1 |
Efeito da irradiação gama na composição química da dentina radicular / Gamma irradiation effect on the root dentin chemical compositionCampi, Lívia Bueno 03 February 2017 (has links)
O presente estudo avaliou a composição química da dentina radicular de dentes submetidos à radioterapia por meio de Espectroscopia Raman Confocal (ERC). Vinte pré-molares inferiores humanos homólogos foram selecionados e distribuídos em dois grupos (n=10) de acordo com a irradiação: não irradiados e irradiados, submetidos à radioterapia fraccionada com raios-X de 6 MV. Os dentes foram seccionados e submetidos à análise da composição química da dentina radicular submetida à radioterapia por meio de ERC, em relação aos picos de fosfato, carbonato e amidas I, II e III. Foi utilizada objetiva de 40x (Olympus), com luz de comprimento de onda de 785 nm, compreendendo a faixa espectral de 400 - 1800 cm-1, na região de baixa frequência, com resolução espacial de 2 µm. Para a geração do espectro, a potência do laser utilizada foi de 21 mW e o tempo de exposição de 5 segundos. A intensidade dos picos fosfato - PO43- (590 cm-1) e carbonato - CO32- (1070 cm-1) no ERC são proporcionais à quantidade de conteúdo inorgânico, enquanto que a amida I (1670 cm-1), II (1453 cm-1) e III (1267 cm-1) são proporcionais ao conteúdo orgânico (colágeno). Os dados obtidos foram submetidos à análise estatística (Teste T, P<0,05) para amostras independentes, avaliando-se a influência da radioterapia nos valores de fosfato, carbonato e amidas I, II e III em diferentes regiões radiculares. Em região de dentina radicular intracanal, o grupo irradiado (1,23±0,06) apresentou menores valores de fosfato quando comparado ao grupo não irradiado (1,40±0,18) (P<0,05). Em relação ao carbonato, foi observado que os dentes irradiados (1,56±0,06) apresentaram menores valores quando comparados ao grupo não irradiado (1,42±0,10) (P<0,05). Para os picos de amida, não foi observada diferença estatística entre os grupos em amida I (P=0,295) e amida II (P=0,792). No entanto, o tratamento radioterápico reduziu significativamente os valores de amida III do grupo irradiado (1,05±0,19) em comparação ao grupo não irradiado (1,28±0,24). Quando avaliada a região da dentina radicular média, o grupo irradiado (1,30±0,12) apresentou menores valores de fosfato quando comparado ao grupo não irradiado (1,48±0,22) (P<0,05); e em relação aos valores de carbonato (P=0,859), amida I (P=0,785), amida II (P=0,771) e amida III (P=0,338) não foi observada diferença estatística entre eles. Na análise em cemento, não houve diferenças estatísticas entre os grupos irradiado e não irradiado para os valores de fosfato (P=0,448), carbonato (P=0,575) e amida I (P=0,225), amida II (P=0,437) e amida III (P=0,187). Dessa forma, pode-se concluir que a radioterapia promoveu alterações nos picos de amida III, indicando modificação estrutural do colágeno. / The present study was to evaluate the root dentin chemical composition of teeth submitted to radiotherapy by Confocal Raman Spectroscopy (CRS). Twenty inferior human homologues premolars were selected and divided in two groups (n = 10) according to the irradiation protocol: non Irradiated and irradiated, submitted to fractional X-ray radiotherapy of 6 MV. The teeth were sectioned and submitted to the analysis of the chemical composition of radicular dentin submitted to radiotherapy by CRS, evaluating the phosphate, carbonate and amides I, II and III peaks. A 40x objective (Olympus) was used, generating a light with a 785 nm wavelength, comprising the spectral range of 400-1800 cm-1 in the low frequency region with spatial resolution of 2 µm. For the spectrum generating the laser power used was 21 mW and the exposure time was 5 seconds. The intensity of the phosphate - PO43- (590 cm-1) and carbonate - CO32- (1070 cm-1) peaks in the CRS are proportional to the amount of inorganic content while the amide I (1670 cm-1), II (1453 cm-1) and III (1267 cm-1) are proportional to organic content (collagen). The data were submitted to statistical analysis (Test T, P<0.05) for independent samples, evaluating the influence of radiotherapy on the phosphate, carbonate and amide I, II and III values in different root regions. In the intracanal dentin root region, the irradiated group (1.23 ± 0.06) had lower phosphate values when compared to the non-irradiated group (1.40 ± 0.18) (P<0.05). In relation to the carbonate, it was observed that the irradiated teeth (1.56 + 0.06) had lower values than the non-irradiated group (1.42 + 0.10) (P<0.05). The amide peaks has no statistical difference observed between the groups in relation to the amide I (P=0,295) and amide II (P=0,792). However, the radiotherapeutic treatment significantly reduced the amide III values of the irradiated group (1.05 + 0.19) compared to the non-irradiated group (1.28 + 0.24). When the middle radicular dentin region was evaluated, the irradiated group (1.30 ± 0.12) had lower phosphate values when compared to the non-irradiated group (1.48 ± 0.22) (P<0.05); and in relation to the carbonate (P=0.859), amide I (P=0.785), amide II (P=0,771) and amide III (P=0,338) peaks no statistical difference was showed between irradiated and non-irradiated teeth. In the cement analysis, there was no statistical difference between the irradiated and non-irradiated groups for the phosphate (p = 0.448), carbonate (P=0.575), amide I P=0.225), amide II (P=0,437) and amide III (P=0,187) values. In conclusion, the radiotherapy was able to promote alterations in the amide III, changing the collagen structure.
|
2 |
Efeito da irradiação gama na composição química da dentina radicular / Gamma irradiation effect on the root dentin chemical compositionLívia Bueno Campi 03 February 2017 (has links)
O presente estudo avaliou a composição química da dentina radicular de dentes submetidos à radioterapia por meio de Espectroscopia Raman Confocal (ERC). Vinte pré-molares inferiores humanos homólogos foram selecionados e distribuídos em dois grupos (n=10) de acordo com a irradiação: não irradiados e irradiados, submetidos à radioterapia fraccionada com raios-X de 6 MV. Os dentes foram seccionados e submetidos à análise da composição química da dentina radicular submetida à radioterapia por meio de ERC, em relação aos picos de fosfato, carbonato e amidas I, II e III. Foi utilizada objetiva de 40x (Olympus), com luz de comprimento de onda de 785 nm, compreendendo a faixa espectral de 400 - 1800 cm-1, na região de baixa frequência, com resolução espacial de 2 µm. Para a geração do espectro, a potência do laser utilizada foi de 21 mW e o tempo de exposição de 5 segundos. A intensidade dos picos fosfato - PO43- (590 cm-1) e carbonato - CO32- (1070 cm-1) no ERC são proporcionais à quantidade de conteúdo inorgânico, enquanto que a amida I (1670 cm-1), II (1453 cm-1) e III (1267 cm-1) são proporcionais ao conteúdo orgânico (colágeno). Os dados obtidos foram submetidos à análise estatística (Teste T, P<0,05) para amostras independentes, avaliando-se a influência da radioterapia nos valores de fosfato, carbonato e amidas I, II e III em diferentes regiões radiculares. Em região de dentina radicular intracanal, o grupo irradiado (1,23±0,06) apresentou menores valores de fosfato quando comparado ao grupo não irradiado (1,40±0,18) (P<0,05). Em relação ao carbonato, foi observado que os dentes irradiados (1,56±0,06) apresentaram menores valores quando comparados ao grupo não irradiado (1,42±0,10) (P<0,05). Para os picos de amida, não foi observada diferença estatística entre os grupos em amida I (P=0,295) e amida II (P=0,792). No entanto, o tratamento radioterápico reduziu significativamente os valores de amida III do grupo irradiado (1,05±0,19) em comparação ao grupo não irradiado (1,28±0,24). Quando avaliada a região da dentina radicular média, o grupo irradiado (1,30±0,12) apresentou menores valores de fosfato quando comparado ao grupo não irradiado (1,48±0,22) (P<0,05); e em relação aos valores de carbonato (P=0,859), amida I (P=0,785), amida II (P=0,771) e amida III (P=0,338) não foi observada diferença estatística entre eles. Na análise em cemento, não houve diferenças estatísticas entre os grupos irradiado e não irradiado para os valores de fosfato (P=0,448), carbonato (P=0,575) e amida I (P=0,225), amida II (P=0,437) e amida III (P=0,187). Dessa forma, pode-se concluir que a radioterapia promoveu alterações nos picos de amida III, indicando modificação estrutural do colágeno. / The present study was to evaluate the root dentin chemical composition of teeth submitted to radiotherapy by Confocal Raman Spectroscopy (CRS). Twenty inferior human homologues premolars were selected and divided in two groups (n = 10) according to the irradiation protocol: non Irradiated and irradiated, submitted to fractional X-ray radiotherapy of 6 MV. The teeth were sectioned and submitted to the analysis of the chemical composition of radicular dentin submitted to radiotherapy by CRS, evaluating the phosphate, carbonate and amides I, II and III peaks. A 40x objective (Olympus) was used, generating a light with a 785 nm wavelength, comprising the spectral range of 400-1800 cm-1 in the low frequency region with spatial resolution of 2 µm. For the spectrum generating the laser power used was 21 mW and the exposure time was 5 seconds. The intensity of the phosphate - PO43- (590 cm-1) and carbonate - CO32- (1070 cm-1) peaks in the CRS are proportional to the amount of inorganic content while the amide I (1670 cm-1), II (1453 cm-1) and III (1267 cm-1) are proportional to organic content (collagen). The data were submitted to statistical analysis (Test T, P<0.05) for independent samples, evaluating the influence of radiotherapy on the phosphate, carbonate and amide I, II and III values in different root regions. In the intracanal dentin root region, the irradiated group (1.23 ± 0.06) had lower phosphate values when compared to the non-irradiated group (1.40 ± 0.18) (P<0.05). In relation to the carbonate, it was observed that the irradiated teeth (1.56 + 0.06) had lower values than the non-irradiated group (1.42 + 0.10) (P<0.05). The amide peaks has no statistical difference observed between the groups in relation to the amide I (P=0,295) and amide II (P=0,792). However, the radiotherapeutic treatment significantly reduced the amide III values of the irradiated group (1.05 + 0.19) compared to the non-irradiated group (1.28 + 0.24). When the middle radicular dentin region was evaluated, the irradiated group (1.30 ± 0.12) had lower phosphate values when compared to the non-irradiated group (1.48 ± 0.22) (P<0.05); and in relation to the carbonate (P=0.859), amide I (P=0.785), amide II (P=0,771) and amide III (P=0,338) peaks no statistical difference was showed between irradiated and non-irradiated teeth. In the cement analysis, there was no statistical difference between the irradiated and non-irradiated groups for the phosphate (p = 0.448), carbonate (P=0.575), amide I P=0.225), amide II (P=0,437) and amide III (P=0,187) values. In conclusion, the radiotherapy was able to promote alterations in the amide III, changing the collagen structure.
|
3 |
Raman spectroscopic studies of the underglaze pigments of porcelain shards of archaeological originsKock, L.D. (Lesotlho David) 06 June 2010 (has links)
The technique of Raman spectroscopy was used in a study of shards of known (Ming and Meissen) and unknown (archaeological) origin. A tile shard from the Citadel of Algiers was included in this study as further confirmation of the consistency of the methods that are developed. The Citadel from which the tile shard was obtained was built in 1516 and represents a landmark from pre-colonial Algeria. The results were compared with those obtained from studies on intact museum pieces of known (Ming) origin. A consistent method of studying underglaze pigments on glazed ceramic artifacts by directing the laser beam through the predominantly silicate glaze was developed. The glaze depth profiling method developed proved to be very useful in the analysis and gives not only a detailed composition for the glaze/ceramic interfacial pigment, but also the order in which the various interfacial pigment layers were applied at the time of manufacture. The information acquired leads to an understanding of the level of technological development of the manufacturers. The detailed study and characterisation of the pigments that were analysed in this way gives insight into trade relations among ancient societies of the Mediterranean and will also assist archaeologists in establishing cut-off dates for the archaeological sites from which the artifacts were recovered. All the shards, except one from Meissen (Germany), were provided by the National Cultural History Museum of South Africa and the intact Ming dynasty plates were provided by the J.A. van Tilburg Museum of the University of Pretoria. The tile shard sample from the Citadel of Algiers was donated for the study. The results indicate that none of the archaeological shards could possibly be of Ming dynasty origin based on, firstly, the use of amorphous carbon to darken the cobalt blue (CoAl2O4) used as decoration on the shards, and secondly on the use of white (synthetic) anatase to whiten the ceramic surface before the application of the pigment since this synthetic anatase is known to have been manufactured for the first time around 1920. An ancient rediscovered ternary pigment (Pb2SnSbO6.5) previously found on Italian paintings of the 16th century, for example, “Lot and his daughters” by G.B. Langetti and “Entrance of Christ in Jerusalem” by Luca Giordano, was identified on the Citadel tile and successfully characterised. A Pb-O vibrational Raman band at 127 cm-1 for this pigment was assigned for the first time. Additional pigments identified on the tile include Naples yellow (Pb2Sb2O7), lead (II) stannate (Pb2SnO4), cobalt blue (CoAl2O4) and cassiterite (SnO2). The bulk of the tile body is composed mainly of hematite (á-Fe2O3), maghemite (ã-Fe2O3), magnetite (Fe3O4) and quartz (á-SiO2), with traces of calcite (CaCO3) and amorphous carbon. The unique non destructive depth profiling method that was developed in this study can now be applied to the study of underglaze pigments on intact porcelain artifacts in museums and private collections around the world for authentication purposes and for comparison with archaeological shard samples. / Thesis (PhD)--University of Pretoria, 2010. / Chemistry / unrestricted
|
4 |
A Laser Raman spectroscopic study of the pH induced structural changes in Guanosine-5’ monophosphate and its derivativesPambi, Daniel 01 December 1988 (has links)
The purpose of this study was to determine the protonation sites in guanosine-5'-monophosphate (5'-GMP), and to correlate the ease of protonation with the chemical nature and composition of substituent groups. The laser Raman spectra of 5'-GMP, 7-methyl-guanosine-5'-monophosphate (m7-GMP), and 8-bromoguanosine-5'-monophosphate (8-Br-GMP) at various pH and pD values were recorded with a Spex Ramalog-6 spectrometer. Based on the spectral changes observed in these studies, the preferred order of protonation sites for 5'-GMP and 8-Br-GMP is N7, 06 and N3. In the case of m7-GMP, the preferred sites are 06 and N3. The opening of the imidazole ring in m7-GMP is observed at pH value of about 9.4. It appears that the presence of the methyl group has a stabilizing effect on the protonated (keto) species. As expected, the vibrational modes of the phosphate group are unaffected by substituents on the guanine part of 5'-GMP. The complete spectra and vibrational assignments for 5'-GMP, m7- GMP and 8-Br-GMP are presented in this thesis.
|
5 |
Raman molecular fingerprints of rice nutritional quality / 米の栄養価のラマン分子フィンガープリントPezzotti, Giuseppe 24 November 2022 (has links)
京都大学 / 新制・論文博士 / 博士(農学) / 乙第13520号 / 論農博第2908号 / 新制||農||1096(附属図書館) / 学位論文||R4||N5420(農学部図書室) / 京都府立医科大学 / (主査)教授 中﨑 鉄也, 教授 土井 元章, 教授 及川 彰, 准教授 田中 朋之 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DGAM
|
6 |
Fourier-transform Raman spectroscopic study of a Neolithic waterlogged wood assemblagePetrou, M., Edwards, Howell G.M., Janaway, Robert C., Thompson, Gill B., Wilson, Andrew S. January 2009 (has links)
No / The use of Fourier-transform Raman spectroscopy for characterising lignocellulosics has increased significantly over the last twenty years. Here, an FT-Raman spectroscopic study of changes in the chemistry of waterlogged archaeological wood of Pinus sp. and Quercus sp. from a prehistoric assemblage recovered from northern Greece is presented. FT-Raman spectral features of biodeteriorated wood were associated with the depletion of lignin and/or carbohydrate polymers at various stages of deterioration. Spectra from the archaeological wood are presented alongside spectra of sound wood of the same taxa. A comparison of the relative changes in intensities of spectral bands associated with lignin and carbohydrates resulting from decay clearly indicated extensive deterioration of both the softwood and hardwood samples and the carbohydrates appear to be more deteriorated than the lignin. The biodeterioration of the archaeological timbers followed a pattern of initial preferential loss of carbohydrates causing significant loss of cellulose and hemicellulose, followed by the degradation of lignin.
|
7 |
Espectroscopia Raman e quimiometria como ferramentas analíticas para química forense e paleontologia / Raman spectroscopy and chemometrics as analytical tools for forensic chemistry and paleontologyAlmeida, Mariana Ramos de, 1985- 26 August 2018 (has links)
Orientador: Ronei Jesus Poppi / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-26T16:15:02Z (GMT). No. of bitstreams: 1
Almeida_MarianaRamosde_D.pdf: 6686279 bytes, checksum: 1e1d5d53538fb99a153ff4425595e0ce (MD5)
Previous issue date: 2015 / Resumo: A motivação para o desenvolvimento dessa tese foi a busca por métodos de análise não destrutivos, com nenhum ou mínimo preparo de amostra e que permitam a obtenção do máximo de informação com a realização de uma única análise na área de forense e paleontologia. Em forense, a espectroscopia Raman e o método de classificação supervisionado PLS-DA (Análise Discriminante por Mínimos Quadrados Parciais) foram empregados para construir modelos de classificação. O primeiro modelo foi construído para discriminar cédulas autênticas de cédulas falsas. A análise foi baseada na caracterização das tintas usadas na confecção das cédulas. O segundo modelo de classificação foi construído para diferenciar o óleo essencial extraído de diferentes partes (caule, folhas e galhos) da árvore amazônica Aniba Rosaeodora. A confiabilidade dos modelos foi avaliada pelo cálculo do intervalo de confiança, que foram calculados usando a técnica de reamostragem bootstrap. Os resultados obtidos mostraram que os modelos de classificação podem ser usados como método complementar à inspeção forense clássica e método de triagem. O desempenho dos modelos de classificação foi avaliado pelo cálculo de sensibilidade, especificidade, eficiência e coeficiente de Mathew. A espectroscopia Raman de imagem e o método de análise de componentes independentes (ICA) foram empregados para a identificação de explosivos em superfícies de cédulas. O método ICA foi avaliado como método de resolução de curvas para extrair os perfis espectrais e as imagens Raman dos constituintes presentes nas superfícies analisadas. Os resultados obtidos mostraram que o método ICA é adequado para resolução de curvas, uma vez que alcançou desempenho equivalente ao método clássico MCR-ALS (Resolução Multivariada de Curvas com Mínimos Quadrados Alternados). O limite de detecção da metodologia apresentada foi de 50 µg.cm-2 para o explosivo TNT. Por fim, a espectroscopia Raman de imagem foi empregada no estudo da composição química de fósseis de peixes, com o objetivo de obter informações sobre características biológicas. Os resultados mostraram informações sobre a composição química do fóssil estudado / Abstract: The motivation for the development of this thesis was to search for non-destructive testing methods, with none or minimal sample preparation and allowing them to obtain maximum information with the completion of a single analysis for forensic and paleontology. In the forensics, the Raman spectroscopy and the PLS-DA (discriminant analysis by Partial Least Squares) classification method were explored to build classification models. The first model was built to discriminate authentic and counterfeit banknotes. The analysis was based on the characterization of inks used in the confection of the banknotes. The second classification model was built to differentiate the essential oil extracted from different parts (wood, leaves and branches) of the Brazilian tree Aniba rosaeodora. The reliability of the models was evaluated by calculating the confidence interval, which was calculated using the bootstrap resampling technique. The results show that the classification models can be used as a complementary method to classical forensic inspection and a screening method. The performance of classification models was evaluated by calculating sensitivity, specificity, efficiency and Matthew coefficient. In a third application, Raman hyperspectral imaging and the independent component analysis (ICA) method were used for identification of explosives on the surfaces of banknotes. The ICA method was evaluated as curve resolution method to extract the Raman spectral profiles and the images of the constituents present in the analyzed surfaces. The results showed that the ICA method is appropriate for curves resolution, once achieved equivalent performance to the classical MCR-ALS (Multivariate Curve Resolution with Alternating Least Squares) method. The methodology presented limit of detection of 50 µg.cm-2 for the explosive TNT. Finally, the Raman hyperspectral imaging was applied in paleontology to study the chemical composition of fish fossil with the aim of obtaining information on biological characteristics. The results showed information about the chemical composition of fossil studied / Doutorado / Quimica Analitica / Doutora em Ciências
|
Page generated in 0.0559 seconds