İstanbul Gelişim Üniversitesi Kurumsal Açık Erişim Arşivi
DSpace@Gelişim, İstanbul Gelişim Üniversitesi tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Conduction mechanisms, relaxation dynamics, and magnetic properties of Se-substituted Sr nanohexaferrites
(ELSEVIER SCIENCE SA, PO BOX 564, 1001 LAUSANNE, SWITZERLAND, 2025) Slimani, Yassine; Ünal, Bayram; Baykal, Abdulhadi; Almessiere, Munirah Abdullah; Demir Korkmaz, Ayşe; Çalışkan, S.
In this study, Se-substituted Sr nanohexaferrites (SrSe3xFe12− 4xO19 (Se→Sr) (x ≤ 0.10) NHFs) have been synthesized via sol-gel combustion route. The X-ray diffraction technique was utilized in order to assess the phase formation of the samples. Furthermore, morphology and crystallinity were shown by SEM, TEM, and HR-TEM investigations. M − H curves are consistent with the response of ferrimagnetic materials under an externally applied magnetic field. A “wasp-waist” behavior was also seen in the registered M − H hysteresis loops. The magnetic investigations displayed an increased tendency for Ms, Mr and Hc as the concentration of selenium (Se) ions increased, achieved their maximum values for the sample with x = 0.05, then reduced as the concentration of Se ions further increased (x > 0.05). The maximum values achieved for the product with x = 0.05 might be useful in permanent magnet applications. This study also investigates the electrical and dielectric properties of Se-substituted Sr-NHFs through AC and DC conductivity measurements, activation energy analysis, and impedance spectroscopy. Results show that Se substitution modifies charge transport by enhancing hopping and thermally activated conduction mechanisms. AC conductivity displays power-law frequency dependence, while DC conductivity reveals temperature-activated behavior. Dielectric measurements indicate reduced dielectric constant and loss at higher frequencies due to interfacial polarization. Cole–Cole and Nyquist analyses confirm non-Debye relaxation and highlight changes in grain and grain boundary effects with Se content. These findings demonstrate the material’s potential for high-frequency devices, energy storage, and electromagnetic shielding applications.
Burden of hypertension, diabetes, and hypercholesterolemia in relation to social and behavioral health determinants: Insights from the 2018 Bangladesh STEPS survey
(W B SAUNDERS CO LTD, 32 JAMESTOWN RD, LONDON NW1 7BY, ENGLAND, 2025) Rahman, Mohammad Meshbahur; Farhana, Zaki; Al Noman, Abdullah; Hossain, Nazmul; Kamil, Anton Abdulbasah; Riaz, Baizid Khoorshid
Objectives: Bangladesh is experiencing a significant shift in its epidemiological landscape, moving from a predominance of communicable diseases to an increasing burden of non-communicable diseases (NCDs). This study aims to identify the risk factors for hypertension, diabetes, and hypercholesterolemia based on the recent STEPS survey in Bangladesh. Study design: Secondary cross-sectional study. Methods: This study analyze the publicly available “National STEPS Survey for Non-communicable Diseases Risk Factors in Bangladesh 2018” dataset. The sample size was 6875, after cleaning the three phases of dataset. Frequency distribution, Spatial distribution, Chi-square test, and Logistic regression models were employed in data analysis. Results: The nationwide prevalence of NCDs revealed 27.3 % for hypertension, 9.8 % for diabetes, and 30.2 % for hypercholesterolemia. The NCDs prevalence significantly varied across divisions in Bangladesh, with Barisal having the highest hypertension (25 %) and Sylhet the lowest (18.1 %). Chittagong led in diabetes prevalence (12.0 %), while Rangpur had the lowest (4.8 %). For hypercholesterolemia, Barisal topped (34.9 %), and Mymensingh had the lowest (20.9 %). The significant risk factors of NCDs included age, occupational status, physical activity, and BMI category. Older age and obesity notably increased significantly (p < 0.05) the odds of hypertension, diabetes, and hypercholesterolemia, while urban residence increased the odds of diabetes. Conclusion: Several factors, mostly age, occupational status, physical activity, and BMI category are responsible for higher prevalence of NCD diseases. The study explores common factors in NCDs and offers regional comparisons, aiding policymakers in focused interventions for specific regions.
Evaluation of minimum pinch force while holding in fbromyalgia patients
(SPRINGER LONDON LTD, 236 GRAYS INN RD, 6TH FLOOR, LONDON WC1X 8HL, ENGLAND, 2025) Zincirci, Dilara Ekici; İlbeği, Sultan; Çakır, Esin; Atar, Sevgi; Demirhan, Esma; Aydın, Tuğrul; Türker, Kemal Sıtkı; Karacan, İlhan; Kuru, Ömer
Objective This study aimed to investigate the relationship between the minimum pinch force applied during object carrying and physical fatigue in patients with fbromyalgia. For this purpose, the study evaluated the association between the minimum and maximum pinch forces exerted while carrying a weight and both isokinetic muscle strength and the isokinetic fatigue index. Methods One hundred eight (54 FMS/54 healthy) women participated. Pinch force was measured with a force sensor, and wrist fexor/extensor strength and fatigue index were evaluated using an isokinetic dynamometer at 180°/s. Results Minimum pinch force did not difer signifcantly between groups, but maximum pinch force was higher in healthy subjects (p=0.011). Wrist fexor and extensor strength were substantially lower in FMS (p<0.001 for both). Fatigue index was lower in FMS, but diferences were not statistically signifcant (p=0.05, p=0.06). In FMS patients, the minimum pinch force correlated with wrist fexor and extensor fatigue, but no correlation was found in controls.
Conclusions Our research shows that the minimum pinch force exerted by women with FMS is not diferent from that exerted by healthy women, but the maximum pinch force is lower. Muscle performance tests measured by isokinetic dynamometry may help assess physical fatigue in FMS patients. Signifcance Although women with FMS can match their healthy peers in minimum pinch force, their lower maximum force may be the main cause of the fatigue they experience during daily activities.
Elucidating the Structure–Spectrum Relationship of Choline and Citicoline: Approaches From Experimental FT-IR and Theoretical DFT/HF Methods
(WILEY-V C H VERLAG GMBH, POSTFACH 101161, 69451 WEINHEIM, GERMANY, 2025) Küçük, Vesile; Ünlü, Nihan; Dirican, Onur; Erdöl, Mehmet Sabri
In this study, the structural and vibrational properties of choline and citicoline at the molecular level were investigated comprehensively through the integration of experimental and theoretical methods. The main purpose of the study is to provide an accurate interpretation of FT-IR spectra of these molecules and to contribute to molecular identification processes. Experimentally, spectral data obtained from pure citicoline powder using ATR/FT-IR spectroscopy were compared theoretically with Hartree–Fock (HF) and density functional theory (DFT) approaches; in this context, B3LYP functional and 6–311++G(d,p) basis set were taken as basis. Thanks to this method, supported by theoretical calculations, full vibrational (IR and Raman) spectra and structural parameters of choline and citicoline were modeled in detail, and systematic assignments were made to vibrational modes. The obtained findings show that experimental and theoretical data are in high agreement; this situation emphasizes the complementarity and reliability of both approaches, especially in terms of functional group analysis of citicoline molecule. In addition, this holistic analysis method provides a strong basis for predicting the potential interactions, chemical stabilities, and possible side effects of choline and citicoline molecules in biological systems at the molecular level. The obtained results contribute to the development of a deeper understanding of the roles of such compounds in biochemical processes, as well as providing guidance for structural optimization and targeted design studies in future pharmaceutical and biotechnological applications.
A cross-sectional analysis of dietary advanced glycation end products intake and its relationship with body composition, mental health, and sleep in adults
(ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2-4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND, 2025) Bayram, Hatice Merve; Öztürkcan, Seyfettin Arda
This cross-sectional study examined the associations between dietary advanced glycation end products (dAGEs) intake, obesity, mental health, and sleep quality in Turkish adults. A total of 383 individuals were evaluated using validated scales (DASS-21, PSQI), anthropometric measurements, and 24-hour dietary recall. Dietary intakes of CML, CEL, and MG-H1 values were estimated using a European AGEs database. Higher dAGEs intake was significantly associated with increased BMI, waist circumference, depression, anxiety, stress, and poor sleep quality (p < .05). The main dAGEs contributors were cereals, meat products, cakes/biscuits, and confectionery items. Results suggest dAGEs intake may negatively impact mental health and sleep.
