Investigation of the thermal stability of Ni/C multilayers by X-ray methods.

Microstructural properties of Ni/C multilayers prepared by PLD (pulsed laser deposition) have been investigated after heat treatment in vacuum at temperatures in the range of 50 degrees C to 500 degrees C. X-ray diffractometry, X-ray reflectometry, fluorescence EXAFS (extended X-ray absorption fine structure) and HREM (high resolution transmission electron microscopy) have been applied to characterize samples in the initial state and after annealing. The multilayer reflectivity remained unchanged or increased at temperatures below 400 degrees C due to sharpening of the interfaces caused by the formation of alpha-nickel and nickel carbide. The reflectivity decreased at temperatures above 400 degrees C because of the fragmentation of the nickel layers. It can be shown, that both chemical and mechanical driving forces are responsible for the observed modifications of the initial specimen state.

Predictors of treatment outcome in young children with autism: a retrospective study.

This study examined predictors of developmental outcomes in 17 children diagnosed with autism or PDD-NOS, who received generic treatment over a mean period of 37 months. Pre-treatment evaluations occurred at a mean age of 31 months with follow-up evaluations at a mean age of 69 months. Significantly different developmental trajectories were observed among the participants at follow-up, separating the participants into two distinct groups (high and low outcome). However, groups did not differ significantly in treatment intensity or other outcome prediction measures. Pre-treatment developmental intelligence levels between the two groups approached significance. The results raise questions regarding the effect of treatment intensity and type, family stress factors, and intelligence ability in very early childhood on, outcome.

Aerosol number concentrations and size distributions at mountain-rural, urban-influenced rural, and urban-background sites in Germany.

Long-term aerosol measurements have been made at three sites in Germany, representing different levels of pollution: Hohenpeissenberg (mountain-rural), Melpitz (urban-influenced rural), and Leipzig (urban background). (Urban background aerosol represents a mixture of aerosols emitted in the city and aerosols transported into the city measured at a site with no direct emissions nearby.) To provide data that will allow better estimates of the influence of environmental aerosol particles on humans, we review diurnal variations of mean total number concentrations and size distributions of submicrometer environmental aerosol particles (including ultrafine particles smaller than 100 nm) for winter and summer periods in these three regions. Number concentrations and size distributions are compared and related to peak traffic periods and to meteorologically induced new-particle formation processes. The number concentration increase with increasing level of pollution. The mountain-rural site shows the smallest and the urban background site the highest number concentration. The relative diurnal variation of the number concentration between day and night, however, is for all sites nearly the same. Generally, traffic-related number concentration during rush-hour periods peaks in the size range of 20-30 nm. Due to weaker atmospheric convective processes in winter, this traffic-related aerosol is more pronounced than that in summer. In summer, meteorologically induced new-particle formation processes add another number concentration peak to the aerosol near 10 nm. This peak occurs near noon, independent of the day of the week. For the mean number concentrations and size distribution, this new-particle formation process was only relevant for the urban-influenced rural and the urban-background sites.

[Assessment of cost-benefit analysis in integration projects on drug addiction]. / Evaluierung von Arbeitsprojekten bei Drogenabhängigen im Rahmen einer Kosten-Nutzen-Analyse.

The purpose of this study is to make a cost-benefit-analysis for integration projects helping drug addicts and substitutes to reintegrate into society. The study is intended to contribute to a better allocation of resources under the trade-off-situation that only a limited number of integration projects can be realized due to budget limitations. This pilot study represents an economic evaluation of health activities on integration based on the example of study projects offered by Mudra e. V. As a result the study showed that the evaluated projects are economically advantageous during the investigated research period. Furthermore, the study contains a non-monetary analysis of intangible effects which shows significant improvements in quality of life. Although the results are substantial, further research is mandatory focussing on the economic benefits of integration projects.

How do the indoor size distributions of airborne submicron and ultrafine particles in the absence of significant indoor sources depend on outdoor distributions?

Although almost all epidemiological studies of smaller airborne particles only consider outdoor concentrations, people in Central Europe actually spend most of their time indoors. Yet indoor pollutants such as organic gases, allergens and dust are known to play a prominent role, often affecting human health more than outdoor ones. The aim of this study was to ascertain how the indoor particle size distributions of submicron and ultrafine particles correlate with the outdoor concentrations in the absence of significant indoor sources. A typical indoor particle size distribution pattern has one or two modes. In the absence of significant indoor activities such as smoking, cooking etc., outdoor particles were found to be a very important source of indoor particles. The study shows that in the absence of significant indoor sources, the number of indoor concentrations of particles in this size range are clearly lower than the outdoor concentrations. This difference is greater, the higher the number of outdoor concentrations. However, the drop in concentration is not uniform, with the decrease in concentration of smaller particles exceeding that of larger ones. By contrast, the findings with larger particle sizes (diameter > 1 microm) exhibit rather linear concentration decreases. The non-uniform drop in the number of concentrations from outdoors to indoors in our measurements considering smaller particles ( >0.01 microm) is accompanied by a shift of the concentration maxima to larger particle diameters.

Concentrations of tetrachloroethene in blood and trichloroacetic acid in urine in workers and neighbours of dry-cleaning shops.

Tetrachloroethene concentrations in blood and trichloroacetic acid concentrations in urine were determined--primarily over the course of a week--for 29 persons living in the vicinity of dry-cleaning shops. The mean levels of tetrachloroethene increased during the week. In some neighbours concentrations were exceeding the German biological threshold limit value for tetrachloroethene (1000 micrograms/l blood), persisting over the whole week in one case. The concentrations of tetrachloroethene in blood depended on the floor and the construction type of the building where these people were living, but not of the type of system used in the dry-cleaning shops. 5 of 12 dry-cleaners were found to have tetrachloroethene levels exceeding the German biological threshold limit value, some of them by a considerable amount.

Congenital enterocyte heparan sulphate deficiency with massive albumin loss, secretory diarrhoea, and malnutrition.

BACKGROUND: The molecular basis of protein-losing enteropathy is unknown. However it has been shown that sulphated glycosaminoglycans may be important in regulating vascular and renal albumin loss. METHODS: We describe three baby boys who presented within the first weeks of life with massive enteric protein loss, secretory diarrhoea, and intolerance of enteral feeds. All required total parenteral nutrition and repeated albumin infusions. No cause could be found in any case despite extensive investigations, including small intestinal biopsy sampling, which were repeatedly normal. FINDINGS: By specific histochemistry, we detected gross abnormality in the distribution of small intestinal glycosaminoglycans in all three infants, with complete absence of enterocyte heparan sulphate. The distribution of vascular and lamina propria glycosaminoglycans was, however, normal. INTERPRETATION: The presentation of these infants suggests that enterocyte heparan sulphate is important in normal small intestinal function.