1,720,968 research outputs found
Technological advances in glioma surgery
No full textIn the recent past, the impact of surgery has increased because of important technical advances which have significantly improved tumour resection for both high- and low-grade gliomas and at the same time patient quality of life. Today, surgery is asked not only to obtain tissue to reach a precise histological and molecular diagnosis but to influence many functional and oncological endpoints. To reach all these complex issues, surgery has significantly changed in the way it is performed. Surgeons have had the opportunity to incorporate many technical advances, particularly in imaging and intraoperative neurophysiology, which has significantly modified the way resection is conceived and technically performed. The surgeon should be able to critically integrate all these technologies, both at the time of surgical planning and also during surgery. Thanks to these improvements, surgery is today able to impact both survival and quality of life in patients with low- and high-grade gliomas
Beautiful eyes guiding powerful hands. The role of intraoperative imaging techniques in the surgical management of gliomas
No full textThe aims of the surgical management of cerebral gliomas are to achieve the widest feasible resection and preserve the patient’s functional integrity. This results in an improved survival rate and a favourable quality of life. When treating this disease, current neuroradiological techniques are important for preoperative depiction and planning, and intraoperative image-guided resection, especially when the tumour involves eloquent cortical and subcortical structures. Knowledge of these techniques and their limitations, and appropriate expertise are therefore necessary to gain the complete benefit of their diagnostic and therapeutic power
Il mappaggio sottocorticale motorio migliora i risultati della resezione chirurgica delle neoplasie gliali in area eloquente
No full textPreoperative diffusion tensor imaging : contribution to surgical planning and validation by intraoperative electrostimulation
No full textTransient inhibition of motor function induced by the Cavitron ultrasonic surgical aspirator during brain mapping
No full textOBJECTIVE: We report, for the first time, the occurrence of interference between a Cavitron ultrasonic surgical aspirator (CUSA) and intraoperative brain mapping performed by direct electrical stimulation (DES). METHODS: Intraoperative polygraphic recordings (electrocorticogram and electromyogram) were gathered from a 44-year-old patient harboring a recurrent Grade II oligoastrocytoma operated on with the aid of a CUSA and DES. RESULTS: Simultaneous use of CUSA and DES at the subcortical level in proximity to the corticospinal tract brought about the abolition of previously evident motor responses. This abolition was fully reversible after the CUSA was turned off. An analogous pattern of motor response inhibition was evident when the DES was applied cortically and the CUSA was used subcortically close to motor pathways. Interestingly, the authors had already observed a similar phenomenon in many patients when the CUSA was used for resection of lesions located within or in proximity to subcortical language pathways. In this setting, the CUSA induced transient speech disturbances that were confirmed afterwards by the DES. This interference with language and motor mapping might be interpreted as a transitory inhibition of axonal conduction. CONCLUSION: The clinical significance of this interference is relevant when the CUSA and DES are used simultaneously for motor mapping because the CUSA can decrease the sensitivity of the brain mapping technique. Further studies will be required to determine the neurophysiological mechanism underlying this interference
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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