64 research outputs found
Ion distribution profiles between polar and charged membranes as observed by anomalous X-ray diffraction
The distribution profiles of rubidium ions near polar,
zwitterionic 1,2-di stearoyl-sn-glycero-3-phospho choline (DSPC) and charged, anionic 1,2-di stearoyl-sn-glycero-3-phospho glycerol (DSPG-)
membranes were determined by means of anomalous X-ray diffraction close to the K-absorption
edge of , which was measured to be 15.225 keV. The samples were
kept in the L-phase at 30. The DSPC suspensions in 2 M RbCl
were examined at 15.125 keV, 15.196Â keV, 15.210Â keV, the
suspensions in 0 M RbCl and 2 M RbCl at 14.667Â keV and 15.196Â keV. This
gave up to seven peaks in the powder-like diffraction pattern and
revealed, for the first time directly, different rubidium ion distributions in
either of the investigated systems: rubodium ions are enriched by 100% in
the proximity of the charged headgroups and depleted by 25%
from the vicinity of the zwitterionic DSPC headgroups. The latter
phenomenon results in rubidium ion concentration maximum in the aqueous
compartment between polar, but uncharged bilayers
Electronic data capture and use of internet technologies in a double-blind randomised intervention trial
SCOPUS: cp.kinfo:eu-repo/semantics/publishe
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