6,171 research outputs found

    Polyelectrolyte Multilayering on a Charged Planar Surface

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    The adsorption of highly \textit{oppositely} charged flexible polyelectrolytes (PEs) on a charged planar substrate is investigated by means of Monte Carlo (MC) simulations. We study in detail the equilibrium structure of the first few PE layers. The influence of the chain length and of a (extra) non-electrostatic short range attraction between the polycations and the negatively charged substrate is considered. We show that the stability as well as the microstructure of the PE layers are especially sensitive to the strength of this latter interaction. Qualitative agreement is reached with some recent experiments.Comment: 28 pages; 11 (main) Figs - Revtex4 - Higher resolution Figs can be obtained upon request. To appear in Macromolecule

    Feasibility of high-voltage systems for a very long drift in liquid argon TPCs

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    Designs of high-voltage (HV) systems for creating a drift electric field in liquid argon TPCs are reviewed. In ongoing experiments systems capable of approx. 100 kV are realised for a drift field of 0.5-1 kV/cm over a length of up to 1.5 m. Two of them having different approaches are presented: (1) the ICARUS-T600 detector having a system consisting of an external power supply, HV feedthroughs and resistive voltage degraders and (2) the ArDM-1t detector having a cryogenic Greinacher HV multiplier inside the liquid argon volume. For a giant scale liquid argon TPC, a system providing 2 MV may be required to attain a drift length of approx. 20 m. Feasibility of such a system is evaluated by extrapolating the existing designs.Comment: 8 pages, 13 figures, to appear in Proc. of 1st International Workshop towards the Giant Liquid Argon Charge Imaging Experiment (GLA2010), Tsukuba (Japan), March 201

    Chronic Contained Rupture of an Abdominal Aortic Aneurysm: From Diagnosis to Endovascular Resolution

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    A male patient, 69 years old, presented with fever, leucocytosis, and persistent low back pain; he also had an abdominal aortic aneurysm (AAA), as previously diagnosed by Doppler UltraSound (US), and was admitted to our hospital. On multislice computed tomography (msCT), a large abdominal mass having no definite border and involving the aorta and both of the psoas muscles was seen. This mass involved the forth-lumbar vertebra with lysis, thus simulating AAA rupture into a paraspinal collection; it was initially considered a paraspinal abscess. After magnetic resonance imaging examination and culture of the fluid aspirated from the mass, no infective organisms were found; therefore, a diagnosisof chronically contained AAA rupture was made, and an aortic endoprosthesis was subsequently implanted. The patient was discharged with decreased lumbar pain. At 12-month follow-up, no evidence of leakage was observed. To our knowledge, this is the first case of endoprosthesis implantation in a patient, who was a poor candidate for surgical intervention due to renal failure, leucocytosis and high fever, having a chronically contained AAA ruptured simulatingspodilodiscitis abscess. Appropriate diagnosis and therapy resolved potentially crippling pathology and avoided surgical graftrelated complications. Keywords Abdominal aortic aneurysm Endoprosthesis implantation Vertebral erosio

    VISUOMOTOR INTEGRATION SKILLS IN CHILDREN AFFECTED BY OBSTRUCTIVE SLEEP APNEA SYNDROME: A CASE-CONTROL STUDY

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    Introduction: Sleep related breathing disorders (SRBD) consist of frequent and repetitive episodes of pharyngeal obstruction during sleep, with consequent intermittent hypoxia, sleep architecture fragmentation, daytime sleepiness and/or behavioural problems and executive impairment in children. When untreated, SRBD and obstructive sleep apnea syndrome (OSA) mainly, may impact school performance, cognition, metabolism, and cardiovascular function. Aim of the present study is assessing the visuomotor integration skills in children affected by OSA. Materials and methods: 57 subjects affected by mild-to severe OSA, PSG diagnosed according to international diagnostic criteria, (31 males and 26 females) (mean age 10.8; SD \ub1 2.49) and 83 healthy children (45 males and 38 females) (mean age 9.95; SD \ub1 1.87; p = 0.725). All subjects underwent assessment of motor coordination skills with Movement-ABC tests and visual-motor integration ability with Visual Motor Integration (VMI) test. Results: The subjects with OSA show a worse average performances in all items of Movement ABC (p <0.001) respect of controls. Specifically, children with OSAS show significantly higher values of total points (p <0.001), manual dexterity (p <0.001), ball skills (p <0.001) and balance (p <0.001). Accordingly, the average centile in OSA children at the MABC-test is significantly reduced compared with controls (p <0.001). (Table 1) On the other hand, the VMI test evaluation among children with OSAS shows worst result in total Visuo-Motor Integration (p <0.001), and in Motor Coordination sub-item (p <0.001) than controls. (Table 1). Conclusion: Our results also support for children and adolescents the hypothesis that executive functioning deficits might be linked primarily to the degree of severity nocturnal hypoxemia rather than daytime sleepiness, although several other studies are needed

    Screening of Spherical Colloids beyond Mean Field -- A Local Density Functional Approach

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    We study the counterion distribution around a spherical macroion and its osmotic pressure in the framework of the recently developed Debye-H"uckel-Hole-Cavity (DHHC) theory. This is a local density functional approach which incorporates correlations into Poisson-Boltzmann theory by adding a free energy correction based on the One Component Plasma. We compare the predictions for ion distribution and osmotic pressure obtained by the full theory and by its zero temperature limit with Monte Carlo simulations. They agree excellently for weakly developed correlations and give the correct trend for stronger ones. In all investigated cases the DHHC theory and its computationally simpler zero temperature limit yield better results than the Poisson-Boltzmann theory.Comment: 10 pages, 4 figures, 2 tables, RevTeX4-styl

    Combination of freezing, low sodium brine, and cold smoking on the quality and shelf-life of sea bass (Dicentrarchus labrax l.) fillets as a strategy to innovate the market of aquaculture products

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    Aquaculture is playing a leading role in both meeting the growing demand for seafood and increasing the sustainability of the fish production sector. Thus, innovative technologies that improve its sustainability, competitiveness, and safety are necessary for growth in the sector. This study aimed to develop cold smoked sea bass fillets from aquaculture. The aptitude of frozen and fresh fillets for cold smoking was investigated by processing both fresh and thawed fillets kept previously at −20◦C for 15, 30, 60, and 90 days. Moreover, to develop a low-salt product, fillets were immersed in low-sodium or standard brine. Sensory, biochemical, and physical-chemical analyses were performed on both the raw fillets and the smoked fillets during vacuum packaged storage for 35 days at 1 ± 0.5◦C. Young modulus values, representative of texture and sensory evaluation, showed that the quality of fresh fillets was better compared to the thawed ones, thus affecting the quality of the final product as the correlation between parameters showed (principal component analysis). Cold smoking was effective in both maintaining the total volatile basic nitrogen (TVB-N) below the threshold for spoilage and preventing lipid peroxidation. Moreover, partial sodium replacement by potassium did not alter the sensory attributes of smoked fillets, which maintained high scores up to 21 days

    Nonlocal properties of entangled two-photon generalized binomial states in two separate cavities

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    We consider entangled two-photon generalized binomial states of the electromagnetic field in two separate cavities. The nonlocal properties of this entangled field state are analyzed by studying the electric field correlations between the two cavities. A Bell's inequality violation is obtained using an appropriate dichotomic cavity operator, that is in principle measurable.Comment: 5 pages, 1 figur
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