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    Correction: Effects of Short-Time Austenitization on Mechanical Properties and Transformation-Induced Plasticity in Alloyed Austempered Ductile Iron (International Journal of Metalcasting, (2022), 16, 4, (1836-1848), 10.1007/s40962-021-00723-3)
    (Springer Science and Business Media Deutschland GmbH, 2023) Nalcaci, Burak; Sahin, Omer; Okur, Onur; Aydin, Murat; Erdogan, Mehmet
    The original online version of this article was revised. The graphical abstract, Fig. 8, Table 4, and miscellaneous values throughout the text were corrected. © 2023, American Foundry Society.
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    Effects of Short-Time Austenitization on Mechanical Properties and Transformation-Induced Plasticity in Alloyed Austempered Ductile Iron
    (Springer Science and Business Media Deutschland GmbH, 2022) Nalcaci, Burak; Sahin, Omer; Okur, Onur; Aydin, Murat; Erdogan, Mehmet
    The present study was performed to investigate the influences of short-time austenitization on mechanical properties and transformation-induced plasticity (TRIP) in austempered ductile iron. For this purpose, Cu–Ni–Mo-alloyed ductile iron (DI) were poured into sand molds and subsequently the DI samples were austenitized at 850 °C for the duration of 15–30–60 min followed by holding in a salt bath at an austempering temperature of 260 °C for 90 min. Characterization studies were carried out with dilatometer, image analyses software, tensile test, hardness test, XRD analysis, optical and scanning electron microscopies. Findings revealed that as the austenitization time increased, carbon content of austenite (total of high carbon and blocky) and bainitic ferrite cell size enhanced, and phase volume fractions of transformation products of austenite changed. Within this context, changes in the mechanical properties were discussed. Optimum combination of strength and ductility and maximum TRIP effect were determined in the shortest (15 min)-austenitized sample. Accordingly, it was determined 15 min austenitization led to progression in the mechanical properties as 146 MPa and 2.8 % increment in the tensile strength and total elongation respectively, compared to 45 min austenitized sample. Graphical Abstract: [Figure not available: see fulltext.] © 2021, American Foundry Society.
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    EFFECTS OF SHORT-TIME AUSTENITIZATION ON MECHANICAL PROPERTIES AND TRANSFORMATION-INDUCED PLASTICITY IN ALLOYED AUSTEMPERED DUCTILE IRON
    (Springer Int Publ Ag, 2022) Nalcaci, Burak; Sahin, Omer; Erdogan, Mehmet; Okur, Onur; Aydin, Murat
    The present study was performed to investigate the influences of short-time austenitization on mechanical properties and transformation-induced plasticity (TRIP) in austempered ductile iron. For this purpose, Cu-Ni-Moalloyed ductile iron (DI) were poured into sand molds and subsequently the DI samples were austenitized at 850 degrees C for the duration of 15-30-60 min followed by holding in a salt bath at an austempering temperature of 260 degrees C for 90 min. Characterization studies were carried out with dilatometer, image analyses software, tensile test, hardness test, XRD analysis, optical and scanning electron microscopies. Findings revealed that as the austenitization time increased, carbon content of austenite (total of high carbon and blocky) and bainitic ferrite cell size enhanced, and phase volume fractions of transformation products of austenite changed. Within this context, changes in the mechanical properties were discussed. Optimum combination of strength and ductility and maximum TRIP effect were determined in the shortest (15 min)-austenitized sample. Accordingly, it was determined 15 min austenitization led to progression in the mechanical properties as 146 MPa and 2.8 % increment in the tensile strength and total elongation respectively, compared to 45 min austenitized sample. [GRAPHICS] .
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    EFFECTS OF SHORT-TIME AUSTENITIZATION ON MECHANICAL PROPERTIES AND TRANSFORMATION-INDUCED PLASTICITY IN ALLOYED AUSTEMPERED DUCTILE IRON (vol 16, pg 1836, 2021)
    (Springer Int Publ Ag, 2023) Nalcaci, Burak; Sahin, Omer; Erdogan, Mehmet; Okur, Onur; Aydin, Murat
    [Abstract No tAvailable]
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    Left atrial function index and left atrial electromechanical functions in anxiety disorders
    (Taylor & Francis Ltd, 2024) Ozturk, Hayriye Mihrimah; Erdogan, Mehmet; Turan, Yasar; Celik, Ibrahim Etem; Ozturk, Selcuk
    BackgroundThere is a close linkage between anxiety disorders (ADs), and development of cardiovascular disease (CVD) and atrial fibrillation (AF). We aimed to investigate left atrial function index (LAFI) and its components, LA mechanical functions and atrial conduction times in AD patients and age- and gender-matched control group patients for the first time in the literature.MethodsA total of 48 AD patients and 33 healthy subjects were enrolled to the study prospectively. Echocardiographic parameters including two-dimensional conventional echocardiography, diastolic functions, LA mechanical functions, LAFI, atrial conduction times and atrial electromechanical delay (AEMD) were calculated.ResultsThe velocity-time integral of the LV outflow tract (LVOT-VTI), LAFI and LA conduit volume were significantly lower in AD patients. Atrial electromechanical coupling as established from lateral mitral annulus (PA lateral) was significantly higher in AD group than control group. Inter-AEMD and left intra-AEMD were also higher in AD group compared to control group. Age, gender, body surface area (BSA), conduit volume, LVOT-VTI and LAFI were significant factors associated with AD in univariate analysis. However, only BSA and LVOT-VTI (Odds ratio [OR]: 0.79, 95 CI%: 0.66-0.95, p = 0.013) were independently associated with AD in multivariate analysis. Age, gender, conduit volume and LAFI (OR: 0.25, 95 CI%: 0.03-2.12, p = 0.204) were not found to be independent associates of AD.ConclusionLAFI is impaired in patients suffering from AD compared to their age- and gender-matched counterparts but this impairment originates from lower levels of LVOT-VTI calculations in AD patients. Thus, LVOT-VTI, but not LAFI, is independently associated with AD.
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    Plasma thrombin-activatable fibrinolysis inhibitor (TAFI) antigen levels in acromegaly patients in remission
    (Tubitak Scientific & Technical Research Council Turkey, 2019) Erdogan, Mehmet; Ozbek, Mustafa; Akbal, Erdem; Ureten, Kemal
    Background/aim: Acromegaly is associated with increased morbidity and mortality, mostly due to cardiovascular complications. Plasma thrombin-activatablc fibrinolysis inhibitor (TAFI) antigen levels arc associated with coagulation/fibrinolysis and inflammation. Plasma TAFI may play a role in arterial thrombosis in cardiovascular diseases. In this study, it was aimed to evaluate the thrombin-activatable fibrinolysis inhibitor (TAFI) antigen and homocysteine levels in patients with acromegaly and healthy control subjects. Materials and methods: Plasma TAFI antigen and homocysteine levels in 29 consecutive patients with acromegaly and 26 age-matched healthy control subjects were measured. All patients included in the study were in remission. The TAFIa/ai antigen in the plasma samples was measured using a commercially available ELISA kit. Results: Routine biochemical parameters, fasting blood glucose, prolactin, thyroid stimulating hormone, total-cholesterol, low density lipoprotein cholesterol, triglyceride, and homocysteine levels were similar in the 2 groups (P > 0.05), whereas the plasma TAFI antigen levels were significantly elevated in the acromegalic patients (154.7 +/- 94.0%) when compared with the control subjects (107.2 +/- 61.6%) (P = 0.033). No significant correlation was identified by Pearson's correlation test between the plasma TAFI antigen and homocysteine levels (r = 0.320, P = 0.250). Conclusion: A significant alteration in the plasma TAFI antigen levels was detected in acromegaly. Increased plasma TAFI antigen levels might aggravate prothrombotic and thrombotic events in patients with acromegaly.
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    The association between total cholesterol and cognitive impairment in chronic obstructive pulmonary disease patients
    (Elsevier Science Inc, 2023) Öztürk, Hayriye Mihrimah; Ogan, Nalan; Erdogan, Mehmet; Akpinar, Evrim Eylem; Ilgar, Ceren; Öztürk, Selcuk
    Aim: Chronic obstructive pulmonary disease (COPD) is primarily a respiratory system disorder associated with extrapulmonary conditions. Cognitive impairment (CoI) is very common among COPD patients This study sought to investigate the association between CoI and clinical parameters, inflammatory markers and lipid profiles in a COPD patient population.Methods: The study population included 111 stable COPD patients. COPD was diagnosed according to Global Initiative for Chronic Obstructive Lung Disease guideline. Total complete blood count test and biochemical measurements including lipid profile were performed. Afterwards, all patients underwent neuropsychological assessment including Hospital Anxiety and Depression Scale (HADS), Pittsburgh Sleep Quality Index and Mon-treal Cognitive Assessment (MoCA) tests.Results: The patients were categorized into two groups according to their MoCA test score: MoCA score & LE; 21 (CoI) (n = 69) and MoCA score > 21 (normal cognition) (n = 42). Total cholesterol (TC) levels were significantly lower in patients with CoI compared to patients with normal cognition. Inflammation related parameters including C -reactive protein were similar among groups. Multivariate logistic regression analysis yielded education, HADS score and TC (OR:1.02, 95% CI:1.00-1.04, p = 0.025) as independent predictors of MoCA score.Conclusion: TC independently associates with CoI in COPD patients. There is comparable inflammatory status in COPD patients with CoI compared to COPD patients with normal cognition.