1,721,104 research outputs found
Gene-environment interactions in the pre-Industrial Era: the cancer of King Ferrante I of Aragon (1431-1494)
No full textKing Ferrante I of Aragon, leading figure of the Italian Renaissance, died in 1494. The autopsy of his mummy revealed a tumor infiltrating the small pelvis. We examined the histologic and molecular features of this ancient tumor to investigate its primary origin. Hematoxylin-eosin, Van
Gieson, and Alcian Blue staining showed neoplastic cells infiltrating muscular fibers and forming pseudo-glandular lumina disseminated in fibrous stroma with scarce mucus. A strong immunoreactivity of the neoplastic cells was shown for pancytokeratins and proliferating cell nuclear antigen. Molecular fingerprints were investigated by examining K-ras, BRAF, and microsatellite instability in ancient
tumor DNA. Sequencing analysis showed G-to-A transition in codon 12 of K-ras. BRAF mutations and microsatellite instability were not observed. Because the presence of K-ras codon 12 mutation could be associated with exposure to chemical carcinogens, possibly present in some food items, paleodietary reconst..
SnO2 RGTO UV activation for CO monitoring
No full textIn this paper, we present recent results regarding the activation of sensors with high density power light of energy in the range of the energy gap of the semiconductor. We report the measurements registered for tin-oxide rheotaxial growth and thermal oxidation deposited layers using CO as a target gas. The influence of doping on the activated gas-sensing properties has been investigated. We have found the value of the incident power corresponding to the best gas-sensing performances (response enhancement and kinetics). The comparison between dark and irradiation condition is presented for the different kind of layers tested
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
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
Patterns of genomic instability in gastric cancer: clinical implications and perspectives.
Full text linkIn gastric cancer (GC) the loss of genomic stability represents a key molecular step that occurs early in the carcinogenesis process and creates a permissive environment for the accumulation of genetic and epigenetic alterations in tumor suppressor genes and oncogenes. It is widely accepted that GC can follow at least two major genomic instability pathways, microsatellite instability (MSI) and chromosome instability (CIN). MSI is responsible for a well-defined subset of GCs. CIN represents a more common pathway comprising heterogeneous subsets of GC. In addition to MSI and CIN, the CpG islands methylator phenotype (CIMP) plays an important role in gastric carcinogenesis. CIMP may lead to the transcriptional silencing of various genes in gastric carcinogenesis. Intriguingly, more recently in addition to CpG island hypermethylation, a global DNA demethylation, that precedes genomic damage, has been observed in GC. Thus, epigenetic alterations may play a relevant role in gastric carcinogenesis as alternative mechanisms. Evidence suggests that although MSI, CIN and CIMP phenotypes can be distinguished from one another, there might be some degree of overlap. This review describes our current knowledge of the instability pathways in gastric carcinogenesis and the potential clinical applications for different forms of genomic instability in GC
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