Share Email Print

Proceedings Paper

Estimation of the cholesterol percentages in mixtures of arachidonic acid and cholesterol
Author(s): Mihaela A. Ghelmez; Maria Honciuc; Cristian Gheorghe
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

Arachidonic acid (AA) samples and mixtures of arachidonic acid - cholesterol (AA-C) were manufactured and subjected to external electric cw or pulsatory optical laser fields. The polarizing microscope showed a pseudohomeotropic smectic C texture for AA at 10 degree(s)C and smectic C textures with fibers for mixtures AA-C at room temperature. The dependences I equals I(U) at t degree(s)C equals const. and I equals I(t) at U equals const., t being time, showed that samples are dielectrics with a weak conduction (I approximately equals 10-9 A, U equals 0 - 40V). Pure acid samples present an electric hysteresis which disappears when cholesterol is added. The current occurred when the electric field is applied, decreases in time, and tends to a constant value. When the temperature was 19 degree(s)C, a cw focussed laser radiation from a He-Ne laser ((lambda) equals 632.8 nm, P equals 20 mW) determined a lenselike effect in AA, but no effect in mixtures. At the same temperature, the samples were crossed by some green pulses ((lambda) equals 532 nm, (tau) equals 200 microsecond(s) ) furnished by an experimental setup containing a Nd3+ glass laser and a KDP crystal for the second harmonic generation. The shape and extension of the pulse in the time domain, displayed on a sampling oscilloscope, are some indications of the cholesterol percentage.

Paper Details

Date Published: 17 August 1994
PDF: 9 pages
Proc. SPIE 2137, Time-Resolved Laser Spectroscopy in Biochemistry IV, (17 August 1994); doi: 10.1117/12.182774
Show Author Affiliations
Mihaela A. Ghelmez, Polytechnic Institute of Bucharest (Romania)
Maria Honciuc, Polytechnic Institute of Bucharest (Romania)
Cristian Gheorghe, Clinical Hospital Fundeni Bucharest (Romania)

Published in SPIE Proceedings Vol. 2137:
Time-Resolved Laser Spectroscopy in Biochemistry IV
Joseph R. Lakowicz, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?