12 research outputs found
One-dimensional Continuum Electronic Structure with the Density Matrix Renormalization Group and Its Implications For Density Functional Theory
We extend the density matrix renormalization group to compute exact ground
states of continuum many-electron systems in one dimension with long-range
interactions. We find the exact ground state of a chain of 100 strongly
correlated artificial hydrogen atoms. The method can be used to simulate 1d
cold atom systems and to study density functional theory in an exact setting.
To illustrate, we find an interacting, extended system which is an insulator
but whose Kohn-Sham system is metallic.Comment: 5 pages, 4 figures. Published version, including new section on exact
Kohn-Sham gap of a Mott insulato
Prognostic factors for adult patients with Burkitt lymphoma treated with dose-adjusted EPOCH-R
Streptococcal dTDP-L-rhamnose biosynthesis enzymes:functional characterization and lead compound identification
Biosynthesis of the nucleotide sugar precursor dTDP-L-rhamnose is critical for the viability and virulence of many human pathogenic bacteria, including Streptococcus pyogenes (Group A Streptococcus; GAS), Streptococcus mutans and Mycobacterium tuberculosis. Streptococcal pathogens require dTDP-L-rhamnose for the production of structurally similar rhamnose polysaccharides in their cell wall. Via heterologous expression in S. mutans, we confirmed that GAS RmlB and RmlC are critical for dTDP-L-rhamnose biosynthesis through their action as dTDP-glucose-4,6-dehydratase and dTDP-4-keto-6-deoxyglucose-3,5-epimerase enzymes respectively. Complementation with GAS RmlB and RmlC containing specific point mutations corroborated the conservation of previous identified catalytic residues. Bio-layer interferometry was used to identify and confirm inhibitory lead compounds that bind to GAS dTDP-rhamnose biosynthesis enzymes RmlB, RmlC and GacA. One of the identified compounds, Ri03, inhibited growth of GAS, other rhamnose-dependent streptococcal pathogens as well as M. tuberculosis with an IC 50 of 120–410 µM. Importantly, we confirmed that Ri03 inhibited dTDP-L-rhamnose formation in a concentration-dependent manner through a biochemical assay with recombinant rhamnose biosynthesis enzymes. We therefore conclude that inhibitors of dTDP-L-rhamnose biosynthesis, such as Ri03, affect streptococcal and mycobacterial viability and can serve as lead compounds for the development of a new class of antibiotics that targets dTDP-rhamnose biosynthesis in pathogenic bacteria
Structural and functional characterisation of proteins facilitating the capping and translocation of <i>Streptococcal</i> cell-wall polysaccharidess
Guaranteed convergence of the Kohn-Sham equations.
A sufficiently damped iteration of the Kohn-Sham (KS) equations with the exact functional is proven to always converge to the true ground-state density, regardless of the initial density or the strength of electron correlation, for finite Coulomb systems. We numerically implement the exact functional for one-dimensional continuum systems and demonstrate convergence of the damped KS algorithm. More strongly correlated systems converge more slowly
Guaranteed Convergence of the Kohn-Sham Equations
A sufficiently damped iteration of the Kohn-Sham equations with the exact
functional is proven to always converge to the true ground-state density,
regardless of the initial density or the strength of electron correlation, for
finite Coulomb systems. We numerically implement the exact functional for
one-dimensional continuum systems and demonstrate convergence of the damped KS
algorithm. More strongly correlated systems converge more slowly.Comment: 5 pages, 4 figure