Cover Image,Volume 141, Issue 17

The cover image by Lizandra Viana Maurat da Rocha highlights one of our innovative biodegradable films, which incorporated molybdenum trioxide and zinc oxide into the poly(butylene adipate-co-terephthalate) matrix through casting. The photo emphasizes its partial transparency and homogeneity. Some analytical results reported as FTIR, TD-NMR, XRD and TGA validates nanomaterial's exceptional mechanical and chemical properties. Icons below underscore its potential as an eco-friendly food packaging,with bacteriostatic features and no formation of microplastics after disposal. DOI: 10.1002/app.55294

     

Use of fluoropolymer permanent release coatings for molded polyurethane foam production

The problem of adhesion of polyurethane foams to fluoropolymer permanent release mold coatings was studied. Two coatings, based on polytetrafluoroethylene (PTFE) and perfluoroalkoxy polymer (PFA) aqueous dispersions, respectively, were applied on aluminum plates, and the foam release performance evaluated. The PTFE coating displayed gradual loss of antiadhesion properties with consecutive exposure to the reactive mixture, which was associated with isocyanate surface penetration. Penetrant mass uptake experiments, performed on free films, indicated that PTFE retains about 10 times more isocyanate than PFA, probably because of its porous surface morphology. A synergistic effect was found by applying a very small quantity of a waterborne release agent on the PTFE coating, before every foam molding cycle. The release agent formed a protective barrier that minimized contact of the coating with the reactive mixture, allowing for stable and robust foam release performance. The problem of polyurea build-up, associated with the use of aqueous release agents, was not observed because of the small amounts of compound used.     

Ganglioside GM1 attenuates scopolamine-induced amnesia in rats and mice

We evaluated ethanol- and HCl-induced mucosal damages in developing rats. The degree of damage induced by ethanol and HCl was greatest in 1-week-old rats and decreased significantly with age until 4 weeks; thereafter it increased again. To evaluate the effect of weaning on the maturational changes in mucosal defense, we compared ethanol-induced mucosal damage among three groups of newborn rats: (1) receiving milk only; (2) receiving only rat chow from 14 days of age, and (3) having free access to milk and chow. There were no significant differences at 18 and 21 days of age. The mucus thickness increased with age until 8 weeks and was not affected by weaning. In conclusion, developmental changes occur in gastric mucosal protection in rats. Weaning does not have a significant effect on these changes.     

MHC class I genes in a New World primate, the cotton-top tamarin (Saguinus oedipus), have evolved by an active process of loci turnover

Lymphocytes of a New World primate, the cotton-top tamarin (Saguinus oedipus), express classical G-related major histocompatibility complex (MHC) class I molecules with unusually limited polymorphism and variability. Three G-related loci, an F locus, an E locus, and two pseudogenes (So-N1 and So-N3) have been identified by cDNA library screening and extensive PCR analysis of both cDNA and genomic DNA from the cotton-top tamarin. Furthermore, each genus of the subfamily Callitrichinae (tamarins and marmosets) appears to express its own unique set of MHC class I genes, likely due to a rapid turnover of loci. The rapid emergence of unique MHC class I genes in the Callitrichinae genera, resulting from an active process of duplication and inactivation of loci, may account for the limited diversity of the MHC class I genes in the cotton-top tamarin. To determine the nature of the entire complement of MHC class I genes in the cotton-top tamarin, we synthesized a genomic DNA library and screened it with MHC class I-specific probes. We isolated nine new MHC class I pseudogenes from this library. These newly isolated tamarin G-related MHC class I pseudogenes are not closely related to any of their functional counterparts in the tamarin, suggesting that they do not share a recent common ancestral gene with the tamarin's currently expressed MHC class I loci. In addition, these tamarin sequences display a high rate of nonsynonymous substitutions in their putative peptide binding region. This indicates that the genes from which they have derived were likely subject to positive selection and, therefore, were once functional. Our data support the notion that an extremely high rate of loci turnover is largely responsible for the limited diversity of the MHC class I genes in the cotton-top tamarin.