Diabetic Cardiomyopathy; Summary of 41 Years

Samet Yilmaz,Ugur Canpolat,Sinan Aydogdu,Hanna Emily Abboud 대한심장학회 2015 Korean Circulation Journal Vol.45 No.4

Patients with diabetes have an increased risk for development of cardiomyopathy, even in the absence of well known risk factors like coronary artery disease and hypertension. Diabetic cardiomyopathy was first recognized approximately four decades ago. To date, several pathophysiological mechanisms thought to be responsible for this new entity have also been recognized. In the presence of hyperglycemia, non-enzymatic glycosylation of several proteins, reactive oxygen species formation, and fibrosis lead to impairment of cardiac contractile functions. Impaired calcium handling, increased fatty acid oxidation, and increased neurohormonal activation also contribute to this process. Demonstration of left ventricular hypertrophy, early diastolic and late systolic dysfunction by sensitive techniques, help us to diagnose diabetic cardiomyopathy. Traditional treatment of heart failure is beneficial in diabetic cardiomyopathy, but specific strategies for prevention or treatment of cardiac dysfunction in diabetic patients has not been clarified yet. In this review we will discuss clinical and experimental studies focused on pathophysiology of diabetic cardiomyopathy, and summarize diagnostic and therapeutic approaches developed towards this entity.

Seismic behavior of liquid storage tanks with 2D and 3D base isolation systems

Samet Kılıç,Bülent Akbaş,Jay Shen,Fabrizio Paolacci 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.5

In past major earthquakes (1994 Northridge, 1995 Kobe, Chi-Chi 1999, Kocaeli 1999), significant damages occurred in the liquid storage tanks. The basic failure patterns were observed to be the buckling of the tank wall and uplift of the anchorage system. The damages in the industrial facilities and nuclear power plants have caused the spread of toxic substances to the environment and significant fires. Seismic isolation can be used in liquid storage tanks to decouple the structure and decrease the structural demand in the superstructure in case of ground shaking. Previous studies on the use of seismic isolation systems on liquid storage tanks show that an isolation system reduces the impulsive response but might slightly increase the convective one. There is still a lack of understanding of the seismic response of seismically isolated liquid storage tanks considering the fluid-structure interaction. In this study, one broad tank, one medium tank, and one slender tank are selected and designed. Two- and three-dimensional elastomeric bearings are used as seismic isolation systems. The seismic performance of the tanks is then investigated through nonlinear dynamic time-history analyses. The effectiveness of each seismic isolation system on tanks’ performance was investigated. Isolator tension forces, modal analysis results, hydrodynamic stresses, strains, sloshing heights and base shear forces of the tanks are compared. The results show that the total base shear is lower in 3D-isolators compared to 2D-isolators. Even though the tank wall stresses, and strains are slightly higher in 3D-isolators, they are more efficient to prevent the tension problem.

Slide Session : OS-END-46 ; Endocrinology : A Rare Cause of Secondary Hypertension: An Unusual Case of Conn`s Syndrome

( Samet Sayilan ),( Yildiz Okuturlar ),( Meral Mert ),( Ozlem Soyluk ),( Serkan Enki ),( Yesim Ozden Inan ),( Ozlem Harmankaya ),( A Baki Kumbasar ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: Primary hyperaldosteronism (PHA) is a syndrome arising from autonomous aldosterone secretion from the adrenal gland and suppression of plasma renin activity. PHA is usually seen due to unilateral adenoma or bilateral hyperplasia. We present a case of Conn`s syndrome with bilateral adrenal lesions but unilateral functioning adenoma. Methods: A 43 years old female admitted to the emergency service due to inability to walk for 3 days, fatigue and generalised pain. She had a history of diabetes mellitus and hypertension for 15 years. She was receiving angiotensin receptor blocker with thiazide, calcium channel blocker, beta-blocker and insulin treatment. Her blood tests revealed alkalosis and severe hypokalemia with normal renal function. In the examinations for the causes of secondary hypertension; 24-hour urinary cortisol, metanephrine, normetanephrine and VMA levels were normal. Results: After cessation of diuretic treatment plasma renin activity (PRA) was measured 0.17 ng / mL/ h while plasma aldosterone level (PAL) was measured 71 ng / dl. The ratio of PAL / PRA was very high. Her abdominal MRI revealed bilateral adrenal lesions with 23x14 mm and 12x8 mm in diameters in the right and left adrenal gland respectively compatible with adenoma. On the other hand adrenal venous sampling (AVS) showed lateralisation for the right side. Conclusions: Most common causes of PHA are unilateral aldosterone secreting adenoma and bilateral adrenal hyperplasia. Although the appearance of bilateral adrenal lesions in MRI in our case, results of AVS were compatible with autonomous aldosteron production on the right side. According to these findings we accepted the case as a unilateral functioning adenoma with an incidentaloma on the other side.

Fractal Structure of the Stock Markets of Leading Asian Countries

Samet Günay 대외경제정책연구원 2014 East Asian Economic Review Vol.18 No.4

In this study, we examined the fractal structure of the Nikkei225, HangSeng, Shanghai Stock Exchange and Straits Times Index of Singapore. Empirical analysis was performed via non-parametric, semi-parametric long memory tests and also fractal dimension calculations. In order to avoid spurious long memory features, besides the Detrended Fluctuations Analysis (DFA), we also used Smith’s (2005) modified GPH method. As for fractal dimension calculations, they were conducted via Box-Counting and Variation tests. According to the results, while there is no long memory property in log returns of any index, we found evidence for long memory properties in the volatility of the HangSeng, the Shanghai Stock Exchange and the Straits Times Index. However, we could not find any sign of long memory in the volatility of Nikkei225 index using either the DFA or modified GPH test. Fractal dimension analysis also demonstrated that all raw index prices have fractal structure properties except for the Nikkei225 index. These findings showed that the Nikkei225 index has the most efficient market properties among these markets.

Investigation of the effect of bolt diameter and end plate thickness change on bolt column-beam connection

Samet Oğuzhan Doğan,Şenol Gürsoy,Ramazan Özmen 국제구조공학회 2024 Structural Engineering and Mechanics, An Int'l Jou Vol.89 No.2

Several types of column-beam connections are used in the design of steel structures. This situation causes different cross-section effects and, therefore, different displacements and deformations. In other words, connection elements such as welds, bolts, continuity plates, end plates, and stiffness plates used in steel column-beam connections directly affect the section effects. This matter reveals the necessity of knowing the steel column-beam connection behaviours. In this article, behaviours of bolted column-beam connection with end plate widely used in steel structures are investigated comparatively the effects of the stiffness plates added to the beam body, the change in the end plate thickness and bolt diameter. The results obtained reveal that the moment and force carrying capacity of the said connection increases with the increase in the end plate thickness and bolt diameter. In contrast, it causes the other elements to deform and lose their capacity. This matter shows that optimum dimensions are very important in steel column-beam connections. In addition, it has been seen that adding a stiffness plate to the beam body part positively contributes to the connection’s moment-carrying capacity.

Pregnant women’s knowledge about and beliefs toward COVID-19 vaccine: a cross-sectional study

Osman Samet Gunkaya 대한백신학회 2023 Clinical and Experimental Vaccine Research Vol.12 No.2

Purpose: The aim of this study was to determine the scope of knowledge, attitudes, and behaviors of pregnant women about the coronavirus disease 2019 (COVID-19) vaccine. Materials and Methods: A total of 886 pregnant women were recruited for the study. A cross-sectional questionnaire was conducted on these selected participants. Data about past infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), SARS-CoV-2 infection of closely related people, and deaths due to COVID-19 among their relatives were questioned. Results: The rate of vaccination was higher (64.1%) in pregnant women with higher education levels. Informing about the vaccine, especially by health professionals, showed that the rates of vaccination (25%) increased (p<0.001). In addition, a significant increase was observed in vaccination rates with increasing age and financial income (p<0.001). Conclusion: The main limitation of our study is that the vaccine, which was approved for “emergency use”, was just started to be administered to pregnant women during the study. Our findings show that our target audience, low-income, low-education, younger pregnant women should be given more attention than those who apply to the doctor for routine follow-up.

Assessing the Formation of Polycyclic Aromatic Hydrocarbons in Grilled Beef Steak and Beef Patty with Different Charcoals by the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) Method with Gas Chromatography–Mass Spectrometry

Ali Samet Babaoğlu 한국축산식품학회 2023 한국축산식품학회지 Vol.43 No.5

This study investigated the effects of different charcoals on the occurrence of 16 polycyclic aromatic hydrocarbons (PAHs) in grilled beef steaks and beef patties. Seven different charcoals were used as follows: from oak wood (C1), from orange wood (C2), from Valonia oak wood (C3), from Marabu wood (C4), extruded charcoal from beech wood (C5), from coconut shells (C6), and from hazelnut shells (C7). The grilling times for each charcoal type were 6 min for the beef patties and 7 min for the beef steaks, until the internal temperature reached at least 74℃. The total concentration of 16 PAHs (PAH16) in beef steaks grilled with C1 (35.75 μg/kg) and C7 (36.39 μg/kg) was higher than that of C3 (23.80 μg/kg) and C6 (24.48 μg/kg; p<0.05). The highest amounts of PAH16 (216.40 μg/kg) were determined in the beef patty samples grilled using C5 (p<0.05). The summation of benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene, referred to as PAH4, was not detected in any of the beef steaks, whereas it was determined in the beef patties grilled with C2 (7.72 μg/kg) and C5 (22.95 μg/kg; p<0.05). The PAH16 concentrations of the beef patty samples in each charcoal group were significantly higher compared to the beef steaks (p<0.05). To avoid the formation of high PAH levels, the use of extruded charcoal and hazelnut shell charcoal should therefore be avoided when charcoal grilling beef steaks and beef patties, and low-fat meat products should be preferred.

COMMON FIXED POINT THEOREMS FOR COMPLEX-VALUED MAPPINGS WITH APPLICATIONS

Maldar, Samet,Atalan, Yunus The Kangwon-Kyungki Mathematical Society 2022 한국수학논문집 Vol.30 No.2

The aim of this paper is to obtain some results which belong to fixed point theory such as strong convergence, rate of convergence, stability, and data dependence by using the new Jungck-type iteration method for a mapping defined in complex-valued Banach spaces. In addition, some of these results are supported by nontrivial numerical examples. Finally, it is shown that the sequence obtained from the new iteration method converges to the solution of the functional integral equation in complex-valued Banach spaces. The results obtained in this paper may be interpreted as a generalization and improvement of the previously known results.

Impact of Public Information Arrivals on Cryptocurrency Market: A Case of Twitter Posts on Ripple

Gunay, Samet Korea Institute for International Economic Policy 2019 East Asian Economic Review Vol.23 No.2

Public information arrivals and their immediate incorporation in asset price is a key component of semi-strong form of the Efficient Market Hypothesis. In this study, we explore the impact of public information arrivals on cryptocurrency market via Twitter posts. The empirical analysis was conducted through various methods including Kapetanios unit root test, Maki cointegration analysis and Markov regime switching regression analysis. Results indicate that while in bull market positive public information arrivals have a positive influence on Ripple's value; in bear market, however, even if the company releases good news, it does not divert out the Ripple from downward trend.

The Presence of Fragmented QRS on 12-Lead Electrocardiography in Patients with Coronary Artery Ectasia

Fatih Sen,Samet Yılmaz,Mevlüt Serdar Kuyumcu,Özcan Özeke,Mustafa Mücahit Balcı,Sinan Aydog˘du 대한심장학회 2014 Korean Circulation Journal Vol.44 No.5

Background and Objectives: Coronary artery ectasia (CAE) is an angiographic finding characterized by dilation of an arterial segment with a diameter at least 1.5 times that of its adjacent normal coronary artery. Fragmented QRS (fQRS) complexes are electrocardiographic signals which reflect altered ventricular conduction around regions of a myocardial scar and/or ischaemia. In the present study, we aimed to evaluate the presence of fQRS in patients with CAE. Subjects and Methods: The study population included 100 patients with isolated CAE without coronary artery disease (CAD) and 80 angiographically normal controls. fQRS was defined as the presence of an additional R wave or notching of R or S wave or the presence of fragmentation in two contiguous leads corresponding to a major coronary artery territory. Results: The two groups were similar in terms of age, sex, hypertension, dyslipidemia, and family history of CAD. The presence of fQRS was significantly (p<0.05) higher in the CAE group than that in the normal coronary artery group (29% vs. 6.2%, p=0.008). Isolated CAE were detected most commonly in the right coronary artery (61%), followed by left anterior descending artery (52%), left circumflex artery (36%), and left main artery (9%). Multivariate stepwise logistic regression analysis showed that CAE {odds ratio (OR) 1.412; 95% confidence interval (CI) 1.085–1.541; p=0.003} and diabetes (OR 1.310; 95% CI 1.025–1.482; p=0.041) were independently associated with fQRS. Conclusion: The presence of fragmented QRS associated with increased risk for arrhythmias and cardiovascular mortality was significantly higher in patients with CAE than in patient with normal coronary artery. Further studies are needed to determine whether the presence of fragmented QRS is a possible new risk factor for patients with CAE.