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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
Pericardial drainage for pericardial tamponade: surgical management criteria
No full textAim of this study is the review of our experience in 82 patients treated by pericardial drainage for cardiac tamponade, to assess the efficacy and safety of different techniques and the related indications. The causes of pericardial effusion were: malignancy in 8 patients (9.7%), post-cardiac surgery in 12 (14.6%), while the others patients were admitted at our Institution with no identified preoperative diagnosis. Thirty-eight patients (46%) underwent subxiphoid pericardial drainage and 44 (54%) were operated on by catheter pericardiocentesis. There were no perioperative deaths. Two patients, who initially underwent pericardiocentesis, needed urgent sternotomy: the first patient developed a severe hypotension and bradicardia related to a vagal reaction and the other one because of accidental right ventricle puncture. Our experience indicates that subxiphoid pericardiocentesis provides expeditious, effective and durable treatment, with low morbidity, in case of pericardial effusions related to all causes. We believe that echocardiography is a powerful tool in the diagnosis and management of pericardial effusion. We conclude that pericardiocentesis seems to be the procedure of choice for patients with pericardial tamponade requiring an emergency treatment
Midterm clinical results in myocardial revascularization using the radial artery
No full textStudy objectives: The aim of this study was to evaluate the immediate and midterm results of coronary artery bypass grafting with the radial artery (RA) as a conduit. Patients: Two hundred forty-one patients underwent myocardial revascularization using the RA. In 78.5% of patients, three coronary vessels were involved, and in 25% of patients, the left main coronary artery was involved. The mean (± SD) preoperative ejection fraction was 58 ± 13%. Interventions: The RA was implanted on branches of the circumflex artery in 81% of the cases, and the left internal mammary artery was implanted on the left anterior descending artery in 94% of patients. Total arterial myocardial revascularization was performed in 58% of patients. Measurements and results: The in-hospital mortality rate was 0.8%. Two patients had acute myocardial infarction, and three patients experienced a transient low-cardiac output syndrome. We reviewed the records of all 171 patients who had undergone at least 6 months of follow-up after surgery. The late mortality rate in this group was 0.6% (one patient died 2 months after surgery because of cardiocirculatory arrest due to untreatable ventricular fibrillation). At a mean follow-up time of 545 ± 253 days, two patients showed class 3 residual angina according to the Canadian Cardiovascular Society (CCS) guidelines. One patient required another hospital admission 6 months after undergoing surgery for PTCA/stenting on a circumflex artery that had not previously undergone bypass. The second patient, 8 months after undergoing coronary artery bypass grafting, underwent angiography and stenting on a stenosed anastomosis of a posterolateral branch of the circumflex artery that previously had been bypassed with the right internal mammary artery. Conclusions: The routine use of the RA for coronary bypass grafting is a safe surgical technique, providing excellent clinical mid-term results in terms of cardiac event-free expectancy
Ischaemic mitral valve regurgitation: a surgical approach
No full textThe aim of this study IS to determine surgical results after surgical mitral valve repair in ischaemic mitral regurgitation. Materials and methods: Between January 1999 and June 2000, 64 patients (5.1% of overall patients) underwent myocardial revascularization and mitral valve surgery. A Cosgrove-Edwards mitral annuloplasty ring was used in 59 cases (92.2%). Average patient age was 64.3±12.4 years (38 males, 21 females). Average degree of mitral regurgitation was 2.8±0.6. Average NYHA class was 3.5±0.5. Average ejection fraction (EF) was 40±12.5 percent. Results: Post-operative 30-day mortality was 3.4% (2 patients). The follow-up was complete for 95 percent (mean 20.4±4.8 months for patients)and data showed an improvement of NYHA class (mean value 1.8±0.2) (p=0.01) and ejection fraction (mean value 51.7±10.2) (p=0.05) with residual mitral regurgitation value of 0.6±0.7. Conclusions: Mitral valve repair in coronary artery disease improves left ventricular function, quality of life and survival rate with low operative risk. Perioperative transesophageal echocardiography has a central role in surgical decision making
Ischaemic mitral valve regurgitation: a surgical approach
No full textThe aim of this study IS to determine surgical results after surgical mitral valve repair in ischaemic mitral regurgitation. Materials and methods: Between January 1999 and June 2000, 64 patients (5.1% of overall patients) underwent myocardial revascularization and mitral valve surgery. A Cosgrove-Edwards mitral annuloplasty ring was used in 59 cases (92.2%). Average patient age was 64.3±12.4 years (38 males, 21 females). Average degree of mitral regurgitation was 2.8±0.6. Average NYHA class was 3.5±0.5. Average ejection fraction (EF) was 40±12.5 percent. Results: Post-operative 30-day mortality was 3.4% (2 patients). The follow-up was complete for 95 percent (mean 20.4±4.8 months for patients)and data showed an improvement of NYHA class (mean value 1.8±0.2) (p=0.01) and ejection fraction (mean value 51.7±10.2) (p=0.05) with residual mitral regurgitation value of 0.6±0.7. Conclusions: Mitral valve repair in coronary artery disease improves left ventricular function, quality of life and survival rate with low operative risk. Perioperative transesophageal echocardiography has a central role in surgical decision making
Cardiac valve reoperations: analysis of operative risk factors in 154 patients
No full textBackground and aims of the study: The study aim was to evaluate the operative risks of reoperation on heart valve prostheses. Methods: Between January 1985 and December 2000, 154 patients (79 males, 75 females, mean age 61.2 ± 9.5 years) underwent cardiac valve reoperation for which indications were prosthetic failure (n = 133; prosthetic mitro-aortic dysfunction occurred in 16 cases), native valve disease in patients with a previous prosthetic valve implantation (n = 12), and both situations concomitantly (n = 9). Total valve replacements numbered 161 (64 in the aortic position, 96 in the mitral position, and one in the tricuspid position). There were 18 valve repairs (eight in the mitral position, 10 in the aortic position). One patient underwent prosthesis thrombectomy (mechanical valve). Results: Overall operative mortality was 8.4% (n = 13); emergency operation (p <0.002), advanced NYHA class (p <0.026), indication for reoperation (p <0.026), gender (p <0.016) and number of previous reoperations (p = 0.05) were independent determinants for reoperation. Non-significant determinants were age and position of replacement. Conclusion: Correct planning of reoperation timing reduces operative risks due to NYHA class (3.8% mortality rate for class II-III versus 21.7% for class IV), and to urgent-emergency procedures (35.7% mortality versus 6.5% for elective operations). The high operative risk of prosthesis thrombosis is a deterrent to implanting mechanical prostheses in patients with disorders of hemostasi
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
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