A novel idea for biochemical microanalysis of heavy metal ions in combination with flow-injection techniques is proposed. The microdetermination of the cofactors based on an apoenzyme reactivation method is reviewed exemplifying the assays for heavy metal ions with use of several kinds of immobilized metalloenzymes as the recognition elements for each metal ion.

Turgor-mediated leaf movements of the legume Samanea saman are associated with the migration of K(+) and Cl(-) between opposing sides of the motor organs (pulvini). We have investigated the pathway of this ion migration by localizing K(+) and Cl(-) within the secondary pulvinus at various times during leaf movements. Ion distributions in freeze-dried cryosections of pulvini were determined by s...

A Cameca IMS 300 ion analyzer has been used to measure fluorine concentrations in tooth material. Samples of human and shark teeth were studied. Negative oxygen primary ions produce secondary mass spectra in which positive as well as negative fluorine ion peaks are well re­ presented. With constant measuring conditions, the reproducibility of the F/Ca ion ratios is satis­ factory. Fluorine conc...

X-ray microanalysis is commonly applied in biomaterials research to study changes in biomaterial composition, calcifications, or to identify particulates in tissue that has been in contact with biomaterials. Studies where the effect of biomaterials on the naturally occurring elements in the cells are studied are rare. Exposure to or contact with biomaterials may give rise to several cellular re...

Copper oxide has been detected in the copper containing alloys of NBS Standard Reference Material (SRM) 482. This occurrence is significant because it represents heterogeneity within a standard reference material that was certified to be homogeneous on a micrometer scale. Oxide occurs as elliptically to spherically shaped precipitates whose size differs with alloy composition. The largest preci...

The authors investigated the physical role of the airway epithelium in response to changes in the airway surface fluid's composition by superperfusing the lumen with nonisotonic solutions. Morphological studies and measurements of changes in ion content in the underlying connective tissue (CT) were carried out. The study used an experimental model of isolated rat trachea. The trachea was mounte...