209 research outputs found

    Aprotic sulfur-metal batteries: lithium and beyond

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    Metal-sulfur batteries constitute an extraordinary research playground that ranges from fundamental science to applied technologies. However, besides the widely explored Li-S system, a remarkable lack of understanding hinders advancements and performance in all other metal-sulfur systems. In fact, similarities and differences make all generalizations highly inconsistent, thus unavoidably suggesting the need for extensive research explorations for each formulation. Here we review critically the most remarkable open challenges that still hinder the full development of metal-S battery formulations, starting from the lithium benchmark and addressing Na, K, Mg, and Ca metal systems. Our aim is to draw an updated picture of the recent efforts in the field and to shed light on the most promising innovation paths that can pave the way to breakthroughs in the fundamental comprehension of these systems or in battery performance

    The functional milk

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    Introduction - In addition to providing all the essential nutrients for the neonate, milk is also a vector of a wide range of immune effector molecules. It has been recently observed that milk IgA can be successfully used for prophylactic or therapeutic treatment against infections by Candida albicans and Helicobacter pylori, which represent serious risk for the health of the digestive system. IgA is the major immunoglobulin present in human milk, but it is 4-5 times less abundant in bovine milk. Since bovine milk is the most consumed milk worldwide, the detection of factors affecting the level of IgA in bovine milk offers great potential to add value to the dairy products. Aim - The present study aimed at evaluating the effect of day in milk and parity on IgA level in colostrum and milk of dairy cows. Materials and methods - Seven primiparous and 7 multiparous healthy Fresian cows were studied for 3 months after calving. All the cows were fed the same experimental diet, over the study period. On day 0, 1, 3, 7, 30, 60 and 90 of lactation, milk yield was recorded, colostrum and milk samples were taken. Colostrum and milk samples were obtained mixing morning and evening milkings and then tested for protein, fat, lactose, casein and urea content, somatic cell count and total bacterial count (TBC). Skimmed colostrum and milk were tested for IgA by ELISA. Data were evaluated by ANOVA. Results - Maximum milk production was observed on day 30 for multiparous cows (43.3 L/d) and on day 60 for the primiparous ones (40.5 L/d). In both groups, the highest levels of IgA were found at calving. The day after, colostrum IgA concentration dramatically decreased, remaining at low levels for the rest of the study period. On calving, IgA level was higher in the colostrum from multiparous than primiparous cows (782 vs. 640 \ub5g/ml; P<0.01). On day 0, 60 and 90, TBC was higher in milk from multiparous than primiparous cows (P=0.06). Between 7 and 90 days of lactation, TBC was negatively correlated whether with milk IgA levels (r = -0.506, P<0.01; r = -0.396, P<0.05 for multiparous and primiparous cows, respectively) and with milk IgA daily yield (r = -0.504, P<0.01; r = -0.501, P<0.01). Conclusions - This research gives a description of the pattern of IgA in colustrum and milk of dairy cows, during the first months of lactation, providing valuable information to maximize the positive effects of milk consumption on consumer health

    Possibility of spontaneous parity violation in hot QCD

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    We suggest that for QCD in the limit of a large number of colors, N, the axial U(1) symmetry of massless quarks is effectively restored at the deconfining=chiral phase transition. If the deconfining transition is of second order, then the chiral transition is weakly first order. In this case, metastable states in which parity is spontaneously broken appear at temperatures below the phase transition. The production of these metastable states would have dramatic signatures, including enhanced production of eta and eta' mesons, which can decay through parity violating decay processes such as eta -> pi^0 pi^0, and global parity odd asymmetries for charged pions. Using a nonlinear sigma model, in QCD these metastable states only appear rather near the phase transition.Comment: 4 pages, REVTe

    Reggeon exchange from gauge/gravity duality

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    We perform the analysis of quark-antiquark Reggeon exchange in meson-meson scattering, in the framework of the gauge/gravity correspondence in a confining background. On the gauge theory side, Reggeon exchange is described as quark-antiquark exchange in the t channel between fast projectiles. The corresponding amplitude is represented in terms of Wilson loops running along the trajectories of the constituent quarks and antiquarks. The paths of the exchanged fermions are integrated over, while the "spectator" fermions are dealt with in an eikonal approximation. On the gravity side, we follow a previously proposed approach, and we evaluate the Wilson-loop expectation value by making use of gauge/gravity duality for a generic confining gauge theory. The amplitude is obtained in a saddle-point approximation through the determination near the confining horizon of a Euclidean "minimal surface with floating boundaries", i.e., by fixing the trajectories of the exchanged quark and antiquark by means of a minimisation procedure, which involves both area and length terms. After discussing, as a warm-up exercise, a simpler problem on a plane involving a soap film with floating boundaries, we solve the variational problem relevant to Reggeon exchange, in which the basic geometry is that of a helicoid. A compact expression for the Reggeon-exchange amplitude, including the effects of a small fermion mass, is then obtained through analytic continuation from Euclidean to Minkowski space-time. We find in particular a linear Regge trajectory, corresponding to a Regge-pole singularity supplemented by a logarithmic cut induced by the non-zero quark mass. The analytic continuation leads also to companion contributions, corresponding to the convolution of the same Reggeon-exchange amplitude with multiple elastic rescattering interactions between the colliding mesons.Comment: 60+1 pages, 14 figure

    Wild horse populations in south-east Australia have a high prevalence of Strongylus vulgaris and may act as a reservoir of infection for domestic horses

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    © 2019 The Authors Australia has over 400,000 wild horses, the largest wild equid population in the world, scattered across a range of different habitats. We hypothesised that wild horse populations unexposed to anthelmintics would have a high prevalence of Strongylus vulgaris infections. Verminous endarteritis and colic due to migrating S. vulgaris larvae is now absent or unreported in domestic horses in Australia, yet wild horses may pose a risk for its re-emergence. A total of 289 faecal egg counts (FECs) were performed across six remote wild horse populations in south-east Australia, of varying densities, herd sizes and habitats. Total strongyle egg counts ranged from 50 to 3740 eggs per gram (EPG, mean 1443) and 89% (257/289) of faecal samples had > 500 EPG, classifying them as ‘high level shedders’. There were significant differences in mean total strongyle FECs between different locations, habitats and population densities. Occurrence of S. vulgaris was not predictable based on FECs of total strongyle eggs or small (<90 ÎŒm) strongyle eggs. A high prevalence of S. vulgaris DNA in faecal samples was demonstrated across all six populations, with an overall predicted prevalence of 96.7%. This finding is important, because of the ample opportunity for transmission to domestic horses. The high prevalence of S. vulgaris suggests vigilance is required when adopting wild horses, or when domestic horses graze in environments inhabited by wild horses. Appropriate veterinary advise is required to minimize disease risk due to S. vulgaris. Monitoring horses for S. vulgaris using larval culture or qPCR remains prudent. Gastrointestinal parasites in wild horse populations may also serve as parasite refugia, thus contributing to integrated parasite management when facing emerging anthelmintic resistance

    Preliminary study on MC1R polymorphism in some cattle breeds raised in Italy

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    Ricerche preliminari sul polimorfismo del gene MC1R in alcune razze bovine allevate in Italia – Il gene MC1R Ăš stato analizzato in 193 soggetti appartenenti a 8 razze bovine, tramite PCR, per la presenza di due mutazioni ad effetto fenotipico noto sulla pigmentazione del mantello: la delezione G310 e la sostituzione T296C, associate rispettivamente al fenotipo feomelanico (e) ed eumelanico nero (Ed). Sessanta soggetti di razza Limousine e Pezzata Rossa Italiana presentano genotipo e/e; 27 soggetti di razza Frisona Italiana mostrano genotipo Ed/Ed mentre 2 genotipo Ed/e. Gli 84 soggetti appartenenti alle razze Cabannina, Chianina, Marchigiana e Piemontese non presentano tali mutazioni, analogamente a 18 soggetti di razza Romagnola, nella quale perĂČ si sono anche osservati 2 soggetti portatori dell’allele e allo stato eterozigote

    Linking the Quark Meson Model with QCD at High Temperature

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    We model the transition of a system of quarks and gluons at high energies to a system of quarks and mesons at low energies in a consistent renormalization group approach. Flow equations interpolate between the physics of the high-temperature degrees of freedom and the low-temperature dynamics at a scale of 1 GeV. We also discuss the dependence of the equation of state on baryon density and compare our results with recent lattice gauge simulations.Comment: 11 pages, 4 figures additional discussion of the second order phase transitio

    4,4â€Č-(Anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(1-methyl-1-pyridinium) Lead Iodide C30H22N2Pb2I6: A Highly Luminescent, Chemically and Thermally Stable One-Dimensional Hybrid Iodoplumbate

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    A new one-dimensional hybrid iodoplumbate, namely, 4,4â€Č-(anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(1-methyl-1- pyridinium) lead iodide C30H22N2Pb2I6 (AEPyPbI), is reported here for the first time with its complete characterization. The material exhibits remarkable thermal stability (up to 300 °C), and it is unreactive under ambient conditions toward water and atmospheric oxygen, due to the quaternary nature of the nitrogen atoms present in the organic cation. The cation exhibits strong visible fluorescence under ultraviolet (UV) irradiation, and when its iodide is combined with PbI2, it forms AEPyPb2I6, an efficient light-emitting material, with a photoluminescence emission intensity comparable to that of high-quality InP epilayers. The structure determination was obtained using three-dimensional electron diffraction, and the material was extensively studied by using a wide range of techniques, such as X-ray powder diffraction, diffuse reflectance UV−visible spectroscopy, thermogravimetry-differential thermal analysis, elemental analysis, Raman and infrared spectroscopies, and photoluminescence spectroscopy. The emissive properties of the material were correlated with its electronic structure by using state-of-the-art theoretical calculations. The complex, highly conjugated electronic structure of the cation interacts strongly with that of the Pb−I network, giving rise to the peculiar optoelectronic properties of AEPyPb2I6. The material, considering its relatively easy synthesis and stability, shows promise for lightemitting and photovoltaic devices. The use of highly conjugated quaternary ammonium cations may be useful for the development of new hybrid iodoplumbates and perovskites with optoelectronic properties tailored for specific applications

    Exact solution (by algebraic methods) of the lattice Schwinger model in the strong-coupling regime

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    Using the monomer--dimer representation of the lattice Schwinger model, with Nf=1N_f =1 Wilson fermions in the strong--coupling regime (ÎČ=0\beta=0), we evaluate its partition function, ZZ, exactly on finite lattices. By studying the zeroes of Z(k)Z(k) in the complex plane (Re(k),Im(k))(Re(k),Im(k)) for a large number of small lattices, we find the zeroes closest to the real axis for infinite stripes in temporal direction and spatial extent S=2S=2 and 3. We find evidence for the existence of a critical value for the hopping parameter in the thermodynamic limit S→∞S\rightarrow \infty on the real axis at about kc≃0.39k_c \simeq 0.39. By looking at the behaviour of quantities, such as the chiral condensate, the chiral susceptibility and the third derivative of ZZ with respect to 1/2k1/2k, close to the critical point kck_c, we find some indications for a continuous phase transition.Comment: 22 pages (6 figures

    Topological and confining properties of Abelian-projected SU(3)-QCD

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    In this talk, we discuss several topics related to the Abelian-projected SU(3)-QCD. First of them is the Aharonov-Bohm effect emerging during the extension of this theory by the introduction of the Θ\Theta-term. Another topic is devoted to various consequences of screening of the dual vector bosons by electric vortex loops. In particular, it is demonstrated that this effect modifies significantly the interaction of quarks. Next, the influence of screening to electric and magnetic field correlators in the four-dimensional Abelian-projected SU(3)-QCD is studied. Finally, the bilocal correlator of electric field strengths in the three-dimensional gas of SU(3) Abelian-projected monopoles is discussed.Comment: 6 pages, LaTeX2e, no figures, presented at High Energy Physics International Euroconference on Quantum Chromo Dynamics - QCD '00, Montpellier, France, 6-13 Jul 2000, minor corrections, subm. to Nucl. Phys. B (Proc. Suppl.
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