The behaviour of trace elements during the volcanic ash-liquid interaction. Example of marine and human systems.

I processi d’interazione solido-liquido sono alla base dei meccanismi che governano la disponibilità degli elementi in tracce in fase liquida. In questo lavoro tali processi sono stati studiati attraverso l’utilizzo degli elementi delle Terre Rare (REE) che come serie di elementi, per le loro peculiari caratteristiche sono degli ottimi traccianti di processi geochimici. Lo scopo della prima parte di questo lavoro è stato quello di studiare la reattività di un particolato vulcanico durante l’interazione con un’acqua marina sintetica. Tale indagine è stata effettuata attraverso esperimenti di tipo batch, per un periodo massimo di 6 mesi. Ulteriori indagini sono state effettuate aggiungendo NaHCO3 (160 mg/L) e umati (5 mg/L) alla soluzione salina, al fine di testare l’eventuale effetto sia sul solido che sul comportamento degli elementi in soluzione. Dal momento che l’ash vulcanico (proveniente dall’eruzione dell’Etna del 2001) è costituito principalmente da vetro (70%), olivina e clinopirosseno, è stata inoltre studiata anche la reattività delle singola frazione vetrosa e mineralogica a contatto con la soluzione salina senza leganti. I risultati mostrano che e concentrazioni di Terre Rare misurate nella soluzione a contatto con il vetro vulcanico sono maggiori mediamente di 2 volte rispetto alla frazione mineralogica, suggerendo che tali elementi sono principalmente rilasciati dalla frazione vetrosa. In tutti gli esperimenti le Terre Rare mostrano un aumento delle concentrazioni in soluzione intervallato da concentrazioni che tendono a diminuire. Questo andamento suggerisce che a parte la dissoluzione, che è il principale processo, si realizza anche un processo di adsorbimento superficiale, probabilmente su cristalli di neoformazione. La presunta presenza di tali minerali è suggerita dalle variazioni temporali del rapporto Y/Ho. Nella soluzione a contatto con i minerali si hanno, ad esempio, valori del rapporto Y/Ho in aumento nelle ultime fasi temporali, suggerendo che sulla superficie dei minerali si formano ossi-idrossidi di Al e Fe, dove l’Ho è preferibilmente adsorbito. Al contrario nella soluzione a contatto con il vetro il rapporto tende a diminuire suggerendo la presenza sulla superficie di minerali argillosi dove si ha di preferenza scavenging di Y. La presenza dei minerali di neoformazione sopracitati è inoltre Abstract -4- confermata da osservazioni al microscopio elettronico a scansione (SEM) e da analisi in XRD. Infine l’aggiunta di specie leganti in soluzione non determina un aumento della dissoluzione ma ha un effetto sulla distribuzione degli elementi in tracce in fase liquida. Nella seconda parte del lavoro lo studio delle Terre Rare è stato applicato ad un sistema umano. Le Terre Rare sono, infatti, state utilizzate per indagare gli effetti causati dall’interazione tra particolato atmosferico inalato e fluidi broncoalveolari (BAL). Tale indagine è stata eseguita su soggetti esposti ad un intenso fallout di particolato vulcanico. Il pattern delle Terre Rare normalizzate presenta una forma concava nei BAL che è molto simile a quello osservato in soluzioni che presentano co-precipitazione di Terre Rare con i fosfati. Questo dato suggerisce che nei polmoni si ha precipitazione delle Terre Rare con i fosfati, come conseguenza dell’inalazione di particelle vulcaniche e della loro interazione con i fluidi polmonari. Questo processo è confermato da simulazioni termodinamiche e cinetiche indicanti la cristallizzazione di fosfato di Terre Rare e altre fasi autigene come conseguenza della dissoluzione della frazione solubile della cenere vulcanica. Nello stesso sistema biologico sono infine state analizzate anche le concentrazioni di elementi minori ed in tracce, al fine di identificare l’esatta origine e la natura del particolato inalato. Tale studio è stato affrontato calcolando il fattore di arricchimento (EF) nei fluidi broncoalveolari rispetto a materiale di diversa origine. La presenza di V, Cr, Mn, Fe, Co e U nel sistema polmonare indica l’effetto della parziale dissoluzione della componente vulcanica a contatto con i fluidi polmonari. Tuttavia il budget di particolato inalato è anche influenzato dalla presenza di particelle di origine antropica che interagendo con i fluidi bronchiali portano ad un arricchimento in Ni, Cu, Cd e Pb. Arricchimenti in La nei BAL suggeriscono inoltre l’effetto di un ulteriore input di particolato inalato, riconducibile a quello industriale. La combinazione del frazionamento delle Terre Rare nei fluidi bronchiali può rappresentare un potenziale tracciante dell’esposizione al fallout atmosferico ed è un buon parametro diagnostico di esposizione a contaminati ambientali.The solid-liquid interaction processes regulate the mechanisms governing the availability of trace elements in liquid phase. In this paper, these processes have been studied through the use of the Rare Earth Elements (REE) since they are excellent tracers of geochemical processes. The purpose of the first part of this work was to study the reactivity of volcanic particulates during the interaction with synthetic seawater. This investigation was carried out through batch experiments for a maximum period of 6 months. Further investigation was carried out by adding NaHCO3 (160 mg/L) and humic acids (5 mg/L) to the synthetic seawater, in order to test the possible effects on the solid and on the elements behaviour in the solution. Since the volcanic ash (in this study from the eruption of Etna in 2001) consists mainly of glass (70%), olivine and clinopyroxene, it was also considered the reactivity both of glass and mineral fractions interacting with the synthetic solution without ligands. The results show that concentrations of REE measured in the solution interacting with volcanic glass, are about 2 times greater than experiments with mineral fraction, suggesting that these elements are mainly released by the glassy fraction. In all experiments REEs show concentration increases in solution but there are intervals where concentrations tend to decrease. This trend suggests that apart from the dissolution, which is the main process, a surface adsorption process also occurs, probably on the surface of newly formed crystals. The supposed presence of these minerals is suggested by the temporal variation of the Y/Ho ratio. In the solution with minerals the Y/Ho ratio, for example, at the end of the experiment rising, suggesting the formation on the mineral surfaces consisting of Al and Fe oxy-hydroxides, where Ho is preferably adsorbed. On the contrary, in the solution with glass the Y/Ho ratio decreases suggesting the presence of clay minerals on the surface, where Y is preferentially scavenged. The presence of the above mentioned newly formed minerals, is confirmed by SEM observations and XRD analysis. Finally the addition of ligand species to dissolved media does not increase dissolution rate of volcanic particles but modify the YLn distribution in liquid phase. Abstract -2- In the second part of this work, the Rare Earth study was applied to a human system. These elements were used, in fact, to investigate the effects due to the interactions between the inhaled atmospheric particulate matter and the lung fluids (BAL), in people exposed to fallout of volcanic ash. The observed concave shale of normalised YLn patterns in BAL is very similar to those recognised in parent solutions that experienced co-precipitation of YLn-phosphates. This result suggests that phosphate precipitation occurs in lungs as a consequence of inhalation of volcanic particles and their interactions with lung fluids. This process is confirmed by thermodynamic and kinetic simulations indicating that crystallisation of YLnphosphates and other authigenic phases occurs as a consequence of the soluble ash fraction dissolution. Finally, in the same biological system, minor and trace element concentrations were analysed in order to identify the origin and the nature of inhaled particulate matter. This study was carried out taking in account the enrichment factor (EF) in bronchoalveolar fluids with respect to the composition of the parent magma, the upper continental crust and the road dust. The effects of partial dissolution of a volcanic component in contact with lung fluids is recognised as the source of V, Cr, Mn, Fe, Co and U delivered to pulmonary system. Nevertheless the inhaled particle budget is also influenced by the presence of anthropogenic particles that interact with bronchial fluids enriching Ni, Cu, Cd and Pb in the fluid. Moreover the occurrence of the further industrial input is detected by means of La enrichment in BAL solutions. The combination of YLn fractionation in bronchial fluids can represent a potential tracer of exposure to atmospheric fallout and is suitable as a diagnostic parameter of environmental contaminant exposure

The stability and activity of human neuroserpin are modulated by a salt bridge that stabilises the reactive centre loop

Neuroserpin (NS) is an inhibitory protein belonging to the serpin family and involved in several pathologies, including the dementia Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB), a genetic neurodegenerative disease caused by accumulation of NS polymers. Our Molecular Dynamics simulations revealed the formation of a persistent salt bridge between Glu289 on strand s2C and Arg362 on the Reactive Centre Loop (RCL), a region important for the inhibitory activity of NS. Here, we validated this structural feature by simulating the Glu289Ala mutant, where the salt bridge is not present. Further, MD predictions were tested in vitro by purifying recombinant Glu289Ala NS from E. coli. The thermal and chemical stability along with the polymerisation propensity of both Wild Type and Glu289Ala NS were characterised by circular dichroism, emission spectroscopy and non-denaturant gel electrophoresis, respectively. The activity of both variants against the main target protease, tissue-type plasminogen activator (tPA), was assessed by SDS-PAGE and chromogenic kinetic assay. Our results showed that deletion of the salt bridge leads to a moderate but clear reduction of the overall protein stability and activity

Trace elements release from volcanic ashes to seawater. Natural concentrations in Central Mediterranean sea.

Distributions and concentrations of many minor and trace elements in epicontinental basins, as Mediterranean Sea, are mainly driven to atmospheric fallout from surroundings. This mechanism supplies an estimated yearly flux of about 1000 kg km-2 of terrigenous matter of different nature on the whole Mediterranean basin. Dissolution of these materials and processes occurring at solid-liquid interface along the water column drive the distributions of many trace elements as V, Cr, Mn, Co, Cu, and Pb with contents ranging from pmol l-1 (Co, Cd, Pb) to nmol l-1 scale in Mediterranean seawater, with some local differences in the basin. The unwinding of an oceanographic cruise in the coastal waters of Ionian Sea during the Etna’s eruptive activity in summer 2001 led to the almost unique chance to test the effects of large delivery of volcanic ash to a coastal sea water system through the analyses of distribution of selected trace elements along several seawater columns. The collection of these waters and their analyses about V, Cr, Mn, Co, Cu, and Pb contents evidenced trace element concentrations were always higher (about 1 order of magnitude at least) than those measured concentrations in the recent past in Mediterranean seawater, apart from Pb. Progressive increase of concentrations of some elements with depth, sometimes changing in a “conservative” behaviour without any clear reason and the observed higher concentrations required an investigation about interaction processes occurring at solid-liquid interface between volcanic ash and seawater along water columns. This investigation involving kinetic evaluation of trace element leaching to seawater, was carried out during a 6 months time period under laboratory conditions. X-ray investigations, SEM-EDS observations and analyses on freshly-erupted volcanic ash evidenced formation of alteration clay minerals onto glass fraction surfaces. Chemical analyses carried out on coexisting liquid phase demonstrated that trace element leaching occurs through a first quick followed by a slow second step that attaints to an apparent equilibrium after 6 months. Amplitude of kinetic rate constant measured for SiO2 release during the first step and behaviour of Ti/Si and Cr/Si rations in primary volcanic minerals, glass fraction and leaching solutions during the first 1 month stage of the experimental interaction allowed to demonstrate that trace element release mainly occurs from glassy materials and Ti-rich magnetite

Investigation on MMACHC-R161Q pathological mutant from cblC disease

The cblC disease is a rare inborn disorder of the vitamin B12 (cobalamin, Cbl) metabolism characterized by combined methylmalonic aciduria and homocystinuria. The clinical consequences are devastating and, even when early treated with current therapies, the affected children manifest symptoms involving vision, growth, and learning. The molecular genetic cause of the disease was found in the mutations of the gene coding for MMACHC, a 282 amino acid protein that transports and processes the various forms of Cbl. Here we present the biophysical characterization of wild type MMACHC and a variant, p.R161Q, resulting from the most common missense pathological mutation found in cblC patients. By using a biophysical approach we investigated the stability of the two proteins and their ability to bind and transform the vitamin B12, and to assemble in a dimeric structure. Moreover, interesting indications about the behaviour of the proteins resulted from the Molecular Dynamics (MD) simulations. Overall, our results reveal how a biophysical approach based on the complementarity of computational and experimental methods can offer new insights in the study of the specific effects of the pathological cblC mutation and help prospecting new routes for the cblC treatment

GERD in the elderly: an endoscopic experience.

Analyzing medical issues related to the elderly patients, particularly in the gastroenterological sphere, Gastro-Esophageal Reflux Disease (GERD) seems to be a disease that reaches an important role in terms of diagnosis and therapy, as well as adversely affect the quality of life of these “frail” patients. Comorbidities that affect these patients often lead to reduce the importance of this disease, which in fact, not infrequently, it is difficult to identify because of mild symptom picture compared to younger patients. Is important to remember that GERD, although in most cases provokes only vague dyspeptic symptoms, can also lead to serious complications, such as bleeding especially in patients with impaired hemostasis, aspiration pneumonia, or even to cancerization of Barrett’s esophagus. In addition, there are several factors favoring GERD, for example polypharmacy carried out for other conditions, which can modify the physiology of the anti-reflux mechanisms. This review addresses the problem of GERD, analyzing it in all its aspects

Il Fenomeno delle Dipendenze nella Provincia di Varese. Anno 2010

Report on the state of legal and illegal substances use in the territory of the Local Healthcare Service VareseIl Report analizza il fenomeno delle dipendenze nella ASL di Varese. La descrizione del fenomeno si sviluppa intorno all\u27analisi degli indicatori individuati dall\u27Osservatorio Europeo delle Dipendenze di Lisbona (OEDT): 1-uso di sostanze nella popolazione generale (questo indicatore va a rilevare i comportamenti nei confronti di alcol e sostanze psicoattive da parte della popolazione generale); 2-prevalenza d\u27uso problematico delle sostanze psicoattive; 3-domanda di trattamento degli utilizzatori di sostanze; 4-mortalit? degli utilizzatori di sostanze; 5-malattie infettive. Altri due importanti indicatori che si stanno sviluppando, e che vengono qui illustrati, sono l\u27analisi delle Schede di Dimissione Ospedaliera (SDO) e gli indicatori relativi alle conseguenza sociali dell\u27uso di droghe (criminalit? droga correlata). Inoltre sono state applicate diverse metodologie standard di stima sia per quantificare la quota parte sconosciuta di utilizzatori di sostanze che non afferiscono ai servizi, sia per identificarne alcune caratteristiche

Le comportement des éléments traces lors de l'interaction de cendres volcaniques-liquide : exemple des systèmes marins et l'homme

Les processus d’interaction solide-liquide régulent les mécanismes qui régissent la disponibilité des oligo-éléments en phase liquide. Dans cet article, ces processus ont été étudiés grâce à l'utilisation des éléments de terres rares (REE), car ils sont d'excellents traceurs des processus géochimiques. Le but de la première partie de ce travail était d'étudier la réactivité des particules volcaniques lors de l'interaction avec l'eau de la mer synthétique. Les résultats montrent que en dehors de la dissolution, qui est le processus principal, un procédé d'adsorption de surface se produit également, probablement sur la surface des cristaux nouvellement formé. La présence supposée de ces minéraux est suggéré par la variation temporelle de l'Y/Ho, des observations SEM et analyse XRD. Enfin, l'ajout des ligand dissous ne pas augmenter le taux de dissolution des particules volcaniques, mais modifiant la distribution de REE en phase liquide. Dans la deuxième partie de ce travail, l'étude des terres rares a été appliquée à un système humain. Ces éléments ont été utilisés, en fait, d'enquêter sur les fluides du poumon (BAL) chez les personnes exposées aux retombées de cendres volcaniques. Le résultat suggère que la co-précipitation du YLn-phosphates se produisent dans les poumons, à la suite de l'inhalation de particules volcaniques. Ce processus est confirmé par des simulations thermodynamiques et cinétiques indiquant que la cristallisation de YLn-phosphates et d'autres phases authigènes apparaît comme la conséquence de la dissolution de la fraction solubles de cendresThe solid-liquid interaction processes regulate the mechanisms governing the availability of trace elements in liquid phase. In this paper, these processes have been studied through the use of the Rare Earth Elements (REE) since they are excellent tracers of geochemical processes. The purpose of the first part of this work was to study the reactivity of volcanic particulates during the interaction with synthetic seawater. The results show that apart from the dissolution, which is the main process, a surface adsorption process also occurs, probably on the surface of newly formed crystals. The supposed presence of these minerals is suggested by the temporal variation of the Y/Ho ratio, by SEM observations and XRD analysis. Finally the addition of ligand species to dissolved media does not increase dissolution rate of volcanic particles but modify the YLn distribution in liquid phase. In the second part of this work, the Rare Earth study was applied to a human system. These elements were used, in fact, to investigate the effects due to the interactions between the inhaled atmospheric particulate matter and the lung fluids (BAL), in people exposed to fallout of volcanic ash. The results suggest that YLn-phosphate co-precipitation occurs in lungs as a consequence of inhalation of volcanic particles and their interactions with lung fluids. This process is confirmed by thermodynamic and kinetic simulations indicating that crystallisation of YLn-phosphates and other authigenic phases occurs as a consequence of the soluble ash fraction dissolution. The combination of YLn fractionation in bronchial fluids can represent a potential tracer of exposure to atmospheric fallou