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SETTING Interferon-gamma (IFN-γ) release assays (IGRAs) play an important role in the diagnosis of Mycobacterium tuberculosis infection. However, in children with tuberculosis (TB), some studies have shown increased frequencies of false-negative or indeterminate IGRA results. OBJECTIVE To analyse the spectrum of different cytokines to improve the(More)
A method is described which reliably quantifies the degree of intercellular communication via gap junctions by combining a dye-loading technique with fluorescence-activated flow cytometry. Our experiments expand former measurements of other groups by analyzing the time- and density-dependent onset of coupling with a fixed ratio of donor to recipient cells.(More)
In vivo administration of islet-activating protein to rats resulted in an increase in fat cell lipolysis in vitro, which was associated with almost complete resistance of adipocytes towards the antilipolytic effects of N6-phenylisopropyladenosine, prostaglandin E2 and nicotinic acid. Concomitantly, the inhibitory effects of these compounds on adenylate(More)
If phase-measurement interferometry (PMI) is applied for a high numerical aperture (NA), specific errors can occur. The resulting phase no longer varies linearly with the height difference in the test surface. Thus, for height measurements, a constant correction factor or NA scaling factor, which depends only on the NA and the illumination of its stop, does(More)
The rotation method for the absolute testing of three flats by the evaluation of four interference patterns of pairs of these flats is developed further. Least-squares methods for determining and minimizing the effect of random measuring errors are fully applied. This application makes an optimal resolution in depth and an enhanced lateral resolution(More)
A further-developed three-plate rotation method [Appl. Opt. 31, 3767 (1992)] for the absolute testing of flats is used as a measuring method for establishing flatness standards. A special phase-stepping Fizeau interferometer was built that permits flats of diameters up to 200 mm to be tested. First results show a mean error between 0.002 and 0.003 λ in the(More)