1,720,959 research outputs found
Haemodynamic significance of ostial side branch nipping following percutaneous intervention at bifurcations: a pressure wire pilot study
No full textCombining carotid intima-media thickness with carotid plaque on screening for coronary heart disease
No full textBACKGROUND: Ultrasound-detected carotid artery intima-media thickness (IMT) and carotid plaque are possible screening tests for coronary heart disease (CHD) among asymptomatic individuals.OBJECTIVE: To assess the increase in screening performance of combining carotid IMT and plaque compared with each measurement alone in the identification of individuals with CHD.METHODS: Ultrasound examination of left and right carotid arteries was performed on 100 individuals (median age 57), 55 with a history of CHD (unstable angina or myocardial infarction) and 45 without. IMT measurements were taken from the common carotid artery and plaque was identified above, at and below the carotid bifurcation. Associations between IMT and plaque were determined using logistic regression, and screening performance was assessed from the distributions of IMT and plaque among cases and controls.RESULTS: At a false-positive rate of 5%, IMT (cut-off >0.75 mm) identified 30% (95% CI 14-58) of affected individuals. There was an increase in the detection rate of 8 percentage points (1-33%) using IMT and plaque combined compared with IMT alone. As the false-positive increased, the difference in the detection rate increased, up to a maximum of 20 percentage points (5-38%) at a false-positive rate of 20%. The comparison of IMT and plaque combined with plaque alone could only be estimated for the false-positive rate observed using plaque alone (18%); at this point the detection rate was 72% for plaque and 75% for plaque and IMT combined, an increase of 3 percentage points (0-4%).CONCLUSION: In screening for CHD, combining carotid IMT measurement with plaque assessment is better than using either measurement alone, but the improvement in discrimination is not sufficient to make carotid ultrasound screening for CHD worthwhile
Long-term continuation on cardiovascular drug treatment in patients with coronary heart disease
No full textBACKGROUND: Combination therapy to reduce risk factors is effective in preventing recurrent cardiovascular disease events in patients with coronary heart disease (CHD), but medications need to be continued indefinitely to maximize the benefits. OBJECTIVE: To evaluate the extent of long-term continuation with cardiovascular drug therapy and its expected impact on the prevention of CHD. METHODS: We studied 242 patients with CHD who underwent percutaneous coronary intervention following an acute coronary syndrome over a 6 month period in 2004. We prospectively examined the extent to which specific drugs and drug combinations were continued over time by reviewing medication use at the time of hospital discharge and after 2 years. The results were used to estimate the expected loss in preventive efficacy due to discontinuation of therapy. RESULTS: The changes over a 2 year period in the proportions of patients taking each drug class were as follows: 15% reduction for aspirin (95% CI, -21 to -9), 10% reduction for statins (95% CI, -16 to -5), 19% reduction for angiotensin-converting enzyme inhibitors (95% CI, -26 to -12), 12% reduction for beta-blockers (95% CI, -18 to -6), 0% increase for calcium-channel blockers (95% CI, -5 to 6), 2% increase for thiazides (95% CI, -2 to 6), and 12% increase for angiotensin-II receptor blockers (95% CI, 6 to 18). The combination of aspirin, statin, and at least 2 blood pressure lowering drugs was prescribed to 81% of patients, three-quarters of whom remained on this combination after 2 years. The overall expected preventive effect on CHD of the combined medication taken during hospitalization and after 2 years was 80% and 74%, respectively. CONCLUSIONS: In patients with CHD, long-term continuation of combination cardiovascular drug therapy is considerably greater than generally perceive
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
ЭФФЕКТИВНОСТЬ ВЫПОЛНЕНИЯ ПРОФИЛАКТИЧЕСКОЙ АНГИОПЛАСТИКИ КОРОНАРНЫХ АРТЕРИЙ ПРИ ИНФАРКТЕ МИОКАРДА: РЕЗУЛЬТАТЫ РАНДОМИЗИРОВАННОГО ИССЛЕДОВАНИЯ PRAMI
Full text linkWald D.S., Morris J.K., Wald N.J., et al. Preventive angioplasty in myocardial infarction // N. Engl. J. Med. – 2013. – Vol. 369. – P. 1115–1123.Источник: Wald D.S., Morris J.K., Wald N.J., et al. Preventive angioplasty in myocardial infarction // N. Engl. J. Med. – 2013. – Vol. 369. – P. 1115–1123
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
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