Evidence map›Paper›PMID 19651038›Full record

ArticleBiophysical journal2009

Size of bicelle defects probed via diffusion nuclear magnetic resonance of PEG.

Ronald Soong, Daniel Majonis, Peter M Macdonald

Abstract read
In one paragraph

Article in Biophysical journal, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Article
  2. Bicelles at low concentrations.Molecular pharmaceutics · 2012
    Article
  3. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Ronald SoongDepartment of Chemistry, University of Toronto, Toronto, Ontario, Canada.
Daniel Majonis
Peter M Macdonald

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Diffusion of various poly(ethylene glycol) (PEG) tracers of well-defined molecular weight and narrow polydispersity confined within the aqueous interstices between positively magnetically aligned bicelles was measured using pulsed-field-gradient (1)H nuclear magnetic resonance. The bicelles consisted of mixtures of dimyristoylphosphatidylcholine (DMPC), dimyristoylphosphatidylglycerol (DMPG), and dihexanoylphosphatidylcholine (DHPC) in the molar ratios q = [100 DMPC +5 DMPG]/[DHPC] = 3.5, 4.5, and 5.5, to which Yb(3+) had been added in the ratio 1:75 Yb(3+)/phospholipid. The field gradients were applied such that diffusion was measured in the direction parallel to the normal to the bicelles' planar regions, thereby rendering the experiment sensitive to the ability of PEG to traverse lamellar defects within the bicelles. The pulsed-field-gradient nuclear magnetic resonance diffusive intensity decays were diffusion-time-independent in all cases, with diffusive displacements corresponding to many hundreds of bicellar lamellae. This permitted a description of such diffusive decays in terms of a mean behavior involving a combination of straight obstruction effects common to all PEG, with hindrance to diffusion proportional to the relative size of a given PEG with respect to the size of the lamellar defects. Across the range of PEG molecular weights (200-4600) and bicelle compositions examined, the apparent radial dimension of the lamellar defects decreased from 165 A with q = 3.5 to 125 A with q = 5.5. This is opposite to the trend predicted from static geometric models of either bicelle disks or perforated lamellae. Qualitatively, the observed trend suggests that mobility of the obstructions to diffusion will need to be considered to reconcile these differences.

Indexed as

Membranes, ArtificialMicellesAlgorithmsChromatographyDiffusionDimyristoylphosphatidylcholineMagnetic Resonance SpectroscopyModels, ChemicalPhosphatidylcholinesPhosphatidylglycerolsPhospholipidsPhosphorus IsotopesPolyethylene GlycolsProtonsTime FactorsWater1,2-hexanoylphosphatidylcholineDimyristoylphosphatidylcholinedimyristoylphosphatidylglycerolMembranes, ArtificialMicellesPhosphatidylcholinesPhosphatidylglycerolsPhospholipidsPhosphorus IsotopesPolyethylene GlycolsProtonsWaterYtterbium

Identifiers

PMID19651038
PMCPMC2718149

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.