Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Bayraktar, Bülent(3)
- Dertli, Enes(2)
- Okur, Süheyb(2)
- Akbulut, Sezgin(1)
- Akkoyunlu, Ebubekir(1)
- Ayazoglu, Rabil(1)
- Bozkurt, Fatih(1)
- Bozok, Ümmü Gülşen(1)
- Colquhoun, Ian J.(1)
- Cuce, Erdem(1)
- Cuce, Pinar Mert(1)
- Kahveci, Hakan(1)
- Kaya, Yasemin(1)
- Kaya, Yunus(1)
- Kosunalp, Selahattin(1)
- Kızıl, Hamit E.(1)
- Mayer, Melinda J.(1)
- Narbad, Arjan(1)
- Riffat, Saffa(1)
- Sağdıç, Osman(1)
- Topyay, Yusuf(1)
- Tosun Köse, Fatma(1)
- Yetim, Nurdan Kurnaz(1)
- Çorapsız, Muhammed Reşit(1)
- Özcan, Gülbahar Böyük(1)
- Özdemir, Akın(1)
- Özen, Doğukan(1)
- Özkan, Elvan Hasanoğlu(1)
- Öğütçü, Hatice(1)
- İspirli, Hümeyra(1)
- Şengül, Mustafa(1)
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ1Development and characterization of postbiotic-enriched biodegradable films with antifungal activity for tomato storage
Kaya, Yasemin; İspirli, Hümeyra; Bozkurt, Fatih; Sağdıç, Osman; Şengül, Mustafa; Dertli, Enes
BACKGROUND: One of the major contributors to postharvest losses in tomatoes is the development of infectious mold diseases. In this study, four distinct biodegradable film formulations were developed incorporating postbiotics derived from Lactiplantibacillus plantarum Y48 and the polysaccharide alternan. The formulations included alternan, sodium alginate and glycerol (AAG), alternan, postbiotic, sodium alginate and glycerol (APAG), postbiotic, sodium alginate and glycerol (PAG), and sodium alginate and glycerol (AG) as a control. The films were characterized in terms of their physical, mechanical, thermal, and morphological properties. To assess antifungal efficacy, tomatoes artificially inoculated with Alternaria alternata were coated with each film and stored at ambient temperature for 8 days. RESULTS: The incorporation of alternan and postbiotics enhanced both the mechanical strength and thermal stability of the films. Fourier-transform infrared (FTIR) analysis confirmed the successful integration of the bioactive components into the polymer matrix. Scanning electron microscopy (SEM) imaging revealed that postbiotic addition contributed to a rougher and more rigid surface morphology, while alternan improved the structural cohesion of the films. All film formulations exhibited significant inhibitory effects against A. alternata, with the PAG formulation demonstrating the most pronounced antifungal activity. CONCLUSION: These results suggest that the PAG film, enriched with postbiotics, represents a promising biocontrol strategy for mitigating fungal spoilage in tomatoes. In conclusion, this study underscores the potential of combining postbiotics and alternan for the development of active, biodegradable edible films with antifungal functionality for postharvest preservation.
AtıfScopus2WoS2OpenAlex3
İncele - MakaleAçık Erişim2026Scopus SJRQ2Acute Music-Frequency Exposure Modulates Salivary Stress and Neurotrophic Markers in Young Adults: A Randomized Controlled Trial
Bozok, Ümmü Gülşen; Özcan, Gülbahar Böyük; Bayraktar, Bülent; Özen, Doğukan
Background: The exam period is a period full of intense stress and anxiety that deeply affects cognitive and physiological responses for university students. Listening to music has the potential to protect cellular health and alleviate the negative effects of stress by affecting individuals' mood, and cognitive functions. This study aimed to investigate the differential effects of 528 and 432 Hz music frequencies on salivary BDNF, CREB, and GRP78 levels in young adults, along with their association with cognitive performance under exam-related stress. Methods: A total of 162 healthy university students were randomly assigned to three groups: no music (control), 528 Hz instrumental music, and 432 Hz instrumental music. Participants listened to music for 20 min, after which saliva samples were collected and analyzed for brain-derived neurotrophic factor (BDNF), glucose-regulated protein 78 (GRP78) and cyclic AMP response element-binding protein (CREB) levels using ELISA. Cognitive performance was assessed using the Stroop word-color test administered by medical doctor. Results: Exposure to 528 Hz music significantly increased salivary BDNF (3.84 [2.76–4.13]) and CREB levels (1.5 [1.38–1.59]) compared to control (p < 0.05), whereas GRP78 levels were elevated in the 432 Hz group (0.51 [0.47–0.58]) (p < 0.05). No significant differences were observed between groups in Stroop test performance. Conclusion: These findings suggest that specific music frequencies elicit distinct biological responses under exam-related stress, even in the absence of immediate cognitive performance differences. Salivary neurotrophic and stress-related biomarkers may offer valuable non-invasive insights into music's neuromodulatory effects. Trial Registration: ClinicalTrials.gov identifier: AMU-EC-8522.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ2Recitation Mode Is Associated With Salivary CREB and Cortisol Responses during Qur'anic Recitation
Okur, Süheyb; Topyay, Yusuf; Bayraktar, Bülent
Background: Spiritual practices such as Qur'anic recitation are commonly associated with psychological and physiological regulation; however, their salivary biomarker correlates remain insufficiently understood. This exploratory study examined whether different modes of Qur'anic recitation were associated with changes in salivary cAMP response element-binding protein (CREB), a biomarker related to plasticity-associated pathways, and cortisol, a marker of hypothalamic-pituitary-adrenal axis activity. Methods: The sample comprised three nonrandomized, criterion-defined conditions: Passive Control (n = 20; participants unable to read Qur'anic Arabic), Sight-Reading (n = 30), and Memorized Recitation (n = 30). Saliva samples were collected immediately before and after the experimental task or passive rest period. Salivary CREB and cortisol concentrations were quantified using ELISA. Post-task CREB levels were analyzed using ANCOVA with baseline CREB as a covariate. Cortisol responses were analyzed using change scores, Welch's ANOVA, and an additional robust factorial model with HC3 heteroscedasticity-consistent standard errors to evaluate exploratory Condition × Gender patterns. Results: After controlling for baseline CREB levels, experimental condition had a significant effect on post-task salivary CREB, F(2, 76) = 8.16, p < 0.001, η2p = 0.18. Memorized recitation showed higher adjusted post-task CREB levels than both sight-reading and passive control conditions. Cortisol change scores also differed significantly across conditions, Welch's F(2, 40.02) = 30.76, p < 0.001. Both active recitation conditions were associated with cortisol reduction relative to passive rest, with no significant difference between sight-reading and memorized recitation. Although descriptive data suggested a possible gender-related divergence in the memorized recitation condition, the Condition × Gender interaction did not remain statistically significant under robust estimation and was therefore interpreted as exploratory. Conclusion: These preliminary findings suggest that Qur'anic recitation modes are associated with distinct salivary biomarker patterns. Memorized recitation was linked to higher adjusted salivary CREB levels, whereas both active recitation modes were associated with cortisol attenuation relative to passive rest. Because the present design did not include active non-Qur'anic vocalization or neutral reading control conditions, the specificity of these effects to Qur'anic content cannot be determined. Future studies should include active control conditions and larger gender-stratified samples to clarify the mechanisms underlying these biomarker responses.
AtıfWoS1OpenAlex1İncele - MakaleAçık Erişim2026Scopus SJRQ1Shape-Directed Hydrothermal Design of Zinc Oxide Nanoparticles for Antimicrobial and Anticancer Applications
Özkan, Elvan Hasanoğlu; Yetim, Nurdan Kurnaz; Kızıl, Hamit E.; Öğütçü, Hatice
The emergence of antibiotic-resistant bacteria represents one of the most pressing challenges in global healthcare. In this study, metal oxide–based nanomaterials are gaining prominence due to their antimicrobial and anticancer potential. In the present study, six new zinc oxide nanoparticles (ZnO-NPs) synthesized via the hydrothermal method using different surfactants were characterized, and their biological activities were evaluated. ZnO-NPs, whose structural properties were determined by a range of analytical methods including BET, FT-IR, SEM-EDX, XRD, and XPS, exhibited significant antibacterial and antifungal effects on a range of bacterial and fungal strains. The study revealed that variations in the morphology and surface area had a direct impact on antimicrobial efficacy. In antimicrobial assays, the inhibition zones ranged from 10.5 mm to 25.5 mm, with ZnO-6 exhibiting the highest efficacy against S. epidermidis (25.5 mm). In cytotoxicity assays, ZnO-6 demonstrated the strongest anticancer potential against H460 cells with the lowest IC50 value of 31.9 µg/mL. Furthermore, a strong correlation was revealed between the physicochemical properties of ZnO-NPs and their anticancer activity, as evidenced by the results of tests conducted on H460 lung cancer cells. Specifically, ZnO-6, which possesses a flower-like morphology and the highest surface area, exhibited the strongest anticancer effect with an IC50 value of 31.9 µg/mL. The parallel enhancement in both antimicrobial and anticancer activities observed in ZnO-6 suggests a common underlying mechanism, likely driven by the high surface area and specific flower-like morphology that facilitates increased interaction with cell membranes and ROS generation. The findings demonstrate that the controlled design of ZnO-NPs in terms of morphology and surface area offers significant potential in both antimicrobial and anticancer applications.
AtıfScopus3WoS3OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ2The Relationship Between Metacognitive Beliefs and Salivary Cortisol, BDNF, and NDNF Levels: A Cross-Sectional Study
Okur, Süheyb; Bayraktar, Bülent; Tosun Köse, Fatma
Purpose: The main objective of this study is to non-invasively investigate the relationship between metacognitive beliefs and cortisol, the primary stress output of the hypothalamic-pituitary-adrenal (HPA) axis, as well as neurotrophic factors associated with neuroplasticity brain-derived neurotrophic factor and neuron-derived neurotrophic factor (BDNF and NDNF). Within this framework, the hypotheses that negative metacognitions would be associated with increased cortisol and decreased BDNF levels, and that cortisol might play a mediating role in this relationship, were tested. Method: The study was designed in a cross-sectional model with 60 university students. Participants' metacognitive beliefs were measured using the Metacognitions Questionnaire-30 (MCQ-30). Salivary cortisol, BDNF, and NDNF levels were analyzed using the ELISA method. Pearson correlation and hierarchical multiple regression analyses were used for data analysis. Finding: The results showed a significant positive relationship between the total metacognition score and cortisol (r = 0.589, p < 0.01) and a strong negative relationship between cortisol and BDNF (r = −0.662, p < 0.01). Hierarchical regression analysis supported a partial mediation model, indicating that dysfunctional metacognitive beliefs have both a significant direct negative association with BDNF and an indirect association mediated by cortisol. In the final model, both metacognition (β = –0.298, p < 0.05) and cortisol (β = –0.281, p < 0.05) were significant factors associated with lower BDNF levels. NDNF showed a positive relationship with BDNF (r = 0.571) but not with other variables. Conclusion: These findings point to a psychobiological model where dysfunctional metacognitive beliefs are linked to suppressed neuroprotective mechanisms like BDNF, both directly and indirectly through HPA axis activation. The results shed light on the potential neurobiological mechanisms underlying the effectiveness of metacognitive therapies.
AtıfScopus4WoS4OpenAlex4İncele - MakaleAçık Erişim2022Scopus SJRQ1Double adaptive power allocation strategy in electric vehicles with battery/supercapacitor hybrid energy storage system
Çorapsız, Muhammed Reşit; Kahveci, Hakan
This paper proposes a new energy management strategy (EMS) for electric vehicles (EVs) with battery/supercapacitor hybrid energy storage systems (HESS). Firstly, the battery/supercapacitor HESS configuration and obtaining the load current from the driving cycle are comprehensively explained. Secondly, fixed and adaptive frequency-based (AFB) EMS are discussed in detail. In the proposed method, the current demanded by the load is separated into low and high-frequency components with the help of an adaptive low-pass filter (A-LPF). In addition, adaptive battery current (ABC) is generated according to the supercapacitor (SC) state of charge (SoC), and a double adaptive power allocation strategy is performed. The proposed method is compared with the AFB-EMS for load currents, load powers, DC link voltages, filter cut-off frequencies, battery, and SC SoCs on the UDDS driving cycle. When the obtained results were evaluated together, it was observed that the proposed method completed the driving cycle with a higher battery SoC and realized the adaptive cut-off frequency in a narrower band.
AtıfScopus14WoS12OpenAlex14İncele - MakaleAçık Erişim2022Scopus SJRQ3IoT-TDMA: A performance evaluation of TDMA scheme for wireless sensor networks with Internet of Things
Kosunalp, Selahattin; Kaya, Yunus
This article focuses on the design and implementation of an improved version of TDMA scheme for wireless sensor networks (WSNs) exploiting the Internet of Things (IoT) phenomena. The main motivation behind this work is to create an environment for WSNs to benefit from IoT opportunities. An extensive review of the state-of-the-art medium access control (MAC) approaches proposed for IoT is carried out underlying their basic principles and features. An adaptation of TDMA strategy, called IoT-TDMA, is proposed to enhance the channel performances particularly throughput and latency. To test the performance of IoT-TDMA practically, a low-cost node hardware with the capability of Internet connection is essentially designed. IoT-TDMA has been implemented on real-world highly scalable single-hop and multi-hop topologies. Performance results indicate significant improvements in terms of channel throughput and end-to-end delay in comparison to a recently proposed efficient MAC scheme.
AtıfScopus17OpenAlex18İncele - MakaleYalnız künye2020Scopus SJRQ1D-optimal experimental design for production models in nonstandard experiments
Özdemir, Akın
Robust design is an effective Quality by Design method to reduce product variation by selecting levels of design factors. For a number of situations, a nonstandard design region with linearly limited resources is needed to conduct an experiment. In the literature, little attention has been given to the development of robust design models for the nonstandard design region with a combination of linearly limited resources and a limited number of design points. In this paper, a selection scheme of D-optimal experimental design points is proposed to generate design points using the modified exchange algorithm for the nonstandard design region while specifying linearly limited resources and the limited number of design points. The modified exchange algorithm is able to generate global design points with less time complexity than the improved Fedorov algorithm. In addition, robust design models linking a D-optimal experimental design with quality considerations are proposed in order to obtain optimum settings of design factors for the product. Comparative studies are also presented. Finally, a real-life experimental study shows that the proposed models with the desirability function and the sequential quadratic programming technique achieve greater variance reduction than the traditional counterparts.
AtıfScopus16WoS15OpenAlex15İncele - MakaleAçık Erişim2020Scopus SJRQ1Existence of multiple solutions of Schrödinger-Kirchhoff-type equations involving the p(.) -Laplacian in ℝN
Ayazoglu, Rabil; Akbulut, Sezgin; Akkoyunlu, Ebubekir
In this paper, we prove the existence of multiple solutions for the nonhomogeneous Schrödinger-Kirchhoff-type problem involving the p(.)-Laplacian (Formula presented.) where b≥0 is a constant, N ≥2, Δp(.)u:=div(|∇u|p(.)−2∇u) is the p(.)-Laplacian operator, (Formula presented.) is Lipschitz continuous, (Formula presented.) is a coercive type potential, (Formula presented.) and (Formula presented.) functions verifying suitable conditions. We propose different assumptions on the nonlinear term (Formula presented.) to yield bounded Palais-Smale sequences and then prove that the special sequences we found converge to critical points, respectively. The solutions are obtained by the Mountain Pass Theorem, Ekeland variational principle, and Krasnoselskii genus theory.
AtıfScopus1WoS1İncele - MakaleAçık Erişim2016Scopus SJRQ1EpsA is an essential gene in exopolysaccharide production in Lactobacillus johnsonii FI9785
Dertli, Enes; Mayer, Melinda J.; Colquhoun, Ian J.; Narbad, Arjan
Lactobacillus johnsonii FI9785 has an eps gene cluster which is required for the biosynthesis of homopolymeric exopolysaccharides (EPS)-1 and heteropolymeric EPS-2 as a capsular layer. The first gene of the cluster, epsA, is the putative transcriptional regulator. In this study we showed the crucial role of epsA in EPS biosynthesis by demonstrating that deletion of epsA resulted in complete loss of both EPS-1 and EPS-2 on the cell surface. Plasmid complementation of the epsA gene fully restored EPS production, as confirmed by transmission electron microscopy and nuclear magnetic resonance (NMR) analysis. Furthermore, this complementation resulted in a twofold increase in the expression levels of this gene, which almost doubled amounts of EPS production in comparison with the wild-type strain. Analysis of EPS by NMR showed an increased ratio of the heteropolysaccharide to homopolysaccharide in the complemented strain and allowed identification of the acetylated residue in EPS-2 as the (1,4)-linked βGlcp unit, with the acetyl group located at O-6. These findings indicate that epsA is a positive regulator of EPS production and that EPS production can be manipulated by altering its expression.
AtıfScopus43WoS38OpenAlex39İncele - MakaleAçık Erişim2016Scopus SJRQ1Novel glazing technologies to mitigate energy consumption in low-carbon buildings: A comparative experimental investigation
Cuce, Erdem; Cuce, Pinar Mert; Riffat, Saffa
Buildings play a key role in total world energy consumption as a consequence of poor thermal insulation characteristics of facade materials. Among the elements of a typical building envelope, windows are responsible for the greatest energy loss because of their notably high overall heat transfer coefficients. About 60% of heat loss through the building fabric can be attributed to the glazed areas. In this respect, novel cost-effective glazing technologies are needed to mitigate energy consumption, and thus to achieve the latest targets toward low/zero carbon buildings. Therefore in this study, three unique glazing products called vacuum tube window, heat insulation solar glass and solar pond window which have recently been developed at the University of Nottingham are introduced, and thermal performance analysis of each glazing technology is done through a comparative experimental investigation for the first time in literature. Standardized co-heating test methodology is performed, and overall heat transfer coefficient (U-value) is determined for each glazing product following the tests carried out in a calibrated environmental chamber. The research essentially aims at developing cost-effective solutions to mitigate energy consumption because of windows. The results indicate that each glazing technology provides very promising U-values which are incomparable with conventional commercial glazing products. Among the samples tested, the lowest U-value is obtained from the vacuum tube window by 0.40W/m2K, which corresponds to five times better thermal insulation ability compared to standard air filled double glazed windows.
AtıfScopus35WoS33OpenAlex37İncele - DergiMicrobial Biotechnology
- DergiQuality and Reliability Engineering International
- DergiJournal of the Science of Food and Agriculture
- DergiInternational Journal of Energy Research
- DergiMathematical Methods in the Applied Sciences
- DergiConcurrency and Computation: Practice and Experience
- DergiBrain and Behavior
- DergiBioinorganic Chemistry and Applications