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

Diffusion in PdCuNiP alloys from the amorphous to the liquid state

Interdiffusion in molten PdCuNiP alloys above melting temperature and impurity diffusion in Pd40Cu30Ni10P20 above and below the glass transition were investigated. For the interdiffusion measurements in the liquid alloys capillary methods were used in the temperature range from 973 1373 K. Uphill diffusion was observed for Pd and P in the presence of chemical gradients of Cu and Ni, respectively. This result correlates with mixing enthalpies calculated for the partial ternary systems. The measured temperature dependence of the interdiffusion coefficients is in accordance with the prediction of the mode coupling theory. The temperature dependence of the impurity diffusion coefficients in the non relaxed glass shows non linear Arrhenius behaviour with a kink near the glass transition. After long time relaxation at temperatures well below the glass transition the coefficients follow an uniform Arrhenius dependence over the entire temperature range with reduced diffusion coefficients below the glass transition