DSpace Arşivi :: by Yazar "Köytepe, Süleyman" değerine göre listeleniyor

Yazar "Köytepe, Süleyman" seçeneğine göre listele

Listeleniyor 1 - 16 / 16

Ce/Sm co-doped hydroxyapatites: synthesis, characterization, and band structure calculation
(Springer, 2020) Kaygılı, Ömer; Vural, Gülay; Keser, Serhat; Yahia, İ.S.; Bulut, Niyazi; Ateş, Tankut; Köytepe, Süleyman; Temüz, Mehmet Mürşit; Ercan, Filiz; İnce, Turan
In this paper, Ce/Sm co-doped hydroxyapatites (HAps) were synthesized by a wet chemical route. The amount of Ce was kept at constant at the value of at.% 0.4, and the second dopant of Sm was used at different amounts of at.% 0, 0.6, 1.2, and 1.8, respectively. The effects of these co-dopants on the crystal structure, morphology, and thermal properties of HAp were determined experimentally using X-ray diffraction (XRD), scanning electron microscopy (SEM), differential thermal analysis (DTA), and thermogravimetric analysis (TGA). Furthermore, the band structure of the prepared samples was modeled theoretically using the quantum calculations of the density of states and band structure. A gradual increase from 26.56 to 36.23 nm in the crystallite size was observed. Although the amounts of the co-dopants of Ce and Sm did not affect the thermal stability and microstructure of HAp, its crystal structure-related parameters were affected by the amount of these co-additives. The partial substitution of both co-dopants was detected. The 0.4Ce-1.2Sm-HAp sample may be considered as the best crystal structure with a steady-state. It was seen that the band structure and density of states were also affected by these co-dopants. The bandgap value decreased gradually from 4.6078 to 4.0477 eV due to these dopants.
Chemistry and engineering of brush type polymers: Perspective towards tissue engineering
(Elsevier, 2022) Karaca Açarı, İdil; Sel, Evren; Özcan, İmren; Ateş, Burhan; Köytepe, Süleyman; Thakur, Vijay Kumar
In tissue engineering, it is imperative to control the behaviour of cells/stem cells, such as adhesion, proliferation, propagation, motility, and differentiation for tissue regeneration. Surfaces that allow cells to behave in this way are critical as support materials in tissue engineering. Among these surfaces, brush-type polymers have an important potential for tissue engineering and biomedical applications. Brush structure and length, end groups, bonding densities, hydrophilicity, surface energy, structural flexibility, thermal stability, surface chemical reactivity, rheological and tribological properties, electron and energy transfer ability, cell binding and absorption abilities for various biological molecules of brush-type polymers were increased its importance in tissue engineering applications. In addition, thanks to these functional properties and adjustable surface properties, brush type polymers are used in different high-tech applications such as electronics, sensors, anti-fouling, catalysis, purification and energy etc. This review comprehensively highlights the use of brush-type polymers in tissue engineering applications. Considering the superior properties of brush-type polymer structures, it is believed that in the future, it will be an effective tool in structure designs containing many different biomolecules (enzymes, proteins, etc.) in the field of tissue engineering.
The Cytotoxicity, DNA Fragmentation, and Decreasing Velocity Induced By Chromium(III) Oxide on Rainbow Trout Spermatozoa
(Springer, 2022) Özgür, Mustafa Erkan; Ulu, Ahmet; Gürses, Canbolat; Özcan, İmren; Samir Abbas Ali, Noma; Köytepe, Süleyman; Ateş, Burhan
The present study aimed to determine the cytotoxicity of chromium(III) oxide micro particles (Cr2O3-Ps) in rainbow trout (Oncorhynchus mykiss) spermatozoa. Firstly, Cr2O3-Ps were synthesized and structurally characterized the surface, morphological for particle size and thermal properties. In addition, its structural and elemental purity was determined using energy-dispersive X-ray (EDX) spectrum and elemental maps. Structural purity, thermal properties, and stability of Cr2O3-Ps were also examined in detail by performing thermal analysis techniques. The cytotoxicity of Cr2O3-Ps was measured by the observation of velocities, antioxidant activities, and DNA damages in rainbow trout spermatozoa after exposure during 3 h in vitro incubation. The straight line velocity (VSL), the curvilinear velocity (VCL), and the angular path velocity (VAP) of spermatozoa decreased after exposure to Cr2O3-Ps. While the superoxide dismutase (SOD) and the catalase (CAT) decreased, the lipid peroxidation increased in a dose-dependent manner. However, the total glutathione (tGSH) was not affected in this period. DNA damages were also determined in spermatozoa using Comet assay. According to DNA in tail (%) data, DNA damages have been detected with gradually increasing concentrations of Cr2O3-Ps. Furthermore, all of class types which are categorized as the intensity of DNA fragmentation has been observed between 50 and 500 µg/L concentrations of Cr2O3-Ps exposed to rainbow trout spermatozoa. At the end of this study, we determined that the effective concentrations (EC50) were 76.67 µg/L for VSL and 87.77 µg/L for VCL. Finally, these results about Cr2O3-Ps may say to be major risk concentrations over 70 µg/L for fish reproduction in aquatic environments.
Determination of characterization, antibacterial and drug release properties of POSSbased film synthesized with sol-gel technique
(TÜBİTAK, 2021) Karaca Açarı, İdil; Köytepe, Süleyman; Ateş, Burhan; Yılmaz, İsmet; Seçkin, Turgay
In the study, antibacterial film synthesis was aimed using sol-gel technique from POSS structure with various functional groups. For this purpose, antibacterial properties have been acquired by metronidazole to the films to be synthesized. The films obtained were coated on glass surface samples by dip coating method. Antibacterial activities of surface coated glass samples were observed in E.coli and S. aureus bacteria. Metronidazole release studies in the film samples were followed by UV spectrophotometer. It was observed that drug release reached 68.90% at the end of the 24th h. As a result, it is thought that the synthesized film will be a good candidate especially for biomedical surface coating areas.
Experimental characterization and theoretical investigation of Zn/Sm co-doped hydroxyapatites
(Elsevier, 2022) Hssain, Ala Hamd; Bulut, Niyazi; Ateş, Tankut; Köytepe, Süleyman; Kuruçay, Ali; Kebiroğlu, Hanifi; Kaygılı, Ömer
In this study, the wet chemical method was used to synthesize Zn-doped hydroxyapatite (HAp) samples, and the effects of varying the amount of Sm addition on structural, thermal, and biocompatibility in vitro properties were studied. In addition, a density functional theory was used for modeling the as-synthesized samples to obtain the theoretical calculation results. XRD results confirmed the formation of biphasic compositions for all samples, and FTIR data supported the formation of the functional groups of hydroxyl and phosphate. More than 98% of samples showed the formation of the HAp phase. The addition of Sm resulted in an increase in the secondary phase of the ?-TCP from 0.60% to 1.49%. The lattice parameters (aandc),unit cell volume (V), lattice strain(?), and lattice stress? varied when Sm was added as a dopant. The crystallite size and crystallinity decreased as the Sm content increased, however, the anisotropic energy density gradually increased. Thermal analysis results confirmed that all samples seemed to be thermally stable. The addition of Sm did not result in any notable morphological modifications. Cell viability values of theZn-based HAp sharply decreased as a result of an increase in the Sm additive. Theoretical studies show that when the amount of Sm in the Zn-based HAp structure increases, the bandgap energy decreases from 4.68 to 4.40eV. An increasing density and decreasing unit cell volume have been observed, as confirmed by the theoretical results. In addition, there was a decrease in crystallinity as well as an increase in anisotropic energy density.
Fe ve Ti katkılı Çift Fazlı Kalsiyum Fosfatların Sentez ve Karakterizasyonu
(Malatya Turgut Özal Üniversitesi, 2021) Ateş, Tankut; İnce,Turan; Acar, Serdar; Kaygılı, Ömer; Bulut, Niyazi; Keser,Serhat; Köytepe, Süleyman
Bu çalışmada, Ti katkısının Fe esaslı çift fazlı kalsiyum fosfat malzemelerinin yapısal, morfolojik ve termal özellikleri üzerine etkileri araştırılmıştır. X-ışını kırınımı (XRD) analizi, üretilen numunelerin hem hidroksiapatit (HAp) hem de beta trikalsiyum fosfat (?-TCP) fazlarına sahip olduğunu doğrulamaktadır. Ayrıca, Ti katkısındaki artışla ?-TCP fazının miktarının arttığı görülmektedir. Fourier dönüşümlü kızılötesi (FTIR) spektroskopisi sonuçları, numunelerdeki karakteristik fonksiyonel grupların varlığını doğrulamaktadır. Ti miktarı morfolojiyi etkilemektedir. Numunelerin ısıl davranışları birbirine benzerdir ve oda sıcaklığından 1000 °C’ye kadar tüm numuneler termal olarak kararlıdırlar. Bu sıcaklık aralığında numunelerdeki kütle kayıpları % 1,63’e eşit veya altındadır.
Interaction of nickel ferrite nanoparticles with nucleic acids
(Elsevier B.V., 2022) Topkaya, Seda Nur; Kaya, Hüseyin Oğuzhan; Özcan, İmren; Köytepe, Süleyman; E.Cetin, Arif
In this article, we introduced an electrochemical biosensor employing graphite electrodes (GE) decorated with Nickel ferrite (NiFe2O4) nanoparticles for nucleic acid detection. NiFe2O4 nanoparticles in a narrow size distribution were synthesized with co-precipitation technique. Their chemical and crystallographic properties were characterized with FTIR and X-ray spectroscopies. Nanoparticle size distribution and hydrodynamic diameter were determined with particle size analyzer. Elemental content and purity of nanoparticles were analyzed with EDX analysis. Our analyses showed a diameter of ~10 nm for NiFe2O4 nanoparticles. Electrochemical properties of NiFe2O4 nanoparticles were examined with different analysis methods. Conductivity properties of NiFe2O4 nanoparticles were investigated with Cyclic Voltammetry (CV), which confirmed that nanoparticles on GE surface have a high surface area and conductivity. More importantly, in this article, the interactions between NiFe2O4 nanoparticles and double stranded DNA (dsDNA), single stranded DNA (ssDNA), and RNA were for the first time examined using Differential Pulse Voltammetry (DPV), CV, and Electrochemical Impedance Spectroscopy (EIS). Oxidation peak currents of NiFe2O4 nanoparticles and guanine bases of dsDNA, ssDNA, and RNA showed that NiFe2O4 nanoparticles effectively interacts with nucleic acids via an electrostatic mode.
Interaction of nickel ferrite nanoparticles with nucleic acids
(Elsevier B.V. All, 2022) Topkaya, Seda Nur; Açarı Karaca, İdil; Kaya, Hüseyin Oğuzhan; Özcan, İmren; Köytepe, Süleyman; Çetin, Arif E.
In this article, we introduced an electrochemical biosensor employing graphite electrodes (GE) decorated with Nickel ferrite (NiFe2O4) nanoparticles for nucleic acid detection. NiFe2O4 nanoparticles in a narrow size distribution were synthesized with co-precipitation technique. Their chemical and crystallographic properties were characterized with FTIR and X-ray spectroscopies. Nanoparticle size distribution and hydrodynamic diameter were determined with particle size analyzer. Elemental content and purity of nanoparticles were analyzed with EDX analysis. Our analyses showed a diameter of ~10 nm for NiFe2O4 nanoparticles. Electrochemical properties of NiFe2O4 nanoparticles were examined with different analysis methods. Conductivity properties of NiFe2O4 nanoparticles were investigated with Cyclic Voltammetry (CV), which confirmed that nanoparticles on GE surface have a high surface area and conductivity. More importantly, in this article, the interactions between NiFe2O4 nanoparticles and double stranded DNA (dsDNA), single stranded DNA (ssDNA), and RNA were for the first time examined using Differential Pulse Voltammetry (DPV), CV, and Electrochemical Impedance Spectroscopy (EIS). Oxidation peak currents of NiFe2O4 nanoparticles and guanine bases of dsDNA, ssDNA, and RNA showed that NiFe2O4 nanoparticles effectively interacts with nucleic acids via an electrostatic mode.
Investigation of the effects of Ni-doping on the structural and thermal properties of ZnAl2O4 spinels prepared by wet chemical method
(Springer, 2021) Ercan, Filiz; Ateş, Tankut; Kaygılı, Ömer; Bulut, Niyazi; Köytepe, Süleyman; Alahmari, Fatimah; Ercan, İsmail; Hssain, Ala Hamd
n this study, a more detailed characterization of the un-doped and Ni-doped ZnAl2O4 spinel structures prepared via a facile wet chemical route was carried out. Significant effects of the additive of Ni on the ZnAl2O4 structure were observed. For all the samples, the ZnO phase was detected as the second phase, and the third phase of NiO was observed for two samples having the highest Ni content. X-ray diffraction (XRD) results showed that the crystallinity percent, lattice parameter, and volume of the unit cell decreased continuously with adding of Ni. Fourier transform infrared (FTIR) spectra verify the formation of the ZnAl2O4 structure for all the samples. The thermal behaviors, including the recrystallization temperature and mass losses, of the ZnAl2O4 structure, were also affected by the amount of Ni. The morphology varied with adding of Ni. These properties were not reported before.
Investigation of toxic effects of amorphous SiO2 nanoparticles on motility and oxidative stress markers in rainbow trout sperm cells
(Springer, 2019) Özgür, Mustafa Erkan; Ulu, Ahmet; Özcan, İmren; Balcıoğlu, Sevgi; Ateş, Burhan; Köytepe, Süleyman
In this study, we investigated the effects of SiO2 nanoparticles (SiO2-NPs) (1, 10, 25, 50, and 100 mg/L) for 24 h in vitro on the motility parameters and oxidative stress markers such as total glutathione (TGSH), catalase (CAT), and malondialdehyde (MDA) of rainbow trout, Oncorhynchus mykiss sperm cells. Therefore, SiO2-NPs were synthesized with sol-gel reaction from tetraethoxy orthosilicate (TEOS). The prepared nanoparticle structures were characterized for chemical structure, morphology and thermal behavior employing Fourier transform infrared spectroscopy, X-ray spectroscopy, scanning electron micrograph, and thermal analysis (DTA/TGA/DSC) techniques. After exposure, there was statistically significant (p
Melatonin protects sperm cells of Capoeta trutta from toxicity of titanium dioxide nanoparticles
(Springer, 2020) Özgür, Mustafa Erkan; Ulu, Ahmet; Noma, Samir Abbas Ali; Özcan, İmren; Balcıoğlu, Sevgi; Ateş, Burhan; Köytepe, Süleyman
In this study, it was aimed to determine the protective effects of melatonin (0.01, 0.1, and 1 mM) against 10 mg/L titanium dioxide nanoparticles (TiO2-NPs) on kinematic and oxidative indices in the sperm cells of Capoeta trutta. Therefore, TiO2 nanoparticles were synthesized primarily within the scope of the study. The synthesized nanoparticles were characterized by structurally different techniques. Then, melatonin and TiO2 were applied to Capoeta trutta sperm cells by in vitro. According to our data, all doses of melatonin showed protective effects on all velocities of sperm cells such as the straight line velocity (VSL), the curvilinear velocity (VCL), and the angular path velocity (VAP) against TiO2-NPs, while 0.1 and 1 mM doses of melatonin improved the VSL value. Although TiO2-NPs increased total glutathione (tGSH), malondialdehyde (MDA) lipid peroxidation, and superoxide dismutase (SOD) compared to the control group, there were positive treatment effects for all doses of melatonin on antioxidant capacity of sperm cells. At the end of this research, it is suggested that over 0.1 mM dose of melatonin improves the velocity of sperm cells and it plays a protective role against the toxic effects of TiO2-NPs.
Preparation of 10-undecenoic acid based polyurethane/PCL fibers by electrospinning method and investigation of their antifungal properties
(Springer, 2022) Açarı Karaca, İdil; Boran, Filiz; Kolak, Seda; Tatlıcı, Eray; Yeşilada, Özfer; Köytepe, Süleyman; Ateş, Burhan
Nowadays, in the treatment of such fungal infections, antifungal drugs in various forms are one of the most preferred methods. These medications can be in the form of creams and lotions, shampoos, pills, suppositories, powders, or sprays. The dose of the drugs is adjusted according to the type and growth area of the fungus, the severity of the symptoms, and the medical history of the patients. Dressing materials with antifungal properties are an alternative treatment method used for the treatment of fungal skin infections. These covers not only treat fungal infections but also prevent their spread. Within the scope of this study, polyurethane-based wound dressing materials (PU-UDA/PCL) with antifungal properties were developed. Electrospining method was used to produce these dressing materials and the surface area of the wound dressing material was increased, thereby increasing the effect of antifungal property. Polypropylene glycol, glycerol, and catechin as polyol were preferred in polyurethane (PU) synthesis. These structures were polymerized with isophorone diisocyanate and modified with 10-undecenoic acid. Obtained 10-undecenoic acid modified polyurethane (PU-UDA) structures were transformed into wound dressing structure with polycaprolactone (PCL) by electrospinning method. Structural, morphological, and thermal properties of the wound dressing materials were analyzed with different instrumental analysis methods. The antifungal activities of PU-UDA/PCL were tested. Antifungal tests were performed on C. albicans and C. tropicalis. Therefore, PU-UDA/PCL series could be used as an efficient antifungal agent. Finally, it was determined that the obtained 10-undecenoic acid-based polyurethane fibers have a suitable structure and feature for the treatment of many fungal infections.
Synthesis and Characterization of Co-Doped SnO2 Samples
(Bilecik Şeyh Edebali Üniversitesi, 2020) Ateş, Tankut; Kaygılı, Ömer; Bulut, Niyazi; Okur, Havva Esma; Keser, Serhat; Yahia, İ.S.; Köytepe, Süleyman; Seçkin, Turgay; Özcan, İmren; İnce, Turan
The un-doped and Co-doped SnO2 samples having high crystallinity were successfully prepared. The effects of Co content on the structural, thermal and morphological properties of SnO2 were investigated. Changes in the crystallite size and unit cell parameters were detected with adding of Co. The phase composition did not alter with the addition of Co. Both X-ray diffraction and Fourier transform infrared results confirmed the formation of the SnO2 structure for each sample. The thermal stability of the as-produced samples from room temperature to 900 °C was observed. The morphology was affected by Co content, and energy dispersive X-ray results verified the introduction of Co into the SnO2 structure.
Synthesis of polyhedral oligomeric silsesquioxane-n-acetylcysteine conjugate with click chemistry and ıts antioxidant response and biocompatibility
(Cumhuriyet Üniversitesi, 2020) Karaca Açarı, İdil; Balcıoğlu, Sevgi; Ateş, Burhan; Köytepe, Süleyman; Yılmaz, İsmet; Seçkin, Turgay
In this study, polyhedral oligomeric silsesquioxane-N-acetylcysteine (POSS-NAC) conjugate as a potential antioxidant molecule was synthesized from N-acetylcysteine (NAC) and aminofunctional POSS structure by click chemistry. The chemical structures and thermal properties of the synthesised POSS-NAC conjugate was characterized by spectroscopic and thermal analysis techniques. The antioxidant capacity of the POSS-NAC conjugate was also determined by the 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and reducing power methods. According to the reducing power method, POSS-NAC structure has lower reducing activity than standard ascorbic acid and trolox (p<0.001). It was found from the ABTS radical scavenging activity results that the synthesized POSS-NAC conjugate had a significantly higher radical scavenging effect than the standards (p <0.001). Biocompatibility properties of the POSS-NAC structure were detected in vitro cell culture system with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test on L-929 mouse fibroblast cells. The synthesized POSS-NAC conjugate exhibits high antioxidant activity and good biocompatibility
Theoretical and experimental characterization of Pr/Ce co-doped hydroxyapatites
(Elsevier, 2021) İbrahimzade, Lala; Kaygılı, Ömer; Dündar, Serkan; Ateş, Tankut; Dorozhkin, Sergey V.; Bulut, Niyazi; Köytepe, Süleyman; Ercan, Filiz; Gürses, Canbolat; Ercan, Filiz; Hssain, Ala Hamd
This study presents a more extensive report on the experimental and theoretical characterization of the Ce-doped hydroxyapatite (HAp) samples additionally doped with Pr at varying amounts. To achieve this goal, four Ce-containing (a constant amount of 0.35 at.%) HAps additionally doped with Pr at various amounts (0.35, 0.70, 1.05, and 1.40 at.%) were synthesized via a combustion method. Besides, all these samples were modeled theoretically by using a density functional theory (DFT). Theoretical results showed that the bandgap energy decreased continuously from 4.5156 to 4.3097 eV. For all samples, the linear attenuation (or absorption) coefficient increased with the increasing amount of Pr and this parameter had a decreasing trend with the increase in the photon energy. An increase in the theoretical density and the lattice parameter c and a decrease of both the lattice parameter a and the unit cell volume were found. After analyzing the experimental data, the following results were observed: X-ray diffraction (XRD) and Fourier transform infrared (FTIR) data verified the formation of HAp phase (above 94% for all the samples) as the major phase and beta-tricalcium phosphate (?-TCP) as the minor one. The amount of ?-TCP phase was found to increase from 3.4 to 5.9% with the addition of Pr. Similar to the theoretical findings, an increasing trend for the density and decreasing one for the unit cell volume were detected. Both a decrease in the crystallinity and an increase in the anisotropic energy density were found. The results of the thermal analysis supported the thermal stability of all the samples. The cell viability was found to be affected by Pr-content.
The toxicity assessment of iron oxide (Fe3O4) nanoparticles on physical and biochemical quality of rainbow trout spermatozoon
(Multidisciplinary Digital Publishing Institute (MDPI), 2018) Özgür, Mustafa Erkan; Ulu, Ahmet; Balcıoğlu, Sevgi; Özcan, İmren; Köytepe, Süleyman; Ateş, Burhan
The aim of this study was to evaluate the in vitro effect of different doses (50, 100, 200, 400, and 800 mg/L) of Fe3O4 nanoparticles (NPs) at 4 degrees C for 24 h on the kinematics of rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) spermatozoon. Firstly, Fe3O4 NPs were prepared at about 30 nm from Iron (III) chloride, Iron (II) chloride, and NH3 via a co-precipitation synthesis technique. Then, the prepared Fe3O4 NPs were characterized by different instrumental techniques for their chemical structure, purity, morphology, surface properties, and thermal behavior. The size, microstructure, and morphology of the prepared Fe3O4 NPs were studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) spectroscopy, and scanning electron microscopy (SEM) equipped with an energy-dispersive X-ray spectrometer (EDS). The thermal properties of the Fe3O4 NPs were determined with thermogravimetric analysis (TGA), differential thermal analysis (DTA), and differential scanning calorimeter (DSC) analysis techniques. According to our results, there were statistically significant (p < 0.05) decreases in the velocities of spermatozoon after treatment with 400 mg/L Fe3O4 NPs. The superoxide dismutase (SOD) and catalase (CAT) activities were significant (p < 0.05) decrease after 100 mg/L in after exposure to Fe3O4 NPs in 24 h. As the doses of Fe3O4 NPs increases, the level of malondialdehyde (MDA) and total glutathione (tGSH) significantly (p < 0.05) increased at doses of 400 and 800 mg/L.

Yazar "Köytepe, Süleyman" seçeneğine göre listele

Sayfa Başına Sonuç

Sıralama seçenekleri