Versatile hydrogels: An efficient way to clean paper artworks

In this work we present innovative materials able to remove in a single, simple and not invasive treatment, different contaminants like starch paste from paper artworks. The materials, based on biocompatible hydrogels, overcome many of the problems usually faced by restorers during the cleaning of paper sample

Impact of a complex food microbiota on energy metabolism in the model organism Caenorhabditis elegans

The nematode Caenorhabditis elegans is widely used as a model system for research on aging, development, and host-pathogen interactions. Little is currently known about the mechanisms underlying the effects exerted by foodborne microbes. We took advantage of C. elegans to evaluate the impact of foodborne microbiota on well characterized physiological features of the worms. Foodborne lactic acid bacteria (LAB) consortium was used to feed nematodes and its composition was evaluated by 16S rDNA analysis and strain typing before and after colonization of the nematode gut. Lactobacillus delbrueckii, L. fermentum, and Leuconostoc lactis were identified as the main species and shown to display different worm gut colonization capacities. LAB supplementation appeared to decrease nematode lifespan compared to the animals fed with the conventional Escherichia coli nutrient source or a probiotic bacterial strain. Reduced brood size was also observed in microbiota-fed nematodes. Moreover, massive accumulation of lipid droplets was revealed by BODIPY staining. Altered expression of nhr-49, pept-1, and tub-1 genes, associated with obesity phenotypes, was demonstrated by RT-qPCR. Since several pathways are evolutionarily conserved in C. elegans, our results highlight the nematode as a valuable model system to investigate the effects of a complex microbial consortium on host energy metabolism

Hydrodynamic effects produced by submerged breakwaters in a coastal area with a curvilinear shoreline

A three-dimensional numerical study of the hydrodynamic effect produced by a system of submerged breakwaters in a coastal area with a curvilinear shoreline is proposed. The three-dimensional model is based on an integral contravariant formulation of the Navier-Stokes equations in a time-dependent curvilinear coordinate system. The integral form of the contravariant Navier-Stokes equations is numerically integrated by a finite-volume shock-capturing scheme which uses Monotonic Upwind Scheme for Conservation Laws Total Variation Diminishing (MUSCL-TVD) reconstructions and an Harten Lax van Leer Riemann solver (HLL Riemann solver). The numerical model is used to verify whether the presence of a submerged coastal defence structure, in the coastal area with a curvilinear shoreline, is able to modify the wave induced circulation pattern and the hydrodynamic conditions from erosive to accretive

Boundary Condition in the Oscillating Turbulent Boundary Layer for the Simulation of Wave Breaking

In this paper a new numerical model for the simulation of the wave breaking is proposed. In order to represent the complex geometry of coastal regions, the three-dimensional equations of motion are expressed in integral contravariant form and are solved on a curvilinear boundary conforming grid. A time-dependent transformation of the vertical coordinate that is a function of the oscillation of the turbulent wave boundary layer is proposed. New boundary condition bottom for the equations of motion expressed in contravariant form are proposed. In order to correctly simulate the height of the breaking waves, the importance of the correct positioning, inside the oscillating turbulent boundary layer, of the centre of the calculation grid cell closest to the bottom, is demonstrated

A new sustainable and innovative work for paper artworks cleaning process: Gellan hydrogel combined with hydrolytic enzymes

Paper has been used as writing and drawing support for thousands of years. The conservation of paper artworks plays a fundamental role in the field of our cultural heritage. Moreover, restoration of paper artworks is difficult due to their inherent fragility, the presence of many components and their degradation state. Among the factors that may contribute to paper deterioration are the use of glue for the application of different materials (as a lining, mounting or as a repair intervention) on the paper artifact. During a natural ageing process, glue become yellow, acid and less compact, accelerating the degradation processes of the artwork itself. The removal of glues from paper artworks represents, therefore, an important procedure for their preservation. Here we present a sustainable alternative to the common removal systems (e.g. solvents or localized enzymatic packs on the support to be cleaned). For this goal we used a rigid Gellan hydrogel (totally removable in one step) containing hydrolytic enzyme, such as proteinase K. The enzyme works as a selective cleaning agent hydrolyzing animal glues into smaller fragments, soluble into the gel. Our system represents an effective alternative to the traditional techniques because it is easy to be prepared, eco-friendly and efficient

In vitro and in vivo selection of potentially probiotic lactobacilli from Nocellara del Belice table olives

Table olives are increasingly recognized as a vehicle as well as a source of probiotic bacteria, especially those fermented with traditional procedures based on the activity of indigenous microbial consortia, originating from local environments. In the present study, we report characterization at the species level of 49 Lactic Acid Bacteria (LAB) strains deriving from Nocellara del Belice table olives fermented with the Spanish or Castelvetrano methods, recently isolated in our previous work. Ribosomal 16S DNA analysis allowed identification of 4 Enterococcus gallinarum, 3 E. casseliflavus, 14 Leuconostoc mesenteroides, 19 Lactobacillus pentosus, 7 L. coryniformis, and 2 L. oligofermentans. The L. pentosus and L. coryniformis strains were subjected to further screening to evaluate their probiotic potential, using a combination of in vitro and in vivo approaches. The majority of them showed high survival rates under in vitro simulated gastro-intestinal conditions, and positive antimicrobial activity against Salmonella enterica serovar Typhimurium, Listeria monocytogenes and enterotoxigenic Escherichia coli (ETEC) pathogens. Evaluation of antibiotic resistance to ampicillin, tetracycline, chloramphenicol, or erythromycin was also performed for all selected strains. Three L. coryniformis strains were selected as very good performers in the initial in vitro testing screens, they were antibiotic susceptible, as well as capable of inhibiting pathogen growth in vitro. Parallel screening employing the simplified model organism Caenorhabditis elegans, fed the Lactobacillus strains as a food source, revealed that one L. pentosus and one L. coryniformis strains significantly induced prolongevity effects and protection from pathogen-mediated infection. Moreover, both strains displayed adhesion to human intestinal epithelial Caco-2 cells and were able to outcompete foodborne pathogens for cell adhesion. Overall, these results are suggestive of beneficial features for novel LAB strains, which renders them promising candidates as starters for the manufacturing of fermented table olives with probiotic added value