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We develop a ReaxFF reactive force field used for the molecular dynamics simulations of thermophysical properties of liquid Cu and Zr metals. The ReaxFF parameters are optimized by fitting to the first-principles density-functional calculations on the equations of state for bulk crystal structures and surface energies. To validate the force field, we compare the ReaxFF results with those from experiments and embedded-atom-method (EAM) potentials. We demonstrate that the present ReaxFF force field well represents structural characteristics and diffusion behaviors of elemental Cu and Zr up to high-temperature liquid regions. It reasonably reproduces the thermodynamic processes associated with crystal-liquid interface. In particular, the equilibrium melting temperatures show better agreement with experimental measurements than the results from EAM potentials. The ReaxFF reactive force field method exhibits a good transferability to the nonreactive processes of liquid systems. [ABSTRACT FROM AUTHOR]

Liquids attain a metastable state without crystallizing by cooling rapidly to a given temperature below the melting point. With increasing supercooling, the nucleation rate would show an increase based on the prediction of the classical nucleation theory. It is generally thought that the nucleation rate will reach the maximum upon approaching the glass transition temperature, Tg, for glass-forming liquids. We report that there exists a supercooled region above Tg in which the crystallization has actually been severely suppressed. Our molecular dynamics simulations show that the growth of embryos in the supercooled Cu60Zr40 melt is subjected to a strong anisotropic stress associated with the dynamic heterogeneity. Its long-range effect drives the embryo to grow into a ramified morphology so that the interface energy dominates over the embryo growth, leading to the suppression of nucleation. [ABSTRACT FROM AUTHOR]

FeNiN films with 0–56 at % Ni concentrations were prepared by dual ion beam sputtering in a nitrogen–argon gas mixture. Effects of nitrogen and nickel concentrations on the structure and magnetic properties of FeNiN films have been studied. FeNiN films with lower nickel and nitrogen concentrations contained the bcc α-(FeNi) phase, films with 8–12 at % nitrogen and 5–25 at % Ni concentrations contained α[sup ″]-(Fe, Ni)[sub 16]N[sub 2] and γ[sup ′]-(Fe, Ni)[sub 4]N phases, and films with 30–56 at % Ni concentrations consisted of a mixture of fcc γ-FeNi alloy and γ[sup ′]-(Fe, Ni)[sub 4]N phases. The FeNiN films with 8–12 at % nitrogen and 5–15 at % nickel concentrations showed high saturation magnetization of 2.2–2.3 T and low coercivity of 96–110 A/m. The variation of the magnetic properties was attributed to the change in the structure of the films. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Abstract Objectives To provide a summary of evidence for the diagnostic accuracies of three multiplex PCR systems (mPCRs)—BioFire FilmArray RP (FilmArray), Nanosphere Verigene RV+ test (Verigene RV+) and Hologic Gen-Probe Prodesse assays—on the detection of viral respiratory infections. Methods A comprehensive search up to 1 July 2017 was conducted on Medline and Embase for studies that utilized FilmArray, Verigene RV+ and Prodesse for diagnosis of viral respiratory infections. A summary of diagnostic accuracies for the following five viruses were calculated: influenza A virus (FluA), influenza B virus, respiratory syncytial virus, human metapneumovirus and adenovirus. Hierarchical summary receiver operating curves were used for estimating the viral detection performance per assay. Results Twenty studies of 5510 patient samples were eligible for analysis. Multiplex PCRs demonstrated high diagnostic accuracy, with area under the receiver operating characteristic curve (AUROC) equal to or more than 0.98 for all the above viruses except for adenovirus (AUROC 0.89). FilmArray, Verigene RV+ and ProFlu+ (the only Prodesse assay with enough data) demonstrated a summary sensitivity for FluA of 0.911 (95% confidence interval, 0.848–0.949), 0.949 (95% confidence interval, 0.882–0.979) and 0.954 (95% confidence interval, 0.871–0.985), respectively. The three mPCRs were comparable in terms of detection of FluA. Conclusions Point estimates calculated from eligible studies showed that the three mPCRs (FilmArray, Verigene RV+ and ProFlu+) are highly accurate and may provide important diagnostic information for early identification of respiratory virus infections. In patients with low pretest probability for FluA, these three mPCRs can predict a low possibility of infection and may justify withholding empirical antiviral treatments. [ABSTRACT FROM AUTHOR]