Yazar "Yilmaz, Selahattin" seçeneğine göre listele

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    Aptamer-based electrochemical biosensing strategy toward human non-small cell lung cancer using polyacrylonitrile/polypyrrole nanofibers
    (Springer Heidelberg, 2020) Kivrak, Ezgi; Ince-Yardimci, Atike; Ilhan, Recep; Kirmizibayrak, Petek Ballar; Yilmaz, Selahattin; Kara, Pinar
    In the present study, a sensitive electrochemical aptamer-based biosensing strategy for human non-small cell lung cancer (NSCLC) detection was proposed using nanofiber-modified disposable pencil graphite electrodes (PGEs). the composite nanofiber was comprised of polyacrylonitrile (PAN) and polypyrrole (PPy) polymers, and fabrication of the nanofibers was accomplished using electrospinning process onto PGEs. Development of the nanofibers was confirmed using scanning electron microscopy (SEM). the high-affinity 5 '-aminohexyl-linked aptamer was immobilized onto a PAN/PPy composite nanofiber-modified sensor surface via covalent bonding strategy. After incubation with NSCLC living cells (A549 cell line) at 37.5 degrees C, the recognition between aptamer and target cells was monitored by electrochemical impedance spectroscopy (EIS). the selectivity of the aptasensor was evaluated using nonspecific human cervical cancer cells (HeLa) and a nonspecific aptamer sequence. the proposed electrochemical aptasensor showed high sensitivity toward A549 cells with a detection limit of 1.2 x 10(3)cells/mL. the results indicate that our label-free electrochemical aptasensor has great potential in the design of aptasensors for the diagnostics of other types of cancer cells with broad detection capability in clinical analysis.
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    Catalytic activity of heteropolytungstic acid encapsulated into mesoporous material structure
    (Walter De Gruyter Gmbh, 2007) Gunduz, Gonul; Dimitrova, Rayna P.; Yilmaz, Selahattin
    The paper presents a spectroscopic and catalytic study of encapsulated Keggin type heteropoly acid (12-tungstophosphoric acid, HPW) in the mesopores of MCM-41 molecular sieves. Nitrogen physisorption, FTIR, SEM, XRD and catalytic methods have been used to characterize and compare the properties of the samples. Methanol conversion, alpha-pinene isomerization and ethyl acetate oxidation have been applied as model reactions for the evaluation of acid site activity. The combined physicochemical and catalytic investigations clearly show that the introduction of 12-tungstophosphoric acid into MCM-41 causes significant changes in the properties of the sample.
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    Fe Containing ZSM-5 Zeolite as Catalyst for Wet Peroxide Oxidation of Orange II
    (Walter De Gruyter & Co, 2011) Bolova, Emre; Gunduz, Gonul; Dukkanci, Meral; Yilmaz, Selahattin; Yaman, Yadigar Ceyda
    This study presents the catalytic performances of iron containing ZSM-5 zeolites, prepared by ion exchange or hydrothermal synthesis, in catalytic Fenton-like oxidation of Orange II in aqueous solution. The catalyst, ZSM-5 zeolite with Si/Al ratio of 42 loaded with iron by ion exchange, showed the highest activity. The decolorization of 99.7 percent, degradation of 87.0 percent and COD removal of 81.2 percent were achieved over this catalyst at an initial pH of 3.5. Incorporation of iron into ZSM-5 structure increased its catalytic activity. The hydrothermally prepared FeZSM-5 catalyst was more stable against leaching at low pH value due to the iron being in the framework.
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    The use of superporous p(3-acrylamidopropyl)trimethyl ammonium chloride cryogels for removal of toxic arsenate anions
    (Academic Press Ltd- Elsevier Science Ltd, 2015) Sahiner, Nurettin; Demirci, Sahin; Sahiner, Mehtap; Yilmaz, Selahattin; Al-Lohedan, Hamad
    Poly((3-Acrylamidopropyl)trimethylammonium chloride) (p(APTMACl)) cryogels were used as a superporous polymer network for the removal of toxic arsenate anions from an aqueous medium. The fast swelling in water, in about 7 s, was shown to be very useful leading to fast arsenate adsorption by p(APTMACl) cryogels within 30 min in comparison to 12 h for bulk common p(APTMACl) hydrogels. A maximum adsorption capacity of about 120 (mg/g) arsenate was obtained for p(APTMACl) cryogels. Both the Langmuir and Freundlich adsorption isotherms were applied for adsorption of arsenate anions by p(APTMACl) cryogels, and it was observed that the adsorption of arsenate anions by p(APTMACl) cryogels are represented better via Langmuir adsorption isotherm providing the R-2 value of 0.998. Furthermore, mag-p(APTMACl) cryogels were synthesized, and shown to be very useful in the fast removal of toxic arsenate anions. The mag-p(APTMACl) cryogels including the adsorbed arsenate were removed by an externally applied magnetic field, with some reduction in the arsenate ion adsorption capacity. It was also further demonstrated that p(APTMACl) cryogels can be reused in the adsorption of arsenate 5 times from aqueous environments without significant loss of adsorption capacity, from 113.47 +/- 9 to 102.67 +/- 6 mg/g. (C) 2015 Elsevier Ltd. All rights reserved.
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    The use of superporous p(3-acrylamidopropyl)trimethyl ammonium chloride cryogels for removal of toxic arsenate anions
    (Academic Press Ltd- Elsevier Science Ltd, 2015) Sahiner, Nurettin; Demirci, Sahin; Sahiner, Mehtap; Yilmaz, Selahattin; Al-Lohedan, Hamad
    Poly((3-Acrylamidopropyl)trimethylammonium chloride) (p(APTMACl)) cryogels were used as a superporous polymer network for the removal of toxic arsenate anions from an aqueous medium. The fast swelling in water, in about 7 s, was shown to be very useful leading to fast arsenate adsorption by p(APTMACl) cryogels within 30 min in comparison to 12 h for bulk common p(APTMACl) hydrogels. A maximum adsorption capacity of about 120 (mg/g) arsenate was obtained for p(APTMACl) cryogels. Both the Langmuir and Freundlich adsorption isotherms were applied for adsorption of arsenate anions by p(APTMACl) cryogels, and it was observed that the adsorption of arsenate anions by p(APTMACl) cryogels are represented better via Langmuir adsorption isotherm providing the R-2 value of 0.998. Furthermore, mag-p(APTMACl) cryogels were synthesized, and shown to be very useful in the fast removal of toxic arsenate anions. The mag-p(APTMACl) cryogels including the adsorbed arsenate were removed by an externally applied magnetic field, with some reduction in the arsenate ion adsorption capacity. It was also further demonstrated that p(APTMACl) cryogels can be reused in the adsorption of arsenate 5 times from aqueous environments without significant loss of adsorption capacity, from 113.47 +/- 9 to 102.67 +/- 6 mg/g. (C) 2015 Elsevier Ltd. All rights reserved.
  • Küçük Resim Yok
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    The use of superporous p(3-acrylamidopropyl)trimethyl ammonium chloride cryogels for removal of toxic arsenate anions
    (Academic Press Ltd- Elsevier Science Ltd, 2015) Sahiner, Nurettin; Demirci, Sahin; Sahiner, Mehtap; Yilmaz, Selahattin; Al-Lohedan, Hamad
    Poly((3-Acrylamidopropyl)trimethylammonium chloride) (p(APTMACl)) cryogels were used as a superporous polymer network for the removal of toxic arsenate anions from an aqueous medium. The fast swelling in water, in about 7 s, was shown to be very useful leading to fast arsenate adsorption by p(APTMACl) cryogels within 30 min in comparison to 12 h for bulk common p(APTMACl) hydrogels. A maximum adsorption capacity of about 120 (mg/g) arsenate was obtained for p(APTMACl) cryogels. Both the Langmuir and Freundlich adsorption isotherms were applied for adsorption of arsenate anions by p(APTMACl) cryogels, and it was observed that the adsorption of arsenate anions by p(APTMACl) cryogels are represented better via Langmuir adsorption isotherm providing the R-2 value of 0.998. Furthermore, mag-p(APTMACl) cryogels were synthesized, and shown to be very useful in the fast removal of toxic arsenate anions. The mag-p(APTMACl) cryogels including the adsorbed arsenate were removed by an externally applied magnetic field, with some reduction in the arsenate ion adsorption capacity. It was also further demonstrated that p(APTMACl) cryogels can be reused in the adsorption of arsenate 5 times from aqueous environments without significant loss of adsorption capacity, from 113.47 +/- 9 to 102.67 +/- 6 mg/g. (C) 2015 Elsevier Ltd. All rights reserved.