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Öğe A comprehensive review on the usability of black phosphorus in energy and wastewater treatment(Elsevier Inc., 2024) Kaya, Gul; Eskikaya, Ozan; Kucukosman, Ridvan; Ocakoglu, Kasim; Dizge, Nadir; Balakrishnan, Deepanraj; Singh Chohan, JasgurpreetIncreasing population and industrial development brings with it many problems that need to be solved, such as energy production, storage, saving, protection of limited reserves, and environmental pollution. Nanomaterials, which emerged with the introduction of nanotechnology into our lives, play an important role in many areas. The novel two-dimensional nanomaterial black phosphorus (BP) exhibits great potential in photocatalytic applications, energy technologies, and purification with properties such as broad light absorption spectrum, tunable direct band gap, and exceptionally high charge carrier mobility. This review gives a outline of the manufacturing techniques, structural, chemical, electrical and thermal properties of BP. Then, the success of BP derivatives with different dimensions and morphologies in environmental and energy applications is presented by comparing them with previous studies in these fields. The results show that heterojunction structures produced by combining BP with MoS2 and MOFs improve the electrochemical properties of BP, while carbonization processes increase its efficiency in battery and supercapacitor applications. Finally, in this review, a summary of BP's potential future uses, awareness of easy production methods, and its activities in environmental and energy applications are discussed in a broad context. © 2024Öğe A Cr2AlC MAX Phase-Based Electrochemical Probe for the Detection of Asciminib in Biological and Pharmaceutical Samples(Wiley-V C H Verlag Gmbh, 2025) Genc, Asena Ayse; Bouali, Wiem; Erk, Nevin; Kaya, Gul; Ocakoglu, KasimThe Cr2AlC MAX phase, a two-dimensional transition metal carbide, offers a compelling combination of properties ideal for electrochemical sensor fabrication. The exceptional electrical conductivity, high surface area, and inherent electrocatalytic activity of the catalyst enable the sensitive and selective detection of diverse analytes, including biomolecules of critical clinical relevance. This work presents the construction of a novel electrochemical sensor featuring a nanoscale Cr2AlC MAX phase-modified electrode, demonstrating its exceptional analytical performance in Asciminib detection, a crucial aspect of chronic myeloid leukemia (CML) treatment. The sensor exhibits a low limit of detection (0.212 mu M) and a low limit of quantification (0.698 mu M) and demonstrates excellent sensitivity toward Asciminib in the linear range of 1 mu M-10 mu M. Moreover, a rigorous tolerance limit has been established, allowing the sensor to tolerate the highest concentration of interfering substances with an error of less than +/- 5% in determining ASC current. Successful quantification of Asciminibin biological samples further validates the method's reliability for real-world applications. This novel electrochemical approach provides a rapid and cost-effective alternative to existing methods and contributes significantly to the nanomaterial-enabled advancement of CML management, ensuring precise Asciminib quantification at the nanoscale.Öğe A novel approach utilizing rapid thin-film microextraction method for salivary metabolomics studies in lung cancer diagnosis(Elsevier, 2024) Pelit, Fusun; Erbas, Ilknur; Ozupek, Nazli Mert; Gul, Merve; Sakrak, Esra; Ocakoglu, Kasim; Pelit, LeventThis study investigated the potential of targeted salivary metabolomics as a convenient diagnostic tool for lung cancer (LC), utilizing a rapid TFME-based method. It specifically examines TFME blades modified with SiO2 nanoparticles, which were produced using a custom-made coating system. Validation of the metabolite biomarker analysis was performed by these blades using liquid chromatography-tandem mass spectroscopy (LCMS/MS). The extraction efficiencies of SiO2 nanoparticle/polyacrylonitrile (PAN) composite-coated blades were compared for 18 metabolites. Response surface methodology (RSM) was used to optimize the analysis conditions. Linear calibration plots were obtained for all metabolites at concentrations between 0.025 to 4.0 mu g/mL in the presence of internal standard, with correlation coefficients (R-2) ranging from 0.9975 to 0.9841. The limit of detection (LOD) and limit of quantitation (LOQ) were in the range of 0.014 to 0.97 mu g mL(-1) and 0.046 to 3.20 mu gmL(-1), respectively. The %RSD values for all analytes were within the acceptable range (less than 20 %) for the proposed method. The method was applied to the saliva samples of 40 patients with LC and 38 healthy controls. The efficacy of metabolites for LC diagnosis was determined by in silico methods and the results reveal that phenylalanine and purine metabolism metabolites (e.g., hypoxanthine) are of great importance for LC diagnosis. Furthermore, potentially significant biomarker analysis results from the ROC curve data reveal that proline, hypoxanthine, and phenylalanine were identified as potential biomarkers for LC diagnosis.Öğe Adsorption and Fenton oxidation of azo dyes by magnetite nanoparticles deposited on a glass substrate(Elsevier, 2019) Unal, Bahar Ozbey; Bilici, Zeynep; Ugur, Naz; Isik, Zelal; Harputlu, Ersan; Dizge, Nadir; Ocakoglu, KasimFenton oxidation is an efficient and useful method for wastewater treatment. To increase overall reaction efficiencies and inhibit environmental impacts, developing advanced catalysts are crucial in this matter. The main goal of this study was to investigate the catalytic activity of the magnetite (Fe2+Fe23+O42-, FeFe2O4, or Fe3O4) nanoparticles (NPs) coated borosilicate glass on the color removal of basic red 18 (BR18) and acid red 8 (AR88) azo dyes by adsorption and Fenton oxidation reaction. The efficiency of powder magnetite NPs was also tested to compare to magnetite NPs coated borosilicate glass. The effect of solution pH (2.5-9.0), catalyst loading (0.25-3.0 g/L), and dye concentration (0.1-0.3 mM) were tested to achieve maximum color removal efficiency using powder magnetite NPs. The color removal efficiencies were measured 44% at pH 9.0 and 76% at pH 3.5 for adsorption and Fenton oxidation of BR18 dye (0.1 mM). Moreover, the color removal efficiencies were measured 81% at pH 3.5 and 100% at pH 6.0 for adsorption and Fenton oxidation of AR88 dye (0.1 mM). The effect of hydrogen peroxide (H2O2) concentration (2.5-25 mM) was also optimized and 10 mM was found optimum H2O2 dosage for Fenton oxidation. However, magnetite NPs coated borosilicate glass enhanced maximum 77% and 82% color removal efficiencies for adsorption and Fenton oxidation of BR18 dye. Maximum 86% and 100% color removal efficiencies were obtained for adsorption and Fenton oxidation of AR88 dye. Stability of the powder magnetite NPs and magnetite NPs coated borosilicate glass catalyst was also investigated. The reusability of the catalyst showed that magnetite NPs coated borosilicate glass could be used at least 3 times without significant loss of activity compared to powder magnetite NPs for Fenton oxidation. The characterization of the catalyst was carried out using scanning electron microscope with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray powder diffraction (XRD), and zeta potential analyses before and after adsorption.Öğe Antibacterial properties of subphthalocyanine and subphthalocyanine-TiO2 nanoparticles on Staphylococcus aureus and Escherichia coli(World Scientific Publ Co Pte Ltd, 2018) Ozturk, Ismail; Tuncel, Ayga; Ince, Mine; Ocakoglu, Kasim; Hosgor-Limoncu, Mine; Yurt, FatmaNowadays the problem of antimicrobial resistance is the most important cause of morbidity and mortality in the treatment of infectious diseases worldwide. Treatment options for antimicrobial-resistant microorganisms are quite limited. Therefore, alternative treatment strategies are needed to control infectious diseases. Antimicrobial photodynamic therapy (aPDT) is one of the new treatment modalities proposed for a wide variety of infections. In the basic principle of aPDT, photosensitizers (PS) produce free radicals by irradiating them with harmless light at the appropriate wavelength, and this causes microorganism cell cytotoxicity. In this study, light emitting diodes (LED) (630-700 nm, 17.4 mW/cm(2)) were used on Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) at different light doses under the minimum inhibitory concentration (MIC) values of SubPc and SubPc-integrated TiO2 nanoparticles (SubPc-TiO2) concentration. Both compounds show good phototoxicity toward S. aureus when high light doses (16, 24 J/cm(2)) were applied. In addition, SubPc-TiO2 were found to be more effective than SubPc in aPDT of S. aureus. In E. coli, the success of aPDT has been shown to be dependent on the increased light dose (20, 30 J/cm(2) ) for both compounds. As a result, the aPDT activity of SubPc-TiO2 is more effective than SubPc in increasing light doses.Öğe Antifouling and antibacterial performance evaluation of polyethersulfone membranes modified with AZ63 alloy(Iwa Publishing, 2023) Ozay, Yasin; Alterkaoui, Aya; Kahya, Kursat; Ozdemir, Sadin; Gonca, Serpil; Dizge, Nadir; Ocakoglu, KasimAntibacterial membranes have attracted researchers' interest in recent years as a possible approach for dealing with biofouling on the membrane surface. This research aims to see if blending AZ63 Mg alloy into a polyethersulphone (PES) membrane can improve antifouling and separation. The composite membranes' pure water flux continued to increase from pristine PES to PES/AZ63 2.00 wt%. The results showed that PES/AZ63 2.00 wt% membrane supplied the highest permeate flux of E. coli. The steady-state fluxes of AZ63 composite membranes were 113.24, 104.38 and 44.79 L/m(2)h for PES/AZ63 2.00 wt%, 1.00 wt%, and 0.50 wt%, respectively. The enhanced biological activity of AZ63 was studied based on antioxidant activity, DNA cleavage, antimicrobial, anti-biofilm, bacterial viability inhibition and photodynamic antimicrobial therapy studies. The maximum DPPH scavenging activity was determined as 81.25% with AZ63. AZ63 indicated good chemical nuclease activity and also showed moderate antimicrobial activity against studied strains. The highest biofilm inhibition of AZ63 was 83.25% and 71.63% towards P. aeruginosa and S. aureus, respectively. The cell viability inhibition activity of AZ63 was found as 96.34% against E. coli. The photodynamic antimicrobial therapy results displayed that AZ63 demonstrated 100% bacterial inhibition when using E. coli.Öğe Antifungal photodynamic activities of phthalocyanine derivatives on Candida albicans(Elsevier, 2020) Ozturk, Ismail; Tuncel, Ayca; Yurt, Fatma; Biyiklioglu, Zekeriya; Ince, Mine; Ocakoglu, KasimAntimicrobial resistance is one of the most important causes of morbidity and mortality in the treatment of infectious diseases worldwide. Candida albicans is one of the most virulent and common species of fungi to cause invasive fungal infections on humans. Alternative treatment strategies, including photodynamic therapy, are needed for controlling these infectious diseases. The aim of this study was to investigate the antifungal photodynamic activities of phthalocyanine derivatives on C. albicans. The minimum inhibitory concentration (MIC) values of compounds were determined by the broth microdilution method. Uptake of the compounds in C. albicans and dark toxicity of the compounds were also investigated. Photodynamic inhibition of growth experiments was performed by measuring the colony-forming unit/mL (CFU/mL) of the strain. Maximum uptake into the cells was observed in the presence of 64 mu g/mL concentration for each compound except for ZnPc. Compounds did not show dark toxicity/inhibitory effects at sub-MIC concentrations on C. albicans when compared to the negative control groups. Zn(II)Pc, ZnPc, and ZnPc-TiO2 showed fungicidal effect after irradiation with the light dose of 90 J/cm(2) in the presence of the compounds. In addition to the fungicidal effects, SubPc, SubPc-TiO2, Es-SiPc, and Es-SubPc compounds were also found to have inhibitory effects on the growth of yeast cells after irradiation.Öğe Antiinflammatory photodynamic therapy potential of polyoxyethylene-substituted perylene diimide, nitrocatechol, and azo dye(Tubitak Scientific & Technological Research Council Turkey, 2021) Hakli, Ozgul; Ocakoglu, Kasim; Ayaz, FurkanPhotodynamic therapy (PDT) applications enable light-controlled activation of drug candidates instead of their constitutive activities to prevent undesired side effects associated with their constant activities. A specific wavelength of light is utilized to enable electron mobility in the chemical structure, which results in differential activities that may alter cell viability and cellular functions. Canonical photodynamic therapy applications mostly focus on cytotoxicity-based antimicrobial and anticancer properties of the PDT agents. In this study, we focused on subtoxic concentrations of three different molecules containing polyoxyethylene group and examined their antiinflammatory activities on stimulated mammalian macrophages. Stimulated macrophages produce proinflammatory cytokines TNF and IL6. In the presence of a light source, our PDT agents were activated for 5 and 10 min during their application to the macrophages. Based on the ELISA results, the compounds had anti-inflammatory PDT activities. Trypan blue staining results suggest that these derivatives exerted their activities without leading to cytotoxicity. Our results suggest noncanonical PDT applications of these derivatives that can alter cellular activities without leading to cell death.Öğe Antimicrobial photodynamic therapy against Staphylococcus aureus using zinc phthalocyanine and zinc phthalocyanine integrated TiO2 nanoparticles(World Scientific Publ Co Pte Ltd, 2019) Tuncel, Ayca; Ozturk, Ismail; Ince, Mine; Ocakoglu, Kasim; Hosgor-Limoncu, Mine; Yurt, FatmaAntibiotic resistance is an increasing healthcare problem worldwide. In the present study, the effects of antimicrobial photodynamic therapy (APDT) of ZnPc and ZnPc-integrated TiO2 nanoparticles (ZnPc-TiO2) were investigated against Staphylococcus aureus. A light emitting diode (LED) (630-700 nm, 17.4 mW/cm(2)) was used on S. aureus at different light doses (8 J/cm(2) for 11 min, 16 J/cm(2) for 22 min, 24 J/cm(2) for 33 min) in the presence of the compounds under the minimum inhibitory concentration values. Both compounds showed similar phototoxicity toward S. aureus when high light doses (16 and 24 J/cm(2)) were applied. In addition, the success of APDT increased with an increasing light dose.Öğe Antimicrobial photodynamic therapy against Staphylococcus Aureus using zinc phthalocyanine and zinc phthalocyanineintegrated TiO2 nanoparticles(World Scientific Publishing Co., 2020) Tunçel, Ayça; Öztürk, İsmail; Ince, Mine; Ocakoglu, Kasim; Hoşgör-Limoncu, Mine; Yurt, FatmaAntibiotic resistance is an increasing healthcare problem worldwide. In the present study, the effects of antimicrobial photodynamic therapy (APDT) of ZnPc and ZnPc-integrated TiO2 nanoparticles (ZnPc-TiO2) were investigated against Staphylococcus aureus. A light emitting diode (LED) (630-700 nm, 17.4 mW/cm2) was used on S. aureus at different light doses (8 J/cm2 for 11 min, 16 J/cm2 for 22 min, 24 J/cm2 for 33 min) in the presence of the compounds under the minimum inhibitory concentration values. Both compounds showed similar phototoxicity toward S. aureus when high light doses (16 and 24 J/cm2) were applied. In addition, the success of APDT increased with an increasing light dose. © 2021 by World Scientific Publishing Co. Pte. Ltd.Öğe Antioxidant activity, DNA cleavage ability, and antibacterial properties of ceramic membrane coated with cobalt nanoparticles(Elsevier Ltd, 2025) Belibagli, Pinar; Dogan, Ali Can; Kaya, Gul; Dizge, Nadir; Ocakoglu, Kasim; Özdemir, Sadin; Tollu, GülsahCeramic membranes are increasingly used in water/wastewater treatment due to their excellent filtration/separation performance, mechanical, thermal and long-term stability. In this study, ceramic clay membranes coated with cobalt nanoparticles (Co NP) were produced to increase the antibacterial properties of ceramic membranes produced using clay, a natural and cost-effective material. The morphological structure of Co NP ceramic clay membranes was determined by SEM analysis and the surface of the ceramic clay membrane coated with Co NP gained a smooth surface feature close to homogeneity. The antioxidant activity of CoNPs was 69.26 % at 100 mg/L. Plasmid DNA was entirely degraded at 50 mg/L nanoparticle concentrations. At a concentration of 100 mg/L, α-amylase inhibition of 86.39 % was exhibited by the CoNPs solution. CoNPs exhibited significant antimicrobial activities against L. pneumophila subsp. pneumophila, E. hirae, and E. faecalis (Minimum Inhibition concentration (MIC):16 mg/L). The cell viability inhibitory effect of the NPs was 98.27 % at 20 mg/L concentration against E. coli. The antibiofilm activities of the CoNPs were determined 82.13 % and 71.67 % against S. aureus and P. aeruginosa, respectively. Furthermore, the E. coli elimination performance of CoNP coated on the solid surface of the ceramic membrane was obtained as 94.64 %. In line with all these results, it has been clearly proven that Co NP ceramic clay membranes can be used in water and wastewater treatment due to their convenient, cheap, and effective antibacterial properties. © 2024 Elsevier Ltd and Techna Group S.r.l.Öğe Bimodal functionality of highly conductive nanostructured silver film towards improved performance of photosystem I-based graphene photocathode(Elsevier Science Sa, 2025) Szalkowski, Marcin; Kiliszek, Malgorzata; Harputlu, Ersan; Izzo, Miriam; Unlu, C. Gokhan; Mackowski, Sebastian; Ocakoglu, KasimWe present the novel design of photosystem I (PSI)-based biosolar cell, whereby conductive transparent electrode materials, such as ITO or FTO, are replaced with glass covered with silver island film. This nanostructured metallic layer combines high electric conductance with enhancing the absorption efficiency of the PSI biocatalyst via the plasmonic effect. We demonstrate strong enhancement of the photocurrent generated in the biohybrid electrode composed of oriented layers of PSI reaction centers due to plasmonic interactions of the PSI fluorophores and redox centres with the conductive silver island film.Öğe Combustion characteristics of gasoline fuel droplets containing boron-based particles(Elsevier Science Inc, 2023) Kucukosman, Ridvan; Degirmenci, Huseyin; Yontar, Ahmet Alper; Ocakoglu, KasimBoron-based particles are dense energy carriers that are promising for a future carbon-neutral world, to store and transport abundant energy. Although it is prominent as a slurry fuel component in liquid aviation fuels, its effects on the combustion behavior of traditional hydrocarbon fuels used in public or industrial areas have not yet been clarified. In this study, combustion characteristics of gasoline-based fuel droplets containing 86-88%, and 95-97% < 1 mu m amorphous boron, 10 mu m AlB12, 28 - 35 mu m MgB2 particles and 1% oleic acid surfactant. The experimental process was recorded via a high-speed camera and a thermal camera. The results showed that the ignition delay time was reduced in all gasoline-based fuels containing boron-based particles. The fuels with the lowest extinction time were gasoline-based fuel droplets containing AlB 12 particles (similar to 1245 ms). Amorphous boron particles were transported to the flame region more than other particles and caused severe atomization phenomena. The highest maximum flame temperature for gasoline droplets at 2.5% particle load was recorded in high-purity amorphous boron particles with 537 K. At 7.5% particle load, the highest flame temperature and agglomerate temperature were observed at 513 K and 653 K, respectively, in gasoline droplets containing high-purity amorphous boron particles. In electric field tests, the shortest extinction time was detected for gasoline droplets with MgB12. Also, the addition of amorph boron particles into gasoline increase of 4.6% was seen in the flame speed. Droplet diameter regression plots show that particulate gasoline-based fuel droplets exhibit a decreasing trend, mostly following the D-2-law. It has been revealed low-cost amorphous boron derivatives can be an important energy carrier for liquid hydrocarbon fuels. (c) 2023 The Combustion Institute. Published by Elsevier Inc. All rights reserved.Öğe Detection of Kallikrein-Related Peptidase 4 with a Label-free Electrochemical Impedance Biosensor Based on a Zinc(II) Phthalocyanine Tetracarboxylic Acid-Functionalized Disposable Indium Tin Oxide Electrode(Amer Chemical Soc, 2021) Aydin, Elif Burcu; Aydin, Muhammet; Yuzer, Abdulcelil; Ince, Mine; Ocakoglu, Kasim; Sezginturk, Mustafa KemalA new impedimetric biosensing system based on kallikrein-related peptidase 4 (KLK 4) antigen-specific antibodies and a zinc(II) phthalocyanine tetracarboxylic acid (Zn-PcTCa) matrix material was developed for the first time in this study. First, a Zn-PcTCa-coated indium tin oxide surface was used as an interface matrix material for the immobilization of anti-KLK 4 antibodies, and they bound to the platform via amide bonds. In the presence of KLK 4 antigens, the anti-KLK 4 antibodies specifically captured these antigens and caused changes in the electrochemical properties of the system. Randles equivalent circuit was utilized to evaluate the impedimetric signal, which was measured with the help of an electrochemical impedance spectroscopy method. After the specific interaction, the electron transfer resistance (R-ct) was remarkably increased and displayed a linear relationship with the level of the KLK 4 antigen in the range of 0.02-15 pg/mL, with a a detection limit of 6.8 fg/mL. The designed biosensor was able to detect a KLK 4 antigen with good sensitivity, excellent specificity, and high stability. In addition, because of having a low-cost and robust procedure for fabrication, it could be repeatedly used in several areas including clinical diagnosis.Öğe Development of antimicrobial nanocomposite scaffolds via loading CZTSe quantum dots for wound dressing applications(Iop Publishing Ltd, 2022) Ceylan, Seda; Sert, Buse; Yurt, Fatma; Tuncel, Ayca; Ozturk, Ismail; Demir, Didem; Ocakoglu, KasimThe antimicrobial properties of scaffolds designed for use in wound healing are accepted as an important factor in the healing process to accelerate the wound healing process without causing inflammation. For this purpose, chitosan-polyvinyl alcohol composite membranes loaded with Cu2ZnSnSe4 quantum dots (CZTSe QDs) as an antibacterial and cytocompatible biomaterial to regulate the wound healing process were produced. CZTSe QDs particles were synthesized under hydrothermal conditions. Polymer-based nanocomposites with different concentrations of the synthesized nanoparticles were produced by the solvent casting method. After detailed physicochemical and morphological characterizations of CZTSe QDs and composite membranes, antibacterial activities and cell viability were extensively investigated against gram-positive and gram-negative bacterial and yeast strains, and L929 mouse fibroblast cells lines, respectively. The results show that the preparation of composite scaffolds at a QDs concentration of 3.3% by weight has the best antimicrobial activity. Composite scaffold membranes, which can be obtained as a result of an easy production process, are thought to have great potential applications in tissue engineering as wound dressing material due to their high mechanical properties, wettability, strong antibacterial properties and non-toxicity.Öğe Development of Ruthenium Oxide Modified Polyethersulfone Membranes for Improvement of Antifouling Performance Including Decomposition Kinetic of Polymer(Springer, 2023) Yigit, Basak; Ozay, Yasin; Emen, Fatih Mehmet; Kutlu, Emine; Ocakoglu, Kasim; Dizge, NadirIn this study, RuO2-embedded PES membrane was prepared and it was used for protein separation. The antifouling properties of the fabricated composite membranes were also investigated using bovine serum albumin (BSA) as protein solution. The mean roughness increased proportionally by introducing RuO2 particles. The porosity of the composite membranes was higher than that of the pristine PES membrane. On the other hand, composite membranes has smaller average pore size after addition of RuO2 particles. The blending of RuO2 particles to the PES membrane caused to increase the hydrophilicity. The contact angle was measured 76.67 +/- 1.21 degrees, 73.23 +/- 0.84 degrees, 70.28 +/- 0.77 degrees, and 67.13 +/- 0.80 degrees for pristine PES, PES/RuO2 0.50 wt%., PES/RuO2 0.75 wt%., and PES/RuO2 1.00 wt%, respectively. The pure water flux of the membranes decreased from 439.7 to 379.3 L/m(2)/h for the pristine PES and PES/RuO2 1.00 wt%. The pore size was calculated as 16.47 nm for the pristine PES and pore size decreased up to 6.05 nm when RuO2 particles increased up to 1.00 wt%. BSA fluxes were 84.1 +/- 2.1, 86.3 +/- 2.5, and 93.9 +/- 3.2 L/m(2)/h for pristine, PES/RuO2 0.50 wt%, and PES/RuO2 0.75 wt% membranes, respectively. PES/RuO2 1.00 wt%. membrane supplied the lowest BSA flux (73.6 +/- 3.1 L/m(2)/h). BSA rejection efficiencies increased from 45.5 +/- 1.8% to 92.6 +/- 1.5% when blended RuO2 particles increased from 0 to 1.00 wt%. The results depicted that R-ir values decreased while R-r values increased after the blending of RuO2. The thermal studies of the PES/RuO2 membranes were also performed by DTA/TG. The Activation Energy (E-a) values of the PES/RuO2 membranes were found to be 57.67-641.34 kJ/mol for Flynn-Wall-Ozawa (FWO) and 55.13-659.10 kJ/mol for Kissenger-Akahira-Sunose (KAS).Öğe Differential effects of aminochlorin derivatives on the phagocytic and inflammatory potentials of mammalian macrophages(Elsevier, 2020) Ayaz, Furkan; Ocakoglu, KasimChlorin derivatives have been known for their biological activities. Especially due to their advanced electron transfer capacity they have been used as photodynamic therapy agent both a clinical and laboratory scales. Photodynamic therapy (PDT) against cancer or an infectious disease aims the development of less side effect on the patient since the activation of the inert drug molecule will start only after the light treatment. In order to increase our library of photodynamic therapy agents, we generated a set of chlorin derivatives and tested their PDT potential on the immune system cells; macrophages. Macrophages are known for their primary role as an inflammatory cell type that have been found in the inflamed tissues of the patients with autoimmune and inflammatory disorders as well as in the tumor environment as tumor associated macrophages. Our derivatives had anti-inflammatory PDT potential in the presence of a danger mimic but they lacked immunostimulatory effect. Moreover, these cells' ability to eliminate an infectious agent or present the danger molecules to the other immune cells were tested by phagocytosis assay in the presence of our compounds. Chlorin derivatives were able to differentially regulate the phagocytic activity of the mammalian macrophages.Öğe Differential Immunomodulatory Activities of Schiff Base Complexes Depending on their Metal Conjugation(Springer/Plenum Publishers, 2019) Ayaz, Furkan; Gonul, Ilyas; Demirbag, Burcu; Ocakoglu, KasimImmunomodulatory compounds have become crucial with advances in immunotherapy. Using our own immune system cells, we can direct the immune cell function and develop desired response against a certain threat. Immunotherapy applications have been suggested against tumors, autoimmune disorders, and infectious diseases. Vaccination can be considered as one of the best known example of immunotherapy. Infectious agent's signature molecular structures are introduced to the immune cells together with the adjuvants that further activate the immune cells to mount a proper immune response and memory. Immunotherapy and vaccine formulations are in constant need of a library of immunomodulatory reagents that can be applied depending on the target. In order to expand the number of immunomodulatory reagents that can find medicinal applications, our group has been testing unique chemical structures on the immune system cells, especially macrophages. Schiff base complexes are known for their anti-inflammatory and antimicrobial activities. In this study, we used previously characterized Schiff base complexes with different metal conjugations. These molecules had differential immunostimulatory and immunomodulatory potentials on macrophages in vitro depending on the type of the conjugated metal. After light exposure, these complexes changed their characteristics and became powerful anti-inflammatory complexes. Due to their possible antimicrobial potentials, we also tested their activities against gram negative and gram positive bacteria. All of the complexes exerted antimicrobial activities which were not light responsive. Here, we present Schiff base complexes with differential immunostimulatory and immunomodulatory activities that can also efficiently eliminate gram positive and gram negative bacteria. Upon photo activation, they block the production of inflammatory TNF alpha cytokine. Therefore, together with the light, they can be used to treat bacterial infections associated with damaging inflammation.Öğe Effects of Spinel Oxide Combustion Catalysts on the Combustion Behavior and Secondary Atomization Mechanism of Gasoline Droplets(Taylor & Francis Inc, 2025) Kucukosman, Ridvan; Yontar, Ahmet Alper; Unlu, Cumhur Gokhan; Ocakoglu, KasimThe catalytic activity of Mg-based spinel oxide nanoparticles (NPs) on the combustion behavior of gasoline and their effects on the atomization behavior were determined by droplet scale combustion experiments. MgFe2O4, MgCo2O4 and MgMnO3 spinel oxide NPs were produced by the sol-gel technique and doped into gasoline. The particles with the highest surface oxygen were MgCo2O4 and MgFe2O4 NPs, while the NPs with the largest surface area were MgCo2O4 NPs (517.8433 m(2)/g). The size of the flame envelope tends to shrink as the oxygen concentration of the particles rises, but an increase in their surface area tends to shorten ignition delay periods. MgFe2O4 NPs increased the flame temperature by 163 & DEG;C compared to the pure gasoline. While MgFe2O4 and MgMnO3 NPs increased the extinction time of gasoline, MgCo2O4 NPs decreased the severe time by about 75% with the violent micro-explosions they created. In this study, we focused on the production of spinel oxide agents customized for combustion with improved catalytic activity, high flammability, and different component designs, and the results showed that these particles can reduce the soot formation of conventional hydrocarbons.Öğe Evaluation of photodynamic therapy and nuclear imaging potential of subphthalocyanine integrated TiO 2 nanoparticles in mammary and cervical tumor cells(World Scientific Publishing Co. Pte Ltd, 2019) Yurt, Fatma; Ocakoglu, Kasim; Er, Ozge; Soylu, Hale Melis; Ince, Mine; Avci, Clglr Biray; Kurt, Cansu CaliskanThis study, subphthalocyanines (SubPc) and SubPc integrated TiO2 nanoparticles (SubPc-TiO2) were synthesized as novel photosensitizers. Their PDT effects were evaluated. Furthermore, nuclear imaging potential of 131I-labelled SubPc/SubPc-TiO2 were examined in mouse mammary carcinoma (EMT6) and cervix adenocarcinoma (HeLa) cell lines. The uptake results show that SubPc labelled with 131I radionuclide (131I-SubPc) in EMT6 and HeLa cell lines was found to be approximately the same as in the WI38 cell line. However, the uptake values of SubPc-TiO2 labelled with 131I (131I-SubPc-TiO2) in EMT6 and HeLa cell lines were determined to be two times higher than in the WI38 cell line. In other words, the target/non-target tissue ratio was identified as two in the EMT6 and HeLa cell lines. 131I-SubPc-TiO2 is promising for imaging or treatment of breast and cervix tumors. In vitro photodynamic therapy studies have shown that SubPc and SubPc-TiO2 are suitable agents for PDT. In addition, SubPc-TiO2 has higher phototoxicity than SubPc. As a future study, in vivo experiments will be held and performed in tumor-bearing nude mice. © 2019 World Scientific Publishing Company.
