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41.
Random copolymers of 3-methyl thienylmethacrylate and methyl methacrylate were synthesized via free radical polymerization. Electro-copolymerizations of random copolymers with thiophene and/or pyrrole were carried out in acetonitrile-tetrabutylammonium tetrafluoroborate (TBAFB), water-p-toluene sulfonic acid (PTSA) solvent-electrolyte couples. Oxidative polymerization of thiophene functionalized random copolymer was also achieved by constant current electrolysis and chemical polymerization. The characterizations were done by conductivity measurements, cyclic voltammetry (CV), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermal gravimetry analysis (TGA), scanning electron microscopy (SEM). 相似文献
42.
Abdu Y. Bunch Xueqin Wang Umit S. Ozkan 《Journal of molecular catalysis. A, Chemical》2007,270(1-2):264-272
Effect of H2S on the catalytic performance of the reduced and sulfided Ni–Mo/Al2O3 catalysts in hydrodeoxygenation of benzofuran is studied. The steady-state reaction experiments showed a decrease in activity for both reduced and sulfided catalysts when H2S was introduced into the feed. The reaction conversion of benzofuran over the reduced catalyst still remained superior to that of the sulfided catalyst in the presence of H2S, however, at high reaction temperatures, the product distribution over the pre-reduced catalyst is similar to the sulfided catalyst. The studies with temperature-programmed desorption (TPD), temperature-programmed reaction (TPRxn) and X-ray photoelectron spectroscopy (XPS) techniques showed a partial sulfidation of the reduced catalysts when exposed to H2S under reaction conditions, however, the catalyst does not go through a complete conversion to a molybdenum sulfide phase. Instead oxygen–sulfur exchange on the surface leaves behind oxisulfide species, with catalytic activity closely resembling that of the reduced catalysts. The effect of H2S on the reaction performance is mainly coming from the competitive adsorption between H2S and benzofuran and the formation of SH groups with decomposition of H2S at high temperatures. 相似文献
43.
S. Zh. Ozkan I. S. Eremeev G. P. Karpacheva T. N. Prudskova E. V. Veselova G. N. Bondarenko G. A. Shandryuk 《Polymer Science Series B》2013,55(3-4):107-115
Polymers of diphenylamine-2-carboxylic acid are prepared by chemical oxidative polymerization in an aqueous solution of ammonium hydroxide. In accordance with the IR data, during the polymerization of diphenylamine-2-carboxylic acid in a solution of ammonium hydroxide, polymer-chain growth occurs via C-C joining into 2 and 4 positions of phenyl rings with respect to nitrogen. The distinctive feature of the polymer is the absence of quinodiimine units in its structure, even if the oxidizer is in excess. The resulting polymers are amorphous, electroactive, and thermally stable. 相似文献
44.
45.
S. Irem Kaya Ahmet Cetinkaya Mehmet G. Caglayan Sibel A. Ozkan 《Electrophoresis》2022,43(9-10):1035-1049
Biopharmaceuticals (recombinant technology-based products, vaccines, whole blood and blood components, gene therapy, cells, tissues, etc.,) are described as biological medical products produced from various living sources such as human, microbial, animal, and so on by manufacturing, extraction, or semi-synthesis. They are complex molecules having high molecular weights. For their safety and efficacy, their structural, clinical, physicochemical, and chemical features must be carefully controlled, and they must be well characterized by analytical techniques before the approval of the final product. Capillary electrophoresis (CE) having versatile modes can provide valuable safety and efficacy information, such as amino acid sequence, size variants (low and high molecular weight variants), charged variants (acidic and basic impurities), aggregates, N-linked glycosylation, and O-linked glycosylation. There are numerous applications of CE in the literature. In this review, the most significant and recent studies on the analysis of recombinant DNA technology-based products using different CE modes in the last ten years have been overviewed. It was seen that the researches mostly focus on the analysis of mAbs and IgG. In addition, in recent years, researchers have started to prefer CE combined mass spectrometry (MS) techniques to provide a more detailed characterization for protein and peptide fragments. 相似文献
46.
Nilay Aladag Dilsat Ozkan‐Ariksoysal Duygu Gezen‐Ak Selma Yilmazer Mehmet Ozsoz 《Electroanalysis》2010,22(5):590-598
Electrochemical detection of nucleic acid base mismatches related to Apa I single nucleotide polymorphism (SNP) in the vitamin D receptor gene was performed successfully using 7‐dimethyl‐amino‐1,2‐benzophenoxazinium salt (Meldola's blue, MDB) with 10.9 pmol/100 μL of detection limit. MDB reduction signals obtained from probe, mismatch(probe‐SNP containing target) and hybrid(probe‐target) modified pencil graphite electrode(PGE) increased respectively. The sensor was able to clearly distinguish perfect match from mismatch DNA in a 30 min. detection time. Several factors affecting on the hybridization and indicator response are studied to maximize sensitivity and selectivity. The advantages of the biosensor are discussed in comparison with previous electrochemical assays for DNA hybridization. 相似文献
47.
Dilsat Ozkan‐Ariksoysal Ozlem Akgul Seyma Aydinlik Seda Nur Topkaya Nilay Aladag Mehmet Ozsoz 《Electroanalysis》2010,22(19):2225-2234
In this work, an electrochemical DNA‐based sensor was developed for the detection of the interaction between the anticonvulsant compounds 2‐phthalimido‐N‐substituted phenylethanesulfonamides (PMPES‐derivatives) and 24‐mer short DNA sequences by using differential pulse voltammetry (DPV) based on both compound and guanine oxidation signals at the renewable carbon graphite electrode (CGE) surface. The influence of compounds on DNA showed differences depending on the nature and position of the substituent on the N‐phenyl ring. Compounds bearing 3‐methoxy, 4‐chloro and 2,6‐dimethyl substituents bind to single stranded probe DNA more strongly than the other derivatives of PMPES. Thus, these compounds were evaluated for use as an electrochemical hybridization label (indicator). 相似文献
48.
Applications of fractional complex transform and $\left( \frac{G^{\prime }}{G}\right) $-expansion method for time-fractional differential equations 下载免费PDF全文
Ahmet Bekir Ozkan Guner Omer Unsal Mohammad Mirzazadeh 《Journal of Applied Analysis & Computation》2016,6(1):131-144
In this paper, the fractional complex transform and the $\left( \frac{G^{\prime }}{G}\right) $-expansion method are employed to solve the time-fractional modfied Korteweg-de Vries equation (fmKdV),Sharma-Tasso-Olver, Fitzhugh-Nagumo equations, where $G$ satisfies a second order linear ordinary differential equation. Exact solutions are expressed
in terms of hyperbolic, trigonometric and rational functions. These solutions may be useful and desirable to explain some nonlinear physical phenomena in genuinely nonlinear fractional calculus. 相似文献
49.
Electrocyclizations of 1,3,5-hexatrienes containing up to four electron-donating and/or electron withdrawing substituents have been studied computationally using the hybrid density functional, B3LYP. Electron donating substituents at positions C-1 and C-5 decrease activation barriers by 0.3 to 2.3 kcal/mol. Introducing of an electron-withdrawing group, CO(2)Me, at C-4 further decreases the activation energy by 7 kcal/mol. Electron-withdrawing groups (NO(2), SO(2)Ph and C=N(+)Me(2)) at C-2 have a profound effect of 17-25 kcal/mol on the activation energy. 相似文献
50.
Erik M. Holmgreen Matthew M. Yung Umit S. Ozkan 《Journal of molecular catalysis. A, Chemical》2007,270(1-2):101-111
Pd-based sulfated zirconia catalysts have been prepared through a single step (one-pot) sol–gel preparation technique, in which both sulfate and Pd precursors were dissolved in an organic solution before the gelation step. Observation of the calcination procedure through TGA/DSC and mass spectrometry revealed that the addition of increasing amounts of Pd resulted in the evolution of organic precursor species at lower temperatures. In situ XRD experiments showed that tetragonal zirconia is formed at lower temperatures and larger zirconia crystallites are formed when Pd is added to the gel. Although tetragonal zirconia was the only phase observed through XRD, Raman spectra of samples calcined at 700 °C showed the presence of both the tetragonal and the monoclinic phase, indicating a surface phase transition. DRIFTS experiments showed NO species adsorbed on Pd2+ cations. Pd/SZ catalysts prepared through this single step method were active for the reduction of NO2 with CH4 under lean conditions. Calcination temperature had a significant effect on this activity, with samples calcined at 700 °C being much more active than those calcined at 600 °C, despite the observed transition to the monoclinic phase. This activity may be linked to observed changes in the surface sulfate species at higher calcination temperatures. 相似文献