WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 1İnsan Kolon Kanseri Hücrelerine Karşı İnorganik Nanopartikül-temelli İlaç Taşıyıcı Sistemlerin Kullanılması: Partikül Büyüklüğünün Antikanser Aktivitesine Etkisi(Gazi Üniversitesi, 2020) Dağlıoğlu, Cenk; Dağlıoğlu, Cenk; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyToday's nanoparticle technology enables the synthesis of nanoparticle-based drug delivery systems with desired size, shape, and materials especially for the applications of cancer nanomedicine. Thereby, understanding impact of particle sizes on anticancer activity will contribute to development of new drug delivery systems in cancer therapy. For this reason, in this study, two different sized nanoparticles (with -55 and 314 nm) were used as drug delivery systems and the effects of their size on the cellular uptake, cytotoxicity and apoptosis were investigated against the human colon carcinoma Caco-2 and HCT-116 cells. The results demonstrated that small nanoparticles promoted fast nanoparticle accumulation in both cancer cells in comparison to large particles. Small nanoparticles exhibited higher cytotoxicity in cancer cells with lower half maximal inhibitory concentration (IC50) values than large nanoparticles in 48 h. On the other hand, both nanoparticles showed similar IC50 values after 72 h prolonged exposure. Moreover, it was found that small nanoparticles increased the number of apoptotic cells in 24 h, whereas large nanoparticles induced apoptosis when exposure time increased to 72 h. These observations show that small sized drug delivery systems could be more efficient for improving the anticancer effects of chemotherapeutic drugs against human colon carcinoma as compared to large sized drug delivery systems.Article Citation - WoS: 19Citation - Scopus: 20Controlling the Distribution of Oxygen Functionalities on Go and Utilization of Pedot:pss-Go Composite as Hole Injection Layer of a Solution Processed Blue Oled(Elsevier Ltd., 2017) Diker, Halide; Diker, Halide; Varlıklı, Canan; Yeşil, Fatih; Varlıklı, Canan; 01. Izmir Institute of Technology; 04.04. Department of Photonics; 04. Faculty of ScienceGraphene oxide (GO) was synthesis by Tour method. Particle size distribution effects of raw graphite on the resulting structural, morphological, optical and electrical properties of GO samples and their poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) composites are studied for the graphite particle distributions of <150, 45–75 and 25–45 μm. It is determined that particle size of raw graphite have an impact on oxidation degree, the chemical nature of oxygen functional groups on GO and it also affects the lateral size of obtained GO. PEDOT:PSS-GO composites are utilized as hole injection layer (HIL) in a solution process blue organic light emitting diode. Presence of GO caused negative differential resistance (NDR) and NDR intensity was decreased with the decrease in lateral size of GO, increase in the graphite particle size and carboxyl% of obtained GO. All PEDOT:PSS-GO composite based devices presented better performance than the bare PEDOT:PSS based reference device. The maximum luminous and external quantum efficiency values of the device that contain HIL of PEDOT:PSS-GO(150) were more than 40% and 50% higher than that of the reference, respectively. Two folds of increase in these performance values were able to be reached with the concentration optimization of GO/150 in PEDOT:PSS.Article Citation - WoS: 20Citation - Scopus: 23Estimation of Suspended Sediment Concentration in Rivers Using Acoustic Methods(Springer Verlag, 2009) Elçi, Şebnem; Aydın, Ramazan; Elçi, Şebnem; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyAcoustic Doppler current meters (ADV, ADCP, and ADP) are widely used in water systems to measure flow velocities and velocity profiles. Although these meters are designed for flow velocity measurements, they can also provide information defining the quantity of particulate matter in the water, after appropriate calibration. When an acoustic instrument is calibrated for a water system, no additional sensor is needed to measure suspended sediment concentration (SSC). This provides the simultaneous measurements of velocity and concentration required for most sediment transport studies. The performance of acoustic Doppler current meters for measuring SSC was investigated in different studies where signal-to-noise ratio (SNR) and suspended sediment concentration were related using different formulations. However, these studies were each limited to a single study site where neither the effect of particle size nor the effect of temperature was investigated. In this study, different parameters that affect the performance of an ADV for the prediction of SSC are investigated. In order to investigate the reliability of an ADV for SSC measurements in different environments, flow and SSC measurements were made in different streams located in the Aegean region of Turkey having different soil types. Soil samples were collected from all measuring stations and particle size analysis was conducted by mechanical means. Multivariate analysis was utilized to investigate the effect of soil type and water temperature on the measurements. Statistical analysis indicates that SNR readings ob tained from the ADV are affected by water temperature and particle size distribution of the soil, as expected, and a prediction model is presented relating SNR readings to SSC mea surements where both water temperature and sediment characteristics type are incorporated into the model. The coefficients of the suggested model were obtained using the multivariate anal ysis. Effect of high turbidity conditions on ADV performance was also investigated during and after rain events.Article Kinetics of Proton Transfer in the Zeolitic Tuff(Central European Science Journals, 2009) Çakıcıoğlu Özkan, Seher Fehime; Özkan, Seher Fehime; Özkan, Seher Fehime; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe kinetics of a proton transfer into dilute acid solutions containing natural zeolitic tuff was studied by following the pH evolution of the liquid phase. Four different solutions with tuff contents of 9, 3, 1 and 0.5 (% wt) and three different particle size fractions (≤ 2000 μm) were studied. The proton concentration of the solution was decreased by increasing the zeolite amount and decreasing the particle size fraction. The proton transfer reaction was analyzed with chemical reactions and diffusion model equations. Analysis shows that the adsorption and/or ion exchange are possible mechanisms and are expressed by a second order reaction model.Article Citation - WoS: 26Citation - Scopus: 28Thermal Stability of Ag-Exchanged Clinoptilolite Rich Mineral(Springer Verlag, 2008) Akdeniz, Yelda; Ülkü, Semra; Ülkü, Semra; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThermal stability of clinoptilolite rich mineral from Western Anatolia, Turkey and its Ag-exchange forms was investigated. Parent mineral of different sizes were heated up to 1000°C with heating rate of 2 and 10°C min -1 using differential thermal analyzer (DTA) and thermogravimetric analyzer (TG). Ag exchange was conducted both in conventional constant temperature waterbath and microwave at 40, 60 and 80°C. The exchanged minerals were then characteized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), DTA and TG. The particle size and heating rate do not have significant effect on the thermal behavior of the parent mineral and no structural changes were observed with Ag exchange, only decomposition temperature was lowered. It was finally concluded that, Ag-exchanged clinoptilolite rich minerals were less thermally stable compared to parent mineral that does not affect their use for possible applications.