Дисертації з теми "Elastin fibers"
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Grant, Tyler M. "Microstructural deformation of tendon." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:0ad70415-af7a-4b97-a93a-d17a73d8ff44.
Повний текст джерелаToroian, Damon Armen. "The Size exclusion characteristics of collagen and elastin fibers and role of fetuin in their calcification." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3266770.
Повний текст джерелаTitle from first page of PDF file (viewed August 6, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
Ferron, Florence Joelle. "The implications of fibulin-5 on elastin assembly and its role in the elastic fiber /." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101846.
Повний текст джерелаSmith, Kinley. "The distribution and function of elastin and elastic fibres in the canine cruciate ligament complex." Thesis, University of Liverpool, 2010. http://livrepository.liverpool.ac.uk/1437/.
Повний текст джерелаCholst, Beth (Beth Ellen). "Elastic stretchable optical fibers." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105710.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (pages 23-24).
The utilization of soft materials in the design of optical systems provides opportunities for imparting these optical systems with completely unprecedented properties. This will enhance performance of systems, such as optical fibers, and enable new application scenarios. Here, we report the design, manufacture and characterization of elastic stretchable optical fibers. Analogous to conventional optical fibers, the elastic fibers consist of a high index core, made from a polystyrene-polyisoprene triblock copolymer, and a low refractive index cladding, formed by a fluorinated thermoplastic elastomer. The fibers are manufactured by co-extrusion of their constituent materials. They can be stretched to 300% strain repeatedly. Axial deformation of the fibers results in a variation of their light guiding properties. The fibers' attenuation coefficient was determined to be 0.021 ± 0.003 dB/mm, which is 2 orders of magnitude higher than for standard optical glass fibers. The high attenuation coefficient is likely due to scattering of light by air inclusions incorporated during manufacturing at the core-cladding interface. The fibers elastic modulus is 960 ± 280 kPA and their yield strength lies in the range of 2150 ± 480 kPA. The variation in intensity of guided light as a function of strain applied axially to the fibers was measured with a customized optical setup. Our experiments show that elastic optical fibers have properties that make them desirable as mechanical sensors and components in a range of other applications, provided current manufacturing shortcomings are addressed. The fibers could be used for light delivery to individual pixels of flexible deformable displays. They could be incorporated into clothing for delivery of light for display purposes or textile-integrated photonic circuits to create functional textiles. Because the fibers can stretch, the textiles or displays will be able to undergo deformation without damage or loss in performance.
by Beth Cholst.
S.B.
Newcomb, Bradley Allen. "Gel spun PAN and PAN/CNT based carbon fibers: From viscoelastic solution to elastic fiber." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54881.
Повний текст джерелаVieira, Gislaine. "Analise da arquitetura da aorta de pacientes hipertensos e normotensos." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/310241.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
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Resumo: Fibras elásticas são componentes essenciais da aorta e remodelamento é acompanhado em muitas doenças e eventos que ameaçam a vida, como dissecção e rupturas. Fibras elásticas podem ser facilmente visualizadas quando coradas com H&E e examinadas por microscopia de fluorescência. Nosso objetivo foi criar um sistema de análise automática da textura das fibras elásticas comparando aorta de pacientes normotensos e hipertensos. O sistema de análise foi composto por Microscópio invertido Olympus IX-81 equipado com scanner FV 300 que utiliza laser FV-5 COMB2, utilizando laser de argônio a 488 nm, objetiva 40x usando óleo de imersão. A espessura da aorta varia de 2 a 3 mm, e a imagem completa foi composta por justaposição de imagens de 220x220 µm utilizando software Fluoview. Para análise foi utilizado o programa gliding box , que é uma caixa deslizadora de 128x128 pixels, que percorre a imagem da aorta pixel a pixel em toda sua extensão. Para análise computadorizada da textura foram utilizados programas computacionais (entropia, homogeneidade local e segundo momento angular derivado da matriz de co-ocorrência de Haralick). Foram calculados e plotados em diagramas resultados equivalentes à topografia histológica da imagem. Em cada caminho o gliding box percorreu entre 2000 e 3000 pixels da textura, revelando a topografia local e sua variação. Foi comparada a textura de fibras elásticas de cortes histológicos corados com HE de 24 pacientes normotensos e 30 hipertensos, adultos de ambos os sexos oriundos de autópsias realizadas no Depto de Anatomia Patológica. Para comparação entre textura e idade utilizou-se Correlação de Pearson, e a textura foi comparada entre os grupos com o auxílio do teste t. Resultados: Tanto nos pacientes normotensos como nos hipertensos não houve correlação entre: número de fibras elásticas ou distâncias entre elas, para as análises de Haralick e idade dos pacientes. No entanto, a entropia em pacientes normotensos (r=0,60; p=0,004) e a homogeneidade local (r=0,43; p =0,049) demonstraram acréscimo da variação topográfica com o envelhecimento, fato que não ocorreu nos hipertensos. Quando comparadas com aortas normotensas, as hipertensas revelaram menos fibras elásticas (p<0,0001), maior variabilidade e distâncias (p<0,0001), aumento da média da espessura e maior variabilidade da espessuras das fibras ( p<0,0001). Conclusão: Demonstramos que o presente método é uma ferramenta que permite uma análise objetiva da textura de fibras elásticas da aorta com a possibilidade de quantificar processos patológicos. Observamos que em pacientes normotensos, o número médio de fibras elásticas e a distância entre elas são constantes e ocorrem discretas alterações da arquitetura com o aumento da idade. Em hipertensos, o distúrbio arquitetural é mais evidente e ocorrem perdas de fibras elásticas.
Abstract: The elastic fiber network is an essential component of the aorta. Its remodeling accompanies many diseases and may provoke life-threatening events, such as dissection or rupture. Elastic fibers can be easily demonstrated in eosin-stained histologic sections examined by fluorescence microscopy. The aim of our study was to create an automatic texture analysis system of the elastic fibers and to apply it in human aortas comparing normotensive and hypertensive patients. The analysis sytem was composed of an Olympus IX-81 inverted microscope, a FV300 scan head and a FV-5 COMB2 laser combiner. The fluorescence of the hematoxylin and eosin-stained slides was excited with the 488 nm line of an Argon laser using a 40x oil immersion objective. The Fluoview software was used to reconstruct the images. The full image of the whole sample (2 or 3mm long) was composed by several 220x220. Then a gliding box of 128x128 pixels was running in 1-pixel steps along a predefined axis parallel to the bottom line of the image. For every new box, computerized analysis of texture features (entropy, local homogeneity and the second angular moment derived from the gray-level co-occurrence matrix) were calculated and plotted in diagrams, where the position on the x-axis was equivalent to the topography in the histologic picture. In that way for each "run" of the gliding box about 2000 to 3000 values of a texture feature were obtained, thus revealing precisely its topographic postion and its variabilty. We compared the elastic fiber texture in routinely HE-stained histologic slides of the aorta ascendens in 24 normotensive and 30 hypertensive adult patients of both sexes and of similar age from our autopsy files. Pearson correlations were calculated between the texture features and the age. Texture features were compared between both groups with the help of the t-test. Results: In normotensive and hypertensive patients no correlations were found between the number of elastic fibers, their thickness or their distance and the Haralick features and the age of the patients. But in normotensive patients entropy (r=0,60; p=0,004) and local homogeneity (r=0,43; p =0,049) showed increasing topographic variations in patients with advanced age, which was not the case for hypertensive patients. When comparing with normotensive aortas, the hypertensive ones revealed less elastic fiber layers (p<0,0001), a greater variabilty of the fiber distance (p<0,0001), increased mean fiber thickness and a greater varaibilty of the fiber thickness( p<0,0001) Conclusion: We showed that the presented method provides a new tool for an objective automatic texture analysis of the elastic fiber texture of the aorta with the possibility of quantification of the disease process. Although in normotensive patients, the mean number and distance of the elastic fibers is constant, discrete local alterations of the architecture appear with increasing age. In hypertensive patients there are more pronounced architectural alterations with loss of the fiber layers.
Universidade Estadual de Campi
Biologia Estrutural, Celular, Molecular e do Desenvolvimento
Mestre em Fisiopatologia Médica
Alves, Calebe de Andrade. "Dinâmica de degradação e reparação de fibras elásticas sob tensão." reponame:Repositório Institucional da UFC, 2013. http://www.repositorio.ufc.br/handle/riufc/13737.
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Extracelular matrix, the biological structure that supports cells in animal tissue, is composed of elastic fibers such as collagen and elastin. It is known that enzymes activity plays an important role in maintenance of these elastic fibers. The imbalance between destruction and repair of the elastic fibers can lead to diseases such as fibrosis and emphysema. In this study, we present a simple model to simulate enzymatic digestion and repair of elastic fibers under tension. The fiber is represented by a chain of linearly elastic springs in series surrounded by two layers of sites along which particles representing enzymes and fragments can diffuse. These particles can biding-unbinding in the fiber simulating the reaction process by changing the local stiffness by a multiplicative factor. We study the distribution of the number of visits of particles to the springs as function of time and the consequent change of the fiber stiffness, under different initial conditions (model parameters). We show that, due to no linearity of the model, the degradation effect prevails even when the concentrations of the two type of agents are the same. There is no relation between the number of degradative and rigidifying particles that garantee that the fiber stiffness remains constant. When an anisotropy factor is included on the model and the system behaviour becomes dependent on the tension applied to the fiber, we show that the increase of tension in general contributes to the increase on enzymatic activity. We believe this study can help better understand progression of diseases such as emphysema and fibrosis.
A Matriz Extracelular, a estrutura biológica que sustenta as células em tecidos animais, é composta de fibras elásticas como colágeno e elastina. Sabe-se que a atividade enzimática desempenha papel fundamental na manutenção dessas fibras elásticas. O desequilíbrio entre destruição e reparo das fibras elásticas pode levar a doenças como fibrose e enfizema. Neste estudo, nós apresentamos um modelo simples para simular digestão enzimática e reparo de fibras sob tensão. A fibra é representada por uma cadeia de molas linearmente elásticas em série. A fibra é cercada por duas camadas de sítios ao longo dos quais partículas representantes de enzimas e fragmentos podem se difundir. Estas partículas podem se ligar e se desligar da fibra, simulando o processo de reação ao alterar a constante elástica local por um fator multiplicativo. Estuda-se a distribuição do número de visitas de partículas degradadoras e enrijecedoras às molas em função do tempo de difusão e a consequente variação da rigidez da fibra, sob diversas condições iniciais (parâmetros do modelo). Mostra-se que, devido a características matemáticas intrínsecas ao modelo, o efeito de degradação prevalece sobre o de enrijecimento ainda quando a concentração de agentes de ambos os tipos é a mesma. Não há relação entre o número de partículas degradadoras e enrijecedoras que garanta a estabilidade da constante elástica da fibra. Quanto um fator de anisotropia é incluído no modelo e o comportamento do sistema passa a depender da tensão aplicada à fibra, mostra-se que o aumento da tensão em geral contribui para o aumento da atividade enzimática. Este estudo poderá ajudar a entender a progressão da degradação de tecidos em doenças como enfisema e fibrose.
Lima, Vanessa Morais. "Efeitos da penicilina G na pelve renal de ratos Wistar (Rattus norvegicus albinus) normais e diabéticos." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/10/10132/tde-09102013-180434/.
Повний текст джерелаPenicillin G is the most important antibiotics. Besides having a low cost and proven effectiveness of treatment, it shows great possibilities for reducing morbidity and mortality from infectious diseases worldwide. As this medicine may cause sequelae in the renal parenchyma and associated structures, and since the net renal tubular secretion contributes to the excretion of penicillin G, where about 60% of the antibiotic is eliminated in urine, this study aims to investigate the main structural and ultrastructural changes occurring in the kidney of normal and diabetes rats. Thus, this project aims to describe and analyze the collagen fibers, smooth muscle and elastic fibers of the renal pelvis of Wistar rats, comparing control and penicillin G-treated animals. The animals were divided into 4 groups, normal rats (N), Wistar rats treated with penicillin G (NP); rats induced diabetes (D), diabetic Wistar rats with penicillin G (DP). The diabetes was induced in groups D and DP by alloxan. The fibrotic region of the renal pelvis was collected and reduced into small fragments. The sections were used for the transmission electron microscopy and stained by the following methods for optic microscopic: Iron Hematoxylin for disclosure of elastic fibers; Resorcin fuchsin for disclosure of elastic and elauninic fibers; Resorcin fuchsin after oxidation with 1% aqueous solution of oxone for disclosure of elastic, elauninic and oxytalan fibers; Azan evidencing the collagen and smooth muscle components; Picrosirius for observation of the collagen component (specifically type I and III); and Hematoxylin and Eosin, to show the cellular component. Microscopic and histomorphometry analysis showed that penicillin G alters the fibrous components of the renal pelvis, increasing areas of smooth muscle fibers and collagen type III deposition and decreasing mature elastic fibers (in this case, only between N and NP). Diabetes mellitus proved to be a metabolic disease also able to alter the morphology of the pelvis, leading to the augmentation of smooth muscle fiber area. Moreover, the area of type I collagen and the amount of mature elastic and elauninic fibers were diminished, while oxytalan fibers increased, together with a remarkable increase in the number of mitochondria. We can infer that the antibiotic therapy made by penicillin G and the diabetes, cause structural and ultrastructural differences in the renal pelvis of rats, mainly in the organization of elastic fiber, muscular and collagen components.
Rosado, João Pedro Gaio Meireles. "Alterações estruturais da matriz extracelular do prepúcio humano causadas pelo tabagismo." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=3859.
Повний текст джерелаOs autores têm como objetivo, investigar a matriz extra celular, musculatura lisa e densidade vascular do prepúcio de pacientes tabagistas. Espécimes de prepúcio foram obtidas de 20 jovens adultos (média de idade= 27.2) submetidos a postectomia. Dentre os pacientes analisados, um grupo (n=10) possui história prévia de tabagismo (3 to 13 maços/ano, média = 5.8 3.2), e outro grupo (n=10) formam o grupo controle, não fumantes. A coloração de Tricrômico Masson foi utilizada para quantificar tecido conectivo, musculatura lisa e vasos. A coloração Resorcina-fucsina de Weigert foi utilizada para estabelecer as fibras do sistema elástico e a coloração, Vermelho de Picrosirius para o estudo do colágeno. O estudo estereológico foi realizado utilizando o software Image J, para determinar as densidades volumétricas. Para a análise bioquímica o colágeno total foi determinado em μg de hidroxiprolina por MG de tecido seco. O estudo estatístico foi realizado lançando mão do t-teste (p<0,05). Fibras do sistema elástico de fumantes apresentaram-se aumentadas em 42.5% quando comparado ao grupo controle (p=0,002). Em contraste, musculatura lisa (p=0,42) e densidade vascular (p=0,16) não mostraram nenhuma diferença estatística. Foi realizado uma análise quantitativa utilizando Vermelho de Picrosirius sob luz polarizada, que evidenciou a presença de colágeno tipo I e III, sem diferença estatisticamente significativa. A concentração total do colágeno não mostrou diferença entre tabagistas e o grupo controle. (73.1μg/mg 8.0 vs. 69.2μg/mg 5.9, respectivamente, p=0,23). Tabagismo está associado a um significante aumento de fibras do sistema elástico do tecido prepucial. Estes resultados podem, possivelmente, explicar os altos índices de falha na uretroplastia peniana, com uso de flap de prepúcio em fumantes
It has been speculated by McAninch et al. (1), that smokers might experience worse results after urethral reconstruction. We decided to investigate the extracellular matrix, smooth muscle and vascular density in the foreskin of smoker patients. Foreskin samples were obtained from 20 young adults (ranging in age from 23 to 36 years; mean SD = 27.2 5.8) submitted to circumcision from July 2008 to October 2009. Of the patients analyzed, one group (n=10) had a previous history of chronic smoking (3 to 13 packs/year, mean = 5.8 3.2) i.e., one pack per day for 3 to 13 years. The control group was composed of 10 non-smoker patients. Foreskin samples were studied by histology and biochemistry. Means were compared using the two-tailed t-test (p<0.05). The elastic system fibers in the foreskin of smoker patients increased in 42.5% when compared to the control group. In contrast, the smooth muscle fibers, vascular density and total collagen concentration did not show any significant variation between smokers and controls. Smoking is associated with a significant increase of elastic system fibers in foreskin tissue. These results could possibly explain the high failure rate of penile urethroplasty in smokers by using foreskin flaps
Herreros, Fernanda Oliveira Camargo. "Remodelamento da derme humana apos aplicação de salicilato de silanol." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/311629.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
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Resumo: A intradermoterapia é um processo terapêutico com poucas publicações científicas em revistas indexadas. Em 2005, um estudo duplo-cego randomizado demonstrou os benefícios proporcionados para a pele, cabelos e unhas de mulheres com fotoenvelhecimento pelo consumo de um suplemento oral de silanol. Frente a esses dados, realizou-se um estudo com o objetivo de comparar as alterações histológicas entre a pele humana que recebeu injeção intradérmica de silanol e as encontradas na pele em que foi injetado soro fisiológico. Dez mulheres caucasianas, sadias, com grau moderado de fotoenvelhecimento, voluntariamente receberam dez sessões semanais de injeções com salicilato de silanol 0,1% no antebraço esquerdo, e injeções de soro fisiológico no antebraço direito. No momento da biópsia, duas semanas depois, três pacientes recusaram-se a realizar o procedimento. Os achados histológicos nas áreas injetadas com silanol e com soro fisiológico, encontrados em biópsias, foram avaliados e comparados por um pesquisador de forma cega e as fibras colágenas e elásticas de cada lado foram quantificadas. A análise da textura da derme foi feita a partir das imagens microscópicas digitalizadas, por meio da dimensão fractal de Sarkar e do cálculo das amplitudes (valores de inércia), após a transformada rápida de Fourier. A área injetada com silanol revelou um aumento estatisticamente significativo da densidade de fibras colágenas e elásticas. A análise de textura revelou uma distribuição mais compacta e mais homogênea das fibras de colágeno. O resultado desse estudo sugere que a aplicação de um silício orgânico pode estimular a síntese das fibras elásticas e colágenas, levando a um remodelamento da estrutura da derme, o que pode explicar a melhora da aparência da pele, observada em estudos clínicos. Com base nestes resultados, relatou-se o caso de uma paciente com cicatrizes atróficas resultantes de micobacteriose atípica tratada com doxiciclina por seis meses. A paciente havia se submetido à hidrolipoclasia por ultra-som e a infecção desenvolveu-se nos locais do procedimento. Esta complicação ainda não havia sido descrita na literatura médica associada a tal procedimento. As cicatrizes foram submetidas a cinco sessões de intradermoterapia com salicilato de silanol, apresentando melhora parcial da aparência
Abstract: Mesotherapy is a technique that lacks scientifical clinical trials. In 2005, a controlled double-blind study in patients with photo-aged facial skin demonstrated the beneficial role of oral intake of silanol for skin, hair and nails. Facing it, a study was developed to compare histological alterations in human skin that received intradermal injections of silanol. Ten healthy female caucasian volunteers with a moderate degree of photoaged skin received ten sessions of weekly injections of 0.1% salicylate silanol in the left ventral lateral forearm and physiological solution injections on the right forearm. At biopsy time, three patients denied to receive this procedure. The histological features of punch biopsies of the treated area and the nontreated contralateral arm were compared and the collagen and elastic fibers were quantified by a blind physician. Texture analysis was performed on digitalized microscopic images by analyzing the Sarkar fractal dimension and amplitudes (inertia values) after Fast Fourier transformation. The treated area revealed a statistically significant increase of the density of both collagen and elastic fibers. Texture analysis showed more compact and homogenously distributed collagen fibers after silicon injection. This result suggests that the application of silicon may stimulate the production of collagen and elastic fibers leading to remodeling of the dermal fiber architecture, which may explain the improvement of the skin surface observed in clinical studies. Also, a case report illustrates a mycobacteria infection following an ultrasound hydrolipoclasia procedure, complication not previously reported in medical literature. After the antibiotic treatment, the patient developed atrophic scars, that received five sessions of mesotherapy with silanol, with some improvement in scar appearance
Doutorado
Clinica Medica
Doutor em Clínica Médica
Rocha, Vinícius Novaes. "Estudo dos efeitos da hipertensão arterial nas alterações morfológicas da valva atrioventricular esquerda (mitral) de ratos hipertensos induzidas por L-NAME." Universidade do Estado do Rio de Janeiro, 2009. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=4653.
Повний текст джерелаThe heart valves are designed to maintain the unidirectional blood flow and for this reason they have an anisotropic architecture of the extracellular matrix that ensures and maintains proper function under conditions of high and low pressure. The valve disease is a disorder that can affect any of the heart valves, marked by any change in its structure that prevents its proper operation. Studies show that the mechanical stress caused by blood flow may interfere with the organizational structure of cells and extracellular matrix of the valve. This study aimed to investigate the possible structural and ultrastructural changes that hypertension, induced by L-NAME, can cause to the left atrioventricular valve (mitral) from hearts of rats. The animals received L-NAME (40mg/kg/dia), previously diluted in water, for five weeks. At the end of the fifth week euthanasia of animals was performed and the valve parietal fragments were collected and processed for light microscopy (histochemistry) and electron microscopy (ultrastructural histochemistry and ultrastructural immunohistochemistry). It was analyzed the morphological structure of the valves at both structural (light microscopy) and ultrastructural (electron microscopy), as well as the thickness of the valve and quantification (% / area) of the elastic and collagen fibers through the ImagePro-Plus 4.5. The animals treated with L-NAME developed hypertension from the second week of administration of the drug. Structurally, it was possible to identify a disorganization of the elastic and collagen fibers with regions of fragmentation. The hypertension animals showed thicker valve regions than control, plus a smaller amount of collagen fibers. Ultrastructurally, it was identified changes of the endothelium in animals treated with L-NAME, where it presented irregular contours and accumulations of vesicles inside. Furthermore, it was also observed fragmentation of basal lamina, disorientation of collagen fibers, fiber oxytalan accumulation near the endothelium and fragmentation of elastic fibers of the atrial layer. This study concluded that increased blood pressure, characterized by hypertension, causes changes in the morphological structure of the valve, which may be linked in with the synergistic inhibition of nitric oxide synthesis, and may thus undermine its perfect operation.
Patricio, Licia Mioko Yoshizaki Akinaga. "Efeitos da poluição atmosférica de origem veicular no sistema cardiopulmonar de camundongos Swiss (Mus musculus L.) recém-natos expostos até a idade adulta." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-16122008-102039/.
Повний текст джерелаINTRODUCTION: The continuous exposition since birth to atmospheric pollution of great urban centers originated by vehicles predominantly, contributes to cardiopulmonary events in adults. The remodeling and inflammation induced by airborne pollutants may modulate the vascular response to mediators and alter the vascular patency and reactivity which may contribute to ischemic events. METHODS: To verify the inflammatory and structural alterations of the lungs and heart of Swiss male mice chronically and continuously exposed since birth to adulthood, to selective chambers with (clean) or without (polluted) filter devices for particles and toxic gases, 7days/24h/4 months, located 20m far from a cross-road with heavy traffic in Sao Paulo city downtown. Measurements of PM2,5; NO2 and Black Carbon (BC) inside the chambers and in the external environment and morphometric analyses of the lung and heart were made. RESULTS: Filters cleared 100% of BC, 47% of PM2,5 and 68% of NO2 in the clean chamber. In the lungs, pollutants affected predominantly the peribronchiolar area. Animals submitted to the polluted chamber presented peribronchiolar inflammation characterized by increased perivascular influx (p=0.022), bronchiolar epithelial hyperplasia (p=0.037), total inflammatory scores (p=0.015), and decrement of polymorphonuclear cells infiltration in the distal septa (p=0.001). There was no difference of the lumen/wall ratio (L/W) of peribronchiolar vessels (p=0.094) between groups. However, mice from polluted chamber presented structural remodeling characterized by decrement of elastic fibers in both adventitia (p=0.006) and media layers (p= 0.008) and collagen content in the adventitia (p= 0.016). In the heart, there was an increase of nucleus of myocytes/left ventricle area, but no alteration of the myocardial weight between groups (p=0.005). Although the coronary arterioles from mice exposed to polluted ambient did not show differences of L/W ratio when compared to those from clean ambient, pollutants induced increment of collagen and elastic fibers in the adventitia and media vascular layer (p<0.001; p=0.03 respectively), even when vessels were categorized by caliber and per ventricle chamber separately (p<0.001). CONCLUSION: The continuous exposure to atmospheric pollution of São Paulo city, Brazil, since birth to adulthood, induced inflammatory and structural alterations in the lungs and heart. The lung response was characterized by inflammation and decrement of extracellular matrix fibers while in the heart, there was fibrosis and elastin increment in the coronary arteriolar wall. These results reinforce the hypothesis that urban airborne pollution predominantly generated by traffic, induces silent but significant organ-specific alterations, which may impair vascular patency and reactivity and may contribute to ischemic cardiac events in the adulthood
Alves, Calebe de Andrade. "DinÃmica de degradaÃÃo e reparaÃÃo de fibras elÃsticas sob tensÃo." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=9511.
Повний текст джерелаA Matriz Extracelular, a estrutura biolÃgica que sustenta as cÃlulas em tecidos animais, à composta de fibras elÃsticas como colÃgeno e elastina. Sabe-se que a atividade enzimÃtica desempenha papel fundamental na manutenÃÃo dessas fibras elÃsticas. O desequilÃbrio entre destruiÃÃo e reparo das fibras elÃsticas pode levar a doenÃas como fibrose e enfizema. Neste estudo, nÃs apresentamos um modelo simples para simular digestÃo enzimÃtica e reparo de fibras sob tensÃo. A fibra à representada por uma cadeia de molas linearmente elÃsticas em sÃrie. A fibra à cercada por duas camadas de sÃtios ao longo dos quais partÃculas representantes de enzimas e fragmentos podem se difundir. Estas partÃculas podem se ligar e se desligar da fibra, simulando o processo de reaÃÃo ao alterar a constante elÃstica local por um fator multiplicativo. Estuda-se a distribuiÃÃo do nÃmero de visitas de partÃculas degradadoras e enrijecedoras Ãs molas em funÃÃo do tempo de difusÃo e a consequente variaÃÃo da rigidez da fibra, sob diversas condiÃÃes iniciais (parÃmetros do modelo). Mostra-se que, devido a caracterÃsticas matemÃticas intrÃnsecas ao modelo, o efeito de degradaÃÃo prevalece sobre o de enrijecimento ainda quando a concentraÃÃo de agentes de ambos os tipos à a mesma. NÃo hà relaÃÃo entre o nÃmero de partÃculas degradadoras e enrijecedoras que garanta a estabilidade da constante elÃstica da fibra. Quanto um fator de anisotropia à incluÃdo no modelo e o comportamento do sistema passa a depender da tensÃo aplicada à fibra, mostra-se que o aumento da tensÃo em geral contribui para o aumento da atividade enzimÃtica. Este estudo poderà ajudar a entender a progressÃo da degradaÃÃo de tecidos em doenÃas como enfisema e fibrose.
Extracelular matrix, the biological structure that supports cells in animal tissue, is composed of elastic fibers such as collagen and elastin. It is known that enzymes activity plays an important role in maintenance of these elastic fibers. The imbalance between destruction and repair of the elastic fibers can lead to diseases such as fibrosis and emphysema. In this study, we present a simple model to simulate enzymatic digestion and repair of elastic fibers under tension. The fiber is represented by a chain of linearly elastic springs in series surrounded by two layers of sites along which particles representing enzymes and fragments can diffuse. These particles can biding-unbinding in the fiber simulating the reaction process by changing the local stiffness by a multiplicative factor. We study the distribution of the number of visits of particles to the springs as function of time and the consequent change of the fiber stiffness, under different initial conditions (model parameters). We show that, due to no linearity of the model, the degradation effect prevails even when the concentrations of the two type of agents are the same. There is no relation between the number of degradative and rigidifying particles that garantee that the fiber stiffness remains constant. When an anisotropy factor is included on the model and the system behaviour becomes dependent on the tension applied to the fiber, we show that the increase of tension in general contributes to the increase on enzymatic activity. We believe this study can help better understand progression of diseases such as emphysema and fibrosis.
Yang, Lanti. "Mechanical properties of collagen fibrils and elastic fibers explored by AFM." Enschede : University of Twente [Host], 2008. http://doc.utwente.nl/58870.
Повний текст джерелаVilela, Antonella Sachsida Braga. "Matriz extracelular de pericardio fibroso porcino : estudo morfologico e bioquimico." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316956.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Tecido pericardial tem sido utilizado na confecção de biopróteses empregadas na reparação de diferentes lesões. Entretanto, calcificações e falência mecânica têm sido as principais causas de durabilidade limitada de biopróteses cardíacas fabricadas com pericárdio bovino. Nesse trabalho foi realizado um estudo do pericárdio fibroso porcino em sua estrutura microscópica e sua natureza bioquímica. A morfologia geral e a arquitetura das fibras colágenas e elásticas foram estudadas em tecido seccionado e também em montagens totais, corados por diferentes métodos histoquímicos e analisados em microscopia de luz convencional, de polarização, de fluorescência e confocal. O estudo bioquímico da matriz pericardial foram realizados de acordo com procedimentos bioquímicos pertinentes. O pericárdio mostrou-se um tecido altamente celularizado com características de tecido jovem. Os feixes colagênicos apresentaram-se arranjados em camadas multidirecionalmente orientadas, formando uma rede de trama fechada, com um número maior de fibras orientando-se obliquamente, partindo da região central inferior em direção súpero-lateral esquerda em relação ao coração. Uma discreta predominância de fibras colágenas no sentido base-ápice foi verificada na região anterior direita do pericárdio. A matriz extracelular apresentou-se pouco metacromática. Observaram-se finas fibrilas elásticas intimamente associadas às fibras colágenas, entrelaçadas em direções diversas ou paralelas entre si. Extração comparativa de componentes da matriz não revelou diferenças entre proteínas extraídas das regiões direita e esquerda e também entre material fresco e congelado. A análise em SDS-PAGE revelou dezesseis proteínas com valores de massa molecular aparente entre 11 e 109 kDa. Análises realizadas sugerem que o GAG encontrado possivelmente é o dermatam sulfato. Os dados obtidos podem subsidiar novos procedimentos direcionados à obtenção de biomembranas melhor preparadas e funcionalmente mais adequadas à construção de biopróteses.
Abstract: Pericardial tissue has been used to construct bioprostheses employed in the repair different kinds of injuries. However, calcification and mechanical failure have been the main causes of limited durability of cardiac bioprostheses constructed with bovine pericardium. In the course of this work a study has been conducted on the porcine fibrous pericardium and its microscopic structure and its biochemical nature. The general morphology and the architecture of the collagen and elastic fibers have been studied in sectioned tissue and also total assemblies, stained by diverse histochemical methods and analyzed by conventional light, polarizing light, fluorescence and confocal microscopy. Biochemical study of the pericardial matrix was conducted according to pertinent procedures. The pericardium was shown as a highly cellularized tissue with a vascular tree very ramified and collagen fibers arranged in multidirectionally oriented layers. A predominant direction was verified, with a larger number of fibers obliquely oriented, starting at the lower central region towards high-lateral-left relatively to the heart. A discreet predominance of collagen fibers is the base-apex direction was verified in the right-front region of the pericardium. Extracellular matrix with little metachromasy was observed, indicating small quantities of acid glycosaminoglycans. Fine elastic fibrils were observed, intimately associated to collagen fibers, interlaced in various directions or parallel to themselves. No differences were found between proteins extracted from the right or left regions and between fresh or frozen material. The quantities of extracted GAGs were too small to be detected by the method used. The SDS-PAGE showed proteins with values of apparent molecular mass between 11 and 109 kDa included two polydisperse bands around 71 and 85kDa. The ectrophoretic analysis showed that the found GAG is possibly dermatan sulfate.
Doutorado
Histologia
Doutor em Biologia Celular e Estrutural
Sandt, Joseph David. "Scalable manufacture and synchronized optical/mechanical characterization of tunable elastic photonic fibers." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/100094.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (pages 36-37).
In recent decades, advances in optical technologies have been essential to improvements made in the ways we transmit and process information, diagnose health issues in human patients and material problems in man-made devices and infrastructure, modify and monitor materials in manufacturing, and otherwise interact with the world around us. Optical and photonic fibers, in particular, represent a class of optical devices that are invaluable to a variety of applications. Advances in the development of optical devices will continue to provide increased utility to science and industry, though somewhat surprisingly, research related to such efforts continues to focus on a limited set of highly optimized materials, restricting the progress that could potentially be made. Increasing the breadth of materials used in optical and photonic fibers opens doors to novel capabilities of familiar technology. Herein, the mechanical and optical characterization, and attempted scaling of manufacture, of mechano-responsive, color-tunable elastic photonic fibers is discussed. When deformed, the fibers respond with a predictable, linear variation in the wavelength of light they reflect, which results in a pronounced change in their color. This characterization was accomplished with a custom-built setup designed to simultaneously collect information about stress and strain in the fiber, as well as a fiber image and spectral reflection data from selected points on the fiber. Fibers have been subjected to up to 5000 cycles of stretching and relaxation, and initial results indicate that their optical response to longitudinal strain can be exceptionally consistent, even after several thousand cycles. Sensors that rely on optical technologies have several inherent advantages over more traditional resistance-based sensors and other systems, including being lightweight, immune to electromagnetic interference, and inexpensive. Once a viable method of manufacturing fibers with length on the order of meters or kilometers is found, the fibers have great potential to find application in medicine, structural health monitoring, textiles, communication, and other industries. The vast potential of these fibers comes from the use of novel, elastic materials in the implementation of well-known optical concepts.
by Joseph David Sandt.
S.M.
Hegg, Meredith Michelle. "Exact Relations and Links for Fiber-Reinforced Elastic Composites." Diss., Temple University Libraries, 2012. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/164322.
Повний текст джерелаPh.D.
Predicting the effective elastic properties of a composite material based on the elastic properties of the constituent materials is extremely difficult, even when the microstructure is known. However, there are cases where certain properties in constituents always carry over to a composite, regardless of the microstructure of the composite. We call such instances exact relations. The general theory of exact relations allows us to find all of these instances in a wide variety of contexts including elasticity, conductivity, and piezoelectricity. We combine this theory with ideas from representation theory to find all exact relations for fiber-reinforced polycrystalline composites. We further extend these ideas to the concept of links. When two composites have the same microstructure but different constituent materials, their effective tensors may be related. We use the theory of exact relations to find such relations, which we call links. In this work we describe a special set of links between elasticity tensors of fiber-reinforced polycrystalline composites. These links allow us to generalize certain results from specific examples to generate new information about this widely-used class of composites. In particular, we apply the link to obtain information about composites made from two transversely isotropic materials and polycrystals made from one orthotropic material.
Temple University--Theses
Braga, Guilherme Gambogi 1985. "Avaliação da elastogênese em cultura de células obtidas de camungongos deficientes em Fibrilina-1 : estudo do efeito do Losatan." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314063.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Fibrilina-1 é um importante componente da rede de microfibrilas da matriz extracelular. As microfibrilas estão presentes nas fibras elásticas que são responsáveis pela elasticidade e resistência de tecidos dos pulmões, pele e grandes vasos. Mutações no gene da Fibrilina-1 estão associadas com a síndrome de Marfan. Pacientes com esta síndrome apresentam muitas manifestações clínicas nos pulmões, sistema cardiovascular e olhos. Modelos de síndrome de Marfan tem sido criados no sentido de obter informações sobre o desenvolvimento desta doença. Estudos recentes em modelos de camundongos tem sugerido a importância da atividade exacerbada do TGF ? promovendo a quase totalidade das alterações fenotípicas encontradas nestes camundongos, o que pode ser revertido pelo tratamento com o Losartan. O principal objetivo deste projeto foi avaliar a formação de fibras elásticas em cultura de células obtidas de animais deficientes em fibrilina-1, bem como o possível efeito do tratamento destas células com losartan. Os fibroblastos derivados de animais deficientes em fibrilina- 1 foram estudados usando imunofluorescência, western blotting, microscopia eletrônica de varredura e transmissão e real-time PCR. Assim, a deficiência em fibrilina-1 ocasionou uma redução conjunta da deposição de fibrilina-2, MAGP-1 e tropoelastina na matriz extracelular em cultura de fibroblastos de derme. Foi possível verificar aumento no níveis de expressão das metaloproteinases MMP-2 e MMP-9. O tratamento dos fibroblastos derivados de animais deficientes em fibrilina-1 com o fármaco losartan levou a recuperação parcial da deposição das proteínas Fibrilina-2, MAGP-1 e tropoelastina na matriz extracelular de cultura in vitro. Porém, o tratamento dos fibroblastos derivados de animais deficientes em fibrilina-1 com fármaco Captopril e os peptídeos de Angiotensina I e II não influenciaram na deposição das mesmas na matriz extracelular de cultura in vitro
Abstract: Fibrillin-1 is an important microfibril network component. Microfibrils are present in elastic fiber responsible for resilience and elastic properties from structures like lungs, skin and large vessels. Mutations in Fibrillin-1 gene are associated with Marfan's Syndrome. Marfan's Syndrome patients shown many different clinical manifestations in lungs, cardiovascular system and eyes tissues. Marfan's models have been created to get better insights about this disease development. Recent studies from mice models have suggested an important role to unbalanced TGF ? activity promoting almost whole alterations found in those mice which might be rescued by losartan treatment. Our main goal were evaluate elastic fiber formation in cell culture obtained from fibrillin-1 defficient mice as well as losartan's treatment effect on those cells. The fibroblasts derived from deficient animals in fibrillin-1 were studied using immunofluorescence, western blotting, scanning electron microscopy and transmission and real-time PCR. Thus, the deficiency in fibrillin-1 led to a joint reduction of the deposition of fibrillin-2, MAGP-1 and tropoelastin in the extracellular matrix in culture of fibroblasts in the dermis. It was possible to observe an increase in levels of expression of metalloproteinases MMP-2 and MMP-9 were found. The treatment of the fibroblasts derived from deficient animals in fibrillin-1 with the drug losartan has led to the partial recovery of the deposition of protein fibrillin-2, MAGP-1 and tropoelastin in the extracellular matrix of culture in vitro. However, the treatment of fibroblasts derived from deficient animals in fibrillin-1 with drug Captopril and the peptides of Angiotensin I and II not influenced in the deposition of the same in the extracellular matrix of culture in vitro
Mestrado
Bioquimica
Mestre em Biologia Funcional e Molecular
Soares, Leila Cristina. "Composição da matriz extracelular do ligamento cardinal de mulheres na pós-menopausa com e sem prolapso uterino." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=2497.
Повний текст джерелаUterine prolapse has increase of incidence after menopause. The aim of this study was to identify the changes in extracellular matrix of cardinal ligaments associated to menopause and uterine prolapse. Cardinal ligament of 3 different groups (pre-menopause, menopause and uterine prolapse) are identified and biopsied during 57 womens abdominal or vaginal hysterectomy. Biopsy specimens were assessed by biochemical methods to characterize and quantify sulfated glycosaminoglycans and collagen. Relative concentrations of GAG were obtained by electrophoresis. Histological procedures are made to identify elastic fibers (Weigert) collagen distribution (Picro sirius) and decorin (immunohistochemistry). Our results showed increase in GAG concentration 72.2% in uterine prolapse group compared to menopause group (p<0.05). Collagen concentration was 37% lower in uterine prolapse group compared to menopause group (p<0.04). Relative concentration of GAG: heparan sulfate, chondroitin sulfate and dermatan sulfate showed no differences among three groups. Elastic fibers showed a significant reduction of approximately 22% uterine prolapse group compared to menopause group (p<0.05). Collagen organization was similar in three groups and the staining pattern of decorin seemed to be decreased in uterine prolapse group. Our results indicate changes in connective tissue metabolism. Cardinal ligament in postmenopausal women has a denser extracellular matrix. This change is not observed in women with uterine prolapse.
Alves, Calebe de Andrade. "A study concerning homeostasis and population development of colagen fibers." reponame:Repositório Institucional da UFC, 2017. http://www.repositorio.ufc.br/handle/riufc/27811.
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Collagen is a generic name for the group of the most common proteins in mammals. It confers mechanical stability, strength and toughness to the tissues, in a large number of species. In this work we investigate two properties of collagen that explain in part the choice by natural selection of this substance as an essential building material. In the first study the property under investigation is the homeostasis of a single fiber, i.e., the maintenance of its elastic properties under the action of collagen monomers that contribute to its stiffening and enzymes that digest it. The model used for this purpose is a onedimensional chain of linearly elastic springs in series coupled with layers of sites. Particles representing monomers and enzymes can diffuse along these layers and interact with the springs according to specified rules. The predicted lognormal distribution for the local stiffness is compared to experimental data from electronic microscopy images and a good concordance is found. The second part of this work deals with the distribution of sizes among multiple collagen fibers, which is found to be bimodal, hypothetically because it leads to a compromise between stiffness and toughness of the bundle of fibers. We propose a mechanism for the evolution of the fiber population which includes growth, fusion and birth of fibers and write a Population Balance Equation for that. By performing a parameter estimation over a set of Monte Carlo simulations, we determine the parameters that best fit the available data.
Collagen is a generic name for the group of the most common proteins in mammals. It confers mechanical stability, strength and toughness to the tissues, in a large number of species. In this work we investigate two properties of collagen that explain in part the choice by natural selection of this substance as an essential building material. In the first study the property under investigation is the homeostasis of a single fiber, i.e., the maintenance of its elastic properties under the action of collagen monomers that contribute to its stiffening and enzymes that digest it. The model used for this purpose is a onedimensional chain of linearly elastic springs in series coupled with layers of sites. Particles representing monomers and enzymes can diffuse along these layers and interact with the springs according to specified rules. The predicted lognormal distribution for the local stiffness is compared to experimental data from electronic microscopy images and a good concordance is found. The second part of this work deals with the distribution of sizes among multiple collagen fibers, which is found to be bimodal, hypothetically because it leads to a compromise between stiffness and toughness of the bundle of fibers. We propose a mechanism for the evolution of the fiber population which includes growth, fusion and birth of fibers and write a Population Balance Equation for that. By performing a parameter estimation over a set of Monte Carlo simulations, we determine the parameters that best fit the available data.
Dyer, S. J. R. "Elastic anisotropy in fibre reinforced composites." Thesis, University of Leeds, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373548.
Повний текст джерелаAya, Rino. "Regeneration of elastic fibers by three-dimensional culture on a collagen scaffold and the addition of latent TGF-β binding protein 4 to improve elastic matrix deposition". Kyoto University, 2016. http://hdl.handle.net/2433/215396.
Повний текст джерелаFink, Gisele Miozzo. "Estudo da distribuição diferencial das fibras do sistema elástico no ventrículo esquerdo do coração de ratos normais." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-16062009-162743/.
Повний текст джерелаThe connective tissue elasticity has a protective function acting as a tensile spring during muscular work. Nevertheless, few is known about the distribution of the elastic system fibers in the heart. Considering that a) the study of the distribution of these fibers may help understand the cardiac mechanics, and b) rat models are used to study cardiac dysfunctions, our aim is to study the distribution of elastic system fibers in the ventricular endocardium, epicardium and myocardium of normal rats. Histological tissue sections of left ventricle (obtained from adult rats) were studied by comparing the typical ultrastructural picture of each of the fiber types with Resorcinfuchsin staining technique for light microscopy. The ultrastructural observation was made in tissues fixed with tannic acid-glutaraldehyde, which provided a reliable means to identify the elastic system fibers, as oxytalan, elaunin and elastic fibers. A semiquantitative evaluation was performed. The analysis of the histological sections stained by Resorcin-fuchsin technique after oxidation shows a stratum of elastic system fibers in close association to the endothelium in the endocardium and to the mesothelium in the epicardium. When observed at the transmission electron microscope, it was possible to see that in both locations the elastic system fibers are arranged in two orthogonally disposed layers. At the ultrastructural level, the epimysium presents fibroblasts, thick collagen, elaunin and elastic fibers interspersed in the amorphous substance. In the perimysium, the electron microscope disclosed a great amount of microfibrils, surrounding all fibrilar components: elastic fibers, elaunin fibers and even collagen fibers. Frequently, at this location, the microfibrils are closely packed, forming bundles devoid of elastin that correspond to the ultrasctructural picture of the oxytalan fibers. The endomysium is rich in oxytalan fibers in a close association with the basal lamina of the myocytes. A microfibrilar network interconnects the endomysium elements each other. In spite of the functional implications being speculative, the differential distribution of the elastic system fibers in the compartments of the ventricular wall suggests that the differences in elasticity provide biomechanical versatility to the intire system. Ultrastructural analysis shows that oxytalan fibres and thin collagen fibrils are co-localized in endomysium and perimysium, whereas, the presence of thicker collagen fibrils coincides with elaunin and elastic fibers in endo- and epicardium. These specific co-localizations suggest that elastic system, in co-evolution with collagen, has contributed to accommodating functional diversity
Zhang, Xu. "Fabrication, Characterization, and Application of Elastic Hydrophobic Electrospun Fiber Mats." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1481017775403681.
Повний текст джерелаArmani, Andre. "A influência da emissão sonora nos constituintes da lâmina própria da prega ventricular." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/17/17151/tde-20072016-093512/.
Повний текст джерелаThe vocal folds (VF) are unique structures, highly specialized in vibrating for sound production. This specialization is mainly due to a layered structure of the lamina propria (LP). This layered structure is not present at birth, and develops only after a several years of phonation. The LP of the mature vocal fold consists of three layers. The ventricular folds (VTF) are not originally vibrating structures for sound production, and in its LP the layers are poorly organized. It is not known what happens to the constituents of the LP in the VTF in subjects that use VTF vibration as a source of voice production. In the present study, the distribution and quantity of collagen and elastic fibers of the lamina propria from VTF of patients that use it as the main source of vibration for voice production were compared with the VTF from control subjects. Six individuals that used at least one of the VTF as source of vibration for sound production for minimum of six years were selected. A small fragment of VTF (0.5 cm2) used as vibration source of sound production was collected from each subject. The samples were processed for histological analysis. Collagen fibers were stained with Picrosirus Red and elastic fibers were stained with Weigert\'s Resorcin-Fuchsin. A total of 54 images were obtained from the superficial layer of the LP from each VTF for each stain. After image acquisition, collagen type I, III, total collagen and elastic fibers were quantified and compared with the VTF from the control group. Quantification was done using Image-Pro Plus software. Statistics were performed using an unpaired Student T test. The amount of total collagen in the most superficial layer of LP when the VTF was used as the source of vibration for the production of sound was significantly higher when compared to controls. The same result was seen for the amount of type I collagen in both groups. There was no difference in the quantity of type III collagen and elastic fibers between the two groups. Vibration of the VTF as a source of sound, for at least six years, leads to an increase in the amount of total collagen fibers and an increase in type I collagen, but does not increase the amount of type III collagen and elastic fibers in the most superficial layer of LP. These results may help elucidate the unique development of the lamina propria of the vocal fold
Gudienė, Devika. "Su amžiumi susiję žmogaus pamatinės arterijos struktūros pokyčiai." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080827_131740-59360.
Повний текст джерелаThe aim of the investigation was to examine and evaluate age-related structural changes in media of human basilar artery The main objectives of the thesis were as follows: 1. To examine the quantitative changes in the collagen fibres in media of basilar artery; 2. To evaluate the quantitative changes in muscular cells in the media of basilar artery; 3. To evaluate the quantitative changes in the elastic fibres in the media of basilar artery; 4. To evaluate the changes in the thickness of the tunica media; 5. To examine the structural changes in the human basilar artery intima and internal elastic membrane; 6. To assess the relation of different quantitative histological changes and to determine their correlation with age. Academic novelity of the investigation Cerebrovascular diseases cause huge mortality and disablement. Epidemiologic research has revealed that the morbidity and mortality rates due to cerebrovascular diseases tend to increase. We evaluated basilar artery wall structural changes occuring while ageing. Histomorphometrically analysed material enabled to evaluate general cerebral artery wall peculiarities related to age. We evaluated histomorphometrically quantitative changes of elastic and collagen fibres, muscular cells in ageing in different age groups. We also made analysis not only of elastic and collagen fibres area, but also of perimeter and number of fibres. We analyzed the changes in the thickness of the tunica media. We examined the structural... [to full text]
Ishiko, Toshihiro. "Chondroitinase injection improves keloid pathology by reorganizing the extracellular matrix with regenerated elastic fibers." Kyoto University, 2013. http://hdl.handle.net/2433/179347.
Повний текст джерелаMachado, Denise. "Caracterização do domínio da glicoproteína associada a microfibrila-1 (MAGP-1) com atividade pró-trombótica." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314065.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-16T09:01:31Z (GMT). No. of bitstreams: 1 Machado_Denise_M.pdf: 1404386 bytes, checksum: e811cae8e94f35d5b473fe2881261fd8 (MD5) Previous issue date: 2010
Resumo: Nos últimos anos, o principal objetivo de nosso laboratório é esclarecer a participação da GlicoProteína Associada a Microfibrila-1 (MAGP-1) na formação de trombos no modelo de trombose arterial fotoquímica. Dados indicam que a MAGP-1 não interage diretamente com as plaquetas, importante componente na trombose arterial, mas que, provavelmente, a MAGP-1 esteja interagindo com uma molécula que tenha participação neste processo. Neste sentido, a interação da MAGP-1 com moléculas importantes na formação do trombo foi estudada. A MAGP-1 tem a capacidade de interagir com o fator de von Willebrand, bem como com fibrinogênio e fibronectina. Além disto, foi verificado que a injeção da MAGP-1 recombinante em camundongos deficientes em MAGP-1 é capaz de reestabelecer o tempo normal de formação de trombos nestes animais. Considerando a ausência da MAGP-1 e seu efeito na formação de trombos, foi questionado se a morfologia dos trombos obtidos em camundongos deficientes em MAGP-1 era diferente dos trombos obtidos em camundongos selvagens. Dados iniciais sugeriam que os trombos de camundongos deficientes em MAGP-1 apresentavam ultraestrutura diferente, onde um número maior de plaquetas apresentavam aparentemente, os seus grânulos e corpos densos intactos, sugerindo uma ativação ineficiente na ausência de MAGP-1. No presente trabalho, além de análise ultraestrutural mais detalhada, foram feitos estudos para determinar qual a região da MAGP-1 é responsável pela atividade trombogênica. Neste sentido, proteínas mutadas, truncadas e peptídeos derivados da MAGP-1 foram obtidos e então injetados nos camundongos selvagens e deficientes em MAGP-1. Como resultados, pudemos observar que os trombos dos camundongos selvagens bem como dos camundongos deficientes em MAGP-1 apresentam basicamente a mesma morfologia, levando em consideração as técnicas utilizadas, microscopia eletrônica de transmissão e varredura. Em relação ao mapeamento dos domínios, quando utilizada a molécula inteira, seja de camundongo, seja bovina, o tempo normal de oclusão foi reestabelecido. A injeção da forma truncada da região carboxiterminal foi suficiente para obter este mesmo resultado que está principalmente relacionado a um peptídeo também determinado. O mecanismo pelo qual este peptídeo atua normalizando o tempo de oclusão normal ainda não é conhecido e será objeto de estudos futuros
Abstract: In the last years, the main purpose of our laboratory has been to clarify the participation of the Microfibril-Associated GlycoProtein-1 (MAGP-1) in forming thrombus in photochemically-induced artery thrombosis model. It was considered that MAGP-1 does not interact directly with platelets, important component in artery thrombosis and probably MAGP-1 is interacting with a molecule which has participation in this process. In this sense, the interaction of the MAGP-1 with important molecules in the thrombus formation was studied. The MAGP-1 has the ability to interact with von Willebrand factor, as well as with fibrinogen and fibronectin. In addition, it was verified that the injection of recombinant MAGP-1 in MAGP-1-deficient mice was able to restores normal time of thrombus formation in these animals. Considering the MAGP-1 absence and its effect on the thrombi formation, it was questioned whether thrombi morphology obtained from MAGP-1-deficient mice was different from thrombi obtained from wild-type mice. Initial data suggested that the thrombi from MAGP-1-deficient mice had different structure, where platelets apparently showed their intact granules and dense bodies, suggesting an inefficient activation in the MAGP-1 absence. In this work, besides the ultra-structural analysis, more detailed studies have been made to determine which region of the MAGP-1 is responsible for the thrombogenic activity. In this sense, truncated proteins, mutated proteins and peptides, were obtained and then injected into MAGP-1-deficient mice to verify their activities. As result, we noticed that the thrombi have similar structure taking into consideration used techniques, scanning electron microscopy and transmission electron microscopy. Furthermore, in relation to MAGP-1 mapping domains studies when we inject recombinant full-length molecule either mice or bovine, the normal time occlusion was restored. The injection of carboxy-terminal region was enough to get this same result what is mainly related to an also determined peptide. Mechanisms involved in this process are unknown and will be our aim in the future studies
Mestrado
Bioquimica
Mestre em Biologia Funcional e Molecular
Edginton, Ryan Stuart. "The multiscale biomechanics and mechanochemistry of the extracellular matrix protein fibres, collagen & elastin." Thesis, University of Exeter, 2018. http://hdl.handle.net/10871/34619.
Повний текст джерелаKorkmaz, Ayşe Hilal Usal Melek. "Fiber takviyeli elastik malzemelerin sürekli ortam hasar mekaniğine dayalı bünye denklemlerinin modellenmesi /." Isparta : SDÜ Fen Bilimleri Enstitüsü, 2009. http://tez.sdu.edu.tr/Tezler/TF01328.pdf.
Повний текст джерелаParietti, Lucie. "Micromechanical finite element model for constitutive elastoplastic analysis of unidirectional fiber-reinforced composites." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06232009-063447/.
Повний текст джерелаSimpson, Andreja. "Fibulin-4 mutations in cutis laxa." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/fibulin4-mutations-in-cutis-laxa(fcf5936a-e6a4-42a0-b58a-a16876b0f01f).html.
Повний текст джерелаLorion, Chloé. "Développement, caractérisation et potentiels thérapeutiques d’Elactiv’, une protéine élastique biomimétique, inspirée de la tropoélastine humaine." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10312/document.
Повний текст джерелаElastin-like peptides are excellent examples of biomimetic polymers recently proposed in regenerative medicine, particularly for soft tissue engineering (skin, blood vessels, lung ...) for which modeling is a complex task requiring functional elasticity to insctruct cells properelly. Fine-tuning of ELP’s primary structure can modulate or improve physicochemical, structural and functional properties of the native protein. In addition, the adjustment of ELP physicochemical characteristics through external stimuli (temperature, pH) defined them as intelligent polymers. These bioactive polymers thus provide a wide range of very promising applications in tissue engineering and drug delivery, although this has been under-explored until then. In this thesis, we have developed, characterized and evaluated therapeutic potentials of Elactiv', a synthetic elastic protein inspired by the unique structure of the human tropoelastin, the soluble precursor of elastin. Elactiv’ retains physicochemical characteristics (thermoresponsive behavior, self-assembly properties) and biological functions of the native protein (proliferation, differentiation and survival of human keratinocytes and dermal fibroblasts, susceptibility to enzymatic degradation). Besides, Elactiv’ is able to incorporate into neosynthesized elastic fibers by healthy dermal fibroblasts, and to induce fibrillar tropoelastin synthesis by pathological fibroblasts, Williams-Beuren syndrome, which do not synthesize or very few elastic fibres. A hydrogel formed exclusively of Elactiv’ allowed to access to mechanical properties of the scaffold and to verify its biocompatibility in vitro and its safety and resorption in vivo. Finally, the association of Elactiv' protein to poly(L-lysine) dendrigrafts, highly functionalizable synthetic polymers, enabled to evolve the hydrogel's architecture to a hybrid biomaterial in order to increase its mechanical and biological properties for skin tissue engineering. Taken together, biomimetic and therapeutic potentials of Elactiv' protein make it a promising candidate for soft tissue regeneration
Tsarouchas, Dimitris. "Fibre network materials : architecture and effective linear elastic properties." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610878.
Повний текст джерелаNoda, Kazuo. "Latent TGF-β binding protein 4 promotes elastic fiber assembly by interacting with fibulin-5". Kyoto University, 2013. http://hdl.handle.net/2433/179349.
Повний текст джерелаCai, Liang-Wu 1965. "Full-scale simulation of multiple scattering of elastic waves in fiber reinforced composites." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9573.
Повний текст джерелаStarkey, Carl Alan. "Analysis of the Failure Modes of Twisted Fiber Structures." Marietta College Honors Theses / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=marhonors1210352501.
Повний текст джерелаSaville, Charis Rowan. "Hormonal modulation of ageing skin microstructure and mechanical properties." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/hormonal-modulation-of-ageing-skin-microstructure-and-mechanical-properties(fa635be5-a695-4b7a-989a-43db3868237b).html.
Повний текст джерелаCaptain, V. S. "The effect of inextensibility on elastic surface and interfacial waves." Thesis, University of East Anglia, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378895.
Повний текст джерелаKondo, Yasuhiro. "Measurement of Σ-p Elastic Scattering Cross Sections with a Scintillating-Fiber Active Target". 京都大学 (Kyoto University), 2000. http://hdl.handle.net/2433/151663.
Повний текст джерелаCaselman, Elijah. "Elastic property prediction of short fiber composites using a uniform mesh finite element method." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5036.
Повний текст джерелаThe entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on March 19, 2008) Includes bibliographical references.
Middleton, Joseph Ervin. "Elastic property prediction of long fiber composites using a uniform mesh finite element method." Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5684.
Повний текст джерелаThe entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 13, 2009) Includes bibliographical references.
Darya, zadeh S., and G. I. Lvov. "A new numerical method for determination of effective elastic constants in a composite with 3D orthogonal nonwoven fibers." Thesis, НТУ "ХПИ", 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/25080.
Повний текст джерелаWalton, Lucy Anne. "From molecules to tissues : characterising the relationship between structure and function in ageing arteries." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/from-molecules-to-tissues-characterising-the-relationship-between-structure-and-function-in-ageing-arteries(b06aab9a-6845-41d2-ac97-0aac85e71e1a).html.
Повний текст джерелаMasri, Haji Mohammad Khairul Ja'afar Awang Haji. "Elastic properties and local buckling of pultruded fibre reinforced plastic profiles." Thesis, Cardiff University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.548179.
Повний текст джерелаBoizot, Jérémy. "Modélisation de la plaie chronique : contrôle de la formation de fibres élastiques en conditions hypoxiques." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10111.
Повний текст джерелаDoué, Manon. "Rôle de la carbamylation des protéines matricielles dans l’altération des propriétés de la paroi vasculaire : application à l'anévrysme aortique." Thesis, Reims, 2019. http://www.theses.fr/2019REIMS042.
Повний текст джерелаNonenzymatic post-translational modifications of proteins, such as glycation or carbamylation, alter their structural and functional properties, and result in their molecular aging. The carbamylation reaction corresponds to the binding of cyanate, mainly derived from urea, to the amino groups of proteins. Several studies have demonstrated a link between protein carbamylation and cardiovascular complications. The aim of this work was to determine how carbamylation of matrix proteins could participate in the modification of the mechanical properties of the vascular wall and in the development of aortic aneurysm. Our experiments show that vascular matrix proteins, including elastin, are carbamylated. Although fiber morphology is unchanged, carbamylated elastin is more sensitive to pancreatic elastase degradation. The increased carbamylation rate of aortic matrix proteins in a murine model fed with water supplemented with cyanate leads to an increased stiffness of elastic fibers, as evaluated by atomic force microscopy, which is associated with an increase of pulse wave velocity. Cyanate-diet mice have less frequently aortic aneurysms and a smaller proportion of aneurysm ruptures. Finally, in vitro carbamylated proteins are able to stimulate the migration of vascular smooth muscle cells and to induce an oxidative stress. These results suggest that the carbamylation of matrix proteins participates in the remodeling of the vascular wall and leads to the alteration of its mechanical properties
Mera, S. L. "The composition and integrity of elastic fibres in health and disease : A morphological and histochemical study." Thesis, University of Bristol, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373832.
Повний текст джерелаBispo, Rodrigo Freitas Monte. "Efeitos do extrato etanólico da Himatanthus bracteatus e Ocotea longifolia nas fibras elásticas e túnica média da aorta de camundongos C57BL6J em um modelo de aterosclerose experimental." Universidade Federal de Alagoas, 2016. http://www.repositorio.ufal.br/handle/riufal/1772.
Повний текст джерелаA aterosclerose é responsável pelo maior índice de morbidade e mortalidade que ocorre no mundo. Esta doença ocorre inicialmente através do acúmulo de colesterol e proliferação de células musculares lisas no endotélio, que leva a sua inflamação, endurecimento e espessamento da parede das artérias. No Brasil, o Ministério da Saúde regulamentou a proposta de Política Nacional de Práticas Integrativas e Complementares no Sistema Único de Saúde, que incentiva a pesquisa e o desenvolvimento de medicamentos fitoterápicos a partir de plantas medicinais. A Himatanthus bracteatus pesquisas mostraram ação no ácido araquidônico em ratos e uma potente atividade analgésica e antiinflamatória e antitumoral, já a Ocotea longifolia foram encontradas evidências de atividade antimibacteriana com eficácia na inibição COX-1, COX-2. Sendo assim é relevante verificar a eficácia dos extratos etanólicos da Himatanthus bracteatus e Ocotea longifolia na espessura da túnica média e nas fibras elásticas na parte descendente da aorta de camundongos C57BL6J. Os objetivos foram verificar a espessura da túnica média e percentual de fibras elásticas da parte descendente da artéria aorta de camundongos induzidos a aterosclerose experimental. Foi um estudo experimental em animais por 42 dias. Os animais foram camundongos C57BL6J, submetidos a dieta aterosclerótica (1,25% de colesterol, 0,5% de ácido cólico e gordura de 15%).Os animais foram divididos em 7 grupos: grupo C (controle 1mL de soro fisiológico 0,9%, n=7), grupo H (hiperlipidêmico 1,25% de colesterol, 0,5% de ácido cólico e gordura de 15%, n=7), grupo HT25 (Himatanthus bracteatus 25mg/mL, n=7), grupo HT12,5 (Himatanthus bracteatus 12,5mg/mL, n=7), grupo OT25 (Ocotea longifolia 25mg/mL, n=7), grupo OT12,5 (Ocotea longifolia 12,5mg/mL, n=7) e grupo R (rosuvastatina 0,27mg/mL, n=7) total de 49 animais. As variáveis primárias foram a média da espessura da tunica média e percentual de fibras elásticas da parte descendente da aorta. Variáveis secundárias foram: colesterol total, HDL, LDL, triglicerídeos, massa corpórea, peso do coração, glicemia, expressão dos marcadores TNF-α, CD-68 e isoprostano. A análise estatística foi realizada usando como ferramenta software GraphPad Prism (versão 5.0), os dados desta análise foram expressos em média, desvio padrão e erro padrão. Para os resultados que não seguiram a distribuição normal foi utilizado o teste de KRUSKAL-WALLIS e o pós-teste DUNNS. Para comparações entre os grupos será utilizado o ANOVA one-way e o pós-teste de TUKEY para os dados que seguem a distribuição normal. Foi calculado o intervalo de confiança de 95% para cada ponto estimado. Os extratos etanólicos da Himatanthus bracteatus e Ocotea longifolia reduziram de forma significante a espessura da túnica média da parte descendente da aorta, contudo não houve diferença significante no percentual de fibras elásticas. Os extratos obtiveram redução significante dos parâmetros sanguíneos: colesterol total, LDL, triglicerídeos e através da análise imunohistoquímica do TNF-α, CD-68 e isoprostano.