1,720,985 research outputs found
Trace elements analysis in biological samples by proton nuclear activation
No full textA method for the multielemental analysis of trace elements in biological samples by medium energy proton nuclear activation (PNA) has been developed. The response linearity, reproducibility and reliability of the method have been tested by a set of preliminary measurements. Results concerning the quantitative determination of the concentrations of Sr, Cu, Fe, Zn and Se in human serum are presented. Activation was induced with a 23 MeV proton beam from the AVF cyclotron of the University of Milan, by means of (p, 2n) reactions on the nuclei of the elements under study. The quantitative determination was obtained by an internal reference method and by comparison with a standard sample of serum doped with known quantities of the elements of interest. A clinical investigation of the zinc content of serum in children has been performed
Response functions of an X-ray detecting system for spectral analysis of therapeutic beams
No full textCadmium and titanium in human serum determined by proton nuclear activation
No full textAn investigation of the quantitative content of Cd and Ti in human serum samples by proton nuclear activation (PNA) has been performed and the results are presented. The activation had been induced by a 13.5 MeV proton beam of the AVF cyclotron of the University of Milan, via a (p, n) reaction on the nuclei of the target. For the quantitative determination a known amount of a reference element has been added to the samples and comparison has been made with a standard sample containing also known quantities of the elements studied. Response linearity, reproducibility and possible contaminations have been tested
Response functions of an X-rays detecting system for spectral analysis of therapeutic beams
No full textDetailed analysis by means of a Ge(Li) crystal of continuous X-ray spectra produced by medical accelerator
No full textChromium in human serum determined by proton activation
No full textA method for Cr determination in biological samples based on proton nuclear activation is presented. The activation was induced by a 13.8 MeV proton beam of the AVF Cyclotron of Milan University via a (p, n) reaction on the nuclei of the target. For the quantitative determination Cd has been chosen as reference element. The method has been applied to Cr determination in human serum samples. The experimental procedure is described and results are presented and discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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