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Space radiation-induced bystander effect : kinetics of biologic responses, mechanisms, and significance of secondary radiationsGonon, Géraldine 12 December 2011 (has links) (PDF)
Widespread evidence indicates that exposure of cell cultures to α particles results in significant biological changes in both the irradiated and non-irradiated bystander cells in the population. The induction of non-targeted biological responses in cell cultures exposed to low fluences of high charge (Z) and high energy (E) particles is relevant to estimates of the health risks of space radiation and to radiotherapy. Here, we investigated the mechanisms underlying the induction of stressful effects in confluent normal human fibroblast cultures exposed to low fluences of 1000 MeV/u iron ions (linear energy transfer (LET) ~151 keV/µm), 600 MeV/u silicon ions (LET ~50 keV/µm) or 290 MeV/u carbon ions (LET ~13 keV/µm). We compared the results with those obtained in cell cultures exposed, in parallel, to low fluences of 0.92 MeV/u α particles (LET ~109 keV/µm).Induction of DNA damage, changes in gene expression, protein carbonylation and lipid peroxidation during 24 h after exposure of confluent cultures to mean doses as low as 0.2 cGy of iron or silicon ions strongly supported the propagation of stressful effects from irradiated to bystander cells. At a mean dose of 0.2 cGy, only ~1 and 3 % of the cells would be targeted through the nucleus by an iron or silicon ion, respectively. Within 24 h post-irradiation, immunoblot analyses revealed significant increases in the levels of phospho-TP53 (serine 15), p21Waf1 (also known as CDKN1A), HDM2, phospho-ERK1/2, protein carbonylation and lipid peroxidation. The magnitude of the responses suggested participation of non-targeted cells in the response. Furthermore, when the irradiated cell populations were subcultured in fresh medium shortly after irradiation, greater than expected increases in the levels of these markers were also observed during 24 h. Together, the results imply a rapidly propagated and persistent bystander effect. In situ analyses in confluent cultures showed 53BP1 foci formation, a marker of DNA damage, in more cells than expected based on the fraction of cells traversed through the nucleus by an iron or silicon ion. The effect was expressed as early as 15 min after exposure, peaked at 1 h and decreased by 24 h. A similar tendency occurred after exposure to a mean absorbed dose of 0.2 cGy of 3.7 MeV α particles, but not after 0.2 cGy of 290 MeV/u carbon ions.Analyses in dishes that incorporate a CR-39 solid state nuclear track detector bottom identified the cells irradiated with iron or silicon ions and further supported the participation of bystander cells in the stress response. Mechanistic studies indicated that gap junction intercellular communication, DNA repair, and oxidative metabolism participate in the propagation of the induced effects.We also considered the possible contribution of secondary particles produced along the primary particle tracks to the biological responses. Simulations with the FLUKA multi-particle transport code revealed that fragmentation products, other than electrons, in cells cultures exposed to HZE particles comprise <1 % of the absorbed dose. Further, the radial spread of dose due to secondary heavy ion fragments is confined to approximately 10-20 µm Thus, the latter are unlikely to significantly contribute to the stressful effects in cells not targeted by primary HZE particles.
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Identificació de paràmetres cinètics i estequiomètrics del procés de depuració de fangs actius mitjançant tècniques respiromètriquesGutiérrez Garcia-Moreno, Oriol 16 October 2003 (has links)
El sistema de depuració de tipus Fangs Actius constitueix una de les tècniques més esteses arreu del món pel tractament biològic de les aigües residuals. Els softwares de modelització i simulació permeten adquirir coneixements de forma ràpida i senzilla sobre el funcionament dels processos de fangs actius, dur a terme la comparació entre diferents tecnologies de tractament i determinar les estratègies d'operació més rentables d'una EDAR minimitzant els costos.L'objectiu de la present tesi consisteix en la identificació dels principals paràmetres cinètics i coeficients estequiomètrics que caracteritzen el procés de fangs actius a partir de la mesura de la velocitat de consum d'oxigen de la biomassa. En aquest sentit s'ha dissenyat i desenvolupat un Respiròmetre Tancat Seqüencial (RTS), un Respiròmetre Tancat (RT) i un Programa d'Anàlisi de Respirometries (PAR) per la determinació dels paràmetres cinètics més representatius i característics dels sistemes de fangs actius en diferents casos. / The Activated Sludge treatment system is one of the techniques more used around the world as a biologic treatment of waste water. Modelling and Simulation software's allow to get knowledge about the behaviour of Activated Sludge processes in a fast and easy way, to compare different treatment technologies and to determine which are the most economic operation strategies for a WWTP. The aim of this thesis consists of the identification of the main kinetic parameters and stoichiometric coefficients that characterize the Activated Sludge process using the measure of oxygen uptake rate of the biomass. Two different kind of instruments has been designed to measure the Activated Sludge respiration: a Sequential Closed Respirometre (RTS, from Respirometre Tancat Seqüencial) and a Closed Respirometre (RT from Respirometre Tancat). Also a Program for the Analysis of Respirometries (PAR from Programa d'Anàlisi de Respirometries) has been developed to determine the most representatives kinetics parameters and activated sludge characteristics in different cases.
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Caracterização físico-química do vinho paulista / Physicochemical characterization of the paulista wineRoberto Sobrinho, Merenice 21 August 2018 (has links)
Orientador: Helena Teixeira Godoy / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-21T19:42:12Z (GMT). No. of bitstreams: 1
RobertoSobrinho_Merenice_D.pdf: 1477674 bytes, checksum: 5fe6158bfbdcf36f980d7b9780573936 (MD5)
Previous issue date: 2013 / Resumo: A legislação brasileira define o vinho como um produto elaborado com uvas frescas, sãs e maduras, produzido por processo fermentativo adequado. Não é permitida a adição de água como constituinte do produto; a adição de sacarose na correção do mosto é restrita a 3ºGL (20ºC) e a presença de contaminantes deve controlada a fim de garantir a saúde pública. A vitivinicultura do estado de São Paulo está passando por um processo de revitalização cujo objetivo é a melhoria da qualidade do produto. As variedades de uvas mais utlizadas, Vitis labrusca e híbridas não são as mais indicadas para a vinificação. O uso de matéria prima inadequada ou a realização do processo fermentativo de forma equivocada pode levar à obtenção de um vinho com parâmetros de identidade e qualidade em desacordo com a legislação brasileira, comprometendo a ascenção de mercado. Dentre a literatura consultada, são escassos os dados quanto a composição dos vinhos produzidos no estado de São Paulo. O objetivo desse trabalho foi realizar a caracterização físico-quimica e investigar os padrões de identidade e qualidade dos vinhos paulistas. Neste estudo, foram realizadas diversas análises a fim de proporcionar dados que possam contribuir para a avaliação da qualidade do vinho paulista e, consequentemente, direcionar as correções necessárias nos processos de vinificação. Para tanto, foram realizadas análises de pH, acidez total, acidez volátil bruta, acidez volátil corrigida, açúcares totais, anidrido sulfuroso total, grau alcoólico, acetaldeído, metanol, razão isotópica de carbono e oxigênio. Foram analisadas 24 amostras de vinhos paulistas, elaborados por 12 produtores, a partir de uvas americanas, híbridas e viníferas na safra de 2011. A partir dos resultados obtidos foi possível observar que 87,5% das amostras estudadas atenderam aos requisitos legais do Padrão de Identidade e Qualidade. Apenas duas amostras, de produtores diferentes, excederam os limites legais para acidez, que pode ser explicado pelo excesso de chuvas verificado durante a safra de 2011 na região. Quanto ao teor de açúcares, apenas uma amostra apresentou divergência entre o valor referenciado na rotulagem e o encontrado nos ensaios. Todos os vinhos avaliados apresentaram graduação alcoólica adequada aos limites legais, porém houve divergência de até 16,4% entre os teores registrados nos rótulos e os verificados nos ensaios. Os níveis de metanol encontrados estiveram abaixo do limite máximo estabelecido. Para o acetaldeído as concentrações variaram entre 4,51± 0,52 mg.L-1 e 87,22 ± 2,21 mg.L-1, sendo que o recomendado na literatura é de até 50 mg.L-1. Os resultados para a razão isotópica de carbono demonstraram que 55% dos vinhos avaliados se apresentaram fora dos limites legais para a correção da graduação alcoólica. Para a razão isotópica de oxigênio todas as amostras analisadas se encontraram acima dos valores de referência para vinhos de São Paulo da safra de 2011, indicando que não há adição de água exógena. No entanto, amostras que se apresentaram em desacordo com a legislação, indicam que há necessidade de intensificar as orientações aos produtores para que possam realizar um controle mais efetivo no processo de produção para a melhoria da qualidade do produto / Abstract: The wine industry in the state of São Paulo is undergoing a revitalization process aimed at improving the quality of the product. Brazilian law defines wine as a product made from fresh, healthy and ripe grapes, produced by appropriate fermentation. It is not permitted to add water as a constituent of the product; adding sucrose to correct the wort is restricted to 3 GL (20 ° C) and the presence of contaminants must be controlled to ensure public health. The most utilized varieties are vitis labrusca and hybrid, but they are not quite suitable for winemaking. The use of inappropriate raw material or inadequate performance of the fermentation process can lead to obtaining a wine with parameters of quality and identity that differ from the Brazilian legislation, undermining the rising market. Among the literature, there are few data regarding the composition of the wines produced in the state of São Paulo. In this study, several analysis were conducted to provide data that can help to evaluate the quality of the Paulista wine and consequently direct the necessary corrections in the process of winemaking. The aim of this study was to characterize physico-chemically and investigate the patterns of identity and quality of the wines described by Brazilian law. Thus, we performed analyzes of pH, total acidity, volatile acidity crude, volatile acidity adjusted, total sugars, total sulfur dioxide, alcohol content, acetaldehyde, methanol, and carbon isotope ratio of oxygen. We analyzed 24 samples of Paulista wines, processed by 12 producers from American, wine grapes and hybrid grapes from the 2011harvest. From the results, it was observed that 87.5% of the samples met the legal requirements. Only two samples from different producers, exceeded the legal limits for acidity, which can be explained by excessive rainfall occurred during the harvest of 2011. As for the sugar content, only one sample showed divergence between the value found in the assays and the value referenced in labeling. All wines showed high alcohol content appropriate to the legal limits, but there was a difference of up to 15% percent from the levels recorded on labels and checked in for tests. The levels of methanol were found below the limit. For acetaldehyde concentrations ranged between 4.51 ± 0.52 mg.L-1 and 87.22 ± 2.21 mg.L-1, and the recommended is 50 mg.L-1. The results for the carbon isotope ratio demonstrated that 55% of the wines evaluated were out of the legal limits for correction of alcoholic content. For oxygen isotope ratio of all samples were found above the reference values for wines from São Paulo crop of 2011, indicating no addition of exogenous water. However, the samples that are at odds with the legislation indicate that there is a need to strengthen the guidelines for producers and perform a more effective control of the production process / Doutorado / Ciência de Alimentos / Doutora em Ciência de Alimentos
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Space radiation-induced bystander effect : kinetics of biologic responses, mechanisms, and significance of secondary radiations / Effet de proximité induit par ions lourds d'origine cosmique : cinétique des réponses biologiques, mécanismes et importance des radiations secondairesGonon, Géraldine 12 December 2011 (has links)
De nombreuses études ont montré que l'exposition de cultures cellulaires à des particules α conduit à des changements biologiques importants autant dans les cellules irradiées que dans les cellules bystander non-irradiées. L'étude des réponses biologiques non-ciblées dans des cultures cellulaires exposées à de faibles fluences d’ions lourds permet d’estimer les risques pour la santé du rayonnement spatial et de la radiothérapie. Nous avons caractérisé les mécanismes sous-jacents de l'induction d'effets stressants dans des cultures confluentes de fibroblastes normaux humains exposés à de faibles fluences d’ions fer de 1000 MeV/u (transfert d'énergie linéique (TEL) ~151 keV/µm), d’ions silicium de 600 MeV/u (TEL ~50 keV/µm) ou d’ions carbone de 290 MeV/u (TEL ~13 keV/µm). Nous avons comparé ces résultats avec ceux obtenus dans des cultures cellulaires exposées, en parallèle, à de faibles fluences de particules α de 0,92 MeV/u (TEL ~109 keV/µm). L'induction de dommages à l'ADN, les changements dans l'expression des gènes, la carbonylation des protéines et la peroxydation lipidique durant les 24 h suivant l'exposition de cultures confluentes à de faibles doses (0,2 cGy et plus) d’ions fer ou d'ions silicium ont très largement contribué à la propagation d’effets stressants des cellules irradiées aux cellules bystander non-irradiées. Pour une dose moyenne de 0,2 cGy, seules ~1 et 3 % des cellules seraient irradiées dans le noyau par un ion, respectivement, fer ou silicium. Les immunoblots ont révélés des augmentations significatives des niveaux de phospho-TP53 (sérine 15), p21Waf1 (CDKN1A), HDM2, phospho-ERK1/2, de carbonylation des protéines et de peroxydation lipidique dans les 24 h suivant l’exposition. L'ampleur de ces réponses suggère la participation de cellules non ciblées dans les effets observés. De plus, lorsque les populations cellulaires irradiées ont été ré-ensemencées dans un milieu de culture frais peu après l'irradiation, les niveaux de ces marqueurs ont aussi augmentés durant 24 h. Ensemble, ces résultats montrent un effet rapidement propagé et persistant. Des analyses in situ réalisées dans des cultures cellulaires confluentes ont montré que la formation de foyers de la protéine 53BP1, marqueur de dommages à l'ADN, touchait un nombre de cellules plus important que celui auguré par la fraction de cellules traversées dans le noyau par un ion fer ou silicium. Cet effet est exprimé dès 15 min suivant l'exposition, atteint son maximum 1 h après l’exposition puis diminue jusqu’à 24 h. Une tendance similaire s'est produite après exposition à une dose moyenne absorbée de 0,2 cGy de particules α de 3,7 MeV, mais non après 0,2 cGy d’ions carbone de 290 MeV/u.Des analyses utilisant des puits de cultures intégrant une fine épaisseur de CR-39, détecteur solide de traces nucléaires, et permettant ainsi l’identification des cellules irradiées aux ions fer ou silicium, confirment la participation de cellules bystander dans la réponse au stress. Des études mécanistiques ont, de plus, indiqué que les jonctions gap permettant la communication intercellulaire, certaines voies de la réparation de l’ADN, ainsi que le métabolisme oxydatif participent à la propagation des effets non ciblés induit par des radiations de haut TEL. Nous avons également examiné la contribution possible des particules secondaires produites le long des traces d’ions primaires dans les réponses biologiques. Les simulations réalisées avec le code de transport de particules FLUKA ont révélé que la dose due aux produits de fragmentation, autres que les électrons, est inférieure à 1 % de la dose absorbée dans les cultures cellulaires exposées à des ions lourds. De plus, la dose radiale des ions lourds secondaires est limitée à ~10-20 µm autour de l’ion primaire. Ainsi, ces derniers sont peu susceptibles de contribuer de manière significative à la réponse biologique observée dans des cellules non ciblées par des ions lourds primaires / Widespread evidence indicates that exposure of cell cultures to α particles results in significant biological changes in both the irradiated and non-irradiated bystander cells in the population. The induction of non-targeted biological responses in cell cultures exposed to low fluences of high charge (Z) and high energy (E) particles is relevant to estimates of the health risks of space radiation and to radiotherapy. Here, we investigated the mechanisms underlying the induction of stressful effects in confluent normal human fibroblast cultures exposed to low fluences of 1000 MeV/u iron ions (linear energy transfer (LET) ~151 keV/µm), 600 MeV/u silicon ions (LET ~50 keV/µm) or 290 MeV/u carbon ions (LET ~13 keV/µm). We compared the results with those obtained in cell cultures exposed, in parallel, to low fluences of 0.92 MeV/u α particles (LET ~109 keV/µm).Induction of DNA damage, changes in gene expression, protein carbonylation and lipid peroxidation during 24 h after exposure of confluent cultures to mean doses as low as 0.2 cGy of iron or silicon ions strongly supported the propagation of stressful effects from irradiated to bystander cells. At a mean dose of 0.2 cGy, only ~1 and 3 % of the cells would be targeted through the nucleus by an iron or silicon ion, respectively. Within 24 h post-irradiation, immunoblot analyses revealed significant increases in the levels of phospho-TP53 (serine 15), p21Waf1 (also known as CDKN1A), HDM2, phospho-ERK1/2, protein carbonylation and lipid peroxidation. The magnitude of the responses suggested participation of non-targeted cells in the response. Furthermore, when the irradiated cell populations were subcultured in fresh medium shortly after irradiation, greater than expected increases in the levels of these markers were also observed during 24 h. Together, the results imply a rapidly propagated and persistent bystander effect. In situ analyses in confluent cultures showed 53BP1 foci formation, a marker of DNA damage, in more cells than expected based on the fraction of cells traversed through the nucleus by an iron or silicon ion. The effect was expressed as early as 15 min after exposure, peaked at 1 h and decreased by 24 h. A similar tendency occurred after exposure to a mean absorbed dose of 0.2 cGy of 3.7 MeV α particles, but not after 0.2 cGy of 290 MeV/u carbon ions.Analyses in dishes that incorporate a CR-39 solid state nuclear track detector bottom identified the cells irradiated with iron or silicon ions and further supported the participation of bystander cells in the stress response. Mechanistic studies indicated that gap junction intercellular communication, DNA repair, and oxidative metabolism participate in the propagation of the induced effects.We also considered the possible contribution of secondary particles produced along the primary particle tracks to the biological responses. Simulations with the FLUKA multi-particle transport code revealed that fragmentation products, other than electrons, in cells cultures exposed to HZE particles comprise <1 % of the absorbed dose. Further, the radial spread of dose due to secondary heavy ion fragments is confined to approximately 10-20 µm Thus, the latter are unlikely to significantly contribute to the stressful effects in cells not targeted by primary HZE particles.
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New insights in photodynamic theraphy: production, diffusion and reactivity of singlet oxygen in biological systemsJiménez Banzo, Ana María 25 April 2008 (has links)
S'ha estudiat la cinètica de fotosensibilització de l'oxigen singlet (1O2) en cèl·lules eucariotes en suspensió mitjançant un espectròmetre d'última generació amb resolució temporal per sota del microsegon. Els estudis revelen que la cinètica del 1O2 depèn del seu lloc de formació. Per una banda, la producció del 1O2 es més lenta en els lisosomes que en el nucli. Per altra banda, el 1O2 es capaç d'escapar de les cèl·lules quan es fotosensibilitza en el nucli, però es queda confinat al interior si es fotosensibilitza en els lisosomes. Malgrat que el temps de vida del 1O2 es troba en els microsegons, la desactivació principal ve donada per interaccions amb les biomolècules característiques de cadascú dels orgànuls. La incertesa respecte a la producció de 1O2 en un orgànul determinat es pot eliminar mitjançant l'ús de fotosensibilitzadors modificats genèticament, ja que aquets poden ésser expressats selectivament. Amb aquesta finalitat, s'avaluen les propietats fotosensibilitzants de mutants de proteïna fluorescent verd (GFP). Algunes de les GFPs estudiades sensibilitzen la formació del 1O2 malgrat amb baixa eficiència. Els resultats obtinguts es comparen amb els del cromòfor de la GFP i mostren que l'estructura proteínica, a sobre de modular les propietats fotofísiques del cromòfor, també el protegeix de la desactivació col·lisional. Finalment, s'estudien les propietats d'absorció bifotónica del 2,7,12,17-tetrafenilporficé i del seu complex de pal·ladi (II). L'eficiència de formació del 1O2 per part dels dos compostos, desprès de l'absorció simultània de dos fotons, es aproximadament 100 vegades superior a la dels seus anàlegs porfirínics, amb seccions d'absorció bifotòniques δ ~ 25 GM. Les excel·lents propietats d'aquestos compostos s'expliquen mitjançant arguments qualitatius i s'analitzen les seves perspectives de cara al seu ús en teràpia fotodinámica. / Se ha estudiado la cinética de fotosensibilización de 1O2 en células eucariotas en suspensión, usando un espectrómetro de última generación con resolución temporal por debajo del microsegundo. Los estudios revelan que la cinética del 1O2 depende de su lugar de formación. Por una parte, la producción de 1O2 es más lenta en los lisosomas que en el núcleo. Por otra parte, el 1O2 es capaz de escapar de las células cuando es fotosensibilizado en el núcleo, mientras que queda confinado en el interior si se fotosensibiliza en los lisosomas. A pesar de que el tiempo de vida del 1O2 se encuentra en los microsegundos, la desactivación principal viene dada por interacciones con las biomoléculas características de cada orgánulo. La incertidumbre respecto a la producción de 1O2 en un orgánulo determinado puede ser eliminada mediante el uso de fotosensibilizadores modificados genéticamente ya que pueden ser expresados selectivamente. Con este fin, se evalúan las propiedades fotosensibilizantes de mutantes de proteína fluorescente verde (GFP). Algunas de las GFPs estudiadas sensibilizan la formación de 1O2 aunque con baja eficiencia. Los resultados obtenidos se comparan con los del cromóforo de la GFP y muestran que la estructura proteínica, además de modular las propiedades fotofísicas del cromofóro, también lo protege de la desactivación colisional. Finalmente, se estudian las propiedades de absorción bifotónica del 2,7,12,17-tetrafenilporficeno y de su complejo de paladio (II). La eficacia de formación de 1O2 de ambos compuestos, tras la absorción simultánea de dos fotones, es aproximadamente 100 veces superior a la de sus análogos porfirínicos, con secciones de absorción bifotónica δ ~ 25 GM. Las excelentes propiedades de estos compuestos se explican mediante argumentos cualitativos y se analizan sus perspectivas de cara a su uso en terapia fotodinámica. / The kinetics of singlet oxygen (1O2) photosensitisation in human skin fibroblasts have been investigated by means of an ultrasensitive near-infrared spectrometer with submicrosecond time resolution. The results indicate that the 1O2 kinetics are site-dependent. On one hand, the production of 1O2 is slower in the lysosomes than in the nucleus. On the other hand, 1O2 is able to escape out of the cells when photosensitised in the nucleus, while 1O2 photosensitized in the lysosomes is confined. Despite showing a lifetime in the microsecond time domain, the decay of 1O2 is governed by interactions with the biomolecules within the organelle there it is produced. The uncertainty as to the intracellular site of 1O2 production may be removed by the use of genetically-encoded photosensitisers, which can be expressed in any desired organelle. Towards this end, the ability of some fluorescent proteins (GFPs) to photosensitise 1O2 has been studied. Some of the studied proteins are able to produce 1O2 albeit with a very low quantum yield. The results obtained are compared to those of the synthetic GFP chromophore and indicates that the protein scaffold not only plays a role in modulating the photophysical properties of the chromophore but also has a protective function from collisional quenching. Finally, the two-photon absorption properties of tetraphenylporphycene and its palladium (II) complex have been determined. These compounds are ca. 100-fold more efficient two-photon 1O2 photosensitisers than their isomeric porphyrin counterparts, with two-photon absorption cross sections δ ~ 25 GM. Qualitative symmetry-based arguments are provided to explain the excellent two-photon properties and the prospects for photodynamic therapy are discussed.
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