1,720,986 research outputs found
Trombosi murale apicale del ventricolo sinistro dopo infarto miocardico acuto:valutazione ecocardiografica ed indirizzo terapeutico
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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
Sphenoidal pneumosinus dilatans due to anterior skull base meningiomas - CT and MRI aspects: Report of two new cases and literature review
No full textWe report on two patients disclosing a pneumosinus dilatans (PSD) and an anterior skull base meningioma. Our findings, together with those from the pertinent literature, support the thought that this infrequent anomaly of paranasal sinuses is a useful clue to suspect a concomitant meningioma. Moreover, hypotheses concerning the pathophysiology of PSD are discussed
Langerhans cell histiocytosis with uncommon liver involvement: A case report
No full textObjective: Background: Case Report: Conclusions: Rare disease Langerhans cell histiocytosis (LCH), also called histiocytosis X, belongs to a group of rare neoplasms and is a clonal pathology characterized by infiltration of Langerhans cells. The pathology can occur with the involvement of only 1 organ, more frequently the bone or with multi-visceral involvement, and patients frequently receive a delayed diagnosis and empirical treatments. We report a case of LCH in a 60-year-old woman who presented atypical symptoms, imaging findings of lung and liver involvement. Imaging showed increased liver volume and subverted structure by multiple nodular formations. For the differential diagnosis with other neoplastic liver diseases, the patient underwent liver biopsy, with microscopic typical findings of the disease and positive immunohistochemical markers. Liver involvement in LCH is rare and the differential diagnosis with neoplastic pathology may pose a challenge for the clinician and radiologist, also due to the possible association between LCH and malignant tumors
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
Renovascular anatomic variants at CT angiography.
No full textThe aim of this paper was to assess the origin and course variations of vessels forming the renal vascular pedicle.
METHODS:
The IRB approved study retrospectively evaluated 921 consecutive patients (503 females, 418 males; mean age, 54 years), who underwent multidetector computed tomographic (MDCT) of the abdomen for various purposes at our Department of Radiology, between January 2012 and December 2013. Multiplanar and volumetric reformations were performed in all cases. For each set of images, the locations of renal artery origins and renal venous drainage, such as all renal vessels variations, including division variations and presence of extrarenal vessels, were investigated.
RESULTS:
The tract of the aorta between the upper margin of L1 and the lower margin of L2 originated 96% of main renal arteries and 72% of extra renal arteries. The most common location for renal artery origin was the L1- L2 intervertebral disc level. Sixty-nine percent of patients showed a single renal artery, with multiple arteries in 31%, bilateral multiple arteries in 11%, and early division in 6% of cases. Additional renal arteries were detected on the right side in 5% and on the left side in 12% of cases. With regard to the venous drainage, 89.8% of patients showed a single renal vein, with multiple vein in 10.2%, while 23.8% showed a retro-aortic course of the renal vein.
CONCLUSION:
Renal arteries and veins variations of origin and course are not infrequent. Extrarenal vessels may compromise renal surgery. The awareness of any possible renovascular anomaly is crucial in case of a non-invasive diagnostic search for renal artery stenosis, and when renal surgery related to renal arteries is performed, such as in case of interventional radiological procedures, urological and vascular operations, and renal transplantation
Value of diffusion-weighted magnetic resonance imaging in the characterization of complex adnexal masses
No full textDispelling 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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