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Öğe Effect of sex steroids on soleus muscle response in hypocalcemic medium (in vitro)(Academic Press Inc Elsevier Science, 2013) Kokcam, S. Said; Tekin, Sakir; Kartal, Adil; Ayaz, Murat; Sahin, Mustafa; Acar, Fahreddin; Cakir, MuratPurpose: Postoperative hypocalcemia is a frequently encountered complication of thyroid surgery. Since hypocalcemic symptoms are closely associated with sex, the aim of this study is to investigate the effects of sex steroids on muscle tissue under hypocalcemic conditions. Methods: Six groups consisting of control male (M), control female (F), gonadectomized male (M -), gonadectomized female (F-), estradiol- applied gonadectomized male (MX), and testosterone- applied gonadectomized female (FX) rats were used. Contraction recordings were obtained from soleus muscle flaps. Maximal tension (PT), frequency required for 50% of PT (F50), contraction velocity at F50 (V50), and changes in contraction values (d[PT], d[F50], d[V50]) between normocalcemic and hypocalcemic conditions were calculated. Results: d[PT], d[F50], and d[V50] were significantly higher in M - and MX groups compared with control M group. Whereas d[PT], d[F50], and d[V50] parameters of the F- group were significantly higher than control F group, d[F50] and d[PT] of the FX group showed no significant change and d[V50] for the FX group was significantly lower. A comparison of control groups showed that d[PT], d[F50], and d[V50] of the F group were significantly higher than those of the M group. Conclusion: Whereas absence of both testosterone and estradiol caused an increase in hypocalcemia- induced changes in contraction parameters of rat skeletal muscle, presence or application of testosterone clearly stabilized contraction parameters. (C) 2013 Elsevier Inc. All rights reserved.Öğe ESR Characterization of Two Oxovanadium (IV) Schiff Base Complexes Derived from Tris(2-aminoethyl)amine(Taylor & Francis Inc, 2012) Sahin, Mustafa; Kocak, Nuriye; Sayin, Ulku; Yilmaz, MustafaThe compounds, C21H27N4O3(L-1) and C21H27N7(L-2), is a tripodal Schiff base that was obtained from the reaction of tris(2-aminoethyl)amine (tren) and furan-2-carbaldehyde and pyrole-2-carbaldehyde. The tripodal Schiff bases and their oxovanadium complexes have been characterized on the basis of the results of the elemental analysis, magnetic susceptibility measurements and spectroscopic studies FT-IR, H-1-NMR, UV-Vis, ESR, magnetic moment and thermal analysis (TGA). Job's method of continuous variation shows 3: 2 metal to ligand ratio.Öğe Experiences of Single Incision Cholecystectomy(Ivyspring Int Publ, 2013) Yilmaz, Huseyin; Alptekin, Husnu; Acar, Fahrettin; Ciftci, Ilhan; Tekin, Ahmet; Sahin, MustafaPurpose: Single incision laparoscopic surgery in suitable cases is preferred today because it results in less postoperative pain, a more rapid recovery period, more comfort, and a better cosmetic appearance from smaller incisions. This study aims to present our experiences with single incision laparoscopic cholecystectomy to evaluate the safety and feasibility of this procedure. Methods: A total of 150 patients who underwent single incision laparoscopic cholecystectomy between January 2009 and December 2011 were evaluated retrospectively. In this serial, two different access techniques were used for single incision laparoscopy. Results: Single incision laparoscopic cholecystectomy was performed successfully on 150 patients. Median operative time was 29 (minimum-maximum=5-66) minutes. Median duration of hospital stay was found to be 1.33 (minimum-maximum=1-8) days. Patients were controlled on the seventh postoperative day. Bilier complication was not seen in the early period. Five patients showed port site hernia complications. Other major complications were not seen in the 36-month follow-up period. Conclusion: Operation time of single incision laparoscopic cholecystectomy is significantly shortened with the learning curve. Single incision laparoscopic cholecystectomy seems a safe method.Öğe A Novel Chitosan Nanoparticle-Schiff Base Modified Carbon Paste Electrode as a Sensor for the Determination of Pb(II) in Waste Water(Esg, 2013) Kucukkolbasi, Semahat; Erdogan, Zehra Ozden; Barek, Jiri; Sahin, Mustafa; Kocak, NuriyeThis paper describes the preparation and electrochemical application of a modified carbon paste electrode with a new kind of chitosan nanoparticle-Schiff base for the determination of Pb(II) ions in waste water using differential pulse anodic stripping voltammetry (DPASV). Firstly a new kind of chitosan nanoparticle-Schiff base (CNSB) was synthesized by chitosan nanoparticle reaction with 2,4-dihydroxybenzaldehyde. CNSB structure was characterized by FT-IR spectroscopy, elemental analysis, particle size and zeta potential. Afterwards, a novel, simple and effective chemically modified carbon paste electrode with CNSB was prepared and characterized using scanning electronic microscopy (SEM-EDX) and anodic stripping voltammetry. The modified electrode showed only one oxidation peak in the anodic scan at -0.35 V (vs. Ag/AgCl) for the oxidation of Pb(II). The electrochemical properties and applications of the modified electrode, including the pH, supporting electrolyte, preconcentration time, reduction potential and time, and percentage of modifier were investigated. The best voltammetric response was observed for a paste composition of 73.7% (w/w) of graphite powder, 5.3% (w/w) of chitosan and 21% (w/w) of paraffin oil, with 0.2 mol L-1 NaAc solution at pH 6.0 as supporting electrolyte, preconcentration time of 600 s, a reduction potential of -0.1 V and reduction time of 10 s. The new electrode displays excellent response to Pb(II) which is linear in the range from 1x10(-6) to 1x10(-4) mol L-1, with a correlation coefficient of 0.998 and a detection limit of 7.24x10(-7) mol L-1.Öğe Synthesis and characterization of novel nano-chitosan Schiff base and use of lead (II) sensor(Elsevier Science Bv, 2012) Kocak, Nuriye; Sahin, Mustafa; Kucukkolbasi, Semahat; Erdogan, Zehra OzdenA new kind of nano-chitosan Schiff base ligand (CHNS) with particle size of 34 nm was formed by the reaction between the 2-amino groups of glucosamine residue of nano-chitosan and a 2,5-dihydroxybenzaldehyde. The chemical structures of the nano-chitosan and nano-chitosan Schiff base were characterized by FT-IR spectra, particle sizer, zeta potential, and elemental analysis. A new, simple and effective chemically modified carbon paste electrode with CHNS was prepared and used as a lead (II) sensor. The prepared electrode was characterized using scanning electronic microscopy (SEM-EDX) and cyclic voltammetry (CV). The modified electrode showed only one oxidation peak in the anodic scan at -0.34 V (vs. Ag/AgCl) for the oxidation of lead (II). The dedection limit (LOD) was calculated as 1.36 x 10(-7) for a 10-min preconcentration time at pH 6.0. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.Öğe Synthesis and Characterization of Sporopollenin-Supported Schiff Bases and Ruthenium(III) Sorption Studies(Springer, 2012) Sahin, Mustafa; Gubbuk, Ilkay Hilal; Kocak, NuriyeTwo Schiff base derivatives, (2-pycolylimino)benzen-1,4-diol and (2-pyridylimino)benzen-1,4-diol) were immobilized onto sporopollenin (Lycopodium clavatum) surfaces. The compounds were fully characterized by an infrared spectroscopy, elemental analysis, scanning electron microscopy, and X-ray diffraction techniques. The sorption capacities of the immobilized surfaces toward Ru(III) ions were investigated by batch sorption experiments. For the sorption experiment, the Ru(III) concentration, initial pH, and the temperature effects were studied. The isotherm data of Ru(III) ions were correlated reasonably well as a Freundlich sorption isotherm. The thermodynamic studies showed that the Ru(III) sorption onto immobilized sporopollenin derivatives is a non-spontaneous, endothermic and physical reaction.Öğe Synthesis of asymmetrical tridendate Schiff bases and metal complexes and investigation of anticarcinogen effects on human colon and cervical cancers(Taylor & Francis Inc, 2017) Sahin, Mustafa; Korkmaz, Hatice; Kocak, Nuriye; Sahin, Ozlem; Karakurt, Serdar; Yilmaz, MustafaThe metal complexes of Zn(II), Ni(II), Cu(II) and Pb(II) with asymmetrical Schiff bases were synthesized. The asymmetrical Schiff base was obtained through the condensation of 1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine, 2-hydroxy-1-napthaldehyde and biphenyl-4-carbaldehyde. The new Schiff base ligands (L-1' and L-2') and their metal complexes were characterized by TG/DTG, FT-IR, H-1-NMR, UV-Vis, ESR, powder XRD, elemental analysis, magnetic moment and fluorescence studies. The powder XRD studies indicate that Co(II) and Cu(II) complexes are amorphous, while Ni(II) and Zn(II) complexes are crystalline. The anticarcinogenic effects of L-1' and L-2' were also investigated against colon (SW-620) and cervical cancer (HeLa) cell lines and compound L-2' was found to possess the highest anticarcinogenic potential, with 16.7 mu M and 27.5 mu M of IC50 values for HeLa and SW620 cells, respectively.Öğe The Use of Voltammetry for Sorption Studies of Pb2+ from Aqueous Media using Schiff Base Immobilized Biologic Polymer Material(Springer International Publishing Ag, 2013) Kucukkolbasi, Semahat; Erdogan, Zehra Ozden; Kocak, Nuriye; Sahin, Mustafa; Gubbuk, Ilkay HilalAdsorption by low-cost adsorbents and biosorbents is recognized as an effective and economic method for low-concentration heavy metal. The purpose of this study was to investigate the possibility of the utilization of N,N'-bis(2,5-dihydroxybenzylidene)-1, 4-diaminobenzene (DHDB)-immobilized sporopollenin (Schiff base-immobilized sporopollenin, Sp-DHDB) as a sorbent for removal of lead (II) ion from aqueous solution. The effects of different parameters (such as sorbate concentration, sorbent dosage, and pH of the medium) were investigated by differential pulse anodic stripping voltammetry (DPASV) technique. The experimental data were analyzed by the Freundlich, Langmuir, and Dubinin-Radushkevich (D-R) isotherms. Equilibrium data fitted well with the Freundlich model and the procedure developed was successfully applied for the removal of lead ions in aqueous solutions. This investigation reveals a new, simple, environmentally friendly, and cost-effective method for the removal of lead ions from aqueous solutions by a new Sp-DHDB material.Öğe Zn(II), Ni(II), Cu(II) and Pb(II) complexes of tridentate asymmetrical Schiff base ligands: Synthesis, characterization, properties and biological activity(Pergamon-Elsevier Science Ltd, 2013) Sahin, Mustafa; Kocak, Nuriye; Erdenay, Damla; Arslan, UgurNew asymmetrical tridentate Schiff base ligands were synthesized using 1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine, 2-hydroxy-1-napthaldehyde, 9-anthracenecarboxaldehyde. Schiff base ligands and their metal complexes were synthesised and characterized by using FT-IR, H-1 NMR, C-13 NMR, UV-Vis, XRD, ESR, elemental analysis and fluorescence studies. The antimicrobial activity of the ligands and their metal complexes were studied against Staphylococcus aureus ATCC 29213, S. aureus ATCC 25923, Streptococcus mutans RSHM 676, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853. The determination of the antibacterial activity was done using the broth microdilution methods. In general, it has been determined that the studied compounds have MIC values similar to Gram-positive and Gram-negative bacteria. It has been found that Ni, Pb, Zn derivatives of HL1A and ZnL(2)A has lower MIC values than ampicillin for P. aeruginosa ATCC 27853 strain. (c) 2012 Elsevier B.V. All rights reserved.
