974 resultados para 2-Bromo-1,4-naphthoquinone


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AIMS: Solute carrier 2a2 (Slc2a2) gene codifies the glucose transporter GLUT2, a key protein for glucose flux in hepatocytes and renal epithelial cells of proximal tubule. In diabetes mellitus, hepatic and tubular glucose output has been related to Slc2a2/GLUT2 overexpression; and controlling the expression of this gene may be an important adjuvant way to improve glycemic homeostasis. Thus, the present study investigated transcriptional mechanisms involved in the diabetes-induced overexpression of the Slc2a2 gene. MAIN METHODS: Hepatocyte nuclear factors 1α and 4α (HNF-1α and HNF-4α), forkhead box A2 (FOXA2), sterol regulatory element binding protein-1c (SREBP-1c) and the CCAAT-enhancer-binding protein (C/EBPβ) mRNA expression (RT-PCR) and binding activity into the Slc2a2 promoter (electrophoretic mobility assay) were analyzed in the liver and kidney of diabetic and 6-day insulin-treated diabetic rats. KEY FINDINGS: Slc2a2/GLUT2 expression increased by more than 50% (P<0.001) in the liver and kidney of diabetic rats, and 6-day insulin treatment restores these values to those observed in non-diabetic animals. Similarly, the mRNA expression and the binding activity of HNF-1α, HNF-4α and FOXA2 increased by 50 to 100% (P<0.05 to P<0.001), also returning to values of non-diabetic rats after insulin treatment. Neither the Srebf1 and Cebpb mRNA expression, nor the SREBP-1c and C/EBP-β binding activity was altered in diabetic rats. SIGNIFICANCE: HNF-1α, HNF-4α and FOXA2 transcriptional factors are involved in diabetes-induced overexpression of Slc2a2 gene in the liver and kidney. These data point out that these transcriptional factors are important targets to control GLUT2 expression in these tissues, which can contribute to glycemic homeostasis in diabetes.

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Die vorliegende Arbeit befasst sich mit der Bedeutung des § 2 Abs. 1 BetrVG für die Reichweite und die Grenzen der Mitbestimmung des Betriebsrates nach § 87 BetrVG.. Ebenso wie im BetrVG 1952 bildet auch im BetrVG 1972 und im BetrVG 2001 der vierte Teil mit den Regelungen über die Mitwirkung und Mitbestimmung der Arbeitnehmer das eigentliche Kernstück des Gesetzes. Zentralvorschrift für die Mitbestimmung des Betriebsrats in sozialen Angelegenheiten ist dabei § 87 BetrVG. Diese Regelung umfasst alle Arbeitsbedingungen, die nicht schon gesetzlich oder tariflich geregelt sind, anderseits aber oft nur einheitlich für alle Arbeitnehmer im Betrieb geregelt werden können. Soweit die Tatbestandsvoraussetzungen der einzelnen Gegenstände in § 87 Abs. 1 Nr. 1 bis Nr. 13 BetrVG erfüllt sind, hat der Betriebsrat eine umfassende funktionelle Zuständigkeit zur Mitbestimmung in sämtlichen sozialen Angelegenheiten. Aufgabe der vorliegenden Arbeit soll es daher sein, Rechtsnatur, Struktur und Anwendungsbereich des Gebots der vertrauensvollen Zusammenarbeit und der Mitbestimmungsrechte gem. § 87 BetrVG zu klären. Hier ist insbesondere zu erörtern, ob Mitbestimmungsrechte des Betriebsrats gem. § 87 Abs. 1 BetrVG außerhalb des Katalogs der gesetzlichen Vorschriften aus dem Grundsatz der vertrauensvollen Zusammenarbeit herzuleiten sind. Ein weiterer Schwerpunkt liegt in der Herausarbeitung der Korrektur- und Schrankenfunktion des § 2 Abs. 1 BetrVG im Bereich der Mitbestimmung nach § 87 Abs. 1 BetrVG.

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2-Phenoxyethanol (ethylene glycol monophenyl ether) is used as solvent for cellulose acetate, dyes, inks, and resins; it is a synthetic intermediate in the production of plasticizers, pharmaceuticals, and fragrances. Phenoxyethanol is obtained industrially by reaction of phenol with ethylene oxide, in the presence of an homogeneous alkaline catalyst, typically sodium hydroxide. The yield is not higher than 95-96%, because of the formation of polyethoxylated compounds. However, the product obtained may not be acceptable for use in cosmetic preparations and fragrance formulations, due to presence of a pungent “metallic” odor which masks the pleasant odor of the ether, deriving from residual traces of the metallic catalyst. Here we report a study aimed at using ethylene carbonate in place of ethylene oxide as the reactant for phenoxyethanol synthesis; the use of carbonates as green nucleophilic reactants is an important issue in the context of a modern and sustainable chemical industry. Moreover, in the aim of developing a process which might adhere the principles of Green Chemistry, we avoided the use of solvents, and used heterogeneous basic catalysts. We carried out the reaction by using various molar ratios between phenol and ethylene carbonate, at temperatures ranging between 180 and 240°C, with a Na-mordenite catalyst. Under specific conditions, it was possible to obtain total phenol conversion with >99% yield to phenoxyethanol in few hours reaction time, using a moderate excess of ethylene carbonate. Similar results, but with longer reaction times, were obtained using a stoichiometric feed ratio of reactants. One important issue of the research was finding conditions under which the leaching of Na was avoided, and the catalyst could be separated and reused for several reaction batches.

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Nell’ottica di uno sviluppo ecosostenibile, la progettazione e la realizzazione di imballaggi alimentari devono necessariamente tener conto del destino del materiale al termine della sua vita utile. Negli ultimi anni, infatti, il considerevole incremento dei volumi dei rifiuti plastici e le difficoltà legate al loro smaltimento e riciclo hanno rappresentato le forze motrici per l’individuazione di soluzioni concrete ai problemi connessi alla gestione di tali scarti. Lo sviluppo di nuovi polimeri che soddisfino requisiti di degradabilità, compatibilità con l’ambiente di smaltimento e rilascio di prodotti di degradazione con un basso livello di tossicità, oltre che possedere proprietà fisico-meccaniche adatte per l’applicazione richiesta, offre una possibile soluzione a tali questioni ad oggi irrisolte. Tra i polimeri biodegradabili, il poli(butilene 1,4-cicloesandicarbossilato) (PBCE) è un materiale di grande interesse, in quanto la presenza dell’anello alifatico nell’unità monomerica conferisce al materiale un’elevata cristallinità, una notevole stabilità termica e interessanti proprietà meccaniche. Per contro, l’eccessiva rigidità e fragilità del materiale e la sua lenta cinetica di biodegradazione lo rendono poco versatile e ne limitano notevolmente la gamma di possibili applicazioni. Per tali ragioni, si è scelto di incentrare il presente lavoro sullo sviluppo di copolimeri a base di PBCE, dotati sia di migliori proprietà meccaniche che di una maggiore velocità di degradazione. Lo scopo previsto è stato raggiunto mediante sintesi di due sistemi di copolimeri a blocchi contenenti eteroatomi lungo la catena principale.