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Order parameters of the orientation distribution of collagen fibers in Achilles tendon by 1 H NMR of multipolar spin states
Author(s) -
Fechete R.,
Demco D. E.,
Blümich B.
Publication year - 2003
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.854
Subject(s) - achilles tendon , legendre polynomials , anisotropy , dipole , molecular physics , chemistry , spin (aerodynamics) , multipole expansion , nuclear magnetic resonance , moment (physics) , condensed matter physics , physics , tendon , optics , classical mechanics , anatomy , quantum mechanics , thermodynamics , medicine , organic chemistry
The angular distribution function of collagen fibrils in a sheep Achilles tendon was investigated by 1 H NMR of multipolar spin states represented by dipolar‐encoded longitudinal magnetization and double‐quantum filtered signals. For the first time the angular distribution function based on the Legendre moment expansion is used. Order parameters were obtained from the anisotropy of 1 H residual dipolar couplings of bond water, which were determined model‐free from the excitation efficiency of the multipolar spin states and from double‐quantum filtered line splitting. The orientation distribution function of collagen fibrils in Achilles tendon measured from the anisotropy of the residual dipolar couplings is characterized by the average values of center $\tilde{\beta}_0 = 1.8 \pm 0.2^\circ$ and order parameters $\langle {P_2} \rangle = 0.93 \pm 0.04$ , $\langle {P_4} \rangle = 0.78 \pm 0.04$ and $\langle {P_6} \rangle = 0.58 \pm 0.04$ . The order of many biological tissues in the presence of ageing, injuries or regeneration can be quantified by the order parameters of the angular distribution function. Copyright © 2003 John Wiley & Sons, Ltd.