The reaction of recombinant tissue-type plasminogen activator with the inverse substrate 4-amidino-2-nitrophenyl 4'-anisate results in the rapid release of the chromogen 4-amidino-2-nitrophenol and the accumulation of the relatively stable 4-anisoyl-enzyme. Spectrophotometric monitoring of the reaction enables the operational molarity of the enzyme to be determined.

The 1,3-distal cone-calix[4]arene dialdehyde 1 undergoes Cannizzaro disproportionation in the presence of strong base, but its 1,2-vicinal regioisomer 3 and the analogous monoaldehyde 2 are unreactive under the same conditions. The high intramolecular reactivity of the 1,3-distal regioisomer 1 is measured and discussed in terms of Effective Molarity (EM).

Self-assembly of the linear segmental ligand L5, consisting of a tridentate binding unit flanked with two bidentate binding units, with a mixture of Fe(II)/Ag(I) yields the trinuclear coordination-captured [2]catenate [AgFeAg(L5)(2)](4+) instead of the planned isomeric double-stranded helicate. Replacing the octahedral (Fe(II)) and tetrahedral (Ag(I)) cations with Zn(II), which is compatible wi...

A simple dye-binding method for determining serum albumin, which employs the dye, 2-(4’-hydroxybenzeneazo) benzoic acid (HBABA), is described. Albumin in 0.1 ml. of serum is determined colorimetrically at 510 m s. Reliability of the method has been established by comparison with another method using HBABA and with a salt fractionation-biuret method, by recovery experiments, variation in ambient...

Pepstatin has been shown to be an extremely potent inhibitor of human renin (Ki = 1.3 X lo-lo M). Kinetic analyses by several techniques show reversible interaction of pepstatin with renin and classical noncofipetitive inhibition. The high affinity of pepstatin for renin allows kinetic determination of the molarity of the enzyme in partially purified preparations. This method has been validated...

This article presents and discusses the results of a study that investigates university students’ comprehension concept molar concentration, following teaching evaluation subject. The specific problems underlying learning this have not yet been focused on in sufficient detail or depth. A “Reasoning with molarity” questionnaire, which explores logical–mathematical relationships between variables...

A highly efficient bicarbonate hydrogenation catalyst system based on ppm concentrations of a Ru-PNP pincer complex is presented. It allows converting supersaturated slurries to aqueous formate solutions up 12 M in molarity.