Acoustic dynamics of supercooled indomethacin probed by Brillouin light scattering.

Acoustics dynamics of the molecular glass-former indomethacin (IMC) have been investigated by Brillouin light scattering (BLS) at GHz frequencies. Elastic response of the system has been tracked from the melting temperature down to the glass transition through the supercooled liquid. Both the structural arrest and the vibrational dynamics are described by modeling the experimentally determined dynamic structure factor within the framework of the Langevin equation, through a simplified choice of memory function which allows one to determine sound velocity and the acoustic attenuation coefficient as a function of temperature. The density fluctuation spectra in the glassy phase, as probed by BLS, are compared with time-domain results from photoacoustics experiments. The arising scenario is discussed in the context of current literature reporting inelastic X-ray scattering and BLS in platelet geometry. The link between the probed elastic properties and the non-ergodicity factor of the glass phase is finally scrutinized.

Coherent anti-Stokes Raman spectroscopy of single and multi-layer graphene.

Spontaneous Raman spectroscopy is a powerful characterization tool for graphene research. Its extension to the coherent regime, despite the large nonlinear third-order susceptibility of graphene, has so far proven challenging. Due to its gapless nature, several interfering electronic and phononic transitions concur to generate its optical response, preventing to retrieve spectral profiles analogous to those of spontaneous Raman. Here we report stimulated Raman spectroscopy of the G-phonon in single and multi-layer graphene, through coherent anti-Stokes Raman Scattering. The nonlinear signal is dominated by a vibrationally non-resonant background, obscuring the Raman lineshape. We demonstrate that the vibrationally resonant coherent anti-Stokes Raman Scattering peak can be measured by reducing the temporal overlap of the laser excitation pulses, suppressing the vibrationally non-resonant background. We model the spectra, taking into account the electronically resonant nature of both. We show how coherent anti-Stokes Raman Scattering can be used for graphene imaging with vibrational sensitivity.

Skrjabinelazia rizzoi n. sp. (Nematoda: Seuratoidea) from a Sicilian lacertid, with comments on specific and biological diversity in the genus.

Skrjabinelazia rizzoi n. sp. (Seuratoidea), from Podarcis sicula captured at Cammarata, Agrigento Province, Sicily, is distinct from the 13 known species of the genus, including Skrjabinelazio sp. Rizzo from Catania. It is identified with the following set of characters: in the male, short spicules and gubernaculum, thin body; in the female, buccal cavity with a crown of leaflets, body cuticle without internal ornamentation, presence of cephalic and caudal vesicles, tail with a terminal digitiform spike 42-48 microm long. The morphology of the new species supports our previous hypothesis of two Skrjabinelazia lineages, one with spicules and one without spicules, respectively linked to Lacertidae and Gekkonidae. In Palearctic lacertids, five named species are presently known, S. taurica from Crimea (Ukraine), S. hoffmanni from Beijing (China), S. pyrenaica from Pyrenees (Spain), S. vozae from Cevennes (France), S. rizzoi from Agrigento Province, Sicily (Italy), but analysis of some published works suggests a greater diversity. S. rizzoi infection, found in April-May in 1/5 lizards, was recent with young females in the host's stomach and intestine, and males in the stomach. One female contained four membranous-shelled eggs. The two other females contained a few hatched infective larvae, membranous-shelled eggs with developing embryos and, unexpectedly at this early stage, a few thick-shelled divided eggs. As in several other Skrjabinelazia species, the progeny of S. rizzoi are adapted for intra-host suprainfection and inter-host transmission, but in this species the production of resistant eggs appears in very young females.

Raman spectroscopy of graphene under ultrafast laser excitation.

The equilibrium optical phonons of graphene are well characterized in terms of anharmonicity and electron-phonon interactions; however, their non-equilibrium properties in the presence of hot charge carriers are still not fully explored. Here we study the Raman spectrum of graphene under ultrafast laser excitation with 3 ps pulses, which trade off between impulsive stimulation and spectral resolution. We localize energy into hot carriers, generating non-equilibrium temperatures in the ~1700-3100 K range, far exceeding that of the phonon bath, while simultaneously detecting the Raman response. The linewidths of both G and 2D peaks show an increase as function of the electronic temperature. We explain this as a result of the Dirac cones' broadening and electron-phonon scattering in the highly excited transient regime, important for the emerging field of graphene-based photonics and optoelectronics.

Terminal arbors of individual "feedback" axons projecting from area V2 to V1 in the macaque monkey: a study using immunohistochemistry of anterogradely transported Phaseolus vulgaris-leucoagglutinin.

In the present study, the anterograde tracer Phaseolus vulgaris-leucoagglutinin (PHA-L) was injected into area V2 in order to demonstrate the precise morphology of individual axons from area V2 to V1. On the basis of 28 complete axon reconstructions, several characteristic features have been identified. 1) Individual axons arborize in multiple layers: 1, 2, 5, and (inconstantly) 3. A single axon may have numerous terminal clusters in layers 1 and 2, but at most one in layer 3. 2) Axons typically ascend to layer 1, turn asymmetrically in one direction, and travel for long distances in this layer (1.10-4.30 mm; dimensions uncorrected for shrinkage). A few axons (three of 28 reconstructed) were found to have a single terminal cluster (0.3-0.5 mm wide) in layers 1 and 2. 3) Collaterals in layer 5 seem to extend over shorter distances (0.60 mm or less). 4) Delicate sprays of boutons (both beads and spines) are clustered along the main trunk. Spacing is variable but usually ranges from 0.35 mm to 0.65 mm. 5) In addition to clustered boutons, there can be linear collaterals, continuously studded with boutons, parallel to the main axon in layer 1. These results indicate that axons from V2 have complex radial and tangential distributions in V1. Terminations in different layers may be directed to different sets of neurons or to different portions of the dendritic tree (for example, distal portions of pyramidal neuron apical dendrites in layers 1 and 2, but more proximal portions in layer 3). Clustered terminations over wide tangential areas may imply a divergent innervation by a single axon of multiple compartmental structures, such as ocular dominance columns or cytochrome oxidase patches.

Persistence of human myiasis by Oestrus ovis L. (Diptera: Oestridae) among shepherds of the Etnean area (Sicily) for over 150 years.

From a study carried out in 22 townships of the Etnean area, by interviewing 112 shepherds, it was confirmed that 90 of them (80.3%), once or more in their lives, had contracted myiasis by Oestrus ovis L., habitual agent of estriasis in sheep. The most frequent sites of involvement were the pharynx (77 times), often extending to the larynx, the conjunctiva (56), followed by the nose (32) and rarely the ear (1). Multiple simultaneous sites involvement was also frequent affecting 54.4% of the shepherds. The chief symptom was pain, sometimes accompanied by fever and malaise. The shepherds go rarely to see a doctor (only 7 out of 90), the greater part preferring traditional remedies. It is curious to note that myiasis associated with Oe. ovis was already observed more than 150 years ago by a Sicilian physician, G. A. Galvagni, who had pointed out the high incidence of the myiasis in shepherds in the area. The persistence of human myiasis in the Etnean area appears to be related to the fact that in this region the conditions of sheep farming and the lifestyle of shepherds have not changed so much since then.

New record of Nosopsyllus (Nosopsyllus) barbarus (Jordan and Rothschild, 1912) (Aphaniptera: Dolichopsyllidae) from Sicily. Morphology at scanning electron microscopy of N. (N.) barbarus and N. (N.) fasciatus (Bosc D'Antic, 1800).

Nosopsyllus (N.) fasciatus, species or complex cosmopolitan and very polymorphic, is established in most of Italian regions, in association with murine rodents, especially domestic species. N. (N.) barbarus, similar to N. fasciatus in modified segments of the male and perhaps in ecology, is presently known from North Africa regions and a few Mediterranean islands; in Italy it is reported from Sardinia and Egadi islands. In this note the N. barbarus presence in Sicily (Palermo) and the contemporary record of N. fasciatus from the same country and host species (Rattus rattus frugivorus) are reported for the first time. The coexistence of both species was shown until now, only in Sardinia. A scanning electron microscope was used to describe the clasper of the male of N. fasciatus and the main diagnostic surface differences between females of N. fasciatus and N. barbarus.

Research of canine filariasis in Trapani province (western Sicily). Morphology on SEM of male Dirofilaria repens.

The prevalence of canine filariasis was investigated in 4 municipalities of Trapani province (Campobello di Mazara, Castelvetrano, Marsala and Mazara del Vallo), an area where 8 human cases of dirofilariasis due to Dirofilaria (Nochtiella) repens have occurred during the last decade. Blood samples were collected late in the afternoon, during August and September 1995, and examined by Knott technique for the presence of microfilariae. Sixtythree (29.3%) out of 215 domestic dogs (98 males, 117 females; 40 sub-adults, 175 adults) proved to be positive for microfilariae: 55 (25.6%) for D. repens, 13 (6.0%) for Dipetalonema reconditum, 1 (0.5%) for D. immitis; 6 (2.8%) mixed infections (5 D. repens + D. reconditum and 1 D. repens + D. immitis) were also found. The surface topography via SEM of an adult male specimen of D. repens found in a dog during necroscopy is also described. The relatively large number of human cases of dirofilariasis appears to be related to the high prevalence of D. repens observed in dogs of Trapani province. This matter should be investigated more extensively in this area.

Chasing bacteria within the cells using levofloxacin-loaded hyaluronic acid nanohydrogels.

In the present work, an innovative approach based on the delivery of levofloxacin (LVF) from polysaccharide nanohydrogels for the treatment of bacterial intracellular infections is described. The nanohydrogels (NHs) were obtained by self-assembling of the hyaluronic acid-cholesterol amphiphilic chains in aqueous environment. LVF, a fluoroquinolone antibiotic scarcely efficient in intracellular infections, was entrapped within such NHs by nanoprecipitation, thus forming a drug delivery system (LVF-NHs) that was tested for its activity on different bacteria strains. The MIC values of levofloxacin-loaded nanohydrogels were determined for Staphylococcus aureus and Pseudomonas aeruginosa strains and compared to those obtained using free LVF. The intracellular antimicrobial activity of LVF-NHs and free LVF was compared on HeLa epithelial cell line infected by the above mentioned bacteria, and the increase in antibacterial efficacy of LVF-NHs with respect to that of free LVF was evidenced. The obtained results allow to conclude that this new approach can be considered as really promising method for intracellular infection treatments.

Preparation and characterization of antimicrobial wound dressings based on silver, gellan, PVA and borax.

Silver-loaded dressings are designed to provide the same antimicrobial activity of topical silver, with the advantages of a sustained silver release and a reduced number of dressing changes. Moreover, such type of dressing must provide a moist environment, avoiding fiber shedding, dehydration and adherence to the wound site. Here we describe the preparation of a novel silver-loaded dressing based on a Gellan/Hyaff(®) (Ge-H) non woven, treated with a polyvinyl alcohol (PVA)/borax system capable to enhance the entrapment of silver in the dressing and to modulate its release. The new hydrophilic non woven dressings show enhanced water uptake capability and slow dehydration rates. A sustained silver release is also achieved. The antibacterial activity was confirmed on Staphylococcus aureus and Pseudomonas aeruginosa.

Investigation on the load-displacement curves of a human healthy heel pad: In vivo compression data compared to numerical results.

The aims of the present work were to build a 3D subject-specific heel pad model based on the anatomy revealed by MR imaging of a subject's heel pad, and to compare the load-displacement responses obtained from this model with those obtained from a compression device used on the subject's heel pad. A 30 year-old European healthy female (mass=54kg, height=165cm) was enrolled in this study. Her left foot underwent both MRI and compression tests. A numerical model of the heel region was developed based on a 3D CAD solid model obtained by MR images. The calcaneal fat pad tissue was described with a visco-hyperelastic model, while a fiber-reinforced hyperelastic model was formulated for the skin. Numerical analyses were performed to interpret the mechanical response of heel tissues. Different loading conditions were assumed according to experimental tests. The heel tissues showed a non-linear visco-elastic behavior and the load-displacement curves followed a characteristic hysteresis form. The energy dissipation ratios measured by experimental tests (0.25±0.02 at low strain rate and 0.26±0.03 at high strain rate) were comparable with those evaluated by finite element analyses (0.23±0.01 at low strain rate and 0.25±0.01 at high strain rate). The validity and efficacy of the investigation performed was confirmed by the interpretation of the mechanical response of the heel tissues under different strain rates. The mean absolute percentage error between experimental data and model results was 0.39% at low strain rate and 0.28% at high strain rate.

Diffusion of meticillin-resistant Staphylococcus aureus USA300 strains in central Italy.

Meticillin-resistant Staphylococcus aureus (MRSA) is an outstanding, clonally evolving pathogen that in recent years, under the selective pressure of antibiotics, has acquired the crucial ability to infect people outside of hospitals. MRSA USA300 has progressively become synonymous with severe community-associated staphylococcal disease worldwide. Whilst spreading worldwide, these clones have progressively acquired resistance to several antibiotics and have gained the ability to cause infections in hospital settings. Recently, USA300-related strains showing resistance to several antibiotics have been isolated from community-acquired infections in Italy. This paper reports the high frequency of isolation of USA300-related strains both from community- and hospital-acquired infections in central Italy as well as their genotypic characteristics and antibiotic susceptibility. Analysis of these characteristics by partial least squares discriminant analysis enabled it to be demonstrated that whilst moving from the community to the hospital setting these isolates underwent an adaptive process that generated clones showing distinctive characteristics. These observations further support the hypothesis that the threatening generation of strains combining both resistance and virulence is becoming a reality, and stress the necessity of constant molecular epidemiological surveillance of MRSA.

Organization of individual cortical axons projecting from area V1 (area 17) to V2 (area 18) in the macaque monkey.

The present study uses the anterograde tracer, Phaseolus vulgaris-leucoagglutinin (PHA-L), to investigate the detailed morphology of individual axons projecting from area V1 to prestriate area V2. Observations are derived from serial reconstructions of 45 axons. Axons are found to differ both in laminar distribution and in arbor size. The majority (25/45; 56%) terminate in the upper half of layer 4 and the lower part of layer 3. Terminal clusters typically measure about 200 microns in diameter (dimensions are uncorrected for shrinkage), and are either in one, two, or occasionally three patches. Patches are separated by 200-500 microns. Of these 25 axons, four also have minor collaterals to layer 5. Of the remaining 20 axons in our sample, eight have one or two terminal arbors (about 200 microns in diameter) mainly in layer 3; another eight have terminations, organized as a single field (about 350 microns in diameter), within layer 4; and four axons have much larger terminal fields (1.0-1.2 mm x 0.3 mm), in layers 3 and 4. These morphological differences might constitute a gradient or, alternately, indicate distinct subgroups within the striate efferent population. Large terminal fields are asymmetrical, with their long axis oriented in an anterior-posterior fashion toward the depth of the lunate sulcus. Axons with two terminal arbors have a similar bias. As this arrangement is approximately perpendicular to the border of V1, we suggest that striate axons may be extended preferentially along the length of the stripelike compartments in V2. These compartments are also arrayed perpendicular to the border between areas V1 and V2. Reconstruction of small groups of 2-4 convergent axons demonstrates that axons with different morphology (i.e. large or small terminal fields) can occur within the same projection focus. Terminal arbors belonging to different axons can overlap, but tend not to be superimposed exactly.

[Antibodies against Toxocara canis in human serum from western Sicily]. / Anticorpi anti-Toxocara canis in sieri umani della Sicilia occidentale.

335 human sera of western Sicily were examined with an ELISA method for the prevalence of antibodies anti-Toxocara canis. The results (13% pos. in psychiatric patients,9.4% in farmers, 1.9% in children and 1.2% in blood donors) seem to indicate a strong correlation between style of life and infestation risk.