Formation of Liquid Ordered Lamellar Phases in the Palmitic Acid/Cholesterol System
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
The phase behavior of the palmitic acid (PA)−cholesterol system in aqueous buffer at pH 5.5 has been investigated using infrared spectroscopy and 2 H NMR spectroscopy of both chain deuterated PA and partially deuterated cholesterol. The results indicate that at temperatures below 50 °C, both lipids exist in a crystalline phase and are not miscible. However, we report the formation of a lamellar liquid ordered (lo) phase upon heating. In this phase, the acid and cholesterol molecules experience an axial symmetric motion while the acid acyl chains are conformationally ordered. Despite this unusual composition, the lo phase formed by PA−cholesterol exhibits similar properties to the phospholipid−cholesterol lo phases. The acyl chain order, the thermal expansivity of the bilayer, and the orientation and the dynamics of cholesterol are similar to those previously measured on phospholipidic lo phases. A temperature−composition diagram is proposed for the PA−cholesterol system. This diagram includes the presence of a eutectic with a PA/cholesterol molar composition of 30:70. It is proposed that melted palmitic acid provides a nonpolar environment for the solubilization of cholesterol and the latter induces a straightening of the fatty acid chains, promoting a molecular order compatible with bilayer formation. The implications of these findings in the understanding of the structure of the stratum corneum and in the development of non-phospholipidic liposomes are discussed.
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.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 it