938 research outputs found
Stato, beneficenza e previdenza pubblica : considerazioni / Guido Capitani
No full textStato, beneficenza e previdenza pubblica : considerazioni / Guido Capitani
Torino : Tip. G. Derossi, 1888
174 p. ; 25 cm
I capitani. Con alcuni discorsi curiosi.
No full text"Saggio dell'opera De' prencipi e capitani illvstra del Sig. Giouanni Botero" (p. 213-250) has special t.p.Mode of access: Internet
The peculiar crystal-chemistry of phlogopite from metasomatized peridotites: evidence from laboratory and nature
No full textExperimental petrology suggested that phlogopite has a peculiar mineral chemistry at high pressure: excess of Si coupled with a decrease in IVAl and deficiency in K+Na. This K-edenite exchange, □XIISi(K+Na)-1Al-1, where □XII is a vacancy in the interlayer, should imply that phlogopites incorporate significant amount of talc component. At high pressure conditions, however, in a fluid saturated system, a talc component might translate into a 10 Å phase component, being the latter phase the product of the reaction talc + H2O = 10 Å phase occurring at P = 4-5 GPa and at T = 600-700 °C. We aim to study the structure of natural and synthetic phlogopites showing this peculiar mineral chemistry. Samples were analysed by single-crystal X-ray diffraction, powder X-ray diffraction with full profile fitting, EMP, SIMS, TEM and Mössbauer spectroscopy. The natural samples were recovered from spinel and garnet wedge peridotites of the Ulten Zone Eastern Italian Alps, (Italy), whereas synthetic ones were obtained from high pressure synthesis in a K-doped lherzolite system. The single crystal X-ray refinements of natural phlogopites, together with the EMP analysis, showed two coupled substitutions: Tschermak (Si + Mg = IVAl + VIAl) and talc exchanges (□ + Si = K + Al), with no octahedral vacancies. The Rietveld refinement of the synthetic samples confirmed the ipersilicic character and K deficiency found with EMPA and SIMS analysis. The c lattice parameter of both synthetic and natural phlogopites positively correlates with the increase of vacancies at the interlayer site, pointing toward the c lattice parameter of the 10Å phase. The tetrahedral α rotation angle of natural phlogopites was about 9°, lower than that expected by Tschermak substitution. The present data indicate that the 10 Å phase component, instead of the talc component, stabilizes the phlogopite structure by reducing the α rotation under high pressure condition. This increases the pressure conditions needed to reach the upper limit value for the tetrahedral rotation
Prefazione
No full textNella prefazione viene condotta una ricognizione della storiografia critica su Giordano Bruno nel secolo XIX, con particolare riferimento a Bertrando Spaventa, Francesco Fiorentino e Felice Tocco.
Si propone inoltre un inquadramento del volume di G. Albarani tra altri lavori contemporanei di argomento affine
Multiscale porosimetric description of pore network in building stones
No full textAs is well known, porosity strong affects physical and mechanical behavior of stones. In
addition, being able to vehicle moisture, porosity has a great influence on durability.
Therefore, the complete knowledge of the pore architecture and the behavior of stones
interested by weathering processes represents a key element in understanding mechanism of
degradation and prevent damage [1-2]. Pore network of stone is traditionally investigated by
porosimetric techniques based on gas adsorption and mercury intrusion. Nevertheless, these
methods appear inadequate for the complete modeling of the microstructure of the rock, since
they are destructive, measure only the open porosity and explore a limited dimensional range.
Moreover, most of these techniques, are based on assumptions about pores shape and
dimension, representing an ideal geometric model of them [2]. As aforementioned, the
quantitative description of stones pore network cannot be generally achieved by a single
technique, considering the real complex geometry and the variability in the dimensional
distribution of voids [3]. In recent years, the use of nuclear magnetic resonance (NMR) as
useful tool for studying pore structure in stones has largely increased, also in association with
other methodologies [5-7]. In detail, the technique allows to get information about the pore
size distribution in a water-saturated rock by measuring the transverse and longitudinal
relaxation times of water hydrogen nuclei in a non destructive and non invasive way.
Furthermore the investigation of water diffusion through the porous structure provides
information on the restricted geometry of the network and the obtainment of the average pores
radius and pores interconnection. The main goal of this study is to compare portable NMR
and mercury intrusion porosimetry in characterizing pore size distributions of building stones
and quantify pore network modification due to salt weathering. In detail, this methodological
approach has been applied on a coarse grained calcarenite from Sabucina (Caltanissetta,
Sicily, Italy) widely used as building and replace stone. The obtained data allow to highlight
potential and limitation of the applied analytical methodologies in studying building stone
materials.
[1] D. Benavente, M.A. García del Cura, R. Fort, S. Ordóñez, Engineering Geology 74, 2004, 113–127.
[2] S. Yu, C. T. Oguchi, Engineering Geology 115, 2010, 226–236.
[3] C. A. León y León, Advances in Colloid and Interface Science 76-77, 1998, 341-372.
[4] G. Barbera, G. Barone, V. Crupi, F. Longo, G. Maisano, D. Majolino, P. Mazzoleni, S. Raneri, J. Teixeira, V.
[5]Venuti, European Journal of Mineralogy 26(1), 2014, 189 – 198.
[6]V. Di Tullio, M. Cocca, R. Avolio, G. Gentile, N. Proietti, P. Ragni, M. E. Errico, D. Capitani, M. Avella
Magnetic Resonance in Chemistry, 53, 2015, 64-77.
[7] G. P. Matthews, C. F. Canonville, A. K. Moss, Physical Review E 73, 2006, 031307.
G.S. Padhy, C. Lemaire, E.S. Amirtharaj, M.A. Ioannidis, Colloids and Surfaces A: Physicochem. Eng. Aspects
300, 2007, 222–234
Increase in nuclear phosphatidylinositol 3-kinase activity and phosphatidylinositol (3,4,5) trisphosphate synthesis precede PKC-zeta translocation to the nucleus of NGF-treated PC12 cells.
No full textWe and others have previously demonstrated the existence of an autonomous nuclear polyphosphoinositide cycle that generates second messengers such as diacylglycerol (DAG), capable of attracting to the nucleus specific protein kinase C (PKC) isoforms (Neri et al. (1998) J. Biol. Chem. 273, 29738-29744). Recently, however, nuclei have also been shown to contain the enzymes responsible for the synthesis of the non-canonical 3-phosphorylated inositides. To clarify a possible role of this peculiar class of inositol lipids we have examined the question of whether nerve growth factor (NGF) induces PKC-zeta nuclear translocation in PC12 cells and whether this translocation is dependent on nuclear phosphatidylinositol 3-kinase (PI 3-K) activity and its product, phosphatidylinositol 3,4, 5-trisphosphate [PtdIns(3,4,5)P(3)]. NGF increased both the amount and the enzyme activity of immunoprecipitable PI 3-K in PC12 cell nuclei. Activation of the enzyme, but not its translocation, was blocked by PI 3-K inhibitors wortmannin and LY294002. Treatment of PC12 cells for 9 min with NGF led to an increase in the nuclear levels of PtdIns(3,4,5)P(3). Maximal translocation of PKC-zeta from the cytoplasm to the nucleus (as evaluated by immunoblotting, enzyme activity, and confocal microscopy) occurred after 12 min of exposure to NGF and was completely abrogated by either wortmannin or LY294002. In contrast, these two inhibitors did not block nuclear translocation of the conventional, DAG-sensitive, PKC-alpha. On the other hand, the specific phosphatidylinositol phospholipase C inhibitor, 1-O-octadeyl-2-O-methyl-sn-glycero-3-phosphocholine, was unable to abrogate nuclear translocation of the DAG-insensitive PKC-zeta. These data suggest that a nuclear increase in PI 3-K activity and PtdIns(3,4,5)P(3) production are necessary for the subsequent nuclear translocation of PKC-zeta. Furthermore, they point to the likelihood that PKC-zeta is a putative nuclear downstream target of PI 3-K during NGF-promoted neural differentiation.-Neri, L. M., Martelli, A. M., Borgatti, P., Colamussi, M. L., Marchisio, M., Capitani, S. Increase in nuclear phosphatidylinositol 3-kinase activity and phosphatidylinositol (3,4, 5) trisphosphate synthesis precede PKC-zeta translocation to the nucleus of NGF-treated PC12 cells
Grading citologico del mastocitoma cutaneo del cane
No full textLo scopo di questo studio è stato quello di verificare la possibilità di attuare un grading prognosticamente attendibile su preparati citologici di mastocitoma, che potrebbe consentire di pianificare opportunamente la terapia già al momento della diagnosi. Il sistema di grading proposto da Kiupel5 è stato pertanto applicato a preparati citologici allestiti da 41 mastocitomi cutanei di cane di cui fossero a disposizione le corrispondenti sezioni istologiche per valutare, complessivamente e parametro per parametro, la concordanza del grading fra citologia e istologia. Dal momento che il grading di Kiupel6 prevede di esaminare 10 CFI del preparato istologico a disposizione, si è proceduto, come prima valutazione, a verificare che in ogni preparato citologico fosse presente un numero di cellule integre almeno pari a quello conteggiato nei 10 CFI a maggior densità cellulare della corrispondente sezione istologica. Nei preparati citologici e istologici è stato poi valutato in modo indipendente il grading di Kiupel5. In particolare, ogni striscio è stato valutato nella sua interezza annotando numero di mitosi, nuclei bizzarri, cellule multinucleate e l’eventuale presenza di cariomegalia; sono stati inoltre valutati cellularità (alta o bassa), quantità di granulazioni intracitoplasmatiche (MCT altamente o mediamente/scarsamente granulari) e numero di cellule binucleate. Il livello di concordanza nell’attribuzione del grado di Kiupel6 e dei singoli parametri che lo compongono nei preparati citologici e istologici è stato valutato mediante il coefficiente kappa (κ).I risultati ottenuti suggeriscono che il grading proposto da Kiupel6 pare applicabile a preparati citologici: soltanto 5 dei 41 MCT inclusi nello studio, infatti, non raggiungevano la cellularità minima richiesta e nell’80.6% dei casi gli strisci esaminati sono stati classificati ad alta cellularità. Il coefficiente di concordanza citologia e istologia nell’attribuzione del grado è risultato soddisfacente (κ = 0.77; P < 0,001), dimostrando una buona capacità di predire il grado istologico a partire da preparati citologici. In particolare, tutti i 7 MCT ad alto grado alla citologia lo erano anche all’istologia, mentre 3 MCT definiti ad alto grado all’istologia risultavano di basso grado alla citologia. Nel complesso, quindi, il grading citologico non è risultato coerente con quello istologico solo in 3 casi su 36 (8,3%).
La capacità di predire il grado istologico varia in base alla cellularità dei preparati esaminati, nonostante tale differenza non sia risultata statisticamente significativa (casi a bassa cellularità: κ = 0.59; P = 0,088; casi ad alta cellularità: κ = 0.81; P < 0,001). Appare pertanto sbagliato assumere che nei preparati citologici a bassa cellularità non possa essere effettuato un grading, anche se nei preparati a elevata cellularità il dato è da considerare più attendibile.
La concordanza citologia/istologia è stata anche valutata parametro per parametro. Il coefficiente di concordanza è risultato elevato per il parametro “cellule multinucleate” (κ = 0.72; P < 0,001) e “nuclei bizzarri” (κ = 0.68; P < 0,001), moderato “ cariomegalia” (κ = 0.54; P < 0,001) e nullo per “numero di mitosi”. La principale difficoltà nell’applicazione del grading di Kiupel6 nei preparati citologici sembrerebbe quindi legato all’identificazione delle mitosi: a differenza di quanto rilevato nelle sezioni istologiche, in nessuno dei 7 casi giudicati ad alto grado il numero di mitosi raggiungeva infatti il cut-off di 7 mitosi in 10 CFI. La difficoltà nell’identificazione delle mitosi nei preparati citologici potrebbe essere conseguente alle granulazioni citoplasmatiche che nei MCT ben differenziati possono impedire una completa visualizzazione del nucleo o a una maggiore fragilità delle cellule in mitosi. Per compensare questa limitazione si è identificato tramite il metodo delle curve ROC un cut–off per il numero di mito..
Cannonite [Bi2O(SO4)(OH)2] from Alfenza (Crodo, Italy): Crystal structure and morphology
No full textCanonite from Alfenza grows as crowded, radiating, acicular aggregates covering bismuthinite
crystals. Individual crystals have a lozenge-shaped habit on {010}, the presumed cleavage plane of
cannonite. Crystal structure refinements in the P21/c space group of two single crystals led to the
following cell parameters: a = 7.7196(5) A ̊ , b = 13.8856(9), c = 5.6980(4), b = 109.174(1)o (R1 =
0.0424); and a = 7.7100(8), b = 13.8717(14), c = 5.6939(6), b = 109.155(2)o (R1 = 0.0438). Hydrogen
atoms were also localized in the density-difference Fourier map and refined with soft restraints on the
bond distances. Raman and IR spectroscopy confirm the presence of OH groups and the absence of
molecular water, and deliver OH···O geometry wholly comparable with the structure refinement.
Electron microprobe analyses revealed no significant levels of elements other than those expected in
the ideal formula except fluorine which was present up to 0.14 a.p.f.u. The crystal structure can be
described in terms of anion-centred OBi4 edge-sharing tetrahedra forming chains running parallel to z
and strongly cemented along x by isolated SO4 tetrahedra. Each OBi4 tetrahedron is further connected
along y by OH groups, making walls of composition Bi4O2(SO4)2(OH)4 parallel to (010). These walls
are tied to each other along y by fewer Bi–O–S bridges and weaker OH···O bonds
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