News of Science
March 22, 2009

PHYSICS;
Studies from S.G. Gevorkian and colleagues reveal new findings on physics

According to recent research from Yerevan, Armenia, "We measured the
Young’s modulus at temperatures ranging from 20 to 100 degrees C for a
collagen fibril that is taken from a rat’s tendon. The hydration
change under heating and the damping decrement were measured as well."

"At physiological temperatures 25 to 45 degrees C, the Young’s modulus
decreases, which can be interpreted as an instability of the
collagen. For temperatures between 45 and 80 degrees C, the Young’s
modulus first stabilizes and then increases when the temperature is
increased. The hydrated water content and the damping decrement have
strong maximums in the interval 70 to 80 degrees C indicating complex
intermolecular structural changes in the fibril," wrote S.G. Gevorkian
and colleagues.

The researchers concluded: "All these effects disappear after
heat-denaturation of the sample at 120 degrees C. Our main achievement
is a five-stage mechanism by which the instability of a single
collagen at physiological temperatures is compensated by the
interaction between collagen molecules."

Gevorkian and colleagues published their study in Physical Review
Letters (Thermal (In)Stability of Type I Collagen Fibrils. Physical
Review Letters, 2009;102(4):8101).

For additional information, contact S.G. Gevorkian, Yerevan Physics
Institute, Alikhanian Bros St. 2, Yerevan 375036, Armenia.

Publisher contact information for the journal Physical Review Letters
is: American Physical Society, One Physics Ellipse, College Pk, MD
20740-3844, USA.