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Human skin sandwich for assessing shunt route penetration during passive and iontophoretic drug and liposome delivery.Essa, Ebtessam A., Bonner, Michael C., Barry, Brian W. January 2002 (has links)
No / This work explored the role of skin appendages (shunt route) in passive and iontophoretic drug and liposome penetration. The technique used an epidermis and stratum corneum sandwich from the same skin donor with the additional stratum corneum forming the top layer of the sandwich. Penetration was monitored during occluded passive and iontophoretic (0.5 mA cm-2) delivery of mannitol and estradiol solutions, and ultradeformable liposomes containing estradiol. The shunt route had a significant role during passive penetration of mannitol (hydrophilic compound), but was negligible during penetration of estradiol (lipophilic drug) and liposomes. In iontophoresis, the shunt route significantly contributed to the overall flux of all preparations, being highest for mannitol. However, shunts were not the only pathway for iontophoretic drug delivery and evidence was observed for the creation of new aqueous pathways via disorganization of the intercellular lipid domain of stratum corneum. The skin sandwich technique should prove valuable for general studies on routes of skin penetration.
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Heterogeneous photocatalytic degradation of organic pollutants in water over nanoscale powdered titanium dioxide : the photocatalytic degradation of organic compounds in water (Reactive Orange 16, Triclocarbon, Clopyralid and Estrogens (estrone, 17ß-estradiol, and 17α-ethinylestradiol)) was studied : the reaction kinetics and the effect of the operating parameters on the performance of the system were determined; a comparison with other advanced oxidation processes (O₃, H₂O₂, UV) was also madeMezughi, Khaled M. January 2010 (has links)
Organic contaminants from industrial and/or domestic effluents may be harmful to humans directly or indirectly by degrading the quality of the aquatic environment. Consequently these contaminants must be reduced to levels that are not harmful to humans and the environment before disposal. Chemical, physical and biological methods exist for the removal of these pollutants from effluents. Among the available chemical methods, heterogeneous photocatalytic oxidation has been found particularly effective in removing a large number of persistent organics in water. In this study, photocatalytic degradation was explored for the removal of reactive azo-dye (textile dye), triclocarban (disinfectant), clopyralid (herbicide) and three endocrine disrupting compounds (EDCs) (estrone, 17ß-estradiol and 17α-ethinylestradiol) from synthetic effluents. The major factors affecting the photocatalytic processes including the initial concentration of the target compounds, the amount of catalyst, the light intensity, the type of catalyst, the electron acceptor, the irradiation time and the pH were studied. Other oxidation techniques including (O3, H2O2, UV) were also studied. Generally UV light is used in combination with titanium dioxide, as photocatalyst, to generate photoinduced charge separation leading to the creation of electron-hole pairs. The holes act as electron acceptors hence the oxidation of organics occur at these sites. These holes can also lead to the formation of hydroxyl radicals which are also effective oxidants capable of degrading the organics. The results obtained in this study indicated that photolysis (i.e. UV only) was found to have no effect on the degradation of reactive azo-dye (RO16). However, complete photocatalytic degradation of 20 mg/L (3.24×10-2 mM) RO16 was achieved in 20 minutes in the presence of 1g/L TiO2 Degussa P25 at pH 5.5. Comparison between various types of catalysts (i.e. Degussa P25, VP Aeroperl, Hombifine N) gave varied results but Degussa P25 was the most effective photocatalyst hence it was selected for this study. For RO16 the optimum catalyst concentration was 0.5 g/L TiO2 with initial concentration of 20 mg/L RO16. It was found that the disappearance of RO16 satisfactorily followed the pseudo first-order kinetics according to Langmuir-Hinshelwood (L-H) model. The rate constant was k= 0.0928 mol/min. Photodegradation of TCC was studied in 70%v acetonitrile: 30%v water solutions. UV light degraded TCC effectively and the reaction rates increased with decreasing initial concentration of TCC. UV/TiO2 gave unsatisfactory degradation of triclocarban (TCC) since only 36% were removed in 60 minutes with initial concentration of TCC 20 mg/L. The degradation of clopyralid and the EDCs was studied using three oxidation systems UV/TiO2, UV/H2O2 and O3. Complete degradation of clopyralid (3,6-DCP) was achieved with UV/TiO2 in about 90 minutes at an optimum catalyst concentration of 1g/L. Zero-order kinetics was found to describe the first stage of the photocatalytic reaction in the concentration range 0.078-0.521 mM. At pH 5 the rate constant was 2.09×10⁻⁶ ± 4.32×10⁻⁷ M.s⁻¹. Complete degradation of all the three EDCs was achieved with UV/H₂O₂ in 60 minutes at catalyst concentration of (2.94×10⁻² M). On the other hand complete degradation of the EDCs was achieved in just 2 minutes with ozonation. For high concentration EDCs, TiO₂/UV gave low efficiency of degradation as compared with ozone and H2O2/UV. First-order kinetics was found to describe the photocatalytic reaction of the EDCs.
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Expression of Borderline Personality Disorder Symptoms across the Ovulatory Cycle: A Multilevel InvestigationEisenlohr-Moul, Tory A. 01 January 2013 (has links)
Borderline Personality Disorder (BPD) is a disabling condition characterized by chronic emotion dysregulation and behavioral impulsivity. Prospective studies that test proposed mechanisms of within-person change in BPD hold the key to improving symptom predictability and control in this disorder. A small body of evidence suggests that fluctuations in estradiol such as those occurring naturally at ovulation during the monthly female reproductive cycle may increase symptoms in women with BPD (DeSoto et al., 2003). Furthermore, there is preliminary evidence that both self-esteem and feelings of social rejection are highest at ovulation, when estradiol peaks (Durante and Hill, 2009; Eisenlohr-Moul et al., under review). Such feelings have been reliably linked to increases in BPD-related behavior in all individuals (e.g., Twenge et al., 2002). The purpose of this dissertation was to test a cyclical vulnerability model for women with BPD in which ovulatory estradiol shifts are associated with reductions in felt social acceptance, which in turn are associated with increased BPD symptom expression. 40 women, sampled to achieve a flat distribution of BPD symptoms, completed 28 daily diaries online, as well as four 1-hour weekly visits to the laboratory to complete longer assessments and provide saliva samples, which were assayed for estradiol. In addition, participants underwent the Structured Clinical Interview for the Diagnosis of BPD at the end of the study.
Results of multilevel models revealed the opposite of the predicted effects of within-person changes in estradiol and their interaction with trait BPD. The data suggest a pattern in which women high in trait BPD show increases in felt acceptance and reductions in BPD symptom expression at higher levels of conception probability and higher-than-usual levels of estradiol. Women low in trait BPD show the opposite pattern in some cases. Several alternative moderators were tested, and results suggest that some risk factors for BPD (e.g., Neuroticism, Sexual Abuse) interact with high trait levels of estradiol to predict greater symptoms. Both average levels of estradiol and monthly fluctuations in estradiol may have relevance for women with BPD. It is recommended that future studies utilize clinical samples and additional physiological measures to further elucidate the mechanisms through which estradiol exerts clinically-relevant change.
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The effects of estrogenic endocrine disruptors on the osmoregulatory functions in euryhaline fishAl-Jandal, Noura January 2011 (has links)
Osmoregulation is an essential process to maintain water and ionic balance and when euryhaline fish move between freshwater and seawater environments as part of their life cycle this presents additional osmoregulatory challenges. Migrating fish can be exposed in both environments to pollutants such as endocrine disrupting chemicals (EDCs) that include natural hormones (e.g. 17β-estradiol; E2), synthetic hormones (e.g. 17α-ethinylestradiol; EE2), and industrial chemicals (e.g. nonylphenol). The focus of this thesis was to study the effects of different categories of EDCs on the osmoregulatory functions of euryhaline fish such as three-spined sticklebacks (Gasterosteus aculeatus) and rainbow trout (Oncorhynchus mykiss). Osmoregulatory variables (such as osmolality, water and ionic content) were compared in plasma and tissues (white muscle and carcass) of rainbow trout. This validated the use of specific tissue parameters as a surrogate of plasma responses to various osmoregulatory challenges. Waterborne exposure to 17α-ethinylestradiol revealed differential sensitivity of vitellogenesis in the three-spined sticklebacks (no induction) and rainbow trout, but had a significant effect on calcium homeostasis in both species. Intraperitoneal implants of 17β-estradiol reduced CaCO3 production and apparent water absorption in the intestine and increased in tissue calcium stores of seawater-acclimated trout, but fish were able to compensate and showed no overall osmoregulatory disturbance. Waterborne exposure to nonylphenol in freshwater trout was also investigated, but no effects on osmoregulation were found up to 2 ng/l. Overall, estrogens can affect osmoregulation differentially in euryhaline fish species, and sometimes at EDC levels lower than the threshold for reproductive effects (i.e. vitellogenin induction).
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Investigating the Effects of 17α-Ethynylestradiol on Mitochondrial Genome StabilityChivers, Alicia M. 23 May 2016 (has links)
Environmental toxicants are ubiquitous throughout the environment as a result of human activity. Among these toxicants, environmental estrogens are a category of particular concern due to their environmental prevalence and potency in altering reproductive traits. While many studies have addressed the detrimental effects of environmental estrogens on both aquatic and terrestrial organisms, few have analyzed the potential for these compounds to alter mitochondrial function. Mitochondria are the primary energy-generating system for all eukaryotic life, supporting all aspects of development, metabolism, and growth. Each cell within the body contains many mitochondria which in turn contain multiple copies of their own DNA genome, mitochondrial DNA (mtDNA). Mutations in mtDNA are responsible for a wide range of human diseases such as metabolic syndromes, cancers, and obesity. Among these mitochondrial diseases many are characterized by increased levels of heteroplasmy, multiple mitochondrial DNA haplotypes within an individual. Increased heteroplasmy can alter normal mitochondrial function and influence disease initiation and progression.
To date, no studies have investigated the effects of synthetic estrogens on mitochondrial genome stability. Synthetic estrogens have the capacity to bind to estrogen receptors and initiate estrogenic responses through translocation into the mitochondrion. Despite our knowledge about the relationship of heteroplasmy and disease, we still do not have a complete grasp of the mechanisms of heteroplasmic induction. Here we report our analysis of the effects of 17α-ethynylestradiol (EE2) exposure in three studies to investigate its effect on mitochondrial genome stability. Data analysis reveals a statistically significant relationship between EE2 exposure and increased heteroplasmic frequency.
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Devenir de polluants émergents lors d'un traitement photochimique ou photocatylitique sous irradiation solaire / Fate of emerging pollutants during photochemical or photocatalytic treatment under solar irradiationMaroga Mboula, Vanessa 13 November 2012 (has links)
L’industrialisation et l’utilisation dans la vie courante d’un nombre croissant de produits chimiques et médicamenteux sont responsables de la dissémination dans l’environnement de substances variées nommées« polluants émergents ». Les traitements des eaux usées existants ne sont pas conçus pour éliminer cette catégorie de pollution et les polluants émergents sont alors rejetés dans le milieu récepteur. Une possible solution pour limiter le rejet de ces composés par les effluents de station d’épuration serait l’utilisation de procédés de traitement additionnels tels que les procédés d’oxydation avancés. C’est dans ce contexte qu’a démarré le projet Européen Clean Water en 2009 associant 7 entités dont le GEPEA-Ecole des Mines de Nantes. Le concept du projet est de développer des procédés photocatalytiques mettant en œuvre des nanomatériaux actifs sous la lumière solaire. Ces procédés visent à éliminer les polluants émergents tels que les perturbateurs endocriniens ou les produits pharmaceutiques. Dans ce programme, le laboratoire GEPEA est concerné par l’évaluation de l’efficacité des matériaux vis-à-vis de l’élimination des polluants émergents sous irradiations UV et visibles. Pour cela, une méthodologie expérimentale a été établie de façon à exprimer les performances des catalyseurs testés en termes de constantes cinétiques de dégradation, de taux de conversion et de minéralisation des molécules étudiées mais aussi en fonction de la formation de produits intermédiaires. Ces performances sont également évaluées en termes de biodégradabilité, d’effet de toxicité et de perturbation endocrinienne des produits intermédiaires. Dans un premier temps, la méthodologie expérimentale établie a été testée sur la dégradation de la tétracycline en utilisant un catalyseur de référence puis, elle a été appliquée sur la dégradation respective du bisphénol A et de la 17β-oestradiol en utilisant un catalyseur de référence et les catalyseurs élaborés dans le cadre du projet Clean Water. Les résultats sur la dégradation de la tétracycline ont montré que i) les intermédiaires réactionnels sont moins toxiques que la tétracycline, ii) la structure des intermédiaires réactionnelles est semblable à celle de la tétracycline ce qui explique la faible biodégradabilité de ces intermédiaires. Concernant la dégradation du bisphénol A et de la 17β-oestradiol, les résultats ont montré que i) les catalyseurs sont efficaces sous irradiation solaire simulée. Cependant, l’efficacité photocatalytique du catalyseur dépend du composé à dégrader, ii) la nature des intermédiaires réactionnels identifiés du bisphénol A dépend du catalyseur utilisé, iii) l’effet œstrogénique de la solution d’oestradiol persiste au cours du traitement photocatalytique. / Industrialisation, the use of numerous chemical products in domestic activities and the use of medicine drugs have led to the release in the environment of various substances named "emerging pollutants”. The existing wastewater treatments are not designed to eliminate this kind of pollution and then these pollutants are released into the natural aquatic media. To limit the release of these compounds by waste water treatment plant effluent, a solution could be the use of additional treatment processes such as advanced oxidation processes. In this context, the European project Clean Water has started in 2009. Clean Water involves 7 entities including the GEPEA laboratory-Ecole des Mines de Nantes. The aim of the Clean Water project is to develop sustainable and cost effective water treatment and detoxification processes using TiO2 nanomaterials with UV-visible light response under solar light. These processes act to remove emerging contaminants such as endocrine disruptors and pharmaceuticals. In this program, theGEPEA laboratory is concerned with the evaluation of the efficiency of novel photocatalysts under UV and visible irradiations for the elimination of emerging pollutants. For this purpose, an experimental methodology was established to express the efficiency of the tested catalysts in terms of degradation kinetic constants, pollutants conversion and mineralisation and also in terms of the intermediate products formed. The efficiency of photocatalysts is also evaluated in terms of intermediates biodegradability, toxicity and endocrine disruption effects. First, the experimental methodology was tested on the degradation of tetracycline with a reference catalyst. Then, it was applied to the degradation of bisphenol A and estradiol respectively with the reference catalyst and the catalysts developed within the Clean Water Project. The results obtained on the tetracycline degradation have showed that: i) tetracycline intermediate products are less toxic than tetracycline ii) the intermediates structure is similar to that of tetracycline, this can explain the low biodegradability observed for these intermediates. For the degradation of bisphenol A and estradiol, the results showed that: i) the photocatalysts are efficient under simulated solar irradiation. However, the catalyst photocatalytic efficiency depends on the compound to be degraded ii) the nature of the bisphenol A reaction intermediates identified depends on the catalyst used iii)the estrogenic effect of the estradiol treated solution persists during the photocatalytic treatment.
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Aerogéis de hidroxipropil metilcelulose: síntese, caracterização e aplicação como adsorventes para 17α-etinilestradiol / Hydroxypropyl methylcellulose based aerogels: Synthesis, characterization and application as adsorbents for 17α-ethinyl estradiolMartins, Bianca Fernandes 05 December 2017 (has links)
Aerogéis de hidroxipropil metilcelulose (HPMC) com diferentes graus de substituição por grupos metila (DS) e hidroxipropila (MS) foram preparados por liofilização utilizando diferentes ácidos como agentes de reticulação, a saber: ácido cítrico, ácido oxálico e ácido tereftálico. Nanocristais de celulose bacteriana (BCN) neutros e negativamente carregados foram utilizados como carga de reforço nas concentrações de 5% (m/m) e 15% (m/m) em relação à massa da matriz. Os resultados indicaram que HPMCs com menores valores de DS e maiores valores de MS resultam em aerogéis com maior eficiência na reticulação. Além disso, agentes de reticulação insolúveis em água minimizaram a capacidade de reticulação, enquanto agentes de reticulação com uma maior quantidade de grupos funcionais ácidos aumentaram a probabilidade e a eficiência da reação de reticulação das cadeias de HPMC. Os aerogéis apresentaram alta estabilidade em água, solventes orgânicos e meio ácido, além de apresentar resiliência quanto à deformação em meio aquoso. Os aerogéis apresentaram porosidade de ~98%, densidade média variando de 0,021 à 0,026 (± 0,002) g.cm-3, módulo de Young variando de 101 à 150 (± 19) kPa e capacidade média de absorção de água de 18 g de água/g de aerogel. A adição de carga de reforço resultou em um aumento de até 13% na densidade aparente do aerogel e um aumento médio de 20% no módulo de Young dos materiais. A morfologia dos poros dos aerogéis sintetizados é irregular, com ampla faixa de distribuição de tamanho de poros, podendo variar cerca de 5 µm a 500 µm. Nos aerogéis reforçados, as BCNs encontram-se preferencialmente no interior das paredes dos aerogéis, onde o reforço mecânico é mais eficiente. Isotermas de adsorção de 17α-etinilestradiol (EE) foram realizadas, resultando em capacidades de remoção de até 90%, com possibilidade de reciclo. As isotermas indicam que a matriz HPMC J5MS possui maior afinidade para adsorção de EE e que a adição de BCNs aumenta a afinidade das moléculas pelo substrato. As isotermas foram melhor ajustadas com o modelo de Freundlich, indicando que a adição de 5% de BCNs aumenta a capacidade de adsorção do aerogel, enquanto a adição de 15% de BCNs provoca uma diminuição nesta propriedade. / Aerogels of Hydroxypropyl methylcellulose (HPMC), with different degrees of substitution for methyl groups (MS) and hydroxypropyl groups (DS) were prepared by freeze-drying. The HPMCs were combined with three organic acids as crosslinking agents: citric acid, oxalic acid and terephthalic acid. Bacterial cellulose nanocrystals (BCN) neutral and negatively charged were used as reinforcement particles from 5% to 15% m/m in relation to the polymer mass. The results indicated that HPMC with lower DS and higher MS levels result in aerogels with higher crosslink efficiency. Besides that, crosslinking agents that are water insoluble minimized the crosslinking capacity, while crosslinking agents with more functional acid groups presented higher probability and efficiency in the crosslinking reaction. The aerogels presented high stability in water, organic solvents and acid media, and presented mechanical resilience in aqueous media. The resulting aerogels presented porosity of ~98%, average density of 0.021 to 0.026 (± 0.002) g.cm-3, Young modulus of 101 to 150 (± 19) kPa and an average capacity of water absorption of 18 g of water/g of aerogel. The addition of reinforcement particles resulted in an increase in density up to 13% and an average increase in the Young modulus of 20%. The morphology of the aerogels was irregular, with a wide pore size distribution, varying between de 5 µm a 500 µm. In the reinforced aerogels, the BCNs were found preferably inside the aerogels walls, were the mechanical reinforcement is more efficient. Adsorption isotherms of 17 ethinyl estradiol (EE) revealed removal capacity up to 90% and possibility of adsorbent recycling. The isotherms indicated that the HPMC J5MS has higher affinity for EE molecules and that the use of BCNs increases aerogels affinity. The isotherms were well fitted with the Freundlich model, indicating that the addition of 5% BCN increases the adsorption capacity of the aerogels, while the addition of 15 % BCN results in a decrease in this property.
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Aerogéis de hidroxipropil metilcelulose: síntese, caracterização e aplicação como adsorventes para 17α-etinilestradiol / Hydroxypropyl methylcellulose based aerogels: Synthesis, characterization and application as adsorbents for 17α-ethinyl estradiolBianca Fernandes Martins 05 December 2017 (has links)
Aerogéis de hidroxipropil metilcelulose (HPMC) com diferentes graus de substituição por grupos metila (DS) e hidroxipropila (MS) foram preparados por liofilização utilizando diferentes ácidos como agentes de reticulação, a saber: ácido cítrico, ácido oxálico e ácido tereftálico. Nanocristais de celulose bacteriana (BCN) neutros e negativamente carregados foram utilizados como carga de reforço nas concentrações de 5% (m/m) e 15% (m/m) em relação à massa da matriz. Os resultados indicaram que HPMCs com menores valores de DS e maiores valores de MS resultam em aerogéis com maior eficiência na reticulação. Além disso, agentes de reticulação insolúveis em água minimizaram a capacidade de reticulação, enquanto agentes de reticulação com uma maior quantidade de grupos funcionais ácidos aumentaram a probabilidade e a eficiência da reação de reticulação das cadeias de HPMC. Os aerogéis apresentaram alta estabilidade em água, solventes orgânicos e meio ácido, além de apresentar resiliência quanto à deformação em meio aquoso. Os aerogéis apresentaram porosidade de ~98%, densidade média variando de 0,021 à 0,026 (± 0,002) g.cm-3, módulo de Young variando de 101 à 150 (± 19) kPa e capacidade média de absorção de água de 18 g de água/g de aerogel. A adição de carga de reforço resultou em um aumento de até 13% na densidade aparente do aerogel e um aumento médio de 20% no módulo de Young dos materiais. A morfologia dos poros dos aerogéis sintetizados é irregular, com ampla faixa de distribuição de tamanho de poros, podendo variar cerca de 5 µm a 500 µm. Nos aerogéis reforçados, as BCNs encontram-se preferencialmente no interior das paredes dos aerogéis, onde o reforço mecânico é mais eficiente. Isotermas de adsorção de 17α-etinilestradiol (EE) foram realizadas, resultando em capacidades de remoção de até 90%, com possibilidade de reciclo. As isotermas indicam que a matriz HPMC J5MS possui maior afinidade para adsorção de EE e que a adição de BCNs aumenta a afinidade das moléculas pelo substrato. As isotermas foram melhor ajustadas com o modelo de Freundlich, indicando que a adição de 5% de BCNs aumenta a capacidade de adsorção do aerogel, enquanto a adição de 15% de BCNs provoca uma diminuição nesta propriedade. / Aerogels of Hydroxypropyl methylcellulose (HPMC), with different degrees of substitution for methyl groups (MS) and hydroxypropyl groups (DS) were prepared by freeze-drying. The HPMCs were combined with three organic acids as crosslinking agents: citric acid, oxalic acid and terephthalic acid. Bacterial cellulose nanocrystals (BCN) neutral and negatively charged were used as reinforcement particles from 5% to 15% m/m in relation to the polymer mass. The results indicated that HPMC with lower DS and higher MS levels result in aerogels with higher crosslink efficiency. Besides that, crosslinking agents that are water insoluble minimized the crosslinking capacity, while crosslinking agents with more functional acid groups presented higher probability and efficiency in the crosslinking reaction. The aerogels presented high stability in water, organic solvents and acid media, and presented mechanical resilience in aqueous media. The resulting aerogels presented porosity of ~98%, average density of 0.021 to 0.026 (± 0.002) g.cm-3, Young modulus of 101 to 150 (± 19) kPa and an average capacity of water absorption of 18 g of water/g of aerogel. The addition of reinforcement particles resulted in an increase in density up to 13% and an average increase in the Young modulus of 20%. The morphology of the aerogels was irregular, with a wide pore size distribution, varying between de 5 µm a 500 µm. In the reinforced aerogels, the BCNs were found preferably inside the aerogels walls, were the mechanical reinforcement is more efficient. Adsorption isotherms of 17 ethinyl estradiol (EE) revealed removal capacity up to 90% and possibility of adsorbent recycling. The isotherms indicated that the HPMC J5MS has higher affinity for EE molecules and that the use of BCNs increases aerogels affinity. The isotherms were well fitted with the Freundlich model, indicating that the addition of 5% BCN increases the adsorption capacity of the aerogels, while the addition of 15 % BCN results in a decrease in this property.
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Degradação de etinilestradiol por meio de fotocatálise heterogênea e radiação UV / Ethinyl degradation through photocatalysis of heterogeneous and UV radiationIsecke, Bruna Guimarães 28 April 2015 (has links)
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Previous issue date: 2015-04-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Several studies point to the presence of emerging pollutants in surface water, groundwater and public water supply in many countries. Such substances are not covered by legislation and derived from effluent discharges with inadequate or no treatment. In this context, fall within the synthetic estrogens as EE2 (ethinylestradiol) that are found in the residual medium in the environment, which can have adverse effects on aquatic organisms as well as for terrestrial organisms. These hormones are absorbed by the body, suffer metabolic reactions and a quantity of them, both in its form as unmetabolised in metabolized form, it is excreted to the environment. As these substances are not easily biodegradable and have harmful pharmacological properties when used incorrectly, through contaminated water, there is growing concern about its destination, especially when taking into account the environmental risk assessment. For these reasons, the detection, elimination and investigation of the fate of these estrogens has become priority on environmental chemistry. These products are found in low concentrations (μg.L-1 and ng.L-1), but even so, can be harmful to organisms through bioaccumulation. There are still few ecotoxicological studies related to the exposure of organisms to substances considered endocrine disruptors. The aim of the study was to develop and validate an analytical method for high-performance liquid chromatography (HPLC) to identify and quantify ethinyl estradiol, the study of degradation of the same compound in a photocatalytic reactor and also the calculation of the reaction kinetics for each curve ethinyl estradiol degradation. For analytical validation experiments were performed as set forth in the RE 899 2003 ANVISA. For the degradation experiments were carried application of UV settling and also photocatalysis experiments using titanium dioxide (TiO2) in suspension. By applying a 22 factorial design pH parameters were studied and mass of the catalyst and also its interaction with regard to treatment efficiency. The reactor was operated in batch and in continuous flow, in both cases there optimization. The analytical method was effective for detection and quantification of ethinylestradiol. The photocatalytic degradation test batch procedure presented great efficiency degradation of ethinyl estradiol present in water, obtaining a mean degradation of about 99% in about 120 minutes. The factorial design has shown that the most relevant factor in relation to the degradation efficiency was the pH, although there has been the appearance of a degradation by-product when used a basic pH (8.0). A greater treatment efficiency with smaller mass of TiO2 (0.05 gL-1). The reaction order and constant speed found for the experiments were as between 1 and 2. When the system is operating in continuous flow ethinyl estradiol degradation was approximately about 84% after optimization. The study shows that photocatalysis is very efficient to ethinyl estradiol degradation in water. / Vários estudos realizados apontam a presença de poluentes emergentes em águas superficiais, subterrâneas e de abastecimento público em vários países do mundo. Tais substâncias não são contempladas pela legislação e derivam de lançamentos de efluentes com tratamento inadequado ou inexistente. Nesse contexto, inserem-se os estrogênios sintéticos como o EE2 (etinilestradiol) que são encontrados em forma residual no meio ambiente, o que pode acarretar efeitos adversos tanto em organismos aquáticos quanto em organismos terrestres. Esses hormônios são absorvidos pelo organismo, sofrem reações metabólicas e uma quantidade deles, tanto em sua forma não metabolizada quanto em forma metabolizada, é excretada ao meio ambiente. Como essas substâncias não são facilmente biodegradáveis e possuem propriedades farmacológicas danosas quando utilizadas de forma incorreta, através de águas contaminadas, é crescente a preocupação em relação à sua destinação, principalmente ao se levar em consideração a avaliação de risco ambiental. Por tais motivos, a detecção, a eliminação e investigação do destino desses estrogênios tem se tornado prioridade em relação à química ambiental. Estes produtos são encontrados em baixas concentrações (μg.L-1 e ng.L-1) mas, mesmo assim, podem ser danosos aos organismos por meio de bioacumulação. Ainda existem poucos estudos ecotoxicológicos relacionados à exposição de organismos a substâncias consideradas desreguladoras do sistema endócrino. O objetivo do estudo foi desenvolver e validar um método analítico em cromatografia líquida de alta eficiência (CLAE) para identificação e quantificação de etinilestradiol, o estudo de degradação do mesmo composto em um reator fotocatalítico e também o cálculo da cinética de reação para cada curva de degradação de etinilestradiol. Para a validação analítica foram realizados experimentos conforme estabelecidos na RE 899 de 2003 da ANVISA. Para os experimentos de degradação foram realizados aplicação de radicação UV e também experimentos de fotocatálise com a utilização de dióxido de titânio (TiO2) em suspensão. Através da aplicação de um planejamento fatorial 22 foram estudados os parâmetros pH e massa do catalisador e também sua interação em relação a eficiência de tratamento. O reator foi operado em batelada e em fluxo contínuo, em ambos os casos houve a otimização. O método analítico se mostrou eficiente para detecção e quantificação de etinilestradiol. Os ensaios de degradação fotocatalítica em regime de batelada apresentaram grande eficiência na degradação do etinilestradiol presente em água, obtendo-se degradação média de cerca de 99% em aproximadamente 120 minutos. O planejamento fatorial nos mostrou que o fator mais relevante em relação à eficiência de degradação foi o pH, embora, tenha havido a aparição de um subproduto de degradação quando se utilizou um pH básico (8,0). Houve maior eficiência de tratamento com menor massa de TiO2 (0,05 g.L-1). A ordem de reação e constantes de velocidades encontradas para os experimentos foram de ordem entre 1 e 2. Quando o sistema foi operando em fluxo contínuo houve degradação de etinilestradiol em cerca de aproximadamente 84%, após sua otimização. O estudo nos mostrou que a fotocatálise é bastante eficiente para a degradação de etinilestradiol em água.
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Circuiterie neuronale impliquée dans les effets génomiques et non-génomiques des strogènes sur l'expression du comportement sexuel mâleTaziaux, Mélanie 21 March 2008 (has links)
Laromatase est un enzyme-clé qui catalyse la conversion de la testostérone en stradiol. Cette conversion constitue une étape limitante dans le contrôle du comportement sexuel mâle. Bien quencore partiellement incompris aujourdhui, différents mécanismes de contrôle de lactivité aromatasique ont été mis en évidence par de récentes études. Dune part, l'activité aromatasique du cerveau peut être modifiée par une action lente, génomique et synergique des androgènes et des strogènes agissant via leurs récepteurs intracellulaires spécifiques. Ce mécanisme relativement lent implique que la variation de la biodisponibilité en strogènes et, en dernière analyse, le comportement sexuel soient corrélés à des variations à long terme des taux plasmatiques de stéroïdes telles que les variations saisonnières ou développementales. Cet effet génomique des strogènes sur le comportement sexuel est aujourdhui communément accepté: lexpression du comportement sexuel consommatoire mâle ainsi quun des indices du comportement sexuel appétitif mâle (réponse apprise de proximité sociale) chez la caille sont strictement dépendants de laromatisation de la testostérone en stradiol. Dautre part, la production d'strogènes dans le cerveau peut être modifiée de façon rapide, non-génomique, par des processus qui impliquent des phosphorylations sous l'action de certains neurotransmetteurs tels que le glutamate et la dopamine. Lexistence dune telle régulation rapide de lactivité aromatasique, et donc de la production subséquente doestrogènes, est en adéquation avec les effets rapides des strogènes dans le cerveau rapportés par de nombreuses études au cours des 20 dernières années.
Cette thèse a donc été consacrée à la caractérisation des effets génomiques et non-génomiques des strogènes dans le contrôle du comportement sexuel mâle et à lidentification des substrats neuroanatomiques qui sous-tendent ces deux types deffets dans le contrôle du comportement reproducteur. Dans ce cadre, notre travail sest articulé en trois parties distinctes mais fonctionnellement liées.
Dans une première partie, nous avons dabord exploré plus avant le contrôle hormonal dun indice de la motivation sexuelle : les contractions rythmiques des muscles cloacaux (RCSM) en réponse à la vue dune femelle. Nous avons donc montré que lexpression des RCSM dépend de laromatisation de la testostérone en stradiol. Par la suite, nous avons démontré que les composantes appétitives et consommatoires du comportement sexuel mâle étaient contrôlées par des réseaux neuronaux en partie distincts mais incluant de façon proéminente laire préoptique médiane, et plus spécifiquement le noyau préoptique médian.
La deuxième partie de cette thèse a été consacrée à lanalyse plus approfondie du contrôle hormonal dune réponse sexuelle conditionnée - les contractions rythmiques des sphincters cloacaux conditionnées (RCSM conditionnées) et des sites nerveux responsables de lactivation de cette réponse. Nous démontrons que les RCSM conditionnées dépendent également de laromatisation de la testostérone en strogènes, comme cela est le cas pour leur versant inné. Par la suite, nous avons montré que lexposition à un stimulus sexuel conditionné avant la copulation provoque une activité neuronale accrue dans des régions cérébrales jouant un rôle-clé dans le contrôle du comportement sexuel, laire préoptique médiane et la partie médiane noyau du lit de la strie terminale (BSTM).
Finalement, dans une troisième partie, nous nous sommes attachés à létude de la modulation rapide du comportement sexuel mâle par les strogènes. Dans ce cadre, nous avons montré que la régulation positive et négative des concentrations cérébrales en strogènes affectent rapidement lexpression du comportement sexuel mâle chez une espèce aviaire (caille) et une espèce murine (souris). Ce dernier modèle nous a de plus permis de valider la spécificité neuroendocrinienne des effets comportementaux rapides observés.
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