Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Selective Catalytic Conversion of Cellulose and Glucose Into Sorbitol in Subcritical Water(Izmir Institute of Technology, 2020) Sapmaz, Aycan; Yüksel, AslıThe goal of this study was to add high value to cellulose as the most abundant source of biomass and glucose by producing a building-block chemical-Sorbitol-, which is not produced in our country and has very large market share. In this manner, the effect of reaction time (1-2 h), catalyst amount (1-2 g) and catalyst type on conversion of cellulose and glucose and yield of sorbitol with presence of various catalysts in subcritical water environment were investigated. The hydrogenation of both glucose and cellulose over Ruthenium based catalysts (Ru/AC, Ru/SiO2, Ru-SBA15 and Ru-SBA15/SO3), using a high pressure-high temperature reactor (Parr 5500 High Pressure Compact Reactor) at a reaction pressure of 5 bar and reaction temperature of 150°C were studied. Ruthenium based catalysts were prepared by wet impregnation method. The synthesized Ru based catalysts with various metal based were characterized by various characterization tools such as Scanning Electron Microscope (SEM), Fouirer Transform Infrared Spektrofotometre (FT-IR) and Brunauer-Emmett-Teller (BET). The catalytic performances were evaluated in hydrogenation of cellulose and also glucose to produce sorbitol under subcritical water conditions. As a result of these analyzes, the highest sorbitol yield and cellulose conversion were found to be 234.98 ppm and 28.64%, respectively for 2 gram of Ru-SiO2 catalyst for 2 hours. For glucose conversion, the catalyst of Ru-SBA15/SO3 showed better catalytic performance than other catalysts.Master Thesis Investigation of the Molecular and Genetic Response in Enterocytes of Duodenum During Elevated Intracellular Glucose Level(Izmir Institute of Technology, 2016) Boztepe, Tuğçe; Güleç, Şükrü; Seyrantepe, VolkanGlucose is one of the nutritional factor that involves in developing of obesity and type 2 diabetes in human. The studies indicated that enterocyte cells on intestine might play a role in dietary glucose sensing during obesity. Obese people are consumed high amount of dietary glucose and enterocyte cells consequently are exposed to high glucose. Thus, we aimed to find relevant physiological pathways and genome-wide mRNA expression profiles that can be regulated by glucose in fully differentiated human intestinal epithelial (CaCo-2). The cells were maintained two different glucose levels (5.5mM for control, 25mM for high glucose) at least three passages. The cells were grown on transwell system for 21 days to mimic human intestine system. Transepithelial electrical resistances (TEER) were measured to control monolayer formation and polarization. RNA isolation was performed and whole genome mRNA expression profile were determined following gene ontology analysis to find affected molecular pathways. Compared to control relative glucose level was found high in basolateral side of CaCo-2 cells that were under high glucose condition without effecting TEER. GLUT2, SGLT1, GLUT5 mRNA levels were significantly reduced during elevated glucose levels which is consistent with literature. Significant fold change analysis showed that 351 genes upregulated and 468 genes under high glucose condition. We found high glucose significantly leads changes of molecular pathways (downregulated; glycolysis and gluconeogenesis, adherens junction, fructose/mannose metabolism, pentose phosphate pathway and upregulated; protein export). These results provide us better understanding and open new window for glucose metabolism of enterocytes during obesity.