Sublittoral soft bottom communities and diversity of Mejillones Bay in northern Chile (Humboldt Current upwelling system)

The macrozoobenthos of Mejillones Bay (23°S; Humboldt Current) was quantitatively investigated over a 7-year period from austral summer 1995/1996 to winter 2002. About 78 van Veen grab samples taken at six stations (5, 10, 20 m depth) provided the basis for the analysis of the distribution of 60 species and 28 families of benthic invertebrates, as well as of their abundance and biomass. Mean abundance (2,119 individuals m-2) was in the same order compared to a previous investigation; mean biomass (966 g formalin wet mass m-2), however, exceeded prior estimations mainly due to the dominance of the bivalve Aulacomya ater. About 43% of the taxa inhabited the complete depth range. Mean taxonomic Shannon diversity (H', Log e) was 1.54 ± 0.58 with a maximum at 20 m (1.95 ± 0.33); evenness increased with depth. The fauna was numerically dominated by carnivorous gastropods, polychaetes and crustaceans (48%). About 15% of the species were suspensivorous, 13% sedimentivorous, 11% detritivorous, 7% omnivorous and 6% herbivorous. Cluster analyses showed a significant difference between the shallow and the deeper stations. Gammarid amphipods and the polychaete family Nephtyidae characterized the 5-mzone, the molluscs Aulacomya ater, Mitrella unifasciata and gammarids the intermediate zone, while the gastropod Nassarius gayi and the polychaete family Nereidae were most prominent at the deeper stations. The communities of the three depth zones did not appear to be limited by hypoxia during non-El Niño conditions. Therefore, no typical change in community structure occurred during El Niño 1997–1998, in contrast to what was observed for deeper faunal assemblages and hypoxic bays elsewhere in the coastal Humboldt Current system

Vassoio per l'essiccazione/disidratazione o la lievitazione di prodotti alimentari e procedimento per la sua fabbricazione.

La presente invenzione concerne vassoio per l'essiccazione/disidratazione o la lievitazione di prodotti alimentari e procedimento per la sua fabbricazione

ARTICOLO DI ARREDO BAGNO

La presente invenzione si riferisce ad un articolo di arredo bagno o arredo cucina in polimero termoplastico comprende almeno una carica minerale costituita da ossido di alluminio in quantità compresa tra il 5% ed il 50% in peso sul peso totale polimero più carica minerale

Hybrid scaffolds with a 3D-printed polymer lattice core and a bioactive hydrogel shell for bone regeneration

Recent research in the field of tissue engineering is focusing on the realization of hybrid scaffolds as multi-material systems which allow to successfully combine the advantages of different biomaterials. In addition, additive manufacturing technologies are currently explored for their production, as means to control and personalize the scaffold structure. In this paper, composite scaffolds with a core–shell structure are studied, the core consisting of a rigid poly-l-lactic acid lattice realized by fused deposition modeling, and the shell consisting of a bioactive hydrogel, grafted upon the core and freeze-dried to develop porous microstructure. Different lattice structures are designed and realized as repetition of unit cells having different size and strut arrangement. Compression tests reveal the suitability of the mechanical properties of the scaffolds for bone tissue regeneration, and the possibility to modulate their stiffness and strength upon the lattice parameters. Moreover, the interconnected porous structure of the shell, assessed by morphological analysis at the microscope, may promote cell colonization and proliferation, while its composition may support osteogenic differentiation

Intumescent material fire stop device

An intumescent material fire stop device, comprising a support body shaped so as to take a collar-like shape around an axis and to define an opening intended to house a pipe, an expandable element, made up of at least one intumescent material and positioned in the support body, and one or more foldable fin joined to the support body by at least one respective hinge portion along a radially inner peripheral edge of said opening. Due to the expansion of the expandable element, the fins are movable between an initial position, in which the fins are substantially parallel to each other and not intercepting said opening, to a closing position, in which the fins converge towards the axis to close at least partially the opening. Advantageously the expandable element is made of at least one first intumescent material, expandable at temperatures equal to or greater than a first activation temperature T1, and at least one second intumescent material, expandable at temperatures equal to or greater than a second activation temperature T2 higher than said first activation temperature T1. The first intumescent material and the second intumescent material are axially staggered

Characterization of recycled end-of-life rubber tire filled with black slag

o date, discarded tires are reused in many applications, however, because of the enormous quantity decommissioned annually, it is essential to continue researching new recycling methods as well as applications to reduce waste and preserve new resources. In the present study, a simple recycling technology of end-of-life tire (ELT) powder is proposed, and the influence of steel slag as filler is assessed. Europe produces about 7 Mt of steel slag annually, and although most of it is reused as an artificial aggregate, about 15% is still landfilled. Also in the case of steel slag, the study of new applications is mandatory so that the combination of these two waste materials, in a 100% recycled composite fits across different industrial sectors facing the same environmental issue. It was found that the leaching of the slag incorporated in the rubber matrix is reduced and that the ELT powder recycled by this technology gives rise to a well-cohesive material. A good rubber-filler interaction was found by swelling test and differential scanning calorimetry (DSC) analysis. The slag reduces the friction coefficient and increases the thermal conductivity. The experimental results showed how some properties of recycled ELT can be improved by adding the steel slag

Polysaccharides on gelatin-based hydrogels differently affect chondrogenic differentiation of human mesenchymal stromal cells

Selection of feasible hybrid-hydrogels for best chondrogenic differentiation of human mesenchymal stromal cells (hMSCs) represents an important challenge in cartilage regeneration. In this study, three-dimensional hybrid hydrogels obtained by chemical crosslinking of poly (ethylene glycol) diglycidyl ether (PEGDGE), gelatin (G) without or with chitosan (Ch) or dextran (Dx) polysaccharides were developed. The hydrogels, namely G-PEG, G-PEG-Ch and G-PEG-Dx, were prepared with an innovative, versatile and cell-friendly technique that involves two preparation steps specifically chosen to increase the degree of crosslinking and the physical-mechanical stability of the product: a first homogeneous phase reaction followed by directional freezing, freeze-drying and post-curing. Chondrogenic differentiation of human bone marrow mesenchymal stromal cells (hBM-MSC) was tested on these hydrogels to ascertain whether the presence of different polysaccharides could favor the formation of the native cartilage structure. We demonstrated that the hydrogels exhibited an open pore porous morphology with high interconnectivity and the incorporation of Ch and Dx into the G-PEG common backbone determined a slightly reduced stiffness compared to that of G-PEG hydrogels. We demonstrated that G-PEG-Dx showed a significant increase of its anisotropic characteristic and G-PEG-Ch exhibited higher and faster stress relaxation behavior than the other hydrogels. These characteristics were associated to absence of chondrogenic differentiation on G-PEG-Dx scaffold and good chondrogenic differentiation on G-PEG and G-PEG-Ch. Furthermore, G-PEG-Ch induced the minor collagen proteins and the formation of collagen fibrils with a diameter like native cartilage. This study demonstrated that both anisotropic and stress relaxation characteristics of the hybrid hydrogels were important features directly influencing the chondrogenic differentiation potentiality of hBM-MSC