Fatty Acids Influence “Solid” Phase Formation in Models of Stratum Corneum Intercellular Membranes
Bibliographic record
Abstract
Stacked intercellular lipid membranes in the uppermost epidermal layer, the stratum corneum (SC), are responsible for skin's barrier function. These membranes are unique in composition, the major lipids being ceramides (Cer), cholesterol, and free fatty acids (FFA) in approximately equimolar proportions. Notably, SC lipids include chains much longer than those of most biological membranes. Previously we showed that Cer's small hydrophilic headgroup enabled SC model membranes composed of bovine brain ceramide (BBCer), cholesterol, and palmitic acid in equimolar proportion to solidify at pH 5.2. In order to determine the influence of FFA chain length on the phase behavior of such membranes, we used 2H NMR and FT-IR to study BBCer/cholesterol/FFA dispersions containing linear saturated FFA 14-22 carbons long. Independent of chain length, the solid phase dominated the FFA spectrum at physiological temperature. Upon heating, each dispersion underwent phase transitions to a liquid crystalline phase (only weakly evident for the membrane containing FFA-C22) and then to an isotropic phase. The phase behavior, the lipid mixing properties, and the transition temperatures are shown to depend strongly on FFA chain length. A distribution of FFA chain lengths is found in the SC and could be required for the coexistence of a proportion of solid lipids with some more fluid domains, which is known to be necessary for normal skin barrier function.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".