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R Blume

Publications and source records attributed to R Blume.

53 records · Page 3Linked to original sources
PubMedDate not supplied

Toxicological investigations in the semiconductor industry: IV. Studies on the subchronic oral toxicity and genotoxicity of vacuum pump oils contaminated by waste products from aluminum plasma etching processes.

Dry etching processes in semiconductor manufacturing use ionized gases in closed reactors at pressures below 1 torr. Vacuum pump systems that service the reaction chambers are potential sources of exposure to complex mixtures of inorganic and organic compounds. These mixtures consist of unused process gases and process by-products that condense and accumulate in the vacuum pump oils. To evaluate potential hazards of dry etch vacuum equipment, a contaminated vacuum pump oil sample from a BCl3/Cl2 etching process was analyzed. The waste oil was administered by gavage for 14 or 28 days to male and female Wistar rats. Neither death nor behavioral changes occurred after subchronic treatment or during a 14-day posttreatment period. Only slight effects on body weights, clinical chemistry, and hematology data were seen in the exposed animals, although the livers of all waste oil-exposed rats of both sexes showed remarkable hypertrophic degenerations. Genotoxicological investigations were performed through the Ames assay (Salmonella assay) and the Micronucleus assay. The contaminated oil sample caused clear genotoxic effects in both test systems.

Administration, Oral↗
PubMedDate not supplied

[Histomorphometric contribution to W. Beier's exponent of the aging function].

We determined aging changes of the nucleus-cytoplasm-relation in the epithelium of the epiglottis and intestine of human beings and rats. The results were compared with data about the proliferation of connective tissue and the decrease of muscle cells in the wall of the intestine and in the ciliary muscle. We adapted exponential functions to the measured results. For comparing the several equations and the derivable aging velocities, the nucleus-cytoplasm-relation must be transformed into nucleus volume rate of the total cell volume. Similarities in the decrease of the aging speed in the course of life and in the value of the exponent of the aging function by W. Beier (approximately equal to 0,03) were demonstrated.

Adult↗