Dental composite resins often face challenges related to secondary caries, polymerization shrinkage and fracture failure. This study aimed to synthesize an experimental composite resin modified with grapefruit seed extract-mediated titanium dioxide nanoparticles (GSE-TiO₂NPs) and evaluate its antibacterial activity and mechanical and physical properties. Green synthesis of TiO₂ nanoparticles was conducted utilizing GSE. The chemical profile of GSE was identified through gas chromatography-mass spectrometry. The as-prepared nanoparticles were incorporated into experimental composites at concentrations of 10 wt.% (10 wt.% GSE-TiO₂NPs group) and 20 wt.% (20 wt.% GSE-TiO₂NPs group), with an unmodified composite as the control group. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) confirmed the morphology and size of synthesized nanoparticles, with SEM revealing uniform particle distribution in the composite. Antibacterial activity against Streptococcus mutans was assessed using the agar disc diffusion method. Mechanical properties, including flexural strength (FS) and flexural modulus (FM), were evaluated according to ISO 4049 standards. Microhardness was tested according to the American Society for Testing Materials (ASTM E-384:1999) criteria. Polymerization shrinkage was measured using the strain gauge method. Modified composites exhibited significantly greater antibacterial activity against S. mutans compared to the control (p < 0.001). The 10 wt.% GSE-TiO₂NPs group demonstrated increased FS and FM values compared to the control group (p < 0.05). All groups surpassed the clinically acceptable microhardness threshold without significant differences (p = 0.588). Polymerization shrinkage was reduced in the modified groups (p < 0.01), with the 20 wt.% GSE-TiO₂NPs group showing the lowest value (13.06 ± 0.92%). Incorporating GSE-TiO₂NPs into composite resins enhances antibacterial activity, improves mechanical properties, and reduces polymerization shrinkage, suggesting a promising approach for developing advanced dental materials with integrated natural bioactive components. Graphical abstract

Despite extensive research to decipher the immunological basis of coronavirus disease ( COVID-19), limited evidence on immunological correlates of COVID-19 severity from MENA region and Egypt was reported. In a single-center cross-sectional study, we have analyzed 25 cytokines that are related to immunopathologic lung injury, cytokine storm, and coagulopathy in plasma samples from 78 hospitalized Egyptian COVID-19 patients in Tanta University Quarantine Hospital and 21 healthy control volunteers between April 2020 and September 2020. The enrolled patients were divided into 4 categories based on disease severity, namely mild, moderate, severe, and critically ill. Interestingly, interleukin (IL)-1-α, IL-2Rα, IL-6, IL-8, IL-18, tumor necrosis factor-alpha (TNF-α), FGF1, CCL2, and CXC10 levels were significantly altered in severe and/or critically ill patients. Moreover, principal component analysis (PCA) demonstrated that severe and critically ill COVID-19 patients cluster based on specific cytokine signatures that distinguish them from mild and moderate COVID-19 patients. Specifically, levels of IL-2Rα, IL-6, IL-10, IL-18, TNF-α, FGF1, and CXCL10 largely contribute to the observed differences between early and late stages of COVID-19 disease. Our PCA showed that the described immunological markers positively correlate with high D-dimer and C-reactive protein levels and inversely correlate with lymphocyte counts in severe and critically ill patients. These data suggest a disordered immune regulation, particularly in severe and critically ill Egyptian COVID-19 patients, manifested as overactivated innate immune and dysregulated T-helper1 responses. Additionally, our study emphasizes the importance of cytokine profiling to identify potentially predictive immunological signatures of COVID-19 disease severity.

Soybean mosaic virus (SMV) is a devastating disease that threatens soybean plants worldwide. The different soybean genotypes displayed different responses to SMV strains. This study aimed to investigate the response of different selected soybean cultivars to SMV infection in Egypt based on their specific genetic makeup. The symptoms of SMV infection and the viral concentration were evaluated in eight soybean cultivars (Giza 21, Giza 22, Giza 35, Giza 82, Giza 111, Crawford, H4L4, and PI416937) using ELISA assay. The results indicated that Giza 21 and Giza 35 were moderately tolerant to SMV infection, while Giza 82 was the least tolerant cultivar. Giza 22, Giza 111, and PI416937 were less tolerant; however, H4L4 and Crawford were identified as the most tolerant cultivars against SMV infection. The chi-square analysis showed a significant association between the different selected cultivars and their response against SMV infection. The PCR test showed the presence of RSV1 (3gG2), RSV1 (5gG3), and RSV3 loci, and the absence of the RSV4 locus gene. The expression analysis of the selected defense genes (EDS1, PAD4, EDR1, ERF1, and JAR) showed variations in the fold changes between infected and non-infected soybean cultivars, suggesting that these genes might play a crucial role in this pathosystem. Additionally, there was a strong positive association between the expression levels of EDR1 and ERF1. The study found the presence of RSV1 (3gG2), RSV1 (5gG3), and RSV3 loci in selected soybean cultivars, but not RSV4. The analysis of gene expression indicated that certain defense genes may play a vital role in the pathosystem. This research is the first of its kind in Egypt to genotype soybean cultivars regarding different RSV loci. The findings could be beneficial for further research on understanding the molecular mechanisms involved in SMV infection and its management.

Magnetic nanocomposites loaded with antimicrobial drugs have grown in popularity for treating infectious diseases due to their magnetic properties and the ability to penetrate bacteria cells. In this research, CuxFe3-xO4 nanoparticles and CuxFe3-xO4/PANI nanocomposites were synthesized, characterized, and examined for their antimicrobial activity. The in-situ oxidative polymerization of aniline in the presence of CuxFe3-xO4 nanoparticles produced CuxFe3-xO4/PANI nanocomposites with distinct spinel ferrites. XRD, FT-IR, VSM, SEM, EDX, TEM, and XPS techniques confirmed the successful synthesis of the CuxFe3-xO4/PANI nanocomposites. The analysis of magnetization patterns of CuxFe3-xO4/PANI nanocomposites revealed their superparamagnetic characteristics. With increasing Cu2+ ratios, both the pure copper ferrites nanoparticles and the CuxFe3-xO4/PANI nanocomposites exhibited enhanced antimicrobial effects against gram-positive (Staph), gram-negative (E. coli, P. aeruginosa, and K. pneumoniae), and fungi such as (C. albicans), which is consistent with decreasing the order of crystal size (nm) and the lattice strain, where crystal size and lattice strain decreased with increasing Cu2+ ratio. SEM micrographs revealed changes in bacterial shape, deformation of fungal cell walls, and bacterial and yeast colonies collapsing. Furthermore, the nanocomposites are more effective against gram-negative bacteria and Candida albicans than gram-positive bacteria, displaying the alteration of bacterial shape, fungal cell wall deformation, and collapsing bacterial and yeast colonies. Furthermore, the synthesized nanocomposites have a more substantial effect on gram-negative bacteria and Candida albicans than gram-positive bacteria. The results presented an approach for using CuxFe3-xO4 and CuxFe3-xO4/PANI as an alternative promising antimicrobial agent against several multidrug-resistant microbes.