1,720,956 research outputs found
Comparison of femoro-femoral and aortofemoral bypass for aortoiliac occlusive disease.
No full textBACKGROUND: Role and results of femorofemoral bypass grafting, usually reserved to high-risk patients affected with unilateral iliac artery occlusion, are still debated.
METHODS:
EXPERIMENTAL DESIGN: retrospective clinical study.
SETTINGS: University Hospital.
PATIENTS: seventy-six high-risk patients (group 1) who underwent a primary expanded polytetrafluoroethylene (ePTFE) externally supported femorofemoral bypass graft were retrospectively compared to two additional groups of patients selected from the entire series of patients who underwent an aortobifemoral bypass graft. Patients of group 2 (n=80) were randomly chosen to determine differences in risk factors, associated diseases, previous abdominal operations, operative indications, preoperative findings and outcome. Patients of group 3 (n=50) were matched for sex, risk factors, associated diseases, previous abdominal operations, operative indications and preoperative findings with those of group 1 to assess the importance of the type of operation in determining the outcome of the procedure.
RESULTS: Postoperative mortality (6, 4 and 6%, respectively), 5-year primary and secondary patency (71, 80, 83% and 80, 87, 87%, respectively) and limb salvage rates (78, 87 and 87%, respectively) were similar among the groups (p=NS, p=NS, p=NS, respectively). Five-year survival rate of group 2 was significantly better than that of group 1 and 3 (p<0.04 and p<0.04, respectively).
CONCLUSIONS: Primary ePTFE externally supported femorofemoral bypass graft in high-risk patients is safe and produces long-term results similar to aortofemoral reconstructio
Femorofemoral bypass grafts: factors influencing long-term patency rate and outcome
No full textBACKGROUND: Crossover femorofemoral bypass graft (CFFBG) was proposed in the early days of modern vascular surgery to treat patients affected with unilateral iliac artery disease who were a high surgical risk. We investigated factors influencing short- and long-term outcomes of CFFBG:
METHODS: The study was designed as a retrospective clinical study in a university hospital setting with a base of 228 patients. Of these patients, 154 (67.5%) presented a high surgical risk. The indication for operation was limb-threatening ischemia in 188 (82.5%) patients. All patients underwent CFFBG: The procedure was performed in 150 patients as the primary operation and in 78 patients after previous vascular graft failure or infection, or both. A preoperative percutaneous transluminal angioplasty was performed in 57 patients (25%) to correct donor iliac artery disease. In 127 patients (55.7%), an associated vascular procedure was performed to improve the outflow. Postoperative complications; 5- and 10-year primary, secondary, and limb salvage rates; and factors influencing short- and long-term results were assessed.
RESULTS: Thirteen (5.7%) postoperative deaths occurred. Postoperative mortality and morbidity rates were significantly higher in patients aged more than 65 years (7.9% versus 3.5% and 18.6% versus 6.1%, respectively, P <.03). Primary and secondary patency rates at 5 and 10 years were 70.2% and 48.1%, 82.8% and 63.2%, respectively; 5- and 10-year limb salvage and survival rates were 85.5% and 80.1%, 63.3% and 31.0%, respectively. Ten-year primary and secondary patency and limb salvage rates were significantly lower when the procedure was performed after previous vascular graft failures (50.2% versus 26.5%, P <.007; 74.1% versus 44.1%, P <.01; and 84.3% versus 72.5%, P <.03, respectively). Five- and 8-year patency rates of autogenous vein CFFBG (34.3% and 22.8%, respectively, P <.03) were significantly lower than those of expanded polytetrafluoroethylene (71.1% and 59.8%, respectively) and polyester (77.3% and 50.3%, respectively) CFFBG: Moreover, 5- and 10-year primary and secondary patency rates were significantly better when externally supported grafts were used as compared with those without external support (80.1% and 69.9% versus 61.1% and 21.1%, P <.01; 88.8% and 75.9% versus 78.9% and 45.4%, P <.05, respectively). Multivariate analysis showed that the only variable associated with poor primary and secondary patency and limb salvage rates was the operation performed after previous vascular graft failures (P <.04, P <.03 and P<.05, respectively).
CONCLUSIONS: CFFBG allows early and long-term results similar to those obtained with reconstructions originating from the aorta when it is performed as a primary operation when an adequate outflow is provided and externally supported prosthetic material is used
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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