Recep Tayyip Erdoğan Üniversitesi Kurumsal Akademik Arşivi
DSpace@RTEÜ, Recep Tayyip Erdoğan 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 yayınların etkisini artırmak için telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Metal–organic frameworks for analytical chemistry: Solid-phase microextraction and dispersive (micro)-solid phase extraction
(Elsevier, 2026) Kıztanır, Gamze; Demir, Selçuk; Tokalıoğlu, Şerife; Şahan, Halil
Metal–organic frameworks (MOFs), owing to their high surface areas, tunable pore sizes, and selective interaction capabilities, have emerged as promising sorbents in analytical chemistry for the separation and enrichment of various chemicals from complicated matrices, such as human body fluids and environmental water samples. Recent studies have demonstrated their effectiveness in selectively extracting various analytes, including pesticides, heavy metals, drug residues, antibiotics, mycotoxins, and persistent organic pollutants from complex biological, environmental, and food matrices. Magnetic MOFs and molecularly imprinted MOF hybrids offer significant advantages, such as compliance with green chemistry principles, reusability, and enhanced selectivity, thereby broadening their application scope. Moreover, ultrasound-assisted and automation-compatible extraction systems reduce processing times, enable multi-analyte detection, and hold potential for field-deployable applications. Herein, we systematically review the literature on MOFs for solid-phase microextraction (SPME), dispersive solid-phase extraction (D-SPE), and dispersive micro-solid phase extraction (D-μ-SPE) for biomedical applications, extraction of organic molecules, agricultural pest control, and metal adsorption. The investigation of MOFs as adsorbents has not only broadened their application scope but may also address critical issues associated with adsorption methods, such as selectivity, stability, cost-effectiveness, and time efficiency, which are paramount in adsorption technology. The structure, pore dimensions, and functional groups of MOFs are all modifiable, enabling distinctive interactions with guest molecules to attain certain physical-chemical adsorption properties. Moreover, the stability and simplicity of MOF production demonstrate that they are optimal adsorbents for analytical chemistry.
A universal mem-element emulator with a single MO-OTA core: Memristor, memcapacitor, and meminductor in one reconfigurable circuit
(Elsevier, 2026) Gül, Fatih; Babacan, Yunus
A universal mem-element emulator is built around a single multi-output operational-transconductance-amplifier (MO-OTA) core, one analog multiplier and one grounded resistor–capacitor pair. The same core reproduces the pinched-hysteresis dynamics of the memristor, the memcapacitor and the meminductor; only the front-end coupling and the reflection law change. An explicit state equation follows from Chua's flux–charge formulation, with the integrator voltage vC as the state. The memristor reflection law is calibrated against the Strukov–Williams compact model of an HP TiO2 device, matching its memristance excursion to 0.9% and its loop area to 5.9% over 5–100 kHz. Both active blocks are transistor-level in TSMC 0.18μm CMOS: a 15-MOSFET MO-OTA and a new 9-MOSFET four-quadrant multiplier that runs from ±0.9V with 0.16% THD and zero systematic offset. The 24-MOSFET emulator dissipates 0.61mW and preserves pinched v–i, q–v and φ–i loops from 1 kHz to 22MHz. Robustness spans 45 process–voltage–temperature corners and a 500-run Monte-Carlo analysis with per-device threshold-mismatch; the modulated element stays positive-definite in every run (σ/μ=9.7%). In the Itoh–Chua oscillator it yields a double-scroll attractor with λmax=0.311, against 0.276 for an ideal memristor. It stays fully floating, needs no mutator or switching network, and uses the smallest active-block count among universal emulators.
First-aid knowledge among undergraduate and specialist dental students in Turkey: a cross-sectional study
(BioMed Central Ltd, 2026) Erdem, Rahime Zeynep; Bedir, Fatih
Background: Dental professionals frequently treat patients with systemic conditions, and medical emergencies can occur during dental procedures, circumstances that underscore the importance of first-aid competence in dental training. In this study, specialist dental students refers to postgraduate students enrolled in accredited dental specialty programmes (e.g., orthodontics, endodontics, periodontics). This cross-sectional study aimed to evaluate and compare first-aid knowledge levels among pre-clinical (years 1–3), clinical (years 4–5), and specialist dental students enrolled in Turkish dental faculties, and to assess whether the proportion reporting formal first-aid training differed across these groups. Methods: Data were collected using a validated 23-item questionnaire (Cronbach’s α = 0.87) distributed via Google Forms (Google, Mountain View, CA, USA) across Turkish dental faculties in October 2023. A total of 1,093 students participated. Group comparisons were performed with Kruskal-Wallis and Mann-Whitney U tests; the Chi-square test was used for categorical variables. Binary logistic regression identified independent predictors of adequate knowledge. Effect sizes were calculated using eta-squared (η²) and r. Results: A statistically significant difference in first-aid knowledge was identified across the three groups (p < 0.001). Adequate knowledge was demonstrated by 82.1% of specialist students, 61.8% of clinical students, and 41.7% of pre-clinical students. Overall, 35.5% of participants reported prior formal first-aid training, with the proportion differing significantly across groups (p < 0.001). Logistic regression identified training stage (specialist vs. pre-clinical: OR 5.39, 95% CI 3.32–8.77; clinical vs. pre-clinical: OR 2.15, 95% CI 1.61–2.85) and prior first-aid training (OR 1.40, 95% CI 1.06–1.84) as independent predictors. Sex was not significant (p = 0.175). Conclusions: First-aid knowledge in dental students is more closely tied to progression through training stages than to sex, yet the persistence of knowledge gaps among specialist students indicates that clinical seniority alone does not guarantee first-aid competence. These findings support treating first-aid proficiency as an outcome to be deliberately verified at successive stages of dental training rather than assumed to accrue with experience.
Attenuation of cisplatin-induced oxidative ovarian injury by usnic acid in rats through inhibition of inflammation and endoplasmic reticulum stress
(Elsevier, 2026) Demir, Selim; Alemdar, Nihal Türkmen; Livaoglu, Ayten; Demir, Elif Ayazoglu; Yaman, Hüseyin; Menteşe, Ahmte; Aliyazıcıoğlu, Yüksel
Despite its effectiveness as a DNA intercalator in the treatment of numerous cancers, cisplatin (CIS) exerts deleterious effects on healthy cells, including those that function in reproductive organs. Usnic acid (UA) is a dibenzofuran derivative that is naturally present in lichens and is widely employed in traditional medicine on account of its antioxidant and analgesic activity. The current study aimed to evaluate the therapeutic potential of UA in counteracting CIS-induced ovotoxicity. The experiments comprised five groups of 6 rats each, which were categorised as follows: control, UA (10 mg/kg), CIS (5 mg/kg), CIS + UAs (5 and 10 mg/kg). Subsequent to the conclusion of the experimental procedures, the serum and ovarian tissues collected were subjected to biochemical and histopathological analysis. The results revealed that the CIS administration led to the suppression of the antioxidant system, which resulted from the depletion of the reduced glutathione (GSH) pool within the ovarian tissue. Furthermore, the administration of CIS was found to induce lipid peroxidation (LPO), inflammation, and endoplasmic reticulum stress (ERS). Conversely, UA treatments following CIS administration led to a substantial reduction in LPO levels by means of regeneration of the intracellular GSH pool. Furthermore, the administration of UA treatments resulted in the suppression of inflammatory and ERS processes, which was achieved via modulation of the Nrf2 pathway. Furthermore, the chemoprotective potential of UA was confirmed by serum anti-mullerian hormone levels and histological analysis. Consequently, UA may be considered as a potential chemotherapy-supporting molecule that can protect ovarian tissue following CIS chemotherapy.
Influence of regional artificial cavity layouts on flow boiling in micro heat sinks with stepwise-decreasing pin-fin heights
(Elsevier, 2026) Atci, Fatih; Markal, Burak; Evcimen, Alperen
Novel heat sink configurations and associated flow boiling physics were examined. Specifically, the influence of regional artificial cavity layouts on flow boiling in micro heat sinks with stepwise decreasing pin-fin heights was investigated. Four heat sinks with stepwise decreasing fin heights were compared. One of them has microcavities only in the downstream region (DPFH-1D), the other has microcavities both in middle and downstream regions (DPFH-2D), and another has microcavities in all regions (DPFH-3D). Additionally, the fourth one has no microcavities (DPFH) and was used as reference case. Under various heat fluxes (212 – 462 kWm−2) and mass fluxes (151 and 222 kg m−2 s−1), tests were conducted at an approximately constant inlet temperature (≈77°C). DPFH-1D provided the best overall thermal performance and the highest two-phase heat-transfer coefficients, although DPFH-3D yielded slightly lower wall-superheat values at the two highest heating powers. The maximum heat-transfer-coefficient enhancements of DPFH-1D reached 286.2% and 528.4% at 151 and 222 kgm−2s−1, respectively. Despite producing the highest pressure drop, DPFH-1D’s PEC value remained above 1 throughout dataset, with a maximum of 3.49. Downstream microcavities most effectively promoted capillary liquid retention and surface rewetting, whereas upstream and middle microcavities provided limited additional benefits at low and moderate heat loads.
