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A selectivity study on the use of caffeine and theobromine imprinted polypyrrole surface electrodes /Vinjamuri, Anil Kiran Kumar. January 2008 (has links)
Thesis (M.S.)--Western Kentucky University, 2008. / Tables. Includes bibliographical references (leaves 59-60).
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The liking for chocolate : attitudes, mood and psychopharmacological effectsSmit, Hendrick Jan January 1998 (has links)
No description available.
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Efeito da Adição de teobromina sobre as propriedades do cimento de ionômero de vidro / Vision effect of the theobromine about the properties of the glass ionomer cementCevallos Gonzalez, Fabricio Marcelo 18 June 2018 (has links)
A proposta deste trabalho experimental in vitro foi avaliar se a incorporação de 1% - em peso - do alcalóide teobromina (Sigma Aldrich, Darmstadt, Alemanha) ao cimento de ionômero de vidro (CIV) convencional (GC Gold Fuji 9, GC Corp, Japão) tem a capacidade de alterar as propriedades físico-químicas desse material. Para tanto, dois grupos experimentais foram propostos: G1 - CIV convencional e G2 - CIV com adição de teobromina. Foram confeccionados 160 discos de CIV de acordo com as instruções do fabricante, utilizando matrizes circulares. Para analisar as mencionadas propriedades, os discos foram submetidos a testes específicos, de acordo com as normas da International Standard Organization (ISO) para cada uma das propriedades. Discos de 15mmx1mm de diâmetro foram utilizados para as provas de sorção (n=5) e de solubilidade (n=5), com o auxílio de balança analítica, dissecadores e estufa a 23 e 37ºC por várias semanas. O ensaio de microdureza foi realizado em amostras (n=20) de 15mm×1mm submetidas a cinco edentações, com carga de 25 gramas e 30 segundos, à temperatura ambiente. Para a avaliação da cor, discos (n=20) de 15mm×1mm foram submetidos ao espectrofotômetro, adotando-se a guia colorimétrica da Comissão internacional de Iluminação (CIE). No ensaio de resistência flexural, os espécimes (n=60) de 12mm×1mm foram armazenados em estufa a 37ºC durante 24 horas para posterior analise na máquina de ensaios universal. Para avaliar a influência da teobromina adicionada ao CIV na formação de biofilme por Streptococcus mutans,, sobre os corpos da prova (n=40) de 12mm×1mm biofilmes foram desenvolvidos. As cepas de S.mutans foram cultivadas em Tryptic Soy Agar (TSA, Difco) a 37°C. Também a dosagem de flúor foi avaliada, em discos de prova (n=10) armazenados em saliva artificial e submersos em solução TISAB para posterior análise com eletrodo de flúor e obtenção da curva da liberação dessa substância. Os dados obtidos nos testes de sorção e solubilidade, microdureza, cor e resistência flexural foram submetidos à análise de variância ANOVA um fator e ao teste de Tukey para comparação entre os grupos, adotando-se 5% de nível de significância (p<0,05). O ensaio da influência da teobromina adicionada ao CIV na quantidade de biofilme de Streptococcus mutans formado e o teste de dosagem de flúor foram submetidos à análise de variância two-way ANOVA e ao teste de Tukey, com nível de significância de 5% para comparação entre os grupos experimentais. O segundo fator avaliado nestes dois ensaios foi o tempo. Os resultados não revelaram alteração da sorção e da solubilidade no CIV que recebeu teobromina (p>0,05). A microdureza aumentou com a adição de teobromina ao CIV (p<0,05). Não houve alteração de cor do CIV que recebeu teobromina (p>0,05). A resistência na flexão biaxial diminuiu quando da adição de teobromina ao CIV (p<0,05). Já a quantidade de biofilme formado foi menor em G2 (p<0,05). Em relação à liberação de flúor, observou-se que a adição de teobromina não altera essa propriedade do CIV (p>0,05). Com base em tais achados, conclui-se que a adição de teobromina a 1% ao cimento do ionômero de vidro convencional não produz alterações significativas nas propriedades desse material, podendo até mesmo otimizar algumas dessas propriedades. Ainda assim, estudos adicionais sobre o assunto devem ser realizados. / The purpose of this experimental in virtro work, was to evaluate if the incorporation of the 1% in weight of an alkaloid: theobromine (Sigma Aldrich Darmstadt, Germany) to the conventional glass ionomer cement (GIC) (GC Gold Fuji 9; GCC Japan Corp) has the capacity to change the properties physicochemical of this material. Whereby, it was proposed two experimental groups: G1 - Conventional GIC and G2 GIC incorporated with theobromine. According to the instructions of the creator, there were created 160 specimens, for which it was used circular matrices. To analyze the mentioned properties, the specimens were analyzed under the International Standard Organization (ISO) for each property. It was used matrices of 15mmx1mm diameter for the sorption (n=5) solubility (n=5) tests. With the help of an analytical balance, desiccators and a stove at 23º and 37° for various weeks; it was made essays of micro firmness using 20 matrices of 15mmx1mm, were submitted to five indentations with a charge of 26 grams and 30 seconds in environmental temperature. For the color evaluation it was used 20 matrices of 15mmx1mm, that were submitted to a spectrophotometer following the colorimetric guide of the International Commission of Illumination (CIE). An essay of biaxial flexural strength was made in 60 matrices of 12mmx1mm that were stored in a stove at 37º for 24 hours, for a later analysis in a universal testing machine. To evaluate the influence of the theobromine incorporated to the glass ionomer cement (GIC) in the creation of biofilm Streptococcus mutans, there were developed 40 matrices of 12mmx1mm of biofilm. The strains of the Streptococcus mutans were cultivated in Tryptic Soy-Agar at 37°. It was also evaluated the fluorine release capacity using 10 test matrices stored in artificial saliva and submerged in TISAB substance for a later analysis with an fluorine electrode, to obtain the release curve of that substance. The obtained information from the test of sorption, solubility, micro strength, color and biaxial flexural strength, were submitted to an analysis of variance ANOVA one factor and Tukey\'s test for a comparison between groups assuming the 5% level of significance (p <0,05). The essay of the influence of the theobromine added to the GIC in the amount of biofilm Streptococcus mutans formed and the test of fluorine release were submitted to the Bidirectional Variance Analysis ANOVA and Tukey\'s test, with a significant level of 5% to the comparison between experimental groups; the second factor evaluated in this two essays was time. The results didn\'t show an alteration in the sorption and solubility in the GIC that received theobromine (p >0,05). The micro strength increased with the addition of the theobromine to the GIC (p< 0,05). There were not any alterations in the color of the GIC that received theobromine (p >0.05). The resistance to the biaxial flexural strength decreased when the theobromine was added to the GIC (p <0.05). The amount of formed biofilm was less in the G2. In relation to the fluorine release it was observed that the addition of theobromine does not change the properties of GIC (p >0.05). Based on these findings, it is concluded that the addition of theobromine in 1% to the conventional glass ionomer cement, does not produce significant changes over this material properties and also, it can optimize some of these properties. However, more studies should be done about this topic.
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Efeito da Adição de teobromina sobre as propriedades do cimento de ionômero de vidro / Vision effect of the theobromine about the properties of the glass ionomer cementFabricio Marcelo Cevallos Gonzalez 18 June 2018 (has links)
A proposta deste trabalho experimental in vitro foi avaliar se a incorporação de 1% - em peso - do alcalóide teobromina (Sigma Aldrich, Darmstadt, Alemanha) ao cimento de ionômero de vidro (CIV) convencional (GC Gold Fuji 9, GC Corp, Japão) tem a capacidade de alterar as propriedades físico-químicas desse material. Para tanto, dois grupos experimentais foram propostos: G1 - CIV convencional e G2 - CIV com adição de teobromina. Foram confeccionados 160 discos de CIV de acordo com as instruções do fabricante, utilizando matrizes circulares. Para analisar as mencionadas propriedades, os discos foram submetidos a testes específicos, de acordo com as normas da International Standard Organization (ISO) para cada uma das propriedades. Discos de 15mmx1mm de diâmetro foram utilizados para as provas de sorção (n=5) e de solubilidade (n=5), com o auxílio de balança analítica, dissecadores e estufa a 23 e 37ºC por várias semanas. O ensaio de microdureza foi realizado em amostras (n=20) de 15mm×1mm submetidas a cinco edentações, com carga de 25 gramas e 30 segundos, à temperatura ambiente. Para a avaliação da cor, discos (n=20) de 15mm×1mm foram submetidos ao espectrofotômetro, adotando-se a guia colorimétrica da Comissão internacional de Iluminação (CIE). No ensaio de resistência flexural, os espécimes (n=60) de 12mm×1mm foram armazenados em estufa a 37ºC durante 24 horas para posterior analise na máquina de ensaios universal. Para avaliar a influência da teobromina adicionada ao CIV na formação de biofilme por Streptococcus mutans,, sobre os corpos da prova (n=40) de 12mm×1mm biofilmes foram desenvolvidos. As cepas de S.mutans foram cultivadas em Tryptic Soy Agar (TSA, Difco) a 37°C. Também a dosagem de flúor foi avaliada, em discos de prova (n=10) armazenados em saliva artificial e submersos em solução TISAB para posterior análise com eletrodo de flúor e obtenção da curva da liberação dessa substância. Os dados obtidos nos testes de sorção e solubilidade, microdureza, cor e resistência flexural foram submetidos à análise de variância ANOVA um fator e ao teste de Tukey para comparação entre os grupos, adotando-se 5% de nível de significância (p<0,05). O ensaio da influência da teobromina adicionada ao CIV na quantidade de biofilme de Streptococcus mutans formado e o teste de dosagem de flúor foram submetidos à análise de variância two-way ANOVA e ao teste de Tukey, com nível de significância de 5% para comparação entre os grupos experimentais. O segundo fator avaliado nestes dois ensaios foi o tempo. Os resultados não revelaram alteração da sorção e da solubilidade no CIV que recebeu teobromina (p>0,05). A microdureza aumentou com a adição de teobromina ao CIV (p<0,05). Não houve alteração de cor do CIV que recebeu teobromina (p>0,05). A resistência na flexão biaxial diminuiu quando da adição de teobromina ao CIV (p<0,05). Já a quantidade de biofilme formado foi menor em G2 (p<0,05). Em relação à liberação de flúor, observou-se que a adição de teobromina não altera essa propriedade do CIV (p>0,05). Com base em tais achados, conclui-se que a adição de teobromina a 1% ao cimento do ionômero de vidro convencional não produz alterações significativas nas propriedades desse material, podendo até mesmo otimizar algumas dessas propriedades. Ainda assim, estudos adicionais sobre o assunto devem ser realizados. / The purpose of this experimental in virtro work, was to evaluate if the incorporation of the 1% in weight of an alkaloid: theobromine (Sigma Aldrich Darmstadt, Germany) to the conventional glass ionomer cement (GIC) (GC Gold Fuji 9; GCC Japan Corp) has the capacity to change the properties physicochemical of this material. Whereby, it was proposed two experimental groups: G1 - Conventional GIC and G2 GIC incorporated with theobromine. According to the instructions of the creator, there were created 160 specimens, for which it was used circular matrices. To analyze the mentioned properties, the specimens were analyzed under the International Standard Organization (ISO) for each property. It was used matrices of 15mmx1mm diameter for the sorption (n=5) solubility (n=5) tests. With the help of an analytical balance, desiccators and a stove at 23º and 37° for various weeks; it was made essays of micro firmness using 20 matrices of 15mmx1mm, were submitted to five indentations with a charge of 26 grams and 30 seconds in environmental temperature. For the color evaluation it was used 20 matrices of 15mmx1mm, that were submitted to a spectrophotometer following the colorimetric guide of the International Commission of Illumination (CIE). An essay of biaxial flexural strength was made in 60 matrices of 12mmx1mm that were stored in a stove at 37º for 24 hours, for a later analysis in a universal testing machine. To evaluate the influence of the theobromine incorporated to the glass ionomer cement (GIC) in the creation of biofilm Streptococcus mutans, there were developed 40 matrices of 12mmx1mm of biofilm. The strains of the Streptococcus mutans were cultivated in Tryptic Soy-Agar at 37°. It was also evaluated the fluorine release capacity using 10 test matrices stored in artificial saliva and submerged in TISAB substance for a later analysis with an fluorine electrode, to obtain the release curve of that substance. The obtained information from the test of sorption, solubility, micro strength, color and biaxial flexural strength, were submitted to an analysis of variance ANOVA one factor and Tukey\'s test for a comparison between groups assuming the 5% level of significance (p <0,05). The essay of the influence of the theobromine added to the GIC in the amount of biofilm Streptococcus mutans formed and the test of fluorine release were submitted to the Bidirectional Variance Analysis ANOVA and Tukey\'s test, with a significant level of 5% to the comparison between experimental groups; the second factor evaluated in this two essays was time. The results didn\'t show an alteration in the sorption and solubility in the GIC that received theobromine (p >0,05). The micro strength increased with the addition of the theobromine to the GIC (p< 0,05). There were not any alterations in the color of the GIC that received theobromine (p >0.05). The resistance to the biaxial flexural strength decreased when the theobromine was added to the GIC (p <0.05). The amount of formed biofilm was less in the G2. In relation to the fluorine release it was observed that the addition of theobromine does not change the properties of GIC (p >0.05). Based on these findings, it is concluded that the addition of theobromine in 1% to the conventional glass ionomer cement, does not produce significant changes over this material properties and also, it can optimize some of these properties. However, more studies should be done about this topic.
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Raman spectroscopic characterisations and analytical discrimination between caffeine and demethylated analogues of pharmaceutical relevanceEdwards, Howell G.M., Munshi, Tasnim, Anstis, M. January 2005 (has links)
No / The FT Raman spectrum of caffeine was analysed along with that of its demethylated analogues, theobromine and theophylline. The similar but not identical structures of these three compounds allowed a more detailed assignment of the Raman bands. Noticeable differences in the Raman spectra of these compounds were apparent and key marker bands have been identified for the spectroscopic identification of these three compounds.
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Konstruktion av en laboration i vätskekromatografi för gymnasieskolan, och genomförande av laborationen i en klass. / Construction of a laboratory lesson for upper secondary school in the area of Liquid Chromatography, including carrying through the laboratory lesson in a classOlsson, Ida January 2009 (has links)
<p> </p><p><strong><em> </em></strong></p><p><strong><em> </em></strong></p><p><strong><em> </em></strong></p><p><strong><em> </em></strong></p><p><strong>Construction of a laboratory lesson for upper secondary school in the area of Liquid Chromatography, including carrying through the laboratory lesson in a class</strong></p><p><strong> </strong></p><p>Laboratory lessons constitute an important part of science education. There are different sorts of laboratory lessons. In some laboratory lessons the students themselves are active, and in others the teacher demonstrates an experiment for the students. Some laborative work can be defined by the teacher while other can give the students an opportunity to plan an investigation themselves.</p><p> </p><p>A new laboratory lesson, on the area of Liquid Chromatography, for upper secondary school has been made. In the laboratory lesson chocolate is analysed regarding the content of caffeine and theobromine. The laboratory lesson has been carried out in a class, to see what the students know about solubility, dilution, chromatography and analytical procedure after they have gone through the laboratory lesson. To get information about the students knowledge a questionnaire study was done. Teachers also have been interviewed, for their opinion about laboratory lessons as a part of science education.</p><p> </p><p>All students showed some knowledge about solubility, and most students also had knowledge about chromatography even if they described different aspects of it. Dilutions was not a problem for most of the students. Many students also showed an understanding of the analytical procedure. For the teachers interviewed laborative work was an important part of science education.</p><p> </p><p><strong>Key words:</strong> Liquid chromatography, laboratory lesson, upper secondary school, chocolate, theobromine, caffeine, questionnaire study, and interviews.</p><p> </p><p> </p><p>Advisor: <strong>Margareta Sandahl, </strong>Lund University</p><p><strong>Olle Eskilsson, </strong>Kristianstad University</p><p>Degree project 30 credits in Chemistry/Educational Science 2008/2009</p><p>Department of Chemistry, Lund University</p><p>School of Teacher Education, Kristianstad University</p>
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Konstruktion av en laboration i vätskekromatografi för gymnasieskolan, och genomförande av laborationen i en klass. / Construction of a laboratory lesson for upper secondary school in the area of Liquid Chromatography, including carrying through the laboratory lesson in a classOlsson, Ida January 2009 (has links)
Construction of a laboratory lesson for upper secondary school in the area of Liquid Chromatography, including carrying through the laboratory lesson in a class Laboratory lessons constitute an important part of science education. There are different sorts of laboratory lessons. In some laboratory lessons the students themselves are active, and in others the teacher demonstrates an experiment for the students. Some laborative work can be defined by the teacher while other can give the students an opportunity to plan an investigation themselves. A new laboratory lesson, on the area of Liquid Chromatography, for upper secondary school has been made. In the laboratory lesson chocolate is analysed regarding the content of caffeine and theobromine. The laboratory lesson has been carried out in a class, to see what the students know about solubility, dilution, chromatography and analytical procedure after they have gone through the laboratory lesson. To get information about the students knowledge a questionnaire study was done. Teachers also have been interviewed, for their opinion about laboratory lessons as a part of science education. All students showed some knowledge about solubility, and most students also had knowledge about chromatography even if they described different aspects of it. Dilutions was not a problem for most of the students. Many students also showed an understanding of the analytical procedure. For the teachers interviewed laborative work was an important part of science education. Key words: Liquid chromatography, laboratory lesson, upper secondary school, chocolate, theobromine, caffeine, questionnaire study, and interviews. Advisor: Margareta Sandahl, Lund University Olle Eskilsson, Kristianstad University Degree project 30 credits in Chemistry/Educational Science 2008/2009 Department of Chemistry, Lund University School of Teacher Education, Kristianstad University
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Valorisation of Compounds with High Nutritional Value from Cocoa By-Products as Food Ingredients and AdditivesRojo Poveda, Olga 17 May 2021 (has links) (PDF)
This doctoral thesis was conducted in the framework of a co-supervised PhD between the Department of Agriculture, Forestry and Food Sciences of the University of Turin and the Unit of Pharmacognosy, Bioanalysis and Drug Discovery of the Faculty of Pharmacy at the Université libre de Bruxelles. The present manuscript was conceived as a thesis of articles and is composed of 9 different scientific publications. The general introduction of the work was issued from a published narrative review, while the result and discussion part is composed by eight chapters based on different scientific articles issued from the PhD project. The cocoa bean shell (CBS) is the external tegument that covers the cocoa bean, and is one of the major by-products in cocoa industry. It is normally discarded or underutilized, which could result in economical and environmental issues. However, CBS represents a notable source of polyphenols and methylxanthines (theobromine and caffeine) which can give it different biofunctionalities such as antioxidant and antidiabetic properties, among others. It also contains high amounts of dietary fiber (about 50% w/w), minerals, vitamins, and proteins. CBS has low-fat content, and interesting cocoa-aroma compounds. All this could make CBS useful as a food ingredient, and source of biofunctional compounds. The first part of the experimental work of this thesis is devoted to the chemical characterization of CBS and the establishment of its polyphenolic and volatile organic compound (aroma) profiles. The utilization of such profiles, determined by both complete characterization methods and screening methods, was also proposed for authentication purposes of CBS depending on its geographical origin and variety. In a second step, the utilization of CBS as a low-cost food ingredient for functional food production was envisaged. CBS-based beverages and biscuits were proposed as model foods. The influence of the CBS addition to the model foods was evaluated from both technological and nutritional points of view. Changes on the physicochemical characteristics of the model foods were assessed as well as their content in compounds of interest and potential biofunctionalities. Moreover, these studies served also to evaluate the effect of the different food matrices on the bioaccessibility and intestinal permeability of the bioactive compounds contained in CBS. In the third and last part of this work, a different utility was given to the study of the cocoa by-product. The antimicrobial potential of CBS was assessed against different bacterial and fungal strains and a metabolomic strategy was applied in order to individualize the putative active compounds against the Streptococcus mutans proliferation. This work was a contribution for the valorization of a high add-value product such as the CBS, and a step towards a zero-waste cocoa industry within the frame of sustainable circular economy. / Doctorat en Sciences biomédicales et pharmaceutiques (Pharmacie) / info:eu-repo/semantics/nonPublished
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