M L Barcellona

University of Catania, Catania, Sicily, Italy

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Publications (51)128.45 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: We describe a method based on fluorescence-lifetime imaging microscopy (FLIM) to assess the fluidity of various membranes in neuronal cells at different stages of development [day 12 (E12) and day 16 (E16) of gestation]. For the FLIM measurements, we use the Laurdan probe which is commonly used to assess membrane water penetration in model and in biological membranes using spectral information. Using the FLIM approach, we build a fluidity scale based on calibration with model systems of different lipid compositions. In neuronal cells, we found a marked difference in fluidity between the internal membranes and the plasma membrane, being the plasma membrane the less fluid. However, we found no significant differences between the two cell groups, E12 and E16. Comparison with NIH3T3 cells shows that the plasma membranes of E12 and E16 cells are significantly more fluid than the plasma membrane of the cancer cells.
    Cell Biochemistry and Biophysics 05/2014; · 1.91 Impact Factor
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    ABSTRACT: Gold nanoparticles (AuNPs) conjugated to DNA are widely used for biomedical targeting and sensing applications. DNA functionalization is easily reached on laser generated gold nanoparticles because of their unique surface chemistry, not reproducible by other methods. In this context, we present an extensive investigation concerning the attachment of DNA to the surface of laser generated nanoparticles using Dynamic Light Scattering and UV-Vis spectroscopy. The DNA conjugation is highlighted by the increase of the hydrodynamic radius and by the UV-Vis spectra behavior. Our investigation indicates that Dynamic Light Scattering is a suitable analytical tool to evidence, directly and qualitatively, the binding between a DNA molecule and a gold nanoparticle, therefore it is ideal to monitor changes in the conjugation process when experimental conditions are varied.
    PLoS ONE 01/2014; 9(3):e89048. · 3.53 Impact Factor
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    ABSTRACT: The appearance of the slow mode, revealed by dynamic light scattering (DLS) measurements in Micrococcus luteus DNA with high GC content, and the effect of guanine sequences on changes of DNA physical state and conformational transitions were investigated. We used two different spectroscopic approaches: DLS, to evidence the relatively slowly diffusing particles arising at high salt concentration, ascribable to the formation of large unspecific molecular aggregates, and circular dichroism spectroscopy, to identify these entities. Our results bring us to conclude that a peculiar, unconventional, structural transition, due to the presence of long guanine stretches, in a well-defined experimental condition, can occur. We comment on the biological implications to detect, by spectroscopic measurements, such an unusual structure involved in the stability, protection and replication maintenance along the human telomeric G-rich strand.
    Biophysics of Structure and Mechanism 02/2012; 41(5):425-36. · 2.44 Impact Factor
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    ABSTRACT: We studied the consequences of freezing/thawing processes on mRNA contents in MII oocytes after slow-freezing/rapid thawing (SF/RT) and vitrification/warming (V/W) protocols, and compared the results to fresh MII oocytes. We quantified the nuclear transcript mRNA responsible for the translation of proteins belonging either to trans-regulatory protein family or to functional structural proteins such as proteins involved in DNA structural organization (NAP1L1, TOP1, H1F0H1), chromosomal structure maintenance (SMC, SCC3, RAD21, SMC1A, SMC1B, STAG3, REC8), mitochondrial energetic pathways (ATP5GJ, SDHC), cell cycle regulation and processes (CLTA, MAPK6, CKS2) and staminal cell potency-development competence stage (DPPA3, OCT4, FOXJ2). Surplus MII oocytes were donated from patients in IVF cycles and divided in three groups of 15 oocytes. Group 1 was comprised of non-cryopreserved oocytes and Groups 2 and 3 underwent SF/RT and V/W procedures, respectively. There was an overall decrease of mRNA extracted from cryopreserved oocytes compared to control group. Only 39.4% of mRNA content were preserved after SF/RT while 63.3% of mRNA content were maintained after V/W. Oocyte cryopreservation is associated with molecular injury associated with the decrease of stored mRNA. However the V/W protocol is more conservative than SF/RT resulting in a level of mRNA sufficient to maintain biologic functions in the subsequent fertilized oocyte.
    Cryobiology 01/2011; 62(2):130-4. · 2.14 Impact Factor
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    ABSTRACT: Aerobic exercise increases free radical production as a consequence of enhanced oxygen consumption. If free radical formation exceeds antioxidant capacity, lipids, proteins, and DNA may be oxidized. Oxidative stress is widely recognized as a factor in many degenerative human diseases. The role of dietary antioxidants in protection against disease is a topic of continuing interest. In fact, there is epidemiological evidence correlating a higher intake of nutrients possessing antioxidant abilities with a lower incidence of various human diseases. This study was directed at investigating whether changes in plasma antioxidant capacity and oxidative stress markers occur in voluntary wheel runners, before and after oral supplementation with lycopene and isoflavones. For this purpose, plasma antioxidant capacity and oxidative stress markers were assessed in long distance runners at the end of a 60-minute run. Comparisons were made between runners before and after 60 days of supplementation with lycopene and isoflavones. DNA damage in blood cells of the same samples was also evaluated by comet assay. This investigation shows that oral supplementation with lycopene and soy-derived isoflavones significantly reduced lipid peroxidation and enhanced plasma nonproteic antioxidant defense.
    Journal of medicinal food 03/2009; 12(1):145-50. · 1.39 Impact Factor
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    ABSTRACT: Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase. It is degraded by the enzyme dimethylarginine dimethylaminohydrolase (DDAH). Rats (n = 50) underwent to 45 min of renal ischemia followed by 30 min, 1 h, and 3 h of reperfusion. Expression of endothelial nitric oxide synthase, inducible nitric oxide synthase, DDAH-1, DDAH-2, renal DDAH activity, plasma NO2(-)/NO3(-), and ADMA levels were evaluated. Inducible nitric oxide synthase expression increased, as confirmed by both plasma (11.89 +/- 1.02, 15.56 +/- 0.93, 11.82 +/- 0.86, 35.05 +/- 1.28, and 43.89 +/- 1.63 nmol/ml in the control, ischemic, 30-min, 1-h, and 3-h groups, respectively) and renal (4.81 +/- 0.4, 4.85 +/- 1, 9.42 +/- 0.7, 15.42 +/- 0.85, and 22.03 +/- 1.11 nmol/mg protein) formations of NO2(-)/NO3(-). DDAH-1 expression decreased after reperfusion, whereas DDAH-2 increased after 30 min, returning to basal levels after 3 h. Total DDAH activity was reduced during all times of reperfusion. Both plasma (0.41 +/- 0.03, 0.43 +/- 0.05, 0.62 +/- 0.02, 0.71 +/- 0.02, and 0.41 +/- 0.01 nmol/ml in the control, ischemic, 30-min, 1-h, and 3-h groups, respectively) and renal (1.51 +/- 0.01, 1.5 +/- 0.01, 1.53 +/- 0.01, 2.52 +/- 0.04, and 4.48 +/- 0.03 nmol/mg protein in the control, ischemic, 30-min, 1-h, and 3-h groups, respectively) concentrations of ADMA increased. Results suggest that ischemia-reperfusion injury leads to reduced DDAH activity and modification of different DDAH isoform expression, thus leading to increased ADMA levels, which may lead to increased cardiovascular risk.
    Anesthesiology 01/2009; 109(6):1054-62. · 5.16 Impact Factor
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    ABSTRACT: This work reports light scattering measurements on DNA in aqueous solutions (100 mM NaCl, 1 mM EDTA and 10 mM Tris–HCl buffer, pH 7.8) over a wide range of molecular weights (102–105 base pairs) and shows that, in the above standard solvent, shorter chains (<104 base pairs) behave as a “wormlike chain” and their diffusion coefficients as obtained by dynamic light scattering measurements, confirm the prediction of standard wormlike model, whilst longer chains (>104 base pairs) behave in a different manner. Dynamic and static light scattering and SEM analysis indicate that DNA molecules 105 base pairs long, condense into compact structures in our solvent conditions. Calculations done using a wormlike model are also presented and discussed in comparison both to our experimental data and to other data reported in the literature.
    International journal of biological macromolecules 01/2009; · 2.37 Impact Factor
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    ABSTRACT: The aim of the present study was to verify whether the oral administration of cyanidin 3-O-beta-D-glucoside (C3G) might counteract damage induced by chronic exposure (28 d) to ochratoxin A (OTA) in rats and if its effect may be mediated by haeme oxygenase-1 (HO-1). Forty male Sprague-Dawley rats, individually caged, were divided into four groups of ten animals. A control group received a commercial diet, group C3G received the control diet supplemented with C3G (1 g/kg feed), group OTA received the control diet supplemented with 200 parts per billion of OTA, and group OTA+C3G received the OTA group diet supplemented with C3G (1 g/kg feed). After 4 weeks of treatment animals were killed and the liver, kidneys and brain of each rat were collected and homogenised to evaluate non-proteic thiol groups (RSH), lipid hydroperoxide (LOOH) levels, HO-1 expression and DNA fragmentation. Rats of the OTA group showed a significant (P < 0.001) decrease in RSH content of kidney and liver and a significant (P < 0.001) increase of LOOH in all the examined tissues compared with the control group. In the OTA+C3G group both RSH content and LOOH levels were similar to those observed in the control group, demonstrating that C3G was able to counteract the effects of OTA. A significant (P < 0.001) induction of HO-1 was evident in kidney and liver of both OTA and C3G groups. DNA damage occurred in all the examined tissues of the OTA group, whereas C3G was able to prevent it. The present study confirmed that the effects of OTA are mediated by oxidative stress and demonstrated that C3G efficiently counteracted deleterious effects of OTA because of its antioxidant and HO-1-inducing properties.
    British Journal Of Nutrition 11/2007; 98(5):937-43. · 3.30 Impact Factor
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    ABSTRACT: The major natural polyphenols of wine are flavonoids. Red wine also contains a natural phytoalexin called resveratrol which recently has been the subject of conflicting reports regarding its protective role against cardiovascular diseases. We have investigated the free radical scavenging capacity of resveratrol, its effects on xanthine oxidase (XO) activity, spontaneous membrane lipid oxidation, and DNA cleavage. Resveratrol showed a dose-dependent free radical scavenging activity, significant inhibition of XO activity, an anti-lipoperoxidative capacity, and a protective effect on DNA cleavage. The antioxidant capacity of resveratrol is ascribed to the concomitant activities of scavenging free radicals, metal chelating, and inhibition of some enzymes involved in free radical generation.
    Journal of Food Science 07/2006; 67(1):137 - 141. · 1.78 Impact Factor
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    ABSTRACT: Several lines of evidence have extensively demonstrated that peroxynitrite plays a pivotal role in Central Nervous System (CNS) injuries. The present study was aimed at elucidating the molecular mechanism by which propofol attenuates peroxynitrite-mediated injury in the brain. Primary cultured astroglial cells were incubated for 18 h with a known peroxynitrite donor (SIN-1,3 mM) in the presence or absence of propofol (40 microM, 80 microM and 160 microM). The protective effects of propofol were evaluated by MTT cytotoxicity assay, LDH release, and caspase-3 activation by Western blot analysis. Appropriate propofol concentrations (ranging from 40 microM to 160 microM) significantly increased HO-1 expression and attenuated SIN-1-mediated cytotoxicity and caspase-3 activation. The protective effects of propofol were mitigated by the addition of tin-mesoporphirin (SnMP), a potent inhibitor of HO activity. The addition of a specific synthetic inhibitor of NF-kappaB abolished propofol-mediated HO-1 induction, suggesting a possible role for this nuclear transcriptional factor in our experimental conditions. These findings indicate that propofol attenuates peroxynitrite-mediated apoptosis in astroglial cells, a property that may be relevant in both physiological and pathological processes in the CNS.
    Current Neurovascular Research 05/2005; 2(2):141-8. · 2.84 Impact Factor
  • Current Neurovascular Research - CURR NEUROVASC RES. 01/2005; 2(2):141-148.
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    ABSTRACT: The concentration of peroxynitrite in the brain increases after central nervous system injuries. The authors hypothesized that propofol, because of its particular chemical structure, mitigates the effects of peroxynitrite-mediated oxidative stress and apoptosis by the induction of heme oxygenase (HO)-1 in primary cultured astroglial cells. Primary cultured astroglial cells were incubated for 18 h with a known peroxynitrite donor (3 mm SIN-1) in the presence or absence of propofol (40 microm, 80 microm, 160 microm, and 1 mm). The protective effects of propofol were evaluated by 3(4,5-dimethyl-thiazol-2-yl)2,5-diphenyl-tetrazolium bromide cytotoxicity assay, lactic dehydrogenase release, DNA ladderization by Comet assay, and caspase-3 activation by Western blot analysis. Appropriate propofol concentrations (ranging from 40 microm to 1 mm) significantly increased HO-1 expression and attenuated SIN-1-mediated DNA ladderization and caspase-3 activation. The protective effects of propofol were mitigated by the addition of tin mesoporphyrin, a potent inhibitor of HO activity. The addition of a specific synthetic inhibitor of nuclear factor kappaB abolished propofol-mediated HO-1 induction, suggesting a possible role of this nuclear transcriptional factor in our experimental conditions. The antioxidant properties of propofol can be partially attributed to its scavenging effect on peroxynitrite as well as to its ability to increase HO-1 expression at higher concentrations, a property that might be relevant to neuroprotection during anesthesia.
    Anesthesiology 01/2005; 101(6):1363-71. · 5.16 Impact Factor
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    ABSTRACT: We discuss the use of fluorescence correlation spectroscopy for the measurement of relatively slow rotations of large macromolecules in solution or attached to other macromolecular structures. We present simulations and experimental results to illustrate the range of rotational correlation times and diffusion times that the technique can analyze. In particular, we examine various methods to analyze the polarization fluctuation data. We have found that by first constructing the polarization function and then calculating the autocorrelation function, we can obtain the rotational motion of the molecule with very little interference from the lateral diffusion of the macromolecule, as long as the rotational diffusion is significantly faster than the lateral diffusion. Surprisingly, for common fluorophores the autocorrelation of the polarization function is relatively unaffected by the photon statistics. In our instrument, two-photon excitation is used to define a small volume of illumination where a few molecules are present at any instant of time. The measurements of long DNA molecules labeled with the fluorescent probe DAPI show local rotational motions of the polymers in addition to translation motions of the entire polymer. For smaller molecules such as EGFP, the viscosity of the solution must be increased to bring the relaxation due to rotational motion into the measurable range. Overall, our results show that polarized fluorescence correlation spectroscopy can be used to detect fast and slow rotational motion in the time scale from microsecond to second, a range that cannot be easily reached by conventional fluorescence anisotropy decay methods.
    Microscopy Research and Technique 12/2004; 65(4-5):205-17. · 1.59 Impact Factor
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    ABSTRACT: Background: The concentration of peroxynitrite in the brain increases after central nervous system injuries. The authors hypothesized that propofol, because of its particular chemical structure, mitigates the effects of peroxynitrite-mediated oxidative stress and apoptosis by the induction of heme oxygenase (HO)-1 in primary cultured astroglial cells.
    Anesthesiology 11/2004; 101(6):1363-1371. · 5.16 Impact Factor
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    ABSTRACT: Oxidative modification of low-density lipoprotein (LDL) appears to play a pivotal role in atherosclerosis. In the present study the effect of several concentrations of rutin, its aglycon quercetin, cyanidin 3-O-β-d-glucoside, its aglycon cyanidin, hydroxycinnamic acids, and a standardized red orange (Citrus sinensis varieties) extract (ROE) on LDL oxidation was tested. Lipid peroxidation was monitored by conjugated diene formation and by different electrophoretic mobility of native LDL and oxidized LDL. Results obtained in the present study suggest specific effects of flavonoids tested and, in particular, of ROE on the prevention of LDL oxidation involved in the development of cardiovascular diseases.
    Journal of Food Science 07/2004; 69(6):C480 - C484. · 1.78 Impact Factor
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    ABSTRACT: Anthocyanins, colored flavonoids, are water-soluble pigments present in the plant kingdom; in fact they are secondary plant metabolites responsible for the blue, purple, and red color of many plant tissues. Present in beans, fruits, vegetables and red wines, considerable amounts of anthocyanins are ingested as constituents of the human diet (180-215 mg daily). There is now increasing interest in the in vivo protective function of natural antioxidants contained in dietary plants against oxidative damage caused by free radical species. Recently, the antioxidant activity of phenolic phytochemicals, has been investigated. Since the antioxidant mechanism of anthocyanin pigments is still controversial, in the present study we evaluated the effects of cyanidin and cyanidin 3-O-beta-D-glucoside on DNA cleavage, on their free radical scavenging capacity and on xanthine oxidase activity. Cyanidin and cyanidin 3-O-beta-D-glucoside showed a protective effect on DNA cleavage, a dose-dependent free radical scavenging activity and significant inhibition of XO activity. These effects suggest that anthocyanins exhibit interesting antioxidant properties, and could therefore represent a promising class of compounds useful in the treatment of pathologies where free radical production plays a key role.
    Cell Biology and Toxicology 09/2003; 19(4):243-52. · 2.34 Impact Factor
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    ABSTRACT: Anthocyanins, colored flavonoids, are water-soluble pigments present in the plant kingdom; in fact they are secondary plant metabolites responsible for the blue, purple, and red color of many plant tissues. Present in beans, fruits, vegetables and red wines, considerable amounts of anthocyanins are ingested as constituents of the human diet (180–215 mg daily). There is now increasing interest in thein vivo protective function of natural antioxidants contained in dietary plants against oxidative damage caused by free radical species. Recently, the antioxidant activity of phenolic phytochemicals, has been investigated. Since the antioxidant mechanism of anthocyanin pigments is still controversial, in the present study we evaluated the effects of cyanidin and cyanidin 3-O--D-glucoside on DNA cleavage, on their free radical scavenging capacity and on xanthine oxidase activity. Cyanidin and cyanidin 3-O--D-glucoside showed a protective effect on DNA cleavage, a dose-dependent free radical scavenging activity and significant inhibition of XO activity. These effects suggest that anthocyanins exhibit interesting antioxidant properties, and could therefore represent a promising class of compounds useful in the treatment of pathologies where free radical production plays a key role.
    Cell Biology and Toxicology 07/2003; 19(4):243-252. · 2.34 Impact Factor
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    ABSTRACT: Fumonisins are a group of toxic metabolites mainly produced by Fusarium moniliforme and Fusarium proliferatum, fungi that commonly occur on corn throughout the world. Fumonisin B1 (FB1), structurally resembling sphingoid bases, is an inhibitor of ceramide synthase, a key enzyme involved in de novo sphingolipid biosynthesis and in the reacylation of free sphingoid bases derived from sphingolipid turnover. This inhibitory effect leads to accumulation of free sphinganine (SA) and sphingosine (SO), inducing cell death. However, little is known on the down stream effectors activated by these sphingolipids in the cell death signaling pathway. We exposed rat astrocytes to FB1 with the aim of evaluating the involvement of oxygen free radicals and of some other biochemical pathways such as caspase-3 activity and DNA damage. Our results indicate that FB1 treatment (48, 72 h and 6 days in vitro, DIV, and 10, 50, 100 microM) does not affect cell viability. Conversely, after 72 h of treatment, FB1 (50 and 100 microM) induced DNA damage and an enhancement of caspase-3 activity compared to controls. In addition, FB1 increased the expression of HSP70 at 10 and 50 microM at 48, 72 h, and 6 DIV of treatment. We conclude that DNA damage of apoptotic type in rat astrocytes is caused by FB1 and that the genotoxic potential of FB1 has probably been underestimated and should be reconsidered.
    Neurochemical Research 05/2002; 27(4):345-51. · 2.13 Impact Factor
  • A Russo, M Palumbo, C Scifo, V Cardile, M L Barcellona, M Renis
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    ABSTRACT: Ethanol intake is associated with increase in lipid peroxidation and formation of reactive oxygen species in different cerebral areas, in neurons as well as in astrocytes. The latter's integrity is essential for the normal growth of neurons. In previous studies we observed, in different cerebral areas of both acutely and chronically ethanol-treated rats, correlation between ethanol-induced oxidative stress and the increased expression of HSP70 (70 kDa heat shock proteins), chaperonins having a protective and stabilizing effect on stress-induced cell injury. In this study we examined, in vitro, the role of HSP70 on chronically ethanol-treated rat astrocytes by transfection with an anti-HSP70 antisense oligonucleotide. The results show that treatment with ethanol, from 50 to 100 mmol/L, induces a dose-dependent increase in the production of reactive oxygen species and of HSP70 levels, together with an impairment of the respiratory chain activity and a decrease in cell viability. In addition, our data indicate a drastic reduction of cellular metabolism in HSP70-deprived astrocytes, particularly when these cells were also ethanol-treated. In fact, transfection with HSP70 antisense induced moderate oxidative damage in control astrocytes and, consequently, a drastic decrease in the viability of ethanol-treated cells, with the mitochondrial functionality being particularly affected. Our results confirm that heat shock proteins confer a survival advantage to the astrocytes, preventing oxidative damage and nuclear DNA damage as well, and suggest the development of new drugs exerting a cytoprotective role either in physiological, or pathological conditions.
    Cell Biology and Toxicology 02/2001; 17(3):153-68. · 2.34 Impact Factor
  • M L Barcellona, Y Chen, J D Müller, E Gratton
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    ABSTRACT: The binding of 4',6-diamidino-2-phenylindole (DAPI) to double-stranded GC polymers either in the alternating or in homopolymer sequence was investigated using fluorescence techniques. We employed fluctuation correlation spectroscopy, which measures the diffusion coefficient of fluorescent particles, to demonstrate that the fluorescence was originating from relatively slowly diffusing entities. These entities display a very large heterogeneity of diffusing coefficients, indicating that molecular aggregation is extensive in our samples. We used frequency domain fluorometry to characterize the fluorescence lifetime of the species, while varying the GC polymer-dye coverage systematically. At very low coverage we observed a relatively bright fluorescent component with a lifetime value of approximately 4 ns. The stoichiometry of binding of this bright species was such that it can only arise from rare molecular structures, either unusual loops or large molecular aggregates. The amount and characteristics of this bright fluorescent component were different between the homo and the alternating polymer, indicating that the difference in sequence of the two polymers is responsible for the different aggregates which are then detected in the fluorescence experiment. At large GC polymer coverage we observed a relatively wide distribution of fluorescent species with short lifetime values, in the range between 0.12 and 0.2 ns. Given the stoichiometry of binding of this fluorescent component, we concluded that it could arise either from intercalative and/or non-specific binding to the DNA double-stranded molecules. We comment on the origin of the rare but brightly fluorescent binding sites and discuss the potential to detect such unusual DNA structures.
    European Biophysics Journal 02/2001; 30(2):98-109. · 2.27 Impact Factor

Publication Stats

743 Citations
128.45 Total Impact Points

Institutions

  • 1981–2014
    • University of Catania
      • • Department of Drug Science (DSF)
      • • Department of Chemical Sciences
      Catania, Sicily, Italy
  • 2002
    • Mediterranean University of Reggio Calabria
      Reggio di Calabria, Calabria, Italy
  • 1990–1991
    • University of Illinois, Urbana-Champaign
      • Department of Physics
      Urbana, IL, United States