Plutonium segregation in glassy aerodynamic fallout from a nuclear weapon test.

This study combines electron microscopy equipped with energy dispersive spectroscopy to probe major element composition and autoradiography to map plutonium in order to examine the spatial relationships between plutonium and fallout composition in aerodynamic glassy fallout from a nuclear weapon test. A sample set of 48 individual fallout specimens were interrogated to reveal that the significant chemical heterogeneity of this sample set could be described compositionally with a relatively small number of compositional endmembers. Furthermore, high concentrations of plutonium were never associated with several endmember compositions and concentrated with the so-called mafic glass endmember. This result suggests that it is the physical characteristics of the compositional endmembers and not the chemical characteristics of the individual component elements that govern the un-burnt plutonium distribution with respect to major element composition in fallout.

Effect of common over-the-counter medications on blood alcohol levels.

OBJECTIVE: To assess the clinical and legal significance of the potential pharmacokinetic interaction between common over-the-counter (OTC) medications and alcohol that may result in increased blood alcohol levels (BALs). DATA SOURCES: A MEDLINE search (1966-February 2000) of English-language articles was performed using the terms aspirin, acetaminophen, histamine (H2)-receptor antagonist, ethanol, and blood alcohol level and then supplemented by a bibliographic review of relevant articles. STUDY SELECTION AND DATA EXTRACTION: Two H2-receptor antagonist studies using methodologies representative of other published trials and a meta-analysis of 24 H2-receptor antagonist trials were chosen for detailed review. All identified studies examining aspirin and acetaminophen were addressed. DATA SYNTHESIS: More than 30 studies have examined the potential interaction between OTC drugs and blood alcohol. Because this issue has important medical and legal implications for patients, prescribing physicians, and pharmaceutical manufacturers, a critical analysis of the literature addressing this potential interaction is presented. CONCLUSIONS: Numerous factors arguing against a clinically significant interaction were identified. First, data from the relevant studies cannot be extrapolated to the general population because of the multitude of variables that determine an individual's BAL. Also, a publication bias for small studies (< or = 10 subjects) finding a statistically significant increase in peak BAL was observed. In addition, study results supporting an increase in BAL were often irreproducible when these trials were repeated under similar conditions. Finally, although some studies detected statistically significant increases in peak BAL, these changes were often clinically irrelevant.