1,720,989 research outputs found
Valutazione di strategie cognitivo-motivazionali nella prevenzione del drop-out accademico: il ruolo dell’orientamento in itinere
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Topiramate and metabolic acidosis during whole body hypothermia in neonatal hypoxic-ischemic encephalopathy
No full textBACKGROUND: Topiramate (TPM) seems to have neuroprotective functions in asphyxiated newborn. TPM is reported to have multiple mechanisms of action, including inhibition of carbonic anhydrase, which may result in metabolic acidosis from decreased serum bicarbonate (HCO3).
OBJECTIVE: Aim of the study was to investigate the appear of metabolic acidosis in asphixiated newborn treated whit whole body hypothermia (H) and TPM.
DESIGN/METHODS: We studied 54 neonates with HIE (G.E. 274.5 ± 15.4 d, BW 3355 ± 645 g), treated with H (30-33.5°C) for 72 h. 27 newborns were treated with H and 27 with H and TPM (H-TPM). 16 newborns received 5 mg/kg/day for three days, 11 newborns received 5 mg/kg on the first day and 3 mg/kg on the second and third day. Blood gas analysis (BGA) parameters were coollected every 24 hours during hypothermia.
RESULTS: BGAs, which were corrected for body temperature, were comparable in the two groups; no consistent metabolic acidosis was detected in H-TPM. Blood pH, pCO2, pO2 and lactate levels never reached statistically different values. Base excess (BE) and HCO3 were significantly lower in H in the first day of treatment (-7.4 ± 3.7 vs. -3.6 ± 3.5 mmol/L, p <0.001, and 18.8 ± 2.8 vs. 21.1 ± 3.1, p =0.004, respectively); in both groups, values have been increasing, but in H-TPM the trend showed a significant decrease compared to H. It became significantly lower in H-TPM in the third day of treatment (-0.9 ± 3.9 vs. 1.5 ± 1.7 mmol/L, p = 0.018, and 23.2 ± 3.2 vs. 25.5 ± 2.3, p = 0.013, respectively), despite pH remained normal.
CONCLUSIONS: The inhibition of carbonic anhydrase may result in a hyperchloremic metabolic acidosis, most likely from a renal tubular acidosis rather than from a more central mechanism. In our study HCO3 resulted higher in H-TPM than in H before the beginning of hypothermia, but reversed to lower on the third day of treatment, possibly due to TPM induced HCO3 loss, which might have occurred even if pH was not significantly different between the two groups. The same trend was observed for BE, again on the third day of treatment. The observed effect on HCO3 and BE is hardly attributable to TPM, since in infants metabolic acidosis usually occurs after 8-26 days of treatment, with dosages as high as 8.2 to 26 mg/kg/d. Monitoring HCO3 before and during TPM therapy may be indicated, especially with conditions that predispose to acidosis
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
MODELLO COMPUTERIZZATO DI BIOMECCANICA ARTERIOSA: VALUTAZIONE DELLA PARETE DI ANEURISMA ROTTO DELL’AORTA ADDOMINALE TRAMITE ANALISI AGLI ELEMENTI FINITI
No full textVariations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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