WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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Access Right: Closed AccessAuthor: search.filters.author.Yılmaz, Selahattin

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  • Article
    Citation - WoS: 34
    Citation - Scopus: 39
    Aptamer-Based Electrochemical Biosensing Strategy Toward Human Non-Small Cell Lung Cancer Using Polyacrylonitrile/Polypyrrole Nanofibers
    (Springer, 2020) Kıvrak, Ezgi; İnce Yardımcı, Atike; İlhan, Recep; Ballar Kırmızıbayrak, Petek; Yılmaz, Selahattin; Kara, Pınar
    In the present study, a sensitive electrochemical aptamer-based biosensing strategy for human non-small cell lung cancer (NSCLC) detection was proposed using nanofiber-modified disposable pencil graphite electrodes (PGEs). The composite nanofiber was comprised of polyacrylonitrile (PAN) and polypyrrole (PPy) polymers, and fabrication of the nanofibers was accomplished using electrospinning process onto PGEs. Development of the nanofibers was confirmed using scanning electron microscopy (SEM). The high-affinity 5 '-aminohexyl-linked aptamer was immobilized onto a PAN/PPy composite nanofiber-modified sensor surface via covalent bonding strategy. After incubation with NSCLC living cells (A549 cell line) at 37.5 degrees C, the recognition between aptamer and target cells was monitored by electrochemical impedance spectroscopy (EIS). The selectivity of the aptasensor was evaluated using nonspecific human cervical cancer cells (HeLa) and a nonspecific aptamer sequence. The proposed electrochemical aptasensor showed high sensitivity toward A549 cells with a detection limit of 1.2 x 10(3)cells/mL. The results indicate that our label-free electrochemical aptasensor has great potential in the design of aptasensors for the diagnostics of other types of cancer cells with broad detection capability in clinical analysis.
  • Article
    Citation - WoS: 14
    Particle Deposition Simulation Using the Cfd Code Fluent
    (Maney Publishing, 2000) Yılmaz, Selahattin; Cliffe, K. R.
    Particles of Soda Lime Silica Glass were used to simulate fly ash in the modelling of particle deposition from a high-temperature flue gas on to a superheater tube. The computational fluid dynamic code FLUENT was used and experimental deposition data were obtained from a rig comprising a small scale furnace containing an air-cooled probe. The effects of particle size, gas velocity and temperature on deposition were investigated. The effects of inertia, eddy impaction, thermophoresis and gravity on the particle trajectories were considered. The number of particles captured by the probe and the furnace surfaces were predicted and agreement with experimental results was found to be a function of particle size with the best agreement achieved for 16- and 26-mu m particles. Deposition was controlled by the kinetic energy of the particles and the adhesive forces of the surface. It is postulated that, for small particles, there was insufficient energy to bond them to the surface whereas for larger particles their kinetic energy was too targe. Thermophoresis did not play a significant part in the deposition process because, although the temperature gradient was large, 400 degrees C mm(-1) in the thermal boundary layer, the small particles (6 and 8 mu m) were unable to reach the thermal boundary layer (9 mm) which was much smaller than the hydrodynamic boundary layer (49.5 mm).
  • Article
    Citation - WoS: 8
    Citation - Scopus: 8
    Synthesis of Butyl Glucoside Over Sulphated Zr-Sba and Tungstophosphoric Acid Incorporated Sba-15 Catalysts
    (Elsevier Ltd., 2021) Mutlu, Nahide Nuran; Yılmaz, Selahattin
    Glycosidation of glucose with n-butanol was studied over sulphated Zr incorporated SBA-15 and tungstophosphoric acid (TPA) incorporated SBA-15 catalysts. The catalysts were prepared with different Zr, TPA and SO4 amounts via hydrothermal synthesis. SBA-15 structure was preserved and Zr and TPA were successfully incorporated. Sulphation improved the acidity of Zr-SBA-15 and the ratio of Brønsted to Lewis acid sites (B/L) increased. Thus, much higher butyl glucoside yields (about 70 %) were obtained over SO4/Zr-SBA-15 catalysts. However, 15 % activity loss was observed after 2 re-use due to sulphate leaching. TPA-SBA-15 catalysts had the highest B/L and provided very high catalytic activity with butyl glucoside yields above 95 %. The initial rate of butyl glucoside formation over TPA-SBA-15 catalysts were close to that of H2SO4. These catalysts were found stable and reusable. Reaction temperature and catalysts amount was studied as the reaction parameters over the most active and selective catalyst. © 2020 Elsevier B.V.