1,720,970 research outputs found
A rare trifocal presentation of a choroid plexus papilloma : case report and review of the literature
No full textAbstract: Introduction: CPP's present as slow-growing intraventricular neoplasms arising from epithelium of choroid plexus. They account for approximately 0.5-4% of intracranial neoplasms in adults and children, respectively. A trifocal presentation is exceedingly rare. Research question: We describe the case of a trifocal presentation of a CPP and explored the importance of genetic analyses. Material and methods: We present the case of an 18-year old adolescent who was treated for a fourth ventricular and suprasellar neoplasm. Brain MRI revealed an intraventricular lesion in the fourth ventricle, as well as a suprasellar lesion and a lesion located in the left internal auditory meatus. An adult-subtype CPP (WHO grade 1) was confirmed by means of histological and genetic analyses in the first two regions. Results: Optimal treatment strategy remains controversial, although it is accepted that surgical resection alone remains the gold standard, whereas chemoradiotherapy is reserved for specific cases. There are only a few articles reporting on a multifocal presentation or the coexistence of synchronous histologically different primary brain neoplasms. Reports on genetic examination are scarce. Discussion and conclusion: CPP's should be included in the differential diagnosis of posterior fossa tumors, both in children and adults. Genetic analyses (TP53/TERT mutations) should be considered, since they entail important diagnostic, prognostic and therapeutic implications. When a TERT mutation is present, adjuvant radiotherapy should be used with caution, since it plays a role in tumorigenesis, even when GTR could not be achieved. There is an association between TERT methylation status and malignant transformation, indicating that these patients should be followed more closely
Total cranial vault remodelling versus minimally invasive suturectomy with postoperative helmet therapy in sagittal craniosynostosis
No full textAbstract: Different surgical techniques have been explored over time to treat children with scaphocephaly. The objective of this study is to compare morbidity and cosmetic outcomes in total cranial vault remodelling (TCVR) and minimally invasive suturectomy with postoperative helmet therapy (MISPH) in patients with scaphocephaly. The authors performed a retrospective comparative cohort study, including 43 patients with isolated sagittal craniosynostosis who underwent TCVR (n=17) or MISPH (n=26) at the Antwerp University Hospital between April 2008 and December 2022. MISPH was associated with significantly shorter procedure duration (TCVR 199 +/- 48 min, MISPH 69 +/- 12 min, P<0.001), decreased blood loss (TCVR 610 +/- 298 mL, MISPH 85 +/- 73 mL, P<0.001) and lower transfusion rate (TCVR 100%, MISPH 54%, P<0.001). Mean length of stay at the intensive care unit and the hospital were significantly shorter after MISPH (TCVR 6 +/- 1 d, MISPH 3 +/- 0.5 d). The change in CI after TCVR was significantly larger than after MISPH during the first postoperative year. However, the CI in the MISPH group was significantly higher during the first year compared with the TCVR group. Mean CI of the MISPH group reached normal limits during the first year, while in the TCVR group, mean CI reached normal values 5 years after surgery. The authors could not find a statistically significant difference in cosmetic outcome between the 2 groups. The authors conclude that MISPH is associated with decreased morbidity and comparable cosmetic results when compared with TCVR in the treatment of scaphocephaly
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
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