Pain-Free Alpha-Synuclein Detection by Low-Cost Hierarchical Nanowire Based Electrode

Analytical methods for the early detection of the neurodegenerative biomarker for Parkinson's disease (PD), α-synuclein, are time-consuming and invasive, and require skilled personnel and sophisticated and expensive equipment. Thus, a pain-free, prompt and simple α-synuclein biosensor for detection in plasma is highly demanded. In this paper, an α-synuclein electrochemical biosensor based on hierarchical polyglutamic acid/ZnO nanowires decorated by gold nanoparticles, assembled as nanostars (NSs), for the determination of α-synuclein in human plasma is proposed. ZnO NSs were prepared by chemical bath deposition (CBD) and decorated with electrodeposited Au nanoparticles (Au NPs). Then, electro-polymerized glutamic acid was grown and functionalized with anti-α-synuclein. A synergistic enhancement of electrode sensitivity was observed when Au NPs were embedded into ZnO NSs. The analytical performance of the biosensor was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), using the Fe(II)(CN)64-/Fe(III)(CN)63- probe. The charge transfer resistance after α-synuclein recognition was found to be linear, with a concentration in the range of 0.5 pg·mL-1 to 10 pg·mL-1, a limit of detection of 0.08 pg·mL-1, and good reproducibility (5% variation) and stability (90%). The biosensor was also shown to reliably discriminate between healthy plasma and PD plasma. These results suggest that the proposed biosensor provides a rapid, quantitative and high-sensitivity result of the α-synuclein content in plasma, and represents a feasible tool capable of accelerating the early and non-invasive identification of Parkinson's disease.

Enlightening the bimetallic effect of Au@Pd nanoparticles on Ni oxide nanostructures with enhanced catalytic activity

Bimetallic decoration of semiconductor electrodes typically improves catalytic and sensing performances because of a well-claimed synergistic effect. A microscopic and quantitative investigation of such an effect on energy bands of semiconductor can be really useful for further exploitation. Au, Pd and Au@Pd (core@shell) nanoparticles (10-20 nm in size) were synthesized through chemical reduction method and characterized with scanning and transmission microscopy, Rutherford backscattering spectrometry, cyclic voltammetry electrochemical impedance spectroscopy and Mott-Schottky analysis. The nanoparticles have been used to decorate Ni-based nanostructured electrodes with the aim to quantitatively investigate the effect of decoration with mono or bimetallic nanoparticles. Decorated electrodes show higher redox currents than bare ones and a shift in redox peaks (up to 0.3 V), which can be ascribed to a more efficient electron transport and improved catalytic properties. These effects were satisfactorily modeled (COMSOL) employing a nano Schottky junction at the nanoparticle-semiconductor interface, pointing out large energy band bending (up to 0.4 eV), space charge region and local electric field (up to [Formula: see text]) in bimetallic decoration. Sensing test of glucose and H₂O₂ by decorated Ni oxide electrodes were performed to consolidate our model. The presence of bimetallic nanoparticles enhances enormously the electrochemical performances of the material in terms of sensitivity, catalytic activity, and electrical transport. The modification of energy band diagram in semiconductor is analyzed and discussed also in terms of electron transfer during redox reactions.

AZO Nanoparticles-Decorated CNTs for UV Light Sensing: A Structural, Chemical, and Electro-Optical Investigation

Nanocomposites formed by aluminum-doped zinc oxide nanoparticles (AZO-NP) and multiwall carbon nanotubes (CNT) are proposed here as a promising material for UV light sensing applications, with the great advantage of operating in air, at room temperature, and at low voltage. Nanocomposite layers were prepared with different AZO:CNT weight ratios by a simple methodology at room temperature. They were characterized by means of UV-Vis spectroscopy, scanning and transmission electron microscopies (SEM and TEM), and X-ray photoelectron spectroscopy (XPS). The interaction between the two nanomaterials was demonstrated by comparing the properties of the nanocomposite with the ones shown by the AZO-NPs. Dense AZO-CNT nanocomposite layers were deposited between two metal electrodes on a SiO₂/Si substrate, and the electrical properties were investigated in dark condition and under UV light irradiation. The electrical response to the UV light was a sudden current increase that reduced when the light was switched off. Several UV on/off cycles were performed, showing good repeatability and stability of the response. The mechanisms involved in the electrical response are discussed and compared to the ones previously reported for ZnO-CNT nanocomposites.

Engineering of Nanostructured WO3 Powders for Asymmetric Supercapacitors

Transition metal oxide nanostructures are promising materials for energy storage devices, exploiting electrochemical reactions at nanometer solid-liquid interface. Herein, WO₃ nanorods and hierarchical urchin-like nanostructures were obtained by hydrothermal method and calcination processes. The morphology and crystal phase of WO₃ nanostructures were investigated by scanning and transmission electron microscopy (SEM and TEM) and X-ray diffraction (XRD), while energy storage performances of WO₃ nanostructures-based electrodes were evaluated by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) tests. Promising values of specific capacitance (632 F/g at 5 mV/s and 466 F/g at 0.5 A/g) are obtained when pure hexagonal crystal phase WO₃ hierarchical urchin-like nanostructures are used. A detailed modeling is given of surface and diffusion-controlled mechanisms in the energy storage process. An asymmetric supercapacitor has also been realized by using WO₃ urchin-like nanostructures and a graphene paper electrode, revealing the highest energy density (90 W × h/kg) at a power density of 90 W × kg^-1 and the highest power density (9000 W/kg) at an energy density of 18 W × h/kg. The presented correlation among physical features and electrochemical performances of WO₃ nanostructures provides a solid base for further developing energy storage devices based on transition metal oxides.

Orange-Peel-Derived Nanobiochar for Targeted Cancer Therapy

Cancer-targeted drug delivery systems (DDS) based on carbon nanostructures have shown great promise in cancer therapy due to their ability to selectively recognize specific receptors overexpressed in cancer cells. In this paper, we have explored a green route to synthesize nanobiochar (NBC) endowed with graphene structure from the hydrothermal carbonization (HTC) of orange peels and evaluated the suitability of this nanomaterial as a nanoplatform for cancer therapy. In order to compare the cancer-targeting ability of different widely used targeting ligands (TL), we have conjugated NBC with biotin, riboflavin, folic acid and hyaluronic acid and have tested, in vitro, their biocompatibility and uptake ability towards a human alveolar cancer cell line (A549 cells). The nanosystems which showed the best biological performances-namely, the biotin- and riboflavin- conjugated systems-have been loaded with the poorly water-soluble drug DHF (5,5-dimethyl-6a-phenyl-3-(trimethylsilyl)-6,6a-dihydrofuro[3,2-b]furan-2(5H)-one) and tested for their anticancer activity. The in vitro biological tests demonstrated the ability of both systems to internalize the drug in A549 cells. In particular, the biotin-functionalized NBC caused cell death percentages to more than double with respect to the drug alone. The reported results also highlight the positive effect of the presence of oxygen-containing functional groups, present on the NBC surface, to improve the water dispersion stability of the DDS and thus make the approach of using this nanomaterial as nanocarrier for poorly water-soluble drugs effective.

A Two-Dimensional Superconducting Electron Gas in Freestanding LaAlO3/SrTiO3 Micromembranes

Freestanding oxide membranes constitute an intriguing material platform for new functionalities and allow integration of oxide electronics with technologically important platforms such as silicon. Sambri et al. recently reported a method to fabricate freestanding LaAlO₃/SrTiO₃ (LAO/STO) membranes by spalling of strained heterostructures. Here, we first develop a scheme for the high-yield fabrication of membrane devices on silicon. Second, we show that the membranes exhibit metallic conductivity and a superconducting phase below ∼200 mK. Using anisotropic magnetotransport we extract the superconducting phase coherence length ξ ≈ 36-80 nm and establish an upper bound on the thickness of the superconducting electron gas d ≈ 17-33 nm, thus confirming its two-dimensional character. Finally, we show that the critical current can be modulated using a silicon-based backgate. The ability to form superconducting nanostructures of LAO/STO membranes, with electronic properties similar to those of the bulk counterpart, opens opportunities for integrating oxide nanoelectronics with silicon-based architectures.

Phase Change Ge-Rich Ge-Sb-Te/Sb2Te3 Core-Shell Nanowires by Metal Organic Chemical Vapor Deposition

Ge-rich Ge-Sb-Te compounds are attractive materials for future phase change memories due to their greater crystallization temperature as it provides a wide range of applications. Herein, we report the self-assembled Ge-rich Ge-Sb-Te/Sb2Te3 core-shell nanowires grown by metal-organic chemical vapor deposition. The core Ge-rich Ge-Sb-Te nanowires were self-assembled through the vapor-liquid-solid mechanism, catalyzed by Au nanoparticles on Si (100) and SiO2/Si substrates; conformal overgrowth of the Sb2Te3 shell was subsequently performed at room temperature to realize the core-shell heterostructures. Both Ge-rich Ge-Sb-Te core and Ge-rich Ge-Sb-Te/Sb2Te3 core-shell nanowires were extensively characterized by means of scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, Raman microspectroscopy, and electron energy loss spectroscopy to analyze the surface morphology, crystalline structure, vibrational properties, and elemental composition.

Effective Magnetic Field Dependence of the Flux Pinning Energy in FeSe0.5Te0.5 Superconductor

The role of a layered structure in superconducting pinning properties is still at a debate. The effects of the vortex shape, which can assume for example a staircase form, could influence the interplay with extrinsic pinning coming from the specific defects of the material, thus inducing an effective magnetic field dependence. To enlighten this role, we analysed the angular dependence of flux pinning energy U(H,θ) as a function of magnetic field in FeSe0.5Te0.5 thin film by considering the field components along the ab-plane of the crystal structure and the c-axis direction. U(H,θ) has been evaluated from magneto-resistivity measurements acquired at different orientations between the applied field up to 16 T and FeSe0.5Te0.5 thin films grown on a CaF2 substrate. We observed that the U(H,θ) shows an anisotropic trend as a function of both the intensity and the direction of the applied field. Such a behaviour can be correlated to the presence of extended defects elongated in the ab-planes, thus mimicking a layered superconductor, as we observed in the microstructure of the compound. The comparison of FeSe0.5Te0.5 with other superconducting materials provides a more general understanding on the flux pinning energy in layered superconductors.

Ultrasound of Small Bowel Obstruction: A Pictorial Review

Small bowel obstruction (SBO) is a common condition requiring urgent attention that may involve surgical treatment. Imaging is essential for the diagnosis and characterization of SBO because the clinical presentation and results of laboratory tests may be nonspecific. Ultrasound is an excellent initial imaging modality for assisting physicians in the rapid and accurate diagnosis of a variety of pathologies to expedite management. In the case of SBO diagnosis, ultrasound has an overall sensitivity of 92% (95% CI: 89–95%) and specificity of 93% (95% CI: 85–97%); the aim of this review is to examine the criteria for the diagnosis of SBO by ultrasound, which can be divided into diagnostic and staging criteria. The diagnostic criteria include the presence of dilated loops and abnormal peristalsis, while the staging criteria are represented by parietal and valvulae conniventes alterations and by the presence of free extraluminal fluid. Ultrasound has reasonably high accuracy compared to computed tomography (CT) scanning and may substantially decrease the time to diagnosis; moreover, ultrasound is also widely used in the monitoring and follow-up of patients undergoing conservative treatment, allowing the assessment of loop distension and the resumption of peristalsis.

Near-field enhancement in oxidized close gap aluminum dimers

Aluminum bowtie nanoantennas represent a possibility to confine and enhance electromagnetic (EM) field at optical frequencies in subwavelength regions by using an abundant and inexpensive metal. The native oxidation process of this metal is often viewed as a limitation for its application in plasmonics. Here, we show that in close gap configurations, the high refractive index of the native aluminum oxide helps in squeezing the plasmonic mode in extremely reduced size volumes, providing a higher EM near-field confinement and enhancement in the bowtie antenna gaps than achieved in the pure aluminum counterpart. Hence, the study provides new perspectives in the use of such a plasmonic antenna geometry within this aluminum system, which can be useful for improving plasmonics-enabled effects such as surface-enhanced Raman scattering- and light-matter interaction in strong coupling regime.

Gallium chiral nanoshaping for circular polarization handling

In this work we report the local growth of ordered arrays of 3D core-shell chiral nanohelices based on plasmonic gallium metal. The structures can be engineered in a single step using focused ion beam induced deposition, where a Ga⁺ ion source is used to shape the metallic nanohelix core, while the dielectric precursor is dissociated to create dielectric shells. The solubility of gallium in the different investigated dielectric matrices controls the core-shell thickness ratio of the nanohelices. The chiral plasmonic behaviour of these gallium-based nanostructures is experimentally measured by circularly polarized light transmission through nanostructure arrays and compared with numerical simulations. Large chiroptical effects in the visible range are demonstrated due to the plasmonic effects arising from gallium nanoclusters in the core.

Eco-Friendly 1,3-Dipolar Cycloaddition Reactions on Graphene Quantum Dots in Natural Deep Eutectic Solvent

Due to their outstanding physicochemical properties, the next generation of the graphene family-graphene quantum dots (GQDs)-are at the cutting edge of nanotechnology development. GQDs generally possess many hydrophilic functionalities which allow their dispersibility in water but, on the other hand, could interfere with reactions that are mainly performed in organic solvents, as for cycloaddition reactions. We investigated the 1,3-dipolar cycloaddition (1,3-DCA) reactions of the C-ethoxycarbonyl N-methyl nitrone 1a and the newly synthesized C-diethoxyphosphorylpropilidene N-benzyl nitrone 1b with the surface of GQDs, affording the isoxazolidine cycloadducts isox-GQDs 2a and isox-GQDs 2b. Reactions were performed in mild and eco-friendly conditions, through the use of a natural deep eutectic solvent (NADES), free of chloride or any metal ions in its composition, and formed by the zwitterionic trimethylglycine as the -bond acceptor, and glycolic acid as the hydrogen-bond donor. The results reported in this study have for the first time proved the possibility of performing cycloaddition reactions directly to the p-cloud of the GQDs surface. The use of DES for the cycloaddition reactions on GQDs, other than to improve the solubility of reactants, has been shown to bring additional advantages because of the great affinity of these green solvents with aromatic systems.

Free carrier enhanced depletion in ZnO nanorods decorated with bimetallic AuPt nanoclusters

The decoration of semiconductor nanostructures with small metallic clusters usually leads to an improvement of their properties in sensing or catalysis. Bimetallic cluster decoration typically is claimed to be even more effective. Here, we report a detailed investigation of the effects of Au, Pt or AuPt nanocluster decoration of ZnO nanorods on charge transport, photoluminescence and UV sensitivity. ZnO nanorods were synthesized by chemical bath deposition while decoration with small nanoclusters (2-3 nm in size) was achieved by a laser-ablation based cluster beam deposition technology. The structural properties were investigated by scanning electron microscopy, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy and Rutherford backscattering spectrometry, and the optoelectronic properties by current-voltage and photoluminescence measurements. The extent of band bending at the cluster-ZnO interface was quantitatively modeled through numerical simulations. The decoration of ZnO nanorods with monometallic Au or Pt nanoclusters causes a significant depletion of free electrons below the surface, leading to a reduction of UV photoluminescence, an increase of ZnO nanorod dark resistance (up to 200 times) and, as a consequence, an improved sensitivity (up to 6 times) to UV light. These effects are strongly enhanced (up to 450 and 10 times, respectively) when ZnO nanorods are decorated with bimetallic AuPt nanoclusters that substantially augment the depletion of free carriers likely due to a more efficient absorption of the gas molecules on the surface of the bimetallic AuPt nanoclusters than on that of their monometallic counterparts. The depletion of free carriers in cluster decorated ZnO nanorods is quantitatively investigated and modelled, allowing the application of these composite materials in UV sensing and light induced catalysis.

Mechanical milling: a sustainable route to induce structural transformations in MoS2 for applications in the treatment of contaminated water

Two-dimensional (2D) nanomaterials have received much attention in recent years, because of their unusual properties associated with their ultra-thin thickness and 2D morphology. Besides graphene, a new 2D material, molybdenum disulfide (MoS₂), has attracted immense interest in various applications. On the other hand, ball-milling process provides an original strategy to modify materials at the nanometer scale. This methodology represents a smart solution for the fabrication of MoS₂ nanopowders extremely-efficient in adsorbing water contaminants in aqueous solution. This work reports a comprehensive morphological, structural, and physicochemical investigation of MoS₂ nanopowders treated with dry ball-milling. The adsorption performances of the produced nanopowders were tested using methylene blue (MB) dye and phenol in aqueous solution. The adsorption capacity as a function of ball-milling time was deeply studied and explained. Importantly, the ball-milled MoS₂ nanopowders can be easily and efficiently regenerated without compromising their adsorption capacity, so to be reusable for dye adsorption. The eventual toxic effects of the prepared materials on microcrustacean Artemia salina were also studied. The present results demonstrate that ball-milling of MoS₂ offers a valid method for large-scale production of extremely efficient adsorbent for the decontamination of wastewaters from several pollutants.

L10-FeNi films on Au-Cu-Ni buffer-layer: a high-throughput combinatorial study

The fct L10-FeNi alloy is a promising candidate for the development of high performance critical-elements-free magnetic materials. Among the different materials, the Au-Cu-Ni alloy has resulted very promising; however, a detailed investigation of the effect of the buffer-layer composition on the formation of the hard FeNi phase is still missing. To accelerate the search of the best Au-Cu-Ni composition, a combinatorial approach based on High-Throughput (HT) experimental methods has been exploited in this paper. HT magnetic characterization methods revealed the presence of a hard magnetic phase with an out-of-plane easy-axis, whose coercivity increases from 0.49 kOe up to 1.30 kOe as the Au content of the Cu-Au-Ni buffer-layer decreases. Similarly, the out-of-plane magneto-crystalline anisotropy energy density increases from 0.12 to 0.35 MJ/m3. This anisotropy is attributed to the partial formation of the L10 FeNi phase induced by the buffer-layer. In the range of compositions we investigated, the buffer-layer structure does not change significantly and the modulation of the magnetic properties with the Au content in the combinatorial layer is mainly related to the different nature and extent of interlayer diffusion processes, which have a great impact on the formation and order degree of the L10 FeNi phase.

Low-cost synthesis of pure ZnO nanowalls showing three-fold symmetry

ZnO nanowalls (NWLs) represent a non-toxic, Earth abundant, high surface-to-volume ratio, semiconducting nanostructure which has already showed potential applications in biosensing, environmental monitoring and energy. Low-cost synthesis of these nanostructures is extremely appealing for large scale upgrading of laboratory results, and its implementation has to be tested at the nanoscale, at least in terms of chemical purity and crystallographic orientation. Here, we have produced pure and texturized ZnO NWLs by using chemical bath deposition (CBD) synthesis followed by a thermal treatment at 300 °C. We examined the NWL formation process and the new obtained structure at the nanoscale, by means of scanning and transmission electron microscopy in combination with x-ray diffraction and Rutherford backscattering spectrometry. We have shown that only after annealing at 300 °C in nitrogen does the as-grown material, composed of a mixture of Zn compounds NWLs, show its peculiar crystal arrangement. The resulting ZnO sheets are in fact made by ZnO wurtzite domains (4-5 nm) that show a particular kind of texturization; indeed, they are aligned with their own c-axis always perpendicular to the sheets forming the wall and rotated (around the c-axis) by multiples of 20° from each other. The presented data show that low-cost CBD, followed by an annealing process, gives pure ZnO with a peculiarly ordered nanostructure that shows three-fold symmetry. Such evidence at the nanoscale will have significant implications for realizing sensing or catalyst devices based on ZnO NWLs.

Ultrasound as point of care in management of polytrauma and its complication

PURPOSE

Traumatic injuries constitute a major risk for patients in emergency units. Point-of-care ultrasound may be a determinant in reducing the deleterious impact of complications and in prognosis.

METHODS

We describe the case of a 28-year-old female who reported cranial trauma, abdominal and thoracic trauma, and suspected bilateral fracture of the femur.

RESULTS

Ultrasound was useful for evaluating and monitoring multiple organ failure.

CONCLUSION

Combining cost-effective advantages with bedside real-time imaging, ultrasound is a powerful adjunct to standard clinical assessment in the management of polytrauma when it is administered at the point of care.

Site-Selective Surface-Enhanced Raman Detection of Proteins

Strategies for protein detection via surface-enhanced Raman spectroscopy (SERS) currently exploit the formation of randomly generated hot spots at the interfaces of metal colloidal nanoparticles, which are clustered together by intrusive chemical or physical processes in the presence of the target biomolecule. We propose a different approach based on selective and quantitative gathering of protein molecules at regular hot spots generated on the corners of individual silver nanocubes in aqueous medium at physiological pH. Here, the protein, while keeping its native configuration, experiences an intense local E-field, which boosts SERS efficiency and detection sensitivity. Uncontrolled signal fluctuations caused by variable molecular adsorption to different particle areas or inside clustered nanoparticles are circumvented. Advanced electron microscopy analyses and computational simulations outline a strategy relying on a site-selective mechanism with superior Raman signal enhancement, which offers the perspective of highly controlled and reproducible routine SERS detection of proteins.

Programmable Extreme Chirality in the Visible by Helix-Shaped Metamaterial Platform

The capability to fully control the chiro-optical properties of metamaterials in the visible range enables a number of applications from integrated photonics to life science. To achieve this goal, a simultaneous control over complex spatial and localized structuring as well as material composition at the nanoscale is required. Here, we demonstrate how circular dichroic bands and optical rotation can be effectively and independently tailored throughout the visible regime as a function of the fundamental meta-atoms properties and of their three dimensional architecture in a the helix-shaped metamaterials. The record chiro-optical effects obtained in the visible range are accompanied by an additional control over optical efficiency, even in the plasmonic context. These achievements pave the way toward fully integrated chiral photonic devices.

A forest of SiO2 nanowires covered by a TiO2 thin film for an efficient photocatalytic water treatment

Disordered TiO₂/SiO₂ nanowires possess enhanced photocatalytic activity due to the synergy of morphology and light trapping properties of the NW forest.

Atomic layer deposition of ZnO/TiO2 multilayers: towards the understanding of Ti-doping in ZnO thin films

Undoped and Ti-doped ZnO (TZO) films were deposited by atomic layer deposition (ALD).

Effect of Pt Nanoparticles on the Photocatalytic Activity of ZnO Nanofibers

For this study, we originally realized ZnO nanofibers (∼50 nm in mean radius) mixed with Pt nanoparticles (∼30 nm in mean radius), prepared by pulsed laser ablation in liquid, and investigated their photocatalytic performance. The material was synthesized by the simple electrospinning method coupled with subsequent thermal treatments. Methylene blue was employed as a representative dye pollutant to evaluate the photocatalytic activity of the nanofibers. It was found that the Pt-ZnO fibers exhibit a photodegradation reaction rate that is ∼40 % higher than the one obtained for reference ZnO fibers. These encouraging results demonstrate that Pt-ZnO nanofibers can be fruitfully applied for environmental applications.

Thermodynamic stability of high phosphorus concentration in silicon nanostructures

Doping of Si nanocrystals (NCs) has been the subject of a strong experimental and theoretical debate for more than a decade. A major difficulty in the understanding of dopant incorporation at the nanoscale is related to the fact that theoretical calculations usually refer to thermodynamic equilibrium conditions, whereas, from the experimental point of view, impurity incorporation is commonly performed during NC formation. This latter circumstance makes impossible to experimentally decouple equilibrium properties from kinetic effects. In this report, we approach the problem by introducing the dopants into the Si NCs, from a spatially separated dopant source. We induce a P diffusion flux to interact with the already-formed and stable Si NCs embedded in SiO2, maintaining the system very close to the thermodynamic equilibrium. Combining advanced material synthesis, multi-technique experimental quantification and simulations of diffusion profiles with a rate-equation model, we demonstrate that a high P concentration (above the P solid solubility in bulk Si) within Si NCs embedded in a SiO2 matrix corresponds to an equilibrium property of the system. Trapping within the Si NCs embedded in a SiO2 matrix is essentially diffusion limited with no additional energy barrier, whereas de-trapping is prevented by a binding energy of 0.9 eV, in excellent agreement with recent theoretical findings that highlighted the impact of different surface terminations (H- or O-terminated NCs) on the stability of the incorporated P atoms.

An enhanced photocatalytic response of nanometric TiO2 wrapping of Au nanoparticles for eco-friendly water applications

We propose a ground-breaking approach by an upside-down vision of the Au/TiO2 nano-system in order to obtain an enhanced photocatalytic response. The system was synthesized by wrapping Au nanoparticles (∼8 nm mean diameter) with a thin layer of TiO2 (∼4 nm thick). The novel idea of embedding Au nanoparticles with titanium dioxide takes advantage of the presence of metal nanoparticles, in terms of electron trapping, without losing any of the TiO2 exposed surface, so as to favor the photocatalytic performance of titanium dioxide. A complete structural characterization was made by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The remarkable photocatalytic performance together with the stability of the nano-system was demonstrated by degradation of the methylene blue dye in water. The non-toxicity of the nano-system was established by testing the effect of the material on the reproductive cycle of Mytilus galloprovincialis in an aquatic environment. The originally synthesized material was also compared to conventional TiO2 with Au nanoparticles on top. The latter system showed a dispersion of Au nanoparticles in the liquid environment, due to their instability in the aqueous solution that clearly represents an environmental contamination issue. Thus, the results show that nanometric TiO2 wrapping of Au nanoparticles has great potential in eco-friendly water/wastewater purification.

TiO2-coated nanostructures for dye photo-degradation in water

The photocatalytic efficiency of a thin-film TiO2-coated nanostructured template is studied by dye degradation in water. The nanostructured template was synthesized by metal-assisted wet etching of Si and used as substrate for the deposition of a thin film of TiO2 (10 nm thick) by atomic layer deposition. A complete structural characterization was made by scanning and transmission electron microscopies. The significant photocatalytic performance was evaluated by the degradation of two dyes in water: methylene blue and methyl orange. The relevance of the reported results is discussed, opening the route toward the application of the synthesized nanostructured TiO2 for water purification.

Measurement of the proton-air cross section at √s=57 TeV with the Pierre Auger Observatory

We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505±22(stat)(-36)(+28)(syst)] mb is found.

Measurement of the depth of maximum of extensive air showers above 10{18} eV

We describe the measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10;{18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{-21}{+35}) g/cm{2}/decade below 10{18.24+/-0.05} eV, and (24+/-3) g/cm{2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

Diffusion and practice of ultrasound in emergency medicine departments in Italy

INTRODUCTION

This paper reports data from a cognitive survey on the diffusion, practice and organization of ultrasound (US) in emergency medicine departments (EMDs) in Italy. The study was carried out by the Emergency Medicine Section of the Italian Society for Ultrasound in Medicine and Biology (SIUMB) in collaboration with the Italian Society for Emergency Medicine and Urgent Care (SIMEU).

METHODS

We created a questionnaire with 10 items, relating to 4 thematic areas. The questionnaires were administered from September 2007 to February 2008, by email, telephone or regular mail. In August 2008 the data were subjected to nonparametric statistical analysis (Spearman's Rho and Pearson's chi-square - software SPSS).

RESULTS

We analyzed 170 questionnaires from the EMDs of all Italian regions. A US scanner is present in 64.7% of the ERs, emergency US (E-US) is practiced only in 47.6% of the ERs, and only in 24% of these more than 60% of the ER team members have training in US. The diffusion of US in other operative units of the EMDs ranges from 8.2% to 26.5%.

DISCUSSION

The presence of a US scanner in the ER is essential for the practice and training and is correlated with the level of the EMD. The use of US appears to be less common in less equipped hospitals, regardless of the size of the ER and the availability of radiological services. Wider diffusion of US and greater integration with other services for the installment of the required equipment is to be hoped for.

Observation of the suppression of the flux of cosmic rays above 4 x 10 (19) eV

The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.

Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.

Incidence and Timing of Infections After Liver Transplant in Italy

BACKGROUND

Infections are one of the main complications that cause high morbidity and mortality in transplant recipients. This study sought to estimate the incidence of infections and their main determinants in liver transplant recipients in the first year after transplantation.

PATIENTS AND METHODS

A prospective study was conducted on 103 consecutive patients (72% men) who underwent transplantation in three centers in Northern (Bologna) and Central (Rome) Italy in 2005. Person-years (PY) at risk, incidence rates (IR), IR ratios and 95% confidence intervals were computed for viral, fungal, and bacterial infections.

RESULTS

The 103 patients (median age 55 years) contributed a total of 78.2 PYs, with a median follow-up of 286 days (interquartile range: 194 to 365 days). Fifty-eight patients (56.3%) experienced one or more infections, namely, 151 events (IR = 193.2 infections/100 PYs). IR for bacterial, fungal, and viral infections were 110.0, 56.3, and 26.9 infections/100 Pys, respectively. Within the first 30 days after transplantation, 37.9% patients (39/103) developed one or more events. Bacterial infections represented the most frequent event (86/151, 57.0%). Risk factors significantly associated with increased IR were gender (female), age (>50 years), prolonged intensive care stay volume of blood transfused during surgery and posttransplant, and need for retransplantation.

CONCLUSIONS

These preliminary results showed the relevance of infectious events after liver transplantation especially those of bacterial etiology, and identified factors mainly associated with their occurrence.

[Blunt liver trauma: efficacy of non-operative management]

All haemodynamically stable patients with blunt abdominal trauma can be managed conservatively by non-operative management which is the treatment of choice in 80% of liver trauma. Non-operative management, when feasible, yields very good results in terms of survival, need for blood transfusions, morbidity and reduction of hospital stay. The Authors retrospectively analyse their recent experience with liver trauma. Of 53 patients with blunt liver trauma, 36 underwent surgical treatment whereas 17 haemodynamically stable patients received non-operative management. After CT scans, all patients on non-operative management underwent haemodynamic monitoring, US and blood examinations. A percentage of 47.1 % had a > or = grade III trauma. The mortality and morbidity rates were 0% and no blood transfusions were needed. The efficacy of non-operative management was 100% and none of the patients needed subsequent surgical treatment. Our clinical experience demonstrates that non-operative management is feasible and effective even for higher grade traumas, but always requires strict clinical, haemodynamic and US monitoring and careful patient selection. Current progress in the field and recent evidence reported in the literature indicate the likelihood of further developments and more widespread utilisation of non-operative management in liver trauma.

Ultrasound imaging in diagnosis of superior mesenteric artery syndrome

OBJECTIVES

We screened a cohort of subjects affected by various degree of dyspepsia to reveal if they presented a reduction of the aorto-mesenteric angle and to diagnose suspected cases of superior mesenteric artery (SMA) syndrome.

DESIGN

Controlled, prospective, study.

SETTING

Subjects were studied as outpatients.

SUBJECTS

The study investigated a total of 3622 subjects referred to our department by their general practitioners for dyspepsia and/or abdominal pain. Interventions. Abdominal ultrasonography with power colour Doppler, gastroduodenoscopy, hypotonic duodenography, contrast-enhanced spiral computerized tomography were performed. MAIN OUTCOME MEASUREMENT AND RESULTS: Color Doppler revealed a significant reduction of the SMA angle in 29 of 950 subjects; gastroscopy showed duodenal compressive pulsation in 14 of 29 patients and X-ray revealed compression of the third segment of the duodenum in 28 of 29 patients. CT confirmed the presence of a reduced angle and various degrees of duodenal compression in all patients. Ultrasonography and CT examinations gave overlapping results (P > 0.05) in diagnosing pathological aorto-mesenteric angle.

CONCLUSION

The authors believe that the incidence of reduced aorto-mesenteric angle and SMA syndrome might be underrated. Ultrasound power colour Doppler imaging is useful in epidemiological screening of reduced aorto-mesenteric angle to diagnose suspected cases of SMA syndrome.

Infection with Epstein-Barr virus and cancer: an epidemiological review

The Epstein-Barr virus (EBV) is ubiquitous worldwide, with greater than 80% of people over the age of 30 having been infected. Once EBV infection has occurred, it remains for the lifetime of the individual, making EBV one of the most persistant viruses that infect humans. EBV is strongly associated with the development of several cancers, in particular with Burkitt's lymphoma, Hodgkin's disease, and lymphoproliferative disorders which complicate immune suppression conditions. These EBV-associated neoplasms are characterized by peculiar geographic distributions and distinctive epidemiologic features. In this review, the main epidemiological aspects of the relationship between EBV infection and cancer are outlined, and recent advances in the mechanisms underlying EBV-induced growth transformation are summarized.

Hepatocarcinoma, gallstone disease and gallbladder carcinoma: a case report of a rare incidental association

We report a rare case of a patient operated on with a diagnosis of hepatic tumour and gallstone disease, which postoperatively was found to be a hepatocellular carcinoma associated with a gallbladder carcinoma. Spiral CT at admission showed only a hepatic mass in the 4th segment, compatible with hepatocellular carcinoma and gallbladder lithiasis. Cholecystectomy was performed followed by a wedge resection of the 4th segment of the liver. The histopathological examination revealed a well-differentiated hepatocellular carcinoma and, surprisingly, an adenocarcinoma of the gallbladder confined to the mucosa. The association of a hepatocellular carcinoma and gallbladder adenocarcinoma is extremely rare. This association, together with an analysis of the literature showing the increased incidence of gallstones in cirrhotic patients and the consequent greater surgical risk when undergoing subsequent cholecystectomy after liver resection, would suggest that cholecystectomy should be performed routinely during liver resection for hepatocellular carcinoma or cirrhosis, even for minor resections and when there are no evident signs of gallbladder disease.

Non compliance to therapeutic prescriptions in paediatric patients: role of social communication

The aim of this pilot study was to identify prevalent non-compliance behaviour in paediatric antibiotic therapy and to investigate the possible role of its social correlates. Patients' parents were surveyed at two paediatric practices in Catania, Italy, using an interviewer-administered questionnaire. The two practices were chosen for their location, in two different urban areas, to represent different sets of parents in terms of social status. Anticipated suspension of prescribed antibiotic therapy was the most frequently encountered form of non-compliance, shown by 41.2% of the parents. After partitioning the sample by mothers' occupational status--housewives versus working women--anticipated suspension revealed a positive association with educational level among the former group and a negative one, although not statistically significant, among the latter. Exposition to mass media messages about bacterial antibiotic resistance appeared to be a key intervening variable in interpreting these results, especially among more educated parents. Non-compliance was also associated with perceived characteristics of doctor-parents communication, particularly, with parents' perceived understanding of prescribed therapy.

Long-term liver histology improvement in patients with chronic hepatitis C and sustained response to interferon

A retrospective multicentre survey was conducted to evaluate, in patients with chronic hepatitis C, the long-term liver histological changes induced by interferon (IFN). A total of 112 patients (mean age 46.4 years) were studied. All patients had received a 6-12-month IFN-alpha course (6-18 MU/week) and had successively undergone clinical, biochemical and virological follow-up for at least 36 months (range: 36-76). In each patient, two liver biopsies had been performed: 1-6 months before treatment and, 12-76 months after its completion. In 87 patients with biochemical and virological sustained response persisting for 12 months after therapy, post-treatment liver necroinflammation and fibrosis mean(+/-SD) scores (Knodell index) were significantly lower than pretreatment scores (2.9 +/- 2.2 vs 6.8 +/- 2.9 and 0.8 +/- 1.0 vs 1.2 +/- 1.1, respectively; P < 0.01). In 25 patients who relapsed within 1 year, necroinflammation and fibrosis post-treatment mean scores were similar to pretreatment scores (7.4 +/- 3.2 vs 6.9 +/- 3.1 and 1.8 +/- 1.3 vs 1.6 +/- 1.2, respectively; P > 0.05). On an individual basis, necroinflammation decreased in 87% of sustained responders but only in 36% of relapsers (P < 0.001), whereas fibrosis decreased in 44% of sustained responders but only in 14% of relapsers (P < 0.001). In sustained responders with biopsies performed 12-23 months (n=34), 24-35 months (n=26) or more than 36 months (n=27) after treatment, a progressive decrease of mean necroinflammatory score was observed (-2.6 +/- 2.1, -4.1 +/- 3.4 and -5.2 +/- 3.7 points, respectively; P < 0.01). A similar pattern was observed in fibrosis score (-0.3 +/- 0.6, -0.3 +/- 0.7 and -0.7 +/- 0.9 points, respectively; P < 0.05). Hence, among chronic hepatitis C patients treated with IFN, those with a 12-month sustained response, unlike those who relapse, have a long-term progressive reduction and, in some cases, a complete regression of liver histological damage.

Leukocyte and platelet lowering by some interferon types during viral hepatitis treatment

BACKGROUND/AIMS

The hematologic toxicity (leukothrombocytopenia) of interferon therapy is well known and frequently observed; it may vary, however, according to the type of interferon administered.

METHODOLOGY

We retrospectively assessed 158 patients with chronic viral hepatitis treated for 6-12 months with alpha (recombinant, lymphoblastoid or leukocyte) or beta interferon to monitor leukothrombocytopenia.

RESULTS

During treatment, a significant decrease in leukocyte and platelet counts was detected in 48% and 43% of patients, respectively. The maximum decrease (31% and 26% of pre-treatment values; p<0.01) occurred after 4.9 and 4.2 months of treatment. No patient showed clinical symptoms of leukopenia or thrombocytopenia. Beta-interferon yielded the smallest decreases in leukocyte and platelet counts (-21% and -16% of pre-treatment values, respectively). Among alpha interferons, the lymphoblastoid (9 MU/week) produced the largest decrease both in leukocyte (38%; p<0.05 vs any other type) and in platelet (32%) number. The same dose of leukocyte interferon had the smallest effect (leukocytes: -27%; platelets: -2%), while recombinant interferon showed intermediate toxicity (-32% and -26% respectively).

CONCLUSIONS

From this retrospective study, the hematologic toxicity of alpha and alpha interferons usually emerges as mild. However, leukopenia and thrombocytopenia may be induced more frequently by some of these interferon types.

Anticardiolipin antibodies in pre-eclampsia and intrauterine growth retardation

OBJECTIVE

To establish an association of anticardiolipin antibody (ACA) levels and pre-eclampsia or intrauterine growth retardation (IUGR).

METHODS

Twenty-eight patients with pre-eclampsia, 28 with IUGR and 28 normotensive control group were matched for maternal age, race, weight, cigarette smoking, and parity. All had plasma anticardiolipin antibodies (GPL and MPL) detected by the modified enzyme-linked immuno-absorbent assay (ELISA) technique.

RESULTS

No statistical significant difference in ACA values, both GPL and MPL, was found among the three groups studied Furthermore, none reached a value of ACA that could be considered clinically relevant (> 15).

CONCLUSION

No association was found in anticardiolipin antibody levels between pre-eclamptic and IUGR versus the control group.

Electrophysiological alterations in hepatic encephalopathy detected by brain mapping

Analogical electroencephalogram has been used to study electric alterations in the brain during liver encephalopathy. We adopted digital technique brain mapping to study the electric background activity in the brain and to evaluate the diagnostic and prognosis usefulness of this technique compared with the methods routinely used in this disease. We studied 18 patients with liver cirrhosis and varying degrees of liver encephalopathy and 7 healthy control subjects to assess correlation between the severity of encephalopathy and abnormal electric activity in the brain, and to detect the main differences between the brain mapping findings obtained in the two groups. The findings revealed an overall reduction in the rhythm, increased amplitude and anomalous distribution of the waveforms in the cirrhotic patients. Although similar results have already been reported, brain mapping furnished prompt and more easily visualised findings. Moreover, brain mapping facilitated detailed analysis of wave amplitude, frequency and topographic location indicating that this technique is a valid tool in diagnosing brain disorders.

[Significance of prognostic parameters in acute pancreatitis]

The diagnostic and therapeutic approach to Acute Pancreatitis (A.P.) is directly related to the clinical presentation. The Authors reviewed the data of 66 patients, hospitalized between October 1989 and December 1991, to verify the effectiveness of the prognostic criteria suggested by Ranson (1974), Mercadier (1977) and Imrie (1978). A.P. was of biliary origin in the majority of the patients (63.5%); five patients (7.5%) had an acute alcoholic pancreatitis, while the aetiology was traumatic or unknown in the remaining cases. A complicated clinical course was defined by the development of pseudocyst, pancreatic abscess, digestive haemorrhage, death or prolonged hospitalization (more than 20 days). The 28.8% of the patients developed complications during hospitalization. There were seven pancreatic pseudocysts, six pulmonary complications, three renal insufficiencies, two vascular complications, two sepsies and a gastrointestinal haemorrhage. The mean hospitalization period was 15.1 days (range 1-112). The Authors conclude that the three different prognostic criteria are equally useful to test the severity of A.P. attacks allowing to identify patients with the higher risk to develop complications during hospitalization.

Mitochondrial DNA mutation in an Italian family with Leber hereditary optic neuropathy

Mitochondrial (mt) DNA from a Southern Italian family with Leber hereditary optic neuropathy was analyzed for the presence of the reported mutation at position 11778 of the ND4 subunit gene. The point mutation was found in mt DNA extracted from peripheral blood in all members of the family with the exclusion of the father, and was present in a homoplasmic fashion, despite the phenotypic heterogeneity of disease presentation among family members.

[Rehabilitative treatment of severe sensory disorders. Description of 2 cases]

The aim of the work has been to verify the efficacy of a psychomotor rehabilitative treatment undertaken at a late age in two children with multiple handicaps: sensorial (visual and hearing impairment), motor (apostural-akinetic stage) and relational (autistic behavior).

METHODS

Salvatore C, and Ivan S., admitted to the "G. Gaslini" Institute after discharge from an Institution for homeless infants, were affected by prenatal rubella sequelae. They were taken in charge at age 11 and 24 months.

TREATMENT

manipulation and body-to-body interaction to reassure the children, relieve their feelings of fright and reduce the stereotyped behaviour; stimulation of the acquisition of the body-image; strengthening of the unimpaired sensorial skills and of the residual auditory and visual possibilities; postural and motor stimulation, following the autogenetic development; stimulation to achieve spatial organization and orientation; adjusting of interventional and relation modalities common to all the persons interacting with the children.

RESULTS

we obtained a significant reduction of stereotyped behaviour and progressive improvement of the active research of productive interaction with the environment in both children; Salvatore C. was able to walk with little aid after one year of treatment; furthermore he reached a lively and organized motility, supported by a motivational drive. Ivan S. was able to walk with bilateral help after 4 months of treatment; the cognitive development improved at a slower pace; the child became able to reach for objects but used them only in stereotyped or elementary activities. From this observation it seems possible to confirm our hypothesis that psychomotor education is useful even if undertaken lately and in the absence of a supporting family.(ABSTRACT TRUNCATED AT 250 WORDS)

[Scoliosis and lateral gaze paralysis. Description of a case and review of the literature]

The paper reports the case of a girl affected by progressive scoliosis and paralysis of the horizontal gaze, and reviews previously published cases. This is a rare and little known neurological entity transmitted by recessive autosomal inheritance. To all effects, this appears to be the first report of an Italian case. A correct early diagnosis is of considerable importance in view of appropriate genetic counselling.

[Role of somatostatin and parenteral nutrition in the treatment of acute pancreatitis. Personal experience]

The aim of the study was to evaluate and control the therapeutic validity of Somatostatin administration and the clinical benefits of parenteral nutrition during acute pancreatitis. We selected 31 patients with 1st and 2nd degree pancreatitis according to Ranson's classification. Diagnosis was based on clinical and humoral data and confirmed by echography and CT examinations. The most common etiological cause was biliary++ lithiasis (74.2%). All the patients in the study were split into two groups and received conventional treatment. The therapeutic schedule administered to group 1 included somatostatin (250 micrograms/h for 72-96 h), while group 2 received total parenteral nutrition with 2,000-2,500 Kal/day trough a central vein. The data obtained from our study demonstrated that both somatostatin and parenteral nutrition are valid tools during the acute phase of the disease. It must be pointed out that the former significantly influences the clinical course and allows a precise control of the painful symptomatology, the objective picture and the curve of the main hematochemical parameters. Parenteral nutrition betters the anabolic response of the organism during the acute phase and carries out an indirect antienzymatic response, so favouring a quicker recovery than observed in the group treated with somatostatin.

[Toxic adenoma of the thyroid gland: personal experience]

The Authors analyzed the thyroid diseases series of the Institute of 1a Clinica Chirurgica of the University of Catania which includes 1022 patients over the last 17 years, reviewing clinical and laboratory tests usually used in a register of diagnosis for autonomous adenomas of the thyroid. The Authors discuss pathogenesis, likely etiology and epidemiology of Plummer's adenoma, taking into consideration the therapy and the complications related to the therapy itself. They conclude stating that the adenoma is a pathology where the surgical operation solves the dismetabolic condition in a lasting way.