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

Estudo comparativo do preparo do canal radicular de dentes artificiais utilizando diferentes técnicas automatizadas de instrumentação

Camargo, José Maurício Paradella de [UNESP] 04 March 2004 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-03-04Bitstream added on 2014-06-13T21:02:37Z : No. of bitstreams: 1 camargo_jmp_dr_arafo.pdf: 622434 bytes, checksum: e10a27eeda1607b463fd51b6ce1ff55c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Foram avaliados comparativamente três sistemas de técnicas automatizadas de preparo dos canais radiculares, Endo-Eze, K3 e Race. Neste trabalho, foram utilizados 30 pré-molares artificiais, confeccionados em resina, com canais radiculares únicos, com curvatura de quarenta graus. Para a avaliação do preparo dos canais radiculares, os dentes foram divididos em três grupos, incluídos em blocos de resina e seccionados no terço apical das raízes. As secções das raízes foram fotografadas antes e após a instrumentação de forma padronizada e as imagens transferidas para o computador que procedeu às análises comparativas. A avaliação baseou-se na extensão do deslocamento, na direção do movimento do centro do canal radicular e na área desgastada. Em relação ao preparo dos canais, os sistemas Endo-Eze e K3, apresentaram um deslocamento do centro do canal radicular maior do que o sistema Race. Menores valores de desgaste foram observados para o sistema Race, seguido dos sistemas K3 e Endo-Eze. Os dentes utilizados neste estudo mostraram-se eficazes na avaliação de diferentes técnicas de instrumentação. / Three different systems of automated instrumentation techniques of root canal preparation were evaluated, Endo-Eze, K3 and Race. Thirty single rooted artificial resin pre-molars were manufacture with an apical curvature of 40-degree angle each. For the evaluation of the root canal preparation, the artificial teeth were divide in three groups, included in resin blocks and sectioned at the apical third. The sections were photographed before and after the instrumentation on a standardize way and the images obtained were transferred to a computer for the comparative analysis. The evaluation was based on the extension of canal displacement, the direction of the canal center movement and at the removed area. Concerning the root canal preparations, the Endo-Eze and K3 systems presented a bigger deviation of the center of the original root canal bigger them the Race system. Lower values for the Race system were observed fallowed by the K3 and Endo-Eze. The artificial teeth utilized in this study were efficient for the evaluation of different automated instrumentation techniques.
2

Estudo comparativo do preparo do canal radicular de dentes artificiais utilizando diferentes técnicas automatizadas de instrumentação /

Camargo, Maurício. January 2004 (has links)
Orientador: Renato de Toledo Leonardo / Banca: Idomeo Bonetti Filho / Banca: Roberto Miranda Esberard / Banca: Manoel Eduardo de Lima Machado / Banca: Carlos Alberto Ferreira Murgel / Resumo: Foram avaliados comparativamente três sistemas de técnicas automatizadas de preparo dos canais radiculares, Endo-Eze, K3 e Race. Neste trabalho, foram utilizados 30 pré-molares artificiais, confeccionados em resina, com canais radiculares únicos, com curvatura de quarenta graus. Para a avaliação do preparo dos canais radiculares, os dentes foram divididos em três grupos, incluídos em blocos de resina e seccionados no terço apical das raízes. As secções das raízes foram fotografadas antes e após a instrumentação de forma padronizada e as imagens transferidas para o computador que procedeu às análises comparativas. A avaliação baseou-se na extensão do deslocamento, na direção do movimento do centro do canal radicular e na área desgastada. Em relação ao preparo dos canais, os sistemas Endo-Eze e K3, apresentaram um deslocamento do centro do canal radicular maior do que o sistema Race. Menores valores de desgaste foram observados para o sistema Race, seguido dos sistemas K3 e Endo-Eze. Os dentes utilizados neste estudo mostraram-se eficazes na avaliação de diferentes técnicas de instrumentação. / Abstract: Three different systems of automated instrumentation techniques of root canal preparation were evaluated, Endo-Eze, K3 and Race. Thirty single rooted artificial resin pre-molars were manufacture with an apical curvature of 40-degree angle each. For the evaluation of the root canal preparation, the artificial teeth were divide in three groups, included in resin blocks and sectioned at the apical third. The sections were photographed before and after the instrumentation on a standardize way and the images obtained were transferred to a computer for the comparative analysis. The evaluation was based on the extension of canal displacement, the direction of the canal center movement and at the removed area. Concerning the root canal preparations, the Endo-Eze and K3 systems presented a bigger deviation of the center of the original root canal bigger them the Race system. Lower values for the Race system were observed fallowed by the K3 and Endo-Eze. The artificial teeth utilized in this study were efficient for the evaluation of different automated instrumentation techniques. / Doutor
3

Mesure in vivo de la mécanique cellulaire lors de la morphogénèse d'un tissu

Blanc, Olivier 31 May 2013 (has links)
Pendant le développement d'un organisme, les tissus subissent, génèrent des changements morphologiques drastiques nécessaires à l'obtention d'une forme finale ou intermédiaire spécifique et fonctionnelle. On comprend cette acquisition de formes comme un phénomène émergent résultant de l'interaction mécanique entre toutes les cellules composant le tissu. On sait que les structures de protéines du cytosquelette sont capables aussi bien de générer des forces ou de changer les propriétés mécaniques des cellules i.e de changer la réaction de celles-ci à un stress mécanique. Ces phénomènes émergents font l'objet de nombreuses études et mesures aussi bien lors d'expériences in vitro (solution de protéines purifiées) que sur cellules de cultures. Le travail décrit dans cette thèse s'est attaché à mesurer quantitativement les forces et propriétés mécaniques in vivo durant le développement d'un organisme. À terme, ces mesures sont utiles à l'élaboration d'un modèle mécanique qui amènerait une meilleure compréhension des phénomènes morphogénétiques.Pour réaliser ces mesures, un banc de mesures optiques a été développé. Il permet de réaliser des mesures de microrhéologie passives et actives durant l'extension de la bandelette germinale de l'embryon de drosophile. Des mesures quantitatives de viscosité, de raideur et de force jonctionnelle ont été réalisées. / Pendant le développement d'un organisme, les tissus subissent, génèrent des changements morphologiques drastiques nécessaires à l'obtention d'une forme finale ou intermédiaire spécifique et fonctionnelle. On comprend cette acquisition de formes comme un phénomène émergent résultant de l'interaction mécanique entre toutes les cellules composant le tissu. On sait que les structures de protéines du cytosquelette sont capables aussi bien de générer des forces ou de changer les propriétés mécaniques des cellules i.e de changer la réaction de celles-ci à un stress mécanique. Ces phénomènes émergents font l'objet de nombreuses études et mesures aussi bien lors d'expériences in vitro (solution de protéines purifiées) que sur cellules de cultures. Le travail décrit dans cette thèse s'est attaché à mesurer quantitativement les forces et propriétés mécaniques in vivo durant le développement d'un organisme. À terme, ces mesures sont utiles à l'élaboration d'un modèle mécanique qui amènerait une meilleure compréhension des phénomènes morphogénétiques.Pour réaliser ces mesures, un banc de mesures optiques a été développé. Il permet de réaliser desmesures de microrhéologie passives et actives durant l'extension de la bandelette germinale de l'embryon de drosophile. Des mesures quantitatives de viscosité, de raideur et de force jonctionnelle ont été réalisées.
4

Recherche de matière noire, observation du centre galactique avec H.E.S.S.et modernisation des caméras de H.E.S.S. I / Search for dark matter, Galactic Center observation with H.E.S.S. and upgrade of the H.E.S.S. I camera

Lefranc, Valentin 29 June 2016 (has links)
Le réseau de 5 télescopes Tcherenkov au sol H.E.S.S. (High Energy Stereoscopic System) permet de détecter des rayons gamma à très hautes énergies (E>50GeV) pour sonder les phénomènes non thermiques les plus violents de l'univers. Ces rayons gamma peuvent provenir de l'annihilation de particules de matière noire. L'astronomie gamma permet donc de rechercher les signatures de l'annihilation de particules de matière noire dans les régions denses de l'univers. Cette thèse est composée de trois parties. Après un bref rappel sur l'instrument H.E.S.S., sont présentés en premier lieu les tests de performance effectués pour l'étalonnage de la nouvelle électronique utilisée pour la modernisation des caméras des quatre télescopes CT1 à 4. L'analyse des premières données de la caméra CT1 modernisée montre la réduction du temps mort de lecture du réseau qui permettra de bénéficier pleinement de la stéréoscopie entre les 5 télescopes du réseau. La deuxième partie de la thèse traite des 10 ans d'observations de la région du Centre Galactique avec H.E.S.S. ainsi que les récentes observations obtenues avec l'ajout en 2012 du télescope de 28 mètres de diamètre (CT5) au centre du réseau. L'analyse des données de CT5 en direction de la source centrale HESS J1745-290 permet d'avoir accès aux événements aux plus basses énergies accessibles avec H.E.S.S. (100 GeV). Le spectre de la source centrale est en très bon accord avec celui de HESS J1745-290 mesuré avec CT1-4 et les données en dessous de 150 GeV permettent de raccorder ce dernier à celui de la source Fermi 3FGHL J1745.6-2859c.Dans la troisième partie, les 10 ans de données dans la région du Centre Galactique avec la première phase de H.E.S.S sont analysés pour rechercher un signal d'annihilation de matière noire à l'aide d'une méthode de vraisemblance utilisant les caractéristiques spectrale et spatiale du signal de matière noire par rapport à celles du bruit de fond. En l'absence de signal matière noire, les contraintes sont calculées sur la section efficace d'annihilation et, pour la première fois, un réseau de télescope Tcherenkov au sol est capable de sonder la section efficace d'annihilation thermique dans le cas d'un profil de matière noire piqué. La sensibilité sur la section efficace d'annihilation de l'instrument H.E.S.S. utilisant CT5 est ensuite présentée vers le Centre Galactique et la galaxie naine récemment découverte Reticulum II. La dernière partie de cette thèse étudie le potentiel du futur réseau de télescopes Tcherenkov CTA, (Cherenkov Telescope Array) pour la détection d'un signal d'annihilation de matière noire. Vers la région du Centre Galactique le signal de matière noire attendu est significativement augmenté par la contribution de rayons gamma produits par effet Compton inverse d'électrons et positrons énergétiques sur les champs de radiation ambiants. La sensibilité obtenue permet à CTA de sonder la section efficace d'annihilation thermique dans tous les canaux d'annihilation dans le cas d’un profil de matière noire piqué. L’impact sur la sensibilité de CTA des erreurs systématiques et de l’émission diffuse mesurée par Fermi est aussi montré. Dans le cas des galaxies naines satellites de la Voie Lactée, les performances de CTA permettent de les considérer comme des objets spatialement étendus, et d'obtenir une sensibilité compétitive avec celle du Centre Galactique dans le cas d’un profil à cœur de plusieurs kpc. Dans le cas d'un signal de matière noire de type ligne, CTA sera capable de contraindre fortement des modèles spécifiques de matière noire au TeV grâce à l'effet Sommerfeld, comme le Wino et le MDM-5plet. / The ground-based Cherenkov telescope array H.E.S.S. (High Energy Stereoscopic System) is able to detect gamma rays at very high energies (E> 50GeV) to probe the most violent non-thermal phenomena in the universe. These gamma rays can also come from dark matter particle annihilation. Gamma-ray astronomy provides a promising avenue to search for signatures of these annihilations in overdense regions of the universe. This thesis is composed of three parts. After a brief reminder of the H.E.S.S. instrument, the performance tests to calibrate the new electronics used for the modernization of the four cameras CT1-4 telescopes are presented. The analysis of the upgraded camera raw data shows a reduction global array dead time allowing to maximize the benefit of the stereoscopy between the 5 telescopes. The second part of the thesis deals with 10 years of observations of the Galactic Center region with H.E.S.S. and recent observations taken with the 28-meter-diameter telescope (CT5) located at the center of the array. The data analysis towards the central source HESS J1745-290 provides access to events at lower energies (100 GeV). The spectrum of the central source is in very good agreement with the one of HESS J1745-290 measured with CT1-4 and data below 150 GeV enable to connect it to the Fermi 3FGHL J1745.6-2859c source spectrum. In the third part, the 10 years of data in the region of the Galactic Centre with the first phase of H.E.S.S. are scanned for a dark matter annihilation signal using a likelihood method using the spectral and spatial characteristics of the dark matter signal compared to background. No dark matter signal is detected. The constraints are calculated on the annihilation cross section and, for the first time, a ground-based Cherenkov telescope array is capable to probe the thermal cross section in the case of a cuspy dark matter profile. The sensitivity of the annihilation cross section of the H.E.S.S. instrument using CT5 is then presented toward the Galactic Center and the recently discovered dwarf galaxy Reticulum II. The last part of the thesis studies the potential of the future ground-based instrument CTA (Cherenkov Telescope Array) for the detection of dark matter annihilation signal. Towards the Galactic Center region, the expected dark matter signal is significantly increased by the contribution of gamma rays produced by inverse Compton process of energetic electrons and positrons on ambient radiation fields. The sensitivity obtained enables CTA to probe the thermal cross section in all annihilation channels for a cuspy dark matter profile. The impact on CTA sensitivity of systematic errors and diffuse emission measured by Fermi is also shown. In the case of dwarf galaxy satellites of the Milky Way, the CTA performances enable to consider them as extended objects and provide a competitive sensitivity with the Galactic Centre sensitivity for a kpc-core profile. In the case of a line signal, CTA will be able to strongly constrain specific TeV dark matter models through the Sommerfeld effect, as Wino and MDM-5plet.
5

Instrumentação ultra-sônica subgengival irrigada com óleos essenciais em bolsas residuais: ensaio clínico aleatório / Subgingival ultrasonic instrumentation irrigated with essential oils in residual pockets randomized controlled trial

Feng, Hsu Shao 16 November 2009 (has links)
O objetivo desse estudo foi avaliar o efeito clínico da instrumentação ultra-sônica subgengival irrigada com óleos essenciais na redução de bolsas periodontais em sítios 5mm após a reavaliação. Para tanto foi conduzido um ensaio clínico aleatório, duplo-cego, paralelo e controlado com placebo. Foram convidados para participar deste estudo 64 indivíduos com periodontite crônica. Os pacientes foram aleatoriamente alocados para grupo teste (irrigação com óleos essenciais contendo Timol 0,064%, Eucaliptol 0,092% Salicilato de Metila 0,06%, Mentol 0,042% e Álcool 21,6%) ou controle (irrigação com placebo, solução alcoolica 21%). Foram avaliados os parâmetros clínicos profundidade clínica de sondagem (PCS), nível clínico de inserção (NCI), retração da margem gengival (R), sangramento à sondagem (SS) e índice de placa (IP) no início e 4, 12 e 24 semanas após. O indivíduo foi considerado a unidade estatística. As diferenças entre os grupos e as alterações ao longo do tempo foram analisadas de acordo com um modelo linear generalizado (análise de variância de medidas repetidas). Houve redução significativa de PCS (1,59mm teste e 1,16mm controle) e SS (44,4% teste e 52,62% controle) e ganho em NCI (1,15mm teste e 0,91mm controle) nos dois grupos (p<0,001). No entanto, não houve diferenças entre os grupos ao final do estudo. Quando foram analisadas apenas as bolsas com PCS inicial >7mm observou-se redução significativa na PCS no grupo teste (1,60mm, p = 0,004) e controle (1,10mm, p = 0,0008) e ganho de NCI significativo no grupo teste apenas (teste: 1,59mm, p<0,001; controle: 0,71mm, p=0,051), sendo que houve diferença significativa entre os grupos após 24 semanas (p=0,02). Concluiu-se que a instrumentação ultra-sônica subgengival em bolsas residuais promoveu redução significativa em PCS, SS e ganho significativo de NCI. Além disso, o uso de óleos essenciais como agente irrigante promoveu benefícios adicionais em ganho de NCI em bolsas > 7mm, quando comparado com o grupo controle. / The aim of this study was to evaluate the clinical effect of ultrasonic instrumentation irrigated with essential oils in the reduction of sites with a probing depth of 5 mm or more. For this purpose, a randomized, double-blind, parallel-arm and placebocontrolled clinical trial was conducted. Sixty-four individuals with chronic periodontitis were invited to participate in this study. The patients were randomly allocated to the test group (irrigation with essential oils containing 0.064% Thymol, 0.092% Eucalyptol, 0.06% Methyl Salicylate, 0.042% Menthol and 21.6% Alcohol) or control (irrigation with placebo, 21% alcoholic solution). Probing pocket depth (PD), clinical attachment level (CAL), gingival recession (R), bleeding on probing (BOP) and plaque index (PI) were assessed. The individual was considered the statistical unit. The differences between the groups and the alterations over the course of time were analyzed according to a generalized linear model (repeated measures analysis of variance). There was a significant reduction in PD (1.59mm test and 1.16mm control) and BOP (44.4% test and 52.62% control) and CAL gain (1.15mm test and 0.91mm control) in both groups (p<0.001). However, there was no difference between groups at the end of the trial. When sites with PD >7mm at baseline were analyzed, a significant reduction in PD was observed in test (1.60mm, p = 0.004) and control groups (1.10mm, p = 0.0008), as well as a significant gain in CAL in test group only (test: 1.59mm, p<0.001; control: 0.71mm, p=0.051). There was a significant difference between the groups after 24 weeks (p=0.02). It was concluded that subgingival ultrasonic instrumentation in residual pockets promoted reduction in PPD, BOP and gain in CAL. Besides, adjunctive irrigation with essential oils promoted additional benefits in gain of CAL in sites with initial pockets > 7mm, when compared to test group.
6

Instrumentação ultra-sônica subgengival irrigada com óleos essenciais em bolsas residuais: ensaio clínico aleatório / Subgingival ultrasonic instrumentation irrigated with essential oils in residual pockets randomized controlled trial

Hsu Shao Feng 16 November 2009 (has links)
O objetivo desse estudo foi avaliar o efeito clínico da instrumentação ultra-sônica subgengival irrigada com óleos essenciais na redução de bolsas periodontais em sítios 5mm após a reavaliação. Para tanto foi conduzido um ensaio clínico aleatório, duplo-cego, paralelo e controlado com placebo. Foram convidados para participar deste estudo 64 indivíduos com periodontite crônica. Os pacientes foram aleatoriamente alocados para grupo teste (irrigação com óleos essenciais contendo Timol 0,064%, Eucaliptol 0,092% Salicilato de Metila 0,06%, Mentol 0,042% e Álcool 21,6%) ou controle (irrigação com placebo, solução alcoolica 21%). Foram avaliados os parâmetros clínicos profundidade clínica de sondagem (PCS), nível clínico de inserção (NCI), retração da margem gengival (R), sangramento à sondagem (SS) e índice de placa (IP) no início e 4, 12 e 24 semanas após. O indivíduo foi considerado a unidade estatística. As diferenças entre os grupos e as alterações ao longo do tempo foram analisadas de acordo com um modelo linear generalizado (análise de variância de medidas repetidas). Houve redução significativa de PCS (1,59mm teste e 1,16mm controle) e SS (44,4% teste e 52,62% controle) e ganho em NCI (1,15mm teste e 0,91mm controle) nos dois grupos (p<0,001). No entanto, não houve diferenças entre os grupos ao final do estudo. Quando foram analisadas apenas as bolsas com PCS inicial >7mm observou-se redução significativa na PCS no grupo teste (1,60mm, p = 0,004) e controle (1,10mm, p = 0,0008) e ganho de NCI significativo no grupo teste apenas (teste: 1,59mm, p<0,001; controle: 0,71mm, p=0,051), sendo que houve diferença significativa entre os grupos após 24 semanas (p=0,02). Concluiu-se que a instrumentação ultra-sônica subgengival em bolsas residuais promoveu redução significativa em PCS, SS e ganho significativo de NCI. Além disso, o uso de óleos essenciais como agente irrigante promoveu benefícios adicionais em ganho de NCI em bolsas > 7mm, quando comparado com o grupo controle. / The aim of this study was to evaluate the clinical effect of ultrasonic instrumentation irrigated with essential oils in the reduction of sites with a probing depth of 5 mm or more. For this purpose, a randomized, double-blind, parallel-arm and placebocontrolled clinical trial was conducted. Sixty-four individuals with chronic periodontitis were invited to participate in this study. The patients were randomly allocated to the test group (irrigation with essential oils containing 0.064% Thymol, 0.092% Eucalyptol, 0.06% Methyl Salicylate, 0.042% Menthol and 21.6% Alcohol) or control (irrigation with placebo, 21% alcoholic solution). Probing pocket depth (PD), clinical attachment level (CAL), gingival recession (R), bleeding on probing (BOP) and plaque index (PI) were assessed. The individual was considered the statistical unit. The differences between the groups and the alterations over the course of time were analyzed according to a generalized linear model (repeated measures analysis of variance). There was a significant reduction in PD (1.59mm test and 1.16mm control) and BOP (44.4% test and 52.62% control) and CAL gain (1.15mm test and 0.91mm control) in both groups (p<0.001). However, there was no difference between groups at the end of the trial. When sites with PD >7mm at baseline were analyzed, a significant reduction in PD was observed in test (1.60mm, p = 0.004) and control groups (1.10mm, p = 0.0008), as well as a significant gain in CAL in test group only (test: 1.59mm, p<0.001; control: 0.71mm, p=0.051). There was a significant difference between the groups after 24 weeks (p=0.02). It was concluded that subgingival ultrasonic instrumentation in residual pockets promoted reduction in PPD, BOP and gain in CAL. Besides, adjunctive irrigation with essential oils promoted additional benefits in gain of CAL in sites with initial pockets > 7mm, when compared to test group.
7

Modelo experimental e instrumentação para estudo da função do reticulo sarcoplasmatico no transporte de Ca 2+ no coração / Experimental model and instrumentation for the study of sarcoplasmic reticulum Ca 2+ transport in the heart

Soriano, Diogo Coutinho 20 June 2007 (has links)
Orientadores: Jose Wilson Magalhães Bassani, Rosana Almada Bassani / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-09T15:25:46Z (GMT). No. of bitstreams: 1 Soriano_DiogoCoutinho_M.pdf: 3276695 bytes, checksum: c47b4ce326955b65ff10f5c2891b25c2 (MD5) Previous issue date: 2007 / Resumo: No presente trabalho foi desenvolvido um instrumento capaz de quantificar de forma simultânea o encurtamento celular e a concentração citosólica de Ca2+ ([Ca2+]i), utilizando o indicador fluorescente fluo-3. A instrumentação foi aplicada para estudar o papel da ATPase de Ca2+ do RS (SERCA, principal transportador responsável pelo relaxamento celular e pela reposição do estoque de Ca2+ intracelular) na remoção de Ca2+ do citosol em miócitos cardíacos isolados de rato, o que exigiu o desenvolvimento de um protocolo experimental específico. O protocolo experimental desenvolvido consistiu em tornar inoperante o principal competidor da SERCA pelo Ca2+ citosólico, o trocador Na+/Ca2+ (NCX), pela perfusão da célula com solução sem Ca2+ e sem Na+. Nesta situação, considera-se que os demais transportadores de Ca2+ (ATPase de Ca2+ do sarcolema e uniporter mitocondrial de Ca2+) transportem o íon a uma taxa baixa demais para competir com a SERCA. A liberação do Ca2+ do RS foi induzida por pulsos rápidos de cafeína, e foram medidos a amplitude (?[Ca2+]i) e tempo para 50 % de queda (t1/2) dos transientes de [Ca2+]i na ausência e na presença de fármacos que afetam a taxa de captação de Ca2+ pela SERCA. Foram analisados os efeitos do agonista de receptores beta-adrenérgicos isoproterenol (ISO), que promove estimulação da SERCA, e de 2,5-di-(tert-butil) hydroquinona (tBQ), que atua como inibidor da enzima. ISO causou redução significativa do t1/2 de queda do [Ca2+]i (p< 0,01), sem alteração significativa de ?[Ca2+]i (p> 0,05). Já no caso do tBQ, foi observado um aumento significativo do t1/2 de queda do [Ca2+]i (p< 0,01) e redução da ?[Ca2+]i, (p< 0,05). Um modelo teórico da literatura foi adaptado para descrever matematicamente o modelo experimental proposto. As simulações com alterações nos parâmetros cinéticos da SERCA pelos fármacos (de acordo com dados da literatura) foram razoavelmente bem sucedidas em reproduzir os dados experimentais com relação ao tempo de remoção do Ca2+ do citosol. Portanto, foi apresentada aqui uma nova ferramenta experimental e teórica para estudar a captação de Ca2+ pela SERCA em miócitos cardíacos intactos / Abstract: The goal of this work was to develop an instrument for simultaneous measurement of cell shortening and cytosolic Ca2+ concentration ([Ca2+]i), by using the fluorescent Ca2+ indicator fluo-3. The instrument was applied to study the uptake of cytosolic Ca2+ by the sarcoplasmic reticulum (RS) Ca2+- ATPase (SERCA, the main transporter responsible for cell relaxation in intact isolated rat ventricular myocytes). For this purpose, the development of a specific experimental protocol was required. In this protocol, the main competitor of SERCA by cytosolic Ca2+, the Na+/Ca2+ exchanger (NCX), was disabled by removal of extracellular Ca2+ and Na+. In this situation, it may be assumed that the other Ca2+ transporters (sarcolemmal Ca2+-ATPase and mitochondrial Ca2+ uniporter) are too slow to compete with SERCA. SR Ca2+ release was induced by short, rapid caffeine pulses, and the amplitude (?[Ca2+]i) and time for 50% [Ca2+]i decline (t1/2) of the resulting [Ca2+]I transients were measured in the absence and in the presence of drugs that affect the rate of SR Ca2+ uptake by SERCA, namely the beta-adrenergic receptor agonist isoproterenol (ISO), which causes increase in SERCA activity, and 2,5-di-(tert-butyl) hydroquinone (tBQ), which inhibits the enzyme. ISO caused significant reduction of t1/2 (p< 0,01), without any significant change in ?[Ca2+]i (p> 0,05). In case of tBQ, significant increase of t1/2 (p< 0,01) and reduction of ?[Ca2+]I (p< 0,05) were observed. A theoretical model (Tang & Othmer, 1994) was adapted for mathematical description of the experimental model proposed. Simulation of the effects of the drugs, in which SERCA kinetic parameters were changed according to data obtained from literature, were reasonably successful at reproducing the cytosolic [Ca2+]i kinetics observed experimentally / Mestrado / Engenharia Biomedica / Mestre em Engenharia Elétrica

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