1,721,078 research outputs found
The aging process modifies the distensibility of elastic but not muscular arteries
No full textAging decreases the distensibility of large elastic arteries; however, the effects of age on the functional parameters of muscular, medium-sized arteries are not well determined. This study evaluated the consequences of aging on the functional parameters of the carotid and radial arteries in normotensive men. A total of 62 elderly subjects (aged 74+/-2 years) were compared with 87 young subjects (aged 35+/-3 years). Internal diameter and intima-media thickness (IMT) were measured by a high-resolution echo-tracking system to calculate distensibility and incremental elastic modulus (Einc). Although in the normal range, systolic and diastolic blood pressure levels were statistically different in the 2 groups at 128+/-19 and 74+/-13 mm Hg versus 121+/-27 and 71+/-18 mm Hg in the young and elderly subjects, respectively (P<0.05). At the carotid artery level, elderly subjects exhibited a greater IMT (742+/-144 versus 469+/-132 microm; P<0.01) and internal diameter (7067+/-828 versus 6062+/-1026 microm; P<0.01) than young subjects; elderly subjects also had lower distensibility (12+/-2 versus 21+/-2 kPa(-1) x 10(-3); P<0.01) and higher Einc (0.9+/-0.2 versus 0.7+/-0.3 kPa x 10(3); P<0.01). At the radial artery level, both IMT (240+/-42 versus 218+/-51 microm; P<0.01) and internal diameter (2685+/-432 versus 2491+/-444 microm; P<0.01) were greater in elderly subjects, but no differences in distensibility and Einc were observed between the 2 groups. All differences remained significant, even after adjusting for mean blood pressure. These results indicate that the increase of the internal diameter and IMT observed during the aging process can have opposite effects on the functional parameters of large elastic or medium-sized muscular arteries
[Are the 1999 World Health Organization-International Society of Hypertension recommendations applicable to clinical practice?]
No full textThe aim of the 1999 WHO-ISH guidelines is to help the physicians in the management of hypertensive patients. The institution of antihypertensive treatment represents an important stage of this management sometimes at the detriment of lifestyle measures (non pharmacological treatments)
[The estimation of cardiovascular risk in hypertensive patients is not modified by management of the hypertension]
No full textTo compare antihypertensive therapeutic strategies and efficacy whether the physicians were aware or not of the calculated cardiovascular risk at 10 years obtained from the Framingham equation. It was also possible to evaluate the concordance of the general physicians estimation of the cardiovascular risk with the calculated percentage
Orthostatic hypotension in very old individuals living in nursing homes: the PARTAGE study.
No full textOBJECTIVE:
Orthostatic hypotension has a prognostic role in determining cardiovascular and all-cause mortality. The aim of this study was to assess the prevalence of orthostatic hypotension and its association with blood pressure (BP) levels, arterial stiffness, cardiovascular and metabolic disorders and medication in individuals aged 80 years and over living in nursing home.
METHODS:
In 994 individuals (77% women, mean age 88±5 years), the presence of orthostatic hypotension was tested according to American Autonomic Society and American Academy of Neurology guidelines. Arterial stiffness was evaluated with carotid-femoral pulse wave velocity (cf-PWV), peripheral to central pulse pressure amplification (PPA) and augmentation index. Cardiovascular and metabolic disorders as well as medications were recorded from patients' medical records.
RESULTS:
The prevalence of orthostatic hypotension was 18%. Treated hypertensive patients with SBP 140 mmHg or less had a lower prevalence of orthostatic hypotension than patients with SBP more than 140 mmHg (respectively, 13 vs. 23%; P < 0.001). Individuals with orthostatic hypotension exhibited higher brachial and central PP than individuals without orthostatic hypotension (respectively, 69±18 vs. 65±16 mmHg and 57±17 vs. 54±15 mmHg; P < 0.01). In these same individuals, a significant increase in augmentation index (31.1±14.0 vs. 27.2±13.6%; P < 0.01), but not in cf-PWV or in PPA, was observed. Individuals with orthostatic hypotension were treated more frequently with β-blockers and less frequently with angiotensin receptor blockers or nitrates than individuals without orthostatic hypotension (P < 0.05 for both).
CONCLUSION:
Contrary to the general belief, elderly individuals with well controlled BP (SBP < 140 mmHg) show lower orthostatic hypotension, thus constituting a complementary argument for efficaciously treating hypertension in these individuals
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
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