Irradiation- Induced Extremes Create Hierarchical Face- /Body- Centered- Cubic Phases in Nanostructured High Entropy Alloys

A nanoscale hierarchical dual- phase structure is reported to form in a nanocrystalline NiFeCoCrCu high- entropy- alloy (HEA) film via ion irradiation. Under the extreme energy deposition and consequent thermal energy dissipation induced by energetic particles, a fundamentally new phenomenon is revealed, in which the original single- phase face- centered- cubic (FCC) structure partially transforms into alternating nanometer layers of a body- centered- cubic (BCC) structure. The orientation relationship follows the Nishiyama- Wasser- man relationship, that is, (011)BCC || (- 1¯1¯1)FCC and [100]BCC || [- 11¯0]FCC. Simulation results indicate that Cr, as a BCC stabilizing element, exhibits a tendency to segregate to the stacking faults (SFs). Furthermore, the high densities of SFs and twin boundaries in each nanocrystalline grain serve to accelerate the nucleation and growth of the BCC phase during irradiation. By adjusting the irradiation parameters, desired thicknesses of the FCC and BCC phases in the laminates can be achieved. This work demonstrates the controlled formation of an attractive dual- phase nanolaminate structure under ion irradiation and provides a strategy for designing new derivate structures of HEAs.A nanoscale hierarchical dual- phase structure is reported to form in a nanocrystalline NiFeCoCrCu high- entropy- alloy film via ion- irradiation- induced face- centered- cubic to body- centered- cubic phase transformation. Both kinetic and thermodynamic conditions for the phase transformation are explored. The results provide a new strategy for tailoring material structures on the nanometer or sub- nanometer scales.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162803/3/adma202002652_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162803/2/adma202002652.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162803/1/adma202002652-sup-0001-SuppMat.pd

Prolonged dual antiplatelet therapy in patients with non-ST-segment elevation myocardial infarction: 2-year findings from EPICOR Asia.

BACKGROUND: Patients with non-ST-segment elevation myocardial infarction (NSTEMI) have a generally poor prognosis and antithrombotic management patterns (AMPs) used post-acute coronary syndrome (ACS) remain unclear. Duration of dual antiplatelet therapy (DAPT) and patient characteristics was evaluated in NSTEMI patients enrolled in EPICOR Asia. HYPOTHESIS: Patients stopping DAPT early may benefit from more intensive monitoring. METHODS: EPICOR Asia was a prospective, real-world, primary data collection, cohort study in adults with an ACS, conducted in eight countries/regions in Asia, with 2 year follow-up. Eligible patients were hospitalized within 48 hours of symptom onset and survived to discharge. We describe AMPs and baseline characteristics in NSTEMI patients surviving ≥12 months with DAPT duration ≤12 and > 12 months post-discharge. Clinical outcomes (composite of death, myocardial infarction, and stroke; and bleeding) were also explored. RESULTS: At discharge, 90.8% of patients were on DAPT (including clopidogrel, 99%). At 1- and 2-year follow-up, this was 79.2% and 60.0%. Patients who stopped DAPT ≤12 months post-discharge tended to be older, female, less obese, have prior cardiovascular disease, and have renal dysfunction. While causality cannot be inferred, the incidence of the composite endpoint over the subsequent 12 months was 10.6% and 3.1% with shorter vs longer use of DAPT, and mortality risk over the same period was 8.4% and 1.6%. CONCLUSIONS: Over 90% of NSTEMI patients were discharged on DAPT, with 60% on DAPT at 2 years. Patients stopping DAPT early were more likely to have higher baseline risk and may therefore benefit from more intensive monitoring during long-term follow-up

Structural evolution of GeMn/Ge superlattices grown by molecular beam epitaxy under different growth conditions

GeMn/Ge epitaxial 'superlattices' grown by molecular beam epitaxy with different growth conditions have been systematically investigated by transmission electron microscopy. It is revealed that periodic arrays of GeMn nanodots can be formed on Ge and GaAs substrates at low temperature (approximately 70°C) due to the matched lattice constants of Ge (5.656 Å) and GaAs (5.653 Å), while a periodic Ge/GeMn superlattice grown on Si showed disordered GeMn nanodots with a large amount of stacking faults, which can be explained by the fact that Ge and Si have a large lattice mismatch. Moreover, by varying growth conditions, the GeMn/Ge superlattices can be manipulated from having disordered GeMn nanodots to ordered coherent nanodots and then to ordered nanocolumns

Coherent magnetic semiconductor nanodot arrays

In searching appropriate candidates of magnetic semiconductors compatible with mainstream Si technology for future spintronic devices, extensive attention has been focused on Mn-doped Ge magnetic semiconductors. Up to now, lack of reliable methods to obtain high-quality MnGe nanostructures with a desired shape and a good controllability has been a barrier to make these materials practically applicable for spintronic devices. Here, we report, for the first time, an innovative growth approach to produce self-assembled and coherent magnetic MnGe nanodot arrays with an excellent reproducibility. Magnetotransport experiments reveal that the nanodot arrays possess giant magneto-resistance associated with geometrical effects. The discovery of the MnGe nanodot arrays paves the way towards next-generation high-density magnetic memories and spintronic devices with low-power dissipation

An Updated Search of Steady TeV γ−\gamma-Ray Point Sources in Northern Hemisphere Using the Tibet Air Shower Array

Using the data taken from Tibet II High Density (HD) Array (1997 February-1999 September) and Tibet-III array (1999 November-2005 November), our previous northern sky survey for TeV $\gamma-$ray point sources has now been updated by a factor of 2.8 improved statistics. From $0.0^{\circ}$ to $60.0^{\circ}$ in declination (Dec) range, no new TeV $\gamma-$ray point sources with sufficiently high significance were identified while the well-known Crab Nebula and Mrk421 remain to be the brightest TeV $\gamma-$ray sources within the field of view of the Tibet air shower array. Based on the currently available data and at the 90% confidence level (C.L.), the flux upper limits for different power law index assumption are re-derived, which are approximately improved by 1.7 times as compared with our previous reported limits.Comment: This paper has been accepted by hepn

Precision measurement of the branching fractions of J/psi -> pi+pi-pi0 and psi' -> pi+pi-pi0

We study the decays of the J/psi and psi' mesons to pi+pi-pi0 using data samples at both resonances collected with the BES III detector in 2009. We measure the corresponding branching fractions with unprecedented precision and provide mass spectra and Dalitz plots. The branching fraction for J/psi -> pi+pi-pi0 is determined to be (2.137 +- 0.004 (stat.) +0.058-0.056 (syst.) +0.027-0.026 (norm.))*10-2, and the branching fraction for psi' -> pi+pi-pi0 is measured as (2.14 +- 0.03 (stat.) +0.08-0.07 (syst.) +0.09-0.08 (norm.))*10-4. The J/psi decay is found to be dominated by an intermediate rho(770) state, whereas the psi' decay is dominated by di-pion masses around 2.2 GeV/c2, leading to strikingly different Dalitz distributions.Comment: 15 pages, 2 figure

Higher-order multipole amplitude measurement in ψ(2S)→γχc2\psi(2S)\to\gamma\chi_{c2}

Using $106\times10^6$ $\psi(2S)$ events collected with the BESIII detector at the BEPCII storage ring, the higher-order multipole amplitudes in the radiative transition $\psi(2S)\to\gamma\chi_{c2}\to\gamma\pi\pi/\gamma KK$ are measured. A fit to the $\chi_{c2}$ production and decay angular distributions yields $M2=0.046\pm0.010\pm0.013$ and $E3=0.015\pm0.008\pm0.018$, where the first errors are statistical and the second systematic. Here $M2$ denotes the normalized magnetic quadrupole amplitude and $E3$ the normalized electric octupole amplitude. This measurement shows evidence for the existence of the $M2$ signal with $4.4\sigma$ statistical significance and is consistent with the charm quark having no anomalous magnetic moment.Comment: 14 pages, 4 figure

Genotype V Japanese Encephalitis Virus Is Emerging

Japanese encephalitis (JE) is a global public health issue that has spread widely to more than 20 countries in Asia and has extended its geographic range to the south Pacific region including Australia. JE has become the most important cause of viral encephalitis in the world. Japanese encephalitis viruses (JEV) are divided into five genotypes, based on the nucleotide sequence of the envelope (E) gene. The Muar strain, isolated from patient in Malaya in 1952, is the sole example of genotype V JEV. Here, the XZ0934 strain of JEV was isolated from Culex tritaeniorhynchus, collected in China. The complete nucleotide and amino acid sequence of XZ0934 strain have been determined. The nucleotide divergence ranged from 20.3% to 21.4% and amino acid divergence ranged from 8.4% to 10.0% when compared with the 62 known JEV isolates that belong to genotype I–IV. It reveals low similarity between XZ0934 and genotype I–IV JEVs. Phylogenetic analysis using both complete genome and structural gene nucleotide sequences demonstrates that XZ0934 belongs to genotype V. This, in turn, suggests that genotype V JEV is emerging in JEV endemic areas. Thus, increased surveillance and diagnosis of viral encephalitis caused by genotype V JEV is an issue of great concern to nations in which JEV is endemic