1,720,977 research outputs found
Bioimpedance based determination of cardiac index does not show enough trueness for point of care use in patients with systolic heart failure
No full textCardiac output (CO) is a key parameter in diagnostics and therapy of heart failure (HF). The thermodilution method (TD) as gold standard for CO determination is an invasive procedure with corresponding risks. As an alternative, thoracic bioimpedance (TBI) has gained popularity for CO estimation as it is non-invasive. However, systolic heart failure (HF) itself might worsen its validity. The present study validated TBI against TD. In patients with and without systolic HF (LVEF ≤ 50% or > 50% and NT-pro-BNP < 125 pg/ml, respectively) right heart catheterization including TD was performed. TBI (Task Force Monitor©, CNSystems, Graz, Austria) was conducted semi-simultaneously. 14 patients with and 17 patients without systolic HF were prospectively enrolled in this study. In all participants, TBI was obtainable. Bland-Altman analysis indicated a mean bias of 0.3 L/min (limits of agreement ± 2.0 L/min, percentage error or PE 43.3%) for CO and a bias of -7.3 ml (limits of agreement ± 34 ml) for cardiac stroke volume (SV). PE was markedly higher in patients with compared to patients without systolic HF (54% vs. 35% for CO). Underlying systolic HF substantially decreases the validity of TBI for estimation of CO and SV. In patients with systolic HF, TBI clearly lacks diagnostic accuracy and cannot be recommended for point-of-care decision making. Depending on the definition of an acceptable PE, TBI may be considered sufficient when systolic HF is absent. Trial registration number: DRKS00018964 (German Clinical Trial Register, retrospectively registered
Validity of transit time–based blood pressure measurements in patients with and without heart failure or pulmonary arterial hypertension across different breathing maneuvers
No full textPurpose: Pulse transit time (PTT) derived by ECG and plethysmographic signal can be a promising alternative to invasive or oscillometry-based blood pressure (BP) monitoring in sleep laboratories because it does not cause arousals from sleep. Therefore, this study assessed the validity of PTT for BP monitoring under sleep laboratory-like conditions. Methods: Ten volunteers (55.8 ± 19.6 years), 12 patients with heart failure with reduced ejection fraction (HFrEF; 67.3 ± 8.6 years), and 14 patients with Nizza class I pulmonary arterial hypertension (PAH; 59.5 ± 13.4 years) performed different breathing patterns to simulate nocturnal sleep-disordered breathing (SDB). BP was measured at least every 15 min over 1 h using oscillometry (Task Force MonitorTM) and PTT (SOMNOscreenTM) devices in free breathing conditions and during SDB simulation (alternating phases of hyperventilation and apneas). Results: One hundred forty-two points of measurements were collected. No difference was found in both mean systolic BP (SBP) and diastolic BP (DBP) between oscillometric PTT-based BP measurements in the whole population and throughout the whole recording (SBP 111.3 ± 15.1 mmHg versus 110.0 ± 14.7 mmHg, p = 0.051; DBP 69.9 ± 12.2 versus 69.9 ± 14.2 mmHg, p = 0.701). Likewise, no significant difference in SBP and DBP was found between the two methods in the subgroups of healthy subjects, HFrEF patients and PAH patients, both in free breathing conditions (p > 0.05) and during SDB simulation (p > 0.05). Conclusions: When monitoring BP in healthy subjects, and in patients with HFrEF or PAH, PTT provides a BP estimation comparable with oscillometric measurement, though slightly inaccurate, both in the condition of regular and unstable breathing
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
Variations 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
Diaphragm Involvement in Heart Failure: Mere Consequence of Hypoperfusion or Mediated by HF-Related Pro-inflammatory Cytokine Storms?
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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
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
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