Single-molecule diffusion was considered to be brownian motion, and the diffusion coefficient (D), representing the amount of substance diffusing across an area through a unit concentration gradient in unit time, was calculated according to the following equations: All statistical analyses were carried out by using the StatMate III software program (ATMS Co. Ltd., Tokyo, Japan).
According to this principle, a dissolved substance diffuses down a concentration gradient; that is, given no energy from an outside source, it moves from a place where its concentration is high to a place where its concentration is low.
In sublingual exposure, a substance diffuses into the blood through the mucous membrane under the tongue.
The sublingual mucosa is highly vascularized; thus, a substance diffusing across this oral mucosal membrane has direct access to the systemic circulation via capillaries and venous drainage and will avoid first-pass hepatic metabolism (Patel et al. 2011).
Issues connected with fluorescence methods of detection of oil substances diffused in aquatic environment are analysed.
The special technological medium for carburizing [12] with additives of a low-molecular polyethylene as a carbon content diffusing substance was used as a coolant.
The differences in the methods involve the type of substances diffusing through the semipermeable barrier and whether an external field or pressure is applied across the membrane.
Because most also lack a circulatory system, supplying muscle tissues with fuel and oxygen can be no faster than the rate at which these substances diffuse through solid tissue.
In the wake of cortical spreading depression (CSD) it has been suggested that noxious substances diffuse through the dura with resulting firing of epidural nerves.
Hypothetically, molecules may be transferred across the stratum corneum by three different pathways [33]: (1) paracellular (the substances diffuse through intercellular lipids), (2) transcellular (through the cellular compartment), and (3) transappendageal (substances circumvent keratinocytes by hair shunts or glands).
In particular she is interested in how chemicals are absorbed and penetrate through skin and according to her, "the techniques used to model how substances diffuse through skin are not so different from those used to model the flow of oil through rocks!" Defensive Layer.
