Recep Tayyip Erdoğan University

In this study, one new compound (1) and eight known compounds (2–9) were identified from the aerial parts of endemic Scorzonera coriacea. The chemical structures of the isolated compounds were elucidated using extensive spectroscopic analyses (1D and 2D NMR, FT-IR, UV, and LC-QTOF-MS). The antimicrobial activities of 1–9 were evaluated against 10 microorganisms. Compounds 3 and 8 exhibited the best activity against Mycobacterium smegmatis at concentration of 35 μg/mL and 25 μg/mL (MIC), respectively. Compound 1 was the most effective against Pseudomonas aeruginosa among the microorganisms tested (MIC 125 μg/mL). The best activity was observed at 25 μg/mL (MIC) for compounds 9 and 5 against yeast fungi. Compounds 1, 3, 4, and 5 exhibited low cytotoxicity toward L929 cells. Molecular docking (MD) studies supported the in vitro biological activity findings by revealing the binding modes of the compounds to the target proteins of M. smegmatis, Candida albicans, and Escherichia coli and by identifying their critical amino acid interactions.

Despite acknowledging the complementary role of chemical equilibrium-based pedagogical treatments on students’ academic performance, the related science education literature has not examined their practical effectiveness and significance via a meta-analysis method. Therefore, this study intends to meta-analytically explore their effectiveness in improving students’ academic performance. It included 55 studies (k) from 51 unique sources. The results of the meta-analysis showed that the overall effect-size (Hedges’ g = 1.028) fell into the large effect. This means that the treatments are more effective in enhancing students’ academic performance of chemical equilibrium than the controlled ones. Nevertheless, the variability in the effect-sizes revealed the importance of the treatment types and educational contexts. Also, the results indicated that the moderator variables were statistically non-significant (p > 0.05) but categorically played a crucial role at predicting the students’ academic performance through the treatments. Given the descriptive findings, the current meta-analysis offers the following individual moderator levels to better teach and measure the topic “chemical equilibrium”: university (for educational level), inquiry-based learning (for type of treatment), open-ended question (for question type) and teacher (for practitioner). Of course, chemistry teachers and science educators should take into consideration the role of educational contexts in learning chemical equilibrium, while deciding the type of treatment to teach it.

Post-endodontic pain is a major concern that negatively impacts patients’ quality of life. To date, there is no study examining the effect of the menstrual cycle on post-endodontic pain. Thus, this study aimed to elucidate any significant differences in post-endodontic pain perception between genders and across different menstrual phases. This clinical study included 97 patients (21 males and 76 females) requiring endodontic treatment for asymptomatic necrotic mandibular molars. Female participants were categorized into menstrual (n = 24), proliferative (n = 22), and secretory (n = 30) phase groups according to self-reported menstrual cycle timing. Postoperative pain was assessed using the Visual Analog Scale (VAS) at 8 h, day 1, day 2, and day 3 after treatment, and analgesic intake was also recorded. Repeated pain measurements were analyzed using a linear mixed-effects model adjusted for age, treatment time, and baseline pain score. No significant differences in postoperative pain scores were observed among the menstrual, proliferative, and secretory phase groups at any evaluated time point. At 8 h, postoperative pain scores were significantly higher in the menstrual phase group (p = 0.002) and the secretory phase group (p = 0.025) than in the male group, whereas the proliferative phase group did not differ significantly from males (p = 0.112). No significant differences between female phase groups and males were detected at postoperative day 1, day 2, or day 3. The highest proportions of pain reporting and analgesic use were observed in the secretory phase group. Menstrual cycle phase was not associated with significant differences in post-endodontic pain among female patients. However, female patients in the menstrual and secretory phases experienced higher early postoperative pain than males at 8 h. These findings suggest that menstrual cycle phase may be relevant to early post-endodontic pain perception, particularly when comparing female patients with males.

Hazelnut (Corylus avellana L.) is an economically important crop, and improving fruit yield and quality is a key objective in its cultivation. This study aimed to evaluate the effects of basal and root sucker pruning on fruit traits of the ‘Sivri’ hazelnut cultivar grown in the Rize region. The experiment was conducted during a 2-year period, comparing pruned and unpruned plants. Fruit yield and various fruit characteristics were measured, including fruit weight, dimensions, and kernel properties. The results indicated that basal and root sucker pruning significantly affected fruit weight, kernel weight, and fruit size. Pruned plants produced higher yield (2.97 kg) compared to unpruned plants (1.28 kg), corresponding to an increase of 43.07

Chatter significantly limits productivity in deep-hole boring operations. Identifying stable combinations of spindle speed and depth of cut through trial-and-error approaches is both time-consuming and costly. Therefore, a reliable stability prediction that directly incorporates tool dynamics and cutting mechanics is needed to reduce the risk of chatter. This study presents an experimentally grounded stability prediction approach for a commercial boring bar and quantifies how overhang distance and insert geometry shift stability limit during the boring of Ti-6Al-4 V alloy. Frequency Response Functions (FRF) were obtained via hammer testing by using three overhang distances (LO = 125, 160, 195 mm), and cutting-force coefficients were calculated by using the measured cutting forces. These inputs were implemented in CutPRO to generate stability diagrams. The predicted stability limits were subsequently validated through cutting experiments and detailed surface inspections. Results showed that increasing overhang distance reduces the stability limit by more than 90