Browsing by Author "Duman S."

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    SU‐GG‐T‐77: Effect of Mobile Seed Components on Dosimetry of Theragenic Model 200 Pd‐103 Seed Source
    (2010) Yegin G.; Duman S.; Aydogdu G.; Camgoz B.; Aras S.; Kumru M.
    Purpose: To investigate the influence of mobile internal source components of Theragenic Model 200 seed source on its dose rate distribution and TG‐43 parameters. Method and Materials : By using BrachyDose Monte Carlo code, the geometry of Theragenic Model 200 seed source was modeled in five different configurations. In each configuration, internal components are located at different positions in order to take into account the effect of gravitational force on the seed geometry. Physical dimensions of seed components are identical in all seed models. Air kerma strenghts and dose per unit activitiy were determined separately for each seed design on a plane which is in a direction where dose variations are expected to be maximum. Calculated data were used to produce TG‐43 parameters. Results: Comparison of TG‐43 dosimetric parameters for each seed configuation showed that dose rate constant varies up to 11% due to the position of internal source elements. For radial dose fuction, there are significant differences increasing up to 40% at distances 0.1≤ r <0.5 cm and for radial distances r >0.5 discrepancies are negligible (i.e. about 1–2%). Anisotropy functions were calculated at radial distances of 0.25, 0.5, 1.0 and 5.0 cm. It is observed that anisotropy function changes adruptly (up to 40%) for polar angels θ<15° and θ>165° at all radial distances. Differences are less than 5% for all other angles and decreases with increasing radial distance. Conclusions: The geometry variation effects investigated in this study are ignored in the TG‐43 formalism. This work indicates that these effects may change absorbed dose values significantly at some points around the Theragenic Model 200 seed source. This investigation was supported by Celal Bayar University (Project number: 2009/138) and ULAKBIM High Performance and Grid Computing Center (TR‐grid). © 2010, American Association of Physicists in Medicine. All rights reserved.
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    Multi-Center Experience of Coronary Artery Perforation during Percutaneous Coronary Intervention: Clinical and Angiographic Characteristics, Management, and Outcomes between 2010 and 2020
    (Turkish Society of Cardiology, 2022) Gündüz R.; Yıldız B.S.; Çetin N.; Özgür S.; Çizgici A.Y.; Tülüce K.; Tülüce S.Y.; Özen M.B.; Duman S.; Bayturan Ö.
    Background: Coronary artery perforations are one of the most feared, rare, and catastrophic complication of percutaneous coronary intervention. Despite the remarkable increase in coronary angiography and percutaneous coronary intervention, there is no large database that collects coronary artery perforation for the Turkish population. Our study aimed to report our experience over a 10-year period for clinical and angiographic characteristics, management strategies, and outcomes of coronary artery perforation during the percutaneous coronary intervention at different cardiology departments in Turkey. Methods: The study data came from a retrospective analysis of 48 360 percutaneous coronary intervention procedures between January 2010 and June 2020. A total of 110 cases who had coronary artery perforation during the percutaneous coronary intervention were found by angiographic review. Analysis has been performed for the basic clinical, angiographic, procedural characteristics, the management of coronary artery perforation, and outcome of all patients. Results: The coronary artery perforation rate was 0.22%. Out of 110 patients with coronary artery perforation, 66 patients showed indications for percutaneous coronary intervention with acute coronary syndrome and 44 patients with stable angina pectoris. The most common lesion type and perforated artery were type C (34.5%) and left anterior descending (41.8%), respectively. The most observed coronary artery perforation according to Ellis classification was type III (37.2%). Almost 52.7% of patients have a covered stent implanted in the perforated artery. The all-cause mortality rate of coronary artery perforation patients in the hospital was 18.1%. Conclusion: The observed rate of coronary artery perforation in our study is consistent with the studies in this literature. However, the mortality rates related to coronary artery perforation are higher than in other studies in this literature. Especially, the in-hospital mortality rate was higher in type II and type III groups due to perforation and its complications. Nevertheless, percutaneous coronary intervention should be done in selected patients despite catastrophic complications. Copyright@Author(s) - Available online at anatoljcardiol.com.
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    Frontal QRS/T angle can predict mortality in COVID-19 patients
    (W.B. Saunders, 2022) Gunduz R.; Yildiz B.S.; Ozgur S.; Ozen M.B.; Bakir E.O.; Ozdemir I.H.; Cetin N.; Usalp S.; Duman S.
    Aims: The frontal QRS-T (fQRS) angle has been investigated in the general population, including healthy people and patients with heart failure. The fQRS angle can predict mortality due to myocarditis, ischaemic and non-ischaemic cardiomyopathies, idiopathic dilated cardiomyopathy, and chronic heart failure in the general population. Moreover, no studies to date have investigated fQRS angle in coronavirus disease 2019 (COVID-19) patients. Thus, the purpose of this retrospective multicentre study was to evaluate the fQRS angle of COVID-19 patients to predict in-hospital mortality and the need for mechanical ventilation. Methods and results: An electrocardiogram was performed for 327 COVID-19 patients during admission, and the fQRS angle was calculated. Mechanical ventilation was needed in 119 patients; of them, 110 died in the hospital. The patients were divided into two groups according to an fQRs angle >90° versus an fQRS angle ≤90°. The percentages of mortality and the need for mechanical ventilation according to fQRS angle were 67.8% and 66.1%, respectively, in the fQRs >90° group and 26.1% and 29.9% in the fQRS ≤90°group. Heart rate, oxygen saturation, fQRS angle, estimated glomerular filtration rate, and C-reactive protein level were predictors of mortality on the multivariable analysis. The mortality risk increased 2.9-fold on the univariate analysis and 1.6-fold on the multivariate analysis for the fQRS >90° patient group versus the fQRS ≤90° group. Conclusion: In conclusion, a wide fQRS angle >90° was a predictor of in-hospital mortality and associated with the need for mechanical ventilation among COVID-19 patients. © 2022 Elsevier Inc.
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    Hemodialysis Consumes the World's Plenty of Water Water: the Analysis of Water Discharged from Reverse Osmosis and Usefulness; [Hemodiyaliz Dünyanın Suyunu Tüketiyor: Ters Osmozdan Atılan Suyun Analizi ve Kullanılabilir Olması]
    (Turk Nefroloji Diyaliz ve Transplantasyon Hemsireleri Dernegi, 2023) Yeşil S.A.; Asana İ.; Adibelli Z.; Kurt H.; Duman S.; Hür E.
    Introductıon: In the hemodialysis water system, "raw water" refers to mains or artesian water, while "pure water" denotes the purified water used for diluting concentrated hemodialysis solutions. There is often confusion between "rejected water," which is discharged from the reverse osmosis device and usually discarded into the sewer, and hemodialysis wastewater, which comes into contact with a patient's blood post-treatment. Our study aims to assess the quality of this rejected water and explore ways to repurpose it rather than disposing of it. Materıal and Method: Approval was obtained from the Manisa Celal Bayar University Ethics Committee for the study titled "Hemodialysis Consumes the World's Water." The fundamental principle of the reverse osmosis system is to filter water from harmful and contaminating substances by passing it through a semi-permeable membrane under high pressure. In our study, we conducted microbiological and chemical analyses of the water discharged from the reverse osmosis water treatment system into the sewer. Results: Microbiological and chemical tests were conducted at the Afyonkarahisar Public Health Laboratory by taking water samples using the appropriate technique from various points within the hemodialysis unit's water system at Merkezefendi State Hospital. The analyses of water samples from four different points in the reverse osmosis water system, including the inlet, post-treatment, inter-tank, and rejected water sections, revealed that all these sections were microbiologically sterile (Enterocuc/Fecal streptococ, E. Coli, total coliform). Additionally, Aluminum and Iron levels were found to be zero. The Ammonium levels were 0.15, 0.13, 0.12, and 0.13 mg/L, respectively, and the conductivity was measured as 540, 546, 492, 623 mS/cm. The water was deemed suitable in terms of odor, turbidity, and color, with a pH range of 7.50-7.70, falling within the standard range established by the Turkish and USA EPA Conclusion: This study demonstrates that the water rejected in the reverse osmosis system can be used for all kinds of purposes. Given the decreasing availability of the world's water resources, this research represents the first national study showing that water can be conserved by preventing the disposal of water into the sewerage system, which places a burden on the economy and the natural environment. © 2023, Turk Nefroloji Diyaliz ve Transplantasyon Hemsireleri Dernegi. All rights reserved.