65 research outputs found
Surface structure of Al-Pd-Mn quasicrystals: Existence of supersaturated bulk vacancy concentrations
Trace elements in hemodialysis patients: a systematic review and meta-analysis
<p>Abstract</p> <p>Background</p> <p>Hemodialysis patients are at risk for deficiency of essential trace elements and excess of toxic trace elements, both of which can affect health. We conducted a systematic review to summarize existing literature on trace element status in hemodialysis patients.</p> <p>Methods</p> <p>All studies which reported relevant data for chronic hemodialysis patients and a healthy control population were eligible, regardless of language or publication status. We included studies which measured at least one of the following elements in whole blood, serum, or plasma: antimony, arsenic, boron, cadmium, chromium, cobalt, copper, fluorine, iodine, lead, manganese, mercury, molybdenum, nickel, selenium, tellurium, thallium, vanadium, and zinc. We calculated differences between hemodialysis patients and controls using the differences in mean trace element level, divided by the pooled standard deviation.</p> <p>Results</p> <p>We identified 128 eligible studies. Available data suggested that levels of cadmium, chromium, copper, lead, and vanadium were higher and that levels of selenium, zinc and manganese were lower in hemodialysis patients, compared with controls. Pooled standard mean differences exceeded 0.8 standard deviation units (a large difference) higher than controls for cadmium, chromium, vanadium, and lower than controls for selenium, zinc, and manganese. No studies reported data on antimony, iodine, tellurium, and thallium concentrations.</p> <p>Conclusion</p> <p>Average blood levels of biologically important trace elements were substantially different in hemodialysis patients, compared with healthy controls. Since both deficiency and excess of trace elements are potentially harmful yet amenable to therapy, the hypothesis that trace element status influences the risk of adverse clinical outcomes is worthy of investigation.</p
Policy Implications of Present Knowledge on the Development and Prevention of Physical Aggression
THE USE OF LASER MICROPROBE MASS ANALYSIS IN BIOMEDICAL RESEARCH
Le LAMMA donne la possibilité d'analyser, par spectrométrie de masse, de très petits volumes de matière. En évaporant des microvolumes d'échantillons, le faisceau laser produit des ions qui sont analysés au moyen d'un spectromètre de masse. En recherche biomédicale, le LAMMA permet d'identifier et de localiser des éléments à l'état de trace. Il permet également d'identifier des molécules ou des fragments de molécules.The Laser-Microprobe-Mass-Analyser LAMMA permits the mass spectrometric analysis of very small volumes of matter. The method is based on laser beam induced ion production by evaporation of microvolumes of a specimen and the mass spectrometric analysis of the ions. In biomedical research, important applications of LAMMA are the identification and localization of trace elements and the identification of molecules or molecular fragments
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