Improving the optical, thermal, mechanical, electrical properties and antibacterial activity of PVA-chitosan by biosynthesized Ag nanoparticles: Eco-friendly nanocomposites for food packaging applications.

In this study, nanocomposite films were produced by blending polyvinyl alcohol (PVA) and chitosan (Cs) polymers with 70 % PVA and 30 % Cs, incorporating silver nanoparticles (Ag NPs) via a solution-casting method. The research aims to investigate the impact of the biosynthesized Ag NPs by Chenopodium murale leaf extract on optical, morphological, mechanical, thermal, electrical, and antibacterial properties. XRD analysis showed a decrease in crystallinity degree with Ag NPs addition. TEM revealed Ag NPs in cubic and spherical shapes with an average size of 23.4 nm. SEM and AFM indicated surface morphology changes. FT-IR spectra showed interaction between Ag ions and the blend. The energy gap decreased with increasing Ag NPs concentration. TGA exhibited enhanced thermal stability. Mechanical properties improved significantly. AC electrical conductivity and dielectric parameters were studied. Antibacterial activity against Gram-positive and Gram-negative bacteria was observed. Overall, PVA/Cs-Ag NPs films show promise for food packaging and optoelectronic applications.

Schistosomiasis status in urban Sharkia Governorate, Egypt: prevalence and intensity of infection.

The study was implemented in Sharkia Governorate, to determine the magnitude of schistosomiasis in urban areas. A multistage sampling technique was the method chosen to carry out the study. According to the population size, the urban areas of Sharkia Governorate were classified into two strata: small sized cities and large sized cities. Two cities were selected randomly from each stratum. Among the 5012 individuals selected from the four cities, 3524 and 3457 individuals gave urine and stool specimens respectively. An overall prevalence of 6.8% was observed for Schistosoma mansoni (S. mansoni) infection with a geometric mean egg count (GMEC) of 45.8 eggs per gram stool. Only three cases of Schistosoma haematobium were detected. Results of the survey suggest that small sized cities had a significantly higher level of infection than large sized cities. Age and sex related prevalence and intensities showed that the highest rates were noticed among adult males.