Tesi: "Irradiation quality"

1

Moreno, Tinjaca Maria Alexandra. "Effect of electron beam irradiation on quality and shelf-life of Tommy Atkins mango (Mangifera indica l.) and blueberry (Vaccinium corymbsum l.)". Texas A&M University, 2005. http://hdl.handle.net/1969.1/4726.

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The main goal of this research was to determine the feasibility of using electron beam irradiation as an alternative disinfestation technology while preserving the overall quality of mangoes, and to verify its suitability for the preservation shelf life of blueberries. Physicochemical and sensory characteristics of the fruits were evaluated. Mangoes were irradiated at 1.0, 1.5 and 3.1 kGy using a 10MeV (10 kW) linear accelerator (LINAC) with double beam fixture. Samples were stored at 12ÃÂºC and 62.7% RH for 21 days. Blueberries packed in plastic clamshell containers were irradiated at 1.1, 1.6 and 3.2 kGy doses using the same linear accelerator with a single beam. The shelf life of the berries stored at 5ÃÂºC and 70.4% RH was evaluated for 14 days. The firmness of mangoes irradiated at 1.5 and 3.1 kGy significantly (p > 0.05) decreased during storage. There was a reduction of total sugars (8.1% and 14.1%) in samples irradiated at 1.0 kGy and 1.5 kGy, respectively. All irradiated mangoes had significantly lower (50- 70 %) ascorbic acid content throughout storage. The phenolic compounds increased in samples irradiated at 1.5 kGy (27.4%) and 3.1 kGy) (18.3%). Sensory evaluation of the fruits irradiated with 3.1 kGy showed significantly less acceptability for overall quality, color, texture and aroma. Irradiation of blueberries at 1.1 kGy had no significant (p > 0.05) effect on the fruits' physicochemical characteristics with the exception of ascorbic acid which decreased by 17% after 14 days. A significant decrease in texture (firmness) of irradiated berries was observed during storage time. Total sugars decreased in all irradiated fruits while total phenolics and tannins increased (10 -20%). Sensory attributes of samples irradiated with 1.1 kGy and 1.6 kGy were found acceptable by the panelists. The high dose-treated fruits were considered unacceptable. The results from this research suggest that a 1.5 kGy is the best treatment to maintain the quality attributes of mangoes and increase the shelf life by three days. The electron beam irradiation of packed blueberries at doses of 1.1 and 1.6 kGy ensures and enhances the quality and the shelf life of blueberries up to 14 days.

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2

Tewfik, Ihab Hamdy. "Rapid methods for the identification of gamma irradiated lipid containing foods". Thesis, London South Bank University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267387.

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3

Schmidt, Heather Martin. "Improving the microbiological quality and safety of fresh-cut tomatoes by low dose electron beam irradiation". Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/2767.

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The effect of electron beam irradiation upon microbiological quality and safety of fresh-cut tomatoes was studied. Preliminary studies were conducted to ensure reliability of the rifampicin-resistant strain versus the parent strain of Salmonella serovar Montevideo for use in this study. Growth curve, heat tolerance and lactic acid resistance studies were performed, all of which showed no differences in behavior between the organisms. Fresh tomatoes were obtained from a local supplier and then cut into cubes with stem scars being separated. Both cubes and stem scars were inoculated with a rifampicin- resistant strain of either Salmonella Montevideo or Salmonella Agona, separated into treatment groups and treated by electron beam irradiation at 0.0 kGy (control), 0.7 kGy or 0.95 kGy. The effect of electron beam irradiation was determined for Salmonella, yeast, mold, and lactic acid bacteria (LAB) populations as well as pH on tomato cubes and stem scars over a 15-day storage period at 4??C. Results indicated that while irradiation treatment significantly reduced most microbial populations on tomato samples, there were no differences in the microbial populations between treatments of 0.7 kGy or 0.95 kGy. Irradiation at either dose resulted in a significant reduction of Salmonella Montevideo when compared to the control, with an initial reduction of 1.8 and 2.2 log10 CFU/g on tomatoes for 0.7 kGy and 0.95 kGy, respectively. LAB, yeasts and molds were more resistant to the treatment than Salmonella. Populations present on stem scars and tomato cubes did experience some differences in log reductions, possibly due to the protective effect of the stem scar on microorganisms. However, no differences were detected between the two Salmonella serotypes in response to irradiation treatment. This study indicates that doses of irradiation greater than 1 kGy should be used in fresh-cut tomatoes to eliminate significant populations of pathogens, as well as to ensure the microbial quality of the product. Additional studies also need to be conducted to examine the effects of higher irradiation doses on the sensory qualities of fresh-cut tomatoes.

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4

Anderson, Cody. "Benchmarking of different solar spectra quality control methods". Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/201343/1/Cody_Anderson_Thesis.pdf.

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This thesis addresses the current lack of quality control tools available to assess solar spectral irradiance measurements. Spectral measurements are very data rich and can be overwhelming to manually check. The purpose of this project was aimed towards developing a solar spectra data screening method and ultimately create an automated quality control and assurance tool. Measured spectra were assessed as good or bad by comparing them to the spectral model AeroSMARTS. Efficacy of the novel methodologies was demonstrated by cross comparison with a manually screened reference dataset.

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5

Palekar, Mangesh Prafull. "Attachment of Salmonella on cantaloupe and effect of electron beam irradiation on quality and safety of sliced cantaloupe". Texas A&M University, 2004. http://hdl.handle.net/1969.1/3285.

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Increase in consumption of fresh produce over the past decade has resulted in a rise in incidents of foodborne outbreaks due to pathogens. Chemical sanitizers have been extensively used in the industry for decontamination of fresh produce. However, they are ineffective in certain commodities and under certain processing conditions, necessitating the evaluation of alternative technologies. Electron beam irradiated sliced cantaloupe were tested for 21 days of storage for total aerobic bacterial counts, texture, color and sensory parameters as a function of irradiation doses 0, 0.7 and 1.4 kGy and the wash treatments, water and 200 mg/L chlorine applied to the melons before cutting. Melons washed only with water prior to cutting had total aerobic bacterial counts of 4.0, 2.0 and 0.8 log cfu/g on day 0 at irradiation doses of 0, 0.7 and 1.4 kGy respectively. On day 0, melons washed with chlorine prior to cutting had total aerobic bacterial counts of 2.7, and 0.7 log cfu/g at irradiation doses of 0 and 0.7 kGy and below detection limit at 1.4 kGy. Texture measured as compression force was lower only for cantaloupe irradiated at 1.4 kGy. Irradiation did not affect objective color and descriptive attribute flavor and texture sensory attributes of cantaloupe. Irradiation reduced Salmonella Poona by 1.1 log cfu/g at 0.7 kGy and 3.6 log cfu/g at 1.5 kGy. The D-value of S. Poona on irradiated sliced cantaloupe was found to be 0.211 kGy. Among the spoilage organisms, lactic acid bacteria and mold were reduced effectively by irradiation but there was no significant effect on reduction of yeasts. Our results show that electron beam irradiation in combination with chemical sanitizers is effective in decontamination of fresh-cut produce. Electron microscopy images provided valuable information on attachment sites of S. Poona on cantaloupe rind. The ineffectiveness of chemical sanitizers due to possible inaccessibility to pathogens in these attachment sites provides the basis for application of irradiation in decontamination of fresh produce.

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6

Silva, Marcus Henriques da. "Efeitos da radiação gama do cobalto-60 em semente de café arábica e conillon: avaliação físico-química". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/64/64134/tde-18012013-141525/.

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O Brasil é o maior produtor e exportador de café do mundo. O café em grãos é um dos principais produtos da balança comercial brasileira. Duas espécies de café são as mais importantes economicamente: o Coffea arabica L. e Coffea canephora Pierre sendo o maior representante do Coffea canephora Pierre o conillon. A irradiação de alimentos é uma área de pesquisa que tem por objetivo aumentar a vida útil de prateleira dos alimentos e controlar as pragas. Este trabalho teve como objetivo verificar se as variáveis físico-químicas do café arábica e conillon foram afetadas quando submetidas à doses de radiação gama do Cobalto-60. As amostras foram cedidas pelo Polo de Tecnologia em Qualidade do Café da Universidade Federal de Lavras - UFLA. As amostras de café foram submetidas à irradiação com doses de: 0 (testemunha), 5 kGy e 10 kGy, em um irradiador multiproposito do IPEN - Instituto de Pesquisas Energética e Nucleares da Universidade de São Paulo, sob uma taxa de 7,5 kGy/hora. Para a irradiação as amostras foram embaladas a vácuo em embalagens aluminizadas apropriadas. Após o processo de irradiação as amostras foram armazenadas a uma temperatura de 15 ± 1ºC e umidade relativa de 17 ± 1%. Foram realizadas as seguintes análises: teores de açucares totais, glicose, sacarose, cafeína, umidade, pH, acidez total titulável, fibras e condutividade elétrica. As análises foram realizadas 1, 30, 60 e 90 dias após a irradiação e os resultados obtidos foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5%. Observou-se que os resultados das análises das amostras irradiadas com doses de 5 kGy e 10 kGy apresentaram valores semelhantes ao da testemunha. Foi concluído que a irradiação não induziu efeitos deletérios nas sementes de café arábica e conillon irradiados com 5 kGy e 10 kGy até 90 dias após a irradiação
Brazil is the largest producer and exporter of coffee in the world. The coffee bean is one of the main products of the Brazilian trade balance. Two species of coffee are the most economically important: the Coffea arabica L. and Coffea canephora Pierre is the largest representative of the Coffea canephora Pierre is the coffea conillon. Food irradiation is an area of research that aims to increase the shelf life of foods and controlling pests. This study aimed to verify the physicochemical variables of Arabica coffee and conillon were affected when exposed to doses of gamma radiation from cobalt-60. The samples were provided by Polo in Coffee Quality Technology, Federal University of Lavras - UFLA. The coffee samples were subjected to irradiation doses: 0 (control), 5 kGy and 10 kGy, a multipurpose irradiator of IPEN - Research Institute of Nuclear Energy and the University of São Paulo, at a rate of 7.5 kGy / hour. For irradiation the samples were vacuum-packed in appropriate packaging aluminised. After the process of irradiation the samples were stored at a temperature of 15 ± 1 º C and relative humidity of 17 ± 1%. The following analyzes were performed: levels of total sugars, glucose, sucrose, caffeine, humidity, pH, total acidity, electrical conductivity and fibers. Analyses were performed 1, 30, 60 and 90 days after irradiation, and the results were submitted to analysis of variance and means were compared by Tukey test at 5%. It was observed that the analysis results of the samples irradiated with 5 kGy and 10 kGy showed values similar to the control. It was concluded that irradiation did not induce deleterious effects on arabica coffee seeds and conillon irradiated with 5 kGy and 10 kGy to 90 days after irradiation

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7

BOARATTI, MARIA de F. G. "Analise de perigos e pontos criticos de controle para alimentos irradiados no Brasil". reponame:Repositório Institucional do IPEN, 2004. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11224.

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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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8

Udrescu, Mihaela. "Développement d'une technique de radiothérapie stéréotaxique des cancers de la prostate reposant sur deux concepts différents de préservation de la paroi rectale". Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10319/document.

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Le présent travail de thèse décrit le développement d'un protocole d'irradiation stéréotaxique combinée à une radiothérapie conformationnelle avec modulation d'intensité. Ce projet a été initiée dans le service de radiothérapie-oncologie du Centre Hospitalier Lyon Sud. La première partie de ce travail fait état d'une revue de littérature sur les techniques d'irradiation du cancer de la prostate. Trois grands thèmes de recherche ont été identifiés et developpés : un premier thèse de recherche portant sur la définition optimale des volumes à irradier lors d'une irradiation stéréotaxique de la prostate et la fiabilité d'uin repérage de l'oragane par des marqueurs intra-prostatiques. La deuxième thématique de recherche était dédiée à la planification du traitement stéréotaxique de la prostate avec pour principal objectif une protection optimale de la paroi rectale avec deux approches différentes : a) une augmentation focalisée de la dose d'irradiation uniquement sur la tumeur macroscopiquement visible, ou b) l'utilisation d'un gel injecté entre la paroi du rectum et la prostate. Le nombre optimal de faisceaux à utiliser ainsi que l'énergie la mieux adaptée ont été évalués dans le cadre de la première approche avec uin boost intégré.. La trosième thématique portait sur les contrôles qualité à réaliser dans le cadre de la mise en route de cette technique d'irradiation. Trois détecteur dédiés aux contrôles de la distribution de dose sous l'accélarateur ont été évalués. L'ensemble de ces travaux serviront de supports à la réalisation d'une étude de phase II intégrant une irradiation stéréotaxique des cancers de la prostate avec injection de gel d'acide hyaluronique entre le rectum et la prostate
The current work decribes the implementation of a protocol for stereotactic body radiotherapy (SBRT) combined with an intensity-modulated radiation therapy technique (IMRT). the project was initiated in the Department of Radiation-Oncology from Lyon Sud Hospital. The first part summarizes the state of the art of prostate cancer with a literature review on irradiation techniques. Three research themes were described and developped : The first theme discusses the optimal definition of the volumes to be irradiated during a prostate SBRT and the accuracy of the target localization using intraprostatic markers. The second theme of research describes the treatment planning for prostate SBRT having as main purpose an optimal protection of the rectal-wall with two different approaches: a) an augmentation of the dose with simultaneous integrated boost only into visible macroscopic tumor, or b) the use of a gel injected between the rectal-wall and the prostate. The optimal number of fields, as well as the most favorable energy, was evaluated in the context of the first approach with a simultaneous integrated boost. The third theme discusses the quality assurance (QA) that needs to be performed for an IMRT-SBRT technique. Three detectors that ara dedicated to the QA of dose distribution under accelerator were evaluated. The results of all these studies will be used for the implementation of a phase II study for prostate SBRT with an injection of hyaluronic acid between the rectum and the prostate

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9

Hirashima, Hideaki. "Establishment of machine and patient-specific quality assurance methods for advanced volumetric modulated arc therapy". Kyoto University, 2019. http://hdl.handle.net/2433/242352.

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10

Le, roy Julien. "Optimisation des explorations tomodensitométriques des artères coronaires chez l’enfant atteint de cardiopathie congénitale". Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTT058.

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L’angioscanner des artères coronaires est utilisé de façon croissante chez l’enfant dans le diagnostic, le suivi, et les bilans pré- et post-chirurgicaux des pathologies à risque d’atteinte coronaire, et plus particulièrement dans certaines cardiopathies congénitales. Son utilisation en pédiatrie reste cependant limitée par la présence d’artefacts de mouvements cardiaques, dégradant la qualité d’image et entravant potentiellement le diagnostic, ainsi que par le caractère irradiant de l’examen, et le risque de cancer radio-induit associé à prendre en considération dans cette population pédiatrique.L’objectif de ce travail de thèse a été d’évaluer et de proposer des stratégies d’amélioration de l’angioscanner des artères coronaires réalisé chez l’enfant atteint de cardiopathie congénitale.Cinquante enfants âgés de moins de 18 ans, d’une cohorte de patients présentant une cardiopathie congénitale impliquant la réalisation d’un angioscanner des artères coronaires, ont été prospectivement inclus dans le protocole de recherche clinique COROPEDIA (Observational study for feasibility and performance of sub-millisievert coronary computed tomography angiography for coronary artery anomalies in paediatric patients), mis en place au cours de cette thèse. Entre 2017 et 2018, ces enfants ont ainsi bénéficié d’un angioscanner des artères coronaires, réalisé sur un scanner mono-source à large collimation.La première partie de ce travail a consisté en l’élaboration d’un protocole d’acquisition optimisé, dérivé des dernières études réalisées chez l’adulte (très peu de publications chez l’enfant). Quinze scenarii d’acquisitions spécifiques ont ainsi été mis en place en fonction du rythme cardiaque du patient et de sa variabilité. Ces acquisitions multiphasiques sélectives ont permis de répondre à la question clinique posée dans 100% des cas, pour une dose efficace équivalente à moins de 4 mois d’irradiation naturelle.Afin d’améliorer d’avantage la qualité de visualisation des structures tout en réduisant les durées d’irradiation, deux autres études ont été menées. Ainsi, l’impact d’algorithmes de correction d’artefacts de mouvements a été évalué en pédiatrie. Une interprétabilité équivalente aux reconstructions multiphasiques a été obtenue dans une unique phase cardiaque reconstruite par le logiciel, alors que les reconstructions monophasiques traditionnelles montraient une interprétabilité significativement inférieure. Ces solutions logicielles permettraient donc d’améliorer la visualisation des structures cardiaques, tout en réduisant encore les durées d’acquisitions scanographiques nécessaires au diagnostic et donc les doses délivrées aux enfants.Enfin, dans un troisième temps, les artefacts cinétiques de chacun des 50 patients ont été quantifiés dans 7 phases cardiaques différentes. Cette évaluation portant sur un total de 5733 structures cardiaques, a permis de définir les positions (70%, 80%, 40%, 47%, 50%, 54% de l’intervalle R-R, respectivement) et durées optimales (10%, 20%, 50%, 50%, 20%, 10% du cycle cardiaque, respectivement) des fenêtres d’acquisition, en fonction du rythme cardiaque de l’enfant (≤60 bpm, 61-75 bpm, 76-85 bpm ; 86-100 bpm ; 101-130 bpm ; >130 bpm).La mise en application simultanée de ces stratégies d’optimisation, devraient permettre la réalisation d’angioscanner des artères coronaires de qualité diagnostique chez n’importe quel enfant, pour une dose d’irradiation inférieure à 0,5 mSv, soit moins de 2 mois d’exposition naturelle
Coronary computed tomography angiography (CCTA) has been increasingly used in pediatrics for diagnosis, follow-up, and pre or post-surgery assessment of coronary artery anomalies, and more generally in congenital heart diseases. However, its use remains limited by cardiac motion artifacts, potentially resulting in non-diagnostic acquisitions, and by children’s exposure associated with a risk of radiation induced cancers.The aim of this thesis was to evaluate and optimize CCTA performed in children with congenital heart disease.Fifty children (<18 years old), with congenital heart disease requiring coronary artery imaging were prospectively enrolled in the COROPEDIA clinical trial, specifically designed during the thesis (Observational study for feasibility and performance of sub-millisievert coronary computed tomography angiography for coronary artery anomalies in paediatric patients). Between 2017 and 2018, these children underwent a coronary CT angiography, performed on a wide-coverage, single-source CT. The first part of this work was dedicated to elaborating an optimized acquisition protocol, derived from adult studies (very few studies have been conducted with pediatric patients). Fifteen acquisition schemes were designed to deliver irradiation at the best theoretical moment, as a function of patient’s heart rate and variability. These selective multiphasic acquisitions fully answered the clinical question for every child, delivering a radiation dose equivalent to less than 4 months of natural background irradiation.Two additional studies were conducted to improve cardiac structure visualization while reducing further children’s exposure.The impact of motion correction algorithms in children undergoing CCTA was investigated. The results suggested that multiple phases provided significantly better interpretability than traditional single-phase acquisitions. However, the second motion correction algorithm generation offered similar interpretability in a single retrospectively processed cardiac phase and could be adopted to improve coronary artery visualization while reducing beam-on-time and children’s exposure to radiation.Finally, motion artifacts of every fifty patients were quantified in seven different cardiac phases. On a total of 5733 cardiac structures evaluated, optimal positions (70%, 80%, 40%, 47%, 50%, 54% of the R-R interval, respectively) and durations (10%, 20%, 50%, 50%, 20%, 10% of the cardiac cycle, respectively) of the acquisition window were defined as a function of children’s heart rates (≤60 bpm, 61-75 bpm, 76-85 bpm ; 86-100 bpm ; 101-130 bpm ; >130 bpm).These optimization strategies might be simultaneously implemented to achieve CCTA of diagnostic quality in any children, for less than 0.5 mSv, or two month of natural background irradiation

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SUMIYA, LUIZ C. do A. "Estudo de parâmetros relevantes na irradiação de sup(124)Xe, visando a otimização na obtenção de sup(123)I ultra puro no ciclotron cyclone-30 IPEN-CNEN/SP". reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11477.

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IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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12

Pires, Juliana Angelo. "Efeito da radiação gama (60Co) em fermentado de jabuticaba, tipo vinho tinto". Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-21062018-090921/.

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A jabuticaba é uma fruta tropical, tipicamente brasileira, sendo originária da região centro-sul. Popularmente apreciada por suas características sensoriais in natura, é também utilizada em produtos como geleias, licores e bebidas fermentadas. Qualquer fruta que contenha níveis razoáveis de açúcar é possível de se produzir um bom vinho, com sabores característicos de cada fruta. Fermentado de fruta é a bebida com graduação alcoólica de quatro a quatorze por cento em volume, a vinte graus Celsius, obtida pela fermentação alcoólica do mosto de fruta sã, fresca e madura. O objetivo deste trabalho foi de fabricar e irradiar vinhos de jabuticaba com radiação gama (Co60) para possível envelhecimento precoce. Para a fabricação do vinho as jabuticabas foram higienizadas com ácido Peracético PAC 200 e 24kg das frutas selecionadas foram prensadas ate o rompimento das bagas. O mosto obtido juntamente com as cascas e sementes foram colocados em balde fermentador devidamente higienizados. O mosto foi tratado com 2,4g de metabissulfito de sódio e após alguns minutos foi adicionado 250g de leveduras Saccharomyces cerevisiae do tipo Fleishmann e 2kg de açúcar para a correção dos sólidos solúveis. A fermentação ocorreu por 7 dias até que os sólidos solúveis estivessem próximos de zero. Depois o vinho foi filtrado e centrifugado para a retirada das leveduras e envasado em recipientes de vidro escuro sendo divididas em quatro tratamentos (controle e irradiados nas doses de 5; 10 e 15kGy) por período de armazenamento de 0, 60 e 120 dias após a irradiação, em triplicata. Realizou-se análises físico-químicas de sólidos solúveis totais (SST), pH, acidez total, acidez volátil, acidez fixa, teor alcóolico, teor de antocianinas, taninos e idade química e cinzas. Foi realizada análise para determinar o tipo de leveduras após a fermentação através da análise de PCR. Através dos resultados obtidos observa-se que para o teor alcoólico as três doses utilizadas diminuíram o teor alcoólico, mas que ao longo dos dias analisados todas as amostras se elevaram. A maioria dos padrões apresentaram-se dentro da legislação vigente, para quantificação de antocianina averiguou-se que quanto maior a dose aplicada maior a degradação das mesmas e também o mesmo se observa para o tempo analisado; para quantificação de taninos observou-se que o aumento da dose causa decaimento dos mesmos, e que ao longo do tempo a tendência dos mesmos é aumentar, seja irradiado ou não; para análise de idade química observou-se que aparentemente houve envelhecimento das amostras irradiadas, mas que o fator tempo é um grande interferente nos efeitos iniciais causados pela radiação e para análise de PCR nas leveduras chegou-se ao resultado que a levedura inicial utilizada possuía a mesma sequencia de DNA da levedura colhida após o processo fermentativo. Portanto conclui-se que pelo comportamento observado através das moléculas de pigmentação que polimerizam com a irradiação características de envelhecimento o \"vinho\" tinto de jabuticaba sofreu envelhecimento, que as melhores doses foram a de 5 e 10kGy considerando todas as análises realizadas e as características adquiridas e que o tempo de 120 dias garantem a estabilidade necessária para esta bebida e que os padrões físico-químicos estão dentro da legislação.
Brazilian grape tree is a tropical fruit, typically Brazilian, originating in the south-central region. Popularly appreciated for its sensory characteristics in natura, it is also used in products such as jellies, liqueurs and fermented beverages. Any fruit that contains reasonable levels of sugar is possible to produce a good wine, with flavors characteristic of each fruit. Fermented fruit is a beverage with alcohol content of four to fourteen percent by volume, at twenty degrees Celsius, obtained by the alcoholic fermentation of healthy, fresh and ripe fruit must. The aim of this work was to brew and irradiate Brazilian grape tree wine with gamma radiation (Co60) for possible precocious aging. For the manufacture of the wine were, the Brazilian grape tree were sanitized with Peracetic acid PAC 200 and 24kg of the selected fruits were pressed until the breakage of the berries. The must obtained together with the peels and seeds were placed in fermenter bucket. The must was treated with 2.4 g of sodium metabisulfite and after a few minutes 250g of yeasts Saccharomyces cerevisiae, type Fleishmann, and 2kg of sugar were added to correct soluble solids. The fermentation occurred for 7 days until the soluble solids were close to zero. Then the wine was filtered and centrifuged to remove yeast and bottled in dark glass containers. The containers were divided into four treatment groups (control and irradiated at doses of 5, 10 and 15kGy) for a storage period of 0, 60 and 120 days after irradiation, in triplicate. Physicochemical analyzes were performed: total soluble solids (TSS), pH, total acidity, volatile acidity, fixed acidity, alcohol content, anthocyanin content, tannins, chemical age and ash. Analysis was performed to determine yeast type after fermentation by PCR analysis. From the results obtained, it can be observed that, for the alcoholic content, the three doses used decreased the alcohol content, but during the analyzed days all the samples increased. Most of the standards have been presented within the current legislation. For quantification of anthocyanin, it was found that the higher the dose applied the greater the degradation of the same and also the same is observed for the analyzed time. For anthocyanin quantification, it was found that the higher the dose applied the greater the degradation of the same and also the same is observed for the analyzed time. For tannins quantification, it was observed that the increase of the dose causes them to decay, and that over time the tendency of them is to increase, whether irradiated or not. For chemical age analysis, it was observed that there was aging of the irradiated samples, but that the time factor is a great interferent in the initial effects caused by the radiation. For PCR analysis in the yeasts it was found that the initial yeast used had the same yeast DNA sequence harvested after the fermentation process. Therefore, it was concluded that the behavior of the pigmentation molecules that polymerized with irradiation, characteristic of aged wines, the \"red wine\" of Brazilian grape tree was aged and considering all the analyzes performed and the characteristics acquired, that the best doses were 5 and 10kGy and that the time of 120 days guarantees the stability required for this drink and that physico-chemical standards are within the legislation.

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Moreira, Gláucia Cristina [UNESP]. "Radiação gama ou antimicrobianos naturais na conservação de melão minimamente processado". Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/103244.

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O presente trabalho teve por objetivo verificar os efeitos da radiação gama e de antimicrobianos naturais na conservação de melão minimamente processado, armazenado sob refrigeração. Foram realizados 4 experimentos: 1 e 2 - frutos de melão Cantaloupe e Pele de Sapo provenientes de Baraúna/RN e Juazeiro/BA, respectivamente; 3 e 4 - frutos de melão Cantaloupe e Gália provenientes da região de Cartagena (Espanha). Após a colheita, os frutos dos experimentos 1 e 2 foram transportados ao Laboratório de Frutas e Hortaliças da Faculdade de Ciências Agronômicas – UNESP – Botucatu/SP, e os dos experimentos 3 e 4 transportados para o Laboratório de Postrecolección e Refrigeración da Universidad Politécnica de Cartagena/Espanha. Após o processamento manual (corte em seções trapezoidais) os melões MP (minimamente processados) dos experimentos 1 e 2 foram acondicionados em embalagens de poliestireno expandido recobertas com filme de polietileno e irradiados nas doses: 0,0kGy; 0,1kGy; 0,2kGy; 0,3kGy; 0,4kGy e 0,5kGy. Os melões MP dos experimentos 3 e 4, após o processamento, foram imersos durante 1 minuto a 5ºC em: água (testemunha); vanilina (1000 mg L-1 e 2000 mg L-1); ácido cinâmico (148,16 mg L-1 e 296,32 mg L-1) e outros dois tratamentos consistiram em aplicação de vapor de ácido cinâmico (148,16 mg L-1 e 296,32 mg L-1) nos melões MP dentro da embalagem (bandejas de polipropileno termo seladas com filme de polipropileno). O armazenamento refrigerado foi realizado durante 10 dias 5±1ºC e 85-90% UR (experimentos 1 e 2) e à 5±1ºC e 85-95% UR (experimentos 3 e 4). As alterações na qualidade foram detectadas por meio das análises: perda de massa fresca, conservação pós-colheita, firmeza, pH, acidez titulável, sólidos solúveis, teores de açúcares redutores e redutores totais, ácido ascórbico, vitamina C, taxa respiratória, produção de etileno...
The aim of this research was to evaluated the effects of the gamma radiation and the natural antimicrobials in the conservation of fresh-cut melon storaged under refrigeration. Four experiments were accomplished: 1 and 2 – the varieties used were ‘Cantaloupe’ and ‘Pele de Sapo’ from Baraúna/RN and Juazeiro/BA, respectively; 3 and 4 - the varieties used were ‘Cantaloupe’ and ‘Gália’ from Cartagena (Spain). After harvesting, fruits from experiment 1 and 2 were sent to the Laboratory of Fruits and Vegetables at the University of Sao Paulo State (UNESP – Botucatu/SP). Fruits from experiment 3 and 4 were sent to the Postharvest and Refrigeration Group at the Technical University of Cartagena/Spain. After the manual processing (cut in trapezoidal sections) the fresh-cut melons of the experiment 1 and 2 were conditioned in polystyrene trays involved by polyethylene film and irradiated with doses: 0,0kGy; 0,1kGy; 0,2kGy; 0,3kGy; 0,4kGy and 0,5kGy. After processing, fresh-cut melons from experiment 3 and 4 were immersed for 1 min at 5ºC in water (control); vanillin (1000 mg L-1 and 2000 mg L-1); cinnamic acid (148,16 mg L- 1 and 296,32 mg L-1). Two additional treatments consisted on the application of cinnamic acid vapor (148,16 mg L-1 e 296,32 mg L-1) on fresh-cut melons within the packages (polypropylene trays heat-sealed with polypropylene). The storage was realized during 10 days in a cold camera to 5±1ºC and 85-90% HR (experiment 1 and 2) and to 5±1ºC and 85- 95% HR (experiment 3 and 4). The quality alterations were detected through the analyses: loss of fresh mass, postharvest conservation, firmness, pH, acidity titratable, soluble solids, reducing and total reducing sugar content, ascorbic acid, vitamin C, respiration rate, ethylene production, gas composition (CO2 and O2), enzymes activity (peroxidase, polygalacturonase and pectinmethylesterase), antioxidant... (Complete abstract click electronic access below)

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Camargo, Fabiana Taveira de. "Crescimento e maturação do fruto de café (Coffea arabica L.) em sistema arborizado e em monocultivo". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-19062007-095221/.

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A busca por condições climáticas que minimizem efeitos negativos de extremos de temperatura e irradiância, a arborização pode viabilizar a cafeicultura brasileira, em particular, com o advento das mudanças climáticas. A pesquisa avaliou a dinâmica do crescimento e da maturação do fruto e a produtividade do café sob diferentes níveis de luminosidade. O experimento foi composto por seringueiras e cafeeiros, plantados dentro e na interface do seringal, e em monocultivo. O gradiente de radiação disponível aos cafeeiros nas diferentes distâncias das seringueiras foi de 40, 45, 80 e 100 % e caracterizou os tratamentos. Avaliou-se o acúmulo de matéria seca de frutos nas fases da frutificação e a produtividade. Nas fases chumbinho, expansão e granação, o incremento varia com a quantidade de frutos na planta. A expansão depende da irradiância e a granação, do tempo de deposição de reservas. A matéria seca de frutos verde, verde-cana e cereja é superior nas plantas protegidas da face soalheira, favorecida pela exposição até 80 % de luminosidade. A produtividade aumenta, proporcionalmente, com a disponibilidade de luz, enquanto a expansão, o processo e a uniformidade da maturação são, também, beneficiados à exposição até 80 % da radiação solar.
In the searching for climatic conditions to minimize negative effects of high temperature and radiation excess, the shading system can make possible the Brazilian coffee crop. This research aimed to evaluate the growth and maturation of coffee fruits and its productivity under different levels of natural irradiance. Coffee plants were planted inside and aside of a rubber trees plantation and in monocrop. The irradiance gradient level available to coffee plants at different distances from rubber trees were of 40, 45, 80 and 100% and characterized the treatments. The accumulation of the fruits dry matter was evaluated in the phases of the fruiting / fructification and the productivity. In the fruit set (pellet-like berries), expansion and seed-filling stage phases, that increment varies according to the fruits amount in the plant. The expansion depends on the radiation and the seed-filling stage depends on the reserve deposition time. The dry matter increment of "green fruits", "green-cane" and "cherry" coffee fruits is superior in the shaded plants up to 80% of brightness with shade at afternoon. The productivity (grains.planta-1) increases proportionally to the available irradiância, while the expansion, the maturation and its uniformity are also benefited up to 80% available irradiance.

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DANTAS, DANIELLE M. "Toxicidade aguda e subaguda do radiofármaco sup(18)F-FDG". reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10541.

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IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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16

Moreira, Gláucia Cristina 1981. "Radiação gama ou antimicrobianos naturais na conservação de melão minimamente processado /". Botucatu : [s.n.], 2009. http://hdl.handle.net/11449/103244.

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Orientador: Rogério Lopes Vieites
Banca: Giuseppina Pace Pereira Lima
Banca: Vera Lúcia Mores Rall
Banca: Maria Monteiro Sigrist
Banca: Nelida Lúcia Del Mastro
Resumo: O presente trabalho teve por objetivo verificar os efeitos da radiação gama e de antimicrobianos naturais na conservação de melão minimamente processado, armazenado sob refrigeração. Foram realizados 4 experimentos: 1 e 2 - frutos de melão Cantaloupe e Pele de Sapo provenientes de Baraúna/RN e Juazeiro/BA, respectivamente; 3 e 4 - frutos de melão Cantaloupe e Gália provenientes da região de Cartagena (Espanha). Após a colheita, os frutos dos experimentos 1 e 2 foram transportados ao Laboratório de Frutas e Hortaliças da Faculdade de Ciências Agronômicas - UNESP - Botucatu/SP, e os dos experimentos 3 e 4 transportados para o Laboratório de Postrecolección e Refrigeración da Universidad Politécnica de Cartagena/Espanha. Após o processamento manual (corte em seções trapezoidais) os melões MP (minimamente processados) dos experimentos 1 e 2 foram acondicionados em embalagens de poliestireno expandido recobertas com filme de polietileno e irradiados nas doses: 0,0kGy; 0,1kGy; 0,2kGy; 0,3kGy; 0,4kGy e 0,5kGy. Os melões MP dos experimentos 3 e 4, após o processamento, foram imersos durante 1 minuto a 5ºC em: água (testemunha); vanilina (1000 mg L-1 e 2000 mg L-1); ácido cinâmico (148,16 mg L-1 e 296,32 mg L-1) e outros dois tratamentos consistiram em aplicação de vapor de ácido cinâmico (148,16 mg L-1 e 296,32 mg L-1) nos melões MP dentro da embalagem (bandejas de polipropileno termo seladas com filme de polipropileno). O armazenamento refrigerado foi realizado durante 10 dias 5±1ºC e 85-90% UR (experimentos 1 e 2) e à 5±1ºC e 85-95% UR (experimentos 3 e 4). As alterações na qualidade foram detectadas por meio das análises: perda de massa fresca, conservação pós-colheita, firmeza, pH, acidez titulável, sólidos solúveis, teores de açúcares redutores e redutores totais, ácido ascórbico, vitamina C, taxa respiratória, produção de etileno... (Resumo completo, clicar acesso electrônico abaixo)
Abstract: The aim of this research was to evaluated the effects of the gamma radiation and the natural antimicrobials in the conservation of fresh-cut melon storaged under refrigeration. Four experiments were accomplished: 1 and 2 - the varieties used were 'Cantaloupe' and 'Pele de Sapo' from Baraúna/RN and Juazeiro/BA, respectively; 3 and 4 - the varieties used were 'Cantaloupe' and 'Gália' from Cartagena (Spain). After harvesting, fruits from experiment 1 and 2 were sent to the Laboratory of Fruits and Vegetables at the University of Sao Paulo State (UNESP - Botucatu/SP). Fruits from experiment 3 and 4 were sent to the Postharvest and Refrigeration Group at the Technical University of Cartagena/Spain. After the manual processing (cut in trapezoidal sections) the fresh-cut melons of the experiment 1 and 2 were conditioned in polystyrene trays involved by polyethylene film and irradiated with doses: 0,0kGy; 0,1kGy; 0,2kGy; 0,3kGy; 0,4kGy and 0,5kGy. After processing, fresh-cut melons from experiment 3 and 4 were immersed for 1 min at 5ºC in water (control); vanillin (1000 mg L-1 and 2000 mg L-1); cinnamic acid (148,16 mg L- 1 and 296,32 mg L-1). Two additional treatments consisted on the application of cinnamic acid vapor (148,16 mg L-1 e 296,32 mg L-1) on fresh-cut melons within the packages (polypropylene trays heat-sealed with polypropylene). The storage was realized during 10 days in a cold camera to 5±1ºC and 85-90% HR (experiment 1 and 2) and to 5±1ºC and 85- 95% HR (experiment 3 and 4). The quality alterations were detected through the analyses: loss of fresh mass, postharvest conservation, firmness, pH, acidity titratable, soluble solids, reducing and total reducing sugar content, ascorbic acid, vitamin C, respiration rate, ethylene production, gas composition (CO2 and O2), enzymes activity (peroxidase, polygalacturonase and pectinmethylesterase), antioxidant... (Complete abstract click electronic access below)
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Al, Khawaja Mohamad Safa. "Quel niveau de qualité de traitement peut être obtenu par un système d'irradiation robotisé guidé par l'image en radiothérapie (CyberKnife TM)". Electronic Thesis or Diss., Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL076N.

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Le CyberKnifeTM est composé d’un accélérateur linéaire de 6 MV monté sur un bras robotisé, avec 6 axes de rotation et d’un système d’imagerie permettant de guider le faisceau d’irradiation sur la cible à traiter. Le but est d'améliorer la précision du traitement et la réduction de l’irradiation des organes critiques environnants. Le traitement est réalisé par la convergence « isotrope » d’une centaine d’orientation pour créer jusqu’à 1200 mini faisceaux dirigés sur la cible avec une précision sub-millimétrique. Cet ensemble est complété par une table de traitement montée sur un bras robotisé qui offre 6 degrés de liberté supplémentaires, permettant d’améliorer encore la précision du traitement et de lever d’éventuelles limitations. Grâce à son sous système SynchronyTM, le CyberKnifeTM est capable de traiter les tumeurs abdo-thoraciques, qui bougent avec la respiration en déplaçant dynamiquement le LINAC afin de compenser le mouvement respiro-induit. La forte dose utilisée dans ce genre de traitement hypofractionné, rend toute erreur même minimale inacceptable et impose une très grande précision géométrique, tout en assurant une précision dosimétrique maximale.Notre travail est consacrée à évaluer la qualité de traitement en termes des précisions géométrique et dosimétrique, pour les différents modes de suivi disponibles dans le système en statique, et en dynamique avec suivi respiratoire. Dans cette étude, nous avons utilisé différents types de détecteurs, et trois plateformes afin de simuler des simples mouvements respiratoires, des mouvements réels provenant des patients traités et enfin des mouvements complexes avec hystérésis
The CyberKnifeTM consists of 6MV LINAC mounted on a robotic arm, with six degree of freedom and is coupled to an image guiding system, allowing us to guide the irradiation beams toward the target. The aim is to improve the treatment accuracy and to reduce the irradiation of critical surrounding organs. The treatment is realized by the isotropic convergence of hundreds of orientations for creating up to 1200 mini-beams, which are orientated to the target with submillimetric accuracy. This group is completed by a treatment couch, which is also mounted on a robotized arm, that offers 6 additional degrees of freedom, allowing an additional improvement of accuracy, and eliminates the possible limitations. Using its subsystem SynchronyTM, the CyberKnifeTM is capable of treating the abdo -thoracic tumors, which move with respiration, by moving dynamically the LINAC to compensate the respiratory motion of the tumors. The high dose level, which is used in this kind of hypofractionated treatment, makes the smallest error unacceptable, and needs a very high geometric accuracy with keeping a maximal dosimetric accuracy. Our work is dedicated to evaluate the quality of treatment, in the terms of dosimetric and geometric accuracies. For the different modes of tracking, which are available in the system in static mode, and dynamic mode with respiratory motion tracking. By using different kinds of detectors (ionization chambers, radiochromic films) and three different platforms, which allow simulating simple respiratory motion, real respiratory motion coming from real treated patients, and finally complex motion with hysteresis

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Miranda, Mariana Branco de. "Avaliação físico-química de cachaças comerciais e estudo da influência da irradiação sobre a qualidade da bebida em tonéis de carvalho". Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/11/11141/tde-18112005-144555/.

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Neste trabalho foi feito um levantamento da qualidade de cachaças comerciais. As barreiras que a cachaça enfrenta, principalmente no mercado exterior, se devem à baixa qualidade e à falta de padronização da bebida. Amostras comerciais de cachaça foram analisadas segundo os padrões de identidade e qualidade estabelecidos pela legislação vigente no Brasil (análises físico-químicas e cromatográficas). Houve uma grande variação na concentração dos componentes, exceto o grau alcoólico, indicando que a cachaça brasileira apresenta uma grande variabilidade de composição química entre as marcas. Das 94 marcas analisadas, 48% não atenderam a pelo menos um desses padrões. Outro estudo realizado foi a influência da madeira carvalho e da radiação gama no envelhecimento da cachaça. O processo de envelhecimento ou maturação da bebida proporciona uma melhora nas características sensoriais da cachaça, tornando-a de qualidade superior e de maior valor econômico. O método tradicional de maturação de bebidas é sua interação com madeiras, porém a irradiação pode acelerar este processo de envelhecimento. A cachaça e os tonéis de carvalho de 20 litros de capacidade foram submetidos à irradiação gama (150 Gy). Análises físico-químicas e cromatográficas foram realizadas periodicamente ao longo de 390 dias do período de envelhecimento da bebida. A irradiação da cachaça e do tonel não alterou a maioria dos componentes voláteis do coeficiente de congêneres como acidez volátil, ésteres, álcoois superiores e furfural durante os 390 dias. Há evidências, entretanto, que os parâmetros de alguns componentes como aldeídos, taninos, cor e teor de cobre são de alguma forma influenciados, resultando em aceleração parcial do processo de maturação ou envelhecimento. Ao final do período de envelhecimento, foi feita uma análise sensorial com 30 provadores não treinados. A aceleração do processo de envelhecimento foi confirmada pela avaliação sensorial, onde a cachaça e/ou tonel irradiados receberam maior indicação de aprovação em todos os parâmetros analisados (aroma, sabor e aparência).
It was performed in this study a survey on the quality of commercial sugar cane spirits. The problems that the cachaça faces, mainly in the international market, are due to its low quality and to the lack of standardization of the drink. Commercial samples of sugar cane spirits were analyzed according to the standards of the identity and quality established by the Brazilian law (physical-chemical and chromatographic analyses). There was a great variation in the concentration of the compounds, except in alcoholic content, indicating that the Brazilian sugar cane spirit presents a great variability in the chemical composition among the brands. Among the 94 analyzed brands, 48% did not answer at least one of the standards. Another study performed was the influence of oak wood and the gamma radiation on the sugar cane spirits aging. The aging or maturation process of the drink improves the sensorial characteristics of the product, making it a qualified drink with a higher economical value. The traditional maturation method of the drinks is their interaction with the wood, but the irradiation can accelerate this aging process up. The sugar cane spirit and the oak barrels with 20 liters capacity were subjected to gamma irradiation treatments (150 Gy). Physical-chemical and chromatographic analyses were performed constantly for 390 days during the drink aging period. The sugar cane spirit and barrel irradiation didn't change most of volatile components of the same type coefficient such as volatile acidity, esters, superior alcohols and furfural during the 390 days. There are evidences, however, that some components parameters like aldehydes, tannin, color and copper concentration are in some way influenced, resulting in partial acceleration of the aging or maturing process. At the end of the aging period, a sensorial analysis was made using 30 non-trained people who tasted the drink. The aging process acceleration was confirmed by the sensorial evaluation, where the sugar cane spirit and/or barrel irradiated received higher approval indication in respect of all parameters analyzed (scent, flavor, and appearance).

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Hernandes, Nilber Kenup. "Aplica??o de Baixas Doses de Radia??o Gama para Extens?o da Vida ?til de Beterraba Vermelha (Beta vulgaris ssp. vulgaris L.), cv. Early Wonder, Minimamente Processada". Universidade Federal Rural do Rio de Janeiro, 2006. https://tede.ufrrj.br/jspui/handle/tede/542.

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This study was aimed at investigating the effects of low-dose gamma irradiation on shelf-life extension and phytosanitary safety of minimally processed red beet with basis on physicochemical; microbiological; chemical and sensory analyses. The samples (Beta vulgaris ssp. vulgaris L.), Early Wonder cultivar, were cultivated in the experimental area of the Horticulture Sector of the Departamento de Fitotecnia of the Instituto de Agronomia, Universidade Federal Rural do Rio de Janeiro, Serop?dica, RJ, as part of two experiments performed during the second semester of 2005. In each experiment, 1200 plants (40 per linear meter of terrain) were sowed. Physicochemical analyses (fresh mass; length; average diameter and total soluble solids) of the edible part of the red beets (their tuberous roots) were periodically carried out in order to assess the most appropriate time for harvest by monitoring the development of the plants. Those times were found to be 104 and 73 days after transplanting, respectively. The harvested edible part of the roots were minimally processed and separated in two groups: (1) gamma irradiated (with doses of 0.5; 1.0 and 1.5 kGy) and (2) non-irradiated (control). All samples were stored at 8 ?C. Microbiological analyses were performed during the storage period (22 and 21 days, for experiments 1 and 2, respectively) in order to evaluate the phytosanitary quality of the samples (Salmonella sp.; coliforms and total count of mesophilic aerobic and lactic acid bacteria). The samples irradiated with 1.0 and 1.5 kGy were found to remain appropriate for consumption for 21 days, as compared to only 7 days for the control. Monitoring of chemical composition was also performed and included the determination of saccharose; glucose; fructose and vitamins B1 and B2. No difference was found between the concentrations of those vitamins in irradiated and control samples at the end of the storage period, whereas significant changes in sugar contents were detected independently of the dose. In addition, physicochemical analyses investigated the evolution of pH; total acidity; total soluble solids and ascorbic acid throughout storage. Samples from experiment 2 were also subjected to sensory analyses for overall appearance and aroma at 4 different post-irradiation times. The results indicated that the samples irradiated with 1.0 and 1.5 kGy remained good for consumption for 20 days. Therefore it can be concluded that the application of those doses extended the shelf life of the samples without harming their nutritional and sensory quality. Finally, the results indicate that the dose of 1.0 kGy is the most appropriate for the conservation of red beet among those tested.
O objetivo deste estudo foi avaliar, por meio de an?lises microbiol?gicas; qu?micas; f?sicoqu?micas e sensoriais, os efeitos de baixas doses de radia??o gama na extens?o da vida ?til e na garantia da seguran?a microbiol?gica da beterraba vermelha (Beta vulgaris ssp. vulgaris L.), cultivar Early Wonder minimamente processada. Dois experimentos foram realizados, em condi??es de campo, em ?rea experimental do Setor de Horticultura do Departamento de Fitotecnia do Instituto de Agronomia da UFRRJ, Serop?dica, RJ, no segundo semestre de 2005. Em cada experimento, foram transplantadas 1200 mudas (40 por metro linear de canteiro). Foram realizados ensaios f?sico-qu?micos (massa fresca; comprimento; di?metro m?dio e teor de s?lidos sol?veis totais) da parte comest?vel (por??o tuberosa) da beterraba, para avalia??o do est?gio de desenvolvimento das plantas, visando ? determina??o do ponto ideal de colheita. As beterrabas dos experimentos 1 e 2 foram colhidas 104 e 73 dias ap?s o seu transplante, respectivamente. As partes tuberosas foram minimamente processadas e separadas em 2 grupos de amostras: controle (n?o irradiadas) e irradiadas (0,5; 1,0 e 1,5 kGy), sendo que todas foram armazenadas a 8 ?C. Avalia??es realizadas ao longo do per?odo de armazenamento (22 e 21 dias, nos experimentos 1 e 2, respectivamente) permitiram monitorar a: qualidade microbiol?gica (Salmonella sp.; coliformes; contagem total de bact?rias aer?bias mes?filas e contagem de bact?rias l?ticas); a composi??o qu?mica (determina??o dos teores de: sacarose; glicose e frutose e vitaminas B1 e B2) e as propriedades f?sico-qu?micas (pH; acidez total titul?vel; teor de s?lidos sol?veis totais e teor de ?cido asc?rbico). As amostras do experimento 2 foram tamb?m submetidas a an?lises sensoriais (apar?ncia e aroma) em quatro ocasi?es ap?s a irradia??o. Os resultados das an?lises microbiol?gicas indicaram que somente as amostras irradiadas com 1,0 e 1,5 kGy mantiveram-se pr?prias para o consumo por 21 dias, enquanto que as n?o irradiadas apresentaram vida ?til inferior a 7 dias. Ao fim do per?odo de avalia??o, n?o foi observada diferen?a entre os teores das vitaminas B1 e B2 das amostras irradiadas em rela??o ?s de controle. Os teores dos a??cares, por outro lado, sofreram altera??es significativas ao longo do tempo, independentemente das doses aplicadas. Em contraste, n?o foram constatadas altera??es indesej?veis nas propriedades f?sico-qu?micas ocasionadas pela irradia??o. Os resultados das an?lises sensoriais indicaram que as amostras irradiadas com doses de 1,0 e 1,5 kGy mantiveram-se dentro dos padr?es de aceitabilidade por 20 dias. Consistentemente, verificou-se que a aplica??o dessas doses foi eficaz para estender a vida ?til, sem prejudicar a qualidade nutricional ou sensorial das amostras. Finalmente, conclui-se que a dose de 1,0 kGy mostrou-se como a mais apropriada, dentre aquelas estudadas, para a irradia??o de beterraba vermelha minimamente processada.

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Johansson, Bengt. "Long-term outcome research on PDR brachytherapy with focus on breast, base of tongue and lip cancer". Doctoral thesis, Örebro : Örebro University, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-10423.

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21

Adrien, Camille. "Développement d’un outil d’optimisation de la dose aux organes en fonction de la qualité image pour l’imagerie scanographique". Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112172/document.

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Ces dernières années, la multiplication du nombre d’actes d’imagerie scanographique a eu pour conséquence l’augmentation de la dose collective due aux examens d’imagerie médicale. La dose au patient en imagerie scanographique est donc devenue un enjeu de santé publique majeur impliquant l’optimisation des protocoles d’examen, ces derniers devant tenir compte de la qualité image, indispensable aux radiologues pour poser leur diagnostic. En pratique clinique, l’optimisation est réalisée à partir d’indicateurs empiriques ne donnant pas accès à la dose aux organes et la qualité image est mesurée sur des fantômes spécifiques, tel que le fantôme CATPHAN®. Sans aucune information sur la dose aux organes et aucun outil pour prendre en compte l’avis du praticien, il est difficile d’optimiser correctement les protocoles. Le but de ce travail de thèse est de développer un outil qui permettra l’optimisation de la dose au patient tout en préservant la qualité image nécessaire au diagnostic. Ce travail est scindé en deux parties : (i) le développement d’un simulateur de dose Monte Carlo (MC) à partir du code PENELOPE, et (ii) l’estimation d’un critère de qualité image objectif. Dans ce but, le scanner GE VCT Lightspeed 64 a été modélisé à partir des informations fournies dans la note technique du constructeur et en adaptant la méthode proposée par Turner et al (Med. Phys. 36:2154-2164). Les mouvements axial et hélicoïdal du tube ont été implémentés dans l’outil MC. Pour améliorer l’efficacité de la simulation, les techniques de réduction de variance dites de splitting circulaire et longitudinal ont été utilisées. Ces deux réductions de variances permettent de reproduire le mouvement uniforme du tube le long de l’axe du scanner de manière discrète. La validation expérimentale de l’outil MC a été réalisée dans un premier temps en conditions homogènes avec un fantôme fabriqué au laboratoire et le fantôme CTDI, habituellement utilisé en routine clinique pour les contrôles qualité. Puis, la distribution de la dose absorbée dans le fantôme anthropomorphe CIRS ATOM, a été mesurée avec des détecteurs OSL et des films Gafchromic® XR-QA2. Ensuite, la dose aux organes a été simulée pour différentes acquisitions dans le fantôme femme de la CIPR 110 afin de créer une base de données utilisable en clinique. En parallèle, la qualité image a été étudiée en utilisant le fantôme CATPHAN® 600. A partir du module CTP 404, le rapport signal sur bruit (SNR pour signal to noise ratio) a été calculé en utilisant le modèle développé par Rose (J. Opt. Soc. Am. A 16:633-645). Un grand nombre d’images, correspondant à différents paramètres d’acquisition et de reconstruction, ont été analysées afin d’étudier les variations du SNR. Les acquisitions avec un SNR proche du critère de Rose ont été sélectionnées pour permettre des nouvelles acquisitions avec un fantôme préclinique contenant des petites structures suspectes en PMMA de différents diamètres. Ces images ont été analysées par deux radiologues expérimentés. Sur chaque image, ils devaient déterminer si une anomalie était présente ou non et indiquer leur niveau de confiance sur leur choix. Deux courbes ROC ont ainsi été obtenues : une pour les anomalies dites « détectables » par le critère de Rose (SNR > 5), et une pour les anomalies dites « non-détectables ». L’analyse des courbes montre que les deux radiologues détectent plus facilement les lésions suspectes lorsque que le critère de Rose est satisfait, démontrant le potentiel du modèle de Rose dans l’évaluation de la qualité image pour les tâches cliniques de détection. En conclusion, à partir des paramètres d’acquisition, la dose aux organes a été corrélée à des valeurs de SNR. Les premiers résultats prouvent qu’il est possible d’optimiser les protocoles en utilisant la dose aux organes et le critère de Rose, avec une réduction de la dose pouvant aller jusqu’à un facteur 6
Due to the significant rise of computed tomography (CT) exams in the past few years and the increase of the collective dose due to medical exams, dose estimation in CT imaging has become a major public health issue. However dose optimization cannot be considered without taking into account the image quality which has to be good enough for radiologists. In clinical practice, optimization is obtained through empirical index and image quality using measurements performed on specific phantoms like the CATPHAN®. Based on this kind of information, it is thus difficult to correctly optimize protocols regarding organ doses and radiologist criteria. Therefore our goal is to develop a tool allowing the optimization of the patient dose while preserving the image quality needed for diagnosis. The work is divided into two main parts: (i) the development of a Monte Carlo dose simulator based on the PENELOPE code, and (ii) the assessment of an objective image quality criterion. For that purpose, the GE Lightspeed VCT 64 CT tube was modelled with information provided by the manufacturer technical note and by adapting the method proposed by Turner et al (Med. Phys. 36: 2154-2164). The axial and helical movements of the X-ray tube were then implemented into the MC tool. To improve the efficiency of the simulation, two variance reduction techniques were used: a circular and a translational splitting. The splitting algorithms allow a uniform particle distribution along the gantry path to simulate the continuous gantry motion in a discrete way. Validations were performed in homogeneous conditions using a home-made phantom and the well-known CTDI phantoms. Then, dose values were measured in CIRS ATOM anthropomorphic phantom using both optically stimulated luminescence dosimeters for point doses and XR-QA Gafchromic® films for relative dose maps. Comparisons between measured and simulated values enabled us to validate the MC tool used for dosimetric purposes. Finally, organ doses for several acquisition parameters into the ICRP 110 numerical female phantoms were simulated in order to build a dosimetric data base which could be used in clinical practice. In parallel to this work, image quality was first studied using the CATPHAN® 600. From the CTP 404 inserts, the signal-to-noise ratio (SNR) was then computed by using the classical Rose model (J. Opt. Soc. Am. A 16:633-645). An extensive number of images, linked to several acquisitions setups, were analyzed and SNR variations studied. Acquisitions with a SNR closed to the Rose criterion were selected. New acquisitions, based on those selected, were performed with a pre-clinical phantom containing suspect structures in PMMA. These images were presented to two senior radiologists. Both of them reviewed all images and indicated if they were able to locate the structures or not using a 5 confidence levels scale. Two ROC curves were plotted to compare the detection ability if the bead was detectable (SNR > 5) or not. Results revealed a significant difference between the two types of image and thus demonstrated the Rose criterion potential for image quality quantification in CT. Ultimately, organ dose estimations were linked to SNR values through acquisition parameters. Preliminary results proved that an optimization can be performed using the Rose criterion and organ dose estimation, leading to a dose reduction by a factor up to 6

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22

Al, Khawaja Mohamad Safa. "Quel niveau de qualité de traitement peut être obtenu par un système d'irradiation robotisé guidé par l'image en radiothérapie (CyberKnife TM)". Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL076N/document.

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Le CyberKnifeTM est composé d’un accélérateur linéaire de 6 MV monté sur un bras robotisé, avec 6 axes de rotation et d’un système d’imagerie permettant de guider le faisceau d’irradiation sur la cible à traiter. Le but est d'améliorer la précision du traitement et la réduction de l’irradiation des organes critiques environnants. Le traitement est réalisé par la convergence « isotrope » d’une centaine d’orientation pour créer jusqu’à 1200 mini faisceaux dirigés sur la cible avec une précision sub-millimétrique. Cet ensemble est complété par une table de traitement montée sur un bras robotisé qui offre 6 degrés de liberté supplémentaires, permettant d’améliorer encore la précision du traitement et de lever d’éventuelles limitations. Grâce à son sous système SynchronyTM, le CyberKnifeTM est capable de traiter les tumeurs abdo-thoraciques, qui bougent avec la respiration en déplaçant dynamiquement le LINAC afin de compenser le mouvement respiro-induit. La forte dose utilisée dans ce genre de traitement hypofractionné, rend toute erreur même minimale inacceptable et impose une très grande précision géométrique, tout en assurant une précision dosimétrique maximale.Notre travail est consacrée à évaluer la qualité de traitement en termes des précisions géométrique et dosimétrique, pour les différents modes de suivi disponibles dans le système en statique, et en dynamique avec suivi respiratoire. Dans cette étude, nous avons utilisé différents types de détecteurs, et trois plateformes afin de simuler des simples mouvements respiratoires, des mouvements réels provenant des patients traités et enfin des mouvements complexes avec hystérésis
The CyberKnifeTM consists of 6MV LINAC mounted on a robotic arm, with six degree of freedom and is coupled to an image guiding system, allowing us to guide the irradiation beams toward the target. The aim is to improve the treatment accuracy and to reduce the irradiation of critical surrounding organs. The treatment is realized by the isotropic convergence of hundreds of orientations for creating up to 1200 mini-beams, which are orientated to the target with submillimetric accuracy. This group is completed by a treatment couch, which is also mounted on a robotized arm, that offers 6 additional degrees of freedom, allowing an additional improvement of accuracy, and eliminates the possible limitations. Using its subsystem SynchronyTM, the CyberKnifeTM is capable of treating the abdo -thoracic tumors, which move with respiration, by moving dynamically the LINAC to compensate the respiratory motion of the tumors. The high dose level, which is used in this kind of hypofractionated treatment, makes the smallest error unacceptable, and needs a very high geometric accuracy with keeping a maximal dosimetric accuracy. Our work is dedicated to evaluate the quality of treatment, in the terms of dosimetric and geometric accuracies. For the different modes of tracking, which are available in the system in static mode, and dynamic mode with respiratory motion tracking. By using different kinds of detectors (ionization chambers, radiochromic films) and three different platforms, which allow simulating simple respiratory motion, real respiratory motion coming from real treated patients, and finally complex motion with hysteresis

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23

ARICHE, COHEN MICHELE. "Validation et utilisation d'un systeme de criteres de qualite d'image pour l'examen du rachis lombaire". Amiens, 1994. http://www.theses.fr/1994AMIEM048.

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24

Lama, Lucas Sacchini Del. "Caracterização e adaptação do dosímetro Fricke para dosimetria em irradiação de sangue". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-11112013-115906/.

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A Doença Enxerto Contra Hospedeiro Associada à Transfusão (DECH-AT) é uma reação transfusional rara, porém fatal, que ocorre devido à presença de células T no sangue doado e que pode ser prevenida por meio da irradiação do sangue do doador e de seus componentes antes da transfusão. Assim, o controle de qualidade associado à irradiação do sangue é necessário para se garantir a qualidade do produto transfundido. Neste trabalho é proposta a caracterização e a adaptação da resposta do dosímetro Fricke para uso na dosimetria da irradiação de sangue, mais especificamente o Fricke Xilenol Gel (FXG). Este é um dosímetro químico radiocrômico, que apresenta as vantagens de ser tecido equivalente e de permitir a inferência espacial da dose absorvida dentro da faixa de doses usados na prevenção DECH-AT. Dessa maneira, de modo a possibilitar a inferência de dose absorvida em todo o intervalo utilizado na prevenção da DECH-AT (25 a 50 Gy), o FXG foi caracterizado e adaptado para aplicações dosimétricas envolvendo a irradiação de sangue e derivados. Os resultados com o novo dosímetro apontaram adequabilidade para toda a faixa necessária de doses absorvidas, com sensibilidade e desvanecimento temporal satisfatórios para aplicações rotineiras. Além disso, pela metodologia proposta neste trabalho, foi possível determinar as distribuições espaciais das doses absorvidas com o dosímetro proposto de uma maneira rápida e simples, mostrando assim que este dosímetro apresenta características convenientes para o controle de qualidade para a dosimetria da irradiação de sangue e de hemocomponentes.
The Transfusion Associated Graft Versus Host Disease (TA-GVHD) is a rare transfusion reaction, however fatal, which develops due to the presence of donor T lymphocytes in the donated blood and that can be avoided by the irradiation of the donated blood blood and blood components prior to transfusion. Thus, the associated quality control of blood irradiation is necessary to guarantee the quality of the transfused product. In this work it is proposed the characterization and adaptation of the response of a Fricke dosimeter to be used for dosimetry of blood irradiation, more especiafically the Fricke Xylenol Gel (FXG). This is a radiochromic chemical dosimeter, which presents advantages to be tissue equivalent and allows the spatial absorbed dose inference. In this manner, in a way to possibilitate the absorbed dose inference in the full interval used for the prevention of the TA-GVHD (25 to 50 Gy) the FXG was characterized and adapted for dosimetry applications involving blood and blood components irradiation. The results with the new dosimeter showed adequability for the necessary absorbed doses, with satisfactory sensibility and time fading for routine applications. Furthermore, according to the methodology proposed in this work, it was possible to determine the spatial absorbed dose distributions with the new dosimeter in an fast and simple way, showing that this dosimeter presents convenient characteristics for dosimetry quality control of irradiated the blood and blood components.

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Cardozo, Nelson X. "Desenvolvimento de um sistema de irradiação para produção de radioisótopos gasosos aplicados em processos industriais". reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/27408.

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Submitted by Marco Antonio Oliveira da Silva (maosilva@ipen.br) on 2017-05-02T11:34:44Z No. of bitstreams: 0
Made available in DSpace on 2017-05-02T11:34:44Z (GMT). No. of bitstreams: 0
Dentre as diversas aplicações dos radioisótopos, a utilização dos radiotraçadores é considerada uma das mais importantes, no diagnóstico de funcionamento dos equipamentos de processos, em plantas de indústrias químicas e petroquímicas. Os radiotraçadores são utilizados em procedimentos analíticos para obtenção de dados qualitativos e quantitativos de sistemas, em estudos de transferências físicas e físico-químicas. Na produção de radioisótopos gasosos utilizados como traçadores em processos industriais, destacam-se o 41Ar e 79Kr, gases nobres (inertes) que possuem baixa reatividade com os demais elementos químicos. O 41Ar é um emissor gama de alta energia (1,29 MeV) e apresenta elevada porcentagem de transformações com essa energia, o que resulta em quantidades relativamente pequenas necessárias em relação a outras para uma detecção eficaz, mesmo em componentes com grandes espessuras. Atualmente, a produção de radioisótopos gasosos em reatores nucleares de pesquisa é realizada em pequenas quantidades (bateladas), por meio de ampolas de quartzo contendo o gás natural 40Ar ou 78Kr. Nesse sentido, o objetivo desse estudo é desenvolver um sistema de irradiação capaz de produzir em escala contínua, o radioisótopo gasoso 41Ar, dentre outros, com atividade de 7,4x1011 Bq (20 Ci) por ciclo de irradiação, por meio do Reator IEA-R1 de 4,5 MW, fluxo de nêutrons térmicos médio de 4,71 x 1013 ncm-2s-1, para suprir uma demanda existente em empresas de END e inspeções, e pelo próprio Centro de Tecnologia das Radiações, no IPEN/CNEN-SP. O sistema de irradiação (SI) é constituído por uma cápsula de irradiação em alumínio, linhas de transferência, válvulas agulhas, conexões anilhadas, conectores rápidos, manovacuômetro, sistema de vácuo, dewar de liquefação, blindagem em chumbo, cilindros de armazenamento e transporte (CAT), dentre outros. O SI foi aprovado nos testes de estanqueidade e estabilidade (testes de formação de bolhas, pressurização, evacuação e com equipamento leak detector SPECTRON 600 T). Na produção experimental para obtenção de 1,07x1011 Bq (2,9 Ci) de 41Ar, distribuíram-se dosímetros de alanina em diversos componentes e dispositivos do SI. Além disso, determinaram-se as taxas de exposição na parede da blindagem em chumbo, ao concentrar o gás radioativo liquefeito e no CAT, após a transferência do 41Ar, pelo medidor de radiação portátil Teletector ® Probe 6150 AD-t/H.
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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26

Viala, Diego. "Étude de la physique de l'allumage par choc". Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0127.

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Une décennie d'expériences au "National Ignition Facility" a démontré que la fusion par confinement inertiel constitue une approche crédible pour la production d'énergie, avec des résultats allant au-delà du régime d'allumage. Cependant, l'approche par attaque indirecte se révèle inadéquate pour les implosions à gain élevé et une production d'énergie fiable. L'option d'allumage par attaque directe est privilégiée en raison de ses conceptions de cible plus simples et de son meilleur couplage énergétique. Actuellement, aucune installation laser à l'échelle d'allumage n'est configurée selon l'approche directe standard, posant ainsi un défi à relever. Les expériences intégrées d'allumage par attaque directe se sont principalement concentrées sur la compréhension de la physique à des échelles réduites, dans le but ultime de démontrer la nécessité et la faisabilité de construire une installation laser internationale dédiée à l'attaque directe.Ce manuscrit de thèse présente une étude approfondie sur la validation de codes d'hydrodynamique radiative 3D à l'état de l'art, ainsi que sur la compréhension des bas modes d'éclairement laser et du couplage laser-cible, jouant un rôle crucial dans la fusion par confinement inertiel. L'examen attentif des modèles de CBET revêt une importance capitale dans ce contexte, assurant la précision des simulations et contribuant à la conception des futures installations à attaque directe. De plus, l'investigation de l'homogénéité du laser sur la cible est impérative pour appréhender son impact global sur le système
A decade of experiments at the National Ignition Facility has proven that inertial confinement fusion is a credible approach to energy production, with experiments having exceeded the ignition regime. However, the indirect-drive approach is not suited for high gain implosions and reliable energy production. The direct-drive ignition approach is favoured for energy production as it features simpler target designs and couples more energy to them. There are currently no ignition-scale laser facilities configured for the standard direct-drive approach. Integrated direct-drive experiments have mostly been focused on understanding the physics at reduced scales, with the ultimate goal of demonstration of necessity and feasibility of construction of an international direct-drive laser facility.This thesis manuscript presents a study on the validation of state-of-the-art 3D radiative hydrodynamics codes and the understanding of low modes and laser coupling which play crucial roles in the study of inertial fusion energy. Careful examination of CBET models is of paramount importance in this context, ensuring the accuracy of simulations and contributing to the design of future direct-drive facilities. In addition, the investigation of laser homogeneity on target is imperative to understand its overall impact on the system

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Blazy, Léone. "Contrôle qualité des systèmes de planification dosimétrique des traitements en radiothérapie externe au moyen du code Monte-Carlo Penelope". Toulouse 3, 2007. http://thesesups.ups-tlse.fr/11/.

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Les Systèmes de Planification des Traitements (Treatment Planning System - TPS) occupent une position clé au sein du service de radiothérapie : ils réalisent le calcul prévisionnel de la distribution de la dose et des temps de traitement. Traditionnellement, le contrôle qualité des distributions de dose calculées par les TPS s'appuie sur leurs comparaisons avec des distributions de dose mesurées sous l'appareil de traitement. Ce travail de thèse se propose de substituer ces mesures dosimétriques au profit de calculs dosimétriques de référence obtenus par le code Monte-Carlo (MC) PENELOPE. Les simulations MC fournissent un large choix de configurations de test et permettent d'envisager un contrôle qualité des aspects dosimétriques des TPS sans monopoliser les appareils de traitement. Ce contrôle qualité, basé sur des simulations MC, a été expérimenté sur un TPS clinique et a permis de simplifier les procédures qualité du TPS. Ce contrôle qualité plus approfondi, plus précis et plus simple à mettre en œuvre pourrait se généraliser à l'ensemble des centres de radiothérapie
Treatment Planning Systems (TPS) have a main position in a radiotherapy department: they perform calculation of dose distributions and calculate treatment time for each beam. Usually, quality control of dose distributions given by TPS is based on comparisons with measured ones. This study aims at replacing measured dose distributions by reference calculated dose distributions obtained with the PENELOPE Monte-Carlo (MC) code. Monte-Carlo simulations provide several configurations and allow a quality control of TPS dosimetric features without need for the treatment units availability. This quality control, based on MC simulations, was tested for a clinical TPS and allowed to simplify the quality process of the TPS. This control more detailed, more accurate and easily to implement could be applied for all radiotherapy departments

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Kocian, Sonntag Anne. "Evaluation de la qualité des images produites par des photons de haute énergie. Apport de la numérisation et application au contrôle des irradiations thérapeutiques". Toulouse 3, 1991. http://www.theses.fr/1991TOU30265.

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Le role determinant que joue les cliches servant au controle des irradiations therapeutiques quant a l'issue du traitement est mis en evidence. Les principaux detecteurs actuellement utilises pour les cliches de controle de la radiotherapie sont presentes. La formation de l'image radiologique dans le cadre de la radiotherapie est etudie de facon theorique; l'image radiante detectable est simulee (code egs4: methode de monte carlo). Le passage de l'image radiante detectable a l'image exploitable est presentee pour deux types de detecteurs: l'emulsion argentique et les cristaux photostimulables. Les caracteristiques des deux types de systeme d'imagerie radiologique numeriques disponibles dans notre service a savoir le film associe a une camera a numeriser et le systeme fcr 901 dont le principe de base est la photoluminescence stimulee sont etudiees. L'adaptation du systeme fcr 901, initialement concu pour la radiologie a visee diagnostique, a une utilisation en routine pour les cliches de controle de la radiotherapie est decrite. Les cliches de controle obtenus d'une part avec le systeme fcr 901 et d'autre part avec le film associe a une camera a numeriser sont analyses et compares. Les resultats obtenus permettent de definir les caracteristiques d'un detecteur ideal pour les cliches de controle de la radiotherapie

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Mazet, Jean-François. "Couleur et qualité des placages de chêne et étude de leur comportement photochimique". Nancy 1, 1988. http://www.theses.fr/1988NAN10393.

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Dans la première partie, on a cherché à traduire par des mesures objectives l'appréciation professionnelle de la qualité de l'aspect des placages de chêne. Dans la seconde partie, on s'attache à mieux comprendre les mécanismes d'altération de la couleur des placages au cours de l'exposition à la lumière du jour, tout en s'intéressant à quelques moyens possibles de protection

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Berbis, Julie. "Quelle utilité à la mise en œuvre du suivi des enfants et adolescents survivant à une leucémie dans la prise de décision ? : A propos de la cohorte LEA". Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM5086.

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Les progrès thérapeutiques réguliers ont transformé le pronostic des enfants atteints de leucémie aiguë, posant avec une grande acuité le problème des effets secondaires tardifs, de l'insertion sociale mais aussi de la qualité de vie des patients et de leur entourage, ainsi que des déterminants mis en jeu. L'ensemble des acteurs du système de soins ont la responsabilité de l'étude de ces effets secondaires tardifs et de leur prise en compte. En 2004, le projet LEA (Leucémie de l'Enfant et de l'Adolescent) a débuté avec pour objectif d'évaluer l'état de santé et la qualité de vie à moyen et long terme de patients traités pour une leucémie aiguë de l'enfance après 1980. La volonté était de mettre en oeuvre un système pouvant produire de la connaissance dans une démarche de recherche traditionnelle, mais aussi de s'inscrire rapidement dans une démarche pragmatique de production d'informations susceptibles de modifier les pratiques de prise en charge et de suivi. L'objectif général de ce travail cherche à démontrer l'utilité de dispositifs lourds comme la mise en oeuvre d'une cohorte, dans la double logique de fournir une information d'une part directement utile à la décision clinique, et d'autre part susceptible d'éclairer la décision publique. Les travaux scientifiques s'articulent autour de : 1. La visibilité de la cohorte LEA au regard des autres dispositifs existants au niveau international ; 2. Les conséquences à distance des traitements lourds reçus par les patients ; 3. La qualité de vie de l'entourage à distance de l'épisode aigu de la maladie ; 4. L'utilité d'un suivi systématisé dans la diminution des inégalités d'accès au système de santé entre les classes sociales
Regular advances in cancer treatment have dramatically improved the prognosis of children with acute leukemia, raising with a great acuity the problem of the late physical side effects, social integration, quality of life of the patients and their family as well as identification of the determinants of these outcomes. It is the responsibility of all the care system actors to consider these objective and subjective late effects. The LEA project (Leucémie de l'Enfant et de l'Adolescent - childhood and adolescent leukemia) was initiated in 2004 with the aim of studying the long-term health status and quality of life of children treated for leukemia after January 1980. As soon as the project began, the aim was to implement a system that can produce knowledge in a traditional research approach, but also to rapidly become a pragmatic approach of producing information that could affect both care and monitoring practices. The general objective of this manuscript seeks to demonstrate the utility of heavy plan such as the implementation of a cohort, in the double approach of providing information on the one hand directly relevant to clinical decision, and on the other hand likely to enlighten public decision. The present scientific works are based on: 1. The visibility of LEA in relation to other cohorts of childhood cancer survivors existing internationally; 2. The long-term impact of the heavy modalities of treatment, as the hematopoietic stem cell transplantation or irradiation; 3. The quality of life of the family long after the completion of cancer therapy; 4. The usefulness of a systematic follow-up in reducing inequalities in access to health care among social classes

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Karagoz, Isin 1983. "Safety Assurance of Pecans by Irradiation without a Detrimental Effect on Quality". Thesis, 2012. http://hdl.handle.net/1969.1/148092.

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Pecan nuts might become contaminated with foodborne pathogens, such as Salmonella and E. coli., through birds and other potential sources of contamination that can lead to serious illness or even death, as well as financial losses. For example, the outbreak of Salmonella in pecan products in Texas caused major product recalls in 2010. Irradiation with electron beams could be an effective method of preventing potential outbreaks without changing the pecans' taste, color and flavor and without causing any risk of recontamination before the product reaches the consumer. However, when irradiation is applied alone, the shelf life of the product is decelerated because of the detrimental effect of lipid oxidation. Therefore, to extend the shelf of the pecans while assuring their safety, irradiation of pecans under modified atmosphere packing (MAP) conditions could be a viable option. This research showed that when treated with electron beams, surrogates of Escherichia coli (a cocktail of BAA-1427, BAA-1428, and BAA-1430), and Salmonella (S. Typhimurium LT2) were more resistant to ionizing radiation (higher D10 values) when packed under vacuum (VP) than under air or other MAP conditions. This research also showed that lipid oxidation in pecans (due to exposure to ionizing radiation) shows a lag phase, probably due to the antioxidants present in pecan nuts. The lag phase represents a delay period before the pecan nuts start to get rancid (increase in PV formation), and it is best described by a modified Gompertz model. Kinetic evaluation of the lipid oxidation reaction suggests that the dose level has a more drastic effect in PV formation than the type of package used during the irradiation treatment, e.g., vacuum packed versus nitrogen-packed. Moreover, accelerated shelf life studies (4 weeks at 48.9oC) showed that vacuum-packed (VP) pecans can be stored at -25 degrees C up to three years, while irradiated (at 3.0 kGy) VP pecans can be stored only for eight months, without the detrimental effects of lipid oxidation. Therefore, irradiation of pecans under air at 3.0 kGy reduces the shelf life of the nuts in terms of rancidity, but vacuum-packaging can be used to extend their shelf-life. Irradiation in oxygen packaging increases rancidity and the oxidation reaction rate accelerates with increasing dose. Irradiation under nitrogen packaging requires lower doses to achieve the almost same number of log reductions in microbial population. The use of nitrogen packaging also inhibits the oxidative reaction leading to rancidity in pecans. Although there are some drawbacks to the application of nitrogen packaging in an irradiation plant (special machinery and packaging films (permeability specifications for N2 gas)), the savings induced by avoiding recalls may make this technology worthy of consideration.

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32

Keithley, Sarah Elizabeth. "The effect of treatment on the quality of harvested rainwater". Thesis, 2012. http://hdl.handle.net/2152/ETD-UT-2012-05-5825.

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Harvested rainwater is an alternative water resource that can be utilized to help meet the world's growing demand for fresh water. Although harvested rainwater is often considered to have adequate physical and chemical qualities, its microbial quality has been found lacking. This study sought to better understand the effect of common treatment processes on the quality of harvested rainwater for potable use by examining two treatment processes: (1) batch chlorination followed by filtration, and (2) filtration followed by ultraviolet (UV) irradiation. The batch chlorination studies used rainwater harvested from four pilot-scale roofs in Austin, Texas with different roofing materials: concrete tile, green, Galvalume[Trademark] metal, and asphalt-fiberglass shingle. Chlorine tends to react with natural organic matter and produce disinfection byproducts (e.g., trihalomethanes (THMs)) that are harmful to human health. Chlorinating rainwater harvested from the metal and concrete roofs achieved adequate disinfection (total coliforms less than 1 colony forming unit per 100 mL) without forming THMs that exceed the United States Environmental Protection Agency (USEPA) limit of 80 [mu]g/L for public water systems. Chlorinating rainwater harvested from the shingle roof achieved adequate disinfection but had the potential to form excessive THMs. Chlorinating rainwater harvested from the green roof, which had the highest concentration of dissolved organic carbon, did not achieve adequate disinfection and formed THMs that were four times higher than the USEPA limit. Filtering the chlorinated rainwater from every roofing material with a block activated carbon filter generally resulted in increased bacteria concentrations and decreased THM concentrations. To study the effect of UV irradiation, cistern-stored and treated rainwater were sampled from a full-scale residential system in Austin, Texas, where the owner uses rainwater as his primary potable water supply. UV irradiation at the full-scale system effectively disinfected rainwater when the turbidity and total coliform concentrations were low, but disinfection was compromised as these two parameters increased as the drought progressed in 2011 and the ambient temperature increased. This research suggests that under certain conditions, treatment by either chlorination or UV irradiation can improve the quality of harvested rainwater so that it conforms to drinking water standards for public water systems.
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33

Arnold, John. "Evaluating Quality and Palatability Characteristics of Beef Subprimals Treated with Low-dose Irradiation". Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10574.

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This study was conducted to evaluate the impact of low-dose irradiation on beef quality and sensory attributes. Beef top rounds (n=10), bottom round flats (n=10), and knuckles (n=18) were collected from a commercial meat processing facility. Paired subprimals were randomly assigned to treated (irradiated) and control (non-irradiated) groups. The treated group was irradiated with a surface dose of 1-1.5 kGy. Following treatment, subprimals were fabricated into thirds and randomly assigned to one of three aging days (0, 14, or 21). After the aging period, subprimal pieces were trimmed, cut into 2.54 cm steaks, and the resulting trimmings were ground to produce 0.113 kg patties. Steaks and patties were randomly assigned to one of two shelf-life days (2 or 4). During retail display, L*, a*, and b* measurements were taken for raw steak and patty color (0, 2, and 4 day). Steaks and patties from all treatments were evaluated by a trained sensory panel for flavor, basic taste, mouthfeel, after-taste, and texture attributes. Steaks and patties were cooked on open-faced grills, and used for cooked color analysis. Samples from across treatments were used for TBARS analysis. Differences in raw steak and patty color were seen among samples. No differences were evident between cooked steak samples; however, cooked patty color differences were observed. Further, numerous palatability attributes were impacted by treatment. Additionally, differences in TBARS values were seen. These results suggest that if chilled subprimals or carcasses were treated with low-dose e-beam irradiation, quality and palatability characteristics could be negatively impacted.

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34

chen, Pei-Ru, e 陳佩汝. "Effect of Ultraviolet Irradiation on the Quality of Common Mushrooms and Other Edible Mushrooms". Thesis, 1997. http://ndltd.ncl.edu.tw/handle/60483795563503158306.

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碩士
國立中興大學
食品科學系
85
Common mushrooms (Agaricus bisporus) are of good taste, unique flavor and abundant nutrients. But the quality of mushrooms declines rapidly due to the microbial contamination and the damage during picking, packaging or transportion. Therefore, to avoid browning and extend the shelf life of mushrooms are important. Recently, the techniques of food irradiation are advancing quickly and gradually accepted by people. Ultraviolet irradiation is one kind of food irradiation, too. It can inhibit microbial growth and delay the ripening of vegetables and fruits. It also has the function of promoting the activation of vitamin D. Therefore, ultraviolet irradiation should be of positive effect on the preservation of mushrooms and increasing the nutrient value. Therefore, this research was undertaken to study the effect of different doses of ultraviolet C or B (UVC or UVB) irradiation on the volatile compounds of fresh mushrooms and the total plate counts, the lightness, Δ E value and the diameter of the cap, the length of the stipe and the weight loss of common mushrooms and/ or hot mushrooms (Agaricus bitorquis), during storage at 12 ℃. This study also examined the amounts of vitamin D in A. bisporus, A. bitorquis, Volvariella volvecea and Lentinula edodes after ultraviolet irradiation. During the storage, the total plate counts of A. bisporus and A. bitorquis were reduced 70-78% after UVC irradiation. But after day 6, the reduction was eliminated. The amount of 1-octen-3-ol of mushrooms after irradiation was higher than that of the control. But the higher doses did not increase the effect. UVC irradation was not effective in delaying the ripening of common and hot mushrooms, but it increased the browning of the fruit body with doses increased. UVC irradiation increased the amounts of vitamin D of mushrooms. The stronger the irradiation, the higher were the amounts of vitamin D. After UVC irradiation for 2 hours, the amounts of vitamin D of A. bisporus and A. bitorquis reached 332% and 133% of the control, respectively. UVB increased the amounts of vitamin D of common mushrooms in a dose-depend manner. The effect of UVB irradiation was better than that of UVC. After UVB irradiation for 2 hours, the amounts of vitamin D reached to 567% of that of t he control. UVB was also effective on the straw mushroom and shiitake, but the changes of vitamin D was not as large as on those of the common mushrooms. However, the changes increased with increasing doses. The effect of UVB irradiation on the A. bisporus was not as significant as UVC during storage at 12 ℃, but that the changes of volatile compounds were similar to those of UVC irradiation. However, the total plate counts and phenomena were not significantly affected. The color of the mushrooms was darkened with increasing doses and storage time. The effect of ulraviolet irradiation on the mushrooms was not uniform. The users should select the kind and dose depending on their need for extending the shelf life or increasing the nutrient values.

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35

Adavi, Megha Sarthak. "Electron Beam Irradiation for Improving Safety of Fruits and Vegetables". Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9178.

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Increase in consumption of fresh cut produce over the past decade has resulted in a rise in incidents of food borne outbreaks due to pathogens. Conventional techniques of sanitizing washes may not be effective since the organic matter released from the fresh produce use up the free chlorine thus reducing the sanitizing potential of wash water just when it is needed most and a heat treatment step to kill pathogens cannot be applied if the purpose is to consume fresh produce. Electron beam (e-beam) irradiation was used to treat cut cantaloupe, cut roma tomatoes, baby spinach, romaine lettuce which were surface inoculated with a cocktail of Salmonella and E. coli O157:H7. Results showed that irradiation reduced Salmonella and E. coli O157:H7 significantly with increasing doses at 0.2, 0.4, 0.6, 0.8, and 1.0 kGy. The D10-value for Salmonella on irradiated cut cantaloupe, cut roma tomatoes, baby spinach, and romaine lettuce was found to be 0.71 kGy, 0.64 kGy, 0.19 kGy, and 0.23 kGy respectively. The D10-value for E. coli O157:H7 on the produce listed above was found to be 0.73 kGy, 0.54 kGy, 0.18 kGy, and 0.20 kGy respectively. Low dose e-beam irradiation was found to be an excellent tool for ensuring the reduction of spoilage organisms and extending shelf life in cut cantaloupe, cut roma tomatoes, baby spinach, romaine lettuce, strawberries, and green onion. The produce were tested for 12 days of storage for aerobic plate count, yeast and mold, lactic bacteria, color, texture, and respiration rate as a function of irradiation doses 0, 1, 3, and 5 kGy. Aerobic plate counts, yeast counts, and lactic acid bacteria were reduced appreciably at all doses tested on all commodities. Molds did not grow on any samples including control for cut cantaloupe, cut tomatoes, and green onion but for the other commodities, mold was reduced at the same rate as yeasts and vegetative bacteria. Lactic acid bacteria were reduced at all doses while the reduction was highest with 5 kGy in all commodities. When irradiated with 5 kGy, during storage, strawberries, spinach, and green onion displayed wet, soggy and mushy appearance, romaine lettuce leaves were wilted, had a translucent midrib and brown pigmentation. E-beam irradiation increased respiration rate for all samples on day 0 compared to non-irradiated control irrespective of the commodity type and the effect was dose dependent. Firmness reduced appreciably for cut roma tomatoes, baby spinach, strawberries, romaine lettuce, and green onion with increasing doses. Cut cantaloupe was low in firmness but the effect was not dose dependent. Irradiation at low doses is a promising tool to reduce pathogens and enhance keeping quality of cut cantaloupe, cut tomatoes, baby spinach, romaine lettuce, strawberries, and green onion. Irradiation is to be implemented as part of an overall HACCP plan and is not meant to replace existing control measures.

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36

Poon, Patty Wai Bing. "Effect of electron-beam irradiation and vitamin E fortified diet on ground beef quality preservation". Thesis, 2001. http://hdl.handle.net/2429/12730.

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The effects of electron-beam irradiation (EBI) treatment and dietary vitamin E supplementation on microbial and organoleptic quality of ground beef patties were investigated during 21 days refrigerated (4°C) and 6 months frozen (-22°C) storage. Ground beef patties were prepared from meat from cattle fed basal (diet I) and vitamin E supplemented diets (diet II). Plasma vitamin E concentration in cattle fed diets I and II were 1.58 ± 0.42 and from 2.49 ± 0.53 to 2.91 ± 0.57 μg vitamin E/ml plasma, respectively. Patties were then processed with 4 different doses of electron-beam irradiation (0, 2, 5, 10 kGy). Microbial indices monitored at 3-day intervals throughout a 21-day storage period at 4°C and at 1-month intervals during a 6-months storage period at -22°C, included Total Aerobic Plate Count (TAPC), Psychrotroph Counts and Total Coliform and E. coli Counts. Total aerobic and psychrotrophic bacterial growth in ground beef patties stored at 4°C and -22°C were significantly (P < 0.05) reduced by EBI at 2 kGy. Complete inhibition of bacteria occurred at 5 kGy or higher (P < 0.05) dosages of EBI. Beef patties made from steers fed vitamin E (diet II) were found to have a higher (P < 0.05) TAPC and Psychrotrophic bacteria than patties derived from animals fed the basal diet (diet I). From the growth pattern of the two detected classes of microorganisms, psychrotrophic bacteria appeared to recover faster from irradiation stress, and were able to grow more rapidly upon storage than the aerobic bacteria. Neither Coliforms nor E.coli were not detectable in the beef samples during the experimental period due to a low initial count. Parameters such as pH and water activity (a[sub w]) were also measured. Chemical and instrumental indices monitored at 3-day intervals throughout a 21- day storage period at 4°C, and at 1-month intervals during a 6-months storage period at - 22°C included thiobarbituric acid reactive substances (TBARS), color, and texture. Moisture, total crude lipid content and fatty acid compositions were monitored at 7-day intervals throughout a 21-day storage period at 4°C and at 1-month intervals during a 6- months storage period at -22°C. Results indicated that irradiation was associated with higher (P < 0.05) TBA values and greater (P < 0.05) shear force. TBA values of beef patties reached peak levels on Day 9 in 4°C storage and at Month 3 in -22°C storage, respectively. No significant differences were observed in shear values of beef patties irradiated at different doses. With all four levels of irradiation, Hunter a values of beef patties decreased (P < 0.05) significantly, and this effect could be observed immediately after irradiation. Lipid oxidation was significantly retarded in stored beef patties derived from cattle fed vitamin E (diet II). These results indicate that electron beam irradiation pasteurization is an effective method to ensure microbial safety of refrigerated and frozen ground beef patties. The application of electron beam irradiation and vitamin E supplemented diet significantly improved ground beef safety and lipid stability during storage at 4°C and -22°C.

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37

Yang, Ming-Sheng, e 楊明聖. "Effects of gamma irradiation on the quality of shiitake ( Lentinula edodes Sing) and day lily (Hemerocallis fulva L.)". Thesis, 1995. http://ndltd.ncl.edu.tw/handle/63326512091542764485.

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碩士
國立中興大學
園藝學系
83
Fresh shiitake (Lentinula edodes Sing) was irradiated with doses of 0.5, 1.0 and 2.0kGy using 60Co. Effects of gamma irradiation on the appearance and the flavor compounds of shiitake before and after drying were studied.Irradiation with a dose of 0.5kGy reduced mold growth and browning in the fresh shiitake during postharvest storage.The growth of fresh shiitake was absolutely inhibited by doses of 1 or more kGy. The appearance quality of fresh shiitake was not affected With gas chromatography-mass spectrometry after 2kGy irradiation. the volatile components, especially as esters, alcohol and eight- carbon compounds were increased in the fresh shiitake. After being dried the shiitake with 1kGy irradiation contained higher. However, 0.5kGy irradiation was recommended to use in fresh shiitake for inhibiting mold growth, browning and cap- openning and keeping a good appearance and flavor quality during post- harvesting storage. Fresh day lily (Hemerocallis fulva L.) flowers were irradiated with doses of 0.5, 1.0, 2.0, 5.0kGy using 60Co. Effects of gamma irradiated on the appearance and flavor quality were studied with scanning electron microscopy (SEM) and gas- chromatography The flower blooming was inhibited by 2.0 or more kGy irradiation. However, the browning and the tissue breaking were found in the flowers irradiated with 2.0 and 5.0kGy the dropping of flowers occurred after 5.0kGy and irradiation. With 1.0kGy irradiation The volatile components of dried lily flowers were ethyl formate, ethyl acetate, 3-methyl butanol, ethanol, isoamyl alcohol, methyl pyrazine, 2,6-dimethyl pyrazine,furfural , acetic acid, terpinolene, furfuryl formate ,furfuryl acetate, benzene acetaldehy The irradiation was recommended to use to inhibit mold and insects in dried day lily flowers during storage.

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38

Chen, I.-Chi, e 陳翊綺. "Influences of washing with sodium hypochlorite sanitizer, UV irradiation, and storage temperature on shell egg quality during storage". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/gk426k.

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碩士
國立中興大學
動物科學系所
106
Shell eggs are occasionally contaminated by feces, thus leading to the exhibiting of some microorganisms on the surfaces of shell eggs. Some pathogens may enter into eggs from shells. Consumption of those contained eggs, particularly the eggs without washing and raw ones might exhibit a health hazard to consumers. Shell egg cleaning process commonly include physical brushing, sanitizing, and rinsing with running water. Previous studies indicated that sodium hypochlorite (NaOCl) and ultraviolet (UV) irradiation significantly inhibited and sanitized the growth of microorganisms. The objective of the 1st part of the study was to compare the influences of washing, sanitizing with NaOCl and UV irradiation on the quality of eggs stored at different temperatures for 4 weeks; the objective of the 2nd part of the study was to compare the influences of different concentrations of NaOCl and UV irradiation on the quality of eggs stored at refrigerated temperatures. For the 1st part, the results show that the values of water temperatures and free available residual chlorine contents collected from the outlets of washing machines close to the setting ones and conformed to the regulation of Certified Agriculture Standards. The total plate counts detected on the shells of unwashed (U) were significantly higher than those of the ones washed and sanitized with NaOCl (N), as well as the ones washed and sanitized with NaOCl and UV irradiated (NUV), which had the lowest microbial counts. The total plate counts of the inner contents for all groups were less than 25 CFU/mL of egg content. Scanning electron microscope results show that cuticle covering diminished with storage time, while superior cuticle coatings were observed on the ones without washing then stored at 7oC (UC) and 25oC (UR), thus leading to less increases in air cells. The similar change pattern of hydroxyl group intensity detected on the eggshell was also observed, while no significant difference was observed for the eggshell thickness and strength (P > 0.05). After 4-week storage, the performance of Haugh units, pH values and moisture content of albumin, thick albumin ratio, and yolk index of samples stored at 7oC (UC, NC, and NUVC) were superior significantly (P ＜ 0.05) than those stored at 25oC (UR, NR, and NUVR), while no significant difference was observed on the yolk moisture contents of samples (P > 0.05). For the 2nd part, the results show that the values of water temperatures and free available residual chlorine contents collected from the outlets of washing machines close to the setting ones. The total plate counts detected on the shells of unwashed (U) were significantly higher than those of the other treatments, while ones washed and sanitized with NaOCl and irradiated with UV decreased the microbial loads. No significant difference was observed for the eggshell thickness and strength (P > 0.05). The size of air cell increased significantly with storage time, while less increase was observed for the ones without washing. UV irradiation increased the b* values of eggshell (P ＜ 0.05), but for L* values and a* values no significant differences were observed between treatments. After 4-week storage, the Haugh units of samples remained at USDA AA grade, while the yolk index decreased slightly. The pH values of albumin and yolk increased significantly with storage time and no significant differences were observed between treatments. The albumin moisture contents increased with storage time with significant differences between treatments. For the functionality, albumin foaming ability, albumin foaming stability and yolk emulsion capacity were not significantly different between treatments due to the concentrations of NaOCl and UV irradiation (P > 0.05). In conclusion, it is suggested that shell eggs should be washed and sanitized with 50 ppm NaOCl, irradiated by UV, and then storage at refrigerated temperatures in order to maintain the quality as well as the consumption safety.

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39

Kundu, Devapriya. "Effect of low-dose x-ray and e-beam irradiation on Escherichia coli O157:H7, non-O157 (VTEC) Escherichia coli and Salmonella viability on meat surfaces and sensory quality of meat". 2013. http://hdl.handle.net/1993/15794.

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Radiation sensitivity of E. coli O157:H7, non-O157 VTEC and Salmonella to low-dose ionizing irradiation was evaluated. Buffer-suspended E. coli O157 and non-O157 VTEC strains showed similar resistance to 300 Gy X-ray treatments, while Salmonella strains were more resistant. A dose of 1 kGy E-beam radiation reduced two groups of non-O157 E. coli mixtures and one E. coli O157:H7 group inoculated in meat by at least 4 log CFU/g. Salmonella showed only a <2 log CFU/g reduction. Sensory attributes of cooked ground beef patties were not affected (p >0.05) by irradiation. However, irradiated raw carcass muscles were more brown (p < 0.05) but displayed less intense off-aroma (p < 0.05) compared to the control during storage. Therefore, a 1 kGy treatment has the potential to improve microbiological safety with minimal effects on sensory properties of beef; it would be a suitable method for treating carcass trim before preparing ground beef.

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40

Lin, Yu-Chuan, e 林育全. "Effects of Irradiation on Stored Quality of Garlic and Studies on the Extraction Technology and Preservation Method of Allicin". Thesis, 1997. http://ndltd.ncl.edu.tw/handle/35908840450981911510.

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Abstract (sommario):

碩士
國立中興大學
食品科學系
85
ABSTRACT Garlic is used widely, and all round the year, but its production periods are only in April and May of the year. By using traditional method of air-drying, garlic just stored up to September. At that time, the contents of flavor components would be decreased when garlic is sprouting, and garlic would become dried, spoiled or insect-damaged. The intact garlic doesn''t have special flavor before crushing. The main flavor appears when the cell in plant is destroyed, and is formed from some non-volatile flavor precursors by enzyme. The main substance of these precursors is alliin, and the main flavor component thus obtain is allicin. The objectives of the research wre to (A) study the influence of the flavor and quality of garlic by gamma irradiation in order to extend garlic storage life; (B) study the condition by using supercritical carbon dioxide as solvent to proceed systhesis of allcin, and the practicable of preserving allicin by using absorbants, and (C) study the extraction of allicin and alliin from garlic by using microwave-assisted extraction. The results are shown as: (A) At day 30 after, garlic treated with 0.5 kGy, 1 kGy, 5 kGy, 10 kGy of gamma-ray. 5 kGy and 10 kGy treated garlic have been spoiled and become inedible, but 0.5 kGy and 1 kGy treated garlic retained the similar quality as compared to the control one. At day 90 after, 0.5 kGy treated garlic had better quality than control one. (B) By using supercritical carbon dioxide as solvent, the synthesis of alliin as substract and crude alliinase prepared from garlic was to proceeded the synthesis of allicin. Under the condition of 3,000 psi, 35℃ and adding 0.3 % H2O to assist enzyme reaction, results showed that 30-min reaction could obtain the recovery of over 24.83 %, and decrease the production of by-product of enzyme reaction. (C) By using microwave-assisted extraction to study the practicable of extracting allicin and alliin in short time. Garlic bulbs extracted with microwave power of 40 for 1 min obtained the best allicin extraction ratio (0.67 mg/g fresh garlic), with microwave power of 40 for 5 min obtained the best alliin extraction ratio (0.312 mg/g of fresh garlic)。 Sliced garlic extracted with microwave power of 30 for 1 min obtained the best allicin extraction ratio (9.11 mg/g of fresh garlic), and with microwave power of 50 for 3 min obtained the best alliin extraction ratio (2.7 mg/g of fresh garlic). Keywords: garlic, gamma-ray, allicin, alliin, supercritical fluid extraction, microwave-assisted extraction (MAE)

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41

Wong, Peter Yan Yung. "The effects of electron beam irradiation and infusion of L-ascorbic acid on the preservation of quality of fresh ground beef patties". Thesis, 2001. http://hdl.handle.net/2429/11469.

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The objectives of this thesis were to assess the effectiveness of electron beam irradiation (e ⁻ beam) at 5, 10 and 20 kGy in reducing bacterial count in fresh ground beef patties of 4, 17 and 30% fat and to evaluate the effects of infusing L-ascorbic acid (LAA) into beef carcasses on the quality of irradiated fresh ground beef patties of 4, 17 and 30% fat. Aqueous and emulsion model systems, exposed to ultraviolet and electron beam irradiation, were first used to determine the catalytic activity of hemoglobin, the depletion of LAA and the effects of LAA and e" beam on the degree of lipid oxidation. Hemoglobin generated 50% less hydroxyl radicals than ferrous chloride in the Fenton reaction, indicating minor catalytic activity. An increase in irradiation dosage and storage time drastically decreased the concentration of lOmM L-ascorbic acid. Both ultraviolet and e" beam irradiation induced lipid oxidation in a dose-dependent manner, which was further enhanced by the prooxidant activity of 10 mM LAA. The 500 mM LAA exhibited the opposite effect. The effectiveness of electron beam irradiation in controlling microbial growth was then evaluated in ground beef patties made from LAA infused beef carcasses. Viable bacteria were not detected in ground beef patties receiving irradiation at dosages of 5, 10 and 20 kGy. The addition of tallow to increase total crude fat content in the beef patties led to an increase in bacterial counts. An increase in pH of patties was could have been attributed to the metabolic by-product generated by microorganisms. Finally, the physicochemical characteristics of the infused ground beef patties were evaluated. An increase in irradiation dosages resulted in an increase in lipid oxidation in the beef patties. LAA also increased lipid oxidation, as well as, deoxymyoglobin oxidation in the beef patties. Higher fat content resulted in higher lipid oxidation and pigment oxidation in the beef patties. Hardness attribute of the ground beef patty was significantly increased by the addition of fat. In general, the application of low dosage of e ⁻ beam to lean ground beef patties without the addition of LAA is optimum in preserving quality.

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42

Neal, Jack A. "THE EFFECTS OF ELECTRON BEAM IRRADIATION AND SANITIZERS IN THE REDUCTION OF PATHOGENS AND ATTACHMENT PREVENTION ON SPINACH". 2009. http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-289.

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Abstract (sommario):

The effects of electron beam (e-beam) irradiation and sanitizers in the reduction of Escherichia coli O157:H7 and Salmonella counts and attachment prevention on spinach was studied. Survival of these pathogens in spinach was observed at multiple times and temperatures. Inoculated spinach was examined by confocal microscopy to determine attachment sites and internalization of these pathogens. To determine the effectiveness of sanitizers in reducing pathogen numbers, inoculated spinach was treated with L-lactic acid, peroxyacetic acid, calcium hypochlorite, ozone, and chlorine dioxide. Inoculated spinach was exposed to e-beam irradiation and tested for counts of both pathogens immediately after irradiation treatment to determine bacterial reduction, and at 2 day intervals over 8 days to determine effects of ionizing irradiation on pathogen survival. Respiration rates were measured on spinach exposed to e-beam. The effectiveness of e-beam irradiation on the microbiological and sensory characteristics of spinach was studied. For spinach samples stored at 4�C and 10�C for 8 days, E. coli O157:H7 survived and grew significantly in samples stored at 21�C for 24 h. Confocal microscopy images provided valuable information on the attachment sites and internalization of the pathogens on spinach. The greatest reduction by a chemical sanitizer was 55�C L-lactic acid with a 2.7 log CFU/g reduction for E. coli O157:H7 and 2.3 log CFU/g reduction for Salmonella. Each dose of e-beam irradiation significantly reduced populations of both pathogens. Respiration rates of spinach increased as irradiation treatment doses increased. Total aerobic plate counts were reduced by 2.6 and 3.2 log CFU/g at 0.7 and 1.4 kGy, respectively. Lactic acid bacteria were reduced at both doses but grew slowly over the 35 day period. Yeasts and molds were not reduced in samples exposed to 0.7 kGy whereas 1.4 kGy had significantly reduced counts. Gas compositions for samples receiving 0.7 and 1.4 kGy were significantly different than controls. Irradiation did not affect the objective color or basic taste, aromatic or mouthfeel attributes of spinach. These results suggest that low dose e-beam irradiation may be a viable tool for reducing microbial populations or eliminating E. coli O157:H7 and Salmonella from spinach with minimal product damage.

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43

Tsai, Wen-Che, e 蔡汶哲. "Investigation of the Microbial Quality and Residues of Chemical Reagents in Fresh-Cut Vegetables in Taiwan, and the Application of Gamma Irradiation on the Extension of Their Shelf-life". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/f8qts5.

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Abstract (sommario):

碩士
國立中興大學
食品暨應用生物科技學系所
99
Fresh-cut fruits and vegetables are easy to have browning reactions and microbial contamination during the processing. Therefore, manufactories may add antioxidants or antibacterial agents to avoid the quality reduction of these products. Thus, the first part of this study was to investigate the microbial quality and the amounts of chemical residuals in fresh-cut vegetables. In the second part of this study, vegetables which are easily contaminated by microorganisms were irradiated to inhibit the growth of microorganisms and to increase its shelf life. Moreover, the effects of irradiation on the physical and sensory quality of vegetables were also investigated. In the first part, a total of 42 ready-to-eat (RTE) vegetables (classified into leafy vegetable and rhizomes), 15 ready-to-cook (RTC) vegetables, and 24 sprout products were investigated. The total plate counts above 105 CFU/g, coliform counts above 103 MPN/g, and Escherichia coli counts above 10 MPN/g were unacceptable. In addition, Staphylococcus aureus and Salmonella spp. can’t be detected. Among 42 RTE samples, 13 and 12 samples were unacceptable due to the too high amounts of total plate count and coliform count, individually; while, E. coli, S. aureus, and Salmonella spp. were not detectable in all RTE samples. For 15 RTC samples, 10 samples had total plate count higher than 105 CFU/g, and 9 samples had coliform count higher than 103 MPN/g. Since RTC products will be cooked before eating, it is sure that microorganisms normally can be eliminated before ingestion with proper cooking process. There was no contamination of S. aureus and Salmonella spp. in all RTC samples. All 24 sprout products were unacceptable in total plate count and coliform count. Moreover, two samples were contaminated by E. coli, but S. aureus and Salmonella spp. were not detectable in all sprout samples. Additionally, in all RTE, RTC, and sprout samples, no residual chloride and sulfur dioxide was detected, and the content of ascorbic acid and citric acid were all under the legal limits. In the second stage of this study, food irradiation was applied to six common vegetables (lettuce, cabbage, alfalfa sprouts, pea shoot, carrot, and potato). The results showed that gamma irradiation could effectively reduce the growth of microorganism. After the storage for 9 days, the log reduction for total plate counts could reach to 6 log CFU/g, 4 log CFU/g, and 4-6 log CFU/g for 3-kGy irradiated leafy vegetables, rhizome, and sprouts, respectively. Moreover, the log reduction of yeast and mold on leafy vegetables, rhizome, and sprouts were about 6 log CFU/g, 6 log CFU/g, and 4-6 log CFU/g, respectively. The damage level of food irradiation on tissues of vegetables was expressed by the electrolyte leakage value (EL). The EL values at 3 kGy dose were higher than other dosages for all test samples, and the EL also increased with the increase of storage time. Therefore, the tissues of vegetables were affected by both irradiation dose and storage time. After samples were stored for 9 days, the color of irradiated samples had no significant difference compared with non-irradiated samples. The irradiated cabbage and carrot were used to perform the sensory evaluation, for understanding the effects of irradiation on customer’s preference. Due to other vegetables released water or had bad appearance after storage, they were not suitable for sensory evaluation. The appearance score of cabbage treated with 0.5 kGy dose slightly decreased (0.56%); however, odor score (7.22%), texture score (5.00%), and overall acceptability score (5.56%) were increase, as compared to un-irradiated cabbages. At high irradiation dose of 2 kGy, the score of four sensory items decreased, since most people didn’t accept this level of irradiated cabbage. Moreover, the score of carrot treated with 0.5 kGy dose were decreased in appearance (3.33%), odor (2.22%), texture (5.00%), and overall acceptability (0.56%). At irradiation dose of 1 kGy, the score of four sensory items increased compared with carrot treated with 0.5 kGy dose. Carrot irradiated with 2 kGy dose had lower score in overall acceptability than that treated with 1 kGy. Therefore, irradiation dose at 0.5 kGy could improve the sensory and hygiene quality of cabbage, and irradiation dose at 1 kGy had better sensory effect on carrot.

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44

MATĚJKOVÁ, Kateřina. "Tvorba biogenních aminů v mase vybraných druhů ryb". Doctoral thesis, 2013. http://www.nusl.cz/ntk/nusl-170424.

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The thesis deals with the use and effectiveness of some less common methods of conservation of fish meat. The formation of biogenic amines in meat is observed in connection with the non-traditional preservative methods. Amines can serve as indicators of protein degradation. The quality of fish was considered in connection with the increasing content of selected biogenic amines (putrescine, cadaverine, spermidine, spermine, 2-fenylathylamine, histamine, tyramine and tryptamine). Ultra performance liquid chromatography (UPLC) was used as the method for determination of biogenic amines. Amines were derivatized by dansylchloride before their UPLC separation. The fish flesh was vacuum-packed. Samples were stored for several weeks in a thermostat at the selected storage temperature after the application of selected preservative technique. Beta-irradiation and high hydrostatic pressure were used for the preservation of fish flesh. Control samples were not exposed to the â-irradiation and high pressure. The organoleptic properties were studied for all samples (smell/odor, insight and shape). Beta-irradiation was applied to fish meat of common carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss). Both these species of freshwater fish are economically significant. Carp and trout are the species being mostly consumed in the Czech Republic. Fish meat is considered to be provided the flesh is fresh. A testing series of samples was created with common carp to determine the appropriate dose of â-irradiation. The maximum permissible dose of irradiation for fish meat is 3 kGy. Fish samples were exposed this dose in the first experiment. The dose of irradiation was reduced in following experiments based on the experience from the initial experiment. The doses of 0.25, 0.5, 0.75, 1.0 and 2.0 kGy were applied to rainbow trout. The value of 0.75 kGy of â-irradiation or higher (1.0, 2.0 and 3.0 kGy) prolonged the shelf life of fish meat, which was stored for three months (98 days). Prolonging of the shelf life of fish meat to approximately 98 days at 3.5 °C is redundant from technical point of view. For that reason lower doses 0.25, 0.5 and 0.75 kGy were tested in more detail in the repeated experiment with carp meat. Lower doses of â-irradiation are considered to be more acceptable and-at the same time-sufficiently effective for delaying the beginning of degradation processes. 6 High hydrostatic pressure was applied to meat of common carp (Cyprinus carpio), rainbow trout (Oncorhynchus mykiss) and pike (Exos lucius). Pike is another very popular kind of freshwater fish. Pike flesh is very tasty, but in spite of this, pike is not so much popular among consumers compared to carp and trout. The cause is its high price. Samples of pike were stored at standard temperature 3.5 °C and also at higher temperature 12 °C (unlike experiments with â-irradiation). Lower temperature of storage (3.5 °C) followed the conditions of storing of fish meat in industrial refrigeration facilities and households. The high pressure might not be sufficient for preservation at higher storage temperatures. This assumption was based on available information. Samples were treated by high pressure and stored at both 3.5 °C and 12 °C to verify this assumption. Higher temperature simulated either failure of refrigeration equipment or unsuitable store temperature of meat. In all species selected freshwater fish two levels of high pressure were applied ? 300 and 500 MPa. Both levels had significantly reduced the formation of biogenic amines, especially in samples stored at 3.5 °C. At this temperature, the effect of 300 and 500 MPa delayed start of degradation processes in fish meat by 3?4 weeks. At 12 °C and 500 MPa, high pressure extended the sustainability of meat by no more than one week. 500 MPa is effective treatment at the lower temperature of 3.5 °C. High pressure is not reliable preservative techniques at higher temperature.

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45

Johnstone, Christopher Daniel. "Microcomputed tomography dosimetry and image quality in preclinical image-guided radiation therapy". Thesis, 2019. http://hdl.handle.net/1828/10789.

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Motivated by the need to standardize preclinical imaging for image-guided radiation therapy (IGRT), we examine the parameters that influence microcomputed tomography (microCT) scans in the realm of image quality and absorbed dose to tissue, including therapy beam measurements of small fields. Preclinical radiation research aims to understand radiation-induced effects in living tissues to improve quality of life. Small targets and low kilovoltage x-rays create challenges that do not arise in clinical radiation therapy. Evidence based on our multi-institutional study reveals a considerable aberration in microCT image quality from one institution to the next. We propose the adoption of recommended tolerance levels to provide a baseline for producing satisfactory and reproducible microCT image quality scans for accurate dose delivery in preclinical IGRT. Absorbed dose imparted by these microCT images may produce deterministic effects that can negatively influence a radiobiological study. Through Monte Carlo (MC) methods we establish absorbed microCT imaging dose to a variety of tissues and murine sizes for a comprehensive combination of imaging parameters. Radiation beam quality in the small confines of a preclinical irradiator is also established to quantify the effects of beam scatter on half-value layer measurements. MicroCT scans of varying imaging protocols are also compared for murine subjects. Absorbed imaging dose to tissues are established and presented alongside their respective microCT images, providing a visual bridge to systematically link image quality and imaging dose. We then characterize a novel small plastic scintillating dosimeter to experimentally measure microCT imaging and therapy beams in real-time. The presented scintillating dosimeter is specifically characterized for the low energies and small fields found in preclinical research. Beam output is measured for small fields previously only achievable using film. Finally, quality assurance tests are recommended for a preclinical IGRT unit. Within this dissertation, a narrative is presented for guiding preclinical radiotherapy towards producing high quality microCT images with an understanding of the absorbed imaging dose deposited to tissues, including providing a tool to measure small radiation fields.
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