1,103 research outputs found
Draft Genome Sequences of Five Enterococcus Species Isolated from the Gut of Patients with Suspected Clostridium difficile Infection
Indexación: Scopus.We present draft genome sequences of five Enterococcus species from patients suspected of Clostridium difficile infection. Genome completeness was confirmed by presence of bacterial orthologs (97%). Gene searches using Hidden-Markov models revealed that the isolates harbor between seven and 11 genes involved in antibiotic resistance to tetracyclines, beta-lactams, and vancomycin.http://genomea.asm.org/content/5/20/e00379-17.ful
Fluorographynes: Stability, Structural and Electronic Properties
The presence in the graphyne sheets of a variable amount of sp2/sp1 atoms,
which can be transformed into sp3-like atoms by covalent binding with one or
two fluorine atoms, respectively, allows one to assume the formation of
fulorinated graphynes (fluorographynes) with variable F/C stoichiometry. Here,
employing DFT band structure calculations, we examine a series of
fluorographynes, and the trends in their stability, structural and electronic
properties have been discussed as depending on their stoichiometry: from C2F3
(F/C= 1.5) to C4F7 (F/C= 1.75).Comment: 13 pages, 3 table
Graphene allotropes: stability, structural and electronic properties from DF-TB calculations
Using the density-functional-based tight-binding method we performed a
systematic comparative study of stability, structural and electronic properties
for 12 various types of graphene allotropes, which are likely candidates for
engineering of novel graphene-like materials.Comment: 12 pages, 4 figure
Pairing and Density Correlations of Stripe Electrons in a Two-Dimensional Antiferromagnet
We study a one-dimensional electron liquid embedded in a 2D antiferromagnetic
insulator, and coupled to it via a weak antiferromagnetic spin exchange
interaction. We argue that this model may qualitatively capture the physics of
a single charge stripe in the cuprates on length- and time scales shorter than
those set by its fluctuation dynamics. Using a local mean-field approach we
identify the low-energy effective theory that describes the electronic spin
sector of the stripe as that of a sine-Gordon model. We determine its phases
via a perturbative renormalization group analysis. For realistic values of the
model parameters we obtain a phase characterized by enhanced spin density and
composite charge density wave correlations, coexisting with subleading triplet
and composite singlet pairing correlations. This result is shown to be
independent of the spatial orientation of the stripe on the square lattice.
Slow transverse fluctuations of the stripes tend to suppress the density
correlations, thus promoting the pairing instabilities. The largest amplitudes
for the composite instabilities appear when the stripe forms an antiphase
domain wall in the antiferromagnet. For twisted spin alignments the amplitudes
decrease and leave room for a new type of composite pairing correlation,
breaking parity but preserving time reversal symmetry.Comment: Revtex, 28 pages incl. 5 figure
Economic analysis of an agrosilvipastoral system for a mountainous area in Zona da Mata Mineira, Brazil
Faraday rotation in graphene
We study magneto--optical properties of monolayer graphene by means of
quantum field theory methods in the framework of the Dirac model. We reveal a
good agreement between the Dirac model and a recent experiment on giant Faraday
rotation in cyclotron resonance. We also predict other regimes when the effects
are well pronounced. The general dependence of the Faraday rotation and
absorption on various parameters of samples is revealed both for suspended and
epitaxial graphene.Comment: 10 pp; v2: typos corrected and references added, v3, v4: small
changes and more reference
Tri-meson-mixing of -- and -- in the light-cone quark model
The radiative transition form factors of the pseudoscalar mesons {,
, } and the vector mesons {, , } are restudied
with -- and -- in tri-meson-mixing
pattern, which is described by tri-mixing matrices in the light-cone
constituent quark model. The experimental transition decay widths are better
reproduced with tri-meson-mixing than previous results in a two-mixing-angle
scenario of only two-meson - mixing and - mixing.Comment: 8 pages, 6 figures, final version to appear in EPJ
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Parity Violation Constraints Using Cosmic Microwave Background Polarization Spectra from 2006 and 2007 Observations by the QUaD Polarimeter
We constrain parity-violating interactions to the surface of last scattering using spectra from the QUaD experiment’s second and third seasons of observations by searching for a possible systematic rotation of the polarization directions of cosmic microwave background photons. We measure the rotation angle due to such a possible ‘‘cosmological birefringence’’ to be (random) (systematic) using QUaD’s 100 and 150 GHz temperature-curl and gradient-curl spectra over the spectra over the multipole range 200 << 2000, consistent with null, and constrain Lorentz-violating interactions to <2 10 GeV (68% confidence limit). This is the best constraint to date on electrodynamic parity violation on cosmological scales.Astronom
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