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The acid activation process increased the specific surface area of raw Resadiye bentonite (33.5 m2/g) by ∼ 4-fold whereas the interaction with n-butylamine caused a surface area reduction of acid-a...

We investigated the anti-cancer activity of [Ag(μ-dicl)]n 1 and [AgH(nif)2] 2 complexes against human cancer cell lines (MCF-7, HT-29, and HepG2) and mouse fibroblast (3T3-L1) cell line. Anti-proli...

The novel activated carbon materials were synthesized by the carbonization and chemical activation of agricultural bio-waste from tea woody stems (TWS), and these materials were characterized by using FTIR, SEM, TG/DTA and surface analysis (BET surface area; pore distribution; pore size, area and volume) techniques. The higher carbonization times and amount of chemical reagent generally produce the higher surface area at 400 and 500 °C. The experimental data demonstrated that the highest BET surface area was 789 m2 g−1 at 500 °C, 75 μm particle size, TWS/KOH ratio of 1:2 and carbonization time of 3 h. The activated carbon IR spectrum showed the increases in intense of aromatic C–H out-of-plane bending and C=C vibrations and the disappearance of olefinic C=C functional groups. Thermal analysis curves of TWS are ascribed to decomposition of organic derivate corresponding to lignin, cellulose and hemicelluloses components up to 700 °C from 200 °C. The SEM images and textural analysis data signified that the pore development of carbon skeleton structure during carbonization and activation process formed and type of micropores in these pore structures was dominant.

A folic acid-functionalized carbon nanotube nanomaterial was prepared by immobilizing folic acid molecules on the carbon nanotubes through covalent bonds. The material was characterized using Fouri...

Herein, we report the synthesis, characterization and anticancer activity of six novel complexes of non-steroidal anti-inflammatory drug niflumic acid with Co(II) and Ni(II). In vitro cytotoxicity screening in MCF-7, HepG2 and HT-29 cancer cell lines showed that the complex 3 [Co(nif)2(met)(4-pic)] and complex 6 [Ni(nif)2(met)(4-pic)] among all the complexes exhibited the highest cytotoxicity against MCF-7 cells with IC50 values of 11.14 µM and, 41.47 µM, respectively. Besides, all the complexes exhibited significantly higher selectivity towards mouse fibroblast 3T3L1 cells. Further mechanistic studies with both complexes on MCF-7 cells revealed their cytotoxic action through the mitochondrial-dependent apoptotic pathway causing an increase oxidative/nitrosative stress, decrease in mitochondrial membrane potential (ΔΨm), inducing the multicaspase activation and arresting the cell cycle at S phase. q-PCR analysis resulted in an increase in the expression of the apoptotic marker proteins bax, p53 and caspase-3 and -8 in MCF-7 cells, but a decrease in the expression of antiapoptotic bcl-2 gene. Moreover, both complexes induced the apoptosis through the inhibition of PI3K/Akt signaling pathway by decreasing the expression of PI3K and increasing dephosphorylation form of Akt protein. These results provide a significant contribution to the explanation of the anticancer mechanisms of these complexes in MCF-7 cells.

An efficient photoelectrocatalyst was synthesized by electrochemical deposition of WO3 on the titanium nanotube (TNT) array by subsequent cycling the potential between -0.6 - 1.0 V vs Ag/AgCl. The structural and morphological properties of the electrode obtained (TNT-WO3) was characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopic (SEM) techniques and it was revealed that TNT surfaces were successfully decorated by WO3 species without formation of another oxidation species. Then, the photoelectrocatalytic activity of the composite electrode set at 0.2 V (vs Ag/AgCl), was tested under UV light irradiation on the degradation of Methylene blue (MB), Orange G (OG) and Rhodamine B (RhB), as the model pollutants. Among the azo dyes studied, the electrode has given the best performance against RhB in comparison to the bare TNT electrode. The influence of the deposition conditions on the efficiency was examined and under optimal conditions and it was noted that efficient removal of the dye can be achieved within 10 min. Another advantage of the composite electrode is that PEC performance can be tuned by simply changing the parameters of deposition. (C) 2021 Elsevier B.V. All rights reserved., Ege University Scientific Research project [2018/FEN/036], This study was supported by Ege University Scientific Research project no: 2018/FEN/036.

Magnetite nanoparticles-decorated smectite nanocomposite was prepared by precipitation method and the obtained nanocomposite was used as both nanophotocatalyst for removal of rhodamine B from wastewater under UVA irradiation and electrocatalyst for the electrooxidation of chlorite ion on the carbon paste electrode. The raw smectite, bare magnetite and the synthesized nanocomposite catalyst were comparatively characterized by using XRD, FTIR, SEM, EDX, XPS, VSM, TG/DTG, DTA, DSC, electrophoretic mobility and BET techniques in detail. The XRD, SEM, electrophoretic mobility and VSM results indicated that the magnetite nanoparticles were uniformly distributed on the surface of smectite with a diameter of about 7 nm by electrostatic interactions and the prepared nanocomposite displayed well superparamagnetic behaviour with strong saturation magnetization at room temperature. The XPS, EDX, FTIR and thermal analysis data of synthesized nanocomposite further confirmed that the magnetite nanoparticles were successfully decorated on the smectite without formation of another ferric phase species. Furthermore, the surface area of magnetite smectite nanocomposite is higher than that of raw smectite, which is related to the magnetite nanoparticles decorated onto the smectite. The catalytic activities of all samples were comparatively investigated by using the degradation of aqueous rhodamine B solutions as a model pollutant in the heterogeneous photo-like-Fenton process which is well defined by the pseudo-first-order equation in kinetics. The resultant magnetite-smectite nanocomposite showed excellent magnetic separability and much better photocatalytic activity in a short period compared to the bare magnetite and smectite. The synergetic effect between magnetite and smectite showed high activity not only in photodegradation but also in electrocatalytic applications. Because the developed nanocomposite material exhibited enhanced catalytic activity towards to chlorite ion oxidation it was applied for the voltammetric quantification of chlorite ion in aqueous medium. After the optimization of the measurement parameters, the limit of detection and quantification of the method were calculated as 3.0 and 10.0 μM, respectively.

Six new Ag(I) coordination complexes, namely [Ag4(μ-dicl)4(2-pic)3] 1, [Ag2(μ-mef)2(2-pic)2] 2, [Ag2(μ-dicl)2(3-pic)2] 3, [Ag2(μ-mef)2(3-pic)2] 4, [Ag2(μ-dicl)2(4-pic)2] 5 and [Ag2(μ-mef)2(4-pic)2] 6, were synthesized and characterized by elemental analysis, FT-IR and thermal analysis techniques. The crystal structures of 1, 3, 4 and 5 were determined by X-ray diffraction analysis, whereas 2 and 6 were obtained as microcrystalline powders. X-ray diffraction analysis demonstrated that 1 occurs as a tetranuclear complex, while 3, 4 and 5 have binuclear structures. A short Ag⋯Ag distances of 2.8446 and 2.8823 A for 1, 2.8409 A for 3, 2.8942 A for 4 and 2.8423 A for 5 were found in the complexes, indicating that argentophilic interactions exist between the silver ions. In 1, the dicl ligands act as μ3-O,O′,O′ bridging ligands between three Ag(I) ions. In 3, 4 and 5, the dicl and mef ligands behave as bridging ligands and bind two Ag(I) ions together with the carboxylato oxygen atoms. The simultaneous TG/DTG and DTA techniques were applied to interpret the mass losses, decomposition temperatures and corresponding processes of the thermal behaviours of the complexes. The experimental and calculated mass losses of the proposed structures for complexes 2 and 6 are quite compatible with each other and these complexes have very similar FT-IR spectra to the other complexes, which reflect their same structural geometries and characteristics. The cytotoxic activities of the complexes (1–6) were tested against three different cancer cell lines, MCF-7, HT-29 and HepG2, and one normal cell line, 3 T3-L1. XTT assay results demonstrated that although all the silver(I) complexes showed good cytotoxic activity, depending on the cell types tested, the complexes with mefanamic acid (2, 4 and 6) were found to predominate over those with diclofenac (1, 3 and 5), as well as the superiority of 3-picoline to 4-picoline and 2-picoline. Moreover, compared with the cytotoxic potential of carboplatin, 4 especially exhibited a significant cancer cell inhibitory rate and lower cytotoxicity toward the normal cell line, with much higher selectivity indexes.

In this study, we prepared bentonite-Bi2S3 nanocomposite via decoration of Bi2S3 nanorods on bentonite for the first time to enhance the photocatalytic performance of Bi2S3 nanorods under visible light irradiation. XRD, TEM, SEM-EDX, XPS, UV-DRS, PL, electrochemical impedance spectroscopy, chronoamperometry, zeta potential, and BET techniques were used to compare analysis of structural, morphological, optical, electrochemical and textural properties of raw bentonite, bare Bi2S3 nanorods and bentonite-Bi2S3 nanocomposite. The photocatalytic performances of bentonite-Bi2S3 nanocomposite and bare samples were also investigated and comparatively evaluated by photodegradations of crystal violet and rhodamine B dyes under visible light irradiation. The photocatalytic degradation efficiencies of fabricated bentonite-Bi2S3 nanocomposite for crystal violet and rhodamine B were determined as 100% and 85% after the periods of 30 min and 90 min, respectively, which were more superior compared with those of bare Bi2S3 nanorods. The enhanced photodegradation activity of bentonite-Bi2S3 nanocomposite was assigned to the good visible light absorption ability, enlarged surface area, increased adsorption capability and decreased aggregation of Bi2S3 nanorods with the inclusion of bentonite platform as well as suppressed hole-electron recombination process due to electrostatic interaction between negatively charged bentonite surface and positively charged holes. The reactive species trapping revealed that hydroxyl radicals played a major role on the photodegradation and a plausible mechanism for photodegradation of dye molecules on bentonite-Bi2S3 nanocomposite was suggested. The photodegradation of dyes was found to follow the pseudo-first-order kinetic model. The prepared photocatalyst exhibited good reusability and stability after 4 cycles.

To improve the photocatalytic performance and solve the aggregation problem of BiFeO3 nanoparticles, kaolinite-BiFeO3 photocatalyst was successfully prepared for the first time by decoration of ferromagnetic BiFeO3 nanoparticles onto kaolinite surface. Comparative characteristics of kaolinite, bare BiFeO3 and kaolinite-BiFeO3 photocatalyst were investigated in detail by XRD, TEM, SEM-EDX, XPS, FTIR, VSM, UV-DRS, PL, zeta potential and BET techniques. The photocatalytic activities of the samples were also evaluated by photodegradation of rhodamine B as a model reaction under different irradiations like UVA, visible and sunlight. The kaolinite-BiFeO3 exhibited more superior photocatalytic activity as compared with other samples, which is best fitted to pseudo-first-order kinetic. The reactive species trapping experiments indicated that photogenerated-holes play major roles in the degradation process whereas superoxide radicals possess a secondary effect. Enhanced photocatalytic activity of kaolinite-BiFeO3 is attributed to its kaolinite platform that reduces the recombination opportunities of the photogenerated holes and electrons as well as increases the surface area, decreases the particle size and aggregation of nanoparticles. In addition, we also designed a novel electrocatalytic platform based on gold nanoparticles loaded on kaolinite-BiFeO3 modified carbon paste electrode surface for the examination of electrocatalytic activity for oxygen reduction reaction in alkaline medium. Electrochemical characterizations of the Au/BiFeO3/kaolinite modified carbon paste electrode and other bare surfaces were comparatively carried out with the aid of cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry. Au/BiFeO3/kaolinite modified carbon paste electrode exhibited 15-fold current enhancement together with 100 mV anodic potential shift compared with bare carbon paste electrode.

In this study, TiO2/ZnO hybrid nanocomposites (TZ) were fabricated by two step synthesis route for potential applications as photoanode in dye sensitized solar cells (DSSC). Titania nanotubes were grown on titanium sheets by electrochemical oxidation. ZnO nanorods were decorated with hydrothermal method by equimolar (0.1 M) precursors on TiO2 nanotubes. Hydrothermal temperatures values were changed to find the optimal ZnO decoration density to increase photo conversion efficiency. The characterization of the photoanodes was made using FE-SEM, XRD and XPS techniques. The results show that hydrothermal reaction temperature can dramatically enhance the light harvesting performance of TZ photoanodes. The photo conversation efficiency of DSSC by TZ photoanode was reached 1.67 % for hydrothermal temperature of 130 °C which is twofold higher than that of DSSC by TiO2 nanotubes (0.81 %). The improvement in photo conversation conversion efficiency can be assigned to synergetic effect in TZ photoanode, lower recombination rate and charge transfer resistance.

In this study, anodic TiO 2 nanotube (TNT) arrays with average nanotube diameter from 26 nm to 115 nm and length from 1.3 μm to 6.4 μm were grown by electrochemical method. Anodization process were performed under different voltages from 10 to 50 V in ethylene glycol – ammonium fluoride – water electrolyte. Formation mechanism of TNTs was summarized. Surface morphology, crystal structure, roughness, wettability and elasticity of TNT arrays were characterized by using field emission scanning electron microscope (FESEM), X-Ray diffraction (XRD), atomic force microscope (AFM), optical tensiometer and universal mechanical tester, respectively. Water contact angle measurements and nanoindentation tests proved that water contact angle and elastic modulus of TNT arrays decrease with increasing anodization voltage. Photocurrent-photovoltage curves and electrochemical impedance spectroscopy (EIS) measurements of dye sensitized solar cells (DSSC) were made to investigate the effects of anodization voltages on photoanode performance. The light conversion efficiency and photocurrent density of TNT photoanodes was increased with increasing anodization voltage due to larger nanotube length and surface area. The results show that anodization voltage is significant parameter for the surface properties and dye sensitized solar cell (DSSC) performance TNT arrays.

Platinum decorated heterogeneous catalysts for methanol oxidation reaction have crucial importance for the commercial sustainability of Direct Methanol Fuel Cells (DMFC). In this study, TiO2/ZnO/Pt nanocomposite film was fabricated as a promising electrocatalytic surface to enhance methanol oxidation in alkaline medium. Firstly, an TiO2/ZnO layer was prepared via DC sputtering followed by electrodeposition techniques on FTO electrode and then platinum nanoparticles were decorated onto the obtained nanocomposite film for the first time. The characterization of the developed transparent films was performed by using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cycling voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The XRD, FESEM and XPS results showed that metallic Pt nanoparticles were uniformly distributed onto the TiO2/ZnO film consisting of anatase TiO2 and wurtzite ZnO layers with a thickness of ca. 370 and 320 nm, respectively. Five cycles of deposition of ZnO and Pt nanoparticles showed best catalytic activity after optimization. The oxidation peak of 0.5 M methanol at TiO2/ZnO/Pt was located at −0.17 V and the corresponding peak current increased about 10- and 5-fold in comparison to FTO/Pt and FTO/TiO2/Pt electrodes, respectively.

In this study, two new binuclear silver(I)-tolfenamic acid complexes including picoline derivative ligands, [Ag2(μ-tolf)2(2-pic)2] 1 and [Ag2(μ-tolf)2(4-pic)2] 2, were synthesized and identified by elemental analysis, FT-IR, 1H NMR and thermal analysis techniques. The in vitro cytotoxicity of the complexes was investigated against human breast cancer cell lines by XTT, flow cytometry, enzyme activity and western blot studies. The structures of 1 and 2 were clarified by single-crystal X-ray diffraction determination. The data clearly indicated that the Ag(I) ion is coordinated to one auxiliary ligand (2-pic or 4-pic), two tolfenamato ligands and another Ag(I) ion, demonstrating a distorted tetrahedral geometry. The tolfenamato ligands act as a bridging bidentate ligands. The chains are stabilized by intramolecular Ag(I)⋯π and π···π interactions. The 1H NMR and thermal analyses displayed the presence of picoline and tolfenamato ligands in the coordination sphere and the purity of the complexes. Both complexes exhibited potent cytotoxicity against cancer cell lines with higher selectivity than carboplatin. Flow cytometry and enzyme activity studies indicated that both complexes caused an increase in apoptosis, ROS and NO levels, cell cycle arrest, mitochondrial membrane damage and caspase activity, as well as inhibiting PI3K/Akt phosphorylation and modulating the oxidant/antioxidant balance system. Western blot analyses revealed the up-regulation of bax, caspase-3, caspase-9 and p53 proteins, but the down-regulation of bcl-2. These results demonstrate the vigorous apoptotic potential of the novel Ag(I) complexes in human breast cancer MDA-MB-453 cells.

Herein, we synthesized ferromagnetic BiFeO3 nanoparticles with sizes of 20–60 nm and rhombohedral distorted perovskite structure without any co-formed impurity phases by sol-gel method. Structural, morphological, magnetic, electronic and textural properties of BiFeO3 nanoparticles were characterized by using XRD, SEM-EDX, TEM, FTIR, XPS, VSM, UV-DRS, PL and BET techniques. The peroxidase was isolated from the Cress (Lepidium sativum) and purified by using precipitation of ammonium sulfate and chromatographic techniques; gel filtration and ion exchange chromatography which is showed wide range of thermal stability, maximum activity in the acidic environment and close to the body temperature. Afterwards, a novel amperometric biosensor based on Cress peroxidase entrapped on BiFeO3 nanoparticles modified carbon paste electrode was prepared for the first time to sensitive detection of H2O2. The prepared H2O2 biosensor was operated with the aid of choro-amperometry technique by applying −0.8 V vs Ag/AgCl electrode. The developed biosensor exhibited a linear response towards to H2O2 in the concentration range of 2.0 10−7 to 1.0 10−5 M under the optimal conditions and limit of detection and quantification were estimated as 7.0 10−8 M (2.7 μg L−1) and 2.0 10−7 M (8.7 μg L−1), respectively. The repeatability of the electrode was calculated as 19.2 for 2.0 10−7 M (N = 7) and the accuracy was 81.2% for this concentration. In addition, the H2O2 biosensor exhibited excellent stability up to ten days. Finally, the sensor developed was used for the analysis of H2O2 in milk samples and satisfactory recoveries were obtained under the operating conditions.

The present investigation was undertaken to obtain information about the structural, thermal, morphological, surface charge and textural properties of the synthesized dodecyltrimethylammonium-smectite composites at various surfactant concentrations by means of powder X-ray diffraction, attenuated total reflection Fourier transform infrared, thermal analyses, scanning electron microscopy, electrophoretic mobility and surface area measurement techniques. The basal spacing values of organo-smectites varied between 13.55 and 17.00 angstrom that point out the successful intercalation of the surfactant cations into smectite layers with different molecular arrangements either lateral monolayer or lateral bilayer. Intercalation of surfactant cations led to appreciable decreases in the intensities of the bands at 3402 and 1635 cm(-1) which originate from OH stretching and bending vibration of sorbed water molecules, respectively. Thermal analysis data showed that all organo-smectites had lower adsorbed water losses than raw and sodium-smectite and the removal of surfactant species occurred in the temperature range of 130-720 degrees C. The specific surface areas, pore volumes and micropore surface areas of organo-smectites decreased while the average pore width of these species increased with respect to that of raw smectite. The surfactant cations located in the interlayer spaces caused significant alterations in electrophoretic mobility values and morphology of raw smectite. (C) 2015 Elsevier B.V. All rights reserved.

Niflumic acid is used to treat inflammatory rheumatoid diseases, pain, and fever. The present study reports the experimental, spectroscopic, thermal, structural analyses, and biological activities of this complex. The nonsteroidal anti-inflammatory drug niflumic acid, 3-picoline, and copper(II) chloride were utilized to synthesize a new complex: [Cu2 Cl 2 (nif) 2 (3-pic) 4 ]. The crystal structure of [Cu 2 Cl 2 (nif) 2 (3-pic) 4 ] was determined by X-ray crystallography. The complex crystallizes in the triclinic space group P-1 and each Cu(II) center displayed six-coordinated distorted octahedral geometry. Two Cu(II) centers are connected by a chloro-bridge to form the binuclear metal core. Finally, the in vitro effects of the synthesized new complex and free niflumic acid were evaluated on the human serum paraoxonase 1 enzyme. At low doses, both the new complex and free niflumic acid showed very good inhibition activity with different inhibition mechanisms. In addition, the results showed that the new complex has more inhibition activity than free niflumic acid.

A voltammetric carbon paste sensor (CPS) was described for the detection of chlorite ion in water analysis. For the construction of the voltammetric CPS, organo-bentonites were synthesised by intercalation of N-cetylpyridinium (NCP) at different amounts into interlayer gap of bentonite. Some features of the obtained organo-bentonites such as structural, thermal and morphological were investigated by using various techniques. Afterwards, the voltammetric behaviour of the ClO2− solution was investigated with cyclic voltammetry in the potential range of 0.0–1.0 V at a scan rate of 50 mV s−1 based on the obtained organo-bentonites as electroactive material. The characterisation of the prepared organo-bentonites as electroactive material, the effect of the amount of NCP–bentonite (NCP–B) in modified CPS on the 10.0 mM ClO2− response was tested by chancing the percentage of NCP–B in the range of 2.50–12.50% under identical experimental conditions. The pH of the measurement cell was optimised by using 0.04 M Britton–Robinson buffer in the range of pH 2.0–12.0. Under the optimised conditions, developed sensor exhibited a linear response in the range of 2.0 × 10−5 to 2.0 × 10−4 M chlorite ions concentrations. The detection limit and the limit of quantification were figured out as 6.0 × 10−6 and 2.0 × 10−5 M, respectively. The repeatability and reproducibility of the sensor were calculated as 5.0% and 6.8% (N = 5), respectively. Finally, the sensor was successfully applied for the analysis of bottled water, and the mean recovery was found as 103 ± 3%.

In present study, we report on the synthesis of TiO2/ZnO nanocomposite (TZN) films for potential applications as photocatalyst in heterogeneous photo-degradation of Rhodamine B under UVA irradiations. ZnO nano-rice decorated TiO2 nanotubes were successfully synthesized via a facile and effective two-step route. Firstly, TiO2 nanotube arrays were grown by anodic oxidation. Afterwards, ZnO rice shaped nanostructures were decorated by successive chemical bath deposition cycles of 2, 4, 6 and 8. The XRD, FESEM, XPS and μ-XRF results showed that the rice-shaped wurtzite ZnO nanoparticles with dimensions of ca. 1μm × 100 nm were homogeneously distributed on the anatase TiO2 nanotube arrays with highly uniform in the presence of in zinc nitrate hexahydrate and hexamethylenetetramine precursors with 1:4 M ratios. The photodegradation results showed that the photocatalytic activity of TZN films were gradually increased in parallel with the number of ZnO deposition cycles and the best performance was found for TNZ8 film. The RhB photodegradation efficiency was determined to be 65% for bare TiO2 whereas 95% degradation of Rhodamine B was occurred for TNZ8 film which follow pseudo-first-order kinetic. In addition, TZN films exhibited good photostability after four reuses. Also, photocatalytic activity of TZN were tested under UVC, UVB, UVA and visible region irradiations for comparative purposes.

TiO2 nanotube/ZnO nanorod hybrid nanocomposite (ZTN) photoanodes were synthesized, characterized and assembled as dye-sensitized solar cells (DSSCs) at optimum conditions for improving photovoltaic efficiency. The self-organized and high ordered TiO2 nanotube arrays were growth on titanium foil by anodic oxidation as a substrate for ZnO decoration by hydrothermal method. Zinc nitrate hexahydrate and hexamethylenetetramine precursor concentrations were varied to designate the optimum ZnO decoration density for enhanced photoconversion efficiency. XRD, FESEM and XPS results showed that the crystal structure, morphology, elemental composition and density of ZnO nanorods on the surface of TiO2 nanotubes are very sensitive to ZnO precursor concentrations. It is found that, the highest overall efficiency of DSSC based on ZTN photoanode was measured 1.8% for precursor concentration of 60 mM which was more than double compared to DSSC based on bare-TiO2 nanotubes (0.8%). The improvement of DSSC efficiency originates from suppressing the recombination rate and decreasing the charge transfer resistance due to synergetic effect between TiO2 nanotubes and ZnO nanorods.

Two Ag(I) complexes [Ag2(μ-mef)2(2-pymet)2] 1, [Ag2(μ-mef)2(2-pyet)2] 2 containing mefenamic acid, 2-pyridinemethanol and 2-pyridineethanol were synthesized and characterized by using SCXRD, FT-IR, elemental and thermal analysis techniques. The complex 1 was synthesized as a single crystal whereas the complex 2 was obtained as a microcrystalline powder. The complex 1 consists of binuclear structure. The argentophilic interaction occurs among silver(I) ions due to the short Ag⋯Ag distance (2.8710(10) A). Two Ag(I) centers are connected by carboxylato oxygen-bridge to form the binuclear metal core. The FT-IR spectra and thermal analysis studies confirmed that both complexes exhibited similar structures. In vitro antiproliferative activity of both complexes were evaluated against MCF-7, HT-29 and HepG2 cancer cell lines. The apoptotic effects and intracellular ROS generation from both complexes were investigated in MCF-7 cell line by flow cytometry analysis. The XTT and LDH assays revealed that both complexes showed strong antiproliferative activity with higher selectivity towards cancer cells compared to the normal cells. In addition, Annexin V/propidium iodide assay exhibited that apoptotic cell number was increased in MCF-7 cells with increasing concentrations of Ag(I) complexes. Furthermore, both complexes induced the ROS generation considerably in MCF-7 cells suggesting the possible pro-oxidant activity of the novel synthesized Ag(I) complexes. Taken together, these findings provide a notable support for potential utility of Ag(I) complexes as novel anticancer agents against numerous kind of carcinogenesis.

Chitosan-smectite biocomposite was prepared by intercalation of protonated chitosan molecules into the interlayer space of smectite in monolayer arrangement through cation exchange mechanism and the obtained biocomposite was successfully used as an electroactive component in the structure of a PVC membrane potentiometric sensor for the direct and highly selective determination of monohydrogen phosphate ions. The comparative elemental, structural, thermal and morphological analysis of starting-smectite, neat chitosan and chitosan-smectite were investigated by utilizing EDX, XRD, ATR-FTIR, TG/DTG/DTA, SEM and surface area measurement techniques. The optimum membrane composition, detection limit, response time, pH working range and repeatability of the proposed electrode were determined.

A novel copper(II)-selective electrode based on graphite oxide/imprinted polymer composite was developed for the electrochemical monitoring of copper(II) (Cu2+) ions. The electrode exhibited highly selective potentiometric response to Cu2+ with respect to common alkaline, alkaline earth and heavy metal cations. The composite composition studies indicated that the most suitable composite composition performing the most promising potentiometric properties was 20.0% ionophore (Cu2+-ion imprinted polymer), 10.0% paraffin oil, 5.0% multiwalled carbon nanotubes, and 65.0% graphite oxide. The fabricated electrode exhibited a linear response to Cu2+ over the concentration range of 1.0 x 10(-6)-1.0 x 10(-1) M (correlation coefficient of 0.9998) with a sensitivity of 26.1 +/- 0.9 mV decade(-1). The detection limit of the fabricated electrode was determined to be 4.0 x 10(-7) M. The electrode worked well in the pH range of 4.0-8.0. The electrode had stable, reversible and fast potentiometric response (3 s). In addition, the electrode had a lifetime of more than 1 year. The analytical applications of the proposed electrode were performed using as an indicator electrode for the potentiometric titration of Cu2+ with ethylene diamine tetraacetic acid solution and for the determination of Cu2+ of spiked river, dam, and tap water samples. The obtained results for potentiometric titration and water samples were satisfactory.

In this study, the effects of four novel mononuclear palladium(II) and platinum(II) complexes on the activity of human serum paraoxanase1 were examined. First, four novel mononuclear palladium(II) and platinum(II) complexes were synthesized with a nitrogen donor ligand 1‐(2‐aminoethyl)pyrrolidine and nonsteroidal anti‐inflammatory drugs diclofenac, mefenamic acid. These complexes were characterized by spectroscopic, thermal, and elemental analyses. The crystal structures of complex [Pd(2‐amepyr)2](dicl)2 1 and [Pd(2‐amepyr)2](mef)2 3 were determined by X‐ray crystallography. Then, paraoxonase1 enzyme was purified from human serum. The effects of these complexes on enzyme were evaluated in vitro. The complexes consist of the cationic unit and the counterions. The diclofenac and mefenamic acid acted as a counterion in the complexes. It was observed that all the complexes were stable up to high temperatures. These complexes, even at low doses, inhibited the activity of the enzyme with different inhibition mechanisms., The Research Foundation of Erzincan University is acknowledged for the financial support to this work under the Project Number FEN‐A‐020414‐0068.

WOS: 000331157500036, The expansion by 1.43 Angstrom of basal spacing and the shift to higher frequencies of in-plane ring vibrations of the Pyronin Y molecule at 1603 and 1527 cm(-1) on the formation of Pyronin Y-bentonite composite exhibited that the dye cations might be oriented as a monolayer form in the interlamellar spacing with aromatic rings parallel to clay layers. Thermal analysis results of this composite compared to those of raw bentonite signified the different outer sphere water entities associated with the replacement of inorganic cations with organic dye cations and the gradual decomposition of the organic molecule in the interlamellar spacing. Thermo-Infrared spectra of Pyronin Y-bentonite sample up to high temperatures showed the thermal stability of the dye-clay composite as a result of the presence of it interactions. The pore structure characteristics of Pyronin Y-bentonite composite exhibited the increase in the number of mesopores during formation of the composite. Published by Elsevier B.V., Recep Tayyip Erdogan University and its central laboratory, The authors are grateful to the Recep Tayyip Erdogan University and its central laboratory for the financial and technical supports.

The present investigation was undertaken to obtain information about the structural and morphological properties of the silk of two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) by means of the atomic force microscope (AFM), scanning electron microscope (SEM), energy dispersive X-ray spectrophotometer (EDX) and attenuated total reflection Fourier transmission infrared spectroscopy (ATR-FTIR) techniques. AFM images show that the shapes of silken threads produced by both female and male mites are similar and have non-uniform cylindrical structure. In general, the appearance of silks produced by female mites is smoother than those of the male mites. In addition, it is determined that the silk threads produced by both female and male individuals have single and double stranded structure. There were differences in the thread dimensions of female and male which could depend on the body size of the mites. However, there is no statistically significant correlation between the body size of the mites and their thread dimensions. The silk material was found to consist predominantly of C, N and O elements and minor fractions of Al, P, Cl and K. The ATR-FTIR spectrum of the silk of two-spotted spider mite exhibited characteristic vibrational modes originating from amid groups, which were attributed to random coil and β-sheet molecular conformation in the protein structure of the silk of two-spotted spider mite. Understanding the features of the two-spotted spider mite silks may be of practical importance for the future studies related to biomaterial and material science.

A novel poly(acrylamide-co-methacrylic acid)/organoclay nanocomposite was prepared and its structural, thermal, and morphological properties were investigated by various techniques. The absence of diffraction peaks for the organomodified-smectite nanocomposite showed that dispersion of the clay nanolayers within the polymer matrix was in the form of an exfoliated nanostructure. Morphological studies confirmed that organomodified-clay dispersed homogeneously in the polymer matrix. Infrared spectroscopy results indicated that the organosmectite is physically dispersed in the polymer network without forming any chemical bonds. The thermal analysis data revealed that there are significant increases in temperatures of decomposition and softening points of polymer with addition of organoclay.

The mononuclear six metal(II) complexes ([Co(mef)2(3-pic)2(CH3OH)2] (1), [Ni(mef)2(3-pic)2(CH3OH)2] (2), [Cu(mef)2(3-pic)2] (3), [Co(mef)2(4-pic)2] (4), [Ni(mef)2(4-pic)2] (5), and [Cu(mef)2(4-pic)2] (6) with mefenamic acid and picoline ligands were synthesized, characterized, and their carbonic anhydrase inhibitory activities were evaluated. The six complexes were characterized by elemental analysis, FT-IR spectroscopy, and thermal analyses. The crystal structures of 1, 3, and 6 were determined by X-ray crystallography. The complexes have octahedral geometry. In 1, the mefenamato ligand behaved as monodentate whereas in 3 and 6, the mefenamato ligand acted as a bidentate ligand. Complexes 3 and 6 consist of the mefenamate and 4-picoline ligands. In 1, unlike the other complexes, methanol acted as a ligand and was involved in the coordination. Carbonic anhydrase I and II isoenzymes were purified from human erythrocytes. The in vitro effects of mefenamic acid, 3-picoline, 4-picoline, and the six metal(II) complexes on these isoenzymes were evaluated., The Research Foundation of Erzincan University is acknowledged for the financial support to this work under the Project Number FYL-2017-446.

In this study, the dyeing kinetics of CI Reactive Black 5 dye was statistically investigated. Cotton fabrics were dyed with this dye under different conditions by the exhaustion technique. Dye samples were taken from the dyebath from the start to the end of the process at 10min intervals in order to determine the percentage dye exhaustion. The transmittance of the coloured dyebath samples was measured using a UV-vis spectrophotometer. The results were investigated by statistical methods using analysis of variance and regression curves. The dye exhaustion of the cotton fabrics was found to change as a function of the dyeing parameters. Times of half-dyeing were determined from the regression curves.

A novel kaolinite-nicotinamide composite was prepared utilizing a kaolinite/N-methylformamide intercalation compound as a precursor material and examined the structural properties of the intercalated species. The X-ray powder diffraction pattern illustrated that intercalation of nicotinamide molecules between the layers of kaolinite caused an emergence of new peaks at 6.87 and 13.63(2 θ ) with the distance of 12.86 and 6.49 A, respectively, belonging to the d 001 and d 002 planes of kaolinite-nicotinamide. The expansion of the d 001 basal spacing (5.68 A) point out the existence of nicotinamide species in the layers of kaolinite which are located as a monolayer arrangement. The aromatic rings of the nicotinamide molecules are perpendicular to the aluminum layers of kaolinite and also both top hydrogen atom of pyridine ring and oxygen atom of carbonyl is keyed into the ditrigonal holes in the silicate layers. The appearance of the peaks at 3630, 3533, 1596 and 1441 cm −1 and decrease of intensity of the inner-surface hydroxyls peak at 3696 cm −1 prove that nicotinamide molecules intercalated into kaolinite layers through forming H-bonds via pyridine ring nitrogen with inner-surface hydroxyls of kaolinite. The thermal stability of intercalated NAM molecules is up to 238 °C. The organic molecules located in the interlayer spacing led to an appreciable decrease of particle size and differences in the morphology. The specific and mesoporous surface areas of intercalated composites increased whereas the average pore width of these species decreased with respect to that of pure kaolinite.

Coordination compounds of compositions [Ni(bba)2(bapen)] (1) and [Cu(bba)2(bapen)]0.5H2O (2), where bba = 2-benzoylbenzoate, bapen = N,N′-bis(3-aminopropyl)ethylenediamine, have been prepared. The crystal and molecular structure of (1) and (2) were determined by X-ray analysis. Nickel and copper atoms are six-coordinated by four N atoms of amine and O donor atoms of 2-benzoylbenzoate anions, whereas 0.5 water molecule is situated outside the coordination sphere in (2). The calculated ∆(OCO) values are consistent with presence of monodentate carboxylate. Thermal analysis show that the mass losses of 1 in the temperature ranges 240–343 °C correspond to the decomposition of bba ligands, while the mass losses of 2 in the temperature ranges 105–125 °C correspond to the decomposition of crystal lattice water molecule. [[Ni(bba)2(bapen)] (1) and [Cu(bba)2(bapen)]0.5H2O (2), where bba = 2-benzoylbenzoate, bapen = N,N′-bis(3-aminopropyl)ethylenediamine, have been prepared and characterized by elemental analyses, spectroscopic, and X-ray crystallography techniques.]

WOS: 000287490500001 The aniline species incorporated into the acid-activated bentonite matrices leads to the decay of the skeletal stretches centered at 1041cm-1 and the rise of new features in the phenyl ring frequency region, 1700-1400cm-1, demonstrates clearly the influence of the acid activation on the Lewis sites necessary for coordination of aniline to bentonite. The exothermic DTA features at 507, 684, and 725 degrees C indicate the release of both the clusters and the decomposed fragments of the aniline-clay composite, and the highly stable carbonaceous residue, respectively. The basal difference by 1.0nm and the much smaller surface area (33.8m2/g) than that of the nonintercalated bentonite (129.2m2/g) prove the presence of the tilted aniline species between the interlamellar grooves of the bentonite framework. Research Foundation of Ondokuz Mayis University [F238] The authors are grateful to the Research Foundation of Ondokuz Mayis University for the financial support of this work under Project F238. We also thank Professor Ugur Cevik of Karadeniz Technical University for performing the chemical analysis of the activated clay sample.

The intercalation of dimethyl sulphoxide (DMSO), pyridine (Py), ethanolamine (Ea), and Nmethyl formamide (NMF) molecules into the kaolinite interlayers led to an appreciable decrease of 3697 cm−1 of the hydroxyl band. The appearance of the peaks at 3662, 3541, and 3504 cm−1 proved that the DMSO species are intercalated between the kaolinite layers through forming H-bonds with internal-surface hydroxyl groups. The intensities of the 942 and 796 cm -1 bending peaks arising from inner-surface hydroxyls decreased and new vibrational features appeared due to the intercalation of the guest species. The d001 value of pure kaolinite was found at 7.18 A° , and the d001 values were seen at 11.26, 11.62, 10.77, and 10.67 °A for kaolinite-dimethyl sulphoxide (K-DMSO), kaolinite-pyridine (K-Py), kaolinite-ethanolamine (K-EA), and kaolinite-N-methyl formamide (K-NMF) composites, respectively. The endothermic differential thermal analysis (DTA) peaks at a temperature of 108 - 334 ◦C reflected the changes in the physicochemical properties of the intercalated species. The thermal stability increase followed the order of K-Py

emirik, mustafa/0000-0001-9489-9093 WOS: 000281458400003 BACKGROUND: The removal of Reactive Red 120 (RR 120) from aqueous solutions using cetylpyridinium modified Resadiye bentonite (CP-bentonite) prepared by ion exchange was investigated with particular reference to the effects of temperature, pH and ionic strength on adsorption. RESULTS: Fourier transform infrared (FTIR) and thermal analysis (TG-DTG/DTA) techniques revealed that the anionic dye (RR 120) molecules replaced partly cationic surfactant species on interacting with CP-bentonite. The positive surface charge originating from the cationic surfactant species located on the external surface of the modified bentonite sample increased at low pH values. The significant amount of dye removal by CP-bentonite at high pH values proved the importance of pi and van der Waals interactions other than the electrostatic attraction in the duration of the adsorption process. The adsorption isotherms and the kinetic data were well described by the Langmuir and pseudo-second-order kinetic model, respectively. The Gibbs energy (Delta G), enthalpy (Delta H) and entropy (Delta S) changes in the temperature range 25-65 degrees C pointed out that the RR 120 uptake increased in parallel with the temperature. CONCLUSION: This study showed that the structural arrangement of cetylpyridinium ions in the CP-bentonite sample as well as the pH, temperature and ionic strength of the bulk solution influenced the adsorption of RR 120 dye from aqueous solutions by CP-bentonite. (C) 2010 Society of Chemical Industry Research Foundation of Rize UniversityRecep Tayyip Erdogan University [2009.102.02.2] The Research Foundation of Rize University is gratefully acknowledged for the financial support to this work under the Project number 2009.102.02.2.

We report the synthesis of two square-pyramidal copper(II) complexes, [Cu(2,5-pydc)(2-aepy)(H2O)]·H2O, 1, and [Cu(2,5-pydc)(2-ampy)(H2O)]·H2O, 2 (2-aepy = 2-(aminoethyl)pyridine, 2-ampy = 2-(aminomethyl)pyridine, 2,5-pydc = pyridine-2,5-dicarboxylic acid or isocinchomeronic acid). The synthesized complexes have been characterized by X-ray diffraction, FT-IR, elemental, and thermal analysis techniques. The crystal structure of 1 was established by X-ray analysis. Powder X-ray diffraction analysis showed that the complexes are pure. The inhibition of human serum paraoxonase 1 (PON 1, EC 3.1.8.1) enzyme with these complexes were investigated. We used diethyl 4-nitrophenyl phosphate as a substrate to measure the paraoxonase activity of PON 1 enzyme spectrophotometrically. Complexes 1 and 2 decreased the in vitro PON 1 activity with different inhibition mechanisms. Complexes 1 and 2 inhibited paraoxonase activity of this enzyme as competitively and noncompetitively, respectively.

Temel, Ersin/0000-0002-8822-6674 WOS: 000386021200003 Four new neutral diclofenac-based complexes, [Co(dicl)2(2-pyet)2] 1, [Ni(dicl)2(2-pyet)2] 2, [Cu2(dicl)2(2-pyet)2] 3, and [Cu2(dicl)2(2-pypr)2] 4 have been synthesized and characterized by elemental analysis, FT-IR, thermal analysis. Complexes 1, 3, and 4 have also been characterized by X-ray single-crystal structural analysis. The compounds of Co(II) and Ni(II) have octahedral geometry with two diclofenac and two 2-pyridineethanol ligands in the coordination sphere. The compounds of Cu(II) have square-pyramidal geometry and Cu(II) ions are linked via oxygens to the bridging 2-pyridineethanol or 2-pyridinepropanol ligands. The values acquired by FT-IR are in agreement with the single XRD data. Studies on the thermal properties are reported and the complexes are stable to 196, 216, 215, and 201 degrees C in air, respectively. Two dinuclear Cu(II) complexes have demonstrated catalytic activity on oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone showing saturation kinetics at high substrate concentrations. The diclofenac complexes are investigated as inhibitors of the human cytosolic isoforms hCA I and II. The complexes are good as hCA I inhibitors (Kis of 1.52-55.06M) but only moderately efficient as hCA II inhibitors (Kis of 0.23-5.61M). [GRAPHICS] . Research Foundation of Erzincan UniversityErzincan Binali Yildirim University [110205] This work was supported by the Research Foundation of Erzincan University [grant number 110205].

WOS: 000244313900024 The surface area of kaolinite-benzamide (K-Bz) 6.62 m(2) g(-1), which is noticeably lower than that of kaolinite-dimethyl sulphoxide (K-DMSO) 14.61 m(2) g(-1), the co-perturbation of the inner-surface hydroxyl features at 3697 and 3650 cm(-1), and the increase of d(001) value by 7.44 angstrom are all related to the benzamide species inserted into the kaolinite structure through the replacement of the K-DMSO composites. Disappearance of the DMSO reflections and emergence of well-defined features at 6.04(2 theta) and 11.16(2 theta), 001 and 002 reflections with d values of 14.62 and 7.92 angstrom, respectively point out that the DMSO species were substituted efficiently by benzamide molecules. The thermal stability of the K-Bz derivative up to 300 degrees C can be attributed to the slightly tilted aromatic ring keying into the gibbsitic sheets via the -NH2 groups.

This paper presents a control technique based on structured singular value (μ) approach for a boost converter with voltage-mode control. Boost converter is used in most grid-connected photovoltaic (PV) applications in order to stabilize the fluctuating input voltage. Due to their time-varying uncertainty in the converter structure, control of DC-DC converter is a difficult task. By using this new approach, control of boost converter for all possible parameter variations becomes easier. At first, the derivation of an appropriate linear model for boost converter is explained. After that, the ranges of varying parameters are defined. Input multiplicative perturbation is applied to nominal plant in order to model the effects of unknown time varying parameters. After modeling overall linear fractional transformation (LFT) structure, the robustness of conventional proportional-integral (PI), full and reduced-order μ controllers are evaluated using μ-analysis. Then closed loop responses of nominal model and possible worst case perturbations are given by simulating step responses. Simulation results show that the proposed μ-synthesis based robust control technique is superior to the conventional PI controller. It has a faster dynamics and better robust performance properties than PI controller.