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Öğe Investigation of the biocompatibility and in vivo wound healing effect of Cotinus coggygria extracts(Ankara Univ, 2024) Bozkaya, Esra; Türk, Mustafa; Ekici, Hüsamettin; Karahan, SiyamiCotinus coggygria is widely recognized its antiseptic, anti-inflammatory, antimicrobial, antihemorrhagic, and wound-healing properties. In this, aimed to evaluate the phenolic contents, cytotoxicity/proliferation, hemolytic, antimicrobial, genotoxic, apoptotic, necrotic activities, and in vivo wound healing effects of C. coggygria, , a plant species known to have beneficial effects on wound healing. TOF-LC/MS analyzes revealed that the methanol extract of C. coggygria leaves contained flavonoids and phenolic compounds such as gallic acid (18.5 mg/kg), catechin (4.6 mg/kg), protocatesic acid (0.6 mg/kg), vanillic acid (8.4 mg/kg), ellagic acid (0.1 mg/kg), rosmarinic acid (0.1 mg/kg), quercetin (15 ppb) and C. coggygria stems contained such as gallic acid (24.6 mg/kg), catechin (155.1 mg/kg), chlorogenic acid (1.9 mg/kg), 4hydroxybenzoic acid (383.3 mg/kg), rutin (2.5 mg/kg), ellagic acid (15.1 mg/kg), apigenin 7-glycoside (10.5 mg/kg), rosmarinic acid (0,4 mg/kg), quercetin (15.2 mg/kg), naringenin (279.1 mg/kg). Consequently, C. coggyria has a positive effect on wound healing with antibacterial properties, particularly against E. coli, and without cytotoxic, genotoxic, or hemolytic effects at test concentrations. In the in vivo burn model, wounds treated with leaf and stem extracts healed faster than the control group. Thus, C. coggygria is an effective plant for wound healing with antibacterial properties, particularly against E. coli, and without cytotoxic, genotoxic, and hemolytic effects.Öğe Evaluation of melamine and cyanuric acid cytotoxicity: an in vitro study on L929 fibroblasts and CHO cell line(ANKARA UNIV PRESS, 2020) Melekoglu, Abdullah; Ekici, Husamettin; Arat, Esra; Karahan, SiyamiMelamine and its metabolites pose health concern as they are used in various industrial products including feed and drugs. There are a limited number of studies on melamine and cyanuric acid cytotoxicity and cellular damage without a certain conclusion. The present study aimed to evaluate melamine, cyanuric acid and its combined cytotoxic effects using 3-(4.5-dimethylthiazol-2-yl) methyl thiazole tetrazolium (MTT) bromide test. The study also evaluated apoptotic and necrotic effect using a double staining method of Hoechst 33342 and propidium iodide. Melamine, cyanuric acid and their combination (1:1) were applied to L929 fibroblasts and Chinese hamster ovary (CHO) cells at various concentrations (1000 mu g/mL, 500 mu g/mL, 250 mu g/mL, 125 mu g/mL and 62.5 mu g/mL). At the highest concentration (1000 mu g/mL), the cell viability dropped down approximately to 50% both in CHO cells and L929 cells. Melamine, cyanuric acid and their mixture caused cytotoxicity in CHO cells and L929 fibroblasts in dose-dependent manner Cell death occurred through both apoptosis and mainly necrosis. Both cell types were more sensitive to the mixture of melamine and cyanuric acid and, furthermore, CHO cells were more sensitive than L929 fibroblasts. As a result, melamine, cyanuric acid and their combination caused cytotoxicity in CHO cells and L929 fibroblasts. Further studies should be conducted in different cell lines. These studies should also aim to reveal the mechanism of cytotoxicity and related pathways.Öğe Production of 2-hydroxyethyl methacrylate-g-poly(ethylene terephthalate) nanofibers by electrospinning and evaluation of the properties of the obtained nanofibers(WILEY, 2020) Gok, Zehra Gun; Inal, Murat; Bozkaya, Ogun; Yigitoglu, Mustafa; Vargel, IbrahimNanofiber production was investigated from poly(ethylene terephthalate) (PET) polymers functionalized with hydroxyethyl methacrylate (HEMA) by grafting of HEMA monomers onto the PET fibers. HEMA grafted PET (PET-g-HEMA) copolymers were analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy. PET and PET-g-HEMA were dissolved in trifluoroacetic acid and nanofibers were obtained by electrospinning. It was found that the PET and PET-g-HEMA polymers having grafting yield 20 and 55% could be converted to continuous, smooth, and beadles nanofibers. For characterization of the nanofiber membranes, thermogravimetric analysis, differential scanning calorimeter analysis, surface contact angle measurement, porosity analysis, and mechanical tests were applied. When compared with the original PET nanofibers, the thermal properties and degradation process of PET-g-HEMA nanofibers changed according to the amount of HEMA present in the structure of nanofibers. The contact angles of the nanofibers obtained from PET-g-HEMA polymers decreased whereas the water retention ability of the nanofibers increased compared to original PET nanofibers. The porosity of PET-g-HEMA nanofibers was found be high compared to PET nanofibers and whereas the mechanical properties of PET was higher than PET-g-HEMA nanofibers. The obtained nanofibers can be used in many fields such as biomaterial applications.Öğe Preparation of a novel functionalized magnetic nanobiocomposite as a carrier for protein adsorption(TAYLOR & FRANCIS INC, 2020) Metin, Aysegul Ulku; Dogan, Mustafa; Erdem, Umit; Babacan, Taner; Gungunes, HakanThis study aims the synthesis of a novel functionalized magnetic nanocarrier based on xanthan gum biopolymer. Glycidyl methacrylate was grafted on xanthan gum chains by radical polymerization reaction using two types of initiators: ammonium persulfate and benzoyl peroxide. Characterization studies of the magnetic nanocarrier were performed using several instruments such as Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Energy-Dispersive-X-Ray Spectroscopy, X-Ray Diffraction Spectroscopy, Transmission Electron Microscopy, Mossbauer Spectroscopy, and Vibrating Sample Magnetometer. According to the Vibrating Sample Magnetometer data and Mossbauer analysis, Fe atoms were incorporated successfully in the polymer chains in Fe3+ state and magnetic nanocarrier has super-paramagnetic behavior, respectively. Epoxy groups on magnetic nanoparticles were converted to carboxylic acid groups using iminodiacetic acid and then tested to usability as a carrier for immobilization of proteins such as albumin, lipase and cytochrome c. The adsorption of albumin and lipase on magnetic nanoparticles were pH-dependent while cytochrome c was immobilized in a wide range of pH value. The calculated maximum experimental immobilization capacity of magnetic nanoparticles was 65.10 mg g(-1), 62.0 mg g(-1) and 188.0 mg g(-1) for albumin, lipase and cytochrome c, respectively. Experimental data fitted to Langmuir isotherm better than Freundlich. The rate of cytochrome c adsorption followed the pseudo-second-order kinetic. Results showed that the functionalized magnetic nanoparticles can be effectively used as a carrier for protein separations, especially for cytochrome c. Moreover, the functionalized magnetic nanocarrier had high affinity to Cytochrome c protein even in multiple protein systems.Öğe Investigation on phenol degradation capability of Scenedesmus regularis: influence of process parameters(TAYLOR & FRANCIS LTD, 2020) Basaran Kankilic, Gokben; Metin, Aysegul Ulku; Aluc, YasarPhenol removal from environmental solutions has attracted much attention due to phenol's high toxicity, even at low concentrations. This study aims to reveal the phenol biodegradation capacity of Scenedesmus regularis. Batch system parameters (pH, amount of algal cell, phenol concentration) on biodegradation were examined. After 24 h of treatment, 92.16, 94.50, 96.20, 80.53, 65.32, 52 and 40% of phenol were removed by Scenedesmus regularis in aqueous solutions containing 5, 10, 15, 20, 30, 40 and 50 mg/L of phenol, respectively. To describe the correlation between degradation rate and phenol concentration, the Michaelis-Menten kinetic equation was used where V-max and K-m are 0.82 mg phenol g algea(-1) h(-1) and 24.97 ppm, respectively. Phenol remediation ability of S.regularis can enable the usage of the spent biomass as biofuel feedstock and animal feed makes it a 'green' environmental sustainable process.Öğe Effect of vanadium addition on fundamental electrical quantities of Bi-2223 crystal structure and semi-empirical model on structural disorders-defects(SPRINGER, 2020) Ulgen, A. T.; Erdem, U.; Zalaoglu, Y.; Turgay, T.; Yildirim, G.The primary contribution of the present study is to determine the effect of vanadium addition on the fundamental aspects of characteristic crystalline and electrical quantities for the Bi1.8Sr2.0Ca2.2Cu3.0VxOy (0.00 <= x <= 0.30) crystal system using the powder X-ray diffraction (XRD), temperature-dependent electrical resistivities and semi-empirical approaches founded on the structural disorders-defects. The de electrical resistivity results show that every electrical quantity is found to degrade regularly with the increment in the addition level as a consequence of the induced permanent structural disorders-defects, intergranular grain boundary coupling interaction problems and non-superconducting barrier regions in the bulk Bi-2223 superconducting system. The vanadium addition brings also about the characteristic transition from over-doped state to under-doped state due to the suppression in the overlapping of Cu-3d and O-2p wave functions. The XRD results indicate that the vanadium addition leads to shift the characteristic peaks towards the larger/lower angles in terms of the peak positions in the reference data, enlarge the diffraction peak widths (line broadening of X-ray diffraction), appear or disappear new peaks, increase/decrease the average grain size, lattice cell parameters and superconducting phase fractions founded on the diffraction intensities. Based on the evidences, the presence of vanadium particles in the bulk Bi-2223 superconducting phase damages crucially the fundamental characteristic features. Moreover, it is found that characteristic two-stage (bulk genuine, T-c(mid) and coherence, T-co) transition temperatures decrease systematically with the addition level. On this basis, the presence of vanadium impurity in the system leads to degrade the stabilization of superconductivity in the small homogeneous clusters in the paths and especially effective electron-phonon coupling (bipolaron in the polarizable lattices) probabilities due to the reduction of hole trap energy per Cu ions in the valence band of system. Additionally, the results display that the vanadium particles affect negatively on both the dirty limit characteristic feature and gap coefficient of Bi-2223 ceramic compound as a result of the decrement in the minimum required energy for breaking up the cooper-pairs in the system. At the same time, the electrical resistivity curves enable us to develop a sensitive semi-empirical approach to find the possible highest onset critical transition temperature for the ideal crystallinity. The model founded on the crystallinity quality displays that the possible highest onset transition temperature is about 116.037 K +/- 1.25587 K with R-adj(2) = 0.948.Öğe Determining the lowest sulfur detection limit in diesel fuel by ultraviolet fluorescence(TAYLOR & FRANCIS LTD, 2020) Dogan, MustafaThis technical review article focuses on determining a robust and precise lower-level sulfur detection procedure. When measuring under 0.1 ppm and approaching zero values, the limits of the instrument are pushed to separate real signal response from noise. One of the performance parameters in method validation studies is to determine these near-zero value samples reliably when the instrument works near the noise signal level. The study examined the early stages of the method development process, regarding the determination of the validation parameters limit of blank, limit of detection (LOD), and limit of quantification (LOQ). The sulfur content in diesel fuel was determined with guidance from the standard ISO 20846:2011. The average sulfur readings of a diesel test sample and blank (99% iso-octane) were measured as 3.9 and 0.0196 ppm, respectively. For a 1.5% diluted diesel test sample the mean sulfur value was measured as 0.0613 ppm and this value was verified as the LOD. For a 3% diluted diesel test sample the mean sulfur value was measured as 0.1158 ppm and this result was verified as the LOQ. The LOD and LOQ were tested for conformity. The accuracy of these tested values was checked according to EUROCHEM guidelines.Öğe A novel research on the subject of the load-independent microhardness performances of Sr/Ti partial displacement in Bi-2212 ceramics(SPRINGER, 2020) Zalaoglu, Y.; Turgay, T.; Ulgen, A. T.; Erdem, U.; Turkoz, M. B.; Yildirim, G.This work is interested in the critical changes in the load-independent microhardness performance parameters with the partial substitution of Sr2+ inclusions for the Ti4+ impurities in the Bi-2212 inorganic solids with the help of the theoretical approximations as regards Meyer's law (ML), proportional sample resistance (PSR), modified proportional sample resistance (MPSR), elastic/plastic deformation (EPD), Hays-Kendall (HK) and indentation-induced cracking (IIC) models found on the experimental microhardness tests applied to a variety of test loads between 0.245 and 2.940 N for the first time. Moreover, Ti-substituted Bi-2212 bulk ceramics (Bi2.1Sr2.0-xTixCa1.1Cu2.0Oy) are prepared within mole-to-mole ratios of x = 0.000, 0.010, 0.030, 0.050, 0.070, 0.100 by the standard solid-state reaction method in the atmospheric pressure conditions. It is provided that Ti partial substitution in the superconducting system descends unsmilingly the mechanical durability, stability, strength, toughness, critical stress, stiffness and flexural strengths of Bi-2212 superconducting solids studied owing to the increment of crystal structural problems. Moreover, it is obtained that the degradation in the crystal structural leads to diminish the typical ISE characteristic of Bi-2212 superconducting ceramic compounds. At the same time, the results show that all the models (especially IIC approach) can serve as the suitable descriptors for the determination of the variation in the load-independent mechanical performances of the Bi-2212 superconducting materials.Öğe Thermal, morphological, and spectral changes after Er, Cr:YSGG laser irradiation at low fluences on primary teeth for caries prevention(WILEY, 2021) Erkmen Almaz, Merve; Ulusoy, Nur Burcu; Akbay Oba, Aylin; Erdem, Umit; Dogan, MustafaThe aim of this study was to determine the temperature increase in the pulp chamber and possible thermal effects on molecular structure of primary teeth during the irradiation with Er,Cr:YSGG laser. Primary central incisors were divided into three groups (n = 20). Labial surfaces in each group were irradiated by Er,Cr:YSGG laser within different power and frequencies as following groups: I: 0.25 W, 20 Hz, II: 0.50 W, 20 Hz, III: 0.75 W, 20 Hz. A thermocouple was placed inside the pulp chamber so that the temperature increments were recorded during the enamel irradiation. Morphological changes of enamel surfaces were experimentally evaluated by SEM. Fourier-transform infrared spectroscopy and RAMAN analyses were carried out to determine the differentiations in the molecular structure. The experimental results obtained were analyzed statistically by means of one-way analysis of variance. Statistically significant differences were detected between groups (p < .05). Group III exhibited the highest values for the temperature parameters. Besides, the conical craters, cracks, and formation of ablation areas were observed for all the groups. Also, it was obtained that the hydroxyapatite lost the hydroxyl ions due to the thermal effect of the laser. Temperature rise throughout the Er,Cr:YSGG laser irradiation for prevention of primary enamel demineralization presented a positive correlation with the laser output power level. The formations of adverse morphological and spectral changes were detected on the surface of teeth after the laser application. On this basis, the Er,Cr:YSGG laser applications should be treated with much more caution considering enamel surface and pulpal tissues in primary teeth.Öğe In situ synthesis of silver nanoparticles on modified poly(ethylene terephthalate) fibers by grafting for obtaining versatile antimicrobial materials(SPRINGER, 2020) Gun Gok, Zehra; Demiral, Ayse; Bozkaya, Ogun; Yigitoglu, MustafaBecause of having high mechanical properties and cheapness of PET textiles, functionalization of them for new properties is an active research area. In the present work, methacrylic acid (MAA)-grafted PET fibers (PET-g-MAA) were obtained by grafting of MAA monomers to PET surface for an antimicrobial material synthesis. The morphologies of the obtained graft copolymers were examined with a scanning electron microscopy (SEM), and the chemical modification after grafting was determined with Fourier-transform infrared spectroscopy (FTIR) analysis. Subsequently, silver ions were adsorbed onto the PET-g-MAA fibers surface and the adsorbed ions to the surface were reduced to silver nanoparticles (AgNPs) by UVC light. The morphology of fiber surfaces modified with MAA and coated with AgNPs was examined by SEM studies, and it was observed that AgNPs were disturbed along the fibers. The presence of silver on the surface was also confirmed by energy-dispersive X-ray spectroscopy (EDS) and energy dispersion X-ray fluorescence spectrometry (EDXRF). The crystalline structure of the original PET fiber, PET-g-MAA fiber and PET-g-MAA fiber modified with AgNPs was investigated by X-ray diffraction (XRD). The thermal properties of the obtained fibers were investigated by thermogravimetric analysis (TGA). The immobilization of AgNPs on the grafted fibers leads to a change on the patterns of TGA curves. The most significant change is the less weight reduction in the temperature range of 200-300 degrees C. Disk diffusion test was performed using Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25,922) bacteria in order to investigate the antibacterial ability of the obtained fibers, and it was found that the fibers coated with AgNPs had antibacterial effect on both bacterial species. The cytotoxicity of the groups with the best antibacterial properties was determined by MTT test, and the synthesized material did not have cytotoxic effects on L929 fibroblast cells. The material obtained has the potential to be used in antimicrobial applications.Öğe Determining the effects of black cumin seed oil on performance and meat fatty acid profile of broiler chickens(South African Journal Of Animal Sciences, 2019) Demirci, M.; Karsli, M. A.; Aluc, Y.This study was designed to investigate the effects of adding black cumin (Nigella sativa L.) seed (BCS) oil to diets for broiler chickens on their performance and the meat fatty acid profile of the meat. Broiler chicks were assigned to three groups. The unsupplemented control did not receive BCS oil. The two treated groups received 0.5% and 1% BCS oil. The live weight and live weight gain of the experimental groups were generally greater for the treated groups than for the control group. Feed consumption did not differ among groups, and thus the group that was fed the diet supplemented with 1% BCS oil was most efficient. Total saturated fatty acids were lower, and polyunsaturated fatty acids were greater in the treated groups, but monounsaturated fatty acids were greater in meat from the control group. As a result, it can be concluded that the addition of 0.5-1% BCS oil into the diets of broiler may improve the performance of chicks and enrich the meat quality by creating meaningful changes in meat fatty acid profiles, especially in terms of total polyunsaturated fatty acids.Öğe Silver release of Ag (I) doped hydroxyapatite: In vitro study(Wiley, 2019) Erdem, Umit; Turkoz, Mustafa B.A material is produced by doping of silver (Ag (I)) which has antibacterial property to nano hydroxyapatite (nHAp), to remove the hipersensitivity in the teeth by closing the dentine tubules or dental micro cracks of the teeth and effective against for some bacteria. The doping of Ag (I) can also produces a toxic effect. Ag (I) can be released from the structure as a result of biological, physical and chemical effects and may cause toxicity. Therefore, it is important to determine whether the presence of Ag (I) has a toxic effect. In this study, Ag (I)-doped nHAp was synthesized by precipitation method and tried to determine the release values as a function of time compared to the doping rate by using the ICP-OES. Also, the products we produce in simulated body fluid were kept for retention periods of 4-20 weeks to determine degradation percentages. A cytotoxicity study was performed to observe the toxic effect that may be caused by possible Ag (I) release. According to the analysis, the release values in all products were observed in ppb level. And it is concluded that the materials produced are not degraded. Cell viability values of more than 70% were obtained. It was observed that the release of Ag (I) bound to Ag (I)-doped nHAp hexagonal structure was very low. It was concluded that the products are not degraded and Ag (I)-doped nHAp to a certain ratio is a biocompatible material that can be used in dentistry for treatment.Öğe Elimination of carcinogenic bromate ions from aqueous environment with 4-vinyl pyridine-g-poly(ethylene terephthalate) fibers(Springer Heidelberg, 2019) Gunay, Kubra; Arslan, Metin; Bozkaya, Ogun; Aluc, Yasar; Gok, Zehra GunIn this study, poly(ethylene terephthalate) fibers grafted with 4-vinyl pyridine (PET-g-4VP) was synthesized with using a radical polymerization method and its removal capacity for bromate ions in the aqueous solution was explored. The synthesized graft copolymer was structurally characterized by scanning electron microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR). The effect of some parameters such as pH, grafting rate, processing time, and ion concentration on bromate removal was examined with batch experiments. The sorptions of bromate onto the PET-g-4VP fibers were both verified with FTIR and X-ray fluorescence analysis (XRF) and the remaining amount of bromate after adsorption process was determined with an ion chromatography (Shimadzu). Moreover, kinetic and isotherm studies were also performed for adsorption of bromate with the grafted fibers. The point of zero charge (pH(pzc)) of the PET-g-4VP fibers was found to be 7.5 and the fibers removed maximum amount of bromate from aqueous solution at pH 3. Equilibrium time of adsorption was determined to be 75 min and the adsorption kinetic was found to be pseudo-second-order model. It was observed that the increase in the amount of grafted 4VP onto the PET fibers increased the bromate removal capacity of the fibers; however, when the grafting yield of 4VP was over 80%, the bromate removal ability of the fibers decreased. The maximum bromate removal capacity of the PET-g-4VP was determined to be 183 mg/g when the initial bromate amount was 800 mg/L, treatment time was 75 min, pH of the solution was 3, and 4VP grafting yield was 80%. When the initial bromate concentration was higher than 800 mg/L, the removal rate of the PET-g-4VP fibers was not changed. In addition, bromate ion adsorption data indicated compliance with the Freundlich isotherm. The adsorbent fibers obtained by this study may be promising candidates for the removal of bromate ions from the aqueous media.Öğe Impacts Of High Voltage Electric Field (Hvef) Applications On Germination And Seedling Growth Of Seed (Triticum Aestivum L.) With Analysis By Fourier Transform Infrared (Ftir) Spectroscopy(Parlar Scientific Publications (P S P), 2018) Ince-Yilmaz, Ozlem; Erol, Taskin; Kara, Kamil; Dogan, Mustafa; Erdem, UmitWheat is an important widely grown cereal that its grains used worldwide as a staple food. In this study, germination and seedling growth characteristics of grains of Triticum aestivum, the most widely grown species of the genus, in response to HVEF applications were studied. Three different intensities (50, 100 and 200 kV/m) were applied for 1, 5 and 10 min durations. Germination percentages were not affected by treatments, while germination speeds were inhibited by high intensities at long durations. Maximum enhancement in seedling growth measures which were given as root and shoot lengths and dry weights was determined for 5 min 50 kV/m treatment, where increases in average seedling lengths and dry weights were 34.2 % and 26.1 %, respectively. 1 min durations of treatments were also highly improved seedling growth, particularly at root measures. ATR technique was used to analyze the roots and first foliage leafs of treated seeds at FTIR spectroscopy. FTIR results supported that HVEF treatment could be a useful tool for enhancement of wheat seedling growth in early stages of development.Öğe Does penile tourniquet application alter bacterial adhesion to rat urethral cells: an in vitro study(W B Saunders Co-Elsevier Inc, 2018) Boybeyi-Turer, Ozlem; Kacmaz, Birgul; Arat, Esra; Atasoy, Pinar; Kisa, Ucler; Gunal, Yasemin Dere; Soyer, TutkuPurpose: To investigate the effects of penile tourniquet (PT) application on bacterial adhesion to urothelium. Methods: Fifty-six ratswere allocated into control group (CG), shamgroup (SG), PT group (PTG). No intervention was applied in CG. A 5mm-length urethral repair was performed in SG and PTG. In PTG, a 10-min duration of PT was applied during the procedure and the tissue oxygenation monitor was used to adjust the same degree of ischemia in all subjects. Sampleswere examined for wound healing parameters and tissue levels of inflammatory markers, eNOS, e-selectin, and ICAM-1antibodies. The adhesion of Escherichia coli to urotheliumwas investigated with in vitro adhesion assay. Results: Inflammation was higher and wound healing was worse in SG than CG and in PTG in comparison to CG and SG (p < 0.05). The endothelial damage, as shown by eNOS expression, was significantly higher in PTG compared to CG and SG (p < 0.05). The staining with ICAM-1 and e-selectin antibodies, showing increased inflammatory response to bacterial adhesion, was significantly higher in PTG compared to CG and SG (p < 0.05). In vitro urethral cell proliferation was achieved only in CG and SG revealing significantly increased adhesion in SG compared to CG (p < 0.05). The PT application caused endothelial corruption and prevented cell proliferation in cell culture. Conclusion: The PT application does not improve wound healing and increases bacterial adhesion molecules in penile tissue. The in vitro assays showed that PT causes severe endothelial damage and inhibits endothelial cell proliferation. (c) 2017 Elsevier Inc. All rights reserved.Öğe Dentinal tubule occluding capability of nano-hydroxyapatite; The in-vitro evaluation(Wiley, 2018) Baglar, Serdar; Erdem, Umit; Dogan, Mustafa; Turkoz, MustafaIn this in-vitro study, the effectiveness of experimental pure nano-hydroxyapatite (nHAP) and 1%, 2%, and 3% F doped nano-HAp on dentine tubule occlusion was investigated. And also, the cytotoxicity of materials used in the experiment was evaluated. Nano-HAp types were synthesized by the precipitation method. Forty dentin specimens were randomly divided into five groups of; 1no treatment (control), 2specimens treated with 10% pure nano-HAp and 3, 4, 5 specimens treated with 1%, 2%, and 3% F(-)doped 10% nano-HAp, respectively. To evaluate the effectiveness of the materials used; pH, FTIR, and scanning electron microscopy evaluations were performed before and after degredation in simulated body fluid. To determine cytotoxicity of the materials, MTT assay was performed. Statistical evaluations were performed with F and t tests. All of the nano-HAp materials used in this study built up an effective covering layer on the dentin surfaces even with plugs in tubules. It was found that this layer had also a resistance to degradation. None of the evaluated nano-HAp types were have toxicity. Fluoride doping showed a positive effect on physical and chemical stability until a critical value of 1% F-. The all evaluated nano-HAp types may be effectively used in dentin hypersensitivity treatment. The formed nano-HAp layers were seem to resistant to hydrolic deletion. The pure and 1% F(-)doped nano-HAp showed the highest biocompatibility thus it was assessed that pure and 1% F(-)doped materials may be used as an active ingredient in dentin hypersensitivity agents.Öğe Bioremoval of mercury (II) from aqueous solutions by Phragmites australis: Kinetic and equilibrium studies(Taylor & Francis Inc, 2018) Kankilic, Gokben Basaran; Metin, Aysegul Ulku; Aluc, Yasar; Bozkaya, OgunIn this study, the removal of mercury (II) ions from aqueous solutions by dried biomass of Phragmites australis was investigated in the batch system. The biomass was characterized by Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray fluorescence (ED-XRF), Brunauer-Emmett-Teller (BET) surface area techniques (BET). Inductively Coupled Plasma Atomic Emission Spectrophotometer (ICP-OES, Spectro Blue) was used to analyze Hg(II) concentration and obtained data in batch experiments indicated that Hg (II) was rapidly adsorbed and such adsorption reached equilibrium within 60 min. The initial pH of the solution was effective parameter for Hg (II) biosorption. The biosorption kinetics was in better good fit with pseudo-second order kinetics and the results obtained from the batch experiments were conformed better with the Langmuir isotherm model than Freundlich and D-R isotherm models. The maximum Hg (II) biosorption capacity of P. australis was 20.0 +/- 0.4mg/g. The availability of other metal ions affected mercury biosorption. Adsorption/desorption studies demonstrated that the adsorbed Hg (II) could be desorbed effectively with a 0.1M ethylenediamine tetra-acetic acid (EDTA) solution. The biosorption capacity of the regenerated biosorbent could still be maintained at 72% at the fifth adsorption-desorption cycle. Consequently, it can be said that P. australis can be used as an applicable, cost-efficient, nature friendly biosorbent for treating wastewater. [GRAPHICS] .Öğe The effect of calcium chloride concentration on alginate/Fmoc-diphenylalanine hydrogel networks(Elsevier Science Bv, 2016) Celik, Ekin; Bayram, Cem; Akcapinar, Rumeysaa; Turk, Mustafa; Denkbas, Emir BakiPeptide based hydrogels gained a vast interest in the tissue engineering studies thanks to great superiorities such as biocompatibility, supramolecular organization without any need of additional crosslinker, injectability and tunable nature. Fmoc-diphenylalanine (FmocFF) is one of the earliest and widely used example of these small molecule gelators that have been utilized in biomedical studies. However, Fmoc-peptides are not feasible for long term use due to low stability and weak mechanical properties at neutral pH. In this study, Fmoc-FF dipeptides were mechanically enhanced by incorporation of alginate, a biocompatible and absorbable polysaccharide. The binary hydrogel is obtained via molecular self-assembly of FmocFF dipeptide in alginate solution followed by ionic crosslinldng of alginate moieties with varying concentrations of calcium chloride. Hydrogel characterization was evaluated in terms of morphology, viscoelastic moduli and diffusional phenomena and the structures were tested as 3D scaffolds for bovine chondrocytes. In vitro evaluation of scaffolds lasted up to 14 days and cell viability, sulphated glycosaminoglycan (sGAG) levels, collagen type II synthesis were determined. Our results showed that alginate incorporation into FmocFF hydrogels leads to better mechanical properties and higher stability with good biocompatibility. (C) 2016 Elsevier B.V. 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