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Öğe Assessment of left atrial dysfunction in obstructive sleep apnea patients with the two dimensional speckle-tracking echocardiography(2012) Altekin R.E.; Yanikoglu A.; Karakas M.S.; Ozel D.; Kucuk M.; Yilmaz H.; Demir I.Background The aim of this study was to compare left atrial (LA) longutidinal myocardial function in obstructive sleep apnea (OSA) patients with healthy individuals using two-dimensional speckle-tracking echocardiography method (2D-STE). Method Twenty one healthy individuals and 58 OSA patients were included. According to the AHI (apnea hypopnea index) patients were examined in mild, moderate and severe OSA groups. Images of the LA were acquired from the apical two- and four-chamber views. LA strain (LAS) and strain rate(LASR) parameters [systolic (S), early diastolic (E), late diastolic (A) during atrial contraction] were assessed. Results LA S-S, LASR-S, LAS-E and LASR-E values decreased with severity of OSA. Severe OSA patients have lower LAS-S and LASR-S values (p < 0.03).While a difference in the LA SR-E value between groups was significant beginning with the moderate OSA group (p < 0.03), no LAS-E value differences were observed between moderate and mild OSA groups (p > 0.03). LAS-A and LA SR-A values were increasing with the disease severity up to moderate OSA. LAS-A and LASR-A values of moderate OSA were greater than the mild OSA patients and healthy individuals (p < 0.03). Thesewere lower in severe OSA than the moderate OSA (p < 0.03), however, theywere greater than the healthy individuals (p < 0.03). The AHI was found to be negatively correlated with the LAS-S, LASR-S LA S-E, LASR-E, whereas AHI was not correlated with the LAS-A, LASR-A values. Conclusion LA remodeling and dysfunction that accompany OSA can be detected in the subclinical stage with a detailed evaluation of active and passive functions of the LA using the 2D-STE method. © Springer-Verlag 2012.Öğe Determination of subclinical atherosclerosis in plaque type psoriasis patients without traditional risk factors for atherosclerosis(Turkish Anaesthesiology and Intensive Care Society, 2012) Altekin E.R.; Koç S.; Karakaş M.S.; Yanikoglu A.; Başarici I.; Demir I.; Alpsoy E.Objectives: Systemic inflammation plays an important role in the pathogenesis of atherosclerosis in psoriasis patients. Therefore, persistent skin inflammation in psoriasis patients may contribute to the development of premature atherosclerosis, as it occurs in rheumatoid arthritis and systemic lupus erythematosus. We aimed to evaluate the relationship between subclinical atherosclerosis and psoriasis by using pulse wave velocity (PWV) and the measurement of carotid intima media thickness (CIMT) in psoriatic patients. Study design: Fifty-seven plaque-type psoriasis patients (31 males, 26 females; mean age 41±10.8 years) and 60 healthy individuals (32 males, 28 females; mean age 40±9.4 years) were included. Atherosclerotic risk factors were excluded in both of the groups. Demographic, bio-chemical data, psoriasis area and severity index (PASI) score of the psoriasis group, and disease duration were recorded. Carotid-femoral artery PWV and CIMT values were compared. Results: PWV, and the maximum and average CIMT values of psoriasis patients were higher than those of the healthy group (PWV: 7.04±1.1 m/sn vs. 6.03±0.61 m/sn, p<0.001; maximum CIMT: 0.86±0.09 mm vs. 0.77±0.06 mm, p<0.001; mean CIMT: 0.73±0.09 mm vs. 0.66±0.06 mm p<0.001, respectively). Although there was no difference in the lipid levels of the groups, total/HDL cholesterol (4.40±1.26 vs. 3.88±1.18, p=0.02, respectively), and LDL/HDL cholesterol ratios (2.78±0.98 vs. 2.32±0.92, p=0.01, respectively) of the psoriasis group were higher than those of the healthy group. A positive correlation was observed between PASI and the PWV (r=0.417, p=0.001). Conclusion: Despite the nonexistence of atherosclerotic risk factors, the risk of development of atherosclerosis is higher in psoriasis patients compared to healthy individuals. In addition to damage of the artery wall caused by systemic inflammation, lipid metabolism disorders may contribute to the development of atherosclerosis in these patients. © 2012 Turkish Society of Cardiology.Öğe Effect of grinding time of synthesized gadolinium doped ceria (GDC10) powders on the performance of solid oxide fuel cell(Elsevier B.V., 2014) Aydin F.; Demir I.; Mat M.D.Ceria-based materials are prospective electrolytes for low and intermediate temperature solid oxide fuel cells. In the present work, fully dense CeO2 ceramics doped with 10 mol% gadolinium (Gd0.1Ce0.9O1.95) were prepared with a sol–gel method and commercially purchased GDC10 electrolyte powders were processed. Particle sizes of synthesized electrolyte powders were minimized by ball-milling method. Grinding of the samples were performed in different times intervals (12 h, 15 h, 18 h, 20 h, 25 h, 30 h, 35 h, 40 h and 45 h). Then, these powders were prepared to obtain of solid oxide fuel cells (SOFCs). Performances of these cells having an active area of 1 cm2 were tested using a fuel cell test station that measured in different temperatures (650 and 700 °C). In the present study, gadolinium doped ceria (GDC10) synthesiszed powders were investigated by using XRD and SEM images. Performance values of synthesized GDC10's in different temperature were compared to by commercial GDC10. Commercial GDC10's performance at 650 °C were tested, and maximum current density of 0.413 W/cm2 and maximum current density of 0.949 A/cm2 were obtained. Commercial GDC10 at 650 °C has better result. However, synthesized GDC10's performance at 700 °C demonstrated better results than commercial GDC10's. The performance tests of samples which are 20 h mill showed that they have the maximum power density of was obtained as 0.480 W/cm2 and maximum current density of as 1.231 A/cm2. © 2014 Karabuk UniversityÖğe Evaluation of left atrial function using two-dimensional speckle tracking echocardiography in end-stage renal disease patients with preserved left ventricular ejection fraction(Via Medica, 2013) Altekin R.E.; Yanikoglu A.; Karakas M.S.; Ozel D.; Yilmaz H.; Demir I.Background: Left atrial (LA) deformation analysis by two-dimensional speckle tracking echocardiography (2D-STE) has recently been proposed as an alternative approach for estimating left ventricular (LV) filling pressure and dysfunction. Aim: To assess the LA myocardial function using 2D-STE in end-stage renal disease (ESRD) patients with preserved LV ejection fraction (PLVEF) and to evaluate the relationship of the obtained results with echocardiographically estimated pulmonary capillary wedge pressure (ePCWP). Methods: Eighty-five ESRD patients and 60 healthy individuals were enrolled in the study. Images of the LA were acquired from apical two- and four-chamber views. The LA volumes (LAV) were calculated using the biplane area-length method. The LA volume indices (LAVI) were calculated by dividing the LA volumes by the body surface area. The LA strain (%) (LAS) parameters (systolic [LAS-S], early diastolic [LAS-E], late diastolic [LAS-A] during atrial contraction) were assessed, and the ePCWP was calculated according to the following formula: ePCWP = 1.25(E/E') + 1.9. LA stiffness was calculated non-invasively and based on the ratio of E/E' to LAS-S. Results: In patients with ESRD, the LAS-S (32.22 ± 7.64% vs. 57.93 ± 8.71%; p < 0.001), LAS-E (-15.86 ± 5.7% vs. -33.37 ± 7.71%; p < 0.001), and the LAS-A (-15.41 ± 4.16% vs. -24.57 ± 4.68%; p < 0.001) values were observed to be lower than the healthy group; while the LA stiffness (0.4 ± 0.19 vs. 0.17 ± 0.05; p < 0.001) value was higher. When the patients with ESRD were divided into two groups as those with a maximum LAVI value over 31.34 mL/m2 and those with a maximum LAVI below this value, the LAS-S (30.36 ± 8.32% vs. 34.11 ± 6.43%; p = 0.023) and the LAS-E (-14.97 ± 5.88% vs. -16.76 ± 5.42%; p = 0.039) values were lower in the group with a LAVI value over 31.34 mL/m2; while the LA S-A (-16.06 ± 4.44% vs. -14.75 ± 3.8%; p < 0.001) and LA stiffness (0.4 ± 0.19 vs. 0.17 ± 0.05; p < 0.001) values were higher. An association was observed between the ePCWP and LAS-S (p < 0.001), LAS-E (p = 0.01), LAS-A (p < 0.001), and LA stiffness (p < 0.001) values. Conclusions: The results of our study have demonstrated that LA myocardial function assessed using the 2D-STE method is associated with the ePCWP, which is an echocardiographically calculated marker of LV dysfunction. The LA deformation parameters may be used as echocardiographic findings to predict the LV dysfunction in ESRD patients with PLVEF. Further studies are needed to determine the independent prognostic power of the atrial strain measurement as a predictor of future cardiovascular events in ESRD patients. Copyright © Polskie Towarzystwo Kardiologiczne.Öğe Evaluation of subclinical left ventricular systolic dysfunction using two-dimensional speckle- tracking echocardiography in patients with non- alcoholic cirrhosis(Hellenic Cardiological Society, 2014) Altekin R.E.; Caglar B.; Karakas M.S.; Ozel D.; Deger N.; Demir I.Introduction: Cirrhosis is associated with certain abnormalities in left ventricular (LV) structure and function. Two-dimensional speckle-tracking echocardiography (2D-STE) enables a rapid and accurate analysis of regional LV systolic mechanics in the longitudinal, radial and circumferential directions. The aim of this study was to precisely assess the differences among the 3 directions in the early impairment of LV myocardial contraction in non-alcoholic cirrhotic patients with preserved LV pump function.Method: A total of 75 subjects, including 38 cirrhotic patients and 37 healthy individuals, were enrolled. Using 2D-STE, the strain (S) and systolic strain rate (SRS) values belonging to the radial (R), circumferential (C), and longitudinal (L) functions of the LV were measured.Results: In the cirrhotic group, the LS(20.57 ± 2.1 vs. 28.7 ± 43.1, p<0.001) and LSR-S(1.1 ± 0.24 vs. 1.6 ± 0.3) values were found to be lower, whereas the CS(24.82 ± 2.57 vs. 19.16 ± 4.58, p<0.001) and C SRS(1.41 ± 0.3 vs. 1.2 ± 0.4, p±0.004) values were found to be higher than in the healthy control group. The RSand RSR-Svalues did not differ among the groups. A relationship was observed between the MELD score, which shows the severity of the disease, and the CS value (â: 0.211, p<0.01, 95%CI: 0.086-0.503).Conclusion: LV myocardial contraction was impaired in the longitudinal direction. However, LV pump function was augmented by the circumferential shortening during the ventricular systole. Using the 2D-STE method for the regional evaluation of the LV, the LV damage can be detected in the subclinical phase in cirrhotic patients. © 2014, Hellenic Cardiological Society. All rights reserved.Öğe Relation of neutrophil-to-lymphocyte ratio with GRACE risk score to in-hospital cardiac events in patients with ST-segment elevated myocardial infarction(SAGE Publications Inc., 2015) Oncel R.C.; Ucar M.; Karakas M.S.; Akdemir B.; Yanikoglu A.; Gulcan A.R.; Demir I.In this study, we aimed to investigate the association of the neutrophil-to-lymphocyte ratio (NLR) with Global Registry of Acute Coronary Events (GRACE) risk score in patients with ST-segment elevated myocardial infarction (STEMI). We analyzed 101 consecutive patients with STEMI. Patients were divided into 3 groups by use of GRACE risk score. The association between NLR and GRACE risk score was assessed. The NLR showed a proportional increase correlated with GRACE risk score (P <.001). The occurrence of in-hospital cardiac death, reinfarction, or new-onset heart failure was significantly related to NLR at admission (P <.001). Likewise, NLR and GRACE risk score showed a significant positive correlation (r =.803, P <.001). In multivariate analysis, NLR resulted as a predictor of worse in-hospital outcomes independent of GRACE risk score. Our study suggests that the NLR is significantly associated with adverse in-hospital outcomes, independent of GRACE risk score in patients with STEMI. © 2014 The Author(s).Öğe Synthesis and properties of N'-hydroxy-2-(hydroxyimino)-N-(4-{[(2- hydroxyphenyl)methylene]amino}-1-naphthyl)-ethanimidamide and its metal complexes(2008) Kaya M.; Yenikaya C.; Demir I.; Kalfa O.M.A new vicinal dioxime, N'-hydroxy-2-(hydroxyimino)-N-(4-{[(2-hydroxy- phenyl)methylene]amino}-1-naphthyl)ethanimidamide was synthesized. The initial compound for the synthesis of this dioxime was naphthalene. Complexes of this ligand were obtained with nickel, copper, and cobalt. The dioxime and its complexes were characterized by Fourier IR, UV, 1H NMR spectroscopy, mass spectrometry, elemental analysis, differential thermal analysis, and conductometric measurements. © 2008 MAIK Nauka.Öğe Synthesis of a imine vic-dioxime ligand and its Ni(II), Co(II), Cu(II) complexes(2008) Yenikaya C.; Kaya M.; Demir I.A novel imine vic-dioxime compound and its transition metal complexes were synthesized. The compound, N'-hydroxy-2-(hydroxyimino)-N-(4-(2,4,6- trihydro-xybenzylideneamino)-naphthalen-1-yl)acetimidamide (H2L), has been derived from naphthalene as an imine oxime ligand. The ligand and their complexes were characterized FT-IR, UV, 1H NMR, 13C NMR, MS, elemental analysis and conductometric measurements.
