In commonly used procedures for colorimetric assay of orotic acid in biological materials, certain substances interfere, positively or negatively. Some that interfere negatively are ornithine, cysteine, citrulline, tyrosine, proline, hydroxyproline, and polyamines. Protein and interfering agents are easily removed by first isolating the total organic acid fraction. The orotic acid in this fract...

Metal ion sensors are an important yet challenging field in analytical chemistry. Despite much effort, only a limited number of metal ion sensors are available for practical use because sensor design is often a trial-and-error-dependent process. DNAzyme-based sensors, in contrast, can be developed through a systematic selection that is generalizable for a wide range of metal ions. Here, we summ...

Antipyrine and bromide dilution are frequently used to estimate total body water and extracellular water volumes, respectively. We assessed a potential error with the simultaneous use of these methods. In vitro the bromide concentration of solutions measured by the gold chloride or rosaniline methods decreased linearly with increasing concentrations of antipyrine. With the gold chloride method,...

A fully automated method has been developed for the determination of total cholesterol in blood serum, using the AutoAnalyzer system. According to the new method, based on the cholesterol determination of Abell et a!. (1), the serum sample is saponified and subsequently extracted with carbon tetrachloride. After treatment with Liebermann-Burchard reagent, the amount of cholesterol is determined...

Different hexoprenaline (Hx(2)SO(4)) conventional and coated wire electrodes were constructed and evaluated. Membranes were based on hexoprenalinium phosphotungstate (Hx-PTA) and hexporenalinium phosphomolybdate (Hx-PMA). The electrodes were fully characterized in terms of their composition, response time, life span, pH, and temperature and then were applied to the potentiometric determination ...

Pattern bargaining is a negotiating strategy that is often employed by industry-wide unions in oligopolistic industries to set wages. The conventional wisdom is that pattern bargaining “takes labor out of competition” and therefore softens bargaining between the union and firms, resulting in higher industry wide wages. However, this does not explain why firms agree to pattern bargaining. We int...

We describe the in vitro activity of macrolides and tetracycline antibiotics against Pythium insidiosum. The MICs were determined according to CLSI procedures (visual MIC) and by a colorimetric method [3-(4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT)]. The lowest geometric mean (GM) MIC (MICs in μg/ml) (0.39 and 0.7 by visual reading and colorimetric method, respectively) an...

A series of artificial receptors, based on a sulfonamido system, have been designed and synthesized. The interaction of these receptors with biologically important anions was determined by UV-vis, (1)H NMR titration and electrochemical experiments. Results indicate that these receptors show high recognition abilities for fluoride (F(-)) or acetate (AcO(-)), moderate affinities for dihydrogen ph...

The aim of this study was to determine the efficacy of a colorimetric pupil light reflex (PLR) device (Melan-100(®), U.S.A.) in dogs with sudden acquired retinal degeneration syndrome (SARDS; 16 cases), progressive retinal atrophy (PRA; 10 cases) and optic pathway disease (6 cases). The colorimetric device detected PLR abnormality in 32, 16 and 9 eyes with SARDS, PRA and optic pathway disease, ...

A novel pH sensitive, colorimetric ionic liquid nanosensor based on phosphonium salts of fluorescein is reported. Herein, fluorescein salts of various stoichiometries were synthesized by use of a trihexyltetradecylphosphonium cation [TTP]+ in combination with dianionic [FL]2- and monoanionic [FL]- fluorescein. Nanomaterials derived from these two compounds yielded contrasting colorimetric respo...