Migratory crustaceans as biomonitors of metal pollution in their nursery areas. The Lesina lagoon (SE Italy) as a case study

The Lesina lagoon is located on the southern Adriatic coast of Italy; many marine species, such as the shrimp M. kerathurus, use the Lesina lagoon as a nursery, spending their initial growth phase there. In order to assess the usefulness of migratory species as biomonitors of the environmental quality of this nursery area, we evaluated the metal content of the M. kerathurus juveniles at the end of their growth phase in the lagoon (October), when they are assumed to have bioaccumulated the maximum level of metals from the lagoon environment. The concentrations of Cr, Cd, Pb, Zn, Mn and Cu were measured in the muscle and exoskeleton of the shrimp, and in the sediments and waters of three areas of the Lesina Lagoon. Both the water and sediment levels of the investigated metals tended to fall within the ranges recorded for other lagoon environments characterized by similar anthropic impact and texturally similar sediment; the juveniles of the shrimp M. kerathurus proved to be strong bioaccumulators of heavy metals such as Zn and Cu (biota-sediment accumulation factors - BSAFs - 6.01 and 25.0 respectively), which derive from agricultural activities; therefore, at the end of their growing phase in the lagoon they can be considered useful biomonitors of metal contamination of agricultural origin in their nursery area.

Natural Polysaccharide-Based Gels for Dairy Food Preservation

The innovative packaging systems described in the present work, based on natural gels, have been shown to increase the shelf life of the Mozzarella cheese, without adding any chemical substance and without thermal procedures. Physical, physicochemical, microbiological, analytical, and mechanical analyses were used to monitor the quality of the cheese as a function of storage type and storage time. In particular, microbiological analysis confirmed that the characteristics of the Mozzarella cheese stored at 4 degrees C in gel are maintained for more than 15 d, whereas samples stored in the mother solution lost important characteristics after 5 d. A penetration test (texture) confirmed that the Mozzarella cheese preserved in the gel maintained mechanical properties similar to those of the fresh product, even after storage for 30 d at 4 degrees C.

Biocompatibility studies on biodegradable polyester-based composites of human osteoblasts: a preliminary screening

A series of biodegradable composites with natural hydroxyapatite, designed for possible use in orthopedics applications, were preliminarily screened for biocompatibility by employing primary cultures of human osteoblasts in a direct contact method. The cells were seeded at low density onto the materials under investigation and allowed to grow for 2 weeks. They then were analyzed for morphology, proliferation, viability, alkaline phosphatase activity (AP), osteocalcin (OC) production, and extracellular matrix mineralization. The results showed that all materials have good biocompatibility. Cell viability tests demonstrated that in all cases the values were comparable to the control, and the addition of hydroxyapatite always resulted in an enhancement of performance with respect to the plain polymer. AP and OC analysis confirmed that all composites allowed the expression of phenotypic markers. Scanning electron microscopy provided direct evidence of intense cell adhesion and proliferation on the tested materials.

Investigation of the optothermal properties of a new polymeric blend: polymethyl-methacrylate-poly (ethylene-co-vinylacetate)

A new polymeric blend, polymethyl methacrylate-poly (ethylene-co-vinylacetate) (PMMA-EVA) has been produced recently in our laboratories. The optothermal characterization of PMMA-EVA was carried out by measuring the ultraviolet photoacoustic spectra of PMMA, EVA, and PMMA-EVA (25 degrees C, 220-350 nm), of a PMMA-EVA blend (250-750 nm) at two temperatures (19 degrees C and 65 degrees C), and by measuring the scattering coefficient (at 514.5 nm) of PMMA-EVA versus the temperature in the range 38-86 degrees C. Our measurements show that, in the explored thermal range, the blend undergoes a phase transition when its optical properties change drastically. The peculiar optical and thermal properties observed appear attractive for possible applications as temperature-controlled optical devices.