1,721,004 research outputs found
Immunomodulatory effects of VEGF: Clinical implications of VEGF-targeted therapy in human cancer
No full textAssessment of the conformational features of Vasoactive Intestinal Peptide in solution by limited proteolysis experiments
No full textThe structural features of vasoactive intestinal peptide (VIP) and of its Gln16-diaminopropane derivative (VIP-DAP) in solution were investigated by limited proteolysis experiments with trypsin and thermolysin. The proteolysis of the native peptide by both proteinases takes place near the residues in positions 12 and 21/22, suggesting that these amino acids are embedded in segments more flexible than the rest of the molecule. VIP-DAP appears to be more resistant to the proteolytic attack of trypsin, indicating that the derivatization in position 16 is able to stabilize the structure of the peptide. Moreover, the analysis of the mass spectra of the proteolytic mixtures supports the evidence that the derivatization is also able to protect Met17 against oxidation. From these data it can be concluded that VIP in solution under physiological conditions is characterized by the presence of segments with secondary structure, linked together by ‘‘hinge’’ regions that confer flexibility to the peptide, whereas VIP-DAP is embedded in a more rigid conformation, more suitable to receptor interaction
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
Variations on the Author
Full text link“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
Full text linkWe 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
Assessment of the conformational features of vasoactive intestinal peptide in solution by limited proteolysis experiments
No full textPI3K/Akt/mTOR signaling in medullary thyroid cancer: a promising molecular target for cancer therapy.
No full textThe phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is a central hub for the regulation of cell proliferation, apoptosis, cell cycle, metabolism, and angiogenesis. Several studies have recently suggested that the PI3K/Akt/mTOR signaling pathway is implicated in the pathogenesis and progression of neuroendocrine tumors. Medullary thyroid cancer (MTC) is a neuroendocrine tumor developing from the C cells of the thyroid. Mutations in the RET proto-oncogene are involved in the pathogenesis of several forms of MTC. The deregulation of the PI3K/Akt/mTOR pathway seems to contribute to the tumorigenic activity of RET proto-oncogene mutations. Targeting this pathway through specific inhibitors at simple or multiple sites may represent an attractive potential therapeutic approach for patients with advanced MTCs. The aim of this review is to examine the role of the PI3K/Akt/mTOR pathway in the development and progression of MTC and the new therapeutic options that target this signaling pathwa
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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