1,720,992 research outputs found
Correzione dell'insufficienza polmonare con homograft criopreservato: ottima soluzione ad un problema post-chirurgico non raro
No full textAlthough the results of surgical repair for congenital pulmonary stenosis are generally good, some patients develop progressive symptoms related to pulmonary regurgitation and right ventricular dilation. Pulmonary homograft implantation may have a beneficial effect on these symptoms, due to a reduction in the volume overload of the right ventricle and hemodynamic improvement. We describe our experience of one patient with severe pulmonary regurgitation following pulmonary valvotomy performed with the Brock technique during childhood because of pulmonary valve stenosis. The patient was admitted to our Institution because of dyspnea on exertion (NYHA functional class II-III) and paroxysmal episodes of supraventricular arrhythmias. Echocardiography showed severe pulmonary regurgitation, an important right ventricular dilation associated with severe tricuspid insufficiency and a patent foramen ovale without any significant shunts. Surgical repair was performed through a median sternotomy with cardiopulmonary bypass and moderate hypothermia. The right ventricular infundibulum was opened and a cryopreserved pulmonary homograft was implanted with continuous sutures. De Vega annuloplasty was performed on the tricuspid valve and the patent foramen ovale was closed with a running suture. Postoperative course was uneventful and the patient was discharged on the seventh postoperative day. Three months after surgery the patient is asymptomatic and echocardiographic evaluation shows no evidence of pulmonary or tricuspid regurgitation, a decrease in right ventricular dilation and a significant improvement in biventricular systolic and diastolic function. In conclusion, pulmonary regurgitation after surgical valvotomy can be treated with the implantation of a cryopreserved pulmonary homograft with satisfactory results. It would appear advisable to perform surgical repair of concomitant right heart anomalies, such as secondary tricuspid insufficiency, to obtain both a decrease in right ventricular overload and a regression of its preoperative dilation
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
"Hybrid" percutaneous and surgical coronary revascularization: selection criteria from a single-center experience
No full textBACKGROUND:
The association of minimally invasive direct coronary artery bypass (MIDCAB) to percutaneous transluminal coronary angioplasty (PTCA) of large arteries with focal lesions can be an alternative therapeutic method for patients with multivessel coronary artery disease. We reviewed our experience regarding 42 patients treated at our Institute.
METHODS:
MIDCAB and PTCA of the circumflex or right coronary arteries > 3 mm were performed in 42 patients from September 1997 to December 1999.
RESULTS:
One patient died after MIDCAB in the operating room because of rupture of the left anterior descending anastomosis. Postoperative angiography confirmed patency of the internal mammary artery (IMA) graft in 92.3% of cases: 3 early IMA graft failures occurred. The success rate for PTCA was 98%: in 1 case the wire just would not cross a chronically and totally occluded right coronary artery. The in-hospital morbidity was 12.2%: 2 patients required urgent sternotomy respectively for cardiac tamponade and coronary artery bypass grafting on cardiopulmonary bypass. One patient developed atheroembolism after PTCA with recurrence of symptoms, progressive multiorgan failure and death. Two patients required PTCA on the IMA anastomosis because of early failure of the arterial graft. At a medium follow-up of 535 days, all 40 survivors are in Canadian Cardiovascular Society class I.
CONCLUSIONS:
Hybrid revascularization appears to be an effective treatment for selected patients with multivessel coronary artery disease. The immediate success seems related to the learning curve for MIDCAB
First human case of esophagus-tracheal fistula closure by using a cardiac septal occluder (with video)
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
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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