Barrier effect of hydrolyzed collagen: characterization and chemical-physical behavior

This thesis concerns hydrolyzed collagen, also called gelatin, widely used in pharmaceutical industry both for its nutritional properties, in order to correct the deficiency arising from its insufficient dietary intake, and for its protective action towards aggressive agents, mainly used by topical route. Chemical composition, molecular structure and medical uses of collagen are described together with its metabolism in human body, with particular reference to hydrolyzed collagen. With the above premise, the research was focused on: a) the chemical-physical characterization of the barrier effect of collagen, measuring it towards the erosive action of hydrochloric acid; b) the influence of the aminoacidic composition and degree of hydrolysis on the barrier effect. c) the effectiveness of hydrolyzed collagen and different antacidsin controlling acidity levels in vitro. On the basis of these experimental results a food supplement, based on hydrolyzed collagen and tricalcium phosphate, was developed. Its efficacy and safety were tested by a clinical trial in patients affected from functional dyspepsia. These preliminary findings require validation with additional data from further investigations, including a double-blinded and randomized clinical trial. It is of note, however, that the present study deals with magnitudes in the order of 100 per cent. Their statistical confrontation provides the so called “factual” evidence, which is different from the “experimental” one. Moreover, the present study involved patients that did not respond to current treatments. Therefore, this food supplement should be evaluated from the point of view of “experimental therapy”, rather than “experimental research”

Effects of olive and pomegranate by-products on human microbiota : a study using the SHIME (R) in vitro simulator

Two by-products containing phenols and polysaccharides, a "pate" (OP) from the extra virgin olive oil milling process and a decoction of pomegranate mesocarp (PM), were investigated for their effects on human microbiota using the SHIME (R) system. The ability of these products to modulate the microbial community was studied simulating a daily intake for nine days. Microbial functionality, investigated in terms of short chain fatty acids (SCFA) and NH4+, was stable during the treatment. A significant increase in Lactobacillaceae and Bifidobacteriaceae at nine days was induced by OP mainly in the proximal tract. Polyphenol metabolism indicated the formation of tyrosol from OP mainly in the distal tract, while urolithins C and A were produced from PM, identifying the human donor as a metabotype A. The results confirm the SHIME (R) system as a suitable in vitro tool to preliminarily investigate interactions between complex botanicals and human microbiota before undertaking more challenging human studies

Numerical Analysis of a Low NOx Partially Premixed Burner for Industrial Gas Turbine Applications

Abstract A numerical analysis of a low NOx partially premixed burner for industrial gas turbine applications is presented. In the first part the mixing inside a double annular counter-rotating swirl nozzle where the fuel is injected in a transverse jet configuration is studied. Standard k – ∈ model and Two variable Schmidt number models were assessed in order to find a reliable configuration able to fit the available experimental profiles. Resulting profiles are used to perform reactive simulations of the experimental test rig, where NOx, CO measurement were available Results are compared in terms of NOx concentration at the outlet with experimental data

Ca-Lignosulphonate and sclerotial viability of Sclerotinia sclerotiorum

Lignosulphonates, low cost by-products of the pulping process, have shown suppressive effects against some diseases caused by soil-borne pathogens. In this study, the effect of 1.5% v/v calcium lignosulphonate (Ca-Ls) amendment to two commercial potting mixes (peat + coconut fibres; PC; and municipal compost + peat + pumice; MCPP) on the viability of Sclerotinia sclerotiorum sclerotia was investigated. Sclerotia were buried in the Ca-Ls amended substrates for 30 days. Non-amended PC and MCPP, sterile sand and sterile PC with and without Ca-Ls were used as controls. The viability of sclerotia recovered from PC and MCPP amended with Ca-Ls was reduced by 50 and 42% respectively compared to control treatments. Ca-Ls amendment decreased sclerotial viability by enhancing the activity of the indigenous mycoparasitic fungi, Fusarium oxysporum, Mucor spp. and Trichoderma spp. The biocontrol ability of Ca-Ls against sclerotia was due to the stimulation of microbial activity and is, therefore, strictly dependent on the microbial composition of the substrate

Cortico-Cortical Connectivity between Right Parietal and Bilateral Primary Motor Cortices during Imagined and Observed Actions: A Combined TMS/tDCS Study

Previous transcranial magnetic stimulation (TMS) studies showed functional connections between the parietal cortex (PC) and the primary motor cortex (M1) during tasks of different reaching-to-grasp movements. Here, we tested whether the same network is involved in cognitive processes such as imagined or observed actions. Single pulse TMS of the right and left M1 during rest and during a motor imagery and an action observation task (i.e., an index–thumb pinch grip in both cases) was used to measure corticospinal excitability changes before and after conditioning of the right PC by 10 min of cathodal, anodal, or sham transcranial direct current stimulation (tDCS). Corticospinal excitability was indexed by the size of motor-evoked potentials (MEPs) from the contralateral first dorsal interosseous (FDI; target) and abductor digiti minimi muscle (control) muscles. Results showed selective ipsilateral effects on the M1 excitability, exclusively for motor imagery processes: anodal tDCS enhanced the MEPs’ size from the FDI muscle, whereas cathodal tDCS decreased it. Only cathodal tDCS impacted corticospinal facilitation induced by action observation. Sham stimulation was always uneffective. These results suggest that motor imagery, differently from action observation, is sustained by a strictly ipsilateral parieto-motor cortex circuits. Results might have implication for neuromodulatory rehabilitative purposes