WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14627/6
Browse
9 results
Search Results
Article Selective Recovery and Preconcentration of Catechins from Wine Industry Residues Using Molecularly Imprinted Polymers: An Eco-Friendly Solid Phase Extraction Approach(Springer, 2026) Özen, Seda; Tütem, Esma; Ersoy, Şeyda KaramanMolecularly imprinted polymers (MIPs) are engineered materials that provide exceptional selectivity and stability for target molecule recognition. While most previous catechin-imprinted polymer (CAT-MIP) studies have focused on tea matrices, the present study applies CAT-MIP technology to wine industry residues, particularly grape seeds, which represent sustainable and underutilized sources of bioactive compounds. CAT-MIP was synthesized using CAT as the template molecule and polymerization parameters including functional monomer type, porogen composition, and template-to-monomer-to-crosslinker molar ratios were systematically optimized. Among the tested conditions, 4-vinylpyridine (4-VP) and an acetonitrile: dimethyl sulfoxide (ACN: DMSO, 98:2, v/v) solvent system provided the most favorable imprinting performance. Adsorption studies revealed heterogeneous binding behavior consistent with the Freundlich model, while Langmuir parameters were used for comparative evaluation. The optimized CAT-MIP was successfully applied as a molecularly imprinted solid-phase extraction (MISPE) sorbent, achieving selective recovery of 69.20 +/- 2.45% for CAT and 52.50 +/- 1.77% for epicatechin (ECAT) from white grape seed extracts, with comparable performance observed for red grape seed extracts. This MISPE based approach offers the first comprehensive study applying CAT-MIP technology to wine industry waste valorization, comparing red and white grape varieties, and establishing a fully validated HPLC-PDA (high performance liquid chromatography-photodiode array detection) method for CAT quantification. The eco-friendly approach addresses the growing need for sustainable extraction of valuable high-value natural antioxidants. from agro-industrial byproducts.Article Metabolic Responses to Benzoic Acid Stress and Glutamine Transport-Dependent Vulnerabilities in Escherichia Coli Revealed by NMR Metabolomics(Springer, 2026) Yuksektepe, Ecem; Elgin, Emine Sonay; Onat-Tasdelen, Kadriye Aslihan; Chae, Young Kee; Dogu, Eralp; Catav, Sukru Serter; Ozturkel-Kabakas, HaticeBenzoic acid (BA) is a widely used weak organic acid preservative with antimicrobial activity, yet the metabolic basis of its antibacterial action and the determinants of bacterial sensitivity remain incompletely understood. Here we combined growth assays with H-1 NMR metabolomics to characterize BA-induced metabolic responses in Escherichia coli BW25113 and to examine metabolic changes associated with impaired glutamine transport. Wild-type BW25113 and its BA-sensitive isogenic Delta glnP mutant, lacking the membrane-bound glutamine permease of the high-affinity GlnHPQ transport system, were exposed to sublethal BA concentrations. BA slowed growth and significantly altered the levels of 42 metabolites in the wild-type and 38 in Delta glnP, with the mutant showing stronger growth inhibition and reduced BA tolerance. Both strains exhibited metabolic changes consistent with cellular responses to oxidative and acid stress, including alterations in central carbon metabolism, lysine degradation, cysteine and methionine metabolism, pyrimidine metabolism, and one-carbon pool by folate. However, several metabolic responses differed between the two strains. In wild-type cells, BA exposure was associated with changes in glycerolipid metabolism, glycerophospholipid metabolism, nicotinate and nicotinamide metabolism, lysine biosynthesis, glycine, serine and threonine metabolism, and purine metabolism. In contrast, Delta glnP cells showed distinct alterations in D-amino acid metabolism, arginine biosynthesis, and other carbon fixation pathways. In addition, the mutant displayed substantial baseline differences relative to the wild-type, including altered nucleotide and amino acid pools. Together, these results indicate that both BA exposure and deletion of glnP induce broad metabolic adjustments in Escherichia coli. Loss of glnP is associated with distinct metabolic states and altered responses to BA stress, highlighting the importance of glutamine transport in adaptation to weak organic acid stress.Article Ibuprofen and Nimesulide Derivatives Selectively Induce Apoptosis in HER2-Positive Breast Cancer via Inhibition of the PLA2-COX-2-NF-κB Pathway(Springer, 2026) Bedir, Ipek; Cakirli, Egemen; Kucukguzel, S. Guniz; Yilmaz, Ozgur; Biliz, Yagmur; Telci, DilekBackground Chronic inflammation contributes to breast cancer development through the phospholipase A(2) (PLA(2))-cyclooxygenase-2 (COX-2)-nuclear factor kappa B (NF-kappa B) cascade, which regulates prostaglandin synthesis, oxidative stress, and transcription of pro-inflammatory and anti-apoptotic genes. This pathway is particularly active in HER2-positive breast cancer, promoting proliferation, invasion, and resistance to apoptosis. Non-steroidal anti-inflammatory drugs such as ibuprofen and nimesulide target COX enzymes and have shown potential in suppressing inflammation-driven tumorigenesis. In this study, we evaluated the anticancer and anti-inflammatory activity of newly synthesized, structurally modified ibuprofen and nimesulide derivatives designed to modulate PLA(2)-COX-2-NF-kappa B axis. Methods and Results Cytotoxicity was assessed in HER2-positive breast cancer cells (AU565 and SKBR3) and compared with normal dermal fibroblasts (HDF) and breast epithelial cells (MCF-12A), using WST-1 assays. Apoptosis, cell cycle distribution, caspase-3/7 activation, and ROS generation were analyzed by imaging-based assays, flow cytometry, and fluorescence methods. Gene expression of PLA2G2A and PTGS2 was quantified by qRT-PCR, and NF-kappa B translocation was analyzed by immunocytochemistry. Two ibuprofen triazole derivative (D1) and ibuprofen thioether derivative (D7) and one nimesulide derivative (D8) significantly reduced cell viability in a dose-dependent manner without affecting normal cells. These derivatives induced G(0)/G(1) arrest, caspase-3/7 activation, ROS reduction, and increased late apoptosis. Downregulation of PLA2G2A and PTGS2 expression and inhibition of NF-kappa B translocation confirmed disruption of the PLA(2)-COX-2-NF-kappa B cascade. Conclusion These findings demonstrate that structurally optimized ibuprofen and nimesulide derivatives exert dual anti-inflammatory and anticancer effects in HER2-positive breast cancer by suppressing PLA(2)-COX-2-NF-kappa B pathway and promoting apoptotic cell death.Article Determination of the Susceptibility of Onychomycosis Agents Isolated in Sakarya to Octenidine Dihydrochloride and Hypochlorous Acid(Springer, 2026) Köroğlu, Mehmet; Çiftci, Ihsan Hakkı; Gül, Merve; Yağmur, Ahmet Can; Aydemir, Özlem; Kılbaş, İmdat; Erman, GülayThe aim of this study was to investigate the susceptibility of onychomycosis agents to octenidine dihydrochloride (OCT-D) and hypochlorous acid (HOCl) antiseptics using agar dilution, tube dilution, and flow cytometry methods. In this study, onychomycosis agents including dermatophytes (Trichophyton spp., Microsporum spp., Candida spp.) and secondary agents such as Aspergillus niger and Fusarium solani were cultured on Sabouraud dextrose agar (SDA). Species identification was confirmed using MALDI-TOF MS. The minimum inhibitory concentration (MIC) values of OCT-D, HOCl, and terbinafine for dermatophytes grown on culture plates were determined using the agar dilution method and the broth microdilution (tube dilution) method in accordance with the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Following MIC determination, the minimum fungicidal concentration (MFC) was assessed. Based on the MFC results, flow cytometry analysis was performed using SYTO 9 and propidium iodide (PI) dyes to investigate the fungicidal effects of OCT-D, HOCl, and terbinafine.As a result of antifungal susceptibility testing of onychomycosis agents, approximate MIC values obtained by the agar dilution method were 250 mg/L for OCT-D, 128 mg/L for HOCl, and 0.064 mg/L for terbinafine. Using the tube dilution method, approximate MIC values were 62.5 mg/L, 64 mg/L, and 0.032 mg/L for OCT-D, HOCl, and terbinafine, respectively. Flow cytometry-based viability analyses showed that the results obtained using the tube dilution method were more consistent. Since OCT-D and HOCl demonstrated MIC values far below their commercially available concentrations and exhibited high fungicidal activity, further studies suggest that these agents may be strong alternatives for topical treatment.Article Advances and Strategies in Biosensor-Based Diagnostics for Parasitic Infections: A Comprehensive Scoping Review(Springer, 2026) Aminizadeh, Selva; Alizadeh, Gita; Alizadeh, Zahra; Khalilzadeh, Balal; Abidin, Zurina Zainal; Marzi, Mahdi; Rafiei-Sefiddashti, RahelehParasitic diseases are among the most widespread infections worldwide, causing millions of deaths and illnesses each year. So rapid and accurate diagnosis is essential, requiring highly sensitive and specific tests. Biosensors can provide significant advantages over traditional diagnostic methods because of their specificity, sensitivity, speed, simplicity, ease of use, repeatability, and capacity for early-stage disease detection. Recent advances in modern diagnostic tools for detecting parasitic infections use nanomaterials such as gold nanoparticles, carbon nanofibers, and carbon nanotubes. These developments have significantly lowered detection limits to the picogram and femtogram levels. This review will cover recent advancements in biosensor-based diagnostic techniques in parasitology.Article Citation - WoS: 9Citation - Scopus: 9Social Loneliness and Perceived Stress Among Middle-Aged and Older Adults During the Covid-19 Pandemic(Springer, 2024) Ozdemir, Petek Akman; Celen, Hacer NerminOlder age has been considered a risk factor for physical and mental health during the COVID-19 pandemic, yet many middle-aged and older adults showed resilience. This cross-sectional study aimed to examine the protective factors against social loneliness and perceived stress among Turkish middle-aged and older adults. The data were collected from 464 adults aged 55 and above when the curfew restrictions were still in place. Hierarchical regression analyses revealed that resilience, life satisfaction, self-esteem, satisfaction with social support and internet use negatively predicted both social loneliness and stress. The extent of curfew measures, which were more restrictive for the elderly, did not predict social loneliness and stress. The participants living alone showed higher social loneliness and those with chronic disease reported more stress. Results highlight the significant role of protective factors in enhancing well-being and coping in old age under highly stressful situations such as the pandemic.Article Citation - WoS: 5Citation - Scopus: 6Comparison of <i>in Vitro</I> Antifungal Activity Methods Using Extract of Chitinase-Producing <i>aeromonas</I> Sp. Bhc02(Springer, 2023) Cadirci, Bilge Hilal; Yilmaz, GulesmeBiological control to prevent fungal plant diseases offers an alternative approach to facilitate sustainable agriculture. Since the chitin in fungal cell walls is a target for biocontrol agents, chitinases are one of the important antifungal molecules. In this study, the aim was to investigate a new chitinase isolated from a fluvial soil bacterium and to show the antifungal activity of the characterized chitinase by comparing the three common methods. The bacterium with the highest chitinase activity was identified as Aeromonas sp. by 16 S rRNA sequence analysis. Following the determination of the optimum enzyme production time, the enzyme was partially purified, and the physicochemical parameters of the enzyme were investigated. In the antifungal studies, direct Aeromonas sp. BHC02 cells or partially purified chitinase were used. As a result, in the first method in which the Aeromonas sp. BHC02 cells were spread on the surface of petri dishes, no zone formation was observed around the test fungi spotted on the surface. However, zone formation was observed in the methods in which the antifungal activity was investigated using the partially purified chitinase enzyme. For example, in the second method, the enzyme was spread on the surface of PDA, and zone formation was observed only around Penicillum species among the test fungi spotted on the surface. In the third method, in which the necessary time was given for the formation of mycelium of the test fungi, it was observed that the growth of Fusarium solani, Alternaria alternata and Botrytis cinerea was inhibited by the partially purified chitinase. This study concludes that the results of the antifungal activities depend on the method used and all fungal chitins cannot be degraded with one strain's chitinase. Depending on the variety of chitin, some fungi can be more resistant.Article Citation - WoS: 1Citation - Scopus: 2Reliability, Validity and Normative Data of the Timed Water Swallow Test Accompanied by Semg(Springer, 2024) Selen Akil, Dilan; Bengisu, Serkan; Sezer, Eyup; Krespi, Yakup; Topbas, Saime SeyhunPurpose Swallowing disorders are highly interrelated with increased morbidity and mortality rates; therefore, early detection is crucial. Most screening tools rely on subjective observation, thus making objective assessment tools more vital. Timed Water Swallowing Test (TWST) is a screening tool used in the field providing quantitative data. This study aimed to investigate the swallowing parameters in a wide age range by using TWST and to expand the already existing normative data pool accordingly. It is also aimed to examine the reliability of the TWST and assess its validity in stroke survivors. Materials and methods This study had a cross-sectional design. TWST carried out simultaneously along with surface EMG and laryngeal sensor on 196 healthy subjects aged 10 to 80 for normative data. Also, TWST carried out 30 patients having a history of recent stroke. Test-retest and inter-rater scoring analysis were used for reliability purposes, while Gugging Swallowing Screen (GUSS) test was used for validity purposes. Additionally, the correlations between the participants' TWST scores and GUSS scores were examined using the Spearman correlation coefficient. Results The normative TWST data of healthy participants are tabulated and presented and their average swallowing capacity was found 13.73 ml/s. Furthermore, the mean swallowing capacity of stroke survivors was found 4.61 ml/s. As a result of validity analyses, a statistically strong and significant relationship was found between GUSS and TWST parameters (r = 0.775, p < 0.001). Intraclass correlation coefficient (ICC) and correlation values were found between moderate to good agreement between test-retest measurement (ICC = 0.563 to 0.891, p < 0.05). Also, the agreement between the raters was found to be significant (ICC = 0.949 to 0.995, p < 0.05). Conclusion TWST is a valid and reliable screening tool to evaluate dysphagia on given population. Although the test's performance on healthy individuals is adequate, more research is still needed to confirm that it can be used as a screening tool for stroke.Article Citation - WoS: 2Citation - Scopus: 1Analysis of Substance Use and Mental Disorder Diagnoses in Adolescents With a History of Delinquency: a Cross-Sectional Study(Springer, 2024) Baysan Arabaci, Leyla; Dikec, Gul; Tas Soylu, Gulsenay; Bilac, Oznur; Uzunoglu, Gulcin; Ayakdas Dagli, DilekThis study aimed to evaluate substance use and comorbid mental disorders in delinquent adolescents presenting to a child and adolescent psychiatry outpatient clinic. This study included 47 adolescents aged 15-18 years and had a history of delinquency. Data were collected using the Addiction Profile Index Adolescent Form (API-A) and an information form. Results indicated that the adolescents' mean age is 16.11 +/- 1.05 years, 78.7% had committed crimes against property and 34.0% against the person, and 34.0% were also victims of crime. Mean API-A total scores indicated that their level of substance use was low. In addition, mean API-A total scores showed significant differences according to the adolescents' migration status, age, economic status, school attendance, mental disorder diagnosis, duration of mental disorder, and type of offense (p < 0.05). The benefit provided by timely and appropriate psychosocial interventions may have a key role in solving this problem for adolescents and improving their future as adults.