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Use of S.salivarius 24SMBc as an oral probiotic
No full textABSTRACT (English)
Introduction. Much attention has recently been devoted to the analysis of the oral microbiota to develop a bacteriotherapy focused on prevention and/or treatment of upper respiratory tract infections. The oral cavity harbours some beneficial bacterial species such as Streptococcus salivarius which is considered the predominant 'safe' colonizer, capable of fostering more balanced, health-associated oral microflora, interfering with potential pathogens. This antagonist activity is often mediated by competition for nutriments, better adhesion to target cells and release of bioactive agents such as bacteriocins. In our laboratory, we characterized one strain, S.salivarius 24SMBc, isolated from healthy children which showed excellent inhibitory activity against S.pneumoniae and S.pyogenes and potent capacity of adhesion to HEp-2 cells.
These properties encouraged us to evaluate a possible application of S.salivarius 24SMBc as an oral probiotic for children with recurrent otitis media.
Material and methods. We sequenced the S.salivarius 24SMBc genome by pyrosequencing to verify the presence of virulent factors and to look for genes encoding bacteriocins that inhibit the growth of the pathogens previously described.
Then, we included S.salivarius 24SMBc in a clinical trial protocol conducted on 17 healthy adult volunteers to evaluate its safety for the human host and its ability to colonize and persist in the upper respiratory tract. The presence of S.salivarius 24SMBc in rhinopharynx tissue was determined after different time intervals from nasal administration by molecular identification, antagonism test to evaluate BLIS production and RAPD-PCR to distinguish S.salivarius 24SMBc s genotype from other S.salivarius strains. The following phase for the assessment of the colonization of S.salivarius 24SMBc in the upper respiratory tract of children and its efficacy to reduce the number of episodes of otitis media (OM), was realized through a paediatric randomized, placebo-controlled, double-blind trial. This study enrolled 120 otitis prone children and included phenotypic and molecular identification of S.salivarius 24SMBc and pathogenic strains of OM from the biological samples. Moreover, the level of colonization of our strain was determined by qPCR using a specific genomic target to identify S.salivarius 24SMBc.
Results and conclusion. Genome annotation showed that S.salivarius 24SMBc is free of streptococcal virulent factors. The results of clinical trials demonstrated the absence of adverse effects for the human host and a good capability of S.salivarius 24SMBc to colonize the human rhinopharynx tissue. Prophylactic administration of S.salivarius 24SMB to children with a history of recurrent OM reduces episodes of this disease as well the incidence of infection by some causative pathogens such as S.pneumoniae and S.pyogenes. Therefore, S.salivarius 24SMBc appears a competitive nasopharyngeal - localized strain with a good potential for use as an oral probiotic to prevent OM in paediatric subjects
Neuroprotective effects of PACAP, VIP and NAP against hyperglycaemic retinal damage
No full textDiabetic retinopathy, one the most significant and disabling chronic complications of diabetes mellitus, has mainly been regarded as a microcirculatory disease of the retina. However, there is emerging evidence to suggest that a primary and early neurodegenerative process characterizes DR. The reason for the retinal degeneration resides in the metabolic changes caused by hyperglycemia and in the decreased capability of the retina to adapt to this environment. This situation leads to altered expression patterns of neuropeptides, growth and transcription factors, apoptosis, increased oxidative stress, inflammatory response, angiogenesis and disruption of the blood-retinal barrier (BRB). All major cell types of the retina are affected: neuronal as well as the glial cells and pigment epithelial cells.
Pituitary adenylate cyclase activating polypeptide (PACAP), vasoactive intestinal peptide (VIP) and davunetide (NAP) are three pleiotropic related neuropeptides also expressed in the retina. Their protective role has been shown in different retinal injuries, but little is known about the relationship between these peptides and DR.
The aim of the present thesis was to investigate, using both in vitro and in vivo model of DR, the role of these peptdides on retinal layers by monitoring apoptotic events by western blot and confocal microscopy analysis and measuring the integrity of the outer blood retinal barrier with permeability and transepithelial electrical resistance assay. The underlying signal transduction pathways activated by each peptide and the impact of hyperglicaemia on the expression and distribution at retinal levels of the inflammatory IL-1 mediators were also evaluated. Diabetes was mimicked in adult rats by intraperitoneal injection of streptozotocin (STZ) and human retinal pigment epithelial cells (ARPE19) were cultured for 26 days in high glucose (25mM of D-glucose) and IL-1beta.
The results confirmed that hyperglycemia induced early apoptotic death in the cellular components of the neuroretina, breakdown of the outer blood retinal barrier (BRB) and dysregulation of several components of the metabolic and signaling pathways. The neuropeptides tested activate promising pathways useful for the treatment of this retinal degenerative disease. In particular, PACAP and VIP promote the integrity of the outer BRB, possibly through the modulation of proteins related to tight junctions. Davunetive is able to reduce apoptosis in the diabetic retina by activating the anti-apoptotic p-Akt, p-ERK1, p-ERK2, Bcl-2 and decreasing levels of the pro-apoptotic elements, such as cleaved caspase-3. These results raise the opportunity for the use of these peptides as a possible therapeutic or preventive methods in treating diabetes
Risposta biomolecolare delle cellule alpha e beta pancreatiche al trattamento con citochine
No full textL apoptosi è considerata la forma principale di morte delle beta cellule pancreatiche produttrici di insulina nel Diabete mellito di tipo 1 (T1DM) e di tipo 2 (T2DM). Nel T1DM, la forma autoimmune della patologia, l apoptosi è il risultato di una complessa cascata di eventi che inizia con l esposizione delle beta cellule pancreatiche a molecole citotossiche espresse o secrete dalle cellule del sistema immunitario ed infiltranti l isola del Langerhans nel corso dell insulite; tra le citochine pro-infiammatorie l IL-1b, l IFNg ed il TNFa rappresentano i principali effettori degli eventi descritti. E interessante notare come l azione deleteria delle citochine sia specificatamente rivolta alle cellule beta pancreatiche, mentre le cellule alpha risultano più resistenti ai loro effetti citotossici. Sebbene le pathways proapoptotiche innescate dalle citochine nelle beta cellule siano state ampiamente (anche se non completamente descritte), i meccanismi molecolari alla base della risposta differenziale dei due tipi cellulari erano quasi del tutto inesplorati. Mediante un approccio sperimentale di tipo sistemico, per la prima volta abbiamo indagato il profilo di espressione e la funzione biologica di microRNA e geni codificanti per proteine in cellule aTC1-6 e bTC1 trattate con citochine proinfiammatorie, un sistema modello che mima in vitro lo stato infiammatorio cronico del Diabete Mellito. Scopo di questo lavoro è stato: (i) descrivere i meccanismi molecolari responsabili della resistenza delle cellule alpha pancreatiche e della suscettibilità della controparte beta cellulare all apoptosi indotta dalle citochine pro-infiammatorie (IL-1b, IFNg e TNFa); (ii) identificare nuovi marcatori beta cellulari di disfunzione. L analisi dell espressione genica differenziale nelle due linee cellulari in condizioni fisiologiche (steady state) e dopo trattamento con citochine ci ha permesso di caratterizzare il ruolo dei microRNA 296-3p e 298-5p nella resistenza all apoptosi citochino-mediata delle cellule aTC1-6 [Barbagallo D, Piro S, Condorelli AG et al. miR-296-3p, miR-298-5p and their downstream networks are causally involved in the higher resistance of mammalian pancreatic alpha cells to cytokine-induced apoptosis as compared to beta cells. BMC Genomics, 2013] e del fattore trascrizionale C/EBPa nell apoptosi delle cellule bTC1 [Barbagallo D, Condorelli AG, Piro S et al. CEBPA exerts a specific and biologically important proapoptotic role in pancreatic beta cells through its downstream network targets. Mol Biol Cell, 2014]
Plant secondary compounds in small ruminant feeding: an alternative to synthetic compounds for improving meat quality in low-input farming systems
No full textSheep meat is a source of polyunsaturated (PUFA) and monounsaturated (MUFA) fatty acids that confer beneficial effects to human health, but it also contains high concentration of saturated fatty acids (SFA) that are associated with the development of certain diseases. To attain a healthier intramuscular fatty acid composition, that is, meat with high PUFA to SFA ratio, and low in fatty acids n-6 to n-3 ratio, several strategies focused on animal feeding have been tested. However, a sufficient amount of antioxidants must be present in meat to counterbalance the increase in the content of readily oxidizable unsaturated fatty acids, which is vulnerable to oxidation, and from the associated deterioration of meat colour and proteins, thus antioxidants are crucial in preserving the nutritive value and extending the shelf life of the meat.
The increasing costs of feedstuffs for livestock led to the utilization of cheaper resources as alternatives to reduce the production cost. Here, locally available materials and agro-industrial by-products commonly found in the Mediterranean countries (citrus pulp, carob pulp, and olive cake) were used in feeding trials with lambs and the effects on meat quality were evaluated. These plant-derived materials contain considerable amounts of secondary bioactive metabolites, which affect the fatty acid composition and/or act as antioxidants. Hence, it was hypothesized that at appropriate levels of inclusion in to the lamb diets, these feedstuffs would not negatively affect animal health and productivity, and would represent a strategy to naturally produce a healthy and oxidatively stable meat.
In the first study (Experiment 1), Comisana male lambs were fed for 60 days:a conventional cereal-based concentrate diet, or concentrates in which 24% or 35% dried citrus pulp was included in partial replacement of barley. Following slaughter, the slices of longissimus thoracis et lomborum muscle were packed aerobically and stored for up to 6 days. The inclusion of citrus pulp in the diet effectively inhibited protein oxidation in meat by reducing protein radicals, carbonyl formation, and thiol loss in comparison to the Control. The results showed the ability of citrus pulp to be conveniently included among the ingredients of a concentrate-based diet and to result in an improved oxidative stability of meat proteins.In the second study (Experiment 2), Comisana lambs were fed for 60 days: conventional concentrates or a diet in which cereal concentrates were partially replaced by 24% or 35% carob pulp. The results demonstrated that feeding carob pulp did not affect animal productivity and improved the muscle content of PUFA, among which is rumenic acid, and reduced the SFA concentration and the n-6/n-3 PUFA ratio as compared to the control diet. Moreover, no extensive colour, lipid and protein oxidation in meat were observed over 6 days of aerobic storage. Therefore, dietary carob in lamb diet could be an effective strategy to improve the PUFA content in the meat without compromising animal growth performance and meat oxidative stability. In the third study (Experiment 3), the effect of feeding lambs with diets including linseed and olive cake on the evolution of volatile compounds (VOCs) in meat was assessed. Specifically, Appenninica lambs fed commercial concentrates or diets containing linseed, or olive cake, or combination of both. The VOC profile was determined through SPME-GC-MS analysis of raw and cooked meat The cooked meat showed higher concentrations of VOCs than raw meat and most of these were derived from fatty acid oxidation.Nevertheless, in both raw and cooked meat, none of the lipid oxidation-derived volatiles was significantly affected by the dietary treatments. Therefore, the results suggest that the replacement of cereal concentrates with linseed and/or olive cake in diets for lambs did not cause appreciable changes in VOC profile of meat
Ultra-thin transparent electrodes for energy applications
No full textDue to the unique feature of being contemporarily optically transparent and electrically conducting, Transparent Conductive Oxides (TCOs) play a fundamental role in many technologies: communications, information, energy, buildings. Up to now, the most diffused material in the TCO s family was indium tin oxide (ITO), especially for large-area applications such as flat panel displays. Recently, the increasing expansion of the display market and, even more, of photovoltaics, are endangered by the scarcity and rising price of indium. This is one of the reasons and a strong motivation for searching alternative transparent electrodes, not necessarily oxides, to replace ITO. Moreover, in order to meet the expectations for the growing demand and lower production costs for photovoltaic and electronic applications, new TCOs, or equivalent materials, must be abundant, not expensive and very thin, so to be suitable for flexible electronics. Among new transparent electrodes candidates, Aluminium-doped zinc oxide (AZO) films and very thin multilayers of AZO/Ag/AZO have emerged as a very promising alternative . In particular, AZO films are Indium-free and show electro-optical properties comparable to ITO films of the same thickness (700-900 nm for industrial applications), especially after thermal annealing at 250 °C. On the other hand, AZO/Ag/AZO multilayer structures, 10 times thinner than ITO or AZO single layers, show very high transparency and low resistivity even at room temperature. Replacing thick TCO layers with thin TCO/Ag/TCO multilayers would produce great benefits in terms of material consumption, cost, toxicity and flexibility (a mandatory point for the development of the electronics on plastic). In this context, it is important the study and understanding of the fundamental properties of these materials, the process conditions and post fabrication treatments to optimize their application to different fields. Transparent conductive materials are known since about 100 years and represent one of the strategic topics for the actual industrial research, but still many fundamental properties and mechanisms need to be clarified and explained. Aim of this work is the fabrication, processing and characterization of ultra-thin AZO and TCO/Ag/TCO transparent electrodes. The study focused on the optimization of structural, optical and electrical properties for application in photovoltaics. The thesis is organized as follows. Chapter 1 introduces TCOs and covers the conventional and non materials history, properties, applications and market. Chapter 2 starts with a comprehensive and detailed study about thick AZO grown by RF magnetron sputtering films on glass substrates, focusing on the influence of sputtering process parameters, i.e. power, temperature substrate, and thermal treatment (during or after the deposition) on the film properties. After the work on thick AZO, we report the modification of optical, electrical and structural properties of very thin films (60 nm) upon ion irradiation with different ion type (O+ or Ar+ ions) and energy (30 and 350 keV) at different ion doses (3, 10, 30E15ions/cm-2), before and after thermal treatments up to 400°C. Chapter 3 treats of very thin TCO/Ag/TCO multilayer structures grown by RF magnetron sputtering. Synthesis and properties of AZO/Ag/AZO multilayers as a function of Ag film thickness, with a fixed AZO thickness (~20 nm), are investigated. Then, we studied multilayers with fixed Ag thickness(~10 nm), but different combinations of AZO and ITO as top and bottom TCO layers. Chapter 4 describes the compatibility of the AZO/Ag/AZO multilayers with one of the most important steps for the implementation in thin film photovoltaic technology: laser scribing. AZO/Ag/AZO multilayers must be able to guarantee the same level of TCO reliability under laser scribing processes. In this study, we used a single nanosecond laser pulse to irradiate AZO/Ag/AZO deposited on glass
Control architectures for heterogeneous fleets of UVSs
No full textThe field of aerial robotics, from 20 years ago up to now, has had an incredible growth. The reasons are several, but surely, the key motivation is the development of MEMS sensors and microcontroller more and more cheap and reliable. As regards the UAV features, it is clear as there isn't "a general purpose" drone, capable to accomplish whatever task. For this reason, a keyword in the next years for the researchers will be the cooperation between heterogeneous robotic platforms. More and more often complex tasks require features that a single drone doesn't have. For example, to patrol a huge area, it is required a drone suitable to fly forward with high speed, to be capable to hover and to have a good autonomy. In a few words, it is impossible for a single drone, but also for a homogeneous fleet.
From this consideration is born the objective of this thesis: to develop a fleet of heterogeneous UAV
Sviluppo di un sistema GIS e Webgis a supporto delle attività di bonifica del sito di interesse nazionale di Biancavilla
No full textIn seguito al rilevamento di un cluster di casi di mesotelioma nella città siciliana di Biancavilla, che si trova alle pendici del vulcano Etna, sono stati effettuati studi epidemiologici ad hoc e monitoraggi ambientali per evidenziare il ruolo e l eziologia di una fibra asbestiforme presente in una cava di pietra.
Una dettagliata analisi chimica di anfiboli contenuti in questo materiale ha permesso la scoperta e l'individuazione di una nuova fibra: la fluoroedenite (NaCa2Mg5 (Si7Al) O22F2).
Si è potuto constatare che la fluoroedenite rappresenta un probabile agente cancerogeno, responsabile del mesotelioma pleurico maligno riscontrato a Biancavilla.
Oltre al rischio di mesotelioma, nei residenti di Biancavilla si è mostrato un significativo aumento della mortalità da malattia polmonare cronica ostruttiva, che è stato particolarmente evidente tra le donne. Alla luce di questi risultati, Biancavilla è entrato nella lista dei siti di interesse nazionale (SIN). La prima azione di bonifica ha coinvolto preventivamente l attività della cava, la copertura con asfalto delle strade già realizzate con materiali locali e la rimozione delle fonti di polvere nella zona urbana.
Obiettivo del presente lavoro è stato lo studio dei dati acquisiti nei monitoraggi ambientali svolti tra il 2004 ed il 2005 nel territorio pedemontano. A tal fine, si è reso necessario sia rappresentare e gestire in modo opportuno i dati ottenuti dai monitoraggi ambientali delle fibre asbestiformi mediante piattaforme GIS e Web GIS, che analizzare gli stessi dati mediante modellazione statistica in modo da evidenziare le variabili esplicative fondamentali le quali permettono di comprendere le eventuali relazioni tra le variabili indipendenti (dati meteoclimatici), con le variabili dipendenti quali le concentrazioni di fibre di fluoroedenite riscontrate nelle diverse stazioni di monitoraggio
Eterostrutture di Grafene con Semiconduttori ad ampio Bandgap
No full textGraphene (Gr) is a two dimensional material constituted by an atomically thin carbon membrane, characterized by a unique combination of excellent electrical, optical, thermal and mechanical properties. Its main limitation for microelectronic applications is related to the lack of a bandgap, leading to a poor Ion/Ioff ratio when it is considered as channel material for MOSFET devices. Novel device concepts based on Gr heterostructures with semiconductors are currently under consideration, in order to overcome these limitations. These devices are based on the vertical current transport through Gr interfaces with semiconductors or thin insulators. Their working principle exploits some unique properties of Gr, such as the atomic thickness and the field effect modulation of its workfunction. Some demonstrations of these devices, recently reported in the literature, have been based on the integration of Gr with Si technology.
This thesis work has been focused on the fabrication and the electrical characterization of high quality heterostructures of Gr with wide bandgap semiconductors (WBS), such as Silicon Carbide (4H-SiC), Gallium Nitride (GaN) and related alloys (AlxGa1-xN), which present superior properties for high power and high frequency electronic applications.
At first, the fabrication methods have been discussed, i.e.
(i) the controlled graphitization of the surface by high temperature thermal annealing, for 4H SiC;
(ii) a highly reproducible transfer method to move Gr, grown by CVD on copper foils, to the surface of AlGaN/GaN heterostructures.
A detailed structural, morphological and spectroscopic characterization of these Gr/WBS heterostructures has been carried out by the joint application of several analytical techniques, such as AFM; TEM, micro-Raman spectroscopy.
Secondly, the current transport mechanisms through these heterostructures have been investigated in details by properly fabricated test devices and by nanoscale resolution electrical characterization techniques (CAFM, SCM). A correlation between the nanoscale structural, morphological and electrical properties of the interfaces with the devices average electrical behavior has been achieved.
Basing on these results, some potential devices applications (such as the Gr/SiC Schottky diode with a gate modulated barrier and the hot electron transistor constituted by a Gr/AlGaN/GaN heterostructures with a Gr base) have been discussed and their advantages with respect to the Si counterparts have been estimated
Parkinson's disease and degenerative parkinsonism: relationship between clinical and neurobiological aspects
No full textIl neurovascula coupling indica il processo mediante il quale l unità neuro vascolare modula la complessa relazione tra attività neuronale, fattori emodinamici e segnali intracellulari.
Recenti studi individuano la possibile associazione tra alterazioni dell emodinamica cerebrale e il decadimento della performance cognitiva,in parte riconducibile ad una compromissione del fisiologico signaling tra gli elementi dell unità neuro vascolare.
Obiettivo dello studio è quello di indagare la possibile relazione tra disturbi cognitivi ed alterazioni della reattività cerebrovascolare in pazienti affetti da Malattia di Parkinson (MdP).
È stata valutata una popolazione di 34 pazienti (22 maschi e 12 femmine) affetti da MdP in accordo con UK brain bank Criteria e sottoposta a valutazione clinica,motoria e neuropsicologica,valutazione della funzionalità autonomica mediante SCOPA-AUT,valutazione del carico lesionale della sostanza bianca mediante Risonanza Magnetica Cerebrale applicando la scala visiva semiquantitativa CHS e dettagliata valutazione Ultrasonografica TSA e TCD ,inclusa valutazione della reattività cerebrovascolare mediante Breath Holding Index (BHI). La popolazione è stata divisa in due gruppi in base alla presenza di Mild cognitive Impairment (MCI) in accordo con Diagnostic Criteria for PD-MC da Litvan I 2012.
Dai risultati ottenuti i parametri emodinamici valutati mediante TCD non hanno evidenziato differenze significative al baseline di VMF MCA e PCA. Dopo stimolo ipercapnico si è osservata una differenza statisticamente significativa della reattività cerebrovascolare risultando ridotta nel gruppo PD-MCI
Rapporti fiduciari e circolazione della ricchezza immobiliare
No full textL esigenza di ricorrere a strumenti che consentano di costituire patrimoni separati ed affidarli ad un terzo perché siano gestiti, sembra essere avvertita sempre di più dalla società moderna. Con riferimento al trend ora segnalato, la Convenzione dell Aja del 1985 relativa alla legge sui trusts ed al loro riconoscimento, ha svolto indubbiamente un ruolo importante.
E'ben noto come l effetto più rilevante della Convenzione dell'Aja del 1985 sia stato quello di permettere ai trusts costituiti nei sistemi di common law di operare nei così detti paesi non trust. Dalla limitata operatività della convenzione è, inoltre, derivato un incentivo al trasferimento della gestione delle ricchezze in paesi dove esse possono essere gestite con strumenti più flessibili e snelli di quelli posseduti dai principali ordinamenti di civil law. Per questo motivo, il trust è stato inserito per via legislativa in molti sistemi giuridici cosiddetti misti e anche in alcuni di civil law; altri paesi come la Francia, invece, hanno introdotto nel proprio ordinamento istituti giuridici modellati in parte sull'esempio del trust (fiducie).
Questi istituti possono essere studiati sotto una molteplicità di profili. La ricerca si propone di valutare l'impatto che essi hanno sulla circolazione dei beni che ne compongono il patrimonio.
Nel primo capitolo si tenterà, dunque, di illustrare la disciplina del trust negli ordinamenti inglesi ed in particolare di spigare che esso non comporta uno sdoppiamento della proprietà, ma al contrario ha la funzione di ricompattare tutte le prerogative proprietarie nelle mani di un unico soggetto il trustee, il quale ha il potere di disporre dei beni che compongono il trust fund.
Nel corso del secondo capitolo, ove si analizzeranno le soluzioni tramite cui l esperienza francese nel recepire il trust ha risolto il conflitto segnalato, emergeranno invece le difficoltà che gli ordinamenti di civil law avvertono nel replicare la disciplina del tracing. In particolare, se tutti gli istituiti modellati sull'esempio del trust che sono stati introdotti per via legislativa in molti sistemi giuridici «misti» e anche in alcuni di civil law prevedono, sebbene con tecniche diverse, la separazione del fund dal patrimonio del manger, quasi nessuna di queste discipline prevede un rimedio assimilabile al tracing.
In questo contesto si colloca, inoltre, la Convenzione dell'Aja del 1985 il cui effetto primario, come si è accennato, è quello di permettere che un trust costituito secondo una legge straniera produca effetti in un altro ordinamento.
Poiché lo schema tracciato dal trust prevede il trasferimento della proprietà dei beni che compongono il fund al trustee, sorge la necessità di elaborare dei rimedi efficaci nel caso di abuso di quest'ultimo alla luce del diritto interno. Infatti, in virtù del rinvio alla lex fori di cui all'art. 11, secondo comma, lettera d) della Convenzione, nel caso in cui i beni di cui il trustee abbia abusivamente disposto si trovino in Italia sarà applicabile il diritto italiano. Nel terzo capitolo ci si soffermerà, dunque, su tale problematica e si tenterà di tracciare una possibile soluzione avendo, in articolare, riguardo alla portata degli art. 11 e 12 della Convenzione dell'Aja del 1985 nonché ai principi in materia di trascrizione e le regole poste a tutela dei terzi acquirenti di buona fede.
Infine, alla luce dei risultati ottenuti, si tenterà di individuare nel ordinamento italiano una disciplina che consenta all'autonomia privata di conseguire risultati paragonabili a quelli conseguibili con il trust (o con i cosiddetti trust-like devices) avendo particolare riguardo al negozio fiduciario e all art. 2645-ter c.c