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Öğe The effect of Plantago major Linnaeus on serum total sialic acid, lipid-bound sialic acid, some trace elements and minerals after administration of 7,12-dimethylbenz(a)anthracene in rats(SAGE, 2012-04) Oto, Gökhan; Ekin, Suat; Özdemir, Hülya; Levent, Abdulkadir; Berber, İsmetThe present study was designed to evaluate the effect of Plantago major Linnaeus (PM) extract on serum total sialic acid (TSA), lipid-bound sialic acid (LSA), some trace elements (copper (Cu), zinc (Zn) and iron) and mineral levels (magnesium, calcium and sodium) in Wistar albino rat administrated 7,12-dimethylbenz(a)anthracene (DMBA). Rats were divided into three equal groups (n = 6). Group I comprised the control group, group II was treated with DMBA (100 mg/kg, single dose) and group III was treated with DMBA (100 mg/kg single dose) and aqueous extract of PM 100 mg/kg/day for 60 days. After 60 days, statistical analyses showed that TSA and LSA levels in DMBA and DMBA + PM groups were significantly higher compared to the control group (TSA: p < 0.01, p < 0.05; LSA: p < 0.05, p < 0.05, respectively). Serum Zn levels were decreased in subjects treated with DMBA (p < 0.01) and DMBA + PM (p < 0.05) compared to the control group values. Serum Cu levels were increased in DMBA group and PM-treated group compared to the control group values. The results of this investigation showed that the levels of TSA and LSA changed significantly, which are sensitive markers for detecting the toxic effects of DMBA. On the other hand, observed decline in Zn levels in rats from DMBA + PM group might be due to decreased generation of free radicals and oxidative stress. Results from this study suggest that PM may be partially effective in preventing carcinogenesis initiated by environmental carcinogen DMBA.Öğe Fluorescence properties and electrochemical behavior of some schiff bases derived from n-aminopyrimidine(Springer Nature, 2014-03) Gülcan, Mehmet; Doğrul, Ümit; Öztürk Ürüt, Gülsiye; Levent, Abdulkadir; Akbaş, EsvetA series of Schiff bases (L 1, L 2 and L 3 ) were prepared by refluxing aromatic aldehydes with N-Aminopyrimidine derivatives in methanol and ethanol. The structures of synthesized compounds were characterized by FTIR, 1H NMR, 13C NMR and microanalysis. The electrochemical behaviors of the Schiff base ligands were also discussed. Moreover, the evaluation of absorption and emission properties of the structures were carried out in five different solvents. The products show visible absorption maxima in the range of 304-576 nm, and emission maxima from 636 to 736 nm in all solvents tested.Öğe The changes in the serum, liver, kidney protein and genomic DNA profiles in rats treated with 7,12-Dimethylbenz(A) anthracene and Plantago major L.(RJPBCS, 2014-01) Berber, İsmet; Ekin, Suat; Levent, Abdulkadir; Oto, Gökhan;In the study, the changes in the serum, liver, kidney protein and genomic DNA profiles in Wistar albino rats administrated to 7,12-dimethylbenz(a)anthracene (DMBA) and Plantagomajor L. were investigated. SDS-PAGE profiling of the serum proteins showed that the levels of two proteins molecular weighing 140.8 kDa and 46.8 kDa were significantly lower on the 0th day of treatment than on the 60th day of application in the groups. Furthermore, two proteins (34.5 and 22.3 kDa) were solely present in DMBA-treated liver cell lysates. On the contrary, the kidney protein profiles did not show significant banding variations in groups. Genomic DNA analysis also confirmed that DNA extracted from liver and kidney cells did not fragment in any of the groups after the 60th study day. The proteins 34.5 and 22.3 kDa in liver cell lysates at the 60th day in DMBA-treated group could be extra-prognostic indicators for severe DMBA toxicity.Öğe Sınıf öğretmenliği öğrencilerinin ısı ve sıcaklık konularındaki kavram yanılgılarının giderilmesinde tahmin-gözleaçıkla (TGA) yönteminin etkisi(JASSS, 2013-04) Öner Sünkür, Meral; İlhan, Mustafa; Sünkür, MuratBu araştırmada, sınıf öğretmenliği öğrencilerinin ısı ve sıcaklık konularındaki kavram yanılgılarının giderilmesine TGA yönteminin etkisi araştırılmıştır. Bu amaca uygun olarak, çalışma ön test-son test kontrol gruplu deneysel desene göre yürütülmüştür. Araştırmaya 2010-2011 Öğretim Yılı Bahar Dönemi’nde Dicle Üniversitesi Ziya Gökalp Eğitim Fakültesi sınıf öğretmenliği programına kayıtlı 83 öğrenci dâhil edilmiştir. 42 öğrencinin bulunduğu deney grubunda TGA yöntemine göre öğretim yapılırken, 41 öğrencinin bulunduğu kontrol grubunda doğrulama laboratuvar yaklaşımı kullanılmıştır. Uygulamalar 4 hafta sürmüş olup 28.03.2011 ile 24.04.2011 tarihleri arasında gerçekleştirilmiştir. Araştırmanın verileri Gümüş, Öner, Kara, Orbay ve Yaman (2003) tarafından geliştirilen kavram yanılgıları testi ile toplanmıştır. Araştırmadan elde edilen verilerin analizinde, öğrencilerin ısı ve sıcaklık kavram yanılgıları testinden aldıkları puanlar dikkate alınmıştır. Veriler, SPSS paket programından yararlanılarak ilişkili örneklem t-testi ve ANCOVA testi ile analiz edilmiştir. Araştırma sonucunda, deney grubundaki öğrencilerin kavram yanılgıları ön test ve son test puanları arasında son test puanları lehine istatistiksel olarak anlamlı fark saptanmıştır. Kontrol grubunda ise, ön test ve son test puanları arasında bir fark bulunduğu ancak bu farkın istatistiksel açıdan anlamlı olmadığı belirlenmiştir. Araştırmada ayrıca, deney ve kontrol grubunun ön test puanlarına göre düzeltilmiş son test puanları arasında deney grubu lehine anlamlı fark bulunduğu tespit edilmiştir. Araştırmadan elde edilen bulgulara dayanarak, sınıf öğretmenliği programına devam eden öğrencilerin ısı ve sıcaklık konularındaki kavram yanılgılarının giderilmesinde, TGA yönteminin doğrulama laboratuvar yaklaşımına göre daha etkili olduğu tespit edilmiştir.Öğe Electroanalytical determination of progesterone hormone using borondoped diamond electrode(ICNTC, 2020) Levent, Abdulkadir; Uçar, MuhlisProgesterone is synthesized from pregnenolone, a derivative of cholesterol like other steroids. It is a steroid hormone that has a vital importance in human and animal health. In case of progesterone imbalance, it causes problems such as fertility and infertility. In this study, electrochemical properties of Progesterone hormone Boron doped diamond (BDD) on electrode surface were investigated in strongly acidic environment (HClO4 and H2SO4). A fast, sensitive, selective and simple electroanalytical method was developed for cathodically pre-treated BDD electrodes. A good linear analytical curve in the concentration range of 10 μM to 100 μM at a voltage value of +1.51 V (vs. Ag / AgCl) (after 120 s deposition at +0.1 V voltage) in 0.5 M HClO4 using the square wave stripping technique for the quantification of progesterone hormone obtained. The observability limit is 0.012 µM(3.77 µg L-1); The relative standard deviation value (RSD) for the concentration of 3.1 µM (n = 11) was calculated to be 4.87%. In addition, the developed voltammetric method has been successfully applied to drug and blood serum.Öğe Electrochemical determination of melatonin hormone using a boron-doped diamond electrode(Elsevier, 2012-01) Levent, AbdulkadirIn this study, a boron-doped diamond electrode was used for the electroanalytical determination of melatonin in the pharmaceutical tablet and urine samples by square-wave voltammetry. Melatonin yielded a well-defined voltammetric response in Britton-Robinson buffer, pH 3.0 at + 0.88 V (vs. Ag/AgCl). Using the optimal square-wave voltammetry conditions, the oxidation peak was used to determine melatonin in the concentration range of 5.0 × 107 M to 4.0 × 106 M (r = 0.998, n = 8), a detection limit of 1.1 × 107 M (0.025 μg/mL) and relative standard deviation was 2.06% at the 2.0 × 106 M level (n = 10). Recoveries of melatonin were in the range of 97.67–105%, for both tablet and spiked human urine samples.Öğe Preparation, spectral studies, theoretical, electrochemical and antibacterial investigation of a new Schiff base and its some metal complexes(Elsevier, 2014-10-05) İlhan, Salih; Baykara, Hacı; Seyitoğlu, Mehmet Salih; Levent, Abdulkadir; Özdemir, Sadin; Dündar, Abdurrahman; Öztomsuk, Abdussamet; Cornejo, MauricioA new Schiff base ligand, 1,6-Bis(2-(5-bromo-2-hydroxybenzylideneamino)-4-chlorophenoxy)hexane was synthesized. Some Schiff metal complexes of the new Schiff base were prepared by the reaction of some metal salts and the Schiff base. The complexes are non-electrolytes as shown by their molar conductivities (ΛM). The structures of metal complexes are proposed from elemental analysis, FT-IR, UV–vis, magnetic susceptibility measurements, molar conductivity measurements, mass spectra and thermal gravimetric analysis. In addition theoretical 1H NMR, HOMO–LUMO studies of the ligand; antimicrobial and cyclic voltammetric studies of the compounds were also carried out. In this study antioxidant and antibacterial activities of the compounds were examined via in vitro methods.Öğe Synthesis and characterization of a new difunctional ligand and its metal complexes: An experimental, theoretical, cyclic voltammetric, and antimicrobial study(Taylor & Francis, 2015-07-29) Baykara, Hacı; İlhan, Salih; Öztomsuk, Abdussamet; Seyitoğlu, Mehmet Salih; Levent, Abdulkadir; Okumuş, Veysi; Dündar, AbdurrahmanA new difunctional Schiff base ligand and its some metal complexes were synthesized. The compounds were characterized by elemental analysis, 1H-NMR, 13C-NMR, FT-IR, UV-VIS, magnetic susceptibility measurements, molar conductivity measurements, and thermal gravimetric analysis techniques. Additionally, DPPH scavenging, metal chelating and antibacterial activity of compounds were examined via in vitro methods. The lowest DPPH scavenging activity observed by Co(II) as 36.28% and highest was ligand as 52.00%. A cyclic voltammetric study was also carried out to determine redox potentials of the compounds. Some theoretical studies such as 1H-NMR, HOMO-LUMO, and mapped electron density of the ligand were also carried out successfully.Öğe Sensitive voltammetric determination of testosterone in pharmaceuticals and human urine using a glassy carbon electrode in the presence of cationic surfactant(Elsevier, 2014-05-10) Levent, Abdulkadir; Altun, Ahmet; Yardım, Yavuz; Şentürk, ZühreIn this work, the electrochemical investigation of testosterone, a steroid hormone from the androgen group, was carried out in aqueous and aqueous/surfactant solutions using a glassy carbon (GC) electrode. In cyclic voltammetry, the compound showed one irreversible and adsorption-controlled reduction peak. Addition of cationic surfactant (cetyltrimethylammonium bromide, CTAB) was found to enhance the reduction current signal of testosterone, whereas, anionic (sodium dodecylsulfate, SDS) and non-ionic (Tween 80) surfactants exhibited opposite effect. Using square-wave adsorptive stripping voltammetry, the current showed a linear dependence with concentration in the range between 10 and 70 nM in Britton–Robinson buffer, pH 5.0 containing 3 mM CTAB. A detection limit of 1.18 nM (0.34 ng mL−1), and relative standard deviation of 4.12% for a concentration level of 35 nM (n = 11) were calculated. This method was successfully applied for the analysis of testosterone in oil-based pharmaceutical preparations and urine samples without any separation.Öğe Voltammetric behavior of benzo[a]pyrene at boron-doped diamond electrode: A study of its determination by adsorptive transfer stripping voltammetry based on the enhancement effect of anionic surfactant, sodium dodecylsulfate(Elsevier, 2011-07-15) Yardım, Yavuz; Keskin, Ertuğrul; Levent, Abdulkadir; Şentürk, ZühreBenzo[a]pyrene (BaP), a member of the polycyclic aromatic hydrocarbon (PAH) class, is one of the most potent PAH carcinogens. The electrochemical oxidation of BaP was first studied by cyclic voltammetry at the boron-doped diamond electrode in non-aqueous solvent (dimethylsulphoxide with lithium perchlorate). The compound was irreversibly oxidized in a single step at high positive potential, resulting in the well-resolved formation of a couple with a reduction and re-oxidation wave at much lower potentials. Special attention was given to the use of adsorptive stripping voltammetry together with a medium exchange procedure in aqueous and aqueous/surfactant solutions over the pH range of 2.0–8.0. The technique in aqueous solutions had little value in practice because of too small oxidation peak current. This problem was solved when surfactants were added into the sample solution, by which the oxidation peak currents of BaP were found enhanced dramatically. The employed surfactants were sodium dodecylsulfate (anionic, SDS), cetyltrimethylammonium bromide (cationic, CTAB) and Tween 80 (non-ionic). Using square-wave stripping mode, the compound yielded a well-defined voltammetric response in Britton–Robinson buffer, pH 2.0 containing 2.5 × 10−4 M SDS at +1.07 V (vs. Ag/AgCl) (after 120 s accumulation at +0.10 V). The process could be used to determine BaP in the concentration range of 16–200 nM (4.04–50.46 ng mL−1), with a detection limit of 2.86 nM (0.72 ng mL−1). This method was also applied to determine BaP in model water sample prepared by adding its different concentrations into tap water.
