101 research outputs found

    A Measurement of the Proton Structure Function F ⁣2(x,Q2)F_{\!2}(x,Q^2)

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    A measurement of the proton structure function F ⁣2(x,Q2)F_{\!2}(x,Q^2) is reported for momentum transfer squared Q2Q^2 between 4.5 GeV2GeV^2 and 1600 GeV2GeV^2 and for Bjorken xx between 1.81041.8\cdot10^{-4} and 0.13 using data collected by the HERA experiment H1 in 1993. It is observed that F ⁣2F_{\!2} increases significantly with decreasing xx, confirming our previous measurement made with one tenth of the data available in this analysis. The Q2Q^2 dependence is approximately logarithmic over the full kinematic range covered. The subsample of deep inelastic events with a large pseudo-rapidity gap in the hadronic energy flow close to the proton remnant is used to measure the "diffractive" contribution to F ⁣2F_{\!2}.Comment: 32 pages, ps, appended as compressed, uuencoded fil

    Oxygen reduction reaction features in neutral media on glassy carbon electrode functionalized by chemically prepared gold nanoparticles

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    Gold nanoparticles (AuNPs) were prepared by chemical route using 4 different protocols by varying reducer, stabilizing agent and solvent mixture. The obtained AuNPs were characterized by transmission electronic microscopy (TEM), UV-Visible and zeta potential measurements. From these latter surface charge densities were calculated to evidence the effect of the solvent mixture on AuNPs stability. The AuNPs were then deposited onto glassy carbon (GC) electrodes by drop-casting and the resulting deposits were characterized by cyclic voltammetry (CV) in H2SO4 and field emission gun scanning electron microscopy (FEG-SEM). The electrochemical kinetic parameters of the 4 different modified electrodes towards oxygen reduction reaction (ORR) in neutral NaCl-NaHCO3 media (0.15 M / 0.028 M, pH 7.4) were evaluated by rotating disk electrode voltammetry and subsequent Koutecky-Levich treatment. Contrary to what we previously obtained with electrodeposited AuNPs [Gotti et al., Electrochim. Acta 2014], the highest cathodic transfer coefficients were not obtained on the smallest particles, highlighting the influence of the stabilizing ligand together with the deposits morphology on the ORR kinetics

    Left ventricular non compaction: A poorly known cardiomyopathy.

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    editorial reviewedLeft ventricular non compaction is a rare congenital cardiomyopathy. It is characterised by a thin compacted epicardial layer, prominent trabeculations and deep recesses that communicate with the left ventricular cavity. This condition may lead to chronic heart failure, life threatening ventricular arrhythmias and systemic embolic events

    Prenatal and Early Postnatal Intoxication by Inorganic Mercury Resulting from the Maternal Use of Mercury Containing Soap

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    A case of slight renal tubular dysfunction associated with cataract and anaemia was diagnosed in a 3-month-old black boy in whom high levels of mercury were found in blood and urine. Several arguments suggest that the renal, ocular and haematological defects may have resulted from exposure to mercury during foetal life and the 1-month lactation period due to the extensive use of inorganic mercury containing cosmetics by the mother
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