A device suitable for measuring or quantifying the permeation or diffusion of one or more substances through a membrane, said device including a housing at least part of which is configured to form a first chamber or cell capable of holding a fluid or liquid in use, and a membrane support means to hold or locate at least one membrane in use adjacent to said first chamber or cell, wherein the first chamber or cell includes one or more windows or orifices through which ultraviolet (UV), visible (VIS) and/or infrared (IR) electromagnetic radiation can pass.

Provided are a synchronous fluorescence detector for observing the interface concentration of fluorescent pollutants and application method. The detector comprises a first electric displacement platform, a quartz cuvette, an excitation light path, a collection light path and a second electric displacement platform. The application method comprises the following steps: first exciting fluorescent pollutants by utilizing UV light with specific wavelengths to emit fluorescent light; then collecting fluorescence signals emitted by the excited fluorescent pollutants to the greatest extent by utilizing an UV anti-reflection convex lens combination; and finally, processing the fluorescent signals acquired by a photomultiplier by utilizing a difference method to determine a precise light intensity of a thin layer which is moved at a specific spacing by utilizing the electric displacement platforms so as to determine fugacity distribution of the fluorescent pollutants in the microlayer near an interface.

Disclosed are a procedure and system for live monitoring of staining quality and heavy metal diffusion during electron microscopy preparation protocols for biological samples. The disclosed approach employs x-rays via, e.g., a commercially available micro-CT device, to observe and measure the diffusion and distribution of the heavy metals during conventional biological sample staining procedures for electron microscopy. This allows one to observe and check the quality and homogeneity of the staining without damaging or destroying the sample.

Systems and methods for analyzing a diffusion trend of a diffusible substance. The systems may obtain a plurality of sets of reference information relating to the diffusible substance from a plurality of devices respectively, each of the plurality of sets of reference information at least including a time point when a corresponding device detects the diffusible substance and a location where the device detects the diffusible substance. The plurality of sets of reference information may correspond to a same or a substantially same time domain. The systems may determine the diffusion trend of the diffusible substance based on the plurality of sets reference information.

Disclosed is a method of determining efficacy of a cosmetic composition to inhibit an atmospheric pollutant from contacting skin, comprising the steps of: (i) filling a sample holder of known dimensions with known amount of said composition to form a layer of defined thickness therein, where said sample holder is amenable to fluorescence-based assay; (ii) depositing, on said layer, a known amount of a model fine particulate matter which resembles an atmospheric pollutant at least in size and which comprises a material responsive to fluorescence microscopy which is excitable by a wavelength (λ.sub.ex) and which emits radiation (λ.sub.em) where (λ.sub.ex)≠(λ.sub.em); (iii) irradiating said composition and said model fine particulate matter by said λ.sub.ex and recording intensity of fluorescence at λ.sub.em a plurality of times for a defined period during which said model fine particulate matter interacts with said layer; and, (iv) determining, corrected intensity of fluorescence at λ.sub.em by the following equation; corrected Intensity=recorded intensity/average transmittance where said average transmittance is the average of the transmittance of the composition measured at λ.sub.ex and λ.sub.em determined by Beer-Lambert law by measuring the absorbance at λ.sub.ex and λ.sub.em, where the corrected intensity is inversely proportional to said efficacy of said composition.

The present invention relates to a multi-phase liquid composition including: a first aqueous phase; a second aqueous phase; a lipid bilayer; and an organic phase, a device for measuring the permeability of drugs including the multi-phase liquid composition, and a method for measuring the permeability of drugs.

Disclosed is a method of determining efficacy of a cosmetic composition to inhibit an atmospheric pollutant from contacting skin, comprising the steps of: (i) filling a sample holder of known dimensions with known amount of said composition to form a layer of defined thickness therein, where said sample holder is amenable to fluorescence-based assay; (ii) depositing, on said layer, a known amount of a model fine particulate matter which resembles an atmospheric pollutant at least in size and which comprises a material responsive to fluorescence microscopy which is excitable by a wavelength (λ.sub.ex) and which emits radiation (λ.sub.em) where (λ.sub.ex)≠(λ.sub.em); (iii) irradiating said composition and said model fine particulate matter by said λ.sub.ex and recording intensity of fluorescence at λ.sub.em a plurality of times for a defined period during which said model fine particulate matter interacts with said layer; and, (iv) determining, corrected intensity of fluorescence at λ.sub.em by the following equation; corrected Intensity=recorded intensity/average transmittance where said average transmittance is the average of the transmittance of the composition measured at λ.sub.ex and λ.sub.em determined by Beer-Lambert law by measuring the absorbance at λ.sub.ex and λ.sub.em, where the corrected intensity is inversely proportional to said efficacy of said composition.

An apparatus and method of analysis including at least one microscope means operable to characterize the surface of a sample in use, at least a first conduit to convey one or more solvents to the sample and a further conduit to convey at least part of the solution from the sample. At least one pump means delivers solvent to the sample and/or removes solution from the same.

A method of estimating a parameter for fitting a multi-component Taylorgram model to Taylorgram data g(t) is disclosed. The data comprises a multi-component Taylorgram peak or front at t=t.sub.r. The method comprises: evaluating a value of an integration or differential of the data; determining the parameter, based on an analytical expression that includes the value of the integral or differential of the data, the parameter corresponding with a physical property of a sample from which the Taylorgram data was obtained.

A method of determining a relationship between a mutual diffusion co-efficient D.sub.m and the concentration c of a solute within a solvent. The method comprises: obtaining a Taylorgram comprising a plurality of measurements of solute concentration c; and deriving from the Taylorgram a plurality of mutual diffusion coefficient values D.sub.m corresponding with a plurality of different concentrations c of solute in the solvent.