AND YUEFENG F. XIE aloacetic acids (HAAs) and trihalomethanes (THMs) are the major disinfection by-products (DBPs) found in chlorinated drinking water. Nine species of HAAs are commonly found in chlorinated water: monochloroacetic acid (ClAA), monobromoacetic acid (BrAA), dichloroacetic acid (Cl2AA), bromochloroacetic acid (BrClAA), dibromoacetic acid (Br2AA), trichloroacetic acid (Cl3AA), brom...

General-acid catalysis of the reaction of methoxyamine with phenyl acetate by the proton, carboxylic acids, and ammonium ions follows a nonlinear Bransted curve. This curve agrees quantitatively with the behavior expected for the enforced preassociation mechanism of catalysis that was predicted for this reaction. The stronger acids, including the proton, follow a Bransted slope of a = 0.16 that...

T HE FINAL STEPS OF THE CLOTTING PROCESS, in which fibrinogen (Factor I) is transformed to fibrin through the action of thrombin, is customanily described as taking place in three stages. Initially, thrombin, a proteolytic enzyme of high substrate specificity, cleaves four arginyl-glycine bonds in each fibrinogen molecule, so that two pairs of peptide fragments are released. During the second s...

Delonix regia gum (DRG) is a natural polysaccharide obtained from the endosperm of Delonix regia seeds, chemically classified as galactomannan. The objective of the present study was to derivatise DRG to carboxymethylated Delonix regia gum (CMDRG) using non aqueous method and to overcome limitations of natural polymer viz, fall in viscosity on storage, susceptible to microbial contamination, an...

I N 1948, Laki and Lorand1 observed that “fibrin clots” formed by the addition of calcium throm in to purified fibrinogen solutions were readily soluble in 5 NI urea and 1 per cent monochloroacetic acid. “Plasma clots” formed Iw the recalcification of oxalated plasma were insoluble in these solvents. Urea insolube clots could also be prepared 1w the addition of small amounts of plasma to the pu...

Chitosan (CS) is a biodegradable, biocompatible, and mucoadhesive natural polymer soluble in acidic pH only and can be irritating to the eye. Objective of the study was to synthesize water soluble 6-O-carboxymethyl (OCM-CS) derivative of CS, and to develop CS and OCM-CS nanoparticles (NPs) loaded with dorzolamide hydrochloride (DRZ). CS was reacted with monochloroacetic acid (MCA) for OCM-CS sy...

This paper describes preparation of carboxymethylated and carboxylated cellulosic fibers from waste paper. Chemical properties of the product were distinguished by Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) spectral analysis. To produce carboxylated and crosslinked fibers and also to increase the anionic surface charge of the fibers, maleic anhydride was used in ...