotid artery and right femoral artery. The results were compared using statistical methods of ANOVA, and Kolmogorov-Smirnorv. Results: There was no decrease in serum total cholesterol and fractions, and triglyceride did not increase HDL. There was thickening of the sub endothelial layer and formation of foam cells in G1 and G2. Conclusion: The Omega has no preventive effect in reducing atherosclerotic plaques; there was increased in the arterial lumen at 57.55%. / Fundação de Amparo a Pesquisa do Estado de Alagoas / O ômega-3 é um ácido graxo nutracêutico, que tem sido utilizado para prevenir as doenças cardiovasculares, das quais a aterosclerose é a principal causa de morbidade e mortalidade, tornando o infarto do miocárdio e o acidente vascular encefálico suas principais consequências. Objetivo: Este trabalho teve como objetivos verificar a existência de efeitos preventivos do ômega-3 na formação da doença aterosclerótica, através da indução de dieta hiperlipidêmica em coelhos, quantificar o comprometimento aterosclerótico da luz arterial bem como, analisar os níveis lipídicos séricos (colesterol total, frações, triglicerídeo e HDL). Material e Método: 21 coelhos albinos, machos da raça Nova Zelândia foram distribuídos aleatoriamente em três grupos com sete animais, a saber: Grupo Controle (G1) cujos animais receberam ração e água ad libitum; Grupo Hiperlipidêmico (G2) ração e água ad libitum, mais 20 ml de gema de ovo de galinha em dividida em duas tomadas e o Grupo Tratado (G3) que além dos 20 ml de gema, ingeriu 221 mg/kg/peso de ômega-3, bem como ração e água ad libitum. O sangue foi coletado para verificar os níveis séricos e após 99 dias de experimento, os animais foram submetidos à eutanásia para retirada dos seguintes fragmentos: arco aórtico, artéria carótida comum direita e artéria femoral direita. Os resultados foram comparados pelos métodos estatísticos ANOVA, e teste de Kolmogorov-Smirnorv. Resultados: Não houve diminuição dos níveis séricos do colesterol total, e frações, o triglicerídeo e não aumentou o HDL. Houve espessamento da camada subendotelial e formação de células espumosas, nos grupos G1 e G2. Conclusão: O ômega não tem efeito preventivo na redução das placas ateromatosas, houve aumento do comprometimento da luz arterial em 57,55%.
302

Preservação de cadáver de coelho (Oryctolagus cuniculus) com a solução de Larssen modificada para treinamento em cirurgia videolaparoscópica

Menezes, Cláudio Leonardo Montassieur de January 2012 (has links)
As habilidades psicomotoras são fundamentais para conduzir de forma adequada e segura um procedimento videocirúrgico. A cirurgia laparoscópica difere da cirurgia tradicional, pois o cirurgião deve guiar suas manobras em um ambiente tri-dimensional, através de imagem bi-dimensional, é privado da sensação táctil direta com os tecidos e necessita adquirir coordenação motora para a utilização de um novo tipo de instrumental cirúrgico. Faz-se necessário o desenvolvimento de modelos de treinamento factíveis para a formação de cirurgiões laparoscópicos, que simulem adequadamente as situações vivenciadas na sala de operação. Esta pesquisa objetivou desenvolver um modelo de cadáver de coelho embalsamado, utilizando a solução de Larssen modificada, para treinamento em quatro procedimentos laparoscópicos: colecistectomia, nefrectomia, esplenectomia e criptorquidectomia. Foram utilizados 17 coelhos de diferentes raças, submetidos a dois procedimentos cirúrgicos cada um. Destes, 15 foram eutanasiados, embalsamados e criopreservados. Após uma semana, os animais foram descongelados em caixa plástica com água aquecida a 40ºC e utilizados no treinamento de um cirurgião sem experiência prévia em videocirurgia. Dois coelhos foram operados vivos, sob anestesia geral inalatória, ao final da fase de treinamento, para verificar a capacidade do cirurgião em realizar as quatro técnicas laparoscópicas citadas, sem ocorrência de complicações significativas, sendo estes animais eutanasiados ao final dos procedimentos. Os cadáveres de coelhos mantiveram suas características teciduais semelhantes àquelas encontradas em um animal vivo. A coloração dos tecidos e órgãos abdominais foi bastante similar ao verificado in vivo, enquanto o odor variou entre leve e moderado e a textura variou entre normal e friável. A imersão dos cadáveres em água aquecida foi efetiva para alcançar o descongelamento completo, com mínima interferência da temperatura ambiente, tendo duração de quatro a cinco horas. O modelo experimental proposto neste estudo apresentou boas condições para execução e treinamento de colecistectomia laparoscópica, nefrectomia total laparoscópica e criptorquidectomia laparoscópica. As condições encontradas na cavidade abdominal dos coelhos embalsamados não foram satisfatórias para a prática adequada de esplenectomia laparoscópica, pela dificuldade em estabelecer boa visualização e manipulação do baço. / Psychomotor skills are essential to correctly and safely conduct endoscopic surgical procedures. Laparoscopic surgery differs from traditional surgery because the surgeon must guide his maneuvers in a tri-dimensional environment, through a bi-dimensional image, he’s deprived of direct tactile sensation with the tissues and needs to acquire motor coordination to use a new type of surgical instruments. Its necessary feasible experimental models to train laparoscopic surgeons, which properly simulates the situations experienced in the operation room. This research aims at proposing a embalmed rabbit cadaver model, prepared with the modified Larssen solution, for training in four laparoscopic procedures: cholecystectomy, nephrectomy, splenectomy, cryptorchidectomy. Seventeen rabbits from different breeds were used, each undergoing two surgical procedures. Of these, 15 were euthanized, embalmed and cryopreservated. After one week, they were thawed in a plastic box with water heated to 40ºC and used in the training of a surgeon with no previous experience with endoscopic surgery. Two rabbits underwent surgery under general anesthesia with a volatile agent, at the end of the training step, to check the surgeon’s ability to perform the four mentioned laparoscopic techniques, without the occurrence of major complications, both being euthanized at the end of the procedures. The rabbit cadavers kept tissues properties similar to those found in a living animal. The color of the abdominal tissues and organs was very close to that verified in vivo, although odor tended from slight to moderate and consistency tended from normal to friable. The cadavers immersion in heated water was effective to completely thaw then, with minimum interference of room temperature, within four to five hours. The experimental model proposed in this study presented valuable conditions to perform and train laparoscopic cholecystectomy, laparoscopic total nephrectomy and laparoscopic cryptorchidectomy. The state of the abdominal cavity found in the embalmed rabbits was unsatisfactory for suitable practice of laparoscopic splenectomy, because of the difficulty in establishing good visualization and manipulation of the spleen.
303

Preservação de cadáver de coelho (Oryctolagus cuniculus) com a solução de Larssen modificada para treinamento em cirurgia videolaparoscópica

Menezes, Cláudio Leonardo Montassieur de January 2012 (has links)
As habilidades psicomotoras são fundamentais para conduzir de forma adequada e segura um procedimento videocirúrgico. A cirurgia laparoscópica difere da cirurgia tradicional, pois o cirurgião deve guiar suas manobras em um ambiente tri-dimensional, através de imagem bi-dimensional, é privado da sensação táctil direta com os tecidos e necessita adquirir coordenação motora para a utilização de um novo tipo de instrumental cirúrgico. Faz-se necessário o desenvolvimento de modelos de treinamento factíveis para a formação de cirurgiões laparoscópicos, que simulem adequadamente as situações vivenciadas na sala de operação. Esta pesquisa objetivou desenvolver um modelo de cadáver de coelho embalsamado, utilizando a solução de Larssen modificada, para treinamento em quatro procedimentos laparoscópicos: colecistectomia, nefrectomia, esplenectomia e criptorquidectomia. Foram utilizados 17 coelhos de diferentes raças, submetidos a dois procedimentos cirúrgicos cada um. Destes, 15 foram eutanasiados, embalsamados e criopreservados. Após uma semana, os animais foram descongelados em caixa plástica com água aquecida a 40ºC e utilizados no treinamento de um cirurgião sem experiência prévia em videocirurgia. Dois coelhos foram operados vivos, sob anestesia geral inalatória, ao final da fase de treinamento, para verificar a capacidade do cirurgião em realizar as quatro técnicas laparoscópicas citadas, sem ocorrência de complicações significativas, sendo estes animais eutanasiados ao final dos procedimentos. Os cadáveres de coelhos mantiveram suas características teciduais semelhantes àquelas encontradas em um animal vivo. A coloração dos tecidos e órgãos abdominais foi bastante similar ao verificado in vivo, enquanto o odor variou entre leve e moderado e a textura variou entre normal e friável. A imersão dos cadáveres em água aquecida foi efetiva para alcançar o descongelamento completo, com mínima interferência da temperatura ambiente, tendo duração de quatro a cinco horas. O modelo experimental proposto neste estudo apresentou boas condições para execução e treinamento de colecistectomia laparoscópica, nefrectomia total laparoscópica e criptorquidectomia laparoscópica. As condições encontradas na cavidade abdominal dos coelhos embalsamados não foram satisfatórias para a prática adequada de esplenectomia laparoscópica, pela dificuldade em estabelecer boa visualização e manipulação do baço. / Psychomotor skills are essential to correctly and safely conduct endoscopic surgical procedures. Laparoscopic surgery differs from traditional surgery because the surgeon must guide his maneuvers in a tri-dimensional environment, through a bi-dimensional image, he’s deprived of direct tactile sensation with the tissues and needs to acquire motor coordination to use a new type of surgical instruments. Its necessary feasible experimental models to train laparoscopic surgeons, which properly simulates the situations experienced in the operation room. This research aims at proposing a embalmed rabbit cadaver model, prepared with the modified Larssen solution, for training in four laparoscopic procedures: cholecystectomy, nephrectomy, splenectomy, cryptorchidectomy. Seventeen rabbits from different breeds were used, each undergoing two surgical procedures. Of these, 15 were euthanized, embalmed and cryopreservated. After one week, they were thawed in a plastic box with water heated to 40ºC and used in the training of a surgeon with no previous experience with endoscopic surgery. Two rabbits underwent surgery under general anesthesia with a volatile agent, at the end of the training step, to check the surgeon’s ability to perform the four mentioned laparoscopic techniques, without the occurrence of major complications, both being euthanized at the end of the procedures. The rabbit cadavers kept tissues properties similar to those found in a living animal. The color of the abdominal tissues and organs was very close to that verified in vivo, although odor tended from slight to moderate and consistency tended from normal to friable. The cadavers immersion in heated water was effective to completely thaw then, with minimum interference of room temperature, within four to five hours. The experimental model proposed in this study presented valuable conditions to perform and train laparoscopic cholecystectomy, laparoscopic total nephrectomy and laparoscopic cryptorchidectomy. The state of the abdominal cavity found in the embalmed rabbits was unsatisfactory for suitable practice of laparoscopic splenectomy, because of the difficulty in establishing good visualization and manipulation of the spleen.
304

Estudo comparativo entre a capsulorrafia com sutura simples e com âncora em quadris de coelhos / Comparative evaluation between capsulorrhaphy with simple suture and with anchor in rabbit hip joints

Fernando Cal Garcia Filho 14 July 2010 (has links)
INTRODUÇÃO: A displasia do desenvolvimento do quadril (DDQ) é uma das patologias mais relevantes e polêmicas que acometem as crianças desde o nascimento. A anatomia tridimensional, a complexidade da articulação do quadril, o pouco conhecimento sobre o potencial de remodelação acetabular após luxação ou sub-luxação e as sequelas na marcha e na movimentação suscitam várias discussões sobre esse tema. A revisão bibliográfica a respeito dos diferentes tipos de capsulorrafia é muito pouco discutida entre os pesquisadores. Técnicas menos agressivas e que possibilitem maior resistência à recidiva da luxação após a redução cruenta devem ser pesquisadas. OBJETIVO: a presente pesquisa busca, por meio de ensaios biomecânicos, comparar as capsulorrafias com sutura simples e com âncoras, em quadris de coelhos. MATERIAL E MÉTODO: Foram utilizados 13 coelhos, 26 quadris, todos machos da raça Nova Zelândia albinos (Oryctolagus cuniculus). Inicialmente, realizamos um projeto piloto em três coelhos (06 quadris). Este experimento constou de 10 coelhos, divididos em 02 grupos: o grupo 1 submetido à capsulorrafia (quadris direito e esquerdo) com sutura simples utilizando fio absorvível de ácido poliglicólico e o grupo 2 submetido a capsulorrafia (quadris direito e esquerdo) com âncora de titânio. Após o período de quatro semanas de operados, todos animais foram submetidos à eutanásia e seus quadris congelados. Após um descongelamento prévio das peças no mesmo dia das análises biomecânicas, foram avaliados os parâmetros da rigidez (Rig), força máxima (Fmax), deformidade máxima (Dmax) e energia (E). RESULTADO: não houve diferença estatisticamente significante em relação à força no limite de proporcionalidade, rigidez e força máxima entre os grupos com sutura simples e com âncora. CONCLUSÃO: Por meio dos ensaios biomecânicos, tendo como parâmetro a rigidez (Rig), força máxima (Fmax), deformidade máxima (Dmax) e energia (E), ficou demonstrado que as capsulorrafias em quadris de coelhos com sutura simples e com âncora são semelhantes entre si. / INTRODUCTION:HDD (Hip Development Dysplasia) is one of the most important and controversial pathologies which affect children. The threedimensional anatomy and complexity of the hip joint, as well as the little understanding of the potential of acetabular reconstruction after luxation or sub-luxation and the later effects on the child\'s gait and movement, raise various points of discussion. Little literature exists about the different types of capsulorrhaphy. Techniques which are less aggressive or decrease risk of luxation after surgical reduction must be researched. OBJECTIVE: Using biomechanical studies, this research aims to compare hip capsulorrhaphy in rabbits, carried out with two different techniques: capsulorrhaphy with simple sutures and with anchors. MATERIAL AND METHOD: Thirteen New Zealand Albino (Oryctolagus cuniculus) male rabbits, twenty-six hip joints, were used. First, a pilot project was performed with three rabbits (six hip joints). The experimental group consisted of ten rabbits and was divided in two sub-groups: group 1 underwent capsulorrhaphy on both right and left hips with simple suture using polyglocolic acid absorbable thread, and group 2 underwent capsulorrhaphy with titanium anchors. After a four-week postoperation period, the animals were euthanized and the hip joints were frozen. On the same day the hip joints were unfrozen, a biomechanical study was carried out, evaluating the following parameters: rigidity, maximum force, maximum deformity and energy. RESULTS: There was no relevant statistical difference in rigidity, maximum force, maximum deformity and energy between the simple suture and anchor groups. CONCLUSION: Through biomechanical analyses, using parameters of rigidity, maximum force, maximum deformity and energy, it has been shown that a capsulorrhaphy with simple suture and with an anchor has similar results in rabbit hip joints.
305

Caractérisation moléculaire des procaryotes et facteurs de variation des écosystèmes digestifs chez deux mammifères herbivores : approche comparée vache/lapin / Molecular characterization of prokaryotes and factors of variation of digestive ecosystems in two herbivorous mammals : a comparative approach using cow and rabbit

Michelland, Rory 01 October 2009 (has links)
L’objectif de ce travail était de caractériser la variabilité spécifique (Bos taurus vs Oryctolagus cuniculus), individuelle, spatiale (inter- et intra- fermenteurs digestifs) et temporelle (en conditions non perturbée ou perturbée) des écosystèmes digestifs des mammifères herbivores (communautés procaryotiques et biotope) en comparant deux modèles animaux, la vache et le lapin, et en utilisant des outils moléculaires (CE-SSCP et qPCR). D’un point de vue méthodologique, nous avons développé un programme informatique, StatFingerprints, pour améliorer le traitement et l’analyse statistique des profils CE-SSCP et ainsi mieux extraire l’information écologique qu’ils contiennent en termes de structure et de diversité des communautés. Nous avons également mis au point des systèmes de qPCR plus spécifiques (Firmicutes et Bacteroides Prevotella) que ceux précédemment décrits. D’un point de vue cognitif, nos travaux démontrent une forte influence de l’espèce hôte sur les caractéristiques de son écosystème : les communautés sont plus riches (+8 %, +12 % pour les bactéries et les Archaea, respectivement), plus diverse (+19 % pour les bactéries) mais moins abondantes (-4.9 % de bactéries) dans le rumen de la vache que dans le caecum du lapin. Le biotope ruminal est moins acide (+0.6 unité pH), plus réducteur (-30 mV), et contient moins d’acides gras volatils (-19%) et plus de NH3-N (+39%) que le biotope caecal. Cela suggère un rôle déterminant de la physiologie digestive de l’hôte et/ou des phénomènes de coévolution hôte/microbiote. Nos travaux n’ont pas permis de mettre en évidence un effet de « l’individu hôte » sur les caractéristiques de sa communauté microbienne suggérant que la proximité génétique entre les individus (race) et/ou la forte standardisation des conditions d’élevage (logement, alimentation etc.) tendent à uniformiser l’influence des individus sur le déterminisme de leurs communautés procaryotiques. Nous avons montré qu’il existe une évolution des communautés microbiennes le long du tractus digestif en relation avec la physiologie et les conditions environnementales des différents compartiments à laquelle s’additionne, dans le rumen, une variabilité liée à la fraction, liquide ou solide, considérée. Nos données suggèrent qu’à l’état basal et en situation de perturbation, les communautés procaryotiques des deux espèces hôtes n’évoluent pas de la même façon dans le temps. Ainsi, dans le rumen de la vache, la communauté bactérienne fluctue de façon sporadique suggérant un état d’équilibre dynamique alors qu’elle reste dans un état d’équilibre statique dans le caecum du lapin. Les deux communautés réagissent de façon rapide (< 2jours) et s’adaptent rapidement à une augmentation du ratio amidon/fibres pour atteindre un nouvel équilibre, dynamique dans le rumen et statique dans le caecum. En revanche, nos travaux n’ont pas mis en évidence de corrélations importantes entre les communautés bactériennes et les paramètres de leur environnement. D’un point de vue finalisé, ces données confirment que la nutrition est une voie d’action pertinente pour essayer de réorienter le fonctionnement des écosystèmes digestifs chez ces espèces d’intérêt zootechnique, vers une meilleure santé et/ou efficacité digestive. / The aim of this work was to characterize the specific (Bos taurus vs Oryctolagus cuniculus), individual, spatial (inter- and intra- digestive fermentors) and temporal (in undisturbed or disturbed conditions) variability of the digestive ecosystems (prokaryotic communities and biotope) in herbivorous mammals by comparing two animal models, cow and rabbit, and by using molecular methods (CE-SSCP and qPCR). Concerning methodology, we developed the StatFingerprints program to improve processing and statistical analysis of CE-SSCP profiles and better extract ecological information they contained about structure and diversity of communities. We also developed more specific (Firmicutes and Bacteroides Prevotella) primers than those available. From a cognitive point of view, our work demonstrated a strong effect of host species on ecosystem: communities presented a higher richness (+8 %, +12 % for bacteria and Archaea, respectively), a greater diversity (+19 % for bacteria) but are less abundant (-4.9 % bacteria) in cow rumen than in rabbit caecum. The rumen biotope is less acid (+0.6 pH unit), more reductive (-30 mV), and contains a lower concentration of fatty acids (-19%) and a higher concentration of NH3-N (+39%) than caecal biotope. Taken together, these results suggested a determining role of the digestive physiology of the host and of coevolution phenomena between the host and its microbiota. Our results did not permit to evidence an individual effect on the procaryotic communities suggesting that the genetic similarity between animals we used and/or the strong standardization of breeding conditions (housing, food etc) tended to reduce the influence of the individuals on their prokaryotic communities. We showed that the procaryotic communities evolved along the digestive tract in relation to the physiology and the environmental conditions of the various compartments in which they live. In addition, in the rumen, we evidenced a variability of the bacterial community related to the fraction considered, liquid or solid. Our data suggested that, both in basal and disturbed situations, the bacterial communities of the two host species did not evolve in the same way in time. Indeed, in the rumen of the cow and basal condition, the bacterial community fluctuated sporadically suggesting a dynamic balance whereas it remains in a stable state in the caecum of the rabbit. The two communities reacted quickly (< 2 days) and adapted quickly to an increased ratio starch/fibres to reach a new balance, dynamic in the rumen and stable in the caecum. On the other hand, our work did not highlight important correlations between the bacterial communities and the parameters of their environments. From a finalized point of view, these data confirmed that the nutrition is a relevant way to try to reorientate the functioning of digestive ecosystems in these two species, toward a better digestive health and/or efficiency.
306

Perception des mélanges d'odeurs : étude comportementale et psychophysique chez le lapin nouveau-né et l'homme adulte / Perception of odour mixtures : behavioural and psychophysical study in newborn rabbits and human adults

Sinding, Charlotte 13 April 2012 (has links)
Au travers de nos sens, nous pouvons appréhender la complexité des stimuli du milieu environnant. Dans le règne animal, il existe deux systèmes de lecture de l’information: l’un analytique et l’autre synthétique. Quels facteurs favorisent chacun de ces modes de perception? Perdurent-ils au cours de la vie? Varient-ils d'une espèce à l'autre? Ces questions ont été adressées en partie conjointement chez l’Homme adulte et le lapin nouveau-né, dans le cadre général de la perception d’odeurs issues de mélanges d'odorants plus ou moins complexes (2-6 odorants), et notamment de mélanges accords.Premièrement, nos résultats soulignent, chez l’Homme, que la sensibilité individuelle (seuils de détection) module la perception d'un mélange accord binaire. Deuxièmement, l’expérience répétée des constituants de ce mélange favorise sa perception analytique, chez l’Homme comme le lapereau, alors que l’expérience du même mélange favorise sa perception synthétique seulement chez le lapereau. Troisièmement, chez les deux espèces, un même mélange complexe de six odorants semble engendrer la perception d'une configuration (propre à la notion d'accord), ce qui n'est pas le cas de tout mélange de complexité comparable. Les lapereaux présentent, par ailleurs, des capacités d’analyse de ce mélange plus prononcées. Enfin, une étude prospective, par IRMf, des corrélats neurophysiologiques liés à chacune de ces perceptions a été réalisée chez l’Homme. / Through our senses, we can grasp the complexity of the stimuli that arise from our surroundings. Within the animal kingdom, two systems of information processing exist: one elemental and the other configural. Which factors promote each of these types of perception? Do they persist across lifespan? Do they vary from one species to another? In part, these issues were addressed simultaneously in human adults and newborn rabbits, within the general framework of odour mixture perception (more or less complex: 2-6 odorants), including the perception of blending mixtures.Firstly, our results highlight that in humans individual sensitivity (detection thresholds) modulates the perception of a binary blending mixture. Secondly, repeated experience with the components of a mixture promotes the elemental perception of the mixture both in humans and rabbits, while experience of the mixture promotes its configural perception only in rabbits. Thirdly, in both species, a same complex mixture of six odorants seems to trigger the perception of a configuration (specific to the blending effect); this is however not the case of any mixture of similar complexity. Besides, newborn rabbits display more pronounced elemental skills for this mixture. Finally, a prospective fMRI study was conducted in humans to investigate the neurophysiological correlates of these two modes of perception.The present findings confirm that the olfactory system can work both configurally and elementally, sometimes in the same way for similar mixtures in individuals from different species, and at different stages of development. This dual activity of the olfactory system is modulated by factors inherent to individuals and to mixtures themselves.
307

A Fully Customizable Anatomically Correct Model of the Crystalline Lens

Wilson, Cynthia Nicole January 2011 (has links)
The human eye is a complex optical system comprised of many components. The crystalline lens, an optical component with a gradient index (GRIN), is perhaps the least understood as it is situated inside the eye and as a result is difficult to characterize. Its complex nonlinear structure is not easily measured and consequently not easily modeled. Presently several models of the GRIN structure exist describing the average performance of crystalline lenses. These models, however, do not accurately describe the performance of crystalline lenses on an individual basis and a more accurate individual eye model based on anatomical parameters is needed. This thesis proposes an anatomically correct, individually customizable crystalline lens model. This is an important tool and is needed both for research on the optical properties of human eyes and to diagnose and plan the treatment of optically based visual problems, such as refractive surgery planning. The lens model consisted of an interior GRIN with a constant refractive index core. The anterior and posterior surface was described by conic sections. To realize this eye model, the optical and biometric properties of mammalian lenses were measured and the correlation relationships between these measurements were used to simplify the model down to one fitting parameter which controls the shape of the GRIN. Using this data, an anatomically correct individualizable model of the lens was successfully realized with varying parameters unique to each lens. Using this customizable lens model, customizable human eye models based on measurements of the entire human eye can be realized.
308

Stratégies de limitation de l'ingestion : optimisation des performances zootechniques, impacts physiologiques et conséquences sur la santé digestive / Feed intake limitation strategies : optimization of growth performances, physiological impacts and consequences on digestive health

Knudsen, Christelle 16 December 2014 (has links)
Dans un contexte de limitation de l'utilisation des antibiotiques, de nouvelles stratégies doivent être mises en place pour préserver la santé des animaux, en particulier lors du sevrage. En cuniculture, les stratégies de limitation de l'ingestion permettent de réduire les troubles digestifs en post sevrage et améliorent l'efficacité alimentaire, mais induisent inévitablement un retard de croissance et une baisse du rendement à l'abattage. Ce travail de thèse avait pour objectif d'une part d'optimiser les performances de croissance et de rendement à l'abattage des animaux soumis à une restriction alimentaire via une modulation de la quantité et de la qualité énergétique des aliments et d'autre part d'expliciter les mécanismes physiologiques sous-jacents aux effets bénéfiques d'une ingestion restreinte sur la santé et l'efficacité alimentaire. Nous avons démontré que dans le cadre d'une stratégie de restriction alimentaire un aliment riche en énergie digestible permet d'optimiser la croissance (+2%), le rendement à l'abattage (+0,6 points) et l'efficacité alimentaire (+11%), via notamment une amélioration de l'efficacité digestive, sans pénaliser les paramètres sanitaires, mais ne permet de rattraper que partiellement le retard de croissance induit par la restriction alimentaire (-3% de poids à l'abattage par rapport aux animaux nourris à volonté). Un aliment riche en amidon était favorable à la croissance de ces animaux et en particulier au rendement à l'abattage et n'avait pas d'effet délétère sur les paramètres sanitaires. La restriction alimentaire et la concentration énergétique alimentaire dans une moindre mesure, modulaient la réponse immunitaire via une réduction de la réponse humorale digestive (IgA intestinaux) et systémique (IgA et IgG circulants) sans modification de la réponse inflammatoire. L'activité du microbiote caecal était quant à elle modulée par la masse d'aliment ingérée alors que le profil de la communauté bactérienne caecale, sa diversité et sa richesse ne semblaient pas modifiés par la restriction alimentaire. Toutefois l'abondance relative de certaines familles (Eubacteriaceae, Peptococcaceae et Christensenellaceae) et genres montraient des variations spécifiques à la restriction ou à la concentration énergétique de l'aliment. L'ensemble de ces résultats indiquent que les relations entre les mesures physiologiques et les effets bénéfiques de la restriction alimentaire sur la santé digestive restent complexes et suggèrent l'implication d'autres paramètres métaboliques non évalués. Des hypothèses complémentaires de travail doivent ainsi être envisagées Toutefois nos travaux établissent l'intérêt économique de la restriction alimentaire, quel que soit le contexte sanitaire, et celui de l'utilisation d'aliments à haute valeur énergétique sur les performances zootechniques. Notre étude ouvre dès lors des perspectives de recherches complémentaires d'optimisation des stratégies alimentaires via une modulation de la durée de restriction alimentaire et de la qualité énergétique des aliments. / With the reduction in antibiotic use new strategies are required in order to preserve animal health, particularly around weaning. In rabbit breading feed restriction strategies allow for the reduction of post-weaning digestive disorders and improve feed efficiency, but are inevitably responsible for a reduced growth and carcass yield at slaughter. This work aimed to optimize the growth performances and slaughter yield of restricted fed rabbits through a modulation of the dietary energy concentration and quality. The second objective of this work was to explain the physiological mechanisms underlying the beneficial effects of feed restriction upon health and feed efficiency. We demonstrated that, under a restriction strategy, a diet rich in digestible energy increased growth (+2%), slaughter yield (+0.6 points) and feed efficiency (+11%), through an improved digestive efficiency, without penalizing the sanitary parameters. The reduced growth induced by feed restriction was however only partially compensated for (-3% in final weight compared to the ad libitum fed animals). A diet rich in starch induced a higher growth and slaughter yield and did not penalize the sanitary parameters under a restriction strategy. Feed restriction and, to a lesser extent, the dietary energy concentration, modulated the immune response through a reduced humoral response at the digestive (fecal IgA) and systemic (plasmatic IgA and IgG) levels without modifying the inflammatory response. The cecal microbial activity was modulated by the amount of feed ingested while the cecal bacterial community profile, diversity and richness were not affected by the feed intake level. However, the relative abundance of certain families (Eubacteriaceae, Peptococcaceae and Christensenellaceae) and generas demonstrated specific variations according to the feed intake level and the dietary energy concentration. These results indicate that the relationship between the physiological measurements and the beneficial effects of feed restriction upon health remain complex and suggest the implication of other metabolic parameters that weren't measured. Complementary work hypothesis must therefore be considered. This work however enabled us to establish the economic advantage of feed restriction strategies regardless of the sanitary status and demonstrated the beneficial effects of a high energy diet on growth parameters. Our study opens the door to new complementary research projects regarding the optimization of the feeding strategies through for instance the modulation of the restriction length and the dietary energy quality.
309

Efeitos do gel de plasma rico em plaquetas heterólogo na cicatrização de feridas dérmicas padronizadas em coelhos / Effects of heterologous platelet-rich plasma gel in dermal wound healing standardized in rabbits

Abegão, Karina Gomes Barros 17 March 2014 (has links)
Made available in DSpace on 2016-01-26T18:55:39Z (GMT). No. of bitstreams: 1 Karina.pdf: 2597948 bytes, checksum: d65c6af5a956ec0d8f0afae614fe6d8a (MD5) Previous issue date: 2014-03-17 / The platelet rich plasma is a source of several growth factors and appears as a new biotechnology in tissue repair, with great therapeutic power. Patients with general health problems and the lack of volume of blood required for autologous production of concentrate, may be restricted to receive this innovative treatment. To overcome the limitation, this study evaluated the effects of heterologous platelet-rich plasma gel obtained from a healthy dog, in the healing of dermal wounds in rabbits by standard morphological, morphometric and histological analyzes. Two surgical incisions were made on the back of six rabbits using a punch of 8 mm diameter. Randomly one side was denominated as a Control (A), leaving the contralateral Treaty as (B). 0.9% saline solution and heterologous platelet-rich plasma gel were applied topically to the lesions (A) and (B) respectively, on days 0, 3, 7, 10 and 14 after surgery. Macroscopic observations recorded on the days mentioned above, including the 17th, which is also a biopsy for histological analysis was performed, demonstrated similarity between the lesions in relation to the study variables, pain sensitivity, color of wound edema, hyperemia, exudate, crust and granulation tissue. The process of contraction of the lesion area (A) and (B) similarly developed linearly, so that histologically complete reepithelialization was achieved in 90% of lesions (A) and 100% of the lesions (B), no differences statistically significant. Such differences were also not found between wounds in relation to other histological parameters analyzed: presence of crust, neovascularization, collagen, fibroblasts and macrophages, cell type and intensity of the inflammatory process. The results of this study suggest that the heterologous platelet-rich plasma gel was able to promote the healing of dermal wounds in rabbits, no harmful effects. / O plasma rico em plaquetas é fonte de diversos fatores de crescimento e surge como uma nova biotecnologia na reparação tecidual, com grande potencial terapêutico. Pacientes com problemas de saúde geral e ausência de volume de sangue necessário para produção autóloga deste concentrado, podem ficar limitados para receber este tratamento inovador. Para ultrapassar a limitação, o presente estudo avaliou os efeitos do gel de plasma rico em plaquetas obtido a partir de um cão saudável, na cicatrização de feridas dérmicas padronizadas em coelhos mediante análises morfológicas, morfométricas e histológicas. Foram produzidas duas incisões no dorso de seis coelhos utilizando punch de 8 mm de diâmetro. Aleatoriamente, um dos lados foi denominado Controle (A), permanecendo o contralateral Tratado (B). Solução fisiológica a 0.9% e gel de plasma rico em plaquetas heterólogo foram aplicados topicamente nas lesões (A) e (B) respectivamente, nos dias 0, 3, 7, 10 e 14 de pós-operatório. Observações macroscópicas registradas nos dias mencionados acima, incluindo o 17o, no qual também foi realizada uma biópsia para análise histológica, demonstraram semelhança entre as lesões em relação às variáveis estudadas, sensibilidade dolorosa, cor da ferida, edema, hiperemia, exsudato, crosta e tecido de granulação. O processo de contração da área das lesões (A) e (B) evoluiu similarmente de forma linear, de modo que, histologicamente, reepitelização total foi alcançada em 90% das lesões (A) e 100% das lesões (B), sem diferenças estatisticamente significantes. Tais diferenças também não foram constatadas entre as feridas em relação aos demais parâmetros histológicos analisados: presença de crosta, neovascularização, colagenização, quantidade de fibroblastos e macrófagos, tipo celular e intensidade do processo inflamatório. Os resultados desta pesquisa sugerem que o gel de plasma rico em plaquetas heterólogo foi capaz de promover a cicatrização de feridas dérmicas em coelhos, sem efeitos prejudiciais.
310

Efeitos do gel de plasma rico em plaquetas heterólogo na cicatrização de feridas dérmicas padronizadas em coelhos / Effects of heterologous platelet-rich plasma gel in dermal wound healing standardized in rabbits

Abegão, Karina Gomes Barros 17 March 2014 (has links)
Made available in DSpace on 2016-07-18T17:53:12Z (GMT). No. of bitstreams: 1 Karina.pdf: 2597948 bytes, checksum: d65c6af5a956ec0d8f0afae614fe6d8a (MD5) Previous issue date: 2014-03-17 / The platelet rich plasma is a source of several growth factors and appears as a new biotechnology in tissue repair, with great therapeutic power. Patients with general health problems and the lack of volume of blood required for autologous production of concentrate, may be restricted to receive this innovative treatment. To overcome the limitation, this study evaluated the effects of heterologous platelet-rich plasma gel obtained from a healthy dog, in the healing of dermal wounds in rabbits by standard morphological, morphometric and histological analyzes. Two surgical incisions were made on the back of six rabbits using a punch of 8 mm diameter. Randomly one side was denominated as a Control (A), leaving the contralateral Treaty as (B). 0.9% saline solution and heterologous platelet-rich plasma gel were applied topically to the lesions (A) and (B) respectively, on days 0, 3, 7, 10 and 14 after surgery. Macroscopic observations recorded on the days mentioned above, including the 17th, which is also a biopsy for histological analysis was performed, demonstrated similarity between the lesions in relation to the study variables, pain sensitivity, color of wound edema, hyperemia, exudate, crust and granulation tissue. The process of contraction of the lesion area (A) and (B) similarly developed linearly, so that histologically complete reepithelialization was achieved in 90% of lesions (A) and 100% of the lesions (B), no differences statistically significant. Such differences were also not found between wounds in relation to other histological parameters analyzed: presence of crust, neovascularization, collagen, fibroblasts and macrophages, cell type and intensity of the inflammatory process. The results of this study suggest that the heterologous platelet-rich plasma gel was able to promote the healing of dermal wounds in rabbits, no harmful effects. / O plasma rico em plaquetas é fonte de diversos fatores de crescimento e surge como uma nova biotecnologia na reparação tecidual, com grande potencial terapêutico. Pacientes com problemas de saúde geral e ausência de volume de sangue necessário para produção autóloga deste concentrado, podem ficar limitados para receber este tratamento inovador. Para ultrapassar a limitação, o presente estudo avaliou os efeitos do gel de plasma rico em plaquetas obtido a partir de um cão saudável, na cicatrização de feridas dérmicas padronizadas em coelhos mediante análises morfológicas, morfométricas e histológicas. Foram produzidas duas incisões no dorso de seis coelhos utilizando punch de 8 mm de diâmetro. Aleatoriamente, um dos lados foi denominado Controle (A), permanecendo o contralateral Tratado (B). Solução fisiológica a 0.9% e gel de plasma rico em plaquetas heterólogo foram aplicados topicamente nas lesões (A) e (B) respectivamente, nos dias 0, 3, 7, 10 e 14 de pós-operatório. Observações macroscópicas registradas nos dias mencionados acima, incluindo o 17o, no qual também foi realizada uma biópsia para análise histológica, demonstraram semelhança entre as lesões em relação às variáveis estudadas, sensibilidade dolorosa, cor da ferida, edema, hiperemia, exsudato, crosta e tecido de granulação. O processo de contração da área das lesões (A) e (B) evoluiu similarmente de forma linear, de modo que, histologicamente, reepitelização total foi alcançada em 90% das lesões (A) e 100% das lesões (B), sem diferenças estatisticamente significantes. Tais diferenças também não foram constatadas entre as feridas em relação aos demais parâmetros histológicos analisados: presença de crosta, neovascularização, colagenização, quantidade de fibroblastos e macrófagos, tipo celular e intensidade do processo inflamatório. Os resultados desta pesquisa sugerem que o gel de plasma rico em plaquetas heterólogo foi capaz de promover a cicatrização de feridas dérmicas em coelhos, sem efeitos prejudiciais.

Page generated in 0.0732 seconds