1,720,969 research outputs found
A Five-Year Computed Tomography Follow-up Study of Proximal Aortic Neck Dilatation After Endovascular Aortic Repair Using Four Contemporary Types of Endograft Reply
No full textstatus: Publishe
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
Ventriculo-peritoneal shunt alone does not guarantee spinal cord protection after complex aortic aneurysm repair
No full textINTRODUCTION: Spinal cord ischaemia (SCI) is a devastating complication of the treatment of thoraco-abdominal aneurysms. Peri-operative cerebrospinal fluid (CSF) drainage, typically using a spinal catheter, is a possible preventive measure. There are no reports or guidelines on peri-operative CSF drainage for this indication in patients with a ventriculoperitoneal (VP) shunt. REPORT: A single case of a patient suffering SCI after fenestrated endovascular aortic repair for the treatment of a pararenal aneurysm after previous open repair of an infrarenal aortic aneurysm is presented. Despite the presence of a patent VP shunt, elevated CSF pressures were observed after placement of a CSF drain. DISCUSSION: A VP shunt with a gravitational component may drain insufficiently in bedridden patients who often lie with their head tilted on a cushion. In this position, both the differential pressure component and the gravitational component become active, thereby increasing the overall resistance to CSF outflow, hence increasing intracranial and intraspinal pressure. VP shunts with gravitational components should be managed with caution in the setting of prophylactic or therapeutic drainage of CSF to prevent SCI in extensive aortic repair. For reliable CSF pressure monitoring or active drainage in case of symptoms, the insertion of a spinal drain is indicated.status: Accepte
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
Dealing with symptomatic stenosis of the subclavian artery: Open or endovascular approach? A case report
No full textAbstractINTRODUCTIONStenosis of the subclavian artery is uncommon and it rarely causes symptoms. Only symptomatic patients should be treated.PRESENTATION OF CASEWe report a case of chronic left upper limb ischemia caused by subclavian artery stenosis after repetitive clavicular fixation. The stenosis was first treated with carotid-subclavian bypass and soon followed by angioplasty and stenting of the subclavian artery because of occlusion of the bypass. Finally, failure of these procedures necessitated a subclavian-axillary crossover bypass.DISCUSSIONBoth extra-anatomic bypass and percutaneous transluminal angioplasty are safe and effective. If feasible, many authors use endovascular treatment. According to literature, extra-anatomic bypass still remains the first choice of treatment for symptomatic patients. However, the introduction of routine stent implantation is equalling these results. Because of its lower long-term patency rate, endovascular treatment is favorable for patients at high risk.CONCLUSIONOur case is a good example of difficulties involved in choosing the best treatment option for subclavian artery stenosis
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
External Validation of a Prognostic Model for Survival of Patients With Abdominal Aortic Aneurysms Treated With Endovascular Aneurysm Repair.
Full text linkOBJECTIVE
Current guidelines recommend diameter monitoring of small and asymptomatic abdominal aortic aneurysms (AAAs) due to the low risk of rupture. Elective AAA repair is recommended for diameters ≥ 5.5 cm in men and ≥ 5.0 cm in women. However, data supporting the efficacy of elective treatment for all patients above these thresholds are diverging. For a subgroup of patients, life expectancy might be very short, and elective AAA repair at the current threshold may not be justified. This study aimed to externally validate a predictive model for survival of patients with asymptomatic AAA treated with endovascular aneurysm repair (EVAR).
METHODS
This was a multicentre international retrospective observational cohort study. Data were collected from four European aortic centres treating patients between 2001 and 2021. The initial model included age, estimated glomerular filtration rate (eGFR), and chronic obstructive pulmonary disease (COPD) as independent predictors for survival. Model performance was measured by discrimination and calibration.
RESULTS
The validation cohort included 1 500 patients with a median follow up of 65 months, during which 54.6% of the patients died. The external validation showed slightly decreased discrimination ability and signs of overfitting in model calibration. However, a high risk subgroup of patients with impaired survival rates was identified: octogenarians with eGFR < 60 OR COPD, septuagenarians with eGFR < 30, and septuagenarians with eGFR < 60 and COPD having survival rates of only 55.2% and 15.5% at five and 10 years, respectively.
CONCLUSION
EVAR is a valuable treatment option for AAA, especially for patients unsuitable for open repair. Nonetheless, not all these patients will benefit from EVAR, and an individualised treatment recommendation should include considerations on life expectancy. This study provides a risk stratification to identify patients who may not benefit from EVAR under the present diameter threshold
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