Monitoraggio e amministrazione di reti virtuali

Negli ultimi anni l'attenzione, dei ricercatori e dell'industria, nei confronti dei sistemi di virtualizzazione è incrementata notevolmente. Un sistema di virtualizzazione ha lo scopo di fornire diversi ambienti di esecuzione software, comunemente chiamati macchine virtuali, astraendo dalla risorse hardware e software sottostanti. Uno dei vantaggi principali offerti dalla virtualizzazione, è costituito dalla possibilità di razionalizzare l'utilizzo delle risorse di calcolo a disposizione: innanzitutto è possibile destinare un solo computer allo svolgimento del lavoro che prima veniva svolto da più nodi, garantendo così un notevole risparmio, abbattendo i costi hardware, di manutenzione e il consumo di energia elettrica. Inoltre, è possibile sfruttare la tecnologia di virtualizzazione per progettare un sistema più sicuro. È infatti possibile, eseguire i processi critici, ad esempio un server web, all'interno di macchine virtuali separate, garantendo un elevato grado di isolamento fra applicazioni differenti. Questa tesi presenta uno strumento software per il monitoraggio e l'amministrazione remota di macchine virtuali. Tale strumento analizza le hypercall invocate dal sistema operativo virtualizzato, nei confronti del virtual machine monitor, per fornire una vista dettagliata dello stato di esecuzione della macchina virtuale. La tesi presenta, inoltre, il lavoro svolto per cercare di definire il concetto di sense of self di una macchina virtuale Xen. Tale ricerca ha lo scopo di individuare un metodo efficace per distinguere l'attività lecita svolta da una macchina virtuale, dall'attività anomala, dovuta, ad esempio, ad un tentativo di intrusione. Infine, dopo aver descritto l'architettura complessiva dello strumento, la tesi presenta una prima valutazione delle prestazioni del prototipo realizzato

Proteomics Disclose the Potential of Gingival Crevicular Fluid (GCF) as a Source of Biomarkers for Severe Periodontitis

: Periodontal disease is a widespread disorder comprising gingivitis, a mild early gum inflammation, and periodontitis, a more severe multifactorial inflammatory disease that, if left untreated, can lead to the gradual destruction of the tooth-supporting apparatus. To date, effective etiopathogenetic models fully explaining the clinical features of periodontal disease are not available. Obviously, a better understanding of periodontal disease could facilitate its diagnosis and improve its treatment. The purpose of this study was to employ a proteomic approach to analyze the gingival crevicular fluid (GCF) of patients with severe periodontitis, in search of potential biomarkers. GCF samples, collected from both periodontally healthy sites (H-GCF) and the periodontal pocket (D-GCF), were subjected to a comparison analysis using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). A total of 26 significantly different proteins, 14 up-regulated and 12 down-regulated in D-GCF vs. H-GCF, were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The main expressed proteins were inflammatory molecules, immune responders, and host enzymes. Most of these proteins were functionally connected using the STRING analysis database. Once validated in a large scale-study, these proteins could represent a cluster of promising biomarkers capable of making a valuable contribution for a better assessment of periodontitis

A Proteomic Analysis of Discolored Tooth Surfaces after the Use of 0.12% Chlorhexidine (CHX) Mouthwash and CHX Provided with an Anti-Discoloration System (ADS)

Chlorhexidine (CHX) is considered the gold standard for the chemical control of bacterial plaque and is often used after surgical treatment. However, CHX employment over an extended time is responsible for side effects such as the appearance of pigmentations on the teeth and tongue; the discoloration effects are less pronounced when using a CHX-based mouthwash with added an anti-discoloration system (ADS). The aim of this study was to evaluate, using one- and two-dimensional gel electrophoresis combined with mass spectrometry, the possible proteomic changes induced by CHX and CHX+ADS in the supragingival dental sites susceptible to a discoloration effect. The tooth surface collected material (TSCM) was obtained by curettage after resective bone surgery from three groups of patients following a supportive therapy protocol in which a mechanical control was combined with placebo rinses or CHX or a CHX+ADS mouthwash. The proteomic analysis was performed before surgery (basal conditions) and four weeks after surgery when CHX was used (or not) as chemical plaque control. Changes in the TSCM proteome were only revealed following CHX treatment: glycolytic enzymes, molecular chaperones and elongation factors were identified as more expressed. These changes were not detected after CHX+ADS treatment. An ADS could directly limit TSCM forming and also the CHX antiseptic effect reduces its ability to alter bacterial cell permeability. However, Maillard's reaction produces high molecular weight molecules that change the surface properties and could facilitate bacterial adhesion

How Intraday Index Changes Influence Periodontal Assessment: A Preliminary Study

It is reputed that periodontal indices remain unchanged over a 24-hour period, with great clinical significance. This preliminary study analyzes daily index changes. In 56 selected patients, full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS), periodontal screening and recording (PSR) indices, and periodontal risk assessment (PRA) were recorded at baseline and three times per day (check-I: 08.30, check-II: 11.30, and check-III: 14.30), after appropriate cause-related therapy. Correlation between variables was statistically analyzed by Stata. All periodontal indices improved at the examination phase. Statistical differences were detected for FMPS comparing all thrice daily checks. Statistical differences were detected for FMBS and PRA comparing check-III with check-I and check-II. PSR showed no significant changes. The worst baseline indices produced the widest daily fluctuation at the examination phase. Significant variation of indices is directly related to clinical severity of periodontal conditions at baseline. Patients affected by severe periodontal disease may show significantly greater index changes. As indices are routinely recorded only once per day, the index daily variation has clinical significance. This greatly affects therapeutic strategy as correct periodontal assessment requires multiple evaluations at standardized times, particularly when baseline conditions are severe

Matriz tridimensional con potencial para regeneración ósea

79 páginasLas matrices poliméricas han recibido gran atención en los últimos años, ya que proporcionan un entorno temporal para el crecimiento y la interacción celular, además de la formación de la matriz extracelular, dando soporte a la formación de un nuevo tejido al actuar como un material prostético para regenerar tejido in vivo o como sustrato adhesivo celular para formar tejidos in vitro. El siguiente trabajo presenta la obtención de matrices tridimensionales de PLLA (ácido poliláctico) por medio del método salt leaching/gas foaming y la caracterización morfológica y mecánica de las mismas, mediante técnicas que incluyen hinchamiento, microscopia SEM, microscopia óptica y ensayos mecánicos de compresión.PregradoIngeniero(a) Biomédico(a

The comparison of the proteomic profile of periodontal pocket and of corresponding gingival crevicular fluid to study periodontal disease biomarkers: feasibility study. biomarkers: feasibility study

Aim: Periodontitis is a set of inflammatory disorders characterized by periodontal attachment loss by periodontal pocket development, leading to tooth loss if remain untreated. The etiology and progress of periodontal disease is complex and remains mostly unknown. So, periodontal disease therapy has considerable limitations. The easy, reliable and correct early detection and control of the disease, markedly reduces biological and social costs. However, the diagnosis of periodontitis is established exclusively by clinical criteria based on probing to assess periodontal pockets, which are the pathognomonic expression of periodontal disease. The -omic sciences acquired substantial significance of late years and, in particular, proteomic seemed to be the more promising in this initial stage. Most proteomic analysis regarding periodontal diseases have been performed on saliva, crevicular fluid samples, peripheral blood or periodontal plaque samples which are more easily to harvest than the tissue of the periodontal pocket. However, they failed to provide reliable results for clinical applications. On the contrary, very few studies were directly performed on the periodontal pocket. So, the aim of this study was to compare the proteomic profile of interproximal pocket tissues with that of GCF, and to analyze if they show a significant similarity in the proteomic profile. Methods: in this preliminary study, we enrolled 3 healthy subjects affected by severe periodontitis needing of periodontal surgery. Immediately before the surgery, GCF samples were taken by means of filter paper strips positioned in the gingival sulcus correspondent to periodontal pockets. Then, periodontal pocket tissue, harvested during surgery, was adequately stored for proteomic analyses. All samples were immediately frozen at \u201380\ub0C and maintained until further analysis. Tissue samples were mechanically disrupted and incubated in lysis buffer, while GCF was obtained incubating the collecting paper in phosphate buffered. In both cases, after centrifugation, the supernatant was precipitated in cold acetone overnight and protein content were pelleted by centrifugation and then dissolved in a rehydration buffer. Mono-dimensional gel electrophoresis was used to separate protein content. After staining gel images were acquired and compared. Liquid chromatography coupled to mass spectrometry (LC-MS/MS) analysis was performed to allow protein spot identification. Results: 1-DE gels from periodontal pocket tissue and the correspondent GCF was analyzed by software Quantity One. Almost the same qualitative protein expression profile in pocket tissue and GCF was found from each patient. However, no statistical significant correlation between the quantitative proteomic profile of pocket tissue and GCF was found. Only one band (that of K immunoglobulin) resulted statistically significant between GCF and pocket tissue proteome in all patients. Conclusions To date, this is the first study comparing the proteome of periodontal pocket tissue and corresponding GCF. The periodontal pocket and the GCF are similar as proteomic networks, but the protein network of the periodontal pocket does not influence significantly the GCF protein network and the other way around. So, with the limitations of this study, the preliminary results seem to indicate that the GCF does not seem suitable to study on the pathogenesis of periodontal disease explaining the reason for the failure of studies based only on GCF to control the periodontal disease in real-time

Analysis of protein expression in periodontal pocket tissue: a preliminary study

The periodontal disease is caused by a set of inflammatory disorders characterized by periodontal pocket formation that lead to tooth loss if untreated. The proteomic profile and related molecular conditions of pocket tissue in periodontally-affected patients are not reported in literature. To characterize the proteomic profile of periodontally-affected patients, their interproximal periodontal pocket tissue was compared with that of periodontally-healthy patients. Pocket-associated and healthy tissue samples, harvested during surgical therapy, were treated to extract the protein content. Tissues were always collected at sites where no periodontal-pathogenic bacteria were detectable. Proteins were separated using two-dimensional gel electrophoresis and identified by liquid chromatography/mass spectrometry. After identification, four proteins were selected for subsequent Western Blot quantitation both in pathological and healty tissues

Evaluation of cytotoxicity and antibacterial activity of a new class of silver citrate-based compounds as endodontic Irrigants

In the present study, the cytotoxicity and the antimicrobial activity of two silver citrate-based irrigant solutions were investigated. Cytotoxicity of various concentrations (0.25%, 0.5%, 1%, 2.5%, 5%) of both solutions (BioAKT and BioAKT Endo) was assessed on L-929 mouse fibroblasts using the MTT assay. For the quantitative analysis of components, an infrared (I.R.) spectroscopy was performed. The minimum inhibitory and minimal bactericidal concentrations (M.I.C. and M.B.C., respectively) were ascertained on Enterococcus faecalis strain ATCC 4083. For biofilm susceptibility after treatment with the irrigating agent, a minimum biofilm eradication concentration (M.B.E.C.) and confocal laser scanning microscope (C.L.S.M.) assays were performed. Quantification of E. faecalis cell biomass and percentage of live and dead cells in the biomass was appraised. Normality of data was analyzed using the D’Agostino & Pearson’s test and the Shapiro–Wilk test. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey’s test. Both silver citrate solutions showed mouse fibroblasts viability >70% when diluted to 0.25% and 0.5%. Conversely, at higher concentrations, they were extremely cytotoxic. F.T.-IR spectroscopy measurements of both liquids showed the same spectra, indicating similar chemical characteristics. No substantial contrast in antimicrobial activity was observed among the two silver citrate solutions by using broth microdilution methods, biofilm susceptibility (MBEC-HTP device), and biomass screening using confocal laser scanning microscopy (C.L.S.M.) technique. Both solutions, used as root canal irrigants, exhibited significant antimicrobial activity and low cytocompatibility at dilutions greater than 0.5%