1,720,989 research outputs found
Dendritic cell maturation is inhibited by apoptotic bodies and promoted by necrotic cells from human melanoma
No full textPhases of apoptosis of melanoma cells, but not of normal melanocytes, differently affect maturation of myeloid dendritic cells.
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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
Prognostic value of cell sphingolipid profile and plasma membrane sialidase Neu3 expression in melanoma
No full textMelanoma is the most aggressive and lethal form of skin cancer. Annually, it is responsible for at least 48,000 deaths worldwide and its incidence has risen sharply in recent decades. In addition to characteristic genetic lesions, melanoma cells display a characteristic repertoire of sphingolipids, especially gangliosides, very different from healthy melanocytes. In this report, we analysed the sphingolipid pattern and the mRNA expression of enzymes involved in sphingolipid metabolism in a large panel of short-term melanoma cell lines established from surgical specimens, isolated from VGP (vertical growth phase) primary tumours and from metastatic lesions of melanoma patients.
We demonstrated that the gangliosides profile of melanoma cells varied from patient to patient and that an interesting correlation between ganglioside pattern and patients’ survival existed. In particular, the shortest survival time was recorded in patients carrying tumour cells marked by the presence of GM3, GD3, and sialylparagloboside (Hazard ratio: 7.2, according to Kaplain Meyer survival analysis). Sialylparagloboside is known to be the synthetic precursor of Sialyl Lewis X epitope that is related with increased metastatic potential of cancer cells. In addition, also the expression of some key enzymes involved in gangliosides synthesis and catabolism correlated with patients’ survival. In particular, the expression of the plasma membrane sialidase NEU3 was increased in many melanoma cell lines established from patients, as compared to expression detected in normal melanocytes. This increment was inversely correlated to patients’ survival (Hazard ratio: 3, according to Kaplain Meyer survival analysis).
These results suggest the employment of gangliosides pattern and of NEU3 expression as markers to classify melanomas in addition to histopathologic criteria.
1. Furukawa K et al Proteomics 2008;8(16): 3312-6
Human dendritic cells: natural adjuvants in antitumor immunotherapy
No full textAlthough T-cell-defined tumor antigens have recently been identified in several tumors, human neoplastic cells are considered to be poorly immunogenic. The development of clinical approaches to the immunotherapy of human tumors thus requires the identification of effective adjuvants. Dendritic cells (DC) are a specialized system of antigen-presenting cells (APC) that could be utilized as natural adjuvants to elicit antitumor immune responses. In an attempt to overcome the problem of the low frequency of mature DC in peripheral blood, several methods have been applied for the ex vivo generation of human DC by culturing mobilized CD34+ cells or monocytes with combinations of cytokines. As shown in murine models as well as in the human system, after loading with peptides or tumor lysates or infection with recombinant viral vectors, DC expressing tumor antigens are able to elicit specific antitumor T cells and to mediate tumor regression. These initial results suggest that this new approach may lead to effective antitumor responses even in heavily pretreated patients bearing advanced cancers, but further clinical trials are required to validate the efficacy of vaccination with tumor-antigen-loaded DC
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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