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Prolongation of repolarization dispersion (QT interval dispersion) measured from the 12-lead surface ECG has been associated with sudden cardiac death and ventricular tachyarrhythmias in a variety of cardiac disorders. The aim of our study was to assess the effects of hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) on QT dispersion in end-stage renal disease patients. 20 chronic HD patients (mean age 57.75 ± 13.79 years) and 20 CAPD patients (mean age 50.79 ± 14.94 years) who had no complaints and symptoms of cardiac arrhythmias as well as 20 healthy volunteers (mean age 48.74 ± 10.88 years) underwent ECG testing. All HD patients were on bicarbonate three times weekly with cuprophane capillaries. 12-lead ECGs were recorded on the day after HD. The CAPD patients were on a standard CAPD program (four times daily with 2,000 cm3 peritoneal fluid). ECGs were recorded when the patients were receiving their regular standard CAPD program. All ECGs were analyzed manually by one observer. There were no statistically significant differences in dialysis duration, blood urea nitrogen, creatinine, sodium, calcium, and parathormone values between the HD and CAPD patients. The serum potassium values were significantly higher in HD patients when compared to CAPD patients. There was no difference in the mean of maximal QT among all three groups. The rate of QT interval dispersions was significantly higher in HD and CAPD patients as compared with healthy controls (p < 0.05). There was no statistically significant difference in the QT dispersion rates between HD and CAPD patients. In conclusion, there is a tendency to cardiac arrhythmias in HD patients during the postdialysis period. Although CAPD patients are receiving dialysis daily, they also have higher rates of QT dispersions and accordingly a tendency to arrhythmias.

International Conference on Superlattices, Nano-Structures and Nano-Devices -- JUL 30-AUG 04, 2006 -- Istanbul, TURKEY Finstad, Terje/0000-0003-1293-3126 WOS: 000245877200016 Alternating germanosilicate-siliconoxide layers of 10-30 nm thickness were grown on Si substrates by plasma enhanced chemically vapor deposition (PECVD). The compositions of the grown films were determined by X-ray photoelectron spectroscopy measurements. The films were annealed at temperatures varying from 670 to 1000 degrees C for 5 to 45 minutes under nitrogen atmosphere. High resolution cross section TEM images, electron diffraction and electron energy-loss spectroscopy as well as energy-dispersive X-ray analysis (EDAX) data confirm presence of Ge nanocrystals in each layer. The effect of annealing on the Ge nanocrystal formation in multilayers was investigated by Raman spectroscopy and Transmission Electron Microscopy (TEM). As the annealing temperature is raised to 850 degrees C, single layer of Ge nanocrystals observed at lower annealing temperatures is transformed into a double layer with the smaller sized nanocrystals closer to the substrate SiO2 interface. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. European FP6European Union (EU) [505285]; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG-U/85(103T115)] This work is a supported by European FP6 project SEMINANO with the contract number 505285 and by TUBITAK under contract TBAG-U/85(103T115). We gratefully acknowledge Prof. S. Suzer of Bilkent University, Chemistry Department for the XPS measurements

Yerci, Selcuk/0000-0003-0599-588X; Serincan, Ugur/0000-0002-6305-4343; Serincan, Ugur/0000-0002-6305-4343; Dogan, Ilker/0000-0003-4245-787X WOS: 000241248000070 Silicon nanocrystals, average sizes ranging between 3 and 7 nm, were formed in sapphire matrix by ion implantation and subsequent annealing. Evolution of the nanocrystals was detected by Raman spectroscopy and x-ray diffraction (XRD). Raman spectra display that clusters in the matrix start to form nanocrystalline structures at annealing temperatures as low as 800 degrees C in samples with high dose Si implantation. The onset temperature of crystallization increases with decreasing dose. Raman spectroscopy and XRD reveal gradual transformation of Si clusters into crystalline form. Visible photoluminescence band appears following implantation and its intensity increases with subsequent annealing process. While the center of the peak does not shift, the intensity of the peak decreases with increasing dose. The origin of the observed photoluminescence is discussed in terms of radiation induced defects in the sapphire matrix. (c) 2006 American Institute of Physics.

Objective. To assess the frequency and clinical relevance of anticardiolipin antibodies (aCL) in Behcet's disease (BD). Methods. IgG, IgM and IgA aCL isotypes were investigated by ELISA in 128 patients with BD, 143 healthy controls and 20 systemic lupus erythematosus (SLE) patients. Results. The IgA binding index (BI) was slightly elevated in BD compared with healthy controls (120 ± 53 vs 107 ± 46, P = 0.02), whereas IgG and IgM aCL levels were not significantly different (IgG. BD 2.5 ± 2.4 G phospholipid (GPL), healthy controls 2.8 ± 3.6 GPL, P = 0.6; IgM. BD 0.7 ± 0.9 M phospholipid (MPL), healthy controls 0.9 ± 1.3 MPL, P = 0.6). The frequency of aCL positivity was 7% in BD (IgG 0.8%, IgM 1.6%, IgA 4.6%), 50% in SLE and 5.6% in healthy controls. IgA BI was elevated in the HLA-B5-negative group compared with HLA-B5-positive patients (P < 0.005). In a literature review, the frequency of aCL was found to be 9.5% in studies from Turkey compared with 25.5% in other series (P < 0.0001). Conclusion. These results do not suggest a primary role for aCL in BD. A significantly lower frequency of aCL in Turkish BD patients than in other series indicate that regional determinants, whether environmental or genetic, might also play a role in controlling aCL production in BD.

The purpose of this study was to compare the measurements of fractional flow reserve of the myocardium (FFRmyo) with results of quantitative coronary angiography (QCA) and stress single-photon emission computed tomography thallium-201 (SPECT 201Tl) imaging in patients with intermediate-severity coronary artery disease (ISCAD).We prospectively evaluated 40 lesions of QCA-determined ISCAD in 30 patients (age, 53.3 +/- 10.2 years; 67% male) using a 0. 014 inch pressure wire during elective coronary angiography and compared the results with those of SPECT 201Tl performed within a week of angiography.There was a moderate negative correlation between percent diameter stenosis (%DS) and FFRmyo (53.1 +/- 13.4% and 0.75 +/- 0.09, respectively; r = -0.40; p = 0.01). Twenty-two out of 40 vascular territories (55%) were found to have perfusion defects (Group 1) and 18 territories (45%) were found to be normal (Group 2). While QCA-determined stenosis severity was not different between Group 1 and Group 2 (56 +/- 12% vs. 50 +/- 16%, respectively; p = 0.3), FFRmyo was found to be significantly different between the two groups (0.68 +/- 0.05 vs. 0.83 +/- 0.05, respectively; p = 0.001). When %DS and FFRmyo results were dichotomized as abnormal by 50% and0.75, respectively, and SPECT 201Tl was taken as the gold standard, sensitivity, specificity, positive predictive value and negative predictive value of %DS and FFRmyo were 0.55 vs. 0.91, 0.56 vs. 1.0, 0.60 vs. 1.0 and 0.50 vs. 0. 90, respectively.While FFRmyo seems to accurately predict the presence of ischemia on SPECT 201Tl in patients with ISCAD, QCA does not reliably assess the physiologic impact of the same lesions.

Myocardial fractional flow reserve (FFRmyo) has been demonstrated to be a useful method for determining the physiologic importance of a given coronary lesion. However, the reliability of the FFRmyo measurement is unknown in infarct-related arteries (IRA). The aim of this study was to measure and correlate the FFRmyo results of 14 consecutive patients who had recent acute myocardial infarction (AMI) (Group 1) with 14 consecutive patients who didnOt have AMI (Group 2) before and after percutaneous transluminal coronary angioplasty (PTCA). Quantitative coronary angiography (QCA) and FFRmyo measurements were determined both before and after optimal PTCA for all patients. FFRmyo was measured by use of a 0.014 inch guidewire as the ratio of the pressure distal to the target lesion to the aortic pressure taken during the maximal hyperemia induced by intracoronary adenosine. There were no differences between the two groups related to gender, target artery reference diameter, minimal luminal diameter and percent diameter stenosis of the vessel both before and after PTCA. While FFRmyo results after PTCA were not different between the groups, they were statistically different before PTCA (Group 1: 77.6+/-5.4%, Group 2: 63.3+/-8.4%; p0.001). Although QCA-determined percent diameter stenosis revealed a significant degree of stenosis (66.5+/-10.5%) for Group 1, FFRmyo values were higher than 75% (77.6+/-5.4%), indicating insignificant stenosis. Thus, it was concluded that FFRmyo measurements before PTCA were significantly different between IRA and non-IRA and that the method may not be valid for the determination of stenosis significance in IRA.

Background: Pulmonary hypertension and right heart failure are severe complications of systemic lupus erythematosus (SLE). The potential mechanisms of these complications are multifactorial and may include increased pulmonary artery stiffness (PAS). In this study, we tested the hypothesis suggesting that the PAS is increased in patients with SLE, which may determine right ventricular myocardial performance index (RV MPI) as an echocardiographic parameter summarizing right ventricular function in these patients. Methods: We studied 24 patients with SLE with no cardiac symptoms (age: 33.6±8.4 years) and 24 normal control subjects by echocardiography. RV MPI, defined as the sum of isovolumetric contraction and relaxation time divided by ejection time, was measured by using Doppler echocardiography. To estimate PAS, echocardiographic records of the pulmonary flow trace were obtained and maximal frequency shift of pulmonary flow divided by acceleration time. Correlation between RV MPI and the PAS, right ventricular ejection fraction, age, heart rate, body surface area and the duration of disease were determined by linear regression analysis. Results: Patients versus control subjects had increased PAS and RV MPI. In linear regression analysis, RV MPI was significantly correlated with PAS and the duration of disease (r=0.62, p