Menoufia University

The optimal long-term antithrombotic strategy after apparently successful catheter ablation of atrial fibrillation (AF) remains uncertain, particularly in patients who meet conventional guideline thresholds for oral anticoagulation (OAC). To compare continuation versus cessation strategies of long-term OAC after successful AF ablation and to quantify net clinical benefit (NCB) integrating thromboembolic and bleeding outcomes. We searched PubMed, Cochrane CENTRAL, and Embase from inception through February 2026 for randomized and comparative observational studies evaluating long-term OAC continuation versus cessation (no OAC and/or switch to aspirin) after successful AF ablation. Risk of bias was assessed using RoB2 for randomized trials and a modified Newcastle-Ottawa Scale (NOS) for observational studies. Random-effects meta-analyses used a restricted maximum likelihood estimator with Hartung-Knapp adjustment. NCB was calculated as: thromboembolic event rate - (1.5 × major bleeding rate). Six studies met the inclusion criteria (four randomized trials and two observational cohorts). Stroke/transient ischemic attack (TIA) events were reported in six studies and were not significantly different between OAC continuation and cessation strategies (OR 0.69; 95% CI 0.24-1.99; p = 0.49). Systemic embolism (three studies) did not differ between groups (p = 0.12). Major bleeding (five studies) was numerically higher with continued OAC but not statistically significant (OR 2.07; 95% CI 0.88-4.86; p = 0.09). In NCB analysis, continued OAC yielded more negative or near-neutral NCB values, whereas, the cessation strategies were less negative or marginally positive; the fixed-effect risk difference in NCB (continued OAC vs cessation) was +0.00067 (95% CI -0.00279 to +0.00413). This meta-analysis suggests that after successful AF ablation, continuing OAC does not significantly reduce stroke risk compared to cessation or switching to aspirin, but it may increase major bleeding. While NCB trends favor cessation, the low absolute event rates and the risk of silent AF recurrence necessitate caution.

Abstract This work thoroughly investigates how different durations of ultrasonic treatment affect the structural, chemical, and morphological features of graphene oxide (GO) obtained from graphite through the Staudenmaier method. To ensure efficient exfoliation, a dual-source ultrasonic configuration (40 KHz, 100 W bottom transducer combined with a 100 W submerged probe) was utilized in pulse mode. We elucidate the structural evolution throughout the sonication duration (3, 5, 7, and 12 min) using Raman spectroscopy, x-ray diffraction (XRD), and scanning electron microscopy (SEM) under controlled thermal conditions. The initial GO, which underwent 3 min of sonication, had thick, stacked flakes bearing the markings of an XRD peak at 10.46° (0.845 nm d-spacing), suggesting the presence of highly oxidized and expanded layers evident from the peak intensity ratio ( I D / I G ) of 1.11. The structural evolution of GO during sonication resulted in significant reduction and rearrangement toward an optimum at 7 min, marked by a single dominant remaining reduced graphene oxide (rGO) XRD peak at 26.17° (0.340 nm d-spacing) and a decrease in I D / I G to 0.59, indicating substantial sp 2 lattice restoration and deoxygenation. This was accompanied by substantial structural restoration and deoxygenation. The 5-min mark provided morphological insight into the initial stage of exfoliation of GO, marked by thin, wrinkled sheets. However, prolonged treatment of 12 min led to an energy saturation effect, causing the I D / I G to increase to 0.72 and the dominant XRD peak to shift back toward larger d-spacing at 20.19° (0.439 nm). This suggests a reversal of structural benefits due to mechanical fragmentation and disordered restacking induced by excessive acoustic cavitation.

Abstract Background: Developing proficiency in tooth preparation is a primary objective in undergraduate dental education. Traditional teacher-centered lectures are often used to impart a significant volume of information to a large number of students. In contrast, Case-Based Learning (CBL) offers an interactive, student-centered approach designed to utilize real-life clinical scenarios to promote deeper understanding and reflective thinking. Objectives: This study aimed to evaluate the effectiveness of CBL compared to traditional lecture-demonstration methods in enhancing the foundational knowledge and practical tooth reduction skills of dental students in fixed prosthodontics Materials and Methods: A quasi-experimental study was conducted at the Faculty of Dentistry, Tanta University, involving 60 second-year dental students. Participants were assigned to an experimental group (n=30) receiving four weekly 90-minute CBL sessions and a control group (n=30) receiving traditional lectures and clinical demonstrations. Outcomes were measured using a 10-item multiple-choice pre-test and post-test for knowledge, and technical performance was evaluated using a validated analytic rubric to score tooth preparations on typodont models. Results: Baseline pre-test scores showed no significant difference between the two groups (P=.753), indicating comparable initial knowledge. Following the intervention, the CBL group achieved a significantly higher mean score on the post-test (9.17 ± 1.02) compared to the control group (7.73 ± 1.96). Furthermore, the CBL group demonstrated superior practical performance with a significantly higher mean score (33.9 ± 2.68) than the control group (28.83 ± 1.84). Conclusion: CBL significantly enhances both foundational knowledge and practical tooth reduction skills compared to traditional teaching methods. These findings support the integration of case-based interactive activities into the preclinical dental curriculum to better prepare students for clinical practice Trial registration: Trial registration: ClinicalTrials.gov, NCT07393724, registered on 6 February 2026 (Retrospectively registered).

Abstract Background Thyroid nodules are frequent in clinical settings. Accurate differentiation between benign and malignant lesions is essential for management. Although fine-needle aspiration cytology (FNAC) is the diagnostic reference standard, it is invasive, operator-dependent, and may yield inconclusive results. Ultrasound elastography has emerged as an adjunctive imaging technique that may increase diagnostic confidence and minimize the need for invasive procedures. Objectives To assess the diagnostic performance of ultrasound elastography in preoperative thyroid nodules evaluation and correlate it with histopathological outcomes. Methods This prospective study was conducted on 200 patients complaining of thyroid nodules (40 males and 160 females, aged 30–69 years). All patients underwent a comprehensive neck examination and laboratory evaluation, including thyroid function tests, prothrombin time, and complete blood count. Imaging evaluation included conventional and Doppler ultrasound, shear wave elastography, strain elastography, ultrasound-guided fine-needle aspiration biopsy with histopathological evaluation. Final diagnosis was established by histopathology in surgically treated nodules and by benign cytology with stable clinical and ultrasound follow-up in Bethesda II nodules. Results Malignant nodules demonstrated significantly higher shear wave elastography (SWE) parameters than benign nodules ( P < 0.001). The elasticity ratio (ER) showed superior diagnostic performance, with a cut-off value of 2.5 achieving an AUC of 96.3% (95% CI: 93.3–99.4), with 90.9 % sensitivity and 89.4% specificity. The strain index (SI) showed optimal diagnostic performance at a threshold value of 1.3 achieving an AUC 97%; (95% CI: 93.2–100), with a diagnostic sensitivity of 97% and specificity of 88%. Conclusions Ultrasound elastography demonstrates excellent diagnostic capability in distinguishing malignant from benign thyroid nodules. Its integration with conventional ultrasound may improve risk stratification and help reduce unnecessary FNAC or surgical procedures, particularly in low-to-intermediate risk (TI-RADS 3 and 4) nodules.