Article paru dans la revue ANAE n° 160. Pour la citer

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Theory of Interplay of Nuclear Magnetism and Superconductivity in AuIn2

The recently reported coexistence of a magnetic order, with the critical temperature T_M=35 \mu*K, and superconductivity, with the critical temperature T_S=207 m*K, in AuIn_2 is studied theoretically. It is shown that superconducting (S) electrons and localized nuclear magnetic moments (LM's) interact dominantly via the contact hyperfine (EX) interaction, giving rise to a spiral (or domain-like) magnetic order in superconducting phase. The electromagnetic interaction between LM's and S electrons is small compared to the EX one giving minor contribution to the formation of the oscillatory magnetic order. In clean samples (l>\xi_0) of AuIn$_2$ the oscillatory magnetic order should produce a line of nodes in the quasiparticle spectrum of S electrons giving rise to the power law behavior. The critical field H_c(T=0) in the coexistence phase is reduced by factor two with respect to its bare value.Comment: 4 pages with 2 PS figures, RevTeX, submitted to Physical Review B - Rapid Communication

Magnetic Au Nanoparticles on Archaeal S-Layer Ghosts as Templates

Cell‐ghosts representing empty cells of the archaeon Sulfolobus acidocaldarius, consisting only of their highly ordered and unusually stable outermost proteinaceous surface layer (S‐layer), were used as templates for Au nanoparticles fabrication. The properties of these archaeal Au nanoparticles differ significantly from those produced earlier by us onto bacterial S‐layer sheets. The archaeal Au nanoparticles, with a size of about 2.5 nm, consist exclusively of metallic Au(0), while those produced on the bacterial S‐layer had a size of about 4 nm and represented a mixture of Au(0) and Au(III) in the ratio of 40 to 60 %.   The most impressive feature of the archaeal Au nanoparticles is that they are strongly paramagnetic, in contrast to the bacterial ones and also to bulk gold. SQUID magnetometry and XMCD measurements demonstrated that the archaeal Au nanoparticles possess a rather large magnetic moment of about 0.1B/atom. HR‐ TEM‐EDX analysis revealed that the archaeal Au nanoparticles are linked to the sulfur atoms of the thiol groups of the amino acid cysteine, characteristic only for archaeal S‐layers. This is the first study demonstrating the formation of such unusually strong magnetic Au nanoparticles on a non‐modified archaeal S‐laye

Automatised quality assessment in additive layer manufacturing using layer-by-layer surface measurements and deep learning

Additive manufacturing (AM) has gained high research interests in the past but comes with some drawbacks, such as the difficulty to do in-situ quality monitoring. In this paper, deep learning is used on electron-optical images taken during the Electron Beam Melting (EBM) process to classify the quality of AM layers to achieve automatized quality assessment. A comparative study of several mainstream Convolutional Neural Networks to classify the images has been conducted. The classification accuracy is up to 95 %, which demonstrates the great potential to support in-process layer quality control of EBM.And the error analysis has shown that some human misclassification were correctly classified by the Convolutional Neural Networks

Comparison of erythromycin and oxytetracycline for the treatment of ovine footrot

A microbiological study of 25 cases of ovine footrot was performed. Cultures belonging to Dichelobacter nodosus were isolated in 48% of the sampled animals. The sensitivity of the 99 strict anaerobic bacterial isolates to 5 antibiotics (penicillin G, amoxycillin, spiramycin, erythromycin and oxytetracycline) was studied. The percentage of resistant cultures was in all cases higher than 30%. The efficacy of erythromycin and oxytetracycline in the treatment of ovine footrot was studied. To conduct this test, an intramuscular injection was applied, of one antimicrobial or the other, at the beginning of the treatment. The tolerance of animals to the antimicrobials, the success rate of treatment and the severity of lameness were evaluated. The percentage of animals cured within 15 days was around 75%. In contrast, only 44% improvement was achieved in the lameness. No differences were found between the two antimicrobials in the above indices

Gene Expression Signatures That Predict Radiation Exposure in Mice and Humans

BACKGROUND: The capacity to assess environmental inputs to biological phenotypes is limited by methods that can accurately and quantitatively measure these contributions. One such example can be seen in the context of exposure to ionizing radiation. METHODS AND FINDINGS: We have made use of gene expression analysis of peripheral blood (PB) mononuclear cells to develop expression profiles that accurately reflect prior radiation exposure. We demonstrate that expression profiles can be developed that not only predict radiation exposure in mice but also distinguish the level of radiation exposure, ranging from 50 cGy to 1,000 cGy. Likewise, a molecular signature of radiation response developed solely from irradiated human patient samples can predict and distinguish irradiated human PB samples from nonirradiated samples with an accuracy of 90%, sensitivity of 85%, and specificity of 94%. We further demonstrate that a radiation profile developed in the mouse can correctly distinguish PB samples from irradiated and nonirradiated human patients with an accuracy of 77%, sensitivity of 82%, and specificity of 75%. Taken together, these data demonstrate that molecular profiles can be generated that are highly predictive of different levels of radiation exposure in mice and humans. CONCLUSIONS: We suggest that this approach, with additional refinement, could provide a method to assess the effects of various environmental inputs into biological phenotypes as well as providing a more practical application of a rapid molecular screening test for the diagnosis of radiation exposure