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Effects of intramuscular administration of Mg–Zn alloys on tissue and blood parameters in rats
No full textMagnesium–zinc (Mg–Zn) alloys are widely investigated as potential biodegradable biomaterials, but their systemic safety and tissue-level effects remain incompletely understood. This study aimed to evaluate the biochemical and histopathological responses to intramuscular implantation of Mg–Zn alloys in rats. Thirty-two male Wistar albino rats were randomly assigned to four groups: Control, Mg, MgZn1, and MgZn3, and sacrificed at the 4th and 7th weeks. Blood samples were collected for lipid profile, liver and kidney function tests, and protein analysis. Histopathological examinations of muscle, brain, kidney, liver, and spleen tissues were performed using hematoxylin and eosin (H&E) staining. Biochemical analysis revealed no statistically significant differences among groups (p ≥ 0.05), although the MgZn3 group showed mild elevations in kidney function markers. Histological evaluation demonstrated preserved cortical and hepatic architecture, mild edema and vascular congestion in muscle tissue, focal tubulitis and interstitial lymphocyte infiltration in kidneys, and increased numbers of debris-laden macrophages in spleen sections of MgZn3 animals. No severe or life-threatening alterations were detected. In conclusion, Mg–Zn alloys exhibited favorable short-term biocompatibility with only limited systemic and histological changes, while higher zinc content (MgZn3) was associated with mild renal and splenic responses. These findings highlight the need for further long-term studies using complementary staining methods to confirm safety for biomedical applications
Microstructural and numerical failure analysis of a light-duty DI Diesel engine crankshaft
No full textPolygonum cognatum Meissn. Ethanolic Extract Promotes Apoptosis in Ovarian Cancer Cells: Experimental and Docking Study
No full textThis study investigated the secondary metabolite profiles of Polygonum cognatum (P. cognatum) extracts obtained using various solvents to evaluate their biological activities, including antioxidant, anti-inflammatory, anthelmintic, and cytotoxic effects. Both in vitro and in silico approaches were employed, with a particular focus on apoptosis induction in SKOV-3 human ovarian cancer cells. GC–MS analysis of the ethanolic extract identified major constituents, including vitamin E, 1-docosene, and heptacosyl acetate. The ethanolic extract exhibited the highest total phenolic content (667.22 mg GAE/g) and demonstrated the most potent antioxidant and anti-inflammatory activities. Cytotoxicity assays showed a revealed concentration of 25.35 µg/mL in SKOV-3 cells after 72 h. Annexin V staining indicated dose-dependent apoptosis, which was further supported by RT-qPCR data showing upregulation of pro-apoptotic genes and downregulation of BCL2. Molecular docking studies on CASPASE-9 (PDB ID: 5JUY) corroborated these findings, with vitamin E displaying a strong binding affinity (−7.8 kJ/mol), suggesting its potential involvement in apoptosis modulation. Overall, the ethanolic extract of P. cognatum effectively induces intrinsic apoptosis in SKOV-3 ovarian cancer cells, as evidenced by complementary in vitro and in silico analyses
Dynamic feedback loops in recommender systems: Analyzing fairness, popularity bias, and user group disparities
No full textEnsuring equitable treatment of different user groups in recommender systems is a key challenge, and the issue of fairness has been widely explored in the literature. However, understanding fairness within a robust feedback loop, as it occurs in real-world settings, remains elusive. This study examines the interplay between popularity bias, calibration, accuracy, and beyond-accuracy performance of recommender systems using a novel dynamic feedback loop framework. The framework models iterative interactions between recommendation algorithms and user profiles, enabling the analysis of calibration, accuracy, and beyond-accuracy measures across user groups with varying preferences on popular items, i.e., Popular-, Diverse-, and Niche-focused. Empirical evaluations conducted on two benchmark datasets using three collaborative filtering algorithms reveal distinct disparities in how feedback loops affect different user groups. Niche-focused users, despite being the most active and information-rich, experience the steepest deterioration in system alignment over time, losing much of their initial calibration, long-tail exposure, and diversity advantages, along with proportional declines in accuracy. These results show that feedback dynamics progressively misalign the system with its most valuable users, making them the most disadvantaged over time. Popular-focused users remain most aligned with algorithmic tendencies, achieving steady accuracy gains but remaining confined to narrow, popularity-driven content with little to no long-tail exposure. Meanwhile, Diverse-focused users, initially balanced between popular and niche preferences, undergo gradual calibration drift and consistent reductions in diversity and long-tail representation, gradually converging toward recommendation patterns similar to Popular-focused users. Overall, the results demonstrate that feedback loops magnify structural inequalities, reinforcing popularity bias while reducing diversity and personalization across all user groups
Manipulating the charge transfer pathway in a dual Z-scheme BiOBr/g-C3N4/V2O5-Al2O3 heterojunction toward efficient degradation of textile dyes
No full textBackground: One of the main environmental concerns has recently been the contamination of water sources by organic dyes. Organic dyes are an example of pollutants that can seriously contaminate water and endanger the lives of living things. The present article explores the photocatalytic and synergistic response of BiOBr, g-C3N4, and V2O5 photocatalysts via developing a dual Z-scheme system. Here, we have designed a novel alumina (Al2O3) supported dual Z-scheme BiOBr/g-C3N4/V2O5 heterojunction driven by visible light to remove MB dye effectively. Methods: All photocatalysts were synthesized using an easy-to-use and economical approach. This work employed thermal polycondensation and co-precipitation methods for g-C3N4 and BiOBr fabrication, respectively, while the calcination method was opted for the Al2O3-supported V2O5 photocatalyst. The binary and ternary heterojunctions of Al2O3 supported g-C3N4/V2O5 and BiOBr/g-C3N4/V2O5 were formed using physical mixing and in-situ methods. Significant Findings: The dual Z-scheme charge transferal route amongst BiOBr, g-C3N4, and V2O5 enhanced MB photodegradation performance by extending light absorption, decreasing the recombination rate, and increasing charge separation efficiency, which was validated via optical, PL, and EIS studies. Also, Al2O3 is used in the ternary heterojunction as a supported material for the adsorption of the dye molecules as well as to boost the charge separation and transportation rate. BET analysis confirmed enhancement in the surface area of BiOBr/g-C3N4/V2O5-Al2O3 ternary heterojunction compared to other photocatalysts, leading to improved adsorption. The results explored that the BiOBr/g-C3N4/V2O5-Al2O3 ternary heterojunction outperformed other photocatalysts with an MB degradation efficiency of 91 % within 60 min of light exposure. Additionally, during MB degradation critical function of •O2⁻ and •OH radicals in MB photodegradation was observed, which was validated by ESR and scavenging studies. Furthermore, recyclability studies verified a 78 % degradation rate even after five catalytic cycles and confirmed high stability and reusability of the ternary heterojunction
Dual-functional Ti3+-TiO2/CeO2 S-scheme heterostructures for photoinduced nitrophenol reduction and azo dye oxidation: Experimental and DFT insights
No full textThe rational construction of a photocatalytic system that maximizes sunlight harnessing and facilitates its redox abilities is still an intriguing research domain in photocatalysis technology. The present study reports synthesising a novel S-scheme nanocomposite system combining CeO2 and oxygen vacancies (OVs) modified self-doped Ti³⁺-doped TiO₂. A unique approach of incorporating active site engineering via OVs generation in self-doped Ti3+-TiO2 and Ce3+/Ce4+ valency exchange in CeO2 has synergistically endorsed the photoredox potential in the resulting heterostructure system. Typically, the OVs in Ti3+-TiO2 serve as electron-rich centres, stimulating charge isolation and effective visible light absorption, while the Ce3+/Ce4+ valency exchange dynamics in CeO2 facilitate effective electron shuttling and redox capabilities. This synergistic arrangement not only fosters interfacial charge transference but also expedites the overall redox potential, rendering superior catalytic activity in both oxidation and reduction reactions. As a result, the mid-state energy level and dual redox-active sites equipped Ti3+-TiO2/CeO2 system exhibit 84 % 4-nitrophenol photo-reduction to 4-aminophenol and 90.6 % photo-oxidative degradation of Sunset Yellow dye. Density Functional Theory (DFT) calculations and Bader charge analysis helped in identifying the exposed attacking sites that enabled selective photocatalytic interactions. Moreover, chromatography analyses (HPLC and LCMS-MS) further aided in understanding the reductive and oxidative mechanisms, respectively. The nanocomposite photocatalyst showed excellent stability under the experimental conditions and exhibited up to four cycles with no significant loss in efficacy. This study demonstrates the dual functionality of the S-scheme nanocomposites aimed at designing multifunctional photocatalytic materials to address critical environmental challenges
Concurrent Intracranial Complications of Acute Suppurative Otitis Media: Subdural Empyema, Epidural Abscess and Sigmoid Sinus Thrombosis
No full textAim Intracranial complications of otitis media, although rare in the post-antibiotic era, continue to pose a significant risk of morbidity and mortality. Prompt diagnosis supported by advanced neuroimaging and multidisciplinary management is crucial to achieve favorable clinical outcomes. Case Description A 19-year-old male with no prior systemic illness or trauma presented with a two-month history of left-sided otalgia, purulent otorrhea, and progressive hearing loss unresponsive to oral amoxicillin–clavulanate therapy. His condition was further complicated by persistent headache localized to the left retro-orbital region. Otoscopic examination revealed purulent discharge through a marginal tympanic membrane perforation with postauricular tenderness. Laboratory analysis demonstrated leukocytosis (14,950/µL), neutrophilia (12,520/µL), and elevated Creactive protein (129.8 mg/L). Contrast-enhanced temporal bone CT revealed coalescent mastoiditis with bony erosion and a sigmoid plate defect, while MRI and MR venography confirmed subdural empyema, epidural abscess, and partial thrombosis of the left transverse and sigmoid sinuses. Empirical intravenous antibiotic therapy with vancomycin, meropenem, and metronidazole was initiated under infectious disease supervision and later modified to ceftriaxone following meropenem-induced neutropenia. Anticoagulation with enoxaparin and warfarin was discontinued due to postoperative hematoma formation. On hospital day two, due to clinical deterioration, emergency left tympanomastoidectomy was performed, yielding 8–10 cc of purulent drainage from a bony defect overlying the sigmoid sinus. Postoperatively at the fifth day, the patient developed two generalized status seizures, controlled with diazepam and levetiracetam. Progressive enlargement of the subdural empyema on follow-up imaging necessitated neurosurgical drainage through a left occipitoparietal approach. Following a 46day period of observation, the patient was discharged without any reported sequelae. Conclusion The concurrent development of subdural empyema, epidural abscess, and sigmoid sinus thrombosis represents an exceptionally rare but severe complication of otitis media. Early imaging, timely surgical intervention, and coordinated multidisciplinary care remain essential for preventing adverse outcomes and ensuring complete recovery. Keywords: Otitis media; subdural empyema; epidural abscess; sigmoid sinus thrombosis; intracranial complications</p
MOVPE growth of Si-doped AlN and Schottky diode fabrication
No full textIn this study, AlN films with three different Si flow rates were grown on sapphire substrate by Metal Organic Vapor Phase Epitaxy (MOVPE) and then devices were produced by lithography process. According to SIMS results, Si concentrations were obtained as 2 × 1017 cm−3, 8 × 1017 cm−3 and 2 × 1018 cm−3. In addition, the oxygen concentration was also determined from SIMS measurements, and it was shown that the sample with the highest Si doping level had the least step-like behaviour at the interface of the UID-AlN and n-AlN layers. Dislocation densities were calculated using the full-width at half-maximum (FWHM) values of X-ray diffraction (XRD) ω (0 0 2) and ω (1 0 2) scans. Additionally, peak separation was observed in the XRD ω-2θ scan of the sample exhibiting the highest dislocation density. The AFM measurements revealed stepped and terraced structures at the lowest Si doping level, while the increase in Si doping level resulted in the formation of irregular and non-parallel large grain structures. The Raman spectra showed that the highest Si doping rate changed the stress type and the E2 (high) phonon peak caused the highest FWHM value. Transmittance spectra of AlN films shown that the absorption edge shifts to lower energies as the Si doping increases. Additionally, the sample with the highest Si doping level has the highest transmittance. I-V measurements at 400, 500 and 550 °C exhibit Schottky diode-like properties as the temperature increases. The ideality factor (n) and Schottky barrier height (Φn) were extracted from the forward bias I–V characteristics based on the thermionic emission model. The doping process applied to the AlN layer is expected to activate Si dopants when subjected to high temperatures
