a sensitive and selective kinetic-spectrophotometric method was developed for the determination of trace amounts of uric acid. the method is based on the inhibitory effect of uric acid on the oxidation of janus green by bromate in the presence of sulfuric acid. the reaction was followed spectrophotometrically by measuring the absorbance at 518 nm using the fixed-time method. under optimum exper...

abstract mefenamic acid is a nonsteroidal anti-inflammatory drug (nsaid) that has analgesic,anti-infammatory and antipyretic actions. it is used to relieve mild to moderate pains. solid-phase extraction of mefenamic acid by a polymer grafted to silica gel is reported . poly allyl glycidyl ether/iminodiacetic acid-co-n, n-dimethylacrylamide was synthesized and grafted to silica gel and was used ...

in this article we review the application and procedures involved in scanning electron microscope (sem) to observe biological and live tissues through using sem at high resolution. we discuss practical methods for optimizing tissue preservation to achieve the two principal goals of biological specimen preparation: (a) preserving biological structures as close to their living configuration as po...

Considered in the paper is the problem of selecting a diagnostic biomarker that has the highest classification rate among several candidate markers with dichotomous outcomes. The probability of correct selection depends on a number of nuisance parameters from the joint distribution of the biomarkers and thus can be substantially affected if these nuisance parameters are misspecified. A two-stag...

I suggest for memorization an equation for calculating approximate sample size requirements intended only for a specific set of values (80 per cent power for a two-tailed alpha = 0.05 test) which seems to occur often in biopharmaceutical research. After presenting the formula in terms of variance estimate s2 and effect size d, I derive a few alternative forms and then discuss the accuracy of th...