944 resultados para Ex situ conservation
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Microorganisms are involved in the deterioration of Cultural Heritage. Thus, there is a need to enhance the techniques used for their detection and identification. RNA Fluorescent In Situ Hybridization (RNA-FISH) has been successfully applied for phylogenetic identification of the viable components of the microbial communities colonizing artworks both in situ and ex situ. Until recently, it was time-consuming, taking not less than 6 h for the analysis. We have developed an RNA-FISH in suspension protocol that allowed ex situ analysis of microorganisms involved in artworks’ biodeterioration in 5 h. In this work, three modified protocols, involving microwave heating, were evaluated for further shortening two of the four main critical steps in RNA-FISH: hybridization and washing. The original and modified protocols were applied in cellular suspensions of bacteria and yeast isolates. The results obtained were evaluated and compared in terms of detectability and specificity of the signals detected by epifluorescence microscopy. One of the methods tested showed good and specific FISH signals for all the microorganisms selected and did not produce signals evidencing non-specific or fixation-induced fluorescence. This 3 h protocol allows a remarkable reduction of the time usually required for performing RNA-FISH analysis in Cultural Heritage samples. Thus, a rapid alternative for analyzing yeast and bacteria cells colonizing artworks’ surfaces by RNA-FISH is presented in this work.
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Várias estratégias de conservação de germoplasma estão disponíveis e devem ser conduzidas em conjunto para serem mais representativas e eficientes. Dentre elas tem-se a conservação de DNA, valiosa fonte de informações para subsidiar o manejo de Bancos Ativos de Germoplasma. Mas, para cumprir esse papel necessita ser inventariada e organizada. Assim, realizou-se o inventário das amostras de DNA vegetal conservadas na coleção da Embrapa Amazônia Oriental. No período de maio a julho/2016 foi realizado inventário com 100% de cobertura das amostras de DNA vegetal que compõem a coleção de DNA da Embrapa Amazônia Oriental para serem organizadas por família, espécie e documentadas para viabilizar seu manejo. A coleção apresentou 9.574 amostras de DNA, sendo grande parte deles representantes de acessos dos BAG?s conservados em nível de campo. As amostras agregaram 8 famílias, 12 gêneros e 21 espécies, com a família Arecaceae sendo a melhor representada seguida da Euphorbiaceae. Portanto, essa coleção apresenta possibilidade de fornecer subsídios para o manejo dos BAG?s bem representados, além de fornecer políticas relacionadas à sua coleta, conservação, documentação e melhoramento genéticos das espécies.
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Pós-graduação em Agronomia - FEIS
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Perfusion of liver with plasmid DNA-lipofectin complexes via the portal vein results in efficient accumulation of the vector in hepatocytes. Such hepatocytes, when administered intraperitoneally into a hepatectomized rat, repopulate the liver and express the transgene efficiently. This procedure obviates the need for large-scale hepatocyte culture for ex vivo gene transfer. Further, intraperitoneal transplantation is a simple and cost-effective strategy of introducing genetically modified hepatocytes into liver. Thus, in situ lipofection of liver and intraperitoneal transfer of hepatocytes can be developed into a novel method of non-viral ex vivo gene transfer technique that has applications in the treatment of metabolic disorders of liver and hepatic gene therapy.
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This paper refers to the assessment on site by semi-destructive testing (SDT) methods of the consolidation efficiency of a conservation process developed by Henriques (2011) for structural and non-structural pine wood elements in service. This study was applied on scots pine wood (Pinus sylvestris L.) degraded by fungi after treatment with a biocidal product followed by consolidation with a polymeric product. This solution avoids substitutions of wood moderately degraded by fungi, improving its physical and mechanical characteristics. The consolidation efficiency was assessed on site by methods of drill resistance and penetration resistance. The SDT methods used showed good sensitivity to the conservation process and could evaluate their effectiveness. (C) 2015 Elsevier Ltd. All rights reserved.
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This in situ/ex vivo study evaluated whether saliva stimulated by chewing gum could prevent or reduce the wear and the percent change in microhardness (%SMH) of bovine and human enamel submitted to erosion followed by brushing abrasion immediately or after 1 h. During 2 experimental 7-day crossover phases, 9 previously selected volunteers wore intraoral palatal devices, with 12 enamel specimens (6 human and 6 bovine). In the first phase, the volunteers immersed the device for 5 min in 150 ml of cola drink, 4 times per day (at 8, 12, 16 and 20 h). Immediately after the immersions, no treatment was performed in 4 specimens, 4 other specimens were immediately brushed (0 min) using a fluoride dentifrice, and the device was replaced into the mouth. After 60 min, the remaining 4 specimens were brushed. In the second phase, the procedures were repeated, but after the immersions, the volunteers stimulated the salivary flow rate by chewing a sugar-free gum for 30 min. Changes in wear and %SMH were measured. ANOVA and Tukey's test showed statistical differences (p < 0.05) for the following comparisons. The chewing gum promoted less wear and %SMH. A decreasing %SMH and an increasing enamel wear were observed in the following conditions: erosion only, 60 min and 0 min. The human enamel presented greater %SMH and less wear compared to bovine enamel. The data suggest that the salivary stimulation after an erosive or erosive/abrasive attack can reduce the dental wear and the %SMH.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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This in situ/ex vivo study assessed the effect of different concentrations of fluoride in dentifrices on dentin subjected to erosion or to erosion plus abrasion. Ten volunteers took part in this crossover and double-blind study performed in 3 phases (7 days). They wore acrylic palatal appliances containing 4 bovine dentin blocks divided in two rows: erosion and erosion plus abrasion. The blocks were subjected to erosion by immersion ex vivo in a cola drink (60 s, pH 2.6) 4 times daily. During this step, the volunteers brushed their teeth with one of three dentifrices D (5,000 ppm F, NaF, silica); C (1,100 ppm F, NaF, silica) and placebo (22 ppm F, silica). Then, the respective dentifrice slurry (1: 3) was dripped on dentin surfaces. While no further treatment was performed in one row, the other row was brushed using an electric toothbrush for 30 s ex vivo. The appliances were replaced in the mouth and the volunteers rinsed with water. Dentin loss was determined by profilometry and analyzed by 2-way ANOVA/Bonferroni test (alpha = 0.05). Dentin loss after erosive-abrasive wear was significantly greater than after erosion alone. Wear was significantly higher for the placebo than for the D and C dentifrices, which were not significantly different from each other. It can be concluded that the presence of fluoride concentrations around 1,100 ppm in dentifrices is important to reduce dentin wear by erosion and erosion + abrasion, but the protective effect does not increase with fluoride concentration. Copyright (C) 2008 S. Karger AG, Basel.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Objective: This in situ/ex vivo study assessed the effect of titanium tetrafluoride (TiF4) on permanent human enamel subjected to erosion.Design: Ten volunteers took part in this study performed in two phases. In the first phase (ERO), they wore acrylic palatal appliances containing two enamel blocks, divided into two rows: TiF4 (F) and no-TiF4 (no-F). During the 1st day, the formation of a salivary pellicle was allowed. In the 2nd day, the TiF4 solution was applied on one row (ERO + F), whereas on the other row no treatment was performed (ERO + no-F). From 3rd until 7th day, the blocks were subjected to erosion, 4x per day. In the 2nd phase (no-ERO), the volunteers wore acrylic palatal appliances containing one enamel block, during 2 days, to assess the effect of TiF4 only (no-ERO + F). Enamel alterations were determined using profilometry (wear), microhardness (%SMHC) tests, scanning electron microscope and microprobe analysis. The %SMHC and wear were tested using ANOVA and Tukey's post hoc tests (p < 0.05).Results: The mean of %SMHC and wear ( mu m) values ( +/- S.D.) were, respectively: ERO + F -73.32 +/- 5.16(A)/2.40 +/- 0.60(a); ERO + no-F -83.49 +/- 4.59B/1.17 +/- 0.48(b) and no-ERO + F -67.92 +/- 6.16(A)/0.21:E 0.09(c). In microscope analysis, the no-F group showed enamel with honeycomb appearance. For F groups, it was observed a surface coating with microcracks. The microprobe analysis revealed the presence of the following elements (%) in groups ERO + F, ERO + no-F and no-ERO + F, respectively: Ca (69.9, 72.5, 66.25); P (25.9, 26.5, 26.06); Ti (3.0, 0, 5.93).Conclusions: The TiF4 was unable to reduce dental erosion. (c) 2007 Elsevier Ltd. All rights reserved.
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This in situ/ex vivo study assessed the effect of fluoride dentifrice on eroded enamel subjected to brushing abrasion. In a crossover study performed in 2 phases, 10 volunteers wore acrylic palatal appliances, each containing 3 human enamel blocks. Dentifrice was used to brush the volunteers' teeth and the specimens subjected to abrasion. In phases A and B the dentifrices used had the same formulation, except for the absence or presence of fluoride, respectively. The blocks were subjected to erosion by immersion of the appliances in a cola drink for 5 min, 4 times a day. Then the blocks were brushed, and the appliance was replaced into the mouth. Enamel alterations were determined using profilometry and percentage change in surface microhardness (%SMHC) tests. The data were tested using the paired t test. The mean wear values (+/- SD, mu m) were: group A 6.84 +/- 1.72 and group B 5.38 +/- 1.21 (p = 0.04). The mean %SMHC values (+/- SD) were: group A 54.6 +/- 16.2 and group B 45.7 +/- 6.8 (p = 0.04). Fluoride dentifrice had a protective effect on eroded enamel subjected to brushing abrasion. Copyright (c) 2007 S. Karger AG, Basel.
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Objectives: This in situ/ex vivo study evaluated whether a rinse with an iron solution could reduce wear and the percentage of microhardness change of human enamel and dentine submitted to erosion followed by brushing after 1 or 30 min.Design: During 2 experimental 5-day crossover phases (wash-out period of 10 days), 10 volunteers wore intraoral palatal devices, with 12 specimens (6 of enamel and 6 of dentine) arranged in 3 horizontal rows (4 specimens each). In one phase, the volunteers immersed the device for 5 min in 150 mL of cola drink, 4 times a day. Immediately after immersion, no treatment was performed in one row. The other row was brushed after 1 min using a fluoride dentifrice and the device was replaced into mouth. After 30 min, the remaining row was brushed. In the other phase, the procedures were repeated, but after immersion the volunteers rinsed for 1 min with 10 mL of a 10 mM ferrous sulphate solution. Changes in surface microhardness (%SMH) and wear (profilometry) of enamel and dentine were measured. Data were tested using ANOVA and Tukey's tests (p < 0.05).Results: the enamel presented more wear than dentine, under all experimental conditions. The iron solution caused a significant reduction on the %SMH in enamel, and a significant reduction on the wear in dentine, regardless the other conditions.Conclusions: Rinsing with an iron solution after an erosive attack, followed or not by an abrasive episode, may be a viable alternative to reduce the loss of dental structure. (c) 2006 Elsevier Ltd. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)