ABSTRACT
The properties of the moiré fringes in Talbot interferometry are analyzed for a small inclined angle beta between the two grating planes, which is produced by rotation of the beam splitter grating about the axis perpendicular to the lines of the grating. Theoretical analyses indicate that the tilt angle of the resultant moiré fringes is less sensitive to beta than when the small inclined angle is formed by rotation of the beam splitter grating about the axis parallel to the lines direction of the grating as described earlier [Appl. Opt. 38, 4111 (1999)] and that contrast of the moiré fringes decreases with an increase in beta or in the spatial frequency of the grating and may result in impaired measurement accuracy. The validity of the theoretical analyses is illustrated by experiments.
ABSTRACT
The effects of an arbitrary small inclination between two cross gratings on the moiré fringes in Talbot interferometry are discussed when the frequencies of the grating differ in two perpendicular directions. We show that the small angles, alpha and beta, by which the beam-splitter cross grating is rotated around the two axes parallel to the two perpendicular line directions of the cross grating, have a greater influence on the moiré fringes with cross gratings than that with one-dimensional gratings. A simple and practical detection method for the angles between the two unparallel grating planes in Talbot interferometry is also proposed. The theoretical analyses are proved by experimental results.
ABSTRACT
Methods were evaluated for depressing the acetaldehyde (AcH) inhibition of uridine uptake by Chang liver cells and isolated autologous liver cells, obtained by percutaneous liver biopsy from cases of alcoholic hepatitis. Hepatocytes so obtained were significantly more susceptible to AcH-induced inhibition of uridine uptake than hepatocytes from normal liver, alcoholic fatty liver, stable alcoholic cirrhosis and acute viral hepatitis. Benzylamine (an aldehyde buffer) and pyridoxal-5' phosphate (PLP) counteracted the inhibition of uridine uptake by AcH in vitro. We suggest that benzylamine neutralizes AcH toxicity through a Schiff-base condensation with AcH thus taking AcH out of the field of action. PLP protects against AcH-induced inhibition of uridine uptake by probably forming a Schiff base with cellular amino acids thus blocking further condensation of these amino groups with AcH. In this manner, uridine uptake by liver cells for RNA synthesis can proceed without interference by AcH.
