Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Electron Probe Microanalysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed1995

"Standardless" quantitative electron probe microanalysis with energy-dispersive X-ray spectrometry: is it worth the risk?

"Standardless" procedures for quantitative electron probe X-ray microanalysis attempt to eliminate the need for standardization through calculation of standard (pure element) intensities. Either "first principles" calculations, which account for all aspects of X-ray generation, propagation, and detection, or "fitted standards" calculations, which use mathematical fits to measured intensities from a limited set of pure standards, can form the basis for standardless analysis. The first principles standardless analysis procedure embedded in the National Institutes of Health/National Institute of Standards and Technology comprehensive X-ray calculation engine and database, Desktop Spectrum Analyzer, has been tested against spectra measured on NIST standard reference materials, research materials, and binary compounds. The resulting distribution of errors is broad, ranging from -90% to +150% relative. First principles standardless analysis can thus lead to unacceptably large errors.

Electron Probe Microanalysis↗
PubMed1977

Identification of stainless steel welding fume particulates in human lung and environmental samples using electron probe microanalysis.

Open lung biopsy specimens from two welders and air samples from their workplace environments were examined with the electron probe microanalyzer. X-ray analysis showed that the majority of particles found in the lung tissue from both workers and in the air samples to be composed of varying amounts of iron, chromium, manganese and nickel, the major components of some types of stainless steel. Based upon these analyses, it was concluded that the majority of the particles in both biopsy specimens were a result of the workplace environment.

Air Pollutants, Occupational↗
PubMed1995

Electron probe microanalysis of silicon and the role of the macrophage in proximal (capsule) and distant sites in augmentation mammaplasty patients.

Electron probe x-ray microanalysis was used to locate silicon (Si) within macrophages from 12 women who had previously undergone polymer prosthesis augmentation or reconstruction. Silicon was identified within macrophages and extracellularly in all fibrous breast capsules. In four women with arthritic joint pain and one woman with sclerodermatous skin lesions, silicon also was identified within macrophages residing in joint synovium and skin, respectively. It is suggested that the silicon-laden macrophages observed in the remote lesions may have accumulated silicon from other macrophages that had previously resided in the connective-tissue capsule around the silicone breast implants.

Adult↗
PubMed1983

Diagnosis of early human myocardial ischemic damage with electron probe microanalysis.

We determined the Na/K x-ray intensity ratio in frozen sections of myocardial tissues obtained at autopsy from patients who died from various causes, using electron probe analysis. We have been able to distinguish between the ischemically injured and normal cells. The method is simple, fast, and dependable even when the duration of ischemia is only 30 minutes.

Adolescent↗
PubMed1983

Combined energy detector-wavelength dispersive spectrometer electron probe microanalysis of biological soft tissue samples.

A Si(Li)energy detector has been coupled with a fully automated, four wavelength dispersive spectrometer electron probe microanalyzer for analysis of freeze-dried, plastic-embedded biological tissue samples. Through the use of a suitable absorber, the unwanted portion of the energy spectrum is suppressed, thus reducing overall counting rate in the energy detector to the point where it is possible to use electron beam currents with high intensities, typical of wavelength dispersive spectrometer operation, while using the configuration of highest energy detector solid angle available in our electron probe microanalyzer. The electron probe automation software has been extended to permit control of the energy detector simultaneously with control of the electron microprobe. A software stopwatch permits accurate compensation for differences between energy detector and wavelength spectrometer dead times. A region of continuum in the energy spectrum is calibrated against background for the spectrometers to provide a different number representing background for each spectrometer. This background information is provided simultaneously with on-peak data collection by treating each region of interest from the Si(Li) energy detector spectrum as an additional data line in the electron probe microanalyzer computer automation package.

Animals↗
PubMed1984

[Localization of iron and sulfur in the lysosomes of thyroid epithelium using electron probe microanalysis and X-ray spectrometry].

Thyroid lysosomes have been studied by means of EPMA combined with an electron microscope. In 4 months old mice, lysosomes are a few number and contain very low iodine concentrations and sulfur load is not significant. In 10 months old mice, iodine only or associated with sulfur is observed in homogeneous lysosomes varying in size and density. Those two types of localizations reflect two eventual steps in hormonal metabolism pathway of iodine.

Animals↗
PubMed1983

Localization of gallium in tumor cells. Electron microscopy, electron probe microanalysis and analytical ion microscopy.

The incorporation of gallium in tumor cells in vitro and in solid tumors was studied with electron microscopy and two microanalytical techniques. It was thus possible (1) to directly prove that gallium is concentrated in lysosomes of tumor cells; (2) to demonstrate that in these lysosomes, gallium is precipitated with phosphorus; and (3) to propose a mechanism of gallium concentration in tumor cells; in this mechanism, the accumulation of gallium as phosphate salts in lysosomes is directly related to the acid phosphatase activity of these organelles.

Animals↗
PubMed1998

Electron probe microanalysis of permanent human enamel and dentine. A methodological and quantitative study.

Sample preparation of dental tissues for quantitative electron microprobe analysis has not been critically examined because of the highly mineralized nature of these structures. The present study was designed to establish the most suitable method for the electron probe quantitative determination of calcium in human permanent enamel and dentine while preserving the morphological features. Comparisons of quantitative data obtained with air-drying and freeze-drying methods showed that calcium in enamel was more accurately measured in specimens prepared with cryopreservation and freeze-drying. No significant differences between the methods tested were found in dentine although cryopreservation and freeze-drying yielded less statistical variability. Moreover this approach did not modify morphological features of interest. We recommend this combination of processing techniques for human permanent teeth not only because it was found the most accurate and least variable in determining calcium concentration, but also because of its potential usefulness in studies of alterations in tooth mineralization.

Calcium↗