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  • Author: T. Brinkmann x
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Abstract

We have evaluated the cardiac troponin I (cTnI) enzyme immunoassay AIA-PACK cTnI 2G (Tosoh Bioscience). The interassay precision at different cTnI levels (0.30 6.70 ng/ml-1) showed coefficients of variation (CV) between 5.00% and 4.71% on the AIA 600 II instrument. These data are in accordance with the functional sensitivity (0.04 ng/ml-1) and analytical sensitivity (0.02 ng/ml-1) specified by the manufacturers. Comparative troponin I measurements in serum samples were performed on the AIA-600 II analyser (Tosoh Bioscience) and the Dimension RxL analyser (Dade Behring). The cTnI concentration of serum samples (n=226) ranged from 0 ng/ml-1 to 114 ng/ml-1. Regression analysis of the cTnI values obtained showed a close correlation between both results (RxL=0.96 AIA+0.38; r=0.960). To induce proteolytic in vitro degradation of the cTnI molecule, patient serum samples (n=20) were incubated at 37C for 24 h and the cTnI concentration was determined before and after the incubation with both analysers. The cTnI concentration measured with the AIA-600 II analyser showed nearly identical values before and after the incubation period. However, cTnI measured with the Dimension RxL analyser showed decreased cTnI values in a range of 10 to 50% after the incubation period. The AIA-PACK cTnI 2G assay uses two different monoclonal antibodies against two epitopes in the proteolytic stable region of the cTnI molecule (between position 40 and 90 of the cTnI amino acid sequence). Therefore, measurement of cTnI in serum remains precise and specific in spite of in vitro proteolysis.

In einem zweiteiligen Artikel wird über streifende Inzidenz-Interferometrie mit Hilfe von diffraktiven Referenzelementen berichtet. Streifende Inzidenz-Interferometrie ermöglicht auch das interferometrische Vermessen der Oberflächengestaltabweichungen bei rauhen Oberflächen.

Dabei werden im Teil I das Prinzip, die zugrunde liegende Theorie, die Designprinzipien angepaßter diffraktiver Phasenmasken sowie die Lösung der Justierprobleme der technischen Testobjekte relativ zum Interferometer dargestellt.

Dies ist Teil II des zweiteiligen Artikels (Teil I: siehe tm 1/2000) über die Streifende-Inzidenz-Interferometrie. Hier werden die Auswertemethoden, Messbeispiele für technische Objekte, wie (1) Ebene, (2) Zylinder und (3) mathematisch konvexe Objekte und (4) allgemeine Meridiankurven von Stäben, die auftretenden systematischen Fehler aufgrund des Prinzips aber auch aufgrund der Herstellgenauigkeit lithographischer Maschinen und schließlich auch noch Erweiterungen in den mittleren IR-Bereich diskutiert. Um die Übersicht zu erleichtern, sind die Kapitel fortlaufend nummeriert, beginnend mit Kapitel 9.

Abstract

Motility of Euglena gracilis shows free running circadian rhythms. The circadian system is sensitive to light and temperature signals, but it is always masked by direct responses of motility to light (photokinesis) and temperature (thermokinesis). By means of a compartimental model which defines the interrelations between the pathways of thermokinesis, photokinesis and the circadian system a unifying view of effects of temperature and light input signals is outlined. According to the model, and using double sine input signals the dynamics of thermokinesis is described by a differential amplifier with constant gain.

Although thermokinesis heavily masks circadian responses to temperature signals, the limited range of circadian entrainment is indirectly demonstrated by a limited reappearance of free running circadian oscillations after stopping the temperature program. Free running circadian oscillations do reappear only after pretreatment with temperature periods near the circadian eigenperiod.

A white mutant lacking photosynthesis is used to investigate the role of photosynthesis in the signal processing. Although light synchronizes the circadian rhythms of the white mutant if applied as single input, it does not affect the motility if applied together with temperature inputs near the circadian eigenperiod. These results indicate frequency dependent mutual interactions between the model compartments.