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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Dyeing of Wool and Silk Fibres with a Conductive Polyelectrolyte and Comparing Their Conductance

Ahsen Khan, Muhammad January 2012 (has links)
Polyelectrolytes are conductive polymers because of their ionic side group and PEDOT-S is one of those conductive polyelectrolytes. Previously, recombinant silk fibre has been dyed with PEDOT-S. PEDOT-S showed that it can be dyed with recombinant silk fibre over a very wide range of pH from 11 to 1.7. Previous experiments of dyeing recombinant silk fibre with PEDOT-S has shown that it is a very versatile process and can also be applied on other types of protein-based fibres, and that prompted me to dye wool and silk fibre from Bombyx Mori and make these fibres functionalized. So in this thesis dyeing of wool and silk fibres with PEDOT-S has been carried out. By this bottom-up approach of making an organic polymer electrically conductive and utilising the flexibility of organic polymer, one can integrate it in OLEDs and in smart textiles. In this thesis dyeing of silk and wool fibres with different dyeing pH has been carried out to maximise the exhaustion of dyes on to the fibres to acquire maximum conductance. Then the wool and silk fibres’ conductance and mechanical properties after dyeing were compared. Wool showed better conductance and mechanical properties as compare to silk after being dyed with PEDOT-S. These results helped to propose a model that tells about the interaction between protein-based fibres and polyelectrolytes and gives us better understanding of how these protein-based fibres show certain conductivity at different pH. Results also showed that these conductive fibres can be used further in special purposes and applications. / Program: Magisterutbildning i textilteknologi
202

Elaboration de films minces électroluminescents à base de polymère conducteur électronique et de nanotubes de carbone / Synthesis of light-emitting films based on conductive polymers and carbon nanotube layers

Raies, Ahlem 02 November 2015 (has links)
Le sujet de cette thèse se situe dans le contexte de l'électronique organique à base de polymères conjugués et de nanotubes de carbone. Nous avons choisi la famille des polyfluorènes principalement en raison de leur émission dans le bleu, leur bon rendement quantique ainsi que pour la facilité avec laquelle on peut modifier leurs propriétés en greffant différents groupements fonctionnels sur la structure de base du fluorène. L'originalité des recherches effectuées au laboratoire concerne la structure des films électroluminescents que nous réalisons. Leur principe de fonctionnement repose sur l'utilisation de nanotubes de carbone en tant que film support pour le dépôt du polymère. Le travail réalisé au cours de cette thèse a principalement consisté à élaborer des films de polymères avec des épaisseurs et des taux de dopage contrôlés à la surface des nanotubes de carbone en optimisant les divers paramètres de synthèse électrochimique. Nous avons également utilisé des groupements fonctionnels pour améliorer les performances du polyfluorène et augmenter la compatibilité entre les couches polymère/nanotubes de carbone. Dans cette optique, nous avons mis en œuvre l'utilisation de différents outils pour la caractérisation des propriétés des films. Les propriétés intrinsèques des nanotubes de carbone ont donc pour effet de doper le polymère et d'améliorer le transport des charges au sein des couches tout en maintenant les performances de luminescence dans le bleu des polyfluorènes. / The subject of this thesis lies in the context of organic electronic based on conjugated polymers. We have chosen the class of polyfluorene mainly because of their blue emission, good quantum efficiency and possibility of modifying their properties by grafting side chain groups. The originality of our research relies upon the use of a particular devices structure. The structure of our electroluminescent films is based on the use of a thin layer of carbon nanotubes added to the structure of the emissive layer without involving any chemical modification.The work done in this thesis has mainly consisted of deposing polymer films with thicknesses and doping level controlled on the surface of carbon nanotubes by optimizing various parameters of the electrochemical synthesis. Functional groups have also been grafted on the side of chains in order to improve the performances of the polymer and to increase the compatibility between the polymer layer and the carbon nanotube dispersion. The use of carbon nanotubes should improve the charge carriers whitout quenching the photophysical properties of the polymers.
203

Efeitos da suplementação da dieta com ácido linoleico conjugado (CLA) e óleo de peixe isolados ou em conjunto sobre o metabolismo energético mitocondrial, celular e corporal / Effects of dietary supplementation with conjugated linoleic acid (CLA) and fish oil either alone or in combination on mitochondrial, cellular and body energy metabolism

Rossignoli, Camila Pederiva 07 July 2016 (has links)
Atualmente no Brasil mais da metade da população adulta tem excesso de peso e 21% estão obesos. A obesidade é uma doença que se encontra em evidente crescimento, sendo considerada a epidemia do século XXI. Como alternativa de tratamento e prevenção, o uso de ácidos graxos que possuem habilidade de induzir a expressão de genes com importante papel em modulações metabólicas e mitocondriais têm sido estudados. O ácido linoleico conjugado (CLA, 18:2) é da família ômega-6, descrito por sua propriedade antiobesidade relacionada à diminuição da adiposidade e ao aumento do metabolismo corporal. O óleo de peixe (OP) é uma mistura de ácidos graxos poli-insaturados eicosapentaenóico (EPA, 20:5) e docosahexaenóico (DHA, 22:6) da família ômega-3, conhecido por aumentar a sensibilidade à insulina, o colesterol-HDL, pelas suas propriedades antiinflamatórias e sua ação protetora sobre o sistema nervoso. O objetivo deste estudo foi verificar os efeitos da suplementação da dieta de camundongos C57BL6 com CLA em conjunto com OP durante 60 dias sobre aspectos bioquímicos, moleculares e fisiológicos do metabolismo mitocondrial e corporal. Verificamos que a suplementação da dieta com CLA e OP in vivo: aumenta o metabolismo corporal, efeito atribuído à ambos os óleos; prejudica o metabolismo da glicose circulante, proporcionado exclusivamente pelo CLA; reduz o nível de movimentação, proporcionado exclusivamente pelo OP. No fígado: aumenta a expressão de UCP2, a atividade de proteínas desacopladoras e a ?- oxidação, efeito atribuído à ambos os óleos; aumenta o número de mitocôndrias, proporcionado exclusivamente pelo OP. CLA aumenta a produção de espécies reativas de O2 (EROs) a qual é revertida pelo OP em conjunto. No músculo sóleo: aumenta a biogênese mitocondrial via PGC- 1? e a expressão de UCP2, proporcionados pelo OP. Por fim, no hipocampo: aumenta o número de mitocôndrias, estimulo dado por ambos os óleos; aumenta a atividade desacopladora e reduz a produção de EROs, proporcionados exclusivamente pelo CLA. Concluímos que na suplementação conjunta os efeitos do OP são predominantes nos metabolismos corporal, hepático e muscular, e na movimentação corporal, enquanto que o efeito predominante do CLA é a diminuição na sensibilidade à insulina. Já no cérebro, o OP potencializa os efeitos do CLA. / Currently in Brazil more than a half of adult population has overweight, and 21% are obese. This evident growing disease is considered the 21th century\'s epidemy. Some fatty acids have been considered an alternative treatment and prevention strategy for obesity due to their ability to stimulate gene expression with important role in cellular and mitochondrial metabolisms. Conjugated linoleic acid (CLA, 18:2) from omega-6 family, with anti-obesity properties related to diminution of adiposity and increments in body metabolism. The fish oil (FO) is a mixture of the poli-unsaturated fatty acids eicosapentaenoic (EPA, 20:5) and docosahexaenoic (DHA, 22:6) from omega-3 family, known for improving insulin sensibility and HDL-cholesterol, anti-inflammatory properties and protective action over the central nervous system. The objective of this study was to examine the effects of dietary supplementation of CLA in conjunction with FO during 60 days over biochemical, molecular and physiological aspects of mitochondrial and body metabolism in C57BL6 mice. Diet supplementation with CLA and FO in vivo: raise body metabolism, an effect attributed to both oils; affect glucose metabolism, exclusively proportionate by CLA; diminish the level of mice movement, exclusively proportionate by FO. In liver: increase UCP2 expression, uncoupling proteins activity and ?-oxidation, stimulated by both oils; increase mitochondrial density, exclusively proportionate by FO. CLA also raises the reactive oxygen species (ROS) production, which is reversed by FO in conjunction. In soleus muscle: increase mitochondrial biogenesis through PGC-1? and the UCP2 expression, exclusively proportionate by FO. Lastly, in hippocampus: increase mitochondrial density, stimulated by both oils; stimulate uncoupling activity and diminish ROS production, exclusively proportionate by CLA. In conclusion, in the dietary supplementation with CLA and FO in conjunction the FO effects are prevalent in metabolisms of body, liver and muscle, and in body movement, while the CLA effects are prevalent in decreasing insulin sensitivity. However in the brain, the FO potentiates the effects of CLA.
204

Low cost, more efficient, and less toxic synthetic routes to conjugated polymers

Ayuso Carrillo, Josue January 2016 (has links)
As key components of flexible organic electronics, the synthesis of polythiophenes via less toxic and more cost-effective routes is demanded. An efficient synthetic route for the production of thienyl-containing homopolymers and copolymers has been developed. The synthetic approach consists of: i) the synthesis in high yield and high purity of thienyl borane monomers protected with N-methyliminodiacetic acid (MIDA) via C-H electrophilic borylation. This reaction uses a combination of inexpensive reagents BCl3, AlCl3, and 2,6-dichloropyridine (Cl2Py) for the regioselective electrophilic aromatic substitution of thiophenes, followed by addition of a second aprotic amine pre-esterification to reduce the Brønsted acidity of the reaction mixture. In situ esterification provided the desired thienyl MIDA boronateester monomers in one-pot at room temperature. ii) Subsequent Suzuki-Miyaura polymerisation of the synthesised monomers to produce well defined thienyl containing pie-conjugated polymers in high molecular weight and high yields. Key reaction parameters for successful Suzuki-Miyaura polymerisation of thienyl-derived MIDA boronate esters under mild temperatures (i.e., 55 °C in THF) were found: a) an optimal monomer:H2O:base ratio, which enables controlled hydrolysis of the BMIDA moiety into its corresponding boronic acid at appropriate rates for high fidelity polymerisation. b) Nature of the base, where K3PO4 provided the best results for production of homopolymers (e.g., rr-P3HT), or KOH which gave excellent results for the formation of copolymers across a range of electronically different comonomers (e.g., pCPDT-BT). Thus, it is demonstrated that the approach is a general strategy for the highly efficient production of thienyl containing pie-conjugated regioregular, regiosymmetric and Donor-Acceptor polymers.
205

Perfil dos glicosaminoglicanos no útero de ratas ooforectomizadas e tratadas com estrogênios e/ou progestagênios / Profiles of glycosaminoglycans in the uterus of adult ooforectomized rats treated with estrogen and/or progestagen

Ricardo dos Santos Simões 15 June 2010 (has links)
Objetivo: Avaliar os efeitos dos estrogênios conjugados eqüinos (ECE), isolados ou associados ao acetato de medroxiprogesterona (AMP) sobre os glicosaminoglicanos do colo e do corno do útero de ratas. Métodos: 40 ratas adultas, após 30 dias de ooforectomia foram distribuídas em quatro grupos: GI - controle (veículo); GII - ECE (50 g/Kg, por dia); GIII - AMP (0,2 mg/Kg, por dia) e GIV - ECE (50 g/Kg, por dia) + AMP (0,2 mg/Kg, por dia). As substâncias foram administradas por gavagem por 28 dias consecutivos, sendo que ao final, após anestesia, o colo e o corpo do útero foram retirados e mergulhados em acetona para detecção e quantificação dos glicosaminoglicanos. Os glicosaminoglicanos sulfatados foram submetidos a eletroforese em gel de agarose e o ácido hialurônico a ensaio fluorimétrico (ELISA-like). Os resultados foram analisados pelo teste de t de Student e de ANOVA, complementado pelo teste de Tukey-Kramer (p<=0,05). Resultados: Foi detectada, em todos os grupos, maior concentração de glicosaminoglicanos sulfatados tanto no colo como nos cornos uterinos, em especial do dermatam sulfato. Já a concentração de ácido hialurônico foi maior no corno do que no colo. Com relação ao dermatam sulfato, os estrogênios promoveram incremento, tanto no colo quanto no corpo, sendo que a medroxiprogesterona bloqueou esta ação nos cornos uterinos. Os estrogênios e a medroxiprogesterona, por sua vez, apresentaram ação positiva nos níveis de heparam sulfato no colo do útero, já no corno este efeito foi atribuído à medroxiprogesterona. Conclusões: O perfil e a quantificação dos glicosaminoglicanos nas duas porções do útero de ratas são diferentes. Os glicosaminoglicanos sulfatados, em especial o dermatam sulfato, mostrou-se em maior concentração tanto no colo quanto no corno uterino. Os estrogênios e a medroxiprogesterona têm ação positiva nos glicosaminoglicanos sulfatados do colo, enquanto a medroxiprogesterona apresenta efeito antagônico no corno. O ácido hialurônico apareceu em maior concentração no corno do que no colo uterino. / Objective: To evaluate the effects of conjugated equine estrogens (CEE) alone or associated to medroxyprogesterone acetate (MPg) on glycosaminoglycans (GAGs) in the cervix and horns of the rat uterus. Methods: Thirty days after ovariectomy, 40 adult rats were randomly divided into four groups: GI, control (treated with drug vehicle); GII, CEE (50 ?g/Kg per day); GIII, MPg (0.2 mg/Kg per day), and GIV, CEE + MPg (doses as in GII and GIII). Drugs and vehicle were given by gavage during 28 days. After this the animals were euthanized, the uterine cervix and body were removed, fixed in acetone and further processed for GAGs quantification. Agarose gel electrophoresis was used for sulphated GAGs analyses; the hyaluronic acid was assayed with an ELISA-like method. Statistical analysis was done by the Student\'s t test and the Tukey-Kramer test. Significant differences were set at p<=0.05. Results: In all groups sulphated GAGs concentration (especially dermatan sulphate) was higher than that of nonsulphated GAGs, both in the cervix and in the uterine horns. Hyaluronic acid concentration in uterine horns was higher than in the cervix. With regard to dermatan sulphate, CEE exerted trophic effects both in horns and cervices, whereas MPg blocked this action in the uterine horn. The cervical concentration of heparan sulphate was rised by CEE and by MPg; in the uterine horns the same rise was observed, and this effect was attributed to MPg. Conclusions: The qualitative and quantitative profiles of GAGs in the horns and cervix of rat uterus are distinct. Sulphated GAGs (especially dermatan sulphate) are more concentrated than the non-sulphated ones in both uterine regions. With regard to sulphated GAGs, estrogens and medroxyprogesterone have trophic actions on sulphated GAGs at the cervix, whereas at the uterine horn MPg shows an antagonistic action. The concentration of hyaluronic acid in the uterine horns was higher than in the cervix.
206

Modulatory effects of conjugated linolenic acid (CLN) on the proliferation and apoptosis of human myeloid leukemia cells.

January 2007 (has links)
Yip, Wai Ki. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 203-228). / Abstracts in English and Chinese. / ACKNOWLEDGMENTS --- p.i / ABBREVIATIONS --- p.iii / ABSTRACT --- p.x / 撮要 --- p.xiv / TABLE OF CONTENTS --- p.xvii / Chapter CHAPTER 1: --- GENERAL INTRODUCTION / Chapter 1.1 --- Hematopoiesis and Leukemia / Chapter 1.1.1 --- An Overview on Hematopoiesis Development --- p.1 / Chapter 1.1.1.1 --- Hematopoietic Growth Factors --- p.4 / Chapter 1.1.1.2 --- Site Switching of Hematopoiesis --- p.5 / Chapter 1.1.2 --- An Overview on Leukemia --- p.7 / Chapter 1.1.2.1 --- Classification of Leukemia --- p.7 / Chapter 1.1.2.2 --- Conventional Therapy of Leukemia --- p.10 / Chapter 1.1.2.3 --- Novel Approaches to Leukemia Therapy: Apoptosis and Differentiation Induction --- p.13 / Chapter 1.2 --- Polysaturated Fatty Acids / Chapter 1.2.1 --- An Overview on Polyunsaturated Fatty Acids --- p.16 / Chapter 1.2.2 --- An Overview on Essential Fatty Acids --- p.17 / Chapter 1.2.2.1 --- Alpha Linolenic Acids (ALA) --- p.17 / Chapter 1.2.2.2 --- Gamma Linolenic Acid (GLA) --- p.18 / Chapter 1.2.3 --- "An Overview on Conjugated Fatty Acids: Conjugated Linoleic Acid (CLA), Conjugated EPA and Conjugated DHA" --- p.20 / Chapter 1.2.4 --- Conjugated Linolenic Acid (CLN) --- p.24 / Chapter 1.2.4.1 --- Identification and Production of CLN --- p.28 / Chapter 1.2.4.2. --- Metabolism of CLN --- p.29 / Chapter 1.2.4.3 --- Anti-Obese and Hypolipidemic Effect of CLN --- p.30 / Chapter 1.2.4.4 --- Anti-Proliferative Effect of CLN --- p.30 / Chapter 1.2.4.5 --- Other Novel Effects of CLN --- p.32 / Chapter 1.3 --- Aims and Scopes of This Investigation --- p.34 / Chapter CHAPTER 2: --- MATERIALS AND METHODS / Chapter 2.1 --- Materials --- p.36 / Chapter 2.1.1 --- Animals --- p.36 / Chapter 2.1.2 --- Human Cell Lines --- p.36 / Chapter 2.1.3 --- "Cell Culture Medium, Buffers and Other Reagents" --- p.38 / Chapter 2.1.4 --- Reagents and Buffer for Flow Cytometry --- p.44 / Chapter 2.1.5 --- Reagents for DNA Extraction --- p.47 / Chapter 2.1.6 --- Cell Death Detection ELISApLus --- p.48 / Chapter 2.1.7 --- Reagents for Measuring Caspase Activity --- p.50 / Chapter 2.1.8 --- Reagents for FACE´ёØ ELISA Kit --- p.53 / Chapter 2.1.9 --- Reagents for Western Blotting --- p.55 / Chapter 2.2 --- Methods --- p.65 / Chapter 2.2.1 --- Culturing the Tumor Cell Lines --- p.65 / Chapter 2.2.2 --- "Isolation, Preparation and Culturing of Murine Peritoneal Macrophages and Bone Marrow Cells" --- p.66 / Chapter 2.2.3 --- Anti-proliferation Assays --- p.67 / Chapter 2.2.4 --- Cell Viability Determination --- p.68 / Chapter 2.2.5 --- Determination of Anti-leukemia Activity In Vivo (In Vivo Tumorigenicity Assay) --- p.69 / Chapter 2.2.6 --- Cell Cycle Analysis by Flow Cytometry --- p.69 / Chapter 2.2.7 --- Detection of Apoptosis --- p.70 / Chapter 2.2.8 --- Assessment of Differentiation-associated Characteristics --- p.74 / Chapter 2.2.9 --- Measurement of Caspase Activities --- p.76 / Chapter 2.2.10 --- Protein Expression Study --- p.78 / Chapter 2.2.11 --- Detection of Phosphorylation of JNK by FACE´ёØ JNK ELISA Kit --- p.83 / Chapter 2.2.12 --- Detection of Phosphorylation of NF-kB by FACE´ёØ NF-kB p65 Profiler --- p.85 / Chapter 2.2.13 --- Statistical Analysis --- p.85 / Chapter CHAPTER 3: --- STUDIES ON THE ANTI PROLIFERATIVE EFFECTS OF CONJUGATED LINOLENIC ACIDS ON THE HUMAN MYELOID LEUKEMIA CELLS / Chapter 3.1 --- Introduction --- p.86 / Chapter 3.2 --- Results / Chapter 3.2.1 --- Anti-proliferative Activity of CLN Isomers on Various Myeloid Leukemia and Lymphoma Cell Lines In Vitro --- p.88 / Chapter 3.2.2 --- Direct Cytotoxic Effect of Jacaric Acid on HL-60 Cells In Vitro --- p.95 / Chapter 3.2.3 --- Cytotoxic Effect of Jacaric Acid on Primary Murine Cells and Human Normal Cell Lines In Vitro --- p.98 / Chapter 3.2.4 --- Kinetics and Reversibility Studies of the Anti-proliferative Effect of Four CLN Isomers on the Human Promyelocytic Leukemia HL-60 Cells --- p.101 / Chapter 3.2.5 --- Synergistic Anti-proliferative Effect of Jacaric Acid with Vitamin D3 and All Trans-Retinoic Acid (ATRA) on the Human Promyelocytic Leukemia HL-60 Cells In Vitro --- p.114 / Chapter 3.2.6 --- Effect of Jacaric Acid on the Cell Cycle Profile of the HL-60 Cells In Vitro --- p.116 / Chapter 3.2.7 --- Effect of Jacaric Acid on the In Vivo Tumorigenicity of the HL-60 Cells --- p.119 / Chapter 3.3 --- Discussion --- p.121 / Chapter CHAPTER 4: --- STUDIES ON THE APOPTOSIS-INDUCING AND DIFFERENTIATION-INDUCING EFFECTS OF CONJUGATED LINOLENIC ACIDS ON THE HUMAN MYELOID LEUKEMIA CELLS / Chapter 4.1.1 --- Introduction --- p.128 / Chapter 4.2 --- Results / Chapter 4.2.1 --- Induction of Apoptosis in the Human Promyelocytic Leukemia HL-60 Cells by Jacaric Acid --- p.134 / Chapter 4.2.2 --- Apoptosis-Inducing Effect of Jacaric Acid on the Human Promyelocytic Leukemia HL-60 Cells as Detected by Annexin V-GFP PI Double Staining Method --- p.138 / Chapter 4.2.3 --- Effect of Jacaric Acid on the Mitochondrial Membrane Potential in the Human Promyelocytic Leukemia HL-60 Cells --- p.140 / Chapter 4.2.4 --- Effects of Jacaric Acid on the Caspase Activities in the Human Promyelocytic Leukemia HL-60 Cells --- p.142 / Chapter 4.2.5 --- Effects of Jacaric Acid and Antioxidants on the ROS Induction in the Human Promyelocyic Leukemia hl-6 Cells --- p.147 / Chapter 4.2.6 --- Effect of N-acetyl-L-Cysteine on the Apoptosis-Inducing Activity of Jacaric Acid in the Human Promyelocytic Leukemia HL-60 Cells --- p.149 / Chapter 4.2.7 --- Morphological Studies on the Jacaric Acid-treated Human Promyelocytic Leukemia HL-60 Cells --- p.151 / Chapter 4.2.8 --- Cell Size and Granularity of the Human Promyelocytic Leukemia HL-60 Cells after Treatment with Different CLN Isomers --- p.153 / Chapter 4.2.9 --- Expression of Differentiation-Related Cell Surface Markers in the Human Promyelocytic Leukemia HL-60 Cells after Treatment with Jacaric Acid --- p.155 / Chapter 4.3 --- Discussion --- p.158 / Chapter CHAPTER 5: --- STUDIES ON THE APOPTOSIS-ASSOCIATED PROTEINS AND SIGNALING PATHWAYS IN CONJUGATED LINOLENIC ACID-INDUCED APOPTOSIS OF THE HUMAN MYELOID LEUKEMIA CELLS / Chapter 5.1 --- Introduction --- p.165 / Chapter 5.2 --- Results / Chapter 5.2.1 --- Expression of Fas and Fas Ligand Proteins in the Jacaric Acid- treated Human Promyelocytic Leukemia HL-60 Cells --- p.171 / Chapter 5.2.2 --- Expression of Bcl-2 Family Member Proteins in the Jacaric Acid- treated Human Promyelocytic Leukemia HL-60 Cells --- p.173 / Chapter 5.2.3 --- Cytochrome c Release in the Jacaric Acid-treated Human Promyelocytic Leukemia HL-60 Cells --- p.175 / Chapter 5.2.4 --- Cleavage of Poly(ADP-ribose) Polymerase (PARP) in the Jacaric Acid-treated Human Promyelocytic Leukemia HL-60 Cells --- p.177 / Chapter 5.2.5 --- Phosphorylation of ERK in the Jacaric Acid-treated Human Promyelocytic Leukemia HL-60 Cells --- p.179 / Chapter 5.2.6 --- Phosphorylation of JNK in the Jacaric Acid-treated Human Promyelocytic Leukemia HL-60 Cells --- p.181 / Chapter 5.2.7 --- Phosphorylation of NF-kB Protein in the Jacaric Acid-treated Human Promyelocytic Leukemia HL-60 Cells --- p.183 / Chapter 5.3 --- Discussion --- p.185 / Chapter CHAPTER 6: --- CONCLUSIONS AND FUTURE PERSPECTIVES --- p.195 / REFERENCES --- p.203
207

Perfil dos glicosaminoglicanos no útero de ratas ooforectomizadas e tratadas com estrogênios e/ou progestagênios / Profiles of glycosaminoglycans in the uterus of adult ooforectomized rats treated with estrogen and/or progestagen

Simões, Ricardo dos Santos 15 June 2010 (has links)
Objetivo: Avaliar os efeitos dos estrogênios conjugados eqüinos (ECE), isolados ou associados ao acetato de medroxiprogesterona (AMP) sobre os glicosaminoglicanos do colo e do corno do útero de ratas. Métodos: 40 ratas adultas, após 30 dias de ooforectomia foram distribuídas em quatro grupos: GI - controle (veículo); GII - ECE (50 g/Kg, por dia); GIII - AMP (0,2 mg/Kg, por dia) e GIV - ECE (50 g/Kg, por dia) + AMP (0,2 mg/Kg, por dia). As substâncias foram administradas por gavagem por 28 dias consecutivos, sendo que ao final, após anestesia, o colo e o corpo do útero foram retirados e mergulhados em acetona para detecção e quantificação dos glicosaminoglicanos. Os glicosaminoglicanos sulfatados foram submetidos a eletroforese em gel de agarose e o ácido hialurônico a ensaio fluorimétrico (ELISA-like). Os resultados foram analisados pelo teste de t de Student e de ANOVA, complementado pelo teste de Tukey-Kramer (p<=0,05). Resultados: Foi detectada, em todos os grupos, maior concentração de glicosaminoglicanos sulfatados tanto no colo como nos cornos uterinos, em especial do dermatam sulfato. Já a concentração de ácido hialurônico foi maior no corno do que no colo. Com relação ao dermatam sulfato, os estrogênios promoveram incremento, tanto no colo quanto no corpo, sendo que a medroxiprogesterona bloqueou esta ação nos cornos uterinos. Os estrogênios e a medroxiprogesterona, por sua vez, apresentaram ação positiva nos níveis de heparam sulfato no colo do útero, já no corno este efeito foi atribuído à medroxiprogesterona. Conclusões: O perfil e a quantificação dos glicosaminoglicanos nas duas porções do útero de ratas são diferentes. Os glicosaminoglicanos sulfatados, em especial o dermatam sulfato, mostrou-se em maior concentração tanto no colo quanto no corno uterino. Os estrogênios e a medroxiprogesterona têm ação positiva nos glicosaminoglicanos sulfatados do colo, enquanto a medroxiprogesterona apresenta efeito antagônico no corno. O ácido hialurônico apareceu em maior concentração no corno do que no colo uterino. / Objective: To evaluate the effects of conjugated equine estrogens (CEE) alone or associated to medroxyprogesterone acetate (MPg) on glycosaminoglycans (GAGs) in the cervix and horns of the rat uterus. Methods: Thirty days after ovariectomy, 40 adult rats were randomly divided into four groups: GI, control (treated with drug vehicle); GII, CEE (50 ?g/Kg per day); GIII, MPg (0.2 mg/Kg per day), and GIV, CEE + MPg (doses as in GII and GIII). Drugs and vehicle were given by gavage during 28 days. After this the animals were euthanized, the uterine cervix and body were removed, fixed in acetone and further processed for GAGs quantification. Agarose gel electrophoresis was used for sulphated GAGs analyses; the hyaluronic acid was assayed with an ELISA-like method. Statistical analysis was done by the Student\'s t test and the Tukey-Kramer test. Significant differences were set at p<=0.05. Results: In all groups sulphated GAGs concentration (especially dermatan sulphate) was higher than that of nonsulphated GAGs, both in the cervix and in the uterine horns. Hyaluronic acid concentration in uterine horns was higher than in the cervix. With regard to dermatan sulphate, CEE exerted trophic effects both in horns and cervices, whereas MPg blocked this action in the uterine horn. The cervical concentration of heparan sulphate was rised by CEE and by MPg; in the uterine horns the same rise was observed, and this effect was attributed to MPg. Conclusions: The qualitative and quantitative profiles of GAGs in the horns and cervix of rat uterus are distinct. Sulphated GAGs (especially dermatan sulphate) are more concentrated than the non-sulphated ones in both uterine regions. With regard to sulphated GAGs, estrogens and medroxyprogesterone have trophic actions on sulphated GAGs at the cervix, whereas at the uterine horn MPg shows an antagonistic action. The concentration of hyaluronic acid in the uterine horns was higher than in the cervix.
208

Estudo de sondas supressoras de quimiluminescência biológicas / Biological chemiluminescence suppressor probes

Velosa, Adriana Correia de 22 December 2003 (has links)
Os compostos carbonílicos no estado triplete (CCT) são considerados espécies reativas de oxigênio uma vez que possuem comportamento químico semelhante ao de radicais alcoxil. Quando formadas em sistemas biológicos, estas espécies podem estar envolvidas tanto em processos benéficos quanto deletérios ao organismo, como é o caso da lipoperoxidação, onde CCT não só são gerados como também iniciam ou amplificam o processo. Visando estudar a capacidade de dienos conjugados de suprimir a energia triplete de tais compostos, de forma a diminuir seus efeitos deletérios, determinou-se as constantes de supressão, para quatro diferentes dienos, de acetona triplete gerada pela da termólise do tetrametil-1 ,2- dioxetano e pelo sistema enzimático isobutanal/ \"horseradish peroxidase\"/O2 Todos os dienos apresentaram constantes de supressão de ordem difusional. Foi analisada também a forma pela qual os dienos suprimem a acetona triplete e concluiu-se que tanto dienos com hidrogênios alílicos (2,4-hexadienoato e seu éster etílico), potencialmente abstraíveis, quanto dienos sem estes hidrogênios (2 ,4-pentadienoato e seu éster metílico), suprimem a acetona por um processo físico de transferência de energia, que leva à sua fotoisomerização cis,trans. A reatividade destes dienos frente a espécies reativas de oxigênio comumente formadas em sistemas de lipoperoxidação, como o oxigênio singlete, radicais hidroxil, peroxil e superóxido, foi também testada, mostrando que nenhum dos dienos apresenta atividade sequestradora destas espécies. Experimentos preliminares de lipoperoxidação em sistemas biomiméticos (mitocôndrias e microssomos isolados de fígado de rato), mostraram que o trans, trans-2,4-hexadienoato de etila é capaz de inibir o inchamento mitocondrial induzido por benzofenona triplete e de suprimir a quimiluminescência de microssomos induzida por Fe2+/ ascorbato. Concluiu-se assim que dienos conjugados, contendo ou não hidrogênios alílicos, podem ser usados como supressores específicos de compostos carbonílicos triplete em sistemas biológicos e contribuir para o esclarecimento dos mecanismos de reação destes processos. / Triplet carbonyls can be named reactive oxygen species once they behave chemically as alkyloxyl radicals and therefore can potentially drive beneficial and deleterious processes in biological systems. In the case of lipid peroxidation, these species have been found not only to be reaction products but also to amplify the radical chain by hydrogen abstraction of polyunsatured lipid molecules. With the aim of finding efficient and reliable chemical probes for triplet carbonyls, we studied here the quenching properties of conjugated dienes, namely 2,4-hexadienoate and 2,4- pentadienoate anions and corresponding alkyl esters, upon triplet acetone generated either chemically (thermolysis of tetramethyl-1 ,2-dioxetane) or enzymically (aerobic oxidation of isobutanal/horseradish peroxidase). As expected, the quenching rate constants were found to be diffusion controlled, although those for the pentadienoate derivatives were 3-fold lower than those measured for the hexadienoates. Therefore, independently of the presence of allylic hydrogens in the diene probe, the triplet acetone quenching occurred by a physical process followed by cis,trans-isomerization, without hydrogen abstraction from the quencher. The reactivity of the studied dienes towards oxygen reactive species known to be formed during lipid peroxidation, such as singlet oxygen, and peroxyl, hydroxyl and superoxide radicals, was also investigated to assure they would not interfere with the radical lipoperoxidation chain. Indeed, none of the dienes showed antioxidant activity on classical model systems. Preliminary experiments with model systems widely used to study lipid peroxidation showed that the trans, trans-ethyl sorbate can inhibit the mitochondrial swelling induced by enzymically formed triplet benzophenone and to quench the chemiluminescence of microsome preparations challenged with iron/ascorbate. This is in agreement with reported work showing that the lipid peroxidation chain associated with mitochondria permeabilization and polyunsaturated fatty acid peroxidation is amplified by intermediate triplet carbonyl products. Altogether our data indicate that conjugated dienes can be used as specific quenchers of triplet carbonyls formed in biological systems without reacting with other reactive intermediates.
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Studies of Inverted Organic Solar Cells Fabricated by Doctor Blading Technique

Tang, Zheng January 2010 (has links)
<p>Over the last few decades, bulk-heterojunction organic photovoltaic devices comprising an intimately mixed donor-acceptor blend have gained serious attention due to their potential for being cheap, light weight, flexible and environmentally friendly. In this thesis, APFO-3/PCBM bulk-heterojunction based organic photovoltaic devices with an inverted layer sequence were investigated systematically. Doctor blade coating is a technique that is roll-to-roll compatible and cost efficient and has been used to fabricate the solar cells.</p><p>Initial studies focused on optimization of the electrodes. A thin film of the conductive polymer PEDOT:PSS was chosen to be the transparent anode. Different PEDOT:PSS films with respect to the film thickness and deposition temperature were characterized in terms of conductivity and transmission. Decent conductance and transmittance were obtained in the films deposited with wet film thickness setting of 35 μm, The cathode was fabricated from a metal bilayer comprising Al and Ti with an area about 1 cm<sup>2</sup>, and the best-working cathodes contained a 70 nm thick Al layer covered by a thin Ti layer of about 10 -15 nm.</p><p>Optimized coating temperature and wet film thickness settings for the active layer and PEDOT:PSS layer were experimentally determined. The highest efficiency of the APFO-3/PCBM based inverted solar cells fabricated by doctor blading was 0.69%, which exceeded the efficiency of spin-coated inverted cells.</p><p>A higher efficiency (0.8 %) was achieved by adding a small amount of high molecular weight polystyrene to the active layer. Morphological changes after adding of the polystyrene were observed by optical microscopy and AFM. A coating temperature dependent phase separation of the APFO-3/PCBM/polystyrene blend was found.</p><p> </p>
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Microstructure and Temperature Stability of APFO-3:PCBM Organic Photovoltaic Blends

Bergqvist, Jonas January 2010 (has links)
<p>In this thesis, the microstructure of organic photovoltaic APFO-3:PC<sub>61</sub>BM bulk-heterojunction blends was examined. Earlier studies have focused on the microstructure after spin coating. This thesis aims to give a better insight into microstructural degradation as the films are annealed above the glass transition temperature, T<sub>g</sub>, and the mixture approaches thermodynamic equilibrium. Electro- and photoluminescence studies indicate that the polymer and PC<sub>61</sub>BM are intermixed on a scale shorter than the exciton diffusion length of 10 nm, even when annealed above T<sub>g</sub>. The temperature stability of APFO-3:PC<sub>61</sub>BM was also investigated with respect to the molecular weight of the polymer. The photovoltaic performance of these blends was found to be stable up to temperatures approaching the glass transition temperature, especially if a high molecular-weight APFO-3 grade was used.</p><p> </p><p>The crystallization of PC<sub>61</sub>BM was also investigated. Above T<sub>g</sub>, PC<sub>61</sub>BM crystallization was found to commence, albeit slowly at temperatures close to T<sub>g</sub>. At elevated temperatures instead, micrometer sized crystals were observed to form. It was also noted that illumination while annealing APFO-3:PC<sub>61</sub>BM thin films above T<sub>g</sub> affected PC<sub>61</sub>BM crystallization, the origin of which is so far unclear although chemical degradation could be largely excluded.</p>

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