Global ETD Search

91	Effects of plant extracts and phytoconstituents on the intestinal transport of indinavir / K.H. Roos. Roos, Karin Hester January 2012 (has links) There is a global rise in the use of herbal products in combination with allopathic medicines, while most patients do not inform their health care providers of the use of these natural products. Both pharmacodynamic and pharmacokinetic interactions between herbal products and conventional drugs must be avoided for the wellbeing of the patient. Increasing evidence from in vitro and in vivo studies indicate that changed drug pharmacokinetics by co-administered herbs may be attributed to modulation of efflux drug transporters such as P-glycoprotein (P-gp). Garlic (Allium sativum), lemon (Citrus limonum) and beetroot (Beta vulgaris) are widely used by human immunodeficiency virus (HIV) patients, especially following the pronouncement by a former President of South Africa and the Ministers of Health at that time who promoted the use of these botanicals in HIV patients. The aim of this study was to measure the bi-directional in vitro transport of indinavir, a protease inhibitor, in the presence of crude extracts and pure phytoconstituents of A. sativum (L-alliin and diallyl disulphide), C. limonum (hesperidin and eriocitrin) and B. vulgaris (betaine monohydrate and ß-carotene) across excised porcine intestinal tissue in Sweetana-Grass diffusion chambers. In the negative control group, the transport of indinavir alone (200 M) was determined with no modulator added. In the positive control group, the transport of indinavir was determined in the presence of verapamil (100 M), a known P-gp related efflux inhibitor. The control experiments were used to indicate that the effects of the test compounds were caused by their action and not by chance interferences or external factors. Samples collected at pre-determined time intervals were analysed by means of a validated high performance liquid chromatography (HPLC) method and the transport was expressed as the apparent permeability coefficient (Papp) and the transepithelial flux (J) from which the efflux ratio (ER) and the net flux (Jnet) values were calculated. Statistical analysis was used to compare the results of the test compounds with the control groups in order to indicate significant differences. The mean ER value for indinavir in the negative control group was 1.41 ± 0.170 and in the positive control group it was 0.56 ± 0.0426. Statistically significant (p < 0.05) inhibition of indinavir efflux as indicated by reduced ER values was obtained for L-alliin (ER = 0.280 ± 0.030), diallyl disulphide (ER = 0.505 ± 0.034) and ß-carotene (ER = 0.664 ± 0.075). Inhibition of indinavir efflux will lead to increased transport and therefore a potentially higher bioavailability. Statistically significant (p < 0.05) promotion of indinavir efflux as indicated by increased ER values was obtained for C. limonum crude extract (ER = 5.551 ± 0.575) and hesperidin (ER = 3.385 ± 0.477), which potentially may lead to lower bioavalability. B. vulgaris crude extract (p = 0.8452), betaine monohydrate (p = 0.9982), A. sativum crude extract (p = 0.7161) and eriocitrin (p = 0.4431) displayed no statistically significant effect compared to the negative control group on indinavir transport across excised porcine intestinal tissue. The results from this study demonstrate that L-alliin, diallyl disulphide and ß-carotene have an inhibitory effect on indinavir efflux, which may significantly increase indinavir plasma levels after oral administration. C. limonum crude extract and hesperidin promote indinavir efflux, which may significantly reduce indinavir plasma levels. These pharmacokinetic interactions between certain drugs and plant extracts may negatively affect the anti-retroviral treatment of HIV patients, but deliberate and controlled inclusion of L-alliin, diallyl disulphide and ß-carotene in dosage forms may possibly cause more effective delivery of protease inhibitors after oral administration resulting in less frequent dosing intervals. / Thesis (MSc (Pharmaceutics))--North-West University, Potchefstroom Campus, 2013. Herbal medicine in vitro models efflux P-glycoprotein (P-gp) garlic lemon beetroot Sweetana-Grass diffusion chambers human immunodeficiency virus (HIV) indinavir kruiemiddels in vitro modelle effluks P-glikoprotein (P-gp) knoffel suurlemoen beet Sweetana-Grass diffusiesisteem menslike immuniteitsgebrekvirus (MIV)
92	Effects of plant extracts and phytoconstituents on the intestinal transport of indinavir / K.H. Roos. Roos, Karin Hester January 2012 (has links) There is a global rise in the use of herbal products in combination with allopathic medicines, while most patients do not inform their health care providers of the use of these natural products. Both pharmacodynamic and pharmacokinetic interactions between herbal products and conventional drugs must be avoided for the wellbeing of the patient. Increasing evidence from in vitro and in vivo studies indicate that changed drug pharmacokinetics by co-administered herbs may be attributed to modulation of efflux drug transporters such as P-glycoprotein (P-gp). Garlic (Allium sativum), lemon (Citrus limonum) and beetroot (Beta vulgaris) are widely used by human immunodeficiency virus (HIV) patients, especially following the pronouncement by a former President of South Africa and the Ministers of Health at that time who promoted the use of these botanicals in HIV patients. The aim of this study was to measure the bi-directional in vitro transport of indinavir, a protease inhibitor, in the presence of crude extracts and pure phytoconstituents of A. sativum (L-alliin and diallyl disulphide), C. limonum (hesperidin and eriocitrin) and B. vulgaris (betaine monohydrate and ß-carotene) across excised porcine intestinal tissue in Sweetana-Grass diffusion chambers. In the negative control group, the transport of indinavir alone (200 M) was determined with no modulator added. In the positive control group, the transport of indinavir was determined in the presence of verapamil (100 M), a known P-gp related efflux inhibitor. The control experiments were used to indicate that the effects of the test compounds were caused by their action and not by chance interferences or external factors. Samples collected at pre-determined time intervals were analysed by means of a validated high performance liquid chromatography (HPLC) method and the transport was expressed as the apparent permeability coefficient (Papp) and the transepithelial flux (J) from which the efflux ratio (ER) and the net flux (Jnet) values were calculated. Statistical analysis was used to compare the results of the test compounds with the control groups in order to indicate significant differences. The mean ER value for indinavir in the negative control group was 1.41 ± 0.170 and in the positive control group it was 0.56 ± 0.0426. Statistically significant (p < 0.05) inhibition of indinavir efflux as indicated by reduced ER values was obtained for L-alliin (ER = 0.280 ± 0.030), diallyl disulphide (ER = 0.505 ± 0.034) and ß-carotene (ER = 0.664 ± 0.075). Inhibition of indinavir efflux will lead to increased transport and therefore a potentially higher bioavailability. Statistically significant (p < 0.05) promotion of indinavir efflux as indicated by increased ER values was obtained for C. limonum crude extract (ER = 5.551 ± 0.575) and hesperidin (ER = 3.385 ± 0.477), which potentially may lead to lower bioavalability. B. vulgaris crude extract (p = 0.8452), betaine monohydrate (p = 0.9982), A. sativum crude extract (p = 0.7161) and eriocitrin (p = 0.4431) displayed no statistically significant effect compared to the negative control group on indinavir transport across excised porcine intestinal tissue. The results from this study demonstrate that L-alliin, diallyl disulphide and ß-carotene have an inhibitory effect on indinavir efflux, which may significantly increase indinavir plasma levels after oral administration. C. limonum crude extract and hesperidin promote indinavir efflux, which may significantly reduce indinavir plasma levels. These pharmacokinetic interactions between certain drugs and plant extracts may negatively affect the anti-retroviral treatment of HIV patients, but deliberate and controlled inclusion of L-alliin, diallyl disulphide and ß-carotene in dosage forms may possibly cause more effective delivery of protease inhibitors after oral administration resulting in less frequent dosing intervals. / Thesis (MSc (Pharmaceutics))--North-West University, Potchefstroom Campus, 2013. Herbal medicine in vitro models efflux P-glycoprotein (P-gp) garlic lemon beetroot Sweetana-Grass diffusion chambers human immunodeficiency virus (HIV) indinavir kruiemiddels in vitro modelle effluks P-glikoprotein (P-gp) knoffel suurlemoen beet Sweetana-Grass diffusiesisteem menslike immuniteitsgebrekvirus (MIV)
93	Avaliação da atividade antimicrobiana do óleo essencial de distintos quimiotipos de Lippia alba (Mill.) N.E.Brown Formolo, Fernanda 15 December 2009 (has links) Lippia alba é uma espécie nativa, conhecida como erva cidreira , utilizada na medicina popular para o tratamento de distintas afecções. Estudos farmacológicos atribuem a sua atividade antimicrobiana aos terpenóides presentes no óleo essencial. Considerando a variação na composição de óleos essenciais de L. alba, o presente trabalho teve por objetivo determinar a composição química do óleo essencial de sete acessos de L. alba coletados no sul do Brasil, e avaliar a atividade antimicrobiana dos mesmos sobre um painel de 22 espécies bacterianas e 9 espécies de leveduras. Os óleos essenciais foram extraídos por hidrodestilação e analisados por Cromatografia gasosa e Cromatografia gasosa acoplada a um detector seletivo de massas. A atividade antimicrobiana (Dose de inibição 50% e Concentração inibitória mínima) foi determinada através do método de diluição seriada (0 a 10 mg/ml) em microplacas, com avaliação do crescimento por absorbância a 595nm. Para a determinação de Dose de inibição 50% e Concentração inibitória mínima foram consideradas as concentrações de óleo essencial que reduzidam o crescimento em 50% e 90%, respectivamente. A atividade bactericida e bacteriostática foi deteminada após 3h de tratamento dos microrganismos com a Concentração inibitória mínima pré-determinada para cada óleo. Com base nos seus componentes majoritários, os resultados permitiram caracterizar os sete acessos de L. alba como pertencentes aos quimiotipos: citral, 1,8-cineol/cânfora, linalol, linalol/mirceno/cânfora, carvona/cariofileno, linalol/1,8-cineol/germacreno D, e limoneno. Entre os quimiotipos, o óleo essencial citral exibiu o espectro antimicrobiano mais amplo, inibindo tanto bactérias como leveduras. Óleos com alta concentração de carvona/cariofileno e limoneno foram particularmente eficientes sobre leveduras, enquanto os quimiotipos linalol e linalol/1,8-cineol/germacreno D exibiram atividade inibitória sobre várias bactérias Gram positivas e negativas. Na Concentração inibitória mínima, o quimiotipo citral mostrou ação bactericida sobre leveduras e Salmonella sp. Entretanto, outros óleos apresentaram apenas efeito bacteriostático sobre a maioria dos microrganismos avaliados. Em geral, nossos resultados confirmam a atividade dos óleos essenciais de L. alba sobre microrganismos de importância clínica e industrial, mas apontam a necessidade de avaliação adequada da composição dos mesmos afim de escolher aquele mais efetivo para o controle de um microrganismo específico. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-06-04T18:06:34Z No. of bitstreams: 1 Dissertacao Fernanda Formolo.pdf: 1268224 bytes, checksum: 2cde3df8d5929f9192359c2c9beb98df (MD5) / Made available in DSpace on 2014-06-04T18:06:34Z (GMT). No. of bitstreams: 1 Dissertacao Fernanda Formolo.pdf: 1268224 bytes, checksum: 2cde3df8d5929f9192359c2c9beb98df (MD5) / Lippia alba is a native species, known as "erva cidreira", currently used in folk medicine for the treatment of several diseases. Pharmacologic studies attributed their antimicrobial activity to the terpenoids present in the essential oils. Considering the variation on essential oil composition among L. alba accessions, the present work aimed to determine the essential oil composition of seven accession of L. alba collected in South Brazil, and to evaluate their antimicrobial activity against a panel of 22 bacterial and 9 yeast species. Essential oils were extracted by hydrodistillation and analyzed by GC and GC/MS. Antimicrobial activity (ID50 and MIC) were determined by a serial dilution method (0 to 10 mg/ml) on microplates with growth evaluation by absorbance at 595nm. For ID50 and MIC determination were considered the essential oil concentrations that reduced microbial growth on 50% and 90%, respectively. Bactericidal and bacteriostatic activities were determined after 3h treatment of the microorganisms with their individual MIC of each essential oil. Based on their main constituents, the results allowed characterizing the seven accessions of L. alba as chemotypes: citral, 1,8-cineol/camphor, linalool, linalool/mircene/camphor, carvone/caryophyllene, linalool/1,8-cineol/germacrene D, and limonene. Among these chemotypes, citral essential oils showed the largest antimicrobial spectrum, inhibiting both bacteria and yeasts. Oils with high concentration of carvone/caryophyllene, and limonene, were particularly effective against yeasts, and oils from chemotypes linalool and linalool/1,8-cineol/germacrene D exhibited inhibitory activity against several Gram positive and negative bacteria. At the MIC, citral showed bactericide effect on yeasts and Salmolella. However, other oils showed just bacteriostatic effects on most microorganisms. In general, our results confirm the activity of L. alba essential oils on both clinical and industrial microorganisms, but point out the necessity to properly evaluate essential oil composition to choose those more effective for the control of a specific microorganism. Ciências Biológicas Lippia alba Quimiotipos Atividades antimicrobiana Biotecnologia Essências e óleos essenciais Erva-cidreira Agentes antiinfecciosos Lippia alba Chemotypes Antimicrobial activity Biotechnology Essences and essential oils Lemon balm Anti-infective agents
94	Avaliação da atividade antimicrobiana do óleo essencial de distintos quimiotipos de Lippia alba (Mill.) N.E.Brown Formolo, Fernanda 15 December 2009 (has links) Lippia alba é uma espécie nativa, conhecida como erva cidreira , utilizada na medicina popular para o tratamento de distintas afecções. Estudos farmacológicos atribuem a sua atividade antimicrobiana aos terpenóides presentes no óleo essencial. Considerando a variação na composição de óleos essenciais de L. alba, o presente trabalho teve por objetivo determinar a composição química do óleo essencial de sete acessos de L. alba coletados no sul do Brasil, e avaliar a atividade antimicrobiana dos mesmos sobre um painel de 22 espécies bacterianas e 9 espécies de leveduras. Os óleos essenciais foram extraídos por hidrodestilação e analisados por Cromatografia gasosa e Cromatografia gasosa acoplada a um detector seletivo de massas. A atividade antimicrobiana (Dose de inibição 50% e Concentração inibitória mínima) foi determinada através do método de diluição seriada (0 a 10 mg/ml) em microplacas, com avaliação do crescimento por absorbância a 595nm. Para a determinação de Dose de inibição 50% e Concentração inibitória mínima foram consideradas as concentrações de óleo essencial que reduzidam o crescimento em 50% e 90%, respectivamente. A atividade bactericida e bacteriostática foi deteminada após 3h de tratamento dos microrganismos com a Concentração inibitória mínima pré-determinada para cada óleo. Com base nos seus componentes majoritários, os resultados permitiram caracterizar os sete acessos de L. alba como pertencentes aos quimiotipos: citral, 1,8-cineol/cânfora, linalol, linalol/mirceno/cânfora, carvona/cariofileno, linalol/1,8-cineol/germacreno D, e limoneno. Entre os quimiotipos, o óleo essencial citral exibiu o espectro antimicrobiano mais amplo, inibindo tanto bactérias como leveduras. Óleos com alta concentração de carvona/cariofileno e limoneno foram particularmente eficientes sobre leveduras, enquanto os quimiotipos linalol e linalol/1,8-cineol/germacreno D exibiram atividade inibitória sobre várias bactérias Gram positivas e negativas. Na Concentração inibitória mínima, o quimiotipo citral mostrou ação bactericida sobre leveduras e Salmonella sp. Entretanto, outros óleos apresentaram apenas efeito bacteriostático sobre a maioria dos microrganismos avaliados. Em geral, nossos resultados confirmam a atividade dos óleos essenciais de L. alba sobre microrganismos de importância clínica e industrial, mas apontam a necessidade de avaliação adequada da composição dos mesmos afim de escolher aquele mais efetivo para o controle de um microrganismo específico. / Lippia alba is a native species, known as "erva cidreira", currently used in folk medicine for the treatment of several diseases. Pharmacologic studies attributed their antimicrobial activity to the terpenoids present in the essential oils. Considering the variation on essential oil composition among L. alba accessions, the present work aimed to determine the essential oil composition of seven accession of L. alba collected in South Brazil, and to evaluate their antimicrobial activity against a panel of 22 bacterial and 9 yeast species. Essential oils were extracted by hydrodistillation and analyzed by GC and GC/MS. Antimicrobial activity (ID50 and MIC) were determined by a serial dilution method (0 to 10 mg/ml) on microplates with growth evaluation by absorbance at 595nm. For ID50 and MIC determination were considered the essential oil concentrations that reduced microbial growth on 50% and 90%, respectively. Bactericidal and bacteriostatic activities were determined after 3h treatment of the microorganisms with their individual MIC of each essential oil. Based on their main constituents, the results allowed characterizing the seven accessions of L. alba as chemotypes: citral, 1,8-cineol/camphor, linalool, linalool/mircene/camphor, carvone/caryophyllene, linalool/1,8-cineol/germacrene D, and limonene. Among these chemotypes, citral essential oils showed the largest antimicrobial spectrum, inhibiting both bacteria and yeasts. Oils with high concentration of carvone/caryophyllene, and limonene, were particularly effective against yeasts, and oils from chemotypes linalool and linalool/1,8-cineol/germacrene D exhibited inhibitory activity against several Gram positive and negative bacteria. At the MIC, citral showed bactericide effect on yeasts and Salmolella. However, other oils showed just bacteriostatic effects on most microorganisms. In general, our results confirm the activity of L. alba essential oils on both clinical and industrial microorganisms, but point out the necessity to properly evaluate essential oil composition to choose those more effective for the control of a specific microorganism. Ciências Biológicas Lippia alba Quimiotipos Atividades antimicrobiana Biotecnologia Essências e óleos essenciais Erva-cidreira Agentes antiinfecciosos Lippia alba Chemotypes Antimicrobial activity Biotechnology Essences and essential oils Lemon balm Anti-infective agents
95	Influência da idade da planta na composição química do óleo essencial de Lippia alba e de um ciclo de seleção recorrente na atividade formicida / Influence of plant age on the chemical composition of the essential oil of Lippia alba and of a recurrent selection cycle on formicidal activity Pinto, Vanderson dos Santos 31 July 2017 (has links) Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Brazilian lemon balm (Lippiaalba (Mill.) N. E. Brown) is a medicinal and aromatic species widely used to fight diseases. Its essential oil, rich in carvone, has insecticidal activity on pests of agricultural interest. Cutting ants cause severe economic damage to forest and horticultural species and hinder cultivation worldwide. Plant aging is one of the main factors that alter the biological activity of essential oils. The objective of this work was to evaluate the influence of plant age on the essential oil of L. alba accessionsand of a recurrent selection cycle onformicidal activity. The experiments were carried out at the Experimental Farm - Campus Rural UFS.The experiment consisted of a randomized blocks design with three replications. For the first experiment, 18 L. albaaccessions were used at two plant ages: one-year-old plants (February2006), and ten-year-old plants (February 2016). In the second experiment, a recurrent selection cycle was carried out with three accessions of the limonene/carvonechemotype. For the progeny competition experiment, three parent genotypes and 11 progenies were taken to the field. In the first experiment, plant age influenced the essential oil production and the chemical composition.The highest essential oil content increase was observed for accessions LA-41 (0.69-2.48%) and LA-53 (0.76-2.84%). The compounds with the greatest variation in the second harvest were p-cymene (0.00-5.12%), limonene (0.00-11.08%), and elemol (0.00-10.54%), because of plant aging. In the second experiment, the highest dry weight of aerial part was observed for parental LA-56 (57.54 g plant-1). The essential oil content was higher in the progeny LA-57-10 (2.844%) and the parental LA-57 (2.664%). Carvone concentration was higher for LA-57 (59.02%), with a significant difference when compared with the evaluated progenies. Among the progenies, the highest carvone concentration was observed for LA-56-04 (57.78%) and the lowest for LA-57-01 (17.71%) and LA-57-02 (17.27%).One recurrent selection cycle resulted in increased formicidal activity of some progenies. Higher mortility of Acromyrmex balsani was caused by the essential oils of the progenies LA-56-04 and LA-70-03. / A erva-cidreira-brasileira [Lippia alba (Mill.) N. E. Brown] é uma espécie medicinal e aromática que apresenta vários quimiotipos. O óleo essencial rico em carvona possui atividade inseticida sobre pragas de interesse agrícola. Diante disso, o objetivo do trabalho foi avaliar a influência da idade da planta nos óleos essenciais de acessos de L. alba e de um ciclo de seleção recorrente na atividade formicida. Os ensaios foram conduzidos na Fazenda Experimental “Campus Rural da UFS”. Para o primeiro ensaio foram testados 18 acessos de L. alba, que foram colhidos quando as plantas estavam com um ano de idade (fevereiro/2006) e dez anos (fevereiro/2016). No segundo experimento foi realizado um ciclo de seleção recorrente com três acessos com alto teor de carvona no seu óleo essencial. Para o ensaio de competição de progênies foi implantado um ensaio testando 11 progênies e os três parentais. A idade da planta influenciou na produção e composição química dos óleos essenciais dos acessos de L. alba testados. Observou-se maior aumento doteor de óleo essencial para os acessos LA-41 (0,69-2,48%) e LA-53 (0,76-2,84%). Com o envelhecimento das plantas notou-se maior variação nos óleos essenciais para os compostos p-cimeno (0,00-5,12%), limoneno (0,00-11,08%) e elemol (0,00-10,54%). No segundo experimento a maior produção de massa seca da parte aérea foi observada para o genótipo LA-56 (57,54 g planta-1). O teor de óleo essencial foi superior na progênie LA-57-10 (2,844%) e o parental LA-57 (2,644%). A carvona foi superior para o LA-57 (59,02%) com diferença significativa em comparação as progenies avaliadas. Entre as progênies, o maior teor foi observado para a progênie LA-56-04 (57,78%) e o menor para o LA-57-01 (17,71%) e LA-57-02 (17,27%). Um ciclo de seleção recorrente resultou no aumento da atividade formicida de algumas progênies.Maior mortalidade de Acromyrmex balsani foi causada pelos essenciais das progênies LA-56-04 e LA-70-03. / São Cristóvão, SE Erva-cidreira Essências e óleos essenciais Plantas Composição das plantas Melhoramento genético Erva-cidreira-brasileira Metabolismo secundário Melhoramento vegetal Atividade inseticida Brazilian lemon balm Secondary metabolism Plant breeding Insecticidal activity. CIENCIAS AGRARIAS
96	Aromaticky aktivní látky vybraných druhů bylin / Aroma active compounds of selected types of herbs Škutová, Pavla January 2018 (has links) This diploma thesis deals with the identification of aroma active compounds in medicinal herbs. The group consists of 5 types of herbs: lemon balm (Melissa officinalis), pot marigold (Calendula officinalis), clary sage (Salvia sclarea), milk thistle (Silybum marianum), goat’s rue (Galega officinalis). These plants are known for their positive effects in folk medicine. The SPME-GC-MS method was chosen to characterize the fragrances. During the identification of volatile compounds, emphasis was put on suspected fragrance allergens listed in EC Regulation 1223/2009 in Annex III. Overall 106 compounds were identified together with 8 allergens in lemon balm, pot marigold contained 104 compounds with 7 allergens included, 82 compounds including 5 allergens in clary sage, 73 compounds were identified in milk thistle including 6 allergens and 110 compounds with 9 allergens included in goat’s rue.
97	ANTIFUNGAL CHITOSAN-BASED FILMS AND COATINGS CONTAINING ESSENTIAL OILS FOR FRUIT APPLICATIONS Perdones Montero, Ángela 15 December 2016 (has links) [EN] Chitosan films and coatings have been obtained, by incorporating different essential oils (EO) and using different homogenization conditions of the film forming emulsions, in order to obtain antifungal materials for fruit preservation. The effect of oleic acid (OA) on the stability of the initial emulsions and on the film properties was analysed. Coatings were applied to control fungal decay in strawberries. The blending of chitosan with methylcellulose (MC) was also used in coating applications to tomato plants and fruits to prevent fungal infections. The films' functional properties as a function of their composition were analysed, as well as their antimicrobial activity through in vitro and in vivo tests. OA incorporation in the chitosan films (1:1 wt. ratio) reduced water vapour permeability (WVP) values to about 50 % of those of net chitosan films, with a small positive effect of the microfluidization process. EO (cinnamon, thyme and basil) did not notably reduced the WVP values of the chitosan films but a significant improvement in water barrier capacity was induced when OA was also added at 1:1 or 1:0.5 CH:OA ratios. In contrast, lipids slightly promoted oxygen permeability of the films. Lipid addition decreased the film stretchability and stiffness, with a lesser impact on the resistance to break, slightly depending on the droplet sizes. Essential oils also modulated the mechanical behaviour of the films, depending on their composition. Thyme and basil EO greatly promoted film stiffness and resistance to break, whereas cinnamon oil slightly reduced these mechanical attributes. Optical properties of the chitosan films were also affected by lipid incorporation. OA reduced the film transparency and gloss depending on the concentration, but provoked small changes in the colour parameters and whiteness index. EO affected transparency to a lesser extent, but had greater impact on the colour coordinates and whiteness index of the chitosan films due to the selective light absorption of their compounds. EO blend with oleic acid mitigated the colour changes in the films. Likewise, blending of OA with EO significantly reduced the losses of volatiles during the film formation due to the promotion of the stability of the film forming emulsions. Films containing cinnamon EO were effective in reducing the growth of Aspergillus niger, Botrytis cinerea and Rhizopus stolonifer, although thyme and basil EO encapsulated in the films did not exhibit antifungal action against these three fungi. When chitosan-cinnamon EO coatings were applied to strawberries inoculated with R. stolonifer, they reduced the fungal decay of the fruits during 14 days, at 10 °C, at the same time that total coliform counts were maintained at the initial levels. Chitosan coatings with lemon essential oil were also active at controlling fungal decay in strawberries. These did not significantly affect the physicochemical parameters of strawberries throughout cold storage, while they slowed down the respiration rate of the fruits and enhanced the chitosan antifungal activity against B. cinerea. The coatings, with and without lemon EO, affected the strawberry volatile profile, although it was only sensory appreciated for samples coated with chitosan-lemon oil. Blend films of CH and MC (1:1) containing oregano EO caused phytotoxic problems at "3 Leaves" stage of tomato plants, although the total biomass and crop yield was not affected. In the "Fruit" stage, the treatments had no negative effects. Coatings reduced the respiration rate of tomatoes, diminished weight loss during postharvest storage and were effective to decrease the fungal decay of tomatoes inoculated with R. stolonifer. Migration of thymol and carvacrol from CH-MC films in food simulants could overcome the stablished specific migration limit (60 mg/kg) for food contact packaging materials in aqueous and low pH systems if films contain a 1:1 polymer essential oil weight ratio. / [ES] En la presente tesis doctoral se han desarrollado diferentes materiales antifúngicos para su uso en conservación de frutas. Para ello, se han incorporado diferentes aceites esenciales (AE) en recubrimientos y películas de quitosano (Q). Se ha analizado el efecto de la adición de ácido oleico (AO) y las condiciones de homogeneización sobre la estabilidad de las emulsiones y sobre las propiedades de las películas. Se ha estudiado el efecto de los recubrimientos de Q sobre el deterioro fúngico en fresas y el efecto preventivo frente a infecciones fúngicas de las mezclas de metilcelulosa (MC) con Q en plantas de tomate. Se ha estudiado el efecto de la composición de las películas sobre las propiedades funcionales de las mismas, así como su actividad antimicrobiana in vitro e in vivo. La incorporación de AO en las películas de Q (proporción 1:1) redujo la permeabilidad al agua (PVA) en un 50% comparado con la de Q puro. La microfluidización indujo un efecto positivo sobre dicha reducción. La adición de AE (hoja de canela, tomillo o albahaca) no supuso una disminución notable de los valores de permeabilidad obtenidos para las películas de Q. Cuando se añadió AO a las formulaciones de Q y AE (proporciones 1:1 o 1:2), se promovió una mejora significativa en la PVA de las películas. En cambio, la adición de lípidos aumentó ligeramente la permeabilidad al oxígeno, disminuyó la elasticidad y la rigidez, y produjo un menor impacto sobre la resistencia a la rotura. A su vez, la adición de AE modificó el comportamiento mecánico de las películas. Los AE de tomillo y albahaca aumentaron considerablemente la rigidez y la resistencia a la rotura, mientras que el AE de hoja de canela redujo estos parámetros ligeramente. La adición de lípidos a las películas de Q afectó las propiedades ópticas de las mismas. El AO redujo la transparencia y el brillo, en función de la concentración añadida. La adición de AE tuvo un mayor impacto sobre los parámetros de color y el índice de blancura. Las mezclas de AE y AO mitigaron estos cambios de color. Además, la incorporación de las mezclas AE-OA redujo las pérdidas de volátiles del AE durante la formación de las películas. Las películas formuladas con el AE de hoja de canela fueron efectivas contra el crecimientos de A. niger, B. cinerea y R. stolonifer, aunque los AE de tomillo y albahaca encapsulados en las películas no mostraron ninguna actividad antifúngica. La aplicación de los diferentes recubrimientos de Q AE de C en fresas inoculadas con R. stolonifer dio lugar a una reducción en el deterioro fúngico de los frutos almacenados durante 14 días a 10°C. Los recubrimientos de Q-AE de limón también fueron efectivos en el control del deterioro fúngico en fresas. Estos recubrimientos no afectaron significativamente los parámetros físico-químicos de las fresas durante el almacenamiento en refrigeración, disminuyeron la tasa de respiración de los frutos y acentuaron la actividad antifúngica del Q frente a B. cinerea. Tanto los recubrimientos con AE como los de Q puro modificaron el perfil de volátiles de las fresas, aunque estos cambios solo fueron apreciados sensorialmente en el caso de los frutos recubiertos con AE. Las mezclas de Q y MC que contenían AE de orégano causaron efectos fitotóxicos en plantas de tomate en el estadio "3 hojas", aunque no afectaron a la biomasa total. En el estadio "frutos" los tratamientos no tuvieron ningún efecto negativo. Los recubrimientos redujeron la tasa de respiración de los tomates, disminuyeron la pérdida de peso durante el almacenamiento post-cosecha y fueron efectivos contra el deterioro fúngico de tomates inoculados con R. stolonifer. La migración de los compuestos fenólicos timol y carvacrol, contenidos en las películas de Q-MC, podría superar el límite de migración específica establecido (60 mg/Kg) para materiales de envase en contacto con alimentos en los casos de sistemas acuosos y d / [CAT] En la present tesi doctoral s'han desenvolupat diferents materials antifúngics per al seu ús en conservació de fruites. Per a açò, s'han incorporat diferents olis essencials (OE) en recobriments i pel·lícules de quitosano (Q). S'ha analitzat l'efecte de l'addició d'àcid oleic (AO) i les condicions d'homogeneïtzació sobre l'estabilitat de les emulsions i sobre les propietats de les pel·lícules obtingudes. S'ha estudiat l'efecte dels recobriments de Q sobre la deterioració fúngica en maduixes i l'efecte preventiu enfront d'infeccions fúngiques de les mescles de metilcelulosa (MC) amb Q en plantes de tomaca. S'ha estudiat l'efecte de la composició de les pel·lícules sobre les propietats funcionals de les mateixes, així com la seua activitat antimicrobiana in vitro i in vivo. La incorporació de AO en les pel·lícules de Q (1:1) va reduir la permeabilitat al vapor d'aigua (PVA) en un 50% comparat amb la de Q pur. La microfluidització va induir un petit efecte positiu sobre aquesta reducció. L'addició de AE (fulla de canyella, C, timó, T, i alfàbrega, A) no va suposar una disminució notable dels valors de permeabilitat obtinguts per a les pel·lícules de Q. Quan es va afegir AO a les formulacions de Q i AE, es va promoure una millora significativa en la PVA de les pel·lícules. Per contra, l'addició de lípids va augmentar lleugerament la permeabilitat a l'oxigen, va disminuir l'elasticitat i la rigidesa, i va produir un menor impacte sobre la resistència al trencament. Al seu torn, l'addició de OE va modificar el comportament mecànic de les pel·lícules. Els OE de T i d'A van augmentar considerablement la rigidesa i la resistència al trencament, mentre que l'OE de C va reduir aquests paràmetres lleugerament. L'addició de lípids a les pel·lícules de Q també va afectar les propietats òptiques de les mateixes. L'AO va reduir la transparència i la lluentor, en funció de la concentració afegida. L'addició d'OE va tenir un major impacte sobre el paràmetres de color i l'índex de blancor. Les mescles d'OE i AO van mitigar aquests canvis de color. A més, la incorporació de les mescles OE-AO va reduir les pèrdues de volàtils de l'OE durant la formació de les pel·lícules. Les pel·lícules formulades amb l'OE de C van ser efectives contra el creixements d'A. niger, B. cinerea i R. stolonifer, encara que els OE de T i A encapsulats en les pel·lícules no van mostrar cap activitat antifúngica. L'aplicació dels diferents recobriments de Q OE de fulla de canyella en maduixes inoculades amb R. stolonifer va donar lloc a una reducció en la deterioració fúngica dels fruits emmagatzemats durant 14 dies a 10°C. Els recobriments de Q-OE de llimó també van ser efectius en el control de la deterioració fúngica en maduixes. Aquests recobriments no van afectar significativament els paràmetres fisicoquímics de les maduixes durant l'emmagatzematge en refrigeració, van disminuir la taxa de respiració dels fruits i van accentuar l'activitat antifúngica del Q enfront de B. cinerea. Tant els recobriments amb OE com els de Q pur van modificar el perfil de volàtils de les maduixes, encara que aquests canvis sol van ser apreciats sensorialment en el cas dels fruits recoberts amb OE. Les mescles de Q:MC que contenien OE d'orenga van causar efectes fitotòxics en plantes de tomaca en l'estadi "3 fulles", encara que no van afectar a la biomassa total. En l'estadi "fruits" els tractaments no van tenir cap efecte negatiu. Els recobriments van reduir la taxa de respiració de les tomaques, van disminuir la pèrdua de pes durant l'emmagatzematge post collita i van ser efectius contra la deterioració fúngica de tomaques inoculades amb R. stolonifer. La migració dels compostos fenòlics timol i carvacrol, continguts en les pel·lícules de Q-MC, podria superar el límit de migració específica establit (60 mg/Kg) per a materials d'envàs en contacte amb aliments en els casos de sistemes aquosos i d / Perdones Montero, Á. (2015). ANTIFUNGAL CHITOSAN-BASED FILMS AND COATINGS CONTAINING ESSENTIAL OILS FOR FRUIT APPLICATIONS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59413 / TESIS Biopolymer Chitosan Methylcelullose Essential oil Cinnamon leaf Basil Lemon Oregano Thyme Coating Film Microfluidization Emulsion stability Essential oil retention Essential oil migration Food simulant Antifungal activity Antioxidant activity Barrier properties Mechanical properties Optical properties Microstructure Strawberry Tomato Pre-harvest Post-harvest Decay Sensory profile Volatile profile TECNOLOGIA DE ALIMENTOS
98	Výpočtové modelování radiálních hydrodynamických ložisek pro vodní stroje / Computational modeling of radial hydrodynamic bearings for water machines Pokorný, Jan January 2018 (has links) The aim of this thesis is to calculate the stiffness and damping coefficients for radial hydrodynamic bearings. Cylindrical and lemon hydrodynamic bearings are considered. The solution to this problem mainly depends on the hydrodynamic pressure in the bearing. The numerical solution of the Reynolds equation is used to calculate the pressure. The effect of variable viscosity and density of the lubricant due to temperature changes is considered. The static equilibrium position of the journal centre is also solved. The stiffness and damping coefficients are determined using small amplitude journal motions about the equilibrium position. Three methods for determining these coefficients are presented. The outcome of this thesis is an algorithm for the calculation of stiffness and damping coefficients for cylindrical and lemon bearings. Results for lemon bearings are presented and comparison with the commercial software DynRot BR is made. The benefit of this thesis is the creation of an algorithm for the calculation of journal centre equilibrium position, a new way of incorporating the temperature changes in the viscosity and the density of the lubricant, and the modification of a method for calculating stiffness and damping coefficients based on experimental analogy.
99	Russians abroad in postcommunist cinema Kristensen, Lars Lyngsgaard Fjord January 2010 (has links) No description available.
100	Birds, bats and arthropods in tropical agroforestry landscapes: Functional diversity, multitrophic interactions and crop yield Maas, Bea 20 November 2013 (has links) No description available. 630 birds bats arthropods multitrophic interactions agroforestry tropical landscape forest margin landscape functional diversity crop yield exclosure experiments experimental exclusion arthropod suppression avian predation ecosystem services mist netting point counts artificial plasticine caterpillar dummy experiment biological control monitoring mapping Lemon-bellied White-eye Grosbeak Starling Zosterops chloris Scissiostrum dubium Theobroma cacao cacao agroforestry cacao diseases cacao harvest cacao pests flying vertebrates aerial insectivores volant vertebrates logging breeding colony flower herbivory mesopredator release predatory insects ants spiders aphids Lepidoptera Coleoptera Lepidopteran larvae sustainable agriculture sustainable agroforestry management implications management recommendations applied managament extensive land use management landscape management conservation biodiversity-friendly dbh distance to forest forest proximity habitat conversion herbivory Indonesia insectivorous bats insectivorous birds invertebrates Central Sulawesi Napu valley leaf gleaning leaf herbivory pests insects phytophagous insects plant productivity remnant forest trees shade tree managament South-east Asia Paleotropics tropical landscape tree height landscape gradient local shade management Cacao Pod Borer Cherelle Wilt fruit abortion Helopeltis sulawesi deforestation habitat fragmentation land use intensification forest margin species critical decline predation experiment species-specific functions Southeast Asia biodiversity conservation mesopredators food security human welfare human well-being poverty alleviation poverty reduction smallholder cacao smallholder plantation cacao farmers sustainable cacao management landscape perspective landscape scale large scale field experiment long term field experiment human wellbeing economic importance economic value valuation ecosystem services landscape matrix yield quality yield quantity fruit productivity species identity species diversity species richness ecosystem functioning pesticide use chemical compounds complex food web tritrophic interactions wildlife-friendly rural livelihoods endangered bird species endangered bat species endemic endemic birds endemic bats beneficial impact IUCN Lore Lindu National Park bioindicator indicator species forest margin agricultural habitat agroforestry systems population density predation activity species activity cacao flower cacao pod Orthoptera linear mixed effect models Tukey Post Hoc Test AICc model selection generalized least squares restricted maximum likelihood model simplification species richness estimator species accumulation linear mixed-effects models Likelihood Ratio Test Maximum Likelihood nocturnal insects diurnal arthropods nocturnal arthropods diurnal insects landscape context Land- und Forstwirtschaft (PPN621302791)

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