STUDIO DELL'EFFETTO PREVENTIVO DELLA METFORMINA SUI DANNI ASSOCIATI ALLA SEDENTARIETA' IN MODELLI MURINI

Metformin (METF), historical antihyperglycemic drug, is a likely candidate for lifespan extension, treatment and prevention of sedentariness damages, insulin resistance and obesity. Skeletal muscle is a highly adaptable tissue, capable to increase its mass in response to exercise and to regenerate new fibrils after damage. Aims of this work were to investigate METF ability to prevent sedentariness injury and enhance skeletal muscle function. Sedentary 12-weeks old C57BL/6 mice were treated with METF (250 mg/kg per day, in drinking water) for 60 days. METF role on skeletal muscle differentiation was studied in vitro using murine C2C12 myoblasts. Muscular performance evaluation revealed that METF enhanced mice physical performance. Tissues analysis indicated that in liver METF increased AMPK and CAMKII signaling, while inactivated ERKs, principal kinases involved in hepatic stress conditions. In skeletal muscle, METF activated AKT, key kinase in skeletal muscle maintenance. In in vitro studies, Immunofluorescence and Western blot analysis showed that METF did not modify the C2C12 proliferation capacity, while positively influenced the differentiation process and myotube maturation. Together, our novel results suggest that METF may have a positive action not only on the promotion of healthy aging but also on the prevention of sedentariness damages.\u200

Finite-dimensional representations of twisted hyper loop algebras

We investigate the category of finite-dimensional representations of twisted hyper loop algebras, i.e., the hyperalgebras associated to twisted loop algebras over finite-dimensional simple Lie algebras. The main results are the classification of the irreducible modules, the definition of the universal highest-weight modules, called the Weyl modules, and, under a certain mild restriction on the characteristic of the ground field, a proof that the simple modules and the Weyl modules for the twisted hyper loop algebras are isomorphic to appropriate simple and Weyl modules for the non-twisted hyper loop algebras, respectively, via restriction of the action

Extensions and block decompositions for finite-dimensional representations of equivariant map algebras

Suppose a finite group acts on a scheme $X$ and a finite-dimensional Lie algebra $\mathfrak{g}$. The associated equivariant map algebra is the Lie algebra of equivariant regular maps from $X$ to $\mathfrak{g}$. The irreducible finite-dimensional representations of these algebras were classified in previous work with P. Senesi, where it was shown that they are all tensor products of evaluation representations and one-dimensional representations. In the current paper, we describe the extensions between irreducible finite-dimensional representations of an equivariant map algebra in the case that $X$ is an affine scheme of finite type and $\mathfrak{g}$ is reductive. This allows us to also describe explicitly the blocks of the category of finite-dimensional representations in terms of spectral characters, whose definition we extend to this general setting. Applying our results to the case of generalized current algebras (the case where the group acting is trivial), we recover known results but with very different proofs. For (twisted) loop algebras, we recover known results on block decompositions (again with very different proofs) and new explicit formulas for extensions. Finally, specializing our results to the case of (twisted) multiloop algebras and generalized Onsager algebras yields previously unknown results on both extensions and block decompositions.Comment: 41 pages; v2: minor corrections, formatting changed to match published versio

Depth profile investigations of surface modifications of limestone artifacts by laser-induced breakdown spectroscopy.

Made available in DSpace on 2017-11-01T23:23:05Z (GMT). No. of bitstreams: 1 PROCI17Depthprofileinvestigations....pdf: 1977315 bytes, checksum: f46ba065d28554ead651738267cea5a4 (MD5) Previous issue date: 2017-10-30bitstream/item/165807/1/PROCI-17-Depth-profile-investigations....pd

Formalism for obtaining nuclear momentum distributions by the Deep Inelastic Neutron Scattering technique

We present a new formalism to obtain momentum distributions in condensed matter from Neutron Compton Profiles measured by the Deep Inelastic Neutron Scattering technique. The formalism describes exactly the Neutron Compton Profiles as an integral in the momentum variable $y$. As a result we obtain a Volterra equation of the first kind that relates the experimentally measured magnitude with the momentum distributions of the nuclei in the sample. The integration kernel is related with the incident neutron spectrum, the total cross section of the filter analyzer and the detectors efficiency function. A comparison of the present formalism with the customarily employed approximation based on a convolution of the momentum distribution with a resolution function is presented. We describe the inaccuracies that the use of this approximation produces, and propose a new data treatment procedure based on the present formalism.Comment: 11 pages, 8 figure

L-Carnitine counteracts in vitro fructose-induced hepatic steatosis through targeting oxidative stress markers

Purpose: Nonalcoholic fatty liver disease (NAFLD) is defined by excessive lipid accumulation in the liver and involves an ample spectrum of liver diseases, ranging from simple uncomplicated steatosis to cirrhosis and hepatocellular carcinoma. Accumulating evidence demonstrates that high fructose intake enhances NAFLD development and progression promoting inhibition of mitochondrial \u3b2-oxidation of long-chain fatty acids and oxidative damages. l-Carnitine (LC), involved in \u3b2-oxidation, has been used to reduce obesity caused by high-fat diet, which is beneficial to ameliorating fatty liver diseases. Moreover, in the recent years, various studies have established LC anti-oxidative proprieties. The objective of this study was to elucidate primarily the underlying anti-oxidative mechanisms of LC in an in vitro model of fructose-induced liver steatosis. Methods: Human hepatoma HepG2 cells were maintained in medium supplemented with LC (5 mM LC) with or without 5 mM fructose (F) for 48 h and 72 h. In control cells, LC or F was not added to medium. Fat deposition, anti-oxidative, and mitochondrial homeostasis were investigated. Results: LC supplementation decreased the intracellular lipid deposition enhancing AMPK activation. However, compound C (AMPK inhibitor-10 \u3bcM), significantly abolished LC benefits in F condition. Moreover, LC, increasing PGC1 \u3b1 expression, ameliorates mitochondrial damage-F induced. Above all, LC reduced ROS production and simultaneously increased protein content of antioxidant factors, SOD2 and Nrf2. Conclusion: Our data seemed to show that LC attenuate fructose-mediated lipid accumulation through AMPK activation. Moreover, LC counteracts mitochondrial damages and reactive oxygen species production restoring antioxidant cellular machine. These findings provide new insights into LC role as an AMPK activator and anti-oxidative molecule in NAFLD

Modulation of cell cycle progression by 5-azacytidine is associated with early myogenesis induction in murine myoblasts

Myogenesis is a multistep process, in which myoblasts withdraw from the cell cycle, cease to divide, elongate and fuse to form multinucleated myotubes. Cell cycle transition is controlled by a family of cyclin-dependent protein kinases (CDKs) regulated by association with cyclins, negative regulatory subunits and phosphorylation. Muscle differentiation is orchestrated by myogenic regulatory factors (MRFs), such as MyoD and Myf-5. DNA methylation is crucial in transcriptional control of genes involved in myogenesis. Previous work has indicated that treatment of fibroblasts with the DNA-demethylating agent 5-azacytidine (AZA) promotes MyoD expression. We studied the effects of AZA on cell cycle regulation and MRFs synthesis during myoblast proliferation and early myogenesis phases in C2C12 cells. During the proliferation phase, cells were incubated in growth medium with 5\u3bcM AZA (GMAZA) or without AZA (GM) for 24 hours. At 70% confluence, cells were kept in growth medium in order to spontaneously achieve differentiation or transferred to differentiation medium with 5\u3bcM AZA (DMAZA) or without AZA (DM) for 12 and 24 hours. Cells used as control were unstimulated. In the proliferation phase, AZA-treated cells seemed to lose their characteristic circular shape and become elongated. The presence of AZA resulted in significant increases in the protein contents of Cyclin-D (FC:1.23 GMAZA vs GM p 640.05), p21 (FC: 1.23 GMAZA vs GM p 640.05), Myf-5 (FC: 1.21 GMAZA vs GM p 640.05) and MyoD (FC: 1.20 GMAZA vs GM p 640.05). These results propose that AZA could inhibit cell proliferation. During 12 hours of differentiation, AZA decreased the downregulation of genes involved in cell cycle arrest and in restriction point (G1 and G1/S phase) and the expression of several cyclins, E2F Transcription Factors, cyclin-dependent kinase inhibitors, specific genes responsible of cell cycle negative regulation. During 24 hours of differentiation, AZA induced an increment in the protein expression of Myf-5 (FC: 1.57 GMAZA vs GM p 640.05), MyoD (FC: 1.14 DM vs GM p 640.05; FC: 1.47 DMAZA vs GM p 640.05), p21 (FC: 1.36 GMAZA vs GM p 640.01; FC: 1.49 DM vs GM p 640.05; FC: 1.82 DMAZA vs GM p 640.01) and MyHC (FC: 1.40 GMAZA vs GM p 640.01; FC: 2.39 DM vs GM p 640.05; FC: 3.51 DMAZA vs GM p 640.01). Our results suggest that AZA-induced DNA demethylation can modulate cell cycle progression and enhance myogenesis. The effects of AZA may open novel clinical uses in the field of muscle injury research and treatment

Fabrication and characterization of thin piezoelectric β-poly(vinylidene fluoride) films

The polymer polyvinylidene fluoride (PVDF) has four phases, each characterized by different molecular configurations of the polymer chains. In its beta phase it arranges in an all-trans configuration with dipolar symmetry, exhibiting piezoelectric effects. During the production of thin PVDF films by spin-coating, the polymer chains are not aligned and the dipoles are not oriented. To achieve the desired piezoelectric behavior, it is necessary to optimize both the chain alignment and the dipole orientation processes. We here present an easy procedure to maximize the percentage of the beta phase in the polymer production. The efficiency and reliability of such method has been assessed through Fourier-Transform Infra-Red and Raman spectroscopies, while the morphological differences of the two phases have been analyzed through Scanning Electron Microscopy. The results confirm the efficiency of this method

Laser-induced breakdown spectroscopy associated with multivariate analysis applied to discriminate fertilizers of different nature.

Made available in DSpace on 2017-11-24T23:20:19Z (GMT). No. of bitstreams: 1 PLaserinducedbreakdown....pdf: 277933 bytes, checksum: cfd2c91da7bb377fd7e089171b43d4b1 (MD5) Previous issue date: 2017-11-24bitstream/item/167439/1/P-Laser-induced-breakdown....pd