1,720,961 research outputs found
Antitumoral action of bovine seminal ribonuclease.
No full textThe antitumor action of bovine seminal RNAase is studied as a function of the enzyme concentration and of the number of plated cells. With polyoma transformed hamster kidney cells, a 50\% inhibition of cell growth is obtained with a 10 micrograms/ml of enzyme, while at this concentration growth of normal cells is very little affected. On the other hand the higher the number of plated cells, the lesser is the effect. The enzyme is found to be very effective also on tumor cells derived from a spontaneous tumor (neuroblastoma) and on cells derived from a chemically induced tumor (glioma). Amphoterycin B which is known to alter the permeability of eukariotic cells, does not affect the resistance of normal cells to the cytotoxic action of the enzyme
In vitro studies on selective inhibition of tumor cell growth by seminal ribonuclease.
No full textThe effect on cell growth of bovine seminal RNase has been tested on cells cultured in vitro. A selective inhibition of growth has been observed on tumor cells as compared to normal cells using several virus-transformed cell lines and a neuroblastoma line. The different cellular response of virus-transformed cells does not appear to depend on a differential permeability to the protein of transformed cells with respect to nontransformed ones. The selective cytotoxic action of seminal RNase on tumor cell growth was also compared with the action of other structurally related RNases and of various RNase derivatives prepared by specific chemical modifications. The results indicate that the protein dimeric structure and its enzymic activity are essential requirements for its action
The Antitumor Action of Seminal Ribonuclease Tested With the Plasmacytoma Spleen Colonization Assay
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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