1,720,961 research outputs found
Hemodynamic, respiratory, and metabolic effects of medium-chain triglyceride-enriched lipid emulsions following valvular heart surgery
No full textStudy: A lipid emulsion containing 10 percent medium-chain triglycerides (MCT) and 10 percent long-chain triglycerides (LCT) was infused at a rate of 1 ml/kg/h (3.3 mg/kg/min) for 2 h, in 12 patients (2 males, 10 females; mean age, 54 ± 3 (SEM) years; range, 34 to 67 years) 24 h after open-heart surgery (mitral valve replacement). Methods: Hemodynamic factors (pulmonary and radial artery indwelling catheters), oxygen and carbon dioxide partial pressures, oxygen saturation, oxygen delivery and consumption, and intrapulmonary shunt fraction were obtained before, during, and after lipid infusion (for 2 h), at 30-s intervals, along with some metabolic indexes (triglycerides, free fatty acids, glucose, insulin, lactate, acetoacetate). Results: No statistically significant changes in heart rate, cardiac index, systemic and pulmonary pressures and resistances, central venous and pulmonary capillary pressures, or arterial oxygen partial pressure were observed during infusion. Arterial carbon dioxide partial pressure values were constantly reduced throughout and after the end of lipid infusion, as compared with baseline values, while oxygen consumption was increased significantly without any change in oxygen delivery. No adverse effects on intrapulmonary shunt fraction were observed. Statistically significant increases of triglycerides, free fatty acids, acetoacetate and insulin (peak values at end of the lipid infusion) were found in comparison with baseline values. Plasma glucose increased significantly during lipid infusion and remained higher than baseline values until the end of the study. Lactate levels were unchanged, except for a slight decrease at the end of the study, without any derangement of acid-base equilibrium. Neither arrhythmias nor adverse clinical reactions were observed as a consequence of lipid infusion. Conclusion: Fat emulsions containing both MCT and LCT, when given at 3.3 mg/kg/min for 120 min following valvular heart surgery, do not exert negative cardiopulmonary effects, and could represent a source of rapidly metabolized substrates
Hemodynamic and respiratory effects of medium-chain and long-chain triglyceride fat emulsions: A prospective, randomized study
No full textBackground: Intravenous fat emulsions (IVFE) containing long-chain triglycerides (LCTs) (chain length 20 carbon atoms) have been associated with adverse hemodynamic and respiratory effects in postoperative on intensive care unit patients. Recently, medium-chain triglycerides (MCTs) (chain length 6 to 12 carbons atoms) have been introduced as a component of IVFE. Objectives: The study was aimed at comparing cardiopulmonary effects of IVFE with different composition (MCTs + LCTs vs LCT-based IVFE). Design: Prospective, double-blind, randomized, parallel-group controlled trial. Setting: Heart surgery postoperative intensive care unit. Patients: With approval of the Institutional Review Board of Human Studies, and after obtaining written informed consent, twenty-six spontaneously breathing patients were enrolled in the study 24 hours after open heart surgery for mitral valve replacement (22 females, 4 males, mean age 57 years, range 35-73). Interventions: Patients were randomized into two groups, to receive 1 mL/kg/hour for two hours (3.3 mg/kg/min) of the LCT-based IVFE or the IVFE containing a physical mixture of MCTs + LCTs (50:50%). Group comparisons were made using repeated measures of ANOVA; main statistical comparisons were made in each group between baseline values and data collected during and after two hours of IVFE infusion (Dunnett multiple comparison test). A p < .05 level was used to establish statistical significance. Measurements and main results: In each group hemodynamic measurements and arterial blood gases were obtained before, during and after (for another two hours) IVFE infusion, at 30' intervals; oxygen transport/utilization parameters and intrapulmonary shunt fraction were also calculated. No change in heart rate, cardiac index, systemic and pulmonary pressures or resistance, central venous and pulmonary capillary pressures, nor in arterial blood gases was observed in the MCTs + LCTs group, as compared to pre-infusion values. IVFE administration reduced the cardiac index (-15% at 60' and 120' of infusion) only in the group receiving the LCT-based IVFE; significant increases in both pulmonary artery pressures and vascular resistances were observed in the same group, with PaO2 decrease during IVFE administration. Oxygen consumption was constantly increased (+15% vs baseline values) during and after MCTs + LCTs infusion. Oxygen delivery was unmodified by LCTs + MCTs, but it was significantly reduced by the LCT-based IVFE. Neither changes in the intrapulmonary shunt fraction nor arrhythmias or adverse clinical reactions were observed during or after the infusion of either IVFE. Conclusions: Unlike IVFE based on LCTs only, MCTs + LCTs IVFE do not exert adverse cardiopulmonary effects at clinically useful doses following valvular heart surgery and could represent a safe source of rapidly metabolized substrates
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
Effects of different cardiopulmonary bypass procedures on intracellular energy metabolism, acid-base equilibrium and muscle water compartments in patients undergoing aortocoronary bypass grafting.
No full textThis study compares the effects of cardiopulmonary bypass with different flows and pressures on intracellular energy metabolism, acid-base equilibrium and muscle water compartments in two groups of patients undergoing aortocoronary bypass grafting. Eighteen patients (16 males, 2 females, mean age 54 yrs, +or- 7DS, NYHA class 1-2) undergoing Low-Flow (LF) (Flow rate 1.5 L/m/m2 at 26°). Low Pressure, CPB as well as ten age- and sex-matched patients undergoing normal-flow (Flow rate 2.2 L/m/m2 at 26°) Normal-pressure CPB were studied. Intracellular acid-base equilibrium, cell energetics and muscle water compartments were evaluated in quadriceps muscle specimens obtained by needle biopsy before and at the end of CPB. In both LF-LP and NF-NP groups, ATP levels were unchanged at the end of CPB, whereas PCr was decreased; muscle total water and extracellular water increased without variations of intracellular water; muscle and plasma lactate increased as HCO3 decreased; pH values remained unchanged. The present study suggests that a) CPB is associated with the overall preservation of intracellular compartment metabolism in skeletal muscle (about 40% of body cell mass) of patients undergoing aortocoronary bypass grafting, even though low PCr values and increased plasma and muscle lactate values found at the end of CPB could be an expression of cell functional reserve exhaustion; b) CPB effects on cell metabolism are comparable, regardless of the flows and pressures utilized
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