1,720,972 research outputs found
Cardiovascular stability during haemodialysis, haemofiltration and haemodiafiltration
No full textSeveral comparative studies have claimed that procedures based substantially or exclusively on pressure-driven water-solute transport, such as haemodiafiltration or haemofiltration, afford better protection of the cardiovascular tolerance to fluid removal than conventional haemodialysis. During each depurative modality, several factors are set in motion that might impact, each in its own right, upon the haemodynamic response to fluid withdrawal. To explore the haemodynamic effect of each of them singularly, one needs to keep all other components unvaried. However, this is very difficult to accomplish. For instance, to confirm the alleged greater protection of cardiovascular stability by pure convection vs diffusion, one needs to keep unvaried all the other factors potentially affecting haemodynamic tolerance, i.e. the rate of body fluid removal, the membrane, the buffer, the blood temperature in the extracorporeal circuit, depuration efficiency, the sodium balance, the fluid sterility and so on. Such studies are still awaited. However, clinical trials published to date have not resolved the question of whether haemofiltration and haemodiafiltration provide a better haemodynamic tolerance to fluid removal. If we limit our consideration to controlled trials only, most prospective studies have adopted a cross-over design implemented on very small patient samples and for very short periods. Such an approach is liable to generate misleading results because the incidence of dialysis hypotension often fluctuates from time to time. Owing to such fluctuations, results can be strongly affected by the 'order effect' of the cross-over from one technique to the other. The negative results provided by parallel comparisons of procedures should be taken with caution because patients samples did not include a suitable proportion of unstable patients
[Early diagnosis of rapidly progressive glomerulonephritis]
No full textThe term rapidly progressive glomerulonephritis (RPGN) designates a group of glomerular diseases with different pathogenetic and clinical features, rapidly leading to renal or patient death in about 90% of the untreated cases. Histopathologically, it is characterized by glomerular crescents in at least 50-75% of the glomeruli (necrotizing crescentic glomerulonephritis), and very often, glomerular necrosis. The situation is, however, potentially reversible if adequately treated, and a favourable outcome depends largely on early diagnosis and treatment. Early diagnosis can be achieved if due importance is given to even seemingly unspecific manifestations such as "flu like syndrome" associated with "glomerular" hematuria. These manifestations are detectable before the down-hill course of renal functional derangement becomes evident and should lead the physician to consider RPGN among the diagnostic possibilities. Final diagnosis rests on serological tests and kidney biopsy. The battery of diagnostic serological tests (anti-GBM, anti-DNA antibodies, cryoglobulins, etc.) has recently been enriched by the assay of anti-neutrophil cytoplasmic antibodies (ANCA). These antibodies are detectable in over 90% of cases of Wegener's granulomatosis and primary necrotizing crescentic glomerulonephritis with or without lung involvement. ANCA-associated glomerulonephritis is the commonest form of RPGN, and the new serological assay provides an important tool for its early recognition. Renal biopsy is necessary to evaluate the severity of the nephritic process and modulate treatment accordingly. Timely diagnosis is one of the most important factors contributing to successful treatment outcome over both the short and the long term
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
Bivariate normal values of the bioelectrical impedance vector in adult and elderly populations.
No full textCharacterization of myocardial tissue in patients undergoing maintainance hemodialysis by quantitative echocardiography
No full textVariations 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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