1,720,975 research outputs found
Endovascular management of abnormal placental implantation deliveries. Expanding IR Boundaries
No full textEndovascular Management of Abnormal Placental Implantation Deliveries: Expanding IR Boundarie
The superior horizontal pancreatic artery of Popova: a review and an anatomoradiological study of an important morphological variant of the pancreatica magna artery
No full textPurpose: the superior horizontal pancreatic artery was described in 1910 and after a few years it was forgot by most investigators. This research is aimed to revive the description of this artery, describing course, pattern of branching and frequency.
Methods: more than 1000 of angiographies including studies of the superior mesenteric artery, celiac trunk and its branches, were selected from the angiographic archives of the ex-institutes of Radiology of Siena, Rome (University of Sacro Cuore), and Perugia and the arterial anatomy of the pancreas was studied.
Results: a pancreatic branch of the splenic artery running along the superior border of the pancreatic body and tail was observed in 25.93% of cases. This branch matched the description of the superior horizontal pancreatic artery and, when existing, replaced the pancreatica magna artery. For this reason, we considered the superior horizontal pancreatic artery as a variant of the pancreatica magna artery. Variable in calibre and importance, in most cases the superior horizontal pancreatic artery gave off descending branches that anastomosed with the inferior pancreatic artery.
Conclusions: a superior horizontal pancreatic artery could be visualized more easily by selective angiography of the splenic artery. When coupled with the inferior pancreatic artery, the presence of the superior horizontal pancreatic artery outlined a longitudinally arranged pattern of blood supply of the distal pancreas that should be known. In particular circumstances, extended resections of the gland cutting both longitudinal arteries might jeopardize the surviving of the pancreas remnant
The arterial blood supply of the pancreas: a review. V. The dorsal pancreatic artery. An anatomic and a radiologic study
No full textThe present article is the fifth part of a comprehensive review on the arterial blood supply of the pancreas and deals with the dorsal pancreatic artery. The aim of this review is to summarise the anatomic studies, starting from Haller's reports, and to supply, as far as possible with original material, angiographic evidence for the classic anatomic notions. For this purpose, the overall research was carried out by studying 1015 selective angiographies (celiac trunk and its branches, superior mesenteric artery) taken from the angiographic archives of the Institutes of Radiology of Siena, Rome (Catholic University), and Perugia. Angiographically, the authors could demonstrate the dorsal pancreatic artery, present in most instances, as arising from the splenic artery, common hepatic artery, superior mesenteric artery or celiac trunk and accessory right hepatic artery as coming from the superior mesenteric artery. Variations in the course and length of the dorsal pancreatic artery were demonstrated as well as some collateral branches. The authors underline the discordant opinions still existing regarding the incidence of the different ways the dorsal pancreatic artery arises, and discuss its uncertain embryologic development and surgical relevance
The arterial blood supply of the pancreas: a review I. the superior pancreaticoduodenal and the anterior superior pancreaticoduodenal arteries. An anatomical and radiological study
No full textThe gross anatomy of the pancreatic blood supply has been subjected to numerous studies. The results of such studies, however, have never been summarized in detail, even in the most important textbooks. For this reason, a certain confusion was generated, especially regarding the interpretation of the nomenclature used to identify pancreatic arteries. This review summarizes more than two centuries of studies of the gross anatomy of the pancreatic blood supply, clarifies the arterial nomenclature, and underlines the aspects about which anatomists are not in agreement. Moreover, it supplies, as far as possible, documentary evidence for numerous observations previously reported only verbally. For this purpose, more than 200 references were directly consulted to provide the anatomical background of the topic, and more than 1000 angiograms were studied to support the review with original figures. The present paper, on the superior pancreaticoduodenal and anterior superior pancreaticoduodenal arteries, is the first of a series of articles dealing with the pancreatic blood supply
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
- …
