bioactive materials including glass and glass-ceramics are nowadays used as medical implants for orthopedic applications. in this study several samples of glass-ceramics have been prepared using both heat treatment and sol-gel processes. the structure and bioactivity of these samples based on their interaction with simulated body fluid (sbf) have been determined. in-vitor, using the raman spect...

194 CLINICAL CHEMISTRY, Vol. 25, No. 1, 1979 gas chromatography before and after acid (6 mol/L HC1) and alkaline (NaOH) hydrolysis. We frequently observe a peak in the lactic acid position after alkaline hydrolysis. After acid hydrolysis of the same urine no lactate isobserved, but a peak appears in the position of levulinic acid. The mass spectra of these two peaks were identical with those of...

Bioactive materials including glass and glass-ceramics are nowadays used as medical implants for orthopedic applications. In this study several samples of glass-ceramics have been prepared using both heat treatment and sol-gel processes. The structure and bioactivity of these samples based on their interaction with simulated body fluid (SBF) have been determined. In-vitor, using the Raman s...

In this article we describe some of the recent work that has been performed using ion mobility measurements to deduce structural information for polyatomic ions. Determining the structure of a polyatomic ion in the gas phase is a challenging problem, that is usually approached by indirect methods such as dissociation or reactivity studies. Ion mobility measurements have recently emerged as a te...

Partially coalified, structurally intact latex fibers found in a low rank coal were characterized by analytical methods. The latex fibers have a high sulfur content of approximately 10 percent. It has been proposed in previous studies, and it appears to be the case here, that the latex material has been “naturally” vulcanized during the early diagenetic period. Two fossilized latex samples reco...

Drcarboxylic aciduria is a condition sometimes encountered during routine urine screening for inborn errors of metabolism [l] and may be due to ketosrs, a transient condition m some neonates [2] or a number of enzyme deficiencies mainly involving fatty acid metabolism or transport. Unsaturated dicarboxylic acids have also been reported m some of these conditions. These compounds are usually det...

The aim of this work was to study the biodiesel production from cotton seed oil by lipase produced by Pichia guilliermondii lipase, which was immobilized onto hydrophobic magnetic particles (HMPs). The optimum reaction conditions were determined for lipase dosage, methanol-to-oil molar ratio, temperature and water content. Using response surface methodology, a quadratic polynomial equation was ...