Effect of early and current Helicobacter pylori infection on the risk of anaemia in 6.5-year-old Ethiopian children

Background: Epidemiological and clinical studies in high income countries have suggested that Helicobacter pylori (H. pylori) may cause anaemia, but evidence is lacking from low income countries.We examined associations between H. pylori infection in early childhood and anaemia at the age of 6.5 years in an Ethiopian birth cohort. Methods: In 2011/12, 856 children (85.1 % of the 1006 original singletons in a population-based birth cohort) were followed up at age six and half. An interviewer-led questionnaire administered to mothers provided information on demographic and lifestyle variables. Haemoglobin level and red cell indices were examined using an automated haematological analyzer (Cell Dyn 1800, Abbott, USA), and stool samples analyzed for H. pylori antigen. The independent effects of H. pylori infection (measured at age 3.5 and 6.5 years) on anaemia, haemoglobin level, and red cell indices (measured at age 6.5 years) were determined using multiple logistic and linear regression. Results: The prevalence of anemia was 34.8 % (257/739), and the mean (SD) haemoglobin concentration was 11.8 (1.1) gm/dl. Current H. pylori infection at age 6.5 years was positively, though not significantly related to prevalence of anaemia (adjusted OR, 95 % CI, 1.15; 0.69, 1.93, p = 0.59). Any H. pylori infection up to age 6.5 years was significantly associated with an increased risk of anaemia at age 6.5 (adjusted OR, 95 % CI, 1.68; 1.22, 2.32, p = 0.01). A significant reduction in haemoglobin concentration and red cell indices was also observed among children who had any H. pylori infection up to age 6.5 (Hb adjusted β = −0.19, 95 % CI, −0.35 to −0.03, p = 0.01; MCV adjusted β = −2.22, 95 % CI, −3.43 to −1.01, p = 0.01; MCH adjusted β = −0.63, 95 % CI, −1.15 to - 0.12, p = 0.01; and MCHC adjusted β = −0.67, 95 % CI, −1.21 to −0.14, p = 0.01), respectively. Conclusion: This study provides further evidence from a low income country that any H. pylori infection up to age 6.5 is associated with higher prevalence of anaemia, and reduction of haemoglobin level and red cell indices at age 6.5

Selective oxidation of Fe-Si binary alloy

International audienceThe present study will focus on the formation of the oxide particles formed during continuous annealing. Seven binaryFe-Si alloys (with a Si content from 0.03 to 0.5 wt.%) were chosen for the study. The samples were annealed by means ofa laboratory furnace with a temperature profile relevant to galvanizing line practice. The selective oxide particles werethen characterized using several analysis techniques (field emission gun scanning electron microscope, transmissionelectron microscope and electron diffraction, optical surface profiler). Image analysis was used to obtain the geometricparameters that characterize oxide particles in two dimensions (e.g., oxides’ surface density, Féret diameter).Si diffuses towards the surface where it forms SiO2 oxide particles. The Féret diameter of the oxide particles is similar forall the alloys. The oxide surface density increases when the Si content in the binary alloy increases, leading to an increasein the surface area fraction covered by the oxides

Understanding of selective oxidation of Fe-Mn binary alloys during continuous annealing through X-ray photoelectron spectroscopy

Selective oxidation of Fe-Mn alloys was characterizied through X-ray photoelectron spectroscopy and scanning/transmission electron microscopy during industrial continuous annealing (in an atmosphere of N2–5 vol.% H2 with traces of water at 800 °C). After annealing, only MnO oxides are formed on and below the surface and few iron oxides appear on the top surface due to oxidation of ambient air or the formation of FeO-MnO solid solutions. Mn concentration profiles exhibit typical selective oxidation and show similar features. Mn concentration first increases to a peak value at a depth of 5–10 nm from surface, and then decreases to the minimum at the oxidation front, following with a floating up and down to bulk composition. According to XPS spectra and Mn concentration profiles as a function of depth, the annealed alloy surfaces can be divided into four zones: ambient air contaminated zone, MnO enrichment zone (external and internal oxidation coexisting here), Mn depletion zone and bulk composition zone. Mn concentration reaches a minimum value at the oxidation front, whose position is deeper with annealing temperature and time increasing. The value of Mn diffusion coefficient in ferrite estimated using diffusion flux at the oxidation front is 2.9 × 10−15 m2 s−1 at 800 °C, which is slightly greater than that in literature

Analytical model of selective external oxidation of Fe-Mn binary alloys during isothermal annealing treatment

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Morphogenesis mechanisms in the solvothermal synthesis of BaTiO3 from titanate nanorods and nanotubes

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Catalytic activity of carbon supported Pt nano(electrocatalysts. Why reducing the size of Pt nanoparticles is not always beneficial

International audienceCarbon-supported Pt catalysts prepared by the impregnation method in water - dimethyl sulfoxide (DMSO) solutions were investigated. Using X-ray diffraction (XRD) technique for estimation of the particle size and shapes, we show that morphology of the Pt/C catalysts depends strongly on the DMSO content in the solutions. The average particles size reduces and a shape of the Pt nanocrystals changes from a truncated octahedron to a cuboctahedron, and eventually to a truncated cube with increasing DMSO concentration in the reaction mixture. Antibate effects of the size and shape cause non-monotonic dependence of the catalytic activity for the oxygen reduction reaction (ORR) with electric current maximum at an average particle size of 2.7nm