title: Diffusion characteristics of ethylene glycol in skeletal muscle.
abstract: Part of the optical clearing study in biological tissues concerns the determination of the diffusion characteristics of water and optical clearing agents in the subject tissue. Such information is sufficient to characterize the time dependence of the optical clearing mechanisms—tissue dehydration and refractive index (RI) matching. We have used a simple method based on collimated optical transmittance measurements made from muscle samples under treatment with aqueous solutions containing different concentrations of ethylene glycol (EG), to determine the diffusion time values of water and EG in skeletal muscle. By representing the estimated mean diffusion time values from each treatment as a function of agent concentration in solution, we could identify the real diffusion times for water and agent. These values allowed for the calculation of the correspondent diffusion coefficients for those fluids. With these results, we have demonstrated that the dehydration mechanism is the one that dominates optical clearing in the first minute of treatment, while the RI matching takes over the optical clearing operations after that and remains for a longer time of treatment up to about 10 min, as we could see for EG and thin tissue samples of 0.5 mm.
authors.affiliation: Polytechnic of Porto, School of Engineering, Physics Department, Rua Dr. António Bernardino de Almeida, 431, 4200-072 Porto, PortugalbPorto University, School of Engineering, Rua Dr. Roberto Frias, 4200-465 Porto, PortugalcCentre of Innovation in Engineer.
authors.forename: Luís M
authors.initials: LM
authors.lastname: Oliveira
authors.affiliation: Porto University, School of Engineering, DEEC, Rua Dr. Roberto Frias, 4200-465 Porto, PortugaleINESC TEC, FEUP, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
authors.forename: Maria Inês
authors.initials: MI
authors.lastname: Carvalho
authors.affiliation: Polytechnic of Porto, School of Engineering, Physics Department, Rua Dr. António Bernardino de Almeida, 431, 4200-072 Porto, PortugalcCentre of Innovation in Engineering and Industrial Technology, ISEP, Rua Dr. António Bernardino de Almeida, 431, 4200-072.
authors.forename: Elisabete M
authors.initials: EM
authors.lastname: Nogueira
authors.affiliation: Saratov State University, Research-Educational Institute of Optics and Biophotonics, 83, Astrakhanskaya Street, Saratov 410012, RussiagInstitute of Precise Mechanics and Control RAS, Laboratory of Laser Diagnostics of Technical and Living Systems, 24 Rabo.
authors.forename: Valery V
authors.initials: VV
authors.lastname: Tuchin
mesh_terms: D000818:Animals; D004058:Diffusion; D019855:Ethylene Glycol / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry; D008027:Light; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism*; D055095:Optics and Photonics; D051381:Rats; D017208:Rats, Wistar; D012031:Refractometry; D012542:Scattering, Radiation; D013053:Spectrophotometry; D013997:Time Factors; D014867:Water
chemical_list: D014867:Water; D019855:Ethylene Glycol; D005947:Glucose