1,720,988 research outputs found
Reduced coronary flow reserve and parasympathetic dysfunction in patients with cardiovascular syndrome X
No full textOBJECTIVE:
Although cardiovascular syndrome X was described many years ago, its causes are still unclear. Many studies have addressed the autonomic function, whereas others have investigated the coronary reserve. The purpose of this study was to investigate the correlations between parasympathetic dysfunction and coronary flow reserve deficiency.
BASIC METHODS:
Eleven consecutive women suffering from cardiovascular syndrome X were enrolled in the study. All the patients underwent the analysis of heart rate and blood pressure variability, the cold face test and noninvasive evaluation of the coronary flow reserve by transthoracic echocardiography. Comparison was made with healthy volunteers.
RESULTS:
Seven patients (64%) showed vagal impairment in the analysis of heart rate and blood pressure variability and a pathological response to the cold face test, whereas four patients (36%) did not show significant differences from the control group. In these three groups, patients with and without vagal impairment and controls, there was a difference in the mean diastolic coronary velocity reserve (1.94+/-0.48; 3.73+/-0.95, 2.88+/-0.55, P=0.0005) and in maximal diastolic velocity reserve (2.00+/-0.48, 3.26+/-0.64, 2.65+/-0.57, P=0.0047). Post-hoc analysis demonstrated that the mean and maximal diastolic velocity reserves of the patients with vagal impairment seemed to be reduced compared with those of the other groups (P<0.05), which were similar.
CONCLUSIONS:
This study confirmed that syndrome X patients represent a heterogeneous group. More than half of the patients exhibited vagal dysfunction. In these patients, coronary flow reserve was abnormal compared with controls and other syndrome X patients without vagal impairment
Evaluation of hematocrit bias on blood glucose measurement with six different portable glucose meters.
No full textINTRODUCTION:
Measurement and monitoring of blood glucose levels in hospitalized patients with portable glucose meters (PGMs) is performed widely and is an essential part of diabetes monitoring, despite the increasing evidence of several interferences which can negatively bias the accuracy of measurements. The purpose of this study was to evaluate the effect of the hematocrit on the analytical performances of different PGMs as compared with a reference laboratory assay.
MATERIALS AND METHODS:
The effect of various hematocrit values (approximiately 0.20, approximiately 0.45 and approximiately 0.63 L/L) were assessed in three whole blood specimens with different glucose concentration (approximiately 1.1, approximiately 13.3, and approximiately 25 mmol/L) by using six different commercial PGMs. The identical samples were also tested with the laboratory reference assay (i.e., hexokinase). The percentage difference from the laboratory assay (%Diff) was calculated as follows: % Diff = average PGM value - value from laboratory assay x 100 / value from laboratory assay.
RESULTS:
The %Diff of the six different PGMs were rather broad, and comprised between 56.5% and -34.8% in the sample with low glucose concentration (approximiately 1.1 mmol/L), between 40% and -32% in the sample with high glucose concentration (approximiately 13.3 mmol/L), and between -50% and 15% in the sample with very high glucose concentration (approximiately 25 mmol/L), respectively. It is also noteworthy that a very high hematocrit value (up to 0.63 L/L) generated a remarkable negative bias in blood glucose (-35%) as measured with the laboratory assay, when compared with the reference sample (hematocrit 0.45 L/L).
CONCLUSION:
The results of this analytical evaluation clearly confirm that hematocrit produces a strong and almost unpredictable bias on PGMs performances, which is mainly dependent on the different type of devices. As such, the healthcare staff and the patients must be aware of this limitation, especially in the presence of extreme hematocrit levels, when plasma glucose assessment with the reference laboratory technique might be advisable
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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