The mutual diffusion coefficient for (meth)acrylate monomers as determined with a nuclear microprobe.

The value of the mutual diffusion coefficient DV of two acrylic monomers is determined with nuclear microprobe measurements on a set of polymer films. These films have been prepared by allowing the monomers to diffuse into each other for a certain time and subsequently applying fast ultraviolet photo-polymerization, which freezes the concentration profile. The monomer diffusion profiles are studied with a scanning 2.

Production of chemically pure gaseous [13N]NH3 pulses for PEP studies using a modified DeVarda reduction.

A fast and reproducible production method for pure gaseous [13N]NH3 pulses has been developed. 13N was produced by irradiation of water with 500 nA of 16 MeV protons via the 16O(p,alpha)13N reaction. A mixture of DeVarda's alloy and NaOH was used to convert the produced nitrate/nitrite to ammonia.

Microbeam PIXE analysis of Na, K, Mg, and Ca in severely damaged cardiac tissue.

The aim of the study was to measure with microbeam PIXE elements such as Na, K, Mg, and Ca in cardiac tissue after various treatments in vivo, which affect the cardiomyocyte integrity. It was assumed that local deviations from normal electrolyte levels indicate the degree of cardiac damage. The first step in this feasibility study was comparison of severely damaged cardiac tissues with controls.

Pixe microanalysis of trace elements of normoxic, ischemic and reperfused rat hearts.

With a 3 x 3 mu m(2) proton microbeam spatial distributions of Na, Mg, P, S, K, Ca and Fe were measured via PIXE in 50 x 50 mu m(2) areas of rat heart, sliced into 10-15 mu m thick cryosections. The isolated rat hearts were subjected to normal perfusion, ischemia and reperfusion. Substantial changes in the elemental distribution were found in tissue after 40 min.