Assessment of the interaction of Portland cement-based materials with blood and tissue fluids using an animal model

Portland cement used in the construction industry improves its properties when wet. Since most dental materials are used in a moist environment, Portland cement has been developed for use in dentistry. The first generation material is mineral trioxide aggregate (MTA), used in surgical procedures, thus in contact with blood. The aim of this study was to compare the setting of MTA in vitro and in vivo in contact with blood by subcutaneous implantation in rats. The tissue reaction to the material was also investigated. ProRoot MTA (Dentsply) was implanted in the subcutaneous tissues of Sprague-Dawley rats in opposite flanks and left in situ for 3 months. Furthermore the material was also stored in physiological solution in vitro. At the end of the incubation time, tissue histology and material characterization were performed. Surface assessment showed the formation of calcium carbonate for both environments. The bismuth was evident in the tissues thus showing heavy element contamination of the animal specimen. The tissue histology showed a chronic inflammatory cell infiltrate associated with the MTA. MTA interacts with the host tissues and causes a chronic inflammatory reaction when implanted subcutaneously. Hydration in vivo proceeds similarly to the in vitro model with some differences particularly in the bismuth oxide leaching patterns.peer-reviewe

Distribution of Tylos spp. in the Maltese Islands and population dynamics of Tylos europaeus

Two species of the oniscid genus Tylos occur in the Maltese Islands, T. sardous and T. europaeus, which are allopatric and restricted to just one and two sandy beaches, respectively. The dynamics of the largest locallyoccurring T. europaeus population were investigated during the period 2001-2003. Seasonal variation in the sex ratio, length of the 5th segment of the pereion as a proxy for age, and the proportion of adults and juveniles in the population were assessed during each calendar season. The vertical distribution of male, female and juvenile individuals in the sand was determined in the field during summer 2003. Laboratory experiments were made to test sand moisture preferences. The surface activity of the isopods was studied by means of pitfall trap constellations whilst zonation on the beach was studied by sieving sand collected from quadrats placed at regular intervals along a shore-normal transect starting from mean sea-level (MSL), and counting the number of individuals in each sample. For the Tylos europaeus population studied, males outnumbered females in seven of eight seasonal sampling sessions, with a mean male:female ratio of 1.46, although differences between the abundances of adult males and females were only statistically significantly different during the two spring seasons. Juveniles were consistently more abundant than adults, abundances ranging between 220-450 individuals/m3 for juveniles and between 450-3200 individuals/m3 for adults. Males consistently exhibited larger pereion sizes than females: mean pereion length was 1.91mm (± 0.43mm) for males and 1.79mm (± 0.39mm) for females.peer-reviewe

Distribution of Tylos spp. (Crustacea, Isopoda) on Maltese sandy beaches and observations on Tylos Europaeus

The occurrence of Tylos europaeus and T. sardous on 10 Maltese beaches was investigated. T. europaeus occurred on two beaches on Gozo and T. sardous on a single beach on Malta. The largest population was of T. europaeus at Ramla l-Hamra on Gozo, but even here the isopods occupied a limited zone close to sea-level. The diurnal and nocturnal distribution of this population as well as temporal changes in distribution pattern over two years were studied in order to provide baseline information for the conservation of this rare psammophile in the Maltese Islands.peer-reviewe

Feeding habits of the small-spotted catshark Scyliorhinus Canicula (l., 1758) in the Central Mediterranean

The catshark Scyliorhinus canicula is a common demersal elasmobranch in the Mediterranean. It has a wide geographical and bathymetric distribution and is found primarily over sandy, muddy or gravelly bottoms. Studies on the feeding habits have been made in various regions, but not in the Central Mediterranean. The present study addresses this gap by presenting information on the diet of the species for this region, for the first time.peer-reviewe

Experimental and Computational Study of Supercritical Fluid Extraction (SFE) of Omega-3 Components from Fish Oil in Structured Packing

The benefits of polyunsaturated fatty acids and their implications for human health have gained scientific attention to their extraction from biological sources, not being produced by the human body. Most known industrial productions of omega-3 fatty acids often work under operating conditions that may degrade these components and they often use toxic or flammable solvents that can adversely affect human health. In this sense, innovative and interesting prospects are provided by Supercritical Fluid Extraction (SFE). In this work, two parallel studies were carried out: an experimental activity in a laboratory apparatus using supercritical carbon dioxide (scCO2) and preliminary computational fluid dynamics (CFD) simulations, limited to the hydrodynamic aspects of the process. In the experimental apparatus a Sulzer® EX structured packing, made up of corrugated metal gauze sheets, was used as the column filler. The study made it possible to identify the optimal operating conditions leading to an enrichment of the starting mixture in Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA), target products. CFD simulations were based on the Volume of Fluid (VOF) approach, suitable to the present complex multiphase system with two phases in close contact (transesterified fish oil and scCO2). The meatus created by the corrugations of the metal gauze was chosen as the calculation domain representative of the system. The computations were performed by the commercial software Ansys Fluent®, which allowed the prediction of the hydrodynamic evolution of the system through transient simulations. CFD predictions were in qualitative agreement with the experimental result

Kinetic of the Sewage Treatment: The Consumption of Organic Carbon of The Microalga Chlorella sp

As well known, microalgae are eukaryotic or procaryotic microorganisms able to photosynthesize, namely transforming inorganic substrates and sun light into organic compounds and chemical energy. They result very promising in treating civil wastewaters thanks to their ability to employ nitrates and phosphates as nutrients (Lima et al., 2019). Autotrophic microalgae are, anyway, not useful in decreasing the organic carbon content of wastewaters, and for this reason, they cooperate with heterotrophic bacteria. The usefulness of microalgaebacteria consortia in treating wastewaters and the ratio of their inoculum was investigated in a previous work (Lima, 2022a). Contrarily to autotrophic microalgae, mixotrophic microalgae are able to decrease the organic content of the matrix in which they are grown. In this work, we preliminarily investigated the capability of the autochthonous microalga Chlorella sp. CW2 to grow in mixotrophy and decrease the organic content of the artificial wastewater in which they are grown. Several batch cultivations were performed with glucose in different concentrations. Kinetic parameters were obtained and employed to determine the dilution rate (D) ideal for the abatement of glucose from the artificial wastewater

Kinetic of the Sewage Treatment: The Consumption of Organic Carbon of The Microalga Chlorella sp.

As well known, microalgae are eukaryotic or procaryotic microorganisms able to photosynthesize, namely transforming inorganic substrates and sun light into organic compounds and chemical energy. They result very promising in treating civil wastewaters thanks to their ability to employ nitrates and phosphates as nutrients (Lima et al., 2019). Autotrophic microalgae are, anyway, not useful in decreasing the organic carbon content of wastewaters, and for this reason, they cooperate with heterotrophic bacteria. The usefulness of microalgae-bacteria consortia in treating wastewaters and the ratio of their inoculum was investigated in a previous work (Lima, 2022a). Contrarily to autotrophic microalgae, mixotrophic microalgae are able to decrease the organic content of the matrix in which they are grown. In this work, we preliminarily investigated the capability of the autochthonous microalga Chlorella sp. CW2 to grow in mixotrophy and decrease the organic content of the artificial wastewater in which they are grown. Several batch cultivations were performed with glucose in different concentrations. Kinetic parameters were obtained and employed to determine the dilution rate (D) ideal for the abatement of glucose from the artificial wastewater

A hydrogeological study to support the optimized management of the main sea level aquifer of the island of Malta

Management groundwater resources, coastal aquifer, seawater intrusion, safe-yield, Malta

Multidisciplinary geological excursion in the open-air laboratory of the Island of Malta. 11-18 November 2010. Field-Trip Guide.

Si tratta della guida all'escursione geologica multidisciplinare tenutasi a Malta dall'11 al 18 novembre 2010, nell'ambito del progetto di internazionalizzazione dell'Università di Modena e Reggio Emilia dal titolo "Multidisciplinary research in the open-air laboratory of the island of Malta: an internazional network for landslide hazard assessment in coastal areas" (2008-2010) finanziato dalla Fondazione Cassa di Risparmio di Modena e Reggio Emilia, per i Corsi di Laurea Triennale in Scienze Geologiche e Magistrale in Scienze e Tecnologie Geologiche