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The results of a combined experimental and computational investigation of the structural evolution of Au81Si19, Pd82Si18, and Pd77Cu6Si17 metallic glass forming liquids are presented. Electrostatically levitated metallic liquids are prepared, and synchrotron x-ray scattering studies are combined with embedded atom method molecular dynamics simulations to probe the distribution of relevant structural units. Metal–metalloid based metallic glass forming systems are an extremely important class of materials with varied glass forming ability and mechanical processibility. High quality experimental x-ray scattering data are in poor agreement with the data from the molecular dynamics simulations, demonstrating the need for improved interatomic potentials. The first peak in the x-ray static structure factor in Pd77Cu6Si17 displays evidence for a Curie–Weiss type behavior but also a peak in the effective Curie temperature. A proposed order parameter distinguishing glass forming ability, 1 / S T , q 1 − 1 , shows a peak in the effective Curie temperature near a crossover temperature established by the behavior of the viscosity, TA. [ABSTRACT FROM AUTHOR]

Sonia Benammar,1,2 Alix Pantel,3,4 Fabien Aujoulat,5 Messaoud Benmehidi,1,2 René Courcol,6,7 Jean-Philippe Lavigne,3,4 Sara Romano-Bertrand,5,8 Hélène Marchandin3,5 1Department of Microbiology, University Hospital Center Touhami Benflis, Batna, Algeria; 2Department of Medicine, University Batna 2, Batna, Algeria; 3Department of Microbiology, Nîmes University Hospital, Nîmes, France; 4Faculty of Medicine, National Institute of Health and Medical Research, INSERM U1047, University of Montpellier, Nîmes, France; 5HydroSciences Montpellier, CNRS, IRD, University of Montpellier, University Hospital of Montpellier-Nîmes, Montpellier, France; 6Faculty of Medicine, University of Lille, Lille, France; 7Department of Bacteriology, Institute of Microbiology, Lille University Hospital, Lille, France; 8Department of Infection Control, Montpellier University Hospital, Montpellier, France Purpose: Vancomycin-resistant Enterococcus (VRE) faecium (VREfm) are highly resistant bacteria emerging worldwide and rarely studied using molecular tools in Algeria since their first report in 2006. The aim of the study was to investigate healthcare-associated infections (HAIs) involving the first VRE in Batna University Hospital, Algeria, and characterize isolates using molecular tools.Patients and methods: Medical charts were reviewed for patients with VREfm. van genes were detected by multiplex polymerase chain reaction (PCR), and strains were characterized by automated repetitive sequence-based PCR (rep-PCR), multiplex rep-PCR, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST).Results: During a 6-month period, VREfm infections occurred in four patients hospitalized in three wards. The four isolates were E. faecium vanA belonging to the hospital-adapted clonal complex 17. PCR-based methods did not discriminate the isolates but MLST and PFGE delineated a subgroup of three VREfm of identical pulsotype and sequence type (ST) 80 (yet identified for five isolates in the international PubMLST database) while the fourth isolate was of ST789 (not previously identified for a VREfm) and displayed an unrelated pulsotype. The three genotypically related isolates were recovered in patients who underwent surgery in the same department, suggesting an outbreak for which the source and route of transmission remained unidentified.Conclusion: This first molecular epidemiology study of VRE in Algeria was useful in delimiting an outbreak involving three of the four HAI cases and revealed rarely encountered genotypes. Considering the threat and burden of VRE infections worldwide, particularly in the USA, and the late emergence in Algeria, our study supports the urgent need for improved and early adequate infection control measures to avoid VRE spread in North African hospitals. Keywords: outbreak, genotyping, MLST, rep-PCR, PFGE, molecular epidemiology

The results of a combined structural and dynamical study of Cu–Zr–Al metallic glass forming liquids are presented. Containerless high-energy x-ray scattering experiments made using electrostatic levitation are combined with molecular dynamics simulations to probe the onset of rapid structural ordering as well as the temperature-dependent diffusivity and viscosity in three liquids: Cu49Zr45Al6, Cu47Zr45Al8, and Cu43Zr45Al12. These compositions were chosen because they are reported to have dramatically different glass forming-ability. Experimental data show that the first peak in the x-ray static structure factor displays evidence for a Curie–Weiss type behavior, but also a peak in the effective Curie temperature. The evidence provided here for the onset of cooperativity, marked by a crossover temperature, TA (which is usually above the liquidus temperature), is accompanied by the onset of development of more spatially extended structural order in the liquids. Based on the molecular dynamics simulations, each of the liquids exhibits a clear breakdown of the Stokes–Einstein relation at a temperature near, but below, the crossover temperature, TA. The breakdown is manifest as a rapid reduction in the relative diffusion coefficients between Cu, Zr, and Al. [ABSTRACT FROM AUTHOR]