lose ammonia to give a ketenimine, followed by isomerization and expulsion of nitriteWhen the reaction with TNM was carried out in aqueous ethanol, significantly decreased yields of 2 resulted, suggesting alternate reaction pathways. In preliminary experiments, TNM on tryptophan peptides in aqueous solvents gave a mixture of nitrated products with the spectral characteristics of nitroindoles.17 We are now looking into the reaction of tryptophan peptides with TNM in organic solvents.

No abstract

A rapid method for determination of glutaraldehyde (GA) is described based on formation of the GA-bisulfite complex followed by iodometric titration of unreacted bisulfite. A 1-mi aliquot of 2-6% GA is added to 20 ml of 0.25 M Na bisulfite. A reaction time of 5 mm is allowed, and the solution is titrated with 0

No abstract

No abstract

No abstract

No abstract

Requirements for tissue-equivalent mixtures are discussed, and methods are described for formulating mixtures exact in elemental composition and density. Methods are also given for estimating the densities and vapour pressures of mixtures of known compounds, as well as a list of the properties of compounds useful in tissueequivalent formulations. A density value of 1.066 f 0.003 g at 37 ' c is obtained for lean mammalian muscle, from the literature and from experiments. A density of 1.063 g cm-3 at 37'c is obtained from the literature, for Standard Man exclusive of air voids. Tissue-equivalent liquids and their properties are presented for Standard Man and for lean muscle. These are exact in composition for C, H, 0, S, Ca, P, S, K, Sa, Cl and Mg, range from 1.012 to 1.106 g in density at 25 "c, and include mixtures for the standard density range of 1.06-1.07 g cm-3. Two simplified mixtures are also described, correct only for C, H, 0 and N, for use where exact elemental composition is not important.