UV/Vis visible optical waveguides fabricated using organic-inorganic nanocomposite layers

Nanocomposite layers based on silica nanoparticles and a methacrylate matrix are synthesized by a solvent-free process and characterized in order to realize UV/Vis transparent optical waveguides. Chemical functionalization of the silica nanoparticles permits to interface the polymers and the silica. The refractive index, roughness and wettability and the machinability of the layers can be tuned changing the silica nanoparticle concentration and chemical modification of the surface of the nanoparticles. The optical transparency of the layers is affected by the nanoparticles organization between the organic chains, while it increased proportionally with respect to silica concentration. Nanocomposite layers with a concentration of 40 wt% in silica reached UV transparency for a wavelength of 250 nm. UV/Vis transparent waveguides were micromilled through nanocomposite layers and characterized. Propagation losses were measured to be around 1 dB cm(-1) at a wavelength of 350 nm.     

A software laboratory for visual inspection and recognition

We present the design criteria and the basic structure of GYPSY, a software laboratory for visual inspection and recognition in industrial automation tasks.GYPSY analyzes images of objects on the basis of their two-dimensional shape. It is fully portable and easily programmable. The user can write application programs in a Pascal-like language to give the system the ability to take over various tasks.GYPSY has been developed for a multi-microprocessor architecture designed in Italy especially for industrial automation.     

Degradation of sulphur containing s-triazines during water chlorination

The reactions of four sulphur containing s-triazines (prometryne, terbutryne, ametryne and desmetryne) with hypochlorous acid (HClO) and chlorine dioxide (ClO₂) have been investigated using an 11 ppm/3 ppm oxidant/herbicide ratio. The main objective of the study was the identification of by-products. Additionally, to study the effect of oxidant concentration on the reaction rate, two more oxidant/herbicide ratios (3 ppm/3 ppb and 11 ppb/3 ppb) have been investigated only for prometryne. Oxidation reactions were monitored by high performance liquid chromatography (HPLC), while, the identification of by-products was initially carried out by low resolution HPLC-mass spectrometry (HPLC-MS) and confirmed by accurate mass measurement. Under the experimental conditions (T = 20°C, pH = 8, reaction TIME = 48 h), the results indicate that all the investigated triazines react in the same way with each oxidant. The reactions with HClO occur much faster than those with ClO₂ and give rise to three identified oxidation by-products: the sulfoxide, the sulfone and the sulfone's hydrolysis product. The reactions with ClO₂, instead, give rise to a sole oxidation by-product: the sulfoxide. With both oxidants, as expected, the lower the oxidant concentration the slower the oxidation rate.

Based on the obtained results, a general pathway for the oxidation of sulphur containing s-triazines is proposed.     

One-dimensional modelling of ‘verso’ laser cleaning

In this paper we present a one-dimensional model describing the verso laser cleaning technique, already experimentally tested, for particle removal from a substrate. The equation for displacement is treated for a one-dimensional case, and the temporal behaviour of the rear surface deformation is determined. Taking into account the van der Waals adhesion force and elastic deformation of a spherical particle (JKR model), the ejection condition has been obtained. Numerical values for an example are consistent with experimental observation.     

Photodegradation of Anthracene and Benzo[a]anthracene in Polar and Apolar Media: New Pathways of Photodegradation

The photochemical reactions of anthracene and benzo[a]anthracene polycyclic aromatic hydrocarbons (PAHs) in polar and apolar solvents (cyclohexane and water/acetonitrile) were studied using spectroscopic and chromatographic techniques. These homogenous photolysis experiments are used as simplified models to compare PAHs photochemistry in water and oil (or oil films). Moreover, these processes were to some extent used as model in literature in order to study those occurring on particulate matter and aerosol surfaces. In both media, new photochemical reaction products were found. Generally, the reaction rate in the polar medium is faster than that in the apolar medium, and the photodegradation quantum yields increase with increasing polarity of the medium. HPLC-absorption/emission analysis confirmed the literature reports that mainly oxygenated photoproducts, such as PAH-hydroxides, were formed. The novelty of this article is that GC-MS data revealed the presence of new photoproducts that have not yet been described. This simplified model system allowed us to characterize the product distribution, thus simplifying the interpretation of the photodegradation mechanism. The identification of new photofragmentation paths, originating by irradiation of primary PAH photoproducts, may suggest an innovative way of remediation triggered by light.     

Vascular Damage in Patients with Nonalcoholic Fatty Liver Disease: Possible Role of Iron and Ferritin

Non Alcoholic Fatty Liver Disease (NAFLD) is the most common chronic liver disease in Western countries. Recent data indicated that NAFLD is a risk factor by itself contributing to the development of cardiovascular disease independently of classical known risk factors. Hyperferritinemia and mild increased iron stores are frequently observed in patients with NAFLD and several mechanisms have been proposed to explain the role of iron, through oxidative stress and interaction with insulin metabolism, in the development of vascular damage. Moreover, iron depletion has been shown to decrease atherogenesis in experimental models and in humans. This review presents the recent evidence on epidemiology, pathogenesis, and the possible explanation of the role of iron and ferritin in the development of cardiovascular damage in patients with NAFLD, and discusses the possible interplay between metabolic disorders associated with NAFLD and iron in the development of cardiovascular disease.     

Galloflavin (CAS 568-80-9): a novel inhibitor of lactate dehydrogenase

One of the most prominent alterations in cancer cells is their strict dependence on the glycolytic pathway for ATP generation. This observation led to the evaluation of glycolysis inhibitors as potential anticancer agents. The inhibition of lactate dehydrogenase (LDH) is a promising way to inhibit tumor cell glucose metabolism without affecting the energetic balance of normal tissues. However, the success of this approach depends chiefly on the availability of inhibitors that display good selectivity. We identified a compound (galloflavin, CAS 568‐80‐9) which, in contrast to other inhibitors of human LDH, hinders both the A and B isoforms of the enzyme. To determine the mechanism of action, we collected LDH‐A and ‐B inhibition data in competition reactions with pyruvate or NADH and evaluated the results using software for enzyme kinetics analysis. We found that galloflavin inhibits both human LDH isoforms by preferentially binding the free enzyme, without competing with the substrate or cofactor. The calculated K_i values for pyruvate were 5.46 μM (LDH‐A) and 15.06 μM (LDH‐B). In cultured tumor cells, galloflavin blocked aerobic glycolysis at micromolar concentrations, did not interfere with cell respiration, and induced cell death by triggering apoptosis. To our knowledge, the inhibition of LDH is, to date, the only biochemical effect described for galloflavin. Because galloflavin is not commercially available, we also describe herein a procedure for its synthesis and report its first full chemical characterization.     

Survival of Lactobacillus rhamnosus strains inoculated in cheese matrix during simulated human digestion

Survival of probiotic bacteria during transit through the gastrointestinal (GI) tract is influenced by a number of environmental variables including stomach acidity, bile salts, digestive enzymes and food matrix. This study assessed survival of seven selected Lactobacillus rhamnosus strains delivered within a model cheese system to the human upper GI tract using a dynamic gastric model (DGM). Good survival rates for all tested strains were recorded during both simulated gastric and duodenal digestion. Strains H12, H25 and N24 demonstrated higher survival capacities during gastric digestion than L. rhamnosus GG strain used as control, with H12 and N24 continuing to grow during duodenal digestion. Strains L. rhamnosus F17, N24 and R61 showed adhesion properties to both HT-29 and Caco-2 cells. The ability to attach to the cheese matrix during digestion was confirmed by scanning electron microscopy, also indicating production of extracellular polysaccharides as a response to acid stress.     

Effect of micro-oxygenation on sensory characteristics and consumer preference of Cabernet Sauvignon wine

BACKGROUND: The main objective of this study was to improve the structure of a Cabernet Sauvignon red wine in a short period of time by micro‐oxygenation (MOX) at high rates (25 and 50 mL L^?1 month^?1), the effects of which were evaluated based on sensory characteristics and consumer preference. Sensory data were analysed by principal component analysis, discriminant analysis and ordinal logistic regression (OLR). RESULTS: MOX led to significant differences in the colour, colour stability and phenolic compounds of wine. Sensory characteristics also changed through MOX treatment, and wine experts were able to discriminate between MOX‐treated and untreated samples, with olfactory intensity, complexity, astringency and roundness being the main discriminating characteristics. Ordinal logistic regression enabled identification of the sensory characteristics that drove consumer preference. CONCLUSION: MOX at high rates improved the sensory characteristics of wine and may therefore be considered a valid technique for obtaining structured wines in a short period of time, i.e. within just a few months after the vintage. The results highlight the need for (i) careful selection of the MOX dosage rate and duration (the 25 mL L^?1 month^?1 dose for 6 days provided the best result) and (ii) continuous monitoring of the MOX treatment. Copyright © 2011 Society of Chemical Industry