Significantly more patients were treated with antimicrobials for more than 3 days during the 3-month period before isolation in the BSI group. Prior antimicrobial therapy may be a risk factor for BSIs due to B. cereus.”
“Ras proteins regulate signaling cascades crucial for cell proliferation and differentiation by switching between GTP- and GDP-bound conformations. Distinct Ras isoforms have unique physiological functions with individual

isoforms associated with different cancers and developmental diseases. Given the small structural differences among isoforms and mutants, it is currently unclear how these functional differences and aberrant properties arise. Here we investigate whether the subtle differences among isoforms and mutants

are associated with detectable dynamical differences. Extensive molecular dynamics simulations reveal that wild-type K-Ras GDC-0973 price and mutant H-Ras A59G are intrinsically more dynamic than wild-type H-Ras. The crucial switch 1 and switch 2 regions along with loop 3, helix 3, and loop 7 contribute to this enhanced flexibility. Removing the gamma-phosphate of the bound GTP from the structure of A59G led to a spontaneous GTP-to-GDP conformational transition in a 20-ns unbiased simulation. The switch 1 and 2 regions exhibit enhanced flexibility and correlated CUDC-907 nmr motion when compared to non-transitioning wild-type H-Ras over a similar timeframe. Correlated motions between loop 3 and helix 5 of wild-type H-Ras are absent in the mutant A59G reflecting the enhanced dynamics of the loop 3 region. Taken together with earlier findings, these results suggest the existence of a lower energetic barrier between GTP and GDP states of the mutant. Molecular dynamics simulations combined with principal component analysis of available

Ras crystallographic structures can be used to discriminate ligand-and sequence-based dynamic perturbations with potential functional implications. Furthermore, the identification of specific conformations associated with distinct Ras isoforms and mutants provides useful information for efforts that attempt to selectively interfere with the aberrant Protein Tyrosine Kinase inhibitor functions of these species.”
“We investigated the thickness and composition dependence of perpendicular magnetic anisotropy (PMA) in L1(0) Fe1-xPtx (x = 0.4, 0.5, and 0.55) films. The FePt films with different thicknesses of 35 and 70 A were grown at the substrate temperature T-s = 300 degrees C by molecular beam epitaxy coevaporation technique. A (001)-oriented epitaxial L1(0) FePt film was grown on the thin (001)oriented fcc Pt layer, while a poorly crystallized FePt film was formed on the (111)-textured Pt layer. Our results showed that, at a fixed thickness of 70 A, the PMA of FePt alloy films is enhanced as Pt content increases from 40% to 55%. (C) 2011 American Institute of Physics. [doi:10.1063/1.