İstanbul Sağlık ve Teknoloji Üniversitesi Kurumsal Akademik Arşivi
DSpace@İSTÜN, Üniversite mensupları 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
Topology optimization-based lightweight chassis design: A case study on structural efficiency enhancement for an autonomous scale vehicle
(Dicle University, 2025) Taş, Kerem Ali; Karabıyık, Mehmet Can; Tanrıver, Kürşat; Ak, Mine
This study aims to enhance structural efficiency and achieve material savings by employing the topology optimization method for the lightweight design of an autonomous model vehicle chassis. During the design process, the penalty-based Solid Isotropic Material with Penalization (SIMP) method, available within ANSYS Academic software, was utilized. Initially, a structural analysis of the chassis was conducted, followed by the application of topology optimization based on the finite element method (FEM) results. Through iterative solutions under specified loading conditions and boundary constraints, a mass reduction of approximately 27% was achieved compared to the initial geometry. Despite the reduction in mass, the design maintained its structural integrity. Graphical analyses indicated that the optimization process reached convergence after the fifth iteration, with a stabilized distribution of material. The results demonstrate the potential of topology optimization to develop low-cost, lightweight, yet robust structural solutions, emphasizing its effectiveness as an engineering tool in systems where weight reduction is critical, such as autonomous model vehicles.
Antimicrobial and antibiofilm activities of paracetamol in combination with various antimicrobials
(Istanbul University Press, 2025) Altıner Kurt, Eda; Hacıoğlu, Mayram
Background and Aims: In recent years, very few new antimicrobial agents have been approved and used for the treatment of infectious diseases. Paracetamol (acetaminophen) is one of the nonsteroidal anti inflammatory drugs with analgesic and antipyretic effects, which is frequently preferred and used safely in our country and in many other countries. In addition, because it is the most frequently prescribed drug after antibiotics and is often administered with antimicrobial therapy, understanding the interactions between these two drug classes is extremely important for drug repurposing. Methods: For this purpose, the effects of paracetamol alone or in combination with various antimicrobial agents and their activities on adhesion and biofilm formation were investigated against various standard bacteria and yeasts. Results: The minimum inhibitory concentration of paracetamol against standard strains was found 10,000 μg/mL, and the minimum bactericidal and fungicidal concentrations were found 10,000 - > 20,000 μg/mL. Cefepime and paracetamol combinations against Escherichia coli and Achromobacter xylosoxidans, and gentamicin and paracetamol combinations against Klebsiella pneumoniae and Acinetobacter baumannii showed synergistic effect. No antagonism was observed. According to the biofilm adhesion and formation inhibition assays, it was found that paracetamol was more effective against gram-negative bacteria than gram-positive bacteria and yeasts. Conclusions: In conclusion, this study proved that paracetamol, which is one of the most common analgesic and antipyretic agents in clinical use for many years, has antimicrobial and antibiofilm activity and can show synergistic effect in combination with various antibiotics.
Improving nutritional quality, aroma profile and bioactive retention of rocket juice via thermosonication: A support vector regression-based optimization
(Frontiers Media S. A., 2026) Levent, Okan; Şimşek, Mehmet Ali; Yıkmış, Seydi; Demirel, Selinay; Türkol, Melikenur; Tokatlı Demirok, Nazan; Er, Hatice; Aljobair, Moneera O.; Karrar, Emad; Tokatlı, Nazlı; Mohamed Ahmed, I. A.
This study investigates the application of thermosonication (TS) to improve the functional properties of roka (Eruca vesicaria subsp. sativia) water. Processing parameters, including time (8–16 min), amplitude (60–100%), and temperature (40–60 °C), were optimised using a comparative approach combining the response surface method (RSM) and support vector regression (SVR). The total phenolic content (TPC) increased to 86.04 mg GAE/100 mL with TS, representing an 8.1% rise compared to the control group and an 18.3% increase over pasteurization. Likewise, the total chlorophyll level reached 16.98 mmol TE/L from 9.67 g/100 mL, and β-carotene rose to 24.90 mg/100 mL (p < 0.05). Pasteurization caused losses of 15–30% in these components. In the phenolic profile, significant increases were observed in chlorogenic acid (42.05 μg/mL), caffeic acid (15.66 μg/mL), and quercetin (4.28 μg/mL). A total of 31 compounds were identified in aroma analysis; with TS treatment, levels of 3-Hexen-1-ol (15.70 μg/kg) and 1-hexanol (2.01 μg/kg) were preserved or increased. In in vitro digestion tests, the TS group demonstrated the highest bioavailability, even during the intestinal phase. For example, RSM demonstrated high compliance coefficients (R2 = 0.99), while SVR showed strong predictive performance (CV R2 = 0.84), particularly for FRAP. Overall, the results suggest that thermosonication is an innovative method for protecting and enhancing bioactive compounds in rocket juice.
Aloe vera-derived Ag-doped TiO2 nanoparticles immobilized by chitosan films for photo(electro)catalytic and antimicrobial functions
(Elsevier, 2025) Kaba, İbrahim; Bozkurt, Rabia Nur; Altıner Kurt, Eda; Kerkez Kuyumcu, Özge; Koca, Atıf
In this study, as an environmentally friendly and sustainable approach, TiO2 nanoparticles (TiO2 NPs) were prepared by green synthesis method using deep eutectic solvent (DES, ChCl/glycerol (1:2)) based Aloe vera leaves extract obtained by Soxhlet extraction. The DES system functioned concurrently as a green solvent and a functional medium, while the bioactive chemicals in the Aloe vera leaves extract operated as natural reducing and stabilizing agents. The produced TiO2 NPs were doped with silver (Ag) at molar ratios of 0.25, 0.50, and 0.75, and immobilized on a chitosan matrix (Ag/TiO2-CS) to facilitate recovery from the reaction media. The materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), photoluminescence (PL) spectroscopy, scanning electron microscopy-energy dispersive X ray analysis (SEM-EDX) and X-ray photoelectron spectroscopy (XPS). Characterization validated the TiO2 phase, effective Ag incorporation, diminished band gap energy (from 3.34 eV to 2.83 eV), and uniform nanoparticle distribution. PL measurements confirmed that Ag doping reduces carrier charge recombination. The 0.50Ag/ TiO2-CS film displayed the best photocatalytic degradation efficiency for malachite green (93.3 %) under solar irradiation and exhibited a higher photocurrent response relative to undoped TiO2. Moreover, antimicrobial assays demonstrated that 0.50 and 0.75 Ag/TiO2 NPs exhibited significant suppression of S. aureus and E. coli, with low minimum inhibitory concentrations (MIC) (0.40–0.20 µg/mL) and minimum bactericidal concentra tions (MBC), signifying robust bactericidal efficacy. The findings indicate that DES-assisted Aloe vera-mediated synthesis provides an economical and scalable method for producing multifunctional nanocomposites with considerable potential in environmental remediation and biomedical fields.
The role of exosomal micrornas in cancer metastasis: An in-depth guide
(Türk Radyasyon Onkolojisi Derneği, 2025) Tahan, Rana; Yazıcı, Hülya
Exosomes and their contents play a vital role in forming a unique communication system that carries and transmits signal molecules, which alter the physiological state of cells and are linked to the on set and progression of numerous diseases including cancers. Focusing on exosomal cargo, microRNAs (miRNAs), which are small non-coding, single-stranded RNAs that regulate gene expression of target genes, are suggested to be transferred via exosomes in a selective manner that facilitates cancer progres sion and dissemination. In this context and through ongoing cancer research, researchers have currently been focusing on exosomal microRNA as a specific communication message delivered from cancer cells to the other cells that plays a crucial role in the immune response, tumor migration, tumor cell invasion, and development of metastasis In this review, we aim to evaluate the expected role of exosome-derived microRNAs in the development of cancer metastasis and their possible role of molecular markers in metastasis sites by the current literature on cancer research.
