Search NASA⌕ Search

SEARCH · Search NASA

Results for “CsGd”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

4 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on CsGd by Materials Project

CsGd is alpha Samarium-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Cs is bonded to six equivalent Cs and six equivalent Gd atoms to form CsCs6Gd6 cuboctahedra that share corners with eighteen equivalent CsCs6Gd6 cuboctahedra, edges with six equivalent CsCs6Gd6 cuboctahedra, edges with twelve equivalent GdCs6Gd6 cuboctahedra, faces with eight equivalent CsCs6Gd6 cuboctahedra, and faces with twelve equivalent GdCs6Gd6 cuboctahedra. All Cs–Cs bond lengths are 3.95 Å. All Cs–Gd bond lengths are 4.39 Å. Gd is bonded to six equivalent Cs and six equivalent Gd atoms to form GdCs6Gd6 cuboctahedra that share corners with eighteen equivalent GdCs6Gd6 cuboctahedra, edges with six equivalent GdCs6Gd6 cuboctahedra, edges with twelve equivalent CsCs6Gd6 cuboctahedra, faces with eight equivalent GdCs6Gd6 cuboctahedra, and faces with twelve equivalent CsCs6Gd6 cuboctahedra. All Gd–Gd bond lengths are 3.95 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsGd(MoO4)2 by Materials Project

CsGd(MoO4)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Cs1+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of Cs–O bond distances ranging from 2.93–3.44 Å. Gd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Gd–O bond distances ranging from 2.36–2.75 Å. Mo6+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Mo–O bond distances ranging from 1.78–2.44 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Cs1+ and two equivalent Mo6+ atoms. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Cs1+, two equivalent Gd3+, and one Mo6+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Cs1+, one Gd3+, and two equivalent Mo6+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Cs1+, one Gd3+, and one Mo6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Potentiating antibiotic efficacy via perturbation of non-essential gene expression

Proliferation of multidrug-resistant (MDR) bacteria poses a threat to human health, requiring new strategies. Here we propose using fitness neutral gene expression perturbations to potentiate antibiotics. We systematically explored 270 gene knockout-antibiotic combinations in Escherichia coli, identifying 90 synergistic interactions. Identified gene targets were subsequently tested for antibiotic synergy on the transcriptomic level via multiplexed CRISPR-dCas9 and showed successful sensitization of E. coli without a separate fitness cost. These fitness neutral gene perturbations worked as co-therapies in reducing a Salmonella enterica intracellular infection in HeLa. Finally, these results informed the design of four antisense peptide nucleic acid (PNA) co-therapies, csgD, fnr, recA and acrA, against four MDR, clinically isolated bacteria. PNA combined with sub-minimal inhibitory concentrations of trimethoprim against two isolates of Klebsiella pneumoniae and E. coli showed three cases of re-sensitization with minimal fitness impacts. Our results highlight a promising approach for extending the utility of current antibiotics.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2020

PchE Regulation of Escherichia coli O157:H7 Flagella, Controlling the Transition to Host Cell Attachment

Shiga toxins and intimate adhesion controlled by the locus of enterocyte effacement are major enterohemorrhagic Escherichia coli (EHEC) virulence factors. Curli fimbriae also contribute to cell adhesion and are essential biofilm components. The transcriptional regulator PchE represses the expression of curli and their adhesion to HEp-2 cells. Past studies indicate that pchE also represses additional adhesins that contribute to HEp-2 cell attachment. In this study, we tested for pchE regulation of several tissue adhesins and their regulators. Three adhesin-encoding genes (eae, lpfA1, fliC) and four master regulators (csgD, stpA, ler, flhDC) were controlled by pchE. pchE over-expression strongly up-regulated fliC but the marked flagella induction reduced the attachment of O157:H7 clinical isolate PA20 to HEp-2 cells, indicating that flagella were blocking cell attachments rather than functioning as an adhesin. Chemotaxis, motor, structural, and regulatory genes in the flagellar operons were all increased by pchE expression, as was PA20 motility. This study identifies new members in the pchE regulon and shows that pchE stimulates flagellar motility while repressing cell adhesion, likely to support EHEC movement to the intestinal surface early in infection. However, induced or inappropriate pchE-dependent flagellar expression could block cell attachments later during disease progression.

59 BASIC BIOLOGICAL SCIENCES↗