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Articles 1 - 30 of 89
Full-Text Articles in Physical Sciences and Mathematics
Polyethyleneimine-Coated Capillaries For The Separation Of Dna By Capillary Electrophoresis, M. Sai̇d Nutku, F. Bedi̇a Eri̇m Berker
Polyethyleneimine-Coated Capillaries For The Separation Of Dna By Capillary Electrophoresis, M. Sai̇d Nutku, F. Bedi̇a Eri̇m Berker
Turkish Journal of Chemistry
A new capillary electrophoresis of DNA fragments has been achieved with the cooperative effects of the electrophoretic and electroosmotic mobilities realized via the polyethyleneimine (PEI) coating of the capillary walls. As a result, seven of the 11 different-sized DNA fragments have produced resolved CE peaks. Our results demonstrate that analyses of DNA constituents can be performed under a wide range of conditions by the appropriate tuning of the coating and filler within the capillary.
Search For A Nonelectrocyclic Cyclization Of Nitrosostyrene: Rearrangements Of Michael Adducts From Dmad And \Alpha-Dialkylamino Oximes, Necdet Coşkun, Nevi̇n Arikan
Search For A Nonelectrocyclic Cyclization Of Nitrosostyrene: Rearrangements Of Michael Adducts From Dmad And \Alpha-Dialkylamino Oximes, Necdet Coşkun, Nevi̇n Arikan
Turkish Journal of Chemistry
The aza-Claisen rearrangement product of the Michael adducts 2 from \alpha-dialkylaminoacetophenone oximes and DMAD underwent fragmentation to give dialkylaminomaleate, and benzonitrile at reflux in acetonitrile. The fragmentation was assumed to proceed through an unstable 4H-1,2-oxazete 6. The same reaction performed at room temperature, in addition to the nitrile and maleate, gave the corresponding 2-(2-dialkylamino-1-phenylethylideneaminooxy)-but-2- enedioic acid dimethyl esters 8 and 9. Compounds 9 isomerized to 8 on heating in acetonitrile.
Synthesis Of Some New Benzimidazole Carbamate Derivatives For Evaluation Of Antifungal Activity, Canan Kuş, Nurten Altanlar
Synthesis Of Some New Benzimidazole Carbamate Derivatives For Evaluation Of Antifungal Activity, Canan Kuş, Nurten Altanlar
Turkish Journal of Chemistry
The synthesis and structure elucidation of methyl 5(6)-fluoro-6(5)-substituted-1H-benzimidazole carbamate derivatives are performed and their antifungal activities evaluated against Candida albicans.
Changes In Chlorophyll-Carotenoid Contents, Antioxidant Enzyme Activities And Lipid Peroxidation Levels In Zn-Stressed Mentha Pulegium, Ni̇lgün Candan, Leman Tarhan
Changes In Chlorophyll-Carotenoid Contents, Antioxidant Enzyme Activities And Lipid Peroxidation Levels In Zn-Stressed Mentha Pulegium, Ni̇lgün Candan, Leman Tarhan
Turkish Journal of Chemistry
The relationships between chlorophyll-carotenoid contents, the antioxidant enzyme activities, such as superoxide dismutase (SOD), catalase (CAT), ascorbate-dependent peroxidase (AsA-dep POD) and guaiacol-dependent peroxidase (Gua-dep POD), and lipid peroxidation (LPO) levels were investigated in leaves at different positions of M. pulegium grown in nutrient medium containing 0-1 \mu M Zn. The maximum chlorophyll-carotenoid content's SOD and CAT activities and the minimum LPO level were observed in leaf 6 at 7.6 10^{-2} \mu M Zn (as control). While chlorophyll-carotenoid contents in the absence of Zn were lower than those of the control, SOD and CAT activities significantly increased with decreasing Zn concentration. …
Determination Of H_{2}O_{2} Content Of Various Water Samples Using A Chemiluminescence Technique, Tuğba Tüğsüz, Elmas Gök, Serdar Ateş
Determination Of H_{2}O_{2} Content Of Various Water Samples Using A Chemiluminescence Technique, Tuğba Tüğsüz, Elmas Gök, Serdar Ateş
Turkish Journal of Chemistry
Hydrogen peroxide (H_{2}O_{2}) plays an important role in natural water samples. In this study H_{2}O_{2} concentrations were quantified in different water samples by chemiluminescence detection. This method was chosen because of its high sensitivity and suitability for determining low concentrations of H_{2}O_{2}. H_{2}O_{2} is introduced to the oxidation reaction of alkaline luminol solutions in the presence of Co^{2 + } ion catalyst. When these components are mixed, blue light (\lambda = 440 nm) is emitted. Maximum chemiluminescence intensity occurs within 2 s after mixing and is continuous for up to a few minutes, permitting accurate measurements at selected delay times. …
Chromatographic Determination Of Phenolic Acids In The Snowdrop By Hplc, Mustafa Tüzen, Mustafa Özdemi̇r
Chromatographic Determination Of Phenolic Acids In The Snowdrop By Hplc, Mustafa Tüzen, Mustafa Özdemi̇r
Turkish Journal of Chemistry
Free and esterified phenolic acids of Galanthus elwesii (snowdrop) were extracted with petroleum ether and determined by HPLC. Cinnamic, ferulic, vanillic, p-coumaric, p-hydroxy benzoic, and caffeic acids were detected by a linear gradient elution with acetic acid/water (2:98 v/v) and acetic acid/acetonitrile/water (2:30:68 v/v) as the mobile phases in 30 min with a flow rate of 1.5 mL/min. Among the acids from snowdrop extracts, p-hydroxy benzoic was the major constituent followed by vanillic and ferulic acids.
Differential Pulse Polarographic Determination Of Enalapril Maleate, Fi̇kri̇ye Elmali, Güzi̇n Alpdoğan, Şule Aycan, Sidika Sungur
Differential Pulse Polarographic Determination Of Enalapril Maleate, Fi̇kri̇ye Elmali, Güzi̇n Alpdoğan, Şule Aycan, Sidika Sungur
Turkish Journal of Chemistry
A differential pulse polarographic (DPP) method has been developed for the quantitative analysis of enalapril maleate. Enalapril maleate gives a peak at -1.4 V in methanol. A calibration curve was constructed for the 20 -100 \mu g ml^{-1} concentration range. As a reference method, a reversed phase high performance liquid chromatographic procedure has been developed. Commercially available tablets were analysed by the two methods. Statistical evaluations indicated that there was no significant difference between the mean values and precisions of the two methods at a 95\% confidence level.
Purification And Partial Characterization Of Catalase From Chicken Erythrocytes And The Effect Of Various Inhibitors On Enzyme Activity, Tüli̇n Aydemi̇r, Kevser Kuru
Purification And Partial Characterization Of Catalase From Chicken Erythrocytes And The Effect Of Various Inhibitors On Enzyme Activity, Tüli̇n Aydemi̇r, Kevser Kuru
Turkish Journal of Chemistry
Catalase plays a major role in the protection of tissues from the toxic effects of H_{2}O_{2} and partially reduced oxygen species. A nearly 136-fold enzyme purification was obtained from chicken erythrocyte by acetone precipitation, ethanol-chloroform treatment, CM-cellulose and Sephadex G-200 chromatography. The specific activity of purified enzyme was 42,556 U/mg. The molecular weight of the native chicken erythrocyte catalase was estimated at 240 kDa by gel filtration. SDS-gel electrophoresis results indicated that chicken erythrocyte catalase consists of four apparently identical subunits, with a molecular weight of around 57.5 kDa. The optical spectrum of the purified enzyme shows a Soret band …
Kinetics Of Aqueous Pyrite Oxidation By Potassium Dichromate - An Experimental Study, Paul Chirita
Kinetics Of Aqueous Pyrite Oxidation By Potassium Dichromate - An Experimental Study, Paul Chirita
Turkish Journal of Chemistry
The kinetics of pyrite oxidation in perchloric acid solutions were investigated at temperatures ranging from 30°C to 40°C, potassium dichromate concentration from 0.001 to 0.05 mol L^{ - 1}, particle size fractions from 50 to 150 \mu m and pH values down to 2.83. The rate of the oxidation reaction is described by the following expression: r = bkS^{0.51}[K_{2}Cr_{2}O_{7}]^{0.64}[H^{+} ]^{0.22} where S is the surface area of reacting solid, r represents the amount of Fe release in solution per unit surface area per unit time, b is a stoichiometric factor, k is the rate constant, and [K_{2}Cr_{2}O_{7}] and [H^{+} ] …
A Novel Silver Recovery Method From Waste Photographic Films With Naoh Stripping, Nuri̇ Naki̇boğlu, Duygu Toscali, Gürel Ni̇sli̇
A Novel Silver Recovery Method From Waste Photographic Films With Naoh Stripping, Nuri̇ Naki̇boğlu, Duygu Toscali, Gürel Ni̇sli̇
Turkish Journal of Chemistry
A novel, simple, fast, cheap and pollution-free method was developed for recovering the silver from waste X-ray photographic films with NaOH stripping. The method has a number of advantages because it obviates the need for burning, oxidizing, electrolysis or purifying steps. Moreover, all experiments were carried out in the same flask, unlike other techniques. Silver recovery conditions were optimized and silver a purity level of 99\% was recovered. The metal impurities (Al, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Sn) in the recovered silver were determined using the ICP-MS method. The results were compared with results in …
Synthesis, Characterization And Electrical Conductivity Of Poly(P-Phenylene Vinylene), Ali̇ Çirpan, Zuhal Küçükyavuz, Savaş Küçükyavuz
Synthesis, Characterization And Electrical Conductivity Of Poly(P-Phenylene Vinylene), Ali̇ Çirpan, Zuhal Küçükyavuz, Savaş Küçükyavuz
Turkish Journal of Chemistry
Poly(p-phenylene vinylene) (PPV) was prepared electrochemically from p-xylene-bis(diethylsulphonium chloride) in a solvent-electrolyte couple of acetonitrile-tetrabutylammonium tetrafluoroborate (TBAFB). The polymer obtained from the electrode surface was converted to PPV by the thermal elimination of diethyl sulfide, HCl and ethyl sulfide. PPV was also obtained chemically in order to investigate the effect of the synthetic method on the structure and electrical conductivity. The characterization of the polymers was carried out by means of fourier transform infrared spectrometer (FTIR), differential scanning calorimetry (DSC) and thermal gravimetry analysis (TGA) techniques. The doping effect on the conductivity of the PPV was investigated by using different …
Electrochemical Behaviour Of Thymolphthalein, Mustafa Uçar, Necati̇ Menek
Electrochemical Behaviour Of Thymolphthalein, Mustafa Uçar, Necati̇ Menek
Turkish Journal of Chemistry
The polarographic and voltammetric behaviour of thymolphthalein in ethanol-water (1/5 v/v) was studied using various electrochemical techniques. The reduction of thymolphthalein on a mercury drop electrode was investigated. The adsorption effect on the electrode surface was observed. The rate constants for the electron transfer steps were determined by and without taking adsorption into occount using the Laviron technique and Nicholson technique respectively. The diffusion coefficients were calculated from the cyclic voltammetric data using the method developed by Garrido. Reversibility for the electrode reaction was investigated and a mechanism for the electrode reaction was proposed.
Studies On The Mechanism Of Base-Catalyzed Decomposition Of Bicyclic Endoperoxides, Ebru Mete, Ramazan Altundaş, Hasan Seçen, Meti̇n Balci
Studies On The Mechanism Of Base-Catalyzed Decomposition Of Bicyclic Endoperoxides, Ebru Mete, Ramazan Altundaş, Hasan Seçen, Meti̇n Balci
Turkish Journal of Chemistry
Kinetic studies were performed to clarify the Kornblum-Delamare reaction mechanism of bicyclic endoperoxides. Ascaridol and 1,4-diphenyl-2,3-dioxa-bicyclo[2.2.2]oct-5-ene, not having \alpha -protons, did not provide any reaction with bases. Reaction with different bases has revealed that reaction rates for the base-catalyzed decomposition of 2,3-dioxa-bicyclo[2.2.2]oct-5-ene depend strongly on the base strength. The stronger the base used, the faster the conversion rate. Reaction rate values k of endoperoxides with different skeletons were also studied with NEt_{3}. It has been noted that the strength of the base plays the dominant role in determining the rate of the reactions.
Vibrational Spectroscopic Studies On Trans-1,4-Polychloroprene, V. Arjunan, S. Subramanian, S. Mohan
Vibrational Spectroscopic Studies On Trans-1,4-Polychloroprene, V. Arjunan, S. Subramanian, S. Mohan
Turkish Journal of Chemistry
Fourier transform infrared and Raman spectra of trans-1,4-polychloroprene have been recorded in the range of 4000-400 and 3500-100 cm^{-1}, respectively. In the present investigation, detailed assignments of the observed fundamental bands of trans-1,4-polychloroprene were analysed in terms of peak positions and relative intensities. In the hope of providing more effective information on the fundamental vibrations, a normal coordinate analysis was performed on trans-1,4-polychloroprene, by assuming C_{S} symmetry. The simple general valance force field (SGVFF) was employed in normal coordinate analysis and to calculate the potential energy distribution (PED) for each fundamental vibration. The PED contribution corresponding to each of the …
Synthesis Of New Antimicrobial Agents; Amide Derivatives Of Pyranones And Pyridinones, Mutlu Di̇lsi̇z Aytemi̇r, Robert C. Hider, Di̇lek Demi̇r Erol, Meral Özalp, Meli̇ke Eki̇zoğlu
Synthesis Of New Antimicrobial Agents; Amide Derivatives Of Pyranones And Pyridinones, Mutlu Di̇lsi̇z Aytemi̇r, Robert C. Hider, Di̇lek Demi̇r Erol, Meral Özalp, Meli̇ke Eki̇zoğlu
Turkish Journal of Chemistry
In this study, 4(1H)-pyridinones with an amide function in Position 2 of the pyridinone ring showed antimicrobial activity. The synthesis and the biological properties of some novel amide derivatives of pyran-4(1H)-one and 4(1H)-pyridinone have been reported. Amide derivatives of pyran-4(1H)-one and 4(1H)-pyridinone were prepared using two different methods. Antimicrobial activities were determined as MIC values using the microdilution broth method against the bacteria Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa and the fungi Candida albicans, Candida krusei and Candida parapsilosis. Compounds 6 and 9 exhibited the best inhibitor activity against S. aureus.
Synthesis, Characterization And Applications Of Sol-Gel Derived Zirconium Oxide Adsorbent Powder: Removal From Aqueous Solution Of Phenol And P-Chlorophenol, Murat Akarsu, Hi̇kmet Sayilkan, Şadi̇ye Şener, Funda Sayilkan, Ertuğrul Arpaç
Synthesis, Characterization And Applications Of Sol-Gel Derived Zirconium Oxide Adsorbent Powder: Removal From Aqueous Solution Of Phenol And P-Chlorophenol, Murat Akarsu, Hi̇kmet Sayilkan, Şadi̇ye Şener, Funda Sayilkan, Ertuğrul Arpaç
Turkish Journal of Chemistry
Adsorbent powders were prepared from the uncatalysed hydrolysis-condensation reactions of different complexes that were synthesized by the reactions of Zr(OPr^{n})_{4} with different chelating ligands (such as allylacetic acid [AAH], vinylacetic acid [VAH] and citraconic acid [CAH]). The complex products were characterized by FT-IR, ^{1}H-NMR and ^{13}C-NMR spectra. The maximum combination ratios of AAH/Zr(OPr^{n})_{4}, VAH/Zr(OPr^{n})_{4} and CAH/Zr(OPr^{n})_{4} were 1.7, 0.9 and 1.3, respectively. The hydrolysis-condensation products of these complexes were calcinated at 900 °C and half of them were coated with 3-glycidyloxypropyltrimethoxysilane (GLYMO). The surface area and average pore diameter of the powders were estimated by the analysis of adsorption/desorption BET …
The Effect Of Tert-Butylhydroperoxide On The Thiol Redox Status In Human Erythrocytes And The Protective Role Of Glucose And Antioxidants, Yasemi̇n Aksoy, İ. Hamdi̇ Öğüş, Nazmi̇ Özer
The Effect Of Tert-Butylhydroperoxide On The Thiol Redox Status In Human Erythrocytes And The Protective Role Of Glucose And Antioxidants, Yasemi̇n Aksoy, İ. Hamdi̇ Öğüş, Nazmi̇ Özer
Turkish Journal of Chemistry
For survival, living cells maintain their thiol redox status within acceptable limits by three different mechanisms: i. glutathione disulfide export, ii. reduction of glutathione disulfide by pentose phosphate pathway and, iii. reduction of glutathione disulfide by Protein-SH. To assess the relative contribution of each one of the systems, intracellular [glutathione], [glutathione disulfide] and their export, in fresh and aged erythrocytes subjected to oxidative stress, in \pm glucose and \pm antioxidants, were measured. Glutathione was rapidly oxidized by tert-butylhydroperoxide in \pm glucose in both groups. The regeneration of glutathione, in both groups, in \pm glucose was about 100 and 50%, respectively. …
Synthesis Of New 4-(5-Chloro-2-Oxo-3h-Benzoxazol-3-Yl)Butanamide Derivatives And Their Analgesic And Anti-Inflammatory Properties, H. Ozan Gülcan, Serdar Ünlü, Erden Banoğlu, M. Fethi̇ Şahi̇n, Esra Küpeli̇, Erdem Yeşi̇lada
Synthesis Of New 4-(5-Chloro-2-Oxo-3h-Benzoxazol-3-Yl)Butanamide Derivatives And Their Analgesic And Anti-Inflammatory Properties, H. Ozan Gülcan, Serdar Ünlü, Erden Banoğlu, M. Fethi̇ Şahi̇n, Esra Küpeli̇, Erdem Yeşi̇lada
Turkish Journal of Chemistry
In this preliminary screening study for developing potent analgesic and anti-inflammatory compounds, eight new 4-(5-chloro-2-oxo-3H-benzoxazol-3-yl)butanamide derivatives were synthesized and screened for their analgesic and anti-inflammatory activities as well as gastric ulceration potential in tested animals. Their structures were elucidated by their IR, ^{1}H-NMR and elemental analysis. All of the compounds exhibited high analgesic and anti-inflammatory activities. None of the compounds except compound 2g caused gastric lesions or bleeding in tested animals.
Voltammetric And Flow Injection Amperometric Determination Of Cysteine At A Glassy Carbon Electrode In The Presence Of Copper(Ii) Ions, Zekerya Dursun, İlyas Şahbaz, F. Ni̇l Ertaş, Gürel Ni̇şli̇
Voltammetric And Flow Injection Amperometric Determination Of Cysteine At A Glassy Carbon Electrode In The Presence Of Copper(Ii) Ions, Zekerya Dursun, İlyas Şahbaz, F. Ni̇l Ertaş, Gürel Ni̇şli̇
Turkish Journal of Chemistry
The voltammetric behaviour of cysteine was investigated in the presence of Cu(II) ions at a rotating glassy carbon electrode (RGCE). Two reduction peaks related to the successive reduction of the cysteine complexes of Cu(II) and Cu(I) ions were observed at --0.30 and --0.60 V vs. SCE respectively. These peaks were increased upon the addition of cysteine into a pH 9.20 borate buffer solution containing 0.1 M KNO_{3} and 1.0 x 10^{-5} M Cu(II) ions. The calibration curve was linear in the concentration range of 5.0 x 10^{-10}- 2.0 x 10^{-8} M for cysteine by utilising the peak current at --0.6 …
Micelle Formation In Sodium Dodecyl Sulfate And Dodecyltrimethylammonium Bromide At Different Temperatures, Yüksel Bayrak
Micelle Formation In Sodium Dodecyl Sulfate And Dodecyltrimethylammonium Bromide At Different Temperatures, Yüksel Bayrak
Turkish Journal of Chemistry
pH changes as a function of concentration for sodium dodecyl sulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) were observed by the addition of 1 N HCl and 1 N KOH. pH values increased up to the critical micellar concentration (CMC) for the SDS/HCl system and decreased for the DTAB/KOH system. In the SDS/HCl and DTAB/KOH systems, the micellar phase had a fixed composition and was homogeneous and monodisperse above the CMC. However, in the SDS/KOH and DTAB/HCl systems, pH values increased in a continuous and gradual manner below and above the CMC, and the properties of the micellar phase changed with …
Thermogravimetric Characterization Of Turkish Bituminous Coals For Combustion, Sai̇t Kizgut, Di̇lek Cuhadaroğlu, İhsan Toroğlu
Thermogravimetric Characterization Of Turkish Bituminous Coals For Combustion, Sai̇t Kizgut, Di̇lek Cuhadaroğlu, İhsan Toroğlu
Turkish Journal of Chemistry
This study focused on the thermal gravimetric characterization of Turkish bituminous coals for combustion. The combustion properties considered were based on the burning profile of coal samples and their chars produced in a PL 1500 TGA apparatus. The coal seam samples used in the study were obtained from TTK (Turkish Hardcoal Enterprise) mines as channel samples. The majority of the samples from 12 seams were medium-volatile bituminous and only three of them were high-volatile bituminous. Combustion profile parameters of coal samples and chars were correlated with petrographic, proximate and ultimate analysis data in order to establish the combustion differences of …
Synthesis, Characterization And Primary Antituberculosis Activity Evaluation Of 4-(3-Coumarinyl)-3-Benzyl-4-Thiazolin-2-One Benzylidenehydrazones, Aysel Gürsoy, Ni̇lgün Karali̇
Synthesis, Characterization And Primary Antituberculosis Activity Evaluation Of 4-(3-Coumarinyl)-3-Benzyl-4-Thiazolin-2-One Benzylidenehydrazones, Aysel Gürsoy, Ni̇lgün Karali̇
Turkish Journal of Chemistry
In this study a new series of 4-(3-coumarinyl)-3-benzyl-4-thiazolin- 2-one benzylidenehydrazones 3a-t was synthesized. Structures of the title compounds were elucidated by elemental analyses and spectrometric data (IR, ^1H-NMR, ^{13}C-NMR and EIMS). 3a-t were evaluated for antituberculosis activity against Mycobacterium tuberculosis} H37Rv in BACTEC 12B medium using the BACTEC 460 radiometric system.
Cerimetric Determination Of Propranolol In Bulk Drug Form And In Tablets, Kanakapura Basavaiah, Umakanthappa Chandrashekar, H. Chandrashekar Prameela
Cerimetric Determination Of Propranolol In Bulk Drug Form And In Tablets, Kanakapura Basavaiah, Umakanthappa Chandrashekar, H. Chandrashekar Prameela
Turkish Journal of Chemistry
Two simple, accurate and precise methods are described for the determination of propranolol hydrochloride with cerium(IV) sulphate. The titrimetric method is based on the oxidation of the drug by a known excess amount of cerium(IV) sulphate and back titration of the unconsumed oxidant with ammonium ferrous sulphate. In the spectrophotometric method, the unreacted cerium(IV) sulphate is treated with iron(II) sulphate, and the iron(III) sulphate produced is complexed with thiocyanate and measured at 480 nm, thereby permitting the determination of the amount of unreacted cerium(IV) sulphate. In both procedures, the amount of the reacted oxidant corresponds to the drug content. Different …
Silver Removal From Aqueous Solution By Adsorption On Concrete Particles, Shakila Begum
Silver Removal From Aqueous Solution By Adsorption On Concrete Particles, Shakila Begum
Turkish Journal of Chemistry
The ability of concrete to remove silver from its aqueous solutions was studied. Silver removal is favored by low concentration and high pH at room temperature. The intrinsic acidity constants, average pK_{a1}^{int} and average pK_{a2}^{int} were determined. The calculated pH_{PZC} (5.4) is in agreement with the pH_{PZC} values determined from zeta potential measurements, indicating that the concrete particulate behaves amphoterically. The total acidity capacity for the negative and positive surface was 0.5 \muC/cm^2. A surface complex formation model (SCFM) was used to describe the adsorption of silver onto concrete particles. In general the equilibrium constants, the pK_S^i values, decrease as …
Effects Of Sucrose Concentration During Citric Acid Accumulation By Aspergillus Niger, Ayşegül Peksel, Cristian P. Kubicek
Effects Of Sucrose Concentration During Citric Acid Accumulation By Aspergillus Niger, Ayşegül Peksel, Cristian P. Kubicek
Turkish Journal of Chemistry
A number of regulatory mechanisms are involved in increasing citric acid production under certain conditions. The accumulation of citric acid takes place under the high concentration of carbon sources. The effect of sucrose as a carbon source on the accumulation of citric acid and tyrosine phosphorylated proteins during high glycolytic conditions was investigated using Aspergillus niger ATCC 11414. When mycelia are treated by different sucrose concentrations, a protein of \sim 27 kDa becomes tyrosine phosphorylated. This tyrosine phosphorylation takes place in response to signal transduction from the extracellular milieu. A possible role of this \sim 27 kDa protein in signal …
Catalytic Spectrophotometric Determination Of Manganese In Some Medicinal Plants And Their Infusions, Kostantin L. Mutaftchiev
Catalytic Spectrophotometric Determination Of Manganese In Some Medicinal Plants And Their Infusions, Kostantin L. Mutaftchiev
Turkish Journal of Chemistry
The catalytic effect of manganese (II) on the oxidation of the dye 1,3-Dimethyl- 2 [4-N (N,N-dimethylamino) phenylazo] imidazolium perchlorate (BR) with potassium periodate in the presence of 1,10-phenanthroline was investigated. The reaction was followed spectrophotometrically by measuring the decrease in the absorbance of the dye at 540 nm. Under optimum conditions (5 \times 10^{-5} mol dm^{-3} BR, 2 \times 10^{-4} mol dm^{-3} potassium periodate, 1 \times 10^{-4} mol dm^{-3} 1,10-phenanthroline, 0.1 mol dm^{-3} buffer -- pH 3.0, 70 °C, 5 min) manganese (II) in the range 0.1--4.5 ng cm^{-3} can be determined by the fixed-time method with a detection limit …
Study On Papain Immobilization On A Macroporous Polymer Carrier, Liang Ding, Zihua Yao, Tong Li, Qiang Yue, Jia Chai
Study On Papain Immobilization On A Macroporous Polymer Carrier, Liang Ding, Zihua Yao, Tong Li, Qiang Yue, Jia Chai
Turkish Journal of Chemistry
Macroporous resin microbeads of methyl methacrylate-divinyl benzene copolymer were synthesized by radical suspension polymerization of acrolein with divinylbenzene in the presence of a pore-creating agent, petroleum ether. The microbeads had a large specific surface area and large pores covered the entire surface of the resin. This macroporous polymer carrier was aminated by hydrazine hydrate that produced a large number of amino groups on the carrier. Papain was immobilized on the porous polymer carrier by glutaraldehyde cross-linking or diazo-coupling. The factors involved in the activity recovery of the immobilized papain and the enzymic properties of the resulting immobilized papain were studied …
Adsorption Of Arsenate And Chromate From Waters On Hydrophobized Zeolitic Media, Eva Chmielewska
Adsorption Of Arsenate And Chromate From Waters On Hydrophobized Zeolitic Media, Eva Chmielewska
Turkish Journal of Chemistry
A laboratory setup was used to examine the uptake of chromate and arsenate from aqueous solutions by octadecylammonium acetate [ODA]-modified inland clinoptilolite. In trials, a natural variety of montmorillonite was compared to organic, i.e. surfactant loaded clinoptilolite. and some inorganically substituted (Ag, Pb) monoforms. The arrangement of the surface-attached ODA chains was the important factor for differences in the adsorption states of the guest species (oxyanions). A novel nano-structure inorganic-organic composite was prepared and was characterized by SEM, thermogravimetry, HR TEM, UV-VIS diffuse reflectance and powder XRD spectral analytical methods. Finally, the adsorption isotherms of the studied system were expressed. …
Solid Phase Extraction Of Copper(Ii) By Modified Octadecyl Silica Membrane Disks With 3-{2-[2-(2-Hydroxyimino-1-Methyl-Propylideneamino)- Ethylamino]-Ethyl-Imino}-Butan-2-One~Oxime, Ömer Dalman, Serdar Karaböcek, Ahmet Demi̇rak, Mehmet Tüfekçi̇
Solid Phase Extraction Of Copper(Ii) By Modified Octadecyl Silica Membrane Disks With 3-{2-[2-(2-Hydroxyimino-1-Methyl-Propylideneamino)- Ethylamino]-Ethyl-Imino}-Butan-2-One~Oxime, Ömer Dalman, Serdar Karaböcek, Ahmet Demi̇rak, Mehmet Tüfekçi̇
Turkish Journal of Chemistry
A simple, selective and rapid method for determining trace amounts of copper(II) ions in various types of water samples using atomic absorption spectrophotometry was investigated. Copper(II) ions from water samples were preconcentrated by solid phase extraction using octadecyl silica membrane disks modified with 3-{2-[2-(2-hydroxyimino- 1-methyl-propylideneamino)-ethylamino]-ethyl-imino}-butan-2-one oxime, (H_{2}mdo). The experimental conditions were optimized by changing several parameters such as volume of eluting solvent, the effect of pH, eluent flow rates, the amount of H_2mdo, breakthrough the volume, limit of detection and maximum capacity of the disks for Cu^{2+} recovery. The method was applied to the recovery of Cu(II) ions from seven …
Synthesis, Characterization And Biological Applications Of Organotin(Iv) Derivatives Of 2-(2-Fluoro-4-Biphenyl)Propanoic Acid, Sohail Mahmood, Saqib Ali, Moazzam Hussain Bhatti, Mohammad Mazhar, Rashid Iqbal, Khalid Mohammed Khan, Ghulam Mustafa Maharvi
Synthesis, Characterization And Biological Applications Of Organotin(Iv) Derivatives Of 2-(2-Fluoro-4-Biphenyl)Propanoic Acid, Sohail Mahmood, Saqib Ali, Moazzam Hussain Bhatti, Mohammad Mazhar, Rashid Iqbal, Khalid Mohammed Khan, Ghulam Mustafa Maharvi
Turkish Journal of Chemistry
A series of organotin(IV) derivatives with the general formula R_{4 - n}SnL_{n} (where n = 1 or 2, R = Me, Et, n-Bu, Ph and L = 2-(2-fluoro-4-biphenyl)propanoate) have been synthesized and characterized by infrared, multinuclear NMR (^{1}H, ^{13}C, ^{119}Sn), ^{119m}Sn Mössbauer spectroscopy and mass spectrometry. Screening tests of these compounds showed that they are highly active against various bacteria and fungi.