Search PubMed⌕ Search

Biomedical subjects

I Steiner

Publications and source records attributed to I Steiner.

At least 217 records · Page 12Linked to original sources
PubMedDate not supplied

[The migration of acetaldehyde from polyethylene terephthalate bottles for fresh beverages containing carbonic acid].

The migration of acetaldehyde from polyethylene terephthalate (PET) under various conditions was analysed by headspace gas chromatography and flame ionisation detection. The residual amounts of new PET bottles were about 6.3 mg/kg with a migration value of 200 micrograms/l. On studying the migration at different temperatures and times, behaviour curves characteristic of packing materials made from plastics are obtained. The amount of acetaldehyde diffusing from PET at a temperature of 40 degrees C reached a constant level after 4 days which was about 10% of the residual value of acetaldehyde. On increasing the temperature by 20 degrees C, this level was raised up to 50%. The results of the analysis of acetaldehyde in soft drinks containing carbonic acid show that the migration in fact is not sufficiently high to influence the taste of these soft drinks. A negative effect on the taste may be recognized with mineral waters and soda when they are exposed to higher temperatures (e.g. 40 degrees C or more) over a longer period of time.

Acetaldehyde↗
PubMedDate not supplied

Effects of lipofuscin on in situ hybridization in human neuronal tissue.

In situ hybridization is a highly sensitive technique for detecting nucleic acid sequences within tissues, and is frequently employed in neurovirology. However, this technique requires many appropriate controls in order to recognize and avoid potential artifactual hybridization. We have encountered abundant reaction to lipofuscin in neurons in human peripheral and central nervous systems, using various DNA probes, which could be misinterpreted as positive signals. This pseudohybridization reaction was resistant to treatment with RNase or DNase and was also present in tissue sections treated with hybridization mixture or nuclear autoradiographic emulsion in the absence of any radioactive probes. Characteristics used to distinguish between authentic in situ hybridization and the reaction to neuronal lipofuscin include cellular localization, color, margins and granular appearance, sensitivity to treatment with nucleases and the effect of exposure time on signal intensity. These guidelines should be used to avoid potential misinterpretation of in situ hybridization results with human tissue.

Adult↗
PubMedDate not supplied

Non-linear CT windows.

The display of computerized tomographic (CT) data requires data compression because of the limited shades of grey which the eye can differentiate. This may lead to information loss which can be minimized by a more efficient utilization of the available levels of grey than that afforded by conventional linear windows. Automated histogram equalization for grey level assignment has not been satisfactory because of the underlying assumption that the information content at any given CT level is proportional to the number of pixels at that level. For four different anatomic regions; the lumber spine, abdomen, brain and chest, an empiric graph of the clinical information content vs CT levels was integrated to yield the shape of a graph assigning shades of grey vs CT level i.e. a non-linear window. This non-linear window curve was utilized in the same manner as the linear window, namely the window center and width were under the direct control of the observer through the window center and width knobs. Each non-linear window was implemented on images of its anatomic region and interactively optimized on the screen till a maximal display of information was obtained. These optimal non-linear windows compared favorably with linear windows in most cases. This method provides the means to display more information on a CT image with no extra processing time, additional equipment or special training.

Brain↗