1,721,118 research outputs found
Tumori cardiaci pediatrici
No full textdistinguono
in benigni e maligni e possono essere
primari o secondari a processi metastatici. Sono
relativamente rari e la loro incidenza dipende dalla
modalità con cui vengono rilevati. Molte serie
autoptiche riportano una incidenza variabile tra
0.0017% e 0.28%, mentre nella popolazione sottoposta
ad indagine ecografica l’incidenza varia
da 017% a 0.2% (10). Il miglioramento delle tecniche
diagnostiche ha determinato un aumento
della incidenza dei tumori cardiaci pediatrici, passando
da 0.06% dei primi anni ’80 a 0.32% nella
metà degli anni ‘90 (2).
La maggior parte di tumori cardiaci primitivi
che si riscontrano in età pediatrica sono per lo
più benigni e costituiscono circa il 90% di tutte
le forme, mentre i tumori maligni sono il 10%
(3,10,12,19). I tumori maligni secondari sono più
diffusi di quanto non lo siano i primitivi, in particolare
sono frequenti i secondarismi di natura
renale (ad es. il tumore di Wilms). Nella vita fetale
e nell’infanzia il tumore cardiaco più comune
è il rabdomioma, mentre è raro il mixoma, il più
frequente invece in età adulta. Altri tumori in ordine
di frequenza nell’infanzia sono il teratoma,
il fibroma e l’emangioma. Il rabdomioma e il teratoma
del pericardio rappresentano il 70% dei
tumori primari del cuore nel feto, nel neonato e
nei bambini (9).
Sintomatologia
La sintomatologia in genere è legata alle caratteristiche
del tumore ma si possono evidenziare
delle manifestazioni cliniche comuni.
Nella vita fetale molto frequentemente le neoplasie
cardiache possono manifestarsi con aritmie,
insufficienza cardiaca congestizia e idrope.
Nella vita postnatale si presentano, nella maggior
parte dei casi, con cianosi, difficoltà respiratoria,
disfunzione miocardica, insufficienza valvolare,
aritmie e fenomeni tromboembolici. In alcuni casi
si può verificare una morte improvvisa per aritmie
o per ostruzione delle valvole atrioventricolari o
dell’efflusso ventricolare (1,3,10-11,14). Sintomi
aspecifici, come si verifica anche in presenza di
tumori cardiaci dell’adulto, possono essere perdita
di peso, stanchezza, febbre, sensazione di
malessere. Inoltre i tumori possono dare alterazioni
ematologiche, tra cui anemia, policitemia,
leucocitosi, trombocitosi ed elevata velocità di
sedimentazione per la produzione di interleuchine
infiammatorie (ad es. IL-6) (4,10)
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
Comparison between rDNA magnification and bb lethal mutation frequencies in Drosophila melanogaster.
No full textUnequal mitotic sister strand crossing over has been evoked to explain the occurrence of phenotypically bb+ males in the progeny of phenotypically bobbed males during magnification. If this is the case, complementary bbl loci should be obtained together with the bb+. To test this hypothesis we compared the frequency of bb lethal mutations in the sperms of bb males with the percentages of phenotypically bb+ males obtained during magnification of these bb males. We then compared these values with those occurring in phenotypically bb+ control males. We found that, while the number of bb+ males obtained during magnification, though variable, is high, the bb lethal mutation occurs at a very low frequency in all the genetic conditions, whatever the phenotype of the parental male
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
Epigenomic profiling of cancer cells
No full textDNA methylation, post-translational modifications of histones and high order organization of chromatin in cell nuclei are the components of the epigenome. Epigenetic regulation of gene expression is specific for each cell type, within different tissues, according to stages of development and (in the adult organism) of differentiation. Almost invariably, this regulation is altered in disease states, including cancer. The complete understanding of the identity of the epigenome of cancer has been so far hampered, due to the technical limitations and costs of the genome-wide analyses required. The recent development of next generation sequencing (NGS) technologies, however, holds the promise of fast, reliable and cost-effective analyses. Here we review the main approaches employed thus far to identify altered epigenetic patterns in cancer cells, and analyse how they are predicted to evolve in the scenario of the ultra high-throughput (UHT) screenin
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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