Supramolecular complexes of spin-labelled cyclodextrins

EPR spectra of cyclodextrins labelled with TEMPO derivatives (SL-CDs) are sensitive to complexation with large guest molecules. We used SL-CDs to explore the behaviour of concentrated PEG/PPG solutions. The relationship between rotational correlation times and solvent viscosity showed significant deviations from the Debye-Stokes-Einstein equation, probably due to self-aggregation of alkylene glycols in concentrated solutions. The data fit the fractional Debye-Stokes-Einstein equation well. We have also studied complexation of SL-CDs with adamantane-functionalised DAB dendrimers. The strength of binding increases with dendrimer generation; formation of supramolecular aggregates at high concentrations was observed with the generation 3 dendrimer.

Solvent-induced textural changes of as-synthesized mesoporous alumina, as reported by spin probe electron spin resonance spectroscopy

The effect of solvent used during the synthesis and postsynthesis treatment on textural properties of organized mesoporous aluminas was investigated and related to the behavior of spin probes studied by electron spin resonance (ESR) spectroscopy. It was found that the structure of surfactant aggregates serving in the as-synthesized precipitates as templates could be easily modified by treatment with different solvents. This treatment induces corresponding variations in surface areas, mesopore volumes, and mesopore diameters of the final products. The ESR spectrum of 5-doxyl stearic acid spin probe properly reflects the changes in template structure based on changes of the solvent used and represents an early indicator of the corresponding textural modifications of the mesoporous alumina.

Spin-labelled cyclodextrins as hosts for large supramolecular assemblies

EPR spectroscopy was used to study formation of inclusion complexes of monofunctionalised spin-labelled beta-cyclodextrins; this method is very sensitive to the interactions of cyclodextrins with large guest molecules.

Oral health status among schoolchildren in Romania, 1992

In Romania, systematic information on the occurrence of oral diseases in children is scarce. The purpose of the present study was to describe the prevalence and the pattern of dental caries in schoolchildren, and to use the data to provide a baseline for planning and evaluation of oral health care. A national sample of children at grade 1 (n = 729) and grade 6 (n = 660) was chosen consistent with the WHO pathfinder principle. Clinical examinations were carried out according to the recording system for the Danish Municipal Dental Service and the following results were obtained. In children of grade 1 (7-yr-olds) the prevalence proportion of caries in primary teeth was 86% and in permanent teeth 39%. The mean caries indices were 11.4 defs and 1.3 DMFS. At grade 6 (12-yr-olds) the prevalence proportion of caries in primary teeth was 17% and in permanent teeth 90%. The mean caries experience was 0.8 defs and 6.5 DMFS, and a mean of 4.1 DMFT was observed. In both groups, the D-component of the caries index was dominant. The children were also classified by caries severity zone. At grade 1, 61% had a very severe pattern of caries in the primary teeth, i.e. caries in pits/fissures, proximal surfaces, smooth surfaces, and incisors. Forty-three percent of the children at grade 6 showed this pattern in permanent teeth. In Romanian schoolchildren the present level and pattern of dental caries are most severe and the implementation of oral health promotion and prevention at the community level is urgently needed.