In-line catalytic derivatization method for selective detection of chlorinated aromatics with a hyphenated gas chromatography/laser mass spectrometry technique: a concept for comprehensive detection of isomeric ensembles

The combination of gas chromatography (GC) and laser-based resonance-enhanced multiphoton ionization-time-of-flight mass spectrometry (REMPI-TOFMS) represents a three-dimensional analytical method, using the gas chromatographic retention time, the wavelength of the ionization laser for REMPI, and the molecular mass as analytical parameters. In this work, a novel analytical scheme for detection of chlorinated aromatic compounds, including isomeric ensembles, by GC/REMPI-TOFMS is presented. The concept uses an in-line hydrodechlorination catalyst for post- or precolumn derivatization of chlorinated aromatic compounds. The chlorinated aromatics are quantitatively reduced, forming their respective aromatic skeletons. These aromatic skeletons are detected selectively by REMPI-TOFMS. The first results for substance class selective detection of chlorinated benzene isomers are given, and potential applications in the field of the analysis of compounds such as polychlorinated dibenzo-p-dioxins and -furans are discussed.     

Holzinger, A.: Basiswissen Multimedia Bd. 1: Technik. Zahlir Abb., 284 S. ISBN 3-8023-1856-0; Bd. 2: Lernen. Zahlr. Abb., 290 S. ISBN 3-8023-1857-0; Bd. 3: Design. Zahlr. Abb., 280 S. ISBN 3-8023-1858-0. Vogl, Würzburg, 2000. DM 59,-, ATS 431,- (je Band)

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Holzinger, A.: Basiswissen Multimedia Bd. 1: Technik. Zahlir Abb., 284 S. ISBN 3-8023-1856-0; Bd. 2: Lernen. Zahlr. Abb., 290 S. ISBN 3-8023-1857-0; Bd. 3: Design. Zahlr. Abb., 280 S. ISBN 3-8023-1858-0. Vogl, Würzburg, 2000. DM 59,-, ATS 431,- (je Band)     

A Novel Insight into the Cardiotoxicity of Antineoplastic Drug Doxorubicin

Doxorubicin is a commonly used antineoplastic agent in the treatment of many types of cancer. Little is known about the interactions of doxorubicin with cardiac biomolecules. Serious cardiotoxicity including dilated cardiomyopathy often resulting in a fatal congestive heart failure may occur as a consequence of chemotherapy with doxorubicin. The purpose of this study was to determine the effect of exposure to doxorubicin on the changes in major amino acids in tissue of cardiac muscle (proline, taurine, glutamic acid, arginine, aspartic acid, leucine, glycine, valine, alanine, isoleucine, threonine, lysine and serine). An in vitro interaction study was performed as a comparison of amino acid profiles in heart tissue before and after application of doxorubicin. We found that doxorubicin directly influences myocardial amino acid representation even at low concentrations. In addition, we performed an interaction study that resulted in the determination of breaking points for each of analyzed amino acids. Lysine, arginine, β-alanine, valine and serine were determined as the most sensitive amino acids. Additionally we compared amino acid profiles of myocardium before and after exposure to doxorubicin. The amount of amino acids after interaction with doxorubicin was significantly reduced (p = 0.05). This fact points at an ability of doxorubicin to induce changes in quantitative composition of amino acids in myocardium. Moreover, this confirms that the interactions between doxorubicin and amino acids may act as another factor most likely responsible for adverse effects of doxorubicin on myocardium.     

Integrated simulation method for investment decisions of micro production systems

From a production logistics point of view, micro production systems need special methods due to their special requirements and characteristics. In this paper a new approach for the assessment of different investment scenarios during the planning period with integrated cost simulation is presented. In particular, the use of single-purpose and multi-purpose machines and the cost effectiveness of function integration are examined. Thereby alternative machine pool configurations and optimal costs can be analysed, determined and taken into consideration for investment decisions.     

Hemispheric asymmetries in category-specific word retrieval

We examined whether 53 adult non-aphasic patients with either left (22) or right temporal lobe lesions (31) demonstrate dissociable patterns of hemispheric asymmetries in category-specific word fluency tasks. The patients were asked to articulate as many appropriate words as possible within 60 or 90 s in response to six target categories. There was no effect of patient groups on the overall fluency. However, patients with a left-sided temporal lobe lesion were impaired retrieving words to 'initial letters' and to the category 'animals'. Right temporal lobe patients were impaired retrieving 'tools' and words referring to specific visual attributes. There were no fluency differences for 'food-supermarket goods' and 'flat interior'. We conclude that temporal lobe damage can result in category-specific impairments in word retrieval depending on the affected hemisphere.     

Zunderverhalten und Ausscheidungshärtung von hochkarätigen Gold-Titan-Legierungen

The behaviour of oxidation and precipitation hardening of very goldrich gold-titan alloys The oxidation behavior of gold rich Au-Ti alloys with contents of titanium between 0.5 und 1.3 weight-% was investigated in synthetic and natural air in dependence on the oxidation temperature and time. A closed homogeneous layer of titanium oxid was not formed. The nucleation of TiO₂ (Rutil) starts at prefered sites (grain boundaries, structure defects) below the surface of the alloys. The precipitations grow without formation a gapless cover of the grain boundaries. Between the precipitations the concentrations of titanium and oxygen are zero. The titanium is transported out of the interior of the specimen by volume diffusion. Based on an experimentally observed linear relationship between the oxygen uptake and the oxidation time the speed constants could be determined for 750°C, 825°C and 900°C. Between the natural logarithm of the speed constant and the reciprocal temperature a linear connection exists. For this reason it is possible to calculate the kinetics by a well-defined mathematical expression for the speed constant of the titanium oxidation in dependence on the titanium content and the oxidation temperature. The connection between the speed constant and the optical outfit of the surface is illustrated. Furthermore the precipitation hardening of the alloys at temperatures between 100°C and 700°C is described. A noticable increase of the hardness is already produced at relatively low temperatures. Whith increasing temperatures the hardness maximum is shifted to shorter times. With increasing titanium content the hardness maximum increases and it is obtained after shorter times. Cold working before the ageing, raises the hardness maximum and accelerates the precipitation. The precipitations are formed to little plates with high coherency to the matrix preferentialy at the grain boundaries. X-ray analysis sensitively responds to the kinetics of precipitation and gives reliable information about the concentration variations of the matrix. The results concerning the oxidation behavior and the precipitation hardening make it possible to find the conditions of an optimized heat treatment with high hardness but without negative changes of the surface.