83 research outputs found
progettazione e sintesi di derivati 4-idrossi-2-oxo-1,2-diidro-1,8-naftiridin-3-carbossiammidici quali ligandi di recettori cannabinoidi CB2
Il sistema cannabinoide Ăš un complesso sistema biochimico coinvolto in diversi processi fisiologici. Tale sistema comprende : due recettori di membrana, i recettori cannabinoidi CB1 (prevalentemente espressi a livello centrale) e i recettori CB2 ( maggiormnte espressi a livello periferico, in particolare nelle cellule del sistema immunitario);ligandi endogeni, (i piĂč conosciuti sono l'anandamide e il 2-arachidonoilglicerolo); diversi enzimi che si occupano di sintetizzare, metabolizzare gli endocannabinoidi.L'attivazione di tale sistema ci permette di modulare il sistema immunitario, sia a livello centrale che periferico,regolare l'appetito, la nausea e il dolore.Per questo motivo il laboratorio di ricerca dove ho svolto la mia tesi , da diversi anni, si occupa della sintesi di molecole attive sui recettori del sistema cannabinoide , con maggior interesse verso i recettori CB2. Sono stati descritti precedentemente una serie di derivati 1,8-naftiridin-4-idrossi-2-oxo-3-carbossiammidici, i quali si sono rivelati particolarmente attivi verso tali recettori. Lo scopo della mia tesi Ăš stato quello di approfondire le relazioni struttura attivitĂ dei composti della serie 1,8-naftiridin-4-idrossi-2-oxo-3-carbossiammidici, sintetizzando nuovi derivati caratterizzati dalla presenza del gruppo cicloeptilcarbossiammidico in posizione 3, dei sostituenti p-Fluoro-benzile,n-pentile in posizione 1 che si erano dimostrati particolarmente attivi nelle serie precedenti. Inoltre sono stati introdotti in posizione 6 diversi sostituenti al fine di valutare la loro influenza sull'attivitĂ funzionale dei composti
LEAD ISOTOPE CHARACTERIZATION OF COPPER INGOTS FROM SARDINIA (ITALY): INFERENCES ON THEIR ORIGINS
ABSTRACT The provenance of the materials making up the metal artifacts represents a fundamental question for archaeological research. The complex processes necessary to extract the metals from the minerals cause considerable changes in their chemical composition. By contrast, the ratio of the different lead isotopes in artifacts is not influenced by metallurgic processes. Therefore, the raw mineral material and the extracted metal exhibit the same isotope "footprint". Over the course of history, Sardinia has played a major role in maritime routes. Its considerably rich mineral resources, with copper, lead and iron mineralizations, moreover complemented its strategic importance. During the 10th and 9th centuries BC Sardinia, because of its strategic location, was to become directly involved in the "precolonial" Phoenician expansion. Two repositories of copper ingots recovered at different levels within a nuragic village in northwest Sardinia, can be placed within this historical context of intense traffic and exchange of goods between native Sardinian and Phoenician communities. The ingots were made in different shapes: plane-convex, biconvex, truncated cone and irregular. The analyzed ingots exhibit a considerable lead isotopic variability, although no systematic differences in isotope composition were revealed between the ingots from the two different repositories. Moreover, no systematic isotopic variations were observed between the different shapes in which the material was found. Overall, the ingots exhibit a linear distribution in the lead/lead diagrams. The group of ingots with the lowest isotope ratios project onto the area defined by the northwestern Sardinian mineralizations. The ingot located on the other extreme end of the straight line in the Pb diagrams overlaps the area defined by the southern Sardinian deposits. The isotope footprints of the intermediate samples seem to indicate that they stem from the mixing of two components from two different mining areas of Sardinia, one in the north, the other in the south. Therefore, widespread exchange of metal must have taken place throughout the island, and such an exchange does not seem to have been hindered by the advent of the Phoenicians in Sardinia. The results of the present investigation indicate that the majority of the examined ingots was produced with metal from the northwest of the island, and that these mines were therefore known and exploited in nuragic times. Such findings shed new light on the complex issues involved in proto-historic Sardinian metallurgy
Pre-metamorphic melt infiltration in metasediments : geochemical, isotopic (Sr, Nd, and Pb), and field evidence from Serie dei Laghi (Southern Alps, Italy)
Gradual transitions from K-feldspar free gneisses to K-feldspar bearing augengneisses
are sometimes observed in metamorphic terranes. They have been explained with
metasomatic porphyroblastic growth connected with regional metamorphism, or with
pre-metamorphic presence of magmatic megacrysts. A transition of this kind can be
observed in the Serie dei Laghi (Southern Alps, Italy), where coarse-grained metaarenites
(Cenerigneiss) grade into Ceneri augengneisses with large K-feldspar porphyroclasts,
and banded amphibolites of the \u2018\u2018Strona Ceneri Border Zone\u2019\u2019 grade into Hbl
augengneisses rich in K-feldspar.
The Ceneri augengneisses are chemically indistinguishable from the Cenerigneiss, but
have higher 87Sr=86Sr (0.7256\u20130.7258 vs. 0.7215\u20130.7233), similar to those of the Ordovician
granites that were intruded, before the regional metamorphism, into the protoliths
of both Cenerigneiss and amphibolites. The Cenerigneiss contains two types of zircons:
(1) highly luminescent, rounded grains or fragments, yielding U\u2013Pb SHRIMP
ages from 0.43 to 1.0 Ga; (2) euhedral grains with oscillatory zoning (magmatic), with
U\u2013Pb SHRIMP concordant ages of 466 13 Ma. This age coincides with the Rb\u2013Sr
whole rock emplacement age of the Ordovician granitoids (466 5Ma).The Hbl augengneisses form three groups with distinct geochemical patterns,
whose distributions on inter-element diagrams trend towards the Ordovician metagranites
and meta-aplites. In addition, the Hbl augengneisses have higher 87Sr=86Sr
(0.7132\u20130.7147 vs. 0.7031\u20130.7046) and lower 143Nd=144Nd (0.51214\u20130.51219 vs.
0.51273\u20130.51297) than the amphibolites, suggesting the addition of an isotopically
evolved component.
The observed chemical and isotope patterns, as well as the vicinity of the augen
gneisses to the Ordovician intrusions, lead us to conclude that the Ceneri augengneisses
and Hbl augengneisses are the result of infiltration of residual hydrous
magmas into the protolith of both the Cenerigneiss and the amphibolites at the time
of Ordovician granite emplacement, long before the regional metamorphism in the Serie dei Laghi
Kinematics and Age of Syn-Intrusive Detachment Faulting in the Southern Alps: Evidence for Early Permian Crustal Extension and Implications for the Pangea A Versus B Controversy
Permian basin formation and magmatism in the Southern Alps of Italy have been interpreted as expressions of a WSWâENEâtrending, dextral megashear zone transforming Early Permian Pangea B into Late Permian Pangea A between ~285 and 265 Ma. In an alternative model, basin formation and magmatism resulted from NâS crustal extension. To characterize Permian tectonics, we studied the Grassi Detachment Fault, a lowâangle extensional fault in the central Southern Alps. The footwall forms a metamorphic core complex affected by upwardâincreasing, topâtoâtheâsoutheast mylonitization. Two granitoid intrusions occur in the core complex, the synmylonitic Val Biandino Quartz Diorite and the postmylonitic Valle San Biagio Granite. UâPb zircon dating yielded crystallization ages of 289.1 ± 4.5 Ma for the former and 286.8 ± 4.9 Ma for the latter. Consequently, detachmentârelated mylonitic shearing took place during the Early Permian and ended at ~288 Ma, but kinematically coherent brittle faulting continued. Considering 30° anticlockwise rotation of the Southern Alps since Early Permian, the extension direction of the Grassi Detachment Fault was originally ~NâS. Even though a dextral continental wrench system has long been regarded as a viable model at regional scale, the local kinematic evidence is inconsistent with this and, rather, supports NâS extensional tectonics. Based on a compilation of >200 UâPb zircon ages, we discuss the evolution and tectonic framework of Late Carboniferous to Permian magmatism in the Alps
"For nothing was simply one thing". La doppia edizione di To the Lighthouse: un'analisi delle varianti.
Il presente elaborato si propone di presentare la questione della doppia edizione di To the Lighthouse di Virginia Woolf e di analizzare le differenze tra la pubblicazione britannica e quella statunitense. Lâindagine si suddivide in tre parti, la prima delle quali consiste nellâintroduzione e contestualizzazione dellâautrice sulla base dei piĂč importanti eventi biografici e delle opere letterarie di vario tipo da lei prodotte sino allâanno della sua morte. Segue un capitolo allâinterno del quale verranno approfondite struttura, tematiche e tecniche dellâopera presa in esame, nonchĂ© analizzate le vicende piĂč salienti delle due case editrici di riferimento per la pubblicazione dellâopera. Dopo aver brevemente presentato anche il rapporto della stessa autrice nei confronti dei due paesi nei quali il romanzo venne dato alle stampe, si arriva al cuore dellâanalisi, che consiste nella comparazione delle variazioni presenti tra lâedizione britannica e quella statunitense. In seguito alla suddivisione delle divergenze sulla base di categorie, si proporranno dunque unâanalisi di queste, un tentativo di interpretare le motivazioni alla base della doppia edizione e, infine, una riflessione sulla possibilitĂ di una nuova edizione che possa contenere entrambi i testi
DUE RACCONTI COLOMBIANI PER LâINFANZIA Traduzione di Francisco Leal Quevedo, El Mordisco de la Medianoche Jairo AnĂbal Niño, Zoro
"Zoro" di Jairo AnĂbal Niño e "El mordisco de la medianoche" di Francisco Leal Quevedo sono due esempi di letteratura infantile colombiana. Vincitori rispettivamente del Premio Enka e Barco de Vapor, rappresentano due modalitĂ profondamente differenti di letteratura per l'infanzia, accomunati dalla volontĂ di dare espressione e voce alle minoranze culturali e linguistiche della Colombia. La traduzione di questi due testi ha reso possibile confrontarsi con diverse problematiche inerenti alla traduzione e, di conseguenza, con diverse strategie traduttive. Particolare attenzione Ăš stata rivolta alle varietĂ linguistiche dello spagnolo colombiano, ai riferimenti culturali e quindi al tentativo di trasmetterli anche nella lingua d'arrivo, senza dimenticare che il destinatario Ăš un pubblico infantile
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