TR Dizin İndeksli Yayınlar Koleksiyonu / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14365/4
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Article Model-Based Feature Selection Using Structural Equation Modeling for Enhanced Classification Performance in High-Dimensional Datasets(Gazi University, 2025-09-01) Albayrak, Muammer; Turhan, KemalFeature selection is becoming more and more important for machine learning and data mining. Especially for high dimensional datasets, it is necessary to filter out irrelevant and unnecessary features to overcome the problems of overfitting and multidimensionality. We hypothesized that an effective feature selection can be made with a model-based approach using the Structural Equation Modeling (SEM) method. The dataset consists of 2969 samples and 117 features. First, a measurement model created was tested with confirmatory factor analysis (CFA) and the number of features was reduced to 58 by removing the statistically insignificant features. In SEM analysis, sub-feature sets consisting of 55, 52, 41 and 35 features were obtained by removing the variables whose relationship was below the threshold values determined for the standardized regression coefficient (SRC). The obtained sub-feature sets were tested with a multilayer perceptron (MLP) and their effect on performance was examined. Results were compared with random forest feature importance as baseline method. SEM and random forest have generally performed very closely. While sub-feature sets created with the random forest in two-class classification produced better results, the sub-feature sets created with the suggested SEM-based method in three and five-class classification provided better performance. These results showed that effective feature selection can be made with the proposed model-based approach using SEM. With this approach, it is possible to obtain sub-feature sets that form a model which statistically significant and consistent with field knowledge by including expert knowledge in the modeling process.Article Complications and Therapeutic Approaches in a Sciatic Nerve Injury Rat Model(2025-04-30) Adali, Yasemen; Barış, Elif; Daştan, Ali Engin; Öztürk, VolgaSciatic nerve injury (SNI) is a common model for studying peripheral nerve damage and regeneration. This study investigates the complications associated with acute nerve injury (ANI) by laceration of sciatic nerve in rats including infection, edema, and cannibalism, and evaluates the effectiveness of therapeutic interventions to modulate the observed complications. For this purpose eighteen female wistar albino rats were divided into three groups: control, sham-operated, and ANI. The ANI model induced with dissection and repair of the right sciatic nerve. Post-surgical care included the administration of diclofenac sodium for pain management. Observations were made for signs of infection, edema, hematoma, and survival rates within 10 days. The ANI group showed significant complications, including a 41.6% incidence of symptoms of pain (paraesthesia, allodynia, hyperalgesia, decreased activity, piloerection, excessive licking, un-groomed appearance) within 3 days, which increased to 60% by day 5. Edema was observed in 8.3% of the ANI rats, and 33.3% developed hematomas. Cannibalism rates also increased, particularly within 10 days post-injury. Survival rates in the ANI group decreased to 16.6% by day 10, indicating severe post-operative complications. The current study highlights the critical complications associated with ANI in rats, particularly the high rates of pain related symptoms (i.e. paresthesia and cannibalism). These findings suggest the need for improved post-operative care and highlight the importance of therapeutic interventions like opioid analgesics to mitigate these complications and enhance recovery outcomes in peripheral nerve injury models.Article Exploring the Potential of Lavandula stoechas in Smoking Cessation: A Molecular Docking Study of α4β2 Nicotinic Acetylcholine Receptor Interactions(Istanbul Univ, Fac Pharmacy, 2025-05-07) Barış, Elif; Portakal, Hüseyin SaygınBackground: Lavandula stoechas, commonly known as lavender, has traditionally been used in various therapeutic applications, including smoking cessation. The molecular interaction of Lavandula stoechas compounds with the α4β2 nicotinic acetylcholine receptors, which are crucial for smoking cessation, is not well understood. This study aims to analyze these interactions and compare them with the known smoking cessation drug varenicline tartrate. Methods: Molecular docking analysis was performed on essential compounds of Lavandula stoechas to assess their binding affinities to the α4β2 nicotinic acetylcholine receptors. The study utilized the crystal structure of the receptor and conducted virtual drug screening using AutoDock Vina in the PyRx Virtual Screening Tool. ADME (Absorption, Distribution, Metabolism, and Excretion) and toxicity profiles were also predicted using in silico methods. Results: The molecular docking revealed that several Lavandula stoechas compounds exhibited signif7 icant binding affinities to the α4β2 receptor. Compounds with the highest binding affinities were identified and compared with varenicline. The ADME and toxicity profiles indicated that these compounds had more favorable properties than varenicline, suggesting their potential as alternative smoking cessation agents. Discussion: The findings demonstrate that Lavandula stoechas contains compounds with significant binding affinities to the α4β2 nicotinic acetylcholine receptors, similar to varenicline. This indicates a potential role for Lavandula stoechas in smoking cessation therapy. The favorable ADME and toxicity profiles of these compounds further support their potential as alternatives to current smoking cessation drugs. This study paves the way for further research into the therapeutic applications of Lavandula stoechas in smoking cessation.Article Aile Hekimlerinin Sağlıklı Yaşam Biçimi Davranışlarının ve Klinik Uygulamalarında Yaşam Biçimi Tıbbının Değerlendirilmesi(Galenos Publishing House, 2025-04-15) Semin, Ilgi; Kazdağlı, Hasan; Gökdemir, Özden; Semin, Makbule IlgiAmaç: Bu çalışmanın amacı, aile hekimlerinin sağlıklı yaşam biçimi davranışlarını değerlendirmek ve klinik uygulamalarında yaşam biçimi tıbbına yönelik katılımlarını incelemektir. Yöntemler: Temmuz 2018 ile Ağustos 2019 tarihleri arasında aile hekimlerinden veri toplamak amacıyla çevrimiçi bir anket geliştirildi. Tanımlayıcı ve korelasyonel bir araştırma deseni kullanıldı. Çalışmada uygulanan anket, “katılımcıların kişisel bilgileri” ve “Sağlıklı Yaşam Biçimleri Davranış Ölçeği-II”i içermektedir. Kesitsel bir çalışma olarak tasarlanan bu araştırmada, örneklem kolayda örnekleme metodu ile sekiz ülkeden belirlenmiştir, ve anketler katılımcılara elektronik ortamda uygulanmıştır. Katılımcılara anketin süresi, veri saklama işlemleri, saklama süresi, araştırmacıların kimliği ve çalışmanın amacı hakkında bilgi verilmiştir. Bulgular: Çalışmaya 131 aile hekimi katılmış olup, erkek katılımcı oranı daha yüksek bulunmuştur. Sigara içme sıklığının Türk aile hekimleri arasında anlamlı derecede yüksek olduğu tespit edilmiştir (p=0,013). Ancak, ölçek toplam puanı veya altı boyutta alınan puanlar açısından aile hekimleri arasında istatistiksel olarak anlamlı bir fark bulunmamıştır. Sonuç: Çoğu aile hekimi, bu alanda daha fazla eğitim almak istediklerini belirtmiştir, bu da tıp fakültelerinin müfredatına eğitim müdahalelerin dahil edilmesi gerekliliğini göstermektedir. Ayrıca, iyi yapılandırılmış web tabanlı kitlesel çevrimiçi kurslar, aile hekimlerinin sağlıklı yaşam biçimi davranışları ve yaşam biçimi tıbbı uygulamalarına yönelik eğitim gereksinimlerini karşılamada etkili bir çözüm olabilir.Article Prolonged Β-Hydroxybutyrate Ketosis Enhances Ponatinib Response of K562 Chronic Myeloid Leukaemia Cells(Dokuz Eylul Univ inst Health Sciences, 2025-01-31) Özkaya, Ali Burak; Geyik, Öykü Gönül; Malcanlı, SenanurPurpose: Ketosis is a metabolic state characterized by production of ketone bodies, including acetoacetate, β-hydroxybutyrate (BHB), and acetone, in response to reduced blood glucose levels. BHB stands out as the principal ketone body in nutritional ketosis which has diverse therapeutic implications for metabolic, nondegenerative and neoplastic disorders. In current study we investigated the impact of ketosis on chronic myeloid leukaemia (CML) cell viability and drug response. Materials and Methods: We investigated the impact of BHB-mediated ketosis on the viability of K562 cells, an in vitro model of CML, and explored the influence of BHB on the sensitivity of these cells to ponatinib, a multi-targeted tyrosine kinase inhibitor used in CML treatment. We used MTT assay to measure cell viability and Hoechst/PI assay to measure cell death. Results: Our findings reveal that BHB concentrations ranging from 1 mM to 5 mM, which fall within the physiological range of ketosis, elicit a minimal yet concentration-dependent reduction in cell viability. We also observed that while a 24-hour pre-treatment with BHB did not enhance the response of K562 cells to ponatinib, prolonged ketosis (4 days) improved response of cells to the drug by decreasing final cell viability from 25.15% to 13.12%. The primary mode of viability inhibition by ponatinib was cell death which was further intensified by exposure to prolonged ketosis. Conclusion: Ketosis induced by ketogenic diet of ketone body supplementation is considered as safe and effective adjuvant cancer therapy options and here, we report its potential effectiveness in the context of CML.