464 research outputs found

    Colloidal stability of tannins: astringency, wine tasting and beyond

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    Tannin-tannin and tannin-protein interactions in water-ethanol solvent mixtures are studied in the context of red wine tasting. While tannin self-aggregation is relevant for visual aspect of wine tasting (limpidity and related colloidal phenomena), tannin affinities for salivary proline-rich proteins is fundamental for a wide spectrum of organoleptic properties related to astringency. Tannin-tannin interactions are analyzed in water-ethanol wine-like solvents and the precipitation map is constructed for a typical grape tannin. The interaction between tannins and human salivary proline-rich proteins (PRP) are investigated in the framework of the shell model for micellization, known for describing tannin-induced aggregation of beta-casein. Tannin-assisted micellization and compaction of proteins observed by SAXS are described quantitatively and discussed in the case of astringency

    Electrophoretic co-deposition of Mn1.5Co1.5O4, Fe2O3 and CuO: Unravelling the effect of simultaneous addition of Cu and Fe on the microstructural, thermo-mechanical and corrosion properties of in-situ modified spinel coatings for solid oxide cell interconnects

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    A systematic microstructural, thermo-mechanical and electrical characterization of simultaneous Fe–Cu doped Mn–Co spinel coatings processed by electrophoretic co-deposition on Crofer 22 APU is here reported and discussed. An innovative approach for the simultaneous electrophoretic deposition of three spinel precursors is designed, conceived and optimised, with the aim of outlining time- and energy-saving spinel modification routes. The effect of different levels of Cu and Fe co-doping is observed on the stability of the modified Mn–Co spinel phase, the coefficient of thermal expansion (CTE), the corrosion resistance and on the densification behaviour of the obtained coatings. Cu determines an increase of CTE, while Fe has the opposite behavior. The synergic effect of the simultaneous Fe and Cu co-doping results in an improved densification and the stabilization of the MnCo2O4 cubic phase. The most interesting results in terms of corrosion resistance are obtained for the Mn1.28Co1.28Fe0.15Cu0.29O4 spinel

    Unarousable child with a short bowel

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    Unarousable child with short bowel: A 4-year-old boy was admitted with progressive lethargy of a few hours' duration and no other symptoms. His medical history was relevant for short bowel syndrome (SBS), following neonatal volvulus, with residual bowel length of 23 cm and intact ileocecal valve. He had similar self-limiting episodes in the past, after weaning parenteral nutrition, especially after eating large meals. The day before, he had consumed a large amount of apples. Arterial blood gas (ABG) analysis showed metabolic acidosis with normal lactacidaemia (pH 7.09, pCO2 19 mm Hg, pO2 101 mm Hg, HCO3 5.8 mmol/L, BE -24, anion gap 29.4, chloride 116 mmol/L, L-lactate level 4 mmol/L). On admission, the child could be awakened, but he was confused with slurred speech (Glasgow Coma Scale 14), with a body temperature of 37 C°, a heart rate of 125 beats/min and a respiratory rate of 38 breaths/min. The abdomen was distended, without guarding and with normal bowel sounds. Blood glucose levels were normal, as well as white blood cell count, liver and kidney function test and C reactive protein. An abdominal ultrasound ruled out an intussusception. An abdominal X-ray was performed too (seefigure 1). Figure 1 Abdominal distension with gas and bloating. Questions: Which is the most likely diagnosis? Encephalitis D-lactic acidosis Dehydration with third space fluid collection and acidosis Hereditary fructose intolerance. How is this diagnosis confirmed? D lactic dosage Breath test for bacterial overgrowth Urine organic acid dosage Search for reductive substances in the stools. How should this patient be managed? Intravenous fluids to facilitate D-lactic excretion Restrict carbohydrates in the diet Intravenous bicarbonates Antibiotic treatment to reduce bowel bacterial overgrowth. Answers can be found on page 2

    Recent advances on spinel-based protective coatings for solid oxide cell metallic interconnects produced by electrophoretic deposition

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    The application of ceramic protective coatings to the metallic interconnects in solid oxide cells (SOCs) is a viable and effective method to limit interconnect degradation issues. This featured letter provides a critical overview of the main outcomes of current research on the use of the electrophoretic deposition (EPD) technique to produce protective coatings for SOC metallic interconnects, specifically focusing on different approaches to stabilise spinel-based suspensions, as well as the possible sintering procedures. The protective properties of EPD coatings are reviewed and discussed in terms of oxidation kinetics and area specific resistance evaluation

    Optimization of electrophoretic deposition technique to control doping and densification of protective spinel coatings for SOC interconnects

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    Manganese cobaltite spinel coatings have been reported to limit oxidation and Cr-evaporation from ferritic stainless steel interconnects in solid oxide cell stacks; however, the implementation of the functional properties of the base Mn–Co spinel coating and compatibility with the substrate can be pursued through the optimisation of the coating composition, as well as the deposition method and sintering profile. Electrophoretic deposition (EPD) allows to deposit homogeneous layers in few seconds on complexly shaped steel components; it also offers the possibility to produce in-situ doped coatings, avoiding time and energy consuming multi-step processes. In this work, various EPD suspensions are optimised to achieve a single step co-deposition of CuO, Fe2O3 and Mn1,5Co1,5O4 on Crofer 22 APU. Different Fe-Cu doped Mn–Co spinel are successfully obtained by controlling the precursors amount in the EPD suspension and subsequent reactive sintering, as proved by detailed SEM and TEM analyses. Improved functional properties of produced coatings are evaluated in terms of oxidation kinetics and area specific resistance. Both the iron and copper amount in the coating and the sintering process significantly influence the coating densification, with benefits to the protective properties and thermomechanical compatibility with the interconnect

    Comparative Effects of Methylphenidate, Modafinil, and MDMA on Response Inhibition Neural Networks in Healthy Subjects

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    Psychostimulants such as methylphenidate and modafinil are increasingly used by healthy people for cognitive enhancement purposes, whereas the acute effect of 3,4-methylenedioxymethamphetamine (ecstasy) on cognitive functioning in healthy subjects remains unclear. This study directly compared the acute effects of methylphenidate, modafinil, and 3,4-methylenedioxymethamphetamine on the neural mechanisms underlying response inhibition in healthy subjects.; Using a double-blind, within-subject, placebo-controlled, cross-over design, methylphenidate, modafinil, and 3,4-methylenedioxymethamphetamine were administrated to 21 healthy subjects while performing a go/no-go event-related functional magnetic resonance imaging task to assess brain activation during motor response inhibition.; Relative to placebo, methylphenidate and modafinil but not 3,4-methylenedioxymethamphetamine improved inhibitory performance. Methylphenidate significantly increased activation in the right middle frontal gyrus, middle/superior temporal gyrus, inferior parietal lobule, presupplementary motor area, and anterior cingulate cortex compared with placebo. Methylphenidate also induced significantly higher activation in the anterior cingulate cortex and presupplementary motor area and relative to modafinil. Relative to placebo, modafinil significantly increased activation in the right middle frontal gyrus and superior/inferior parietal lobule, while 3,4-methylenedioxymethamphetamine significantly increased activation in the right middle/inferior frontal gyrus and superior parietal lobule.; Direct comparison of methylphenidate, modafinil, and 3,4-methylenedioxymethamphetamine revealed broad recruitment of fronto-parietal regions but specific effects of methylphenidate on middle/superior temporal gyrus, anterior cingulate cortex, and presupplementary motor area activation, suggesting dissociable modulations of response inhibition networks and potentially the superiority of methylphenidate in the enhancement of cognitive performance in healthy subjects

    Kohn-Luttinger instability of the t-t' Hubbard model in two dimensions: variational approach

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    An effective Hamiltonian for the Kohn-Luttinger superconductor is constructed and solved in the BCS approximation. The method is applied to the t-t' Hubbard model in two dimensions with the following results: (i) The superconducting phase diagram at half filling is shown to provide a weak-coupling analog of the recently proposed spin liquid state in the J_1-J_2 Heisenberg model. (ii) In the parameter region relevant for the cuprates we have found a nontrivial energy dependence of the gap function in the dominant d-wave pairing sector. The hot spot effect in the angular dependence of the superconducting gap is shown to be quite weak

    Pressure assisted flash sintering of Mn-Co based spinel coatings for solid oxide electrolysis cells (SOECs)

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    Pressure assisted flash sintering was used to process Mn-Co-Cu based spinel coatings, electrophoretically deposited on a Crofer22APU interconnect. This method resulted in highly dense coatings, heat-treated for only a short duration (200 °C/min). The high heating rate promoted Cu modified Mn-Co spinel and limited the formation of a Cr-oxide scale on the Crofer22APU substrate. Flash sintering was found to be a promising and time efficient sintering technique to overcome some of the issues related to low coating density and oxide scale formation in solid oxide electrolysis cell conditions

    Exercise Intensity Modulation of Hepatic Lipid Metabolism

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    Lipid metabolism in the liver is complex and involves the synthesis and secretion of very low density lipoproteins (VLDL), ketone bodies, and high rates of fatty acid oxidation, synthesis, and esterification. Exercise training induces several changes in lipid metabolism in the liver and affects VLDL secretion and fatty acid oxidation. These alterations are even more conspicuous in disease, as in obesity, and cancer cachexia. Our understanding of the mechanisms leading to metabolic adaptations in the liver as induced by exercise training has advanced considerably in the recent years, but much remains to be addressed. More recently, the adoption of high intensity exercise training has been put forward as a means of modulating hepatic metabolism. The purpose of the present paper is to summarise and discuss the merit of such new knowledge

    Magnetic and superconducting instabilities of the Hubbard model at the van Hove filling

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    We use a novel temperature-flow renormalization group technique to analyze magnetic and superconducting instabilities in the two-dimensional t-t' Hubbard model for particle densities close to the van Hove filling as a function of the next-nearest neighbor hopping t'. In the one-loop flow at the van Hove filling, the characteristic temperature for the flow to strong coupling is suppressed drastically around t'_c approx. -0.33t, suggesting a quantum critical point between d-wave pairing at moderate t'>t'_c and ferromagnetism for t'<t'_c. Upon increasing the particle density in the latter regime the leading instability occurs in the triplet pairing channel.Comment: 4 pages, to appear in Physical Review Letter
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