Yazar "Topcuoglu, N" seçeneğine göre listele

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    The effects of the Harmonic Scalpel on the vasoreactivity and endothelial integrity of the radial artery: A comparison of two different techniques
    (Mosby, Inc, 2001) Cikirikcioglu, M; Yasa, M; Kerry, Z; Posacioglu, H; Boga, M; Yagdi, T; Topcuoglu, N; Buket, S; Hamulu, A
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    Electrochemical genosensor based on colloidal gold nanoparticles for the detection of Factor V Leiden mutation using disposable pencil graphite electrodes
    (Amer Chemical Soc, 2003) Ozsoz, M; Erdem, A; Kerman, K; Ozkan, D; Tugrul, B; Topcuoglu, N; Ekren, H; Taylan, M
    Electrochemical genosensors for the detection of the Factor V Leiden mutation from polymerase chain reaction (PCR) amplicons using the oxidation signal of colloidal gold (Au) is described. A pencil graphite electrode (PGE) modified with target DNA, when hybridized with complementary probes conjugated to Au nanoparticles, responded with the appearance of a Au oxide wave at similar to+ 1.20 V. Specific probes were immobilized onto the Au nanoparticles in two different modes: (a) Inosine-substituted probes were covalendy attached from their amino groups at the 5' end using N-(3-dimethylamino)propyl)-N'-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysulfosuccinimide (NHS) as a coupling agent onto a carboxylate-terminated L-cysteine self-assembled monolayer (SAM) preformed on the Au nanoparticles, and (b) probes with a hexanethiol group at their 5' phosphate end formed a SAM on Au nanoparticles. The genosensor relies on the hybridization of the probes with their complementary targets, which are covalendy immobilized at the PGE surface. Au-tagged 23-mer capture probes were challenged with the synthetic 23-mer target, 131-base single-stranded DNA or denatured 256-base polymerase chain reaction (PCR) amplicon. The appearance of the Au oxidation signal shortened the assay time and simplified the detection of the Factor V Leiden mutation from PCR amplified real samples. The discrimination between the homozygous and heterozygous mutations was also established by comparing the peak currents of the Au signals. Numerous factors affecting the hybridization and nonspecific binding events were optimized. The detection limit for the PCR amplicons was found to be as low as 0.78 fmol; thus, it is suitable for point-of-care applications.
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    Electrochemical genosensor based on colloidal gold nanoparticles for the detection of Factor V Leiden mutation using disposable pencil graphite electrodes
    (Amer Chemical Soc, 2003) Ozsoz, M; Erdem, A; Kerman, K; Ozkan, D; Tugrul, B; Topcuoglu, N; Ekren, H; Taylan, M
    Electrochemical genosensors for the detection of the Factor V Leiden mutation from polymerase chain reaction (PCR) amplicons using the oxidation signal of colloidal gold (Au) is described. A pencil graphite electrode (PGE) modified with target DNA, when hybridized with complementary probes conjugated to Au nanoparticles, responded with the appearance of a Au oxide wave at similar to+ 1.20 V. Specific probes were immobilized onto the Au nanoparticles in two different modes: (a) Inosine-substituted probes were covalendy attached from their amino groups at the 5' end using N-(3-dimethylamino)propyl)-N'-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysulfosuccinimide (NHS) as a coupling agent onto a carboxylate-terminated L-cysteine self-assembled monolayer (SAM) preformed on the Au nanoparticles, and (b) probes with a hexanethiol group at their 5' phosphate end formed a SAM on Au nanoparticles. The genosensor relies on the hybridization of the probes with their complementary targets, which are covalendy immobilized at the PGE surface. Au-tagged 23-mer capture probes were challenged with the synthetic 23-mer target, 131-base single-stranded DNA or denatured 256-base polymerase chain reaction (PCR) amplicon. The appearance of the Au oxidation signal shortened the assay time and simplified the detection of the Factor V Leiden mutation from PCR amplified real samples. The discrimination between the homozygous and heterozygous mutations was also established by comparing the peak currents of the Au signals. Numerous factors affecting the hybridization and nonspecific binding events were optimized. The detection limit for the PCR amplicons was found to be as low as 0.78 fmol; thus, it is suitable for point-of-care applications.
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    The nature and origin of intraocular metallic foreign bodies appearing after phacoemulsification
    (Karger, 2003) Kose, S; Mentes, J; Uretmen, O; Topcuoglu, N; Kokturk, U; Yilmaz, H
    In order to evaluate the nature and origin of metallic foreign bodies embedded in the iris after uneventful phacoemulsification, we aimed to produce metallic fragments by applying ultrasound power with the same phaco machine and handpiece in an experimental model in vitro. In a glass bottle, we used linear phaco power of 100% continuously for 5 min first with a new phaco tip and then with a used tip. Afterwards, the fluid in the bottle was filtered through a Millipore filter. The remains on the filter were studied by scanning electron microscopy (SEM) and microprobe. Small particles remained on the filter which was used for the new tip. Microprobe micro-analysis showed that these particles were mainly titanium, the same as the phaco tip. SEM of both the new and the used tips showed small fragments on the exterior surface and lumen. Intraocular metallic foreign bodies after phacoemulsification are likely to be shaken loose from the phaco tip. Although it is mostly agreed that these fragments are well tolerated, their overall effect remains to be evaluated in the long term. Copyright (C) 2003 S. Karger AG, Basel.
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    The nature and origin of intraocular metallic foreign bodies appearing after phacoemulsification
    (Karger, 2003) Kose, S; Mentes, J; Uretmen, O; Topcuoglu, N; Kokturk, U; Yilmaz, H
    In order to evaluate the nature and origin of metallic foreign bodies embedded in the iris after uneventful phacoemulsification, we aimed to produce metallic fragments by applying ultrasound power with the same phaco machine and handpiece in an experimental model in vitro. In a glass bottle, we used linear phaco power of 100% continuously for 5 min first with a new phaco tip and then with a used tip. Afterwards, the fluid in the bottle was filtered through a Millipore filter. The remains on the filter were studied by scanning electron microscopy (SEM) and microprobe. Small particles remained on the filter which was used for the new tip. Microprobe micro-analysis showed that these particles were mainly titanium, the same as the phaco tip. SEM of both the new and the used tips showed small fragments on the exterior surface and lumen. Intraocular metallic foreign bodies after phacoemulsification are likely to be shaken loose from the phaco tip. Although it is mostly agreed that these fragments are well tolerated, their overall effect remains to be evaluated in the long term. Copyright (C) 2003 S. Karger AG, Basel.