Three accurate, rapid and simple atomic absorption spectrometric, conductometric and colorimetric methods were developed for the determination of norfloxacin (NRF), ciprofloxacin (CIP), ofloxacin (OFL) and enrofloxacin (ENF). The proposed methods depend upon the reaction of ammonium reineckate with the studied drugs to form stable precipitate of ion-pair complexes, which was dissolved in aceton...

the formation constants and gibbs free energy for the interaction of rnsnclm (n = m = 2, r = me, ph, n-bu or n = 4, m = 0, r = ph) compounds as acceptors, with ml complexes (h2l = n,n'-bis(salicylidene)-2-aminobenzylamine (salabza-h2) and its derivatives, m = mn2+ or zn2+), as donors in n,n'-dimethylformamide (dmf) as solvent were studied. these parameters were measured by using uv-vis spectrop...

We examined the mechanism by which hypertriglyceridemia interferes with the Roche Diagnostics "Amylochrome" procedure for measurement of amylase in lactescent samples with normal and above-normal amylase activity. The serum blank recommended in the Amylochrome protocol to compensate for lactescence remains inappropriately turbid, compared with the test, and is partly responsible for the underes...

A proteoglycan isolated from a rat yolk sac tumor and characterized as a chondroitin sulfate proteoglycan with a smaller amount of dermatan sulfate was studied with respect to complex formation with collagen and fibronectin. The proteoglycan co-precipitated with native collagen from neutral salt solutions at 6 degrees C and 37 degrees C. Addition of fibronectin in such precipitation mixtures re...

Oxynitride glasses are found as grain boundary phases in silicon nitride ceramics. They are effectively alumino-silicate glasses in which nitrogen substitutes for oxygen in the glass network, and this causes increases in glass transition and softening temperatures, viscosities (by two to three orders of magnitude), elastic moduli and microhardness. Calcium silicate-based glasses containing fluo...

Acid mine drainage (AMD) is usually treated by air oxidation followed by addition of lime to precipitate metal hydroxides and calcium sulfate. Geo2 Limited of Melbourne, Australia, has developed and patented a novel alternative precipitation scheme based on the formation of mixed valency, M(II)-M(III), hydroxide sulfate salts. When the composition of AMD has an appropriate ratio of Fe(II):Fe(II...

The ability to use GFP-tagged proteins to perform correlative light and electron microscopy has been a desirable but elusive method. The high quantum yield of GFP that makes it excellent for fluorescence imaging also makes it extremely inefficient for production of the reactive oxygen needed to trigger formation of an electron-dense precipitate for electron microscopy. This roadblock has finall...

Solid titration was used to explore the solubility isotherms of partially (Srx-HAp, x=1, 5, 10, 40, 60 mol.%) and fully substituted strontium hydroxyapatite (Sr-HAp). Solubility increased with increasing strontium content. No phase other than strontium-substituted HAp, corresponding to the original titrant, was detected in the solid present at equilibrium; in particular, dicalcium hydrogen phos...