Instrument with an ultra-wide dynamic detection range for the optical counting and sizing of individual particles in suspensions.

The characterization of dispersions, suspensions, and emulsions is important in a wide range of scientific applications and industries. Samples can consist of different materials and a wide range of particle sizes and concentrations. A single particle sizing and counting instrument with a dynamic detection range of ≥6 decades has been developed to detect single nano- and microparticles in aqueous suspensions based on light scattering measured in two directions.

Improved Metrological Traceability of Particle Size Values Measured with Line-Start Incremental Centrifugal Liquid Sedimentation.

Line-start incremental centrifugal liquid sedimentation (disc-CLS) is a powerful method to determine particle size based on the principles of Stokes' law. Because several of the input quantities of the Stokes equation cannot be easily determined for this case of a rotating disc, the disc-CLS approach relies on calibrating the sedimentation time scale with reference particles. To use these calibrant particles for establishing metrological traceability, they must fulfill the same requirements as those imposed on a certified reference material, i.

Water relations of the pine exine.

Background And Aims: Water adhesion forces, water absorption capacity and permeability of the pine exine were investigated to consider a possible function of sporopollenin coatings in the control of water transport.

Methods: The experiments were carried out with sporopollenin capsules obtained from pine pollen consisting of an empty central capsule and two sacci. Changes in the concentration of excluded dextran molecules in the medium were analysed to quantify water absorption by purified exine fragments and the osmotic volume flow out of the intact central capsule.

Reversal of breast cancer resistance protein-mediated drug resistance by tryprostatin A.

MDR in human cancers is one of the major causes of failure of chemotherapy. A member of the superfamily of ABC transporters, BCRP, was demonstrated to confer an atypical MDR phenotype to tumor cells. To overcome the BCRP-mediated drug resistance, the fungal secondary metabolite TPS-A, a diketopiperazine, was analyzed with regard to its potency to reverse the BCRP-mediated drug-resistant phenotype.

Enhanced exposure of phosphatidylserine in human gastric carcinoma cells overexpressing the half-size ABC transporter BCRP (ABCG2).

Members of the ABC (ATP-binding cassette) transporter super-family are emerging to be involved in lipid transport. In the present study, we studied the organization of phospholipids in the plasma membrane of EPG85-257 human gastric carcinoma cells overexpressing BCRP (breast cancer resistance protein, ABCG-2), a half-size transporter belonging to the ABCG subfamily. A significantly increased plasma membrane association of the PS (phosphatidylserine)-binding probe FITC-Annexin V in comparison with control cells was observed.