Browsing by Publisher "SpringerOpen"
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Item Polymer Film Supported Bimetallic Au–Ag Catalysts for Electrocatalytic Oxidation of Ammonia Borane in Alkaline Media(SpringerOpen, 2016) Karabiberoğlu Ş.U.; Koçak Ç.C.; Koçak S.; Dursun Z.Abstract: Ammonia borane is widely used in most areas including fuel cell applications. The present paper describes electrochemical behavior of ammonia borane in alkaline media on the poly(p-aminophenol) film modified with Au and Ag bimetallic nanoparticles. The glassy carbon electrode was firstly covered with polymeric film electrochemically and then, Au, Ag, and Au–Ag nanoparticles were deposited on the polymeric film, respectively. The surface morphology and chemical composition of these electrodes were examined by scanning electron microscopy, transmission electron microscopy, electrochemical impedance spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. It was found that alloyed Au–Ag bimetallic nanoparticles are formed. Electrochemical measurements indicate that the developed electrode modified by Au–Ag bimetallic nanoparticles exhibit the highest electrocatalytic activity for ammonia borane oxidation in alkaline media. The rotating disk electrode voltammetry demonstrates that the developed electrode can catalyze almost six-electron oxidation pathway of ammonia borane. Our results may be attractive for anode materials of ammonia borane fuel cells under alkaline conditions. Graphical Abstract: [Figure not available: see fulltext.] © 2016, The Author(s).Item Comparison of generic and lung cancer-specific quality of life instruments for predictive ability of survival in patients with advanced lung cancer(SpringerOpen, 2016) Eser S.; Göksel T.; Erbaycu A.E.; Baydur H.; Başarık B.; Yanık A.Ö.; Gürsul K.K.; Çelik P.; Ediz E.Ç.; Hatipoğlu O.; Yayla B.A.; Başer S.; Eser E.Background: Our purpose is to examine the relationship of Health related quality of life measured by EORTC QLQc30, QLQ-LC13; FACT-L, LCSS, Eq5D) with survival in advanced lung cancer patients. A total of 299 Lung Cancer (LC) patients were, included in this national multicenter Project entitled of “the LC Quality of Life Project (AKAYAK). Baseline scores were analyzed by using Cox’s proportional hazard regression to identify factors that influenced survival. Univariate and multivariate models were run for each of the scales included in the study. Results: Mean and median survival were 12.5 and 8.0 months respectively. Clinical stage (as TNM), comorbidity; symptom scales of fatigue, insomnia, appetit loss and constipation were associated with survival after adjustment for age and sex. Global, physical and role functioning scales of QLQc30; physical and functional scales of LCS and TOI of the FACT-L was also associated with survival. Mobility and Usual activities dimensions of the Eq5D; Physical functioning and the constipation symptom scale of the QLQ-c30; and LCS and TOI scores of the FACT-L remained statistically significant after adjustment. LC13 and LCSS scales were not predictors of survival. Conclusions: HRQOL serves as an additional predictive factor for survival that supplements traditional clinical factors. Besides the strong predictive ability of ECOG on survival, FACT-L and the Eq5D are the most promising HRQOL instruments for this purpose. © 2016, The Author(s).Item Numerical solutions and error estimations for the space fractional diffusion equation with variable coefficients via Fibonacci collocation method(SpringerOpen, 2016) Bahşı A.K.; Yalçınbaş S.In this study, the Fibonacci collocation method based on the Fibonacci polynomials are presented to solve for the fractional diffusion equations with variable coefficients. The fractional derivatives are described in the Caputo sense. This method is derived by expanding the approximate solution with Fibonacci polynomials. Using this method of the fractional derivative this equation can be reduced to a set of linear algebraic equations. Also, an error estimation algorithm which is based on the residual functions is presented for this method. The approximate solutions are improved by using this error estimation algorithm. If the exact solution of the problem is not known, the absolute error function of the problems can be approximately computed by using the Fibonacci polynomial solution. By using this error estimation function, we can find improved solutions which are more efficient than direct numerical solutions. Numerical examples, figures, tables are comparisons have been presented to show efficiency and usable of proposed method. © 2016, The Author(s).Item Application of the perturbation iteration method to boundary layer type problems(SpringerOpen, 2016) Pakdemirli M.The recently developed perturbation iteration method is applied to boundary layer type singular problems for the first time. As a preliminary work on the topic, the simplest algorithm of PIA(1,1) is employed in the calculations. Linear and nonlinear problems are solved to outline the basic ideas of the new solution technique. The inner and outer solutions are determined with the iteration algorithm and matched to construct a composite expansion valid within all parts of the domain. The solutions are contrasted with the available exact or numerical solutions. It is shown that the perturbation–iteration algorithm can be effectively used for solving boundary layer type problems. © 2016, Pakdemirli.Item Biocompatibility of vertically aligned multi-walled carbon nanotube scaffolds for human breast cancer cell line MDA-MB-231(SpringerOpen, 2017) Akinoglu E.M.; Ozbilgin K.; Sonmez P.K.; Ozkut M.M.; Giersig M.; Inan S.; Gumustepe E.; Kurtman C.The aim of the current study was to determine whether the MWCNT-based scaffold has a suitable structure for cell growth and provides a biocompatible environment for human MDA-MB-231 cell lines. MWCNT-based nanostructured scaffolds were produced by plasma-enhanced chemical vapor deposition (PECVD) technique. MDA-MB-231 cells were seeded on MWCNTs-textured silicon scaffolds and on pristine silicon surfaces. After 1 week of culturing, the scaffolds were prepared for SEM analysis and immunocytochemical staining was performed for the two groups (MWCNT scaffold and pristine silicon surface), using MMP-2, MMP-9, PI3K, AKT and NF-κB primary antibodies. SEM analyses showed that the MDA-MB-231 cells better adhered to the MWCNT-based nanostructured scaffold than the pristine silicon surface. Immunohistochemical activity of the MDA-MB-231 cells on both materials has similar staining with anti-AKT MMP-2, MMP-9 and NF-κB primary antibodies. Therefore, the results of the present study suggest that the MWCNT-based scaffolds enhanced cell adhesion to the scaffold and exhibited more biomimetic properties and physiological adaptation with the potential to be used for in vitro metastasis studies of BrCa cell lines. © 2017, The Author(s).