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Efeitos do azul de metileno na lesão pulmonar aguda induzida por ácido oleico em ratos / Effects of methylene blue in acute lung injury induced by oleic acid in ratsAna Paula Cassiano Silveira 10 June 2014 (has links)
INTRODUÇÃO. O termo Lesão Pulmonar Aguda (LPA) é usado para descrever a resposta pulmonar à lesão que ocorre diretamente ou indiretamente nos pulmões. A quebra da barreira alvéolo-capilar determina o influxo de líquido rico em proteínas para dentro dos espaços alveolares, sendo necessária a reabsorção desse líquido no processo de resolução da LPA. A infusão intravenosa de Ácido Oleico (AO) em ratos provoca agudamente edema alveolar difuso e focos hemorrágicos intra-alveolares, sendo um bom modelo de indução. Estudos relatam que o Azul de Metileno (AM) atenua tais lesões, com efeito protetor, no tecido pulmonar, e reduz o edema presente na LPA em animais com sepse através da inibição da guanilato ciclase solúvel (GCs), uma enzima ativadora da via NO-GMPc. OBJETIVO. Estudar a repercussão da inibição da GCs pelo AM na permeabilidade capilar pulmonar ministrando-o antes e após a indução da lesão pulmonar por AO. MÉTODO. Ratos Wistar foram divididos em 5 grupos: Sham com infusão de salina em bolus; AM com infusão de AM por 2h; AO com infusão de AO em bolus, AM/AO com infusão de AM por 2h, sendo que, após 5 min do início, recebeu AO simultaneamente em bolus e AO/AM com infusão de AO em bolus e, após 2h, infusão de AM por mais 2h. Após 4h foi realizada a coleta de materiais (sangue, lavado bronco-alveolar e tecido pulmonar) para análise do NO plasmático e tecidual, gasometria arterial, cálculo do peso úmido/peso seco (PU/PS) e histologia do tecido pulmonar de todos os grupos. A estatística utilizada foi a análise de variância (one-way ANOVA) com p<0.05. RESULTADO. Não foi encontrado hipoxemia grave após 4h de lesão. O grupo AO apresenta um aumento no número de proteínas no lavado bronco-alveolar e na relação PU/PS comparado aos grupos controle: Sham e AM, confirmando a presença de lesão e alteração de permeabilidade pulmonar. Os grupos tratados com AM apresentaram melhora na permeabilidade pulmonar, porém, apenas o grupo pré-tratamento (AM/AO) apresentou diferença estatística na redução do extravasamento de proteínas no lavado. Não foram encontradas diferenças significativas no NO plasmático e tecidual. Na microscopia, a congestão capilar foi intensa, acompanhada de múltiplos focos de edema alveolar, exsudato intra-alveolar proteico, áreas de hemorragia e infiltrado inflamatório neutrofílico, tanto no interstício quanto nos septos alveolares.Os grupos tratados com AM apresentaram diminuição das áreas de edema, exsudação e hemorragia, porém, com maior evidência no grupo AM/AO. CONCLUSÃO. O AM diminui a permeabilidade pulmonar quando administrado de maneira precoce amenizando os danos causados pela LPA induzida por AO. / BACKGROUND. The term Acute Lung Injury (ALI) is used to describe the response to lung injury that occurs directly or indirectly in the lungs. The rupture of the alveolar - capillary barrier determines the influx of protein-rich fluid into the alveolar spaces, the reabsorption of this fluid in the process of resolving the ALI is required. Intravenous infusion of oleic acid (OA) in rats acutely causes diffuse alveolar edema and intra-alveolar hemorrhagic foci, being a good role model induction. Studies have reported that Methylene Blue (MB) attenuates such injuries, with a protective effect in lung tissue and reduce edema present in the ALI present in with sepsis by inhibition of soluble guanylate cyclase (sGC), an activator of the enzyme NO- cGMP pathway. OBJECTIVE. To study the effect of inhibition of sGC by MB in pulmonary capillary permeability ministering to the before and after induction of lung injury by OA. METHOD. Wistar rats were divided into 5 groups: Sham infused with saline bolus, MB infused with MB for 2hrs, OA infused with OA bolus, MB/OA infused with MB for 2hrs, and after 5 min from the beginning, simultaneously received OA bolus and OA/MB infused with OA bolus and after 2hrs, MB infusion for 2hrs. After 4hrs the collection of materials was performed (blood, bronchoalveolar lavage and lung tissue) for analysis of plasma and tissue NO, arterial blood gases, calculation of the wet weight/dry weight (WW/DW) and histology of lung tissue from all groups. The statistic used was analysis of variance (one-way ANOVA) with p<0.05. RESULTS. Not found severe hypoxemia after 4hrs of injury. The OA group shows an increase in the number of proteins in bronchoalveolar lavage and in WW/DW ratio compared to the control groups: Sham and MB, confirming the presence of injury and alterations of lung permeability. The groups treated with MB showed improvement in lung permeability, however, only the pretreatment group (MB/OA) showed statistical significance in reducing the leakage of protein in the lavage. No significant differences were found in plasma and tissue NO. In microscopy, capillary congestion was intense, accompanied by multiple foci of alveolar edema, intra-alveolar proteinaceous exudates, areas of hemorrhage and neutrophilic inflammatory infiltrate in both the interstitium and in the alveolar septa. The groups treated with MB showed reduction in areas of edema, exudation and hemorrhage, however, most obviously in MB/OA group. CONCLUSION. The MB decreases lung permeability when administered as early as possible, mitigating the damage caused by OA-induced ALI.
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Superlubricity und tribochemischer Verschleiß: Interaction of Tetrahedral Amorphous Carbon Coatings with Fatty Acid-based LubricantsMakowski, Stefan 18 January 2021 (has links)
Wasserstofffreie tetraedrisch amorphe Kohlenstoffschichten, auch ta-C-Schichten, weisen aufgrund ihrer hohen Härte und Passivität überragende Reib- und Verschleißeigenschaften aus. In zahlreichen Anwendungen führen sie zu nennenswerter Reibungsminderung, höherer Verschleiß- und Fressbeständigkeit sowie besseren Notlaufeigenschaften. Sie sind kompatibel mit konventionellen Schmierölen, Wasser oder können auch trocken eingesetzt werden.
In der vergleichsweise jungen Wissenschaft der Schichttribologie gibt es jedoch noch zahlreiche bemerkenswerte Phänomene, die bislang noch nicht ausreichend verstanden wurden. Hierzu zählt die Wechselwirkung von ta-C-Schichten mit fettsäurebasierten Schmierstoffen, welche aus Pflanzenölen gewonnen werden. Die vorhandenen Forschungsarbeiten berichten unter anderem von Supraschmierung (englisch Superlubricity), teilweise auch von starkem Verschleiß.
Insbesondere der Supraschmiereffekt, bei dem die Reibungsverluste nahezu vollständig verschwinden, ist in Kombination mit nachhaltigen Schmierstoffen zum Erreichen aktueller klima- und umweltpolitischer Ziele von höchster Relevanz. In der vorliegenden Arbeit wird zunächst die Literatur zur Schmierstoffwechselwirkung von ta-C-Schichten umfassend aufgearbeitet. Anschließend wird die tribologische Interaktion speziell mit fettsäurebasierten Schmierstoffen anhand systematischer Experimente untersucht, wobei verschiedene Parameter, wie beispielsweise Schmiermittel, Temperatur, Flächenpressung und Gegenkörpermaterial eines oszillierenden Kugel-Scheibe-Modellsystems nacheinander variiert werden. Im Ergebnis werden Zustände des tribologischen Systems identifiziert, bei denen trotz höchster Härte der Oberfläche einer sehr starker Verschleiß auftritt. Dieses Phänomen wird als tribochemischer Verschleiß erkannt, von dem sonst sehr geringen abrasiven Verschleiß abgegrenzt und in Bezug auf die vorhandene Literatur eingeordnet. Unter anderen günstigen Umständen kann der Verschleiß an ta-C-Schichten unter der Messgrenze liegen und Supraschmierung auftreten. Sowohl für den tribochemischen Verschleiß als auch die Supraschmierung wird die Rolle der Kohlenstoff-Doppelbindung der Ölsäure herausgearbeitet, welche oft Hauptbestandteil fettsäurebasierter Schmierstoffe ist. Insgesamt können mit der Kombination von ta-C-Schichten und fettsäurebasierten Schmierstoffen verschiedene außergewöhnliche tribologische Eigenschaften erzielt werden. Eine dafür notwendige Systematisierung der möglichen Wechselwirkungen und erforderlichen Parameterfenster sind in dieser Arbeit dargelegt und bieten die Grundlage für eine zukünftige industrielle Anwendung von supraschmierenden Systemen.:Danksagung
Abkürzungsverzeichnis
1. Einleitung
2. Grundlagen
2.1 Tetraedrisch amorphe Kohlenstoffschichten
2.1.1 Die Modifikationen des Kohlenstoffs
2.1.2 Klassifikation amorpher Kohlenstoffschichten
2.1.3 Wachstumsmechanismus
2.1.4 Beschichtungsverfahren
2.1.5 Eigenschaften und Struktur
2.1.6 Temperaturstabilität
2.1.7 Strukturaufklärung mit Raman-Spektroskopie
2.1.8 Technische Anwendung
2.2 Tribologie
2.2.1 Geschichte, Definition und Bedeutung
2.2.2 Beschreibung tribologischer Systeme
2.2.3 Reibung und Verschleiß
2.2.4 Schmierung und Stribeck-Kurve
2.2.5 Schmierstoffe
2.2.6 Tribologische Prüfung
2.2.7 Tribologie von Schichtsystemen
2.3 Superlubricity
2.3.1 Geschichte, Definition und aktuelle Bedeutung
2.3.2 Definition und Einteilung
2.3.3 Funktionsmodelle und Beispielsysteme
2.4 Tribologische Eigenschaften von ta-C-Schichten
2.4.1 Überblick
2.4.2 Eigenschaften der Oberfläche
2.4.3 Schmierung mit konventionellen Schmierstoffen und Additiven
2.4.4 Schmierung mit Gasen, feuchter Luft und Wasser
2.4.5 Superlubricity auf ta-C
2.4.6 Rehybridisierung und Grafitisierung
2.4.7 Verschleiß - Größenordnung und Mechanismen
2.4.8 Mechanisch dominierte Verschleißmechanismen
2.4.9 Tribochemische Prozesse
3. Arbeitsziele
4. Experimentelle Methoden
4.1 Tribologische Prüfung
4.1.1 Prüfkörpergeometrie und Flächenpressung
4.1.2 Werkstoffe und Beschichtungen
4.1.3 Verwendete Schmiermittel
4.1.4 Aufbau und Funktion des Tribometers
4.1.5 Versuchsdurchführung
4.1.6 Prüfparameter
4.1.7 Bestimmung der Reibung
4.1.8 Bestimmung des Verschleißes
4.1.9 Einordnung und Relevanz der untersuchten Systeme
4.1.10 Versuchsplanung
4.2 Raman-Spektroskopie
4.3 Mikroskopie
5. Ergebnisse
5.1 Tribochemischer Verschleiß
5.1.1 Referenzzustand
5.1.2 Schmierstoffeinfluss
5.1.3 Struktur der Kohlenstoffphase
5.1.4 Temperatureinfluss
5.1.5 Oberflächenzustand
5.1.6 Gegenkörpermaterial
5.1.7 Quantifizierung und Analyse des Verschleißmechanismus
5.2 Superlubricity
5.2.1 Schmierstoffeinfluss
5.2.2 Relative Schmierfilmhöhe
5.2.3 Rehybridisierung
5.2.4 Materialpaarung
6. Diskussion
6.1 Verschleiß an ta-C-Schichten
6.1.1 Abrasiver und tribochemischer Verschleiß
6.1.2 Tribochemischer Mechanismus
6.1.3 Verschleißkinetik
6.2 Reibungsminderung auf ta-C-Schichten
6.2.1 Ultra-low friction
6.2.2 Superlubricity
6.2.3 Glättung
6.2.4 Schmierungszustand
6.2.5 Bedeutung der Rehybridisierung für Superlubricity
6.3 Forschungsbedarf
7. Zusammenfassung und Ausblick
Literaturverzeichnis / Hydrogen-free tetrahedral amorphous carbon coatings, called ta-C coatings, show superior friction and wear properties due to their high hardness and passivity. In numerous applications, they account for noteworthy friction reduction, increased wear and fretting resistance as well as improved emergency running properties. They are compatible with conventional lubrication oils and water, or can be used without lubricant. In the comparably young science of coating tribology there are further noteworthy phenomena, which are not sufficiently understood. One of them is the interaction of ta-C coatings with fatty acid-based lubricants, which can be derived from vegetable oils. Among other, existing research reports superlubricity and sometimes very strong wear. Especially superlubricity, where friction losses nearly vanish and sustainable lubricants are used, is a topic of utmost relevance to achieve current climate political and environmental goals. In the presented work, the available literature to lubricant interaction of ta-C coatings is comprehensively reviewed. Then, tribological interaction with fatty acid-based lubricants in particular is investigated with systematic experiments, successively varying parameters like lubricant, temperature, contact pressure and counter body material in an oscillating ball-on-flat model system. As a result, conditions of the tribological system are identified in which strong wear occurs, despite highest hardness of the surface. The phenomenon is then attributed to tribochemical wear, distinguished from usually much lower abrasive wear and discussed with respect to existing literature. In other beneficial circumstances, wear decreases below measurability and superlubricity can occur. For both tribochemical wear and superlubricity the role of the carbon double bond in oleic acid is highlighted, which is the main component fatty acid-based lubricants. In summary, various exceptional tribological properties can be achieved when combining ta-C coatings and fatty acid-based lubricants. This work presents both a systematic categorization as well as parameter windows, and thus the foundation for future industrial application of superlubricious systems.:Danksagung
Abkürzungsverzeichnis
1. Einleitung
2. Grundlagen
2.1 Tetraedrisch amorphe Kohlenstoffschichten
2.1.1 Die Modifikationen des Kohlenstoffs
2.1.2 Klassifikation amorpher Kohlenstoffschichten
2.1.3 Wachstumsmechanismus
2.1.4 Beschichtungsverfahren
2.1.5 Eigenschaften und Struktur
2.1.6 Temperaturstabilität
2.1.7 Strukturaufklärung mit Raman-Spektroskopie
2.1.8 Technische Anwendung
2.2 Tribologie
2.2.1 Geschichte, Definition und Bedeutung
2.2.2 Beschreibung tribologischer Systeme
2.2.3 Reibung und Verschleiß
2.2.4 Schmierung und Stribeck-Kurve
2.2.5 Schmierstoffe
2.2.6 Tribologische Prüfung
2.2.7 Tribologie von Schichtsystemen
2.3 Superlubricity
2.3.1 Geschichte, Definition und aktuelle Bedeutung
2.3.2 Definition und Einteilung
2.3.3 Funktionsmodelle und Beispielsysteme
2.4 Tribologische Eigenschaften von ta-C-Schichten
2.4.1 Überblick
2.4.2 Eigenschaften der Oberfläche
2.4.3 Schmierung mit konventionellen Schmierstoffen und Additiven
2.4.4 Schmierung mit Gasen, feuchter Luft und Wasser
2.4.5 Superlubricity auf ta-C
2.4.6 Rehybridisierung und Grafitisierung
2.4.7 Verschleiß - Größenordnung und Mechanismen
2.4.8 Mechanisch dominierte Verschleißmechanismen
2.4.9 Tribochemische Prozesse
3. Arbeitsziele
4. Experimentelle Methoden
4.1 Tribologische Prüfung
4.1.1 Prüfkörpergeometrie und Flächenpressung
4.1.2 Werkstoffe und Beschichtungen
4.1.3 Verwendete Schmiermittel
4.1.4 Aufbau und Funktion des Tribometers
4.1.5 Versuchsdurchführung
4.1.6 Prüfparameter
4.1.7 Bestimmung der Reibung
4.1.8 Bestimmung des Verschleißes
4.1.9 Einordnung und Relevanz der untersuchten Systeme
4.1.10 Versuchsplanung
4.2 Raman-Spektroskopie
4.3 Mikroskopie
5. Ergebnisse
5.1 Tribochemischer Verschleiß
5.1.1 Referenzzustand
5.1.2 Schmierstoffeinfluss
5.1.3 Struktur der Kohlenstoffphase
5.1.4 Temperatureinfluss
5.1.5 Oberflächenzustand
5.1.6 Gegenkörpermaterial
5.1.7 Quantifizierung und Analyse des Verschleißmechanismus
5.2 Superlubricity
5.2.1 Schmierstoffeinfluss
5.2.2 Relative Schmierfilmhöhe
5.2.3 Rehybridisierung
5.2.4 Materialpaarung
6. Diskussion
6.1 Verschleiß an ta-C-Schichten
6.1.1 Abrasiver und tribochemischer Verschleiß
6.1.2 Tribochemischer Mechanismus
6.1.3 Verschleißkinetik
6.2 Reibungsminderung auf ta-C-Schichten
6.2.1 Ultra-low friction
6.2.2 Superlubricity
6.2.3 Glättung
6.2.4 Schmierungszustand
6.2.5 Bedeutung der Rehybridisierung für Superlubricity
6.3 Forschungsbedarf
7. Zusammenfassung und Ausblick
Literaturverzeichnis
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Efeito da terapia com células-tronco musculares e células-tronco mesenquimais na regeneração do músculo esquelético: modulação por ácido oléico. / Effect of muscle stem cells and mesenchymal stem cells transplantation on skeletal muscle regeneration: modulatory effect of oleic acid.Pinheiro, Carlos Hermano da Justa 26 June 2012 (has links)
O objetivo do presente trabalho foi investigar alterações na composição de ácidos graxos durante a diferenciação de células-tronco musculares (CTmusc) e seu possível envolvimento na miogênese. Aumento no conteúdo de ácido oléico foi observado. Quando as CTmusc foram tratadas com esse ácido graxo, a miogênese foi acelerada através da estimulação da via de sinalização da beta-catenina. Ainda nas CTmusc, o ácido oléico inibiu a sinalização do Notch e a capacidade proliferativa. Nenhum efeito do tratamento com ácido oléico foi observado na capacidade proliferativa de células-tronco mesenquimais. O transplante de CTmusc e células-tronco mesenquimais aceleram a regeneração e recuperação da função no músculo esquelético lacerado. O pré-tratamento com ácido oléico reduziu a ativação, proliferação e enxerto de CTmusc no músculo esquelético lesionado do hospedeiro e não teve efeito sobre o enxerto de células-tronco mesenquimais. Dessa maneira, o ácido oléico tem efeito modulador no efeito da terapia celular no músculo esquelético lesionado. / The purpose of the present study was to investigate alterations on fatty acid (FA) composition and a possible involvement of FA on muscle stem cell function. Na increase in content of oleic acid was observed when muscle stem cell (muscSC) differentiated to myotube. The treatment with oleic acid accelerated myogenesis through stimulation of beta-catenin signaling pathway. Notch signaling pathway was inhibited by oleic acid reducing the proliferative capacity of muscSC. No effects were observed in mesenchymal stem cells. Transplantation of both muscSC and mesenchymal stem cells accelerates muscle regeneration and recovery of function. The pre-treatment with oleic acid decreased activation, proliferation, differentiation and engrafment of muscSC in host injured muscle. Thus, oleic acid has modulatory effect on cellular therapy in injured skeletal muscle.
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OtimizaÃÃo do Processo de ObtenÃÃo de Biodiesel atravÃs da AdsorÃÃo de Ãgua formada durante a ReaÃÃo de EsterificaÃÃo / Optimization of the process of obtaining Biodiesel through adsorption of water formed during the reaction of esterificationIzabelly Larissa Lucena 18 April 2008 (has links)
CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / O objetivo desta dissertaÃÃo foi de otimizar a reaÃÃo de esterificaÃÃo para a produÃÃo de biodiesel por meio da aplicaÃÃo de tÃcnicas de adsorÃÃo. A aplicaÃÃo da adsorÃÃo teve o intuito de remover a Ãgua formada no processo, uma vez que a mesma leva a desativaÃÃo do catalisador e desloca o equilÃbrio quÃmico para reaÃÃo de hidrolise. A presenÃa de Ãgua reduz o rendimento da reaÃÃo de esterificaÃÃo, o que torna necessÃrio a utilizaÃÃo de elevadas concentraÃÃes de Ãlcool no meio reacional. Para tanto, foi realizado dois planejamentos experimentais para as reaÃÃes de esterificaÃÃo sem e com adsorÃÃo da Ãgua formada no processo. Em ambos os planejamentos foram investigadas as variÃveis temperatura, concentraÃÃo de catalisador e razÃo molar entre o Ãlcool e o Ãcido graxo. No planejamento experimental realizado para a reaÃÃo de esterificaÃÃo sem adsorÃÃo da Ãgua formada, as variÃveis concentraÃÃo de catalisador e razÃo molar entre reagentes mostraram-se estatisticamente significativas para a resposta conversÃo a 95 % de confianÃa. O melhor resultado experimental foi obtido a temperatura de 110ÂC com uma razÃo molar de 9:1 e uma concentraÃÃo de 1% de catalisador. Jà no planejamento experimental para a reaÃÃo de esterificaÃÃo com a remoÃÃo da Ãgua formada no processo, as variÃveis temperatura e a concentraÃÃo de catalisador foram significativas estatisticamente para o intervalo de confianÃa estudado (95%). Observou-se que quanto maior a temperatura e maior a concentraÃÃo de catalisador, melhor foi o resultado experimental obtido. Os experimentos cinÃticos mostraram que ao realizar a reaÃÃo de esterificaÃÃo aplicando-se tÃcnicas de adsorÃÃo, o processo tornou-se mais sensÃvel a temperatura, uma vez que o valor de energia de ativaÃÃo aparente obtido para a reaÃÃo com adsorÃÃo de Ãgua foi de 26,66 kJ/mol e para a reaÃÃo sem adsorÃÃo da Ãgua formada foi de 18,43 kJ/mol. A anÃlise via CG/MS mostrou que o acompanhamento da reaÃÃo por meio do Ãndice de acidez à satisfatÃrio para acompanhar a dinÃmica da reaÃÃo, pois os valores de conversÃo obtidos pelos dois mÃtodos foram equivalentes. Na caracterizaÃÃo do biodiesel obtido com adsorÃÃo da Ãgua formada os parÃmetros de densidade, Ãndice de iodo e viscosidade cinemÃtica atenderam as especificaÃÃes exigidas pela ANP. Ao aplicar a metodologia desenvolvida no respectivo trabalho (aplicaÃÃo de tÃcnicas de adsorÃÃo na reaÃÃo de esterificaÃÃo), os teores de Ãsteres metÃlicos obtidos foram de 98,9 % e 99,4 % para os experimentos realizados a razÃo molar de 3:1, concentraÃÃo de 1% de catalisador e temperaturas de 90 e 100ÂC, respectivamente. / This dissertation aimed to optimize the esterification reaction for biodiesel production using an adsorption reaction system. Adsorption was applied to remove the water formed in the process, because water deactivates the catalyst and shifts the equilibrium towards the hydrolysis reaction. Water reduces the yield of the esterification reaction, which requires high concentrations of alcohol in the reaction medium. Two experimental designs were carried out for the esterification reactions. One with and one without adsorbing the water formed in the process. In both designs, the variables temperature, catalyst concentration, and molar ratio between alcohol and fatty acid were investigated. Catalyst concentration and the alcohol to FFA molar ratio were the most statistically significant responses on conversion (within a 95% level of confidence) when the reaction was carried out without the adsorption system. The best result was obtained in experimental temperature of 110ÂC with a molar ratio of 9:1 and with a concentration of 1% of catalyst. Temperature and catalyst concentration were the most statistically significant variables in the experiments carried out with the adsorption system (for the confidence level of 95%). Higher temperatures and higher catalyst concentration enhanced the yield into biodiesel. The kinetic experiments showed that with the adsorption system the process became more sensitive to temperature, since the value of the apparent activation energy of the reaction was 26.66 kJ/mol and without adsorption system the apparent activation energy was 18.43 kJ/mol. GC/MS analysis showed that acidity index was very satisfactory to evaluate the yield of biodiesel., because the conversions obtained in both methods were equivalent. Density, iodine value and kinematics viscosity were within the specifications required by ANP. The methodology developed in this study resulted in conversions of oleic acid into methyl esters of 98.9% and 99.4% for the experiments performed with a molar ratio of 3:1, concentration of 1% of catalyst and temperatures of 90 and 100  C, respectively.
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Factors genètics i ambientals i les seves interaccions com a determinants de l'efecte protector de la paraoxanasa1 en la malaltia cardiovascularTomás Mestres, Marta 12 February 2003 (has links)
La present tesi avalua els efectes de certs factors ambientals sobre la paraoxonasa1 (PON1), enzim antioxidant, possiblement protector enfront les malalties cardiovasculars, a través de dos estudis d'intervenció i un de transversal. En primer lloc, el tractament amb simvastatina dels pacients amb hipercolesterolèmia familiar, que presentaven una activitat paraoxonasa baixa, s'associava a un increment de l'activitat fins a valors similars als d'individus normolipèmics, independentment dels polimorfismes PON1-55 o PON1-192. En segon lloc, l'entrenament físic s'associava a un augment de l'activitat paraoxonasa en els individus QQ i una disminució de la mateixa en els portadors de l'al·lel R pel polimorfisme PON1-192. L'increment de l'activitat paraoxonasa immediatament després de l'exercici físic agut era seguit per una disminució subseqüent de l'activitat. La recuperació dels nivells basals d'activitat paraoxonasa a les 24h de l'exercici físic agut es donava en els individus QQ independentment del seu estat d'entrenament, i en els individus portadors de l'al·lel R només quan estan entrenats. En tercer lloc, el consum elevat d'àcid oleic comportava un augment de la concentració de c-HDL i de l'activitat paraoxonasa en els homes portadors dels genotips QR i RR del polimorfisme PON1-192, respectivament.Paraules claus: paraoxonasa, PON1, genotips, simvastatina, hipercolesterolèmia familiar, interacció gen-dieta, lipoproteïna d'alta densitat (HDL), exercici físic agut, entrenament físic, estrès oxidatiu, àcid oleic, oli d'oliva, peròxids lipídics, malaltia cardiovascular. / The present thesis evaluates some environmental factor effects on paraoxonase1 (PON1), an possibly protective against cardiovascular disease antioxidant enzyme, through two intervention studies and a cross-sectional one. First, treatment with simvastatin of the familial hypercholesterolemic patients, which had low paraoxonase activity, was associated with an increase in the activity to values similar to the normolipemic ones, regardless of the PON1-55 or PON1-192 polymorphisms. Second, Regular exercise was associated with an increase in PON1 activity in QQ subjects and with a decrease in R carriers. Increased PON1 activity immediately after a bout of exercise was subsequently followed by a decrease of activity. The recovery of the basal PON1 activity levels at 24 h was found in QQ subjects regardless of their training status and in trained R carriers, but not in untrained R carriers. Third, high oleic acid intake was associated with increased HDL cholesterol and PON1 activity levels only in men who were QR and RR of the PON1-192 polymorphism, respectively.
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Oxidation of lipids in a supercritical-fluid mediumSparks, Darrell Lynn, January 2008 (has links)
Thesis (Ph.D.)--Mississippi State University. Dave C. Swalm School of Chemical Engineering. / Title from title screen. Includes bibliographical references.
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Genetische und agronomische Charakterisierung von Raps-Mutanten mit gesteigertem Ölsäuregehalt / Genetic and agronomic characterization of mutants in winter oilseed rape with increased oleic acid contentKahlmeyer, Maria 19 November 2009 (has links)
No description available.
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Avalia??o cin?tica e potencial do Nb2O5 obtido a partir de um complexo de ni?bio para forma??o do oleato de metila atrav?s da rea??o de esterifica??o do ?cido oleico / Evaluation of the kinetic and potential Nb2O5 obtained from a niobium complex to the formation of methyl oleate by esterification of oleic acidOliveira, Samuel Alves de 30 January 2014 (has links)
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Previous issue date: 2014-01-30 / Among the heterogeneous catalysts materials made from niobium show up as an alternative to meet the demand of catalysts for biodiesel production. This study aims to evaluate the potential of a heterogeneous catalyst derived from a complex of niobium in the reaction of methyl esterification of oleic acid. The catalyst was synthesized after calcination at different temperatures of a niobium complex ((NH4)3[NbO(C2O4)3].H2O) generating a niobium oxide nanostructure with a different commercial niobium oxide used to synthesize the complex. The commercial niobium oxide, the complex niobium and niobium catalyst were characterized by thermogravimetry (TG and DTA), surface area analysis (BET), scanning electron microscopy (SEM) and X-ray diffraction (XRD), showing the catalyst has researched morphological and crystallographic indicating a catalytic potential higher than that of commercial niobium oxide characteristics. Factorial with central composite design point, with three factors (calcination temperature, molar ratio of alcohol/oleic acid and mass percentage of catalyst) was performed. Noting that the optimal experimental point was given by the complex calcination temperature of 600?C, a molar ratio alcohol/oleic acid of 3.007/1 and the catalyst mass percentage of 7.998%, with a conversion of 22.44% oleic acid in methyl oleate to 60 min of reaction. We performed a composite linear and quadratic regression to determine an optimal statistical point of the reaction, the temperature of calcination of the complex at 450?C, the molar ratio of alcohol/oleic acid 3.3408/1 and mass percentage of catalyst of 7.6833% . Kinetic modeling to estimate parameters for heterogeneous catalysis it set well the experimental results with a final conversion of 85.01% with 42.38% of catalyst and without catalyst at 240 min reaction was performed. Allowing to evaluate the catalyst catalytic studied has the potential to be used in biodiesel production / Dentre os catalisadores heterog?neos os materiais a base de ni?bio mostram-se como uma alternativa para suprir a demanda de catalisadores para a produ??o de biodiesel. O presente trabalho visa avaliar o potencial de um catalisador heterog?neo derivado de um complexo de ni?bio na rea??o de esterifica??o met?lica do ?cido oleico. O catalisador foi sintetizado ap?s a calcina??o em diferentes temperaturas de um complexo de ni?bio ((NH4)3[NbO(C2O4)3].H2O) gerando um ?xido de ni?bio com uma nanoestrutura diferente do ?xido de ni?bio comercial, usado para sintetizar o complexo. O ?xido de ni?bio comercial, o complexo de ni?bio e o catalisador de ni?bio foram caracterizados por termogravimetria (TG e DTA), an?lise de ?rea superficial (BET), microscopia eletr?nica de varredura (MEV) e difra??o de raios-X (DRX), demostrando que o catalisador pesquisado possui caracter?sticas morfol?gicas e cristalogr?ficas que indicam um potencial catal?tico superior ao ?xido de ni?bio comercial. Foi realizado um planejamento fatorial composto com ponto central, com tr?s fatores (temperatura de calcina??o, raz?o molar de ?lcool/?cido oleico e percentual m?ssico de catalisador). Verificando que o ponto ?timo experimental se deu mediante a temperatura de calcina??o do complexo em 600?C, uma raz?o molar de ?lcool/?cido oleico de 3,007/1 e percentual m?ssico de catalisador de 7,998%, apresentando uma convers?o de 22,44% do ?cido oleico em oleato de metila em 60 min de rea??o. Realizou-se uma regress?o linear e quadr?tica composta para se determinar de um ponto ?timo estat?stico da rea??o, sendo a temperatura de calcina??o do complexo em 450?C, raz?o molar de ?lcool/?cido oleico de 3,3408/1 e percentual m?ssico de catalisador de 7,6833%. Foi realizada uma modelagem cin?tica para estima??o de par?metros para a cat?lise heterog?nea que se ajustou satisfatoriamente aos resultados experimentais com uma convers?o final de 85,01% com catalisador e de 42,38% sem o catalisador em 240 min de rea??o. Permitindo avaliar que o catalisador estudado possui potencial catal?tico para ser utilizado na produ??o de biodiesel
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Avalia??o da estabilidade oxidativa e determina??o da cin?tica de oxida??o de ?leos vegetais, ?cido oleico e biodiesel utilizando o m?todo PetroOXY (ASTM D7545)Machado, Yguatyara de Luna 02 July 2014 (has links)
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Previous issue date: 2014-07-02 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A Ag?ncia Nacional de Petr?leo, G?s Natural e Biocombust?veis tem como principal miss?o regulamentar e especificar toda a produ??o e comercializa??o do biodiesel produzido em territ?rio nacional. Para a sua comercializa??o ? necess?rio que o biodiesel passe por um controle r?gido de qualidade, bem como esteja devidamente especificado pelas principais normas. A estabilidade oxidativa que ? um dos par?metros incluso pela norma europ?ia EN 14214 vem adquirindo cada vez mais espa?o em pesquisas por estar intrinsecamente relacionada ? qualidade do biodiesel. Biodiesel ? uma mistura de ?steres alqu?licos de ?cidos graxos obtido, convencionalmente, atrav?s da rea??o de transesterifica??o de um ?leo vegetal ou gordura animal. No entanto, a natureza da mat?ria-prima a qual lhe dar? origem ? um dos fatores determinantes em seu grau de estabilidade, visto que por apresentarem insatura??es em n?mero e em distintas posi??es os tornam suscept?veis ao ataque do oxig?nio atmosf?rico e a condi??es de elevadas temperaturas proporcionando, assim, a sua degrada??o. Uma das principais problem?ticas enfrentadas, atualmente, pela ind?stria de biodiesel prov?m da sua baixa estabilidade levando a uma diminui??o de sua qualidade por longos per?odos de armazenamento sendo necess?ria a aplica??o de antioxidantes. Nesta tese, um estudo cin?tico experimental baseado no consumo de diferentes antioxidantes sint?ticos adicionados em distintas concentra??es foi realizado com amostras de ?leos vegetais de moringa (Moringa oleifera) e de maracuj? (Passiflora edulis), ?cido ol?ico estocado (AO) durante seis e dezoito meses e biodiesel de soja (Glycine max L.) e girassol (Helianthus annuus) em diferentes temperaturas, a uma press?o de oxig?nio puro a 700 kPa, utilizando a metodologia ASTM D7545 (PetroOXY). O modelo de primeira ordem obtido para o ?leo de moringa, amostras de ?cido ol?ico estocado (AO) e biodiesel de soja permitiu obter informa??es a respeito de par?metros, tais como: concentra??o cr?tica e concentra??o de antioxidante natural inerente ? amostra avaliada , informando que o ?ltimo n?o exerceu influ?ncia, a n?o ser inicialmente, no processo oxidativo das mesmas. Enquanto, o par?metro determinado para o modelo de ordem zero para as amostras de ?leo de maracuj? e girassol relacionou-se a diferentes reatividades da mat?ria-prima. A estabilidade das amostras determinadas pela entalpia de ativa??o (?HA) deu-se na seguinte ordem: ?HA (?leo de moringa) > ?HA (?leo de maracuj?); ?HA (AO 6 meses) ?HA (AO 18 meses) e ?HA (biodiesel de soja) > ?HA (biodiesel de girassol). Fatores de estabiliza??o desempenharam diferentes pap?is na estabiliza??o dos sistemas estudados. Concentra??o de antioxidante e temperatura mostraram distintas influ?ncias, no processo oxidativo, para as amostras de ?leos vegetais e ?cido ol?ico estocadas (AO) acompanhadas pelos seus ?ndices de acidez. / Oxidative stability is a parameter included in the European standard EN 14214 and is closely associated with the quality of biodiesel. The biodiesel is usually obtained in a transterification reaction vegetable oil or animal fat. However, the composition of the raw resources biodiesel is obtained from influences the stability degree of the latter, particularly when biodiesel is stored for long periods of time, causing its degradation, thereby reducing biodiesel quality and making it inadequate for trade. In this thesis, an experimental kinetic study based on the consumption of several synthetic antioxidants added in various concentrations to vegetable oils of moringa (Moringa oleifera), passion fruit (Passiflora edulis) and oleic acid (AO) stored for six and eighteen months at the temperatures 110 ?C, 120 ?C, 130 ?C and 140 ?C, as well as biodiesel from soybean (Glycine max L.) and sunflower (Helianthus annuus) oils at the temperatures 130 ?C, 135 ?C, 140 ?C and 145 ?C at a 700 kPa pure oxygen pressure, using the ASTM D7545 Method (PetroOXY). It has been obtained a first order reaction kinetic model for oleic acid, soybean biodiesel and moringa oil samples, while for passion fruit oil and sunflower biodiesel samples a zero order reaction kinetic model has been obtained. Parameter
0,CICCCC???
determined for the zero order model was related to distinct composition variations of the raw resources. The stability order of samples established using activation enthalpy (?HA) was the following: ?HA (moringa oil) > ?HA (Passion fruit oil); ?HA (oleic acid stored for six months) ? ?HA (oleic acid stored for eighteen months) and ?HA (soybean biodiesel) > ?HA (sunflower biodiesel). In all evaluated temperatures except for 140?C, acid numbers for passion fruit oil with antioxidants added have increased after storage, while for the moringa oil a random behavior has been observed.
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Efeito da terapia com células-tronco musculares e células-tronco mesenquimais na regeneração do músculo esquelético: modulação por ácido oléico. / Effect of muscle stem cells and mesenchymal stem cells transplantation on skeletal muscle regeneration: modulatory effect of oleic acid.Carlos Hermano da Justa Pinheiro 26 June 2012 (has links)
O objetivo do presente trabalho foi investigar alterações na composição de ácidos graxos durante a diferenciação de células-tronco musculares (CTmusc) e seu possível envolvimento na miogênese. Aumento no conteúdo de ácido oléico foi observado. Quando as CTmusc foram tratadas com esse ácido graxo, a miogênese foi acelerada através da estimulação da via de sinalização da beta-catenina. Ainda nas CTmusc, o ácido oléico inibiu a sinalização do Notch e a capacidade proliferativa. Nenhum efeito do tratamento com ácido oléico foi observado na capacidade proliferativa de células-tronco mesenquimais. O transplante de CTmusc e células-tronco mesenquimais aceleram a regeneração e recuperação da função no músculo esquelético lacerado. O pré-tratamento com ácido oléico reduziu a ativação, proliferação e enxerto de CTmusc no músculo esquelético lesionado do hospedeiro e não teve efeito sobre o enxerto de células-tronco mesenquimais. Dessa maneira, o ácido oléico tem efeito modulador no efeito da terapia celular no músculo esquelético lesionado. / The purpose of the present study was to investigate alterations on fatty acid (FA) composition and a possible involvement of FA on muscle stem cell function. Na increase in content of oleic acid was observed when muscle stem cell (muscSC) differentiated to myotube. The treatment with oleic acid accelerated myogenesis through stimulation of beta-catenin signaling pathway. Notch signaling pathway was inhibited by oleic acid reducing the proliferative capacity of muscSC. No effects were observed in mesenchymal stem cells. Transplantation of both muscSC and mesenchymal stem cells accelerates muscle regeneration and recovery of function. The pre-treatment with oleic acid decreased activation, proliferation, differentiation and engrafment of muscSC in host injured muscle. Thus, oleic acid has modulatory effect on cellular therapy in injured skeletal muscle.
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