1,720,959 research outputs found
ADC maps in non invasive characterization of IDH mutation status in high grade glioma
No full textIntroduction The new brain tumor classification (2016 WHO) distinguishes diffuse glioma based on their molecular characteristics of isocitrate dehydroge- nase (IDH) in IDH-mutant, IDH-wild type and IDH NOS (not otherwise specified). The evaluation of IDH mutation status has diagnostic, prog- nostic and therapeutic implications. The aim of this study was to evaluate whether the analysis of ADC maps can non-invasively predict the IDH mutation status. Materials Conventional MR images and ADC maps of 28 patients (11-F, 17-M) with histological confirmed diffuse high-grade glioma (WHO-grade III- IV) were reviewed and correlated with the IDH mutation status (18-MUT, 10-WT). MRI was performed on a 1.5T MR scan (GE-Optima 450). In order to place the ROIs on the solid components of the lesion, the ADC maps were elaborated and co-registered with the T2-w and Gd-enhanced T1-w images. For each tumor 4-5 ROIs were placed and the mean ADC- values (ADCmean) were calculated, choosing the lowest values for each patient. The comparison of the ADCmean values between IDH-MUT and IDH-WT was performed using the Student's "t" test, considering signifi- cant a value of p <0.05. Results The ADCmean values in IDH-WT patients (0.86x10-3mm2/s +/- 0.06) were lower than those of IDH-MUT patients (1.24x10-3mm2 /s +/- 0.19) and the difference between both groups was statistically significant (p <0.01). The value of ADC ≥ 1.01 x10-3mm2/s can be considered as a "cut-off" value to differentiate the IDH mutation status. Conclusions Adding quantitative data such as evaluation of ADC-values to conven- tional MR imaging can be used as a non-invasive marker of specific molecular patterns
Utilizzo delle mappe ADC nella valutazione non invasiva dello stato di mutazione dell’IDH in gliomi di alto grado.
No full textTesto dell'abstract Scopo La nuova classificazione dei tumori cerebrali (2016 WHO) distingue i gliomi diffusi in base alle caratteristiche molecolari dell’isocitrato deidrogenasi (IDH) in IDH mutati, IDH wild type e non altrimenti specificati. La valutazione dello stato di mutazione dell’IDH ha implicazioni diagnostiche, prognostiche e terapeutiche. Lo scopo di questo studio è valutare se l’analisi quantitativa delle mappe ADC possa predire in modo non invasivo lo stato di mutazione dell’IDH. Materiale e metodi Sono state esaminate retrospettivamente RM e mappe ADC di 28 pazienti (11 F, 17 M) con diagnosi istologica di glioma diffuso di alto grado (G-III, G-IV WHO) e valutazione dello stato di mutazione dell’IDH1 (18 MUT, 10 WT). Gli esami sono stati condotti su apparecchio RM 1,5 T. Le mappe ADC sono state elaborate e co-registrate con le immagini T2w e T1 post mdc in modo da posizionare le ROI sulle componenti solide della lesione, evitando le componenti emorragica, cistica o necrotica. Sono state posizionate 4-5 ROI per ogni tumore e calcolati i valori medi di ADC (ADCmean) scegliendo tra i valori più bassi per ogni Paziente. La comparazione dei valori ADCmean tra IDH-MUT e IDH-WT è stata condotta utilizzando il “t” test di Student, considerando statisticamente significativo un valore di p<0. Risultati I valori ADCmean nei pazienti IDH-WT (0,86x10-3mm2 /s)(+/- 0,06) sono risultati più bassi rispetto a quelli dei pazienti IDH-MUT (1,24x10-3mm2 /s)(+/- 0,19) con differenza tra i due gruppi significativa per p<0,01. Il valore minimo di ADC =1,01 x10-3mm2 /s può essere considerato come“cut-off “per differenziare lo stato di mutazione. Conclusioni L’aggiunta di dati quantitativi come la valutazione dell’ADC all’imaging RM convenzionale potrebbe essere utilizzata di routine come marker non-invasivo di pattern molecolari specifici
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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