Scattering and absorption of light by a homogeneous distribution of intergalactic large dust grains has been proposed as an alternative, non-cosmological explanation for the faintness of Type Ia supernovae at z ∼ 0.5. We investigate the differential extinction for high-redshift sources caused by extragalactic dust along the line of sight. Future observations of Type Ia supernovae up to z ∼ 2, e...

Cartilage glycosaminoglycans (GAGs) were measured by a spectrophotometric assay in synovial fluid obtained from 30 normal bovine hock joints and 15 osteoarthritic human knee joints. Results were compared with those obtained by radioimmunoassay (RIA). The spectrophotometric method (dimethylmethylene blue (DMB) assay) was found to be simple, safe, and sufficiently reproducible to be of potential ...

In this paper, methods of sample preparation for potentiometric measurement of phenylalanine are presented. Basing on the spectrophotometric measurements of phenylalanine, the concentrations of reagents of the enzymatic reaction (10 mM L-Phe, 0,4 mM NAD, 2U L-PheDH) were determined. Then, the absorption spectrum of the reaction product, NADH, was monitored (maximum peak at 340 nm). The results ...

A small regional survey of direct spectrophotometric methods and a larger Australian and New Zealand survey of paediatric bilirubin analyses are described. The overall performance of both groups was unsatisfactory with an unacceptable high interlaboratory variation. This interlaboratory variation was reduced significantly by the use of a spectrophotometric method with a common standard of methy...

This document describes the Imager for Mars Pathfinder (IMP) calibration targets and outlines a procedure for their use in first-order spectrophotometric image calibration. The Mars Pathfinder mission and landing site are discussed, as are previous observations of Mars. Bidirectional reflectance theory relevant to target design and usage as well as planetary surface measurement will be develope...

A method is proposed for automatic instrumentation of enzyme activity determinations which involve spectrophotometric measurements. The procedure utilizes a kinetic method to produce one instrumental reading that is proportional to enzyme concentration. The single spectrophotometric reading can be processed by analog or digital computation, using the known absorptivity constant of the reactant ...

We describe a new technique for monitoring intra-cuvette temperatures in temperature-controlled spectrophotometric cells by use of two solutions, one for which absorbance is highly sensitive to temperature and one for which absorbance is insensitive to temperature. The first solution, cresol red in tris(hydroxymethyl)aminomethane buffer, is used to construct an absorbance-vs.-temperature calibr...

Several methods for determining urea in blood and urine are in use in clinical laboratories, but none is ideal in mass routine analysis. The spectrophotometric method based on a modified Ehrlich reagent proposed by Watt and Chrisp (1954) for pure solutions is therefore of interest because it can be modified for use in mass clinical analyses of blood and urine. Brown (1959) has modified the meth...

A lag phase in the spectrophotometric assay progress curve of aldehyde oxidation by HL-ADH was observed and characterised. The aldehyde oxidation and aldehyde dismutation reactions were shown to be related, and a mechanism to explain net aldehyde oxidation was proposed. The spectrophotometric assay was shown to be unsuitable for measurement of kinetic parameters for aldehyde oxidation by HL-ADH...

the aerial oxidation of hydroquinone in a freshly prepared developer solution at 20°c has been studied through the measurement of concentration changes by a spectrophotometric method. the concentration of consumed hydroquinone is directly proportional to time, and the equation til2 = c, / 0.0786 was obtained to calculate the half-life of the developer. in this equation, the half-life is in hour...