1,720,957 research outputs found
Arterial hypertension and cognitive deficit
No full textCognitive impairment and dementia are more and more common in the elderly. The first begins, it advances silently and it leads to dementia in few years. Arterial hypertension represents the most important cerebrovascular risk factor after age. In numerous studies an inverse relationship between blood pressure values and cognitive performance emerges: it is possible that arterial hypertension plays a role in the pathogenesis of cognitive decline. Even in asymptomatic subjects the magnetic resonance signs of cerebral damage accompany cognitive impairment development. Antihypertensive therapy influence on cognitive function represents a subject of actual interest. The most studied drugs are calcium antagonists and ACE-inhibitors; they seem to have a protective effect on cognitive impairment, with regard to diuretics and beta-blockers. It would be important to study hypertensive patients, above all young asymptomatic hypertensives, even about cognitive functions, to prevent and consider cognitive decline and effective organ damage
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
Bioequivalence study of nicardipine solution versus nicardipine tablets
No full textThe bioequivalence of a solution (investigational product) and a tablet (reference product) formulation of the dihydropyridine-type derivative Ca2+ antagonist nicardipine were investigated by measuring plasma levels of the compound after single randomized administration of 20 mg of the two formulations. Drugs were given orally in a single dose to 24 healthy volunteers (12 males and 12 females) at the beginning of the experiment and after a two weeks wash-out. Nicardipine is available in oral and intravenous formulations, the second being used for the short-term treatment of hypertensive crises. Oral formulations of nicardipine most diffused include immediate release (20 or 30 mg, three times a day administration), sustained release (30 mg, 45 mg or 60 mg, twice a day administration) and modified release (80 mg, once a day administration) tablets. A nicardipine solution is available only in Spain, but no published studies on the kinetics of this formulation are available. In the last 15 years, the main efforts were aimed to develop sustained or controlled release formulations of nicardipine to improve patient compliance by reducing the number of doses required each day. However, the use of twice a day or once a day administration of Ca2+ antagonists should be not overemphasized in particular situations like those of possible risk of cerebrovascular and/or coronary steal effect primarily in the elderly. The oral formulation of nicardipine investigated with a bioequivalence range > 70% compared to nicardipine immediate release tablets may represent an additional resource for treating elderly patients with concomitant cerebrovascular or coronary heart disease
Blood pressure in patients with primary aldosteronism is influenced by bradykinin B2 receptor and alpha-adducin gene polymorphism
No full textArterial hypertension: a cause of cognitive impairment and of vascular dementia
No full textArterial hypertension is a well-documented modifiable risk factor for cerebrovascular disease and for both cerebral infarction and intracerebral hemorrhage. Recent studies indicate a relationship between high blood pressure in midlife and dementia in late life and suggest that arterial hypertension may represent a cause of vascular dementia (VaD). This paper has reviewed the main evidence of a link between arterial hypertension and vascular cognitive impairment or VaD. Brain lesions induced by hypertension, diagnostic procedures for early diagnosis of vascular cognitive impairment in at risk subjects and the need to include cognitive assessment in patient's general visits in hypertension units are discussed
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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