A new method was developed for the analysis of fluorescein exchange between the aqueous humor and cornea which enables calculation of the permeability coefficient of the corneal endothelium and the steady-state aqueous-cornea distribution ratio from one experiment. After intravenous fluorescein injection, aqueous and corneal fluorescence was measured at intervals, using an objective fluorophoto...

The impact of humic acid fouling on the membrane transport of two pharmaceutically active compounds (PhACs) - namely carbamazepine and sulfamethoxazole - in forward osmosis (FO) was investigated. Deposition of humic acid onto the membrane surface was promoted by the complexation with calcium ions in the feed solution and the increase in ionic strength at the membrane surface due to the reverse ...

In order to achieve a fair description of radon transport through concrete certain information is needed on the concrete structure, porosity and permeability, on processes causing the transport of radon, on radon’s interaction with environment, factors favouring the generation of radon, etc. The concrete characteristics (that depend on its composition and especially on the W/C ratio) which infl...

Lung injury is a broad descriptor that can be applied to conditions ranging from mild interstitial edema without cellular injury to massive and fatal destruction of the lung. This review addresses those methods that can be readily applied to rats and mice whose small size limits the techniques that can be practically used to assess injury. The methodologies employed range from nonspecific measu...

The aim of this study was to investigate the effect of Poly(amidoamine) (PAMAM) dendrimers on corneal permeation of puerarin (PUE). Permeation studies were performed using excised cornea of rabbits by a Valia-Chien diffusion apparatus. Drug-treatment studies were carried out by measuring the penetration of puerarin on cornea in PAMAM-PUE physical mixture or PAMAM-PUE complex, and cornea-treatme...

materials and methods liposomes were prepared by thin film method using soya lecithin and cholesterol. physicochemical characteristics of the liposomes such as, particle size, drug encapsulation efficiency were determined. also, drug release and in vitro skin permeability through rat skin were evaluated using franz diffusion cells. results the results showed that the maximum drug encapsulation ...

Unidirectional (24)Na fluxes across the dog red blood cell membrane were measured. The kinetics were incompatible with a single time constant but could be accounted for in terms of a two-series compartment cell model, with approximately 1% of cell Na in the outer compartment. Dog red blood cells are known to be inhomogeneous in their Na and K permeabilities. Theoretical analysis showed that suc...

The osmotic permeability coefficient, P(f), and the tagged water permeability coefficient, P(d), were determined for thin (<100 A) lipid membranes formed from ox brain lipids plus DL-alpha-tocopherol; their value of approximately 1 x 10(-3) cm/sec is within the range reported for plasma membranes. It was established that P(f) = P(d). Other reports that P(f) > P(d) can be attributed to the prese...

The physics of moisture transfer is complex and as a result modelling is normally carried out on a macroscopic basis, with empirical coefficients used to simulate the transport process. These coefficients are not single values but depend on the moisture content of the material. The application of this data within the simulation environment requires the determination of a systematic methodology ...

permeability is a key parameter in reservoir characterization. in fact, without accurate information about reservoir permeability, there is no good solution for reservoir engineering problems. up to now, permeability values of a reservoir have been calculated through laboratory measurements or well testing methods. these methods are useful but they cannot describe a reservoir reliably and preci...