𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Cracking cholesterol from a phase transition at body temperatures

✍ Scribed by S. Kumar; S.J. Burns


Publisher
Elsevier Science
Year
1995
Tongue
English
Weight
663 KB
Volume
3
Category
Article
ISSN
0928-4931

No coin nor oath required. For personal study only.

✦ Synopsis


The microstructure of cholesterol crystals grown from gallstone melt have been studied using hot-stage microscopy. The microstructure is comprised of needle-shapedcrystals growing radially from a unique nucleation center. The growth direction has been found to he [ 0011 using X-ray diffraction methods. The radial growth rate has been reported over a range of temperatures. The growth kinetic curve and the microstructural evidence clearly suggest that cholesterol grows by a spherulitic mechanism. The phase transitions in cholesterol have been studied using differential scanning calorimetry. Anhydrous cholesterol has a phase change a few degrees below body temperature. Optical microscopy establishes that this phase transformation cracks the spherulitic crystals perpendicular to the fast growth direction. Thermal expansion measurements delmonstrate that upon cooling across this phase boundary large shrinkage is induced in the growth direction with an expansion in the perpendicular direction. This phase transition and repeated cracking may prove to be useful in destroying natural gallstones, while suppressing this transformation and its associated cracking might aid in securing other cholesterol deposits within the human body.


πŸ“œ SIMILAR VOLUMES


Phase Transition from the Cubic Zintl Ph
✍ Helmut Ehrenberg; Hermann Pauly; Thomas Hansen; Jean-Christophe Jaud; Hartmut Fu πŸ“‚ Article πŸ“… 2002 πŸ› Elsevier Science 🌐 English βš– 247 KB

The binary face-centered cubic Zintl phase LiIn (NaTl-type, B32 in the classification of the ''Strukturberichte'') undergoes a tetragonal distortion from Fd % 3m into I4 1 =amd. This phase transition is reversible and ''translationengleich''. The transition temperature of 170(10) K was determined ba