title: Dielectric relaxation of normothermic and hypothermic rat corneas.
abstract: This paper aims at the presentation of the results of in vitro research on the dielectric properties of the cornea specimen collected from the rats subjected to in vivo hypothermia. The average values of the relative permittivity and dielectric loss are about 40% higher for the hypothermic cornea than those for the normothermic tissue at the same water content of 12% for both samples and at 25°C. Whereas, at 50°C this effect of increase in the dielectric properties of the hypothermic cornea when compared to the normothermic one is observed clearly only in the relative permittivity of about 19%. In the temperature range of 25-50°C, the activation energy of conductivity associated with the release of loosely bound water takes the average values of 45kJ/mol and 30kJ/mol for the normothermic and hypothermic corneas, respectively. The study provided information on dielectric polarization and conductance mechanisms in the cornea which may be helpful in interpreting clinical results of human cornea examination, currently obtained by means of such electrodiagnostic methods as conductive keratoplasty, electroretinography or electrooculography.
authors.affiliation: Department of Bionics and Bioimpedance, University of Medical Sciences, Parkowa 2, 60-775 Poznań, Poland. Electronic address: ewaklcde@amu.edu.pl.
authors.forename: E
authors.initials: E
authors.lastname: Marzec
authors.affiliation: Department of Physiology, University of Medical Sciences, Święcickiego 6, 60-781 Poznań, Poland.
authors.forename: P
authors.initials: P
authors.lastname: Sosnowski
authors.affiliation: Department of Bionics and Bioimpedance, University of Medical Sciences, Parkowa 2, 60-775 Poznań, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Olszewski
authors.affiliation: Department of Physiology, University of Medical Sciences, Święcickiego 6, 60-781 Poznań, Poland.
authors.forename: H
authors.initials: H
authors.lastname: Krauss
authors.affiliation: Certus Hospital, Grunwaldzka 165, Poznań, Poland.
authors.forename: K
authors.initials: K
authors.lastname: Bahloul
authors.affiliation: Department of Physiotherapy, Rheumatology and Rehabilitation, University of Medical Sciences, 28 Czerwca 1958r., 60-545 Poznań, Poland.
authors.forename: W
authors.initials: W
authors.lastname: Samborski
authors.affiliation: Department of Physiotherapy, Rheumatology and Rehabilitation, University of Medical Sciences, 28 Czerwca 1958r., 60-545 Poznań, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Krawczyk-Wasielewska
mesh_terms: D000818:Animals; D003315:Cornea / Q000737:chemistry / Q000502:physiology*; D058266:Dielectric Spectroscopy / Q000379:methods; D004594:Electrophysiology / Q000379:methods; D007035:Hypothermia / Q000503:physiopathology*; D008297:Male; D017208:Rats, Wistar; D013696:Temperature
keywords: Activation energy; Dielectric polarization; Hypothermia; Rat cornea; Water