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Articles 61 - 90 of 694
Full-Text Articles in Physical Sciences and Mathematics
A Rapid, Efficient, And Green Synthesis Of Benzo[$A$]Chromeno[2,3-$C$]Phenazine Derivatives Via Microwave Assistance And Dabco~Catalyzed A Novel Domino Cyclization, Seid-Ali Mirmiran-Yazdi, Afshin Yazdani Elah Abadi, Nasim Shams, Razieh Mohebat
A Rapid, Efficient, And Green Synthesis Of Benzo[$A$]Chromeno[2,3-$C$]Phenazine Derivatives Via Microwave Assistance And Dabco~Catalyzed A Novel Domino Cyclization, Seid-Ali Mirmiran-Yazdi, Afshin Yazdani Elah Abadi, Nasim Shams, Razieh Mohebat
Turkish Journal of Chemistry
An efficient, convenient, and environmentally benign procedure for the synthesis of novel benzo[$a$]chromeno[2,3-$c$]phenazine derivatives has been developed by domino four-component condensation reaction between 2-hydroxynaphtha- lene-1,4-dione, $o-$phenylenediamine, aromatic aldehydes, and naphthols or phenol in the presence of a catalytic amount of DABCO as an expedient, ecofriendly, and reusable base catalyst under microwave irradiation in EtOH/H$_{2}$O (1:1). This green process produces biologically and pharmacologically significant heterocycles in a single one-pot operation and offers considerable advantages such as operational simplicity, short reaction time, high yields, reusability of the catalyst, absence of any tedious workup or purification, and avoidance of hazardous reagents/solvents.
A New Method For Simultaneous Determination Of Trace Amounts Of Cu(Ii) And Ni(Ii) Ions By Preconcentration And Spectrophotometric Analysis, Berri̇n Topuz, Şennur Merve Adanur, Arda Yalçuk
A New Method For Simultaneous Determination Of Trace Amounts Of Cu(Ii) And Ni(Ii) Ions By Preconcentration And Spectrophotometric Analysis, Berri̇n Topuz, Şennur Merve Adanur, Arda Yalçuk
Turkish Journal of Chemistry
Immediate preconcentration and spectrophotometric methods have been developed for the determination of trace amounts of cupric ion (Cu(II)) and nickel ion (Ni(II)) through a solid phase extraction with XAD-4-N,N'-bis-(salicylidene) cyclohexanediamine (XAD-4-SCHD) resin and a complex color reaction of the ions with 2,6-dimethyl-morpholine dithiocarbamate (DMMDTC) in Triton X-100 media. A high preconcentration factor of 125 was achieved. The spectrophotometric method was based on the measurements of the absorption of colored chelates of ions complexing with DMMDTC, and the adsorptions of the complex solutions were measured at their maximum absorption peaks at 460 and 328 nm for Cu(II) and Ni(II) ions, respectively. …
Synthesis Of Phosphorus-Containing Polyurethanes And Poly(Urethane-Acrylate)S, Mahi̇r Burak Südemen, Hacer Ayşen Önen
Synthesis Of Phosphorus-Containing Polyurethanes And Poly(Urethane-Acrylate)S, Mahi̇r Burak Südemen, Hacer Ayşen Önen
Turkish Journal of Chemistry
Solvent-based polyurethanes and poly(urethane-acrylate)s were synthesized using phosphorus-containing polyester polyols in order to compare the thermal properties of different polymer types. Since the location of the phosphorus group might have vital importance when comparing the thermal properties, phosphorus groups were kept on the pendant chains in poly(urethane-acrylate)s using phosphorus-containing urethane macromonomers while they were kept on the backbone in polyurethanes. The effect of molar mass of polyurethanes and pendant urethane chains of poly(urethane-acrylate)s on thermal properties was also investigated. Characterization of the synthesized polymers was carried out using FT-IR, GPC, NMR, and DSC followed by evaluation of the thermal properties.
Photoemissive Polymer Composite Based On New Y(Iii), Gd(Iii), And Tb(Iii) Complexes With N-Hydroxyphthalimide, Catalina Yarodara Rosca, Petronela Horlescu, Corneliu S.Stan, Daniel Sutiman
Photoemissive Polymer Composite Based On New Y(Iii), Gd(Iii), And Tb(Iii) Complexes With N-Hydroxyphthalimide, Catalina Yarodara Rosca, Petronela Horlescu, Corneliu S.Stan, Daniel Sutiman
Turkish Journal of Chemistry
In the present work, a green emitting composite with attractive photoluminescent properties was obtained through the embedding of the Tb$^{3+}$ complex with N-hydroxyphthalimide in a poly-(N-vinyl-pyrrolidone) matrix, which was further processed in thin or thick films. First, several complexes of Gd$^{3+}$, Tb$^{3+}$, and Y$^{3+}$ with N-hydroxyphthalimide with the general formula [M(NHF)$_{3}$(DMF)$_{2}$] were prepared at a 1:3 metal/ligand ratio. The Tb$^{3+}$ complex presents specific emission peaks, with the most intense peak located at 543 nm, thus being selected for incorporation in the poly(N-vinyl-pyrrolidone) matrix. The prepared complexes and composites were investigated through elemental analysis, thermal analysis, FT-IR, P-XRD, and SEM. The …
Synthesis And Antinociceptive Activities Of Some Novel Benzimidazole-Piperidine Derivatives, Ümi̇de Demi̇r Özkay, Özgür Devri̇m Can, Nazli Turan, Betül Kaya Çavuşoğlu
Synthesis And Antinociceptive Activities Of Some Novel Benzimidazole-Piperidine Derivatives, Ümi̇de Demi̇r Özkay, Özgür Devri̇m Can, Nazli Turan, Betül Kaya Çavuşoğlu
Turkish Journal of Chemistry
In this study, a series of benzimidazole-piperidine derivatives were synthesized with the objective of developing potent antinociceptive agents. Some 2-(4-substituted-phenyl)-1-[2-(piperidin-1-yl)ethyl]-1$H$-benzimidazole derivatives were obtained by microwave-supported reaction of an appropriate 2-(4-substituted-phenyl)-1$H$-benzimidazole with 2-(piperidine-1-yl)ethyl chloride. The chemical structures of the compounds were elucidated by FT-IR, $^{1}$H NMR, $^{13}$C NMR, and HRMS spectral data. Antinociceptive activity was assessed by conducting hot-plate, paw-pressure, and formalin tests. Morphine (5 mg/kg, i.p) was used as a reference drug. Among the tested compounds 2a-2d and 2f-2h (10 mg/kg) increased the maximum possible effect (MPE) % values calculated for the hot-plate and paw-pressure tests and decreased the paw …
Synthesis And Mao Inhibitory Activity Of Novel Thiazole-Hydrazones, Özlem Atli, Yusuf Özkay
Synthesis And Mao Inhibitory Activity Of Novel Thiazole-Hydrazones, Özlem Atli, Yusuf Özkay
Turkish Journal of Chemistry
A series of new thiazole-hydrazones 3a-3n were synthesized, characterized, and screened for their $h$MAO-A and $h$MAO-B inhibitory activity by an in vitro fluorometric method. Selectivity indexes (SIs) were expressed as IC$_{50}$ (MAO-A) / IC$_{50}$ (MAO-B). Compound 3f showed promising $h$MAO-A inhibition with an IC$_{50}$ value of 1.20 $\mu $M and displayed a very significant SI of 0.04 towards $h$MAO-A. The mechanism of $h$MAO-A inhibition was investigated by enzyme kinetics using Lineweaver--Burk graphics. Compound 3f was further screened for its cytotoxicity by using a healthy NIH/3T3 mouse embryonic fibroblast cell line (ATCC CRL1658) and was evaluated as nontoxic at its effective …
Achieving Elusive Transformations With Organocatalysis: Direct $\Beta $-Carbon Activation Of Saturated Carbonyl Compounds, Rafik Rajjak Shaikh
Achieving Elusive Transformations With Organocatalysis: Direct $\Beta $-Carbon Activation Of Saturated Carbonyl Compounds, Rafik Rajjak Shaikh
Turkish Journal of Chemistry
Direct $\beta $-carbon activation of saturated carbonyl compounds for carrying out fast forward $\beta$-functionalization has been one of the most difficult to achieve tasks in catalysis. In the past few years, this challenging issue has attracted considerable attention among the chemical community that has led to fruitful developments to accomplish this elusive transformation. In this short review, we highlight recent developments for direct $\beta $-carbon functionalization of saturated carbonyl compounds based on conceptually new methods including oxidative enamine catalysis, $N$-heterocyclic carbene (NHC)-assisted catalysis, and photoredox catalysis.
Removal Of Pb(Ii) And Cd(Ii) From Aqueous Solution Using Alkaline-Modified Pumice Stone Powder (Psp): Equilibrium, Kinetic, And Thermodynamic Studies, Vivian Jonasi, Kaina Matina, Upenyu Guyo
Removal Of Pb(Ii) And Cd(Ii) From Aqueous Solution Using Alkaline-Modified Pumice Stone Powder (Psp): Equilibrium, Kinetic, And Thermodynamic Studies, Vivian Jonasi, Kaina Matina, Upenyu Guyo
Turkish Journal of Chemistry
Adsorption processes of Cd(II) and Pb(II) from aqueous solutions onto pumice stone powder (PSP) were investigated in batch mode. The influences of solution pH, contact time, adsorbent dosage, initial metal (M) concentration, and temperature on adsorption process were investigated. The kinetic and isotherm data were analysed using different model equations. The adsorption process was consistent with the Langmuir model for both metal ions with high R$^{2}$ and low $\chi^{2}$ values for both Pb(II) and Cd(II). The maximum monolayer adsorption capacities were 28.09 and 27.17 mg g$^{-1}$ for Pb(II) and for Cd(II), respectively. The pseudo-second order kinetic model explained the kinetic …
Nanocomposite Copper Metal As An Efficient Heterogeneous Catalyst In Click Synthesis Of 1,2,3-Triazoles In Aqueous Media, Vajihe Nejadshafiee, Hossein Naeimi
Nanocomposite Copper Metal As An Efficient Heterogeneous Catalyst In Click Synthesis Of 1,2,3-Triazoles In Aqueous Media, Vajihe Nejadshafiee, Hossein Naeimi
Turkish Journal of Chemistry
Copper/periodic mesoporous organosilica (Cu/PMO) nanocomposites provided a highly active, reusable, globular, solid-phase catalyst for click chemistry. The reaction proceeds by mixing organohalides, sodium azide, alkyne, and the catalyst in an aqueous medium to afford the desired products. The cost efficiency and recyclability of the catalyst up to six runs without appreciable loss of activity and high yields of products make this procedure greener.
Synthesis, In Vitro Dna Interactions, Cytotoxicities, Antioxidative Activities, And Topoisomerase Inhibition Potentials Of Mn(Ii), Co(Ii), Ni(Ii), Cu(Ii), And Zn(Ii) Complexes With Azo-Oxime Ligands, Melek Çol Ayvaz, İbrahi̇m Turan, Bayram Dural, Seli̇m Demi̇r, Kaan Karaoğlu, Yüksel Ali̇yazicioğlu, Keri̇m Serbest
Synthesis, In Vitro Dna Interactions, Cytotoxicities, Antioxidative Activities, And Topoisomerase Inhibition Potentials Of Mn(Ii), Co(Ii), Ni(Ii), Cu(Ii), And Zn(Ii) Complexes With Azo-Oxime Ligands, Melek Çol Ayvaz, İbrahi̇m Turan, Bayram Dural, Seli̇m Demi̇r, Kaan Karaoğlu, Yüksel Ali̇yazicioğlu, Keri̇m Serbest
Turkish Journal of Chemistry
Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) transition metal complexes of 2-hydroxy-5-[(E)-(4-phenyl) diazenyl] benzaldehyde oxime and 2-hydroxy-5-[(E)-(4-nitrophenyl) diazenyl] benzaldehyde oxime ligands were synthesized and characterized through NMR, IR, ESI mass, and UV analysis. DNA binding abilities of the complexes were revealed using a UV-Vis spectrophotometer with the absorption titration and competitive binding techniques. Hydrolytic and oxidative DNA cleavage activities under different conditions were also proved. Topoisomerase I inhibition efficiencies and in vitro free radical scavenging activities of all complexes were examined. Finally, the selective cytotoxic potentials of all complexes were evaluated in human colon cancer, normal colon, and fibroblast cell lines …
The Multiple Effects Of Organoclay And Solvent Evaporation On Hydrophobicity Of Composite Surfaces, Haci Hasan Yolcu, Ahmet Gürses, Rabah Boukherroub
The Multiple Effects Of Organoclay And Solvent Evaporation On Hydrophobicity Of Composite Surfaces, Haci Hasan Yolcu, Ahmet Gürses, Rabah Boukherroub
Turkish Journal of Chemistry
A superhydrophobic high-density polyethylene (HDPE)/organoclay composite material with a water-static contact angle of $\sim $162$^{\circ}$ and low hysteresis (7$^{\circ})$ was prepared by a simple solution-intercalation technique. This one-step method consists of the insertion of organoclay, produced through cation exchange with cetyltrimethylammonium bromide (CTAB), in the polymer matrix at 120 $^{\circ}$C in xylene. In this process, evaporation of the solvent and organoclay amount are key factors for the achievement of superhydrophobicity. We characterized composite material with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and contact angle measurements. The characterizations showed that the organoclay provides a place for …
Palladium Nanoparticles Entrapped In Melamine-Formaldehyde Resin Microparticles For Mizoroki--Heck Reactions, Shaofeng Zhong
Palladium Nanoparticles Entrapped In Melamine-Formaldehyde Resin Microparticles For Mizoroki--Heck Reactions, Shaofeng Zhong
Turkish Journal of Chemistry
Melamine-formaldehyde resin (MFR) microparticles with average diameters of 1.06 $\mu $m were synthesized with PEG-20000 as the particle-forming agent. Palladium nanoparticles were entrapped in and adsorbed on the MFR microparticles, consecutively. Scanning electron microscopy (SEM) was used to characterize the morphologies of MFR microparticles. X-ray diffraction (XRD) and transition electron microscopy (TEM) showed that the palladium nanoparticles entrapped in the MFR microparticles dispersed much more homogeneously than those adsorbed on the MFR microparticles. Mizoroki--Heck reaction catalysis results demonstrated that the entrapped palladium catalyst had similar catalytic activity with the adsorbed palladium catalyst. Moreover, this novel entrapped palladium catalyst could be …
Understanding Of Phenolic Compound Retention Mechanisms On Pes-Uf Membrane, Amine Mnif, Meral Mouelhi, Bechir Hamrouni
Understanding Of Phenolic Compound Retention Mechanisms On Pes-Uf Membrane, Amine Mnif, Meral Mouelhi, Bechir Hamrouni
Turkish Journal of Chemistry
Ultrafiltration (UF) is investigated as a possible alternative to remove organic compounds from aqueous synthetic solution. This paper presents a comprehensive study towards a better understanding of phenolic compound retention mechanisms during UF processes. Thus, removal of phenol and resorcinol was studied using a polyethersulfone ultrafiltration (PES-UF) membrane. The influence of main operating conditions (feed concentration, transmembrane pressure, and pH) on the retention was evaluated. Membrane--solute interactions were found to play an important role during the process, suggesting the adsorption of the target compounds on the PES-UF membrane. The level of adsorption was consequently evaluated by measuring the quantity of …
Investigation Of Photochemical And Photophysical Properties Of Novel Silicon(Iv) Phthalocyanines And Their $\Mu $-Oxo Dimers, Ömer Güngör, Mahmut Durmuş, Vefa Ahsen
Investigation Of Photochemical And Photophysical Properties Of Novel Silicon(Iv) Phthalocyanines And Their $\Mu $-Oxo Dimers, Ömer Güngör, Mahmut Durmuş, Vefa Ahsen
Turkish Journal of Chemistry
The synthesis and characterization of novel tetraalkylthio (SC$_{6}$H$_{13}$ or SC$_{12}$H$_{25})$ substituted $\mu $-oxo silicon(IV) phthalocyanines (3a and 3b) and their $\mu$-oxo derivatives (4a and 4b) were described in this study. These silicon(IV) phthalocyanines were characterized using different spectroscopic techniques such as UV-Vis, $^{1}$H NMR, FT-IR, and mass and elemental analysis, as well. Furthermore, the photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen generation) properties of the newly synthesized silicon(IV) phthalocyanines (3a, 3b, 4a, and 4b) were investigated in dimethylformamide solution. The absorption and fluorescence excitation wavelengths of the studied silicon(IV) phthalocyanines were blue-shifted when they converted to their …
Synthesis Of Pds/Zns--Cds-Type Photocatalysts Using Zns As Sulphide Source, Radu Banica, Petrica Linul, Cristina Mosoarca
Synthesis Of Pds/Zns--Cds-Type Photocatalysts Using Zns As Sulphide Source, Radu Banica, Petrica Linul, Cristina Mosoarca
Turkish Journal of Chemistry
In this work, a new method for the growth of large CdS crystals into PdS/ZnS--CdS-type photocatalysts is presented. In order to accomplish this, in the first stage zinc sulphide was synthesised and hydrothermally crystallised. In the second stage, after PdS decoration, the recrystallised zinc sulphide was utilised as sulphur source for the synthesis of PdS/ZnS--CdS-type photocatalysts. The photocatalysts were characterised by X-ray diffraction, transmission electron microscopy, energy dispersive X-ray spectroscopy, and diffuse reflectance spectroscopy. In the third stage magnetic polymer supports were manufactured and loaded with photocatalyst. Finally photocatalysis experiments under blue light illumination were conducted for the hydrogen evolution …
Methanolysis Of Jatropha Curcas Oil Using K$_{2}$Co$_{3}$/Cao As A Solid Base Catalyst, Gajanan Sahu, Sujan Saha, Sudipta Datta, Prakash Chavan, Satyanarayan Naik
Methanolysis Of Jatropha Curcas Oil Using K$_{2}$Co$_{3}$/Cao As A Solid Base Catalyst, Gajanan Sahu, Sujan Saha, Sudipta Datta, Prakash Chavan, Satyanarayan Naik
Turkish Journal of Chemistry
Biodiesel, fatty acid methyl ester produced by the transesterification of vegetable oil with methanol, is a promising alternative to petroleum-based diesel fuel. In the present study, the methanolysis of high free fatty acid (FFA) $Jatropha$ $curcas$ oil in a transesterification reaction using K$_{2}$CO$_{3}$/CaO solid base catalyst was studied. The various reaction parameters in the transesterification reaction were also discussed. The catalyst was characterized by means of Fourier transform infrared, X-ray diffraction, temperature programmed desorption of CO$_{2}$, scanning electron microscopy, particle size analyzer, true density, and surface area analyzer. The optimum conversion of jatropha oil was 92% when the transesterification reaction …
Cyclic Voltammetry Behavior Of Tamoxifen In Different Electrolytes, Electrochemical Characterization, And Its Measurement By Differential Pulse Anodic Voltammetry, Zeinab Deris Falahieh, Mehdi Jalali, Mohammad Alimoradi
Cyclic Voltammetry Behavior Of Tamoxifen In Different Electrolytes, Electrochemical Characterization, And Its Measurement By Differential Pulse Anodic Voltammetry, Zeinab Deris Falahieh, Mehdi Jalali, Mohammad Alimoradi
Turkish Journal of Chemistry
Cyclic voltammetry (CV) was performed on tamoxifen (tam) using different electrodes and in various acidic electrolytes containing 10% v v$^{-1}$ methanol (MeOH). Tam oxidation was found to be most favorable using 0.1 mol L$^{-1}$ H$_{2}$SO$_{4}$. To investigate the mechanism, we performed chronoamperometry, CV at different scan rates, differential pulse anodic voltammetry (DPAV), and electrochemical impedance spectroscopy on tam-covered glassy carbon electrodes (GCEs). The electrode area, diffusion coefficient, and surface concentration ($\Gamma )$ of tam were calculated to be 0.062 cm$^{2}$, 3.65 $\times $ 10$^{-6}$ cm$^{2}$ s$^{-1}$, and 3.2 $\times $ 10$^{-10}$ mol cm$^{-2}$ respectively. Then the effects of different parameters …
Investigation Of Photoinduced Polymerization Of Doxycycline-Imprinted Hydrogels: Effect Of Template On Initiator Reactivity, Conversion, And Reaction Rate, Di̇lek Dalgakiran, Tuğçe İnan, Fatma Seni̇ha Güner
Investigation Of Photoinduced Polymerization Of Doxycycline-Imprinted Hydrogels: Effect Of Template On Initiator Reactivity, Conversion, And Reaction Rate, Di̇lek Dalgakiran, Tuğçe İnan, Fatma Seni̇ha Güner
Turkish Journal of Chemistry
Photopolymerization kinetics of doxycycline hyclate (DOX)-imprinted hydrogels were monitored by real-time Fourier transform infrared spectroscopy and differential photocalorimetry. 2-Hydroxyethyl methacrylate-based hydrogels were synthesized by using ethylene glycol dimethacrylate as a cross-linker, acrylic acid (AA) as a functional monomer, and 2,2-dimethyl-2-hydroxy acetophenone as a photoinitiator. For imprinting DOX in hydrogels, the molar ratio of template to functional monomer (DOX:AA) was chosen as 1:8 and 1:16. The polymerization was achieved at two different initiator concentrations. The conversion and reaction rate were calculated as a function of the molar ratio of template, and the results were compared to those of nonimprinted ones. In …
Separation And Recovery Of Gallium(Iii) Ions From Aqueous Phase By Liquid--Liquid Extraction Using A Novel Extractant, Cyphos Il 101, Sumitra Nayak, Niharbala Devi
Separation And Recovery Of Gallium(Iii) Ions From Aqueous Phase By Liquid--Liquid Extraction Using A Novel Extractant, Cyphos Il 101, Sumitra Nayak, Niharbala Devi
Turkish Journal of Chemistry
The present study describes the extraction behavior of gallium(III) using a novel ionic liquid trihexyl(tetradecyl) phosphonium chloride (Cyphos IL 101) diluted with kerosene from acidic chloride medium. The extraction of gallium was found to depend on the hydrochloric acid concentration and quantitative extraction of gallium took place at 2.0 mol/L HCl concentration. The nature of the extracted complex in the organic phase was determined using Job's method and proposed to be [R$_{3}$R$^\prime $PGaCl$_{4}$]. The loading capacity of 5.0 $\times$ 10$^{-3}$ mol/L Cyphos IL 101 was determined to be 320.0 mg/L. Two stages of stripping were required for complete removal of …
Naked Eye And Smartphone Applicable Detection Of Toxic Mercury Ions Using Fluorescent Carbon Nanodots, Burcu Baç, Rükan Genç
Naked Eye And Smartphone Applicable Detection Of Toxic Mercury Ions Using Fluorescent Carbon Nanodots, Burcu Baç, Rükan Genç
Turkish Journal of Chemistry
Chitosan passivated carbon nanodots (C-Dots$_{CHIT})$ were synthesized from expired molasses via a simple and green thermal synthesis procedure. As-synthesized C-Dots were nitrogen-doped (NC-Dots$_{CHIT})$ by posttreatment with liquid ammonia and used as nanoprobes for fluorometric detection of mercury ions (Hg(II)$_{aq.})$. Fluorescence response of NC-Dots$_{CHIT}$ in the presence of mercury was evaluated and compared with that of the polyethylene glycol passivated C-Dots$_{PEG}$. This sensing strategy using NC-Dots$_{CHIT}$ displayed a wide linear working range from 1.25 $\mu $g/mL to 43.54 $\mu $g/mL with a detection limit of 1.41 $\mu $g/mL. The fluorescence of C-Dots$_{PEG}$ did not show any significant change upon mercury addition. …
Ultrasound-Assisted Surfactant/Ionic Liquid Aqueous Two-Phase System Extraction Prior To High Performance Liquid Chromatography For The Determination Of Tetracyclines In Milk And Honey Samples, Hayri̇ye Mi̇ne Antep, Taşkin Mumcu, Kami̇l Bostanci, Serap Seyhan Bozkurt, Melek Merdi̇van
Ultrasound-Assisted Surfactant/Ionic Liquid Aqueous Two-Phase System Extraction Prior To High Performance Liquid Chromatography For The Determination Of Tetracyclines In Milk And Honey Samples, Hayri̇ye Mi̇ne Antep, Taşkin Mumcu, Kami̇l Bostanci, Serap Seyhan Bozkurt, Melek Merdi̇van
Turkish Journal of Chemistry
In this work, an ultrasonic-assisted surfactant/ionic liquid aqueous two-phase system (ATPS) extraction method was developed to extract six tetracycline antibiotics from food samples before their chromatographic determination using high performance liquid chromatography. The ATPS was formed with 1-allyl-3-methyl-imidazolium bromide, Triton X-100, and dipotassium hydrogen phosphate. The parameters including type and amount of surfactant, ionic liquid and salt, pH of sample solution, and sonication time were optimized. Under the optimized conditions, linear calibration curves of the six tetracyclines were obtained in the range of 10--500 $\mu $g L$^{-1}$ with $>$ r$^{2} =$ 0.990 (n $=$ 9). The proposed green analytical …
Terrestrial-Marine Sedimentary Cycles In The South Yellow Sea, China: Implications For Paleoenvironmental Reconstruction Since Mis 5, Liangtao Ye, Ge Yu, Mengna Liao, Shouyun Hu, Longsheng Wang, Lei Gao
Terrestrial-Marine Sedimentary Cycles In The South Yellow Sea, China: Implications For Paleoenvironmental Reconstruction Since Mis 5, Liangtao Ye, Ge Yu, Mengna Liao, Shouyun Hu, Longsheng Wang, Lei Gao
Turkish Journal of Earth Sciences
Sedimentary records of the continental shelves since Marine Isotope Stage (MIS) 5 are valuable for paleoenvironmental reconstruction and decipherment of land-sea interactions. Since the 1990s, different perspectives on global glacioclimate magnitudes and the associated evolution of major sedimentary environments during the Late Pleistocene have caused a distinctive understanding of marine transgressions and coastal deposits during MIS 3 and MIS 5. Moreover, the chronology of sediment sequences from this region was primarily determined based on radiocarbon dating, which might be problematic for deposits of 40-50 ka BP or older. In this study, we used both a 150-m-long sedimentary core (YZ07) as …
The Neotectonics Of Southeast Turkey, Northern Syria, And Iraq: The Internal Structure Of The Southeast Anatolian Wedge And Its Relationship With Recent Earthquakes, Gürol Seyi̇toğlu, Korhan Esat, Bülent Kaypak
The Neotectonics Of Southeast Turkey, Northern Syria, And Iraq: The Internal Structure Of The Southeast Anatolian Wedge And Its Relationship With Recent Earthquakes, Gürol Seyi̇toğlu, Korhan Esat, Bülent Kaypak
Turkish Journal of Earth Sciences
In southeastern Turkey, northern Syria, and Iraq, the Southeast Anatolian Wedge (SEAW) is recognized as lying between the high altitude Bitlis-Zagros Suture Zone and the Sincar Mountains on the Mesopotamian plain. This wedge narrows towards the south and contains several thrust and blind thrust zones merging with the basal thrust zone. These zones are determined mainly by locations of fault-propagation folding that generally limit the Plio-Quaternary/Quaternary plains in the region. The positions of these active thrust/blind thrust zones and their relationships to the right and left lateral faults may be used to explain the seismic activity of the region.
Relationships Between Sequence Stratigraphy And Diagenesis Of Corals And Foraminifers In The Middle Eocene, Northern Egypt, Mohamed Tawfik, Abdelbaset S. El-Sorogy, Mahmoud Moussa
Relationships Between Sequence Stratigraphy And Diagenesis Of Corals And Foraminifers In The Middle Eocene, Northern Egypt, Mohamed Tawfik, Abdelbaset S. El-Sorogy, Mahmoud Moussa
Turkish Journal of Earth Sciences
Outcrops of the Middle Eocene in northern Egypt represent a Tethyan reef-rimmed carbonate platform with bedded inner-platform facies. The diagenesis of these outcrops was studied in detail. The facies are characterized by a reef core, back reef and outer lagoon, shoal, inner lagoon, and tidal flat carbonate sequences. The diagenetic sequences on the scleractinian corals and foraminifers were thoroughly examined. These sequences show various diagenetic features during episodes of fluctuating sea levels and appear to be related to the primary composition of the studied components and the transgressive-regressive cycles. The carbonate diagenetic history of the examined samples successively includes marine-phreatic, …
Electrochemical Detection Of Dna Interaction With Mannich Base Derivatives By Disposable Graphite Electrodes, Hüseyi̇n İstanbullu, Hakan Karadeni̇z, Erçi̇n Erci̇yas, Kadri̇ye Arzum Erdem Gürsan
Electrochemical Detection Of Dna Interaction With Mannich Base Derivatives By Disposable Graphite Electrodes, Hüseyi̇n İstanbullu, Hakan Karadeni̇z, Erçi̇n Erci̇yas, Kadri̇ye Arzum Erdem Gürsan
Turkish Journal of Chemistry
Four different Mannich base derivatives containing an aromatic/heteroaromatic propanone structure (C1 (3-(dimethylamino)-1-(thiophen-2-yl)propan-1-one hydrochloride); C2 (3-morpholino-1-(pyridin-3-yl)propan-1-one hydrochloride); C3 (3-(dimethylamino)-1-(1H-indol-3-yl)propan-1-one hydrochloride), C4 (3-(piperidin-1-yl)-1-(pyren-1-yl)propan-1-one hydrochloride)) were earlier synthesized and characterized with $^{1}$H NMR, $^{13}$C NMR, MS, and elemental analysis. The interaction of these compounds with fish sperm double stranded DNA (fs-dsDNA) was investigated by using differential pulse voltammetry (DPV) in connection with a disposable pencil graphite electrode (PGE). After the interaction procedure, there was a meaningful decrease in the oxidation signal of the electroactive DNA base guanine due to possible intercalation and/or alkylation mechanism between these Mannich base derivatives and DNA. The features …
Investigation Of The Effects Of Purification And Characterization Of Turkey (Meleagris Gallopavo) Liver Mitochondrial Thioredoxin Reductase Enzyme And Some Metal Ions On Enzyme Activity, Yusuf Temel, Ö. İrfan Küfrevi̇oğlu, Mehmet Çi̇ftci̇
Investigation Of The Effects Of Purification And Characterization Of Turkey (Meleagris Gallopavo) Liver Mitochondrial Thioredoxin Reductase Enzyme And Some Metal Ions On Enzyme Activity, Yusuf Temel, Ö. İrfan Küfrevi̇oğlu, Mehmet Çi̇ftci̇
Turkish Journal of Chemistry
The thioredoxin system, found in all living creatures, consists of thioredoxin protein (Trx), thioredoxin reductase enzyme (TrxR), and NADPH. In this study, turkey liver mitochondrial TrxR enzyme with 3.07 EU $\times $ mg$^{-1}$ specific activity was purified 990-fold in a yield of 2.05{\%} using 2',5'-ADP Sepharose 4B affinity chromatography. The purity of the enzyme was measured and the molecular weight of its subunits was determined to be 45.5 kDa by SDS-PAGE. The molecular mass of the enzyme's natural state was found to be 88 kDa using Sephadex-G 150 gel filtration chromatography. In addition, characteristic and kinetic properties of the enzyme …
Supramolecular Solvent Microextraction Of Uranium At Trace Levels From Water And Soil Samples, Mansoor Khan, Erkan Yilmaz, Mustafa Soylak
Supramolecular Solvent Microextraction Of Uranium At Trace Levels From Water And Soil Samples, Mansoor Khan, Erkan Yilmaz, Mustafa Soylak
Turkish Journal of Chemistry
A supramolecular solvent microextraction procedure was established for the separation/preconcentration of uranium(VI) (U(VI)) prior to its determination by UV-Vis spectrophotometry. 1-(2-Pyridylazo)-2-naphthol (PAN) was used to form a red chelate (U-PAN) with U(VI) at pH 10. U-PAN was extracted by undecanol in tetrahydrofuran. All the parameters that affect extraction efficiency like solution pH, amount of ligand, type and volume of supramolecular solvent, sample volume, and diverse ion effect were optimized. The preconcentration factor was 17. The detection limit was 0.31 $\mu $g L$^{-1}$. The method was validated using GBW07424 (GSS-10 certified reference material). Microextraction was also applied to water and soil …
Voltammetric Analysis Of Disulfiram In Pharmaceuticals With A Cyclic Renewable Silver Amalgam Film Electrode, Sylwia Smarzewska, Natalia Festinger, Monika Skowron, Dariusz Guziejewski, Radovan Metelka, Mariola Brycht, Witold Ciesielski
Voltammetric Analysis Of Disulfiram In Pharmaceuticals With A Cyclic Renewable Silver Amalgam Film Electrode, Sylwia Smarzewska, Natalia Festinger, Monika Skowron, Dariusz Guziejewski, Radovan Metelka, Mariola Brycht, Witold Ciesielski
Turkish Journal of Chemistry
Electrochemical properties of disulfiram, representative of highly significant bioactive compounds, were studied with a cyclic renewable silver amalgam film electrode (Hg(Ag)FE) using square wave cathodic stripping voltammetry (SWCSV). The influence of various factors such as pH, buffer concentration, buffer composition, and SWCSV parameters on current response was investigated. The optimum results in terms of signal shape and intensity were recorded in Britton--Robinson buffer (pH 7.5) at -0.5 V versus Ag/AgCl/3 mol L$^{-1}$ KCl. An elaborated electroanalytical procedure was used to determine disulfiram at the Hg(Ag)FE in the concentration range from 0.05 to 5.00 $\mu $M. Precision, repeatability, and accuracy of …
Sonochemical Degradation Of Basic Red 29 In Aqueous Media, Zineb Boutamine, Slimane Merouani, Oualid Hamdaoui
Sonochemical Degradation Of Basic Red 29 In Aqueous Media, Zineb Boutamine, Slimane Merouani, Oualid Hamdaoui
Turkish Journal of Chemistry
In this work, the degradation of Basic Red 29 (BR29), an azo dye, was investigated using a high-frequency ultrasonic reactor (300 kHz). The influence of several parameters such as initial substrate concentration (5--200 mg L$^{-1})$, pH (3-10.1), ultrasonic power (20-80 W), and nature of the dissolved gas (Ar, air, and N$_{2})$ on the degradation of BR29 was assessed. Additionally, the impact of natural matrices (seawater and natural and river waters) on the degradation rate of BR29 was clarified. Degradation experiments with radical scavengers, tert-butyl alcohol and glucose, showed that BR29 degraded mainly through HO$^{\bullet }$ radical attack at the gas/liquid …
Synthesis And Cytotoxicity Of Novel Thioxo-Quinazolino[3,4-$A$]Quinazolinones, Negar Mohammadhosseini, Mina Saeedi, Shahram Moradi, Mohammad Mahdavi, Omidreza Firuzi, Alireza Foroumadi, Abbas Shafiee
Synthesis And Cytotoxicity Of Novel Thioxo-Quinazolino[3,4-$A$]Quinazolinones, Negar Mohammadhosseini, Mina Saeedi, Shahram Moradi, Mohammad Mahdavi, Omidreza Firuzi, Alireza Foroumadi, Abbas Shafiee
Turkish Journal of Chemistry
Various thioxo-quinazolino[3,4-$a$]quinazolinones were prepared and evaluated for their cytotoxicity in MOLT-4 (lymphoblastic leukemia) and MCF-7 (breast adenocarcinoma) cell lines. Synthesis of the target compounds was started from isatoic anhydride. Successive reaction of isatoic anhydride with benzylamine and 2-nitrobenzaldehyde, reduction of the nitro group, and reaction with CS$_{2}$ gave 12-benzyl-6-thioxo-6,7,11b,12-tetrahydro-13$H$-quinazolino[3,4-$a$]quinazolin-13-one. The latter compound reacted with various 2-chloro-$N$-substituted acetamides to afford the corresponding fused quinazolinone derivatives.