• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 154
  • 40
  • 39
  • 16
  • 15
  • 9
  • 7
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • Tagged with
  • 343
  • 343
  • 343
  • 44
  • 42
  • 41
  • 37
  • 36
  • 35
  • 34
  • 33
  • 32
  • 31
  • 31
  • 30
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
281

Cocoa flavanols, exercise and the brain / Les flavanols de cacao, l'exercice et le cerveau

Decroix, Lieselot 31 August 2018 (has links)
Les athlètes utilisent les suppléments nutritionnels avec pour objectif d'améliorer leur performance sportive. La performance sportive dépend de facteurs physiques, mais également de facteurs cognitifs. Les suppléments nutritionnels riches en flavanols issu du cacao (CF) peuvent stimuler la fonction vasculaire, réduire le stress oxydant et améliorer la fonction cognitive. L'objectif de cette thèse est donc d’analyser les effets d'une consommation aigue, ou pendant une semaine, de CF, sur la performance physique et cognitive chez des athlètes, chez des sujets actifs et chez des personnes ayant un diabète de type 1 (DT1). De plus, l’objectif est d’investiguer les effets des CF en altitude simulé, où l’hypoxie limite la performance cognitive et physique.La consommation aigue de 900 mg CF (dont 196 mg d'épicatéchine) suscite une augmentation de l’oxygénation cérébrale, mais pas de la concentration de BDNF sérique et n'a pas d’effet sur la fonction cognitive chez des sportifs sains. L’effet bénéfique des CF sur l’oxygénation cérébrale au repos est dépassé par l’ampleur de l’augmentation de la perfusion et de l’oxygénation cérébrale à l’exercice physique et n'est donc plus visible en post-exercice.En hypoxie (altitude simulée de 4000 m), la consommation aigue de 530 mg CF (dont 100 mg d'épicatéchine) augmente la réponse hémodynamique du cortex préfrontal durant une tâche cognitive, mais n’affecte pas l’activité neuronale. Les CF améliorent la pensée abstraite en normoxie, mais n’améliorent aucun autre domaine des fonctions cognitives. Seule la précision lors du test de Stroop est diminuée par l’hypoxie. De plus, la réponse hémodynamique du cortex préfrontale et l’activité neuronale ne diffèrent pas en hypoxie vs. en normoxie.Le diabète de type 1 (DT1) est associé avec une dysfonction endothéliale, qui constitue un des facteurs de déclin cognitif lié au diabète. Dans une 3ième étude, la fonction cognitive n’est pas altérée chez les patients DT1, en comparaison des sujets sains, alors que l'activation cérébrale diffère entre ces 2 groupes. Cette différence d'activation cérébrale pourrait alors jouer un rôle compensatoire chez les patients DT1. La consommation aigue de CF peut améliorer les fonctions exécutives chez des patients DT1 et des sujets sains, et peut augmenter le signal BOLD dans les régions du cerveau activées par les tâches cognitives.Ainsi, la consommation aigue de CF augmente la vasoréactivité cérébrale. Ces changements sont associés avec une meilleure fonction cognitive chez des patients DT1, alors que ce n’est pas le cas chez des sujets entraînés, ni au niveau de la mer, ni en hypoxie. Malgré ces effets bénéfiques des CF, l’exercice physique semble rester un moyen beaucoup plus efficace pour stimuler la vasoreactivité cérébrale et les fonctions cognitives.Nous nous sommes aussi intéressés aux effets de CF sur la capacité antioxydante, le stress oxydant et la production de NO pendant l’exercice, ainsi que sur les implications pour la performance physique et la récupération, chez des athlètes. La consommation aigue de 903 mg CF augmente la capacité antioxydante au repos et pendant l’exercice, mais sans réduire le stress oxydant et la production de NO. La consommation pendant une semaine de 530 mg CF (dont 100 mg d'épicatéchine) atténue la peroxydation lipidique induite par l’exercice, mais n’influence pas la capacité antioxydante. Les CF ne modifient pas la production et la biodisponibilité du NO pendant un exercice en normoxie et en hypoxie (altitude simulée de 3000 m). La consommation de CF pendant une semaine peut augmenter la fonction endothéliale de repos, et peut réduire les effets nuisibles de l'hypoxie sur l’oxygénation préfrontale au repos et pendant l’exercice modéré. Par contre, cet effet disparait pendant l’exercice intense. La consommation aigue, et pendant une semaine, de CF n’augmente pas la performance physique, ni en normoxie, ni en hypoxie. / Sports performance depends on physical factors, but also on cognitive functioning. Nutritional supplements as potential ergogenic aids can impact muscle, but also the brain. Cocoa flavanols (CF) have antioxidant capacities, can stimulate vascular function, and potentially enhance cognitive function. CF intake might thus improve exercise performance and recovery by reducing oxidative stress, increasing NO availability and/or boosting cognitive function. It is the purpose of this PhD to identify the effects of CF on physical and cognitive performance in healthy athletes at sea level and altitude, as well as in patients with type 1 diabetes. Our systematic review showed that CF can reduce exercise-induced oxidative stress, but without improving exercise performance. Combining CF intake and exercise training improves cardiovascular risk factors and vascular function in healthy and overweight participants, but evidence on the synergistic effects of CF and exercise training on oxidative stress, inflammation and fat and glucose metabolism is lacking.In a randomized, placebo-controlled, double blind cross-over study, we showed that 900 mg CF intake increased prefrontal oxygenation in athletes, but without affecting executive function. BDNF was not affected by CF intake. The effects of high-intensity exercise largely overruled the effects of CF intake: large beneficial effects of exercise on prefrontal oxygenation and cognitive function were observed and CF supplementation did not enlarge these effects. In a 2nd study, the effect of acute CF intake (530 mg CF) on performance on a demanding cognitive test was assessed in normoxia and hypoxia (simulated altitude 4000 m). Electroencephalogram and fNIRS were used to analyse neuronal activity and hemodynamic changes. Acute CF intake improved the neurovascular response, but did not affect neuronal activity and cognitive performance in normoxia and hypoxia. Most cognitive functions, the cerebrovascular response and neuronal activity, were not altered in hypoxia in healthy subjects. In a 3rd study, we found that acute intake of 900 mg CF enhanced cognitive performance on the Flanker test in patients with type 1 diabetes, and their healthy matched controls. CF intake increased the BOLD response in brain areas activated during this specific task. While cognitive performance was not deteriorated in patients with type 1 diabetes, a different brain activation pattern during the cognitive task was observed, compared to healthy controls and this brain activation pattern was altered by CF intake. To conclude, acute CF intake improves prefrontal oxygenation and cerebrovascular responsiveness. This can be associated with better cognitive function in patients with type 1 diabetes, but does not result in improved executive function in healthy persons. Compared to exercise, the magnitude of the CF-induced neurovascular changes is small.Two studies were conducted examining the effects of CF on exercise-induced oxidative stress, NO availability and its implications for exercise performance, in well-trained cyclists. We found that acute CF (900 mg) improved the exercise-induced increase in total antioxidant capacity, but did not reduce the exercise-induced increase in lipid peroxidation. One week CF intake (530 mg CF) improved vascular function at rest, and prefrontal oxygenation at rest and during low-intensity exercise, but did not influence muscular oxygenation. One week CF intake partially restored the hypoxia-induced decline in prefrontal oxygenation during rest and low-intensity exercise, but not during high-intensity exercise. One week CF intake reduced exercise-induced lipid peroxidation, but did not alter total antioxidant capacity. Both acute and 1-week CF intake did not improve exercise performance and recovery and do not change NO production during exercise (in normoxia and hypoxia) in well-trained athletes.
282

Douleur et stress aigus en période néonatale : effets de l'utilisation des sucres et intérêts d'une évaluation multimodale de la douleur / Acute pain and stress in neonates : effects of sweet solutions and contribution of a multimodal pain assessment

Roué, Jean-Michel 15 May 2018 (has links)
Le nouveau-né hospitalisé est exposé de manière répétée à des procédures douloureuses ou stressantes pouvant entraîner des conséquences neurodéveloppementales à court et long terme. La prévention de la douleur procédurale est essentiellement basée sur l’utilisation de traitements non pharmacologiques parmi lesquels les solutions sucrées possèdent un niveau de preuve élevé. Cependant, leur efficacité a récemment été remise en cause et leurs mécanismes d’action restent mal compris. Enfin, la dissociation parfois retrouvée entre les réponses comportementales et corticales suggère de monitorer la douleur de manière multimodale. Les objectifs de ce travail étaient : 1) de comparer l’efficacité de l’allaitement maternel et du sucrose sur la douleur procédurale en analysant spécifiquement les réponses corticales, 2) d’étudier les effets périphériques des solutions sucrées au niveau de neurones sensoriels de ratons, 3) d’évaluer l’intérêt d’un modèle d’évaluation multimodale de la douleur chez le nouveau-né à terme et prématuré. Aucune différence entre le sucrose et l’allaitement maternel n’a pu être objectivée sur les réponses corticales(NIRS) à la douleur chez des nouveau-nés à terme à 3 jours de vie. Nous avons objectivé un effet périphérique du glucose et du sucrose sur des neurones sensoriels de ratons nouveau-nés, médié par TRPV1. L'effet du glucose était associé à une diminution de la libération de la substance P. L’évaluation multimodale de la douleur retrouvait des corrélations faibles à modérées entre le score NFCS et la conductance cutanée, le cortisol salivaire et les changements d’ [HbT] mesurés en NIRS. L’étude menée chez les nouveau-nés prématurés nous permettra de préciser l’intérêt de l’utilisation de la variabilité de la fréquence cardiaque (indice NIPE instantané) dans cette indication afin de proposer un modèle multimodal fiable pour de futurs essais randomisés contrôlés. / Hospitalized newborns are exposed to repeated painful or stressful procedures that can lead to short- and long-term neurodevelopmental sequellae.The prevention of procedural pain is essentially based on the use of nonpharmacological treatments among which the sweet solutions appear to be among the most effective. However, their effectiveness has recently been challenged and their mechanisms of action remain poorly understood. Finally, the dissociation frequently found between behavioural and cortical responses shows the importance of monitoring pain in a multimodal way. The objectives of this work were 1) to compare the efficacy of breastfeeding and sucrose on procedural pain by specifically analyzing cortical responses, 2) to study the peripheral effects of sweet solutions on sensory neurons of newborn rats and 3) to evaluate the contribution of a multimodal pain assessment model in term and preterm neonates. No difference between sucrose and breastfeeding was measured on pain-evoked cortical responses (NIRS) in term neonates at 3 days of life.We reported a peripheral effect of glucose and sucrose on afferent sensory neurons from newborns rats mediated byTRPV1. The effect for glucose was associated with a decrease of substance P release.The multidimensional assessment of pain found mild to moderate correlations between the NFCS score, skin conductance, salivary cortisol and changes in [HbT] measured in NIRS.The study conducted in preterm newborns will specify the reliability of heart rate variability (instant NIPE index) in thisindication to provide a suited multimodal pain assessment model for future randomized controlled trials.
283

Processo de fabricação de comprimidos de lamivudina e zidovudina (150+300mg): avaliação retrospectiva da variabilidade e desenvolvimento de metodologia analítica por espectroscopia no infravermelho próximo com transformada de Fourier (FT-NIR) aplicada a avaliação da homogeneidade da mistura de pós / Lamivudine and zidovudine tablet manufacturing process (150 + 300mg): retrospective evaluation of the variability and development of analytical methodology by Fourier transform (FT-NIR) near infrared spectroscopy applied to the evaluation of homogeneity of the powder mixture

Silva, Osvaldo Cirilo da 26 November 2018 (has links)
O uso de ferramentas estatísticas no ciclo de vida de um produto farmacêutico permite verificar e controlar o processo tendo como objetivo a sua melhoria contínua. No presente estudo foi avaliada a estabilidade e a capacidade estatística do processo de fabricação dos comprimidos revestidos de lamivudina 3TC e zidovudina AZT (150 + 300 mg) fabricados pela Fundação para o Remédio Popular \"Chopin Tavares de Lima\" (FURP). Esse medicamento, distribuido gratuitamente pelo programa DST/AIDS do Ministério da Saúde, e fabricado por compressão direta, processo rápido que permite a implementação futura da tecnologia analítica de processo (Process Analytical Technology - PAT). No Capítulo I foi realizada avaliação retrospectiva da variabilidade de atributos criticos da qualidade de 529 lotes dos comprimidos fabricados de acordo com a RDC ANVISA 17/2010 e as monografias oficiais, sendo tais atributos: peso médio, uniformidade de dose unitária e % m/v de fármaco dissolvido, antes e após o revestimento. O objetivo foi identificar eventuais causas especiais de variabilidade dos processos que permitam melhorias contínuas. No Capitulo II foi desenvolvida metodologia analítica empregando a espectroscopia no infravermelho próximo com transformada de Fourier para a avaliação da homogeneidade da mistura dos pós. Nesse estudo foram analisadas amostras de misturas dos fármacos lamivudina 3TC e zidovudina AZT e mistura excipiente, empregando como método de referência a CLAE, para a quantificação desses dois fármacos. No Capitulo I, a avaliação do processo para o peso médio revelou a necessidade de investigação das causa especiais de variabilidade, evidenciada por meio das cartas de controle. Os resultados do ano de 2015 indicaram necessidade de centralização e de consistência do processo, com redução de probabilidade de falha. As cartas de controle para uniformidade de dose unitária, no ano de 2013, revelaram menor variabilidade do processo. Porem, nesse ano, a análise estatística para a dissolução revelou processo descentralizado e sem consistência, com maior evidência para o fármaco 3TC que demonstrou menor desempenho, Cpk<1,0. A avaliação da estabilidade e da capacidade do processo de fabricação de comprimidos de lamivudina + zidovudina (150+300 mg), no período de 2012 a 2015, permitiu o maior entendimento de suas fontes de variação. Foi possível detectar e determinar o grau dessa variação e seu impacto no processo e nos atributos críticos de qualidade do produto com evidentes oportunidades de melhoria do processo, reduzindo os riscos para o paciente. No capítulo II, no desenvolvimento do método, as estatísticas de validação revelaram que os menores valores de BIAS foram observados para a 3TC, 0,000116 e 0,0021, respectivamente para validação cruzada e validação. Os valores de BIAS próximos a zero indicaram reduzida porcentagem de variabilidade do método. O presente estudo demonstrou a viabilidade do uso do modelo desenvolvido para a quantificação da 3TC e AZT por FT-NIR apos ajustes que contribuam para a elevação de R, R2 e RPD para valores aceitáveis. Valores de RPD acima de 5,0 que permitem o uso do modelo para uso em controle de qualidade. / The use of statistical tools in the life cycle of a pharmaceutical product allows verifying and controlling the process aiming at its continuous improvement. In the present study, the stability and statistical capacity of the lamivudine coated tablets 3TC and zidovudine AZT (150 + 300 mg) manufactured by the Chopin Tavares de Lima Foundation (FURP) were evaluated. This drug, distributed free of charge by the Ministry of Health\'s DST/AIDS program, is manufactured by direct compression, a rapid process that allows the future implementation of Process Analytical Technology (PAT). In Chapter I, a retrospective evaluation of the variability of critical quality attributes of 529 batches of tablets manufactured was carried out, such attributes being: mean weight, unit dose uniformity and % m/v of dissolved drug substances, before and after coating. The objective was to identify possible special causes of variability of the processes that allow continuous improvements. In Chapter II an analytical methodology was developed employing the near infrared spectroscopy with Fourier transform for the evaluation of the homogeneity of the powder mixture. In this study, samples of mixtures of the drugs lamivudine 3TC and zidovudine AZT and excipient mixture were analyzed, using as reference method the HPLC, for the quantification of these two drugs. In Chapter I, the evaluation of the process for the mean weight revealed the need to investigate the special cause of variability, as evidenced by the charts. The results of the year 2015 indicated the need for centralization and process consistency, with a reduction in the probability of failure. The control charts for unit dose uniformity, in the year 2013, revealed less process variability. However, in that year, the statistical analysis for dissolution revealed a decentralized process with no consistency, with greater evidence for the 3TC drug that showed lower performance, Cpk<1.0. The evaluation of the stability and capacity of the lamivudine + zidovudine tablet manufacturing process (150 + 300 mg) in the period from 2012 to 2015 allowed a better understanding of its sources of variation. It was possible to detect and determine the degree of this variation and its impact on the process and the critical quality attributes of the product with evident opportunities to improve the process, reducing risks for the patient. In Chapter II, in the development of the method, the validation revealed that the lowest values of BIAS were observed for 3TC, 0.000116 and 0.0021, respectively for cross validation and validation. BIAS values close to zero indicated a reduced percentage of variability of the method. The present study demonstrated the feasibility of using the model developed for the quantification of 3TC and AZT by FT-NIR after adjustments that contribute to the elevation of R, R2 and RPD to acceptable values. RPD values above 5.0 that allow the use of the model for use in quality control.
284

NEAR-INFRARED SPECTROSCOPY FOR REFUSE DERIVED FUEL : Classification of waste material components using hyperspectral imaging and feasibility study of inorganic chlorine content quantification

Ševčík, Martin January 2019 (has links)
This degree project focused on examining new possible application of near-infrared (NIR) spectroscopy for quantitative and qualitative characterization of refuse derived fuel (RDF). Particularly, two possible applications were examined as part of the project. Firstly, use of NIR hyperspectral imaging for classification of common materials present in RDF. The classification was studied on artificial mixtures of materials commonly present in municipal solid waste and RDF. Data from hyperspectral camera was used as an input for machine learning models to train them, validate them, and test them. Three classification machine learning models were used in the project; partial least-square discriminant analysis (PLS-DA), support vector machine (SVM), and radial basis neural network (RBNN). Best results for classifying the materials into 11 distinct classes were reached for SVM (accuracy 94%), even though its high computational cost makes it not very suitable for real-time deployment. Second best result was reached for RBNN (91%) and the lowest accuracy was recorded for PLS-DA model (88%). On the other hand, the PLS-DA model was the fastest, being 10 times faster than the RBNN and 100 times faster than the SVM. NIR spectroscopy was concluded as a suitable method for identification of most common materials in RDF mix, except for incombustible materials like glass, metals, or ceramics. The second part of the project uncovered a potential in using NIR spectroscopy for identification of inorganic chlorine content in RDF. Experiments were performed on samples of textile impregnated with a water solution of kitchen salt representing NaCl as inorganic chlorine source. Results showed that contents of 0.2-1 wt.% of salt can be identified in absorbance spectra of the samples. Limitation appeared to be water content of the examined samples, as with too large amount of water in the sample, the influence of salt on NIR absorbance spectrum of water was too small to be recognized. / FUDIPO
285

Implication du système nerveux central dans la faiblesse musculaire périphérique du patient atteint de broncho-pneumopathie chronique obstructive / Involvement of central nervous system in peripheral muscle weakness of patients with chronic obstructive pulmonary disease

Alexandre, François 03 July 2015 (has links)
La faiblesse des muscles périphériques, définie par une diminution de la force maximale volontaire en dehors de tout état de fatigue neuromusculaire, est une complication fréquente de la broncho-pneumopathie chronique obstructive (BPCO). La force maximale volontaire dépend à la fois des propriétés musculaires périphériques (i.e. volume et architecture musculaire, qualités contractiles) et de la capacité du système nerveux à activer le muscle maximalement. Dans la BPCO, plusieurs travaux ont souligné l'existence paradoxale d'une perte de force maximale volontaire sans altérations musculaires périphériques et sans qu'un déficit d'activation volontaire n'ait clairement été identifié. Pourtant, les patients atteints de BPCO présentent de nombreuses altérations du système nerveux, compatibles avec une capacité d'activation volontaire altérée.L'objectif de ce travail de thèse était donc de tester l'implication du système nerveux dans la faiblesse musculaire de la BPCO et d'en déterminer les mécanismes sous-jacents. Au cours de nos travaux, nous avons mis en évidence une activité corticale diminuée dans la BPCO lors de contractions maximales et sous-maximales volontaires. Nous avons par ailleurs rapporté une perte d'excitabilité du cortex moteur et un déficit d'activation volontaire spécifique aux patients atteints de faiblesse musculaire. Ces résultats sont en accord avec une implication des altérations cérébrales dans la faiblesse musculaire périphérique de la BPCO. Nous sommes ensuite parvenus à identifier une origine potentielle des altérations cérébrales : les désaturations en O2 au cours du sommeil avec mouvements non-rapides des yeux (NREM). Cette hypothèse a été corroborée par l'observation d'un niveau d'activation volontaire réduit chez les patients désatureurs en sommeil NREM. En revanche, aucune répercussion significative n'a pu être observée sur la force maximale volontaire de ces patients, suggérant l'existence d'un mécanisme compensatoire. In fine, nos résultats constituent une avancée importante dans la compréhension du phénomène de faiblesse musculaire, classiquement attribué à la seule perte de masse musculaire. L'implication du système nerveux central dans la faiblesse musculaire ouvre notamment la voie à de nouvelles modalités de prise en charge par des approches spécifiques, dans l'optique de lutter contre la faiblesse musculaire et ses multiples répercussions négatives dans la vie du patient atteint de BPCO. / Peripheral muscle weakness, as defined by a reduced voluntary strength outside any state of neuromuscular fatigue, is a common complication of chronic obstructive pulmonary disease (COPD). Maximal voluntary strength is determined by both peripheral muscle properties (i.e. muscle volume and architecture, contractile quality) and the nervous system's ability to activate the muscle maximally. In COPD, many studies highlighted the paradoxical existence of maximal voluntary strength loss without any peripheral muscle impairment, and without a clearly identified voluntary activation deficit. However, patients with COPD exhibited several nervous system alterations compatible with a reduced maximal voluntary activation capacity. The aim of this thesis was to test the nervous system implication in COPD muscle weakness and to determine the involved mechanisms. As major results, we found a reduced cortical activity in COPD during maximal and sub-maximal voluntary contractions. Furthermore, we reported reduced motor cortex excitability and voluntary activation deficit, specifically in patients with muscle weakness. These results are in accordance with an involvement of cortical alterations in COPD muscle weakness. Then, we indentified a potential origin for cortical alterations: O2 desaturation during non-rapid eye movement (NREM) sleep. This hypothesis has been corroborated by the observation of a reduced voluntary activation in patients with NREM sleep desaturation. However, no significant repercussion could have been observed on maximal voluntary strength in these patients, suggesting a compensatory mechanism.Our results are an important step forward in understanding the COPD muscle weakness that was classically attributed to loss of muscle mass only. The involvement of the central nervous system in COPD muscle weakness also brings about new patient care opportunities via tailored approaches, in order to fight against muscle weakness and its deleterious consequences on a patient's life.
286

Processo de fabricação de comprimidos de lamivudina e zidovudina (150+300mg): avaliação retrospectiva da variabilidade e desenvolvimento de metodologia analítica por espectroscopia no infravermelho próximo com transformada de Fourier (FT-NIR) aplicada a avaliação da homogeneidade da mistura de pós / Lamivudine and zidovudine tablet manufacturing process (150 + 300mg): retrospective evaluation of the variability and development of analytical methodology by Fourier transform (FT-NIR) near infrared spectroscopy applied to the evaluation of homogeneity of the powder mixture

Osvaldo Cirilo da Silva 26 November 2018 (has links)
O uso de ferramentas estatísticas no ciclo de vida de um produto farmacêutico permite verificar e controlar o processo tendo como objetivo a sua melhoria contínua. No presente estudo foi avaliada a estabilidade e a capacidade estatística do processo de fabricação dos comprimidos revestidos de lamivudina 3TC e zidovudina AZT (150 + 300 mg) fabricados pela Fundação para o Remédio Popular \"Chopin Tavares de Lima\" (FURP). Esse medicamento, distribuido gratuitamente pelo programa DST/AIDS do Ministério da Saúde, e fabricado por compressão direta, processo rápido que permite a implementação futura da tecnologia analítica de processo (Process Analytical Technology - PAT). No Capítulo I foi realizada avaliação retrospectiva da variabilidade de atributos criticos da qualidade de 529 lotes dos comprimidos fabricados de acordo com a RDC ANVISA 17/2010 e as monografias oficiais, sendo tais atributos: peso médio, uniformidade de dose unitária e % m/v de fármaco dissolvido, antes e após o revestimento. O objetivo foi identificar eventuais causas especiais de variabilidade dos processos que permitam melhorias contínuas. No Capitulo II foi desenvolvida metodologia analítica empregando a espectroscopia no infravermelho próximo com transformada de Fourier para a avaliação da homogeneidade da mistura dos pós. Nesse estudo foram analisadas amostras de misturas dos fármacos lamivudina 3TC e zidovudina AZT e mistura excipiente, empregando como método de referência a CLAE, para a quantificação desses dois fármacos. No Capitulo I, a avaliação do processo para o peso médio revelou a necessidade de investigação das causa especiais de variabilidade, evidenciada por meio das cartas de controle. Os resultados do ano de 2015 indicaram necessidade de centralização e de consistência do processo, com redução de probabilidade de falha. As cartas de controle para uniformidade de dose unitária, no ano de 2013, revelaram menor variabilidade do processo. Porem, nesse ano, a análise estatística para a dissolução revelou processo descentralizado e sem consistência, com maior evidência para o fármaco 3TC que demonstrou menor desempenho, Cpk<1,0. A avaliação da estabilidade e da capacidade do processo de fabricação de comprimidos de lamivudina + zidovudina (150+300 mg), no período de 2012 a 2015, permitiu o maior entendimento de suas fontes de variação. Foi possível detectar e determinar o grau dessa variação e seu impacto no processo e nos atributos críticos de qualidade do produto com evidentes oportunidades de melhoria do processo, reduzindo os riscos para o paciente. No capítulo II, no desenvolvimento do método, as estatísticas de validação revelaram que os menores valores de BIAS foram observados para a 3TC, 0,000116 e 0,0021, respectivamente para validação cruzada e validação. Os valores de BIAS próximos a zero indicaram reduzida porcentagem de variabilidade do método. O presente estudo demonstrou a viabilidade do uso do modelo desenvolvido para a quantificação da 3TC e AZT por FT-NIR apos ajustes que contribuam para a elevação de R, R2 e RPD para valores aceitáveis. Valores de RPD acima de 5,0 que permitem o uso do modelo para uso em controle de qualidade. / The use of statistical tools in the life cycle of a pharmaceutical product allows verifying and controlling the process aiming at its continuous improvement. In the present study, the stability and statistical capacity of the lamivudine coated tablets 3TC and zidovudine AZT (150 + 300 mg) manufactured by the Chopin Tavares de Lima Foundation (FURP) were evaluated. This drug, distributed free of charge by the Ministry of Health\'s DST/AIDS program, is manufactured by direct compression, a rapid process that allows the future implementation of Process Analytical Technology (PAT). In Chapter I, a retrospective evaluation of the variability of critical quality attributes of 529 batches of tablets manufactured was carried out, such attributes being: mean weight, unit dose uniformity and % m/v of dissolved drug substances, before and after coating. The objective was to identify possible special causes of variability of the processes that allow continuous improvements. In Chapter II an analytical methodology was developed employing the near infrared spectroscopy with Fourier transform for the evaluation of the homogeneity of the powder mixture. In this study, samples of mixtures of the drugs lamivudine 3TC and zidovudine AZT and excipient mixture were analyzed, using as reference method the HPLC, for the quantification of these two drugs. In Chapter I, the evaluation of the process for the mean weight revealed the need to investigate the special cause of variability, as evidenced by the charts. The results of the year 2015 indicated the need for centralization and process consistency, with a reduction in the probability of failure. The control charts for unit dose uniformity, in the year 2013, revealed less process variability. However, in that year, the statistical analysis for dissolution revealed a decentralized process with no consistency, with greater evidence for the 3TC drug that showed lower performance, Cpk<1.0. The evaluation of the stability and capacity of the lamivudine + zidovudine tablet manufacturing process (150 + 300 mg) in the period from 2012 to 2015 allowed a better understanding of its sources of variation. It was possible to detect and determine the degree of this variation and its impact on the process and the critical quality attributes of the product with evident opportunities to improve the process, reducing risks for the patient. In Chapter II, in the development of the method, the validation revealed that the lowest values of BIAS were observed for 3TC, 0.000116 and 0.0021, respectively for cross validation and validation. BIAS values close to zero indicated a reduced percentage of variability of the method. The present study demonstrated the feasibility of using the model developed for the quantification of 3TC and AZT by FT-NIR after adjustments that contribute to the elevation of R, R2 and RPD to acceptable values. RPD values above 5.0 that allow the use of the model for use in quality control.
287

Multivariate non-invasive measurements of skin disorders

Nyström, Josefina January 2006 (has links)
<p>The present thesis proposes new methods for obtaining objective and accurate diagnoses in modern healthcare. Non-invasive techniques have been used to examine or diagnose three different medical conditions, namely neuropathy among diabetics, radiotherapy induced erythema (skin redness) among breast cancer patients and diagnoses of cutaneous malignant melanoma. The techniques used were Near-InfraRed spectroscopy (NIR), Multi Frequency Bio Impedance Analysis of whole body (MFBIA-body), Laser Doppler Imaging (LDI) and Digital Colour Photography (DCP).</p><p>The neuropathy for diabetics was studied in papers I and II. The first study was performed on diabetics and control subjects of both genders. A separation was seen between males and females and therefore the data had to be divided in order to obtain good models. NIR spectroscopy was shown to be a viable technique for measuring neuropathy once the division according to gender was made. The second study on diabetics, where MFBIA-body was added to the analysis, was performed on males exclusively. Principal component analysis showed that healthy reference subjects tend to separate from diabetics. Also, diabetics with severe neuropathy separate from persons less affected.</p><p>The preliminary study presented in paper III was performed on breast cancer patients in order to investigate if NIR, LDI and DCP were able to detect radiotherapy induced erythema. The promising results in the preliminary study motivated a new and larger study. This study, presented in papers IV and V, intended to investigate the measurement techniques further but also to examine the effect that two different skin lotions, Essex and Aloe vera have on the development of erythema. The Wilcoxon signed rank sum test showed that DCP and NIR could detect erythema, which is developed during one week of radiation treatment. LDI was able to detect erythema developed during two weeks of treatment. None of the techniques could detect any differences between the two lotions regarding the development of erythema.</p><p>The use of NIR to diagnose cutaneous malignant melanoma is presented as unpublished results in this thesis. This study gave promising but inconclusive results. NIR could be of interest for future development of instrumentation for diagnosis of skin cancer.</p>
288

Combinaison des techniques de biologie moléculaire et de la spectrométrie dans le proche infrarouge pour l'authentification des denrées destinées à l'alimentation humaine et animale

Fumière, Olivier 11 May 2010 (has links)
Résumé: Lauthentification est un concept large dans lequel il sagit de pouvoir contrôler ladéquation entre le produit et les informations indiquées sur létiquette. Les techniques utilisant la spectrométrie dans le proche infrarouge dune part, et celles basées sur la PCR dautre part, permettent daborder lauthentification des produits alimentaires sous des angles totalement différents. Loriginalité de ce travail était de les associer pour résoudre deux problèmes précis : 1. lauthentification des poulets de chair à croissance lente utilisés dans des productions de qualité différenciée soumises à des cahiers des charges contraignants ; 2. la détection des farines animales dans lalimentation pour le bétail. Nos travaux sur les poulets de chair nous ont permis de développer des modèles de discrimination reposant sur les spectres dans le proche infrarouge de la viande de poulet. Ils distinguent, pour plus de 80 % des individus, les poulets issus de souches à croissance lente de ceux issus de souches à croissance rapide. Les résultats dune expérimentation animale ont également démontré que la spectrométrie dans le proche infrarouge était capable de mettre évidence des fraudes au niveau de lalimentation des animaux. Deux marqueurs moléculaires spécifiques du type de souche de poulets ont été mis en évidence et caractérisés. Pour le marqueur moléculaire caractéristique des poulets à croissance rapide, un test rapide utilisable en routine a été développé. Dans le cas de la détection des farines animales dans lalimentation du bétail, une méthode de PCR en temps réel sensible et spécifique a été mise au point participant avec succès à des études inter-laboratoires internationales. Associée dans une stratégie originale à la MPIR (microscopie dans le proche infrarouge), elle permet la détection spécifique de particules de farines de viande et dos. Summary: Authentication is a large concept focussing on the control of the correspondance between the product and the information provided on the label. Techniques based on near infrared spectroscopy on the one hand, and those based on PCR on the other hand, allow to tackle the authentication of food and feed products by different sides. The originality of this work was to associate both techniques to solve two specific problems : 1. authentication of slow growing chickens bred in high quality productions according to restricting specifications ; 2. the detection of meat and bone meals in feedingstuffs. The work on the chicken allowed us to develop discriminant models using the near infrared spectra of chicken meat. These models discriminate the chicken from slow- vs. fast-growing chicken for more than 80 % of the animals. The results of an animal experimentation also showed that near infrared spectroscopy was able to detect feeding frauds. Two molecular markers specific of the type of chicken strains were found and characterised. For the one related to the fast-growing chicken strains, a rapid assay applicable in routine testing was conceived. In the case of the meat and bone meal detection in feedingstuffs, a specific and sensitive real time PCR method was developed. It participated succesfully to international inter-laboratory studies. Its combination with NIRM (near infrared microscopy) through an original strategy allows the specific detection of meat and bone meal particles.
289

Methodische Untersuchungen zum Einsatz der Nahinfrarot-Spektroskopie (NIRS) zur Qualitätsbeurteilung von High-Oleic-Sonnenblumen / Investigations for the estimation of several quality parameters of high oleic sunflower achenes by near-infrared spectroscopy (NIRS)

Moschner, Christian R. 12 July 2007 (has links)
No description available.
290

Nahinfrarotspektroskopische Erfassung und Charakterisierung der nutritiven und fermentativen Qualität von Grassilage im ungetrockneten Zustand / Near infrared spectroscopic measuring and characterisation of the nutritive and fermentative quality of grass silage in undried state

Gibaud, Hélène 25 January 2008 (has links)
No description available.

Page generated in 0.0838 seconds