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Articles 3901 - 3930 of 10319
Full-Text Articles in Physical Sciences and Mathematics
A Novel Dtc-Svm Approach For Two Parallel-Connected Induction Motors Fed By Matrix Converter, Mahdi Jafari, Karim Abbaszadeh, Mustafa Mohamadian
A Novel Dtc-Svm Approach For Two Parallel-Connected Induction Motors Fed By Matrix Converter, Mahdi Jafari, Karim Abbaszadeh, Mustafa Mohamadian
Turkish Journal of Electrical Engineering and Computer Sciences
AC machines fed by a single inverter are widely used in industries such as railroad electrification systems where speed synchronization does not have to be exact. The low cost and volume and the small number of power electronic components are attractive aspects of single-inverter multi-motor systems. This paper proposes a novel approach to controlling the speed and torque of two induction motors connected in parallel and fed by a matrix converter under unbalanced load condition. This single-inverter dual-motor (SIDM) drive uses average and differential values of speed and torque together with stator and rotor flux parameters based on the flux …
Biological Study On Novel Coumarinyl 1,3,4-Oxadiazoles, Maja Molnar, Ana Amic, Valentina Pavic, Tihomir Kovac, Marija Kovac, Elizabeta Has-Schön
Biological Study On Novel Coumarinyl 1,3,4-Oxadiazoles, Maja Molnar, Ana Amic, Valentina Pavic, Tihomir Kovac, Marija Kovac, Elizabeta Has-Schön
Turkish Journal of Chemistry
Coumarinyl 1,3,4-oxadiazoles were synthesized from Schiff bases and acetic anhydride. All compounds were characterized by melting points and their structures confirmed by mass and $^{1}$H and $^{13}$C NMR spectrometry. These novel coumarinyl derivatives were subjected to antibacterial, antifungal, anta atoxigenic, and antioxidant activity. Their activity varied depending on their structure, where 2-(3-acetyl-5-(((4-methyl-2-oxo-2H-chromen-7-yl)oxy)methyl)- 2,3-dihydro-1,3,4-oxadiazol-2-yl)-1,4-phenylene diacetate showed significant antioxidant and antibacterial activity on B. subtilis. 4-(3-Acetyl-5-(((4-methyl-2-oxo-2H-chromen-7-yl)oxy)methyl)-2,3-dihydro-1,3,4-oxadiazol-2-yl)-1,2-phenylene diacetate was found to possess excellent antifungal and antia atoxigenic activity.
Cu(Ii) Immobilized On Fe$_{3}$O$_{4}$ @Agarose Nanomagnetic Catalyst Functionalizedwith Ethanolamine Phosphate-Salicylaldehyde Schiff Base: A Magnetically Reusablenanocatalyst For Preparation Of 2-Substituted Imidazolines, Oxazolines, Andthiazolines, Zeinab Zarei, Batool Akhlaghinia
Cu(Ii) Immobilized On Fe$_{3}$O$_{4}$ @Agarose Nanomagnetic Catalyst Functionalizedwith Ethanolamine Phosphate-Salicylaldehyde Schiff Base: A Magnetically Reusablenanocatalyst For Preparation Of 2-Substituted Imidazolines, Oxazolines, Andthiazolines, Zeinab Zarei, Batool Akhlaghinia
Turkish Journal of Chemistry
Herein we synthesized Cu(II) immobilized on Fe$_{3}$O$_{4}$ @Agarose functionalized with ethanolamine phosphate{ salicylaldehyde Schiff base (Fe$_{3}$O$_{4}$ @Agarose/SAEPH$_{2}$ /Cu(II)) as a new and cost-effective nanomagnetic catalyst. The nanomagnetic catalyst was characterized by FT-IR, XRD, VSM, SEM-EDX, TEM, TGA, and ICP techniques and it was found that the particles were about 9-25 nm in size and spherical with entrapment of the Fe$_{3}$O$_{4}$ particles in the hollow pore structure of the agarose. The prepared nanomagnetic catalyst showed excellent activity for preparation of 2-substituted imidazolines, oxazolines, and thiazolines. The catalyst is easy to prepare and exhibits higher catalytic activity than some commercially available copper …
Kinetics Of Silver(I)-Catalyzed Oxidation Of Allyl Alcohol By Peroxodiphosphate Inacetate Buffers, Priyamvada Sharma, Riya Sailani, Deepmala Pareek, Chandra Lata Khandelwal
Kinetics Of Silver(I)-Catalyzed Oxidation Of Allyl Alcohol By Peroxodiphosphate Inacetate Buffers, Priyamvada Sharma, Riya Sailani, Deepmala Pareek, Chandra Lata Khandelwal
Turkish Journal of Chemistry
The kinetics and mechanism of silver(I)-catalyzed oxidation of allyl alcohol with peroxodiphosphate in acetate buffers have been studied. The rate is independent of allyl alcohol concentration. The effect of other reaction parameters such as hydrogen and acetate ions has also been studied. The rate law accounting for all experimental observations corresponds to the proposed mechanism. The energy and entropy of activation have also been evaluated by employing Eyring plots.
Sodium Borohydride For The Near-Future Energy: A ''Rough Diamond'' For Turkey, Ümi̇t Bi̇lge Demi̇rci̇
Sodium Borohydride For The Near-Future Energy: A ''Rough Diamond'' For Turkey, Ümi̇t Bi̇lge Demi̇rci̇
Turkish Journal of Chemistry
Boron-based materials are potential solutions in the field of energy. They have been regarded as hydrogen storage materials, liquid fuels of direct liquid-fed fuel cells (DLFCs), electrolytes of battery, and/or energetic substances. A typical example is sodium borohydride (NaBH$_{4}$. In sodium hydroxide-stabilized aqueous solutions, it is seen as an efficient H$_{2}$ generator or a performing fuel of DLFCs. Actually, it plays a wider role; it is also the precursor of several boron-based materials of interest in the field of energy. In other words, it is indirectly considered for other energy applications, i.e. solid electrolytes of all solid-state batteries and hypergolic …
Experimental And Theoretical Studies Of Carbazole-Based Schiff Base As A Fluorescent Fe$^{3+}$ Probe, Hakan Kandemi̇r, Abdulkadi̇r Koçak, Süreyya Oğuz Tümay, Bünyemi̇n Çoşut, Yunus Zorlu, İbrahi̇m Fazil Şengül
Experimental And Theoretical Studies Of Carbazole-Based Schiff Base As A Fluorescent Fe$^{3+}$ Probe, Hakan Kandemi̇r, Abdulkadi̇r Koçak, Süreyya Oğuz Tümay, Bünyemi̇n Çoşut, Yunus Zorlu, İbrahi̇m Fazil Şengül
Turkish Journal of Chemistry
Synthesis of a new (E)-N1-((9-ethyl-9H-carbazol-3-yl)methylene)-5-nitrobenzene-1,2-diamine as a fluorescent chemosensor for selective detection of Fe$^{3+}$ ion over a number of other metal ions is described. The method for the synthesis of the carbazole Schiff base was based on the condensation of carbazole-3-carbaldehyde with 4-nitro-o-phenyldiamine in dimethylformamide in a moderate yield. The structure of the final compound was characterized by $^{1}$H NMR, $^{13}$C NMR, IR, mass spectrometry, and single crystal X-ray diffraction. The final compound exhibited exceptional selective and sensitive turn-on fluorescence response to the Fe$^{3+}$ cation. The fluorescent intensity of the final compound was increased 20-fold and the stoichiometry ratio of …
Effect Of Ph And $\Beta$-Cyclodextrin On The Photophysical Properties Of Lamotrigine, Raed Ghanem, Fakhri Yousef, Omar Abu Awwad
Effect Of Ph And $\Beta$-Cyclodextrin On The Photophysical Properties Of Lamotrigine, Raed Ghanem, Fakhri Yousef, Omar Abu Awwad
Turkish Journal of Chemistry
Photophysical properties of lamotrigine (LMT) were investigated at different pH values. Lamotrigine exhibited a broad absorption band at 308 nm that was shifted to 268 nm at pH 2.0 due to protonation (HLMT$+)$. Emission spectra of LMT at different pH values showed a single band at 483 nm except for at pH 2.0, where a second band at 502 nm was observed due to the deprotonation from the singlet excited state. LMT pH profile was used to calculate p$K$a of LMT in excited and ground states (p$K$a* $=$ 4.50 and p$K$a $=$ 5.90). Absorption spectra of LMT at different pH …
Tetrahydronaphthalene As A Precursor Of New Series Of Chalcones, Flavanones, And Flavones, Ahmed Meddeb, Ghalia Bouhalleb, Julien Legros, Farhat Rezgui
Tetrahydronaphthalene As A Precursor Of New Series Of Chalcones, Flavanones, And Flavones, Ahmed Meddeb, Ghalia Bouhalleb, Julien Legros, Farhat Rezgui
Turkish Journal of Chemistry
An efficient synthetic route for a novel series of chalcones 2a-2d as well as for the corresponding flavanones 3a-3d and flavones 4a-4d, using functionalized tetrahydronaphthalene (THN), is described herein. The Claisen-Schmidt condensation of such THN and aromatic aldehydes, in the presence of an aqueous solution of KOH (40%), selectively gives the expected chalcones 2a-2d, which may further undergo an intramolecular oxa-Michael addition using piperidine, affording the corresponding flavanones 3a-3d in high yields. Alternatively, treatment of such chalcones 2a-2d with I$_{2}$/DMSO provides rapidly, in a one-pot oxidative cyclization, a series of flavones 4a-4d in excellent yields ranging from 85% to 90%.
Simultaneous Determination Of Copper(Ii) And Zinc(Ii) Via Simple Acid-Base Titrimetry Using Glass Ph Electrode, Emi̇ne Gül Cansu Ergün, Adnan Kenar
Simultaneous Determination Of Copper(Ii) And Zinc(Ii) Via Simple Acid-Base Titrimetry Using Glass Ph Electrode, Emi̇ne Gül Cansu Ergün, Adnan Kenar
Turkish Journal of Chemistry
The combination of potentiometric methods with multivariate calibration techniques allows complex mixtures to be analyzed. In this study, a new method was developed and reported for simultaneous determination of copper(II) and zinc(II) cations in a mixture by titrimetric methods. The developed method permits simultaneous cation analysis with low detection limits, just by using a pH electrode. This work has achieved the challenging goal of developing a cost-effective and applicable method that can be applied in most laboratories due to independence of any chemical instruments. Partial least squares 1, one of the multivariate calibration techniques, was used in the analysis of …
Transfer Of The Protonable Surfactant Dipalmitoyl-Phosphatidylcholine Across A Large Liquid/Liquid Interface: A Voltammetric Study, İbrahi̇m Uyanik
Transfer Of The Protonable Surfactant Dipalmitoyl-Phosphatidylcholine Across A Large Liquid/Liquid Interface: A Voltammetric Study, İbrahi̇m Uyanik
Turkish Journal of Chemistry
Adsorption behavior of the zwitterionic phospholipid dipalmitoyl-phosphatidylcholine (DPPC) at the polarizable liquid/liquid interface formed between water and 1,2-dichloroethane electrolyte solutions is studied taking into account both the pH of the aqueous phase and the concentration of the phospholipid in the organic phase by cyclic voltammetry. Experimental results showed that the adsorption of the phospholipid strongly depends on the pH of the aqueous phase, which determines the surface ionization of the polar head of the phospholipid molecule and hence the stability of the adsorbed layer of phospholipids.
Spectroscopic And Thermodynamic Approach To The Interaction Of Nonperipherally Substituted Cationic Phthalocyanines With Calf Thymus (Ct)-Dna, Sevgi̇can Tuncer, İbrahi̇m Özçeşmeci̇, Behi̇ce Şebnem Sesalan, Ayfer Kalkan Burat
Spectroscopic And Thermodynamic Approach To The Interaction Of Nonperipherally Substituted Cationic Phthalocyanines With Calf Thymus (Ct)-Dna, Sevgi̇can Tuncer, İbrahi̇m Özçeşmeci̇, Behi̇ce Şebnem Sesalan, Ayfer Kalkan Burat
Turkish Journal of Chemistry
Novel, nonperipherally tetrasubstituted cationic metal-free and metallophthalocyanines (Zn, In) were synthesized in the present study. The binding constants, the disappearance of quenching effect of all cationic phthalocyanines on the fluorescence intensity of SYBR Green--disodium salt of deoxyribonucleic acid (DNA) from calf thymus complex, and the changes in T$_{m}$ of double helix DNA with thermal denaturation profile were investigated by UV-Vis and fluorescence spectrophotometric methods. To investigate the spontaneity of the reactions between DNA and novel quaternized phthalocyanines in buffer, thermodynamic parameters were employed.
Voltammetric Determination Of Vanillin In Commercial Food Products Using Overoxidized Poly(Pyrrole) Film-Modified Glassy Carbon Electrodes, Şükri̇ye Ulubay Karabi̇beroğlu, Çağri Ceylan Koçak
Voltammetric Determination Of Vanillin In Commercial Food Products Using Overoxidized Poly(Pyrrole) Film-Modified Glassy Carbon Electrodes, Şükri̇ye Ulubay Karabi̇beroğlu, Çağri Ceylan Koçak
Turkish Journal of Chemistry
In this work, a very simple, rapid, cheap, sensitive, and selective polymer film-modified electrode for vanillin determination in commercial food products was developed via electrochemical polymerization and overoxidation of pyrrole. The formation of both poly(pyrrole) and overoxidized poly(pyrrole) films on a glassy carbon electrode surface was characterized by electrochemical impedance spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. Under optimized conditions, the calibration graph comprises two linear segments of 0.032-1.500 $\mu $mol L$^{-1}$ and 3.00--150.00 $\mu $mol L$^{-1}$ with a detection limit of 0.012 $\mu $mol L$^{-1}$. The selectivity of the modified electrode was examined in the presence of metals, …
Synthesis And Biological Properties Of Novel1-Methyl-2-(2-(Prop-2-Yn-1-Yloxy)Benzylidene) Hydrazine Analogues, Ari̇f Kivrak, Can Yilmaz, Meti̇n Konuş, Hali̇l Koca, Selahatti̇n Aydemi̇r, Jeger Ali Oagaz
Synthesis And Biological Properties Of Novel1-Methyl-2-(2-(Prop-2-Yn-1-Yloxy)Benzylidene) Hydrazine Analogues, Ari̇f Kivrak, Can Yilmaz, Meti̇n Konuş, Hali̇l Koca, Selahatti̇n Aydemi̇r, Jeger Ali Oagaz
Turkish Journal of Chemistry
1-Methyl-2-(2-(prop-2-yn-1-yloxy)benzylidene)hydrazine analogues were readily prepared in good yields by the reaction of 2-(prop-2-yn-1-yloxy)benzaldehydes and methyl hydrazine. The reaction tolerates a variety of substituents on the 2-hydroxybenzaldehyde to form nitro-, halo-, methoxy-, and naphthyl-substituted 1-methyl-2-(2-(prop-2-yn-1-yloxy)benzylidene)hydrazines. The in vitro antioxidant capacity measurements revealed that among all the analyzed hydrazine analogues that surpassed the Trolox standard, 1-(2-(but-3-ynyl)-5-nitrobenzylidene)-2-methylhydrazine had the maximum value, which was approximately 1.7 times that of Trolox.
A New Member Of Mo36- Polyoxoanion's Family: Synthesis, Crystal Structure, And Physico-Chemical Properties Of K$_{10}$[Mo$_{36}$O$_{110}$ (Oh)$_{6}$ (H$_{2}$O)$_{12}$].38 H$_{2}$O, Jawaher Baizig, Anissa Haj Abdallah, Amor Haddad
A New Member Of Mo36- Polyoxoanion's Family: Synthesis, Crystal Structure, And Physico-Chemical Properties Of K$_{10}$[Mo$_{36}$O$_{110}$ (Oh)$_{6}$ (H$_{2}$O)$_{12}$].38 H$_{2}$O, Jawaher Baizig, Anissa Haj Abdallah, Amor Haddad
Turkish Journal of Chemistry
The new giant Mo$_{36}$ polyoxomolybdate formulated as K$_{10}$[Mo$_{36}$O$_{110}$(OH)$_{6}$ (H$_{2}$O)$_{12}$].38 H$_{2}$O (1) was isolated by conventional solution method by the reaction of K$_{2}$MoO$_{4}$ and KNO$_{3}$ in aqueous solution (pH = 1.8), at room temperature, and structurally characterized by single-crystal X-ray diffraction methods. The title compound crystallized in the monoclinic system, space group P2$_{1}$/n with unit a = 16.5180 (0) Å, b = 18.4485 (0) Å, c = 24.2424 (0) Å, $\alpha $ = 90.00$^{\circ}$, $\beta $ = 99.51$^{\circ}$, $\gamma $ = 90.00$^{\circ}$, V = 7285.79 (0) Å$^{3}$, and Z = 2. The refinement of the structure led to a residual factor …
The Synthesis Of New Oxindoles As Analogs Of Natural Product 3,3$^\Prime $-Bis(Indolyl)Oxindole And In Vitro Evaluation Of The Enzyme Activity Of G6pd And 6pgd, Si̇nan Bayindir, Adnan Ayna, Yusuf Temel, Mehmet Çi̇ftci̇
The Synthesis Of New Oxindoles As Analogs Of Natural Product 3,3$^\Prime $-Bis(Indolyl)Oxindole And In Vitro Evaluation Of The Enzyme Activity Of G6pd And 6pgd, Si̇nan Bayindir, Adnan Ayna, Yusuf Temel, Mehmet Çi̇ftci̇
Turkish Journal of Chemistry
Natural and synthetic derivatives that contain an indole core are being used in medical treatments and technological processes. Therefore, the development of new synthetic methods for the synthesis of indole derivatives is very popular. In this study, new oxindoles with reaction of 4,7-dihydro-1$H$-indole (2) and isatin (4) were synthesized as analogs of natural product 3,3$^\prime $-bis(indolyl)oxindole. The biological properties of the compounds obtained during this study were also studied, showing that compounds 5, 7, and 12 inhibited the activity of G6PD with an IC$_{50}$ of 99 $\mu $M, 231 $\mu $M, and 304 $\mu $M respectively. The activity of rat …
Development Of A Molecularly Imprinted Polymer-Based Electrochemical Sensor For Tyrosinase, Aysu Yarman
Development Of A Molecularly Imprinted Polymer-Based Electrochemical Sensor For Tyrosinase, Aysu Yarman
Turkish Journal of Chemistry
For the first time a molecularly imprinted polymer (MIP)-based sensor for tyrosinase is described. This sensor is based on the electropolymerization of scopoletin or o-phenylenediamine in the presence of tyrosinase from mushrooms, which has a high homology to the human enzyme. The template was removed either by treatment with proteinase K or by alkaline treatment. The measuring signal was generated either by measuring the formation of a product by the target enzyme or by evaluation of the permeability of the redox marker ferricyanide. The o-phenylenediamine-based MIP sensor has a linear measuring range up to 50 nM of tyrosinase with a …
Protein Ion-Exchange Chromatography On A Biomacromolecule-Immobilized Monolithic Cryogel, Ahmet Eren Özkan, Idris Guven, Orhan Gezici
Protein Ion-Exchange Chromatography On A Biomacromolecule-Immobilized Monolithic Cryogel, Ahmet Eren Özkan, Idris Guven, Orhan Gezici
Turkish Journal of Chemistry
An efficient and inexpensive monolithic stationary phase (PHEMA-HA) has been prepared through an easy process comprising addition of humic acid (HA) to a mixture of 2-hydroxyethyl methacrylate (HEMA) and N,N'-methylenebisacrylamide (MBAAm) and subsequent radical-polymerization at -20 $^{\circ}$C. The prepared monolithic material was characterized in terms of various techniques and methods such as elemental analysis, FTIR spectroscopy, scanning electron microscopy, mercury porosimetry, hydrolytic stability tests, pH$_{pzc}$ measurements, water-holding capacity, and water permeability. The amount of HA incorporated into the structure was calculated as 45 mg/g from the elemental analysis results. The study was conceptualized on the basis of protein ion-exchange chromatography, …
Nickel(Ii)-Pph$_{3}$ Complexes With Ons And Onn Chelating Thiosemicarbazones: Synthesis And Inhibition Potential On Influenza A Viruses, Şükri̇ye Güveli̇, Kadi̇r Turan, Bahri̇ Ülküseven
Nickel(Ii)-Pph$_{3}$ Complexes With Ons And Onn Chelating Thiosemicarbazones: Synthesis And Inhibition Potential On Influenza A Viruses, Şükri̇ye Güveli̇, Kadi̇r Turan, Bahri̇ Ülküseven
Turkish Journal of Chemistry
Tetra-coordinated nickel(II) complexes of two ONS (1, \2) and seven ONN (3a-3g) chelating 2-hydroxy-3-methoxy-benzaldehyde thiosemicarbazones were synthesized. The dibasic ligands and complexes bearing PPh$_{3}$ as a coligand were characterized by means of analytical and spectroscopic data. Cytotoxic activities of the ligands and nickel(II) complexes were determined using the MTT assay in vitro against MDCK cells, and then all the compounds were tested on influenza virus replication by plaque assays. The compounds showed GI$_{50}$ values varying from concentrations of 15.9 up to 161.8 $\mu$ g/mL for MDCK cells. The plaque assays indicated that one ONS (1) and two ONN (3c and …
Peg-Peptide Conjugate Containing Cathepsin B Degradation Unit As A Doxorubicin Carrier System, Nesli̇gül Şentürk, Ayben Top
Peg-Peptide Conjugate Containing Cathepsin B Degradation Unit As A Doxorubicin Carrier System, Nesli̇gül Şentürk, Ayben Top
Turkish Journal of Chemistry
A drug delivery system (DDS) containing a cathepsin B degradable sequence and pH-responsive histidines was prepared by methoxypolyethylene glycol and peptide conjugation. Doxorubicin was attached to the carrier system using amide linkage to give the final form of the DDS, denoted as mPEG-AT3-DOX. mPEG-AT3-DOX exhibited a bimodal size distribution at about 15 and 30 nm independent of pH, whereas the size of the control DDS containing no peptide sequence, mPEG-DOX, was measured as $\sim$ 15-20 nm. At the end of 72 h, % doxorubicin release from both of the DDSs was observed to be below 8.5 $\pm$ 3% in the …
Synthesis, Biological Evaluation, And In Silico Study Of Some Unique Multifunctional 1,2,4-Triazole Acetamides, Almas Sattar, Aziz Ur Rehman, Muhammad Athar Abbasi, Sabahat Zahra Saddiqui, Shahid Rasool, Hira Khalid, Muhammad Arif Lodhi, Farman Ali Khan
Synthesis, Biological Evaluation, And In Silico Study Of Some Unique Multifunctional 1,2,4-Triazole Acetamides, Almas Sattar, Aziz Ur Rehman, Muhammad Athar Abbasi, Sabahat Zahra Saddiqui, Shahid Rasool, Hira Khalid, Muhammad Arif Lodhi, Farman Ali Khan
Turkish Journal of Chemistry
The imperative demand for antibacterial agents and enzyme inhibitors prompted us to synthesize some new compounds, 6a-6k, bearing multifunctional moieties. The target acetamides were derived from 4-phenyl-5-(1-tosylpiperidin-4-yl)-4$H$-1,2,4-triazole-3-thiol (3). The structural analysis was carried out using modern spectroscopic techniques including IR, NMR, and EIMS spectral analysis. The antibacterial activity was screened against five bacterial strains including three gram-negative and two gram-positive ones. Enzyme inhibition was carried out against lipoxygenase enzyme and results were supported by in silico study. The synthesized compounds were proved to be potent antibacterial agents and enzyme inhibitors.
Oxime-Containing Acetylcholinesterase Reactivators And Their Complexes With Pd(Ii) And Pt(Ii) Ions: Recent Developments, Ivayla Pantcheva, Ahmed Nedzhib, Liudmil Antonov
Oxime-Containing Acetylcholinesterase Reactivators And Their Complexes With Pd(Ii) And Pt(Ii) Ions: Recent Developments, Ivayla Pantcheva, Ahmed Nedzhib, Liudmil Antonov
Turkish Journal of Chemistry
The ability of oxime-containing acetylcholinesterase reactivators BT-07 (K005), BT-08 (K033), BT-07-4M (K074), and obidoxime (H$_{2}$LX$_{2}$, X = Cl$^{-}$, Br$^{-})$ to bind palladium(II) or platinum(II) cations was evaluated in aqueous solutions (pH 7.4) at metal-to-ligand molar ratio varying from 1:10 to 10:1. Spectral changes were monitored within a week after mixing the reagents in the range from 220 nm to 500 nm. Results showed that depending on chemical structure and reaction time, oximes form two complex species of composition, [MHL]$^{3+}$ or [M$_{2}$L]$^{4+}$ (M = Pd(II), Pt(II)). It was also found that complexation of platinum(II) ions proceeds slower as compared to palladium(II). …
A Novel Hypobromous Acid Scavenging Activity Assay Using $P$-Cresol As A Spectrofluorometric Probe, Burcu Bekdeşer, Gülüzar Zeytünlü, Mustafa Özyürek, Mustafa Reşat Apak
A Novel Hypobromous Acid Scavenging Activity Assay Using $P$-Cresol As A Spectrofluorometric Probe, Burcu Bekdeşer, Gülüzar Zeytünlü, Mustafa Özyürek, Mustafa Reşat Apak
Turkish Journal of Chemistry
In this study, a novel spectrofluorometric assay based on $p$-cresol (4-methyl phenol) probe is developed for the measurement of HOBr scavenging activity. It is the first study involving the use of a $p$-cresol probe for the determination of the HOBr scavenging activity of biothiols. While the $p$-cresol probe ($\lambda_{ex}$ = 260 nm, $\lambda_{em}$ = 305 nm) has fluorescence characteristics, its brominated derivatives emerging at the end of the oxidation reaction with HOBr do not show fluorescence. The initial fluorescence intensity of the $p$-cresol probe is decreased in the presence of the brominating agent, HOBr, and this decrease is lower in …
Electrochemical Polymerization Of A New Alkoxy-Bridged Dithieno (3,2-B:2',3'-D) Pyrrole Derivative, Ari̇f Kivrak, Hüseyi̇n Beki̇r Yildiz, Selahatti̇n Gökyer, Buket Çarbaş
Electrochemical Polymerization Of A New Alkoxy-Bridged Dithieno (3,2-B:2',3'-D) Pyrrole Derivative, Ari̇f Kivrak, Hüseyi̇n Beki̇r Yildiz, Selahatti̇n Gökyer, Buket Çarbaş
Turkish Journal of Chemistry
A novel alkoxy-bridged dithieno (3, 2-B:2',3'-D) pyrrole (DTP) derivative was synthesized and its corresponding polymer poly(1,2-bis(2-(4H-dithieno[3,2-b:2',3'-d]pyrrol-4-yl)ethoxy)ethane) (P(DTP-alkoxy-DTP)) was successfully obtained electrochemically. The effects of alkoxy bridge in the structure on the electrochemical and spectroelectrochemical properties of the polymer were also investigated in detail. The results showed that the polymer film exhibits multielectrochromic behavior and a low band gap of 1.82 eV.
Application Of A Pencil Graphite Electrode For Voltammetric Simultaneous Determination Of Ascorbic Acid, Norepinephrine, And Uric Acid In Real Samples, Abdulkadi̇r Levent, Günay Önal
Application Of A Pencil Graphite Electrode For Voltammetric Simultaneous Determination Of Ascorbic Acid, Norepinephrine, And Uric Acid In Real Samples, Abdulkadi̇r Levent, Günay Önal
Turkish Journal of Chemistry
A pencil graphite electrode (PGE) was used for the simultaneous detection of ascorbic acid (AA), norepinephrine (NE), and uric acid (UA) by differential pulse voltammetry and cyclic voltammetry. The anodic peaks of AA, NE, and UA in their mixture can be well separated in 0.1 M Britton--Robinson buffer solution at pH 4.0. The effects of various experimental parameters such as pH, scan rate, and voltammetric parameters on the voltammetric response of these compounds were investigated. Under optimum conditions, linear calibration graphs were obtained from the AA, NE, and UA concentration ranges, which were 100-800 nM, 20-170 nM, and 40-175 nM, …
Application Of The Taguchi Approach To Optimize Zno Synthesis Via Hydrothermally Assisted Sol-Gel Method, Zahra Khaghanpour, Sanaz Naghibi
Application Of The Taguchi Approach To Optimize Zno Synthesis Via Hydrothermally Assisted Sol-Gel Method, Zahra Khaghanpour, Sanaz Naghibi
Turkish Journal of Chemistry
ZnO powder was synthesized via a hydrothermally assisted sol-gel method. Synthesis variables including Zn-precursor type, pH value, time, and temperature of hydrothermal treatment were analyzed using the Taguchi approach. The experimental procedures were defined based on the L9 array for four variables in three levels. The influences of those variables on the response parameters, i.e. crystallite size, crystallinity, band gap energy ($E_{g})$, and degradation constants ($k)$, were evaluated. XRD results and $E_{g}$ values showed that ZnO wurtzite appeared to be the only crystalline phase in the samples. Taguchi analysis predicted that the optimized conditions to achieve the highest photoactivity are …
Influence Of Manganese Content On The Supercapacitive Performance Of Pbo$_{2}$-Mno$_{2}$ Electrodes, Yingwu Yao, Mengyao Li, Xinghua Zhang, Zunming Lu, Feng Wei
Influence Of Manganese Content On The Supercapacitive Performance Of Pbo$_{2}$-Mno$_{2}$ Electrodes, Yingwu Yao, Mengyao Li, Xinghua Zhang, Zunming Lu, Feng Wei
Turkish Journal of Chemistry
PbO$_{2}$-MnO$_{2}$ electrodes were prepared by electrochemical codeposition methods. The electrodes were characterized by scanning electron microscope, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The content of manganese in the electrodes increased with the increase in manganese ion concentration in the solution, which can reach 48.4%. The codeposition of manganese decreased the grain sizes and formed the porous structure. Cyclic voltammetry and galvanostatic charge-discharge measurements were used to evaluate the influence of manganese content in the electrodes on the specific capacitive performance of PbO$_{2}$-MnO$_{2}$ electrodes. The specific capacitance of PbO$_{2}$-MnO$_{2}$ (48.4%) electrodes could reach 374.5 F g$^{-1}$. The …
Synthesis And Biological Evaluation Of Novel Chalcones Bearing Morpholine Moiety As Antiproliferative Agents, Bedri̇ye Seda Kurşun Aktar, Emi̇ne Elçi̇n Oruç-Emre, İbrahi̇m Demi̇rtaş, Ayşe Şahi̇n Yağlioğlu, Ayşegül Karaküçük İyi̇doğan, Çağlar Güler, Şevki̇ Adem
Synthesis And Biological Evaluation Of Novel Chalcones Bearing Morpholine Moiety As Antiproliferative Agents, Bedri̇ye Seda Kurşun Aktar, Emi̇ne Elçi̇n Oruç-Emre, İbrahi̇m Demi̇rtaş, Ayşe Şahi̇n Yağlioğlu, Ayşegül Karaküçük İyi̇doğan, Çağlar Güler, Şevki̇ Adem
Turkish Journal of Chemistry
In this research, a new series of ($E)$-3-(4-substitutedphenyl)-1-(4'-morpholinophenyl)prop-2-en-1-one derivatives 1-7 was synthesized, aiming to develop effective antiproliferative agents. The antiproliferative activities of compounds 1-7 were examined against HeLa and C6 cell lines at eight different concentrations using the BrdU ELISA assay. The activity results were compared with reference anticancer drug 5-fluorouracil (5-FU). Compound 1 had almost the same antiproliferative activity as 5-FU. Compounds 1-7 were found to have greater effects against the C6 cell line than the HeLa cell line. These compounds were also tested in order to determine their effects on enzyme activities. Compounds 2 and 3 exhibited strong …
Removal Of Five Cationic Dyes Using A Resin Coated With Nickel/Nickel Boride Nanoparticles, Merve Çinar, Yasemi̇n İşlek Coşkun, Tüli̇n Deni̇z Çi̇ftçi̇
Removal Of Five Cationic Dyes Using A Resin Coated With Nickel/Nickel Boride Nanoparticles, Merve Çinar, Yasemi̇n İşlek Coşkun, Tüli̇n Deni̇z Çi̇ftçi̇
Turkish Journal of Chemistry
Resins coated with nickel/nickel boride nanoparticles were used to remove brilliant green, methyl violet, methylene blue, phenosafranine, and brilliant cresyl blue from water. The effects of pH, adsorbent dose, contact time, and initial dye concentration on the adsorption efficiencies were investigated. The point of zero charge for the adsorbent was pH 9.5. Isotherm studies were conducted using Langmuir, Freundlich, and Dubinin--Radushkevich models, and thermodynamic studies were also performed. Adsorption of the five dyes was found to obey the Langmuir isotherm model and was endothermic. The maximum adsorption capacities calculated from the Langmuir isotherm were 66.7, 88.5, 144.9, 56.2, and 147.1 …
Multiwall Carbon Nanotube Paste Electrode As A Sensor For Sensitive Determination Of Deferasirox In The Presence Of Uric Acid: Application For The Analysis Of Pharmaceutical And Biological Samples, Golnaz Parvizi Fard, Reza Emamali Sabzi
Multiwall Carbon Nanotube Paste Electrode As A Sensor For Sensitive Determination Of Deferasirox In The Presence Of Uric Acid: Application For The Analysis Of Pharmaceutical And Biological Samples, Golnaz Parvizi Fard, Reza Emamali Sabzi
Turkish Journal of Chemistry
In this work, the electrochemical oxidation of deferasirox at a multiwall carbon nanotube paste electrode (MWCNTPE) was described. The electrochemical behavior of deferasirox was studied using cyclic voltammetry and chronoamperometry techniques and parameters such as charge transfer coefficient ($\alpha )$, the number of electrons involved in the rate-determining step ($n_{a})$, and diffusion coefficient ($D)$ were calculated. The capability of the electrode for the determination of deferasirox at low concentrations was investigated using the differential pulse voltammetry technique. It was found that the calibration graph of deferasirox was linear in the concentration range of 0.16-16.5 $\mu $M and its detection limit …
Biological Evaluation And Synthesis Of New Pyrimidine-2(1h)-Ol/-Thiol Derivatives Derived From Chalcones Using The Solid Phase Microwave Method, Seda Fandakli, Nuran Kahri̇man, Tayyi̇be Beyza Yücel, Şengül Alpay Karaoğlu, Nuretti̇n Yayli
Biological Evaluation And Synthesis Of New Pyrimidine-2(1h)-Ol/-Thiol Derivatives Derived From Chalcones Using The Solid Phase Microwave Method, Seda Fandakli, Nuran Kahri̇man, Tayyi̇be Beyza Yücel, Şengül Alpay Karaoğlu, Nuretti̇n Yayli
Turkish Journal of Chemistry
Twenty-five new hydroxy- and methoxy-substituted 4,6-diarylpyrimidin-2(1H)-ol (20-34) and 4,6-diarylpyri\-midine-2(1H)-thiol derivatives (35-44) were synthesized from the reaction of the corresponding 1,3-diaryl-2-propene-1-one compounds (1-19) with urea or thiourea using the solid-phase microwave method. All the new synthetic compounds (20-44) were evaluated with regard to their $\alpha $-glucosidase activity. However, only compounds 22-25, 27,31,34, 35,37, and 40 exhibited a greater inhibitory effect than standard acarbose. The IC$_{50}$ values of the active compounds ranged between 2.36 and 13.34 $\mu $M. The 25 new compounds were also screened for their in vitro pancreatic lipase activity and compounds 20-27and 35-39 were found to be active. Of …