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Radionuclide Sources
Published in Michael Pöschl, Leo M. L. Nollet, Radionuclide Concentrations in Food and the Environment, 2006
Jeffrey S. Gaffney, Nancy A. Marley
Traditionally radionuclides have been separated into three categories or types: (1) primordial and secondary, (2) cosmogenic, and (3) anthropogenic. Primordial radionuclides, such as uranium, thorium, and certain isotopes of potassium, have very long lifetimes and were produced at or before the creation of planet Earth. Secondary radionuclides are derived through radioactive decay of the long-lived primordial parent nuclides. These decay products are commonly referred to as daughters. Along with the parent sources, the daughters constitute radiogenic decay families or “chains” that are an important source of natural radioactivity. Cosmogenic radionuclides are formed by the interaction of cosmic rays with Earth’s atmosphere or lithosphere, while anthropogenic radionuclides are formed from human activities that create artificial radionuclides or enhance the levels of certain radionuclides already present on Earth. In this chapter we discuss the three types of radionuclide sources separately and highlight some of the more important examples.
The association of overhydration with megafistulas in hemodialysis patients
Published in Renal Failure, 2019
Mihály Tapolyai, Mária Faludi, Klára Berta, Melinda Forró, Lajos Zsom, Ákos G. Pethő, László Rosivall, Tibor Fülöp
All of our patients routinely undergo bimonthly pre-dialysis fluid status evaluations at the designated medical care facility by using a multi-channel bioimpedance spectroscopy apparatus (BCM – Body Composition Monitor, Software version 3.2; Fresenius Medical Care, Bad Homburg, Germany) as part of our standard clinical practice. The etiology of the proband group’s ESRD was heterogeneous including PCKD (1), urological anomalies (1), nephrectomy because of renal cell carcinoma (2), presumably hypertension (1), diabetes (3), glomerulonephritis (2), and unknown. We have previously described the measurement method [16]; however, it shall be added that we measured the patients’ fluid compartments by positioning them flat on their backs and placing two conductive electrodes on their hands and ankles on the same side at the same time. With this method, we measured their total body water (TBW), extracellular water (ECW), intracellular water (ICW), and overhydration (OH) levels in liters and acquired the percentage (OH%) of the excess fluid that is greater than the anticipated ECW. The validation of the bioimpedance methods for measuring fluid spaces has been done historically with various isotopes (of potassium, bromide, hydrogen), tagged albumin and DEXA scans and reviewed earlier in details [21].