TY  - JOUR
A1  - Okada, Michio
A1  - Rotenberg, Eli
A1  - Kevan, S. D.
A1  - Schäfer, J.
A1  - Ujfalussy, Balazs
A1  - Stocks, G. Malcolm
A1  - Genatempo, B.
A1  - Bruno, E.
A1  - Plummer, E. W.
T1  - Evolution of the electronic structure in \(Mo_{1-x}Re_x\) alloys
JF  - New Journal of Physics
N2  - We report a detailed experimental and theoretical study of the electronic structure of \(Mo_{1-x}Re_x\) random alloys. We have measured electronic band dispersions for clean and hydrogen-covered \(Mo_{1-x}Re_x\) ( 110) with x = 0-0.25 using angle-resolved photoemission spectroscopy. Our results suggest that the bulk and most surface electronic bands shift relative to the Fermi level systematically and approximately rigidly with Re concentration. We distinguish and quantify two contributions to these shifts: a raise of the Fermi energy and an increase of the overall bandwidth. Alloy bands calculated using the first-principles Korringa-Kohn-Rostoker coherent-potential-approximation method accurately predict both of these effects. As derived from the rigid band model, the Fermi energy shift is inversely related to the bulk density of states in this energy region. Using our results, we also characterize an electronic topological transition of the bulk Fermi surface and relate this to bulk transport properties. Finally, we distinguish effects beyond the rigid band approximation: a highly surface-localized state and a composition-dependent impact of the spin-orbit interaction.
KW  - topological transitions
KW  - surface state
KW  - metals
KW  - total energy
KW  - W(110)
KW  - hydrogen
KW  - mo
KW  - superconductivity
KW  - spectra
KW  - coherent potential approximation
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122993
SN  - 1367-2630
VL  - 15
IS  - 093010
ER  - 
TY  - JOUR
A1  - Makgotlho, Phuti E.
A1  - Marincola, Gabriella
A1  - Schäfer, Daniel
A1  - Liu, Quian
A1  - Bae, Taeok
A1  - Geiger, Tobias
A1  - Wasserman, Elizabeth
A1  - Wolz, Christine
A1  - Ziebuhr, Wilma
A1  - Sinha, Bhanu
T1  - SDS Interferes with SaeS Signaling of Staphylococcus aureus Independently of SaePQ
JF  - PLOS ONE
N2  - The Staphylococcus aureus regulatory saePQRS system controls the expression of numerous virulence factors, including extracellular adherence protein (Eap), which amongst others facilitates invasion of host cells. The saePQRS operon codes for 4 proteins: the histidine kinase SaeS, the response regulator SaeR, the lipoprotein SaeP and the transmembrane protein SaeQ. S. aureus strain Newman has a single amino acid substitution in the transmembrane domain of SaeS (L18P) which results in constitutive kinase activity. SDS was shown to be one of the signals interfering with SaeS activity leading to inhibition of the sae target gene eap in strains with SaeS(L) but causing activation in strains containing SaeS(P). Here, we analyzed the possible involvement of the SaeP protein and saePQ region in SDS-mediated sae/eap expression. We found that SaePQ is not needed for SDS-mediated SaeS signaling. Furthermore, we could show that SaeS activity is closely linked to the expression of Eap and the capacity to invade host cells in a number of clinical isolates. This suggests that SaeS activity might be directly modulated by structurally non-complex environmental signals, as SDS, which possibly altering its kinase/phosphatase activity.
KW  - host-cell invasion
KW  - 2-component system
KW  - strain Newman
KW  - allelic replacement
KW  - genome sequence
KW  - locus
KW  - gene
KW  - activation
KW  - expression
KW  - infection
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128469
SN  - 1932-6203
VL  - 8
IS  - 8
ER  -