269 resultados para Dentin tubule occlusion
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Xylella fastidiosa is the causal agent of citrus variegated chlorosis and Pierce's disease which are the major threat to the citrus and wine industries. The most accepted hypothesis for Xf diseases affirms that it is a vascular occlusion caused by bacterial biofilm, embedded in an extracellular translucent matrix that was deduced to be the exopolysaccharide fastidian. Fourier transform infrared spectroscopy analysis demonstrated that virulent cells which form biofilm on glass have low fastidian content similar to the weak virulent ones. This indicates that high amounts of fastidian are not necessary for adhesion. In this paper we propose a kinetic model for X fastidiosa adhesion, biofilm formation, and virulence based on electrostatic attraction between bacterial surface proteins and xylem walls. Fastidian is involved in final biofilm formation and cation sequestration in dilute sap. (C) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.
Resumo:
The effects of adrenergic stimulation on mean circulatory filling pressure (MCFP), central venous pressure (P-CV) and stroke volume (Vs), as well as the effects of altered MCFP through changes of blood volume were investigated in rattlesnakes (Crotalus durissus). MCFP is an estimate of the upstream pressure driving blood towards the heart and is determined by blood volume and the activity of the smooth muscle cells in the veins (venous tone). MCFP can be determined as the plateau in P-CV during a total occlusion of blood flow from the heart.Vs decreased significantly when MCFP was lowered by reducing blood volume in anaesthetised snakes, whereas increased MCFP through infusion of blood (up to 3 ml kg(-1)) only led to a small rise in Vs. Thus, it seems that end-diastolic volume is not affected by an elevated MCFP in rattlesnakes. To investigate adrenergic regulation on venous tone, adrenaline as well as phenylephrine and isoproterenol (alpha- and beta-adrenergic agonists, respectively) were infused as bolus injections (2 and 10 mu g kg(-1)). Adrenaline and phenylephrine caused large increases in MCFP and P-CV, whereas isoproterenol decreased both parameters. This was also the case in fully recovered snakes. Therefore, adrenaline affects venous tone through both alpha- and beta-adrenergic receptors, but the alpha-adrenergic receptor dominates at the dosages used in the present study. Injection of the nitric oxide donor SNP caused a significant decrease in P-CV and MCFP. Thus, nitric oxide seems to affect venous tone.
Resumo:
The spatial resolution improvement of orbital sensors has broadened considerably the applicability of their images in solving urban areas problems. But as the spatial resolution improves, the shadows become even a more serious problem especially when detailed information (under the shadows) is required. Besides those shadows caused by buildings and houses, clouds projected shadows are likely to occur. In this case there is information occlusion by the cloud in association with low illumination and contrast areas caused by the cloud shadow on the ground. Thus, it's important to use efficient methods to detect shadows and clouds areas in digital images taking in count that these areas care for especial processing. This paper proposes the application of Mathematical Morphology (MM) in shadow and clouds detection. Two parts of a panchromatic QuickBird image of Cuiab-MT urban area were used. The proposed method takes advantage of the fact that shadows (low intensity - dark areas) and clouds (high intensity - bright areas) represent the bottom and top, respectively, of the image as it is thought to be a topographic surface. This characteristic allowed MM area opening and closing operations to be applied to reduce or eliminate the bottom and top of the topographic surface.
Histoarchitectural Features of the Hepatopancreas of the Amazon River Prawn Macrobrachium amazonicum
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
The purpose of this study was to evaluate the setting time and the thermal expansion coefficient of 2 endodontic cements, MTA-Angelus and a novel cement called CER. The setting time was determined in accordance to ANSI/ADA specifications no. 57. Three samples of 10 mm diameter and 2 mm thickness were prepared for each cement. The thermal expansion measurements were performed by strain gauge technique. Four samples of each cement were prepared using silicone rings of 5 mm diameter and 2 mm thickness. The data were analyzed statistically using the Student t test. The setting time obtained for the MTA-Angelus and CER cements was 15 (SD 1) min and 7 (SD 1) min, respectively. The linear coefficient of thermal expansion was 8.86 (SD 0.28) mu strain/degrees C for MTA-Angelus and 11.76 (SD 1.20) mu strain/degrees C for CER. The statistical analysis showed significant difference (P < .05) in the setting time and linear coefficient of thermal expansion between the 2 cements. The CER cement has a coefficient of expansion similar to dentin, which could contribute to a decrease of microleakage degree.
Resumo:
TEMA: medidas da dinâmica respiratória são freqüentemente utilizadas na clínica fonoaudiológica, mas poucos são os dados científicos destas na população infantil. OBJETIVO: estudar a dinâmica respiratória entre crianças que respiram pelo modo nasal. MÉTODO: o estudo foi realizado com uma amostra aleatória estratificada de 106 crianças respiradoras nasais de escolas da cidade de Marília / SP, entre quatro e dez anos de ambos os sexos. Foram realizadas as medidas de capacidade vital (CV), nas posições em pé e sentada, com e sem oclusão nasal; de tempo máximo de fonação (TMF) de vogais e consoantes sustentadas, além de fala em seqüência com a contagem de números. RESULTADOS: a medida média da CV na posição em pé com e sem oclusão nasal foi 1515,56 ml e 1538,67 ml respectivamente e na posição sentada, 1524 ml e 1539,15 ml respectivamente; o TMF das vogais em segundos foi: /a/ = 8,32 , /i/ = 8,61 e /u/ 8,42; o de consoantes foi: /s/ = 6,64 e /z/ = 7,65 e o de seqüência de números foi de 7,76 segundos. Resultados: observou-se que o tempo médio destas medidas aumentou progressivamente conforme as faixas etárias. Tanto para o TMF das vogais como, para o das consoantes, houve diferença estatística significante (p < 0,05) nas idades mais distantes, ou seja, entre quatro e dez anos, quatro e nove, e quatro e oito anos. em faixas etárias consecutivas não houve diferença estatística significante nos valores de CV. Houve forte associação entre a CV e o crescimento físico da criança. CONCLUSÃO: esse estudo mostrou medidas de dinâmica respiratória em crianças que podem ser úteis no diagnóstico e terapia fonoaudiológica. Outras pesquisas deveriam ser desenvolvidas para adicionais informações sobre o assunto.
Resumo:
A fissura de palato, em associação à Sequência de Pierre Robin, pode favorecer o desenvolvimento de produções atípicas (compensatórias), na fala da criança, como é o caso da oclusiva glotal (golpe de glote) comumente observada em substituição aos sons oclusivos (vozeados ou não). No presente estudo, foi realizada a análise dos parâmetros fonético-acústicos da oclusiva glotal produzidas em /k/ e /g/ por uma criança do gênero feminino, com 5 anos, que apresentava fissura de palato reparada, associada à Sequência de Pierre Robin. Para isso, foram selecionadas seis palavras em que a oclusiva velar encontrava-se na posição inicial da palavra e combinada com as vogais /a/, /i/ e /u/ na posição acentuada. Foi ainda realizado julgamento perceptivo-auditivo por três fonoaudiólogos, que apresentou concordância quanto à presença da oclusiva glotal de 100% para ambas as relações (intra e inter-juízes). Na inspeção dos dados via espectrograma foi observada variabilidade dos parâmetros espectrais (burst e transição formântica) e essas variações também puderam ser computadas considerando as vogais separadamente. A análise estatística revelou diferença estatisticamente significante entre as duas consoantes velares (/k/ e /g/) nos parâmetros espectral (burst), temporal (VOT e duração relativa da oclusiva na palavra) e os relativos às características acústicas das vogais adjacentes às oclusivas (período estacionário de F3). Por fim, as características acústicas da oclusiva glotal sugeriram que a criança pode ter utilizado de estratégias para marcar contrastes fônicos na língua, ainda que os mesmos não tenham magnitude suficiente para serem resgatados auditivamente pelo ouvinte.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Guided Tissue Regeneration (GTR) is a regenerative treatment modality that requires the placement of a physical barrier over a bone defect in such a way that the proliferation of the surrounding soft tissues into the barrier-protected area is prevented. Thereby in the guided osseous regeneration allowing bone-forming cells from the existent bone edges to invade the space and produce bone. The physical barriers should be biocompatible, allow cellular occlusion, maintain adequate space, tissue integration and facility in the application. They can be occlusive or permeable, absorbable or non-absorbable. Among various types of physical barriers in the market, the cellulose biosynthetic membrane is emphasizing by the necessary characteristics for GTR and to be a national product developed in low cost.
Resumo:
Some properties of the volatile anesthetics, such as vasodilatation and myocardial depression, combined with the sympathetic inhibition that alpha 2-agonists can produce may determine hemodynamic alterations during aortic, surgery. The interaction between dexmedetomidine (DEX), an alpha 2-agonist, and sevoflurane during aortic surgery is unknown. We studied the effects of DEX on hemodynamics and systemic oxygenation during aortic cross-clamping (Aox) and unclamping (UAox) in sevoflurane-anesthetized dogs Twenty dogs were. anesthetized with sevoflurane and were randomly assigned to two groups prior to Aox and UAox: control, n = 10, received saline infusion only, and DEX (1 mu g.kg(-1) load followed by 1 mu g.kg(-1).h(-1) infusion), n = 10. Hemodynamic and oxygenation variables were measured at baseline, after saline or DEX loading dose, 20 and 40 min after Aox, and 20 and 40 min after UAox. After DEX administration, heart rate, cardiac index l and systemic oxygen transport index (131021) were lower than in control group. Aox increased mean arterial pressure (MAP) and systemic vascular resistance index (SVRI) in both groups, but the effects were greater with DEX. Cl, heart rate, and DO(2)I were lower, while central venous pressure (CVP) and pulmonary artery occlusion pressure were higher in DEX compared to control. After UAox, MAP, CVP and SVRI were maintained higher in DEX in relation to control. We conclude that in sevoflurane-anesthetized dogs DEX alters the cardiovascular response during aortic surgery.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)