Foams stabilized by multilamellar polyglycerol ester self-assemblies.

The importance of surfactant self-assemblies in foam stabilization is well-known. The aim of the current study was to investigate the self-assemblies of the nonionic surfactant polyglycerol ester (PGE) in bulk solutions, at the interface and within foams, using a combined approach of small-angle neutron scattering, neutron reflectivity, and electron microscopy. PGE bulk solutions contain vesicles as well as open lamellar structures.

Characteristics of polyglycerol ester and its different fractions.

Polyglycerol esters obtained from edible oils are commonly used surfactants in the food industry. Despite their widespread application, the composition and properties of these surfactants are still not well characterized. This study reveals the presence of so far unknown tetra-, penta-antennary constituents in polyglycerol esters, which exhibit very strong sodium affinity.

Scanning force microscopy as a tool to investigate the properties of polyglycerol ester foams.

Foamed products are a popular class of food products. The mechanism of stabilization of the air bubbles is often only partially understood. The current study aims at better understanding the stabilization of air-water interfaces through the low molecular weight surfactant polyglycerol ester (PGE).

Sorption of water by bidisperse mixtures of carbohydrates in glassy and rubbery states.

Water sorption by bidisperse carbohydrate mixtures consisting of varying ratios of a narrow-molecular-weight distribution maltopolymer and the disaccharide maltose is investigated to establish a quantitative relation between the composition of the carbohydrate system and the water sorption isotherm. The sorption of water is approached from two limiting cases: the glassy state at low water content and the dilute aqueous carbohydrate solution. In the glassy state, the water content at a given water activity decreases with increasing maltose content of the matrix, whereas in the rubbery state it increases with increasing maltose content.

Microtubules: strange polymers inside the cell.

This paper provides a consistent approach (within a one-dimensional approximation) to the description of the evolution of the microtubule length at both low- and high-density concentrations. We derive general master-type equations which are based on the key chemical reactions involved in the assembly and disassembly of microtubules. The processes included are: polymerization and depolymerization of a single protein dimer, catastrophic disassembly affecting an a piori arbitrary number of dimers, and a rescue event.

Models of assembly and disassembly of individual microtubules: stochastic and averaged equations.

In this paper we present solutions of the master equations for the microtubule length and show that the local probability for rescues or catastrophes can lead to bell-shaped length histograms. Conversely, as already known, non-local probabilities for these events result in exponential length histograms. We also derive master equations for a stabilizing cap and obtain a new boundary condition which provides an explanation of the results obtained in dilution and cutting experiments.

A chemical kinetics model for microtubule oscillations.

A model for microtubule oscillations is presented based on a set of chemical reaction equations. The rate constants for these reactions are largely determined from experimental data. The plots of assembled tubulin and the phase diagram for assembly are compared with the experimental findings and are found to agree quite well.

[Interpretation of the estrogen receptor content of breast cancer].

The biochemical analysis of estrogen receptor (ER) content, using the DCC (dextran-coated charcoal) method, was compared with different plotting methods of the estrogen-receptor immunocytochemical assay (ER-ICA) in 80 primary breast cancers including 9 metastases under routine conditions. It was evident, that the determined content of estrogen receptors depends on the technique of measurement, as well as the microscopic organizations of the individual carcinomas and should be interpreted in respect of their content of stroma and if possible of tumour heterogeneity.

[Representative studies of the vitamin D status of 2-year-old children in Frankfurt am Main].

In a representative sample population of 421 two-year-old Frankfurt children studied for vitamin-D nutritional status, only one case of subclinical rickets was discovered. 93.3% of the children have been a regular vitamin-D supplements during the first 12 month of life, but only 32.

[Microkymography--a method to measure the flow velocity in the microvascular bed after endotoxin administration (author's transl)].

In this paper the application of intravital microkymography on studies of the microcirculation of the hamster cheek pouch is presented. Flow velocity reduction which is one of the characteristic initial alterations in small blood vessels after injection of endotoxin is recorded in a direct way by the strip microkymography. The method of the recording system is described and some examples of the effects of endotoxin as well as of serotonin, one of the mediators of endotoxin, are given.