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Statins in the prevention of postoperative atrial fibrillation: is there really no effect?
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Wybrane parametry funkcji śródbłonka u chorych na niepowikłane nadciśnienie tętnicze z czynnikami ryzyka miażdżycy oraz bez nich
Full text linkBackground Selected parameters of endothelial function in patients with uncomplicated arterial hypertension and with risk factors of atherosclerosis.
Vascular endothelium dysfunction plays an important role in arterial hypertension pathogenesis. Its development is affected by the risk factors of atherosclerosis.
Evaluation of the concentration of nitric oxide metabolites (nitrites and nitrates-Nox) and endothelin-1 (ET-1) in plasma as well as cyclic 3.5 guanosine monophosphate (cGMP) in 24-hour urine collection in patients with uncomplicated arterial hypertension and without risk factors of atherosclerosis.
Material and methods The study comprised 45 subjects (30 men and 15 women) aged 45 ± 6.6 years, divided into 3 groups: I — controls (clinically healthy subjects), II — patients with arterial hypertension without risk factors of atherosclerosis
and III — patients with hypertension and with risk factors of atherosclerosis. Plasma Nox concentration was determined with Griess method, plasma ET-1 with ELISA
and cGMP in urine with immunoenzymatic method.
Results Plasma Nox concentration in group I was 15.86 ±
± 6.32 μmol/L, in group II — 18.62 ± 5.84 μmol/L, and in group III — 9.96 ± 4.72 μmol/L. The differences were
statistically significant between groups I and III (p < 0.05). The concentration of cGMP in urine was in group I — 40 ± 24 pmol/L, in group II — 54 ± 41 pmol/L and in group III — 38 ± pmol/L. The differences between the groups were statistically insignificant. The plasma ET-1 concentration was in group I — 3.83 ± 0.69 pg/mL, in group II — 3.98 ± 0.71 pg/mL and in group III — 4.22 ± 0,64 pg/mL. The differences were statistically significant between
groups I and III, p < 0.05.
Conclusion In patients with uncomplicated arterial hypertension
risk factors of atherosclerosis deteriorate significantly the function of vascular endothelium.Wstęp Istotne znaczenie w patogenezie nadciśnienia tętniczego ma dysfunkcja śródbłonka naczyniowego. Na jej rozwój wywierają wpływ czynniki ryzyka miażdżycy.
Celem badania była ocena zachowania się stężenia metabolitów tlenku azotu (azotynów i azotanów — NOx) oraz endoteliny-1 (ET-1) w osoczu i cyklicznego 3,5 guanozynomonofosforanu (cGMP) w dobowej zbiórce moczu u chorych na niepowikłane nadciśnienie tętnicze z czynnikami ryzyka miażdżycy oraz bez nich.
Materiał i metody Do badań zakwalifikowano 45 osób (30 mężczyzn i 15 kobiet) w wieku 45 ± 6,6 roku, których podzielono na 3 grupy: I — kontrolna (osoby klinicznie zdrowe), II — osoby z nadciśnieniem tętniczym bez czynników ryzyka miażdżycy i III — osoby z nadciśnieniem i z czynnikami ryzyka miażdżycy. Oznaczano stężenie NOx w osoczu metodą Griessa, ET-1 w osoczu metodą ELISA oraz
cGMP w moczu metodą immunoenzymatyczną.
Wyniki Stężenie NOx w osoczu w grupie I - 15,86 ± 6,32 µmol/l, w grupie II - 18,62 ± 5,84 µmol/l, w grupie III - 9,96 ± 4,72 µmol/l. Różnice istotne statystycznie stwierdzono między grupami I i III oraz II i III (p < 0,05). Stężenie cGMP w dobowej zbiórce moczu wynosiło w grupie I - 40 ± 24 pmol/l, w grupie II - 54 ± 41 pmol/l i w gr. III - 38 ± 32 pmol/l. Różnice między grupami były nieistotne statystycznie. Stężenie ET-1 w osoczu wynosiło
w grupie I - 3,83 ± 0,69 pg/ml, w grupie II - 3,98 ± 0,71 pg/ml i w grupie III - 4,22 ± 0,64 pg/ml. Różnice były nieistotne statystycznie.
Wnioski U chorych na niepowikłane nadciśnienie tętnicze
istotny wpływ na pogorszenie funkcji śródbłonka naczyniowego wywierają czynniki ryzyka miażdżycy
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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