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Rational design, biological and in-silico evaluation of quinoline-chalcone hybrids: A new series of antimicrobial and anticancer agents
Full text linkThis study investigates the synthesis, antimicrobial, anticancer, and in silico properties of novel quinoline-chalcone hybrids (nQCa-l), which were synthesized and characterized. Their antimicrobial activity revealed broad-spectrum efficacy, with compound 2QC-h demonstrating superior potency compared to several standard antibiotics and antifungals. The anticancer potential was assessed against gastrointestinal system cancer cell lines (AGS, HepG2, HCT116), where 2QC-h emerged as the most potent antiproliferative agent, often surpassing oxaliplatin in efficacy, particularly in AGS gastric cancer cells. Mechanistic studies have demonstrated that 2QC-h synergistically induces apoptosis and inhibits epithelial-mesenchymal transition (EMT) in AGS cells through the intrinsic mitochondrial pathway, thereby enhancing the anticancer effect of oxaliplatin. Crucially, 2QC-h exhibited selective cytotoxicity towards gastrointestinal system cancer cells (AGS cells: 4.85 ± 0.22 µg/mL and 2.66 ± 0.58 µg/mL, HCT116 cells: 6.61 ± 0.29 µg/mL and 2.39 ± 0.57 µg/mL, and HepG2 cells: 9.14 ± 0.49 µg/mL and 6.15 ± 0.27 µg/mL for 24 h and 48 h, respectively) and minimal morphological effects on healthy HUVEC cells. Computational studies, including DFT analysis, MEP, RDG, ELF, LOL, and ALIE, provided comprehensive insights into the electronic structure, reactivity, and non-covalent interactions, elucidating the structure-activity relationships (SAR). Molecular docking simulations identified VEGFR-2 and EGFR as the preferential targets for these derivatives, with nanomolar binding affinities, which correlated strongly with experimental cytotoxic potencies. ADME highlighted favorable drug-likeness properties while identifying areas for further optimization. Overall, this research establishes quinoline-chalcone hybrids as promising multi-target therapeutic agents with significant potential for developing novel antimicrobial and anticancer drugs. © 2025 Elsevier B.V., All rights reserved
The moderation role of representational fluency in the effect of mental imagery on scientific creativity
Full text linkThis exploratory study examined the moderator role of representational fluency in mental imagery's effect on scientific creativity. The study was conducted with the participation of 125 (60: girls, 65: boys) elementary school students aged 9-10 in D & uuml;zce, T & uuml;rkiye, in the 2024-2025 academic year. The study's hypotheses were analyzed and interpreted using the Process Macro program (for SPSS) developed by Hayes. The moderator variable effect of representational fluency was tested with Model 1, the moderator effect of the sub-dimensions of representational fluency was tested with Model 2, and the moderating effect of gender on the moderator variable was tested with Model 3. The study results show that representational fluency has a moderating role in the effect of mental imagery on scientific creativity. In addition, it was determined that this effect was not significant at different levels of representational fluency. However, only high representational fluency positively regulated the effect of mental imagery on scientific creativity. It was concluded that the connection dimension came to the fore in the moderating effect of representational fluency. Gender was a moderator variable affecting the moderating effect of representational fluency on the effect of mental imagery on scientific creativity. Theoretical explanations and implications related to the research results were shared
Stability analysis and numerical solution of fourth-order neutral Volterra integro-differential equation
Full text linkIn this paper, we study an initial-value problem for a fourth-order neutral Volterra integrodifferential equation. First, the properties of the exact solution are analysed. Next, the problem is solved numerically using the finite difference method containing the composite trapezoidal rule for the integral part of the equation. Error estimate for the approximate solution is carried out and second-order convergence is attained. In support of the idea, numerical examples are given
A potential new approach for preserving historical artifacts through gamma irradiation and green antimicrobials: Microbiological and theoretical screening
Full text linkThis study presents a novel combined treatment process for the decontamination of historical textiles, using gamma irradiation with green antimicrobial agents. Microbiological studies and theoretical approaches were utilized to investigate the effect of treatment processes individually and in combination on isolates from the textile museum. The mean D-10 values and the required doses for complete inactivation were found to be 1.19 and 7.60 kGy for bacteria cocktail and 1.47 and 6.32 kGy for mold cocktail, respectively. The antimicrobial activities of two Schiff bases and their reduced derivatives were tested against gamma-resistant microorganisms by measuring the diameter of the inhibition zones. It was found that reduced derivatives exhibited higher antibacterial activity. All compounds were screened through an in-silico study to evaluate the physicochemical properties, drug-likeness, and toxicity profile. Molecular docking studies were performed to investigate the binding affinity of the title compounds against E. coli DNA gyrase B and topoisomerase IV. From the perspectives of both in vitro studies and computational analysis, L4 exhibited the highest biological activity. This finding revealed that the reduction of the imine bond and molecular flexibility have a significant influence on binding to the active site of the biomolecule. Finally, the combined treatment utilizing L4 with gamma irradiation demonstrated a synergistic effect, leading to a 2.6-fold reduction compared to the control, whereas the individual treatments of L4 and gamma irradiation exhibited approximately a 1-fold reduction. This synergistic effect presents an innovative approach to the historical artifact preservation, providing a more efficient and potentially safer decontamination strategy.International Atomic Energy Agency (IAEA) through the project on Development and Implementa-tion of Cultural Heritage Preservation Using Ionizing Radiation Technology [F22082-CRP-26647]Turkish Energy, Nuclear, and Mineral Research Agency (TENMAK) through Provision of Measurement, Analysis, Testing, IrradiationCalibration Services and Development of Measurement Capabilities [A4.H1.F24]This study has been supported by the International Atomic Energy Agency (IAEA) through the project on Development and Implementa-tion of Cultural Heritage Preservation Using Ionizing Radiation Technology (F22082-CRP-26647) and the Turkish Energy, Nuclear, and Mineral Research Agency (TENMAK) through Provision of Measurement, Analysis, Testing, Irradiation, and Calibration Services and Development of Measurement Capabilities (A4.H1.F24)
Classification of Killing Magnetic Curves In H3
Full text linkIn this paper, we study classification of magnetic curves corresponding to Killing vector fields of H3. First, we solve the geodesic equation analytically. Then we calculate the trajectories generated by all the six Killing vector fields, which are considered as magnetic field vectors, by using perturbation method up to first order with respect to the strength of the magnetic field. We present a comparison of our solution with the numerical solution for one case. We also prove that 3-dimensional (?)-Kenmotsu manifolds cannot have any magnetic vector field in the direction of their Reeb vector fields
Multifunctional GFRC composites: PEDOT: PSS-driven dielectric enhancement for energy storage and sensing applications
Full text linkThis study presents a comprehensive investigation into the development and characterization of multifunctional Glass Fiber Reinforced Cement (GFRC) composites enhanced with Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT: PSS) to impart advanced electrical properties. We systematically analyzed the influence of PEDOT: PSS concentration (0-15 wt %) and curing age on the dielectric behavior of these novel composites, evaluating their capacitance, dielectric constant, loss factor, and electrical modulus across a broad frequency range (10 Hz-10 MHz). The integration of PEDOT: PSS significantly modified the material's electrical characteristics, demonstrating concentration-dependent variations and complex relaxation mechanisms dominated by Maxwell-Wagner interfacial polarization. The optimized P2 formulation (10 wt % PEDOT: PSS) exhibited superior electrochemical performance, maintaining the highest capacitance values and achieving a peak dissipation factor (tan delta) of 0.43 +/- 0.02 at day 15, representing a 185 % enhancement over unmodified GFRC. EDX analysis confirmed successful polymer incorporation, with P2 exhibiting the highest carbon content (5.8 wt %) and sulfur content (1.8 wt %), indicating optimal dispersion. Equivalent circuit models were established and validated (R2 > 0.98), providing insights into complex charge transport mechanisms within this hybrid material. Microstructural analyses via scanning electron microscopy revealed significant morphological modifications, including the formation of crystalline and plate-like structures, while complementary FT-IR and TGA analyses confirmed polymer-cement interaction stability and thermal stability up to 450 degrees C. These findings establish fundamental design principles for creating electrically conductive cementitious materials with tunable dielectric properties, enabling strategic deployment in innovative infrastructure systems, energy storage devices, and electromagnetic shielding technologies
Microstructural characterization, hydration reactions and mechanical properties of cement-based composites produced with silica fume used to develop green, clean and sustainable cement
Full text linkA great deal of research is still being carried out to determine the hydration reactions of silica fume-substituted cementitious composites. The changes in the structure of these composites due to complex hydration reactions vary according to the physicochemical properties of the materials. This study investigated the effectiveness of silica fume in combination with CEM I 42.5 R type Portland cement. For this purpose, the physicochemical properties of the raw materials and the development of hydration products determined by mineralogical, molecular, microstructural, and thermal analyses of silica fume substituted cement pastes at 28-day were monitored. In addition, the effect of the hydration products determined by these analyses on the compressive strength of cement mortars was discussed. The results showed that the compressive strength of the mortars could be improved by silica fume substitution at all hydration ages. Reason for this, silica fume with nano-sized particles and large surface area promotes the hydration of C3S and C2S and the formation of calcium silicate hydrate phase. Moreover, CH produced by cement hydration reacts with the amorphous silica in the silica fume to form an additional C–S–H gel, densifying the microstructure of cement-based composites and reducing voids. These findings indicate that the substitution of silica fume into Portland cement can provide an environmentally friendly, cost-effective and sustainable solution. Additionally, it is determined as a result of standard tests that cement produced with 10 % silica fume substitution meets all the requirements of 52.5 R type cement, which is the upper strength class. © 2025 Elsevier B.V., All rights reserved
The mediating role of agile organizational culture in the effect of digital transformation on job crafting
Full text link17.03.2026 tarihine kadar kullanımı yazar tarafından kısıtlanmıştır.Dijital dönüşüm çağında, çalışanların iş biçimlendirme davranışları yeni iş koşullarına uyum sağlama açısından kritik bir öneme sahiptir. Çevik örgüt kültürü ise bu uyum sürecini destekleyen bir unsur olarak öne çıkmaktadır. Bu bağlamda, araştırma; dijital dönüşümün iş biçimlendirme davranışları üzerindeki etkisini inceleyerek, bu ilişkide çevik örgüt kültürünün nasıl bir aracı rol üstlendiğini ortaya koymak amacıyla gerçekleştirilmiştir. Araştırma kapsamında, Düzce ilinde imalat sanayi sektöründe faaliyet gösteren ve dijital dönüşüm uygulamalarını benimsemiş büyük ölçekli işletmeler ile küçük ve orta ölçekli işletmelerde (KOBİ) görev yapan 481 beyaz yakalı çalışandan anket tekniğiyle veriler toplanmıştır. Nicel araştırma yöntemiyle yürütülen çalışmada, değişkenler arasındaki ilişkileri belirlemek amacıyla oluşturulan modelin test edilmesinde kısmi en küçük kareler yapısal eşitlik modellemesi (PLS-SEM) kullanılmıştır. Elde edilen bulgular doğrultusunda, dijital dönüşümün yalnızca zorlayıcı iş taleplerini artırma davranışı üzerinde doğrudan anlamlı bir etkisi olduğu; buna karşın, diğer iş biçimlendirme davranışlarının üzerinde çevik örgüt kültürü boyutları aracılığıyla dolaylı etkiler yarattığı belirlenmiştir. Bu kapsamda, dijital dönüşümün yapısal iş kaynaklarını artırma davranışları üzerindeki etkisinde çevik dönüşüm boyutunun; sosyal iş kaynaklarını artırma davranışları üzerindeki etkisinde çevik ekipler boyutunun; engelleyici iş taleplerini azaltma davranışları üzerindeki etkisinde ise çevik dönüşüm ve çevik insan kaynakları boyutlarının tam aracılık rolü üstlendiği saptanmıştır. Araştırmanın tali amacı kapsamında gerçekleştirilen farklılık analizleri (bağımsız örneklem t-testi ve tek yönlü ANOVA) sonucunda ise çalışanların demografik özelliklerine göre dijital dönüşüm, çevik örgüt kültürü ve iş biçimlendirme davranışlarına ilişkin algılarında anlamlı farklılıklar gözlemlenmiştir. Sonuç olarak, elde edilen bulgular, dijital dönüşümün iş biçimlendirme üzerindeki etkilerinin çevik örgüt kültürü boyutlarıyla birlikte şekillendiğini ortaya koymaktadır. Ayrıca, çalışanların demografik özelliklerine göre dijital dönüşüm, çevik örgüt kültürü ve iş biçimlendirme algılarında gözlemlenen farklılıklar, örgütsel uygulamaların bireysel farklılıkları gözeten yaklaşımlarla tasarlanması gerektiğine dikkat çekmektedir. Anahtar Sözcükler: Dijital Dönüşüm, Çevik Örgüt Kültürü, İş Biçimlendirme, Yapısal Eşitlik Modeli.In the era of digital transformation, employees' job crafting behaviors are of critical importance in adapting to new working conditions. Agile organizational culture, on the other hand, emerges as a factor that supports this adaptation process. In this context, the study was conducted to examine the effect of digital transformation on job crafting behaviors and to reveal how agile organizational culture plays a mediating role in this relationship. Within the scope of the research, data were collected through a questionnaire from 481 white-collar employees working in large-scale enterprises and small and medium-sized enterprises (SMEs) operating in the manufacturing sector in Düzce province, which have adopted digital transformation practices. The study was carried out using the quantitative research method, and the Partial Least Squares Structural Equation Modeling (PLS-SEM) technique was used to test the model developed to determine the relationships among variables. According to the findings, digital transformation has a significant direct effect only on the behavior of increasing challenging job demands; however, it creates indirect effects on other dimensions of job crafting through the dimensions of agile organizational culture. In this regard, it was determined that the agile transformation dimension plays a full mediating role in the effect of digital transformation on increasing structural job resources; the agile teams dimension in the effect on increasing social job resources; and both the agile transformation and agile human resources dimensions in the effect on reducing hindering job demands. As part of the secondary objective of the study, the difference analyses (independent sample t-test and one-way ANOVA) revealed that there are significant differences in employees' perceptions of digital transformation, agile organizational culture, and job crafting behaviors according to their demographic characteristics. As a result, the findings reveal that the effects of digital transformation on job crafting are shaped together with the dimensions of agile organizational culture. Moreover, the observed differences in perceptions of digital transformation, agile organizational culture, and job crafting according to employees' demographic characteristics highlight the need for organizational practices to be designed with approaches that take individual differences into account
Predictive Value of Intrapartum Transperineal Ultrasonography in Determining Delivery Mode: A Prospective Study
Full text linkObjective: This study aimed to evaluate the usefulness of intrapartum transperineal ultrasonographic (ITU) parameters in predicting delivery mode. Method: This prospective study included 104 pregnant women inAactive labor with ruptured membranes at D & uuml;zce University Health Application and Research Center from April 2023 to April 2024. ITU measured the angle of progression (AoP), head-perineum distance (HPD), and midline angle (MLA). These parameters were compared with digital vaginal examinations and delivery outcomes. Results: Of the participants, 93 (89.4%) had spontaneous vaginal deliveries (SVD), 6 (5.7%) had operative vaginal deliveries (OVD), and 5 (4.8%) had cesarean sections (C/S). AoP1 and AoP2 were significantly higher in the SVD group compared to OVD and C/S groups (p<0.001). The Delta AoP was significantly lower in the OVD group (p=0.044). HPD1 and HPD2 were significantly higher in the C/S group (p=0.031 and p=0.041, Arespectively). MLA1 and MLA2 were significantly lower in the SVD group (p=0.002 and p=0.001, Arespectively). Conclusions: ITU is a valuable tool in predicting delivery mode. AoP, HPD, and MLA measurements provide objective and reliable data to assist clinicians in labor management. Further research with larger sample sizes is needed to validate these findings and establish standardized protocols for clinical use
Examining the problems encountered in furniture education in three different education programs (the case of Düzce)
Full text linkMesleki ve teknik eğitim, ülkelerin ekonomik kalkınmasına ve istihdam politikalarına doğrudan etkileri nedeniyle üzerinde yoğun tartışmaların yaşandığı bir eğitim türüdür. Özellikle ülkemiz gibi genç işgücü potansiyeline sahip ülkelerde mesleki eğitimin önemi çok daha ön plana çıkmaktadır. Yapılan bu çalışma ile Düzce ili için oldukça önemli bir sektör olan ve çok sayıda kişiye istihdam sağlayan mobilya sektörü üzerine eğitim veren farklı düzeyde (ortaöğretim, önlisans ve lisans) eğitim kurumlarındaki öğrencilerin eğitsel sorunlarının belirlenmesi, gelecek beklentilerinin ve meslek algılarının ortaya çıkarılması hedeflenmektedir. Çalışmada, 3 farklı eğitim düzeyinden yani ortaöğretim düzeyinde meslek liselerindeki mobilya ve dekorasyon bölümlerinde okuyan öğrencilerden, önlisans düzeyinde yüksekokullarda yer alan mobilya ve dekorasyon bölümü öğrencilerinden ve lisans düzeyinde de orman endüstri mühendisliği ile ağaç işleri endüstri mühendisliği bölümleri öğrencilerinden veri elde edilmeye çalışılmıştır. Çalışmada veri elde etme aracı olarak araştırmacılar tarafından literatüre bağlı kalınarak hazırlanan anketten yararlanılmıştır. Çalışma kapsamında üç farklı eğitim düzeyinden toplam 247 öğrenciye ulaşılmıştır. Elde edilen veriler irdelendiğinde ilgili bölümlerde ağırlıklı olarak (%89,1) erkek öğrencilerin olduğu belirlenmiştir. Katılımcı öğrencilere göre ilgili bölümleri seçmelerinde en etkili faktör ailelerinin yönlendirmesidir. Eğitim kademesi yükseldikçe öğrencilerin bilgisayar destekli tasarım yapma becerilerinin arttığı ancak üretim becerilerinin azaldığı belirlenmiş ve bu durumlar istatistiksel olarak da ilişkili tespit edilmiştir. Katılımcı öğrencilere göre eğitim kademesi yükseldikçe ders materyallerinde de iyileşmelerin olduğu ancak fiziki alan yetersizliğinin arttığı görülmüştür ve bu durumlarında istatistiksel olarak anlamlı olduğu belirlenmiştir. Yapılan istatistiksel değerlendirmelerde teorik-pratik uyumun iyi olmamasında eğitim kademesi arttıkça sorunların arttığı belirlenmiştir. Eğitim kademelerine göre mesleki öğrenme noktasında en istekli olan grup önlisans öğrencileri olurken, lise düzeyinde mesleği öğrenme isteği diğer eğitim kademelerine göre en düşüktür. Ancak, lisans ve önlisans düzeyindeki öğrencilere göre mezun oldukları bölümle ilgili bir işte çalışmayı daha yüksek oranda isteyenlerin lisans mezunu oldukları tespit edilmiştir.Vocational and technical education is a type of education that is subject to intense debate due to its direct effects on the economic development and employment policies of countries. Especially in countries with a young workforce potential such as ours, the importance of vocational education is much more prominent. This study aims to determine the educational problems of students in educational institutions at different levels (secondary school, associate degree and undergraduate degree) that provide education on the furniture sector, which is a very important sector for the province of Düzce and provides employment to a large number of people, and to reveal their future expectations and perceptions of profession. In the study, data was obtained from students studying in furniture and decoration departments in vocational high schools at the secondary level, from students studying in furniture and decoration departments in colleges at the associate degree level, and from students studying in forestry industry engineering and woodwork industry engineering departments at the undergraduate level. In the study, a survey prepared by the researchers based on literature was used as a data acquisition tool. A total of 247 students from three different educational levels were reached within the scope of the study. When the obtained data were examined, it was determined that there were predominantly male students (89.1%) in the relevant departments. According to the participant students, the most effective factor in choosing the relevant departments is the guidance of their families. It was determined that as the level of education increases, the students' computer-aided design skills increase, but their production skills decrease, and these situations were statistically related. According to the participant students, as the level of education increases, there are improvements in course materials, but the lack of physical space increases, and it was determined that these situations are statistically significant. In the statistical evaluations, it was determined that the problems in the lack of good theoretical-practical harmony increase as the level of education increases. While the group that is most eager in terms of vocational learning according to the levels of education is associate degree students, the desire to learn the profession at the high school level is the lowest compared to other levels of education. However, it was determined that those who want to work in a job related to the department they graduated from are undergraduate and associate degree students at a higher rate