Identificazione del rischio per fenomeni di caduta massi

La nota riferisce sulle modalità descrittive e di quantificazione del rischio in relazione ad eventi franosi localizzati, quali i fenomeni di caduta massi. Ponendo come base il riconoscimento delle caratteristiche geostrutturali e morfologcihe del versante, sono inquadrate le procedure per valutare il passaggio dalle condizioni di ricorrenza dei fenomeni al danno potenziale. Il rimando ad un esempio applicativo denota quali siano i margini di incertezza connessi allo studio di fenomeni per loro natura puntuali e discontinui

Architettura medievale: il Trecento. Modelli, tecniche, materiali

Pubblicazione Open Access. Il presente volume giunge alla pubblicazione al termine di un lungo percorso editoriale. Alla sua origine si collocano i progetti di ricerca MHP – Medieval Heritage Platform. Territorio e insediamenti: nuovi strumenti di ricerca e di divulgazione per il patrimonio e Cistercian Cultural Heritage: knowledge and enhancement in a European framework CCH realizzati grazie al sostegno del Dipartimento Interateneo di Scienze, Progetto e Politiche del Territorio del Politecnico di Torino, che ha reso disponibili notevoli risorse per contribuire alle attività di studio, di analisi e di disseminazione. Gli anni di ricerca trascorsi hanno permesso di costruire occasioni di scambio e di confronto con colleghi appartenenti a differenti discipline storiche e non solo, del restauro e della rappresentazione, di provenienza nazionale e internazionale, riuniti intorno ai temi dell’architettura e della città tardo medievale, tra Duecento e Trecento. Un periodo fecondo di studi che ha dato esito a numerose pubblicazioni edite e in corso di stampa. Nello specifico, il convegno internazionale “Architettura medievale: il Trecento. Modelli, tecniche, materiali”, organizzato il 2-3-4 dicembre 2019 al Politecnico di Torino, presso il castello del Valentino, nasceva dalla convinzione che l’architettura del XIV secolo richiedesse una nuova riflessione critica e un confronto internazionale sulle prospettive di ricerca. Nel panorama complessivo, l’architettura non sembra essere al centro dell’interesse degli studiosi, mentre la pittura ha comprensibilmente attratto l’attenzione, in un secolo dominato in Italia da figure di straordinaria eccellenza. Eppure, l’architettura, a scala europea, conosce sviluppi senza precedenti, in tutti i settori dell’edilizia: nella costruzione di edifici sacri, di palazzi pubblici, di strutture residenziali, di castelli e di complessi fortificati. Ancora oggi mancano lavori di sintesi complessivi e ricerche comparative a lungo raggio, in grado di esplorare le relazioni internazionali che guidano le scelte dei committenti, la circolazione dei modelli, l’elaborazione dei progetti, la mobilità delle maestranze. La visione riduttiva di un’architettura “tardo-gotica”, che eredita le grandi conquiste del Duecento e le adatta ad un contesto europeo colpito da uno stato permanente di crisi, in un clima di guerre, di pestilenze e di rivolte sociali, non sembra corrispondere alla realtà di un impegno costruttivo e di un patrimonio estremamente complesso che il Trecento ci ha consegnato. Dall’esigenza di esplorare con maggiore attenzione la congiuntura del secolo, e di porre a confronto gli sviluppi delle ricerche nei diversi paesi, è nata l’idea di raccogliere ricerche in corso attraverso una call, predisposta da un comitato scientifico composto da Andrea Augenti, Xavier Barral i Altet, Arturo Calzona, Giovanni Coppola, Joan Domenge Mesquida, Bruno Klein, Saverio Lomartire, Nicolas Reveyron, Dany Sandron, Michele Luigi Vescovi e Guglielmo Villa. Al comitato scientifico internazionale si è affiancato il lavoro del gruppo di ricerca costituito dai docenti del Dipartimento, coordinato da Carlo Tosco e formato da Silvia Beltramo, Andrea Bocco, Chiara Devoti, Maurizio Gomez Serito, Elena Gianasso, Laura Antonietta Guardamagna, Gabriele Garnero, Filippo Gemelli e Andrea Longhi

Exploring the potential of graphene oxide nanosheets for porous media decontamination from cationic dyes

Graphene oxide (GO) nanosheets, often embedded in nano-composites, have been studied as promising materials for waste water purification, in particular to adsorb heavy metals and cationic organic contaminants. However, a broader range of potential applications of GO is still unexplored. This work investigated the potential applicability of GO for enhanced in-situ soil washing of secondary sources of groundwater contamination (i.e. the controlled recirculation of a washing GO suspension via injection/extraction wells). The laboratory study aimed at quantifying the capability of GO to effectively remove adsorbed methylene blue (MB) from contaminated sand. The tests were conducted in simplified conditions (synthetic groundwater at NaCl concentration of 20 mM, silica sand) to better highlight the key mechanisms under study. The results indicated a maximum sorption capacity of 1.6 mgMB/mgGO in moderately alkaline conditions. Even though the adsorption of MB onto GO slightly reduced the GO mobility in the porous medium, a breakthrough higher than 95% was obtained for MB/GO mass ratios up to 0.5. This suggests that a very high recovery of the injected particles should be also expected in the field

A Creatine Transporter Is Operative at the Brush Border Level of the Rat Jejunal Enterocyte

Abstract Although ergogenic effects and health benefits have been reported for creatine used as nutritional supplement, to date little is known about the mechanism of creatine absorption in the small intestine. Thus the current study was undertaken to elucidate the mechanism of creatine intake in rat jejunum with the use of well-purified brush border membrane vesicles, isolated from jejunal enterocyte. Creatine uptake was found markedly stimulated by inwardly directed Na(+) and Cl(- )gradients, potential-sensitive, strongly reduced by the substitution of Na(+) and Cl(-) with various cations and anions and positively affected by intravesicular K(+). Moreover, creatine uptake is: 1) significantly inhibited by creatine structural analogs, 2) abolished by low concentrations of 2-aminoethyl methanethiosulfonate hydrobromide (MTSEA), 3) saturable as a function of creatine concentration with an apparent Michaelis-Menten constant of 24.08 +/- 0.80 muM and a maximal velocity of 391.30 +/- 6.19 pmoles mg protein(-1) 30 s(-1). The transport is electrogenic since at least two Na(+) and one Cl(-) are required to transport one creatine molecule. Western blot analysis showed the same amount of creatine transport protein in the jejunal apical membrane when compared to ileum. Thus, these data demonstrate the existence of a Na(+)- and Cl(-)-dependent, membrane potential-sensitive, electrogenic carrier-mediated mechanism for creatine absorption in rat jejunal apical membrane vesicles, which is biochemically and pharmacologically similar to those observed in other tissues. However, in other cell types the stimulatory effect of intravesicular K(+) was never detected

TAS2R38 is a novel modifer gene in patients with cystic fbrosis

The clinical manifestation of cystic fbrosis (CF) is heterogeneous also in patients with the same cystic fbrosis transmembrane regulator (CFTR) genotype and in afected sibling pairs. Other genes, inherited independently of CFTR, may modulate the clinical manifestation and complications of patients with CF, including the severity of chronic sinonasal disease and the occurrence of chronic Pseudomonas aeruginosa colonization. The T2R38 gene encodes a taste receptor and recently its functionality was related to the occurrence of sinonasal diseases and upper respiratory infections. We assessed the T2R38 genotype in 210 patients with CF and in 95 controls, relating the genotype to the severity of sinonasal disease and to the occurrence of P. aeruginosa pulmonary colonization. The frequency of the PAV allele i.e., the allele associated with the high functionality of the T2R38 protein, was signifcantly lower in i) CF patients with nasal polyposis requiring surgery, especially in patients who developed the complication before 14 years of age; and ii) in CF patients with chronic pulmonary colonization by P. aeruginosa, especially in patients who were colonized before 14 years of age, than in control subjects. These data suggest a role for T2R38 as a novel modifer gene of sinonasal disease severity and of pulmonary P. aeruginosa colonization in patients with CF

High levels of soluble CD73 unveil resistance to BRAF inhibitors in melanoma cells

: Melanoma cells express high levels of CD73 that produce extracellular immunosuppressive adenosine. Changes in the CD73 expression occur in response to tumor environmental factors, contributing to tumor phenotype plasticity and therapeutic resistance. Previously, we have observed that CD73 expression can be up-regulated on the surface of melanoma cells in response to nutritional stress. Here, we explore the mechanism by which melanoma cells release soluble CD73 under low nutrient availability and whether this might be affected by agents targeting the proto-oncogene B-Raf (BRAF). We found that starved melanoma cells can release high levels of CD73, able to convert AMP into adenosine, and this activity is abrogated by selective CD73 inhibitors, APCP or PSB-12489. The release of CD73 from melanoma cells is mediated by the matrix metalloproteinase MMP-9. Indeed, MMP-9 inhibitors significantly reduce the levels of CD73 released from the cells, while its surface levels increase. Of relevance, melanoma cells, harboring an activating BRAF mutation, upon treatment with dabrafenib or vemurafenib, show a strong reduction of CD73 cell expression and reduced levels of CD73 released into the extracellular space. Conversely, melanoma cells resistant to dabrafenib show high expression of membrane-bound CD73 and soluble CD73 released into the culture medium. In summary, our data indicate that CD73 is released from melanoma cells. The expression of CD73 is associated with response to BRAF inhibitors. Melanoma cells developing resistance to dabrafenib show increased expression of CD73, including soluble CD73 released from cells, suggesting that CD73 is involved in acquiring resistance to treatment

Estensione dell'analisi di rischio sanitario ambientale a contaminazioni di nanomateriali in sistemi acquiferi

Il largo impiego dei nanomateriali in numerosi processi industriali ha sollevato particolare attenzione attorno alle questioni sanitarie connesse ad una loro potenziale diffusione in ambiente. Tuttavia, a causa della natura polidispersa dei nanomateriali, il rischio sanitario ambientale associato ad una contaminazione da nanoparticelle (NP) non può essere quantificato tramite la procedura ASTM comunemente applicata per le altre sostanze chimiche. NP di dimensione diverse sono infatti caratterizzate da differente tossicità e mobilità nei comparti ambientali. In questo studio viene proposto un approccio per l’adattamento della procedura ASTM al caso di acquiferi contaminati da NP. Le soluzioni analitiche usate per l’analisi di rischio di Livello 2 di sostanze disciolte sono qui adattate ed estese per tenere conto dei meccanismi di trasporto propri delle NP. Vengono infine presentati due casi applicativi della procedura proposta, uno teorico ed uno sperimentale-modellistico, facendo particolare riferimento al ruolo dell’eterogeneità granulometrica delle NP nella quantificazione del rischio sanitario ambientale

Impact of CFTR Modulators on Beta-Cell Function in Children and Young Adults with Cystic Fibrosis

Background: To date, no consistent data are available on the possible impact of CFTR modulators on glucose metabolism. The aim of this study was to test the hypothesis that treatment with CFTR modulators is associated with an improvement in the key direct determinants of glucose regulation in children and young adults affected by Cystic Fibrosis (CF). Methods: In this study, 21 CF patients aged 10–25 underwent oral glucose tolerance test (OGTT) before and after 12–18 months of treatment with Lumacaftor/Ivacaftor or Elexacaftor-Ivacaftor-Tezacaftor. β-cell function (i.e., first and second phase of insulin secretion measured as derivative and proportional control, respectively) and insulin clearance were estimated by OGTT mathematical modelling. Insulin sensitivity was estimated by the Oral Glucose Sensitivity Index (OGIS). The dynamic interplay between β-cell function, insulin clearance and insulin sensitivity was analysed by vector plots of glucose-stimulated insulin bioavailability vs. insulin sensitivity. Results: No changes in glucose tolerance occurred after either treatment, whereas a significant improvement in pulmonary function and chronic bacterial infection was observed. Beta cell function and insulin clearance did not change in both treatment groups. Insulin sensitivity worsened in the Lumacaftor/Ivacaftor group. The analysis of vector plots confirmed that glucose regulation was stable in both groups. Conclusions: Treatment of CF patients with CFTR modulators does not significantly ameliorate glucose homeostasis and/or any of its direct determinants

Glucose tolerance stages in Cystic Fibrosis are idenfied by a unique pattern of defects of Beta-cell function

To assess the order of severity of the defects of three direct determinants of glucose regulation, i.e., beta-cell function, insulin clearance and insulin sensitivity, in patients with CF categorized according their glucose tolerance status, including early elevation of mid-OGTT glucose values (>140 and < 200 mg/dL), named AGT140