N-BUTYL SUBSTITUTED N-HETEROCYCLIC CARBENE-PD(II)-PYRIDINE (PEPPSI) COMPLEXES: SYNTHESIS, CHARACTERIZATION AND CATALYTIC ACTIVITY IN THE SUZUKI-MIYAURA REACTION | Author : Rukiye Firinci | Abstract | Full Text | Abstract :A series of N-butyl substituted imidazolium salts, (1a-c) and their pyridine enhanced precatalyst preparation stabilization and initiation (PEPPSI) themed palladium N-heterocyclic carbene complexes (2a-c) were synthesized and characterized. Pd-NHC complexes were fully determined by elemental analysis and spectroscopic. The synthesized complexes were tested in Suzuki-Miyaura cross-coupling reaction. These complexes were found to be efficient catalysts for the Suzuki-Miyaura reaction of phenylboronic acid with aryl bromides. |
| Synthesis And Characterization of N-((6-methylpyridin-2-yl)carbamothioyl)thiophene-2-carboxamide and Its Co(II), Ni(II) and Cu(II) Complexes: Calculation of Molecular Orbitals, Antioxidant and Antitumor Activities | Author : Tuncay Yesilkaynak | Abstract | Full Text | Abstract :N-((6-methylpyridin-2-yl)carbamothioyl)thiophene-2-carboxamide, C12H11N3OS2 (HL)and its Co(II), Ni(II) and Cu(II) complexes (ML2 type) have been synthesized and characterized by elemental analysis, FT-IR ,1H-NMR and HR-MS methods. In addition, HL was characterized by single crystal X-ray difraction method. The HL crystallizes in the monoclinic crystal system with P 1 21/c 1 space group, Z=4, a=7.2326(8) Å, b=18.3492(16) Å, c=9.7724(9) Å. The [ML2] complex structures were optimized using B97D/TZVP level. Molecular orbitals of HL ligand was calculated at the same level. Antioxidant activity of the complexes were measured by using the DPPH and ABTS assays. Anticancer activity of the complex were studied MTT assay in MCF-7 breast cancer cells.
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| GREEN SYNTHESIS OF NEW AMINO ACID SCHIFF BASES AND THEIR BIOLOGICAL ACTIVITIES | Author : Cigdem Yorur-Goreci, Zulal Demir, Nilay Altas | Abstract | Full Text | Abstract :In this study, four new and two known amino acid Schiff base compounds derived from the condensation reaction of benzaldehyde, salicylaldehyde, pyrrole-2-carbaldehyde, pyridine-2-carbaldehyde, fluorene-2-carbaldehyde and terephthalaldehyde with 2-phenylglycine methyl ester hydrochloride have been synthesized by both conventional method and microwave irradiation protocol. The new compounds were characterized by FTIR, 1H-NMR, LC-MS and electronic spectral studies. A comparative study between conventional heating and microwave irradiation has also been reported. Based on these results, with the microwave synthesis, the yield of the products was increased from 37% upto 96% as compared to conventional method. By microwave, reactions were completed within 5.5-8.5 minutes and the products were obtained in good to high yields, with reduced time, waste, and formation byproduct. DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging effect were performed to determine antioxidant activities of the new compounds. All of the compounds exhibited significant activities in DPPH radical scavenging. |
| THE SYNTHESES AND STRUCTURAL CHARACTERIZATIONS, ANTIMICROBIAL ACTIVITY AND IN VITRO DNA BINDING OF 4-FLUOROBENZYLSPIRO(N/O)CYCLOTRIPHOSPHAZENES AND THEIR PHOSPHAZENIUM SALTS | Author : Gamze Elmas, Aytug Okumus, Zeynel Kiliç, L. Yasemin Gönder, Leyla Açik, Tuncer Hökelek | Abstract | Full Text | Abstract :In the present study, the condensation reaction of N3P3Cl6 (1) with sodium 3-(4-fluorobenzylamino)-1-propanoxide gave partly substituted 4-fluorobenzylspiro cyclotriphosphazene (2). The Cl replacement reactions of 2 with excess benzylamine, n-hexylamine, n-buthylamine and n-propylamine led to the formation of the corresponding 4-fluorobenzylspiro(N/O)tetrabenzylamino (3a), tetrahexylamino (3b), tetrabuthylamino (3c) and tetrapropylamino (3d) cyclotriphosphazenes. The protic ionic liquids (PILs), phosphazenium salts (4a-4d), were obtained from the reactions of the corresponding phosphazene bases (3a-3d) with gentisic acid in dry THF. The structures of all the isolated cyclotriphosphazene derivatives were determined by elemental analyses, FTIR and 1H, 13C{1H}, 31P{1H} NMR techniques. The crystal structure of 4d was verified by X-ray diffraction analysis. All the compounds were screened for antibacterial and antifungal activities against bacteria and yeast strains. The interactions of the compounds with supercoiled pUC18 plasmid DNA were investigated. |
| Al(III), Cu(II), Co(II), Pb(II), Mn(II), and Fe(III) DETERMINATIONS IN VARIOUS SAMPLES by FAAS AFTER SOLID PHASE EXTRACTION | Author : Sule Dinç Zor, Güzin Alpdogan | Abstract | Full Text | Abstract :In this study, a novel method for the preconcentration of of Al(III), Cu(II), Co(II), Pb(II), Mn(II), and Fe(III) in the form of their hematoxylin chelates using a column filled with Amberlite XAD-16 resin was proposed. Metal chelates collected on the resin were eluted by 1 mol/L nitric acid in acetone and determined by flame atomic absorption spectrometry (FAAS). The influences of some analytical parameters including pH, flow rates, sample volume, the type and concentration of eluent on the preconcentration efficiency were examined. Effects of some interfering ions on the recovery values of analytes were also investigated. While optimum pH value was 8.5 for Cu(II), Co(II), Mn(II), and Fe(III) ions, it was 6.5 for Al(III) and Pb(II) ions. Appropriate eluent for quantitative elution was 8 mL of 1 mol/L nitric acid in acetone. Sample and eluent flow rates were found to be 2 mL/min. The maximum sample volume was established by changing the sample volume from 50 mL to 2500 mL. The sample volume does not significantly affect recovery within the range of 50-2000 mL of the sample volume for the investigated metal ions. The preconcentration factor obtained was 400. Under optimized conditions, the detection limits found as concentration which is threefold of the standard deviation of the blank solution were 0.053, 0.080, 0.620, 1.310, 0.330 and 0.120 µg/L for Al(III), Cu(II), Co(II), Pb(II), Mn(II), and Fe(III) ions, respectively and the adsorption capacities for these ions were 0.47 ± 0.02, 0.81 ± 0.01, 0.66 ± 0.01, 0.58 ± 0.01, 0.91 ± 0.01, and 0.73 ± 0.02 mg/g, respectively. By using the certified reference materials, the accuracy of the method was verified. The proposed method was successfully applied to cigarette, hair, and some vegetable species. |
| Production and Investigation of Controlled Drug Release Properties of Tamoxifen Loaded Alginate-Gum Arabic Microbeads | Author : Rukiye Yavaser, Onur Korkmaz, Bernis Girgin, Çagdas Sunna, Arife Alev Karagözler | Abstract | Full Text | Abstract :The entrapment of tamoxifen onto alginate-gum arabic beads and the production of controlled drug release was investigated in this study. The polymeric system that would provide the controlled release of tamoxifen was formed using alginate and gum arabic. In the first phase of the study, the optimization of the alginate-gum arabic beads production was conducted; then the study continued with drug entrapment experiments. Tamoxifen entrapment yield was found to be approximately 90% of initial tamoxifen concentration. In vitro drug release experiments were performed in simulated gastric juice and intestinal fluid where the tamoxifen release was 20% and 53% of the initial drug present, respectively. As a result of this study, it is expected that a valuable contribution to the field of controlled drug release system production is realized. |
| Extraction and Characterization of Chitin and Chitosan from Blue Crab and Synthesis of Chitosan Cryogel Scaffolds | Author : Nimet Bölgen, Didem Demir, Fatma Öfkeli, Seda Ceylan | Abstract | Full Text | Abstract :Polymeric scaffolds produced by cryogelation technique have attracted increasing attention for tissue engineering applications. Cryogelation is a technique which enables to produce interconnected porous matrices from the frozen reaction mixtures of polymers or monomeric precursors. Chitosan is a biocompatible, biodegradable, nontoxic, antibacterial, antioxidant and antifungal natural polymer that is obtained by deacetylation of chitin, which is mostly found in the exoskeleton of many crustacean. In this study, chitin was isolated from the exoskeleton of blue crap (Callinectes sapidus) using a chemical method. Callinectes sapidus samples were collected from a market, as a waste material after it has been consumed as food. Demineralization, deproteinization and decolorization steps were applied to the samples to obtain chitin. Chitosan was prepared from isolated chitin by deacetylation at high temperatures. The chemical compositon of crab shell, extracted chitin and chitosan were characterized with FTIR analyses. And also to determine the physicochemical and functional properties of the produced chitosan; solubility, water binding and fat binding analysis were performed. Chitosan cryogel scaffolds were prepared by crosslinking reaction at cryogenic conditions at constant amount of chitosan (1%, w/v) with different ratios of glutaraldehyde (1, 3, and 6%, v/v) as crosslinker. The chemical structure of the scaffolds were examined by FTIR. Also, the water uptake capacity of scaffolds have been determined. Collectively, the results suggested that the characterized chitosan cryogels can be potential scaffolds to be used in tissue engineering applications. |
| A Study on the sensitivity and selectivity properties of Polymer based gas-vapor sensors | Author : Hüsnü CANKURTARAN, Özlem Yazici, Ferdane Karaman | Abstract | Full Text | Abstract :In this study, the water soluble poly (diphenylamine sulfonic acid) (PSDA) and the diblock copolymer of PSDA with poly(ethylene glycol) (PEG) were used to construct the interdigitated film electrodes (IDEs). Their responses against humidity and various solvent vapors were investigated by impedance measurements. Sorption and desorption behaviors of the solvents were determined by simultaneous registration of the impedance (Z) and the resistive (R, resistance) and capacitive (X, reactance) components of the Z under different potential bias and alternating current (ac) frequencies. The sensor responses were discussed considering the polar/non-polar and polarizability properties of the polymers and solvents. The effect of ac frequency and potential bias on the sensitivity and selectivity of the sensors were discussed. It was found that the solvent polarity is the primary effect on the electrical conductance and capacitance of both PSDA homo polymer and PSDA-b-PEG block copolymer. The results supported that the dipolarity-polarizability properties of solvents have also a critical role on sensor response at low ac frequencies. The more polarizable solvents gave higher sensor responses at lower ac frequencies. The equilibrium response of the PSDA based sensor was correlated with the dielectric constant of the solvents. The values of Z and R of PSDA film under saturated solvent vapors at 1 kHz ac frequency were linearly correlated (R2 was 0.955, 0.993 and 0.957 for Z, R and X, respectively, in semi-logarithmic scale) with the values of the dielectric constants of the solvents, except water. A similar correlation (R2= 0.996) was obtained by using the R values of the PSDA film at 100 kHz ac frequency. In the case of PSDA-b-PEG polymer film, it was also possible to establish an almost linear correlation (R2=0.943) between the R at 100 kHz ac frequency and the values of the dielectric constants of the solvents, except acetone and water. Consequently, it was found that the applied ac frequency was distinctive on both the sensitivity and selectivity of the studied sensor.
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| Evaluation of Energy Consumption in Electrochemical Oxidation of Acid Violet 7 Textile Dye using Pt/Ir Electrodes | Author : Bahadir K. Körbahti, Kezban Meltem Turan | Abstract | Full Text | Abstract :The effects of process parameters were investigated on the electrochemical oxidation of textile dyeing wastewater containing Acid Violet 7 (AV7) at Pt/Ir electrodes in the presence of 75%NaCl+25%Na2CO3 (w/w) supporting electrolyte mixture in a batch electrochemical reactor. Experimental parameters were operated in the range of 300-1500 mg/L textile dye concentration, 4-20 g/L electrolyte concentration, 5-15 mA/cm2 current density, and 20-60°C reaction temperature. Energy consumption decreased with increasing textile dye concentration and electrolyte concentration, and decreasing the current density. In the study, energy consumption values were evaluated for textile dye decolorization (t=15 min) and COD removal (t=120 min) as 2.7-23.3 kWh/kg dye decolorization and 50.9-317.9 kWh/kg COD removal, respectively.
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| SYNTHESIS, CHARACTERIZATION AND ANTIOXIDANT ACTIVITIES OF NOVEL 1-(MORPHOLINE-4-YL-METHYL)-3-ALKYL(ARYL)-4-[4-(DIMETHYLAMINO)-BENZYLIDENAMINO]-4,5-DIHYDRO-1H-1,2,4-TRIAZOL-5-ONES | Author : Özlem Gürsoy Kol, Haydar Yüksek, Sevda Manap, Feyzi Sinan Tokali | Abstract | Full Text | Abstract :In this paper, eight novel 1-(morpholine-4-yl-methyl)-3-alkyl(aryl)-4-[4-(dimethylamino)-benzylidenamino]-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) were obtained by the reactions of 3-alkyl(aryl)-4-[4-(dimethylamino)-benzylidenamino]-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with formaldehyde and morpholine. The novel synthesized compounds were identified by IR, 1H NMR and 13C NMR spectral data. Besides, the newly synthesized compounds were analysed for their in vitro potential antioxidant capacities in three different assays. All of the compounds demonstrated significant activity for metal chelating effect. |
| ELECTRORHEOLOGICAL PROPERTIES OF BIODEGRADABLE CHITOSAN/EXPANDED PERLITE COMPOSITES | Author : Mehmet Çabuk | Abstract | Full Text | Abstract :In this study, chitosan (CS)/expanded perlite (EP) composites with different chitosan fractions (10%, 20% and 50%) were prepared by absorbing chitosan into porous networks of expanded perlite, as a new hybrid smart electrorheological (ER) material. Structural and morphological characterizations of the composites were carried out by FTIR and SEM-EDS techniques. Also, apparent density, particle size, and conductivity of the CS/EP composites were determined. Finally, the effects of electric field strength (E), shear rate, shear stress, and temperature onto ER behavior of the CS/EP/silicone oil system were investigated. The CS/EP/SO ER fluid system showed reversible electrorheological activity when subjected to external electric field strength by showing shear thinning non-Newtonian viscoelastic behavior. The yield stress value reached to 1250 Pa under E = 3 kV/mm for CS/EP3 composite. |
| DETERMINATION OF BISPHENOL A IN THERMAL PAPER RECEIPTS | Author : Mustafa Serkan YALÇIN, Cihan GEÇGEL, Dilek BATTAL | Abstract | Full Text | Abstract :Bisphenol A (BPA) is a chemical substance which is produced in great quantities globally and of which serious negative effects on endocrine system are suspected. It’s a commonly used color developer in thermal paper. BPA used for this purpose is in free, unbound form and one of the potential sources for BPA exposure of humans. In this study, 12 thermal paper receipt samples were collected from various workplaces selected randomly and analyzed. BPA was determined in all samples. Average value of high BPA concentrations obtained from 10 samples was found as 13.83 mg BPA/g paper. At the same time, low values being 0.40 mg BPA/g paper and 0.11 mg BPA/g paper respectively were found in two samples as compared to others. |
| Anticancer Activity of Papaver Somniferum | Author : Döne Asli Güler, Ali Aydin, Mesut Koyuncu, Iskender Parmaksiz | Abstract | Full Text | Abstract :This work describes the pharmacological activity of extracts of Papaver somniferum, a poppy species. P. somniferum products are still considered as a unique source of drug for many diseases. The present study was designed to determine antiproliferative and cytotoxic effects of P. somniferum extracts on HeLa (Human Cervix Carcinoma), HT29 (Human Colorectal Adenocarcinoma), C6 (Rat Brain Tumor Cells), and Vero (African Green Monkey Kidney) cell lines. Alkaloids-rich extracts of P. somniferum exhibited antiproliferative effects on various cancer cell lines, especially at high concentrations. We assessed the ability of extracts of P. somniferum to harm the membrane of the cells. Results indicated that P. somniferum extracts destroy cellular membrane in tumor cell lines at high concentrations. Remarkably, the LDH test results disclosed that cytotoxicity of P. somniferum on cells was low at mid concentrations. This may indicate its cytostatic potential. The results of this study support the efficacy of P. somniferum extracts as an anticancer agent. |
| OPTICAL PROPERTIES OF Al:ZnO THIN FILM DEPOSITED BY DIFFERENT SOL-GEL TECHNIQUES: ULTRASONIC SPRAY PYROLYSIS AND DIP-COATING | Author : Ebru Gungor, Tayyar Gungor | Abstract | Full Text | Abstract :Undoped and Al-doped ZnO polycrystalline thin films have been fabricated on glass substrates by using a computer-controlled dip coating (DC) and ultrasonic spray pyrolysis (USP) systems. The film deposition parameters of DC process were optimized for the samples. In this technique, the substrate was exposed to temperature gradient using a tube furnace. In the study, the other solvent-based technique was conventional USP. The zinc salt and Al salt concentrations in the solution were kept constant as 0.1 M and 2% of Zn salt’s molarity, respectively. The optical properties were compared for the films deposited two different techniques. The optical transmission of Al:ZnO/Glass/Al:ZnO sample dip coated and the optical transmission of Al:ZnO/Glass sample ultrasonically sprayed were determined higher than 80% in the visible and near infrared region. Experimental optical transmittance spectra of the films in the forms of FilmA/Glass/FilmA and FilmA/glass were used to determine the optical constants. It was observed that the optical band gaps of Al doped ZnO films onto glass substrate were increases with increase of Al content and the absorption edge shifted to the shorter wavelength (blue shift) compared with the undoped ZnO thin film. |
| Characterization of Magnetic Polymeric Microparticles | Author : Kazim Köse | Abstract | Full Text | Abstract :The separation process is very important in a variety of scientific fields, especially in biochemistry and biotechnology. The separation performance of a method can be determined by the separation time and the purity of the separated molecule, which is directly proportional with the ligand chosen for the target molecule. The separation time is actually a very important step for the cost and the time-dependent analysis, especially in medical applications. Magnetic separation is a very advantageous technique because it eliminates the time-consuming sample preparation and centrifugation steps. However, the magnetic performance of adsorbent may not be strong enough to respond the magnetic force applied externally. Therefore, in nanoparticle studies, magnetic performance of nanoparticles is highly important. In this study, the magnetic performance of polymeric microparticles synthesized using different magnetic cores (Fe2O3&Fe3O4, Fe&Ni, Ni&Co, Fe&Ni&Co) with a solid support, HEMA (2-hydroxyl ethylmethacrylate), and a functional monomer, AdeM (adenine methacrylate), were compared. Some other properties such as size, zeta potential, surface morphology, etc. were also studied. |
| Production and Drug Release Assesment of Melatonin-Loaded Alginate/Gum Arabic Beads | Author : Rukiye Yavaser, Bernis Girgin, Onur Korkmaz, Arife Alev Karagözler | Abstract | Full Text | Abstract :Melatonin containing alginate-gum arabic beads were produced by ionotropic gelation. The most suitable alginate-gum arabic ratio for bead production was optimized. To the optimized beads the loading of changing amounts of melatonin was conducted to produce the beads with the best melatonin entrapment and release. Entrapment efficiency of the beads as melatonin carrier was calculated to be approximately 70%. Release profiles of melatonin from the beads were generated using in vitro gastric fluid (pH 1.5) and intestinal fluid (pH 7.4). According to results obtained, following a burst in the first half hour, melatonin release from the beads in pH 1.5 medium was approximately 45% in the first 5 hours whereas the release was approximately 50% in pH 7.4 medium. The results indicate that the beads manufactured may be used as carriers for controlled release of melatonin. |
| INFLUENCE OF ALUMINUM CONCENTRATION ON THE ELECTRICAL AND OPTICAL PROPERTIES OF ZnO THIN FILMS | Author : Ebru GÜNGÖR, Tayyar Gungor | Abstract | Full Text | Abstract :Al:ZnO thin films having with different Al concentrations were deposited on glass substrates by a sol-gel technique. The effects of Al doping on the structural, optical and electrical properties of Al:ZnO were investigated using with XRD, optical transmittance and sheet resistance measurements. The concentration of zinc acetate was 0.1 M. Al content in the starting solution was varied from 0 to 20% as the molarity range. Optical transmittance spectra of the films in the form of Film/Glass were used to determine the film thickness and optical band gaps. The optical transmissions of Al:ZnO thin films were higher than 80% in the visible and near infrared region. The optical band gaps of Al:ZnO films decrease with increase of Al content. In order to obtain the average sheet resistance of the films the current and voltage through the probes have been measured for five different position by four-point probe method. The results showed that the sheet resistances of Al:ZnO thin films increased with the Al concentration. Considering the film thickness and geometric factor, the electrical resistivity values were computed. It was observed that the sheet resistance of AZO films up to 10% molarity of Al in the starting solution increased. |
| Antiproliferative effect of Cherry laurel | Author : Ali Aydin, Ramazan Erenler, Bülent Yilmaz, Saban Tekin | Abstract | Full Text | Abstract :Cherry laurel (Prunus laurocerasus) fruits including phenolic and flavonoid contents are consumed as fresh, dried or prepared in marmalade and its leaves containing cyanogenic glycosides have healing activity of a well-known Anatolian folkloric remedy. Herein, Cherry laurel fruits were boiled in water for 2 h then extracted with hexane, EtOAc and BuOH successively. Antiproliferative activities of extracts were evaluated on HeLa (Human Cervix Carcinoma), HT29 (Human Colorectal Adenocarcinoma), C6 (Rat Brain Tumor Cells), and Vero (African Green Monkey Kidney) cell lines. All extracts exhibited slightly antiproliferative effects on various cancer cell lines at high concentration. We assessed the ability of extracts of cherry laurel fruit to devastate the membrane of cells. Results indicated that cherry laurel fruit extracts slightly destroys the cellular membrane in tumor cell lines at high concentration merely. The results of this study not support the efficacy of cherry laurel fruit extracts as an anticancer agent for cancer cells, but it suggests that cherry laurel fruit extracts may be used through reducing cytotoxicity a potential adjuvant therapy to current chemotherapeutic agents. Fatty acids of hexane extract were also determined by GC-MS analysis and found out that linoleic acid, palmitic acid and oleic acid were the major products. |
| Electrochemical Decolorization of Reactive Violet 5 Textile Dye using Pt/Ir Electrodes | Author : Bahadir K. Körbahti, Kezban Meltem Turan | Abstract | Full Text | Abstract :Electrochemical decolorization of textile dyeing wastewater containing Reactive Violet 5 (RV5) were investigated at Pt/Ir electrodes in the presence of 75%NaCl+25%Na2CO3 (w/w) supporting electrolyte mixture in a batch electrochemical reactor. Experimental parameters were operated in the range of 300-1500 mg/L textile dye concentration, 4-20 g/L 75%NaCl+25%Na2CO3 electrolyte concentration, 5-15 mA/cm2 current density, and 20-60°C reaction temperature in 15 min electrolysis time. Reactive Violet 5 decolorization increased with increasing current density and electrolyte concentration, and decreasing the textile dye concentration. Although a slight increase obtained in color removal efficiency, the temperature was not show much significant effect on decolorization. Depending on electrochemical reaction conditions, Reactive Violet 5 textile dye decolorization were obtained between 42.8-100%. |
| CO-PYROLYSIS OF GÖYNÜK OIL SHALE WITH POLYPROPYLENE AND STRUCTURAL CHARACTERIZATION OF PYROLYSIS LIQUID | Author : Pinar Acar Bozkurt, Nagehan Merve Kutlu, Muammer Canel | Abstract | Full Text | Abstract :This study is based on the purpose of obtaining high yields of liquid product by subjecting the oil shale sample taken from one of our countrys important oil shale deposits and polypropylene PP mixtures to co-pyrolysis process. In this study, the oil shale sample and the polypropylene were firstly subjected to pyrolysis process, and then the mixture obtained by mixing of these at certain ratios was subjected to pyrolysis process. Pyrolysis experiments were performed at three different mixture ratios of 33%, 50% and 67% PP in the mixture, and in the temperature range of 600°C-800°C. The gas, liquid and solid product yields obtained as a result of the experiments were calculated, and the effect of PP which was added to oil shale and the changed pyrolysis temperature on the yield of liquid product was examined. As a result of the experiments, the highest liquid product yield was achieved in the mixture ratio containing 67% PP at 800°C. Various catalysts were added to the medium in which the highest liquid product yield was achieved, and the effect of catalysts on the liquid product yield obtained from pyrolysis was examined. The structure of the liquid products which were obtained as a result of the experiments was investigated by various spectroscopic methods such as GC-MS and FTIR, and the effects of experimental conditions on the structure of the liquid product were analyzed. Consequently, a noticeable synergistic effect was observed in the yield of the liquid product which was obtained as a result of the co-pyrolysis of PP and oil shale, and this effect further increased; with the catalyst added to the medium. |
| THE GRAPHENE OXIDE EFFECT ON THE OPTICAL PROPERTIES OF NIPA-GO COMPOSITES | Author : Gülsen Akin Evingur | Abstract | Full Text | Abstract :Poly (N-isopropylacrylamide) (NIPA)-Graphene oxide (GO) composites were polymerizated radically with various contents of GO solution. The gelation process was performed by Steady State Fluorescence Spectroscopy. The results of gelation were modelled by Percolation and Classical Model, respectively. Our results show that the critical exponent of gel fraction is agree with percolation model till 25 µl content of GO solution. On the other hand, the optical energy band gap of the NIPA-GO composite was decided by using UV spectroscopy from the absorbance measurement in the range of 200-800 nm. The effect of graphene oxide dopant on the gap has been examined for NIPA-GO composites. In conclusion, their gelation process and optical energy band gap behavior were investigated and correlated to the GO content in the composites. |
| PHOTOCATALYTIC ACTIVITIES of Ag+ DOPED ZIF-8 and ZIF-L CRYSTALS | Author : Berna Topuz, Husnu Arda Yurtsever, Melis Yagmur Akgunlu, Tugce Kurt, Ali Semih Yurttas | Abstract | Full Text | Abstract :Photocatalysis is expected to contribute to the solution of environmental problems such as water and air pollution in the near future. The design of photocatalysts with high electron-hole generation rates, high surface areas and high light absorption capacities is crucial in producing sustainable and cost-effective photocatalytic processes. Titania, zirconia, copper oxide, zinc oxide, iron oxide are widely used photocatalysts which have good light absorption capacities with moderate surface areas depending on the synthesis conditions. In the last decade metal organic frameworks (MOFs) have been used in photocatalytic applications due to their very high surface areas up to 1000s of m2/g and adequate light absorption capacities. In this study zeolitic imidazolate framework (ZIF) based MOF photocatalytsts were prepared and the effect of silver (Ag) doping on the photocatalytic activity of ZIF-8 and ZIF-L crystals was investigated. Ag doped ZIF-8 and ZIF-L crystals were prepared and their activities in the photocatalytic removal of methylene blue (MB) dye under UV irradiation were determined for the first time in the literature. Doped ZIF-8 and ZIF-L crystals showed better photocatalytic activities compared to the undoped crystals. 100% of MB was removed with 5 mole% Ag+ doped ZIF-8 in 40 min. The photocatalytic activity decreased beyond 5% doping level since Ag+ ions may have segregated due to a possible solid state solubility limit of Ag+ ions in the crystal lattice of ZIF-8. ZIF-L crystals possessed lower photocatalytic activities compared to ZIF-8 crystals. |
| Six coordination compounds: mode of cytotoxic action and biological evaluation | Author : Ali Aydin, Sengül Aslan Korkmaz | Abstract | Full Text | Abstract :This study describes the biological and anticancer properties of followed coordination compounds. IR spectra, magnetic properties, thermal analyses and crystal structures of six cyanido-complexes derivatives with [MII(CN)4]2- (MII= Ni and Pd) and [Co(CN)6]3- anions and N-bishydeten (N,N-bis(2-hydroxyethyl)ethylenediamine) as a capping ligand have been previously reported. Here, we investigated these complexes denoted as[Ni(N-bishydeten)Ni(CN)4] (C1), [Zn2(N-bishydeten)2Ni(CN)4] (C2), [Ni(N-bishydeten)Pd(CN)4] (C3), [Cd(N-bishydeten)2][Pd(CN)4] (C4), [Ni2(N-bishydeten)2Co(CN)6].3H2O (C5) and K[Cd(N-bishydeten)Co(CN)6].1.5H2O (C6), which were tested for their anti-proliferative activity against human cervical cancer (HeLa), human colon cancer (HT29), rat glioma (C6) and African green monkey kidney (Vero) cell lines. The DNA/BSA binding affinities of these compounds were also elucidated by spectroscopic titrations, displacement experiments and electrophoresis measurements. Studies on cancerous cells revealed that C1, C2, C4 and C6 exhibited significant antitumor activity and inhibited tumor progression in testing cell lines and showed high solubility in the solvent. Absorbance and emission spectra data results revealed that the complexes interact with the DNA via groove binding mode of interaction. Overall, these compounds have been found to demonstrate effective anti-proliferative activity against the cancer cell lines, indicating that they are a potent candidate for preclinical or clinical study. |
| THE EFFECT OF SIZING COMPOUND ON THE ELECTROPOLYMERIZATION OF PYRROLE AND THE IMPEDANCE OF CARBON FIBER COATED WITH POLY(PYRROLE) | Author : Hacer DOLAS, Digdem GIRAY, A. Sezai SARAC | Abstract | Full Text | Abstract :Carbon Fiber (CF) is used as strengthening material in resin composites having high performance in most industrial area due to that it has mechanical properties such as low weight, high durability and toughness. The mechanical performances of composite materials depend on the features of fiber and matrix which composed them. The one of methods which improves the features of fiber surface is the coating on fiber surface with thin film.As coated fiber with electropolymer, as increased the mechanical durability of the composite. In this study, carbon fibers were coated with Polypyrrole (PPy) in presence of sizing compound (SC) based on epoxy, electrochemically. During process, it was investigated how current, obtained coating weights and impedance data, especially capacitance, changed by the amount of SC. For this reason, different amount of SC (%0; % 0.18; %1.8 v/v) was added into the electrolyte solution (0.1 M NaClO4-ACN) including 0.1 M Pyrrole (Py).Coating process was carried out by using Constant Potential or Cyclic Voltammetry Techniques. Other techniques for investigations were gravimetrical analysis, electrochemical impedance spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR) and Light Microscopy. In end of the coating the weight of coating and specific capacitance (Csp) values were0.8 mg/g and 114 µF for % 0 of SC 10 mg/g and 57 µF for %0.18 of SC and 1.73 mg/g and 166 µF for %1.8 of SC, respectively. As a result, the coating weight and capacitance data (especially, Csp,) of carbon fiber coated with PPywas changed with the amount of SC added into electrolyte, inversely. |
| PREPARATION OF TiO2/PERLITE COMPOSITES BY USING 23-1 FRACTIONAL FACTORIAL DESIGN | Author : Dilek Duranoglu | Abstract | Full Text | Abstract :Successive impregnation and calcination process was performed in order to produce TiO2/perlite composites. 23-1 fractional factorial design was first applied to optimize the production conditions of TiO2/perlite photocatalysts. Seven TiO2/perlite composites (including three central point experiments) were produced by manipulating three process parameters (amount of TiO2 used in impregnation process, particle size of perlite and calcination temperature). Prepared TiO2/perlite photocatalysts were characterized by X-Ray Diffraction Spectrometer and SEM. XRD patterns indicated that anatase was the main crystalline phase for all produced samples. Degradation capacities of produced TiO2/perlite composites were investigated in methylene blue degradation process. The linear models of TiO2 loading (%) and methylene blue degradation (%) of TiO2/perlite composites were developed by regression analysis of the experimental data. As a result of analysis of variance, it was found that developed models were statistically significant with the p-value of 0.0040 and 0.0003, for TiO2 loading (%) and methylene blue degradation (%), respectively. According to the coefficient of determination (0.9821 and 0.9970 for the models of TiO2 loading and methylene blue degradation, respectively) and error analysis, developed models fit well to the experimental data. Effect of process parameters was investigated by using response surface plots. Amount of TiO2 and particle size were found as the most effective parameters on both TiO2 loading (%) and degradation efficiency (%). Calcination temperature did not affect TiO2 loading but methylene blue degradation capacity. |
| FISH SKIN ISOLATED COLLAGEN CRYOGELS FOR TISSUE ENGINEERING APPLICATIONS: PURIFICATION, SYNTHESIS AND CHARACTERIZATION | Author : Nimet Bölgen, Zeynep Çetinkaya, Didem Demir | Abstract | Full Text | Abstract :Tissue engineering aims regenerating damaged tissues by using porous scaffolds, cells and bioactive agents. The scaffolds are produced from a variety of natural and synthetic polymers. Collagen is a natural polymer widely used for scaffold production in the late years because of its being the most important component of the connective tissue and biocompatibility. Cryogelation is a relatively simple technique compared to other scaffold production methods, which enables to produce interconnected porous matrices from the frozen reaction mixtures of polymers or monomeric precursors. Considering these, collagen was isolated in this study from fish skin which is a non-commercial waste material, and scaffolds were produced from this collagen by cryogelation method. By SEM analysis, porous structure of collagen, and by UV-Vis analysis protein structure was proven, and by Zeta potential iso-electrical point of the protein was determined, and, Amit A, Amit B, Amit I, Amit II and Amit III characteristical peaks were demonstrated by FTIR analysis. The collagen isolation yield was, 14.53% for acid soluble collagen and 2.42% for pepcin soluble collagen. Scaffolds were produced by crosslinking isolated acid soluble collagen with glutaraldehyde at cryogenic conditions. With FTIR analysis, C=N bond belonging to gluteraldehyde reaction with collagen was found to be at 1655 cm-1. It was demonstrated by SEM analysis that collagen and glutaraldeyhde concentration had significant effects on the pore morphology, diameter and wall thickness of the cryogels, which in turned changed the swelling ratio and degradation profiles of the matrices. In this study, synthesis and characterization results of a fish skin isolated collagen cryogel scaffold that may be potentially used in the regeneration of damaged tissues are presented. |
| DETERMINATION of the TRACE ELEMENT LEVELS in HAIR of SMOKERS and NON-SMOKERS by ICP-MS | Author : Elif Varhan Oral | Abstract | Full Text | Abstract :For at least 50 years, determination of the trace element levels in human hair has been used to assess environmental and vocational exposure to toxic elements . As compared to other biological matrices (e.g. blood, urine), human hair is stable and therefore useful as a matrice. In this study, analyses of toxic and essential trace elements, such as Cd, Pb, Cu and Fe, were done in hair samples which we collected from male smokers (10 people) and non-smokers (10 people) who live in Diyarbakir, Turkey and concentrations in hair samples were compared. Hair samples were washed by a standard procedure proposed by the International Atomic Energy Agency. Then the samples were dried for 16 h at 110°C in an oven. Solubilization procedure was carried out by nitric acid hydrogen peroxide mixture (3:1) in closed vessels in a microwave oven. Trace element analyses were carried out by using inductively coupled plasma-mass spectrometry (ICP-MS) technique. In our study, while concentrations of Cd, Pb, and Fe elements were found to be considerably higher in smokers than non-smokers, similar results were observed in Cu concentrations. The precision and accuracy of the method was evaluated by applying spike method to samples. Analytical recovery results were found between 91.2% and 104.6% |
| THEORETICAL AND SPECTROSCOPIC STUDIES OF 1-(MORPHOLINE-4-YL-METHYL)-3-BENZYL-4-(4-ISOPROPYL-BENZYLIDENAMINO)-4,5-DIHYDRO-1H-1,2,4-TRIAZOL-5-ONE MOLECULE | Author : Gül KOTAN, Haydar Yüksek | Abstract | Full Text | Abstract :In this study, 1-(morpholine-4-yl-methyl)-3-benzyl-4-(4-isopropylbenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-one (1) was synthesized by the reaction of compound 3-benzyl-4-(4-isopropylbenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-one with morpholine and formaldehyde. The structure of compound 1 was determined by IR, 1H-NMR, 13C-NMR spectral data. Then, the synthesized compound 1 was optimized by using the B3LYP/6-31G (d,p) and HF/6-31G (d,p) basis sets. 1H-NMR and 13C-NMR isotropic shift values, IR absorption frequencies, bond angles, bond lengths, the HOMO-LUMO energy, electronegativity and mulliken charges were calculated theoretically by using the program package Gaussian G09W. In addition, IR, 1H-NMR, 13C-NMR theoretical spectral data were compared with certain experimental data |
| AN OXOVANADIUM(IV)-CONTAINING N2O2 CHELATE COMPLEX; CRYSTAL STRUCTURE DETERMINATION AND DFT | Author : Berat Ilhan Ceylan | Abstract | Full Text | Abstract :A stable oxovanadium(IV) complex was obtained by template condensation of 2-hydroxynaphthaldehyde S-methylthiosemicarbazone and salicylaldehyde in the presence of VOSO4. The structure of VO(II) centered metal complex was confirmed by elemental analysis and was characterized by single crystal X-ray diffraction technique and density functional theory (DFT/B3LYP) LANL2DZ compared with experimental data. The complex crystal is in the form of dark green-colored small sticks. The experimental data of the monoclinic crystalline structure which belonging P1 21/n1 space group was compared to those obtained with DFT-B3LYP-LANDL2DZ. It was seen that experimental and theoretical values are in a good agreement. |
| MISENS DEVICE AS A NEW AUTOMATED BIOSENSING PLATFORM BASED ON REAL-TIME ELECTROCHEMICAL PROFILING (REP) | Author : Yildiz Uludag | Abstract | Full Text | Abstract :In various fields like health, environmental control, food security and military defense; there is an increasing demand for on-site detection, fast identification and urgent response which brings the necessity to employ laboratory detection procedures on standalone automatic devices. In response to that TUBITAK BILGEM’s Bioelectronic Devices and Systems Group has been developing portable and fully automated biosensor devices using optical and electrochemical biosensor detection techniques. Here we describe a new integrated and fully automated lab-on-a-chip based biosensor device ‘MiSens’. The key features of the MiSens include a new electrode array, an integrated microfluidic system and real-time amperometric measurements during the flow of enzyme substrate. While simple protocols can be controlled from the LCD display on the device, other main device control procedures can be run wireless by a tablet/PC using the MiCont™ software developed by the team. For the device, a new plug and play type sensor chip docking station has been designed that with one move it enables the formation of a ~ 7-10 µl capacity flow cell on the electrode array with the necessary microfluidic and electronic connections. The MiSens device has been developed by our multi-disciplinary team by integrating and automatising the earlier developed sensing platform REP™ (Real-time Electrochemical Profiling). The performance of the MiSens device has been tested using cyclic voltammetry and amperometry tests and the results were compared with an of the shelf potantiostat. |
| DESIGN OF A NOVEL CONDUCTING COMPOSITE SUPPORTED BY PLATINUM NANOPARTICLES FOR HYDROGEN PRODUCTION FROM WATER | Author : Didem BALUN KAYAN, Merve Ilhan, Derya Koçak | Abstract | Full Text | Abstract :Because of the decrease in fossil fuel resources and the continuous increase in energy demands, clean energy requirements become extremely important for future energy generation systems. Hydrogen is well known as an efficient and environmentally friendly energy carrier. Highly catalytic active and low-cost electrocatalysts for hydrogen production are key issues for sustainable energy technologies. Here we report an aluminium electrode modified with polypyrrole (PPy)-chitosan (Chi) composite film decorated with Pt nanoparticles for hydrogen production from water. Hydrogen evolution reaction (HER) is examined by cyclic voltammetry (CV), Tafel polarization curves and electrochemical impedance spectroscopy (EIS) in 0.5M H2SO4. The structural properties of the modified surfaces analyses were investigated by scanning electron microscopy (SEM). The stability tests also performed for aluminium electrode coted with PPy-Chi/Pt composite film. |
| A NOVEL ACRYLONITRILE DERIVATIVE HAVING PHOTOVOLTAIC PERFORMANCE | Author : Cigdem Yorur-Goreci, Mehmet Kazici, Sinem Bozar, Zulal Demir, Abdullah Toraman, Fatih Ongul, Abid Ali, Serap Gunes | Abstract | Full Text | Abstract :A new acrylonitrile derivative 3 (BPCPFA) which offer potential application as organic solar cell material was synthesized with three steps. The structures of the molecules synthesized in these steps were characterized using various spectral analyses. BPCPFA was investigated as an electron acceptor molecule in next generation organic solar cells. Theoretical prediction and experimental studies for photovoltaic performance were performed. Based on these results, it is concluded that BPCPFA with extended conjugated system has good and promising photovoltaic performance with Voc value as 0.96 V. |
| In Vitro Studies on Pesticide-Induced Oxidative DNA Damage | Author : Özlem Demirci, Bircan Çeken Toptanci, Murat Kizil | Abstract | Full Text | Abstract :Pesticides are among the most extensively chemicals used in the world today and they are also among the most hazardous compounds for the human. This study was designed to use the plasmid relaxation assay to describe the association of markers of DNA damage with pesticide exposure. The DNA damage activity of fluoxastrobin and imazamox were checked on pBluescript M13+ plasmid DNA (3.2 kb) in the absence and presence of Cu(II) ions.
It has been found that the fluoxastrobin and imazamox can effectively promote cleavage of plasmid DNA in the absence and presence of Cu(II) ions. DNA cleavage was found to be concentration and dependent.
In conclusion, the present study showed that fluoxastrobin and imazamox can induce DNA damage, which warrants for further investigations to correctly evaluate the hazards of exposure to these chemicals.
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| INTERRELATION AMONG SERUM LITHIUM LEVELS AND BONE METABOLISM AND SOME BIOCHEMICAL PARAMETERS IN PRE AND POST-MENAUPOSAL WOMEN | Author : Ruken Esra Demirdögen, Fatih Mehmet Emen, Derya Kilic, Gokturk Avsar, Tuncay Yesilkaynak, Tunay Askar | Abstract | Full Text | Abstract :The target of this study is to determine the interrelation among serum Li level on bone metabolism (Ca, P, Parathormon, and Vitamin-D), sex and metabolic hormones (estrogen, FSH, LH and TSH), and some biochemical parameters in premenopausal and postmenopausal women. The study is carried out with 10 women: 5 premenopausal and 5 postmenopausal women. The serum Li levels, bone metabolism indicators (i.e., ALP, Ca, P, Mg, Cu, Zn) and some biochemical parameters such as serum tryglyceride, alkalene phosphatase, total cholesterol, HDL, LDL and cholesterol levels were determined. The estrogen blood level of women in menopause period was found to be lower than that of women in pre-menopause period (p<0.01) and the FSH level was found to be higher (p<0.01). In the lipid profile the triglyceride level in the post-menopause period was found to be low (p<0.05) and HDL (p<0.001), LDL (p<0.001) and the cholesterol levels were found to be high (p<0.001). The alkalene phosphatase (p<0.001) and Vitamin-D levels (p<0.001) were found to decrease. When the mineral levels were investigated no meaningful difference was observed in the serum magnesium and copper levels while zinc (p<0.01) and phosphorus (p<0.005) levels were observed to increase, the calcium levels (p<0.05) decreased and Li levels considerably decreased (p<0.0001). According to the results obtained it was determined for the first time that Li defficiency can be related with menopause and the related diseases and thus Li therapy can be used in developing new treatment protocols of menopause as an alternative method. |
| SELECTIVE GAS PHASE OXIDATION OF MONOCHLOROTOLUENES OVER MODIFIED OXOVANADIUM SYSTEMS SUPPORTED ON Al2O3 AND SiO2 | Author : Elmir Magsad Babayev, Arif Javanshir Efendi, Fakhriyya Mashallah Nasiri, Bilqeyis Adil Ismayilova, Firuza Alasgar Yunisova | Abstract | Full Text | Abstract :V-Mo-O/SiO2 materials were prepared by the impregnation techniques and characterized by Scanning Electron Microscopy (SEM), FT-IR, Thermal analysis, N2 adsorption/desorption and X-ray powder diffraction (XRD) to determine the phase structure and loadings of vanadium species. This material was tested for solvent-free catalytic oxidation of monochlorotoluene under chosen conditions. The result shows that V-Mo-O/SiO2 is effective catalysts, exhibiting conversion of monochlorotoluene and selectivity monochloromaleic anhydride 75–85%, 24–32% respectively. Furthermore, the catalyst can be easily recovered and reused for 20-25 hours without a significant loss in its activity and selectivity. The oxidation rate and direction determined by the temperature (315-4500C), proportions between the reagents (1:1–1:15 mol/l), bond dissociation energies, the effects of active components of catalyst and contact time. |
| NITROAROMATIC COMPOUND SENSING APPLICATION OF HEXA-ARMED DANSYL END-CAPPED POLY(epsilon-CAPROLACTONE) STAR POLYMER WITH PHOSPHAZENE CORE | Author : Merve DANDAN DOGANCI, Sümeyra BAYIR, Erdinç DOGANCI, Mesut GORUR, Faruk YILMAZ | Abstract | Full Text | Abstract :Hexa-armed dansyl end-capped poly(e-caprolactone) star polymer with phosphazene core (N3P3-(PCL-Dansyl)6) was prepared in a two-step synthetic procedure including ring opening polymerization (ROP) of e-caprolactone (e-CL) and esterification reactions. The obtained fluorescence-active polymer was employed as a fluorescent probe towards certain nitroaromatic compounds (2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2-nitrotoluene, 3-nitrotoluene, 2,4,6-trinitrophenol (picric acid), 2,4-dinitrophenol, 4-nitrophenol, and 1,2-dinitrobenzene). Fluorescence intensity of N3P3-(PCL-Dansyl)6 was decreased gradually upon the addition of nitroaromatic compounds and the highest quenching efficiency was found to be 100% with TNT. Besides, N3P3-(PCL-Dansyl)6 gave exceptionally selective response toward nitroaromatic compounds, even in the presence of toxic metal cations such as Pb2+, Co2+, Hg2+, Mn2+, Cd2+ and Zn2+. |
| SYNTHESIS OF NOVEL FLUOROQUINOLONE-TRIAZOLE HYBRID COMPOUNDS AS ANTIMICROBIAL AGENTS | Author : Serap Basoglu Özdemir | Abstract | Full Text | Abstract :The hydrazide compound (2) was synthesized starting from 1-(2-fluorophenyl)piperazine via two stage. The reaction of compound (2) with different alkyl(aryl)isothiocyanates afforded the corresponding compounds (3a-c). 1,3-Thiazolidine derivatives (4a-c) were synthesized from the treatment of (3a-c) with ethyl bromoacetate. Mannich bases (6a-d) were yielded the treayment of (5a-c) with various suitable amines in the exictence of formaldehyde. Compound (3) derivatives were converted to 1,2,4-triazole as the starting material of fluoroquinolone analogues (11a-c). Finally synthesized compounds were examined their biological properties and some of these showed potent activity. |
| BIOSORPTION OF METHYLENE BLUE FROM AN AQUEOUS SOLUTION BY IRON OXIDE-COATED CYSTOSEIRA BARBATA | Author : Yeliz Ozudogru, Melek Merdivan, Tolga Göksan | Abstract | Full Text | Abstract :In this study, Cystoseira barbata was coated with iron oxide (Fe3O4) to obtain magnetic biomaterial and used as a sorbent material for the removal of methylene blue from aqueous solution. This biosorbent was characterized by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared spectroscopy (FTIR). Batch adsorption was investigated as functions of pH, contact time, initial methylene blue concentration and different temperature on biosorption. The equilibrium data was analyzed with Langmuir and Freundlich isotherms. The results showed that the maximum adsorption capacities were reached at 300 min at pH 2 and found to be 5.74 mg/g and 1.08 mg/g at 25 ºC and 45 ºC, respectively. |
| PREPARATION OF A HUMAN SKIN-MIMICKING GELS FOR IN VITRO MEASUREMENTS OF THE DUAL-BAND MEDICAL IMPLANT ANTENNA | Author : Erdinç DOGANCI, Mustafa Hikmet Bilgehan Ucar, Adnan Sondas | Abstract | Full Text | Abstract :The purposes of this study are to design of a small size implantable antenna and to present a complementary recipe for a human skin mimicking material for in-vitro testing of implantable antennas operating at MICS (Medical Implant Communications Service, 402–405 MHz) and ISM (Industrial, Scienti?c, and Medical, 2.4 GHz–2.48 GHz) bands. Approximate electrical properties of human tissues at MICS and ISM bands were obtained by mixing de-ionized water, sugar, NaCl, and Poly(acrylic acid) (PAA or Carbomer) with different content percentages. In the literature Agarose, a polysaccharide polymer material, was widely used to ensure the formation of gel of the mixture and in our study we used Carbomer instead of Agarose for this aim. To test the antenna in-vitro, skin mimicking gels were made that to show electrical properties real skin tissue (relative permittivity (er) and conductivity (s)) for the operation frequencies of ISM and MICS bands. For the antenna performance evaluations the measurements of the antenna (return loss (S11)) have been performed by placing in to the skin mimicking gels. The measurements were taken in the 1 GHz - 5 GHz frequency band. The measurement and simulation results are quite good agreement except some discrepancy in S11 levels and frequency bands. |
| HYDROXYETHYL METHACRYLATE BASED NANOCOMPOSITE HYDROGELS WITH TUNABLE PORE ARCHITECTURE | Author : Erhan Bat | Abstract | Full Text | Abstract :Hydroxyethyl methacrylate (HEMA) based hydrogels have found increasing number of applications in areas such as chromatographic separations, controlled drug release, biosensing, and membrane separations. In all these applications, the pore size and pore interconnectivity are crucial for successful application of these materials as they determine the rate of diffusion through the matrix. 2-Hydroxyethyl methacrylate is a water soluble monomer but its polymer, polyHEMA, is not soluble in water. Therefore, during polymerization of HEMA in aqueous media, a porous structure is obtained as a result of phase separation. Pore size and interconnectivity in these hydrogels is a function of several variables such as monomer concentration, cross-linker concentration, temperature etc. In this study, we investigated the effect of monomer concentration, graphene oxide addition or clay addition on hydrogel pore size, pore interconnectivity, water uptake, and thermal properties. PolyHEMA hydrogels have been prepared by redox initiated free radical polymerization of the monomer using ethylene glycol dimethacrylate as a cross-linker. As a nanofiller, a synthetic hectorite Laponite® XLG and graphene oxide were used. Graphene oxide was prepared by the Tour Method. Pore morphology of the pristine HEMA based hydrogels and nanocomposite hydrogels were studied by scanning electron microscopy. The formed hydrogels were found to be highly elastic and flexible. A dramatic change in the pore structure and size was observed in the range between 22 to 24 wt/vol monomer at 0.5 % of cross-linker. In this range, the hydrogel morphology changes from typical cauliflower architecture to continuous hydrogel with dispersed water droplets forming the pores where the pores are submicron in size and show an interconnected structure. Such controlled pore structure is highly important when these hydrogels are used for solute diffusion or when there’s flow through monolithic hydrogels. These robust hydrogels may be useful in separation and biomedical applications. |
| Synthesis of Copper Nanoparticles Using a Different Method: Determination of Its Antioxidant and Antimicrobial Activity | Author : Demet Demirci Gültekin, Azize Alayli Güngör, Hicran Önem, Aynur Babagil, Hayrünnisa Nadaroglu | Abstract | Full Text | Abstract :In this study, it was aimed to obtain copper oxide nanoparticles (CuO NPs) with the method of green synthesis by using peroxidase enzymes which were partly purified from fig (Ficus carica). Copper (II) oxide nanoparticles are successfully synthesized with the green synthesis method on the experiments we performed. UV-VIS spectroscopy of the characterization of acquired CuO NPs were performed with Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). Optimum activation temperature for green synthesis was observed to be in 30 min, pH:8, at 25 oC and in the concentration of 1mM CuCl2. By using peroxidase enzymes with green synthesis, it was found out the results of SEM and XRD measurements that acquired CuO NPs were in the size of 50-120 nm. Afterwards, the antioxidant and antibacterial activities of these nanoparticles were measured and it was understood from the obtained results that CuO NPs had both antioxidant and antimicrobial activities. |
| Thermal, Mechanical and Water Resistance Properties of LDPE/Starch Bio-Based Polymer Blends for Food Packing Applications | Author : Hale Berber Yamak | Abstract | Full Text | Abstract :In this study, low density polyethylene, LDPE was melt blended with starch using twin screw extruder to form biodegradable polymer blends. The LDPE/starch blend films used in food packing were obtained by hot pressing of the granules produced by extrusion process. The starch content was varied from 0 to 40 wt% of LDPE. To provide fine starch dispersion, glycerol and zinc stearate were used as plasticizer and compatibilizer, respectively. The effect of starch content on the properties of LDPE film was investigated. A good dispersion was achieved for low starch contents, but agglomeration of the starch particles occurred in the presence of high amounts of starch. The addition of starch to LDPE reduced the tensile strength, elongation at break, crystallinity and water resistance of LDPE. This decline in the LDPE properties was dramatic when the starch content was increased to 30 wt% in the blend. In addition, silver nanoparticles as antibacterial agent were incorporated to the biodegradable LDPE blend where LDPE/starch weight ratio of 60/40. Antimicrobial activities of the nanocomposite films against gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureus) were determined by measuring the inhibition zone around each film. The effects of these nanoparticles on morphological, mechanical, thermal and water resistance properties of the LDPE/starch biodegradable blend were also investigated. It was observed that the incorporation of nanoparticles to the LDPE/starch blend was completely changed the morphology of the film, and accordingly, the mechanical, thermal and water resistance properties were varied depending on the nanoparticle content in LDPE/starch blend film. |
| Theoretical studies on the thermodynamic properties and detonation properties of cyclotrimethylene trinitramine (RDX) with aluminum and boron metals. | Author : Nilgün Sen, Bayram YÜKSEL | Abstract | Full Text | Abstract :Theoretical studies on the thermodynamic properties and detonation properties of cyclotrimethylene trinitramine (RDX) with aluminum and boron metals.
The B3LYP/6-311++G(2df,2p) density functional theory (DFT) method was used to investigate molecular geometry and thermodynamic properties of RDX and RDX derivatives containing Al and B metals. The detonation velocity (D) and detonation pressure (P), estimated by using Kamlet–Jacobs and in literature equations, respectively. Total energies (Et), frontier orbital energy (EHOMO, ELOMO), energy gap (?ELUMO–HOMO) and theoretical molecular density (?) were calculated with Spartan 14 software package program. It was shown that the presence of aluminum and boron atoms affects the good thermal stabilities. The results show that the composite RDX-Al, RDX-B derivatives have higher detonation performance and higher density than RDX. RDX-Al derivatives appeared to be superior to RDX-B mixtures in terms of these parameters. These results provide information on the moleculer design of new energetic materials. |
| Preparation and Characterization of Montmorillonite/Polycaprolactone Composite Scaffold Containing Strontium for Bone Tissue Engineering Studies | Author : Aysel Koc Demir | Abstract | Full Text | Abstract :Montmorillonite (MMT) has attracted much attention due to its intrinsic ability to incorporate cations. In this study, we developed scaffold combining strontium-modified MMT and polycaprolactone (SrMMT-PCL) to further utilise the osteoconductive properties of strontium. For this purpose, MMT was modified with strontium, and then blended with polycaprolactone (PCL) in specific ratios by using particulate leaching technique to obtain bone tissue-like biocomposite scaffold. The macrostructure and morphology were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The release of Sr2+ from scaffolds into cell culture medium was determined by inductive coupled plasma optical emission spectrometer (ICP-OES). The pore size distrubition of scaffolds was determined by mercury intrusion porosimetry. The mechanical properties were also evaluated. The results of FTIR and XRD confirmed intercalation of PCL into MMT layers. TGA studies concluded that the MMT in PCL promoted the thermal degradation of the matrix. ICP results showed that Sr2+ was released from composite scaffolds. The majority of pore volume seems to be occupied by pores around 250-350 mm. SEM observations demonstrated the macroporous structure of the MMT-PCL sponges obtained by using the particulate leaching method. As a result, gained data suggests that obtained tissue-engineered scaffold has the potential to serve as a suitable templete for bone tissue engineering applications. |
| Synthesis, characterization and investigation of the spectroscopic properties of novel peripherally 2,3,5-trimethylphenoxy substituted Cu and Co phthalocyanines, the computational and experimental studies of the 4-(2,3,5-trimethylphenoxy)phthalonitrile | Author : Nesuhi Akdemir | Abstract | Full Text | Abstract :4-(2,3,5-trimethylphenoxy)phthalonitrile (3) was firstly prepared via aromatic nucleophilic substitution reaction and characterized by FT-IR, mass spectrometry, 1H and 13C NMR techniques. The molecular structure of the compound (3) was optimized using Density Functional Theory (DFT/B3LYP) method with 6-311G(d,p) basis set in the ground state. The molecular geometric parameters which were obtained by X-ray single crystal diffraction method and the spectral results were compared with computed bond lengths and angles, vibrational frequencies and 1H, 13C NMR chemical shifts values of the compound (3). Also, Cu(II) and Co(II) phthalocyanines were synthesized by the treatment of dinitrile derivative with anhydrous CuCl2 or CoCl2 under N2 atmosphere in dry n-pentanol at 140oC. The new compounds have been determined by elemental analysis, FT-IR and electronic absorption. The UV-Vis spectra of the Cu(II) and Co(II) phthalocyanines were recorded with different concentration in THF and also with different solvents as DMF, DMSO, DCM, CHCl3, toluene. |
| UNDERSTANDING THE BEHAVIOUR OF SULPHUR-CENTRED RADICALS DURING POLYMER SELF-HEALING | Author : Isa Degirmenci, Michelle L. Coote | Abstract | Full Text | Abstract :High-level ab initio molecular orbital theory calculations have been used to study self-healing mechanism of materials based on thiuram disulfides and their derivatives (S=C(Z)S–SC(Z)=S, for Z = CH3, NEt2, N(Et)CH2CH2OH, Ph, Bz), and the effects of these Z-substituents on their efficacy. The relative contributions of cross-over and reversible addition fragmentation chain transfer reactions were ascertained, and the likelihood of chain-breaking side reactions was assessed. To rationalize the results, the various stabilization energies of the radicals and closed-shell species were also evaluated. The study revealed that the self-healing mechanism of thiuram disulfides follows predominantly the cross-over reaction because of the high energies of intermediate radicals in the chain transfer mechanism. Based on the study, the most effective self-healing materials are predicted to contain amines as Z-groups, while those containing benzyl and its derivatives are most likely to undergo side reactions. |
| SYNTHESIS AND CHARACTERIZATION OF BIO-BASED POLYESTER POLYOL | Author : Mithat Çelebi, Tugba Yazici | Abstract | Full Text | Abstract :Polyurethanes are versatile polymeric materials and are usually synthesised by isocyanate reactions with polyols. Due to the variety of isocyanates and polyols, particularly polyols, polyurethanes can be easily tailored for wide applications, such as rigid and flexible foams, coatings, adhesives, and elastomers. Considerable efforts have been recently devoted to developing bio-based substitutes for petroleum-based polyuretahanes due to increasing concerns over the depletion of petroleum resources, environment, and sustainability. Polyester polyols based on aliphatic and aromatic dicarboxylic acids are one of the most important materials in polymer technologies. Large volume of plants oils are used as renewable resources to produce various chemicals which are industrially important to make soaps, cosmetic products, surfactants, lubricants, diluents, plasticizers, inks, agrochemicals, composite materials, food industry. This study introduces synthesis and properties of bio-based polyols from different renewable feedstocks including vegetable oils and derivatives. A comparison of bio-based polyol properties with their petroleum-based analogues were investigated. |
| THERMOCHEMICAL CONVERSION BEHAVIOUR OF DIFFERENT BIOMASS FEEDSTOCKS: PYROLYSIS AND GASIFICATION | Author : Isil Gülsaç, Yeliz Çetin, Berrin Engin, Parvana Aksoy, Hakan Karatas, Alper Sarioglan | Abstract | Full Text | Abstract :In this study, a bench-scale bubbling fluidized bed (BFB) gasifier and thermogravimetric analyzer (TGA) were applied for the determination of the thermochemical conversion reactivity of biomass fuels under both gasification and pyrolysis conditions. Six different biomass feedstocks, namely; straw pellet (SP), softwood pellet (WP), torrefied wood chips (TWC), pyrolysis char (PC), miled sunflower seed (MSS) and dried distillers’ grains and solubles (DDGS) were investigated. TGA of biomass feedstocks were carried out under pyrolysis conditions at four different heating rates (2-15 °C/min). Raw data obtained from the experiments were used to calculate the kinetic parameters (A, Ea) of the samples by using two different models; Coats-Redfern and Isoconversional Method. TGA analysis showed that pyrolysis char was the only sample having decomposition temperature above 800 K since it was the pre-pyrolized sample before the gasification. According to DTG profiles, two peaks and two shoulders at around 450-650 K were observed for DDGS whereas no peaks were detected for pyrolysis char as the indication of absence of volatiles/cellulosic components. It was seen that the highest devolatization rates and devolatization temperatures (associated mainly with cellulose decomposition) were obtained for softwood and torrefied wood samples, which had the least char yields among the other biomass feedstocks. It was seen that WP was more reactive for thermochemical conversion and less prone to agglomeration. Furthermore high ash content and agglomeration index of MSS were the potential drawbacks in front of its utilization via thermochemical conversion. During the air gasification of these feedstocks (except DDGS), the product syngas was characterized in terms of main gas composition, tar and sulfur compounds. It was shown that the highest cold gas efficiency, carbon conversion and calorific value were obtained for the gasification of SP. On the other hand, SP had some drawbacks regarding its high agglomeration tendency and low deformation temperature. Among all feedstocks, gasification reactivity of MSS was found to be quite poor. MSS seemed to expose to pyrolization instead of gasification. WP and TWC were gasified with acceptable conversion values and efficiencies when compared with SP. It was understood that WP is the preferred choice for the thermochemical conversions.
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| SYNTHESIS AND ANTIMICROBIAL ACTIVITIES OF NEW 1,2,4- TRIAZOLES, MANNICH BASES, CONAZOLES, AND FLUOROQUINOLONES | Author : Sule CEYLAN | Abstract | Full Text | Abstract :Triazoles are heterocyclic compounds which have been of interest in the development of novel compounds with antidepressant, anti-inflammatory, analgesic, antibacterial, antimycobacterial, antifungal, antiviral, anticancer, and other activities. In this article, a series of fluorine- and piperazine-containing some novel biologically active 1,2,4-triazole-3-one derivatives were synthesized by the Mannich reaction of triazole intermediates. The structures for novel synthesized compounds were elucidated using elemental analysis and FT IR, 13C NMR, 1H NMR, EI MS techniques. These compounds were investigated in vitro for their antimicrobial properties and several compounds have fungicidal activity against Candida albicans and Saccharomyces cerevisiae. And also some of the compounds exhibited excellent activity on Mycobacterium smegmatis, a nonpigmented fast-rising mycobacterium, at the concentration of <1 µg/mL is better than standard drug streptomycin. |
| SYNTHESIS AND CHARACTERIZATION OF CELLULOSE BASED BIO-POLYMER AEROGEL ISOLATED FROM WASTE OF BLUEBERRY TREE (VACCINIUM MYRTILLUS) | Author : Mehmet KAYA | Abstract | Full Text | Abstract :Cellulose aerogel (CA) has highly porous structure, environmentally friendly, thermally stable and flame retardant properties. These properties in material worlds have attracted large interest as a potentially industrial material. In this paper, cellulose aerogel with flame retardant was produced from pruned branches and bushes of blueberries wastes (PBBW). Firstly, cellulose raw material these wastes was obtained and then, cellulose aerogel via freeze-drying, followed by cellulose hydrogel production. Our reports showed that three dimensionally network aerogel structure prepared from NaOH/Urea as scaffold solution. The present cellulose aerogel has excellent flame retardancy, which can extinguish within 140 s. By the way, it was inferred thermal stability performance of cellulose aerogel could be efficient potential thermal insulating material. Besides, this process are sustainable, easily available at low cost and suitable for industrial applications. |
| SYNTHESIS, CHARACTERIZATION, AND CHEMOSENSING APPLICATION OF POLY(METHYL METHACRYLATE-CO-HYDROXYETHYL METHACRYLATE) WITH DANSYL SIDE GROUP | Author : Erdinç DOGANCI, Mesut Gorur | Abstract | Full Text | Abstract :A novel dansyl side-functional polymer (P2) was prepared and employed as the metal cation sensing chemical probe. The synthesis of P2 was performed via free radical polymerization and esterification reactions in a two-step reaction sequence. P2 showed characteristic UV-vis and fluorescence emission bands for the dansyl unit. The fluorescence emission intensity of P2 gradually decreased as the concentrations of the added metal ions were increased. The highest quenching efficiencies (QE) were observed for Pb2+ (84.56%) and Co2+ (83.69%). Besides, the responses of P2 to the addition of Pb2+ cation were quite linear up to 50 equivalent. The presence of Cd2+, Hg2+, Mn2+, and Zn2+ cations did not pose significant interferences. Thus, P2 is a potential candidate for the fluorescence chemical sensor for Pb2+ cation. |
| Investigation of Antioxidant Activity of M.comminus L. from Turkey due to its Essential Oil Composition and Polyphenolic Content | Author : Belma Hasdemir, Hasniye Yasa, Hülya Çelik Onar, Ayse Sergüzel Yusufoglu | Abstract | Full Text | Abstract :In this study, it is aimed to investigate the chemical composition of the essential oils, antioxidant activity, and polyphenol content of methanol extracts of M.comminus L. leaves and berries. M.comminus L. Plant was collected from Yalova, Marmara region of Turkey. Its essential oil was prepared by hydrodistillation in a Clevenger-type apparatus in 0.5%. The chemical composition of the essential oil was analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC–MS), using two columns with stationary phases of different polarity (polar ZB-WaxMS/apolar ZB-5MS). On both columns monoterpenes were determined to be the dominant compounds. The myrtenyl acetate, a-pinene, 1,8-cineole, linalool, and limonene were the remarkable substances. As polyphenol compounds, the flavanoids and anthocyanidins in leaves and berries were detected by HPLC and furthermore, their antioxidant activities were studied with DPPH, Cuprac and Folin – Ciocalteu method of the methanolic extracts. |
| DETERMINATION OF COCAINE AND BENZOYLECGONINE IN BIOLOGICAL MATRICES BY HPLC AND LC-MS/MS. | Author : Zinar Pinar GUMUS, Veysel Umut Celenk, Emine Guler, Bilal Demir, Hakan Coskunol, Suna Timur | Abstract | Full Text | Abstract :Cocaine is a powerfully addictive illicit drug. Cocaine abuse and addiction continue to increase in the world. Most analytical tests for the detection of cocaine use include the analysis of the metabolite, benzoylecgonine, in the urine. Benzoylecgonine is a major urinary metabolite of cocaine. Generally, the most common biologic matrices used for the analysis of cocaine contain the urine and blood however saliva was also added as a matrix in this study. Practical, quick, reliable, precise and accurate, reproducible analytical methods have been developed and validated for cocaine and benzoylecgonine. In addition, this chromatographic techniques were used as both initial test and confirmatory. The validated chromatographic method was successfully applied to the analysis of cocaine and benzoylecgonine compounds in synthetic biological matrix. Confirmation analyses were made by LC-MS/MS to support reliability of HPLC results. As a result of this study, it can be claimed that HPLC could be a good alternative for the analyses of various biological matrices in forensic studies. Also the matrices and concentrations were determined by HPLC instrument could be used where necessary. |
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