PubMed İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8650
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Article Citation - WoS: 2Citation - Scopus: 1Interfacial Behavior and Diffusion Mechanisms of Bni-2 Brazing on Titanium Alloy: Experimental and Molecular Dynamics Insights(Springer, 2025) Goynuk, Tansu; Esen, Ziya; Karakaya, IshakContextJoining titanium alloys, particularly Ti-6Al-4V, is crucial in aerospace applications where reliable, high-performance joints are needed. Brazing offers an effective solution, enabling the joining of dissimilar materials without melting the base metals. However, optimizing the wetting and diffusion behavior of filler metals remains a challenge. This study investigates the high-temperature interaction between BNi-2 filler alloy and Ti-6Al-4V. Boron, the primary melting point depressant in BNi-2, was examined due to its small atomic size and interstitial diffusion mechanism. Elevated temperatures led to improved wetting, reflected by decreased contact angles. Both wetting angles and boron diffusion coefficients were obtained through molecular dynamics simulations and experimental measurements, showing reasonable correlation. These results provide valuable insight into interfacial mechanisms and support further optimization of brazing parameters.MethodsMolecular dynamics simulations were performed using LAMMPS to analyze the temperature-dependent wetting behavior of molten BNi-2 on Ti-6Al-4V and track atomic-scale diffusion. Initial atomic configurations were modeled and simulated under various conditions. Trajectory data were analyzed using OVITO for structural evolution. Boron diffusion was evaluated by calculating mean square displacement from LAMMPS outputs. These values were used to derive diffusion coefficients and activation energies. Parallel experiments were conducted to assess wetting angles and diffusion behavior, and simulation results were compared with experimental data. The consistency between both approaches highlights the reliability of the modeling framework in capturing essential mechanisms during the brazing process.Article Citation - WoS: 43Citation - Scopus: 50Detection of Hip Osteoarthritis by Using Plain Pelvic Radiographs With Deep Learning Methods(Springer, 2020) Ureten, Kemal; Arslan, Tayfun; Gultekin, Korcan Emre; Demir, Ayse Nur Demirgoz; Ozer, Hafsa Feyza; Bilgili, YaseminObjective The incidence of osteoarthritis is gradually increasing in public due to aging and increase in obesity. Various imaging methods are used in the diagnosis of hip osteoarthritis, and plain pelvic radiography is the first preferred imaging method in the diagnosis of hip osteoarthritis. In this study, we aimed to develop a computer-aided diagnosis method that will help physicians for the diagnosis of hip osteoarthritis by interpreting plain pelvic radiographs. Materials and methods In this retrospective study, convolutional neural networks were used and transfer learning was applied with the pre-trained VGG-16 network. Our dataset consisted of 221 normal hip radiographs and 213 hip radiographs with osteoarthritis. In this study, the training of the network was performed using a total of 426 hip osteoarthritis images and a total of 442 normal pelvic images obtained by flipping the raw data set. Results Training results were evaluated with performance metrics such as accuracy, sensitivity, specificity, and precision calculated by using the confusion matrix. We achieved accuracy, sensitivity, specificity and precision results at 90.2%, 97.6%, 83.0%, and 84.7% respectively. Conclusion We achieved promising results with this computer-aided diagnosis method that we tried to develop using convolutional neural networks based on transfer learning. This method can help clinicians for the diagnosis of hip osteoarthritis while interpreting plain pelvic radiographs, also provides assistance for a second objective interpretation. It may also reduce the need for advanced imaging methods in the diagnosis of hip osteoarthritis.Article Citation - WoS: 7Citation - Scopus: 6Turkish Muslim Healers: a Qualitative Investigation of Hocas and Their Methods(Springer, 2020) Canel Cinarbas, Deniz; Tuna, Ezgi; Ar-Karci, YagmurA vast majority of Turkish individuals are Muslim, and several Turkish individuals refer to traditional healers to get help for medical and psychological problems. The purpose of the present study was to investigate Turkish traditional healing methods and to delineate the kinds of presenting problems that the clients bring to healers, methods used by the healers, the healing process, and the effect of healing on the clients. For this purpose, 11 participants were interviewed. The data were analyzed using the consensual qualitative research method. Nine domains emerged from the interviews: symptoms, diagnosis, etiology, treatment, response to treatment, characteristics of healers, clients' beliefs and desire to be healed, all healing coming from Allah (God), and characteristics of jinns. The findings were discussed in light of Kleinman's (Patients and healers in the context of culture: an exploration of the borderland between anthropology, medicine, and psychiatry, University of California Press, Berkeley,1980) illness explanatory model and characteristics of Turkish culture.Article Citation - WoS: 2Citation - Scopus: 3Mining Medline for the Treatment of Osteoporosis(Springer, 2012) Ceken, Cinar; Hassanpour, Reza; Esmelioglu, Sadik; Tolun, Mehmet Resit; Yildirim, PinarIn this paper, we consider the importance of osteoporosis disease in terms of medical research and pharmaceutical industry and we introduce a knowledge discovery approach regarding the treatment of osteoporosis from a historical perspective. Osteoporosis is a systemic skeletal disease in which osteoporotic fractures are associated with substantial morbidity and mortality and impaired quality of life. Osteoporosis has also higher costs, for example, longer hospital stays than many other diseases such as diabetes and heart attack and it is an attractive market for pharmaceutical companies. We use a freely available biomedical search engine leveraging text-mining technology to extract the drug names used in the treatment of osteoporosis from MEDLINE articles. We conclude that alendronate (Fosamax) and raloxifene (Evista) have the highest number of articles in MEDLINE and seem the dominating drugs for the treatment of osteoporosis in the last decade.Article Citation - WoS: 7Citation - Scopus: 10Prediction of Similarities Among Rheumatic Diseases(Springer, 2012) Ceken, Cinar; Hassanpour, Reza; Tolun, Mehmet Resit; Yildirim, PinarWe introduce a method for extracting hidden patterns seen in rheumatic diseases by using articles from the widely used biomedical database MEDLINE. Rheumatic diseases affect hundreds of millions of people worldwide and lead to substantial loss of functioning and mobility. Diagnosing rheumatic diseases can be difficult because some symptoms are common to many of them. We use Facta system as a biomedical text mining tool for finding symptoms and then create a dataset with the frequencies of symptoms for each disease and apply hierarchical clustering analysis to find similarities between diseases. Clustering analysis yields four distinct types or groups of rheumatic diseases. Although our results cannot remove all the uncertainty for the diagnosis of rheumatic diseases, we believe they can contribute to the diagnosis of rheumatic diseases to a certain extent. We hope that some similarities exposed can provide additional information at the stage of decision-making.Article Citation - WoS: 16Citation - Scopus: 15Construct and Face Validity of the Educational Computer-Based Environment (Ece) Assessment Scenarios for Basic Endoneurosurgery Skills(Springer, 2017) Ozcelik, Erol; Sengul, Gokhan; Berker, Mustafa; Cagiltay, Nergiz ErcilBackground In neurosurgery education, there is a paradigm shift from time-based training to criterion-based model for which competency and assessment becomes very critical. Even virtual reality simulators provide alternatives to improve education and assessment in neurosurgery programs and allow for several objective assessment measures, there are not many tools for assessing the overall performance of trainees. This study aims to develop and validate a tool for assessing the overall performance of participants in a simulation-based endoneurosurgery training environment. Methods A training program was developed in two levels: endoscopy practice and beginning surgical practice based on four scenarios. Then, three experiments were conducted with three corresponding groups of participants (Experiment 1, 45 (32 beginners, 13 experienced), Experiment 2, 53 (40 beginners, 13 experienced), and Experiment 3, 26 (14 novices, 12 intermediate) participants). The results analyzed to understand the common factors among the performance measurements of these experiments. Then, a factor capable of assessing the overall skill levels of surgical residents was extracted. Afterwards, the proposed measure was tested to estimate the experience levels of the participants. Finally, the level of realism of these educational scenarios was assessed. Results The factor formed by time, distance, and accuracy on simulated tasks provided an overall performance indicator. The prediction correctness was very high for the beginners than the one for experienced surgeons in Experiments 1 and 2. When non-dominant hand is used in a surgical procedure-based scenario, skill levels of surgeons can be better predicted. The results indicate that the scenarios in Experiments 1 and 2 can be used as an assessment tool for the beginners, and scenario-2 in Experiment 3 can be used as an assessment tool for intermediate and novice levels. It can be concluded that forming the balance between perceived action capacities and skills is critical for better designing and developing skill assessment surgical simulation tools.Article Citation - WoS: 4Citation - Scopus: 4Impaired Redox Homeostasis in the Heart Left Ventricles of Aged Rats Experiencing Fast-Developing Severe Hypobaric Hypoxia(Springer, 2019) Agascioglu, Eda; Colak, Ridvan; Demirel, Haydar; Cakatay, UfukDespite its rare occurrence, humans and animals have been prone to getting fast developing severe hypobaric hypoxia. Understanding the redox homeostasis related response of an aging heart to this type of hypoxia are crucially important, since the metabolism of myocardial tissue depends on the redox status of proteins. Rodents can tolerate hypoxic stress better than human subjects. This study was aimed at investigating the effects of fast developing severe hypobaric hypoxia on redox status biomarkers; such as, advanced oxidation protein products (AOPP), lipid hydroperoxides (LHPs), protein carbonyl groups (PCO), protein thiol groups (P-SH), and total thiol groups (T-SH) on the myocardial left ventricles of young and aged Wistar rats. The rats were gradually ascended and exposed to an 8000-meter hypobaric hypoxia. While AOPP levels showed no difference, the TSH and PSH concentrations decreased, and the PCO and LHP increased in both of the hypoxic groups than the controls. The TSH and PSH were lower, and AOPP, PCO and LHP were found to be higher in the elderly hypoxic groups than in the young ones. The significant outcome of the study represents that an 8000-meter hypobaric hypoxia could be considered as a severe hypoxic stress, but not life-treating for the rats and would affect both the young and aged left ventricles similarly in respect to impaired redox status. However, if the percentage increases are taken into consideration, it seems that the higher rate of protein oxidation occurs in young hearts; meanwhile aged hearts are more prone to T-SH oxidation.