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Articles 421 - 450 of 2628
Full-Text Articles in Physical Sciences and Mathematics
Electrochemical Evaluation Of The Desloratadine At Bismuth Film Electrode In The Presence Of Cationic Surfactant: Highly Sensitive Determination In Pharmaceuticals And Human Urine By Linear Sweep-Cathodic Stripping Voltammetry, Yalçin Altunkaynak, Günay Önal, Abdulkadi̇r Levent
Electrochemical Evaluation Of The Desloratadine At Bismuth Film Electrode In The Presence Of Cationic Surfactant: Highly Sensitive Determination In Pharmaceuticals And Human Urine By Linear Sweep-Cathodic Stripping Voltammetry, Yalçin Altunkaynak, Günay Önal, Abdulkadi̇r Levent
Turkish Journal of Chemistry
In this study, the electrochemical properties of desloratadine, which is in the second generation antihistamines group, were determined by bismuth film electrode (BiFE) in aqueous and aqueous/surfactant solutions. This compound gave an irreversible and diffusion-controlled reduction peak at about -1.65 V by cyclic voltammetry. It was found that the addition of cationic surfactants (cetyltrimethylammonium bromide (CTAB) increased the reduction current signal of desloratadine, while anionic (sodium dodecylsulfate (SDS) and nonionic (Tween 80) surfactants were found to have an adverse effect. Using linear sweep-cathodic stripping voltammetry, the analytical signal showed a linear correlation with a concentration of 0.1 to 4 μM …
Novel Mannich Bases With Strong Carbonic Anhydrases And Acetylcholinesterase Inhibition Effects: 3-(Aminomethyl)-6-{3-[4-(Trifluoromethyl)Phenyl]Acryloyl}-2(3h)- Benzoxazolones, Si̇nan Bi̇lgi̇ner, Bariş Anil, Mehmet Koca, Yeli̇z Demi̇r, İlhami̇ Gülçi̇n
Novel Mannich Bases With Strong Carbonic Anhydrases And Acetylcholinesterase Inhibition Effects: 3-(Aminomethyl)-6-{3-[4-(Trifluoromethyl)Phenyl]Acryloyl}-2(3h)- Benzoxazolones, Si̇nan Bi̇lgi̇ner, Bariş Anil, Mehmet Koca, Yeli̇z Demi̇r, İlhami̇ Gülçi̇n
Turkish Journal of Chemistry
In this study, a new series of Mannich bases, 3-(aminomethyl)-6-{3-[4-(trifluoromethyl)phenyl]acryloyl}-2(3H)- benzoxazolones (1a-g), were synthesized by the Mannich reaction. Inhibitory effects of the newly synthesized compounds towards carbonic anhydrases (CAs) and acetylcholinesterase (AChE) enzymes were evaluated to find out new potential drug candidate compounds. According to the inhibitory activity results, Ki values of the compounds 1 and 1a-g were in the range of 12.3 ± 1.2 to 154.0 ± 9.3 nM against hCA I, and they were in the range of 8.6 ± 1.9 to 41.0 ± 5.5 nM against hCA II. Ki values of acetazolamide (AZA) that was used as …
Development Of A Functional Impedimetric Immunosensor For Accurate Detection Of Thy-Roid-Stimulating Hormone, Engi̇n Asav
Development Of A Functional Impedimetric Immunosensor For Accurate Detection Of Thy-Roid-Stimulating Hormone, Engi̇n Asav
Turkish Journal of Chemistry
Thyroid-stimulating hormone (TSH), which regulates the synthesis of thyroid gland hormones affecting the whole metabo¬lism, is a pituitary hormone. Determination of TSH is crucial for monitoring thyroid gland-related disorders and some metabolic diseases. In this study, a nonlabeled immunosensor based on covalent immobilization of anti-TSH antibody by using the formation of self-as-sembled monolayers (SAM) of 4-mercaptophenylacetic acid (4-MPA) and functionalization of carboxyl ends with 1-ethyl-3-(3-dimeti-laminopropil) carbodiimide (EDC)/N-Hydroxysuccinimide (NHS) was fabricated for detection of TSH. Immobilization steps including the concentration of 4-MPA, the concentration of anti-TSH antibody, and duration of anti-TSH antibody incubation were optimized by utilizing electrochemical impedance spectroscopy. Under …
Evaluation Of The Surface Properties Of 4-(Decyloxy) Benzoic Acid Liquid Crystal And Its Use In Structural Isomer Separation, Bi̇rol Işik, Fati̇h Çakar, Hüsnü Cankurtaran, Özlem Cankurtaran
Evaluation Of The Surface Properties Of 4-(Decyloxy) Benzoic Acid Liquid Crystal And Its Use In Structural Isomer Separation, Bi̇rol Işik, Fati̇h Çakar, Hüsnü Cankurtaran, Özlem Cankurtaran
Turkish Journal of Chemistry
The selectivity of 4-(Decyloxy) benzoic acid (DBA) liquid crystal in surface adsorption region (303.2-328.2 K) and thermodynamic region (423.2 - 433.2 K) was investigated by inverse gas chromatography at infinite dilution (IGC-ID). The selectivity parameters of the structural isomer series named butyl acetate, butyl alcohol, and amyl alcohol series were calculated for the DBA using IGC-ID technique. Additionally, the surface properties including dispersive surface energy (γ SD), free energy (ΔGAS), enthalpy (ΔHAS), and acidity-basicity constants were calculated with net retention volumes obtained from IGC-ID experiment results. When the ΔHAS and ΔGAS are constants, DBA surface was found to be an …
3-Hydroxy-7,8,9,10-Tetrahydro-6h-Benzo[C]Chromen-6-One And 3-Hydroxy-6h-Benzo[C] Chromen-6-One Act As On-Off Selective Fluorescent Sensors For Iron (Iii) Under In Vitro And Ex Vivo Conditions, Karar Shukur, Amirhossein Fallah, Kerem Terali, Rasi̇me Kalkan, Mustafa Gazi, Hayretti̇n Ozan Gülcan
3-Hydroxy-7,8,9,10-Tetrahydro-6h-Benzo[C]Chromen-6-One And 3-Hydroxy-6h-Benzo[C] Chromen-6-One Act As On-Off Selective Fluorescent Sensors For Iron (Iii) Under In Vitro And Ex Vivo Conditions, Karar Shukur, Amirhossein Fallah, Kerem Terali, Rasi̇me Kalkan, Mustafa Gazi, Hayretti̇n Ozan Gülcan
Turkish Journal of Chemistry
Regarding the abundant use of metals for different purposes, it becomes more critical from various scientific and technologi¬cal perspectives to discover novel agents as selective probes for the detection of specific metals. In our previous studies, we have shown that aqueous solutions of natural urolithins (i.e., hydroxyl-substituted benzo[c]chromen-6-one derivatives) are selective Iron (III) sen¬sors in fluorescence assays. In this study, we have extrapolated these findings to another coumarine compound (i.e., 3-Hydroxy-7,8,9,10- tetrahydro-6H-benzo[c]chromen-6-one) and compared the selective metal binding properties with Urolithin B (i.e., 3-Hydroxy-6H-benzo[c]chromen-6-one). Following the synthesis and structure identification studies, the fluorometric studies pointed out that the lactam group …
High Capacity Gas Capture And Selectivity Properties Of Triazatruxene-Basedultramicroporous Hyper-Crosslinked Covalent Polymer, Ali̇ Eni̇s Sadak
High Capacity Gas Capture And Selectivity Properties Of Triazatruxene-Basedultramicroporous Hyper-Crosslinked Covalent Polymer, Ali̇ Eni̇s Sadak
Turkish Journal of Chemistry
Tuning the selective sorption features of microporous organic networks is of great importance for subsequent applications in gas uptake and hiding, while it is more attractive in terms of being both time and cost effective to realize these optimizations without using functional groups in the core and linker. "Knitting" is one of the easiest and most used method to obtain a broad scope of hyper-crosslinked polymers on a large scale from aromatic structures that do not contain functional groups for polymerization. By the use of Knitting method, a hypercrosslinked covalent ultramicroporous organic polymer was obtained via stepwise process from using …
Spectrophotometric And Colorimetric Determination Of Gallium (Iii) With P-Aminohippuricacid-Functionalized Citrate Capped Gold Nanoparticles, Asi̇ye Aslihan Avan
Spectrophotometric And Colorimetric Determination Of Gallium (Iii) With P-Aminohippuricacid-Functionalized Citrate Capped Gold Nanoparticles, Asi̇ye Aslihan Avan
Turkish Journal of Chemistry
A new technique for sensing Ga(III) concentration based on polyvinyl alcohol-citrate capped gold nanoparticle-p-aminohippuric acid hybrid (or three-layer core-shell configurations) has been demonstrated. The p-aminohippuric acid capped citrate-gold nanoparticles were comfortably agglomerated in the presence of Ga(III), and the color of the reaction quickly turned from red to violet or blue. Under the detection conditions, a good linear relationship was ideally obtained between the ratio of the absorbance intensity at 620 nm to that at 520 nm (A620/A520). The linear response range, the detection, and quantification limit was 34.9-418.3 μg/L and 7.6 μg/L, and 25 μg/L, respectively. To reflect the …
Uv-Visible Spectroscopic Study On Multi-Staged Film Formation Mechanisms Of Graphene Oxide-Doped Polystyrene Latex (Ps Latex/Go) Nanocomposites, Asef Etemadi, Bariş Demi̇rbay, Şazi̇ye Uğur
Uv-Visible Spectroscopic Study On Multi-Staged Film Formation Mechanisms Of Graphene Oxide-Doped Polystyrene Latex (Ps Latex/Go) Nanocomposites, Asef Etemadi, Bariş Demi̇rbay, Şazi̇ye Uğur
Turkish Journal of Chemistry
We report the effect of graphene oxide (GO) on film formation and morphological properties of GO-doped polystyrene (PS) latex nanocomposite (PS latex/GO) films using UV-visible absorption spectroscopy and scanning electron microscopy (SEM). PS latex particles were synthesized through emulsion polymerization technique and then nanocomposite blends, each containing different concentrations of GO ranging from 0 wt% to 70 wt%, were obtained. Prepared blends were deposited on glass plates via drop-casting method and coated substrates were annealed at different temperatures between 100 °C and 250 °C. At each annealing temperature, transmitted light intensity of nanocomposite films was recorded. Void closure and Prager-Tirrell …
Aspect Ratio Dependent Air Stability Of Pbse Nanorods And Photovoltaic Applications, Demet Asi̇l, Tuğba Haciefendi̇oğlu
Aspect Ratio Dependent Air Stability Of Pbse Nanorods And Photovoltaic Applications, Demet Asi̇l, Tuğba Haciefendi̇oğlu
Turkish Journal of Chemistry
Development of unique strategies to overcome Shockley-Queisser (SQ) limit in solar cells has gained a great deal of interest. Multiple exciton generation (MEG) process has been considered as one of the best approaches to the SQ limitation. In this respect, PbSe quantum dots (QDs) and nanorods (NRs) have been regarded as promising solar energy harvesting materials owing to their noticeable MEG yields. Although air stability has been regarded as one of the main disadvantage of PbSe QDs, no study has pointed out to the air sensitivity of PbSe NRs yet. Here, we reveal the effect of aspect ratio on air …
Pan-Based Activated Carbon Nanofiber/Metal Oxide Composites For Co2 And Ch4adsorption: Influence Of Metal Oxide, Çi̇sem Kirbiyik Kurukavak, Burak Zafer Büyükbekar, Mustafa Ersöz
Pan-Based Activated Carbon Nanofiber/Metal Oxide Composites For Co2 And Ch4adsorption: Influence Of Metal Oxide, Çi̇sem Kirbiyik Kurukavak, Burak Zafer Büyükbekar, Mustafa Ersöz
Turkish Journal of Chemistry
In the present study, we successfully prepared two different electrospun polyacrylonitrile (PAN) based-activated carbon nanofiber (ACNF) composites by incorporation of well-distributed Fe2O3 and Co3O4 nanoparticles (NPs). The influence of metal oxide on the structural, morphological, and textural properties of final composites was thoroughly investigated. The results showed that the morphological and textural properties could be easily tuned by changing the metal oxide NPs. Even though, the ACNF composites were not chemically activated by any activation agent, they presented relatively high surface areas (SBET) calculated by Brunauer?Emmett? Teller (BET) equation as 212.21 and 185.12 m2/g for ACNF/Fe2O3 and ACNF/Co3O4 composites, respectively. …
Scalable Activated Carbon/Graphene Based Supercapacitors With Improved Capacitanceretention At High Current Densities, İffet Işil Gürten
Scalable Activated Carbon/Graphene Based Supercapacitors With Improved Capacitanceretention At High Current Densities, İffet Işil Gürten
Turkish Journal of Chemistry
Scalable, highly stable supercapacitor electrodes were developed from the mixture of a tea factory waste based activated carbon (AC) and a low-cost electrochemical exfoliated graphene (EEG). The hybrid electrodes showed notably enhanced stability at high current densities. The AC sample was prepared by chemical method and exposed to a further heat treatment to enhance electrochemical performance. Graphene used in the preparation of hybrid electrodes was obtained by direct electrochemical exfoliation of graphite in an aqueous solution. Detailed structural characterization of AC, EEG, and hybrid material was performed. The original electrochemical performances of AC and EEG were examined in button size …
Binding Of Permanganate Anion To Pentaammineazidocobalt(Iii) Cation In Solution And Solid Phases: Synthesis, Characterization, X-Ray Structure, And Genotoxic Effects Of [Co(Nh3)5n3](Mno4)2•H2o, Ritu Bala, Jinkwon Kim, Vinit Prakash
Binding Of Permanganate Anion To Pentaammineazidocobalt(Iii) Cation In Solution And Solid Phases: Synthesis, Characterization, X-Ray Structure, And Genotoxic Effects Of [Co(Nh3)5n3](Mno4)2•H2o, Ritu Bala, Jinkwon Kim, Vinit Prakash
Turkish Journal of Chemistry
A pentaammineazidocobalt(III) complex, [Co(NH3)5N3](MnO4)2XH2O has been synthesized by an one-pot synthesis method. It was characterized by studies such as infrared (IR) and UV-visible spectroscopy. The single crystal X-ray structure analysis revealed that the title complex crystallizes in space group Cc. The cobalt center is six coordinated with slightly octahedral geometry. The supramolecular architecture is also formed by intermolecular N-H…O (anion and H2O) and Mn-O…O-H hydrogen bonds. The binding property of the cation, [Co(NH3)5N3]2+ with the anion, MnO4- has also been determined (in solution phase) with the help of UV-visible spectroscopic titrations. Further, the genotoxic effects of KMnO4, [Co(NH3)5N3]Cl2 and [Co(NH3)5N3](MnO4)2XH2O …
Multiple Objective Optimization Of Air Assisted Liquid-Liquid Microextraction Combined With Solidified Floating Organic Drop Microextraction For Simultaneous Determination Of Trace Copper And Nickel, Fereshteh Islami-Bonab, Sanaz Sajedi-Amin, Saeed Mohammad Sorouraddin, Simin Maleknia, Abdolhossein Naseri
Multiple Objective Optimization Of Air Assisted Liquid-Liquid Microextraction Combined With Solidified Floating Organic Drop Microextraction For Simultaneous Determination Of Trace Copper And Nickel, Fereshteh Islami-Bonab, Sanaz Sajedi-Amin, Saeed Mohammad Sorouraddin, Simin Maleknia, Abdolhossein Naseri
Turkish Journal of Chemistry
he impact of rising levels of various heavy metals in the environment from multiple industrial, agriculture, domestic, and technological activities is of great concerns, as heavy metals cause serious health effects for both humans and wildlife. An effective and green chemistry procedure was used for simultaneous extraction of ultra-trace copper and nickel ions in natural waters (e.g. river and well waters) by air assisted liquid-liquid microextraction combined with solidified floating organic drop microextraction (AALLME-SFOD). The extraction of metal ions was conducted in a timescale of several minutes by conversion to metal chelates using sodium diethyldithiocarbamate (DDTC) as a chelating agent …
Feature Of Catalysis On Bimetallic Alloys Zr With V, Mo, And Fe In The Reaction Of Methanol Oxidation, Arif Efendi, Lala Magerramova, Adila Aliyeva, Lyudmila Kozharova, Elmir Babayev
Feature Of Catalysis On Bimetallic Alloys Zr With V, Mo, And Fe In The Reaction Of Methanol Oxidation, Arif Efendi, Lala Magerramova, Adila Aliyeva, Lyudmila Kozharova, Elmir Babayev
Turkish Journal of Chemistry
Catalytic behaviors of bimetallic catalysts-alloys of zirconium with vanadium, molybdenum, and iron was investigated in the oxidative dehydrogenation of methanol. The conditions for the formation of the catalyst's active surface were revealed. The conversion of methanol into formaldehyde, dimethyl ether, and dimethoxymethane on bimetallic catalysts was studied. The characterization of catalysts was performed by XRD, XPS, and SEM. It was shown that the activity of samples increases after O2 + H2 treatment and was associated with segregation of the active components of alloys (V, Mo) on the surface of catalysts and realization of their optimal oxidation state under catalysis conditions.
Green Biosynthesis, Characterization, And Cytotoxic Effect Of Magnetic Iron Nanoparticles Using Brassica Oleracea Var Capitata Sub Var Rubra (Red Cabbage) Aqueous Peel Extract, Ömer Erdoğan, Sali̇h Paşa, Gülen Meli̇ke Demi̇rbolat, Özge Çevi̇k
Green Biosynthesis, Characterization, And Cytotoxic Effect Of Magnetic Iron Nanoparticles Using Brassica Oleracea Var Capitata Sub Var Rubra (Red Cabbage) Aqueous Peel Extract, Ömer Erdoğan, Sali̇h Paşa, Gülen Meli̇ke Demi̇rbolat, Özge Çevi̇k
Turkish Journal of Chemistry
The green method of nanoparticle synthesis, which is an environment and living-friendly method, is an updated subject that has appeared as an alternative to conventional methods such as physical and chemical synthesis. In this presented study, the green synthesis of magnetic iron oxide nanoparticles (IONPs) from iron (III) chloride by using Brassica oleracea var. capitata sub.var. rubra aqueous peel extract has been reported. The prepared IONPs were characterized with fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-VIS), zeta potential, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The cytotoxic effects of IONPs on MCF-7 breast cancer cell line were studied …
Turkish Perlite Supported Nickel Oxide As The Heterogeneous Acid Catalyst For A Series Of Claisen?Schmidt Condensation Reactions, Sakshi Kabra Malpani, Deepti Goyal, Stuti Katara, Ashu Rani
Turkish Perlite Supported Nickel Oxide As The Heterogeneous Acid Catalyst For A Series Of Claisen?Schmidt Condensation Reactions, Sakshi Kabra Malpani, Deepti Goyal, Stuti Katara, Ashu Rani
Turkish Journal of Chemistry
Potentially active and eco-friendly solid acid catalysts have been synthesized by loading different weight percentages (10, 15, and 50) of nickel oxide on thermally activated Turkish perlite through the deposition-precipitation method. Structural features of prepared catalysts were analyzed using BET surface area analysis, X-ray diffraction, scanning electron microscope (SEM), SEM-EDX, transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR), pyridine adsorbed FT-IR, UV-Vis diffuse reflectance spectroscopy (DRS), and thermogravimetric analysis (TGA) techniques. Pyridine adsorbed FT-IR analysis confirmed the presence of the optimum amount of Bronsted acidic sites in a catalyst having 15 wt. % loading of nickel oxide, which was tested for …
Synthesis And Characterization Of Benzodioxinone Mono-Telechelics And Their Use In Block Copolymerization, Cumali̇ Çeli̇k
Synthesis And Characterization Of Benzodioxinone Mono-Telechelics And Their Use In Block Copolymerization, Cumali̇ Çeli̇k
Turkish Journal of Chemistry
Poly(methyl methacrylate) (PMMA) and poly(ethylene glycol) methyl ether (mPEG)-based monotelechelics were quantitatively prepared by copper (I)-catalyzed azide/alkyne cycloaddition (CuAAC) click reactions using azido-terminated polymers and alkyne functional benzodioxinones. The monotelechelic containing dimethyl moities (2,2-dimethyl-5-(prop-2-yn-1-yloxy)-4H-benzo[d][1,3]dioxin-4-one) was heat-sensitive, whereas the monotelechelic containing diphenyl moieties (2,2-diphenyl-5-(prop-2-yn-1-yloxy)-4H-benzo[d][1,3]dioxin-4-one) was UV light sensitive. Based on the FT-IR, 1 H-NMR, and GPC investigations, the CuAAC click reactions enable the quantitative syntheses of monotelechelics under mild conditions. Moreover, the photosensitive mPEG-based monotelechelic was further utilized for the block copolymer synthesis upon UV-light irradiation. The photoinduced acylation of mPEG monotelechelic consist of (2,2-diphenyl-5-(prop-2-yn-1-yloxy)-4H-benzo[d][1,3]dioxin-4-one) in the presence of hydroxy-terminated poly(epsilon …
Theoretical Investigation On The Addition Reaction Of The Germylenoid H2gelicl With Acetone, Xiaolin Zhang, Bingfei Yan, Wenzuo Li
Theoretical Investigation On The Addition Reaction Of The Germylenoid H2gelicl With Acetone, Xiaolin Zhang, Bingfei Yan, Wenzuo Li
Turkish Journal of Chemistry
In this work, theoretical calculations were performed on the addition reaction of the germylenoid H2GeLiCl with acetone. The DFT M06-2X method was used to optimize the geometries of the whole stationary points on the potential energy surfaces and the QCISD method to calculate the single-point energy. The results reveal that the addition reaction of H2GeLiCl with acetone firstly generates an oxagermacyclopropane c-H2GeOC(CH3)2 and then c-H2GeOC(CH3)2 further reacts with acetone along two possible pathways, pathway I and pathway II, in which the 2,4-dioxagermolane is formed at the end of pathway I and 2,5-dioxagermolane is formed at the end of pathway II, …
Preparation Of Ethyl Levulinate From Wheat Stalk Over Zr(So4)2/Sio2, Ding-Kai Wang, Wei Zhao, Ming-Yu Cui, Tian-Tian Guo, Shui-Yuan Fu, Wei-Gang Li
Preparation Of Ethyl Levulinate From Wheat Stalk Over Zr(So4)2/Sio2, Ding-Kai Wang, Wei Zhao, Ming-Yu Cui, Tian-Tian Guo, Shui-Yuan Fu, Wei-Gang Li
Turkish Journal of Chemistry
A series of Zr(SO4)2/SiO2 solid acid catalysts with different Zr(SO4)2 loadings were prepared by water-soluble-impregnation method at room temperature. Then, the prepared catalysts were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectrum, X-ray diffraction, adsorption/desorption of N2, and temperature-programmed desorption of NH3. The results showed that the active component Zr(SO4)2 was successfully adhered to the mesoporous SiO2, and the acid amount of Zr(SO4)2/SiO2 increased with the increasing of the Zr(SO4)2 loadings. Finally, the wheat stalk was used as raw material and depolymerized over Zr(SO4)2/SiO2 to produce ethyl levulinate (EL). The reaction mixture was separated and …
Structural Rearrangement Of Neisseria Meningitidis Transferrin Binding Protein A (Tbpa) Prior To Human Transferrin Protein (Htf) Binding, Gi̇zem Nur Duran, Mehmet Özbi̇l
Structural Rearrangement Of Neisseria Meningitidis Transferrin Binding Protein A (Tbpa) Prior To Human Transferrin Protein (Htf) Binding, Gi̇zem Nur Duran, Mehmet Özbi̇l
Turkish Journal of Chemistry
Gram-negative bacterium Neisseria meningitidis, responsible for human infectious disease meningitis, acquires the iron (Fe3+) ion needed for its survival from human transferrin protein (hTf). For this transport, transferrin binding proteins TbpA and TbpB are facilitated by the bacterium. The transfer cannot occur without TbpA, while the absence of TbpB only slows down the transfer. Thus, understanding the TbpA-hTf binding at the atomic level is crucial for the fight against bacterial meningitis infections. In this study, atomistic level of mechanism for TbpA-hTf binding is elucidated through 100 ns long all-atom classical MD simulations on free (uncomplexed) TbpA. TbpA protein underwent conformational …
Quercetin Enhances Vitamin D2 Stability And Mitigate The Degradation Influenced By Elevated Temperature And Ph Value, Sukkum Ngullie Chang, Jeong Jun Lee, Hyun Jin Kim, Sun Chul Kang
Quercetin Enhances Vitamin D2 Stability And Mitigate The Degradation Influenced By Elevated Temperature And Ph Value, Sukkum Ngullie Chang, Jeong Jun Lee, Hyun Jin Kim, Sun Chul Kang
Turkish Journal of Chemistry
Vitamin D2 (vit. D2) is a nutraceutical essentially needed for good health. However, it is susceptible to oxygen and high temperature. The use of natural products such as bioflavonoids possessing anti-degradative effect of vit. D2 degradation has not been described before. A combinational effect of vit. D2 with quercetin showed a positive effect and inhibited vit. D2 degradation when exposed to high temperature (50 oC and 75 oC) at different time points. The results obtained revealed vit. D2 degradation was drastically increased with longer incubation under thermal treatment. However, quercetin and vit. D2 groups were able to significantly inhibit the …
Hybrid Paper Sheets With Improved Barrier Properties, Çağla Söz
Hybrid Paper Sheets With Improved Barrier Properties, Çağla Söz
Turkish Journal of Chemistry
Hybrid paper sheets were prepared by applying a thin coating layer of cross-linked polydimethylsiloxane (PDMS) and inorganic particles onto Whatman Grade 1 filter paper substrates. Several coatings with different inorganic particle contents and types were applied onto the paper substrates to investigate the effect of the variation in the coating formulation on the (i) wetting, (ii) water barrier properties, (iii) air barrier properties, (iv) surface roughness, and (v) mechanical properties of the samples. It was revealed that the superhydrophobic hybrid paper sheets with significantly low air permeability and high water barrier properties could be prepared which is an indication that …
Remarkable Bismuth-Gold Alloy Decorated On Mwcnt For Glucose Electrooxidation: The Effect Of Bismuth Promotion And Optimization Via Response Surface Methodology, Ömer Faruk Er, Berdan Ulaş, Hi̇lal Demi̇r Kivrak
Remarkable Bismuth-Gold Alloy Decorated On Mwcnt For Glucose Electrooxidation: The Effect Of Bismuth Promotion And Optimization Via Response Surface Methodology, Ömer Faruk Er, Berdan Ulaş, Hi̇lal Demi̇r Kivrak
Turkish Journal of Chemistry
In this study, the carbon nanotube supported gold, bismuth, and gold-bismuth (Au/MWCNT, Bi/MWCNT, and Au-Bi/ MWCNT) nanocatalysts were prepared with NaBH4 reduction method at varying molar atomic ratio for glucose electrooxidation (GAEO). The synthesized nanocatalysts at different Au: Bi atomic ratios are characterized via x-ray diffraction (XRD), transmission electron microscopy (TEM), and N2 adsorption-desorption. For the performance of AuBi/MWCNT for GAEO, electrochemical measurements are performed by using different electrochemical techniques namely cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). Monometallic Au/MWCNT exhibits higher activity than Bi/MWCNT with 256.57 mA/mg (0.936 mA/cm2) current density. According …
Preconcentration Of Rifampicin Prior To Its Efficient Spectroscopic Determination In The Wastewater Samples Based On A Nonionic Surfactant, Afaq Ullah Khan, Faheem Shah, Rafaqat Ali Khan, Bushra Ismail, Asad Muhammad Khan, Haji Muhammad
Preconcentration Of Rifampicin Prior To Its Efficient Spectroscopic Determination In The Wastewater Samples Based On A Nonionic Surfactant, Afaq Ullah Khan, Faheem Shah, Rafaqat Ali Khan, Bushra Ismail, Asad Muhammad Khan, Haji Muhammad
Turkish Journal of Chemistry
Every year, tuberculosis affects the lungs of millions of people and rifampicin is the commonly used medicine for its treatment due to its antibiotic nature. The frequent use of rifampicin may lead to its increased concentration in the water resources. This research work is focused on the cloud point extraction (CPE) procedure for the preconcentration of rifampicin prior to its determination in water. The UV/vis spectrophotometric method was adapted for the measurement of rifampicin content after the phase separation. Triton-X 100 was used as the nonionic surfactant which contains hydrophilic polyethylene chain feasible for the extraction of analyte. Various analytical …
Sensitive And Selective Determination Of Imidacloprid With Magnetic Molecularly Imprinted Polymer By Using Lc/Q-Tof/Ms, Rai̇f İlktaç, Zi̇nar Pinar Gümüş
Sensitive And Selective Determination Of Imidacloprid With Magnetic Molecularly Imprinted Polymer By Using Lc/Q-Tof/Ms, Rai̇f İlktaç, Zi̇nar Pinar Gümüş
Turkish Journal of Chemistry
In this paper, magnetic-molecularly imprinted polymer was used for the preconcentration of trace levels of imidacloprid in water and apple samples prior to liquid chromatography-quadrupole-time-of-flight mass spectrometric determination. The selectivity of the magnetic polymer was united with the sensitivity and the high resolving power of the chromatographic system. The developed method showed a linear range from 10.0 to 500.0 μg/L. The quantitative recoveries were obtained for water and apple samples in the range of 92.0%-99.0 %. The relative standard deviations of intra-day and inter-day tests were found to be in the range of 0.8%-1.2% and 1.2%-1.6 %, respectively. In addition, …
Supercritical Carbon Dioxide Extraction Of Usnea Longissima (L.) Ach.: Optimization By Box-Behnken Design (Bbd), Ceren Ati̇la Di̇nçer, Ceren Gökalp, Bengü Geti̇ren, Ati̇la Yildiz, Nuray Yildiz
Supercritical Carbon Dioxide Extraction Of Usnea Longissima (L.) Ach.: Optimization By Box-Behnken Design (Bbd), Ceren Ati̇la Di̇nçer, Ceren Gökalp, Bengü Geti̇ren, Ati̇la Yildiz, Nuray Yildiz
Turkish Journal of Chemistry
Usnic acid (UA) was extracted from Usnea longissima (L.) Ach. in supercritical carbon dioxide (SC-CO2) medium. The selected process parameters were extraction temperature (35-45 °C), amount of co-solvent (0%-5%) and extraction time (5-9 h). These parameters were applied to Box-Behnken design (BBD) belonging to response surface methodology (RSM) to determine optimum process parameters for the highest amount of UA in the extract. g UA/100g lichen, extraction yield % and UA content values were calculated in the range of 0.045-0.317, 2.77-5.4 and 71%-82% in different experimental conditions, respectively. The optimum conditions were predicted as 42 °C, 4.3% (ethanol) and 7.48 h. …
Preparation And Characterization Of Templated Porous Carbons From Sucrose By One-Pot Method And Application As A Co2 Adsorbent, Meltem Gürbüz, Fatma Tümsek
Preparation And Characterization Of Templated Porous Carbons From Sucrose By One-Pot Method And Application As A Co2 Adsorbent, Meltem Gürbüz, Fatma Tümsek
Turkish Journal of Chemistry
The templated porous carbons were prepared from sucrose by one-pot method. In this method in which the pre-synthesis of the hard template is eliminated, the porous carbons were produced by organic-inorganic self-assembly of sucrose, tetraethyl ortosilicate (TEOS), Pluronic P123 and n-butanol in an acidic medium, and subsequent carbonization. The synthesis parameters such as sucrose amount, TEOS molar ratio and carbonization temperature were evaluated for describing their effects on the pore structures of the synthesized carbons. The prepared porous carbons were characterized by N2 adsorption, thermogravimetric analysis (TGA), Raman spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission …
Catalytic, Theoretical, And Biological Investigation Of An Enzyme Mimic Model, Gülci̇han Gülseren
Catalytic, Theoretical, And Biological Investigation Of An Enzyme Mimic Model, Gülci̇han Gülseren
Turkish Journal of Chemistry
Artificial catalyst studies were always stayed at the kinetics investigation level, in this work bioactivity of designed catalyst were shown by the induction of biomineralization of the cells, indicating the possible use of enzyme mimics for biological applications. The development of artificial enzymes is a continuous quest for the development of tailored catalysts with improved activity and stability. Understanding the catalytic mechanism is a replaceable step for catalytic studies and artificial enzyme mimics provide an alternative way for catalysis and a better understanding of catalytic pathways at the same time. Here we designed an artificial catalyst model by decorating peptide …
Fibroin Nanofibers Production By Electrospinning Method, Derya Saltik Çi̇rki̇n, Meti̇n Yüksek
Fibroin Nanofibers Production By Electrospinning Method, Derya Saltik Çi̇rki̇n, Meti̇n Yüksek
Turkish Journal of Chemistry
Silk fibroin, which has many characteristic properties such as low inflammation reaction, biodegradation, suppleness, good antithrombogenic details, biocompatibility and high tensile strength is a very good candidate for biomedical applications. Electrospinning procures high surface area, porous, nanofiber dimension fiber generation, which is a plain method. An experimental study was carried out to produce nanofiber structure from silk fibroin by electrospinning and the electrospinning parameters for the spinning of uniform, continuous and silk fibroin fibers were optimized. As a result, the effect of variables of concentration, distance and applied voltage on the strength, thickness, surface structure, fiber diameter of nanomaterial was …
Advances In Polymer Based Friedlander Quinoline Synthesis, Rajendra Patil, Jagdish Chavan, Shivnath Patel, Anil Beldar
Advances In Polymer Based Friedlander Quinoline Synthesis, Rajendra Patil, Jagdish Chavan, Shivnath Patel, Anil Beldar
Turkish Journal of Chemistry
Nitrogen containing heterocyclic compounds has acquired their remarkable and distinct place in the wide area of organic synthesis due to the broad range of applications. Among them, quinoline motifs have attracted researchers in the synthetic chemistry because of its presence in the large number of pharmacologically active compounds. Different methods for synthesis of quinoline derivatives are reported, among them the Friedlander synthesis have provided comparatively more efficient approach. Many of the reported conventional Friedlander methodologies have some problems such as difficult product isolation procedures, poor yields and use of expensive catalysts, etc. Recently, polymer or solid supported synthetic approaches have …