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Articles 37291 - 37320 of 302510

Full-Text Articles in Physical Sciences and Mathematics

Design, Synthesis, And In Vitro Antitumor Activity Of 6-Aryloxyl Substituted Quinazolinederivatives, Meixia Fan, Lei Yao Jan 2022

Design, Synthesis, And In Vitro Antitumor Activity Of 6-Aryloxyl Substituted Quinazolinederivatives, Meixia Fan, Lei Yao

Turkish Journal of Chemistry

Quinazoline derivatives are a class of important antitumor drugs known as small molecule inhibitors that include epidermal growth factor receptor (EGFR) inhibitors. Based on the structure of poziotinib, a series of 6-aryloxyl substituted quinazoline derivatives were designed and synthesized. The in vitro antitumor activities of the compounds were evaluated by the 3-(4,5-dimethyl-thiazol-2- yl)2,5-diphenyltetrazolium bromide (MTT) method using the human gastric cancer N87 (HER2), nonsmall-cell lung cancer H1975 (EGFRT790M/L858R), and A549 (EGFRWT) cell lines. The most promising compound 4m exhibited potent antitumoral activities with IC50 values of 6.3 nM and 7.5 nM for N87 and H1975 cell lines, respectively. Meanwhile, it …

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Adsorption Of Dimethyl Disulfide Onto Activated Carbon Cloth, Fi̇rdevs Mert, Numan Hoda, Ayhan Topuz, Leyla Budama Akpolat, Emrah Eroğlu Jan 2022

Adsorption Of Dimethyl Disulfide Onto Activated Carbon Cloth, Fi̇rdevs Mert, Numan Hoda, Ayhan Topuz, Leyla Budama Akpolat, Emrah Eroğlu

Turkish Journal of Chemistry

Dimethyl disulfide (DMDS) has a specific unpleasant odour and is profoundly toxic with an odour threshold of around 7-12 ppb. In this study, the removal of DMDS was investigated by adsorption on activated carbon cloth (ACC) in the gas phase. Kinetics and isotherm studies were performed. Adsorption kinetics followed by GC-MS and the data were processed using different models. When correlation coefficients (R2) of linear regression analysis are analyzed, it is seen that the concordance of experimental data to the pseudo-second-order equation is quite good. Isotherm data have been examined using Freundlich, Temkin and Langmuir models. The regression coefficient (R2) …

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Electroanalytical Investigation And Voltammetric Quantification Of Antiviral Drug Favipiravir In The Pharmaceutical Formulation And Urine Sample Using A Glassy Carbon Electrode In Anionic Surfactant Media, Zeynep Akca, Hande İzem Özok, Yavuz Yardim, Zühre Şentürk Jan 2022

Electroanalytical Investigation And Voltammetric Quantification Of Antiviral Drug Favipiravir In The Pharmaceutical Formulation And Urine Sample Using A Glassy Carbon Electrode In Anionic Surfactant Media, Zeynep Akca, Hande İzem Özok, Yavuz Yardim, Zühre Şentürk

Turkish Journal of Chemistry

This work describes the electrochemical investigation of a promising antiviral agent, favipiravir (FAV) utilizing a nonmodified glassy carbon (GC) electrode, along with a unique voltammetric approach that can determine FAV with a good degree of accuracy, speed, and cost-effectiveness. Using cyclic voltammetry, the compound demonstrated a single well-defined and an irreversible oxidation peak at approximately +1.12 V (vs. Ag/AgCl) in Britton-Robinson (BR) buffer at pH 10.0. The synergistic effect of anionic surfactant, sodium dodecyl sulfate (SDS) on the adsorption ability of GC electrode remarkably increased the sensitivity of the stripping voltammetric measurements of FAV. Employing square-wave adsorptive stripping voltammetry at …

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Microwave-Assisted Rapid Conjugation Of Horseradish Peroxidase-Dextran Aldehyde With Schiff Base Reaction And Decolorization Of Reactive Blue 19, Mi̇that Çelebi̇, Zafer Ömer Özdemi̇r, Murat Topuzoğullari Jan 2022

Microwave-Assisted Rapid Conjugation Of Horseradish Peroxidase-Dextran Aldehyde With Schiff Base Reaction And Decolorization Of Reactive Blue 19, Mi̇that Çelebi̇, Zafer Ömer Özdemi̇r, Murat Topuzoğullari

Turkish Journal of Chemistry

Microwave irradiation has become a routine technique in homogeneous and effective heating in organic synthesis. However, its application in enzyme-containing reactions is limited since it can cause denaturation of the enzyme. In this study, we have briefly investigated the effect of microwave heating on the conjugation reaction of horseradish peroxidase (HRP) with aldehyde derivative of dextran (D-CHO). The reaction was irradiated by microwave at 50 °C for 5 min. The conjugate was confirmed via GPC, in which the conjugates of HRP and D-CHO coexist with free unbound HRP molecules. Activity studies of HRP revealed that there is a small decrease …

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Microstructure And Ionic Conductivity Investigation Of Samarium Doped Ceria(Sm0.2ce0.8o1.9) Electrolytes Prepared By The Templating Methods, Di̇lara Güçtaş, Vedat Sariboğa, Mehmet Ali̇ Faruk Öksüzömer Jan 2022

Microstructure And Ionic Conductivity Investigation Of Samarium Doped Ceria(Sm0.2ce0.8o1.9) Electrolytes Prepared By The Templating Methods, Di̇lara Güçtaş, Vedat Sariboğa, Mehmet Ali̇ Faruk Öksüzömer

Turkish Journal of Chemistry

Sm0.2Ce0.8O1.9 (SDC20) electrolytes were synthesized with cellulose templating (CT) and PVA templating (PVAT) methods. Powder characteristics were examined using TG/DTA, XRD, and SEM. Pellets are sintered at various temperatures for different durations. Mean grain sizes were calculated from SEM micrographs using the linear intercept method. Grain growth behavior of the electrolytes was investigated and the dominant diffusion mechanism was examined. The grain growth activation energies were obtained for the first time for the mentioned electrolytes prepared by the mentioned methods. The ionic conductivities were calculated by electrochemical impedance spectroscopy. The highest ionic conductivity value was found to be 0.050 S …

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Boric Acid And Schiff Base-Based Fluorescent Sensor For Detection Of L-Tryptophan In Milk And Bsa Samples, Ümran Duru Kamaci, Musa Kamaci Jan 2022

Boric Acid And Schiff Base-Based Fluorescent Sensor For Detection Of L-Tryptophan In Milk And Bsa Samples, Ümran Duru Kamaci, Musa Kamaci

Turkish Journal of Chemistry

In the present paper, the fluorescence sensor based on Schiff base and boric acid was developed for easy and rapid detection of L-tryptophan in different samples such as milk and bovine serum albumin. The photoluminescence intensity was measured by using fluorescent measurements and the results indicated that the developed fluorescent sensor was exhibited selective, sensitive, reliable determination against L-tryptophan, and a series of various analytes such as cations, amino acids, and organic compounds were used to investigate the selectivity of the fluorescent chemosensor. The limit of detection and linear range of the chemosensor were calculated as 0.82 μM, and 0.1?500 …

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Effect Of Promoter Type And Synthesis Method On Catalytic Performance Of Fe-Mn Based Ft-Olefin Catalysts, Gamze Gümüşlü Gür, Özge Ati̇k Jan 2022

Effect Of Promoter Type And Synthesis Method On Catalytic Performance Of Fe-Mn Based Ft-Olefin Catalysts, Gamze Gümüşlü Gür, Özge Ati̇k

Turkish Journal of Chemistry

Direct production of light olefins, building blocks of chemical industry, can be attained by developing efficient catalysts for Fischer?Tropsch synthesis (FTS). The nature of FTS complicates the catalyst development process as the product distribution is affected by the components and the preparation methods of the catalyst. In this work, high-throughput (HT) methodology is employed to overcome this problem by testing many different catalyst formulations. Fast performance screening of 40 different α-Al2O3 supported Fe-Mn based catalysts promoted with Cu, K and Ni, using different impregnation agents, was performed in a HT test system at atmospheric pressure. Promising catalyst candidates identified by …

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Electrically Conductive, Hydrophobic, Uv Protective And Lightweight Cotton Spunlace Nonwoven Fabric Coated With Reduced Graphene Oxide, Beki̇r Cenkkut Gülteki̇n Jan 2022

Electrically Conductive, Hydrophobic, Uv Protective And Lightweight Cotton Spunlace Nonwoven Fabric Coated With Reduced Graphene Oxide, Beki̇r Cenkkut Gülteki̇n

Turkish Journal of Chemistry

In this study, cotton spunlace nonwoven fabrics with four different basis weights were coated with graphene oxide (GO) by conventional dip coating method which is one of the most simple and effortless process in textile industry. The graphene oxide coated cotton nonwoven fabrics were immersed in an aqueous sodium dithionite solution in order to obtain reduced graphene oxide (RGO) coated cotton spunlace nonwoven fabrics. The obtained nonwoven fabrics became electrically conductive with very low surface electrical resistivity of 5.98 × 102 W/sq for the 70 g/m2 basis weight nonwoven fabric. The color measurements and reflectance spectrophotometry were performed in order …

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Synthesis And Characterization Of Amino Sulfonic Acid Functionalized Graphene Oxide As A Potential Carrier For Quercetin, Ali Sadeghi, Mohammad Faeli, Mahmood Tajbakhsh, Abdolreza Abri, Monireh Golpour Jan 2022

Synthesis And Characterization Of Amino Sulfonic Acid Functionalized Graphene Oxide As A Potential Carrier For Quercetin, Ali Sadeghi, Mohammad Faeli, Mahmood Tajbakhsh, Abdolreza Abri, Monireh Golpour

Turkish Journal of Chemistry

In this investigation, a new nanocomposite as a nanocarrier based on functionalized graphene oxide was synthesized by reaction of tetraethylenepentamine and chlorosulfonic acid with functional groups on the surface of GO. The synthesized nanocomposite was characterized by FT-IR, XRD TGA, FE-SEM, EDAX, TEM, and AFM analysis. To explore the potential of nanocomposites in drug delivery, the loading and releases of quercetin as an anticancer drug were investigated. The result displayed that more than 90% of the drug was loaded on the nanocarrier and the release of the drug is depending on the pH of the environment such that the releases …

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Co2 Absorption Into Primary And Secondary Amine Aqueous Solutions With And Without Copper Ions In A Bubble Column, Hamed Yousefzadeh, Cansu Güler, Can Erkey, Erdal Uzunlar Jan 2022

Co2 Absorption Into Primary And Secondary Amine Aqueous Solutions With And Without Copper Ions In A Bubble Column, Hamed Yousefzadeh, Cansu Güler, Can Erkey, Erdal Uzunlar

Turkish Journal of Chemistry

Chemical absorption of CO2 into aqueous amine solutions using a nonstirred bubble column was experimentally investigated. The performance of CO2 absorption of four different primary and secondary amines including monoethanolamine (MEA), piperazine (PZ), 2-piperidineethanol (2PE), and homopiperazine (HPZ) were compared. The effects of initial concentration of amine, the inlet mole fraction of CO2, and solution temperature on the rate of CO2 absorption and CO2 loading (mol CO2/mol amine) were studied in the range of 0.02-1 M, 0.10-0.15, and 25-40 °C, respectively. The effect of the presence of copper ions in the amine solution on CO2 loading was also studied. By …

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Peg4000 Modified Liposomes Enhance The Solubility Of Quercetin And Improve The Liposome Functionality: In Vitro Characterization And The Cellular Efficacy, Gülen Meli̇ke Demi̇rbolat, Ömer Erdoğan, Gökni̇l Peli̇n Coşkun, Özge Çevi̇k Jan 2022

Peg4000 Modified Liposomes Enhance The Solubility Of Quercetin And Improve The Liposome Functionality: In Vitro Characterization And The Cellular Efficacy, Gülen Meli̇ke Demi̇rbolat, Ömer Erdoğan, Gökni̇l Peli̇n Coşkun, Özge Çevi̇k

Turkish Journal of Chemistry

Quercetin, a multifunctional therapeutic agent, is used in various types of cancer. However, its therapeutic effect is limited by virtue of poorly aqueous solubility and instability in the physiological medium. To overcome these limitations, we aimed (i) to design quercetin loaded liposomes with unlinked-PEG4000 with regard to not only surface modification but also solubility enhancement, and (ii) to investigate the antineoplastic effects on HeLa cells. PEG4000 increased the quercetin solubility 2.2 fold. PEG4000 modified liposomes displayed small particle size (254 ± 69 nm), low polydispersity index (0.236 ± 0.018), favorable zeta potential (-35.4 ± 0.6 mV), high quercetin encapsulation efficiency …

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Synthesis Of Polydentate, Multi Metal Ion Sensing, Unsymmetrical Schiff Bases With Complimented Antifungal Activity, Saranya Dhasarathan, Selvaraj Shunmugaperumal, P. Kamatchi Selvaraj Jan 2022

Synthesis Of Polydentate, Multi Metal Ion Sensing, Unsymmetrical Schiff Bases With Complimented Antifungal Activity, Saranya Dhasarathan, Selvaraj Shunmugaperumal, P. Kamatchi Selvaraj

Turkish Journal of Chemistry

Polydentate, unsymmetrical, and multi metal ion sensing Schiff bases comprised of ferrocenecarboxaldehyde attached azomethine group at one side and aromatic aldehyde linked imine on the other side have been synthesized. Cumulative addition of different metal salts solution to receptors solution, changes the electronic spectra contrarily and for the addition of Cu2+ ions, generation of MLCT charge transfer band responsible for the coordination of metal ion with a receptor is observed. Electrochemical data (ΔEp) arrived from the cyclic voltammograms suggest a quasi-reversible process. The modest concentration of metal ions required for effective sensing by the sensory material is calculated from the …

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Intake Of Divalent Copper And Nickel Onto Natural Zeolite From Aqueous Solutions: A Study In Mono- And Dicomponent Systems, Burak Teki̇n, Ünsal Açikel Jan 2022

Intake Of Divalent Copper And Nickel Onto Natural Zeolite From Aqueous Solutions: A Study In Mono- And Dicomponent Systems, Burak Teki̇n, Ünsal Açikel

Turkish Journal of Chemistry

In this study, the noncompetitive and competitive adsorption process of copper (II) and nickel (II) ions on the natural zeolite were examined in simulated wastewater in a batch system with respect to concentration, pH and temperature. Optimum pH values were found as 5,0 for adsorption of copper and nickel ions on the zeolite. The effect of initial concentration and ambient temperature on the yield of adsorption was examined at this pH value. The equilibrium adsorption data of Cu (II) and Ni (II) onto the zeolite were analyzed by the Langmuir's and Freundlich's isotherms, and the experimental metal uptake data fitted …

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Thio-Schiff Bases Derived From 2,2'-Disulfanedianiline Via Nanocerium Oxide: Antimicrobial Effect And Antiproliferative Effects In Melanoma Cells, Aslihan Dalmaz, Sefa Durmuş, Görkem Dülger, Merve Alpay Jan 2022

Thio-Schiff Bases Derived From 2,2'-Disulfanedianiline Via Nanocerium Oxide: Antimicrobial Effect And Antiproliferative Effects In Melanoma Cells, Aslihan Dalmaz, Sefa Durmuş, Görkem Dülger, Merve Alpay

Turkish Journal of Chemistry

In this study, the synthesis of dimeric disulfide-Schiff bases was carried out using two methods. The structures of the obtained Schiff bases were elucidated by various spectroscopic methods as well as elemental analysis. The Schiff base derivative compounds (3a-6) were screened for in vitro antibacterial activity against multidrug-resistant microorganisms using microdilution method. All the tested compounds showed varying inhibition zones against the pathogens. According to MIC results, the compound 2 was shown strong inhibitory activity against all the tested microorganisms compared to antibiotics. In addition, all the tested compounds showed different antiproliferative effects on the melanoma cell line (B16F10). Our …

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Comparison Of A Commercial Water-Gas Shift Catalyst And La Modified Cu-Based Catalysts Prepared By Deposition-Precipitation In Methanol Steam Reforming, Orhan Özcan, Ayşe Ni̇lgün Akin Jan 2022

Comparison Of A Commercial Water-Gas Shift Catalyst And La Modified Cu-Based Catalysts Prepared By Deposition-Precipitation In Methanol Steam Reforming, Orhan Özcan, Ayşe Ni̇lgün Akin

Turkish Journal of Chemistry

Herein, a performance analysis of La-doped copper-based catalysts (CuO/ZrO2/La-Al2O3) in methanol steam reforming (MSR) was conducted and compared with a commercial low temperature water-gas shift catalyst (HiFUEL W220) to produce H2 with low CO selectivity. The physicochemical properties of as-obtained catalysts were characterized by N2 adsorption, XRD, and ICP-OES. Effect of calcination temperature (750 oC and 1000 oC) on the properties of mixed oxide support (La-Al2O3) were discussed based on catalytic activity. The optimum conditions of H23O/CH3OH ratio (1.0-3.0), space-time ratio (WFA0) (40-120 kg s mol-1), and reaction temperature (180-310 oC) were evaluated by a parametric study using the commercial …

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Oxygen Vacancies On Pd/Tio2 Are Detected At Low Pressures By Esr Spectroscopy At Ambient Temperatures, Deni̇z Üner, Meli̇s Yarar Jan 2022

Oxygen Vacancies On Pd/Tio2 Are Detected At Low Pressures By Esr Spectroscopy At Ambient Temperatures, Deni̇z Üner, Meli̇s Yarar

Turkish Journal of Chemistry

A low field benchtop electron spin resonance (ESR) (also referred to as electron paramagnetic resonance (EPR)) spectrometer is used to reveal paramagnetic centres such as oxygen vacancies and Ti+3 centres over 0.5%Pd/TiO2. The measurement was performed at room temperature after the sample was reduced in situ under mild hydrogen pressures and evacuated to P < 10-6 Torr. The measurement was possible due to a T1 compensation effect under vacuum: Correlation times at low pressures enabled sufficient line narrowing and detection of the ESR signal, justifying a method using benchtop spectrometers coupled to vacuum manifolds. The method justification was demonstrated using similar measurements performed on a reference compound, Mn(II) in plasticine: a measurement performed by saturation recovery technique revealed that T1 of the signal due to Mn(II) was smaller in vacuum than its atmosphere exposed counterpart. By applying vacuum, the ESR spectra of 0.5%Pd/TiO2 were collected at ambient temperatures, with features equivalent to the published data obtained at cryogenic temperatures.

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Synthesis Of Novel Oxadiazole Derivatives And Their Cytotoxic Activity Against Various Cancer Cell Lines, Bi̇lgesu Onur Sucu, Eli̇f Beyza Koç Jan 2022

Synthesis Of Novel Oxadiazole Derivatives And Their Cytotoxic Activity Against Various Cancer Cell Lines, Bi̇lgesu Onur Sucu, Eli̇f Beyza Koç

Turkish Journal of Chemistry

Caffeic acid (CA), ferulic acid (FA) and caffeic acid phenethyl ester (CAPE) have a broad anticancer effect on various cell lines. In this study, nine ferulic and caffeic acid-based 1,2,4 and 1,3,4 oxadiazole molecular hybrids were synthesized and their cytotoxic activity was evaluated mainly against Glioblastoma (GBM) cell lines. Compounds 1 and 5 exhibited the highest inhibitory activity against three different GBM cell lines (LN229, T98G, and U87), without toxicity to healthy human mesenchymal stem cells (hMSC). In addition, their cytotoxicity was also evaluated against three additional cancer cell lines and more inhibitory results were found than GBM cell lines. …

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Synthesis And Characterization Of An Electrochromic Copolymer Based On 9, 10-Di (Furan-2-Yl)Anthracene And 3,4-Ethylenedioxythiophene, Ali̇ Kalçik, Ari̇f Kivrak, Buket Çarbaş Jan 2022

Synthesis And Characterization Of An Electrochromic Copolymer Based On 9, 10-Di (Furan-2-Yl)Anthracene And 3,4-Ethylenedioxythiophene, Ali̇ Kalçik, Ari̇f Kivrak, Buket Çarbaş

Turkish Journal of Chemistry

In this study, a new copolymer, which is a combination of two chemical structure (9,10-di(furan-2-yl)anthracene and 3,4-ethylenedioxythiophene was synthesized via electrochemical synthesis methods in the electrolyte medium of 0.1 M TBAPF6/ ACN solution. PEDOT homopolymer was also electrosynthesized for comparator experiments of the polymer formations in the same medium. The characterizations of polymers were achieved with general optical and electrochemical characterization techniques. The corresponding electrochromic copolymer shows blue and lilac color in its neutral and oxidized states, respectively. The copolymer has an optical band gap of 1.65 eV and 24% optical contrast at 500 nm with a high coloration efficiency …

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Synthesis And Investigation Of Antiproliferative Activity Of Ru-Nhc Complexes Against C6 And Hela Cancer Cells, Ramazan Paşahan, Mi̇tat Akkoç, Şeyma Yaşar, Tuğba Kul Köprülü, Şaban Teki̇n, Sedat Yaşar, İsmai̇l Özdemi̇r Jan 2022

Synthesis And Investigation Of Antiproliferative Activity Of Ru-Nhc Complexes Against C6 And Hela Cancer Cells, Ramazan Paşahan, Mi̇tat Akkoç, Şeyma Yaşar, Tuğba Kul Köprülü, Şaban Teki̇n, Sedat Yaşar, İsmai̇l Özdemi̇r

Turkish Journal of Chemistry

The 2-methylpyridine, 2-diethylaminoethyl, and isopentyl linked a series of symmetric and unsymmetric benzimidazolium salts 2a-e were prepared and used in the synthesis of silver-N-heterocyclic carbene (NHC) complexes (3a-e). The Ru(II)-NHC complexes (4a-h) were synthesized via transmetalation reaction from 3a-e. 4a-h complexes were converted to Ru(II)-NHC.HCl complexes (5ah) by HCl solution of diethyl ether and characterized by different spectroscopic techniques such as 1H and 13C NMR, LC/MS-Q-TOF, FT-IR, elemental analysis, and melting point detection. We examined the effect of the structural difference of complexes on anticancer activity via different arenes and metal centers. Antiproliferative activity of 5a-h and 3a was tested …

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Improved Visible Light-Driven Photocatalytic Degradation Of Methylene Blue And Methyl Red By Boron-Doped Carbon Quantum Dots, Bi̇rcan Haspulat Taymaz, Çi̇sem Kirbiyik Kurukavak, Handan Kamiş, Mahmut Kuş Jan 2022

Improved Visible Light-Driven Photocatalytic Degradation Of Methylene Blue And Methyl Red By Boron-Doped Carbon Quantum Dots, Bi̇rcan Haspulat Taymaz, Çi̇sem Kirbiyik Kurukavak, Handan Kamiş, Mahmut Kuş

Turkish Journal of Chemistry

The synthesis of fluorescent carbon quantum dots (CQDs) and their applications have attracted great attention due to their excellent properties. Especially, the unique visible-light absorption and photo-induced electron transfer properties make CQDs available in photocatalytic degradation of organic dye pollutants in water resources. Herein, we synthesized nondoped CQDs and boron-doped CQDs (B-CQDs) by hydrothermal method and compared their photocatalytic degradation activity of methylene blue (MB) and methyl red (MR) dyes under visible light irradiation. The characterization outcomes showed that the optical and structural properties can be easily improved by doping with hetero-atom, thereby photocatalytic performance. As expected, the photodegradation performance …

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Investigation Of Antibacterial Properties Of Polyacrylonitrile Fibers Modified By New Functional Groups And Silver Nanoparticles, Zeynep Okay, Meryem Kalkan Erdoğan, Başar Karaca, Meral Karakişla, Mehmet Saçak Jan 2022

Investigation Of Antibacterial Properties Of Polyacrylonitrile Fibers Modified By New Functional Groups And Silver Nanoparticles, Zeynep Okay, Meryem Kalkan Erdoğan, Başar Karaca, Meral Karakişla, Mehmet Saçak

Turkish Journal of Chemistry

This work reports the surface modification of polyacrylonitrile (PAN) fibers by graft copolymerization to ensure the decoration of homogenous and dense Ag nanoparticles. Two facile and subsequent modification processes resulted in a PAN fiber composite with an intact fibrous structure, sufficiently conductive for antistatic application and antibacterial activity. In the first step, some chemically attractive monomers and monomer mixtures, such as acrylic acid (AA), AA-itaconic acid (AA-IA), AA-acrylamide (AA-AAm), were introduced to the fiber surface by grafting. The grafting process was evidenced by FTIR, 1H-NMR, and SEM techniques. The second step aimed to form a chelate structure by Ag + …

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Discrimination And Authentication Of Geographical Origin Of Turkish Taşköprü Garlic By Investigating Volatile Organosulfur Compound Profiles And Multivariate Analyses, Orhan Destanoğlu Jan 2022

Discrimination And Authentication Of Geographical Origin Of Turkish Taşköprü Garlic By Investigating Volatile Organosulfur Compound Profiles And Multivariate Analyses, Orhan Destanoğlu

Turkish Journal of Chemistry

Nowadays, counterfeiting and adulteration on foods take place around the world in a variety of ways. Identification and authentication of geographical origin of agricultural products has great importance not only for food safety, but for protection of registrations as well. This study aimed at discriminating the Turkish Taşköprü garlic, possessing protected geographical indication (GI) in Turkey and GI registration from the European Union, from the other samples. For this reason, the combination of headspacegas chromatography-mass spectrometry (HS-GC-MS) analysis of the volatile organosulfur compounds (VOSCs) and two multivariate analysis techniques, namely hierarchical cluster analysis (HCA) and principal component analysis (PCA), were …

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Fabrication Of Electrospun Cellulose-Derived Nanofiber Membranes With Enhanced Stability Properties Of Arginase, Ceyhun Işik, Mustafa Teke Jan 2022

Fabrication Of Electrospun Cellulose-Derived Nanofiber Membranes With Enhanced Stability Properties Of Arginase, Ceyhun Işik, Mustafa Teke

Turkish Journal of Chemistry

In this study, cellulose acetate (CA)/polyvinylpyrrolidone (PVP) and CA/PVP/Mn2+ nanofibers were produced by the electrospinning method, and these cellulose-derived membranes were used as carriers for arginase immobilization for the first time. The structural and morphological analysis of these cellulose-derived nanofibers were determined by attenuated total reflection-Fourier to transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). After the immobilization process, it was observed that the thermal properties of the cellulose-derived nanofibers especially improved. The optimum temperature value for free arginase was found to be 35 °C, and this value was found to be 40 …

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Detailed Structure Analyses On Cobalt Doped Pbtio3 Powders, Ebru Erünal Jan 2022

Detailed Structure Analyses On Cobalt Doped Pbtio3 Powders, Ebru Erünal

Turkish Journal of Chemistry

The identification of the defects and secondary phases which significantly affect the material properties are of crucial importance. In this study, a systematic structure examination of PbTiO3 and cobalt doped PbTiO3 powder ceramics was carried out. X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), Raman, and electron paramagnetic resonance (EPR) spectroscopies were applied along with nonsimultaneous thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The doped and undoped PbTiO3 materials were synthesized via a practical sol-gel route that takes place at 50 °C. The perovskite formation for both materials was verified. The dislocation density of cobalt doped PbTiO3 was found to be …

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Comprehensive Evaluation Of Reseda Lutea L. (Wild Mignonette) And 7 Isolated Flavonol Glycosides: Determination Of Antioxidant Activity, Anti-Alzheimer, Antidiabetic And Cytotoxic Effects With In Vitro And In Silico Methods, Hati̇ce Kiziltaş Jan 2022

Comprehensive Evaluation Of Reseda Lutea L. (Wild Mignonette) And 7 Isolated Flavonol Glycosides: Determination Of Antioxidant Activity, Anti-Alzheimer, Antidiabetic And Cytotoxic Effects With In Vitro And In Silico Methods, Hati̇ce Kiziltaş

Turkish Journal of Chemistry

In this study, anticholinergic, antidiabetic, antioxidant and cytotoxic activities of Reseda lutea L. (R. lutea) were determined. Ethanol extracts of R. lutea (EERL) and water extract of R. lutea (WERL) were prepared for biochemical analysis. The antioxidant capacities of EERL and WERL were evaluated with 6 different methods. In addition, acetylcholinesterase (AChE), α-amylase and α-glycosidase enzyme inhibition by EERL were measured. According to the results, EERL exhibited high inhibition effects against α-amylase, α-glycosidase and AChE enzymes. The IC50 values of EERL against AChE (2.21 μg/mL), α-glycosidase (1.38 μg/mL), and α-amylase (0.11 μg/mL) were determined. Also, high cytotoxic effect of EERL …

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A Theoretical Study Of Co Adsorption On Cu(211) Surface With Coverage Effects, Murat Oluş Özbek Jan 2022

A Theoretical Study Of Co Adsorption On Cu(211) Surface With Coverage Effects, Murat Oluş Özbek

Turkish Journal of Chemistry

CO adsorption on the Cu(211) surface was investigated using energy, geometry and vibrational data, which were produced through periodic DFT computations. Adsorption on the (111) terrace, as well as the previously reported top and bridge sites of the step-edges, was studied at 0.25, 0.33, 0.50, 0.66, 0.75, and 1.00 monolayer (ML) CO coverage. Results showed that up to and including 0.50 ML, on-top or bridge adsorption is preferred on the step-edges. When 0.50 ML is exceeded, top-bridge alternating patterns become feasible on the step edges along with possible shifts towards the terrace. Several feasible patterns were identified at 0.66, 0.75, …

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Selective Nanosensor Based On Folic Acid Imprinted Nanostructures, Kevser Kuşat, Serdar Şanli, Suna Ti̇mur, Si̇nan Akgöl Jan 2022

Selective Nanosensor Based On Folic Acid Imprinted Nanostructures, Kevser Kuşat, Serdar Şanli, Suna Ti̇mur, Si̇nan Akgöl

Turkish Journal of Chemistry

Folic acid, which provides the transfer of single carbon atoms in synthesis reactions and metabolic cycles in metabolism, is very important for metabolism. Folic acid also plays an important role in nucleotide synthesis and methylation reactions. There are many disorders caused by defective folic acid metabolism and lack of folic acid. Today, innovative, cost-effective methods are needed to develop folic acid determination methods. The main objective of this study is the development of surface-printed carbon electrodes (SPCE) modified with folic acid imprinted nanostructures (FA-Imp-poly(MPTS-rGO-co-NAT), which will be used for the first time for folic acid determination in commercially human blood …

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Simulation Of Two Electrode Reactions Coupled By The Chemical Reaction, Milivoj Lovric Jan 2022

Simulation Of Two Electrode Reactions Coupled By The Chemical Reaction, Milivoj Lovric

Turkish Journal of Chemistry

A model of an ECE mechanism consisting of two reversible electrode reactions coupled by the kinetically controlled, second order, reversible chemical reaction is developed for the staircase cyclic voltammetry on the rotating disk electrode. The relationship between the limiting current of the second wave and the rate constant of chemical reaction is investigated. The concentration of electroinactive component of the forward reaction influences the half-wave potential of the first wave and the limiting current of the second wave. The responses of the mechanisms with reversible and irreversible chemical reactions are compared.

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1-D And 2-D Coordination Networks Based On Tetrathiacalix[4]Arene Derivative Generated With Mercury And Cobalt Salts, Huri̇ye Akdaş Kiliç, Ernest Graf, Mi̇r Wai̇s Hossei̇ni̇, Nathali̇e Kyri̇tsakas Jan 2022

1-D And 2-D Coordination Networks Based On Tetrathiacalix[4]Arene Derivative Generated With Mercury And Cobalt Salts, Huri̇ye Akdaş Kiliç, Ernest Graf, Mi̇r Wai̇s Hossei̇ni̇, Nathali̇e Kyri̇tsakas

Turkish Journal of Chemistry

The combination of four iso-nicotinate appended tetrathiacalix[4]arene (TCA-1) in 1,2-alternate imposed conformation behaving as neutral tectons with Co(II)Cl2 and Hg(II)Cl2 metallic salts, leads to the formation of neutral, new coordination networks. Indeed, the tetrasubstituted TCA-1 derivative leads to a 1D coordination polymer with Co(II)Cl2 and a 2D grid-like network with, Hg(II)Cl2. The effect of the nature of the metal used on the dimensionality was demonstrated by X-ray diffraction studies on a single crystal.

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Green Synthesis, Characterisation Of Au And Ag Nanoparticles By Various Bioextracts And Their Usability At Graphite Electrode Modification, Emi̇ne Arslan, Ender Bi̇çer, Eli̇f Sekmen, Semi̇ha Çakir Jan 2022

Green Synthesis, Characterisation Of Au And Ag Nanoparticles By Various Bioextracts And Their Usability At Graphite Electrode Modification, Emi̇ne Arslan, Ender Bi̇çer, Eli̇f Sekmen, Semi̇ha Çakir

Turkish Journal of Chemistry

In this study, the biosynthesis of Au and Ag nanoparticles (AuNp and AgNp) with a green chemistry approach was performed by using bioextracts of various fruits and vegetables (Lycopersicon esculentum (LE), Cucumis sativus (CS), Malus domestica (MD), Cucurbita pepo (CP), Apiumgraveolens var. rapaceum (AVR), Prunus cerasifera (PC), Oleraceae var. botrytis (OVB)). In the determination of optimum experimental conditions, the parameters such as the type and concentration of bioextract, concentration of metal ion solutions, the ratio of metal ion solution to bioextract, pH, reaction time and temperature were found to be significant. The characterisation of AuNp and AgNp synthesized by providing …

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