1,720,978 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The 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

    Measurement of local Mr 97,000 and 250,000 protein antigen concentration in sections of human melanoma tumor using in vitro quantitative autoradiography.

    No full text
    An assay method that uses I25l-labeled monoclonal antibody (MoAb) and in vitro quantitative autoradiography was developed to determine the local concentration of tumor-associated antigens in tissue sections. Human melanoma biopsy specimens were evaluated for the expression of the M, 97,000 and 250,000 protein antigens using MoAb-96.5 and MoAb-9.2.27, respectively. Tissue sections were incubated in solutions of increasing concentration of I25l-labeled MoAb with or without an excess of unlabeled antibody. Quantitative autoradiography was performed on the sections and compared with I25I standards to determine tumor-bound radioactivity and calculate bound pmol of MoAb per g of tumor. The total binding, nonsaturable binding, and specific binding of I25l-labeled MoAb to tumor were then computed. Specific binding of MoAbs to tumor tissue was saturable in all antigen-positive tumors. The maximal concentration of specific binding of antibody to tissue (Bmax) represented the tissue antigen concentration. Estimates of the K, of antigen/antibody binding were also made. The reliability of the measurements was con firmed by testing sections from mixtures of antigen-positive and antigen-negative cells
    corecore