1,720,956 research outputs found
The use of robotic technology in the LAST operation
No full textBACKGROUND:
The LAST operation represents a good option for single left anterior descending artery (LAD) revascularization. We report our preliminary experience with the LAST operation performed with the aid of the "da Vinci" Intuitive robotic system.
METHODS:
From January 2000 to May 2001, 12 patients (11 males and 1 female, mean age 62 +/- 8 years) underwent the LAST operation. All patients had a proximal LAD lesion either not suitable for coronary angioplasty or unsuccessfully treated at coronary angioplasty previously. The mean preoperative ejection fraction was 55 +/- 5%. In all patients, left internal mammary artery (LIMA) harvesting was carried out endoscopically using robotic technology. After heparin administration the LIMA was distally divided to check the adequacy of the blood flow. An incision of about 6 cm was then made in the appropriate intercostal space and the LAD was exposed using a special costal retractor. Following the insertion of a temporary intracoronary shunt, the LIMA was anastomosed to the LAD.
RESULTS:
No hospital or delayed death occurred. Uneventful conversion to midline sternotomy was necessary in one patient who developed ischemic changes and hemodynamic instability. One patient had a revision for postoperative bleeding. All patients were discharged within the first postoperative week and in 4 of them optimal patency of the LIMA graft was angiographically documented.
CONCLUSIONS:
The use of robotic technology seems to overcome all the drawbacks associated with the LAST operation and enhances the role of minimally invasive surgery in coronary artery revascularization
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
Acute effects of beating heart coronary surgery on left ventricular performance
No full textBackground. The increasing use of off-pump bypass grafting (OPCABG), requires an evaluation of its effects on left ventricular (LV) performance. Methods. In 8 patients with multivessel coronary disease who were undergoing to off-pump coronary artery bypass grafting, LV performance was analyzed from the pressure-volume (P-V) plane by the conductance catheter technique. Measurements were performed at base line, after the exposure of the vessels, after the application of the stabilization system, and at the end of the procedure. Results. No significant changes in heart rate, LV end-systolic volume, LV end-diastolic pressure, mean pulmonary artery, and mean systemic blood pressure were observed in the various stages of the procedure. Cardiac index decreased during left anterior descending coronary artery grafting after application of the stabilizer with a concomitant decrease in LV end-diastolic volume, together with decreases in LV peak negative -dP/dt and increases in τ, indicating an impairment of LV relaxation but without a change in preload recruitable stroke work, indicating preserved LV contractile state. Exposure of posterior and lateral vessels induced a decrease in cardiac index and preload recruitable stroke work without a decrease in LV preload, indicating a decrease in LV contractile state together with a decrease in peak -dP/dt and increase in τ, indicating an impairment in LV relaxation. Conclusions. Off-pump coronary artery bypass grafting can be performed without decreasing LV performance. Major cardiac displacement like that used for posterior and lateral exposure induces acutely significant decrease in LV contractile state. © 2002 by The Society of Thoracic Surgeons
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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