Insights on the Side Panels of the <Emphasis Type="Italic">Franciscan Triptych</Emphasis> by Fra Angelico Using Terahertz Time-Domain Imaging (THz-TDI)

The side panels of the Franciscan Triptych (St. Jerome, St. John the Baptist, and the Archangel Gabriel and St. Francis, St. Onofrio, and the Virgin Annunciate, by Fra Angelico, before 1429) were scanned by means of terahertz time-domain imaging (THz-TDI). THz analysis supplied information on the stratigraphy of the panel paintings and the associated construction, “gessoing” and gilding techniques. Furthermore, THz-TDI provided information regarding the location of restoration materials within the painting stratigraphy on St. Jerome, St. John the Baptist, and the Archangel Gabriel, as well as on the extension and nature of subsurface cracks in the panel painting of St. Francis, St. Onofrio, and the Virgin Annunciate.     

Extent of cleaning achievable by bioremediation of soil contaminated with petrochemical sludges

Bioremediation is capable of reducing the hydrocarbon concentration of contaminated soil by 75–95% depending on the soil type, the kind of hydrocarbons and the history of the contamination. The impact of different number of petrochemical sludge applications to soil on the degree of PAH elimination was assessed. A simple and reliable extraction and gas chromatographic method was used to facilitate more rapid determination of hydrocarbon contamination in soils and sludge wastes. Its application in a model laboratory bioremediation experiment and a pilot field study were used to illustrate its practical benefits. Post-remediation persistence of sludge constituents was evaluated after a single dose sludge application in the laboratory and after seven sludge applications in the field. A relative increase in the concentration of some PAHs was detected at the end of the experiments, but their individual concentrations were reduced to suggested values for industrial soils. The remaining concentration of total hydrocarbons in soil was found to be similar in both experiments, pointing to soil organic matter adsorption capacity as the factor determining hydrocarbon elimination limits in soil bioremediation. ©1997 SCI     

Lipid Cubic Mesophases Combined with Superparamagnetic Iron Oxide Nanoparticles: A Hybrid Multifunctional Platform with Tunable Magnetic Properties for Nanomedical Applications

Hybrid materials composed of superparamagnetic iron oxide nanoparticles (SPIONs) and lipid self-assemblies possess considerable applicative potential in the biomedical field, specifically, for drug/nutrient delivery. Recently, we showed that SPIONs-doped lipid cubic liquid crystals undergo a cubic-to-hexagonal phase transition under the action of temperature or of an alternating magnetic field (AMF). This transition triggers the release of drugs embedded in the lipid scaffold or in the water channels. In this contribution, we address this phenomenon in depth, to fully elucidate the structural details and optimize the design of hybrid multifunctional carriers for drug delivery. Combining small-angle X-ray scattering (SAXS) with a magnetic characterization, we find that, in bulk lipid cubic phases, the cubic-to-hexagonal transition determines the magnetic response of SPIONs. We then extend the investigation from bulk liquid-crystalline phases to colloidal dispersions, i.e., to lipid/SPIONs nanoparticles with cubic internal structure (“magnetocubosomes”). Through Synchrotron SAXS, we monitor the structural response of magnetocubosomes while exposed to an AMF: the magnetic energy, converted into heat by SPIONs, activates the cubic-to-hexagonal transition, and can thus be used as a remote stimulus to spike drug release “on-demand”. In addition, we show that the AMF-induced phase transition in magnetocubosomes steers the realignment of SPIONs into linear string assemblies and connect this effect with the change in their magnetic properties, observed at the bulk level. Finally, we assess the internalization ability and cytotoxicity of magnetocubosomes in vitro on HT29 adenocarcinoma cancer cells, in order to test the applicability of these smart carriers in drug delivery applications.     

Three-dimensional silicon inverse photonic quasicrystals for infrared wavelengths

Quasicrystals are a class of lattices characterized by a lack of translational symmetry. Nevertheless, the points of the lattice are deterministically arranged, obeying rotational symmetry. Thus, we expect properties that are different from both crystals and glasses. Indeed, naturally occurring electronic quasicrystals (for example, AlPdMn metal alloys) show peculiar electronic, vibrational and physico-chemical properties. Regarding artificial quasicrystals for electromagnetic waves, three-dimensional (3D) structures have recently been realized at GHz frequencies and 2D structures have been reported for the near-infrared region. Here, we report on the first fabrication and characterization of 3D quasicrystals for infrared frequencies. Using direct laser writing combined with a silicon inversion procedure, we achieve high-quality silicon inverse icosahedral structures. Both polymeric and silicon quasicrystals are characterized by means of electron microscopy and visible-light Laue diffraction. The diffraction patterns of structures with a local five-fold real-space symmetry axis reveal a ten-fold symmetry as required by theory for 3D structures.     

Disposable indicators for monitoring lighting conditions in museums

Photoinduced alterations of light-sensitive artifacts represent one of the main problems that conservators and curators have to face for environmental control in museums and galleries. Therefore, increasing attention has been recently devoted to developing strategies of indoor light monitoring, especially aimed at minimizing the cumulated light exposure for the objects on exhibit. In this work a prototype of a light dosimeter, constituted by a photosensitive dyes/polymer mixture applied on a paper substrate, is presented. This indicator, specially designed for a preventive assessment of the risk of damage for highly light-sensitive objects, undergoes a progressive color variation as its exposure to the light increases. Different, easily distinguishable color steps are exhibited depending on the light dose received, so that the dosimeter can be used straightforwardly to have a first, instrumentation-free estimation of the total light exposure. A reflectance spectroscopy study in the 350-860 nm range was carried out on prototype dosimeters exposed to light emitted from a tungsten-halogen lamp to investigate the response of the dosimeter to the light and to study the fading mechanism. Two different approaches were evaluated for the calibration of the prototype: colorimetry and principal component analysis of the reflectance spectra. The usefulness of the two methods in providing a quantitative indication of the light dose received was evaluated.     

Neuroprotective Effects of Cannabidiol but Not Δ9-Tetrahydrocannabinol in Rat Hippocampal Slices Exposed to Oxygen-Glucose Deprivation: Studies with Cannabis Extracts and Selected Cannabinoids

(1) Background: Over the past 10 years, a number of scientific studies have demonstrated the therapeutic potential of cannabinoid compounds present in the Cannabis Sativa and Indica plants. However, their role in mechanisms leading to neurodegeneration following cerebral ischemia is yet unclear. (2) Methods: We investigated the effects of Cannabis extracts (Bedrocan, FM2) or selected cannabinoids (Δ⁹-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabigerol) in rat organotypic hippocampal slices exposed to oxygen-glucose deprivation (OGD), an in vitro model of forebrain global ischemia. Cell death in the CA1 subregion of slices was quantified by propidium iodide fluorescence, and morphological analysis and tissue organization were examined by immunohistochemistry and confocal microscopy. (3) Results: Incubation with the Bedrocan extract or THC exacerbated, whereas incubation with the FM2 extract or cannabidiol attenuated CA1 injury induced by OGD. Δ⁹-THC toxicity was prevented by CB1 receptor antagonists, the neuroprotective effect of cannabidiol was blocked by TRPV2, 5-HT1A, and PPARγ antagonists. Confocal microscopy confirmed that CBD, but not THC, had a significant protective effect toward neuronal damage and tissue disorganization caused by OGD in organotypic hippocampal slices. (4) Conclusions: Our results suggest that cannabinoids play different roles in the mechanisms of post-ischemic neuronal death. In particular, appropriate concentrations of CBD or CBD/THC ratios may represent a valid therapeutic intervention in the treatment of post-ischemic neuronal death.     

Liver Steatosis: A Marker of Metabolic Risk in Children

Obesity is one of the greatest health challenges affecting children of all ages and ethnicities. Almost 19% of children and adolescents worldwide are overweight or obese, with an upward trend in the last decades. These reports imply an increased risk of fat accumulation in hepatic cells leading to a series of histological hepatic damages gathered under the acronym NAFLD (Non-Alcoholic Fatty Liver Disease). Due to the complex dynamics underlying this condition, it has been recently renamed as ‘Metabolic Dysfunction Associated Fatty Liver Disease (MAFLD)’, supporting the hypothesis that hepatic steatosis is a key component of the large group of clinical and laboratory abnormalities of Metabolic Syndrome (MetS). This review aims to share the latest scientific knowledge on MAFLD in children in an attempt to offer novel insights into the complex dynamics underlying this condition, focusing on the novel molecular aspects. Although there is still no treatment with a proven efficacy for this condition, starting from the molecular basis of the disease, MAFLD’s therapeutic landscape is rapidly expanding, and different medications seem to act as modifiers of liver steatosis, inflammation, and fibrosis.     

Piedmont olive oils: Compositional characterization and discrimination from oils from other regions

Piedmont olive oils collected in 2010 were characterized, for the first time, in terms of their fatty acid profile using GC and ¹H NMR and compared to other oils from five Italian regions. Applying NMR spectroscopy on the olive oil samples, without manipulation, it is possible to calculate the proportion of the different acyl groups in the oil samples. As the area of the signals is proportional to the number of each type of proton in the sample, saturated, monounsaturated (oleic acid) and polyunsaturated (linoleic and linolenic acids) fatty acids were determined. All analyzed samples can be categorized as virgin olive oil extra quality according to the oleic/linoleic ratio. Based on a preliminary geographical investigation, olive oils produced in the North of Italy show a good separation from those from Central and Southern regions. Practical applications : Oil characterization of new products is the basis for further nutritional and food technological investigations and the quality of edible oils is of great concern especially for products available on the market. The two adopted techniques show a remarkable agreement in the evaluation of fatty acid composition of oil samples. Also, this research, by means of ¹H NMR, provides information on geographical origin of the olive oils of Northern Italian regions with respect to Central and Southern regions.