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Exogenous Surfactant

Animal studies, uncontrolled case reports and case series suggested a potential benefit to exogenous surfactant replacement therapy in PARDS [136]. However, clinical trials of exogenous surfactant outside of the neonatal population provided mixed results. Nonrandomised studies showed improved oxygenation but no effect on mortality in paediatric patients with moderate-to-severe ARDS according to the NAECC criteria. Calf lung surfactant (calfactant) was compared to placebo in a large, multicentre, randomised, placebo-controlled, masked trial in 153 children with acute lung injury [148]. Surfactant administration significantly improved oxygenation and reduced mortality (19% vs 36%) compared with placebo. However, this beneficial effect of surfactant disappeared after adjusting for immunocompromised state in multivariate analysis. The same group of investigators joined an international, multicentre, placebo-controlled trial comparing calfactant with placebo in both adult and paediatric patients with direct lung injury [149]. The trial utilised a novel form of surfactant, which was twice as concentrated as traditional calfactant. However, the trial was stopped prematurely due to futility. Recent attempts on identifying a possible role for exogenous surfactant through a multinational, prospective, blinded, randomised, controlled phase II trial of intratracheal instillation trial using a synthetic formulation of surfactant (lucinactant) among infants less than 2 years of age also showed no effect on patient outcome [140].

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Surfactancy and Catalysis
Catalysis The art of polyurethane foam formulation is balancing the competing processes by mixing complementary components such that all the processes of Figure 6.4 occur in amount and timing to result in foam of the correct structure and properties. Thus, along with the choice of polyol, isocyanate,...
(Polyurethanes science, technology, markets, and trends)
Surfactancy
Virtually all polyurethane foams are made with the essential addition of surfactants. The role of the surfactant is still not well understood in specific detail, but a sufficient amount of controlled structure-property experimentation has been done to provide FIGURE 6.8 (a) Example reaction for making...
(Polyurethanes science, technology, markets, and trends)
Assumptions of Exogenous Variables
Economic Growth Rates of the USA and the Eurozone We expect the US financial situation to continue to improve through 2015. At the same time, driven by factors such as drop of the jobless rate and low oil prices, the growth of domestic demand in the US economy could overcome the adverse impact...
(China’s Macroeconomic Outlook Quarterly Forecast)
Exploitation of Agro-Industrial Wastes to Produce Low-Cost Microbial Surfactants
Partap Bir Singh and Harvinder Singh Saini Surfactants are amphipathic molecules having characteristic property of reducing interfacial tension between two immiscible liquids which helps to improve their miscibility. Due to these properties, use of synthetic surfactants as emulsifiers, detergents,...
(Biotransformation of Waste Biomass into High Value Biochemicals)
Comparative Account of Biosafety and Surface-Active Properties of Biosurfactants and Synthetic Surfactants
...
(Biotransformation of Waste Biomass into High Value Biochemicals)
Conventional Substrates for Microbial Surfactants Production
The carbon source used in growth medium primarily affects the quantity and quality of biosurfactants produced by microorganisms (Sen 1997; Abouseoud et al. 2008). Different microbes have been reported to use wide range of carbon sources, such as alkanes, pyruvate, fructose, succinate, citrate, glycerol,...
(Biotransformation of Waste Biomass into High Value Biochemicals)
Surfactant Production and Function
Alveoli are subject to dramatic surface tension resulting from the attraction between the molecules of the fluid film that covers the alveolar cell surface. This force supports exhalation but would drive all liquids within the airways to retract, the lung to collapse, and the alveoli to merge into larger...
(Metabolism of Human Diseases)
Research Networks’ Exogenous Evaluation
It is pertinent to remember that the evaluative preferences of members of the networks may be in accordance with external indicators agencies impose. As a Physics researcher interviewed told us, “the evaluation directs posture and not always in a good direction, because objective meet external, exogenous...
(Evaluating Collaboration Networks in Higher Education Research: Drivers of Excellence)
Exogenous Labor Supply
The theoretical literature on tax reform discusses a desirable tax system that assures the required revenue when multiple taxes are available. First, let us compare labor income tax and interest income tax with the equal revenue requirement. Consider a simple two-period model. Let us denote the labor...
(Principles of Public Finance)