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Öğe DETERMINATION OF DEFENSIN HNP-1 IN HUMAN SALIVA OF PATIENTS WITH ORAL MUCOSAL DISEASES(TAYLOR & FRANCIS INC, 2011) Kucukkolbasi, Hasan; Kucukkolbasi, Semahat; Dursun, Recep; Ayyildiz, Filiz; Kara, HuseyinSaliva is a biological fluid that is easily obtainable and that can give useful information both in systemic and oral diseases. In this study, a chromatographic method was applied to determine the amount of defensin HNP-1 in human saliva of patients with oral mucosal diseases before and after treatments and compared with controls. Defensin human neutrophil peptide-1 (HNP-1) was identified and confirmed. The concentration of HNP-1 in saliva was determined by comparing the area of eluted HNP-1 with that of HNP-1 standard. Linear calibration range of defensin HNP-1 was 0.10 to 0.90 mu g/10 mu L with R(2) values of 0.996. The concentrations of HNP-1 in the saliva of patients with oral lichen planus, Behcet's disease, and recurrent apthous stomatitis were 33.6 +/- 10.6, 15.5 +/- 7.6, and 36.3 +/- 9.5 mu gmL(-1) (mean +/- S.D.), respectively. The salivary defensin-1 concentration was significantly higher in patients with oral mucosal diseases than in healthy volunteers; furthermore, in patients with oral mucosal diseases, the concentration was significantly higher before treatment than after treatment.Öğe Interaction Between Ketoconazole and Human Serum Albumin on Epoxy Modified Magnetic Nanoparticles for Drug Delivery(AMER SCIENTIFIC PUBLISHERS, 2013) Maltas, Esra; Ozmen, Mustafa; Yildirimer, Burak; Kucukkolbasi, Semahat; Yildiz, SalihSuperparamagnetic iron oxide nanoparticles (SPIONs) were modified with [3-(2,3-epoxypropoxy)propyl] trimethoxy silane, which resulted in formation of epoxy groups on the particles surface. The epoxy functionalized SPIONs can bind to human serum albumin (HSA). The binding amount of HSA to epoxy modified SPIONs was found to be as 32.7 mu M for 1 mg epoxy modified SPIONs at 280 and 342 nm of excitation and emission wavelengths by using fluorescence spectroscopy. Interaction of ketoconazole with HSA immobilized epoxy functionalized SPIONs was studied at 300 and 390 nm of excitation and emission wavelengths, respectively. Binding mechanism of ketoconazole and HSA was identified by Stern-Volmer equation. Thermodynamic parameters (Delta H, Delta S and Delta G) were also estimated for the interaction. Therefore, the nature of the binding forces was found to be as hydrophobic interaction. Protein and drug attachments were also examined by Infrared spectroscopy (IR) and Scanning Electron Microscopy (SEM). This study show that prepared albumin-based magnetic nanoparticles carrier systems represents an attractive strategy for drug delivery.Öğe Investigating sorption characteristics of copper ions onto insolubilized humic acid by using a continuously monitored solid phase extraction technique(ELSEVIER SCIENCE BV, 2007) Gezici, Orhan; Kara, Huseyin; Yanik, Sema; Ayyildiz, H. Filiz; Kucukkolbasi, SemahatThe sorption characteristics of Cu(II) in an insolubilized humic acid (IHA) mediated column system were investigated at various experimental conditions using a solid phase extraction (SPE) technique. Sodium form of the IHA (INaA) was used as solid phase and sorption behaviors were evaluated by using common adsorption isotherms as well as Scatchard plot analysis. Regeneration, loading, washing and stripping steps of SPE were carried out consecutively, and their progresses were monitored through breakthrough curves obtained from a continuous flow-through cell adapted UV-vis spectrophotometer. So, the breakthrough curves were used to visualize distribution of Cu(II) concentration between mobile phase and solid phase, and amount of the Cu(II) sorbed by INaA was obtained from AAS analysis of effluents collected during the stripping steps of particular run. Thus, from the obtained results, the sorption characteristics and usability of IHA as a solid phase for SPE of metal ions was evaluated in detail. (c) 2007 Elsevier B.V. All rights reserved.Öğe Monitoring of Zn(II), Cd(II), Pb(II) and Cu(II) During Refining of Some Vegetable Oils Using Differential Pulse Anodic Stripping Voltammetry(SPRINGER, 2014) Kucukkolbasi, Semahat; Temur, Osman; Kara, Huseyin; Khaskheli, Abdul RaufIn this study, a novel approach has been developed using differential pulse anodic stripping voltammetry (DPASV) for the simultaneous determination of Zn(II), Cd(II), Pb(II) and Cu(II) in edible oils at hanging mercury drop electrode. The microwave digestion of oil samples was carried out with concentrated HNO3 and H2O2. KNO3 was used as a supporting electrolyte. The experimental conditions optimized such as deposition time, stirring rate and size of mercury drop were 300 s, 600 rpm and 10 mm(2), respectively. The method was applied to quantify Zn(II), Cd(II), Pb(II) and Cu(II) in crude and refined hazelnut, corn, sunflower and olive oils. During refining of different vegetable oils, the removal efficiencies of Zn(II), Cd(II), Pb(II) and Cu(II) were calculated as 98.20-99.91, 98.50-99.90, 95.26-99.76 and 95.93-99.92 %, respectively. The limits of detection for Zn(II), Cd(II), Pb(II) and Cu(II) were 2.1x10(-8), 8.7x10(-10), 7.1x10(-9) and 3.4x10(-9) and the limits of quantification were 6.8x10(-8), 2.9x10(-9), 2.3x10(-8) and 1.1x10(-8) M with linear regression coefficients (R-2) of 0.9930, 0.9928, 0.9893 and 0.9931, respectively. It was observed that the above metals in crude and refined vegetable oils could be determined simultaneously by the DPASV method.Öğe A new non-enzymatic sensor based on TiO2-Ag/polypyrrole for electrochemical detection of tyramine(ELSEVIER SCIENCE SA, 2018) Erdogan, Zehra O.; Akin, Ilker; Kucukkolbasi, SemahatThis study presents electrochemical determination of tyramine (TA) using a new electrochemical sensor (TiO2-Ag/PPy/GCE) based on TiO2-Ag/PPy nanocomposite modified glassy carbon electrode (GCE). In addition to SEM, AFM and XRD analysis, the presented sensor was studied with respect to its response to Fe(CN)(6)(4-/3-) and characterized by CV and EIS techniques. Under the optimum conditions, TiO2-Ag/PPy/GCE showed a good linear relationship over a concentration range from 4.10 x 10(-8) to 3.06 x 10(-6) M with a detection limit of 2 x 10(-6) M. The availability of the sensor was examined by analysis of TA in food samples.Öğe Removal and Preconcentration of Cobalt Ions from Aqueous Media Using ImHA Packed Column by On-Line SPE System(SPRINGER INTERNATIONAL PUBLISHING AG, 2012) Ayyildiz, H. Filiz; Topkafa, Mustafa; Arslan, FatmaNur; Durmaz, Fatih; Kucukkolbasi, Semahat; Tarhan, Ismail; Kara, HuseyinThis work assesses the use of immobilized humic acid (ImHA) onto aminopropyl silica (APS) as a sorbent for the removal and preconcentration of trace amounts of cobalt ions by on-line solid phase extraction (SPE) technique in the column system prepared in our laboratory. Different parameters, such as the effect of the pH, concentration, and flow rate, were studied and throughput was observed by a UV detector. All SPE steps were monitored by breakthrough curves used to visualize distribution of cobalt concentration between mobile and solid phase. The solutions collected from stripping steps were analyzed in atomic absorption spectrometer (AAS) and the amount of sorbed ions was calculated. Sorption characteristics were evaluated by using common adsorption isotherms and Scatchard plot analysis. From the obtained results, it was seen that sorption mechanism of cobalt ions were fitted to Langmuir model on a large scale and thought to be localized. Mean free energy (E = 40.82 kJ mol(-1)) calculated from D-R isotherm showed that chemical interactions are more effective than physical interactions. This investigation reveals a new, simple, environmentally friendly, and cost-effective method for removal and preconcentration of cobalt ions from aqueous solutions by a new aminopropyl silica-immobilized humic acid material.Öğe Role of Different Bleaching Earths for Sunflower Oil in a Pilot Plant Bleaching System(DE GRUYTER OPEN LTD, 2013) Topkafa, Mustafa; Ayyildiz, H. Filiz; Arslan, Fatma Nur; Kucukkolbasi, Semahat; Durmaz, Fatih; Sen, Seyit; Kara, HuseyinThe purpose of present study is to investigate the efficiency of different kinds of Turkish commercial bleaching earth materials for changes in different colour pigment concentrations in neutralized sunflower oils. The bleaching experiments were performed in a pilot system under at stable vacuum (50 mmHg) and temperature (100 degrees C) for 30 min. By examining the changes in chlorophyll, beta-carotene and red colour, bleaching process parameters such as type and dosage of the bleaching material were optimised. The sorption characteristics of colour pigments were evaluated using common adsorption isotherms and Scatchard plot analysis. Ads-3 acid-activated earth material at 1% (w/w) per samples was found to be the most appropriate sorbent and the amount of sorbed pigments was calculated as 1.01x10(-4)mmol/g ads. for chlorophyll, 1.15x10(-3)mmol/g ads. for carotene and 1.70 red on Lovibond colour scale. The procedure indicated that this system can be easily adapted to the actual oil refining systems.Öğe SIMULTANEOUS AND ACCURATE DETERMINATION OF WATER- AND FAT-SOLUBLE VITAMINS IN MULTIVITAMIN TABLETS BY USING AN RP-HPLC METHOD(SOC BRASILEIRA QUIMICA, 2013) Kucukkolbasi, Semahat; Bilber, Onur; Ayyildiz, H. Filiz; Kara, HuseyinIn the present study, a reversed-phase high-performance liquid chromatographic (RP-HPLC) procedure was developed and validated for the simultaneous determination of seven water-soluble vitamins (thiamine, riboflavin, niacin, cyanocobalamin, ascorbic acid, folic acid, and p-aminobenzoic acid) and four fat-soluble vitamins (retinol acetate, cholecalciferol, alpha-tocopherol, and phytonadione) in multivitamin tablets. The linearity of the method was excellent (R-2 > 0.999) over the concentration range of 10-500 ng mL(-1). The statistical evaluation of the method was carried out by performing the intra-and inter-day precision. The accuracy of the method was tested by measuring the average recovery; values ranged between 87.4% and 98.5% and were acceptable quantitative results that corresponded with the label claims.Öğe Universal cell capture by immobilized antimicrobial peptide plantaricin(ELSEVIER SCIENCE BV, 2015) Guralp, Saadet Albayrak; Gubbuk, Ilkay Hilal; Kucukkolbasi, Semahat; Gulari, ErdoganPlantaricin-423 is a short antimicrobial peptide and displays bactericidal activities against several food-borne pathogens and spoilage Gram positive bacteria. The goal of this study was to investigate the potential of using immobilized plantaricin for capturing microorganisms on glass arrays. The peptide used for immobilization consists of N-terminal domain of Plantaricin-423 with an additional cysteine (Pln-17C) to form disulfide bonds with thiol groups present on silanized slides. Our results showed that Pln-17C is able to capture all six strains that were tested with varying affinities. The cell capture occurred within five minutes of incubation and the binding level was highest for Listeria innocua followed by other Gram positive strains tested. Pln-17C was also able to capture Escherichia coli with lower affinity, but the binding was significantly lower for Mycobacterium smegmatis compared to other strains. In addition, we have observed that immobilized Pln-17C maintained its anti-listerial activity; however, it did not kill E. coli as expected. Our results demonstrate the feasibility of utilizing antimicrobial peptides in biosensors for pathogen detection and for creating antimicrobial surfaces. Moreover, in combination with other peptides, different target species from food-borne pathogens to biodefense agents can be captured on more stable, economic, and robust platforms. (C) 2015 Elsevier B.V. All rights reserved.
