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Sample records for surfactant loss control

  1. Surfactant loss control in chemical flooding spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Annual report, September 30, 1992--September 30 1995

    Energy Technology Data Exchange (ETDEWEB)

    Casteel, J. [Bartlesville Project Office, OK (United States)

    1996-07-01

    The aim of this research project was to investigate mechanisms governing adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effects of surfactant structure, surfactant combinations, various inorganic and polymeric species, and solids mineralogy have been determined. A multi-pronged approach consisting of micro & nano spectroscopy, electrokinetics, surface tension and wettability is used in this study. The results obtained should help in controlling surfactant loss in chemical flooding and in developing optimum structures and conditions for efficient chemical flooding processes. During the three years contract period, adsorption of single surfactants and select surfactant mixtures was studied at the solid-liquid and gas-liquid interfaces. Alkyl xylene sulfonates, polyethoxylated alkyl phenols, octaethylene glycol mono n-decyl ether, and tetradecyl trimethyl ammonium chloride were the surfactants studied. Adsorption of surfactant mixtures of varying composition was also investigated. The microstructure of the adsorbed layer was characterized using fluorescence spectroscopy. Changes in interfacial properties such as wettability, electrokinetics and stability of reservoir minerals were correlated with the amounts of reagent adsorbed. Strong effects of the structure of the surfactant and position of functional groups were revealed. Changes of microstructure upon dilution (desorption) were also studied. Presence of the nonionic surfactants in mixed aggregate leads to shielding of the charge of ionic surfactants which in turn promotes aggregation but reduced electrostatic attraction between the charged surfactant and the mineral surface. Strong consequences of surfactant interactions in solution on adsorption as well as correlations between monomer concentration in mixtures and adsorption were revealed.

  2. Surfactant loss control in chemical flooding spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Annual report, September 30, 1993--September 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Somasundaran, P.

    1995-06-01

    The aim of this project is to elucidate the mechanisms underlying adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effect of surfactant structure, surfactant combinations, other inorganic and polymeric species is being studied. A multi-pronged approach consisting of micro and nano spectroscopy, microcalorimetry, electrokinetics, surface tension and wettability is used to achieve the goals. The results of this study should help in controlling surfactant loss in chemical flooding and also in developing optimum structures and conditions for efficient chemical flooding processes. During the second year of this three year contract, adsorption/desorption of single surfactants and select surfactant mixtures on alumina and silica was studied. Surfactants studied include the anionic sodium dodecyl sulfate (SDS), cationic tetradecyl trimethyl ammonium chloride (TTAC), nonionic pentadecylethoxylated nonyl phenol (NP-15) and the nonionic octaethylene glycol n-dodecyl ether (C{sub 12}EO{sub 8}) of varying hydrocarbon chain length. The microstructure of the adsorbed layer in terms of micropolarity and aggregation numbers was probed using fluorescence spectroscopy. Changes of microstructure upon dilution (desorption) were also studied. Presence of the nonionic surfactant in the mixed aggregate led to shielding of the charge of the ionic surfactant which in-turn promoted aggregation but reduced electrostatic attraction between the charged surfactant and the mineral surface. Strong consequences of surfactant interactions in solution upon adsorption as well as correlations between monomer concentrations in mixtures and adsorption were revealed.

  3. Surfactant loss control in chemical flooding: Spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Annual report, September 30, 1992--September 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Somasundaran, P.

    1994-07-01

    The aim of this research project is to investigate mechanisms underlying adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effects of surfactant structure, surfactant combinations, various inorganic and polymeric species, and solids mineralogy will be determined. A multi-pronged approach consisting of micro & nano spectroscopy, microcalorimetry, electrokinetics, surface tension and wettability; is used in this study. The results obtained should help in controlling surfactant loss in chemical flooding and in developing optimum structures and conditions for efficient chemical flooding processes. During the first year of this three year contract, adsorption of single surfactants and select surfactant mixtures was studied at the solid-liquid and gas-liquid interfaces. Surfactants studied include alkyl xylene sulfonates, polyethoxylated alkyl phenols, octaethylene glycol mono n-decyl ether, and tetradecyl trimethyl ammonium chloride. Adsorption of surfactant mixtures of varying composition was also investigated. The microstructure of the adsorbed layer was characterized using fluorescence spectroscopy. Changes interfacial properties such as wettability, electrokinetics and stability of reservoir minerals were correlated with the amount of reagent adsorbed. Strong effects of the structure of the surfactant and position of functional groups were revealed.

  4. Size control of surfactant vesicles made by a mixture of cationic surfactants and organic derivatives.

    Science.gov (United States)

    Kim, Tae-Hwan; Han, Young-Soo; Jang, Jong-Dae; Seong, Baek-Seok

    2014-10-01

    Spontaneous size-controllable vesicles that are prepared by a mixture of surfactants with different alkyl chain lengths (n-alkyltrimethylammonium bromide, C(n)TAB) and an organic derivative (5-methyl salicylic acid, 5mS) in aqueous solution have been investigated. When the organic derivative 5mS is mixed with the C(n)TAB surfactants in aqueous solution, the surfactant vesicles are spontaneously formed above a certain 5mS concentration. Small angle neutron scattering reveals that the core radius of surfactant vesicles is clearly increased from ca. 31 nm to ca. 97 nm with the alkyl chain length of surfactants while the bilayer thickness of the vesicles is nearly constant. The structure of surfactant vesicles maintains against temperature change ranging from 30 degrees C to 45 degrees C, showing no structural change. These results can provide thermally stable surfactant vesicles with various sizes and constant bilayer thickness that may possess a different permeability and may allow the surfactant vesicle to be used in gene or drug delivery for a variety of goods.

  5. Surfactant Based Enhanced Oil Recovery and Foam Mobility Control

    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Clarence A. Miller

    2006-09-09

    Surfactant flooding has the potential to significantly increase recovery over that of conventional waterflooding. The availability of a large number of surfactant structures makes it possible to conduct a systematic study of the relation between surfactant structure and its efficacy for oil recovery. A mixture of two surfactants was found to be particularly effective for application in carbonate formations at low temperature. The mixture is single phase for higher salinity or calcium concentrations than that for either surfactant used alone. This makes it possible to inject the surfactant slug with polymer close to optimal conditions and yet be single phase. A formulation has been designed for a particular field application. It uses partially hydrolyzed polyacrylamide for mobility control. The addition of an alkali such as sodium carbonate makes possible in situ generation of naphthenic soap and significant reduction of synthetic surfactant adsorption. The design of the process to maximize the region of ultra-low IFT takes advantage of the observation that the ratio of soap to synthetic surfactant is a parameter in the conditions for optimal salinity. Even for a fixed ratio of soap to surfactant, the range of salinity for low IFT was wider than that reported for surfactant systems in the literature. Low temperature, forced displacement experiments in dolomite and silica sandpacks demonstrate that greater than 95% recovery of the waterflood remaining oil is possible with 0.2% surfactant concentration, 0.5 PV surfactant slug, with no alcohol. Compositional simulation of the displacement process demonstrates the role of soap/surfactant ratio on passage of the profile through the ultralow IFT region, the importance of a wide salinity range of low IFT, and the importance of the viscosity of the surfactant slug. Mobility control is essential for surfactant EOR. Foam is evaluated to improve the sweep efficiency of surfactant injected into fractured reservoirs as well as a

  6. Use of surfactants to control island size and density

    Energy Technology Data Exchange (ETDEWEB)

    Merrell, Jason; Liu, Feng; Stringfellow, Gerald B.

    2017-08-15

    Methods of controlling island size and density on an OMVPE growth film may comprise adding a surfactant at a critical concentration level, allowing a growth phase for a first period of time, and ending the growth phase when desired island size and density are achieved. For example, the island size and density of an OMVPE grown InGaN thin film may be controlled by adding an antimony surfactant at a critical concentration level.

  7. A systems approach to mapping transcriptional networks controlling surfactant homeostasis

    Directory of Open Access Journals (Sweden)

    Dave Vrushank

    2010-07-01

    Full Text Available Abstract Background Pulmonary surfactant is required for lung function at birth and throughout life. Lung lipid and surfactant homeostasis requires regulation among multi-tiered processes, coordinating the synthesis of surfactant proteins and lipids, their assembly, trafficking, and storage in type II cells of the lung. The mechanisms regulating these interrelated processes are largely unknown. Results We integrated mRNA microarray data with array independent knowledge using Gene Ontology (GO similarity analysis, promoter motif searching, protein interaction and literature mining to elucidate genetic networks regulating lipid related biological processes in lung. A Transcription factor (TF - target gene (TG similarity matrix was generated by integrating data from different analytic methods. A scoring function was built to rank the likely TF-TG pairs. Using this strategy, we identified and verified critical components of a transcriptional network directing lipogenesis, lipid trafficking and surfactant homeostasis in the mouse lung. Conclusions Within the transcriptional network, SREBP, CEBPA, FOXA2, ETSF, GATA6 and IRF1 were identified as regulatory hubs displaying high connectivity. SREBP, FOXA2 and CEBPA together form a common core regulatory module that controls surfactant lipid homeostasis. The core module cooperates with other factors to regulate lipid metabolism and transport, cell growth and development, cell death and cell mediated immune response. Coordinated interactions of the TFs influence surfactant homeostasis and regulate lung function at birth.

  8. Controlling block copolymer phase behavior using ionic surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Ray, D.; Aswal, V. K. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India E-mail: debes.phys@gmail.com (India)

    2016-05-23

    The phase behavior of poly(ethylene oxide)-poly(propylene oxide-poly(ethylene oxide) PEO-PPO-PEO triblock copolymer [P85 (EO{sub 26}PO{sub 39}EO{sub 26})] in presence of anionic surfactant sodium dodecyl sulfate (SDS) in aqueous solution as a function of temperature has been studied using dynamic light scattering (DLS) and small-angle neutron scattering (SANS). The measurements have been carried out for fixed concentrations (1 wt%) of block copolymer and surfactants. Each of the individual components (block copolymer and surfactant) and the nanoparticle–surfactant mixed system have been examined at varying temperature. The block copolymer P85 forms spherical micelles at room temperature whereas shows sphere-to-rod like micelle transition at higher temperatures. On the other hand, SDS surfactant forms ellipsoidal micelles over a wide temperature range. Interestingly, it is found that phase behavior of mixed micellar system (P85 + SDS) as a function of temperature is drastically different from that of P85, giving the control over the temperature-dependent phase behavior of block copolymers.

  9. Magnetic surfactants

    OpenAIRE

    Brown, P.; Alan Hatton, T.; Eastoe, J.

    2015-01-01

    Surfactants are ubiquitous, being important commodity chemicals with wide industrial applications, and essential components of living organisms. With stimuli-responsive surfactants, self-assembly and physicochemical properties of a wide variety of materials may be readily manipulated, both reversibly and irreversibly. Until recently, magnetically responsive surfactants had not been reported. This review reports the recent progress in magnetoresponsive surfactants, covering control of interfac...

  10. Surfactant-enhanced control of track-etch pore morphology

    International Nuclear Information System (INIS)

    Apel', P.Yu.; Blonskaya, I.V.; Didyk, A.Yu.; Dmitriev, S.N.; Orelovich, O.L.; Samojlova, L.I.; Vutsadakis, V.A.; Root, D.

    2000-01-01

    The influence of surfactants on the process of chemical development of ion tracks in polymers is studied. Based on the experimental data, a mechanism of the surfactant effect on the track-etch pore morphology is proposed. In the beginning of etching the surfactant is adsorbed on the surface and creates a layer that is quasi-solid and partially protects the surface from the etching agent. However, some etchant molecules diffuse through the barrier and react with the polymer surface. This results in the formation of a small hole at the entrance to the ion track. After the hole has attained a few annometers in diameter, the surfactant molecules penetrate into the track and cover its walls. Further diffusion of the surfactant into the growing pore is hindered. The adsorbed surfactant layer is not permeable for large molecules. In contrast, small alkali molecules and water molecules diffuse into the track and provide the etching process enlarging the pore. At this stage the transport of the surfactant into the pore channel can proceed only due to the lateral diffusion in the adsorbed layer. The volume inside the pore is free of surfactant molecules and grows at a higher rate than pore entrance. After a more prolonged etching the bottle-like (or 'cigar-like') pore channels are formed. The bottle-like shape of the pore channels depends on the etching conditions such as alkali and surfactant concentration, temperature, and type of the surfactant. The use of surfactants enables one to produce track-etch membranes with improved flow rate characteristics compared with those having cylindrical pores with the same nominal pore diameters

  11. Surfactant controlled switching of water-in-oil wetting behaviour of ...

    Indian Academy of Sciences (India)

    Wintec

    face wettability due to the surfactant diffusion may have implications in oil–water separation, chemical bed reactors and microfluidic devices. Keywords. Wetting control; porous substrate wetting; porous silica film; surfactant mediated wetting; oil–water contact angle. 1. Introduction. Spreading of liquid on a porous solid. 1.

  12. Roentgenographic findings in hyaline membrane disease treated with exogenous surfactant: comparison with control group

    International Nuclear Information System (INIS)

    Lee, Sun Kyoung; Lim, Chae Ha; Lim, Woo Young; Kim, Young Sook; Byen, Ju Nam; Oh, Jae Hee; Kim, Young Chul

    1997-01-01

    To compare, with the use of chest radiographic findings, improvement and complications in newborns treated with exogenous surfactant for hyaline membrane disease (HMD), and an untreated control group. Thirty-six patients with HMD were randomly assigned to a control group (n=18) or surfactant treated group (n=18). As part of an initial evaluation of their pulmonary status, we then performed a retrospective statistical analysis of chest radiographic findings obtained in exogenous surfactant treated and untreated infants within the first 90 minutes of life. Subsequent examinations were performed at less than 24 hours of age. Chest radiograph before treatment showed no significant differences between the two groups, but significant improvement was noted in the surfactant treated group, in contrast to the control group. The most common chest radiographic finding after surfactant administration was uniform (n=15) or disproportionate (n=2) improvement of pulmonary aeration. Patent ductus arteriosus developed in three treated neonates and in four cases in the control group. Air leak occurred in three cases in the treated group and in five cases in the control group. In one treated patient pulmonary hemorrhage developed and intracranial hemorrhage occurred in three treated neonates and in four cases in the control group. Bronchopulmonary dysplasia was developed in 6 cases of treated group and 3 cases of control group. A chest radiograph is considered to be helpful in the evaluation of improvement and complications of HMD in infants treated with surfactant

  13. Efficacy of a surfactant-based wound dressing on biofilm control.

    Science.gov (United States)

    Percival, Steven L; Mayer, Dieter; Salisbury, Anne-Marie

    2017-09-01

    The aim of this study was to evaluate the efficacy of both a nonantimicrobial and antimicrobial (1% silver sulfadiazine-SSD) surfactant-based wound dressing in the control of Pseudomonas aeruginosa, Enterococcus sp, Staphylococcus epidermidis, Staphylococcus aureus, and methicillin-resistant S. aureus (MRSA) biofilms. Anti-biofilm efficacy was evaluated in numerous adapted American Standards for Testing and Materials (ASTM) standard biofilm models and other bespoke biofilm models. The ASTM standard models employed included the Minimum biofilm eradication concentration (MBEC) biofilm model (ASTM E2799) and the Centers for Disease Control (CDC) biofilm reactor model (ASTM 2871). Such bespoke biofilm models included the filter biofilm model and the chamberslide biofilm model. Results showed complete kill of microorganisms within a biofilm using the antimicrobial surfactant-based wound dressing. Interestingly, the nonantimicrobial surfactant-based dressing could disrupt existing biofilms by causing biofilm detachment. Prior to biofilm detachment, we demonstrated, using confocal laser scanning microscopy (CLSM), the dispersive effect of the nonantimicrobial surfactant-based wound dressing on the biofilm within 10 minutes of treatment. Furthermore, the non-antimicrobial surfactant-based wound dressing caused an increase in microbial flocculation/aggregation, important for microbial concentration. In conclusion, this nonantimicrobial surfactant-based wound dressing leads to the effective detachment and dispersion of in vitro biofilms. The use of surfactant-based wound dressings in a clinical setting may help to disrupt existing biofilm from wound tissue and may increase the action of antimicrobial treatment. © 2017 by the Wound Healing Society.

  14. Controlling Active Liquid Crystal Droplets with Temperature and Surfactant Concentration

    Science.gov (United States)

    Shechter, Jake; Milas, Peker; Ross, Jennifer

    Active matter is the study of driven many-body systems that span length scales from flocking birds to molecular motors. A previously described self-propelled particle system was made from liquid crystal (LC) droplets in water with high surfactant concentration to move particles via asymmetric surface instabilities. Using a similar system, we investigate the driving activity as a function of SDS surfactant concentration and temperature. We then use an optical tweezer to trap and locally heat the droplets to cause hydrodynamic flow and coupling between multiple droplets. This system will be the basis for a triggerable assembly system to build and couple LC droplets. DOD AROMURI 67455-CH-MUR.

  15. Control of stain geometry by drop evaporation of surfactant containing dispersions.

    Science.gov (United States)

    Erbil, H Yildirim

    2015-08-01

    Control of stain geometry by drop evaporation of surfactant containing dispersions is an important topic of interest because it plays a crucial role in many applications such as forming templates on solid surfaces, in ink-jet printing, spraying of pesticides, micro/nano material fabrication, thin film coatings, biochemical assays, deposition of DNA/RNA micro-arrays, and manufacture of novel optical and electronic materials. This paper presents a review of the published articles on the diffusive drop evaporation of pure liquids (water), the surfactant stains obtained from evaporating drops that do not contain dispersed particles and deposits obtained from drops containing polymer colloids and carbon based particles such as carbon nanotubes, graphite and fullerenes. Experimental results of specific systems and modeling attempts are discussed. This review also has some special subtopics such as suppression of coffee-rings by surfactant addition and "stick-slip" behavior of evaporating nanosuspension drops. In general, the drop evaporation process of a surfactant/particle/substrate system is very complex since dissolved surfactants adsorb on both the insoluble organic/inorganic micro/nanoparticles in the drop, on the air/solution interface and on the substrate surface in different extends. Meanwhile, surfactant adsorbed particles interact with the substrate giving a specific contact angle, and free surfactants create a solutal Marangoni flow in the drop which controls the location of the particle deposition together with the rate of evaporation. In some cases, the presence of a surfactant monolayer at the air/solution interface alters the rate of evaporation. At present, the magnitude of each effect cannot be predicted adequately in advance and consequently they should be carefully studied for any system in order to control the shape and size of the final deposit. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Nanoparticle size controls aggregation in lamellar nonionic surfactant mesophase.

    Science.gov (United States)

    Venugopal, Edakkal; Aswal, Vinod K; Kumaraswamy, Guruswamy

    2013-08-06

    We show that the size of silica nanoparticles influences the nature of their aggregation in an aqueous solution of a relatively hydrophobic nonionic surfactant, C12E4. We present results for dispersions of silica nanoparticles with sizes varying from 8 to 26 nm, in a 75: 25 C12E4/water system, that forms a lamellar phase, Lα, at room temperature. Addition of silica particles does not affect the formation of the Lα phase. Nanoparticles smaller than about 11 nm aggregate irreversibly in the C12E4/water system. However, nanoparticles larger than about 15 nm aggregate in the Lα phase, but are dispersed at temperatures above the Lα order-disorder temperature. Thus, in contrast to the smaller particles, aggregation of silica nanoparticles larger than about 15 nm is reversible with temperature. We use small-angle neutron scattering (SANS) to demonstrate that these results can be explained by the size-dependent wrapping of nanoparticles by surfactant bilayers. Larger particles, above 15 nm in size, are sterically stabilized by the formation of an adsorbed surfactant bilayer. The cost of bilayer bending inhibits adsorption onto the highly curved surfaces of smaller particles, and these "bare" particles aggregate irreversibly.

  17. Controlled synthesis of gold nanostars by using a zwitterionic surfactant.

    Science.gov (United States)

    Casu, Alberto; Cabrini, Elisa; Donà, Alice; Falqui, Andrea; Diaz-Fernandez, Yuri; Milanese, Chiara; Taglietti, Angelo; Pallavicini, Piersandro

    2012-07-23

    By replacing cetyltrimethylammonium bromide (CTAB) with the zwitterionic lauryl sulfobetaine (LSB) surfactant in the classical seed-growth synthesis, monocrystalline gold nanostars (m-NS) and pentatwinned gold asymmetric nanostars (a-NS) were obtained instead of nanorods. The main product under all synthetic conditions was a-NS, which have branches with high aspect ratios (AR), thus leading to LSPR absorptions in the 750-1150 nm range. The percentage of m-NS versus a-NS, the aspect ratio of the a-NS branches, and consequently the position of their LSPR absorption can be finely tuned simply by regulating the concentration of reductant, the concentration of surfactant, or the concentration of the "catalytic" Ag(+) cation. The m-NS have instead shorter and larger branches, the AR of which is poorly influenced by synthetic conditions and displays an LSPR positioned around 700 nm. A growth mechanism that involves the direct contact of the sulfate moiety of LSB on the surface of the nano-object is proposed, thereby implying preferential coating of the {111} Au faces with weak interactions. Consistent with this, we also observed the straightforward complete displacement of the LSB surfactant from the surface of the nanostars. This was obtained by the simple addition of thiols in aqueous solution to yield extremely stable coated a-NS and m-NS that are resistant to highly acidic, basic, and in similar to in vivo conditions. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Controlling defects and secondary phases of CZTS by surfactant potassium

    Science.gov (United States)

    Zhang, Yiou; Tse, Kinfai; Xiao, Xudong; Zhu, Junyi

    2017-09-01

    C u2ZnSn S4 (CZTS) is a promising photovoltaic absorber material with earth-abundant and nontoxic elements. However, the detrimental native defects and secondary phases of CZTS will largely reduce the energy-conversion efficiencies. To understand the origin of these problems during the growth of CZTS, we investigated the kinetic processes on CZTS (1 ¯1 ¯2 ¯ ) surface, using first-principles calculations. A surface Zn atom was found to occupy the Cu site near the surface easily due to a low reaction barrier, which may lead to a high Z nCu concentration and a Zn-rich secondary phase. These n -type defects may create deep electron traps near the interface and become detrimental to device performance. To reduce the population of Z nCu and the Zn-rich secondary phase, we propose to use K as a surfactant to alter surface kinetic processes. Improvements on crystal quality and device performance based on this surfactant are consistent with early experimental observations.

  19. Controlled Clustering in Binary Charged Colloids by Adsorption of Ionic Surfactants.

    Science.gov (United States)

    Nakamura, Yuki; Okachi, Manami; Toyotama, Akiko; Okuzono, Tohru; Yamanaka, Junpei

    2015-12-15

    We report on the controlled clustering of oppositely charged colloidal particles by the adsorption of ionic surfactants, which tunes charge numbers Z of particles. In particular, we studied the heteroclustering of submicron-sized polystyrene (PS) and silica particles, both of which are negatively charged, in the presence of cetylpyridinium chloride (CPC), a cationic surfactant. The surfactant concentration Csurf was selected below the critical micelle concentration. As CPC molecules were adsorbed, Z values of the PS and silica particles decreased, inverting to positive when Csurf exceeded the isoelectric point Ciep. Hydrophobic PS particles exhibited much lower Ciep than hydrophilic silica particles. At Csurf valuess between their Ciep values, the particles were oppositely charged, and clustering was enabled. To explain the clustering behavior, we investigated adsorption isotherms of the CPC and screened-Coulomb-type pair potential. Expected applications of the present findings are the control of colloidal associations and construction of various particle types into heterogeneous colloidal clusters.

  20. Thermally cleavable surfactants

    Science.gov (United States)

    McElhanon, James R [Manteca, CA; Simmons, Blake A [San Francisco, CA; Zifer, Thomas [Manteca, CA; Jamison, Gregory M [Albuquerque, NM; Loy, Douglas A [Albuquerque, NM; Rahimian, Kamyar [Albuquerque, NM; Long, Timothy M [Urbana, IL; Wheeler, David R [Albuquerque, NM; Staiger, Chad L [Albuquerque, NM

    2006-04-04

    Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments and the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

  1. Thermally cleavable surfactants

    Science.gov (United States)

    McElhanon, James R [Manteca, CA; Simmons, Blake A [San Francisco, CA; Zifer, Thomas [Manteca, CA; Jamison, Gregory M [Albuquerque, NM; Loy, Douglas A [Albuquerque, NM; Rahimian, Kamyar [Albuquerque, NM; Long, Timothy M [Urbana, IL; Wheeler, David R [Albuquerque, NM; Staiger, Chad L [Albuquerque, NM

    2009-11-24

    Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments or the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

  2. CO 2 -Reactive Ionic Liquid Surfactants for the Control of Colloidal Morphology

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Paul; Sresht, Vishnu; Eral, Burak H.; Fiore, Andrew; de la Fuente-Núñez, César [Eli and Edythe L. Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, Massachusetts 02142, United States; Harvard; O’Mahony, Marcus; Mendes, Gabriel P.; Heller, William T. [Biology; Doyle, Patrick S.; Blankschtein, Daniel; Hatton, T. Alan

    2017-07-24

    This article reports on a new class of stimuli-responsive surfactant generated from commercially available amphiphiles such as dodecyltrimethylammmonium bromide (DTAB) by substitution of the halide counterion with counterions such as 2-cyanopyrrolide, 1,2,3-triazolide, and L-proline that complex reversibly with CO2. Through a combination of small-angle neutron scattering (SANS), electrical conductivity measurements, thermal gravimetric analysis, and molecular dynamics simulations, we show how small changes in charge reorganization and counterion shape and size induced by complexation with CO2 allow for fine-tunability of surfactant properties. We then use these findings to demonstrate a range of potential practical uses, from manipulating microemulsion droplet morphology to controlling micellar and vesicular aggregation. In particular, we focus on the binding of these surfactants to DNA and the reversible compaction of surfactant–DNA complexes upon alternate bubbling of the solution with CO2 and N2.

  3. Surfactant controlled switching of water-in-oil wetting behaviour of ...

    Indian Academy of Sciences (India)

    Wintec

    Abstract. Selective permeation of oil and water across a porous medium, as in oil recovery operations, depends on the preferential wetting properties of the porous medium. We show a profound influence of surfactants in wetting of porous media and thus demonstrate a new route for the control of water-in-oil wetting of ...

  4. Band-gap control of GaInP using Sb as a surfactant

    International Nuclear Information System (INIS)

    Shurtleff, J.K.; Lee, R.T.; Fetzer, C.M.; Stringfellow, G.B.

    1999-01-01

    The use of surfactants to control specific aspects of the vapor-phase epitaxial growth process is beginning to be studied for both the elemental and III/V semiconductors. To date, most reported surfactant effects for semiconductors relate to the morphology of the growing films. However, semiconductor alloys with CuPt ordering exhibit much more dramatic effects. The change in the CuPt order parameter induced by the surfactant translates into a marked change in the band-gap energy. Previous work concentrated on the effects of the donor tellurium. Te is less than ideal as a surfactant, since the change in band-gap energy is coupled to a large change in the conductivity. This letter presents the results of a study of the effects of an isoelectronic surfactant on the ordering process in GaInP. Sb has been found to act as a surfactant during organometallic vapor-phase epitaxial growth. At an estimated Sb concentration in the solid of 1x10 -4 , order is eliminated, as indicated by the band-gap energy. Surface photoabsorption (SPA) data indicate that the effect is due to a change in the surface reconstruction. Adding Sb leads to attenuation of the peak at 400 nm in the SPA spectrum associated with [bar 110] P dimers. The addition of Sb during the growth cycle has been used to produce a heterostructure with a 135 meV band-gap difference between two layers with the same solid composition. copyright 1999 American Institute of Physics

  5. Disaturated-phosphatidylcholine and Surfactant protein-B turnover in human acute lung injury and in control patients

    Directory of Open Access Journals (Sweden)

    Rizzi Sabina

    2011-03-01

    Full Text Available Abstract Background Patients with Adult Respiratory Distress Syndrome (ARDS and Acute Lung Injury (ALI have low concentrations of disaturated-phosphatidylcholine and surfactant protein-B in bronchoalveolar lavage fluid. No information is available on their turnover. Objectives To analyze disaturated-phosphatidylcholine and surfactant protein-B turnover in patients with ARDS/ALI and in human adults with normal lungs (controls. Methods 2H2O as precursor of disaturated-phosphatidylcholine-palmitate and 113C-Leucine as precursor of surfactant protein-B were administered intravenously to 12 patients with ARDS/ALI and to 8 controls. Disaturated-phosphatidylcholine and surfactant protein-B were isolated from serial tracheal aspirates, and their fractional synthetic rate was derived from the 2H and 13C enrichment curves, obtained by gas chromatography mass spectrometry. Disaturated-phosphatidylcholine, surfactant protein-B, and protein concentrations in tracheal aspirates were also measured. Results 1 Surfactant protein-B turned over at faster rate than disaturated-phosphatidylcholine both in ARDS/ALI patients and in controls. 2 In patients with ARDS/ALI the fractional synthesis rate of disaturated-phosphatidylcholine was 3.1 times higher than in controls (p Conclusions 1 Disaturated-phosphatidylcholine and surfactant protein-B have a different turnover both in healthy and diseased lungs. 2 In ARDS/ALI the synthesis of these two surfactant components may be differently regulated.

  6. [Exogenous surfactant therapy: new synthetic surfactants].

    Science.gov (United States)

    Lacaze-Masmonteil, Th

    2008-06-01

    There are numerous pulmonary conditions in which qualitative or quantitative anomalies of the surfactant system have been demonstrated. In premature newborns with immature lungs, a functional deficit in surfactant is the main physiopathologic mechanism of the neonatal respiratory distress syndrome (RDS). Since the landmark pilot study of Fujiwara, published more than 20 years ago, the efficacy of exogenous surfactant for the treatment of neonatal RDS has been established by numerous controlled studies and meta-analyses. Enlightened by a growing insight into both the structure and function of the different surfactant components, a new generation of synthetic surfactants has been developed. Various complementary approaches have confirmed the fundamental role of the two hydrophobic proteins, SP-B and SP-C, in the surfactant system, thus opening the way to the design of analogues, either by chemical synthesis or expression in a prokaryotic system. An example of these peptide-containing synthetic surfactant preparations, lucinactant (Surfaxin), has been recently tested in comparison to a synthetic surfactant that does not contain protein as well as to animal derived surfactant preparations. Major clinical outcomes between lucinactant and animal-derived surfactant preparations were fund similar in two randomized controlled trials, opening the way to a new generation of synthetic surfactants in the near future.

  7. COMBINED MICROBIAL SURFACTANT-POLYMER SYSTEM FOR IMPROVED OIL MOBILITY AND CONFORMANCE CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Jorge Gabitto; Maria Barrufet

    2004-08-01

    Many domestic oil fields are facing abandonment even though they still contain two-thirds of their original oil. A significant number of these fields can yield additional oil using advanced oil recovery (AOR) technologies. To maintain domestic oil production at current levels, AOR technologies are needed that are affordable and can be implemented by independent oil producers of the future. Microbial enhanced oil recovery (MEOR) technologies have become established as cost-effective solutions for declining oil production. MEOR technologies are affordable for independent producers operating stripper wells and can be used to extend the life of marginal fields. The demonstrated versatility of microorganisms can be used to design advanced microbial systems to treat multiple production problems in complex, heterogeneous reservoirs. The proposed research presents the concept of a combined microbial surfactant-polymer system for advanced oil recovery. The surfactant-polymer system utilizes bacteria that are capable of both biosurfactant production and metabolically-controlled biopolymer production. This novel technology combines complementary mechanisms to extend the life of marginal fields and is applicable to a large number of domestic reservoirs. The research project described in this report is performed jointly by, Bio-Engineering Inc., a woman owned small business, Texas A&M University and Prairie View A&M University, a Historically Black College and University. This report describes the results of our laboratory work to grow microbial cultures and the work done on recovery experiments on core rocks. We have selected two bacterial strains capable of producing both surfactant and polymers. We have conducted laboratory experiments to determine under what conditions surfactants and polymers can be produced from one single strain. We have conduct recovery experiments to determine the performance of these strains under different conditions. Our results do not show a

  8. Coating nanoparticles with tunable surfactants facilitates control over the protein corona.

    Science.gov (United States)

    Müller, J; Bauer, K N; Prozeller, D; Simon, J; Mailänder, V; Wurm, F R; Winzen, S; Landfester, K

    2017-01-01

    Nanoparticles with long blood circulation time are a prerequisite for targeted drug delivery. To make the nanoparticles invisible for phagocytizing cells, functional moieties on the particle surface are believed to be necessary to attract specific so-called 'stealth' proteins forming a protein 'corona'. Currently, covalent attachment of those moieties represents the only way to achieve that attraction. However, that approach requires a high synthetic effort and is difficult to control. Therefore, we present the coating of model nanoparticles with biodegradable polymeric surfactants as an alternative method. The thermodynamic parameters of the coating process can be tuned by adjusting the surfactants' block lengths and hydrophilicity. Consequently, the unspecific protein adsorption and aggregation tendency of the particles can be controlled, and stealth proteins inhibiting cell uptake are enriched on their surface. This non-covalent approach could be applied to any particle type and thus facilitates tuning the protein corona and its biological impact. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Cationic surfactants for control of fresh- and saltwater mollusks in nuclear cooling systems

    International Nuclear Information System (INIS)

    Post, R.M.; Mallen, E.; Lehmann, F.

    1991-01-01

    One result of the release of the US Nuclear Regulatory Commission's Generic Letter 89-13, Service Water Problems Affecting Safety-Related Equipment, was the heightened awareness of the nuclear industry to the problems of macrofouling in heat exchange systems. The principal mollusk species that contribute to freshwater macrofouling problems are Asiatic Clam (southern United States) and Zebra Mussel (Great Lakes). The predominant saltwater fouling mollusks are the Blue Mussel (Pacific, northern Atlantic), Ribbed Mussel (southern Atlantic, Gulf Coast), and American Oyster (Atlantic, Gulf Coast). The nuclear community's awareness of macrofouling problems and the ineffectiveness of intermittent chlorination programs have led to the development of several chemical control technologies for eliminating macrofouling organism infestation. One technology that has proven effective for the control of macrofouling organisms is the periodic addition of a combination of two cationic charged surfactants, specifically, alkyldimethylbenzylammonium chloride (QUAT) and dodecyl guanidine hydrochloride (DGH). Experience with the cationic surfactants at several nuclear power plants is reported

  10. Carbohydrate-functionalized surfactant vesicles for controlling the density of glycan arrays.

    Science.gov (United States)

    Pond, Monique A; Zangmeister, Rebecca A

    2012-03-15

    We report on the development of a method for rapidly characterizing the glycan binding properties of lectins. Catanionic surfactant vesicles, prepared from cationic and anionic surfactants, spontaneously formed in water and remained stable at room temperature for months. By varying the amount of glycoconjugate added during preparation, glycans were incorporated onto the outer surface of the vesicles in a controlled range of densities. The carbohydrate-functionalized vesicles were applied to commercially available, nitrocellulose-coated slides to generate glycan arrays. As proof of concept, the binding of two lectins, concanavalin A and peanut agglutinin, to the arrays was quantified using a biotin-avidin fluorescence sandwich assay. This facile method of preparing a glycan array by using vesicles to control the glycan density can be expanded to provide a platform for characterizing unknown lectins. Published by Elsevier B.V.

  11. Neo-Geometric Copper Nanocrystals by Competitive, Dual Surfactant-Mediated Facet Adsorption Controlling Skin Permeation

    Directory of Open Access Journals (Sweden)

    Karmani Murugan

    2016-11-01

    Full Text Available Neogeometric copper nanoparticles (CuNPs have various applications yet its synthesis still proves to be challenging with regards to self-assembly and uniformity control. This study aimed to synthesize shape-specific CuNPs in the biomedical application of ascertaining skin permeation and retention of the CuNPs as a drug delivery system. The approach to the shape design involved the dual control of two surfactants to direct the shape organisation of the nanoparticles (NPs while an interesting aspect of the study showed the competitive adsorption of the surfactants onto the nanocrystal facets to direct facet growth. The resulting copper nanoparticles were characterised using X-ray diffraction (XRD and electron diffraction spectra analysis (EDS for elemental and crystalline analysis. Thermogravimetric Analysis (TGA identified the degradation of the surfactant coat and the synthesis of a novel copper-polymer complex and extensive transmission electron microscopy (TEM was conducted to determine the nanoparticle morphology. Epidermal skin tissue served as the model for permeation studies of five idealistic nano-geometries and investigated its application in drug delivery with regards to cellular internalisation and transbarrier transport of the geometric CuNPs. A mechanistic consideration for shape control is discussed.

  12. COMBINED MICROBIAL SURFACTANT-POLYMER SYSTEM FOR IMPROVED OIL MOBILITY AND CONFORMANCE CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Jorge Gabitto; Maria Barrufet

    2005-08-01

    Many domestic oil fields are facing abandonment even though they still contain two-thirds of their original oil. A significant number of these fields can yield additional oil using advanced oil recovery (AOR) technologies. To maintain domestic oil production at current levels, AOR technologies are needed that are affordable and can be implemented by the independent oil producers of the future. Microbial enhanced oil recovery (MEOR) technologies have become established as cost-effective solutions for declining oil production. MEOR technologies are affordable for independent producers operating stripper wells and can be used to extend the life of marginal fields. The demonstrated versatility of microorganisms can be used to design advanced microbial systems to treat multiple production problems in complex, heterogeneous reservoirs. The proposed research presents the concept of a combined microbial surfactant-polymer system for advanced oil recovery. The surfactant-polymer system utilizes bacteria that are capable of both biosurfactant production and metabolically-controlled biopolymer production. This novel technology combines complementary mechanisms to extend the life of marginal fields and is applicable to a large number of domestic reservoirs. The research project described in this report was performed by Bio-Engineering Inc., a woman owned small business, Texas A&M University and Prairie View A&M University, a Historically Black College and University. This report describes the results of our laboratory work to grow microbial cultures, the work done on recovery experiments on core rocks, and computer simulations. We have selected two bacterial strains capable of producing both surfactant and polymers. We have conducted laboratory experiments to determine under what conditions surfactants and polymers can be produced from one single strain. We have conduct recovery experiments to determine the performance of these strains under different conditions. Our results

  13. Statistical quality control a loss minimization approach

    CERN Document Server

    Trietsch, Dan

    1999-01-01

    While many books on quality espouse the Taguchi loss function, they do not examine its impact on statistical quality control (SQC). But using the Taguchi loss function sheds new light on questions relating to SQC and calls for some changes. This book covers SQC in a way that conforms with the need to minimize loss. Subjects often not covered elsewhere include: (i) measurements, (ii) determining how many points to sample to obtain reliable control charts (for which purpose a new graphic tool, diffidence charts, is introduced), (iii) the connection between process capability and tolerances, (iv)

  14. Pulmonary surfactant and lung transplantation

    NARCIS (Netherlands)

    Erasmus, Michiel Elardus

    1997-01-01

    Pulmonary surfactant lowers the surface tension at the air-water interface inside the alveolus. This is achieved by adsorption of surfactant phospholipids at the air-water interface, a process controlled by surfactant-associated proteins, such as SP-A. In this way, surfactant prevents collapse of

  15. Surfactant-controlled etching of ion track nanopores and its practical applications in membrane technology

    International Nuclear Information System (INIS)

    Apel, P.Yu.; Blonskaya, I.V.; Dmitriev, S.N.; Mamonova, T.I.; Orelovitch, O.L.; Sartowska, B.; Yamauchi, Yu.

    2008-01-01

    The effect of surfactants on chemical development of ion tracks in polymers has been studied. It has been shown that surface-active agents added to an alkaline etching solution adsorb on the polymer surface at the pore entrances. This reduces the etch rate, which leads to the formation of pores tapered toward the surface. Self-assembly of surfactant molecules at the pore entrance creates a barrier for their penetration into the etched-out nanopores, whereas hydroxide ions diffuse freely. Due to this, the internal pore volume grows faster than the pore surface diameter. The ability to control pore shape is demonstrated with the fabrication of profiled nano- and micropores in polyethylene terephthalate, polycarbonate. Some earlier published data on small track-etched pores in polycarbonate (in particular, the pore diameter vs. etching time curves measured conductometrically) have been revised in light of the above findings. Adding surfactants to chemical etchants makes it possible to optimize the structure of track membranes, thus improving their retention and permeation properties. Asymmetric membranes with thin skin retention layers have been produced and their performance studied

  16. Surfactant-controlled etching of ion track nanopores and its practical applications in membrane technology

    Energy Technology Data Exchange (ETDEWEB)

    Apel, P.Yu. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)], E-mail: apel@nrmail.jinr.ru; Blonskaya, I.V.; Dmitriev, S.N.; Mamonova, T.I.; Orelovitch, O.L. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Sartowska, B. [Institute of Nuclear Chemistry and Technology, Dorodna Street 16, 03-195 Warsaw (Poland); Yamauchi, Yu. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)

    2008-08-15

    The effect of surfactants on chemical development of ion tracks in polymers has been studied. It has been shown that surface-active agents added to an alkaline etching solution adsorb on the polymer surface at the pore entrances. This reduces the etch rate, which leads to the formation of pores tapered toward the surface. Self-assembly of surfactant molecules at the pore entrance creates a barrier for their penetration into the etched-out nanopores, whereas hydroxide ions diffuse freely. Due to this, the internal pore volume grows faster than the pore surface diameter. The ability to control pore shape is demonstrated with the fabrication of profiled nano- and micropores in polyethylene terephthalate, polycarbonate. Some earlier published data on small track-etched pores in polycarbonate (in particular, the pore diameter vs. etching time curves measured conductometrically) have been revised in light of the above findings. Adding surfactants to chemical etchants makes it possible to optimize the structure of track membranes, thus improving their retention and permeation properties. Asymmetric membranes with thin skin retention layers have been produced and their performance studied.

  17. Surfactant effects in magnetite nanoparticles of controlled size

    International Nuclear Information System (INIS)

    Guardia, P.; Batlle-Brugal, B.; Roca, A.G.; Iglesias, O.; Morales, M.P.; Serna, C.J.; Labarta, A.; Batlle, X.

    2007-01-01

    Magnetite Fe 3 O 4 nanoparticles of controlled size within 6 and 20 nm in diameter were synthesised by thermal decomposition of an iron organic precursor in an organic medium. Particles were coated with oleic acid. For all samples studied, saturation magnetisation M s is size-independent, and reaches a value close to that expected for bulk magnetite, in contrast to results in small particle systems for which M s is usually much smaller due to surface spin disorder. The coercive field for the 6 nm particles is in agreement with coherent rotation, taking the bulk magnetocrystalline anisotropy into account. Both results suggest that the oleic acid molecules covalently bonded to the nanoparticle surface yield a strong reduction in the surface spin disorder. However, although the saturated state may be similar, the approach to saturation is different and, in particular, the high-field differential susceptibility is one order of magnitude larger than in bulk materials. The relevance of these results in biomedical applications is discussed

  18. Controlling interfacial film formation in mixed polymer-surfactant systems by changing the vapor phase.

    Science.gov (United States)

    Mokhtari, Tahereh; Pham, Quoc Dat; Hirst, Christopher; O'Driscoll, Benjamin M D; Nylander, Tommy; Edler, Karen J; Sparr, Emma

    2014-08-26

    Here we show that transport-generated phase separation at the air-liquid interface in systems containing self-assembling amphiphilic molecules and polymers can be controlled by the relative humidity (RH) of the air. We also show that our observations can be described quantitatively with a theoretical model describing interfacial phase separation in a water gradient that we published previously. These phenomena arises from the fact that the water chemical potential corresponding to the ambient RH will, in general, not match the water chemical potential in the open aqueous solution. This implies nonequilibrium conditions at the air-water interface, which in turn can have consequences on the molecular organization in this layer. The experimental setup is such that we can control the boundary conditions in RH and thereby verify the predictions from the theoretical model. The polymer-surfactant systems studied here are composed of polyethylenimine (PEI) and hexadecyltrimethylammonium bromide (CTAB) or didecyldimethylammonium bromide (DDAB). Grazing-incidence small-angle X-ray scattering results show that interfacial phases with hexagonal or lamellar structure form at the interface of dilute polymer-surfactant micellar solutions. From spectroscopic ellipsometry data we conclude that variations in RH can be used to control the growth of micrometer-thick interfacial films and that reducing RH leads to thicker films. For the CTAB-PEI system, we compare the phase behavior of the interfacial phase to the equilibrium bulk phase behavior. The interfacial film resembles the bulk phases formed at high surfactant to polymer ratio and reduced water contents, and this can be used to predict the composition of interfacial phase. We also show that convection in the vapor phase strongly reduces film formation, likely due to reduction of the unstirred layer, where diffusive transport is dominating.

  19. Controlling the capture and release of DNA with a dual-responsive cationic surfactant.

    Science.gov (United States)

    Xu, Lu; Feng, Lei; Hao, Jingcheng; Dong, Shuli

    2015-04-29

    A dual-responsive cationic surfactant, 4-ethoxy-4'-(trimethyl- aminoethoxy) azobenzene trichloromonobromoferrate (azoTAFe), which contains both a light-responsive moiety azobenzene and a paramagnetic counterion, [FeCl3Br](-), was designed and synthesized. Not only does this cationic surfactant abundantly utilize inexhaustible and clean sources, i.e., light and magnetic field, but it also serves as a powerful dual-switch molecule for effectively controlling the capture and release of DNA. Our results could provide potential applications in gene therapy for creating smart and versatile machines to control the transport and delivery of DNA more intelligently and robustly. It was proved that the light switch can independently realize a reversible DNA compaction. The introduction of a magnetic switch can significantly enhance the compaction efficiency, help compact DNA with a lower dosage and achieve a magnetic field-based targeted transport of DNA. In addition, the light switch can make up the irreversibility of magnetic switch. This kind of self-complementation makes the cationic azoTAFe be useful as a potential tool that can be applied to the field of gene therapy and nanomedicine.

  20. Morphological control of seedlessly-synthesized gold nanorods using binary surfactants

    Science.gov (United States)

    Roach, Lucien; Ye, Sunjie; Moorcroft, Samuel C. T.; Critchley, Kevin; Coletta, P. Louise; Evans, Stephen D.

    2018-04-01

    High purity gold nanorods (AuNRs) with tunable morphology have been synthesized through a binary-surfactant seedless method, which enables the formation of monocrystalline AuNRs with diameters between 7 and 35 nm. The protocol has high shape yield and monodispersity, demonstrating good reproducibility and scalability allowing synthesis of batches 0.5 l in volume. Morphological control has been achieved through the adjustment of the molar concentrations of cetyltrimethylammonium bromide and sodium oleate in the growth solution, providing fine tuning of the optical scattering and absorbance properties of the AuNRs across the visible and NIR spectrum. Sodium oleate was found to provide greatest control over the aspect ratio (and hence optical properties) with concentration changes between 10 and 23 mM leading to variation in the aspect ratio between 2.8 and 4.8. Changes in the geometry of the end-caps were also observed as a result of manipulating the two surfactant concentrations.

  1. The Effect of Water Hardness on Surfactant Deposition after Washing and Subsequent Skin Irritation in Atopic Dermatitis Patients and Healthy Control Subjects.

    Science.gov (United States)

    Danby, Simon G; Brown, Kirsty; Wigley, Andrew M; Chittock, John; Pyae, Phyoe K; Flohr, Carsten; Cork, Michael J

    2018-01-01

    Living in a hard water area is associated with an increased risk of atopic dermatitis (AD). Greater skin barrier impairment after exposure to surfactants in wash products, combined with the high calcium levels of hard water and/or high chlorine levels, is a compelling mechanism for this increase. The purpose of this study was to investigate this mechanism in individuals with and without a predisposition to skin barrier impairment. We recruited 80 participants: healthy control subjects and AD patients with and without FLG mutations. The skin of each participant was washed with sodium lauryl sulfate in water of varying hardness levels and chlorine concentrations, rinsed, and covered with chambers to determine the effects of surfactant residues. Sites washed with hard water had significantly increased sodium lauryl sulfate deposits. These deposits increased transepidermal water loss and caused irritation, particularly in AD patients carrying FLG mutations. A clear effect of chlorine was not observed. Water softening by ion-exchange mitigated the negative effects of hard water. Barrier impairment resulting from the interaction between hard water and surfactants is a contributory factor to the development of AD. Installation of a water softener in early life may be able to prevent AD development. An intervention study is required to test this hypothesis. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Surfactant controlled growth of GaInP by organometallic vapor phase epitaxy

    Science.gov (United States)

    Lee, R. T.; Shurtleff, J. K.; Fetzer, C. M.; Stringfellow, G. B.; Lee, S.; Seong, T. Y.

    2000-04-01

    The effect of the surfactant Sb has been studied for GaInP semiconductor alloys grown by organometallic vapor phase epitaxy. Dramatic changes in the optical and electrical properties of GaInP with CuPt ordering have been observed. A small concentration of triethylantimony (TESb) in the vapor is found to cause Sb to accumulate at the surface. In situ surface photoabsorption analysis indicates that Sb changes the surface bonding by replacing the [1¯10] P dimers that are responsible for the formation of the CuPt structure during growth with [1¯10] Sb dimers. As a result, the degree of order for the GaInP layers is decreased, as shown by transmission electron diffraction studies. The 20 K photoluminescence spectra show a 131 meV peak energy increase for GaInP layers grown on vicinal substrates when a small amount of Sb [Sb/P(v)=4×10-4] is added to the system during growth. The use of surfactants to control specific properties of materials is expected to be a powerful tool for producing complex structures. In this article, the growth of heterostructures by modulating the Sb concentration in the vapor is demonstrated.

  3. Surfactants in tribology

    CERN Document Server

    Biresaw, Girma

    2014-01-01

    Surface science and tribology play very critical roles in many industries. Manufacture and use of almost all consumer and industrial products rely on the application of advanced surface and tribological knowledge. The fourth in a series, Surfactants in Tribology, Volume 4 provides an update on research and development activities connecting surfactants and tribological phenomena. Written by renowned subject matter experts, the book demonstrates how improved design of surfactants can be harnessed to control tribological phenomena. Profusely illustrated and copiously referenced, the chapters also

  4. Factors controlling leaching of polycyclic aromatic hydrocarbons from petroleum source rock using nonionic surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Akinlua, Akinsehinwa [Obafemi Awolowo Univ., Ile-Ife (Nigeria). Fossil Fuels and Environmental Geochemistry Group; Jochmann, Maik A.; Qian, Yuan; Schmidt, Torsten C. [Duisburg-Essen Univ., Essen (Germany). Instrumental Analytical Chemistry; Sulkowski, Martin [Duisburg-Essen Univ., Essen (Germany). Inst. of Environmental Analytical Chemistry

    2012-03-15

    The extraction of polycyclic aromatic hydrocarbons (PAHs) from petroleum source rock by nonionic surfactants with the assistance of microwave irradiation was investigated and the conditions for maximum yield were determined. The results showed that the extraction temperatures and type of surfactant have significant effects on extraction yields of PAHs. Factors such as surfactant concentration, irradiation power, sample/solvent ratio and mixing surfactants (i.e., mixture of surfactant at specific ratio) also influence the extraction efficiencies for these compounds. The optimum temperature for microwave-assisted nonionic surfactant extraction of PAHs from petroleum source rock was 120 C and the best suited surfactant was Brij 35. The new method showed extraction efficiencies comparable to those afforded by the Soxhlet extraction method, but a reduction of the extraction times and environmentally friendliness of the new nonionic surfactant extraction system are clear advantages. The results also show that microwave-assisted nonionic surfactant extraction is a good and efficient green analytical preparatory technique for geochemical evaluation of petroleum source rock. (orig.)

  5. ADSORPTION OF SURFACTANT ON CLAYS

    Science.gov (United States)

    Surfactants used to enhance remediation of soils by soil washing are often lost in the process. Neither the amount nor the cause of this loss is known. It is assumed that clays present in the soil are responsible for the loss of the surfactant. In this papere, adsorption prope...

  6. Surfactant-controlled composition and crystal structure of manganese(II sulfide nanocrystals prepared by solvothermal synthesis

    Directory of Open Access Journals (Sweden)

    Elena Capetti

    2015-12-01

    Full Text Available We investigated how the outcome of the solvothermal synthesis of manganese(II sulfide (MnS nanocrystals (NCs is affected by the type and amount of long chain surfactant present in the reaction mixture. Prompted by a previous observation that a larger than stoichiometric amount of sulfur is required [Puglisi, A.; Mondini, S.; Cenedese, S.; Ferretti, A. M.; Santo, N.; Ponti A. Chem. Mater. 2010, 22, 2804–2813], we carried out a wide set of reactions using Mn(II carboxylates and Mn2(CO10 as precursors with varying amounts of sulfur and carboxylic acid. MnS NCs were obtained provided that the S/Mn ratio was larger than the L/Mn ratio, otherwise MnO NCs were produced. Since MnS can crystallize in three distinct phases (rock salt α-MnS, zincblende β-MnS, and wurtzite γ-MnS, we also investigated whether the surfactant affected the NC polymorphism. We found that MnS polymorphism can be controlled by appropriate selection of the surfactant. γ-MnS nanocrystals formed when a 1:2 mixture of long chain carboxylic acid and amine was used, irrespective of the presence of carboxylic acid as a free surfactant or ligand in the metal precursor. When we used a single surfactant (carboxylic acid, alcohol, thiol, amine, α-MnS nanocrystals were obtained. The peculiar role of the amine seems to be related to its basicity. The nanocrystals were characterized by TEM and electron diffraction; ATR-FTIR spectroscopy provided information about the surfactants adsorbed on the NCs.

  7. Synthesis and characterization of pharmaceutical surfactant templated mesoporous silica: Its application to controlled delivery of duloxetine

    Energy Technology Data Exchange (ETDEWEB)

    Mani, Ganesh; Pushparaj, Hemalatha; Peng, Mei Mei; Muthiahpillai, Palanichamy [Department of Chemical Engineering, Hanseo University, Seosan-si 356 706 (Korea, Republic of); Udhumansha, Ubaidulla [Department of Chemical Engineering, Hanseo University, Seosan-si 356 706 (Korea, Republic of); Department of Pharmaceutics, C.L. Baid Metha College of Pharmacy, Chennai (India); Jang, Hyun Tae, E-mail: htjang@hanseo.ac.kr [Department of Chemical Engineering, Hanseo University, Seosan-si 356 706 (Korea, Republic of)

    2014-03-01

    Graphical abstract: - Highlights: • Usefulness of dual pharmaceutical surfactants in silica synthesis was evaluated. • Effects of concentration of secondary template (Tween-40) were studied. • Effects of fixed solvothermal condition on mesostructure formation were studied. • Duloxetine drug loading capability was studied. • Sustained release of duloxetine was evaluated. - Abstract: A new group of mesoporous silica nanoparticles (MSNs) were synthesized using combination pharmaceutical surfactants, Triton X-100 and Tween-40 as template and loaded with duloxetine hydrochloride (DX), for improving the sustained release of DX and patterns with high drug loading. Agglomerated spherical silica MSNs were synthesized by sol–gel and solvothermal methods. The calcined and drug loaded MSNs were characterized using X-ray diffraction (XRD), Braunner–Emmett–Teller (BET), thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), diffuse reflectance ultraviolet–visible (DRS-UV–vis) spectroscopy. MSNs with high surface area and pore volume were selected and studied for their DX loading and release. The selected MSNs can accommodate a maximum of 34% DX within it. About 90% was released at 200 h and hence, the synthesized MSNs were capable of engulfing DX and sustain its release. Further form the Ritger and Peppas, Higuchi model for mechanism drug release from all the MSN matrices follows anomalous transport or Non-Fickian diffusion with the ‘r’ and ‘n’ value 0.9 and 0.45 < n < 1, respectively. So, from this study it could be concluded that the MSNs synthesized using pharmaceutical templates were better choice of reservoir for the controlled delivery of drug which requires sustained release.

  8. A randomized controlled trial of the laryngeal mask airway for surfactant administration in neonates.

    Science.gov (United States)

    Barbosa, Rosilu F; Simões E Silva, Ana C; Silva, Yerkes P

    To compare the short-term efficacy of surfactant administration by laryngeal mask airway versus endotracheal tube. Preterm infants (28-35 weeks of gestational age), weighing 1kg or more, with respiratory distress syndrome, requiring nasal continuous positive airway pressure, with increased respiratory effort and/or fraction of inspired oxygen (FiO 2 )≥0.40 to maintain oxygen saturation 91-95%, were randomized to receive surfactant by LMA following nCPAP or by ETT following mechanical ventilation (MV). The primary outcome was a clinical response defined as FiO 2 ≤0.30 three hours after surfactant. Secondary outcomes for LMA group were: need of surfactant retreatment during the first 24h, MV requirement, and presence of surfactant in gastric content. Forty-eight patients were randomized; 26 in the LMA group and 22 in the ETT group. Six of 26 patients (23%) in the LMA group and five of 22 patients (22.7%) in the ETT group did not meet the primary outcome (p=0.977). Fourteen (53.8%) of the LMA patients were not intubated nor ventilated; 12 (46.1%) were ventilated: for surfactant failure (23%), for nCPAP failure (11.5%), and for late complications (11.5%). Groups were similar regarding prenatal status, birth conditions, and adverse events. No significant gastric content was found in 61.5% of the LMA patients. Oxygen and second dose surfactant requirements, arterial/alveolar ratio, and morbidities were similar among groups. Surfactant administration by LMA showed short-term efficacy, with similar supplementary oxygen need compared to surfactant by ETT, and lower MV requirement. Further studies with larger sample size are necessary to confirm these results. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  9. A surfactant-free recipe for shape-controlled synthesis of CdSe nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Liu Hongmei; Tao Hong; Yang Tingbin; Qin Donghuan; Chen Junwu [Institute of Polymer Optoelectronic Materials and Devices, Key Laboratory of Special Functional Materials, South China University of Technology, Guangzhou 510640 (China); Kong Lingbin, E-mail: qindh@scut.edu.cn, E-mail: psjwchen@scut.edu.cn [State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology, Lanzhou 730050 (China)

    2011-01-28

    We described surfactant-free recipes for the synthesis of CdSe nanocrystals (NCs) with well-controlled morphologies at a relatively low temperature. Dot-, rod-, tetrapod-and sphere-shaped CdSe NCs were prepared with trioctylphosphine oxide (TOPO) as a non-equilibrium solvent and trioctylphosphine selenide (TOPSe) and cadmium carboxylates as Se and Cd precursors, respectively. It was found that the morphology and stacking pattern of the CdSe NCs were related to the preparation conditions such as the concentration of the injected TOPSe(monomer concentration), reaction temperature and chain length of the cadmium carboxylate precursors. At a reaction temperature of 240 deg. C, CdSe NCs with a tetrapod selectivity of up to 85% were obtained in the presence of cadmium myristate under high concentrated TOPSe injection, and the in situ-formed myristic acid supplied the best acidic ligand with optimal amount to stabilize the anisotropic growth of the tetrapods. The intentional addition of more myristic acid in the reaction system would block the growth pathway of the tetrapods. Using cadmium laurate, cadmium palmitate and cadmium stearate as the cadmium precursors would reduce the formation of the tetrapods, showing the very low selectivity of the tetrapods.

  10. Controlled hypothermia may improve surfactant function in asphyxiated neonates with or without meconium aspiration syndrome.

    Science.gov (United States)

    Autilio, Chiara; Echaide, Mercedes; De Luca, Daniele; Pérez-Gil, Jesús

    2018-01-01

    Whole-body hypothermia (WBH) is used to improve neurological outcomes in perinatal asphyxia. Recent studies suggested a beneficial effect of hypothermia for some types of acute respiratory failure. However, no data are available about the biophysical function of human surfactant during WBH. We investigated whether WBH improves surfactant biophysical properties in asphyxiated neonates with or without meconium aspiration syndrome (MAS). Non-bronchoscopic bronchoalveolar lavage (BAL) has been collected from 10 asphyxiated neonates (2 with MAS, 8 with no lung disease (NLD)) at different time-points (pre-WBH, 24h, 48h, 72h of WBH and post-WBH). Surfactant was extracted and tested by captive bubble surfactometry (CBS) in triplicate, at 37°C and 33.5°C, through initial adsorption and dynamic compression-expansion cycling. Phosphatidylcholine and cholesterol were assayed using enzymatic methods. Clinical data were recorded in real-time. Minimum surface tension under dynamic testing was significantly improved as assessed at 33.5°C compared with its behavior at 37°C in NLD neonates: the difference was evident after at least 72h of WBH and remained significant at 6h after rewarming (72h: p = 0.009; rewarming: p = 0.040). Similar results were obtained in MAS patients whose surfactant activity improved already at 48h of hypothermia. Total cholesterol showed a trend to increase at the first 24-48h of hypothermia in NLD patients. Conversely, hypothermia seemed to reduce the excess of exogenous cholesterol in MAS surfactant. Surfactant biophysical properties may improve after 48-72h of WBH in asphyxiated neonates and the improvement is maintained shortly after rewarming. Due to study limitations, further studies are warranted to better clarify the effects of hypothermia on surfactant activity.

  11. Controlled hypothermia may improve surfactant function in asphyxiated neonates with or without meconium aspiration syndrome.

    Directory of Open Access Journals (Sweden)

    Chiara Autilio

    Full Text Available Whole-body hypothermia (WBH is used to improve neurological outcomes in perinatal asphyxia. Recent studies suggested a beneficial effect of hypothermia for some types of acute respiratory failure. However, no data are available about the biophysical function of human surfactant during WBH. We investigated whether WBH improves surfactant biophysical properties in asphyxiated neonates with or without meconium aspiration syndrome (MAS.Non-bronchoscopic bronchoalveolar lavage (BAL has been collected from 10 asphyxiated neonates (2 with MAS, 8 with no lung disease (NLD at different time-points (pre-WBH, 24h, 48h, 72h of WBH and post-WBH. Surfactant was extracted and tested by captive bubble surfactometry (CBS in triplicate, at 37°C and 33.5°C, through initial adsorption and dynamic compression-expansion cycling. Phosphatidylcholine and cholesterol were assayed using enzymatic methods. Clinical data were recorded in real-time.Minimum surface tension under dynamic testing was significantly improved as assessed at 33.5°C compared with its behavior at 37°C in NLD neonates: the difference was evident after at least 72h of WBH and remained significant at 6h after rewarming (72h: p = 0.009; rewarming: p = 0.040. Similar results were obtained in MAS patients whose surfactant activity improved already at 48h of hypothermia. Total cholesterol showed a trend to increase at the first 24-48h of hypothermia in NLD patients. Conversely, hypothermia seemed to reduce the excess of exogenous cholesterol in MAS surfactant.Surfactant biophysical properties may improve after 48-72h of WBH in asphyxiated neonates and the improvement is maintained shortly after rewarming. Due to study limitations, further studies are warranted to better clarify the effects of hypothermia on surfactant activity.

  12. Predicting Loss-of-Control Boundaries Toward a Piloting Aid

    Science.gov (United States)

    Barlow, Jonathan; Stepanyan, Vahram; Krishnakumar, Kalmanje

    2012-01-01

    This work presents an approach to predicting loss-of-control with the goal of providing the pilot a decision aid focused on maintaining the pilot's control action within predicted loss-of-control boundaries. The predictive architecture combines quantitative loss-of-control boundaries, a data-based predictive control boundary estimation algorithm and an adaptive prediction method to estimate Markov model parameters in real-time. The data-based loss-of-control boundary estimation algorithm estimates the boundary of a safe set of control inputs that will keep the aircraft within the loss-of-control boundaries for a specified time horizon. The adaptive prediction model generates estimates of the system Markov Parameters, which are used by the data-based loss-of-control boundary estimation algorithm. The combined algorithm is applied to a nonlinear generic transport aircraft to illustrate the features of the architecture.

  13. Pore Structure Control of Ordered Mesoporous Silica Film Using Mixed Surfactants

    Directory of Open Access Journals (Sweden)

    Tae-Jung Ha

    2011-01-01

    Full Text Available Materials with nanosized and well-arranged pores have been researched actively in order to be applied to new technology fields. Especially, mesoporous material containing various pore structures is expected to have different pore structure. To form a mixed pore structure, ordered mesoporous silica films were prepared with a mixture of surfactant; Brij-76 and P-123 block copolymer. In mixed surfactant system, mixed pore structure was observed in the region of P-123/(Brij-76 + P-123 with about 50.0 wt.% while a single pore structure was observed in regions which have large difference in ratio between Brij-76 and P-123 through the X-ray diffraction analysis. Regardless of surfactant ratio, porosity was retained almost the same. It is expected that ordered mesoporous silica film with mixed pore structure can be one of the new materials which has distinctive properties.

  14. S-nitrosylation of surfactant protein-D controls inflammatory function.

    Directory of Open Access Journals (Sweden)

    Chang-Jiang Guo

    2008-11-01

    Full Text Available The pulmonary collectins, surfactant proteins A and D (SP-A and SP-D have been implicated in the regulation of the innate immune system within the lung. In particular, SP-D appears to have both pro- and anti-inflammatory signaling functions. At present, the molecular mechanisms involved in switching between these functions remain unclear. SP-D differs in its quaternary structure from SP-A and the other members of the collectin family, such as C1q, in that it forms large multimers held together by the N-terminal domain, rather than aligning the triple helix domains in the traditional "bunch of flowers" arrangement. There are two cysteine residues within the hydrophobic N terminus of SP-D that are critical for multimer assembly and have been proposed to be involved in stabilizing disulfide bonds. Here we show that these cysteines exist within the reduced state in dodecameric SP-D and form a specific target for S-nitrosylation both in vitro and by endogenous, pulmonary derived nitric oxide (NO within a rodent acute lung injury model. S-nitrosylation is becoming increasingly recognized as an important post-translational modification with signaling consequences. The formation of S-nitrosothiol (SNO-SP-D both in vivo and in vitro results in a disruption of SP-D multimers such that trimers become evident. SNO-SP-D but not SP-D, either dodecameric or trimeric, is chemoattractive for macrophages and induces p38 MAPK phosphorylation. The signaling capacity of SNO-SP-D appears to be mediated by binding to calreticulin/CD91. We propose that NO controls the dichotomous nature of this pulmonary collectin and that posttranslational modification by S-nitrosylation causes quaternary structural alterations in SP-D, causing it to switch its inflammatory signaling role. This represents new insight into both the regulation of protein function by S-nitrosylation and NO's role in innate immunity.

  15. Study and pilot test on a novel EOR method -- coupling PPG conformance control and surfactant flooding

    Science.gov (United States)

    Muhammed, Farag Awadh

    The interest in enhanced oil recovery (EOR) methods has re-emerged in recent years; however, significant challenges remain for the widespread deployment of these methods. One major downside to the successful application of EOR technologies in mature reservoirs is conformance problems (e.g. heterogeneity). To mitigate these problems, a novel EOR method which couple preformed particle gel (PPGs) conformance treatment with traditional surfactant flooding in one process is introduced. This dissertation provides a comprehensive study for the proposed method. A series of laboratory tests were carried out to understand the chemical interaction between PPGs and surfactants. A new method to evaluate PPGs strength in the oilfield and laboratory was introduced. Core flooding tests were run to investigate to what extent the coupled method can improve oil recovery using fractured carbonate and sandstone cores. Oilfield pilot tests were implemented in several injection wells located in Kansas. The chemical interaction experiments showed that surfactants concentrations influenced the swelling ratio and strength of PPGs. Fractured core flooding tests showed a higher increase in oil recovery through surfactant forced imbibition process by PPGs than a single method. The new PPG strength measurement apparatus provided a reliable technique to quantitatively evaluate PPG properties in the field. Oilfield pilot tests were implemented successfully in several candidate wells. The treatment s effectively increased the injection pressure of injection wells and reduced water production of adjacent production wells. Overall, this method provides a cost-effective approach for improving oil recovery while also reducing excess water production in mature and fractured reservoirs.

  16. Mineral-Surfactant Interactions for Minimum Reagents Precipitation and Adsorption for Improved Oil Recovery

    Energy Technology Data Exchange (ETDEWEB)

    P. Somasundaran

    2008-09-20

    Chemical EOR can be an effective method for increasing oil recovery and reducing the amount of produced water; however, reservoir fluids are chemically complex and may react adversely to the polymers and surfactants injected into the reservoir. While a major goal is to alter rock wettability and interfacial tension between oil and water, rock-fluid and fluid-fluid interactions must be understood and controlled to minimize reagent loss, maximize recovery and mitigate costly failures. The overall objective of this project was to elucidate the mechanisms of interactions between polymers/surfactants and the mineral surfaces responsible for determining the chemical loss due to adsorption and precipitation in EOR processes. The role of dissolved inorganic species that are dependent on the mineralogy is investigated with respect to their effects on adsorption. Adsorption, wettability and interfacial tension are studied with the aim to control chemical losses, the ultimate goal being to devise schemes to develop guidelines for surfactant and polymer selection in EOR. The adsorption behavior of mixed polymer/surfactant and surfactant/surfactant systems on typical reservoir minerals (quartz, alumina, calcite, dolomite, kaolinite, gypsum, pyrite, etc.) was correlated to their molecular structures, intermolecular interactions and the solution conditions such as pH and/or salinity. Predictive models as well as general guidelines for the use of polymer/surfactant surfactant/surfactant system in EOR have been developed The following tasks have been completed under the scope of the project: (1) Mineral characterization, in terms of SEM, BET, size, surface charge, and point zero charge. (2) Study of the interactions among typical reservoir minerals (quartz, alumina, calcite, dolomite, kaolinite, gypsum, pyrite, etc.) and surfactants and/or polymers in terms of adsorption properties that include both macroscopic (adsorption density, wettability) and microscopic (orientation

  17. Controlling electrostatic co-assembly using ion-containing copolymers : from surfactants to nanoparticles

    OpenAIRE

    Berret, J. -F.

    2011-01-01

    In this review, we address the issue of the electrostatic complexation between charged-neutral diblock copolymers and oppositely charged nanocolloids. We show that nanocolloids such as surfactant micelles and iron oxide magnetic nanoparticles share similar properties when mixed with charged-neutral diblocks. Above a critical charge ratio, core-shell hierarchical structures form spontaneously under direct mixing conditions. The core-shell structures are identified by a combination of small-ang...

  18. Surfactant phosphatidylcholine metabolism and surfactant function in preterm, ventilated lambs

    International Nuclear Information System (INIS)

    Jobe, A.H.; Ikegami, M.; Seidner, S.R.; Pettenazzo, A.; Ruffini, L.

    1989-01-01

    Preterm lambs were delivered at 138 days gestational age and ventilated for periods up to 24 h in order to study surfactant metabolism and surfactant function. The surfactant-saturated phosphatidylcholine pool in the alveolar wash was 13 +/- 4 mumol/kg and did not change from 10 min to 24 h after birth. Trace amounts of labeled natural sheep surfactant were mixed with fetal lung fluid at birth. By 24 h, 80% of the label had become lung-tissue-associated, yet there was no loss of label from phosphatidylcholine in the lungs when calculated as the sum of the lung tissue plus alveolar wash. De novo synthesized phosphatidylcholine was labeled with choline given by intravascular injection at 1 h of age. Labeled phosphatidylcholine accumulated in the lung tissue linearly to 24 h, and the labeled phosphatidylcholine moved through lamellar body to alveolar pools. The turnover time for alveolar phosphatidylcholine was estimated to be about 13 h, indicating an active metabolic pool. A less surface-active surfactant fraction recovered as a supernatant after centrifugation of the alveolar washes at 40,000 x g increased from birth to 10 min of ventilation, but no subsequent changes in the distribution of surfactant phosphatidylcholine in surfactant fractions occurred. The results were consistent with recycling pathway(s) that maintained surface-active surfactant pools in preterm ventilated lambs

  19. Control of the composition of Pt-Ni electrocatalysts in surfactant-free synthesis using neat N-formylpiperidine.

    Science.gov (United States)

    Zhang, Na; Tsao, Kai-Chieh; Pan, Yung-Tin; Yang, Hong

    2016-02-07

    This paper describes the facile and surfactant-free synthesis of faceted Pt-Ni alloy nanoparticle electrocatalysts using neat N-formylpiperidine as a new type of solvent. Unlike the widely-used colloidal synthesis based on long-carbon chain surfactants, nanoparticles made in neat N-formylpiperidine possess a directly accessible surface for electrocatalytic reactions, making it a very attractive alternative solvent. The area-specific oxygen reduction reaction (ORR) activity is much higher than the commercial Pt/C catalyst reference and reaches a maximum of 1.12 mA cm(-2) for the Pt-Ni alloy nanoparticles. We observed that the freshly formed Pt-Ni alloy could have controllable bulk and near surface compositions under the same initial reaction conditions and precursor ratio. The change in the composition could be attributed to the effect of CO on the formation of uniform nuclei at the initial stage, and a different deposition rate between Pt and Ni metals during the growth. The well-defined Pt-Ni nanoparticle catalysts show strong composition-dependent catalytic behavior in ORR, highlighting the important role of controlling the growth kinetics in the preparation of active Pt-Ni ORR catalysts.

  20. Wormlike micelles in poly(oxyethylene) surfactant solution: Growth control through hydrophilic-group size variation.

    Science.gov (United States)

    Ahmed, Toufiq; Aramaki, Kenji

    2008-11-01

    Viscoelastic micellar solutions are formed in poly(oxyethylene) cholesteryl ether (ChEO(m), m=15, 30) aqueous solutions on addition of tri(ethyleneglycol) mono n-dodecyl ether (C(12)EO(3)). The steady-shear and dynamic rheological behavior of the systems is characteristic of wormlike micellar solution. In either system, the plateau modulus (G(0)) and relaxation time (tau) are found to increase with increasing cosurfactant mixing fractions. The plateau modulus of the ChEO(30)-C(12)EO(3) system at the maximum viscosity region is found to be higher than that in the ChEO(15)-C(12)EO(3) system at the maximum viscosity region, whereas for the relaxation time the opposite relation is found. The maximum viscosities obtained in the two systems are of the same order of magnitude. In the ChEO(30)-C(12)EO(3) system, the maximum viscosity is obtained at a higher cosurfactant mixing fraction than that in the ChEO(15)-C(12)EO(3) system. It is concluded that decreasing the head-group size of the hydrophilic surfactant favors micellar growth. Monolaurin, another hydrophobic surfactant known to induce growth in some systems, is found to cause phase separation before significant micellar growth occurs in ChEO(m) solutions, although the effect of head-group size of ChEO(m) is found to be similar to the ChEO(m)-C(12)EO(3) systems.

  1. Red, green, and blue lanthanum phosphate phosphors obtained via surfactant-controlled hydrothermal synthesis

    International Nuclear Information System (INIS)

    Sousa Filho, Paulo C. de; Serra, Osvaldo A.

    2009-01-01

    A new solution route for the obtainment of highly pure luminescent rare-earth orthophosphates in hydrothermal conditions was developed. By starting from soluble precursors (lanthanide tripolyphosphato complexes, i.e. with P 3 O 10 5- as a complexing agent and as an orthophosphate source) and by applying surfactants in a water/toluene medium, the precipitations are confined to reverse micelle structures, thus yielding nanosized and homogeneous orthophosphates. The method was employed to obtain lanthanide-activated lanthanum phosphates, which can be applied as red (LaPO 4 :Eu 3+ ), green (LaPO 4 :Ce 3+ ,Tb 3+ ) and blue (LaPO 4 :Tm 3+ ) phosphors. The produced materials were analyzed by powder X-ray diffractometry, scanning electron microscopy, infrared spectroscopy and luminescence spectroscopy (emission, excitation, lifetimes and chromaticity coordinates).

  2. Effects of Surfactant Contamination on the Next Generation Gas Trap for the ISS Internal Thermal Control System

    Science.gov (United States)

    Leimkuehler, Thomas O.; Lukens, Clark; Reeves, Daniel R.; Holt, James M.

    2004-01-01

    The current dual-membrane gas trap is designed to remove non-condensed gas bubbles from the Internal Thermal Control System (ITCS) coolant on board the International Space Station (ISS). To date it has successfully served its purpose of preventing gas bubbles from causing depriming, overspeed, and shutdown of the ITCS pump. However, contamination in the ITCS coolant has adversely affected the gas venting rate and lifetime of the gas trap, warranting a development effort for a next-generation gas trap. Previous testing has shown that a hydrophobic-only design is capable of performing even better than the current dual-membrane design for both steady-state gas removal and gas slug removal in clean deionized water. This paper presents results of testing to evaluate the effects of surfactant contamination on the steady-state performance of the hydrophobic-only design.

  3. Effects of wireless packet loss in industrial process control systems.

    Science.gov (United States)

    Liu, Yongkang; Candell, Richard; Moayeri, Nader

    2017-05-01

    Timely and reliable sensing and actuation control are essential in networked control. This depends on not only the precision/quality of the sensors and actuators used but also on how well the communications links between the field instruments and the controller have been designed. Wireless networking offers simple deployment, reconfigurability, scalability, and reduced operational expenditure, and is easier to upgrade than wired solutions. However, the adoption of wireless networking has been slow in industrial process control due to the stochastic and less than 100% reliable nature of wireless communications and lack of a model to evaluate the effects of such communications imperfections on the overall control performance. In this paper, we study how control performance is affected by wireless link quality, which in turn is adversely affected by severe propagation loss in harsh industrial environments, co-channel interference, and unintended interference from other devices. We select the Tennessee Eastman Challenge Model (TE) for our study. A decentralized process control system, first proposed by N. Ricker, is adopted that employs 41 sensors and 12 actuators to manage the production process in the TE plant. We consider the scenario where wireless links are used to periodically transmit essential sensor measurement data, such as pressure, temperature and chemical composition to the controller as well as control commands to manipulate the actuators according to predetermined setpoints. We consider two models for packet loss in the wireless links, namely, an independent and identically distributed (IID) packet loss model and the two-state Gilbert-Elliot (GE) channel model. While the former is a random loss model, the latter can model bursty losses. With each channel model, the performance of the simulated decentralized controller using wireless links is compared with the one using wired links providing instant and 100% reliable communications. The sensitivity of the

  4. Effects of surfactants on the formation of gelatin nanofibres for controlled release of curcumin.

    Science.gov (United States)

    Deng, Lingli; Kang, Xuefan; Liu, Yuyu; Feng, Fengqin; Zhang, Hui

    2017-09-15

    This work studied the effects of non-ionic Tween 80, anionic sodium dodecyl sulfonate (SDS) and cationic cetyltrimethyl ammonium bromide (CTAB) surfactants on the morphology of electrospun gelatin nanofibres, and on the release behaviour, antioxidant activity and antimicrobial activity of encapsulated curcumin. Scanning electron micrographs showed that addition of SDS significantly increased the nanofibre diameter. Fourier transform infrared and differential scanning calorimetry analysis indicated that gelatin and SDS intimately interacted via electrostatic and hydrophobic interactions. However, these interactions inhibited the release of curcumin from the nanofibres with SDS, while CTAB and Tween 80 both facilitated the release. SDS and Tween 80 showed protective effects on curcumin from the attack of 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radicals, and the increased release of curcumin from nanofibres with CTAB or Tween 80 resulted in a higher reducing power. The antimicrobial activity results suggested that the curcumin encapsulated gelatin nanofibres with CTAB exhibited effective inhibition against Staphylococcus aureus. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Controlling electrostatic co-assembly using ion-containing copolymers: from surfactants to nanoparticles.

    Science.gov (United States)

    Berret, J-F

    2011-09-14

    In this review, we address the issue of the electrostatic complexation between charged-neutral diblock copolymers and oppositely charged nanocolloids. We show that nanocolloids such as surfactant micelles and iron oxide magnetic nanoparticles share similar properties when mixed with charged-neutral diblocks. Above a critical charge ratio, core-shell hierarchical structures form spontaneously under direct mixing conditions. The core-shell structures are identified by a combination of small-angle scattering techniques and transmission electron microscopy. The formation of multi-level objects is driven by the electrostatic attraction between opposite charges and by the release of the condensed counterions. Alternative mixing processes inspired from molecular biology are also described. The protocols applied here consist in screening the electrostatic interactions of the mixed dispersions, and then removing the salt progressively as an example by dialysis. With these techniques, the oppositely charged species are intimately mixed before they can interact, and their association is monitored by the desalting kinetics. As a result, sphere- and wire-like aggregates with remarkable superparamagnetic and stability properties are obtained. These findings are discussed in the light of a new paradigm which deals with the possibility to use inorganic nanoparticles as building blocks for the design and fabrication of supracolloidal assemblies with enhanced functionalities. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Surfactant-controlled morphology and magnetic property of manganese ferrite nanocrystal contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Hu He; Tian Zhiqing; Liang Jie; Yang Hong; Dai Antao; An Lu; Wu Huixia; Yang Shiping, E-mail: shipingy@shnu.edu.cn [Department of Chemistry, Shanghai Normal University, No.100 Guilin Road, Shanghai 200234 (China)

    2011-02-25

    MnFe{sub 2}O{sub 4} nanocrystals (NCs) coated with three different surfactants (oleic acid, oleylamine or 1,2-hexadecanediol) and their mixtures, with sizes in range 6-12 nm, were synthesized by high-temperature decomposition of organometallic precursors. The effects of morphology and surface chemistry of MnFe{sub 2}O{sub 4} NCs on the magnetic properties were systematically investigated by comparing their saturation magnetization values and their capability to improve the negative contrast for magnetic resonance imaging (MRI) after converting the hydrophobic NCs to hydrophilic ones by a ligand exchange protocol. An important finding is that the magnetization values and proton relaxivity rates of MnFe{sub 2}O{sub 4} NCs are strongly dependent on the size and surface state of the particles that covalently bonded with different hydrophobic ligands before ligand exchange. In particular, monodisperse cubic MnFe{sub 2}O{sub 4} NCs could be obtained when oleylamine and 1,2-hexadecanediol were used as mixed stabilizers, and showed excellent morphology and magnetic properties. Furthermore, the low cytotoxicity and good cell uptake MR imaging of the dopamine capped MnFe{sub 2}O{sub 4} NCs make them promising candidates for use as bio-imaging probes.

  7. Beam loss control on the ISIS synchrotron simulations, measurements, upgrades

    CERN Document Server

    Warsop, C M

    2003-01-01

    The ISIS 800 MeV proton synchrotron presently provides 2.5*10/sup 13/ protons per pulse at 50 Hz, corresponding to a mean power of 160 kW. A dual harmonic RF system upgrade, now being installed, is expected to increase the intensity and power to about 3.75*10/sup 13/ ppp and 240 kW respectively. This paper describes work presently underway to understand and optimise beam loss control, which is a dominant factor determining operational performance. The main features of the collimation system are described, and Monte Carlo simulations of the loss control process are used to understand variations of efficiency with beam loss mode (growth rate, plane). Results of simulations are compared with measurements and operational data. Improvements to measurements are also outlined.

  8. Surfactant Free Preparation of Celecoxib Microcrystals by a Controlled Precipitation Process

    Directory of Open Access Journals (Sweden)

    Sepideh Mardani, Maryam Maghsoodi, Hamed Hamishehkar

    2017-09-01

    Full Text Available Background: The antisolvent precipitation technique has evolved into an effective method to prepare microcrystals of drug. Although this method has advantages, such as cost effectiveness, the processing is significantly sensitive to stabilizer. The aim of present study was to prepare celecoxib (CLX microcrystals via antisolvent precipitation technique without any surfactants. Methods: Acetone was used as a solvent for the CLX and water was used as an antisolvent. During the precipitation process, several experimental parameters, such as the volume ratio of antisolvent to CLX solution, the concentration of CLX solution, the temperature and the stirring speed, were investigated. Results: The results showed that external characteristics such as particle size and its distribution were strongly influenced by the process parameters, while the internal structures such as chemical composition and crystal structure were unaffected during the process. Higher volume ratio of antisolvent to CLX solution, lower temperature and more- intense stirring led to the smaller crystals. However, increasing the concentration of CLX solution resulted in aggregation of crystals and consequently formation of large crystals with more heterogeneous distribution. It was found that this effect could be prevented by using of ethanol as co-solvent with volume ratio to acetone 5:1. Under the optimum conditions, the yielded powder had a mean particle size of 7 µm and 70 % of the particles were distributed in the range of 0.3- 15 µm. Conclusion: Results of this study offer a useful starting point for a conceptual framework to guide the preparation of microcrystals without using a stabilizer.

  9. Application experience with ADBAC/DGH cationic surfactants for zebra mussel control in a nuclear service water system

    International Nuclear Information System (INIS)

    Jung, W.R.; Lacy, J.R.; Post, R.

    1992-01-01

    In response to the introduction and rapid growth of the zebra mussel population in the Great Lakes and the issuance of NRC Generic Letter 89-13 (Service Water Problems Affecting Safety-Related Equipment). A midwest nuclear station instituted a zebra mussel monitoring and control program. The nuclear station uses Lake Michigan as a cooling water source for two 1,100 MW Westinghouse 4-loop design, pressurized water reactors (PWR). Two years of monitoring indicated a growth in zebra mussel population from 0.5 organisms/m 2 in July 1990 to 100 organisms/m 2 by November 1990. This rapid increase indicated an urgent need for viable methods of zebra mussel control to protect the plant's essential service water (ESW) and non-essential service water (NESW) systems. In April 1991, the station formulated a plan that combined increased system inlet temperature with targeted application of a proprietary product containing two cationic surfactants, ADBAC/DGH. Sidestream biomonitoring boxes were seeded with zebra mussels and observed as a measure of the efficacy of the treatment. Where recommended dosages and duration were maintained, 100% control was achieved

  10. Colloid and surfactant

    International Nuclear Information System (INIS)

    Kuk, Yun Hwan; Lee, Jeong Jung; Cho, Sun Chae; Ryeo, Su Dong

    1995-08-01

    This book consists of two parts about colloid and surfactant. The first parts has explanations colloid and surface science, which deal with creation and properties of colloidal particles, surfactant and micelle colloid, property of surfactant, membranes, absorption of surface science, electrokinetic phenomenon, emulsion, foam and rheology. The second part mentions surfactant on anionic surfactant with five types, amphoteric surface active agent, non-ionic surface active agent and use of surfactant.

  11. Investigation of Surfactant Type, Dosage and Ultrasonication Temperature Control on Dispersity of Metal-Coated Multi-Walled Carbon Nanotubes.

    Science.gov (United States)

    Liang, Xiaoning; Li, Wei

    2016-04-01

    We studied the dispersity of multi-walled carbon nanotubes (MWNTs) combined with different metal- lic particles (Ni and Fe). An ultrasonic-assisted water-bath dispersion process was used to dis- perse the metal-coated MWNTs in different solutions and the dispersity was measured using an ultraviolet-visible spectrophotometer. The dispersity and morphology of the MWNTs were characterized using field-emission scanning electron microscopy (FE-SEM) together with digital image processing technology. Effects of dispersant type (sodium dodecyl benzene sulfonate (SDBS), oleic acid, and polymer (TNEDIS)) and surfactant dosage on the dispersity of the metal-coated MWNTs were investigated under controlled and uncontrolled temperatures and results were compared with those from the untreated MWNTs. The results showed that the negative effects of temperature on the ultrasonic dispersion process could be eliminated through a temperature-controlled system. Moreover, the TNEDIS, SDBS, and oleic acid were arranged in the descending order of the dispersion effect degree. The untreated MWNTs, Ni-coated MWNTs, and Fe-coated MWNTs were arranged in the descending degree of dispersity order. Since the metal coating makes the MWNTs harder and more fragile, the metal-coated MWNTs are more likely to fracture during the ultrasonic dispersion process.

  12. Loss-of-Control Eating Following Sleeve Gastrectomy Surgery

    Science.gov (United States)

    Ivezaj, Valentina; Kessler, Erin E.; Lydecker, Janet A.; Barnes, Rachel D.; White, Marney A.; Grilo, Carlos M.

    2016-01-01

    Background Post-operative loss-of-control (LOC) eating is related to poorer weight loss outcomes following bariatric surgery, but little is known about LOC eating following sleeve gastrectomy surgery. Objectives To examine LOC eating severity and weight loss following sleeve gastrectomy. Setting University School of Medicine, U.S. Methods Participants were 71 individuals (84.5% female; n=60) who underwent sleeve gastrectomy surgery within the previous 4–9 months and reported LOC eating at least once weekly during the previous 28 days. LOC eating was assessed using the Eating Disorder Examination (EDE) Bariatric Surgery Version. Current mean age and body mass index were 47.3 (SD=10.1) years and 37.9 (SD=8.2) kg/m2. Two groups, bariatric binge-eating disorder (Bar-BED) and loss-of-control eating only (LOC-Only) were created based on modified binge-eating disorder (BED) criteria, which excluded the “unusually large quantity of food” criterion due to limited gastric capacity post-surgery. Bar-BED criteria mirrored BED criteria and consisted of the following: at least 12 LOC eating episodes over the prior three months (once weekly), 3 of 5 associated symptoms, marked distress over LOC eating, and lack of regular compensatory behaviors. Results Based on these revised criteria, 49.3% (n=35) were classified as the Bar-BED group and 50.7% (n=36) as the LOC-Only group. Compared to the LOC-Only group, the Bar-BED group had significantly greater EDE global and subscale scores and lower percent weight loss by six months post-surgery. Conclusions Findings suggest LOC eating that parallels BED post-surgery is associated with poorer outcomes following sleeve gastrectomy including poorer weight loss and greater severity of eating-disorder psychopathology. PMID:27913121

  13. Near optimal admission control for multiserver loss queues in series

    OpenAIRE

    Ku, Cheng-Yuan; Jordan, Scott

    2003-01-01

    This paper considers access control policies in multiserver loss queues in series such as might arise in the context of computer and telecommunication networks. Each queue is presented with both served upstream customers and Poisson arrivals from outside the network, and it may route serviced customers out of the network or to the downstream queue. Service times of each customer are i.i.d. and exponentially distributed. Revenue is earned by each station when it serves a customer, but the amou...

  14. Loss Minimization and Voltage Control in Smart Distribution Grid

    DEFF Research Database (Denmark)

    Juelsgaard, Morten; Sloth, Christoffer; Wisniewski, Rafal

    2014-01-01

    This work presents a strategy for increasing the installation of electric vehicles and solar panels in low-voltage grids, while obeying voltage variation constraints. Our approach employs minimization of active power losses for coordinating consumption and generation of power, as well as reactive...... power control to maintain satisfactory grid operation. Numerical case studies illustrate how our approach can significantly increase installation of both electric vehicles and solar panels, while avoiding unsatisfactory over- and under-voltages throughout the grid....

  15. The Impact of Psychological Support on Weight Loss Post Weight Loss Surgery: a Randomised Control Trial

    OpenAIRE

    Ogden, J; Hollywood, A; Pring, C

    2015-01-01

    BACKGROUND: The purpose of the present study is to evaluate the impact of a health psychology-led bariatric rehabilitation service (BRS) on patient weight loss following bariatric surgery at 1 year. METHODS: A single-site open-randomised parallel group control trial based at St. Richard's Hospital in Chichester in the UK. Patients (n = 162) were recruited immediately prior to Roux-en-Y gastric bypass and randomly allocated to receive either treatment as usual (n = 80) or the BRS (n = 82). The...

  16. Interactions between surfactants and hydrolytic enzymes.

    Science.gov (United States)

    Holmberg, Krister

    2017-12-05

    Hydrolytic enzymes are combined with surfactants in many types of formulations, for instance detergents and personal care products. If the surfactant interacts with the enzyme there may be conformational changes that eventually lead to loss of the enzymatic activity. From a practical point of view it is important to understand the nature and magnitude of these interactions. After an introduction of the topic the review briefly discusses enzyme catalyzed reactions where surfactants are substrates for the enzyme. The rest of the review relates to associations between surfactants and hydrolytic enzymes without the surfactant being a substrate in the reaction. A discussion about general principles for such interactions is followed by a survey of the relevant literature related to four important types of hydrolytic enzymes: lipases, proteases, amylases and cellulases. It is shown in the review that the effect exerted by the surfactant differs between the different types of enzymes; it is therefore difficult to make general statements about which surfactants are most detrimental to the activity of hydrolytic enzymes. However, as a general rule nonionic surfactants can be regarded as more benign to an enzyme than anionic and cationic surfactants. This difference can be ascribed to the difference in binding mode. Whereas a nonionic surfactant only binds to the enzyme through hydrophobic interactions, an ionic surfactant can bind by a combination of electrostatic attraction and hydrophobic interaction. This latter type of binding can be strong and lead to conformational changes already at very low surfactant concentration, often far below its critical micelle concentration. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. pH dependent fluorescence switching in salicylideneaniline: ‘off–on–off’ operation controlled by surfactant micelles

    Energy Technology Data Exchange (ETDEWEB)

    Das, Diganta Kumar, E-mail: digkdas@yahoo.com; Dutta, Kaku

    2014-01-15

    Salaniline, a condensation product of salicylaldehyde and aniline, shows “off–on” fluorescent behaviour with pH in 1:1 (v/v) CH{sub 3}CN:H{sub 2}O and when 3% (w/v) anionic sodium dodecylsulphate (SDS) surfactant is present. The fluorescent switch behaviour of salaniline is forced to “off–on–off” type by 3% (w/v) neutral triton X-100 (TX-100) and 3% (w/v) cationic cetyltrimethylammonium bromide (CTAB) surfactant. The fluorescent “on” window is observed in the pH range 8.0–12.5 for TX-100 and 7.0–11.0 for CTAB. Different charge nature of the surfactants affects the protonation/deprotonation behaviour of salaniline differently, hence the photoinduced electron transfer (PET) processes and the fluorescent switch behaviour. -- Highlights: • Salicylideneaniline act as pH dependent “off–on” fluorescent switch in 1:1 (v/v) CH{sub 3}CN:H{sub 2}O. • In surfactant micelles TX-100 (neutral) and CTAB (positive) make the fluorescent switch “off–on–off” type while in. • In surfactant micelle SDS (negative) the pH dependent fluorescent switch is “off–on” type.

  18. Adjoint-based control of a surfactant-free drop suspended in an axisymmetric straining flow

    Science.gov (United States)

    Bidadi, Shreyas; Bodony, Daniel

    2017-11-01

    Optimal control theory has been remarkably successful in controlling a wide variety of single-phase flows. However, to date there has been no fundamental study on its application to multiphase problems. In this study, the continuous adjoint method is employed for the first time to control a clean, neutrally buoyant droplet of viscosity μI suspended in a low Reynolds number axisymmetric straining flow of viscosity μE. The control variable is the non-dimensional Capillary number C. For the forward problem, each C generates a distinct steady-state droplet. This information is utilized by the inverse problem to compute the adjoint velocities and the corresponding control gradient at the drop interface. The resultant gradient is subsequently used to update C. The algorithm is repeated until the desired shape is realized. To reduce computational cost, both the forward and adjoint velocities are obtained by solving Fredholm integral equations of the second kind. The theory is tested for three viscosity ratios; λ =μI /μE = 0.1 , 1 and 10. For all three cases, the cost functional is successfully minimized. The adjoint gradient is shown to be in good agreement with the corresponding finite-difference approximation of it.

  19. Controlled synthesis of bionic microstructure PbS crystals by mixed cationic/anionic surfactants

    Science.gov (United States)

    Li, Yanjie; Hu, Yongan; Zhang, Hui; Shen, Yuhua; Xie, Anjian

    2013-07-01

    Hexagonal starfish-like PbS crystals have been synthesized by the reaction of lead acetate and thioacetamide (TAA) controlled by mixture of cetyltrimethylammonium bromide/sodium dodecyl sulfate (STAB/SDS) at the molar ratio of 5: 1 through a hydrothermal process at 80°C. It has been found that the hexagonal starfish-like PbS single crystal is in cubic phase, and the six arms of the star extend along the six directions. By changing reaction conditions, such as the molar ratio of CTAB/SDS, temperature, and reaction time, the amounts of TAA and lead sources, the morphology and structure of the PbS crystals can be controlled. Furthermore, possible formation mechanism was preliminarily illustrated. The room-temperature photoluminescence spectra in solid state of the PbS single crystals obtained after different reaction times were investigated, which demonstrated that the PbS single crystals presented excellent optical properties. This work may open a novel route to the shaped-controllable synthesis of semiconductor crystals with various morphologies.

  20. Control rod drive mechanism stator loss of coolant test

    International Nuclear Information System (INIS)

    Besel, L.; Ibatuan, R.

    1977-04-01

    This report documents the stator loss of coolant test conducted at HEDL on the lead unit Control Rod Drive Mechanism (CRDM) in February, 1977. The purpose of the test was to demonstrate scram capability of the CRDM with an uncooled stator and to obtain a time versus temperature curve of an uncooled stator under power. Brief descriptions of the test, hardware used, and results obtained are presented in the report. The test demonstrated that the CRDM could be successfully scrammed with no anomalies in both the two-phase and three-phase stator winding hold conditions after the respective equilibrium stator temperatures had been obtained with no stator coolant

  1. I. Enabling Single-Chain Surfactants to Form Vesicles by Nonamphiphilic Liquid Crystals in Water II. Controlling Attachment and Ligand-Mediated Adherence of Candida albicans on Monolayers

    Science.gov (United States)

    Varghese, Nisha

    This dissertation describes a fundamental study of weak noncovalent interactions and surface forces that exist at the interfaces of various interacting moieties (small molecules or microbes), and its relevance to colloidal and material chemistry. Chapter 1 presents an emulsion system that enables single-chain anionic or nonionic surfactants to sequester and encapsulate certain water-soluble organic salts, leading to the formation of vesicles in water. The water-soluble organic salt in the system comprises of disodium cromoglycate crystals that are emulsified by surfactants in water to form stable liquid crystal droplets. The work provides an exception to the rule of geometric packing factor that dictates formation of micelles by the surfactants in water. Chapter 2 shows that the odd or even number of carbon atoms present in the aliphatic chain of surfactants affect the ability of surfactants to emulsify aqueous-based liquid crystals of disodium cromoglycate. Such an odd-even effect is frequently observed for solid state properties like melting point, heat of fusion and refractive index but is rarely observed for molecules present in solution. When mixed in water, anionic single-chain surfactants with odd number of carbon atoms emulsifies disodium cromoglycate to form liquid crystal droplets, while surfactants with even number of carbon atoms fail to emulsify disodium cromoglycate. Chapter 3 Bolaamphiphiles usually form vesicles only in extreme conditions or in the presence of surfactants. Here, we explore the co-assembly system of synthesized bolaamphiphiles and disodium cromoglycate in water. The combination of the self-assembly forces of the bolaamphiphile and self-associating property of disodium cromoglycate liquid crystals act together at the interface form a unique microemulsion of liquid crystal droplets of disodium cromoglycate embedded in liquid crystal phase. Chapter 4 describes a key event (adhesion) that precedes infections caused by Candida albicans

  2. Surfactant-enhanced cellulose nanocrystal Pickering emulsions.

    Science.gov (United States)

    Hu, Zhen; Ballinger, Sarah; Pelton, Robert; Cranston, Emily D

    2015-02-01

    The effect of surfactants on the properties of Pickering emulsions stabilized by cellulose nanocrystals (CNCs) was investigated. Electrophoretic mobility, interfacial tension, confocal microscopy and three-phase contact angle measurements were used to elucidate the interactions between anionic CNCs and cationic alkyl ammonium surfactants didecyldimethylammonium bromide (DMAB) and cetyltrimethylammonium bromide (CTAB). Both surfactants were found to adsorb onto CNCs with concentration-dependent morphology. At low concentrations, individual surfactant molecules adsorbed with alkyl tails pointing outward leading to hydrophobic CNCs. At higher concentrations, above the surfactant's apparent critical micelle concentration, surfactant aggregate morphologies on CNCs were inferred and the hydrophobicity of CNCs decreased. DMAB, which has two alkyl tails, rendered the CNCs more hydrophobic than CTAB which has only a single alkyl tail, at all surfactant concentrations. The change in CNC wettability from surfactant adsorption was directly linked to emulsion properties; adding surfactant increased the emulsion stability, decreased the droplet size, and controlled the internal phase of CNC Pickering emulsions. More specifically, a double transitional phase inversion, from oil-in-water to water-in-oil and back to oil-in-water, was observed for emulsions with CNCs and increasing amounts of DMAB (the more hydrophobic surfactant). With CNCs and CTAB, no phase inversion was induced. This work represents the first report of CNC Pickering emulsions with surfactants as well as the first CNC Pickering emulsions that can be phase inverted. The ability to surface modify CNCs in situ and tailor emulsions by adding surfactants may extend the potential of CNCs to new liquid formulations and extruded/spray-dried materials. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Controlling the Mobility of the Fluid Interface of Moving Gas Bubbles or Liquid Drops by Using Micellar Solutions of Surfactants

    Science.gov (United States)

    Maldarelli, Charles; Papageorgiou, Demetrios

    1998-01-01

    Microgravity processes must rely on mechanisms other than buoyancy to move bubbles or droplets from one region to another in a continuous liquid phase. One suggested method is thermocapillary migration in which a temperature gradient is applied to the continuous phase. A significant and as yet unresolved impediment to the use of thermocapillary migration to direct bubble or drop motion is that these migrations can be significantly retarded by the adsorption onto the fluid particle surface of surface active impurities unavoidably present in the continuous or (if the particle is a liquid) droplet phases. The focus of our research was to develop a theory for remobilizing fluid particle interfaces retarded by a surfactant impurity in an effort to make more viable the use of thermocapillary migrations for the management of bubbles and drops in microgravity. We postulated that a surfactant at high bulk concentration which kinetically exchanges rapidly with the surface can restore interface mobility. The scaling arguments along with a discussion of the previous literature is reviewed in the context of the scaling framework. The specific objectives of the research were twofold. The first was to prove the remobilization theory by studying a model problem. As the mechanism for remobilization is independent of the force which drives the particle, the fluid particle shape and the presence of fluid inertia, we chose the simplest model consisting of a spherical bubble rising steadily by buoyancy in creeping flow. We solved the hydrodynamic and surfactant transport equations for rapid kinetic exchange to demonstrate that as the concentration increases, the Marangoni retardation at first increases (the low k behavior) and then decreases (the high k behavior). The second objective was to develop a method to determine the kinetic rate constants of a surfactant molecule, since this information is necessary to select surfactants which will exchange rapidly enough relative to the

  4. Gemini (dimeric) Surfactants

    Indian Academy of Sciences (India)

    Gemini, surfactants, micelle. Figure 1. Schematic repre- sentation of the gemini sur- factant structure. B S Sekhon. A gemini surfactant (GS) consists of two conventional surfactant molecules chemically bonded together by a spacer. The two terminal hydrocarbon tails can be short or long; the two polar head groups can be ...

  5. 76 FR 22336 - Controlled Groups; Deferral of Losses

    Science.gov (United States)

    2011-04-21

    ... members may have the effect of eliminating an intercompany loss with respect to a corporation's stock. For... solvent corporation. S sells 30 percent of T's stock at a loss to B, the common parent of the consolidated... and Treasury Department believe that S's loss on the sale or exchange of T stock should be deferred...

  6. Adsorption of anionic surfactants in limestone medium during oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Canbolat, Serhat; Bagci, Suat [Middle East Technical Univ., Dept. of Petroleum and Natural Gas Engineering, Ankara (Turkey)

    2004-07-15

    Foam-forming surfactant performance was evaluated by several experimental methods (interfacial tension, foam stability, corefloods) using commercial surfactants. There is considerable interest in the use of foam-forming surfactants for mobility control in water flood. To provide effective mobility control, the injected surfactant must propagate from the injection well toward the production well. One of the important parameters affecting propagation of foam-forming surfactant through the reservoir is the retention of surfactant due to its adsorption on reservoir rock. The determination of the adsorption of foam-forming surfactants in limestone reservoirs is important for the residual oil recovery efficiency. Adsorption measurements, recovery efficiencies, and surfactant and alkaline flooding experiments carried out with the representative of the selected surfactants alkaline solutions, linear alkyl benzene sulphonic acid (LABSA), sodium lauryl ether sulfate (SLES), and NaOH in a limestone medium. These surfactants were selected with respect to their foaming ability. Calibration curves formed by pH measurements were used to determine the correct adsorption amount of the used surfactants and recovery efficiency of these surfactants compared with base waterflooding. The results showed that LABSA adsorbed more than SLES in limestone reservoirs. The recovery efficiency of SLES was higher than the recovery efficiency of LABSA, and they decreased the recovery efficiency with respect to only the water injection case. (Author)

  7. A randomised control study of partial liquid ventilation after airway lavage with exogenous surfactant in a meconium aspiration syndrome animal model

    Science.gov (United States)

    Nakamura, T.; Matsuzawa, S.; Sugiura, M.; Tamura, M.

    2000-01-01

    AIMS—To test the hypothesis that lavage with exogenous surfactant before partial liquid ventilation in meconium aspiration syndrome (MAS) would improve debris removal, and therefore the effectiveness of partial liquid ventilation.
METHODS—12 newborn piglets were randomised into 4 groups, partial liquid ventilation or gas ventilation, with and without surfactant lavage. Physiological and blood gas data were compared between groups by analysis of variance.
RESULTS—Arterial oxygen pressure (PaO2) was improved in the group treated with surfactant lavage when compared with the group not receiving surfactant. PaO2 in the group receiving surfactant lavage followed by partial liquid ventilation was further improved when compared with the group treated with surfactant lavage followed by gas ventilation and the group receiving partial liquid ventilation alone.
CONCLUSION—The effectiveness of partial liquid ventilation in MAS might be enhanced by pretreatment with exogenous surfactant bronchial lavage.

 PMID:10685992

  8. The effects of alkylammonium counterions on the aggregation of fluorinated surfactants and surfactant ionic liquids.

    Science.gov (United States)

    Pottage, Matthew J; Greaves, Tamar L; Garvey, Christopher J; Tabor, Rico F

    2016-08-01

    The effects of organic counterions with varying carbon number on surfactant aggregation have been analysed by coupling perfluorooctanoate surfactant anions with various alkylammonium counterions. Both the degree of substitution (primary to tertiary) and alkyl chain length (0-3 carbons) of the counterions were varied to provide a comprehensive matrix of geometries and lipophilicities. Surface activity was measured using pendant drop tensiometry, while temperature-controlled small-angle neutron scattering was used to probe changes in aggregation morphology. It was found that the use of such alkylammonium counterions resulted in a strong preference for bilayer formation even at low surfactant concentration (surfactant-rich lamellar phase coexists with a dilute micellar phase. The results indicate that aggregation is controlled by a delicate balance of counterion size, hydrophilicity and diffuseness of charge, providing new methods for the subtle control of surfactant solutions. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  9. Controlling the phase structures of polymer/surfactant complexes by changing macromolecular architecture and adding n-alcohols.

    Science.gov (United States)

    Percebom, Ana Maria; Loh, Watson

    2016-03-15

    Phase behavior of complex salts formed by a cationic surfactant and different ethoxylated polyions was investigated in water and with addition of two n-alcohols of different chain lengths: n-butanol and n-decanol. The polyion possesses a main chain of methacrylic acid randomly grafted with oligo(ethylene oxide) chains. Strong electrostatic interaction between the anionic main chain and the cationic surfactant hexadecyltrimethylammonium (C16TA) leads to the formation of C16TAP(MA-MAEO(n)) x:y complex salts. Modifications in polyion structure, such as changes in the proportion of grafted comonomers and in the side chain length caused differences in the overall balance of interactions with water and n-alcohols, altering the complex salt solubility and, consequently, the formed liquid-crystalline structures. The role of n-decanol as a cosurfactant was verified, but the hydrophilic side chains expanded the capacity of the formed liquid crystalline phases to incorporate water. Additionally, a novel structure, probably cubic bicontinuous (Pn3m), was observed coexisting with lamellar phases at low water concentration. Because n-butanol is known for being a good solvent for poly(ethylene oxide), these side chains intensified the role of this short chain n-alcohol as cosolvent for C16TAP(MA-MAEO(n)) x:y complex salts, favoring the formation of disordered solutions, including a bicontinuous microemulsion. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Cohort Study of the Success of Controlled Weight Loss Programs for Obese Dogs

    OpenAIRE

    German, A.J.; Titcomb, J.M.; Holden, S.L.; Queau, Y.; Morris, P.J.; Biourge, V.

    2015-01-01

    Background Most weight loss studies in obese dogs assess rate and percentage of weight loss in the first 2?3 months, rather than the likelihood of successfully reaching target weight. Objective To determine outcome of controlled weight loss programs for obese dogs, and to determine the factors associated with successful completion. Animals 143 obese dogs undergoing a controlled weight loss program. Methods This was a cohort study of obese dogs attending a referral weight management clinic. Do...

  11. Performance improvement of ionic surfactant flooding in carbonate rock samples by use of nanoparticles

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Ahmadi

    2016-07-01

    Full Text Available Abstract Various surfactants have been used in upstream petroleum processes like chemical flooding. Ultimately, the performance of these surfactants depends on their ability to reduce the interfacial tension between oil and water. The surfactant concentration in the aqueous solution decreases owing to the loss of the surfactant on the rock surface in the injection process. The main objective of this paper is to inhibit the surfactant loss by means of adding nanoparticles. Sodium dodecyl sulfate and silica nanoparticles were used as ionic surfactant and nanoparticles in our experiments, respectively. AEROSIL® 816 and AEROSIL® 200 are hydrophobic and hydrophilic nanoparticles. To determine the adsorption loss of the surfactant onto rock samples, a conductivity approach was used. Real carbonate rock samples were used as the solid phase in adsorption experiments. It should be noted that the rock samples were water wet. This paper describes how equilibrium adsorption was investigated by examining adsorption behavior in a system of carbonate sample (solid phase and surfactant solution (aqueous phase. The initial surfactant and nanoparticle concentrations were 500–5000 and 500–2000 ppm, respectively. The rate of surfactant losses was extremely dependent on the concentration of the surfactant in the system, and the adsorption of the surfactant decreased with an increase in the nanoparticle concentration. Also, the hydrophilic nanoparticles are more effective than the hydrophobic nanoparticles.

  12. Simple control of surface topography of gold nanoshells by a surfactant-less seeded-growth method.

    Science.gov (United States)

    Topete, Antonio; Alatorre-Meda, Manuel; Villar-Álvarez, Eva M; Cambón, Adriana; Barbosa, Silvia; Taboada, Pablo; Mosquera, Víctor

    2014-07-23

    We report the synthesis of branched gold nanoshells (BGNS) through a seeded-growth surfactant-less method. This was achieved by decorating chitosan-Pluronic F127 stabilized poly(lactic-co-gycolic) acid nanoparticles (NPs) with Au seeds (NP-seed), using chitosan as an electrostatic self-assembling agent. Branched shells with different degrees of anisotropy and optical response were obtained by modulating the ratios of HAuCl4/K2CO3 growth solution, ascorbic acid (AA) and NP-seed precursor. Chitosan and AA were crucial in determining the BGNS size and structure, acting both as coreductants and structure directing growth agents. Preliminary cytotoxicity experiments point to the biocompatibility of the obtained BGNS, allowing their potential use in biomedical applications. In particular, these nanostructures with "hybrid" compositions, which combine the features of gold nanoshells and nanostars showed a better performance as surface enhanced Raman spectroscopy probes in detecting intracellular cell components than classical smoother nanoshells.

  13. Genetics Home Reference: surfactant dysfunction

    Science.gov (United States)

    ... Email Facebook Twitter Home Health Conditions Surfactant dysfunction Surfactant dysfunction Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Surfactant dysfunction is a lung disorder that causes breathing ...

  14. DNA compaction by azobenzene-containing surfactant

    International Nuclear Information System (INIS)

    Zakrevskyy, Yuriy; Kopyshev, Alexey; Lomadze, Nino; Santer, Svetlana; Morozova, Elena; Lysyakova, Ludmila; Kasyanenko, Nina

    2011-01-01

    We report on the interaction of cationic azobenzene-containing surfactant with DNA investigated by absorption and fluorescence spectroscopy, dynamic light scattering, and atomic force microscopy. The properties of the surfactant can be controlled with light by reversible switching of the azobenzene unit, incorporated into the surfactant tail, between a hydrophobic trans (visible irradiation) and a hydrophilic cis (UV irradiation) configuration. The influence of the trans-cis isomerization of the azobenzene on the compaction process of DNA molecules and the role of both isomers in the formation and colloidal stability of DNA-surfactant complexes is discussed. It is shown that the trans isomer plays a major role in the DNA compaction process. The influence of the cis isomer on the DNA coil configuration is rather small. The construction of a phase diagram of the DNA concentration versus surfactant/DNA charge ratio allows distancing between three major phases: colloidally stable and unstable compacted globules, and extended coil conformation. There is a critical concentration of DNA above which the compacted globules can be hindered from aggregation and precipitation by adding an appropriate amount of the surfactant in the trans configuration. This is because of the compensation of hydrophobicity of the globules with an increasing amount of the surfactant. Below the critical DNA concentration, the compacted globules are colloidally stable and can be reversibly transferred with light to an extended coil state.

  15. Rotor Field Oriented Control with adaptive Iron Loss Compensation

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Vadstrup, P.; Børsting, H.

    1999-01-01

    It is well known from the literature that iron loses in an induction motor implies field angle estimation errors and hence detuning problems. In this paper a new method for estimating the iron loss resistor in an induction motor is presented. The method is based on a traditional dynamic model...... of the motor referenced to the rotor magnetizing current, and with the extension of an iron loss resistor added in parallel to the magnetizing inductance. The resistor estimator is based on the observation that the actual applied stator voltages deviates from the voltage estimated, when a motor is current...

  16. Next Generation Surfactants for Improved Chemical Flooding Technology

    Energy Technology Data Exchange (ETDEWEB)

    Laura Wesson; Prapas Lohateeraparp; Jeffrey Harwell; Bor-Jier Shiau

    2012-05-31

    The principle objective of this project was to characterize and test current and next generation high performance surfactants for improved chemical flooding technology, focused on reservoirs in the Pennsylvanian-aged (Penn) sands. In order to meet this objective the characteristic curvatures (Cc) of twenty-eight anionic surfactants selected for evaluation for use in chemical flooding formulations were determined. The Cc values ranged from -6.90 to 2.55 with the majority having negative values. Crude oil samples from nine Penn sand reservoirs were analyzed for several properties pertinent to surfactant formulation for EOR application. These properties included equivalent alkane carbon numbers, total acid numbers, and viscosity. The brine samples from these same reservoirs were analyzed for several cations and for total dissolved solids. Surfactant formulations were successfully developed for eight reservoirs by the end of the project period. These formulations were comprised of a tertiary mixture of anionic surfactants. The identities of these surfactants are considered proprietary, but suffice to say the surfactants in each mixture were comprised of varying chemical structures. In addition to the successful development of surfactant formulations for EOR, there were also two successful single-well field tests conducted. There are many aspects that must be considered in the development and implementation of effective surfactant formulations. Taking into account these other aspects, there were four additional studies conducted during this project. These studies focused on the effect of the stability of surfactant formulations in the presence of polymers with an associated examination of polymer rheology, the effect of the presence of iron complexes in the brine on surfactant stability, the potential use of sacrificial agents in order to minimize the loss of surfactant to adsorption, and the effect of electrolytes on surfactant adsorption. In these last four studies

  17. On a multi-channel transportation loss system with controlled input and controlled service

    Directory of Open Access Journals (Sweden)

    Jewgeni Dshalalow

    1987-01-01

    Full Text Available A multi-channel loss queueing system is investigated. The input stream is a controlled point process. The service in each of m parallel channels depends on the state of the system at certain moments of time when input and service may be controlled. To obtain explicitly the limiting distribution of the main process (Zt (the number of busy channels in equilibrium, an auxiliary three dimensional process with two additional components (one of them is a semi-Markov process is treated as semi-regenerative process. An optimization problem is discussed. Simple expressions for an objective function are derived.

  18. Weight control behaviors of highly successful weight loss maintainers: the Portuguese Weight Control Registry.

    Science.gov (United States)

    Santos, Inês; Vieira, Paulo N; Silva, Marlene N; Sardinha, Luís B; Teixeira, Pedro J

    2017-04-01

    To describe key behaviors reported by participants in the Portuguese Weight Control Registry and to determine associations between these behaviors and weight loss maintenance. A total of 388 adults participated in this cross-sectional study. Assessments included demographic information, weight history, weight loss and weight maintenance strategies, dietary intake, and physical activity. Participants lost on average 18 kg, which they had maintained for ~28 months. Their average dietary intake was 2199 kcal/day, with 33 % of energy coming from fat. About 78 % of participants engaged in levels of moderate-plus-vigorous physical activity exceeding 150 min/week (51 % above 250 min/week), with men accumulating 82 more minutes than women (p breakfast. Greater weight loss maintenance was associated with higher levels of physical activity, walking, weight self-monitoring, establishing specific goals, and with reduced portion size use, reduced consumption of carbohydrates, and increased consumption of protein, (p < 0.05). Results indicate that weight loss maintenance is possible through the adoption of a nutritionally-balanced diet and regular participation in physical activity, but also suggest that adopting different (and, to a degree, individualized) set of behavioral strategies is key for achieving success.

  19. Fundamentals of surfactant sputtering

    International Nuclear Information System (INIS)

    Hofsaess, Hans; Zhang Kun

    2009-01-01

    We introduce a new sputter technique, utilizing the steady-state coverage of a substrate surface with up to 10 16 cm -2 of foreign atoms simultaneously during sputter erosion by combined ion irradiation and atom deposition. These atoms strongly modify the substrate sputter yield on atomic to macroscopic length scales and therefore act as surfactant atoms (a blend of 'surface active agent'). Depending on the surfactant-substrate combination, the novel technique allows enhanced surface smoothing, generation of novel surface patterns, shaping of surfaces and formation of ultra-thin films. Sputter yield attenuation is demonstrated for sputtering of Si and Fe substrates and different surfactant species using 5 keV Xe ions at different incidence angles and fluences up to 10 17 cm -2 . Analytical approaches and Monte Carlo simulations are used to predict the sputtering yield attenuation as function of surfactant coverage. For sputtering of Si with Au surfactants we observe high sputter yields despite a steady-state surfactant coverage, which can be explained by strong ion-induced interdiffusion of substrate and surfactant atoms and the formation of a buried Au x Si surfactant layer in dynamic equilibrium.

  20. Dynamic covalent surfactants

    NARCIS (Netherlands)

    Minkenberg, C.B.

    2012-01-01

    In this thesis the development of surfactant aggregates with fast exchange dynamics between the aggregated and non-aggregated state is described. Dynamic surfactant exchange plays an important role in natural systems, for instance in cell signaling, cell division, and uptake and release of cargo.

  1. Hybrid Electric Vehicle Control Strategy Based on Power Loss Calculations

    OpenAIRE

    Boyd, Steven J

    2006-01-01

    Defining an operation strategy for a Split Parallel Architecture (SPA) Hybrid Electric Vehicle (HEV) is accomplished through calculating powertrain component losses. The results of these calculations define how the vehicle can decrease fuel consumption while maintaining low vehicle emissions. For a HEV, simply operating the vehicle's engine in its regions of high efficiency does not guarantee the most efficient vehicle operation. The results presented are meant only to define a literal str...

  2. Controlling Mitochondrial Dynamics to Mitigate Noise-Induced Hearing Loss

    Science.gov (United States)

    2017-10-01

    the inner ear resulting from a single acute sound exposure. 15. SUBJECT TERMS Noise induced hearing loss, mitochondria, reactive oxygen species...application for a single loud sound exposure. Dates: 02/15/2016 – 08/14/2016 C. Major Task 3: Identify effective dosing regimen for intraperitoneal mdivi-1...ear canal mdivi-1 application for a single loud sound exposure. We have continued to make progress towards the completion of this Task that involves

  3. Determination of the Reliability of Product Quality Loss and Control ...

    African Journals Online (AJOL)

    Inconsistency in quality control is a major problem which plagues many indigenous firms in Nigeria. When product quality fluctuates, it negatively impacts on brand status, customer loyalty and confidence. The study was carried out to evaluate the best quality control practices for a brewing plant. Control charts were created ...

  4. The Effect of the Feedback Controller on Superconducting Tokamak AC Losses + AC-CRPP user manual

    International Nuclear Information System (INIS)

    Schaerz, B.; Bruzzone, P.; Favez, J.Y.; Lister, J.B.; Zapretilina, E.

    2001-11-01

    Superconducting coils in a Tokamak are subject to AC losses when the field transverse to the coil current varies. A simple model to evaluate the AC losses has been derived and benchmarked against a complete model used in the ITER design procedure. The influence of the feedback control strategy on the AC losses is examined using this model. An improved controller is proposed, based on this study. (author)

  5. Influence of controlled hypotension versus normotension on amount of blood loss during breast reduction.

    NARCIS (Netherlands)

    Kop, E.C.; Spauwen, P.H.M.; Kouwenberg, P.P.G.M.; Heymans, F.J.; Beem, H.B.H. van

    2009-01-01

    SUMMARY: Controlled hypotension employed during surgical procedures results in a beneficial reduction in blood loss during the operation. Breast reduction is a common cosmetic surgical procedure. Yet, in the Netherlands, controlled hypotension is not standard during breast reduction procedures, and

  6. Preventing Loss of Aircraft Control : Aiding pilots in manual recovery from roll-limited situations

    NARCIS (Netherlands)

    Koolstra, H.J.

    2017-01-01

    Loss of aircraft lateral control can be problem, specifically when multi engine propeller aircraft are faced with an engine failure. Another, less frequent phenomena is the loss of lateral control in case of aircraft damage. In this thesis, a method is developed to determine the minimum required

  7. A Multi-Layer Intelligent Loss-of-Control Prevention System (LPS) for Flight Control Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of the proposed work is to design and develop a multi-layer intelligent Loss-of-control Prevention System (LPS) for flight control applications....

  8. Weed flora, yield losses and weed control in cotton crop

    OpenAIRE

    Jabran, Khawar

    2016-01-01

    Cotton (Gossypium spp.) is the most important fiber crop of world and provides fiber, oil, and animals meals. Weeds interfere with the growth activities of cotton plants and compete with it for resources. All kinds of weeds (grasses, sedges, and broadleaves) have been noted to infest cotton crop. Weeds can cause more than 30% decrease in cotton productivity. Several methods are available for weed control in cotton. Cultural control carries significance for weed control up to a certain extent....

  9. Cycle-Induced Flow and Surfactant Transport in an Alveolus

    Science.gov (United States)

    Wei, H. H.

    2002-11-01

    The flow and transport in an alveolus are of fundamental importance to partial liquid ventilation, surfactant transport, pulmonary drug administration, cell-cell signaling pathways and gene therapy. We model the system in which an alveolus is partially filled with liquid in the presence of surfactants. Assuming a circular interface due to sufficiently strong surface tension, we can apply two-dimensional bipolar coordinates to describe the system. We then combine analytical and numerical techniques to solve the Stokes flow and the surfactant concentration. In the absence of surfactants, there is no steady streaming because of reversibility of the Stokes flow. The presence of surfactants however induces a non-trivial cycle-averaged surfactant concentration gradient along the interface that generates steady streaming. The steady streaming patterns (e.g., number of vortices) depend on the parameters, especially on the ratio of inspiration to expiration periods (I:E ratio). Either smaller or larger I:E ratio exhibits two primary vortices but the direction of primary vortices for small I:E is opposite to large I:E. Extension to soluble surfactants is also discussed. For sufficiently high surfactant bulk concentration, the surfactant transport is sorption-controlled and soluble surfactants diminish the size of steady vortices near the alveolar opening. For the estimated steady velocity u 10-5 cm/s, the corresponding Peclet number is 10-7/ D_m. Therefore, for Dm <= 10-7 cm^2/s, the convective transport dominates.

  10. Interaction effect of psychological distress and asthma control on productivity loss?

    Science.gov (United States)

    Moullec, Grégory; FitzGerald, J Mark; Rousseau, Roxanne; Chen, Wenjia; Sadatsafavi, Mohsen

    2015-06-01

    Little is known about the potential synergistic effect of comorbid psychological distress (PD) and uncontrolled asthma (UA) on productivity loss. We estimated the productivity loss associated with the combination of these two potentially preventable conditions in employed adults with asthma. A population-based random sample of 300 adults with asthma in British Columbia, Canada, was prospectively recruited between Dec 2010 and Aug 2012. PD and productivity loss due to absenteeism and presenteeism was measured using validated instruments, and asthma control was ascertained using 2010 Global Initiative for Asthma management strategy. We used two-part regression models to study the contribution of UA and PD to productivity loss. Compared with reference group (controlled asthma (CA)+noPD), those with UA+noPD had CAD$286 (95%CI $276-297) weekly productivity loss, and those with CA+PD had CAD$465 ($445-485). Those with UA+PD had CAD$449 (437-462) in productivity loss. There was no significant interaction effect of PD with asthma control levels on productivity loss (p=0.22). In patients without PD, uncontrolled asthma was associated with a higher productivity loss than controlled asthma, but this was not the case in patients with PD. This finding can be explained by the fact that the contribution of PD to productivity loss is so large that there is no room for synergy with asthma control. Future studies should assess the impact of interventions that modify PD in patients with asthma. Copyright ©ERS 2015.

  11. Surfactants in the environment.

    Science.gov (United States)

    Ivanković, Tomislav; Hrenović, Jasna

    2010-03-01

    Surfactants are a diverse group of chemicals that are best known for their wide use in detergents and other cleaning products. After use, residual surfactants are discharged into sewage systems or directly into surface waters, and most of them end up dispersed in different environmental compartments such as soil, water or sediment. The toxic effects of surfactants on various aquatic organisms are well known. In general, surfactants are present in the environment at levels below toxicity and in Croatia below the national limit. Most surfactants are readily biodegradable and their amount is greatly reduced with secondary treatment in wastewater treatment plants. The highest concern is the release of untreated wastewater or wastewater that has undergone primary treatment alone. The discharge of wastewater polluted with massive quantities of surfactants could have serious effects on the ecosystem. Future studies of surfactant toxicities and biodegradation are necessary to withdraw highly toxic and non-biodegradable compounds from commercial use and replace them with more environmentally friendly ones.

  12. A level-set method for two-phase flows with soluble surfactant

    Science.gov (United States)

    Xu, Jian-Jun; Shi, Weidong; Lai, Ming-Chih

    2018-01-01

    A level-set method is presented for solving two-phase flows with soluble surfactant. The Navier-Stokes equations are solved along with the bulk surfactant and the interfacial surfactant equations. In particular, the convection-diffusion equation for the bulk surfactant on the irregular moving domain is solved by using a level-set based diffusive-domain method. A conservation law for the total surfactant mass is derived, and a re-scaling procedure for the surfactant concentrations is proposed to compensate for the surfactant mass loss due to numerical diffusion. The whole numerical algorithm is easy for implementation. Several numerical simulations in 2D and 3D show the effects of surfactant solubility on drop dynamics under shear flow.

  13. Surfactant controlled low-temperature thermal decomposition route to zinc oxide nanorods from zinc(II) acetylacetonate monohydrate

    Energy Technology Data Exchange (ETDEWEB)

    Purkayastha, Debraj Dhar; Sarma, Bedabrat; Bhattacharjee, Chira R., E-mail: crbhattacharjee@rediffmail.com

    2014-10-15

    Zinc oxide (ZnO) nanorods were synthesized via a low-temperature thermal decomposition of zinc(II) acetylacetonate monohydrate, [Zn(C{sub 5}H{sub 7}O{sub 2}){sub 2}].H{sub 2}O. A relatively inexpensive surfactant, octadecylamine (C{sub 18}H{sub 37}NH{sub 2}) served both as a reaction solvent and a capping agent during the synthesis of ZnO nanorods. The synthesized nanorods were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), FT-IR, UV–visible, and photoluminescence (PL) studies. The XRD spectrum furnished evidence for the hexagonal wurtzite structure of ZnO. TEM images revealed the material to be rod shaped having diameter 30 nm and length 200 nm. The HRTEM image showed that the lattice fringes between the two adjacent planes are 0.244 nm apart, which corresponds to the interplanar separation of the (1 0 1) plane of hexagonal ZnO. The electron diffraction (ED) pattern confirmed the single crystalline nature of the nanorods. The PL spectrum showed two UV emissions at 356 nm (∼3.48 eV) and 382 nm (∼3.25 eV). ZnO nanorods also showed very weak blue bands at 445, 453 and 470 nm. - Highlights: Low temperature thermal decomposition of zinc(II) acetylacetonate monohydrate gave zinc oxide nanorods. Powder XRD showed hexagonal wurtzite structure of ZnO having average diameter about 24 nm. TEM images revealed the material to be of rod shape having diameter 30 nm and length 200 nm. ZnO showed band gap luminescence at 356 nm, excitonic emission at 382 nm and defect related blue bands. The synthesis is simple and can act as a paradigm for obtaining various metal oxide nanomaterials.

  14. Loss of Control Prevention and Recovery: Onboard Guidance, Control, and Systems Technologies

    Science.gov (United States)

    Belcastro, Christine M.

    2012-01-01

    Loss of control (LOC) is one of the largest contributors to fatal aircraft accidents worldwide. LOC accidents are complex in that they can result from numerous causal and contributing factors acting alone or (more often) in combination. These LOC hazards include vehicle impairment conditions, external disturbances; vehicle upset conditions, and inappropriate crew actions or responses. Hence, there is no single intervention strategy to prevent these accidents. NASA previously defined a comprehensive research and technology development approach for reducing LOC accidents and an associated integrated system concept. Onboard technologies for improved situation awareness, guidance, and control for LOC prevention and recovery are needed as part of this approach. Such systems should include: LOC hazards effects detection and mitigation; upset detection, prevention and recovery; and mitigation of combined hazards. NASA is conducting research in each of these areas. This paper provides an overview of this research, including the near-term LOC focus and associated analysis, as well as preliminary flight system architecture.

  15. Losses in chopper-controlled DC series motors

    Science.gov (United States)

    Hamilton, H. B.

    1982-01-01

    Motors for electric vehicle (EV) applications must have different features than dc motors designed for industrial applications. The EV motor application is characterized by the following requirements: (1) the need for highest possible efficiency from light load to overload, for maximum EV range, (2) large short time overload capability (The ratio of peak to average power varies from 5/1 in heavy city traffic to 3/1 in suburban driving situations) and (3) operation from power supply voltage levels of 84 to 144 volts (probably 120 volts maximum). A test facility utilizing a dc generator as a substitute for a battery pack was designed and utilized. Criteria for the design of such a facility are presented. Two motors, differing in design detail, commercially available for EV use were tested. Losses measured are discussed, as are waves forms and their harmonic content, the measurements of resistance and inductance, EV motor/chopper application criteria, and motor design considerations.

  16. Metathesis depolymerizable surfactants

    Science.gov (United States)

    Jamison, Gregory M [Albuquerque, NM; Wheeler, David R [Albuquerque, NM; Loy, Douglas A [Tucson, AZ; Simmons, Blake A [San Francisco, CA; Long, Timothy M [Evanston, IL; McElhanon, James R [Manteca, CA; Rahimian, Kamyar [Albuquerque, NM; Staiger, Chad L [Albuquerque, NM

    2008-04-15

    A class of surfactant molecules whose structure includes regularly spaced unsaturation in the tail group and thus, can be readily decomposed by ring-closing metathesis, and particularly by the action of a transition metal catalyst, to form small molecule products. These small molecules are designed to have increased volatility and/or enhanced solubility as compared to the original surfactant molecule and are thus easily removed by solvent extraction or vacuum extraction at low temperature. By producing easily removable decomposition products, the surfactant molecules become particularly desirable as template structures for preparing meso- and microstructural materials with tailored properties.

  17. Molecular simulation of surfactant-assisted protein refolding

    Science.gov (United States)

    Lu, Diannan; Liu, Zheng; Liu, Zhixia; Zhang, Minlian; Ouyang, Pingkai

    2005-04-01

    Protein refolding to its native state in vitro is a challenging problem in biotechnology, i.e., in the biomedical, pharmaceutical, and food industry. Protein aggregation and misfolding usually inhibit the recovery of proteins with their native states. These problems can be partially solved by adding a surfactant into a suitable solution environment. However, the process of this surfactant-assisted protein refolding is not well understood. In this paper, we wish to report on the first-ever simulations of surfactant-assisted protein refolding. For these studies, we defined a simple model for the protein and the surfactant and investigated how a surfactant affected the folding behavior of a two-dimensional lattice protein molecule. The model protein and model surfactant were chosen such that we could capture the important features of the folding process and the interaction between the protein and the surfactant, namely, the hydrophobic interaction. It was shown that, in the absence of surfactants, a protein in an "energy trap" conformation, i.e., a local energy minima, could not fold into the native form, which was characterized by a global energy minimum. The addition of surfactants created folding pathways via the formation of protein-surfactant complexes and thus enabled the conformations that fell into energy trap states to escape from these traps and to form the native proteins. The simulation results also showed that it was necessary to match the hydrophobicity of surfactant to the concentration of denaturant, which was added to control the folding or unfolding of a protein. The surfactants with different hydrophobicity had their own concentration range on assisting protein refolding. All of these simulations agreed well with experimental results reported elsewhere, indicating both the validity of the simulations presented here and the potential application of the simulations for the design of a surfactant on assisting protein refolding.

  18. On the rheology of mixed systems of hydrophobically modified polyacrylate microgels and surfactants: Role of the surfactant architecture.

    Science.gov (United States)

    Alves, Luís; Lindman, Björn; Klotz, Björn; Böttcher, Axel; Haake, Hans-Martin; Antunes, Filipe E

    2018-03-01

    The rheological control of suspensions is of key interest in the formulation design. A chemically cross-linked hydrophobically modified poly(acrylic acid) (HMCL-PAA), used as rheology modifier, is pH sensitive and shows swelling behavior above a critical pH due to the ionization of the acrylic acid groups. At low pH, HMCL-PAA suspensions are liquid and turbid. The binding of surfactants to HMCL-PAA, at low pH conditions, can result in significant changes on rheology and transparency of the polymeric suspensions, due to the swelling of the microgel particles. The influence of surfactants addition on the rheological properties and transparency of HMCL-PAA suspensions was determined. A systematic study was performed using different types of surfactants (ionic, non-ionic and zwitterionic). The gelation efficiency of HMCL-PAA suspensions at low pH is strongly dependent on surfactant architecture: ionic surfactants are found to be much more efficient than non-ionic or zwitterionic surfactants. Ionic surfactants lead to a liquid-to-gel transition accompanied by an increase of transparency of the suspensions. Among the ionic surfactants, anionics show stronger interactions with the polymer. Also the surfactant hydrophobicity is relevant; the more hydrophobic the surfactant, the stronger is the binding to the polymer and thus the larger the particle swelling. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Phosphine oxide surfactants revisited.

    Science.gov (United States)

    Stubenrauch, Cosima; Preisig, Natalie; Laughlin, Robert G

    2016-04-01

    This review summarizes everything we currently know about the nonionic surfactants alkyl dimethyl (C(n)DMPO) and alkyl diethyl (C(n)DEPO) phosphine oxide (PO surfactants). The review starts with the synthesis and the general properties (Section 2) of these compounds and continues with their interfacial properties (Section 3) such as surface tension, surface rheology, interfacial tension and adsorption at solid surfaces. We discuss studies on thin liquid films and foams stabilized by PO surfactants (Section 4) as well as studies on their self-assembly into lyotropic liquid crystals and microemulsions, respectively (Section 5). We aim at encouraging colleagues from both academia and industry to take on board PO surfactants whenever possible and feasible because of their broad variety of excellent properties. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Changes in weight control behaviors and hedonic hunger during a 12-week commercial weight loss program.

    Science.gov (United States)

    O'Neil, Patrick M; Theim, Kelly R; Boeka, Abbe; Johnson, Gail; Miller-Kovach, Karen

    2012-12-01

    Greater use of key self-regulatory behaviors (e.g., self-monitoring of food intake and weight) is associated with greater weight loss within behavioral weight loss treatments, although this association is less established within widely-available commercial weight loss programs. Further, high hedonic hunger (i.e., susceptibility to environmental food cues) may present a barrier to successful behavior change and weight loss, although this has not yet been examined. Adult men and women (N=111, body mass index M±SD=31.5±2.7kg/m(2)) were assessed before and after participating in a 12-week commercial weight loss program. From pre- to post-treatment, reported usage of weight control behaviors improved and hedonic hunger decreased, and these changes were inversely associated. A decrease in hedonic hunger was associated with better weight loss. An improvement in reported weight control behaviors (e.g., self-regulatory behaviors) was associated with better weight loss, and this association was even stronger among individuals with high baseline hedonic hunger. Findings highlight the importance of specific self-regulatory behaviors within weight loss treatment, including a commercial weight loss program developed for widespread community implementation. Assessment of weight control behavioral skills usage and hedonic hunger may be useful to further identify mediators of weight loss within commercial weight loss programs. Future interventions might specifically target high hedonic hunger and prospectively examine changes in hedonic hunger during other types of weight loss treatment to inform its potential impact on sustained behavior change and weight control. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Weight loss maintenance in relation to locus of control: The MedWeight study.

    Science.gov (United States)

    Anastasiou, Costas A; Fappa, Evaggelia; Karfopoulou, Eleni; Gkza, Anastasia; Yannakoulia, Mary

    2015-08-01

    Locus of control, i.e. the degree of an individual's belief on the control of his/her life, has been related to many health outcomes, including weight loss in overweight/obese individuals. No information is available on the impact of locus of control in maintaining weight loss. We aimed to investigate the effect of locus of control in weight loss maintenance and explore potential associations with lifestyle factors. Study participants included 239 individuals (41% males) who had lost at least 10% of body weight in the past and either maintained the loss (maintainers: weight maintenance of at least 10% of initial weight) or regained it (regainers). Locus of control was defined by a relevant multi-dimensional scale; participants were categorised to internals and externals, based on "internal" and "others" sub-scales. A significant interaction was found between locus of control and weight loss maintenance status (p locus of control. Individualised treatment, according to locus of control, may increase weight loss maintenance rates in former overweight/obese individuals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Reducing Runoff Loss of Applied Nutrients in Oil Palm Cultivation Using Controlled-Release Fertilizers

    Directory of Open Access Journals (Sweden)

    A. Bah

    2014-01-01

    Full Text Available Controlled-release fertilizers are expected to minimize nutrient loss from crop fields due to their potential to supply plant-available nutrients in synchrony with crop requirements. The evaluation of the efficiency of these fertilizers in tropical oil palm agroecological conditions is not yet fully explored. In this study, a one-year field trial was conducted to determine the impact of fertilization with water soluble conventional mixture and controlled-release fertilizers on runoff loss of nutrients from an immature oil palm field. Soil and nutrient loss were monitored for one year in 2012/2013 under erosion plots of 16 m2 on 10% slope gradient. Mean sediments concentration in runoff amounted to about 6.41 t ha−1. Conventional mixture fertilizer posed the greatest risk of nutrient loss in runoff following fertilization due to elevated nitrogen (6.97%, potassium (13.37%, and magnesium (14.76% as percentage of applied nutrients. In contrast, this risk decreased with the application of controlled-release fertilizers, representing 0.75–2.44% N, 3.55–5.09% K, and 4.35–5.43% Mg loss. Meanwhile, nutrient loss via eroded sediments was minimal compared with loss through runoff. This research demonstrates that the addition of controlled-release fertilizers reduced the runoff risks of nutrient loss possibly due to their slow-release properties.

  3. 40 CFR 52.246 - Control of dry cleaning solvent vapor losses.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control of dry cleaning solvent vapor losses. 52.246 Section 52.246 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... cleaning solvent vapor losses. (a) For the purpose of this section, “dry cleaning operation” means that...

  4. Identifying deficits in balance control following vestibular or proprioceptive loss using posturographic analysis of stance tasks.

    NARCIS (Netherlands)

    Horlings, C.G.; Kung, U.M.; Bloem, B.R.; Honegger, F.; Alfen, N. van; Engelen, B.G.M. van; Allum, J.H.

    2008-01-01

    OBJECTIVE: To distinguish between normal and deficient balance control due to vestibular loss (VL) or proprioceptive loss (PL) using pelvis and shoulder sway measures. METHODS: Body-worn gyroscopes measured pelvis and shoulder sway in pitch (anterior-posterior) and roll (side-to-side) directions in

  5. A Novelty Design Of Minimization Of Electrical Losses In A Vector Controlled Induction Machine Drive

    Science.gov (United States)

    Aryza, Solly; Irwanto, M.; Lubis, Zulkarnain; Putera Utama Siahaan, Andysah; Rahim, Robbi; Furqan, Mhd.

    2018-01-01

    The induction motor has in the industry . More attention has been a focus to develop and design of induction motor drive. With the method of vector control novelty prove the efficiency of induction motor over their entire speed range. In this paper desirable to design a loss minimization controller which can improve the efficiency. Also, this research described Modeling of an induction motor with core loss included. Realization of methods vector control for an induction motor drive with loss element included. The case of the loss minimization condition. The procedure was successful to calculate the gains of a PI controller. Though the problem of obtaining a robust and sensorless induction motor drive is by no means completely solved, the results obtained as part of this work point in a promising direction.

  6. Use Of Dynamic Distortion To Predict And Alleviate Loss Of Control, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The intent of this project is to develop and validate means to alert, constrain and thereby alleviate loss of control (LOC) associated with unfavorable pilot-vehicle...

  7. A packet loss compliant logic-based communication alogoritham for cooperative path following control

    Digital Repository Service at National Institute of Oceanography (India)

    Rego, F.; Aguiar, A.P.; Pascoal, A.M.

    We introduce an event driven communication logic for decentralized control of a network of robotic vehicles (agents). The strategy proposed is robust to packet losses and drives the vehicles to predefined paths while holding a desired geometric...

  8. Use Of Dynamic Distortion To Predict And Alleviate Loss Of Control, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Improvements to aviation safety will be made by the development and validation of means to alleviate, alert, and inhibit loss of control associated with unfavorable...

  9. Cohort Study of the Success of Controlled Weight Loss Programs for Obese Dogs.

    Science.gov (United States)

    German, A J; Titcomb, J M; Holden, S L; Queau, Y; Morris, P J; Biourge, V

    2015-01-01

    Most weight loss studies in obese dogs assess rate and percentage of weight loss in the first 2-3 months, rather than the likelihood of successfully reaching target weight. To determine outcome of controlled weight loss programs for obese dogs, and to determine the factors associated with successful completion. 143 obese dogs undergoing a controlled weight loss program. This was a cohort study of obese dogs attending a referral weight management clinic. Dogs were studied during their period of weight loss, and cases classified according to outcome as "completed" (reached target weight), "euthanized" (was euthanized before reaching target weight), or "stopped prematurely" (program stopped early for other reasons). Factors associated with successful completion were assessed using simple and multiple logistic regression. 87/143 dogs (61%) completed their weight loss program, 11 [8%] died or were euthanized, and the remaining 45 [32%] stopped prematurely. Reasons for dogs stopping prematurely included inability to contact owner, refusal to comply with weight management advice, or development of another illness. Successful weight loss was positively associated with a faster rate (P feeding a dried weight management diet (P = .010), but negatively associated with starting body fat (P dogs on a controlled weight loss program reach their target weight. Future studies should better clarify reasons for success in individual cases, and also the role of factors such as activity and behavioral modification. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  10. Rheology of cellulose nanofibrils in the presence of surfactants.

    Science.gov (United States)

    Quennouz, Nawal; Hashmi, Sara M; Choi, Hong Sung; Kim, Jin Woong; Osuji, Chinedum O

    2016-01-07

    Cellulose nanofibrils (CNFs) present unique opportunities for rheology modification in complex fluids. Here we systematically consider the effect of ionic and non-ionic surfactants on the rheology of dilute CNF suspensions. Neat suspensions are transparent yield-stress fluids which display strong shear thinning and power-law dependence of modulus on concentration, G' ∼ c(2.1). Surfactant addition below a critical mass concentration cc produces an increase in the gel modulus with retention of optical clarity. Larger than critical concentrations induce significant fibril aggregation leading to the loss of suspension stability and optical clarity, and to aggregate sedimentation. The critical concentration was the lowest for a cationic surfactant (DTAB), cc ≈ 0.08%, while suspension stability was retained for non-ionic surfactants (Pluronic F68, TX100) at concentrations up to 8%. The anionic surfactant SDS led to a loss of stability at cc ≈ 1.6% whereas suspension stability was not compromised by anionic SLES up to 8%. Dynamic light scattering data are consistent with a scenario in which gel formation is driven by micelle-nanofibril bridging mediated by associative interactions of ethoxylated surfactant headgroups with the cellulose fibrils. This may explain the strong difference between the properties of SDS and SLES-modified suspensions. These results have implications for the use of CNFs as a rheology modifier in surfactant-containing systems.

  11. Surfactants have multi-fold effects on skin barrier function.

    Science.gov (United States)

    Lemery, Emmanuelle; Briançon, Stéphanie; Chevalier, Yves; Oddos, Thierry; Gohier, Annie; Boyron, Olivier; Bolzinger, Marie-Alexandrine

    2015-01-01

    The stratum corneum (SC) is responsible for the barrier properties of the skin and the role of intercorneocyte skin lipids, particularly their structural organization, in controlling SC permeability is acknowledged. Upon contacting the skin, surfactants interact with the SC components leading to barrier damage. To improve knowledge of the effect of several classes of surfactant on skin barrier function at three different levels. The influence of treatments of human skin explants with six non-ionic and four ionic surfactant solutions on the physicochemical properties of skin was investigated. Skin surface wettability and polarity were assessed through contact angle measurements. Infrared spectroscopy allowed monitoring the SC lipid organization. The lipid extraction potency of surfactants was evaluated thanks to HPLC-ELSD assays. One anionic and one cationic surfactant increased the skin polarity by removing the sebaceous and epidermal lipids and by disturbing the organization of the lipid matrix. Another cationic surfactant displayed a detergency effect without disturbing the skin barrier. Several non-ionic surfactants disturbed the lipid matrix organization and modified the skin wettability without any extraction of the skin lipids. Finally two non-ionic surfactants did not show any effect on the investigated parameters or on the skin barrier. The polarity, the organization of the lipid matrix and the lipid composition of the skin allowed describing finely how surfactants can interact with the skin and disturb the skin barrier function.

  12. Impact of CD4 and CD8 dynamics and viral rebounds on loss of virological control in HIV controllers

    DEFF Research Database (Denmark)

    Chereau, Fanny; Madec, Yoann; Sabin, Caroline

    2017-01-01

    OBJECTIVE: HIV controllers (HICs) spontaneously maintain HIV viral replication at low level without antiretroviral therapy (ART), a small number of whom will eventually lose this ability to control HIV viremia. The objective was to identify factors associated with loss of virological control. MET...

  13. Privacy-preserving smart meter control strategy including energy storage losses

    OpenAIRE

    Avula, Chinni Venkata Ramana R.; Oechtering, Tobias J.; Månsson, Daniel

    2018-01-01

    Privacy-preserving smart meter control strategies proposed in the literature so far make some ideal assumptions such as instantaneous control without delay, lossless energy storage systems etc. In this paper, we present a one-step-ahead predictive control strategy using Bayesian risk to measure and control privacy leakage with an energy storage system. The controller estimates energy state using a three-circuit energy storage model to account for steady-state energy losses. With numerical exp...

  14. "The effects of polysorbate surfactants on the structure of mucus Glycoproteins "

    Directory of Open Access Journals (Sweden)

    Sajadi Tabassi A

    2001-07-01

    Full Text Available A dynamic oscillatory technique was used to assess the effect of polysorbate non-ionic surfactants on mucus rheology. Adherent mucus gel was scraped from the surface mucosa of pig stomachs and purified by gel exclusion chromatography followed by ultrafiltration and gelation. Rheological measurements of this gel were carried out on a Carri-Med Controlled Stress Rheometer. Appropriate volumes of surfactant solution were added to weighed samples of mucus gel so that a final concentration of 20 mM surfactant was achieved in a gel containing 8% w/w solids content. Polysorbate 20 (PS20, polysorbate 40 (PS40, polysorbate 60 (PS60 and polysorbate 80 (PS80 all decreased both storage (elastic modulus G’ and loss (viscous modulus G’’ significantly at 10 Hz (PPS20>PS60>PS40. The mechanisms by which surfactants disturb the mucus structure are not fully understood, nonetheless, they could possibly affect the mucus gel properties by causing depletion of the glycoprotein constituents such as non-mucin proteins and mucin associated lipids. This might lead to the conclusion that polysorbates, by reducing the viscoelasticity of mucus gel could alleviate its barrier properties and facilitate the diffusion of concomitantly administered drugs via mucus gel.

  15. Food irradiation in the control of storage and handling losses in the Philippine onions and garlic

    International Nuclear Information System (INIS)

    Lustre, A.O.; Dianco, A.M.; Vito, F.R.; Manalastas, Z.L.

    1996-01-01

    Information will be provided on the nature and magnitude of the control of postharvest losses in onions and garlic from the application of irradiation. Control of losses is measured in storage and during post storage marketing of the commodities. Information will also be presented on market tests and survey of consumer reaction to irradiated onions. The benefits of irradiation will be discussed in relation to the need to reduce postharvest losses in the food supply and to address consumer concerns over the safety of food due to the use of chemicals. (author)

  16. Control of Refrigeration Systems for Trade-off between Energy Consumption and Food Quality Loss

    DEFF Research Database (Denmark)

    Cai, Junping

    In supermarkets, control strategies determine both the energy consumption of refrigeration systems and the quality loss of refrigerated foodstuffs. The question is, what can be done to optimize the balance between quality loss and energy consumption? This thesis tries to answer this question by a...... strategy is through utilization of the thermal mass of the refrigerated foodstuffs, the day-night temperature variation and the capacity control of the compressor, to realize a trade-off between system energy consumption and food quality loss....

  17. Intratracheal atomized surfactant provides similar outcomes as bolus surfactant in preterm lambs with respiratory distress syndrome.

    Science.gov (United States)

    Milesi, Ilaria; Tingay, David G; Zannin, Emanuela; Bianco, Federico; Tagliabue, Paolo; Mosca, Fabio; Lavizzari, Anna; Ventura, Maria Luisa; Zonneveld, C Elroy; Perkins, Elizabeth J; Black, Don; Sourial, Magdy; Dellacá, Raffaele L

    2016-07-01

    Aerosolization of exogenous surfactant remains a challenge. This study is aimed to evaluate the efficacy of atomized poractant alfa (Curosurf) administered with a novel atomizer in preterm lambs with respiratory distress syndrome. Twenty anaesthetized lambs, 127 ± 1 d gestational age, (mean ± SD) were instrumented before birth and randomized to receive either (i) positive pressure ventilation without surfactant (Control group), (ii) 200 mg/kg of bolus instilled surfactant (Bolus group) at 10 min of life or (iii) 200 mg/kg of atomized surfactant (Atomizer group) over 60 min from 10 min of life. All lambs were ventilated for 180 min with a standardized protocol. Lung mechanics, regional lung compliance (electrical impedance tomography), and carotid blood flow (CBF) were measured with arterial blood gas analysis. Dynamic compliance and oxygenation responses were similar in the Bolus and Atomizer groups, and both better than Control by 180 min (all P < 0.05; two-way ANOVA). Both surfactant groups demonstrated more homogeneous regional lung compliance throughout the study period. There were no differences in CBFConclusion:In a preterm lamb model, atomized surfactant resulted in similar gas exchange and mechanics as bolus administration. This study suggests evaluation of supraglottic atomization with this system when noninvasive support is warranted.

  18. Relative Humidity Controls Ammonia Loss from Urea Applied to Loblolly Pine

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera, Miguel L.; Kissel, David E.; Craig, J. R.; Qafoku, Nikolla; Vaio, N.; Rema, John A.; Morris, Larry A.

    2010-04-01

    In the United States of America, approximately 600,000 ha of southern pine are fertilized with urea each year, with NH3 volatilization losses ranging from <1% to >50% depending on environmental conditions. Previous work showed that timing of rainfall after urea application plays a significant role in controlling NH3 loss, but the effect of other environmental variables is not well understood. We conducted ten 29-d studies under different environmental conditions during two years to identify important variables controlling NH3 loss from urea applied to loblolly pine (Pinus taeda L.) at 200 kg N ha-1. Ammonia loss was measured with dynamic chambers that adjusted the rate of air flow through the system based on wind speed at 1 cm above the soil surface. Regression analysis indicated that a variable related to initial water content of the forest floor and a variable related to relative humidity (RH) during the study explained 85 to 94% of the observed variability in NH3 loss. Relatively high initial water content followed by consistently high RH led to large NH3 losses. In contrast, low initial water contents resulted in slow rates of NH3 loss, which increased when elevated RH led to an increase in the water content of the forest floor. These results indicate that RH can play a significant role in NH3 loss by accelerating urea dissolution and by increasing or decreasing the water content of the forest floor, which in turn can affect the rate of urea hydrolysis.

  19. Evolution of surfactant therapy for respiratory distress syndrome: past, present, and future.

    Science.gov (United States)

    Sardesai, Smeeta; Biniwale, Manoj; Wertheimer, Fiona; Garingo, Arlene; Ramanathan, Rangasamy

    2017-01-01

    Respiratory distress syndrome (RDS) due to surfactant deficiency is the most common cause of respiratory failure in preterm infants. Tremendous progress has been made since the original description that surfactant deficiency is the major cause of RDS. Surfactant therapy has been extensively studied in preterm infants and has been shown to significantly decrease air leaks and neonatal and infant mortality. Synthetic and animal-derived surfactants from bovine as well as porcine origin have been evaluated in randomized controlled trials. Animal-derived surfactants generally result in faster weaning of respiratory support, shorter duration of invasive ventilation, and decreased mortality when compared to first- or second-generation of synthetic surfactants, but some of the second-generation synthetic surfactants are at least not inferior to the animal-derived surfactants. Using a higher initial dose of porcine derived surfactant may provide better outcomes when compared with using lower doses of bovine surfactants, likely, due to compositional difference and/or the dose. Third-generation synthetic surfactant containing peptide analogs of surfactant protein B and C are currently being studied. Less invasive intra-tracheal surfactant administration techniques in spontaneously breathing neonate receiving noninvasive ventilator support are also being evaluated. In the present era, prophylactic surfactant is not recommended as it may increase the risk of lung injury or death. In the future, surfactants may be used as vector to deliver steroids, or used in combination with molecules, such as, recombinant Club Cell Protein-10 (rhCC-10) to improve pulmonary outcomes. Also, noninvasive surfactant administration techniques, such as aerosolization or atomization of surfactant may play a greater role in the future.

  20. Surface shear inviscidity of soluble surfactants.

    Science.gov (United States)

    Zell, Zachary A; Nowbahar, Arash; Mansard, Vincent; Leal, L Gary; Deshmukh, Suraj S; Mecca, Jodi M; Tucker, Christopher J; Squires, Todd M

    2014-03-11

    Foam and emulsion stability has long been believed to correlate with the surface shear viscosity of the surfactant used to stabilize them. Many subtleties arise in interpreting surface shear viscosity measurements, however, and correlations do not necessarily indicate causation. Using a sensitive technique designed to excite purely surface shear deformations, we make the most sensitive and precise measurements to date of the surface shear viscosity of a variety of soluble surfactants, focusing on SDS in particular. Our measurements reveal the surface shear viscosity of SDS to be below the sensitivity limit of our technique, giving an upper bound of order 0.01 μN·s/m. This conflicts directly with almost all previous studies, which reported values up to 10(3)-10(4) times higher. Multiple control and complementary measurements confirm this result, including direct visualization of monolayer deformation, for SDS and a wide variety of soluble polymeric, ionic, and nonionic surfactants of high- and low-foaming character. No soluble, small-molecule surfactant was found to have a measurable surface shear viscosity, which seriously undermines most support for any correlation between foam stability and surface shear rheology of soluble surfactants.

  1. Foaming behaviour of polymer-surfactant solutions

    International Nuclear Information System (INIS)

    Cervantes-MartInez, Alfredo; Maldonado, Amir

    2007-01-01

    We study the effect of a non-ionic amphiphilic polymer (PEG-100 stearate also called Myrj 59) on the foaming behaviour of aqueous solutions of an anionic surfactant (sodium dodecyl sulfate or SDS). The SDS concentration was kept fixed while the Myrj 59 concentration was varied. Measurements of foamability, surface tension and electrical conductivity were carried out. The results show two opposite effects depending on the polymer concentration: foamability is higher when the Myrj 59 concentration is low; however, it decreases considerably when the polymer concentration is increased. This behaviour is due to the polymer adsorption at the air/liquid interface at lower polymer concentrations, and to the formation of a polymer-surfactant complex in the bulk at higher concentrations. The results are confirmed by surface tension and electrical conductivity measurements, which are interpreted in terms of the microstructure of the polymer-surfactant solutions. The observed behaviour is due to the amphiphilic nature of the studied polymer. The increased hydrophobicity of Myrj 59, compared to that of water-soluble polymers like PEG or PEO, increases its 'reactivity' towards SDS, i.e. the strength of its interaction with this anionic surfactant. Our results show that hydrophobically modified polymers have potential applications as additives in order to control the foaming properties of surfactant solutions

  2. History of Weight Control Attempts Among Adolescent Girls with Loss of Control Eating

    Science.gov (United States)

    Vannucci, Anna; Shomaker, Lauren B.; Field, Sara E.; Sbrocco, Tracy; Stephens, Mark; Kozlosky, Merel; Reynolds, James C.; Yanovski, Jack A.; Tanofsky-Kraff, Marian

    2013-01-01

    Objective Loss of control (LOC) eating and a weight control attempt (WCA) history during adolescence are important behavioral risk factors for eating disorders and obesity. The current study investigated the significance of the presence of a WCA history among adolescent girls with LOC eating. Methods Participants were 114 obesity prevention-seeking 12–17-year-old (M=14.5, SD=1.7 years) girls who were between the 75th and 97th body mass index (BMI) percentile (BMI-z: M=1.5, SD=0.3) and reported LOC eating episodes during the previous month (M=4.0, SD=4.9 episodes; Median=2.0). Measures included the Eating Disorder Examination to assess LOC eating, eating pathology, and WCA history, and self-report questionnaires for symptoms of general psychopathology. Eating behavior was observed during a laboratory meal designed to capture a LOC eating episode. Results 67.5% reported a WCA history. As compared to girls without a WCA history (no-WCA), those with a WCA history (WCA) had greater disordered eating attitudes and depressive symptoms (ps.10). During the laboratory meal, WCA consumed less energy from snack-type foods than no-WCA (M=245.0, SD=156.1 vs. M=341.6, SD=192.3 kcal; p=.01). Conclusions Reported WCAs are highly prevalent and are associated with greater psychopathology symptoms among adolescent girls with LOC eating. Prospective data are needed to determine whether these overlapping risk behaviors confer differential vulnerability for developing eating disorders and obesity. PMID:23815764

  3. History of weight control attempts among adolescent girls with loss of control eating.

    Science.gov (United States)

    Vannucci, Anna; Shomaker, Lauren B; Field, Sara E; Sbrocco, Tracy; Stephens, Mark; Kozlosky, Merel; Reynolds, James C; Yanovski, Jack A; Tanofsky-Kraff, Marian

    2014-05-01

    Loss of control (LOC) eating and a weight control attempt (WCA) history during adolescence are important behavioral risk factors for eating disorders and obesity. The current study investigated the significance of the presence of a WCA history among adolescent girls with LOC eating. Participants were 114 obesity-prevention-seeking 12-17-year-old (M = 14.5, SD = 1.7 years) girls who were between the 75th and 97th body mass index (BMI) percentile (BMI-z: M = 1.5, SD = 0.3) and reported LOC eating episodes during the previous month (M = 4.0, SD = 4.9 episodes; Median = 2.0). Measures included the Eating Disorder Examination to assess LOC eating, eating pathology, and WCA history, and self-report questionnaires for symptoms of general psychopathology. Eating behavior was observed during a laboratory meal designed to capture a LOC eating episode. 67.5% reported a WCA history. As compared to girls without a WCA history (no-WCA), those with a WCA history (WCA) had greater disordered eating attitudes and depressive symptoms (ps frequency (ps > .10). During the laboratory meal, WCA consumed less energy from snack-type foods than no-WCA (M = 245.0, SD = 156.1 vs. M = 341.6, SD = 192.3 kcal; p = .01). Reported WCAs are highly prevalent and are associated with greater psychopathology symptoms among adolescent girls with LOC eating. Prospective data are needed to determine whether these overlapping risk behaviors confer differential vulnerability for developing eating disorders and obesity. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  4. Data loss for PLC of nonlinear systems Iterative Learning Control Algorithm

    Directory of Open Access Journals (Sweden)

    Zhang Yinjun

    2016-01-01

    Full Text Available When we use power line as data carrier, due to the complexity of the PLC network environment, data packet loss frequently, so the paper deal with the iterative learning control for a class of nonlinear systems with measurement dropouts in the PLC, and studies the P-type iterative learning control algorithm convergence issues, the data packet loss is described as a stochastic Bernoulli process, on this basis we given convergence conditions for the P-type iterative learning control algorithm. The theoretically analysis is supported by the simulation of a numerical example; the convergence of ILC can be guaranteed when some output measurements are missing.

  5. Hearing Loss, Control, and Demographic Factors Influencing Hearing Aid Use among Older Adults.

    Science.gov (United States)

    Garstecki, Dean C.; Erler, Susan F.

    1998-01-01

    Older adults (N=131) with hearing loss completed measures of hearing, hearing handicap, psychological control, depression, and ego strength. Older adults who accepted advice from hearing professionals to acquire and use hearing aids differed from those not accepting such advice on measures of hearing sensitivity, psychological control, and…

  6. Preferred descriptions for loss of control while eating and weight among patients with binge eating disorder.

    Science.gov (United States)

    Roberto, Christina A; Galbraith, Katharine; Lydecker, Janet A; Ivezaj, Valentina; Barnes, Rachel D; White, Marney A; Grilo, Carlos M

    2016-12-30

    Patients with binge eating disorder (BED) typically also have excess weight, making them vulnerable to stigmatizing attitudes about mental illness and obesity. Further, one of the diagnostic features of BED is experiencing a loss of control during binge eating episodes. It is possible that patients feel negatively judged when clinicians assess for loss of control as it may activate stereotypes of patients with obesity lacking willpower. We developed a questionnaire to assess preferences for common loss of control descriptions and gathered data on preferences for weight-related terms among 46 patients with BED. Analyses revealed the majority of common descriptors for loss of control eating were viewed neutrally, with loss of control being the most preferred term. Descriptions suggesting patients were addicted to food or did not consider stopping eating once they started binge eating were viewed negatively. The following weight descriptions were viewed negatively: heaviness, large size, obesity, excess fat, and fatness. Terms such as BMI, and unhealthy body weight or BMI were viewed more favorably and weight was the most preferred term. These findings provide empirical support for healthcare providers' use of terms to use and terms to avoid when talking to patients with BED about eating and weight. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Expanded findings from a randomized controlled trial of preconception low-dose aspirin and pregnancy loss.

    Science.gov (United States)

    Mumford, Sunni L; Silver, Robert M; Sjaarda, Lindsey A; Wactawski-Wende, Jean; Townsend, Janet M; Lynch, Anne M; Galai, Noya; Lesher, Laurie L; Faraggi, David; Perkins, Neil J; Schliep, Karen C; Zarek, Shvetha M; Schisterman, Enrique F

    2016-03-01

    What is the association between daily preconception-initiated low-dose aspirin (LDA) treatment and very early pregnancy losses or euploid (chromosomally normal) losses among women with one to two prior losses? Daily LDA initiated preconception was not associated with the rate or type of pregnancy loss among women with a history of one to two prior pregnancy losses. LDA is often used to treat recurrent pregnancy loss with reductions in pregnancy loss generally only observed among women with antiphospholipid antibodies, and null associations observed among women without antiphospholipid antibodies. We previously evaluated the association between LDA and pregnancy loss overall among women with one to two prior losses in the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial and found no association, though did not distinguish between potential effects at different stages of pregnancy loss, including implantation failure, or between euploid and aneuploid losses. The EAGeR trial was a multi-site prospective block-randomized double-blind placebo-controlled trial. In total, 1228 women were randomized to daily LDA (81 mg/day) plus folic acid (400 mcg/day), or placebo plus folic acid. Participants were assigned study drug for less than or equal to six menstrual cycles or if they conceived, throughout pregnancy with study drug discontinued at 36 weeks gestation. This analysis includes additional outcome information obtained from chart abstractions after the completion of the trial, as well as testing of stored urine for measurement of hCG and detection of very early pregnancy losses, and karyotyping of the products of conception for assessment of aneuploidy of the losses. Women aged 18-40 with a history of one to two prior losses and actively trying to conceive were randomized (n = 615 LDA and n = 613 placebo) at four clinical centers in the USA (2007-2011). Log-binomial regression was used to estimate risk ratios under the intent-to-treat approach. Daily LDA

  8. Motivation by potential gains and losses affects control processes via different mechanisms in the attentional network.

    Science.gov (United States)

    Paschke, Lena M; Walter, Henrik; Steimke, Rosa; Ludwig, Vera U; Gaschler, Robert; Schubert, Torsten; Stelzel, Christine

    2015-05-01

    Attentional control in demanding cognitive tasks can be improved by manipulating the motivational state. Motivation to obtain gains and motivation to avoid losses both usually result in faster reaction times and stronger activation in relevant brain areas such as the prefrontal cortex, but little is known about differences in the underlying neurocognitive mechanisms of these types of motivation in an attentional control context. In the present functional magnetic resonance imaging (fMRI) study, we tested whether potential gain and loss as motivating incentives lead to overlapping or distinct neural effects in the attentional network, and whether one of these conditions is more effective than the other. A Flanker task with word stimuli as targets and distracters was performed by 115 healthy participants. Using a mixed blocked and event-related design allowed us to investigate transient and sustained motivation-related effects. Participants could either gain money (potential gain) or avoid losing money (potential loss) in different task blocks. Participants showed a congruency effect with increased reaction times for incongruent compared to congruent trials. Potential gain led to generally faster responses compared to the neutral condition and to stronger improvements than potential loss. Potential loss also led to shorter response times compared to the neutral condition, but participants improved mainly during incongruent and not during congruent trials. The event-related fMRI data revealed a main effect of congruency with increased activity in the left inferior frontal gyrus (IFG) and inferior frontal junction area (IFJ), the pre-supplementary motor area (pre-SMA), bilateral insula, intraparietal sulcus (IPS) and visual word form area (VWFA). While potential gain led to increased activity in a cluster of the IFJ and the VWFA only during incongruent trials, potential loss was linked to activity increases in these regions during incongruent and congruent trials. The

  9. Influence of surfactant concentration on nanohydroxyapatite growth

    Indian Academy of Sciences (India)

    Nanohydroxyapatite particles with different morphologies were synthesized through a microwave coupled hydrothermal method using CTAB as a template. A successful synthesis of nanosized HAP spheres, rods and fibres is achieved through this method by controlling the concentration of the surfactant. The concentration ...

  10. Influence of surfactant concentration on nanohydroxyapatite growth

    Indian Academy of Sciences (India)

    Abstract. Nanohydroxyapatite particles with different morphologies were synthesized through a microwave cou- pled hydrothermal method using CTAB as a template. A successful synthesis of nanosized HAP spheres, rods and fibres is achieved through this method by controlling the concentration of the surfactant.

  11. Influence of surfactant concentration on nanohydroxyapatite growth

    Indian Academy of Sciences (India)

    4Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 012, India. MS received 17 ... fibres is achieved through this method by controlling the concentration of the surfactant. The concentration of the ... shown that many clinical applications of HAp mainly depend on shape ...

  12. Asthma and obesity: does weight loss improve asthma control? a systematic review

    Directory of Open Access Journals (Sweden)

    Juel CTB

    2012-06-01

    Full Text Available Caroline Trunk-Black Juel,1 Zarqa Ali,1 Lisbeth Nilas,2 Charlotte Suppli Ulrik11Respiratory Section, Internal Medicine Unit, 2Department of Obstetrics and Gynaecology, Hvidovre Hospital and University of Copenhagen, Hvidovre, DenmarkAim and methods: Obesity is a major health problem, and obesity is associated with a high incidence of asthma and poor asthma control. The aim of the present paper is to systematically review the current knowledge of the effect on overall asthma control of weight reduction in overweight and obese adults with asthma.Results: Weight loss in obese individuals with doctor-diagnosed asthma is associated with a 48%–100% remission of asthma symptoms and use of asthma medication. Published studies, furthermore, reveal that weight loss in obese asthmatics improves asthma control, and that especially surgically induced weight loss results in significant improvements in asthma severity, use of asthma medication, dyspnoea, exercise tolerance, and acute exacerbations, including hospitalizations due to asthma. Furthermore, weight loss in obese asthmatics is associated with improvements in level of lung function and airway responsiveness to inhaled methacholine, whereas no significant improvements have been observed in exhaled nitric oxide or other markers of eosinophilic airway inflammation.Conclusion: Overweight and obese adults with asthma experience a high symptomatic remission rate and significant improvements in asthma control, including objective measures of disease activity, after weight loss. Although these positive effects of weight loss on asthma-related health outcomes seem not to be accompanied by remission or improvements in markers of eosinophilic airway inflammation, it has potentially important implications for the future burden of asthma.Keywords: asthma, weight loss, diet, bariatric surgery, asthma control

  13. Development of improved mobility control agents for surfactant/polymer flooding. First annual report, September 29, 1978-September 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.D.

    1980-05-01

    Phase 1: Based on a literature survey and input solicited from industry, academic, and government sources, inadequacies of the currently used mobility control materials were assessed. Phase 2: Baseline screening of commercially available polymers began in January 1979. Rheological measurements and mobility control test in Berea cores have been completed on Dow Pusher 700, Betz Hi Vis, Nalco Nal-flo, Cyanamid 960S, Kelco Xanflood, and Abbott Xanthan Broth. Similar tests were completed for Pusher 500, Pusher 1000, Amoco Sweepaid 103, and Pfizer Flocon Biopolymer 1035. Shear degradation tests in Berea core plugs have been completed for one acrylamide-type polymer and one xanthan polymer in 0.3% NaCl. Similar tests in 3% NaCl plus 0.3% CaCl/sub 2/ are in progress. Viscosity and screen factor data have been collected for most of the commercially available polymers. Long-term thermal stability tests with one polyacrylamide polymer and one xanthan polymer have been initiated. Phase 3: The polymer synthesis phase of the program is in progress. A series of N-alkyl (N-methyl, N-isopropyl, and N-butyl) acrylamide homopolymers and copolymers with acrylic acid has been synthesized. Variations of the substituents on the acrylamide nitrogen atom did not substantially change the properties of the parent compound. Increasing the molecular weight tends to impart increased shear sensitivity. Degree of hydrolysis also affects performance of the modified polymer. 25 figures, 40 tables.

  14. Improved oil production using economical biopolymer-surfactant blends for profile modification and mobility control. Final report, November 1998

    Energy Technology Data Exchange (ETDEWEB)

    Gabitto, J. [Prairie View A and M Univ., TX (United States); Barrufet, M.A.; Burnett, D.B. [Texas A and M Univ., College Station, TX (United States)

    1998-12-01

    In the past, starch hydrocolloids have not been effective alternates to partially hydrolyzed polyacrylamides, copolymers, and xanthan gum polymers as water shutoff agents in fractures and in matrix flow configurations. Poor injectivity and questionable stability have usually prevented their use in profile control applications. However, in recent years, the demands of the oil and gas drilling industry have led to the development of new drilling, drill-in, and completion fluids with improved functionality. New types of modified starches have contributed to these new drill in fluid (DIF) products. It was felt that the properties of the new products would lend themselves to applications in improved recovery. The objective of this project has been to evaluate the use of agricultural starch biopolymers for gelled and polymer applications in oil recovery processes. The authors believe that there is great potential for finding new functional starch products because of their chemical and structural flexibility, low cost, and wide availability. The goals of this project have been, therefore, to systematically investigate how the physical properties and chemical composition of relatively inexpensive agricultural starch products will influence their use as effective selective permeability control agents or as gels for water shut-off.

  15. Commercial weight loss diets meet nutrient requirements in free living adults over 8 weeks: a randomised controlled weight loss trial.

    Science.gov (United States)

    Truby, Helen; Hiscutt, Rebecca; Herriot, Anne M; Stanley, Manana; Delooy, Anne; Fox, Kenneth R; Baic, Susan; Robson, Paula J; Macdonald, Ian; Taylor, Moira A; Ware, Robert; Logan, Catherine; Livingstone, Mbe

    2008-09-02

    To investigate the effect of commercial weight loss programmes on macronutrient composition and micronutrient adequacy over a 2 month period. Adults were randomly allocated to follow the Slim Fast Plan, Weight Watchers Pure Points Programme, Dr Atkins' New Diet Revolution, or Rosemary Conley's "Eat Yourself Slim" Diet & Fitness Plan. A multi-centre randomised controlled trial. 293 adults, mean age 40.3 years and a mean BMI 31.7 (range 27-38) were allocated to follow one of the four diets or control group. Subjects completed a 7-day food and activity diary at baseline (prior to randomisation) and after 2 months. Diet records were analysed for nutrient composition using WinDiets (research version). A significant shift in the macronutrient composition of the diet with concurrent alteration of the micronutrient profile was apparent with all diets. There was no evidence to suggest micronutrient deficiency in subjects on any of the dietary regimens. However, those sub-groups with higher needs for specific micronutrients, such as folate, iron or calcium may benefit from tailored dietary advice. The diets tested all resulted in considerable macronutrient change and resulted in an energy deficit indicating dietary compliance. Health professionals and those working in community and public health should be reassured of the nutritional adequacy of the diets tested. NCT00327821.

  16. Commercial weight loss diets meet nutrient requirements in free living adults over 8 weeks: A randomised controlled weight loss trial

    Directory of Open Access Journals (Sweden)

    Macdonald Ian

    2008-09-01

    Full Text Available Abstract Objective To investigate the effect of commercial weight loss programmes on macronutrient composition and micronutrient adequacy over a 2 month period. Design Adults were randomly allocated to follow the Slim Fast Plan, Weight Watchers Pure Points Programme, Dr Atkins' New Diet Revolution, or Rosemary Conley's "Eat Yourself Slim" Diet & Fitness Plan. Setting A multi-centre randomised controlled trial. Subjects 293 adults, mean age 40.3 years and a mean BMI 31.7 (range 27–38 were allocated to follow one of the four diets or control group. Subjects completed a 7-day food and activity diary at baseline (prior to randomisation and after 2 months. Diet records were analysed for nutrient composition using WinDiets (research version. Results A significant shift in the macronutrient composition of the diet with concurrent alteration of the micronutrient profile was apparent with all diets. There was no evidence to suggest micronutrient deficiency in subjects on any of the dietary regimens. However, those sub-groups with higher needs for specific micronutrients, such as folate, iron or calcium may benefit from tailored dietary advice. Conclusion The diets tested all resulted in considerable macronutrient change and resulted in an energy deficit indicating dietary compliance. Health professionals and those working in community and public health should be reassured of the nutritional adequacy of the diets tested. Trial Registration Number NCT00327821

  17. Diseases of Pulmonary Surfactant Homeostasis

    Science.gov (United States)

    Whitsett, Jeffrey A.; Wert, Susan E.; Weaver, Timothy E.

    2015-01-01

    Advances in physiology and biochemistry have provided fundamental insights into the role of pulmonary surfactant in the pathogenesis and treatment of preterm infants with respiratory distress syndrome. Identification of the surfactant proteins, lipid transporters, and transcriptional networks regulating their expression has provided the tools and insights needed to discern the molecular and cellular processes regulating the production and function of pulmonary surfactant prior to and after birth. Mutations in genes regulating surfactant homeostasis have been associated with severe lung disease in neonates and older infants. Biophysical and transgenic mouse models have provided insight into the mechanisms underlying surfactant protein and alveolar homeostasis. These studies have provided the framework for understanding the structure and function of pulmonary surfactant, which has informed understanding of the pathogenesis of diverse pulmonary disorders previously considered idiopathic. This review considers the pulmonary surfactant system and the genetic causes of acute and chronic lung disease caused by disruption of alveolar homeostasis. PMID:25621661

  18. Animal derived surfactant extract versus protein free synthetic surfactant for the prevention and treatment of respiratory distress syndrome.

    Science.gov (United States)

    Ardell, Stephanie; Pfister, Robert H; Soll, Roger

    2015-08-24

    A wide variety of surfactant preparations have been developed and tested including synthetic surfactants and surfactants derived from animal sources. Although clinical trials have demonstrated that both synthetic surfactant and animal derived surfactant preparations are effective, comparison in animal models has suggested that there may be greater efficacy of animal derived surfactant products, perhaps due to the protein content of animal derived surfactant. To compare the effect of animal derived surfactant to protein free synthetic surfactant preparations in preterm infants at risk for or having respiratory distress syndrome (RDS). Searches were updated of the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2014), PubMed, CINAHL and EMBASE (1975 through November 2014). All languages were included. Randomized controlled trials comparing administration of protein free synthetic surfactants to administration of animal derived surfactant extracts in preterm infants at risk for or having respiratory distress syndrome were considered for this review. Data collection and analysis were conducted according to the standards of the Cochrane Neonatal Review Group. Fifteen trials met the inclusion criteria. The meta-analysis showed that the use of animal derived surfactant rather than protein free synthetic surfactant resulted in a significant reduction in the risk of pneumothorax [typical relative risk (RR) 0.65, 95% CI 0.55 to 0.77; typical risk difference (RD) -0.04, 95% CI -0.06 to -0.02; number needed to treat to benefit (NNTB) 25; 11 studies, 5356 infants] and a marginal reduction in the risk of mortality (typical RR 0.89, 95% CI 0.79 to 0.99; typical RD -0.02, 95% CI -0.04 to -0.00; NNTB 50; 13 studies, 5413 infants).Animal derived surfactant was associated with an increase in the risk of necrotizing enterocolitis [typical RR 1.38, 95% CI 1.08 to 1.76; typical RD 0.02, 95% CI 0.01 to 0.04; number needed to treat to harm (NNTH) 50; 8

  19. A Hybrid Optimization Method for Reactive Power and Voltage Control Considering Power Loss Minimization

    DEFF Research Database (Denmark)

    Liu, Chengxi; Qin, Nan; Bak, Claus Leth

    2015-01-01

    This paper proposes a hybrid optimization method to optimally control the voltage and reactive power with minimum power loss in transmission grid. This approach is used for the Danish automatic voltage control (AVC) system which is typically a non-linear non-convex problem mixed with both...... in the global range. This approach is tested on the detailed model of the western Danish power system in DIgSILENT Powerfactory, where massive discrete components i.e. tap-able transformers and switchable shunts are employed by AVC for loss minimizations....

  20. Model predictive control of non-linear systems over networks with data quantization and packet loss.

    Science.gov (United States)

    Yu, Jimin; Nan, Liangsheng; Tang, Xiaoming; Wang, Ping

    2015-11-01

    This paper studies the approach of model predictive control (MPC) for the non-linear systems under networked environment where both data quantization and packet loss may occur. The non-linear controlled plant in the networked control system (NCS) is represented by a Tagaki-Sugeno (T-S) model. The sensed data and control signal are quantized in both links and described as sector bound uncertainties by applying sector bound approach. Then, the quantized data are transmitted in the communication networks and may suffer from the effect of packet losses, which are modeled as Bernoulli process. A fuzzy predictive controller which guarantees the stability of the closed-loop system is obtained by solving a set of linear matrix inequalities (LMIs). A numerical example is given to illustrate the effectiveness of the proposed method. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  1. Effects of manipulating eating frequency during a behavioral weight loss intervention: a pilot randomized controlled trial.

    Science.gov (United States)

    Bachman, Jessica L; Raynor, Hollie A

    2012-05-01

    Eating frequency has been inversely related to BMI but the impact of eating frequency on weight loss is unclear. This randomized controlled trial pilot study examined the effect of eating frequency on hunger, energy intake, and weight loss during a 6-month behavioral weight loss intervention. Participants (age: 51.0 ± 9.9 years, BMI: 35.5 ± 4.8 kg/m(2), 57.8% female, 94.1% white) were randomized to one of two eating frequency prescriptions: Three meal (n = 25): three eating bouts/day; or grazing (n = 26): eat at least 100 kcals every 2-3 h. Both groups attended 20 sessions and had identical dietary (1,200-1,500 kcals/day, frequency than three meal at 6 months (5.8 ± 1.1 eating bouts/day vs. 3.2 ± 0.6 eating bouts/day, P weight loss intervention.

  2. Abnormal SDS-PAGE migration of cytosolic proteins can identify domains and mechanisms that control surfactant binding

    Science.gov (United States)

    Shi, Yunhua; Mowery, Richard A; Ashley, Jonathan; Hentz, Michelle; Ramirez, Alejandro J; Bilgicer, Basar; Slunt-Brown, Hilda; Borchelt, David R; Shaw, Bryan F

    2012-01-01

    The amino acid substitution or post-translational modification of a cytosolic protein can cause unpredictable changes to its electrophoretic mobility during SDS-PAGE. This type of “gel shifting” has perplexed biochemists and biologists for decades. We identify a mechanism for “gel shifting” that predominates among a set of ALS (amyotrophic lateral sclerosis) mutant hSOD1 (superoxide dismutase) proteins, post-translationally modified hSOD1 proteins, and homologous SOD1 proteins from different organisms. By first comparing how 39 amino acid substitutions throughout hSOD1 affected SDS-PAGE migration, we found that substitutions that caused gel shifting occurred within a single polyacidic domain (residues ∼80–101), and were nonisoelectric. Substitutions that decreased the net negative charge of domain 80–101 increased migration; only one substitution increased net negative charge and slowed migration. Capillary electrophoresis, circular dichroism, and size exclusion chromatography demonstrated that amino acid substitutions increase migration during SDS-PAGE by promoting the binding of three to four additional SDS molecules, without significantly altering the secondary structure or Stokes radius of hSOD1-SDS complexes. The high negative charge of domain 80–101 is required for SOD1 gel shifting: neutralizing the polyacidic domain (via chimeric mouse-human SOD1 fusion proteins) inhibited amino acid substitutions from causing gel shifting. These results demonstrate that the pattern of gel shifting for mutant cytosolic proteins can be used to: (i) identify domains in the primary structure that control interactions between denatured cytosolic proteins and SDS and (ii) identify a predominant chemical mechanism for the interaction (e.g., hydrophobic vs. electrostatic). PMID:22692797

  3. Scheme for improving laser stability via feedback control of intracavity nonlinear loss.

    Science.gov (United States)

    Jin, Pixian; Lu, Huadong; Su, Jing; Peng, Kunchi

    2016-05-01

    We present a novel and efficient scheme to enhance the stability of laser output via feedback control to a nonlinear loss deliberately introduced to the laser resonator. By means of the feedback control to the intracavity nonlinear loss of an all-solid-state continuous-wave single-frequency laser with high output power at 1064 nm, its intensity and frequency stabilities are significantly improved. A lithium triborate crystal is deliberately placed inside the laser resonator to be an element of the nonlinear loss, and the temperature of the crystal is feedback controlled by an electronic loop. The control signal is generated by distinguishing the deviation of the output power and used for manipulating the intracavity nonlinear loss to compensate the deviation of the laser power actively. With the feedback-control loop, the intensity and frequency fluctuations of the output laser at 1064 nm are reduced from ±0.59% and 21.82 MHz without the feedback to ±0.26% and 9.84 MHz, respectively.

  4. Coacervation with surfactants: From single-chain surfactants to gemini surfactants.

    Science.gov (United States)

    Zhao, Weiwei; Wang, Yilin

    2017-01-01

    Coacervation is a spontaneous process during which a colloidal dispersion separates into two immiscible liquid phases: a colloid-rich liquid phase in equilibrium with a diluted phase. Coacervation is usually divided into simple coacervation and complex coacervation according to the number of components. Surfactant-based coacervation normally contains traditional single-chain surfactants. With the development of surfactants, gemini surfactants with two amphiphilic moieties have been applied to form coacervation. This review summarizes the development of simple coacervation and complex coacervation in the systems of single-chain surfactants and gemini surfactants. Simple coacervation in surfactant solutions with additives or at elevated temperature and complex coacervation in surfactant/polymer mixtures by changing charge densities, molecular weight, ionic strength, pH, or temperature are reviewed. The comparison between gemini surfactants and corresponding monomeric single-chain surfactants reveals that the unique structures of gemini surfactants endow them with higher propensity to generate coacervation. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. A smartphone-supported weight loss program: design of the ENGAGED randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Pellegrini Christine A

    2012-11-01

    Full Text Available Abstract Background Obesity remains a major public health challenge, demanding cost-effective and scalable weight management programs. Delivering key treatment components via mobile technology offers a potential way to reduce expensive in-person contact, thereby lowering the cost and burden of intensive weight loss programs. The ENGAGED study is a theory-guided, randomized controlled trial designed to examine the feasibility and efficacy of an abbreviated smartphone-supported weight loss program. Methods/design Ninety-six obese adults (BMI 30–39.9 kg/m2 will be randomized to one of three treatment conditions: (1 standard behavioral weight loss (STND, (2 technology-supported behavioral weight loss (TECH; or (3 self-guided behavioral weight loss (SELF. All groups will aim to achieve a 7% weight loss goal by reducing calorie and fat intake and progressively increasing moderate intensity physical activity to 175 minutes/week. STND and TECH will attend 8 group sessions and receive regular coaching calls during the first 6 months of the intervention; SELF will receive the Group Lifestyle Balance Program DVD’s and will not receive coaching calls. During months 1–6, TECH will use a specially designed smartphone application to monitor dietary intake, body weight, and objectively measured physical activity (obtained from a Blue-tooth enabled accelerometer. STND and SELF will self-monitor on paper diaries. Linear mixed modeling will be used to examine group differences on weight loss at months 3, 6, and 12. Self-monitoring adherence and diet and activity goal attainment will be tested as mediators. Discussion ENGAGED is an innovative weight loss intervention that integrates theory with emerging mobile technologies. We hypothesize that TECH, as compared to STND and SELF, will result in greater weight loss by virtue of improved behavioral adherence and goal achievement. Trial registration NCT01051713

  6. Ethics of Placebo Control in Trials for Idiopathic Sudden Sensorineural Hearing Loss.

    Science.gov (United States)

    Maldonado Fernández, Miguel; Kornetsky, Susan; Rubio Rodriguez, Laura

    2016-07-01

    Idiopathic sudden sensorineural hearing loss (ISSHL) involves sudden loss of hearing from cochlear or retrocochlear origin of unknown cause. Systemic corticosteroids may be considered in the management of ISSNHL. However, an updated Cochrane systematic review concludes that "the value of steroids in the treatment of idiopathic sudden sensorineural hearing loss remains unclear since the evidence obtained from randomized controlled trials is contradictory in outcome." Therefore, a new clinical trial that addresses this question is mandatory. A first step in its design is to determine if placebo control would be ethically acceptable. We conclude that there is equipoise (uncertainty) about the use of corticosteroids for ISSHL. A new trial is justified-but with the inclusion of interim analyses to detect early imbalances on efficacy or safety and with the ability to stop the trial if needed. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

  7. Surfactant therapy in late preterm infants

    Directory of Open Access Journals (Sweden)

    Murat Yurdakök

    2013-06-01

    randomized, controlled studies and evidence-based guidelines are needed for optimal surfactant therapy in these infants. Proceedings of the 9th International Workshop on Neonatology · Cagliari (Italy · October 23rd-26th, 2013 · Learned lessons, changing practice and cutting-edge research

  8. Low eddy loss axial hybrid magnetic bearing with gimballing control ability for momentum flywheel

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jiqiang, E-mail: tjq_72@163.com [School of Instrument Science and Opto-electronics Engineering, Beihang University, Beijing 100191 (China); Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Sun, Jinji; Fang, Jiancheng [School of Instrument Science and Opto-electronics Engineering, Beihang University, Beijing 100191 (China); Shuzhi Sam, Ge [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore)

    2013-03-15

    For a magnetically suspended momentum flywheel (MSMF), the spinning rotor can be tilted by a pair of the presented axial hybrid magnetic bearing (AHMB) with eight poles and rotates around the radial axes to generate a large torque to maneuver the spacecraft. To improve the control performance and gimballing control ability of the AHMB, characteristics such as magnetic suspension force, angular stiffness and tilting momentum are researched. These segmented stator poles cause the magnetic density in the thrust rotor plate to be uneven unavoidably and the rotational loss is large at high speed, but we optimized the stator poles configuration and caused the thrust rotor plate formed by bulk DT4C and laminated material to make the magnetic density in the thrust rotor plate change less and be smoother. Laminated material such as 1J50 film with a thickness of 0.1 mm can make the variation of the magnetic density in DT4C become very small and the eddy loss of it be negligible, but the stress produced in the 'O' shape stacks by reeling has a bad effect on its power loss. Nanocrystalline can reduce eddy losses and is not affected by the reeling process. Based on the AHBM consisting of the stator with eight improved poles and the presented thrust rotor plate with DT4 and nanocrystalline, the rotational loss of 5-DOF magnetically suspended momentum flywheel with angular momentum of 15 N m s at 5000 rpm has reduced from 23.4 W to 3.2 W, which proved that this AHMB has low eddy loss for the gimballing control ability. - Highlights: Black-Right-Pointing-Pointer Control methods of rotor driven by AHMBs and their characteristics are researched. Black-Right-Pointing-Pointer Optimized stator and rotor of AHMB reduce its eddy losses greatly. Black-Right-Pointing-Pointer Presented the factors affecting the eddy losses of AHMBs. Black-Right-Pointing-Pointer The good performances of AHMB with low eddy loss are proved by experiments.

  9. Developmental Regulation with Progressive Vision Loss: Use of Control Strategies and Affective Well-Being

    Science.gov (United States)

    Schilling, Oliver K.; Wahl, Hans-Werner; Boerner, Kathrin; Horowitz, Amy; Reinhardt, Joann P.; Cimarolli, Verena R.; Brennan-Ing, Mark; Heckhausen, Jutta

    2016-01-01

    The present study addresses older adults' developmental regulation when faced with progressive and irreversible vision loss. We used the motivational theory of life span development as a conceptual framework and examined changes in older adults' striving for control over everyday goal achievement, and their association with affective well-being,…

  10. Risk factors for sensorineural hearing loss in NICU infants compared to normal hearing NICU controls

    NARCIS (Netherlands)

    Coenraad, S.; Goedegebure, A.; van Goudoever, J. B.; Hoeve, L. J.

    2010-01-01

    To evaluate independent etiologic factors associated with sensorineural hearing loss in infants who have been admitted to the neonatal intensive care unit compared to normal hearing controls. Between 2004 and 2009, 3366 infants were admitted to the neonatal intensive care unit of Sophia Children's

  11. Comparison of the Efficacy of Three Natural Surfactants (Curosurf, Survanta, and Alveofact) in the Treatment of Respiratory Distress Syndrome Among Neonates: A Randomized Controlled Trial

    Science.gov (United States)

    Mussavi, Mirhadi; Mirnia, Keyvan; Asadollahi, Khairollah

    2016-01-01

    Background Although several different types of natural surfactants are available, including Alveofact, Curosurf, and Survanta, the preferred type and the magnitude of their effects are unknown. Objectives This study was designed to compare the effects of these three surfactants on the gas exchange and clinical outcomes of neonates with respiratory distress syndrome (RDS). Methods This triple-blind randomized clinical trial studied all preterm neonates ≤ 37 weeks with RDS who were admitted to the neonatal intensive care unit (NICU) of Taleghani hospital (Tabriz, Iran) between 2012 and 2013. The patients were divided into three groups, each of which received one of these surfactants. The incidences of ventilator dependency, patent ductus arteriosus (PDA), broncho-pulmonary dysplasia (BPD), retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH), hospital-stay length, and continuous positive airway pressure (CPAP) failure, as well as blood gas levels, were recorded as endpoint measurements and compared. Results In total, 165 neonates of gestational age ≤ 37 weeks with RDS were examined. Neonates were allocated to three different groups randomly, including a Survanta group (n = 49), a Curosurf group (n = 62), and an Alveofact group (n = 54). The mean gestational age of the neonates was 31.6 ± 3.7 weeks, and their mean weight was 1,840 ± 790 grams. The male/female ratio was 2:1 (67% male, 33% female); 104 (63%) neonates were ≤ 32 weeks gestational age, and 61 (37%) were >32 weeks. There were no significant differences for gender or demographic characteristics among the neonates in relation to the type of applied surfactant. According to the clinical parameters (BPD, IVH, ROP, hospital-stay length, and mechanical ventilation requirement), no significant differences were observed between the groups before and after surfactant administration, but the differences between the Survanta and Alveofact groups for the incidence rates of pneumothorax (P = 0

  12. Economic design of bar X & S control charts based on Taguchi's loss function and its optimization

    Science.gov (United States)

    Guo, Yu; Yang, Wen'an; Liao, Wenhe; Gao, Shiwen

    2012-05-01

    Much research effort has been devoted to economic design of bar X & S control charts, however, there are some problems in usual methods. On the one hand, it is difficult to estimate the relationship between costs and other model parameters, so the economic design method is often not effective in producing charts that can quickly detect small shifts before substantial losses occur; on the other hand, in many cases, only one type of process shift or only one pair of process shifts are taken into consideration, which may not correctly reflect the actual process conditions. To improve the behavior of economic design of control chart, a cost & loss model with Taguchi's loss function for the economic design of bar X & S control charts is embellished, which is regarded as an optimization problem with multiple statistical constraints. The optimization design is also carried out based on a number of combinations of process shifts collected from the field operation of the conventional control charts, thus more hidden information about the shift combinations is mined and employed to the optimization design of control charts. At the same time, an improved particle swarm optimization (IPSO) is developed to solve such an optimization problem in design of bar X & S control charts, IPSO is first tested for several benchmark problems from the literature and evaluated with standard performance metrics. Experimental results show that the proposed algorithm has significant advantages on obtaining the optimal design parameters of the charts. The proposed method can substantially reduce the total cost (or loss) of the control charts, and it will be a promising tool for economic design of control charts.

  13. Considering linear generator copper losses on model predictive control for a point absorber wave energy converter

    International Nuclear Information System (INIS)

    Montoya Andrade, Dan-El; Villa Jaén, Antonio de la; García Santana, Agustín

    2014-01-01

    Highlights: • We considered the linear generator copper losses in the proposed MPC strategy. • We maximized the power transferred to the generator side power converter. • The proposed MPC increases the useful average power injected into the grid. • The stress level of the PTO system can be reduced by the proposed MPC. - Abstract: The amount of energy that a wave energy converter can extract depends strongly on the control strategy applied to the power take-off system. It is well known that, ideally, the reactive control allows for maximum energy extraction from waves. However, the reactive control is intrinsically noncausal in practice and requires some kind of causal approach to be applied. Moreover, this strategy does not consider physical constraints and this could be a problem because the system could achieve unacceptable dynamic values. These, and other control techniques have focused on the wave energy extraction problem in order to maximize the energy absorbed by the power take-off device without considering the possible losses in intermediate devices. In this sense, a reactive control that considers the linear generator copper losses has been recently proposed to increase the useful power injected into the grid. Among the control techniques that have emerged recently, the model predictive control represents a promising strategy. This approach performs an optimization process on a time prediction horizon incorporating dynamic constraints associated with the physical features of the power take-off system. This paper proposes a model predictive control technique that considers the copper losses in the control optimization process of point absorbers with direct drive linear generators. This proposal makes the most of reactive control as it considers the copper losses, and it makes the most of the model predictive control, as it considers the system constraints. This means that the useful power transferred from the linear generator to the power

  14. Weight loss, nutritional status and physical activity in patients with Alzheimer's disease. A controlled study.

    Science.gov (United States)

    Wang, Pei-Ning; Yang, Chueh-Lien; Lin, Ker-Neng; Chen, Wei-Ta; Chwang, Leh-Chii; Liu, Hsiu-Chih

    2004-03-01

    The etiology of weight loss in Alzheimer's disease (AD) patients is still uncertain. This study was designed to investigate the possible factors that might contribute to weight change of AD patients. From July 1999 to June 2001, we recruited 51 AD patients and 27 non-demented controls. Demographic data, neuropsychological tests, Geriatric Depression Scale-Short Form, eating behavior questionnaire, dietary and physical activity diaries, anthropometric and laboratory measures of nutritional status were assessed. More than half of our AD patients developed body weight loss, and overall, the AD patients were significantly thinner than the non-demented subjects. Anthropometric and laboratory measures suggested a poorer nutritional status in the AD patients. The AD patients had fewer daily physical activities. More AD patients had the problem of poor appetite. However, daily calorie intake was not significantly different between the two groups. The AD patients, especially those who presented with body weight loss, even consumed more calories per body weight kilogram (kg) per day. In the food composition analysis, AD patients took more carbohydrate than controls. Multivariate regression analysis showed the existence of AD and poor appetite were the main risk factors of weight loss. We suggest that the pathophysiological process in AD gives rise to the changes of appetite and metabolic state in AD patients, and that these changes contribute to the weight loss.

  15. A parametric AC loss model of the ITER coils for control optimization

    CERN Document Server

    Marinucci, C; Bottura, L

    2010-01-01

    A recent study on AC loss calculation in different operating regimes of relevance for ITER plasma control has shown that AC loss calculations can be performed on a model with a level of complexity and completeness not achieved so far {[}L. Bottura, P Bruzzone, J.B. Lister, C Marinucci, A Portone, Computation of AC losses in the ITER magnets during fast field transients, IEEE Trans Appl Supercond 17 (2) (2007) 2438-2441] The model developed is however too large and computationally expensive for the inclusion in a fast control optimization procedure For this reason a second study was launched aiming at developing a simplified calculation method. The simplified calculation method described here that provides faster estimates of AC loss in the ITER coils The method is based on a Fourier decomposition of the field excitation, calculation for each Fourier component, and sum over all frequencies to estimate the total loss associated with a given current waveform Typical accuracy that can be reached is of the order o...

  16. Weight loss technology for people with treated type 2 diabetes: a randomized controlled trial.

    Science.gov (United States)

    Oshakbayev, Kuat; Dukenbayeva, Bibazhar; Togizbayeva, Gulnar; Durmanova, Aigul; Gazaliyeva, Meruyert; Sabir, Abdul; Issa, Aliya; Idrisov, Alisher

    2017-01-01

    The prevalence of type 2 diabetes is increasing in worldwide despite the development of new treatment methods. Aim of the study was to evaluate a weight loss method on body composition, glycemic, lipid and hormone profiles, blood pressure and reactive oxygen species in people with treated type 2 diabetes. A 24-week open, prospective, randomized, controlled clinical trial including 272 adult patients with treated type 2 diabetes was performed. The patients were divided in two groups: Main group consisted of 208 patients who followed a method including a calorie restriction diet and optimal physical activity; Control included 64 patients who received conventional drug treatment with weight loss. Main Outcome Measures were weight loss, fasting glucose and 2-hour oral glucose tolerance test (OGTT), HbA1c. Secondary endpoints were blood pressure, lipid and insulin blood levels. At 24 weeks, patients in Main weight lost between 8-18 kg (10-21%); their body mass index significantly decreased (-4.2 kg/m2) as well as their waist circumference (-13 cm) compared to Control. In Main weight loss was achieved fatty mass reduction. In Main fasting glucose and OGTT, HbA1c, blood pressure, reactive oxygen species decreased significantly, whereas hemoglobin levels and heel bone mineral density increased. In Main blood insulin levels decreased by 72.0%, cortisol levels decreased by 40.7%, while testosterone levels in men increased by 2.4 times from baseline. The application of the weight loss method led to a decrease in drug doses leading to their complete withdrawal. The results of this study show the beneficial role of a weight loss method in improving glycemic, lipid and hormone profiles, electrolyte and biochemical indices, blood pressure, reactive oxygen species and bone mineral density in patients with treated type 2 diabetes. ClinicalTrials.gov Identifier: NCT02503865. Retrospectively registered November 2015.

  17. Surfactant protein-D predicts prognosis of interstitial lung disease induced by anticancer agents in advanced lung cancer: a case control study.

    Science.gov (United States)

    Nakamura, Kota; Kato, Motoyasu; Shukuya, Takehito; Mori, Keita; Sekimoto, Yasuhito; Ihara, Hiroaki; Kanemaru, Ryota; Ko, Ryo; Shibayama, Rina; Tajima, Ken; Koyama, Ryo; Shimada, Naoko; Nagashima, Osamu; Takahashi, Fumiyuki; Sasaki, Shinichi; Takahashi, Kazuhisa

    2017-05-02

    Interstitial lung diseases induced by anticancer agents (ILD-AA) are rare adverse effects of anticancer therapy. However, prognostic biomarkers for ILD-AA have not been identified in patients with advanced lung cancer. Our aim was to analyze the association between serum biomarkers sialylated carbohydrate antigen Krebs von den Lungen-6 (KL-6) and surfactant protein D (SP-D), and clinical characteristics in patients diagnosed with ILD-AA. Between April 2011 and March 2016, 1224 advanced lung cancer patients received cytotoxic agents and epidermal growth factor receptor tyrosine kinase inhibitors at Juntendo University Hospital and Juntendo University Urayasu Hospital. Of these patients, those diagnosed with ILD-AA were enrolled in this case control study. ΔKL-6 and ΔSP-D were defined as the difference between the levels at the onset of ILD-AA and their respective levels prior to development of ILD-AA. We evaluated KL-6 and SP-D at the onset of ILD-AA, ΔKL-6 and ΔSP-D, the risk factors for death related to ILD-AA, the chest high resolution computed tomography (HRCT) findings, and survival time in patients diagnosed with ILD-AA. Thirty-six patients diagnosed with ILD-AA were enrolled in this study. Among them, 14 patients died of ILD-AA. ΔSP-D in the patients who died was significantly higher than that in the patients who survived. However, ΔKL-6 did not differ significantly between the two groups. Moreover, ΔSP-D in patients who exhibited diffuse alveolar damage was significantly higher than that in the other patterns on HRCT. Receiver operating characteristic curve analysis was used to set the optimal cut off value for ΔSP-D at 398 ng/mL. Survival time for patients with high ΔSP-D (≥ 398 ng/mL) was significantly shorter than that for patients with low ΔSP-D. Multivariate analysis revealed that ΔSP-D was a significant prognostic factor of ILD-AA. This is the first research to evaluate high ΔSP-D (≥ 398 ng/mL) in patients with ILD-AA and to

  18. MICROBIAL SURFACTANTS. I. GLYCOLIPIDS

    Directory of Open Access Journals (Sweden)

    Pirog T. Р.

    2014-02-01

    Full Text Available The review is devoted to surface-active glycolipids. The general characteristics, the physiological role of the rhamnolipids, trehalose lipids, sophorolipids, mannosylerythritol lipids and their traditional producers — the representatives of the genera Pseudozyma, Pseudomonas, Rhodococcus and Candida are given. The detailed analysis of the chemical structure, the stages of the biosynthesis and the regulation of some low molecular glycolipids are done. The own experimental data concerning the synthesis intensification, the physiological role and the practical use of Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 surfactants, which are a complex of the glyco-, phospho-, amino- and neutral lipids (glycolipids of all strains are presented by trehalose mycolates are summarized. It was found that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants have protective, antimicrobial and antiadhesive properties. It was shown that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants preparation of cultural liquid intensified the degradation of oil in water due to the activation of the natural petroleum-oxidizing microflora.

  19. Surfactants at the Design Limit.

    Science.gov (United States)

    Czajka, Adam; Hazell, Gavin; Eastoe, Julian

    2015-08-04

    This article analyzes how the individual structural elements of surfactant molecules affect surface properties, in particular, the point of reference defined by the limiting surface tension at the aqueous cmc, γcmc. Particular emphasis is given to how the chemical nature and structure of the hydrophobic tails influence γcmc. By comparing the three different classes of surfactants, fluorocarbon, silicone, and hydrocarbon, a generalized surface packing index is introduced which is independent of the chemical nature of the surfactants. This parameter ϕcmc represents the volume fraction of surfactant chain fragments in a surface film at the aqueous cmc. It is shown that ϕcmc is a useful index for understanding the limiting surface tension of surfactants and can be useful for designing new superefficient surfactants.

  20. Early pest development and loss of biological control are associated with urban warming.

    Science.gov (United States)

    Meineke, Emily K; Dunn, Robert R; Frank, Steven D

    2014-11-01

    Climate warming is predicted to cause many changes in ectotherm communities, one of which is phenological mismatch, wherein one species' development advances relative to an associated species or community. Phenological mismatches already lead to loss of pollination services, and we predict that they also cause loss of biological control. Here, we provide evidence that a pest develops earlier due to urban warming but that phenology of its parasitoid community does not similarly advance. This mismatch is associated with greater egg production that likely leads to more pests on trees. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  1. Controlled synthesis of La1−xSrxCrO3 nanoparticles by hydrothermal method with nonionic surfactant and their ORR activity in alkaline medium

    International Nuclear Information System (INIS)

    Choi, Bo Hyun; Park, Shin-Ae; Park, Bong Kyu; Chun, Ho Hwan; Kim, Yong-Tae

    2013-01-01

    Graphical abstract: We demonstrate that Sr-doped LaCrO 3 nanoparticles were successfully prepared by the hydrothermal synthesis method using the nonionic surfactant Triton X-100 and the applicability of La 1−x Sr x CrO 3 to oxygen reduction reaction (ORR) electrocatalysis in an alkaline medium. Compared with the nanoparticles synthesized by the coprecipitation method, they showed enhanced ORR activity. - Highlights: • Sr-doped LaCrO 3 nanoparticles were successfully prepared by the hydrothermal method using the nonionic surfactant. • Homogeneously shaped and sized Sr-doped LaCrO 3 nanoparticles were readily obtained. • Compared with the nanoparticles synthesized by the coprecipitation method, they showed an enhanced ORR activity. • The main origin was revealed to be the decreased particle size due to the nonionic surfactant. - Abstract: Sr-doped LaCrO 3 nanoparticles were prepared by the hydrothermal method with the nonionic surfactant Triton X-100 followed by heat treatment at 1000 °C for 10 h. The obtained perovskite nanoparticles had smaller particle size (about 100 nm) and more uniform size distribution than those synthesized by the conventional coprecipitation method. On the other hand, it was identified with the material simulation that the electronic structure change by Sr doping was negligible, because the initially unfilled e g -band was not affected by the p-type doping. Finally, the perovskite nanoparticles synthesized by hydrothermal method showed much higher ORR activity by over 200% at 0.8 V vs. RHE than those by coprecipitation method

  2. Aircraft Loss-of-Control Accident Prevention: Switching Control of the GTM Aircraft with Elevator Jam Failures

    Science.gov (United States)

    Chang, Bor-Chin; Kwatny, Harry G.; Belcastro, Christine; Belcastro, Celeste

    2008-01-01

    Switching control, servomechanism, and H2 control theory are used to provide a practical and easy-to-implement solution for the actuator jam problem. A jammed actuator not only causes a reduction of control authority, but also creates a persistent disturbance with uncertain amplitude. The longitudinal dynamics model of the NASA GTM UAV is employed to demonstrate that a single fixed reconfigured controller design based on the proposed approach is capable of accommodating an elevator jam failure with arbitrary jam position as long as the thrust control has enough control authority. This paper is a first step towards solving a more comprehensive in-flight loss-of-control accident prevention problem that involves multiple actuator failures, structure damages, unanticipated faults, and nonlinear upset regime recovery, etc.

  3. Studies on interfacial tension and contact angle of synthesized surfactant and polymeric from castor oil for enhanced oil recovery

    Science.gov (United States)

    Babu, Keshak; Pal, Nilanjan; Bera, Achinta; Saxena, V. K.; Mandal, Ajay

    2015-10-01

    New synthesized polymeric surfactants have immensely attracted the researchers for further development of chemical enhanced oil recovery method particularly in surfactant flooding. Contact angle and interfacial tension measurement tests are the effective ways to identify proper chemicals/surfactants for enhanced oil recovery by chemical/surfactant flooding. In the present study a new polymeric surfactant was synthesized from pre-synthesized sodium methyl ester sulfonate (surfactant) and acrylamide for application in chemical enhanced oil recovery. The synthesized surfactant and polymeric surfactant were used to measure interfacial tension between their aqueous phase and crude oil phase to investigate the efficiency of the surfactants in reduction of interfacial tension. The synthesized polymeric surfactant has also ability to control the mobility because of its viscous nature in aqueous solution. Contact angles of solid-crude oil-surfactant interface were also measured to study the effect of the synthesized surfactant and polymeric surfactant on wettability alteration mechanism. Synergistic effect was studied by using NaCl and synthesized surfactants on interfacial tension. Dynamic interfacial tensions of the surfactant and polymeric surfactant solutions with crude oil were measured at different NaCl concentrations. Interfacial tension was found to be lowered up to 10-2 to 10-3 mN/m which is effective for oil recovery. Measurement of contact angle indicates the wettability change of the quartz surface. Comparative studies on efficiencies of synthesized sodium methyl ester sulfonate surfactant and polymeric surfactant were also carried out with respect to interfacial tension reduction and contact angle change.

  4. Status of Computational Aerodynamic Modeling Tools for Aircraft Loss-of-Control

    Science.gov (United States)

    Frink, Neal T.; Murphy, Patrick C.; Atkins, Harold L.; Viken, Sally A.; Petrilli, Justin L.; Gopalarathnam, Ashok; Paul, Ryan C.

    2016-01-01

    A concerted effort has been underway over the past several years to evolve computational capabilities for modeling aircraft loss-of-control under the NASA Aviation Safety Program. A principal goal has been to develop reliable computational tools for predicting and analyzing the non-linear stability & control characteristics of aircraft near stall boundaries affecting safe flight, and for utilizing those predictions for creating augmented flight simulation models that improve pilot training. Pursuing such an ambitious task with limited resources required the forging of close collaborative relationships with a diverse body of computational aerodynamicists and flight simulation experts to leverage their respective research efforts into the creation of NASA tools to meet this goal. Considerable progress has been made and work remains to be done. This paper summarizes the status of the NASA effort to establish computational capabilities for modeling aircraft loss-of-control and offers recommendations for future work.

  5. Enhancement of loss detection capability using a combination of the Kalman Filter/Linear Smoother and controllable unit accounting approach

    International Nuclear Information System (INIS)

    Pike, D.H.; Morrison, G.W.

    1979-01-01

    An approach to loss detection is presented which combines the optimal loss detection capability of state estimation techniques with a controllable unit accounting approach. The state estimation theory makes use of a linear system model which is capable of modeling the interaction of various controllable unit areas within a given facility. An example is presented which illustrates the increase in loss detection probability which is realizable with state estimation techniques. Comparisons are made with a Shewhart Control Chart and the CUSUM statistic

  6. Loss Performance Modeling for Hierarchical Heterogeneous Wireless Networks With Speed-Sensitive Call Admission Control

    DEFF Research Database (Denmark)

    Huang, Qian; Huang, Yue-Cai; Ko, King-Tim

    2011-01-01

    A hierarchical overlay structure is an alternative solution that integrates existing and future heterogeneous wireless networks to provide subscribers with better mobile broadband services. Traffic loss performance in such integrated heterogeneous networks is necessary for an operator's network...... dimensioning and planning. This paper investigates the computationally efficient loss performance modeling for multiservice in hierarchical heterogeneous wireless networks. A speed-sensitive call admission control (CAC) scheme is considered in our model to assign overflowed calls to appropriate tiers....... This approach avoids unnecessary and frequent handoff between cells and reduces signaling overheads. An approximation model with guaranteed accuracy and low computational complexity is presented for the loss performance of multiservice traffic. The accuracy of numerical results is validated by comparing...

  7. Prosody Perception and Production in Children with Hearing Loss and Age- and Gender-Matched Controls.

    Science.gov (United States)

    Kalathottukaren, Rose Thomas; Purdy, Suzanne C; Ballard, Elaine

    2017-04-01

    Auditory development in children with hearing loss, including the perception of prosody, depends on having adequate input from cochlear implants and/or hearing aids. Lack of adequate auditory stimulation can lead to delayed speech and language development. Nevertheless, prosody perception and production in people with hearing loss have received less attention than other aspects of language. The perception of auditory information conveyed through prosody using variations in the pitch, amplitude, and duration of speech is not usually evaluated clinically. This study (1) compared prosody perception and production abilities in children with hearing loss and children with normal hearing; and (2) investigated the effect of age, hearing level, and musicality on prosody perception. Participants were 16 children with hearing loss and 16 typically developing controls matched for age and gender. Fifteen of the children with hearing loss were tested while using amplification (n = 9 hearing aids, n = 6 cochlear implants). Six receptive subtests of the Profiling Elements of Prosody in Speech-Communication (PEPS-C), the Child Paralanguage subtest of Diagnostic Analysis of Nonverbal Accuracy 2 (DANVA 2), and Contour and Interval subtests of the Montreal Battery of Evaluation of Amusia (MBEA) were used. Audio recordings of the children's reading samples were rated using a perceptual prosody rating scale by nine experienced listeners who were blinded to the children's hearing status. Thirty two children, 16 with hearing loss (mean age = 8.71 yr) and 16 age- and gender-matched typically developing children with normal hearing (mean age = 8.87 yr). Assessments were completed in one session lasting 1-2 hours in a quiet room. Test items were presented using a laptop computer through loudspeaker at a comfortable listening level. For children with hearing loss using hearing instruments, all tests were completed with hearing devices set at their everyday listening setting. All PEPS

  8. Aircraft Loss-of-Control: Analysis and Requirements for Future Safety-Critical Systems and Their Validation

    Science.gov (United States)

    Belcastro, Christine M.

    2011-01-01

    Loss of control remains one of the largest contributors to fatal aircraft accidents worldwide. Aircraft loss-of-control accidents are complex, resulting from numerous causal and contributing factors acting alone or more often in combination. Hence, there is no single intervention strategy to prevent these accidents. This paper summarizes recent analysis results in identifying worst-case combinations of loss-of-control accident precursors and their time sequences, a holistic approach to preventing loss-of-control accidents in the future, and key requirements for validating the associated technologies.

  9. Surfactant protein A and surfactant protein D variation in pulmonary disease

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Husby, Steffen; Holmskov, Uffe

    2007-01-01

    Surfactant proteins A (SP-A) and D (SP-D) have been implicated in pulmonary innate immunity. The proteins are host defense lectins, belonging to the collectin family which also includes mannan-binding lectin (MBL). SP-A and SP-D are pattern-recognition molecules with the lectin domains binding...... lavage and blood have indicated associations with a multitude of pulmonary inflammatory diseases. In addition, accumulating evidence in mouse models of infection and inflammation indicates that recombinant forms of the surfactant proteins are biologically active in vivo and may have therapeutic potential...... in controlling pulmonary inflammatory disease. The presence of the surfactant collectins, especially SP-D, in non-pulmonary tissues, such as the gastrointestinal tract and genital organs, suggest additional actions located to other mucosal surfaces. The aim of this review is to summarize studies on genetic...

  10. 77 FR 22480 - Guidance Under Section 267(f); Deferral of Loss on Transactions Between Members of a Controlled...

    Science.gov (United States)

    2012-04-16

    ... stock to controlled group members. The proposed regulations provided that a deferred loss is taken into... loss continues to be deferred. For purposes of this paragraph, stock held by S, stock held by B, stock... sells all of the T stock to B at a loss (in a transaction that is treated as a sale or exchange for...

  11. Effect of ethyleneoxide groups of anionic surfactants on lipase activity.

    Science.gov (United States)

    Magalhães, Solange S; Alves, Luís; Sebastião, Marco; Medronho, Bruno; Almeida, Zaida L; Faria, Tiago Q; Brito, Rui M M; Moreno, Maria J; Antunes, Filipe E

    2016-09-01

    The use of enzymes in laundry and dish detergent products is growing. Such tendency implies dedicated studies to understand surfactant-enzyme interactions. The interactions between surfactants and enzymes and their impact on the catalytic efficiency represent a central problem and were here evaluated using circular dichroism, dynamic light scattering, and enzyme activity determinations. This work focuses on this key issue by evaluating the role of the ethyleneoxide (EO) groups of anionic surfactants on the structure and activity of a commercial lipase, and by focusing on the protein/surfactant interactions at a molecular level. The conformational changes and enzymatic activity of the protein were evaluated in the presence of sodium dodecyl sulfate (SDS also denoted as SLE 0 S) and of sodium lauryl ether sulfate with two EO units (SLE 2 S). The results strongly suggest that the presence of EO units in the surfactant polar headgroup determines the stability and the activity of the enzyme. While SDS promotes enzyme denaturation and consequent loss of activity, SLE 2 S preserves the enzyme structure and activity. The data further highlights that the electrostatic interactions among the protein groups are changed by the presence of the adsorbed anionic surfactants being such absorption mainly driven by hydrophobic interactions. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1276-1282, 2016. © 2016 American Institute of Chemical Engineers.

  12. Photosensitive microgels containing azobenzene surfactants of different charges.

    Science.gov (United States)

    Schimka, Selina; Lomadze, Nino; Rabe, Maren; Kopyshev, Alexey; Lehmann, Maren; von Klitzing, Regine; Rumyantsev, Artem M; Kramarenko, Elena Yu; Santer, Svetlana

    2016-12-21

    We report on light sensitive microgel particles that can change their volume reversibly in response to illumination with light of different wavelengths. To make the anionic microgels photosensitive we add surfactants with a positively charged polyamine head group and an azobenzene containing tail. Upon illumination, azobenzene undergoes a reversible photo-isomerization reaction from a trans- to a cis-state accompanied by a change in the hydrophobicity of the surfactant. Depending on the isomerization state, the surfactant molecules are either accommodated within the microgel (trans-state) resulting in its shrinkage or desorbed back into water (cis-isomer) letting the microgel swell. We have studied three surfactants differing in the number of amino groups, so that the number of charges of the surfactant head varies between 1 and 3. We have found experimentally and theoretically that the surfactant concentration needed for microgel compaction increases with decreasing number of charges of the head group. Utilization of polyamine azobenzene containing surfactants for the light triggered remote control of the microgel size opens up a possibility for applications of light responsive microgels as drug carriers in biology and medicine.

  13. Prolactin receptor gene polymorphism and the risk of recurrent pregnancy loss: a case-control study.

    Science.gov (United States)

    Kim, Jin Ju; Choi, Young Min; Lee, Sung Ki; Yang, Kwang Moon; Paik, Eun Chan; Jeong, Hyeon Jeong; Jun, Jong Kwan; Han, Ae Ra; Hwang, Kyu Ri; Hong, Min A

    2018-02-01

    Since the first study was published reporting the candidate association between the prolactin receptor gene intron C/T polymorphism (rs37389) and recurrent miscarriage, no replication study has been performed. In this study, we investigated the role of the prolactin receptor gene C/T polymorphism in 311 Korean women with recurrent pregnancy loss and 314 controls. Genotyping for prolactin receptor gene intron C/T polymorphism was performed using a TaqMan assay. The significance of difference in the genotype distribution was assessed using a chi-square test, and continuous variables were compared using a Student's t-test. The genotype distribution of the prolactin receptor gene C/T polymorphism in the recurrent pregnancy loss group did not differ from that in the control group (CC/CT/TT rates were 49.8%/41.5%/8.7% and 52.5%/37.6%/9.9% for the recurrent pregnancy loss patient and control groups, respectively, p = .587). When the analysis was restricted to patients with three or more consecutive spontaneous miscarriages or patients without prior live birth, there were also no differences in the genotype distribution between these subgroups and controls. In conclusion, the findings of the current study suggest that the prolactin receptor gene intron C/T polymorphism is not a major determinant of the development of recurrent pregnancy loss. Impact statement What is already known: Many studies have investigated whether there is a genetic component for the risk of recurrent pregnancy loss. Recently, one study investigated whether genetic polymorphisms involved in the regulation of the hypothalamic-pituitary-ovarian axis would be associated with recurrent miscarriage. Among 35 polymorphisms in 20 candidate genes, genotype distribution with regard to the prolactin receptor gene intron C/T polymorphism (rs37389) differed between the recurrent miscarriage and the control groups. Since this study reporting the candidate association between the prolactin receptor gene and

  14. Estimated costs of Sustaining Agricultural Production Through Erosional Control and Replenishment of Nutrient Losses in Kenya

    International Nuclear Information System (INIS)

    Onyango, J.W.

    1999-01-01

    Soil erosion is one of the major causes of nutrient depletion in sub-Saharan Africa. Highlights of losses from erosion can be used to explain why agricultural production in this region is not sustainable. annual macronutrient losses were calculated from experimental results at 8 sites in Kenya between 1986 and 1990. these losses were used along with the current local prices of fertiliser to estimate the annual national budget required for there replenishment. On average, 5.72, 29.3 and 0.82 kg ha -1 yr -1 of N, P and K, respectively, were lost annually. These losses are determined by soil types, slope, crop cover characteristics and rainfall amounts. soil losses can be reduced by terracing, contour farming and intercropping to improve crop cover. These efforts reduce the adverse effects of sporadic rainfall on fragile soil types. in order to ensure sustainability however, control measures have to be supplemented by national additions of 64 000 t, 323 000 t and 10 000 t of N, P and K respectively per year. The equivalent costs of these fertilisers will be Ksh 1,408 Ksh 8721 Ksh 220 million for the respective nutrients. This would require a total of some US$256 million (Ksh 10 349 million) annually from the national budget

  15. Taking weight-loss supplements may elicit liberation from dietary control. A laboratory experiment.

    Science.gov (United States)

    Chang, Yevvon Yi-Chi; Chiou, Wen-Bin

    2014-01-01

    Given that changes in diet and exercise habits are difficult to initiate and maintain, the use of weight-loss supplements has become an appealing alternative approach to weight management for many individuals. The current research examined whether the use of weight-loss supplements induced overly optimistic assessments of progress toward weight reduction, leading to psychological abdication of dietary regulation. Participants were randomly assigned to take either an identified placebo or a purported weight-loss supplement (actually the same placebo). Each participant reported perceived progress toward weight reduction following the manipulation. Consumption of snacks in a taste test and choice of sugary drinks were recorded. The results showed that participants receiving a purported supplement ate more in a taste task and preferred larger quantities of sugar in their reward drinks than did controls. Mediation analysis supported that the perception of progress toward weight reduction contributed to the liberating effect. Using weight-loss supplements may increase perceived progress toward weight reduction but decrease dietary self-regulation. These thought-provoking findings can serve as a basis for educating the public about the myth that they are free to feel liberated from the need to regulate their eating when using weight-loss supplements. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. What distinguishes weight loss maintainers of the German Weight Control Registry from the general population?

    Science.gov (United States)

    Feller, Silke; Müller, Astrid; Mayr, Andreas; Engeli, Stefan; Hilbert, Anja; de Zwaan, Martina

    2015-05-01

    Differences between successful long-term weight loss maintainers and the general population with regard to eating and weighing habits, non-normative eating behaviors, and eating-related and general psychopathological parameters are unknown. Self-identified weight loss maintainers from the German Weight Control Registry (GWCR, n = 494) were compared with a representative sample of the general German population (n = 2,129). The samples did not differ in current BMI. Using the same assessment instruments in both cohorts, a variety of eating-related and psychological variables were determined. The GWCR participants reported more self-weighing and higher eating frequency but less hot meal consumption and more eating-out-of-home. Binge eating, compensatory behaviors, and concerns about shape and weight were reported more often by successful weight loss maintainers. Scores of depression and worrying about health were slightly higher whereas severity of somatic symptoms was less pronounced in the GWCR participants. Overall, our data suggest that successful weight loss maintainers are characterized by more concerns about shape and weight, greater binge eating frequency, and higher use of compensatory behaviors. The latter suggests that weight loss maintenance might not only be achieved by healthy strategies but also by non-normative behaviors which might increase the vulnerability for weight regain. © 2015 The Obesity Society.

  17. Role of Platelet Parameters on Sudden Sensorineural Hearing Loss: A Case-Control Study in Iran

    Science.gov (United States)

    2016-01-01

    Sudden sensorineural hearing loss (SSNHL) is a common otological disorder characterized by a hearing loss greater than 30 dB over three consecutive frequencies, in less than 72 hours. It has been established that platelet parameters, such as mean platelet volume, are associated with ischemic heart events, whose clinical manifestations are similar to those of SSNHL. Hence, we aimed to determine if the platelet count, mean platelet volume and platelet distribution width are related to the occurrence and severity of sudden sensorineural hearing loss. A case-control prospective study was conducted in a teaching hospital in Iran. One hundred-eight patients with SSNHL and an equal number of healthy, age- and sex-matched controls were enrolled in the study. Peripheral venous blood samples were collected from the subjects, and the platelet count, mean platelet volume and platelet distribution width were measured with an automated blood cell counter. Analysis of the audiometry and hematological test results using SPSS22 software showed no statistical correlation between the platelet parameters and the occurrence of SSNHL, but correlation coefficients showed a significant correlation between PDW and hearing loss severity in patients group. However, further investigation is required to unequivocally establish the absence of correlation between the platelet parameters and occurrence of SSNHL. PMID:26829393

  18. Loss of control increases belief in precognition and belief in precognition increases control.

    Science.gov (United States)

    Greenaway, Katharine H; Louis, Winnifred R; Hornsey, Matthew J

    2013-01-01

    Every year thousands of dollars are spent on psychics who claim to "know" the future. The present research questions why, despite no evidence that humans are able to psychically predict the future, do people persist in holding irrational beliefs about precognition? We argue that believing the future is predictable increases one's own perceived ability to exert control over future events. As a result, belief in precognition should be particularly strong when people most desire control-that is, when they lack it. In Experiment 1 (N = 87), people who were experimentally induced to feel low in control reported greater belief in precognition than people who felt high in control. Experiment 2 (N = 53) investigated whether belief in precognition increases perceived control. Consistent with this notion, providing scientific evidence that precognition is possible increased feelings of control relative to providing scientific evidence that precognition was not possible. Experiment 3 (N = 132) revealed that when control is low, believing in precognition helps people to feel in control once more. Prediction therefore acts as a compensatory mechanism in times of low control. The present research provides new insights into the psychological functions of seemingly irrational beliefs, like belief in psychic abilities.

  19. Vaping to lose weight: Predictors of adult e-cigarette use for weight loss or control.

    Science.gov (United States)

    Morean, Meghan E; Wedel, Amelia V

    2017-03-01

    Some traditional cigarette smokers are motivated to smoke to lose weight or control their weight. The current study evaluated whether a subset of adult e-cigarette users reported vaping to lose or control their weight and examined potential predictors of vaping for weight management. Adult e-cigarette users (n=459) who reported wanting to lose weight or maintain their weight completed an anonymous online survey. Participants reported on demographics, vaping frequency, e-cigarette nicotine content, cigarette smoking status, preferred e-cigarette/e-liquid flavors, current weight status (i.e., overweight, underweight), use of dieting strategies associated with anorexia and bulimia, lifetime history of binge eating, self-discipline, and impulse control. Binary logistic regression was used to examine whether vaping for weight loss/control was associated with the aforementioned variables. Participants who reported vaping for weight loss/control (13.5%) were more likely to vape frequently (adjOR=1.15; 95% CI [1.00, 1.31]); be overweight (adjOR=2.80; [1.33, 5.90]); restrict calories (adjOR=2.23; [1.13, 4.42]); have poor impulse control (adjOR=0.59; [0.41, 0.86]); and prefer coffee- (adjOR=2.92; [1.47, 5.80]) or vanilla-flavored e-liquid (adjOR=7.44; [1.56, 36.08]). A subset of adult e-cigarette users reported vaping for weight loss/control, raising concerns about expanded, scientifically unsubstantiated uses of e-cigarettes. Identifying where individuals obtain information about vaping for weight loss (e.g., e-cigarette ads, Internet) and whether weight-related motives promote e-cigarette initiation among e-cigarette naïve individuals is important to informing regulatory efforts. Further research also is needed to better understand the link between e-liquid flavors and weight loss motivations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. A pragmatic randomised controlled trial in primary care of the Camden Weight Loss (CAMWEL) programme.

    Science.gov (United States)

    Nanchahal, Kiran; Power, Tom; Holdsworth, Elizabeth; Hession, Michelle; Sorhaindo, Annik; Griffiths, Ulla; Townsend, Joy; Thorogood, Nicki; Haslam, David; Kessel, Anthony; Ebrahim, Shah; Kenward, Mike; Haines, Andrew

    2012-01-01

    To evaluate effectiveness of a structured one-to-one behaviour change programme on weight loss in obese and overweight individuals. Randomised controlled trial. 23 general practices in Camden, London. 381 adults with body mass index ≥25 kg/m(2) randomly assigned to intervention (n=191) or control (n=190) group. A structured one-to-one programme, delivered over 14 visits during 12 months by trained advisors in three primary care centres compared with usual care in general practice. Changes in weight, per cent body fat, waist circumference, blood pressure and heart rate between baseline and 12 months. 217/381 (57.0%) participants were assessed at 12 months: missing values were imputed. The difference in mean weight change between the intervention and control groups was not statistically significant (0.70 kg (0.67 to 2.17, p=0.35)), although a higher proportion of the intervention group (32.7%) than the control group (20.4%) lost 5% or more of their baseline weight (OR: 1.80 (1.02 to 3.18, p=0.04)). The intervention group achieved a lower mean heart rate (mean difference 3.68 beats per minute (0.31 to 7.04, p=0.03)) than the control group. Participants in the intervention group reported higher satisfaction and more positive experiences of their care compared with the control group. Although there is no significant difference in mean weight loss between the intervention and control groups, trained non-specialist advisors can deliver a structured programme and achieve clinically beneficial weight loss in some patients in primary care. The intervention group also reported a higher level of satisfaction with the support received. Primary care interventions are unlikely to be sufficient to tackle the obesity epidemic and effective population-wide measures are also necessary. Trial registrationClincaltrials.gov NCT00891943.

  1. Loss of control eating and weight outcomes after bariatric surgery: a study with a Portuguese sample

    OpenAIRE

    Conceição, Eva Martins; Silva, Ana Isabel Pinto Bastos Leite; Brandão, Isabel; Vaz, Ana Rita Rendeiro Ribeiro; Ramalho, Sofia Marlene Marques; Arrojado, Filipa; Costa, José; Machado, Paulo P. P.

    2014-01-01

    The present study aim is to investigate the frequency of loss of control eating (LOC) episodes in three groups with different assessment times: one before, one at short and one at long-term after bariatric surgery; as well as to explore the association of postoperative problematic eating behaviors and weight outcomes and psychological characteristics. This cross-sectional study compared a group of preoperative bariatric surgery patients (n = 176) and two postoperative groups, one at short-ter...

  2. Stabilization of a Wireless Networked Control System with Packet Loss and Time Delay: An ADS Approach

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2012-01-01

    Full Text Available The stabilization problem of a wireless networked control system is considered in this paper. Both time delay and packet loss exist simultaneously in the wireless network. The system is modeled as an asynchronous dynamic system (ADS with unstable subsystems. A sufficient condition for the system to be stable is presented. A numerical example is given to demonstrate the effectiveness of the proposed approach.

  3. Identifying Mechanisms that Predict Loss of Control (LOC) Eating Using Ecological Momentary Assessment: A pilot study

    Science.gov (United States)

    2013-08-30

    a significant positive correlation was found between emotional overeating and frequency of binge episodes (132). Similarly, among youth, LOC eating ...specific DSM-IV-TR eating disorder diagnoses (8), identifying presence and frequency of binge , LOC and overeating episodes, and assessing disordered...White MA. 2012. Examining the interpersonal model of binge eating and loss of control over eating in women. Int J Eat Disord 45:43-50 13. Appelhans

  4. Childhood loss of control eating over five-year follow-up

    OpenAIRE

    Hilbert, Anja; Brauhardt, Anne

    2016-01-01

    Objective: Emerging prospective evidence from mixed samples, mostly covering short-term follow-up periods, suggests that childhood loss of control (LOC) eating predicts significant impairment in mental and physical health. This study sought to investigate the natural course of childhood LOC eating over the long term and in relation to binge eating disorder (BED) diagnosis, psychopathology, and body weight trajectory in the community. Method: A total of 60 children (8-13 years) with LOC eat...

  5. Comparison of rSP-C surfactant with natural and synthetic surfactants after late treatment in a rat model of the acute respiratory distress syndrome

    Science.gov (United States)

    Häfner, Dietrich; Germann, Paul-Georg; Hauschke, Dieter

    1998-01-01

    In a previous paper we showed that an SP-C containing surfactant preparation has similar activity as bovine-derived surfactants in a rat lung lavage model of the adult respiratory distress syndrome. In this study surfactant was given ten minutes after the last lavage (early treatment). In the present investigation we were interested how different surfactant preparations behave when they are administered 1 h after the last lavage (late treatment). Four protein containing surfactants (rSP-C surfactant, bLES, Infasurf and Survanta) were compared with three protein-free surfactants (ALEC, Exosurf and the phospholipid (PL) mixture of the rSP-C surfactant termed PL surfactant) with respect to their ability to improve gas exchange in this more stringent model when surfactant is given one hour after the last lavage. For better comparison of the surfactants the doses were related to phospholipids. The surfactants were given at doses of 25, 50 and 100 mg kg−1 body weight. The surfactants were compared to an untreated control group that was only ventilated for the whole experimental period. Tracheotomized rats (8–12 per dose and surfactant) were pressure-controlled ventilated (Siemens Servo Ventilator 900C) with 100% oxygen at a respiratory rate of 30 breaths min−1, inspiration expiration ratio of 1 : 2, peak inspiratory pressure of 28 cmH2O at positive endexpiratory pressure (PEEP) of 8 cmH2O. Animals were ventilated for one hour after the last lavage and thereafter the surfactants were intratracheally instilled. During the whole experimental period the ventilation was not changed. Partial arterial oxygen pressures (PaO2, mmHg) at 30 min and 120 min after treatment were used for statistical comparison. All protein containing surfactants caused a dose-dependent increase of the reduced PaO2 values at 30 min after treatment. The protein-free surfactants showed only weak dose-dependent increase in PaO2 values at this time. This difference between the

  6. Mothers and fathers of children with cancer: loss of control during treatment and posttraumatic stress at later follow-up.

    Science.gov (United States)

    Norberg, Annika Lindahl; Boman, Krister K

    2013-02-01

    A child's cancer can lead to changes in parental role functioning, including loss of control. We studied the extent to which parental perceived loss of control during a child's cancer treatment predicted posttraumatic stress symptoms (PTSS) after completion of treatment. The sample of this longitudinal study included 62 parents (36 mothers and 26 fathers) of children currently in treatment for malignant disease (T1) and after completion of treatment (T2). Loss of control was assessed at T1 using a self-report measure, that is the loss of control module of the Parental Psychosocial Distress-Cancer questionnaire. PTSS were assessed at T2 using the Impact of Event Scale-Revised. Main analyses were carried out for mothers and fathers separately. The majority of the parents, 55% (n = 34), reported loss of control on more than half of the assessed domains. Only 5% (n = 3) reported no loss of control whatsoever. At T2, some degree of PTSS was reported by 89% (n = 55). These outcomes were similar for mothers and fathers. Loss of control at T1 predicted stronger PTSS at T2 primarily among mothers. The experience of loss of control during cancer treatment is a salient risk factor for later PTSS in mothers. The situational threat to the regular parental role is discussed as an explanation to this observation. Interventions should address informational needs, parent participation in care, and professional support to maintain a sense of control and functioning in their parental role. Copyright © 2011 John Wiley & Sons, Ltd.

  7. Hunger control and regular physical activity facilitate weight loss after laparoscopic adjustable gastric banding.

    Science.gov (United States)

    Colles, Susan L; Dixon, John B; O'Brien, Paul E

    2008-07-01

    Bariatric surgery facilitates substantial and durable weight loss; however, outcomes vary. In addition to physiological and technical factors, weight loss efficacy is dependent on modification of behavior to maintain a long-term change in energy balance. This study aimed to assess the extent and nature of change in energy intake and physical activity and identify factors associated with percentage weight loss (%WL) 12 months after laparoscopic adjustable gastric banding (LAGB). 129 bariatric surgery candidates (26 men/103 women, mean age 45.2 +/- 11.5, mean body mass index [BMI] 44.3 +/- 6.8, range 31.9 to 66.7) completed the study. Data were collected at baseline and 12 months. Validated questionnaires included the Cancer Council Victoria Food Frequency Questionnaire, Three Factor Eating Questionnaire, Short Form-36, Baecke Physical Activity Questionnaire, and Beck Depression Inventory. Symptoms of "non-hungry eating," "emotional eating," and "grazing" were assessed. Mean %WL was 20.8 +/- 8.5%, and excess weight loss was 50.0 +/- 20.7 (p hunger (beta = -0.275; p = 0.001), physical function (beta = 0.309; p affects marked behavior change and facilitates substantial weight loss in the first 12 months. However, variations in adopted behaviors can affect energy balance and weight loss success. Achievement and maintenance of favorable behaviors should be an important consideration during on-going postsurgical review and counseling. Management should include adequate band adjustment to control physical hunger, optimization of physical function and activity, and reinforcement of strategies to reduce energy intake.

  8. Monitoring corrosion and corrosion control of iron in HCl by non-ionic surfactants of the TRITON-X series - Part III. Immersion time effects and theoretical studies

    International Nuclear Information System (INIS)

    Amin, Mohammed A.; Ahmed, M.A.; Arida, H.A.; Kandemirli, Fatma; Saracoglu, Murat; Arslan, Taner; Basaran, Murat A.

    2011-01-01

    Graphical abstract: . Display Omitted Research highlights: → The inhibition effect of TX-100, TX-165 and TX-305 on iron corrosion in 1.0 M HCl was studied. → TX-305 inhibited iron corrosion more effectively than TX-100 and TX-165. → In most cases, inhibition efficiency increased with time during the first 60 min of immersion, then decreased. → Calculated quantum chemical parameters confirmed the experimental inhibition efficiencies of the tested surfactants. - Abstract: The inhibition performance of three selected non-ionic surfactants of the TRITON-X series, namely TRITONX-100 (TX-100), TRITON-X-165 (TX-165) and TRITON-X-305 (TX-305), on the corrosion of iron was studied in 1.0 M HCl solutions as a function of inhibitor concentration (0.01-0.20 g L -1 ) and immersion time (0.0-8 h) at 298 K. Measurements were conducted based on Tafel polarization, LPR and impedance studies. At high frequencies, the impedance spectrum showed a depressed capacitive loop in the complex impedance plane, whose diameter is a function of the immersion time and the type and concentration of the introduced surfactant. In all cases, an inductive loop was observed in the low frequency and this could be attributed to the adsorption behavior. The inhibition efficiency increased with immersion time, reached a maximum and then decreased. This was attributed to the orientation change of adsorbed surfactant molecules. TX-305 inhibited iron corrosion more effectively than TX-100 and TX-165. The frontier orbital energies, the energy gap between frontier orbitals, dipole moments (μ), charges on the C and O atoms, the polarizabilities, and the quantum chemical descriptors were calculated. The quantum chemical calculation results inferred that for the HOMO representing the condensed Fukui function for an electrophilic attack (f k + ), the contributions belong to the phenyl group and the oxygen atom attached to the phenyl group for each tested surfactant. Quantitative structure

  9. Surfactant monitoring by foam generation

    Science.gov (United States)

    Mullen, Ken I.

    1997-01-01

    A device for monitoring the presence or absence of active surfactant or other surface active agents in a solution or flowing stream based on the formation of foam or bubbles is presented. The device detects the formation of foam with a light beam or conductivity measurement. The height or density of the foam can be correlated to the concentration of the active surfactant present.

  10. Stereological and biophysical characteristics of the ovine surfactant system and its changes caused by ovine pulmonary adenocarcinoma.

    Science.gov (United States)

    Jörger, Ariane; Acevedo, Christa; Busley, Diana; Ganter, Martin; Schmiedl, Andreas; Humann-Ziehank, Esther

    2017-10-01

    Surfactant covers the inner surface of lung alveoli and lowers the surface tension to prevent alveoli from collapsing. A lack of surfactant or its dysfunction causes dyspnea. The Jaagsiekte Sheep Retrovirus (JSRV) causes ovine pulmonary adenocarcinoma (OPA), whose typical clinical appearance is fluid running from nostrils. This fluid might contain surfactant as alveolar type II pneumocytes (AEII) are target cells for JSRV. Therefore, the progressive dyspnea during OPA might be caused partially by surfactant alterations. Bronchoalveolar and intracellular surfactant as well as the biophysical function of surfactant were analyzed in OPA sheep and controls. Transmission electron microscopy and stereological methods were used to characterize ultrastructure and distribution of surfactant subtypes in AEII and bronchoalveolar lavage fluid (BALF). Pulsating Bubble Surfactometry enabled studying the surface activity of the surfactant, while lung volumes were detected by computed tomography. The methods used are suitable to determine intraalveolar and intracellular surfactant subtypes in OPA sheep and controls. OPA sheep showed more lamellar body-like forms, multivesicular vesicles and tubular myelin in BALF compared to controls. These higher amounts of active surfactant subtypes might be a consequence of a higher surfactant production and release. Surfactant subtypes in AEII of OPA sheep showed smaller and more immature lamellar bodies compared to controls. The surfactant surface activity of OPA sheep does not show obvious defects. In conclusion, the general quality of surfactant in OPA appears to be equivalent to surfactant produced in controls, however, dyspnea of OPA might be triggered by quantity of fluid production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Plasmon Injection to Compensate and Control Losses in Negative Index Metamaterials.

    Science.gov (United States)

    Sadatgol, Mehdi; Özdemir, Şahin K; Yang, Lan; Güney, Durdu Ö

    2015-07-17

    Metamaterials have introduced a whole new world of unusual materials with functionalities that cannot be attained in naturally occurring material systems by mimicking and controlling the natural phenomena at subwavelength scales. However, the inherent absorption losses pose a fundamental challenge to the most fascinating applications of metamaterials. Based on a novel plasmon injection (PI or Π) scheme, we propose a coherent optical amplification technique to compensate losses in metamaterials. Although the proof of concept device here operates under normal incidence only, our proposed scheme can be generalized to an arbitrary form of incident waves. The Π scheme is fundamentally different from major optical amplification schemes. It does not require a gain medium, interaction with phonons, or any nonlinear medium. The Π scheme allows for loss-free metamaterials. It is ideally suited for mitigating losses in metamaterials operating in the visible spectrum and is scalable to other optical frequencies. These findings open the possibility of reviving the early dreams of making "magical" metamaterials from scratch.

  12. Time-controllable Nkcc1 knockdown replicates reversible hearing loss in postnatal mice.

    Science.gov (United States)

    Watabe, Takahisa; Xu, Ming; Watanabe, Miho; Nabekura, Junichi; Higuchi, Taiga; Hori, Karin; Sato, Mitsuo P; Nin, Fumiaki; Hibino, Hiroshi; Ogawa, Kaoru; Masuda, Masatsugu; Tanaka, Kenji F

    2017-10-19

    Identification of the causal effects of specific proteins on recurrent and partially reversible hearing loss has been difficult because of the lack of an animal model that provides reversible gene knockdown. We have developed the transgenic mouse line Actin-tTS::Nkcc1 tetO/tetO for manipulatable expression of the cochlear K + circulation protein, NKCC1. Nkcc1 transcription was blocked by the binding of a tetracycline-dependent transcriptional silencer to the tetracycline operator sequences inserted upstream of the Nkcc1 translation initiation site. Administration of the tetracycline derivative doxycycline reversibly regulated Nkcc1 knockdown. Progeny from pregnant/lactating mothers fed doxycycline-free chow from embryonic day 0 showed strong suppression of Nkcc1 expression (~90% downregulation) and Nkcc1 null phenotypes at postnatal day 35 (P35). P35 transgenic mice from mothers fed doxycycline-free chow starting at P0 (delivery) showed weaker suppression of Nkcc1 expression (~70% downregulation) and less hearing loss with mild cochlear structural changes. Treatment of these mice at P35 with doxycycline for 2 weeks reactivated Nkcc1 transcription to control levels and improved hearing level at high frequency; i.e., these doxycycline-treated mice exhibited partially reversible hearing loss. Thus, development of the Actin-tTS::Nkcc1 tetO/tetO transgenic mouse line provides a mouse model for the study of variable hearing loss through reversible knockdown of Nkcc1.

  13. Tunable Oleo-Furan Surfactants by Acylation of Renewable Furans

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dae Sung; Joseph, Kristeen E.; Koehle, Maura; Krumm, Christoph; Ren, Limin; Damen, Jonathan N.; Shete, Meera H.; Lee, Han Seung; Zuo, Xiaobing; Lee, Byeongdu; Fan, Wei; Vlachos, Dionisios G.; Lobo, Raul F.; Tsapatsis, Michael; Dauenhauer, Paul J.

    2016-11-23

    An important advance in fluid surface control was the amphiphilic surfactant comprised of coupled molecular structures (i.e. hydrophilic and hydrophobic) to reduce surface tension between two distinct fluid phases. However, implementation of simple surfactants has been hindered by the broad range of applications in water containing alkaline earth metals (i.e. hard water), which disrupt surfactant function and require extensive use of undesirable and expensive chelating additives. Here we show that sugar-derived furans can be linked with triglyceride-derived fatty acid chains via Friedel-Crafts acylation within single layer (SPP) zeolite catalysts. These alkylfuran surfactants independently suppress the effects of hard water while simultaneously permitting broad tunability of size, structure, and function, which can be optimized for superior capability for forming micelles and solubilizing in water.

  14. Adolescent exergame play for weight loss and psychosocial improvement: a controlled physical activity intervention.

    Science.gov (United States)

    Staiano, Amanda E; Abraham, Anisha A; Calvert, Sandra L

    2013-03-01

    Overweight and obese youth, who face increased risk of medical complications including heart disease and type II diabetes, can benefit from sustainable physical activity interventions that result in weight loss. This study examined whether a 20-week exergame (i.e., videogame that requires gross motor activity) intervention can produce weight loss and improve psychosocial outcomes for 54 overweight and obese African-American adolescents. Participants were recruited from a public high school and randomly assigned to competitive exergame, cooperative exergame, or control conditions. All exergame participants were encouraged to play the Nintendo Wii Active game for 30-60 min per school day in a lunch-time or after-school program. Cooperative exergame participants worked with a peer to expend calories and earn points together, whereas competitive exergame participants competed against a peer. Control participants continued regular daily activities. Outcome measures included changes in weight, peer support, self-efficacy, and self-esteem, measured at baseline, and at ∼10 and 20 weeks. Growth curve analysis revealed that cooperative exergame players lost significantly more weight (mean = 1.65 kg; s.d. = 4.52) than the control group, which did not lose weight. The competitive exergame players did not differ significantly from the other conditions. Cooperative exergame players also significantly increased in self-efficacy compared to the control group, and both exergame conditions significantly increased in peer support more than the control group. Exergames, especially played cooperatively, can be an effective technological tool for weight loss among youth. Copyright © 2012 The Obesity Society.

  15. Surveying the interest of individuals with upper limb loss in novel prosthetic control techniques.

    Science.gov (United States)

    Engdahl, Susannah M; Christie, Breanne P; Kelly, Brian; Davis, Alicia; Chestek, Cynthia A; Gates, Deanna H

    2015-06-13

    Novel techniques for the control of upper limb prostheses may allow users to operate more complex prostheses than those that are currently available. Because many of these techniques are surgically invasive, it is important to understand whether individuals with upper limb loss would accept the associated risks in order to use a prosthesis. An online survey of individuals with upper limb loss was conducted. Participants read descriptions of four prosthetic control techniques. One technique was noninvasive (myoelectric) and three were invasive (targeted muscle reinnervation, peripheral nerve interfaces, cortical interfaces). Participants rated how likely they were to try each technique if it offered each of six different functional features. They also rated their general interest in each of the six features. A two-way repeated measures analysis of variance with Greenhouse-Geisser corrections was used to examine the effect of the technique type and feature on participants' interest in each technique. Responses from 104 individuals were analyzed. Many participants were interested in trying the techniques - 83 % responded positively toward myoelectric control, 63 % toward targeted muscle reinnervation, 68 % toward peripheral nerve interfaces, and 39 % toward cortical interfaces. Common concerns about myoelectric control were weight, cost, durability, and difficulty of use, while the most common concern about the invasive techniques was surgical risk. Participants expressed greatest interest in basic prosthesis features (e.g., opening and closing the hand slowly), as opposed to advanced features like fine motor control and touch sensation. The results of these investigations may be used to inform the development of future prosthetic technologies that are appealing to individuals with upper limb loss.

  16. Pulmonary clearance of {sup 99m}Tc-DTPA in experimental surfactant dysfunction treated with surfactant installation

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, K.; John, J.; Lachmann, B.; Robertson, B.; Wollmer, P.

    1997-02-01

    Background: Breakdown of the alveolo-capillary barrier is a characteristic feature of respiratory distress syndrome. Restoration of alveolo-capillary barrier function may be an important aspect of surfactant replacement therapy. We examined the effect of surfactant installation on alveolo-capillary barrier function in an experimental model of surfactant dysfunction by measuring pulmonary clearance of {sup 99m}Tc-DTPA. Methods: Nineteen rabbits were tracheotomized and mechanically ventilated. Surfactant dysfunction was induced by administration of a synthetic detergent in aerosol form. Detergent was given to 13 rabbits; seven rabbits were then treated with installation of natural surfactant, whereas six rabbits received saline. Six rabbits were used as untreated controls. An aerosol of {sup 99m}Tc-DTPA was administered to all animals and the pulmonary clearance was measured with a gamma camera. Results: {sup 99m}Tc-DTPA cleared from the lungs with a half-life of 71{+-}22 min in the control animals, 21.4{+-}7.4 min in the surfactant-treated animals and 5.8{+-}1.5 min in the saline-treated animals. The difference in half-life between groups was highly significant (P<0.001). There was no change in arterial oxygenation or compliance in controls or in animals treated with saline. In animals treated with surfactant, a small transient reduction in arterial oxygen tension and a more long-standing reduction in compliance were observed. Conclusion: Surfactant treatment thus significantly attenuated the effect of detergent treatment but did not restore alveolo-capillary transfer of {sup 99m}Tc-DTPA to normal. (AU) 26 refs.

  17. Stochastic ℋ∞ Finite-Time Control of Discrete-Time Systems with Packet Loss

    Directory of Open Access Journals (Sweden)

    Yingqi Zhang

    2012-01-01

    Full Text Available This paper investigates the stochastic finite-time stabilization and ℋ∞ control problem for one family of linear discrete-time systems over networks with packet loss, parametric uncertainties, and time-varying norm-bounded disturbance. Firstly, the dynamic model description studied is given, which, if the packet dropout is assumed to be a discrete-time homogenous Markov process, the class of discrete-time linear systems with packet loss can be regarded as Markovian jump systems. Based on Lyapunov function approach, sufficient conditions are established for the resulting closed-loop discrete-time system with Markovian jumps to be stochastic ℋ∞ finite-time boundedness and then state feedback controllers are designed to guarantee stochastic ℋ∞ finite-time stabilization of the class of stochastic systems. The stochastic ℋ∞ finite-time boundedness criteria can be tackled in the form of linear matrix inequalities with a fixed parameter. As an auxiliary result, we also give sufficient conditions on the robust stochastic stabilization of the class of linear systems with packet loss. Finally, simulation examples are presented to illustrate the validity of the developed scheme.

  18. Potential effects of vinasse as a soil amendment to control runoff and soil loss

    Science.gov (United States)

    Hazbavi, Z.; Sadeghi, S. H. R.

    2016-02-01

    Application of organic materials are well known as environmental practices in soil restoration, preserving soil organic matter and recovering degraded soils of arid and semiarid lands. Therefore, the present research focused on evaluating the effectiveness of vinasse, a byproduct mainly of the sugar-ethanol industry, on soil conservation under simulated rainfall. Vinasse can be recycled as a soil amendment due to its organic matter content. Accordingly, the laboratory experiments were conducted by using 0.25 m2 experimental plots at 20 % slope and rainfall intensity of 72 mm h-1 with 0.5 h duration. The effect of vinasse was investigated on runoff and soil loss control. Experiments were set up as a control (with no amendment) and three treated plots with doses of 0.5, 1, and 1.5 L m-2 of vinasse subjected to simulated rainfall. Laboratory results indicated that vinasse at different levels could not significantly (P > 0.05) decrease the runoff amount and soil loss rate in the study plots compared to untreated plots. The average amounts of minimum runoff volume and soil loss were about 3985 mL and 46 g for the study plot at a 1 L m-2 level of vinasse application.

  19. Acute alcohol effects on inhibitory control and implicit cognition: implications for loss of control over drinking

    NARCIS (Netherlands)

    Field, M.; Wiers, R.W.; Christiansen, P.; Fillmore, M.T.; Verster, J.C.

    2010-01-01

    Alcohol impairs inhibitory control, and it alters implicit alcohol cognitions including attentional bias and implicit associations. These effects are seen after doses of alcohol which do not lead to global impairments in cognitive performance. We review studies which demonstrate that the effects of

  20. Selective Antimicrobial Activities and Action Mechanism of Micelles Self-Assembled by Cationic Oligomeric Surfactants.

    Science.gov (United States)

    Zhou, Chengcheng; Wang, Fengyan; Chen, Hui; Li, Meng; Qiao, Fulin; Liu, Zhang; Hou, Yanbo; Wu, Chunxian; Fan, Yaxun; Liu, Libing; Wang, Shu; Wang, Yilin

    2016-02-17

    This work reports that cationic micelles formed by cationic trimeric, tetrameric, and hexameric surfactants bearing amide moieties in spacers can efficiently kill Gram-negative E. coli with a very low minimum inhibitory concentration (1.70-0.93 μM), and do not cause obvious toxicity to mammalian cells at the concentrations used. With the increase of the oligomerization degree, the antibacterial activity of the oligomeric surfactants increases, i.e., hexameric surfactant > tetrameric surfactant > trimeric surfactant. Isothermal titration microcalorimetry, scanning electron microscopy, and zeta potential results reveal that the cationic micelles interact with the cell membrane of E. coli through two processes. First, the integrity of outer membrane of E. coli is disrupted by the electrostatic interaction of the cationic ammonium groups of the surfactants with anionic groups of E. coli, resulting in loss of the barrier function of the outer membrane. The inner membrane then is disintegrated by the hydrophobic interaction of the surfactant hydrocarbon chains with the hydrophobic domains of the inner membrane, leading to the cytoplast leakage. The formation of micelles of these cationic oligomeric surfactants at very low concentration enables more efficient interaction with bacterial cell membrane, which endows the oligomeric surfactants with high antibacterial activity.

  1. The effectiveness of breakfast recommendations on weight loss: a randomized controlled trial123

    Science.gov (United States)

    Dhurandhar, Emily J; Dawson, John; Alcorn, Amy; Larsen, Lesli H; Thomas, Elizabeth A; Cardel, Michelle; Bourland, Ashley C; Astrup, Arne; St-Onge, Marie-Pierre; Hill, James O; Apovian, Caroline M; Shikany, James M; Allison, David B

    2014-01-01

    Background: Breakfast is associated with lower body weight in observational studies. Public health authorities commonly recommend breakfast consumption to reduce obesity, but the effectiveness of adopting these recommendations for reducing body weight is unknown. Objective: We tested the relative effectiveness of a recommendation to eat or skip breakfast on weight loss in adults trying to lose weight in a free-living setting. Design: We conducted a multisite, 16-wk, 3-parallel-arm randomized controlled trial in otherwise healthy overweight and obese adults [body mass index (in kg/m2) between 25 and 40] aged 20–65 y. Our primary outcome was weight change. We compared weight change in a control group with weight loss in experimental groups told to eat breakfast or to skip breakfast [no breakfast (NB)]. Randomization was stratified by prerandomization breakfast eating habits. A total of 309 participants were randomly assigned. Results: A total of 283 of the 309 participants who were randomly assigned completed the intervention. Treatment assignment did not have a significant effect on weight loss, and there was no interaction between initial breakfast eating status and treatment. Among skippers, mean (±SD) baseline weight-, age-, sex-, site-, and race-adjusted weight changes were −0.71 ± 1.16, −0.76 ± 1.26, and −0.61 ± 1.18 kg for the control, breakfast, and NB groups, respectively. Among breakfast consumers, mean (±SD) baseline weight-, age-, sex-, site-, and race-adjusted weight changes were −0.53 ± 1.16, −0.59 ± 1.06, and −0.71 ± 1.17 kg for the control, breakfast, and NB groups, respectively. Self-reported compliance with the recommendation was 93.6% for the breakfast group and 92.4% for the NB group. Conclusions: A recommendation to eat or skip breakfast for weight loss was effective at changing self-reported breakfast eating habits, but contrary to widely espoused views this had no discernable effect on weight loss in free-living adults who

  2. The Breathe Easier through Weight Loss Lifestyle (BE WELL Intervention: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Buist A

    2010-03-01

    Full Text Available Abstract Background Obesity and asthma have reached epidemic proportions in the US. Their concurrent rise over the last 30 years suggests that they may be connected. Numerous observational studies support a temporally-correct, dose-response relationship between body mass index (BMI and incident asthma. Weight loss, either induced by surgery or caloric restriction, has been reported to improve asthma symptoms and lung function. Due to methodological shortcomings of previous studies, however, well-controlled trials are needed to investigate the efficacy of weight loss strategies to improve asthma control in obese individuals. Methods/Design BE WELL is a 2-arm parallel randomized clinical trial (RCT of the efficacy of an evidence-based, comprehensive, behavioral weight loss intervention, focusing on diet, physical activity, and behavioral therapy, as adjunct therapy to usual care in the management of asthma in obese adults. Trial participants (n = 324 are patients aged 18 to 70 years who have suboptimally controlled, persistent asthma, BMI between 30.0 and 44.9 kg/m2, and who do not have serious comorbidities (e.g., diabetes, heart disease, stroke. The 12-month weight loss intervention to be studied is based on the principles of the highly successful Diabetes Prevention Program lifestyle intervention. Intervention participants will attend 13 weekly group sessions over a four-month period, followed by two monthly individual sessions, and will then receive individualized counseling primarily by phone, at least bi-monthly, for the remainder of the intervention. Follow-up assessment will occur at six and 12 months. The primary outcome variable is the overall score on the Juniper Asthma Control Questionnaire measured at 12 months. Secondary outcomes include lung function, asthma-specific and general quality of life, asthma medication use, asthma-related and total health care utilization. Potential mediators (e.g., weight loss and change in physical

  3. Controls upon biomass losses and char production from prescribed burning on UK moorland.

    Science.gov (United States)

    Worrall, Fred; Clay, Gareth D; May, Richard

    2013-05-15

    Prescribed burning is a common management technique used across many areas of the UK uplands. However, there are few data sets that assess the loss of biomass during burning and even fewer data on the effect of burning on above-ground carbon stocks and production of char. During fire the production of char occurs which represents a transfer of carbon from the short term bio-atmospheric cycle to the longer term geological cycle. However, biomass is consumed leading to the reduction in litter formation which is the principal mechanism for peat formation. This study aims to solve the problem of whether loss of biomass during a fire is ever outweighed by the production of refractory forms of carbon during the fire. This study combines both a laboratory study of char production with an assessment of biomass loss from a series of field burns from moorland in the Peak District, UK. The laboratory results show that there are significant effects due to ambient temperature but the most important control on dry mass loss is the maximum burn temperature. Burn temperature was also found to be linearly related to the production of char in the burn products. Optimisation of dry mass loss, char production and carbon content shows that the production of char from certain fires could store more carbon in the ecosystem than if there had been no fire. Field results show that approximately 75% of the biomass and carbon were lost through combustion, a figure comparable to other studies of prescribed fire in other settings. Char-C production was approximately 2.6% of the carbon consumed during the fire. This study has shown that there are conditions (fast burns at high temperatures) under which prescribed fire may increase C sequestration through char production and that these conditions are within existing management options available to practitioners. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Weight loss in a UK commercial all meal provision study: a randomised controlled trial.

    Science.gov (United States)

    Mellor, D D; Whitham, C; Goodwin, S; Morris, M; Reid, M; Atkin, S L

    2014-08-01

    Effective approaches are needed to address the increasing prevalence of overweight and obesity. The present study investigated whether all meal provision was a more effective and acceptable method for weight loss than a self-directed diet. This randomised controlled trial recruited 112 men and women with a body mass index in the range 27-35 kg m(-2), who had no comorbidities, from the local area of Hull. Participants were randomised to receive either meal provision or follow a self-directed diet for a 12-week period that resulted in an estimated 2928 kJ day(-1) (700 kcal day(-1)) deficit. A dietitian supervised both dietary interventions. At 12 weeks [mean (SEM)], percentage weight loss in the meal provision group was 6.6% (0.5%) compared to 4.3% (0.6%) for those on the self-directed diet. In terms of clinically relevant weight loss, 61% of participants lost 5% or more of their body weight with meal provision compared to 22% on the self-directed diet (P meal provision withdrawing from the study compared to 41% of those following the self-directed diet (P Meal provision was a more effective and accepted method for weight loss over a 12-week period compared to a self-directed diet. This may in part represent the difference between being given the meal provision food free of charge. However, longer-term maintenance studies need to be undertaken to ascertain their effects on the maintenance of weight loss. © 2013 The Authors. Journal of Human Nutrition and Dietetics published by John Wiley & Sons Ltd on behalf of British Dietetic Association Ltd.

  5. Failure of Arm Movement Control in Stroke Patients, Characterized by Loss of Complexity.

    Science.gov (United States)

    Goh, Segun; Han, Kyungreem; Ryu, Jehkwang; Kim, Seonjin; Choi, MooYoung

    2015-01-01

    We study the mechanism of human arm-posture control by means of nonlinear dynamics and quantitative time series analysis methods. Utilizing linear and nonlinear measures in combination, we find that pathological tremors emerge in patient dynamics and serve as a main feature discriminating between normal and patient groups. The deterministic structure accompanied with loss of complexity inherent in the tremor dynamics is also revealed. To probe the underlying mechanism of the arm-posture dynamics, we further analyze the coupling patterns between joints and components, and discuss their roles in breaking of the organization structure. As a result, we elucidate the mechanisms in the arm-posture dynamics of normal subjects responding to the gravitational force and for the reduction of the dynamic degrees of freedom in the patient dynamics. This study provides an integrated framework for the origin of the loss of complexity in the dynamics of patients as well as the coupling structure in the arm-posture dynamics.

  6. Adsorption of surfactants on sand surface in enhanced oil recovery: Isotherms, kinetics and thermodynamic studies

    Energy Technology Data Exchange (ETDEWEB)

    Bera, Achinta; Kumar, T.; Ojha, Keka; Mandal, Ajay, E-mail: mandal_ajay@hotmail.com

    2013-11-01

    Adsorption of surfactants onto reservoir rock surface may result in the loss and reduction of their concentrations in surfactant flooding, which may render them less efficient or ineffective in practical applications of enhanced oil recovery (EOR) techniques. Surfactant flooding for EOR received attraction due to its ability to increase the displacement efficiency by lowering the interfacial tension between oil and water and mobilizing the residual oil. This article highlights the adsorption of surfactants onto sand surface with variation of different influencing factors. It has been experimentally found that adsorption of cationic surfactant on sand surface is more and less for anionic surfactant, while non-ionic surfactant shows intermediate behaviour. X-ray diffraction (XRD) study of clean sand particles has been made to determine the main component present in the sand particles. The interaction between sand particles and surfactant has been studied by Fourier Transform Infrared (FTIR) Spectroscopy of the sand particles before and after aging with surfactant. Salinity plays an important role in adsorption of anionic surfactant. Batch experiments were also performed to understand the effects of pH and adsorbent dose on the sorption efficiency. The sand particles exhibited high adsorption efficiency at low pH for anionic and nonionic surfactants. But opposite trend was found for cationic surfactant. Adsorption data were analyzed by fitting with Langmuir, Freundlich, Redlich-Peterson, and Sips isotherm models. Results show that the Langmuir isotherm and pseudo-second order kinetics models suit the equilibrium and kinetics of adsorption on sand surface. Thermodynamics feasibility of the adsorption process was also studied to verify the spontaneity of the process.

  7. Weight loss improves reproductive outcomes in obese women undergoing fertility treatment: a randomized controlled trial.

    Science.gov (United States)

    Sim, K A; Dezarnaulds, G M; Denyer, G S; Skilton, M R; Caterson, I D

    2014-04-01

    For women attempting pregnancy, obesity reduces fertility and is an independent risk factor for obstetric and neonatal complications. The aim of this evaluator-blinded, randomized controlled trial was to evaluate a weight loss intervention on pregnancy rates in obese women undertaking fertility treatment. Forty-nine obese women, aged ≤ 37 years, presenting for fertility treatment were randomized to either a 12-week intervention (n = 27) consisting of a very-low-energy diet for the initial 6 weeks followed by a hypocaloric diet, combined with a weekly group multidisciplinary programme; or a control group (n = 22) who received recommendations for weight loss and the same printed material as the intervention. Anthropometric and reproductive parameters were measured at baseline and at 12 weeks. The 22 women who completed the intervention had greater anthropometric changes (-6.6 ± 4.6 kg and -8.7 ± 5.6 cm vs. -1.6 ± 3.6 kg and -0.6 ± 6.3 cm) compared with the control group (n = 17; P fertility treatment cycles to achieve each pregnancy compared with four in the control group (P = 0.002), and had a marked increase in the number of live births (44% vs. 14%; P = 0.02). A group weight loss programme, incorporating dietary, exercise and behavioural components, is associated with a significant improvement in pregnancy rates and live births in a group of obese women undergoing fertility treatment. © 2014 The Authors; Clinical Obesity © 2014 International Association for the Study of Obesity.

  8. Farm management, not soil microbial diversity, controls nutrient loss from smallholder tropical agriculture

    Directory of Open Access Journals (Sweden)

    Stephen A Wood

    2015-03-01

    Full Text Available Tropical smallholder agriculture supports the livelihoods of over 900 million of the world’s poorest people. This form of agriculture is undergoing rapid transformation in nutrient cycling pathways as international development efforts strongly promote greater use of mineral fertilizers to increase crop yields. These changes in nutrient availability may alter the composition of microbial communities with consequences for rates of biogeochemical processes that control nutrient losses to the environment. Ecological theory suggests that altered microbial diversity will strongly influence processes performed by relatively few microbial taxa, such as denitrification and hence nitrogen losses as nitrous oxide, a powerful greenhouse gas. Whether this theory helps predict nutrient losses from agriculture depends on the relative effects of microbial community change and increased nutrient availability on ecosystem processes. We find that mineral and organic nutrient addition to smallholder farms in Kenya alters the taxonomic and functional diversity of soil microbes. However, we find that the direct effects of farm management on both denitrification and carbon mineralization are greater than indirect effects through changes in the taxonomic and functional diversity of microbial communities. Changes in functional diversity are strongly coupled to changes in specific functional genes involved in denitrification, suggesting that it is the expression, rather than abundance, of key functional genes that can serve as an indicator of ecosystem process rates. Our results thus suggest that widely used broad summary statistics of microbial diversity based on DNA may be inappropriate for linking microbial communities to ecosystem processes in certain applied settings. Our results also raise doubts about the relative control of microbial composition compared to direct effects of management on nutrient losses in applied settings such as tropical agriculture.

  9. On-line iron loss resistance identification by a state observer for rotor-flux-oriented control of induction motor

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, Pablo M. de la; Bossio, Guillermo R.; Garcia, Guillermo O. [Grupo de Electronica Aplicada (GEA), Facultad de Ingenieria, UNRC, Ruta Nacional 36 Km. 601, X5804BYA, Rio Cuarto (Argentina); Solsona, Jorge A. [Instituto de Investigaciones en Ingenieria Electrica ' ' Alfredo Desages' ' , Departamento de Ingenieria Electrica y de Computadoras, UNS, Av. Alem 1253 (8000) Bahia Blanca (Argentina)

    2008-10-15

    A rotor flux state observer considering iron loss, for an Induction Motor (IM), is proposed. The aim of this proposal is to avoid detuning caused by the IM iron loss on a field-oriented control (FOC). An adaptive scheme for the K{sub Fe}, a parameter that represents the IM iron loss, is also proposed. The main objective of this scheme is to improve the dynamic response of control by compensating the variations of iron losses due to possible variations in the stator core characteristics. Simulation results demonstrated that the observer and the adaptive scheme showed a good performance fulfilling then the objectives. (author)

  10. On-line iron loss resistance identification by a state observer for rotor-flux-oriented control of induction motor

    International Nuclear Information System (INIS)

    Barrera, Pablo M. de la; Bossio, Guillermo R.; Solsona, Jorge A.; Garcia, Guillermo O.

    2008-01-01

    A rotor flux state observer considering iron loss, for an Induction Motor (IM), is proposed. The aim of this proposal is to avoid detuning caused by the IM iron loss on a field-oriented control (FOC). An adaptive scheme for the K Fe , a parameter that represents the IM iron loss, is also proposed. The main objective of this scheme is to improve the dynamic response of control by compensating the variations of iron losses due to possible variations in the stator core characteristics. Simulation results demonstrated that the observer and the adaptive scheme showed a good performance fulfilling then the objectives

  11. Overeating with and without loss of control: Associations with weight status, weight-related characteristics, and psychosocial health.

    Science.gov (United States)

    Goldschmidt, Andrea B; Loth, Katie A; MacLehose, Richard F; Pisetsky, Emily M; Berge, Jerica M; Neumark-Sztainer, Dianne

    2015-12-01

    The relative importance of loss of control and overeating in the relationship between binge eating and eating-related and general psychopathology has been debated in the literature. This study assessed the prevalence and correlates of overeating with and without loss of control within a diverse, population-based sample of adolescents. A highly diverse (81.1% non-White) sample of adolescents (n = 2,793) from EAT-2010 (Eating and Activity in Teens) completed self-report questionnaires assessing eating-related psychopathology, substance use, nonsuicidal self-injury, depressive symptoms, and self-esteem. Overeating without loss of control was reported by 6.9% of girls and 5.0% of boys, while 9.6% of girls and 6.3% of boys reported overeating with loss of control (binge eating). Overall, overeating (with or without loss of control) was positively associated with unhealthy or extreme weight control behaviors, dieting, nonsuicidal self-injury, lower body satisfaction, and self-esteem, and higher depressive symptoms relative to no overeating. Among girls, binge eating was associated with unhealthy or extreme weight control behaviors, lower self-esteem, and higher depressive symptoms relative to overeating without loss of control, while in boys, binge eating was associated with greater cigarette usage, lower body satisfaction, and greater depressive symptoms than overeating without loss of control (although cigarette usage was comparable in boys reporting binge eating and no overeating). Any overeating, with or without loss of control, was associated with multiple adverse correlates among adolescents. Loss of control was uniquely associated with multiple health indicators, further highlighting its importance as a marker of severity of overeating. © 2015 Wiley Periodicals, Inc.

  12. Overeating with and without loss of control: associations with weight status, weight-related characteristics, and psychosocial health

    Science.gov (United States)

    Goldschmidt, Andrea B.; Loth, Katie A.; MacLehose, Richard F.; Pisetsky, Emily M.; Berge, Jerica M.; Neumark-Sztainer, Dianne

    2015-01-01

    Objective The relative importance of loss of control and overeating in the relationship between binge eating and eating-related and general psychopathology has been debated in the literature. This study assessed the prevalence and correlates of overeating with and without loss of control within a diverse, population-based sample of adolescents. Method A highly diverse (81.1% non-White) sample of adolescents (n=2,793) from EAT-2010 (Eating and Activity in Teens) completed self-report questionnaires assessing eating-related psychopathology, substance use, non-suicidal self-injury, depressive symptoms, and self-esteem. Results Overeating without loss of control was reported by 6.9% of girls and 5.0% of boys, while 9.6% of girls and 6.3% of boys reported overeating with loss of control (binge eating). Overall, overeating (with or without loss of control) was positively associated with unhealthy or extreme weight control behaviors, dieting, non-suicidal self-injury, lower body satisfaction and self-esteem, and higher depressive symptoms relative to no overeating. Among girls, binge eating was associated with unhealthy or extreme weight control behaviors, lower self-esteem, and higher depressive symptoms relative to overeating without loss of control, while in boys, binge eating was associated with greater cigarette usage, lower body satisfaction, and greater depressive symptoms than overeating without loss of control (although cigarette usage was comparable in boys reporting binge eating and no overeating). Discussion Any overeating, with or without loss of control, was associated with multiple adverse correlates among adolescents. Loss of control was uniquely associated with multiple health indicators, further highlighting its importance as a marker of severity of overeating. PMID:26368333

  13. Maintained inspiratory activity during proportional assist ventilation in surfactant-depleted cats early after surfactant instillation: phrenic nerve and pulmonary stretch receptor activity

    Directory of Open Access Journals (Sweden)

    Schaller Peter

    2006-03-01

    Full Text Available Abstract Background Inspiratory activity is a prerequisite for successful application of patient triggered ventilation such as proportional assist ventilation (PAV. It has recently been reported that surfactant instillation increases the activity of slowly adapting pulmonary stretch receptors (PSRs followed by a shorter inspiratory time (Sindelar et al, J Appl Physiol, 2005 [Epub ahead of print]. Changes in lung mechanics, as observed in preterm infants with respiratory distress syndrome and after surfactant treatment, might therefore influence the inspiratory activity when applying PAV early after surfactant treatment. Objective To investigate the regulation of breathing and ventilatory response in surfactant-depleted young cats during PAV and during continuous positive airway pressure (CPAP early after surfactant instillation in relation to phrenic nerve activity (PNA and the activity of PSRs. Methods Seven anesthetized, endotracheally intubated young cats were exposed to periods of CPAP and PAV with the same end-expiratory pressure (0.2–0.5 kPa before and after lung lavage and after surfactant instillation. PAV was set to compensate for 75% of the lung elastic recoil. Results Tidal volume and respiratory rate were higher with lower PaCO2 and higher PaO2 during PAV than during CPAP both before and after surfactant instillation (p Conclusion PSR activity and the control of breathing are maintained during PAV in surfactant-depleted cats early after surfactant instillation, with a higher ventilatory response and a lower breathing effort than during CPAP.

  14. MICROBIAL SURFACTANTS IN ENVIRONMENTAL TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    T. P. Pirog

    2015-08-01

    Full Text Available It was shown literature and own experimental data concerning the use of microbial surface active glycolipids (rhamno-, sophoro- and trehalose lipids and lipopeptides for water and soil purification from oil and other hydrocarbons, removing toxic heavy metals (Cu2+, Cd2+, Ni2+, Pb2+, degradation of complex pollution (oil and other hydrocarbons with heavy metals, and the role of microbial surfactants in phytoremediation processes. The factors that limit the use of microbial surfactants in environmental technologies are discussed. Thus, at certain concentrations biosurfactant can exhibit antimicrobial properties and inhibit microorganisms destructing xenobiotics. Microbial biodegradability of surfactants may also reduce the effectiveness of bioremediation. Development of effective technologies using microbial surfactants should include the following steps: monitoring of contaminated sites to determine the nature of pollution and analysis of the autochthonous microbiota; determining the mode of surfactant introduction (exogenous addition of stimulation of surfactant synthesis by autochthonous microbiota; establishing an optimal concentration of surfactant to prevent exhibition of antimicrobial properties and rapid biodegradation; research both in laboratory and field conditions.

  15. Acute and subchronic toxicity of metal complex azo acid dye and anionic surfactant oil on fish Oreochromis niloticus.

    Science.gov (United States)

    Amwele, Hilma Rantilla; Papirom, Pittaya; Chukanhom, Kanit; Beamish, Fredrick Henry William; Petkam, Rakpong

    2015-01-01

    The acute toxicity study of metal complex dark green azo acid dye, anionic surfactant oil and their mixture determined the 96 hr LC50, and fish behaviours. Subchronic toxicity determined haematology parameters and concentrations of copper and chromium in blood. The 96 hr LC50 was determined by probit analysis and subchronic toxicity was conducted in 90 days. No mortalities were observed in control and anionic surfactant oil treatments. The 96 hr LC50 value of mixture was 26.7 mg I(-1) (95% CL = 20.7 - 46.8) and that of metal complex dark green azo acid dye was not met as the percentage of dead was below 50% of tested organisms. In a treatment of anionic surfactant oil and that of mixture observed behaviours were respiration response, uncoordinated movement, loss of equilibrium, erratic posture and loss of responsiveness. Subchronic toxicity indicated fluctuations in number of erythrocytes, leukocytes and thrombocytes in all chemical treatments. Erythrocyte morphology such as anisocytosis, erythrocytes hypertrophy, karyolysis, cytoplasm vacuolation, ghost cell were observed in fish blood in all chemical treatments. An inverse relation was observed between total copper and chromium concentration in blood. However, the toxicity effect was chemical dose dependent and length of exposure.

  16. Adaptive Marginal Costs-Based Distributed Economic Control of Microgrid Clusters Considering Line Loss

    Directory of Open Access Journals (Sweden)

    Xiaoqian Zhou

    2017-12-01

    Full Text Available When several microgrids (MG are interconnected into microgrid clusters (MGC, they have great potential to improve their reliability. Traditional droop control tends to make the total operating costs higher as the power is distributed by capacity ratios of distributed energy resources (DERs. This paper proposes an adaptive distributed economic control for islanded microgrids which considers line loss, specifically, an interesting marginal costs-based economic droop control is proposed, and consensus-based adaptive controller is applied, to deal with power limits and capacity constraints for storage. The whole expense can be effectively lowered by achieving identical marginal costs for DERs in MGC. Specially, the capacity constraints only for storages are also included to do further optimization. Moreover, consensus-based distributed secondary controllers are used to rapidly restore system frequency and voltage magnitudes. The above controllers only need to interact with neighbor DERs by a sparse communication network, eliminating the necessity of a central controller and enhancing the stability. A MGC, incorporating three microgrids, is used to verify the effectiveness of the proposed methods.

  17. Agarwood Waste as A New Fluid Loss Control Agent in Water-based Drilling Fluid

    Directory of Open Access Journals (Sweden)

    Azlinda Azizi

    2013-10-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Agarwood has been used widely in various ways, including traditional medicine and art. The usage of agarwood has grown broader in modern times include in therapeutic medicines and perfumery. In this paper the agarwood waste has been explored to be used as a fluid loss control agent to control fluid loss without affecting the drilling fluid rheological properties which are density, pH, viscosity, yield point and gel strength. Agarwood waste was used as an additive in the drilling fluid system due to its unique characteristic. Rheological and filtration measurements were performed on the formulated water-based drilling fluid. Formulations of a base solution of fresh water, sodium hydroxide, bentonite, barite, and xanthan gum were presented. The performance of the agarwood waste as the fluid loss control agent was compared with based fluid formulation and water-based drilling fluid with treating with conventional fluid loss control agent (starch. The filtrate volume of drilling fluid with agarwood waste was about 13 ml while for drilling fluid with conventional fluid loss control agent, starch gave 12 ml of filtrate volume after undergoing filtration test by using LPLT filter press. The performance of drilling fluid with agarwood was efficient as drilling fluid with starch. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso

  18. Structural Studies of Protein-Surfactant Complexes

    International Nuclear Information System (INIS)

    Chodankar, S. N.; Aswal, V. K.; Wagh, A. G.

    2008-01-01

    The structure of protein-surfactant complexes of two proteins bovine serum albumin (BSA) and lysozyme in presence of anionic surfactant sodium dodecyl sulfate (SDS) has been studied using small-angle neutron scattering (SANS). It is observed that these two proteins form different complex structures with the surfactant. While BSA protein undergoes unfolding on addition of surfactant, lysozyme does not show any unfolding even up to very high surfactant concentrations. The unfolding of BSA protein is caused by micelle-like aggregation of surfactant molecules in the complex. On the other hand, for lysozyme protein there is only binding of individual surfactant molecules to protein. Lysozyme in presence of higher surfactant concentrations has protein-surfactant complex structure coexisting with pure surfactant micelles

  19. Remodeling of cortical activity for motor control following upper limb loss

    Science.gov (United States)

    Williams, Laura; Pirouz, Nikta; Mizelle, J.C.; Cusack, William; Kistenberg, Rob; Wheaton, Lewis A.

    2016-01-01

    Objective Upper extremity loss presents immediate and lasting challenges for motor control. While sensory and motor representations of the amputated limb undergo plasticity to adjacent areas of the sensorimotor homunculus, it remains unclear whether laterality of motor-related activity is affected by neural reorganization following amputation. Methods Using electroencephalography, we evaluated neural activation patterns of formerly right hand dominant persons with upper limb loss (amputees) performing a motor task with their residual right limb, then their sound left limb. We compared activation patterns with left- and right-handed persons performing the same task. Results Amputees have involvement of contralateral motor areas when using their sound limb and atypically increased activation of posterior parietal regions when using the affected limb. When using the non-amputated left arm, patterns of activation remains similar to right handed persons using their left arm. Conclusions A remodeling of activations from traditionally motor areas into posterior parietal areas occurs for motor planning and execution when using the amputated limb. This may reflect an amputation-specific adaptation of heightened visuospatial feedback for motor control involving the amputated limb. Significance These results identify a neuroplastic mechanism for motor control in amputees, which may have great relevance to development of motor rehabilitation paradigms and prosthesis adaptation. PMID:27472549

  20. Analysis of Loss of Control Parameters for Aircraft Maneuvering in General Aviation

    Directory of Open Access Journals (Sweden)

    Sameer Ud-Din

    2018-01-01

    Full Text Available A rapid increase in the occurrence of loss of control in general aviation has raised concern in recent years. Loss of control (LOC pertains to unique characteristics in which external and internal events act in conjunction. The Federal Aviation Administration (FAA has approved an Integrated Safety Assessment Model (ISAM for evaluating safety in the National Airspace System (NAS. ISAM consists of an event sequence diagram (ESD with fault trees containing numerous parameters, which is recognized as casual risk model. In this paper, we outline an integrated risk assessment framework to model maneuvering through cross-examining external and internal events. The maneuvering is in the critical flight phase with a high number of LOC occurrences in general aviation, where highly trained and qualified pilots failed to maintain aircraft control irrespective of the preventive nature of the events. Various metrics have been presented for evaluating the significance of these parameters to identify the most important ones. The proposed sensitivity analysis considers the accident, fatality, and risk reduction frequencies that assist in the decision-making process and foresees future risks from a general aviation perspective.

  1. Redox-triggered mixing and demixing of surfactants within assemblies formed in solution and at surfaces.

    Science.gov (United States)

    Smith, Timothy J; Wang, Chenxuan; Abbott, Nicholas L

    2017-09-15

    We report experiments that test the hypothesis that redox-triggered changes in the architectures of surfactants permit control of mixing of surfactants within assemblies. Specifically, we describe surface tension, light scattering, atomic force microscopy, and quartz crystal microbalance measurements that characterize the redox-dependent behaviors of cationic surfactants with a ferrocene group located either at the surfactant terminus (11-ferrocenylundecyl-trimethylammonium bromide; FTMA) or head (N,N-dimethylferrocenylmethyldecylammonium bromide; DMFA). In bulk solution, we find that reduced and oxidized FTMA do not mix within micellar assemblies but that reduced and oxidized DMFA do form mixed micelles. Because oxidized FTMA has the architecture of a bolaform surfactant whereas oxidized DMFA has a conventional surfactant architecture with a divalent head group, these results suggest that redox-triggered changes in molecular architecture permit control of the extent of mixing of surfactants in micellar assemblies in bulk solution. This conclusion receives further support from measurements performed with mixtures of dodecyltrimethylammonium bromide and FTMA, with FTMA in either reduced or oxidized states, and was found to extend to hemimicellar assemblies formed at hydrophobic solid surfaces but not to mixed monolayers formed at the surface of water. The latter is attributed to differences in the conformations of surfactants within monolayers and micellar assemblies. Overall, these results provide insight into the design of surfactant assemblies within which mixing can be controlled reversibly using redox processes. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Surfactant Membrane Phases Containing Mixtures of Hydrocarbon and Fluorocarbon Surfactants

    International Nuclear Information System (INIS)

    de Campo, Liliana; Warr, G.G.

    2005-01-01

    Full text: We describe the structure and stability of sponge and lamellar phases comprising mixtures of hydrocarbon and fluorocarbon surfactants. Such mixtures can show limited miscibility with each other, forming for example coexisting populations of hydrocarbon rich and fluorocarbon rich micelles under some circumstances. Our system is based on the well-characterised lamellar and sponge phases of cetylpyridinium chloride, hexanol and 0.2M brine, into which the partially fluorinated surfactant N-1H,1H,2H,2H-tridecafluorooctylpyridinium chloride is incorporated. By probing the structures with SAXS (small angle x-ray scattering) and SANS (small angle neutron scattering) using contrast variation, and by characterizing the dynamic properties with dynamic light scattering, we will describe the effect of incorporating the fluorinated surfactant on the phase equilibria and properties of the surfactant membrane structures. (authors)

  3. Traces of surfactants can severely limit the drag reduction of superhydrophobic surfaces.

    Science.gov (United States)

    Peaudecerf, François J; Landel, Julien R; Goldstein, Raymond E; Luzzatto-Fegiz, Paolo

    2017-07-11

    Superhydrophobic surfaces (SHSs) have the potential to achieve large drag reduction for internal and external flow applications. However, experiments have shown inconsistent results, with many studies reporting significantly reduced performance. Recently, it has been proposed that surfactants, ubiquitous in flow applications, could be responsible by creating adverse Marangoni stresses. However, testing this hypothesis is challenging. Careful experiments with purified water already show large interfacial stresses and, paradoxically, adding surfactants yields barely measurable drag increases. To test the surfactant hypothesis while controlling surfactant concentrations with precision higher than can be achieved experimentally, we perform simulations inclusive of surfactant kinetics. These reveal that surfactant-induced stresses are significant at extremely low concentrations, potentially yielding a no-slip boundary condition on the air-water interface (the "plastron") for surfactant concentrations below typical environmental values. These stresses decrease as the stream-wise distance between plastron stagnation points increases. We perform microchannel experiments with SHSs consisting of stream-wise parallel gratings, which confirm this numerical prediction, while showing near-plastron velocities significantly slower than standard surfactant-free predictions. In addition, we introduce an unsteady test of surfactant effects. When we rapidly remove the driving pressure following a loading phase, a backflow develops at the plastron, which can only be explained by surfactant gradients formed in the loading phase. This demonstrates the significance of surfactants in deteriorating drag reduction and thus the importance of including surfactant stresses in SHS models. Our time-dependent protocol can assess the impact of surfactants in SHS testing and guide future mitigating designs.

  4. Weight loss in a UK commercial all meal provision study: a randomised controlled trial

    OpenAIRE

    Mellor, D D; Whitham, C; Goodwin, S; Morris, M; Reid, M; Atkin, S L

    2013-01-01

    Background: Effective approaches are needed to address the increasing prev- alence of overweight and obesity. The present study investigated whether all meal provision was a more effective and acceptable method for weight loss than a self-directed diet.\\ud Methods: This randomised controlled trial recruited 112 men and women with a body mass index in the range 27–35 kg m–2, who had no comorbidi- ties, from the local area of Hull. Participants were randomised to receive either meal provision o...

  5. Irradiation in the control of post harvest losses- a NRL contribution

    International Nuclear Information System (INIS)

    Roy, M.K.; Prasad, H.H.

    1994-01-01

    In-vitro growth of Phytophthora parasitica is completely prevented by a dose of 1.5kGy of gamma radiation and that of Phomopsis vexans by a dose of 4.0kGy. These doses, however cannot prevent the growth of other three studied fungi viz. Fusarium ceoruleum, Geotrichum candidum and Alternaria alternata and exerted only a reversible effect on their growth. Irradiation as a method for the control of harvest losses in fruits, tomato, rice etc. were studied at Nuclear Research Laboratory (NRL) and the results are given. 2 figs., 8 tabs

  6. Decentralized Model Predictive Control for Cooperative Multiple Vehicles Subject to Communication Loss

    Directory of Open Access Journals (Sweden)

    Hojjat A. Izadi

    2011-01-01

    Full Text Available The decentralized model predictive control (DMPC of multiple cooperative vehicles with the possibility of communication loss/delay is investigated. The neighboring vehicles exchange their predicted trajectories at every sample time to maintain the cooperation objectives. In the event of a communication loss (packet dropout, the most recent available information, which is potentially delayed, is used. Then the communication loss problem changes to a cooperative problem when random large communication delays are present. Such large communication delays can lead to poor cooperation performance and unsafe behaviors such as collisions. A new DMPC approach is developed to improve the cooperation performance and achieve safety in the presence of the large communication delays. The proposed DMPC architecture estimates the tail of neighbor's trajectory which is not available due to the large communication delays for improving the performance. The concept of the tube MPC is also employed to provide the safety of the fleet against collisions, in the presence of large intervehicle communication delays. In this approach, a tube shaped trajectory set is assumed around the trajectory of the neighboring vehicles whose trajectory is delayed/lost. The radius of tube is a function of the communication delay and vehicle's maneuverability (in the absence of model uncertainty. The simulation of formation problem of multiple vehicles is employed to illustrate the effectiveness of the proposed approach.

  7. Postural control in children with typical development and children with profound hearing loss

    Directory of Open Access Journals (Sweden)

    Monteiro de Sousa AM

    2012-05-01

    Full Text Available Aneliza Maria Monteiro de Sousa,1 Jônatas de França Barros,2 Brígido Martins de Sousa Neto31Faculty of Health Sciences, University of Brasilia, Brasilia, Federal District, Brazil; 2Department of Physical Education at the Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil; 3University Center UNIEURO, Brasilia, Federal District, BrazilPurpose: To describe the behavior of the postural control in children with profound sensorineural hearing loss and compare the results of experimental tests with hearing children aged 7 to 10 years.Patients and methods: This is a cross-sectional study where 100 children were divided into experimental and control groups. We used a force platform, AccuSway Plus, where the tests were conducted under the experimental conditions: open base, eyes open (OBEO; open base, eyes closed (OBEC; closed base, eyes open (CBEO; closed base, eyes closed (CBEC. The body sway velocity (V of the center of pressure, the displacement in the anteroposterior direction (COPap and mediolateral (COPml of the center of pressure were the parameters to evaluate the postural control. For statistical analysis we used the nonparametric Mann–Whitney U test, with a significance level of 5%.Results: In comparisons of variables between the groups, the experimental group outperformed by at least 75% of the control group values. In terms of global trends, the experimental group shows higher values of body oscillations in all experimental conditions and variables evaluated. Children with hearing loss had poorer balance performance compared to the group of hearing. The inferential analysis revealed a statistically significant difference in the balance between deaf and hearing children in the OBEC experimental condition in relation to the COPml parameter (P = 0.04. There were no statistically significant differences in comparisons between the sexes when the groups were analyzed separately. The prevalence of unknown etiology

  8. A randomized controlled trial testing an Internet delivered cost-benefit approach to weight loss maintenance.

    Science.gov (United States)

    Leahey, Tricia M; Fava, Joseph L; Seiden, Andrew; Fernandes, Denise; Doyle, Caroline; Kent, Kimberly; La Rue, Molly; Mitchell, Marc; Wing, Rena R

    2016-11-01

    Weight loss maintenance is a significant challenge in obesity treatment. During maintenance the "costs" of adhering to weight management behaviors may outweigh the "benefits." This study examined the efficacy of a novel approach to weight loss maintenance based on modifying the cost-benefit ratio. Individuals who achieved a 5% weight loss (N=75) were randomized to one of three, 10-month maintenance interventions. All interventions were delivered primarily via the Internet. The Standard arm received traditional weight maintenance strategies. To increase benefits, or rewards, for maintenance behaviors, the two cost-benefit intervention conditions received weekly monetary rewards for self-monitoring and social reinforcement via e-coaching. To decrease behavioral costs (boredom) and increase novelty, participants in the cost-benefit conditions also monitored different evidence-based behaviors every two weeks (e.g., Weeks 1 & 2: steps; Week 3 & 4: red foods). The primary difference between the cost-benefit interventions was type of e-coach providing social reinforcement: Professional (CB Pro) or Peer (CB Peer). Study procedures took place in Providence, RI from 2013 to 2014. Retention was 99%. There were significant group differences in weight regain (p=.01). The Standard arm gained 3.5±5.7kg. In contrast, participants in CB Pro and CB Peer lost an additional 1.8±7.0kg and 0.5±6.4kg, respectively. These results suggest that an Internet delivered cost-benefit approach to weight loss maintenance may be effective for long-term weight control. In addition, using peer coaches to provide reinforcement may be a particularly economic alternative to professionals. These data are promising and provide support for a larger, longer trial. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Peripheral airway impairment measured by oscillometry predicts loss of asthma control in children.

    Science.gov (United States)

    Shi, Yixin; Aledia, Anna S; Galant, Stanley P; George, Steven C

    2013-03-01

    We previously showed that impulse oscillometry (IOS) indices of peripheral airway function are associated with asthma control in children. However, little data exist on whether dysfunction in the peripheral airways can predict loss of asthma control. We sought to determine the utility of peripheral airway impairment, as measured by IOS, in predicting loss of asthma control in children. Fifty-four children (age, 7-17 years) with controlled asthma were enrolled in the study. Spirometric and IOS indices of airway function were obtained at baseline and at a follow-up visit 8 to 12 weeks later. Physicians who were blinded to the IOS measurements assessed asthma control (National Asthma Education and Prevention Program guidelines) on both visits and prescribed no medication change between visits. Thirty-eight (70%) patients maintained asthma control between 2 visits (group C-C), and 16 patients had asthma that became uncontrolled on the follow-up visit (group C-UC). There was no difference in baseline spirometric results between the C-C and C-UC groups, except for FEV1/forced vital capacity ratio (86% vs 82%, respectively; P IOS results, including resistance of the respiratory system at 5 Hz (R5; 6.4 vs 4.3 cm H2O · L(-1) · s), frequency dependence of resistance (difference of R5 and resistance of the respiratory system at 20 Hz [R5-20]; 2.0 vs 0.7 cm H2O · L(-1) · s), and reactance area (13.1 vs 4.1 cm H2O · L(-1)), of group C-UC were significantly higher than those of group C-C (P operating characteristic analysis showed baseline R5-20 and reactance area effectively predicted asthma control status at the follow-up visit (area under the curve, 0.91 and 0.90). Children with controlled asthma who have increased peripheral airway IOS indices are at risk of losing asthma control. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  10. MicroRNAs: control and loss of control in human physiology and disease.

    Science.gov (United States)

    Li, Min; Marin-Muller, Christian; Bharadwaj, Uddalak; Chow, Kwong-Hon; Yao, Qizhi; Chen, Changyi

    2009-04-01

    Analysis of the human genome indicates that a large fraction of the genome sequences are RNAs that do not encode any proteins, also known as non-coding RNAs. MicroRNAs (miRNAs) are a group of small non-coding RNA molecules 20-22 nucleotides (nt) in length that are predicted to control the activity of approximately 30% of all protein-coding genes in mammals. miRNAs play important roles in many diseases, including cancer, cardiovascular disease, and immune disorders. The expression of miRNAs can be regulated by epigenetic modification, DNA copy number change, and genetic mutations. miRNAs can serve as a valuable therapeutic target for a large number of diseases. For miRNAs with oncogenic capabilities, potential therapies include miRNA silencing, antisense blocking, and miRNA modifications. For miRNAs with tumor suppression functions, overexpression of those miRNAs might be a useful strategy to inhibit tumor growth. In this review, we discuss the current progress of miRNA research, regulation of miRNA expression, prediction of miRNA targets, and regulatory role of miRNAs in human physiology and diseases, with a specific focus on miRNAs in pancreatic cancer, liver cancer, colorectal cancer, cardiovascular disease, the immune system, and infectious disease. This review provides valuable information for clinicians and researchers who want to recognize the newest advances in this new field and identify possible lines of investigation in miRNAs as important mediators in human physiology and diseases.

  11. Treatment with exogenous surfactant stimulates endogenous surfactant synthesis in premature infants with respiratory distress syndrome

    NARCIS (Netherlands)

    Bunt, JEH; Carnielli, VP; Janssen, DJ; Wattimena, JLD; Hop, WC; Sauer, PJ; Zimmermann, LJI

    2000-01-01

    Objective: Treatment of preterm infants with respiratory distress syndrome (RDS) with exogenous surfactant has greatly improved clinical outcome. Some infants require multiple doses, and it has not been studied whether these large amounts of exogenous surfactant disturb endogenous surfactant

  12. Responses to Financial Loss During the Great Recession: An Examination of Sense of Control in Late Midlife.

    Science.gov (United States)

    Mejía, Shannon T; Settersten, Richard A; Odden, Michelle C; Hooker, Karen

    2016-07-01

    The "Great Recession" shocked the primary institutions that help individuals and families meet their needs and plan for the future. This study examines middle-aged adults' experiences of financial loss and considers how socioeconomic and interpersonal resources facilitate or hinder maintaining a sense of control in the face of economic uncertainty. Using the 2006 and 2010 waves of the Health and Retirement Study, change in income and wealth, giving help to and receiving help from others, household complexity, and sense of control were measured among middle-aged adults (n = 3,850; age = 51-60 years). Socioeconomic resources predicted both the level of and change in the engagement of interpersonal resources prior to and during the Great Recession. Experiences of financial loss were associated with increased engagement of interpersonal resources and decreased sense of control. The effect of financial loss was dampened by education. Sense of control increased with giving help and decreased with household complexity. Findings suggest that, across socioeconomic strata, proportional loss in financial resources resulted in a loss in sense of control. However, responses to financial loss differed by socioeconomic status, which differentiated the ability to maintain a sense of control following financial loss. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Structure of a scheme of emergency control to avoid blackout due to interconnection lines loss

    Energy Technology Data Exchange (ETDEWEB)

    Luz, L.T. da; Werberich, L.C.; Herve, H.M. [Companhia Estadual de Energia Eletrica do Estado do Rio Grande do Sul (CEEE), Porto Alegre, RS (Brazil)

    1994-12-31

    This work presents the structure of Gravatai Emergency Control Scheme (ECS) with short about its development and operation. This ECS was made to avoid two kinds of problems for the systems of Companhia Estadual de Energia Eletrica (CEEE). The first one is the voltage collapse that happens after the opening of one of the 525 kv LTs of the interconnection with the Brazilian Interconnected System (BIS). The second one is the CEEE isolating after the 525 kV network loss. We show the ECS existence reason and we describe its functional structure, the substations, the circuits and the amount of load shedding involved by the system. Finally, we present the project of a control structure based on microcomputer which is being developed for this ECS. (author) 3 refs., 11 figs.

  14. Controlled Transverse Blow-up of Highenergy Proton Beams for Aperture Measurements and Loss Maps

    CERN Document Server

    Hӧfle, W; Redaelli, S; Schmidt, R; Valuch, D; Wollmann, D; Zerlauth, M

    2012-01-01

    A technique was developed to blow-up transversely in a controlled way high energy proton beams in the LHC. The technique is based on band limited white noise excitation that is injected into the transverse damper feedback loop. The injected signal can be gated to selectively blow-up individual trains of bunches. The speed of transverse blow-up can be precisely controlled. This opens the possibility to perform safely and efficiently aperture measurements and loss maps with high intensity bunch trains well above stored beam energies that are considered to be safe. In particular, lengthy procedures for measurements at top energy, otherwise requiring multiple fills of individual bunches, can be avoided. In this paper, the method is presented and results from beam measurements are discussed and compared with alternative blowup methods.

  15. Are loss of control while eating and overeating valid constructs? A critical review of the literature.

    Science.gov (United States)

    Goldschmidt, Andrea B

    2017-04-01

    Binge eating is a marker of weight gain and obesity, and a hallmark feature of eating disorders. Yet its component constructs - overeating and loss of control (LOC) while eating - are poorly understood and difficult to measure. The objective of this study is to critically review the human literature concerning the validity of LOC and overeating across the age and weight spectrum. English-language articles addressing the face, convergent, discriminant and predictive validity of LOC and overeating were included. Loss of control and overeating appear to have adequate face validity. Emerging evidence supports the convergent and predictive validity of the LOC construct, given its unique cross-sectional and prospective associations with numerous anthropometric, psychosocial and eating behaviour-related factors. Overeating may be best conceptualized as a marker of excess weight status. Binge eating constructs, particularly in the context of subjectively large episodes, are challenging to measure reliably. Few studies addressed overeating in the absence of LOC, thereby limiting conclusions about the validity of the overeating construct independent of LOC. Additional studies addressing the discriminant validity of both constructs are warranted. Suggestions for future weight-related research and for appropriately defining binge eating in the eating disorders diagnostic scheme are presented. © 2017 World Obesity Federation.

  16. Portion controlled ready-to-eat meal replacement is associated with short term weight loss: a randomised controlled trial.

    Science.gov (United States)

    Kuriyan, Rebecca; Lokesh, Deepa P; D'Souza, Ninoshka; Priscilla, Divya J; Peris, Chandni Halcyon; Selvam, Sumithra; Kurpad, Anura V

    2017-01-01

    Strategies to prevent and treat overweight/obesity are urgently needed. This study assessed the effect of a short-term intake of ready-to-eat cereal on body weight and waist circumference of overweight/obese individuals in comparison to a control group. A randomized, controlled 2-arm trial was carried out on 101 overweight/obese (Body Mass Index - 29.2±2.4 kg/m2) females aged 18 to 44 years, at St. John's Medical College Hospital. The intervention group received a low fat, ready to eat cereal, replacing two meals/day for two weeks. The control group was provided with standard dietary guidelines for weight loss and energy requirements for both groups were calculated similarly. Anthropometric, dietary, appetite and health status assessments were carried out at baseline and at the end of two weeks. At the end of two weeks, the mean reductions in body weight and waist circumference were significantly greater in the intervention group, -0.53 kg; 95% CI (-0.86 to -0.19) for body weight and -1.39 cm; 95% CI (-1.78, -0.99) for waist circumference. The intervention group had a significantly higher increase in dietary intakes of certain vitamins, fiber and sugar, and significantly higher reductions in total and polyunsaturated fats and sodium intakes, as compared to the control group (peat cereal could be effective for short-term weight loss, with some improvements in the nutrient intake profile. However, studies of longer duration are needed.

  17. Plant and microbial controls on nitrogen retention and loss in a Humid Tropical Forest

    Energy Technology Data Exchange (ETDEWEB)

    Templer, P.; Silver, W.; Pett-Ridge, J.; DeAngelis, K.M.; Firestone, M.K.

    2009-09-15

    Humid tropical forests are generally characterized by the lack of nitrogen (N) limitation to net primary productivity, yet paradoxically have high potential for N loss. We conducted an intensive field experiment with {sup 15}NH{sub 4} and {sup 15}NO{sub 3} additions to highly weathered tropical forest soils to determine the relative importance of N retention and loss mechanisms. Over half of all the NH{sub 4}{sup +} produced from gross mineralization was rapidly converted to NO{sub 3}{sup -} during the process of gross nitrification. During the first 24 h plant roots took up 28 % of the N mineralized, dominantly as NH{sub 4}{sup +}, and were a greater sink for N than soil microbial biomass. Soil microbes were not a significant sink for added {sup 15}NH{sub 4}{sup +} or {sup 15}NO{sub 3}{sup -} during the first 24 hr, and only for {sup 15}NH{sub 4}{sup +} after 7 d. Patterns of microbial community composition, as determined by Terminal Restriction Fragment Length Polymorphism analysis, were weakly, but significantly correlated with nitrification and denitrification to N{sub 2}O. Rates of dissimilatory NO{sub 3}{sup -} reduction to NH{sub 4}{sup +} (DNRA) were high in this forest, accounting for up to 25 % of gross mineralization and 35 % of gross nitrification. DNRA was a major sink for NO{sub 3}{sup -} which may have contributed to the lower rates of N{sub 2}O and leaching losses. Despite considerable N conservation via DNRA and plant NH{sub 4}{sup +} uptake, the fate of approximately 45% of the NO{sub 3}{sup -} produced and 22% of the NH{sub 4}{sup +} produced were not measured in our fluxes, suggesting that other important pathways for N retention and loss (e.g., denitrification to N{sub 2}) are important in this system. The high proportion of mineralized N that was rapidly nitrified and the fates of that NO{sub 3}{sup -} highlight the key role of gross nitrification as a proximate control on N retention and loss in humid tropical forest soils. Furthermore, our

  18. Applying economic incentives to increase effectiveness of an outpatient weight loss program (TRIO) - A randomized controlled trial.

    Science.gov (United States)

    Finkelstein, Eric A; Tham, Kwang-Wei; Haaland, Benjamin A; Sahasranaman, Aarti

    2017-07-01

    The prevalence of overweight and obesity has more than doubled in the past three decades, leading to rising rates of non-communicable diseases. This study tests whether adding a payment/rewards (term reward) program to an existing evidence-based weight loss program can increase weight loss and weight loss maintenance. We conducted a parallel-group randomized controlled trial from October 2012 to October 2015 with 161 overweight or obese individuals randomized to either control or reward arm in a 1:2 ratio. Control and reward arm participants received a four month weight loss program at the LIFE (Lifestyle Improvement and Fitness Enhancement) Centre at Singapore General Hospital. Those in the reward arm paid a fee of S$165.00 (1US$ = 1.35S$) to access a program that provided rewards of up to S$660 for meeting weight loss and physical activity goals. Participants could choose to receive rewards as guaranteed cash payments or a lottery ticket with a 1 in 10 chance of winning but with the same expected value. The primary outcome was weight loss at months 4, 8, and 12. 161 participants were randomized to control (n = 54) or reward (n = 107) arms. Average weight loss was more than twice as great in the reward arm compared to the control arm at month 4 when the program concluded (3.4 kg vs 1.4 kg, p loss and weight loss maintenance when combined with an evidence-based weight loss program. Future efforts should attempt to replicate this approach and identify how to cost effectively expand these programs to maximize their reach. This study is registered at www.clinicaltrials.gov (Identifier: NCT01533454). Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Metabolic Syndrome Increases the Risk of Sudden Sensorineural Hearing Loss in Taiwan: A Case-Control Study.

    Science.gov (United States)

    Chien, Chen-Yu; Tai, Shu-Yu; Wang, Ling-Feng; Hsi, Edward; Chang, Ning-Chia; Wu, Ming-Tsang; Ho, Kuen-Yao

    2015-07-01

    Sudden sensorineural hearing loss has been reported to be associated with diabetes mellitus, hypertension, and hyperlipidemia in previous studies. The aim of this study was to examine whether metabolic syndrome increases the risk of sudden sensorineural hearing loss in Taiwan. A case-control study. Tertiary university hospital. We retrospectively investigated 181 cases of sudden sensorineural hearing loss and 181 controls from the Department of Otorhinolaryngology, Kaohsiung Medical University Hospital, in southern Taiwan from 2010 to 2012, comparing their clinical variables. We analyzed the relationship between metabolic syndrome and sudden sensorineural hearing loss. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III with Asian modifications. The demographic and clinical characteristics, audiometry results, and outcome were reviewed. Subjects with metabolic syndrome had a 3.54-fold increased risk (95% confidence interval [CI] = 2.00-6.43, P diabetes mellitus, hypertension, and hyperlipidemia. With increases in the number of metabolic syndrome components, the risk of sudden sensorineural hearing loss increased (P for trend Vertigo was associated with a poor outcome (P = .02; 95% CI = 1.13~5.13, adjusted odds ratio = 2.39). The hearing loss pattern may influence the outcome of sudden sensorineural hearing loss (P Vertigo and total hearing loss were indicators of a poor outcome in sudden sensorineural hearing loss. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  20. Asthma control and productivity loss in those with work-related asthma: A population-based study.

    Science.gov (United States)

    Wong, Alyson; Tavakoli, Hamid; Sadatsafavi, Mohsen; Carlsten, Chris; FitzGerald, J Mark

    2017-06-01

    In Canada, asthma is the third leading cause of work loss, yet little is known about the associated productivity loss. The goal of this study was to look at the relationship between asthma control and productivity loss, particularly contrasting those with work-related asthma (WRA) and non-work-related asthma (NWRA). A population-based random sample of adults with asthma in British Columbia, Canada, was prospectively recruited. Asthma control was graded according to Global Initiative for Asthma classification, while productivity loss and presence of WRA was assessed using questionnaires. Ordinal regression models were then used to associate WRA with asthma control. Generalized linear models were applied to estimate the average productivity loss associated with different levels of asthma control among those with WRA and NWRA. The study included 300 employed adults. Sixty (20%) had WRA. The odds of being controlled were significantly lower in those with WRA (OR = 0.23, 95% CI: 0.09, 0.56; P productivity loss due to presenteeism ($659.1 [95% CI: 12.9, 1581.5; P = 0.04]), but not absenteeism ($88.7 [95% CI: -86.5, 279.6; P = 0.35]), when compared to those with NWRA and uncontrolled asthma. There was no significant difference when a similar comparison was made for those with controlled or partially controlled asthma. WRA is associated with worse asthma control and increased productivity loss. Presenteeism makes a significant contribution to productivity loss and should be considered when evaluating the overall economic burden of asthma, particularly WRA.

  1. Shedding light on the different behavior of ionic and nonionic surfactants in emulsion polymerization: from atomistic simulations to experimental observations.

    Science.gov (United States)

    Magi Meconi, Giulia; Ballard, Nicholas; Asua, José M; Zangi, Ronen

    2017-12-06

    surfactants and should help with future development of processes for improved control over polymerization.

  2. Applications of Kalman Filtering to nuclear material control. [Kalman filtering and linear smoothing for detecting nuclear material losses

    Energy Technology Data Exchange (ETDEWEB)

    Pike, D.H.; Morrison, G.W.; Westley, G.W.

    1977-10-01

    The feasibility of using modern state estimation techniques (specifically Kalman Filtering and Linear Smoothing) to detect losses of material from material balance areas is evaluated. It is shown that state estimation techniques are not only feasible but in most situations are superior to existing methods of analysis. The various techniques compared include Kalman Filtering, linear smoothing, standard control charts, and average cumulative summation (CUSUM) charts. Analysis results indicated that the standard control chart is the least effective method for detecting regularly occurring losses. An improvement in the detection capability over the standard control chart can be realized by use of the CUSUM chart. Even more sensitivity in the ability to detect losses can be realized by use of the Kalman Filter and the linear smoother. It was found that the error-covariance matrix can be used to establish limits of error for state estimates. It is shown that state estimation techniques represent a feasible and desirable method of theft detection. The technique is usually more sensitive than the CUSUM chart in detecting losses. One kind of loss which is difficult to detect using state estimation techniques is a single isolated loss. State estimation procedures are predicated on dynamic models and are well-suited for detecting losses which occur regularly over several accounting periods. A single isolated loss does not conform to this basic assumption and is more difficult to detect.

  3. The litter cover of citrus leaves control soil and water losses in chemically managed orchards

    Science.gov (United States)

    Cerdà, A.; Jurgensen, M. F.; González-Peñaloza, F. A.

    2012-04-01

    measured by dessication. All the measurements were conducted during the summer (August 2008). The results show that the litter cover control the erosion processes. The orange leaves lying on the floor can reduce the soil losses to negligible values when the cover is higher than 60 %. After 20 % of litter cover the soil losses are dramatically reduced to values lower than 50 % of the soil losses under bare soil conditions. The litter cover also reduces the runoff rates, but the reduction is in 50 % for 80 % litter cover. The 20 % litter cover results only in a small reduction in the runoff discharge. The research conducted demonstrate that the farmers should maintain the leaves on the floor (do not brush them as they use to do) to control the high erosion rates. This research study is being supported by the the research project CGL2008-02879/BTE

  4. Biomimicry of surfactant protein C.

    Science.gov (United States)

    Brown, Nathan J; Johansson, Jan; Barron, Annelise E

    2008-10-01

    Since the widespread use of exogenous lung surfactant to treat neonatal respiratory distress syndrome, premature infant survival and respiratory morbidity have dramatically improved. Despite the effectiveness of the animal-derived surfactant preparations, there still remain some concerns and difficulties associated with their use. This has prompted investigation into the creation of synthetic surfactant preparations. However, to date, no clinically used synthetic formulation is as effective as the natural material. This is largely because the previous synthetic formulations lacked analogues of the hydrophobic proteins of the lung surfactant system, SP-B and SP-C, which are critical functional constituents. As a result, recent investigation has turned toward the development of a new generation of synthetic, biomimetic surfactants that contain synthetic phospholipids along with a mimic of the hydrophobic protein portion of lung surfactant. In this Account, we detail our efforts in creating accurate mimics of SP-C for use in a synthetic surfactant replacement therapy. Despite SP-C's seemingly simple structure, the predominantly helical protein is extraordinarily challenging to work with given its extreme hydrophobicity and structural instability, which greatly complicates the creation of an effective SP-C analogue. Drawing inspiration from Nature, two promising biomimetic approaches have led to the creation of rationally designed biopolymers that recapitulate many of SP-C's molecular features. The first approach utilizes detailed SP-C structure-activity relationships and amino acid folding propensities to create a peptide-based analogue, SP-C33. In SP-C33, the problematic and metastable polyvaline helix is replaced with a structurally stable polyleucine helix and includes a well-placed positive charge to prevent aggregation. SP-C33 is structurally stable and eliminates the association propensity of the native protein. The second approach follows the same design

  5. Hydrologic Controls on Losses of Individual Components of Crude Oil in the Subsurface

    Science.gov (United States)

    Bekins, B. A.; Baedecker, M. J.; Eganhouse, R. P.; Drennan, D.; Herkelrath, W. N.; Warren, E.; Cozzarelli, I.

    2011-12-01

    The time frame for natural attenuation of crude oil contamination in the subsurface has been studied for the last 27 years at a spill site located near Bemidji, Minnesota, USA. Data from the groundwater contaminant plume show that dissolved benzene concentrations adjacent to the oil decreased by 50% between 1993 and 2007. Previous studies at the site showed that benzene and ethylbenzene undergo minimal degradation in the methanogenic zone of the plume while toluene and o-xylene degrade rapidly in this zone. Other studies have shown that degradation of benzene under methanogenic conditions occurs in some cases but is generally unreliable in the field. In this study concentrations of volatile components in the crude oil source were examined to determine if the observed benzene decrease near the oil source zone was due a change in the ability of the methanogenic microbial community to degrade benzene or long-term depletion of the oil source. Oil samples collected in 2008 had benzene concentrations ranging from 7-61% of values measured in archived oil representative of the spill consistent with depletion of the oil source. Several lines of evidence indicate that dissolution and conservative transport control the losses of benzene and ethylbenzene from the crude oil. Laboratory microcosms constructed using sediments from the methanogenic zone near the source and incubated for over 13 months with an anaerobic mineral salt solution spiked with ~2 mg/L benzene exhibited no benzene losses. Concentrations of benzene and ethylbenzene in oil samples collected from five wells were linearly correlated to interpolated maximum pore space oil saturations adjacent to each well (R2 =0.72 and 0.55 respectively), indicating that losses of these compounds from the oil were controlled by the relative permeability of groundwater through the oil body. Moreover benzene loss from the oil was greater than ethylbenzene, consistent with their relative aqueous solubilities. Losses of other oil

  6. Losses Evaluation for a Two-Level Three-Phase Stand-Alone Voltage Source Converter Using Model Predictive Control

    DEFF Research Database (Denmark)

    Al hasheem, Mohamed; Dragicevic, Tomislav; Rivera, Marco

    2017-01-01

    conventional and improved controller is conducted in terms of losses. The switching and conduction losses for the VSC are calculated using MATLAB/SIMULINK and PLECS software. A power level up to 1 kW is considered for the conventional and the improved schemes. All simulation and experimental results......This paper discusses a Model Predictive Control (MPC) scheme for a Voltage Source Converter (VSC) where the aim is to minimize losses and Total Harmonics distortion (THD) compared to the conventional MPC scheme. Different Cost Functions (CFs) are applied to the stand-alone VSC. A comparison between...

  7. IMMUNE-RESPONSE AFTER SURFACTANT TREATMENT OF NEWBORN-INFANTS WITH RESPIRATORY-DISTRESS SYNDROME

    NARCIS (Netherlands)

    Bambang Oetomo, S.; Bos, A.F.; de Lei, L.; Okken, A.; VANSONDEREN, L; HALLIDAY, HL; WALTI, H

    1993-01-01

    We examined the sera of 68 newborn infants with respiratory distress syndrome; 49 were treated with a natural porcine-derived surfactant preparation and 19 were controls. Serum of the patients was collected before, 3 weeks and 3 months after surfactant treatment. To detect any antibody that had been

  8. A randomised controlled trial of expectant management versus surgical evacuation of early pregnancy loss.

    Science.gov (United States)

    Nadarajah, Ravichandran; Quek, Yek Song; Kuppannan, Kaliammah; Woon, Shu Yuan; Jeganathan, Ravichandran

    2014-07-01

    To show whether a clinically significant difference in success rates exists between expectant and surgical management of early pregnancy loss. Randomised controlled trial comparing expectant versus surgical management of early pregnancy loss over a 1-year period from 1st January to 31st December 2009 at Sultanah Aminah Hospital, Johor Bahru. Pregnant women with missed or incomplete miscarriages at gestations up to 14 weeks were recruited in this study. The success rate in the surgical group was measured as curettage performed without any complications during or after the procedure, while the success rate in the expectant group was defined as complete spontaneous expulsion of products of conception within 6 weeks without any complication. A total of 360 women were recruited and randomised to expectant or surgical management, with 180 women in each group. There was no statistically significant difference in the success rate between the groups and between the different types of miscarriage. With expectant management, 131 (74%) patients had a complete spontaneous expulsion of products of conception, of whom 106 (83%) women miscarried within 7 days. However, the rates of unplanned admissions (18.1%) and unplanned surgical evacuations (17.5%) in the expectant group were significantly higher than the rates (7.4% and 8% respectively) in the surgical group. The complications in both groups were similar. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Validation of Safety-Critical Systems for Aircraft Loss-of-Control Prevention and Recovery

    Science.gov (United States)

    Belcastro, Christine M.

    2012-01-01

    Validation of technologies developed for loss of control (LOC) prevention and recovery poses significant challenges. Aircraft LOC can result from a wide spectrum of hazards, often occurring in combination, which cannot be fully replicated during evaluation. Technologies developed for LOC prevention and recovery must therefore be effective under a wide variety of hazardous and uncertain conditions, and the validation framework must provide some measure of assurance that the new vehicle safety technologies do no harm (i.e., that they themselves do not introduce new safety risks). This paper summarizes a proposed validation framework for safety-critical systems, provides an overview of validation methods and tools developed by NASA to date within the Vehicle Systems Safety Project, and develops a preliminary set of test scenarios for the validation of technologies for LOC prevention and recovery

  10. Subscale Flight Testing for Aircraft Loss of Control: Accomplishments and Future Directions

    Science.gov (United States)

    Cox, David E.; Cunningham, Kevin; Jordan, Thomas L.

    2012-01-01

    Subscale flight-testing provides a means to validate both dynamic models and mitigation technologies in the high-risk flight conditions associated with aircraft loss of control. The Airborne Subscale Transport Aircraft Research (AirSTAR) facility was designed to be a flexible and efficient research facility to address this type of flight-testing. Over the last several years (2009-2011) it has been used to perform 58 research flights with an unmanned, remotely-piloted, dynamically-scaled airplane. This paper will present an overview of the facility and its architecture and summarize the experimental data collected. All flights to date have been conducted within visual range of a safety observer. Current plans for the facility include expanding the test volume to altitudes and distances well beyond visual range. The architecture and instrumentation changes associated with this upgrade will also be presented.

  11. Loss of pH control in Plasmodium falciparum parasites subjected to oxidative stress.

    Directory of Open Access Journals (Sweden)

    Donelly A van Schalkwyk

    Full Text Available The intraerythrocytic malaria parasite is susceptible to oxidative stress and this may play a role in the mechanism of action of some antimalarial agents. Here we show that exposure of the intraerythrocytic malaria parasite to the oxidising agent hydrogen peroxide results in a fall in the intracellular ATP level and inhibition of the parasite's V-type H(+-ATPase, causing a loss of pH control in both the parasite cytosol and the internal digestive vacuole. In contrast to the V-type H(+-ATPase, the parasite's digestive vacuole H(+-pyrophosphatase is insensitive to hydrogen peroxide-induced oxidative stress. This work provides insights into the effects of oxidative stress on the intraerythrocytic parasite, as well as providing an alternative possible explanation for a previous report that light-induced oxidative stress causes selective lysis of the parasite's digestive vacuole.

  12. The role of eating and emotion in binge eating disorder and loss of control eating.

    Science.gov (United States)

    Pollert, Garrett A; Engel, Scott G; Schreiber-Gregory, Deanna N; Crosby, Ross D; Cao, Li; Wonderlich, Stephen A; Tanofsky-Kraff, Marian; Mitchell, James E

    2013-04-01

    Binge eating, defined as the consumption of large amounts of food during which a sense of loss of control (LOC) is experienced, is associated with negative affect. However, there are no data on the experience of LOC after accounting for the effects of negative affect and caloric intake. Nine adult patients with binge eating disorder (BED) and 13 obese nonbinge eating disorder (NBED) participants carried a palmtop computer for 7 days, rating momentary mood and sense of LOC multiple times each day. Electronic food logs were collected once daily. After removing the effects of caloric intake and negative affect, a significant group difference was observed for ratings of LOC between BED and NBED participants. These findings suggest the experience of LOC in adults with BED is a salient feature of binge episodes, beyond that explained by caloric intake and momentary affect. Copyright © 2012 Wiley Periodicals, Inc.

  13. Controlling the opto-mechanics of a cantilever in an interferometer via cavity loss

    Energy Technology Data Exchange (ETDEWEB)

    Schmidsfeld, A. von, E-mail: avonschm@uos.de; Reichling, M., E-mail: reichling@uos.de [Fachbereich Physik, Universität Osnabrück, Barbarastraße 7, 49076 Osnabrück (Germany)

    2015-09-21

    In a non-contact atomic force microscope, based on interferometric cantilever displacement detection, the optical return loss of the system is tunable via the distance between the fiber end and the cantilever. We utilize this for tuning the interferometer from a predominant Michelson to a predominant Fabry-Pérot characteristics and introduce the Fabry-Pérot enhancement factor as a quantitative measure for multibeam interference in the cavity. This experimentally easily accessible and adjustable parameter provides a control of the opto-mechanical interaction between the cavity light field and the cantilever. The quantitative assessment of the light pressure acting on the cantilever oscillating in the cavity via the frequency shift allows an in-situ measurement of the cantilever stiffness with remarkable precision.

  14. Beyond deficit or compensation: new insights on postural control after long-term total visual loss.

    Science.gov (United States)

    Russo, Maitê M; Lemos, Thiago; Imbiriba, Luís A; Ribeiro, Nathalia L; Vargas, Claudia D

    2017-02-01

    Loss of vision is well known to affect postural control in blind subjects. This effect has classically been framed in terms of deficit or compensation depending on whether body sway increases or decreases in comparison with that of sighted subjects with the eyes open. However, studies have shown that postural responses can be modulated by the context and that changes in postural sway may not necessarily mean a worsened or improved postural control. The goal of our study was to test whether balance is affected by the context in blind subjects. Additional to the quantification of center of pressure (COP) displacement, measurements of body motion (COG) and the correspondent net neuromuscular response (COP-COG) were evaluated in anterior-posterior and medial-lateral directions. Thirty-eight completely blind and thirty-two sighted subjects participated of this study. The volunteers were asked to stand barefoot on a force platform for 60 s in two different conditions: feet apart and feet together. Sighted participants performed the tests with both the eyes open and eyes closed. Results showed that the COP-COG displacements in the blind group were greater than those of the sighted group with eyes open in almost all conditions tested, but not in eyes closed condition. However, the COP and COG results confirmed that the postural responses were context dependent. Together these results suggest that total visual loss does not just lead to a balance deficit or compensation, but to a specific postural signature that might imply in enhancing COP, COG and/or COP-COG in specific postural conditions.

  15. Hyperbaric oxygen therapy as salvage treatment for sudden sensorineural hearing loss: a prospective controlled study.

    Science.gov (United States)

    Pezzoli, M; Magnano, M; Maffi, L; Pezzoli, L; Marcato, P; Orione, M; Cupi, D; Bongioannini, G

    2015-07-01

    The most commonly used treatment for sensorineural sudden hearing loss (SSHL) in clinical practice is the administration of steroids; however, a favorable result is not always obtained. We studied 58 patients who failed to recover after primary treatment with IV steroids, 44 of these met our inclusion criteria (mean age 50.7, 27 males, range 30-74). We treated 23 patients (mean age 47.3, 16 males, age range 22-74) with hyperbaric oxygen therapy (HBO) (2.5 ATA for 60 min for 15 treatments), while 21 (mean age 54.5, 11 males, age range 22-71) patients refused to be treated and served as a non-randomized control group. Patients treated with HBO had a mean improvement of 15.6 dB (SD ± 15.3), with 1 of them completely healed, 5 with a good recovery, 10 with a fair recovery and 7 unchanged. Patients who were not treated had a spontaneous mean improvement of 5.0 dB (SD ± 11.4) with 3 patients with a good recovery, 1 patient with a fair recovery and 17 patients unchanged. Mean improvement was significantly better in patients treated with HBO compared to controls (p = 0.0133). Patients with worst hearing had the greater degree of improvement whether or not they were treated in the first 10 days after the onset of the hearing loss or between 11 and 30 days. In conclusion, hyperbaric oxygen therapy can lead to significant improvement of pure tone hearing thresholds in patients with SSHL who failed primary corticosteroid treatment and are within 4 weeks of the onset of deafness.

  16. Laboratory assessment of sudden sensorineural hearing loss: A case-control study.

    Science.gov (United States)

    Fasano, Tommaso; Pertinhez, Thelma A; Tribi, Lorenzo; Lasagni, Daniela; Pilia, Annalisa; Vecchia, Luigi; Baricchi, Roberto; Bianchin, Giovanni

    2017-10-01

    Sudden sensorineural hearing loss (SSHL) is an otologic emergency that affects five to 30 subjects per 100,000/year. The cause of SSHL remains unknown or uncertain in 70% to 90% of cases, and treatment decisions are usually made without knowing the etiology. Prospective case-control study. One hundred thirty-one idiopathic SSHL patients were recruited from January 2014 to June 2015 in concordance with the Statements of Clinical Practice Guideline and divided into groups according to the disease severity. A clinical laboratory assessment was completed on blood samples collected from SSHL patients and control subjects. Multivariable regression analysis was performed to investigate the association between laboratory data and SSHL basis. Only a few SSHL patients were positive for autoimmunity or viral infection. Statistically significant (P < .05) higher levels of blood glucose, glycated hemoglobin (HbA1C), lipoprotein (a), and factor VIII were found in SSHL patients compared to controls. Furthermore, blood glucose, HbA1C, uric acid, factor VIII, and homocysteine were significantly associated to disease severity. Gluco-metabolic, lipidic, and coagulative laboratory data support the vascular hypothesis for SSHL and its severity. 3b Laryngoscope, 127:2375-2381, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  17. Noise-induced hearing loss and associated factors among vector control workers in a Malaysian state.

    Science.gov (United States)

    Masilamani, Retneswari; Rasib, Abdul; Darus, Azlan; Ting, Anselm Su

    2014-11-01

    This study aims to determine the prevalence and associated factors of noise-induced hearing loss (NIHL) among vector control workers in the state of Negeri Sembilan, Malaysia. This was an analytical cross-sectional study conducted on 181 vector control workers who were working in district health offices in a state in Malaysia. Data were collected using a self-administered questionnaire and audiometry. Prevalence of NIHL was 26% among this group of workers. NIHL was significantly associated with the age-group of 40 years and older, length of service of 10 or more years, current occupational noise exposure, listening to loud music, history of firearms use, and history of mumps/measles infection. Following logistic regression, age of more than 40 years and noise exposure in current occupation were associated with NIHL with an odds ratio of 3.45 (95% confidence interval = 1.68-7.07) and 6.87 (95% confidence interval = 1.54-30.69), respectively, among this group of vector control workers. © 2012 APJPH.

  18. Rheological response of methylcellulose toward alkanediyl-α,ω-bis(dimethylcetylammonium bromide) surfactants with varying spacer length.

    Science.gov (United States)

    Shah, Rais Ahmad; Chat, Oyais Ahmad; Maswal, Masrat; Rather, Ghulam Mohammad; Dar, Aijaz Ahmad

    2016-06-25

    The modulation of properties of methylcellulose (MC) by cationic gemini surfactants with varying spacer lengths was studied employing tensiometry, rheometry and turbidimetry. Surface tension measurements anticipate that the gemini surfactant with longer spacer chain length saturates MC at lower concentrations owing to its greater hydrophobicity compared to shorter spacer analogues. Rheometric and turbidimetric measurements suggest that at very low concentrations of gemini surfactants, ion-dipole type of interactions between MC and gemini surfactants promote the extension of polymer chains which is manifested by an initial increase in the low shear viscosity and gelation temperature of MC-gemini surfactant systems, and lowering of turbidity. Such interactions were found to be stronger in case of 16-4-16 than 16-5-16, and almost absent in case of 16-6-16 surfactant system. However at concentrations above CAC, hydrophobic forces operative between MC and gemini surfactants were found to be more for 16-6-16 than that of 16-5-16 and 16-4-16. The final levelling of MC viscosity in presence of all the three gemini surfactants and the variation of gelation temperature suggests the solubilization of network junctions in the surfactant micelles. Moreover, the presence of gemini surfactant strongly affects the interaction of MC with a model hydrophobic drug rifampicin.The results highlight the importance of gemini surfactants and their spacer length in controlling the structural dynamics of MC and its effective use in pharmaceutical and food industry. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. A Technique to Estimate the Equivalent Loss Resistance of Grid-Tied Converters for Current Control Analysis and Design

    DEFF Research Database (Denmark)

    Vidal, Ana; Yepes, Alejandro G.; Fernandez, Francisco Daniel Freijedo

    2015-01-01

    by means of an equivalent series resistance. This paper proposes a method to identify the VSC equivalent loss resistance for the proper tuning of the current control loop. It is based on analysis of the closed-loop transient response provided by a synchronous proportional-integral current controller......, according to the internal model principle. The method gives a set of loss resistance values linked to working conditions, which can be used to improve the tuning of the current controllers, either by online adaptation of the controller gains or by open-loop adaptive adjustment of them according to prestored......Rigorous analysis and design of the current control loop in voltage source converters (VSCs) requires an accurate modeling. The loop behavior can be significantly influenced by the VSC working conditions. To consider such effect, converter losses should be included in the model, which can be done...

  20. Control of blood glucose in type 2 diabetes without weight loss by modification of diet composition

    Directory of Open Access Journals (Sweden)

    Gannon Mary C

    2006-03-01

    Full Text Available Abstract Background Over the past several years our research group has taken a systematic, comprehensive approach to determining the effects on body function (hormonal and non-hormonal of varying the amounts and types of proteins, carbohydrates and fats in the diet. We have been particularly interested in the dietary management of type 2 diabetes. Our objective has been to develop a diet for people with type 2 diabetes that does not require weight loss, oral agents, or insulin, but that still controls the blood glucose concentration. Our overall goal is to enable the person with type 2 diabetes to control their blood glucose by adjustment in the composition rather than the amount of food in their diet. Methods This paper is a brief summary and review of our recent diet-related research, and the rationale used in the development of diets that potentially are useful in the treatment of diabetes. Results We determined that, of the carbohydrates present in the diet, absorbed glucose is largely responsible for the food-induced increase in blood glucose concentration. We also determined that dietary protein increases insulin secretion and lowers blood glucose. Fat does not significantly affect blood glucose, but can affect insulin secretion and modify the absorption of carbohydrates. Based on these data, we tested the efficacy of diets with various protein:carbohydrate:fat ratios for 5 weeks on blood glucose control in people with untreated type 2 diabetes. The results were compared to those obtained in the same subjects after 5 weeks on a control diet with a protein:carbohydrate:fat ratio of 15:55:30. A 30:40:30 ratio diet resulted in a moderate but significant decrease in 24-hour integrated glucose area and % total glycohemoglobin (%tGHb. A 30:20:50 ratio diet resulted in a 38% decrease in 24-hour glucose area, a reduction in fasting glucose to near normal and a decrease in %tGHb from 9.8% to 7.6%. The response to a 30:30:40 ratio diet was similar

  1. The effect of a motivational intervention on weight loss is moderated by level of baseline controlled motivation

    Directory of Open Access Journals (Sweden)

    Tate Deborah F

    2010-01-01

    Full Text Available Abstract Background Clinic-based behavioral weight loss programs are effective in producing significant weight loss. A one-size-fits-all approach is often taken with these programs. It may be beneficial to tailor programs based on participants' baseline characteristics. Type and level of motivation may be an important factor to consider. Previous research has found that, in general, higher levels of controlled motivation are detrimental to behavior change while higher levels of autonomous motivation improve the likelihood of behavior modification. Methods This study assessed the outcomes of two internet behavioral weight loss interventions and assessed the effect of baseline motivation levels on program success. Eighty females (M (SD age 48.7 (10.6 years; BMI 32.0 (3.7 kg/m2; 91% Caucasian were randomized to one of two groups, a standard group or a motivation-enhanced group. Both received a 16-week internet behavioral weight loss program and attended an initial and a four-week group session. Weight and motivation were measured at baseline, four and 16 weeks. Hierarchical regression analysis was conducted to test for moderation. Results There was significant weight loss at 16-weeks in both groups (p p = 0.57 (standard group 3.4 (3.6 kg; motivation-enhanced group 3.9 (3.4 kg. Further analysis was conducted to examine predictors of weight loss. Baseline controlled motivation level was negatively correlated with weight loss in the entire sample (r = -0.30; p = 0.01. Statistical analysis revealed an interaction between study group assignment and baseline level of controlled motivation. Weight loss was not predicted by baseline level of controlled motivation in the motivation-enhanced group, but was significantly predicted by controlled motivation in the standard group. Baseline autonomous motivation did not predict weight change in either group. Conclusions This research found that, in participants with high levels of baseline controlled motivation

  2. The NULevel trial of a scalable, technology-assisted weight loss maintenance intervention for obese adults after clinically significant weight loss: study protocol for a randomised controlled trial.

    Science.gov (United States)

    Evans, Elizabeth H; Araújo-Soares, Vera; Adamson, Ashley; Batterham, Alan M; Brown, Heather; Campbell, Miglena; Dombrowski, Stephan U; Guest, Alison; Jackson, Daniel; Kwasnicka, Dominika; Ladha, Karim; McColl, Elaine; Olivier, Patrick; Rothman, Alexander J; Sainsbury, Kirby; Steel, Alison J; Steen, Ian Nicholas; Vale, Luke; White, Martin; Wright, Peter; Sniehotta, Falko F

    2015-09-22

    Effective weight loss interventions are widely available but, after weight loss, most individuals regain weight. This article describes the protocol for the NULevel trial evaluating the effectiveness and cost-effectiveness of a systematically developed, inexpensive, scalable, technology-assisted, behavioural intervention for weight loss maintenance (WLM) in obese adults after initial weight loss. A 12-month single-centre, two-armed parallel group, participant randomised controlled superiority trial is underway, recruiting a total of 288 previously obese adults after weight loss of ≥5 % within the previous 12 months. Participants are randomly assigned to intervention or control arms, with a 1:1 allocation, stratified by sex and percentage of body weight lost (<10 % vs ≥10 %). Change in weight (kg) from baseline to 12 months is the primary outcome. Weight, other anthropometric variables and 7-day physical activity (assessed via accelerometer) measures are taken at 0 and 12 months. Questionnaires at 0, 6 and 12 months assess psychological process variables, health service use and participant costs. Participants in the intervention arm initially attend an individual face-to-face WLM consultation with an intervention facilitator and then use a mobile internet platform to self-monitor and report their diet, daily activity (via pedometer) and weight through daily weighing on wirelessly connected scales. Automated feedback via mobile phone, tailored to participants' weight regain and goal progress is provided. Participants in the control arm receive quarterly newsletters (via links embedded in text messages) and wirelessly connected scales. Qualitative process evaluation interviews are conducted with a subsample of up to 40 randomly chosen participants. Acceptability and feasibility of procedures, cost-effectiveness, and relationships among socioeconomic variables and WLM will also be assessed. It is hypothesised that participants allocated to the intervention arm will

  3. The interaction of a model active pharmaceutical with cationic surfactant and the subsequent design of drug based ionic liquid surfactants.

    Science.gov (United States)

    Qamar, Sara; Brown, Paul; Ferguson, Steven; Khan, Rafaqat Ali; Ismail, Bushra; Khan, Abdur Rahman; Sayed, Murtaza; Khan, Asad Muhammad

    2016-11-01

    Interactions of active pharmaceutical ingredients (API) with surfactants remain an important research area due to the need to improve drug delivery systems. In this study, UV-Visible spectrophotometry was used to investigate the interactions between a model low molecular weight hydrophilic drug sodium valproate (SV) and cationic surfactant cetyltrimethylammonium bromide (CTAB). Changes in the spectra of SV were observed in pre- and post-micellar concentrations of CTAB. The binding constant (Kb) values and the number of drug molecules encapsulated per micelle were calculated, which posed the possibility of mixed micelle formation and strong complexation between SV and CTAB. These results were compared to those of a novel room temperature surface active ionic liquid, which was synthesized by the removal of inorganic counterions from a 1:1 mixture of CTAB and SV. In this new compound the drug now constitutes a building block of the carrier and, as such, has considerably different surfactant properties to its building blocks. In addition, enhanced solubility in a range of solvents, including simulated gastric fluid, was observed. The study provides valuable experimental evidence concerning the performance of drug based surfactant ionic liquids and how their chemical manipulation, without altering the architecture of the API, leads to control of surfactant behavior and physicochemical properties. In turn, this should feed through to improved and controlled drug release rates and delivery mechanisms, and the prevention of precipitation or formation of polymorphs typical of crystalline form APIs. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Effects of a Dual Sensory Loss Protocol on Hearing Aid Outcomes: A Randomized Controlled Trial

    NARCIS (Netherlands)

    Vreeken, H.L.; van Rens, G.H.M.B.; Kramer, S.E.; Knol, D.L.; van Nispen, R.M.A.

    2015-01-01

    Dual sensory loss (DSL; concurrent vision and hearing loss) negatively affects quality of life. As speechreading is hampered, use of hearing AIDS (HAs) is important for older adults with DSL. However, due to vision loss, use of small and complex HAs is assumed to be difficult. An integrative DSL

  5. The Krafft temperature of surfactant solutions

    Directory of Open Access Journals (Sweden)

    Manojlović Jelena Ž.

    2012-01-01

    Full Text Available Our main motivation to revisit the solution properties of cetyltrimethylammonium bromide is related to the clear requirement for better control of the adsorption parameters to form uniform self-assembled monolayers on muscovite mica substrates. To readily monitor the temporal evolution of structural details in cetyltrimethylammonium bromide solutions, we realized a rather simple conductivity experiment. Conductivity measurements were carried out as a function of temperature, to look closer into the Krafft temperature behavior of this surfactant. We measured the electrical conductivity of different concentrations of aqueous cetyltrimethylammonium bromide solutions, below and above the critical micells concentration.

  6. Clearance of 99mTc-DTPA and experimentally increased alveolar surfactant content

    International Nuclear Information System (INIS)

    Bos, J.A.H.; Wollmer, P.; Bakker, W.; Hannappel, E.; Lachmann, B.

    1992-01-01

    The authors measured clearance of 99m Tc-labeled diethylenetriamine pentaacetic acid ( 99m Tc-DTPA) in rabbits with experimentally increased alveolar surfactant content. In one group of animals, surfactant production was increased by treatment with ambroxol, and another group of animals was treated with tracheal instillation of natural surfactant. A group of untreated control animals and animals treated with instillation of saline were also studied. Clearance was measured during standard conditions of mechanical ventilation and during ventilation with large tidal volumes. In ambroxol- and surfactant-treated groups, clearance rate was reduced compared with untreated control animals. In contrast, clearance rate increased after saline instillation. The differences were observed at both modes of ventilation. The findings indicate that the pulmonary surfactant system is a rate-limiting factor for the clearance of 99m Tc-DTPA and that the volume dependence of clearance is not explained by stretching of the alveolar wall only. 28 refs., 2 figs., 1 tab

  7. Fungal growth on anion surfactant medium.

    Science.gov (United States)

    Hamada, Nobuo; Abe, Niichiro

    2009-12-01

    Before the present study, no fungi using anion surfactant as a nutrient had been identified, although some fungi were known to use nonion surfactant. Washing water collected from 63 washing machines was inoculated onto 0.1% LAS (Sodium dodecyl benzenesulfonate) anion surfactant media to identify fungi that can feed on anion-surfactant. Small dark colonies of fungi were found on several of the Petri-dishes from 12 days after inoculation. These were identified as Cladophialophora boppii and Exophiala spinifera using morphological features and rDNA data. A number of the isolates of C. boppii specifically were recognized as using anion surfactant as a nutrient. The growth characteristics of the two fungal species were examined on surfactant media of three kinds. Apart from anion surfactant, the fungi were also able to grow on nonion surfactant and on soap. The application of these fungi for environmental cleansing after detergent pollution is also discussed.

  8. Synthesis of carbohydrate-based surfactants

    Science.gov (United States)

    Pemberton, Jeanne E.; Polt, Robin L.; Maier, Raina M.

    2016-11-22

    The present invention provides carbohydrate-based surfactants and methods for producing the same. Methods for producing carbohydrate-based surfactants include using a glycosylation promoter to link a carbohydrate or its derivative to a hydrophobic compound.

  9. Controls on Nitrogen Retention and Loss in Urban and Rural Forest Ecosystems.

    Science.gov (United States)

    Templer, P. H.

    2011-12-01

    (Adelges tsugae Annand), an introduced aphid-like insect from Japan, threatens hemlock stands throughout the eastern United States. The hemlock woolly adelgid was first reported in forests of the eastern United States in the early 1950s and is currently leading to mortality of eastern hemlock trees from Georgia to Massachusetts. We found that rates of nitrogen inputs to the forest floor were 4-5 times greater, and rates of nitrogen losses via leachate were more than ten times greater, at the Arnold Arboretum compared to Harvard Forest. Our results also show that current management regimes used to control the hemlock woolly adelgid, such as salvage cutting, may be reducing nitrogen losses in urban areas due to rapid regrowth of vegetation and the associated uptake of nitrogen by those plants. In contrast, cutting of trees in rural areas may be leading to proportionately greater losses of nitrogen in those sites, though the total magnitude of nitrogen lost is still smaller than in urban sites. Results of this study suggest that the combination of the hemlock woolly adelgid, atmospheric nitrogen inputs and management practices lead to changes in the nitrogen cycle within eastern hemlock forest ecosystems.

  10. Surfactant protein A and surfactant protein D variation in pulmonary disease

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Husby, Steffen; Holmskov, Uffe

    2007-01-01

    preferentially to sugars on a broad spectrum of pathogen surfaces and thereby facilitating immune functions including viral neutralization, clearance of bacteria, fungi and apoptotic and necrotic cells, modulation of allergic reactions, and resolution of inflammation. SP-A and SP-D can interact with receptor...... lavage and blood have indicated associations with a multitude of pulmonary inflammatory diseases. In addition, accumulating evidence in mouse models of infection and inflammation indicates that recombinant forms of the surfactant proteins are biologically active in vivo and may have therapeutic potential...... in controlling pulmonary inflammatory disease. The presence of the surfactant collectins, especially SP-D, in non-pulmonary tissues, such as the gastrointestinal tract and genital organs, suggest additional actions located to other mucosal surfaces. The aim of this review is to summarize studies on genetic...

  11. Simulation Modeling Requirements for Loss-of-Control Accident Prevention of Turboprop Transport Aircraft

    Science.gov (United States)

    Crider, Dennis; Foster, John V.

    2012-01-01

    In-flight loss of control remains the leading contributor to aviation accident fatalities, with stall upsets being the leading causal factor. The February 12, 2009. Colgan Air, Inc., Continental Express flight 3407 accident outside Buffalo, New York, brought this issue to the forefront of public consciousness and resulted in recommendations from the National Transportation Safety Board to conduct training that incorporates stalls that are fully developed and develop simulator standards to support such training. In 2010, Congress responded to this accident with Public Law 11-216 (Section 208), which mandates full stall training for Part 121 flight operations. Efforts are currently in progress to develop recommendations on implementation of stall training for airline pilots. The International Committee on Aviation Training in Extended Envelopes (ICATEE) is currently defining simulator fidelity standards that will be necessary for effective stall training. These recommendations will apply to all civil transport aircraft including straight-wing turboprop aircraft. Government-funded research over the previous decade provides a strong foundation for stall/post-stall simulation for swept-wing, conventional tail jets to respond to this mandate, but turboprops present additional and unique modeling challenges. First among these challenges is the effect of power, which can provide enhanced flow attachment behind the propellers. Furthermore, turboprops tend to operate for longer periods in an environment more susceptible to ice. As a result, there have been a significant number of turboprop accidents as a result of the early (lower angle of attack) stalls in icing. The vulnerability of turboprop configurations to icing has led to studies on ice accumulation and the resulting effects on flight behavior. Piloted simulations of these effects have highlighted the important training needs for recognition and mitigation of icing effects, including the reduction of stall margins

  12. Emotion regulation and loss of control eating in community-based adolescents

    Science.gov (United States)

    Goldschmidt, Andrea B.; Lavender, Jason M.; Hipwell, Alison E.; Stepp, Stephanie D.; Keenan, Kate

    2016-01-01

    The current study investigated concurrent and prospective associations between emotion-related constructs and loss of control (LOC) eating in adolescents. Community-based females (N=588) completed annual self-report assessments of LOC eating, emotional awareness, emotion regulation strategies, and neuroticism from ages 16–18 years. Linear regressions and a regression-based multiple mediation model using bootstrapping were computed to examine the relationships among emotion-related constructs and LOC eating frequency. In the concurrent model, age 18 emotional awareness and emotion regulation strategies were associated with age 18 LOC eating, F(6, 416)=12.11, pemotional awareness predicted age 18 LOC eating, F(7, 425)=11.67, peating and age 17 demographics, body mass index, and neuroticism, F change=4.26, p=.015. In the multiple mediation model, age 18 emotion regulation strategies mediated the association between age 17 neuroticism and age 18 LOC eating, indirect effect estimate=.003, 95% confidence interval=.001–.005, after controlling for age 16 LOC eating and age 17 demographics, body mass index, and emotion regulation variables. Results suggest that deficient emotion regulation may contribute to the onset and maintenance of LOC eating in adolescence (although effects were small), and may partially explain the well-established prospective relationship between negative emotionality and later LOC eating. Prevention and early intervention programs should seek to improve adaptive coping in at-risk populations. PMID:27040409

  13. A new algorithm for optimum voltage and reactive power control for minimizing transmission lines losses

    International Nuclear Information System (INIS)

    Ghoudjehbaklou, H.; Danai, B.

    2001-01-01

    Reactive power dispatch for voltage profile modification has been of interest to power utilities. Usually local bus voltages can be altered by changing generator voltages, reactive shunts, ULTC transformers and SVCs. Determination of optimum values for control parameters, however, is not simple for modern power system networks. Heuristic and rather intelligent algorithms have to be sought. In this paper a new algorithm is proposed that is based on a variant of a genetic algorithm combined with simulated annealing updates. In this algorithm a fuzzy multi-objective a approach is used for the fitness function of the genetic algorithm. This fuzzy multi-objective function can efficiently modify the voltage profile in order to minimize transmission lines losses, thus reducing the operating costs. The reason for such a combination is to utilize the best characteristics of each method and overcome their deficiencies. The proposed algorithm is much faster than the classical genetic algorithm and cna be easily integrated into existing power utilities software. The proposed algorithm is tested on an actual system model of 1284 buses, 799 lines, 1175 fixed and ULTC transformers, 86 generators, 181 controllable shunts and 425 loads

  14. Isolation, feeling 'stuck' and loss of control: understanding persistence of depression in British Pakistani women.

    Science.gov (United States)

    Gask, Linda; Aseem, Saadia; Waquas, Ayesha; Waheed, Waquas

    2011-01-01

    Persistent depression is more commonly experienced by British Pakistani women. The processes by which this results in an experience of chronic depression are not well understood. Qualitative thematic analysis of 15 in-depth interviews with British Pakistani women being treated for depression in primary care, collected in the process of a larger three-centre research project to explore experience of depression and its treatment (the QUEST-D study) in England. Three key overlapping themes emerged: a) 'feeling stuck'--for many of the women, the persistence of depression was experienced as inescapable because it was related to family conflict that seemed impossible to resolve; b) 'isolation'--which might be externally determined by social and cultural factors but also in some cases appeared to be self-imposed; c) 'control'--issues related to loss of a sense of control in depression, and attempts to regain it. The study was carried out in only one area of the United Kingdom, East Lancashire. It formed part of a larger study to explore views of treatment, and there were therefore limited opportunities for further development of some of the themes that have subsequently emerged in this secondary analysis of the data. Psychological therapy for this population needs to be tailored to specific needs by identifying and addressing both the underlying cause(s) and the specific consequences of depression and associated social isolation for each individual person. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Affective Aspects of Perceived Loss of Control and Potential Implications for Brain-Computer Interfaces

    Directory of Open Access Journals (Sweden)

    Sebastian Grissmann

    2017-07-01

    Full Text Available Most brain-computer interfaces (BCIs focus on detecting single aspects of user states (e.g., motor imagery in the electroencephalogram (EEG in order to use these aspects as control input for external systems. This communication can be effective, but unaccounted mental processes can interfere with signals used for classification and thereby introduce changes in the signal properties which could potentially impede BCI classification performance. To improve BCI performance, we propose deploying an approach that potentially allows to describe different mental states that could influence BCI performance. To test this approach, we analyzed neural signatures of potential affective states in data collected in a paradigm where the complex user state of perceived loss of control (LOC was induced. In this article, source localization methods were used to identify brain dynamics with source located outside but affecting the signal of interest originating from the primary motor areas, pointing to interfering processes in the brain during natural human-machine interaction. In particular, we found affective correlates which were related to perceived LOC. We conclude that additional context information about the ongoing user state might help to improve the applicability of BCIs to real-world scenarios.

  16. Surfactant Therapy of ALI and ARDS

    OpenAIRE

    Raghavendran, K; Willson, D; Notter, RH

    2011-01-01

    This article examines exogenous lung surfactant replacement therapy and its utility in mitigating clinical acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS). Biophysical research has documented that lung surfactant dysfunction can be reversed or mitigated by increasing surfactant concentration, and multiple studies in animals with ALI/ARDS have shown that respiratory function and pulmonary mechanics in vivo can be improved by exogenous surfactant administration. Exoge...

  17. Cationic surfactants as the hydrolytic micellar catalysts

    OpenAIRE

    Janošcová, Petra

    2013-01-01

    Cationic surfactants as the hydrolytic micellar catalysts Petra Janošcová The effectiveness of hydrolytic cleavage of the pesticide fenitrothionin cationic surfactants micellar media has been tested. All used surfactants increased the rate of fenitrothionhydrolysis, which was the evidence of micellar catalysis. For some surfactants decreases has been evident at the highest rate of hydrolysis concentrations. It has been the result of a phenomenon called the effect of empty micelles. High hydro...

  18. Q-Axis Flux-Based Sensorless Vector Control of Induction Motor Taking into Account Iron Loss

    Science.gov (United States)

    Tsuji, Mineo; Chen, Shuo; Kai, Toshihiro; Hamasaki, Shin-Ichi

    This paper presents a sensorless vector control system for induction motors by taking into account iron loss, in which a flux-observer-based method is applied. Since the flux observer is constructed in a synchronously rotating reference frame with respect to the rotor flux of a current model and the iron loss resistance of parallel exiting circuit is used, the proposed system is very simple and the compensation of iron loss related to the operating frequency is directly realized while calculating rotor fluxes and slip frequency. The accuracies of estimated torque and speed are improved. The effectiveness of the proposed system has been verified by digital simulation and experimentation.

  19. Pre-Meal Affective State and Laboratory Test Meal Intake in Adolescent Girls with Loss of Control Eating

    Science.gov (United States)

    Ranzenhofer, Lisa M.; Hannallah, Louise; Field, Sara E.; Shomaker, Lauren B.; Stephens, Mark; Sbrocco, Tracy; Kozlosky, Merel; Reynolds, James; Yanovski, Jack A.; Tanofsky-Kraff, Marian

    2013-01-01

    Loss of control eating confers risk for excess weight gain and exacerbated disordered eating. Affect theory proposes that loss of control eating is used to cope with negative mood states. Self-report data suggest that negative affect may contribute to the etiology of loss of control eating, but this theory has not been well-tested using laboratory paradigms. We examined associations between pre-meal affective states and intake during a laboratory test meal. One-hundred and ten adolescent girls with reported loss of control eating whose body mass index fell between the 85th and 97th percentile for age and sex completed state mood ratings prior to a test-meal. Results indicated that pre-meal state negative affect was associated with greater carbohydrate and less protein consumption, as well as greater snack and dessert and less fruit and dairy intake. All girls experienced significant decreases in negative affect from pre- to post- meal, but intake during the meal was unassociated with post-meal affect. In support of affect theory, negative affective states reported among girls with loss of control may be a driving factor for increased energy-dense food intake, which may play a role in excess weight gain. PMID:23603224

  20. Binding of cationic surfactants to humic substances

    NARCIS (Netherlands)

    Ishiguro, M.; Tan, W.; Koopal, L.K.

    2007-01-01

    Commercial surfactants are introduced into the environment either through waste products or site-specific contamination. The amphiphilic nature of both surfactants and humic substances (HS) leads to their mutual attraction especially when surfactant and HS are oppositely charged. Binding of the

  1. Surfactant adsorption to soil components and soils

    NARCIS (Netherlands)

    Ishiguro, Munehide; Koopal, Luuk K.

    2016-01-01

    Soils are complex and widely varying mixtures of organic matter and inorganic materials; adsorption of surfactants to soils is therefore related to the soil composition. We first discuss the properties of surfactants, including the critical micelle concentration (CMC) and surfactant adsorption on

  2. Loss to follow-up in a randomized controlled trial study for pediatric weight management (EPOC).

    Science.gov (United States)

    Warschburger, Petra; Kröller, Katja

    2016-11-14

    Attrition is a serious problem in intervention studies. The current study analyzed the attrition rate during follow-up in a randomized controlled pediatric weight management program (EPOC study) within a tertiary care setting. Five hundred twenty-three parents and their 7-13-year-old children with obesity participated in the randomized controlled intervention trial. Follow-up data were assessed 6 and 12 months after the end of treatment. Attrition was defined as providing no objective weight data. Demographic and psychological baseline characteristics were used to predict attrition at 6- and 12-month follow-up using multivariate logistic regression analyses. Objective weight data were available for 49.6 (67.0) % of the children 6 (12) months after the end of treatment. Completers and non-completers at the 6- and 12-month follow-up differed in the amount of weight loss during their inpatient stay, their initial BMI-SDS, educational level of the parents, and child's quality of life and well-being. Additionally, completers supported their child more than non-completers, and at the 12-month follow-up, families with a more structured eating environment were less likely to drop out. On a multivariate level, only educational background and structure of the eating environment remained significant. The minor differences between the completers and the non-completers suggest that our retention strategies were successful. Further research should focus on prevention of attrition in families with a lower educational background. Current Controlled Trials ISRCTN24655766 . Registered 06 September 2008, updated 16 May 2012.

  3. Rubella in Sub-Saharan Africa and sensorineural hearing loss: a case control study.

    Science.gov (United States)

    Caroça, Cristina; Vicente, Vera; Campelo, Paula; Chasqueira, Maria; Caria, Helena; Silva, Susana; Paixão, Paulo; Paço, João

    2017-02-01

    Rubella infection can affect several organs and cause birth defects that are responsible for congenital rubella syndrome (CRS). Congenital hearing loss is the most common symptom of this syndrome, occurring in approximately 60% of CRS cases. Worldwide, over 100 000 babies are born with CRS every year. There is no specific treatment for rubella, but the disease is preventable by vaccination. Since 1969, the rubella vaccine has been implemented in many countries, but in Africa, only a few countries routinely immunize against rubella. The aim of this study was to estimate the rate of infection from the wild-type rubella virus in São Tomé and Príncipe by determining rubella seroprevalence with a DBS method. The goal of this study was to reinforce the need for implementation of the rubella vaccine in this country. As secondary objectives, the validation of a DBS method was first attempted and an association between seroprevalence and hearing loss was assessed. We collected samples from individuals observed during humanitarian missions in São Tomé and Príncipe. All individuals underwent an audiometric evaluation, and a drop of blood was collected for the dried blood spot (DBS). We define two groups: the case group (individuals with unilateral or bilateral hearing loss (HL)) and the control group (individuals with two normal ears). Patients were excluded if they suffered from conductive HL, if they showed evidence of possible causes of HL, if they had developmental delay or if they refused to participate in the study. Among the 315 subjects, we found 64.1% individuals with IgG for the rubella virus, 32.1% without immunity for the rubella virus and 3.8% who were borderline. In the control group, 62.6% were positive for the rubella IgG, whereas in the case group, 72% were positive. Analyzing both groups, with ages ranging from 2 to 14 years of age and from 15 to 35 years of age, we found a seroprevalence of 50.3% to rubella in the younger group and 82.1% in the

  4. Rubella in Sub-Saharan Africa and sensorineural hearing loss: a case control study

    Directory of Open Access Journals (Sweden)

    Cristina Caroça

    2017-02-01

    Full Text Available Abstract Background Rubella infection can affect several organs and cause birth defects that are responsible for congenital rubella syndrome (CRS. Congenital hearing loss is the most common symptom of this syndrome, occurring in approximately 60% of CRS cases. Worldwide, over 100 000 babies are born with CRS every year. There is no specific treatment for rubella, but the disease is preventable by vaccination. Since 1969, the rubella vaccine has been implemented in many countries, but in Africa, only a few countries routinely immunize against rubella. The aim of this study was to estimate the rate of infection from the wild-type rubella virus in São Tomé and Príncipe by determining rubella seroprevalence with a DBS method. The goal of this study was to reinforce the need for implementation of the rubella vaccine in this country. As secondary objectives, the validation of a DBS method was first attempted and an association between seroprevalence and hearing loss was assessed. Methods We collected samples from individuals observed during humanitarian missions in São Tomé and Príncipe. All individuals underwent an audiometric evaluation, and a drop of blood was collected for the dried blood spot (DBS. We define two groups: the case group (individuals with unilateral or bilateral hearing loss (HL and the control group (individuals with two normal ears. Patients were excluded if they suffered from conductive HL, if they showed evidence of possible causes of HL, if they had developmental delay or if they refused to participate in the study. Results Among the 315 subjects, we found 64.1% individuals with IgG for the rubella virus, 32.1% without immunity for the rubella virus and 3.8% who were borderline. In the control group, 62.6% were positive for the rubella IgG, whereas in the case group, 72% were positive. Analyzing both groups, with ages ranging from 2 to 14 years of age and from 15 to 35 years of age, we found a seroprevalence of 50.3% to

  5. Laboratory-and mill-scale study of surfactant spray flotation deinking

    Science.gov (United States)

    Greg Delozier; Yulin Zhao; Yulin Deng; David White; Junyong Zhu; Mark Prein

    2005-01-01

    As the cost of quality waste paper continues to escalate in response to an increased global demand for this finite resource, loss of saleable fiber within flotation rejects becomes both environmentally and economically unacceptable. The ability of surfactant spray technology to reduce fiber loss without detriment to pulp brightness gains has been demonstrated during...

  6. Gender differences in scalp hair growth rates are maintained but reduced in pattern hair loss compared to controls.

    Science.gov (United States)

    Van Neste, D J J; Rushton, D H

    2016-08-01

    Hair loss is related to follicular density, programmed regrowth and hair productivity. The dissatisfaction with hair growth in patients experiencing hair loss might be due to slower linear hair growth rate (LHGR). LHGR and hair diameter was evaluated in Caucasian controls and patients with patterned hair loss employing the validated non-invasive, contrast-enhanced-phototrichogram with exogen collection. We evaluated 59,765 anagen hairs (controls 24,609, patients 35,156) and found thinner hairs grew slower than thicker hairs. LHGR in normal women was generally higher than in normal men. LHGR correlates with hair diameter (P growth rates. Compared with hair of equal thickness in controls, subjects affected with patterned hair loss showed reduced hair growth rates, an observation found in both male and female patients. Males with pattern hair loss showed further reduction in growth rates as clinical severity worsened. However, sample size limitations prevented statistical evaluation of LHGR in severely affected females. Caucasian ethnicity. In pattern hair loss, LHGR significantly contributes to the apparent decrease in hair volume in affected areas. In early onset, LHRG might have a prognostic value in females but not in males. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Tuning metal–carboxylate coordination in crystalline metal–organic frameworks through surfactant media

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Junkuo [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Ye, Kaiqi [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012 (China); He, Mi [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371 (Singapore); Xiong, Wei-Wei; Cao, Wenfang; Lee, Zhi Yi [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Wang, Yue [State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012 (China); Wu, Tom [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371 (Singapore); Huo, Fengwei [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Liu, Xiaogang [Department of Chemistry, National University of Singapore, Singapore 117543 (Singapore); Institute of Materials Research Engineering, Agency for Science, Technology and Research, Singapore 117602 (Singapore); Zhang, Qichun, E-mail: qczhang@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2013-10-15

    Although it has been widely demonstrated that surfactants can efficiently control the size, shape and surface properties of micro/nanocrystals of metal–organic frameworks (MOFs) due to the strong interactions between surfactants and crystal facets of MOFs, the use of surfactants as reaction media to grow MOF single crystals is unprecedented. In addition, compared with ionic liquids, surfactants are much cheaper and can have multifunctional properties such as acidic, basic, neutral, cationic, anionic, or even block. These factors strongly motivate us to develop a new synthetic strategy: growing crystalline MOFs in surfactants. In this report, eight new two-dimensional (2D) or three-dimensional (3D) MOFs have been successfully synthesized in an industrially-abundant and environmentally-friendly surfactant: polyethylene glycol-200 (PEG-200). Eight different coordination modes of carboxylates, ranging from monodentate η{sup 1} mode to tetra-donor coordination µ{sub 3}-η{sup 1}:η{sup 2}:η{sup 1} mode, have been founded in our research. The magnetic properties of Co-based MOFs were investigated and MOF NTU-Z6b showed a phase transition with a Curie temperature (T{sub c}) at 5 K. Our strategy of growing crystalline MOFs in surfactant could offer exciting opportunities for preparing novel MOFs with diverse structures and interesting properties. - Graphical abstract: Surfactants have been used as reaction media to grow MOF single crystals for the first time. Eight new two-dimensional or three-dimensional MOFs were successfully synthesized in surfactant polyethylene glycol-200 (PEG-200). Coordination modes of carboxylates up to eight were founded. Our strategy of growing crystalline MOFs in surfactant could offer exciting opportunities for preparing novel MOFs with diverse structures and interesting properties. Display Omitted - Highlights: • Surfactant-thermal synthesis of crystalline metal–organic frameworks. • Eight new 2-D or 3-D metal–organic frameworks

  8. Surfactant/detergent titration analysis method and apparatus for machine working fluids, surfactant-containing wastewater and the like

    Science.gov (United States)

    Smith, D.D.; Hiller, J.M.

    1998-02-24

    The present invention is an improved method and related apparatus for quantitatively analyzing machine working fluids and other aqueous compositions such as wastewater which contain various mixtures of cationic, neutral, and/or anionic surfactants, soluble soaps, and the like. The method utilizes a single-phase, non-aqueous, reactive titration composition containing water insoluble bismuth nitrate dissolved in glycerol for the titration reactant. The chemical reaction of the bismuth ion and glycerol with the surfactant in the test solutions results in formation of micelles, changes in micelle size, and the formation of insoluble bismuth soaps. These soaps are quantified by physical and chemical changes in the aqueous test solution. Both classical potentiometric analysis and turbidity measurements have been used as sensing techniques to determine the quantity of surfactant present in test solutions. This method is amenable to the analysis of various types of new, in-use, dirty or decomposed surfactants and detergents. It is a quick and efficient method utilizing a single-phase reaction without needing a separate extraction from the aqueous solution. It is adaptable to automated control with simple and reliable sensing methods. The method is applicable to a variety of compositions with concentrations from about 1% to about 10% weight. It is also applicable to the analysis of waste water containing surfactants with appropriate pre-treatments for concentration. 1 fig.

  9. Surfactant/detergent titration analysis method and apparatus for machine working fluids, surfactant-containing wastewater and the like

    Science.gov (United States)

    Smith, Douglas D.; Hiller, John M.

    1998-01-01

    The present invention is an improved method and related apparatus for quantitatively analyzing machine working fluids and other aqueous compositions such as wastewater which contain various mixtures of cationic, neutral, and/or anionic surfactants, soluble soaps, and the like. The method utilizes a single-phase, non-aqueous, reactive titration composition containing water insoluble bismuth nitrate dissolved in glycerol for the titration reactant. The chemical reaction of the bismuth ion and glycerol with the surfactant in the test solutions results in formation of micelles, changes in micelle size, and the formation of insoluble bismuth soaps. These soaps are quantified by physical and chemical changes in the aqueous test solution. Both classical potentiometric analysis and turbidity measurements have been used as sensing techniques to determine the quantity of surfactant present in test solutions. This method is amenable to the analysis of various types of new, in-use, dirty or decomposed surfactants and detergents. It is a quick and efficient method utilizing a single-phase reaction without needing a separate extraction from the aqueous solution. It is adaptable to automated control with simple and reliable sensing methods. The method is applicable to a variety of compositions with concentrations from about 1% to about 10% weight. It is also applicable to the analysis of waste water containing surfactants with appropriate pre-treatments for concentration.

  10. Segregation in like-charged polyelectrolyte-surfactant mixtures can be precisely tuned via manipulation of the surfactant mass ratio.

    Science.gov (United States)

    Wills, Peter W; Lopez, Sonia G; Burr, Jocelyn; Taboada, Pablo; Yeates, Stephen G

    2013-04-09

    In this study, we consider segregative phase separation in aqueous mixtures of quaternary ammonium surfactants didecyldimethylammonium chloride (DDQ) and alkyl (C12, 70%; C14 30%) dimethyl benzyl ammonium chloride (BAC) upon the addition of poly(diallyldimethylammonium) chloride (pDADMAC) as a function of both concentration and molecular weight. The nature of the surfactant type is dominant in determining the concentration at which separation into an upper essentially surfactant-rich phase and lower polyelectrolyte-rich phase is observed. However, for high-molecular-weight pDADMAC there is a clear indication of an additional depletion flocculation effect. When the BAC/DDQ ratio is tuned, the segregative phase separation point can be precisely controlled. We propose a phase separation mechanism for like-charged quaternary ammonium polyelectrolyte/surfactant/water mixtures induced by a reduction in the ionic atmosphere around the surfactant headgroup and possible ion pair formation. An additional polyelectrolyte-induced depletion flocculation effect was also observed.

  11. Respiratory failure following anti-lung serum: study on mechanisms associated with surfactant system damage

    International Nuclear Information System (INIS)

    Lachmann, B.; Hallman, M.; Bergmann, K.C.

    1987-01-01

    Within 2 minutes intravenous anti-lung serum (ALS) into guinea pig induces a respiratory failure that is fatal within 30 min. The relationship between surfactant, alveolar-capillary permeability and respiratory failure was studied. Within two minutes ALS induced a leak in the alveolar-capillary barrier. Within 30 minutes 28.3% (controls, given normal rabbit serum: 0.7%) of iv 131 I-albumin, and 0.5% (controls 0.02%) of iv surfactant phospholipid tracer were recovered in bronchoalveolar lavage. Furthermore, 57% (controls 32%) of the endotracheally administered surfactant phospholipid became associated with lung tissue and only less than 0.5% left the lung. The distribution of proteins and phospholipids between the in vivo small volume bronchoalveolar lavages and the ex vivo bronchoalveolar lavages were dissimilar: 84% (controls 20%) of intravenously injected, lavageable 131 I-albumin and 23% (controls 18%) of total lavageable phospholipid were recovered in the in vivo small volume bronchoalveolar lavages. ALS also decreased lavageable surfactant phospholipid by 41%. After ALS the minimum surface tension increased. The supernatant of the lavage increased the minimum surface tension of normal surfactant. In addition, the sediment fraction of the lavage had slow surface adsorption, and a marked reduction in 35,000 and 10,000 MW peptides. Exogenous surfactant ameliorated the ALS-induced respiratory failure. We propose that inhibition, altered intrapulmonary distribution, and dissociation of protein and phospholipid components of surfactant are important in early pathogenesis of acute respiratory failure

  12. Persurf, a new method to improve surfactant delivery: a study in surfactant depleted rats.

    Directory of Open Access Journals (Sweden)

    Wolfram Burkhardt

    Full Text Available PURPOSE: Exogenous surfactant is not very effective in adults with ARDS, since surfactant does not reach atelectatic alveoli. Perfluorocarbons (PFC can recruit atelectatic areas but do not replace impaired endogenous surfactant. A surfactant-PFC-mixture could combine benefits of both therapies. The aim of the proof-of-principal-study was to produce a PFC-in-surfactant emulsion (Persurf and to test in surfactant depleted Wistar rats whether Persurf achieves I. a more homogenous pulmonary distribution and II. a more homogenous recruitment of alveoli when compared with surfactant or PFC alone. METHODS: Three different PFC were mixed with surfactant and phospholipid concentration in the emulsion was measured. After surfactant depletion, animals either received 30 ml/kg of PF5080, 100 mg/kg of stained (green dye Curosurf™ or 30 ml/kg of Persurf. Lungs were fixated after 1 hour of ventilation and alveolar aeration and surfactant distribution was estimated by a stereological approach. RESULTS: Persurf contained 3 mg/ml phospholipids and was stable for more than 48 hours. Persurf-administration improved oxygenation. Histological evaluation revealed a more homogenous surfactant distribution and alveolar inflation when compared with surfactant treated animals. CONCLUSIONS: In surfactant depleted rats administration of PFC-in-surfactant emulsion leads to a more homogenous distribution and aeration of the lung than surfactant alone.

  13. The effects of plasma shape control on the edge collisionless ion orbit loss

    Energy Technology Data Exchange (ETDEWEB)

    Wu, G. J.; Zhang, X. D.; Li, Y. D.; Sun, P. J.; Cao, G. M. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2013-10-15

    Double null magnetic configurations with different elongation κ and triangularity δ are constructed by using an analytical solution of the Grad–Shafranov equation. The ion orbit losses in plasma edge region are calculated by solving the ion guiding center orbit equation for different values of κ and δ. It is found that the ion orbit loss is larger for a smaller value of κ or δ. The variation of the ion orbit loss fraction on the magnetic surface is also studied.

  14. Piloted Simulation Evaluation of a Model-Predictive Automatic Recovery System to Prevent Vehicle Loss of Control on Approach

    Science.gov (United States)

    Litt, Jonathan S.; Liu, Yuan; Sowers, Thomas S.; Owen, A. Karl; Guo, Ten-Huei

    2014-01-01

    This paper describes a model-predictive automatic recovery system for aircraft on the verge of a loss-of-control situation. The system determines when it must intervene to prevent an imminent accident, resulting from a poor approach. It estimates the altitude loss that would result from a go-around maneuver at the current flight condition. If the loss is projected to violate a minimum altitude threshold, the maneuver is automatically triggered. The system deactivates to allow landing once several criteria are met. Piloted flight simulator evaluation showed the system to provide effective envelope protection during extremely unsafe landing attempts. The results demonstrate how flight and propulsion control can be integrated to recover control of the vehicle automatically and prevent a potential catastrophe.

  15. Surfactant-Enhanced Aquifer Remediation (SEAR) Implementation Manual

    Science.gov (United States)

    2003-04-01

    contaminants (e.g., creosote ) when temperature augmentation for viscosity reduction is not otherwise feasible. The surfactant flooding wellfield will...Section 4.3) to terminate continued hydraulic control measures, for remediation by chemical oxidation, vacuum-enhanced pumping, enhanced bioremediation

  16. Animated sulfonated or sulformethylated lignins as cement fluid loss control additives

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, P.

    1991-05-07

    This patent describes a method of cementing a zone in a well penetrating a subterranean formation comprising injecting down the well and positioning in the zone to be cemented a hydraulic aqueous cement slurry composition. It comprises: a hydraulic cement, and the following expressed as parts by weight per 100 parts of the hydraulic cement, water from about 25 to 105 parts, and a fluid loss control additive comprising from about 0.5 to 2.5 parts of a compound selected from the group consisting of a sulfonated lignin and a sulfomethylated lignin, wherein the lignin has been aminated by reacting it with between about 2-5 moles of a polyamine and 2-5 moles of an aldehyde per 1,000g of the lignin, and 0.1 to 1.5 parts of a compound selected from the group consisting of sodium carbonate, sodium metasilicate, sodium phosphate, sodium sulfite and sodium naphthalene sulfonate and a combination thereof.

  17. A preliminary examination of Loss of Control Eating Disorder (LOC-ED) in middle childhood.

    Science.gov (United States)

    Matherne, Camden E; Tanofsky-Kraff, Marian; Altschul, Anne M; Shank, Lisa M; Schvey, Natasha A; Brady, Sheila M; Galescu, Ovidiu; Demidowich, Andrew P; Yanovski, Susan Z; Yanovski, Jack A

    2015-08-01

    Loss of Control Eating Disorder (LOC-ED) has been proposed as a diagnostic category for children 6-12years with binge-type eating. However, characteristics of youth with LOC-ED have not been examined. We tested the hypothesis that the proposed criteria for LOC-ED would identify children with greater adiposity, more disordered eating attitudes, and greater mood disturbance than those without LOC-ED. Participants were 251 youth (10.29years±1.54, 53.8% female, 57.8% White, 35.5% Black, 2.0% Asian, 4.8% Hispanic, 53.0% overweight). Youth were interviewed regarding eating attitudes and behaviors, completed questionnaires to assess general psychopathology, and underwent measurements of body fat mass. Using previously proposed criteria for LOC-ED, children were classified as LOC-ED (n=19), LOC in the absence of the full disorder (subLOC, n=33), and youth not reporting LOC (noLOC, n=199). LOC-ED youth had higher BMIz (p=0.001) and adiposity (p=0.003) and reported greater disordered eating concerns (pdisordered eating attitudes (p=0.02). SubLOC youth had greater disordered eating concerns (pdisordered eating cognitions and anthropometric measures compared to youth without LOC-ED. Longitudinal studies are needed to determine if those with LOC-ED are at particularly increased risk for progression of disordered eating and excess weight gain. Published by Elsevier Ltd.

  18. Examination of the interpersonal model of loss of control eating in the laboratory.

    Science.gov (United States)

    Shank, Lisa M; Crosby, Ross D; Grammer, Anne Claire; Shomaker, Lauren B; Vannucci, Anna; Burke, Natasha L; Stojek, Monika; Brady, Sheila M; Kozlosky, Merel; Reynolds, James C; Yanovski, Jack A; Tanofsky-Kraff, Marian

    2017-07-01

    The interpersonal model of loss of control (LOC) eating proposes that interpersonal problems lead to negative affect, which in turn contributes to the onset and/or persistence of LOC eating. Despite preliminary support, there are no data examining the construct validity of the interpersonal model of LOC eating using temporally sensitive reports of social stress, distinct negative affective states, and laboratory energy intake. 117 healthy adolescent girls (BMI: 75th-97th %ile) were recruited for a prevention trial targeting excess weight gain in adolescent girls who reported LOC eating. Prior to the intervention, participants completed questionnaires of recent social stress and consumed lunch from a multi-item laboratory test meal. Immediately before the test meal, participants completed a questionnaire of five negative affective states (anger, confusion, depression, fatigue, anxiety). Bootstrapping mediation models were conducted to evaluate pre-meal negative affect states as explanatory mediators of the association between recent social stress and palatable (desserts and snack-type) food intake. All analyses adjusted for age, race, pubertal stage, height, fat mass percentage, and lean mass. Pre-meal state anxiety was a significant mediator for recent social stress and palatable food intake (ps.05). Pre-meal anxiety appears to be the salient mood state for the interpersonal model among adolescent girls with LOC eating. Interventions that focus on improving both social functioning and anxiety may prove most effective at preventing and/or ameliorating disordered eating and obesity in these adolescents. Published by Elsevier Inc.

  19. Loss of control eating and eating disorders in adolescents before bariatric surgery.

    Science.gov (United States)

    Utzinger, Linsey M; Gowey, Marissa A; Zeller, Meg; Jenkins, Todd M; Engel, Scott G; Rofey, Dana L; Inge, Thomas H; Mitchell, James E

    2016-10-01

    This study assessed loss of control (LOC) eating and eating disorders (EDs) in adolescents undergoing bariatric surgery for severe obesity. Preoperative baseline data from the Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) multisite observational study (n = 242; median BMI = 51 kg/m 2 ; mean age= 17; 76% female adolescents; 72% Caucasian) included anthropometric and self-report questionnaires, including the Questionnaire of Eating and Weight Patterns-Revised (QEWP-R), the Night Eating Questionnaire (NEQ), the Beck Depression Inventory (BDI-II), and the Impact of Weight on Quality of Life-Kids (IWQOL-Kids) RESULTS: LOC eating (27%) was common and ED diagnoses included binge-eating disorder (7%), night eating syndrome (5%), and bulimia nervosa (1%). Compared to those without LOC eating, those with LOC eating reported greater depressive symptomatology and greater impairment in weight-related quality of life. Before undergoing bariatric surgery, adolescents with severe obesity present with problematic disordered eating behaviors and meet diagnostic criteria for EDs. LOC eating, in particular, was associated with several negative psychosocial factors. Findings highlight targets for assessment and intervention in adolescents before bariatric surgery. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2016; 49:947-952). © 2016 Wiley Periodicals, Inc.

  20. A Preliminary Examination of Loss of Control Eating Disorder (LOC-ED) in Middle Childhood

    Science.gov (United States)

    Matherne, Camden E.; Tanofsky-Kraff, Marian; Altschul, Anne M.; Shank, Lisa M.; Schvey, Natasha A.; Brady, Sheila M.; Galescu, Ovidiu; Demidowich, Andrew P.; Yanovski, Susan Z.; Yanovski, Jack A.

    2015-01-01

    Loss of Control Eating Disorder (LOC-ED) has been proposed as a diagnostic category for children 6–12y with binge-type eating. However, characteristics of youth with LOC-ED have not been examined. We tested the hypothesis that the proposed criteria for LOC-ED would identify children with greater adiposity, more disordered eating attitudes, and greater mood disturbance than those without LOC-ED. Participants were 251 youth (10.29y ± 1.54, 53.8% female, 57.8 % White, 35.5% Black, 2.0% Asian, 4.8% Hispanic, 53.0% overweight). Youth were interviewed regarding eating attitudes and behaviors, completed questionnaires to assess general psychopathology, and underwent measurements of body fat mass. Using previously proposed criteria for LOC-ED, children were classified as LOC-ED (n = 19), LOC in the absence of the full disorder (subLOC, n = 33), and youth not reporting LOC (noLOC, n = 199). LOC-ED youth had higher BMIz (p = 0.001) and adiposity (p = 0.003) and reported greater disordered eating concerns (p disordered eating attitudes (p = 0.02). SubLOC youth had greater disordered eating concerns (p disordered eating cognitions and anthropometric measures compared to youth without LOC-ED. Longitudinal studies are needed to determine if those with LOC-ED are at particularly increased risk for progression of disordered eating and excess weight gain. PMID:25913008

  1. Puberty and the manifestations of loss of control eating in children and adolescents.

    Science.gov (United States)

    Vannucci, Anna; Tanofsky-Kraff, Marian; Ranzenhofer, Lisa M; Kelly, Nichole R; Hannallah, Louise M; Pickworth, C Katie; Grygorenko, Mariya V; Brady, Sheila M; Condarco, Tania A; Kozlosky, Merel; Demidowich, Andrew P; Yanovski, Susan Z; Shomaker, Lauren B; Yanovski, Jack A

    2014-11-01

    We investigated the manifestations of pediatric loss of control (LOC) eating at different stages of pubertal development. Participants were a nonclinical sample of 468 youth (8-17 years). Physical examination determined pubertal stage. LOC eating and disordered eating attitudes were assessed with the Eating Disorder Examination. In a randomized crossover design, a subset (n = 244) ate ad libitum from two test meals designed to capture normal and LOC eating. There were no differences in the prevalence rates or frequency of reported LOC eating episodes across pubertal stages (ps ≥ 0.50). There were, however, puberty by LOC eating interactions in disordered eating attitudes and palatable food consumption (ps ≤ .05), even after adjusting for age and body composition. LOC eating was associated with elevated global disordered eating attitudes, weight concern, and shape concern in post-pubertal youth (ps ≤ .001), but not pre-pubertal youth (ps ≥ .49). In late-puberty, youth with LOC eating consumed less energy from protein (p weight and shape concerns and more obesogenic food consumption patterns. Interventions for LOC eating during pre-puberty should be evaluated to determine if they are particularly beneficial for the prevention of exacerbated eating disorder psychopathology and adverse weight outcomes. © 2014 Wiley Periodicals, Inc.

  2. Set-shifting abilities, mood and loss of control over eating in binge eating disorder: An experimental study.

    Science.gov (United States)

    Dingemans, Alexandra E; Visser, Hiske; Paul, Linda; van Furth, Eric F

    2015-12-15

    Executive functions play an important role in problem-solving and self-control. Set-shifting is an aspect of executive functioning and represents cognitive flexibility. The inability to control eating in Binge Eating Disorder (BED) may imply deficits in set-shifting which could be exacerbated by negative mood and depressive symptoms. The aim of the study was to test whether there is a causal relationship between set-shifting ability, changes in mood and loss of control over eating in BED. Seventy-five participants diagnosed with BED were randomly assigned to a negative or neutral mood induction. Set-shifting abilities, depressive symptoms, current mood and loss of control over eating were assessed. Having depressive symptoms and poorer set-shifting abilities resulted in a more negative mood after a negative mood induction, whereas this was not observed in the neutral mood induction. Post-hoc analyses revealed that individuals with poorer set-shifting abilities and more changes in negative mood, experienced more feelings of loss of control over eating than individuals whose set-shifting abilities were better and whose mood did not change. The results suggest that both depressive symptoms and deficits in set-shifting abilities may decrease an individual's ability to handle negative affect and increase loss of control over eating in individuals with BED. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. High Efficiency Variable-Frequency Full-Bridge Converter with a Load Adaptive Control Method Based on the Loss Model

    Directory of Open Access Journals (Sweden)

    Lei Zhao

    2015-04-01

    Full Text Available In this paper, a load adaptive control method to improve the efficiency and dynamic performance of the Phase-Shifted Full-Bridge (PSFB converter which works under a wide range of load conditions is presented. The proposed control method can be used as a battery charger since this application demands a wide range of load conditions. The composition of the PSFB converter’s losses and the loss analysis model are both discussed. According to this model, the optimum switching frequency which results in minimum power loss is adopted to improve the efficiency. The relationship between switching frequency and power loss is formulated over a wide load range. Indicated by this kind of relationship, the proposed controller adjusts the switching frequency at different load currents. Moreover, an adaptive gain adjustment controller is applied to replace the traditional controller, with the aim to improve the dynamic performance which is influenced by the changes of the switching frequency and load current. In addition, the experimental results show that the maximum improvement of efficiency is up to 20%. These results confirm the effectiveness of the proposed load adaptive control method.

  4. Inhibitory Control and Hedonic Response towards Food Interactively Predict Success in a Weight Loss Programme for Adults with Obesity

    Directory of Open Access Journals (Sweden)

    Timo Brockmeyer

    2016-10-01

    Full Text Available Objective: Low inhibitory control and strong hedonic response towards food are considered to contribute to overeating and obesity. Based on previous research, the present study aimed at examining the potentially crucial interplay between these two factors in terms of long-term weight loss in people with obesity. Methods: BMI, inhibitory control towards food, and food liking were assessed in obese adults prior to a weight reduction programme (OPTIFAST® 52. After the weight reduction phase (week 13 and the weight loss maintenance phase (week 52, participants' BMI was re-assessed. Results: Baseline BMI, inhibitory control and food liking alone did not predict weight loss. As hypothesised, however, inhibitory control and food liking interactively predicted weight loss from baseline to week 13 and to week 52 (albeit the latter effect was less robust. Participants with low inhibitory control and marked food liking were less successful in weight reduction. Conclusion: These findings underscore the relevance of the interplay between cognitive control and food reward valuation in the maintenance of obesity.

  5. Screen-Time Weight-loss Intervention Targeting Children at Home (SWITCH): a randomized controlled trial.

    Science.gov (United States)

    Maddison, Ralph; Marsh, Samantha; Foley, Louise; Epstein, Leonard H; Olds, Timothy; Dewes, Ofa; Heke, Ihirangi; Carter, Karen; Jiang, Yannan; Mhurchu, Cliona Ni

    2014-09-10

    Screen-based activities, such as watching television (TV), playing video games, and using computers, are common sedentary behaviors among young people and have been linked with increased energy intake and overweight. Previous home-based sedentary behaviour interventions have been limited by focusing primarily on the child, small sample sizes, and short follow-up periods. The SWITCH (Screen-Time Weight-loss Intervention Targeting Children at Home) study aimed to determine the effect of a home-based, family-delivered intervention to reduce screen-based sedentary behaviour on body composition, sedentary behaviour, physical activity, and diet over 24 weeks in overweight and obese children. A two-arm, parallel, randomized controlled trial was conducted. Children and their primary caregiver living in Auckland, New Zealand were recruited via schools, community centres, and word of mouth. The intervention, delivered over 20 weeks, consisted of a face-to-face meeting with the parent/caregiver and the child to deliver intervention content, which focused on training and educating them to use a wide range of strategies designed to reduce their child's screen time. Families were given Time Machine TV monitoring devices to assist with allocating screen time, activity packages to promote alternative activities, online support via a website, and monthly newsletters. Control participants were given the intervention material on completion of follow-up. The primary outcome was change in children's BMI z-score from baseline to 24 weeks. Children (n = 251) aged 9-12 years and their primary caregiver were randomized to receive the SWITCH intervention (n = 127) or no intervention (controls; n = 124). There was no significant difference in change of zBMI between the intervention and control groups, although a favorable trend was observed (-0.016; 95% CI: -0.084, 0.051; p = 0.64). There were also no significant differences on secondary outcomes, except for a trend towards

  6. Bright Light for Weight Loss: Results of a Controlled Crossover Trial

    Directory of Open Access Journals (Sweden)

    Konstantin V. Danilenko

    2013-02-01

    Full Text Available Objective: To investigate whether bright light treatment can reduce body mass in overweight subjects irrespective of their seasonal (= light dependence. Methods: A crossover, placebo-controlled, randomized clinical trial was performed between November and April in Novosibirsk, Russia (55° N. The trial comprised a 3-week in-home session of morning bright light treatment using a device of light-emitting diodes and a 3-week placebo session by means of a deactivated ion generator, separated by an off-protocol period of at least 23 days. The number of placebo and light sessions was matched with respect to season. Data were obtained from 34 overweight women, aged 20-54 years, 10 were seasonal-dependent according to the Seasonal Pattern Assessment Questionnaire. Weekly measures included body weight, percentage body fat by bioimpedancemetry, and subjective scores (appetite, mood, energy levels. Results: Motivation and expectation towards weight loss were similar for the two intervention sessions. With light, compared to the placebo session, weight did not reduce significantly, but percentage fat, fat mass, and appetite were significantly lower (average fat reduction 0.35 kg. The latter two results remained significant after excluding seasonal-dependent subjects from the analysis. Irrespective of the type of intervention, seasonal-dependent subjects had greater weight and fat mass changes during treatment (decline p 0.036 or between sessions (regain p 0.003. Photoperiod (p = 0.0041, air temperature to a lesser extent (p = 0.012, but not sunshine (p = 0.29 was associated with the weight change (greater weight reduction if the second session was in spring. Conclusion: Morning bright light treatment reduces body fat and appetite in overweight women and may be included in weight control programs.

  7. Emotion Dysregulation and Loss-of-Control Eating in Children and Adolescents

    Science.gov (United States)

    Kelly, Nichole R.; Tanofsky-Kraff, Marian; Vannucci, Anna; Ranzenhofer, Lisa M.; Altschul, Annie M.; Schvey, Natasha A.; Shank, Lisa M.; Brady, Sheila M.; Galescu, Ovidiu; Kozlosky, Merel; Yanovski, Susan Z.; Yanovski, Jack A.

    2016-01-01

    Objective To examine the associations among self-reported loss-of-control (LOC) eating, emotion dysregulation, body mass, and objective energy intake among youth. Emotion dysregulation may be one individual factor that promotes excess energy intake and increases in body mass among youth with LOC eating. Methods Children and adolescents (N=230; 8 to 17 years) enrolled in a non-intervention study completed a structured interview to determine the presence or absence of self-reported LOC eating. Children’s emotion dysregulation was assessed via parent-report with the Child Behavior Checklist. Youth also completed two test meals to capture “binge” and “normal” eating. Body composition was examined using air displacement plethysmography. Results After controlling for relevant covariates, youth with self-reported LOC eating had higher parent-reported emotion dysregulation than those without LOC. Parent-reported emotion dysregulation was also associated with greater observed energy intake (after accounting for body mass), as well as higher fat mass. Emotion dysregulation also moderated associations between LOC status/sex and body mass variables; among youth with self-reported LOC eating and girls, those with high parent-described emotion dysregulation (versus low) had significantly higher fat mass and BMIz. Conclusions Data from the current study suggest that emotion dysregulation may play a role in energy intake and obesity, particularly among youth with self-reported LOC eating and girls. Additional studies are needed to identify the prospective mechanisms linking poor emotion regulation and LOC eating. These mechanisms, in turn, may inform future interventions targeting excess energy intake and obesity in pediatric samples. PMID:27505194

  8. In vitro surfactant structure-toxicity relationships: implications for surfactant use in sexually transmitted infection prophylaxis and contraception.

    Directory of Open Access Journals (Sweden)

    Ângela S Inácio

    Full Text Available BACKGROUND: The need for woman-controlled, cheap, safe, effective, easy-to-use and easy-to-store topical applications for prophylaxis against sexually transmitted infections (STIs makes surfactant-containing formulations an interesting option that requires a more fundamental knowledge concerning surfactant toxicology and structure-activity relationships. METHODOLOGY/PRINCIPAL FINDINGS: We report in vitro effects of surfactant concentration, exposure time and structure on the viability of mammalian cell types typically encountered in the vagina, namely, fully polarized and confluent epithelial cells, confluent but non-polarized epithelial-like cells, dendritic cells, and human sperm. Representatives of the different families of commercially available surfactants--nonionic (Triton X-100 and monolaurin, zwitterionic (DDPS, anionic (SDS, and cationic (C(nTAB (n = 10 to 16, C(12PB, and C(12BZK--were examined. Triton X-100, monolaurin, DDPS and SDS were toxic to all cell types at concentrations around their critical micelle concentration (CMC suggesting a non-selective mode of action involving cell membrane destabilization and/or destruction. All cationic surfactants were toxic at concentrations far below their CMC and showed significant differences in their toxicity toward polarized as compared with non-polarized cells. Their toxicity was also dependent on the chemical nature of the polar head group. Our results suggest an intracellular locus of action for cationic surfactants and show that their structure-activity relationships could be profitably exploited for STI prophylaxis in vaginal gel formulations. The therapeutic indices comparing polarized epithelial cell toxicity to sperm toxicity for all surfactants examined, except C(12PB and C(12BZK, does not justify their use as contraceptive agents. C(12PB and C(12BZK are shown to have a narrow therapeutic index recommending caution in their use in contraceptive formulations. CONCLUSIONS

  9. In vitro surfactant structure-toxicity relationships: implications for surfactant use in sexually transmitted infection prophylaxis and contraception.

    Science.gov (United States)

    Inácio, Ângela S; Mesquita, Katia A; Baptista, Marta; Ramalho-Santos, João; Vaz, Winchil L C; Vieira, Otília V

    2011-01-01

    The need for woman-controlled, cheap, safe, effective, easy-to-use and easy-to-store topical applications for prophylaxis against sexually transmitted infections (STIs) makes surfactant-containing formulations an interesting option that requires a more fundamental knowledge concerning surfactant toxicology and structure-activity relationships. We report in vitro effects of surfactant concentration, exposure time and structure on the viability of mammalian cell types typically encountered in the vagina, namely, fully polarized and confluent epithelial cells, confluent but non-polarized epithelial-like cells, dendritic cells, and human sperm. Representatives of the different families of commercially available surfactants--nonionic (Triton X-100 and monolaurin), zwitterionic (DDPS), anionic (SDS), and cationic (C(n)TAB (n = 10 to 16), C(12)PB, and C(12)BZK)--were examined. Triton X-100, monolaurin, DDPS and SDS were toxic to all cell types at concentrations around their critical micelle concentration (CMC) suggesting a non-selective mode of action involving cell membrane destabilization and/or destruction. All cationic surfactants were toxic at concentrations far below their CMC and showed significant differences in their toxicity toward polarized as compared with non-polarized cells. Their toxicity was also dependent on the chemical nature of the polar head group. Our results suggest an intracellular locus of action for cationic surfactants and show that their structure-activity relationships could be profitably exploited for STI prophylaxis in vaginal gel formulations. The therapeutic indices comparing polarized epithelial cell toxicity to sperm toxicity for all surfactants examined, except C(12)PB and C(12)BZK, does not justify their use as contraceptive agents. C(12)PB and C(12)BZK are shown to have a narrow therapeutic index recommending caution in their use in contraceptive formulations. Our results contribute to understanding the mechanisms involved in

  10. Surfactant gene polymorphisms and interstitial lung diseases

    Directory of Open Access Journals (Sweden)

    Pantelidis Panagiotis

    2001-11-01

    Full Text Available Abstract Pulmonary surfactant is a complex mixture of phospholipids and proteins, which is present in the alveolar lining fluid and is essential for normal lung function. Alterations in surfactant composition have been reported in several interstitial lung diseases (ILDs. Furthermore, a mutation in the surfactant protein C gene that results in complete absence of the protein has been shown to be associated with familial ILD. The role of surfactant in lung disease is therefore drawing increasing attention following the elucidation of the genetic basis underlying its surface expression and the proof of surfactant abnormalities in ILD.

  11. Effects of Crop Rotation, N Management, Tillage, and Controlled Drainage on nitrate-N Loss in Drain Flow

    Science.gov (United States)

    Ma, L.; Malone, R.; Ahuja, L.; Kanwar, R. S.

    2007-12-01

    Accurate simulation of agricultural management effects on N loss in tile drainage is vitally important for understanding hypoxia in the Gulf of Mexico. An experimental study was initiated in 1978 at Nashua, Iowa of the USA to study long-term effects of tillage, crop rotation, and N management practices on subsurface drainage flow and associated N losses. The Root Zone Water Quality Model (RZWQM) was applied to evaluate management effects (tillage, crop rotation, N application, and controlled drainage) on N loss in drain flow. RZWQM simulated the observed increase in N concentration in drain flow with increasing tillage intensity from NT (no-till) to RT (ridge till) to CP (chisel plow) and to MP (moldboard plow). It also adequately simulated tillage effects on yearly drain flow and yearly N loss in drain flow. On the other hand, RZWQM adequately simulated lower yearly drain flow and lower flow-weighted N concentration in drain flow under CS (corn-soybean) and SC (soybean-corn) than under CC (continuous corn). The model also simulated higher N loss from fertilizer-N applications than from manure-N applications. Applying the newly suggested N management practice for the Midwest of controlled drainage, the model simulated a 30% reduction in drain flow and a 29% decrease in N losses in drain flow under controlled drainage (CD) compared to free drainage (FD). With most of the simulations in reasonably close agreement with observations, we concluded that RZWQM is a promising tool for quantifying the relative effects of tillage, crop rotation, N application, and controlled drainage on N loss in drainage flow. Further improvements on simulated management effects on N mineralization and plant N uptake are needed, however.

  12. Calcium-tolerant anionic surfactants

    NARCIS (Netherlands)

    Kooreman, Alexander

    1995-01-01

    One of the problems of applying anionic surfactants in, for example, laundry detergents is the precipitation of calcium salts. Much effort has been directed towards avoiding precipitation. There are at least three ways for tackling the problem. The first involves the use of a large quantity of

  13. High Efficiency Variable-Frequency Full-Bridge Converter with a Load Adaptive Control Method Based on the Loss Model

    OpenAIRE

    Lei Zhao; Haoyu Li; Yuan Liu; Zhenwei Li

    2015-01-01

    In this paper, a load adaptive control method to improve the efficiency and dynamic performance of the Phase-Shifted Full-Bridge (PSFB) converter which works under a wide range of load conditions is presented. The proposed control method can be used as a battery charger since this application demands a wide range of load conditions. The composition of the PSFB converter’s losses and the loss analysis model are both discussed. According to this model, the optimum switching frequency which resu...

  14. Respiratory and Systemic Effects of LASSBio596 Plus Surfactant in Experimental Acute Respiratory Distress Syndrome

    Directory of Open Access Journals (Sweden)

    Johnatas Dutra Silva

    2016-02-01

    Full Text Available Background/Aims: Exogenous surfactant has been proposed as adjunctive therapy for acute respiratory distress syndrome (ARDS, but it is inactivated by different factors present in the alveolar space. We hypothesized that co-administration of LASSBio596, a molecule with significant anti-inflammatory properties, and exogenous surfactant could reduce lung inflammation, thus enabling the surfactant to reduce edema and improve lung function, in experimental ARDS. Methods: ARDS was induced by cecal ligation and puncture surgery in BALB/c mice. A sham-operated group was used as control (CTRL. After surgery (6 hours, CTRL and ARDS animals were assigned to receive: (1 sterile saline solution; (2 LASSBio596; (3 exogenous surfactant or (4 LASSBio596 plus exogenous surfactant (n = 22/group. Results: Regardless of exogenous surfactant administration, LASSBio596 improved survival rate and reduced collagen fiber content, total number of cells and neutrophils in PLF and blood, cell apoptosis, protein content in BALF, and urea and creatinine levels. LASSBio596 plus surfactant yielded all of the aforementioned beneficial effects, as well as increased BALF lipid content and reduced surface tension. Conclusion: LASSBio596 exhibited major anti-inflammatory and anti-fibrogenic effects in experimental sepsis-induced ARDS. Its association with surfactant may provide further advantages, potentially by reducing surface tension.

  15. Systems of mechanized and reactive droplets powered by multi-responsive surfactants

    Science.gov (United States)

    Yang, Zhijie; Wei, Jingjing; Sobolev, Yaroslav I.; Grzybowski, Bartosz A.

    2018-01-01

    Although ‘active’ surfactants, which are responsive to individual external stimuli such as temperature, electric or magnetic fields, light, redox processes or chemical agents, are well known, it would be interesting to combine several of these properties within one surfactant species. Such multi-responsive surfactants could provide ways of manipulating individual droplets and possibly assembling them into larger systems of dynamic reactors. Here we describe surfactants based on functionalized nanoparticle dimers that combine all of these and several other characteristics. These surfactants and therefore the droplets that they cover are simultaneously addressable by magnetic, optical and electric fields. As a result, the surfactant-covered droplets can be assembled into various hierarchical structures, including dynamic ones, in which light powers the rapid rotation of the droplets. Such rotating droplets can transfer mechanical torques to their non-nearest neighbours, thus acting like systems of mechanical gears. Furthermore, droplets of different types can be merged by applying electric fields and, owing to interfacial jamming, can form complex, non-spherical, ‘patchy’ structures with different surface regions covered with different surfactants. In systems of droplets that carry different chemicals, combinations of multiple stimuli can be used to control the orientations of the droplets, inter-droplet transport, mixing of contents and, ultimately, sequences of chemical reactions. Overall, the multi-responsive active surfactants that we describe provide an unprecedented level of flexibility with which liquid droplets can be manipulated, assembled and reacted.

  16. Surfactant with and without bronchoalveolar lavage in an experimental model of meconium aspiration syndrome.

    Science.gov (United States)

    Henn, Roseli; Fiori, Renato Machado; Fiori, Humberto Holmer; Pereira, Manuel Ruttkay; Colvero, Maurício Obal; Ramos Garcia, Pedro Celiny; Padoim, Priscila; Stivanin, Jaqueline Basso

    2016-08-01

    To assess the effect of surfactant administration, preceded or not by bronchoalveolar lavage (BAL) with dilute surfactant, on pulmonary function in experimental severe meconium aspiration syndrome. Twenty-one newborn pigs received 20% meconium in saline intratracheally and were randomly allocated to one of three groups: I, control; II, surfactant only (poractant alfa, 200 mg/kg); or III, dilute surfactant BAL followed by 125 mg/kg surfactant. Arterial blood gases (ABGs), lung compliance, and resistance were assessed. Thirty minutes after treatment, mean PaO2 (mm Hg) increased to 72 in group I, to 106 in group II and to 172 in group III (P=0.01). After 3 h, mean PaO2 (mm Hg) was 70 in group I, 95 in group II and 198 in group III (P<0.01). After 6 h, it was 79 in group I, 110 in group II, and 217 in group III (P=0.01). From the 30-min point onward, there were significant differences among treatment groups in all other parameters and at every point of assessment, except for compliance and resistance 3 h after treatment. BAL with dilute surfactant, followed by an additional dose of surfactant, produced significant improvements in ABGs and pulmonary mechanics as compared with a single dose of surfactant.

  17. [Surfactant replacement therapy with a minimally invasive technique: Experience in a tertiary hospital].

    Science.gov (United States)

    Canals Candela, F J; Vizcaíno Díaz, C; Ferrández Berenguer, M J; Serrano Robles, M I; Vázquez Gomis, C; Quiles Durá, J L

    2016-02-01

    Surfactant delivered using a minimally invasive technique, known as MIST (Minimally Invasive Surfactant Therapy) is a method which allows surfactant to be administered to a patient connected to non-invasive respiratory support. This is an increasingly used therapy in Neonatal Units that reduces the intubation rate and the pathology associated with intubation and allows the surfactant to be administered to the patients who clinically need it. In years 2013 and 2014 in the Hospital General Universitario de Elche surfactant was delivered using this method to 19 patients, five of whom were 28 or less weeks of gestation age at birth. A comparison is made with a historical cohort consisting of 28 patients with Respiratory Distress Syndrome treated initially with non-invasive respiratory support. No incidents were recorded that caused the interruption of the administration. A reduction in the fraction of inspired oxygen was observed in all cases after surfactant administration. Fewer intubations in the first 72 hours of life were found in the treatment group compared to the control group (42% vs. 54%). The experience recorded in the Hospital General Universitario de Elche shows that the administration of surfactant using a MIST technique is a reproducible method of treatment, which allows the surfactant distribution during spontaneous breathing with non invasive respiratory support. Copyright © 2015 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

  18. Increased mobility of a surfactant-retarded bubble at high bulk concentrations

    Science.gov (United States)

    Wang, Yanping; Papageorgiou, Demetrios T.; Maldarelli, Charles

    1999-07-01

    We study theoretically the adsorption of surfactant onto the interface of gas bubbles in creeping flow rising steadily in an infinite liquid phase containing surface-active agents. When a bubble rises in the fluid, surfactant adsorbs onto the surface at the leading edge, is convected by the surface flow to the trailing edge and accumulates and desorbs off the back end. This transport creates a surfactant concentration gradient on the surface that causes the surface tension at the back end to be lower than that at the front end, thus retarding the bubble velocity by the creation of a Marangoni force. In this paper, we demonstrate numerically that the mobility of the surfactant-retarded bubble interface can be increased by raising the bulk concentration of surfactant. At high bulk concentrations, the interface saturates with surfactant, and this saturation acts against the convective partitioning to decrease the surface surfactant gradient. We show that as the Péclet number (which scales the convective effect) increases, larger concentrations are necessary to remobilize the surface completely. These results lead to a technologically useful paradigm where the drag and interfacial mobility of a bubble can be controlled by the level of the bulk concentration of surfactant.

  19. Effects of vegetable consumption on weight loss: a review of the evidence with implications for design of randomized controlled trials.

    Science.gov (United States)

    Tapsell, Linda Clare; Dunning, Alicia; Warensjo, Eva; Lyons-Wall, Philippa; Dehlsen, Kate

    2014-01-01

    Vegetable consumption is a key strategy in many weight loss programs but establishing the evidence that vegetable consumption per se assists with weight loss may be difficult. Creating a dietary energy deficit involves the whole diet, so research on the effects of vegetables may need to consider the whole-dietary model. The aims of this review were to examine the evidence on whether a higher vegetable consumption resulted in greater weight loss in overweight adults (compared to lower intakes) in view of a critique study designs with respect to their potential impact on outcomes. Using the PubMed search engine, a systematic review of randomized controlled trials (RCTs) published in the period 1988 to 2011 was conducted. Of the 16 RCTs scrutinized, five reported greater weight loss, nine no difference, one showed weight gain, and one reported a positive association between weight loss and high vegetable consumption. Trials which showed beneficial effects compared a healthy high vegetable diet with a control diet based on usual consumption patterns, and/or included behavioral support and counseling. On face value, the evidence reviewed appeared inconclusive but closer examination of study designs exposed important implications for RCTs that examine effects of foods on weight loss.

  20. 40 CFR 1060.104 - What running loss emission control requirements apply?

    Science.gov (United States)

    2010-07-01

    ... intake system so fuel vapors vented from the tank during engine operation are combusted in the engine...) Marine SI engines and vessels are not subject to running loss emission standards. (2) Large SI engines...) Recreational vehicles are not subject to running loss emission standards. (4) Nonhandheld Small SI engines and...

  1. Low-Voltage Consumption Coordination for Loss Minimization and Voltage Control

    DEFF Research Database (Denmark)

    Juelsgaard, Morten; Sloth, Christoffer; Wisniewski, Rafal

    2014-01-01

    This work presents a strategy for minimizing active power losses in low-voltage grids, by coordinating the consumption of electric vehicles and power generation from solar panels. We show that minimizing losses, also reduces voltage variations, and illustrate how this may be employed for increasing...

  2. Tranexamic acid reduces blood loss during and after cesarean section: A double blinded, randomized, controlled trial

    Directory of Open Access Journals (Sweden)

    Amr H. Yehia

    2014-03-01

    Conclusions: Tranexamic acid can be used safely to reduce blood loss during cesarean section. Reduced blood loss after tranexamic acid was associated with improvement of post-operative hemoglobin, hematocrit and with reduction of post-partum need for iron replacement.

  3. Control of Ore Loss and Dilution at AngloGold Ashanti, Iduapriem ...

    African Journals Online (AJOL)

    Michael

    2016-06-01

    Jun 1, 2016 ... was a benefit of $753 835 which translates into 650% return on investment. Thus, the use of the BMM system has ...... of the entire blast monitored is such that the. Ore Loss. Total Ore. Loss. (t). Grade. (g/t). Ounces. (oz). Recovery at 93%. (oz). Revenue @. $1 200/oz. ($). Differential Cost @. $0.7/t. ($). Net.

  4. Climatic control of nitrate loss from forested watersheds in the northeast United States

    Science.gov (United States)

    Mitchell, M.J.; Driscoll, C.T.; Kahl, J.S.; Likens, G.E.; Murdoch, Peter S.; Pardo, L.H.

    1996-01-01

    Increased losses of nitrate from watersheds may accelerate the depletion of nutrient cations and affect the acidification and trophic status of surface waters. Patterns of nitrate concentrations and losses were evaluated in four forested watersheds (East Bear Brook Watershed, Lead Mountain, ME; Watershed 6, Hubbard Brook Experimental Forest, White Mountains, NH; Arbutus Watershed, Huntington Forest, Adirondack Mountains, NY; Biscuit Brook, Catskill Mountains, NY) located across the northeastern United States. A synchronous pattern was observed in nitrate concentrations of drainage waters from these four sites from 1983 through 1993. Most notably, high concentrations and high drainage water losses followed an anomalous cold period (mean daily temperature -11.4 to -16 ??C in December 1989) for all four sites. After high nitrate losses during the snowmelt of 1990, nitrate concentrations and fluxes decreased at all sites. These results suggest that climatic variation can have a major effect on nitrogen flux and cycling and may influence temporal patterns of nitrate loss in a region.

  5. Surfactant -- Where Are We in 2003?

    Directory of Open Access Journals (Sweden)

    JF Lewis

    2004-01-01

    Full Text Available Surfactant research has progressed over the past several years to the extent that exogenous surfactant administration in patients with the acute respiratory distress syndrome (ARDS is now being evaluated. Unfortunately, clinical responses have been variable, and we now need to take a look at how surfactant is altered in this disease so that more effective treatment strategies can be developed. This review briefly discusses the biophysical and host defense properties of surfactant, the impact of mechanical ventilation (MV on the endogenous surfactant system and the most recent clinical data involving exogenous surfactant administration in patients with ARDS. Discussions regarding future directions of surfactant research both in ARDS and diseases other than acute lung injury are included.

  6. The Role of Exercise in a Weight-Loss Program on Clinical Control in Obese Adults with Asthma. A Randomized Controlled Trial.

    Science.gov (United States)

    Freitas, Patricia D; Ferreira, Palmira G; Silva, Aline G; Stelmach, Rafael; Carvalho-Pinto, Regina M; Fernandes, Frederico L A; Mancini, Marcio C; Sato, Maria N; Martins, Milton A; Carvalho, Celso R F

    2017-01-01

    Clinical control is difficult to achieve in obese patients with asthma. Bariatric surgery has been recommended for weight loss and to improve asthma control; however, the benefits of nonsurgical interventions have been poorly investigated. To examine the effect of exercise training in a weight-loss program on asthma control, quality of life, inflammatory biomarkers, and lung function. Fifty-five obese patients with asthma were randomly assigned to either a weight-loss program plus exercise (WL + E group, n = 28) or a weight-loss program plus sham (WL + S group, n = 27), where the weight-loss program included nutrition (caloric restriction) and psychological therapies. The WL + E group incorporated aerobic and resistance muscle training, whereas the WL + S group incorporated breathing and stretching exercises. The primary outcome was clinical improvement in asthma control over 3 months. Secondary outcomes included quality of life, lung function, body composition, aerobic capacity, muscle strength, and inflammatory/antiinflammatory biomarkers. After 3 months, 51 patients were analyzed. Compared with the WL + S group, the WL + E group demonstrated improved clinical control scores (median [25th to 75th percentile], -0.7 [-1.3 to -0.3] vs. -0.3 [-0.9 to 0.4]; P = 0.01) and greater weight loss (mean ± SD, -6.8% ± 3.5 vs. -3.1% ± 2.6; P exercise to a short-term weight-loss program should be considered as a useful strategy for achieving clinical control of asthma in obese patients. Clinical trial registered with www.clinicaltrials.gov (NCT 02188940).

  7. Comparison of range of commercial or primary care led weight reduction programmes with minimal intervention control for weight loss in obesity: Lighten Up randomised controlled trial

    OpenAIRE

    Jolly, Kate; Lewis, Amanda; Beach, Jane; Denley, John; Adab, Peymane; Deeks, Jonathan J; Daley, Amanda; Aveyard, Paul

    2011-01-01

    Objective To assess the effectiveness of a range of weight management programmes in terms of weight loss. Design Eight arm randomised controlled trial. Setting Primary care trust in Birmingham, England. Participants 740 obese or overweight men and women with a comorbid disorder identified from general practice records. Interventions Weight loss programmes of 12 weeks? duration: Weight Watchers; Slimming World; Rosemary Conley; group based, dietetics led programme; general practice one to one ...

  8. Inhaled Surfactant Therapy in Newborns in Artificial Lung Ventilation

    Directory of Open Access Journals (Sweden)

    S. A. Perepelitsa

    2014-01-01

    Full Text Available Objective: to evaluate the efficiency of inhaled surfactant therapy in neonatal infants with respiratory failure.Subjects and methods. The trial enrolled 13 premature neonatal infants; their mean gestational age was 31.8±2.8 weeks and the birth weight was 1825±600.9 g. They had a oneminute Apgar score of 4.3±1.4. All the neonates needed mechanical ventilation (MV atbirth because the leading clinical sign was respiratory failure caused by acute intranatal hypoxia, neonatal amniotic fluid aspiration, respiratory distress syndrome (RDS, and cerebral ischemia. Curosurf was injected in a dose of 174.7±21 mg/kg in the infants with neonatal RDS at 35 minutes of life. All the babies included in the study were noted to have severe disease and prolonged MV. After stabilization of their status, the neonates received combination therapy involving surfactantBL inhalation to reduce the duration of MV. The dose of the agent was 75 mg. Results. After surfactantBL inhalation, effective spontaneous respiration occurred in 69.2% of the newborn infants; successful extubation was carried out. The median duration ofMV after surfactant BL inhalation was 22 hours (4—68 hours. There were no reintubated cases after inhalation therapy. Following surfactantBL inhalation, 4 (30.8% patients remained to be on MV as a control regimen; 3 of them had highfre quency MV. SurfactantBL inhalation made it possible to change the respiratory support regimen and to reduce MV parame ters in these babies. 

  9. EFFECTS OF NANOPARTICLES AND SURFACTANT CHARGE GROUPS ON THE PROPERTIES OF VES GEL

    Directory of Open Access Journals (Sweden)

    G. Chauhan

    Full Text Available Abstract Application of viscoelastic surfactant (VES fluids in hydraulic fracturing is still in the development stage, though shear thinning behavior and water solubility are the two important characteristics behind increasing interest in their use in fracturing jobs. Effects of ionic characteristics and the concentration of different surfactants on the rheological properties of VES fluid have been investigated in detail in the present study for a number of surfactant systems. Phase behavior of the system was studied and the gel region was identified. Effects of alkali on the viscosity, thermal stability, and miscibility (in water of the developed gel were also investigated. Dynamic rheological study was carried out to determine the storage modulus and loss modulus. This study shows that mixed anionic-anionic system gives improved rheology compared to single anionic and mixed anionic-zwitterionic surfactant systems.

  10. Randomized, double-blind, placebo-controlled trial of orlistat for weight loss in adolescents.

    Science.gov (United States)

    Maahs, David; de Serna, Daniela Gonzalez; Kolotkin, Ronette L; Ralston, Shawn; Sandate, Jeffrey; Qualls, Clifford; Schade, David S

    2006-01-01

    To evaluate the efficacy of orlistat to enhance weight loss in obese adolescents. The study was a 6-month randomized, double-blind, placebo-controlled trial to compare the effects of orlistat (120 mg orally 3 times a day) and placebo on reduction of body mass index (BMI). Forty adolescents between 14 and 18 years of age with a mean BMI of 40 kg/m2 entered the protocol between December 2002 and February 2003. Study subjects stayed overnight in the General Clinical Research Center, during which dietary records were reviewed and lifestyle recommendations were given. The study participants received either orlistat (120 mg orally 3 times a day) or placebo and were assessed monthly for 6 months. At 0, 3, and 6 months, fasting laboratory tests were performed. The primary end point was the change in BMI from baseline to 6 months. Secondary outcomes included changes in weight, lean body mass, and results of blood chemistry studies. No statistically significant difference was noted between the 2 study groups for decrease in BMI from baseline to 6 months (P = 0.39). The decrease in BMI within the orlistat group (-1.3 +/- 1.6 kg/m2; P = 0.04) and within the placebo group (-0.8 +/- 3.0 kg/m2; P = 0.02), however, was statistically significant. Laboratory measurements did not differ between the 2 groups. In comparison with the placebo group, the orlistat group had increased adverse events, primarily gastrointestinal symptoms and findings. In this study of obese adolescents, orlistat did not significantly reduce BMI in comparison with placebo at 6 months.

  11. Interpersonal problem areas and alexithymia in adolescent girls with loss of control eating.

    Science.gov (United States)

    Berger, Sarah Shafer; Elliott, Camden; Ranzenhofer, Lisa M; Shomaker, Lauren B; Hannallah, Louise; Field, Sara E; Young, Jami F; Sbrocco, Tracy; Wilfley, Denise E; Yanovski, Jack A; Tanofsky-Kraff, Marian

    2014-01-01

    This study investigated the links among interpersonal problem areas, depression, and alexithymia in adolescent girls at high risk for excessive weight gain and binge eating disorder. Participants were 56 girls (Mage = 14.30, SD = 1.56; 53% non-Hispanic White) with a body mass index (BMI, kg/m(2)) between the 75th and 97th percentiles (MBMI z = 1.57, SD = 0.32). By design, all participants reported loss of control eating patterns in the past month. Adolescents were individually interviewed prior to participating in a group interpersonal psychotherapy obesity and eating disorder prevention program, termed IPT for the prevention of excessive weight gain (IPT-WG). Participants' interpersonal problem areas were coded by trained raters. Participants also completed questionnaires assessing depression and alexithymia. Primary interpersonal problem areas were categorized as interpersonal deficits [as defined in the eating disorders (ED) literature] (n = 29), role disputes (n = 22), or role transitions (n = 5). Girls with interpersonal deficits-ED had greater depressive symptoms and alexithymia than girls with role disputes (p's ≤ 0.01). However, girls with role transitions did not differ from girls with interpersonal deficits-ED or role disputes. Interpersonal problem area had an indirect association with depression via alexithymia; interpersonal deficits-ED were related to greater alexithymia, which in turn, was related to greater depressive symptoms (p = 0.01). Among girls at risk for excess weight gain and eating disorders, those with interpersonal deficits-ED appear to have greater distress as compared to girls with role disputes or role transitions. Future research is required to elucidate the impact of interpersonal problem areas on psychotherapy outcomes. © 2013.

  12. Interpersonal Problem Areas and Alexithymia in Adolescent Girls with Loss of Control Eating

    Science.gov (United States)

    Berger, Sarah Shafer; Elliott, Camden; Ranzenhofer, Lisa M.; Shomaker, Lauren B.; Hannallah, Louise; Field, Sara E.; Young, Jami F.; Sbrocco, Tracy; Wilfley, Denise E.; Yanovski, Jack A.; Tanofsky-Kraff, Marian

    2014-01-01

    This study investigated the links among interpersonal problem areas, depression, and alexithymia in adolescent girls at high-risk for excessive weight gain and binge eating disorder. Participants were 56 girls (Mage = 14.30, SD = 1.56; 53% non-Hispanic White) with a body mass index (BMI, kg/m2) between the 75th and 97th percentiles (MBMI-z = 1.57, SD = 0.32). By design, all participants reported loss of control eating patterns in the past month. Adolescents were individually interviewed prior to participating in a group interpersonal psychotherapy obesity and eating disorder prevention program, termed IPT for the prevention of excessive weight gain (IPT-WG). Participants’ interpersonal problem areas were coded by trained raters. Participants also completed questionnaires assessing depression and alexithymia. Primary interpersonal problem areas were categorized as interpersonal deficits (as defined in the eating disorders (ED) literature) (n = 29), role disputes (n = 22), or role transitions (n = 5). Girls with interpersonal deficits-ED had greater depressive symptoms and alexithymia than girls with role disputes (ps ≤ 0.01). However, girls with role transitions did not differ from girls with interpersonal deficits-ED or role disputes. Interpersonal problem area had an indirect association with depression via alexithymia; interpersonal deficits-ED were related to greater alexithymia, which in turn, was related to greater depressive symptoms (p = 0.01). Among girls at-risk for excess weight gain and eating disorders, those with interpersonal deficits-ED appear to have greater distress as compared to girls with role disputes or role transitions. Future research is required to elucidate the impact of interpersonal problem areas on psychotherapy outcomes. PMID:24139852

  13. PEG-nanotube liquid crystals as templates for construction of surfactant-free gold nanorods.

    Science.gov (United States)

    Kameta, Naohiro; Shiroishi, Hidenobu

    2018-04-23

    Lyotropic liquid crystals, in which nanotubes coated with polyethylene glycol were aligned side-by-side in aqueous dispersions, acted as templates for the construction of surfactant-free gold nanorods with controllable diameters, functionalizable surfaces, and tunable optical properties.

  14. The adsorption of surfactant at the amorphous polymer solution interface

    International Nuclear Information System (INIS)

    Gilchrist, Valerie A.

    2001-01-01

    polymer. The area per surfactant at the cmc (A cmc ) was found to be around 50A 2 . Good agreement was obtained between SE and SNR, but the latter revealed additional information about the in-situ conformational structure of the surfactant. It was found that at the cmc, the dodecyl chain layer was only 4-5A thick, indicating that the alkyl chains lay virtually flat on PMMA surface. The ethoxylate headgroup layer was however some 16A thick, indicating the projection of the headgroups into the aqueous solution. In contrast, when anionic SDS (sodium dodecyl sulphate) and cationic C 12 TAB (dodecyl trimethyl ammonium bromide) were used, a much reduced adsorption was observed. While these results highlight the role of the type of surfactant headgroups, it shows the power of SNR and the effectiveness of the experimental approach adopted in unraveling molecular information at the interface. This experimental approach was subsequently extended to PBMA and PS for the assessment of different polymeric substrates. The varying extent of surfactant adsorption and the ingress of the surfactant associated with film swelling have clearly shown that with careful control of experimental conditions, detailed structural information can be reliably revealed from the experimental procedures that I have developed. (author)

  15. The effects of subjective loss of control on risk-taking behavior: the mediating role of anger

    Science.gov (United States)

    Beisswingert, Birgit M.; Zhang, Keshun; Goetz, Thomas; Fang, Ping; Fischbacher, Urs

    2015-01-01

    Based on the Appraisal Tendency Framework on the antecedents and consequences of emotions two experimental studies examined the relationship between externally caused loss of control experiences and risk-taking behavior, as well as the assumed mediation of this relationship by the emotion anger. An experimental paradigm for inducing externally caused and consequently externally attributed loss of control which should lead to experiences of anger was developed and pretested in a Pilot Study. The relationship between loss of control experiences, anger, and risk-taking behavior was investigated using two separate student samples from Germany (N = 84, 54% female) and China (N = 125; 64% female). In line with our hypotheses, results showed that anger mediated the link between subjective loss of control experiences and increasing risk-taking behavior. Multiple group comparisons revealing similar patterns in both samples affirmed the results’ cross-cultural generalizability. These results implicate that anger makes people less risk averse in the process of economic decision making. PMID:26217244

  16. An empirical evaluation of the translation to Brazilian Portuguese of the Loss of Control over Eating Scale (LOCES

    Directory of Open Access Journals (Sweden)

    Felipe Q. da Luz

    2016-02-01

    Full Text Available Abstract Background Loss of control over eating is a key feature of the most prevalent eating disorders. The Loss of Control over Eating Scale (LOCES enables a thorough assessment of loss of control over eating. Objective This study empirically evaluated the translation of the LOCES from English to Brazilian Portuguese. Methods The scale was translated to Brazilian Portuguese and back translated to English in order to check accuracy of the translation. Two hundred and ninety-three medicine and nursing students, 60 males and 233 females, 18-55 years old, with mean body mass index (BMI 23.2 kg/m2 (SD 4.1, recruited between August and December 2014, answered the Brazilian Portuguese LOCES. An exploratory factor analysis was performed. Results Exploratory factor analysis of the Brazilian Portuguese LOCES showed three distinct factors of the loss of control over eating (disgust/negative sensations, cognitive experiences/dissociation, and “positive” effects as well as moderate consistency with previous reports of exploratory factor analysis of the English version. Discussion This study showed satisfactory translation of the LOCES from English to Brazilian Portuguese, which is now ready for further validation.

  17. Loss of lateral prefrontal cortex control in food-directed attention and goal-directed food choice in obesity

    NARCIS (Netherlands)

    Janssen, Lieneke K.; Duif, Iris; Loon, van Ilke; Wegman, Joost; Vries, de Jeanne H.M.; Cools, Roshan; Aarts, Esther

    2017-01-01

    Loss of lateral prefrontal cortex (lPFC)-mediated attentional control may explain the automatic tendency to eat in the face of food. Here, we investigate the neurocognitive mechanism underlying attentional bias to food words and its association with obesity using a food Stroop task. We tested 76

  18. Screening of mixed surfactant systems: Phase behavior studies and CT imaging of surfactant-enhanced oil recovery experiments

    Energy Technology Data Exchange (ETDEWEB)

    Llave, F.M.; Gall, B.L.; Lorenz, P.B.; Cook, I.M.; Scott, L.J.

    1993-11-01

    A systematic chemical screening study was conducted on selected anionic-nonionic and nonionic-nonionic systems. The objective of the study was to evaluate and determine combinations of these surfactants that would exhibit favorable phase behavior and solubilization capacity. The effects of different parameters including (a) salinity, (b) temperature, (c) alkane carbon number, (c) hydrophilic/lipophilic balance (HLB) of nonionic component, and (d) type of surfactant on the behavior of the overall chemical system were evaluated. The current work was conducted using a series of ethoxylated nonionic surfactants in combinations of several anionic systems with various hydrocarbons. Efforts to correlate the behavior of these mixed systems led to the development of several models for the chemical systems tested. The models were used to compare the different systems and provided some guidelines for formulating them to account for variations in salinity, oil hydrocarbon number, and temperature. The models were also evaluated to determine conformance with the results from experimental measurements. The models provided good agreement with experimental results. X-ray computed tomography (CT) was used to study fluid distributions during chemical enhanced oil recovery experiments. CT-monitored corefloods were conducted to examine the effect of changing surfactant slug size injection on oil bank formation and propagation. Reducing surfactant slug size resulted in lower total oil production. Oil recovery results, however, did not correlate with slug size for the low-concentration, alkaline, mixed surfactant system used in these tests. The CT measurements showed that polymer mobility control and core features also affected the overall oil recovery results.

  19. In-transit wind erosion losses of coal and method of control

    Energy Technology Data Exchange (ETDEWEB)

    Nimerick, K.H.; Laflin, G.P.

    1979-08-01

    Wind tunnel tests show the effects of wind velocity and particle size on the amount of coal lost while in transit. Different coals were evaluated to determine the variables associated with wind erosion. The erosion losses can be substantially reduced by using a binder, or crusting agent, to consolidate the surfaces of the coal into a solid mass which resists erosion. This not only reduces economic loss but minimizes pollution.

  20. Behavior of microemulsion systems of virgin coconut oil (VCO) using igepal CO-520 and tween 80 surfactant

    Science.gov (United States)

    Safuan, A.; Hamdan, S.; Laili, C. R.

    2017-09-01

    Virgin Coconut Oil (VCO) has been applied in many application and products. Formation of microemulsion region with surfactant was investigated by using phase diagram. The surfactants used are igepal CO-520 and tween 80. The studies showed that formation of microemulsion region were dependent on the behaviour of the surfactant toward VCO. The result showed that microemulsion regions were present in igepal CO-520 system formed a larger water-in-oil microemulsion region compared to tween 80 system. Certain weight ratios of VCO to surfactants were studied by using evaporation test in order to study the water loss of the microemulsion in ambient condition. The evaporation rate of samples was varies depending their compositon of VCO, surfactant and water.

  1. Atomistic simulations of surfactant adsorption kinetics at interfaces

    Science.gov (United States)

    Iskrenova, Eugeniya; Patnaik, Soumya

    2014-03-01

    Heat transfer control and enhancement is an important and challenging problem in a variety of industrial and technological applications including aircraft thermal management. The role of additives in nucleate boiling and phase change in general has long been recognized and studied experimentally and modeled theoretically but in-depth description and atomistic understanding of the multiscale processes involved are still needed for better prediction and control of the heat transfer efficiency. Surfactant additives have been experimentally observed to either enhance or inhibit the boiling heat transfer depending on the surfactant concentration and chemistry and, on a molecular level, their addition leads to dynamic surface tension and changes in interfacial and transfer properties, thus contributing to the complexity of the problem. We present our atomistic modeling study of the interfacial adsorption kinetics of aqueous surfactant (sodium dodecyl sulfate) systems at a range of concentrations at room and boiling temperatures. Classical molecular dynamics and Umbrella Sampling simulations were used to study the surfactant transport properties and estimate the adsorption and desorption rates at liquid-vacuum and liquid-solid interfaces. The authors gratefully acknowledge funding from AFOSR Thermal Science Program and the Air Force Research Laboratory DoD Supercomputing Resource Center for computing time and resources.

  2. Biomimetic oligosaccharide and peptide surfactant polymers designed for cardiovascular biomaterials

    Science.gov (United States)

    Ruegsegger, Mark Andrew

    A common problem associated with cardiovascular devices is surface induced thrombosis initiated by the rapid, non-specific adsorption of plasma proteins onto the biomaterial surface. Control of the initial protein adsorption is crucial to achieve the desired longevity of the implanted biomaterial. The cell membrane glycocalyx acts as a non-thrombogenic interface through passive (dense oligosaccharide structures) and active (ligand/receptor interactions) mechanisms. This thesis is designed to investigate biomimicry of the cell glycocalyx to minimize non-specific protein adsorption and promote specific ligand/receptor interactions. Biomimetic macromolecules were designed through the molecular-scale engineering of polymer surfactants, utilizing a poly(vinyl amine) (PVAm) backbone to which hydrophilic (dextran, maltose, peptide) and hydrophobic alkyl (hexanoyl or hexanal) chains are simultaneously attached. The structure was controlled through the molar feed ratio of hydrophobic-to-hydrophilic groups, which also provided control of the solution and surface-active properties. To mimic passive properties, a series of oligomaltose surfactants were synthesized with increasing saccharide length (n = 2, 7, 15 where n is number of glucose units) to investigate the effect of coating height on protein adsorption. The surfactants were characterized by infra red (IR) and nuclear magnetic resonance (NMR) spectroscopies for structural properties and atomic force microscopy (AFM) and contact angle goniometry for surface activity. Protein adsorption under dynamic flow (5 dyn/cm2) was reduced by 85%--95% over the bare hydrophobic substrate; platelet adhesion dropped by ˜80% compared to glass. Peptide ligands were incorporated into the oligosaccharide surfactant to promote functional activity of the passive coating. The surfactants were synthesized to contain 0%, 25%, 50%, 75%, and 100% peptide ligand density and were stable on hydrophobic surfaces. The peptide surface density was

  3. Isolation of surfactant-resistant pseudomonads from the estuarine surface microlayer.

    Science.gov (United States)

    Louvado, Antonio; Coelho, Francisco J R C; Domingues, Patricia; Santos, Ana L; Gomes, Newton C M; Almeida, Adelaide; Cunha, Angela

    2012-03-01

    Bioremediation efforts often rely on the application of surfactants to enhance hydrocarbon bioavailability. However, synthetic surfactants can sometimes be toxic to degrading microorganisms, thus reducing the clearance rate of the pollutant. Therefore, surfactant-resistant bacteria can be an important tool for bioremediation efforts of hydrophobic pollutants, circumventing the toxicity of synthetic surfactants that often delay microbial bioremediation of these contaminants. In this study, we screened a natural surfactant-rich compartment, the estuarine surface microlayer (SML), for cultivable surfactant-resistant bacteria using selective cultures of sodium dodecyl sulfate (SDS) and cetyl trimethylammonium bromide (CTAB). Resistance to surfactants was evaluated by colony counts in solid media amended with critical micelle concentrations (CMC) of either surfactants, in comparison with non-amended controls. Selective cultures for surfactant-resistant bacteria were prepared in mineral medium also containing CMC concentrations of either CTAB or SDS. The surfactantresistant isolates obtained were tested by PCR for the Pseudomonas genus marker gacA gene and for the naphthalene-dioxygenase-encoding gene ndo. Isolates were also screened for biosurfactant production by the atomized oil assay. A high proportion of culturable bacterioneuston was tolerant to CMC concentrations of SDS or CTAB. The gacA-targeted PCR revealed that 64% of the isolates were Pseudomonads. Biosurfactant production in solid medium was detected in 9.4% of tested isolates, all affiliated with genus Pseudomonas. This study shows that the SML is a potential source of surfactant-resistant and biosurfactant-producing bacteria in which Pseudomonads emerge as a relevant group.

  4. Adsorption of dimeric surfactants in lamellar silicates

    Energy Technology Data Exchange (ETDEWEB)

    Balcerzak, Mateusz; Pietralik, Zuzanna [Department of Macromolecular Physics, Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Domka, Ludwik [Department of Metalorganic Chemistry, Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, 60-780 Poznań (Poland); Skrzypczak, Andrzej [Institute of Chemical Technology, Poznań University of Technology, Berdychowo 4, 60-965 Poznań (Poland); Kozak, Maciej, E-mail: mkozak@amu.edu.pl [Department of Macromolecular Physics, Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland)

    2015-12-01

    Highlights: • The intercalation of dimeric surfactants changed the morphology of MMT samples. • XRD indicated structures formed by surfactant molecules in interlayer space. • The four-step thermal decomposition of dimeric surfactant, confirms intercalation. - Abstract: The adsorption of different types of cationic surfactants in lamellar silicates changes their surface character from hydrophilic to hydrophobic. This study was undertaken to obtain lamellar silicates modified by a series of novel dimeric (gemini) surfactants of different length alkyl chains and to characterise these organophilised materials. Synthetic sodium montmorillonite SOMASIF® ME 100 (M) and enriched bentonite of natural origin (Nanoclay – hydrophilic bentonite®) were organophilised with dimeric (gemini) surfactants (1,1′-(1,4-butanediyl)bis(alkoxymethyl)imidazolium dichlorides). As a result of surfactant molecule adsorption in interlamellar space, the d-spacing (d{sub 001}) increased from 0.97 nm (for the anhydrous structure) to 2.04 nm. A Fourier transform infrared spectroscopy (FTIR) analysis of the modified systems reveals bands assigned to the stretching vibrations of the CH{sub 2} and CH{sub 3} groups and the scissoring vibrations of the NH group from the structure of the dimeric surfactants. Thermogravimetric (TG) and derivative thermogravimetric (DTG) studies imply a four-stage process of surfactant decomposition. Scanning electron microscopy (SEM) images provide information on the influence of dimeric surfactant intercalation into the silicate structures. Particles of the modified systems show a tendency toward the formation of irregularly shaped agglomerates.

  5. A conservative SPH method for surfactant dynamics

    Science.gov (United States)

    Adami, S.; Hu, X. Y.; Adams, N. A.

    2010-03-01

    In this paper, a Lagrangian particle method is proposed for the simulation of multiphase flows with surfactant. The model is based on the multiphase smoothed particle hydrodynamics (SPH) framework of Hu and Adams (2006) [1]. Surface-active agents (surfactants) are incorporated into our method by a scalar quantity describing the local concentration of molecules in the bulk phase and on the interface. The surfactant dynamics are written in conservative form, thus global mass of surfactant is conserved exactly. The transport model of the surfactant accounts for advection and diffusion. Within our method, we can simulate insoluble surfactant on an arbitrary interface geometry as well as interfacial transport such as adsorption or desorption. The flow-field dynamics and the surfactant dynamics are coupled through a constitutive equation, which relates the local surfactant concentration to the local surface-tension coefficient. Hence, the surface-tension model includes capillary and Marangoni-forces. The present numerical method is validated by comparison with analytic solutions for diffusion and for surfactant dynamics. More complex simulations of an oscillating bubble, the bubble deformation in a shear flow, and of a Marangoni-force driven bubble show the capabilities of our method to simulate interfacial flows with surfactants.

  6. The ash in forest fire affected soils control the soil losses. Part 1. The pioneer research

    Science.gov (United States)

    Cerdà, Artemi; Pereira, Paulo

    2013-04-01

    After forest fires, the ash and the remaining vegetation cover on the soil surface are the main protection against erosion agents. The control ash exert on runoff generation mechanism was researched during the 90's (Cerdà, 1998a; 1998b). This pioneer research demonstrated that after forest fires there is a short period of time that runoff and surface wash by water is controlled by the high infiltration rates achieved by the soil, which were high due to the effect of ash acting as a mulch. The research of Cerdà (1998a; 1998b) also contributed to demonstrate that runoff was enhanced four month later upon the wash of the ash by the runoff, but also due to the removal of ash due to dissolution and water infiltration. As a consequence of the ephemeral ash cover the runoff and erosion reached the peak after the removal of the ash (usually four month), and for two years the soil erosion reached the peak (Cerdà, 1998a). Research developed during the last decade shown that the ash and the litter cover together contribute to reduce the soil losses after the forest fire (Cerdà and Doerr, 2008). The fate of the ash is related to the climatic conditions of the post-fire season, as intense thunderstorms erode the ash layer and low intensity rainfall contribute to a higher infiltration rate and the recovery of the vegetation. Another, key factor found during the last two decades that determine the fate of the ash and the soil and water losses is the impact of the fauna (Cerdà and Doerr, 2010). During the last decade new techniques were developed to study the impact of ash in the soil system, such as the one to monitor the ash changes by means of high spatial resolution photography (Pérez Cabello et al., 2012), and laboratory approaches that show the impact of ash as a key factor in the soil hydrology throughout the control they exert on the soil water repellency (Bodí et al., 2012). Laboratory approaches also shown that the fire severity is a key factor on the ash chemical

  7. BEHAVIOR OF SURFACTANT MIXTURES AT SOLID/LIQUID AND OIL/LIQUID INTERFACES IN CHEMICAL FLOODING SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Prof. P. Somasundaran

    2002-09-30

    The aim of the project is to develop and evaluate efficient novel surfactant mixtures for enhanced oil recovery. Surfactant loss by adsorption or precipitation depends to a great extent on the type of surfactant complexes and aggregates formed. Such information as well as techniques to generate the information is lacking currently particularly for surfactant mixtures and surfactant/polymer systems. A novel analytical centrifuge application is explored during the last period to generate information on structures-performance relationship for different surfactant aggregates in solution and, in turn, at interfaces. To use analytical untracentrifuge for surfactant mixtures, information on partial specific volumes of single surfactants and their mixtures is required. Towards this purpose, surface tension and density measurements were performed to determine critical micellar concentrations (cmc), partial specific volumes of n-dodecyl-{beta}-Dmaltoside (DM), nonyl phenol ethoxylated decyl ether (NP-10) and their 1:1 mixtures at 25 C. Durchschlag's theoretical calculation method was adopted to calculate the partial specific volumes. Effects of temperature and mixing, as well as methods used for estimation on micellization and partial specific volumes were studied during the current period. Surface tension results revealed no interaction between the two surfactants in mixed micelles. Partial specific volume measurements also indicated no interaction in mixed micelles. Maximum adsorption density, area per molecule and free energy of micellization were also calculated. Partial specific volumes were estimated by two experimental methods: d{sub {rho}}/dc and V{sub {sigma}}. The difference between the results of using the two methods is within 0.5% deviation. It was found that the partial specific volume is concentration dependent and sensitive to changes in temperature. The information generated in this study will be used for the study of surfactant aggregate mass

  8. Surfactants in tribology, v.3

    CERN Document Server

    Biresaw, Girma

    2013-01-01

    The manufacture and use of almost every consumer and industrial product rely on application of advanced knowledge in surface science and tribology. These two disciplines are of critical importance in major economic sectors, such as mining, agriculture, manufacturing (including metals, plastics, wood, computers, MEMS, NEMS, appliances), construction, transportation, and medical instruments, transplants, and diagnostic devices. An up-to-date reference with contributions by experts in surface science and tribology, Surfactants in Tribology, Volume 3 discusses some of the underlying tribological a

  9. Research on Single-Phase PWM Converter with Reverse Conducting IGBT Based on Loss Threshold Desaturation Control

    Directory of Open Access Journals (Sweden)

    Xianjin Huang

    2017-11-01

    Full Text Available In the application of vehicle power supply and distributed power generation, there are strict requirements for the pulse width modulation (PWM converter regarding power density and reliability. When compared with the conventional insulated gate bipolar transistor (IGBT module, the Reverse Conducting-Insulated Gate Bipolar Transistor (RC-IGBT with the same package has a lower thermal resistance and higher current tolerance. By applying the gate desaturation control, the reverse recovery loss of the RC-IGBT diode may be reduced. In this paper, a loss threshold desaturation control method is studied to improve the output characteristics of the single-phase PWM converter with a low switching frequency. The gate desaturation control characteristics of the RC-IGBT’s diode are studied. A proper current limit is set to avoid the ineffective infliction of the desaturation pulse, while the bridge arm current crosses zero. The expectation of optimized loss decrease is obtained, and the better performance for the RC-IGBTs of the single-phase PWM converter is achieved through the optimized desaturation pulse distribution. Finally, the improved predictive current control algorithm that is applied to the PWM converter with RC-IGBTs is simulated, and is operated and tested on the scaled reduced power platform. The results prove that the gate desaturation control with the improved predictive current algorithm may effectively improve the RC-IGBT’s characteristics, and realize the stable output of the PWM converter.

  10. Enhanced Oil Recovery with Surfactant Flooding

    DEFF Research Database (Denmark)

    Sandersen, Sara Bülow

    Enhanced oil recovery (EOR) is being increasingly applied in the oil industry and several different technologies have emerged during, the last decades in order to optimize oil recovery after conventional recovery methods have been applied. Surfactant flooding is an EOR technique in which the phase...... behavior inside the reservoir can be manipulated by the injection of surfactants and co-surfactants, creating advantageous conditions in order to mobilize trapped oil. Correctly designed surfactant systems together with the crude oil can create microemulsions at the interface between crude oil and water......, thus reducing the interfacial tension (IFT) to ultra low (0.001 mN/m), which consequently will mobilize the residual oil and result in improved oil recovery. This EOR technology is, however, made challenging by a number of factors, such as the adsorption of surfactant and co-surfactant to the rock...

  11. Acute Pathophysiological Effects of Intratracheal Instillation of Budesonide and Exogenous Surfactant in a Neonatal Surfactant-depleted Piglet Model

    Directory of Open Access Journals (Sweden)

    Chia-Feng Yang

    2010-08-01

    Conclusions: Intratracheal instillation of surfactant or surfactant plus budesonide can improve oxygenation and pulmonary histologic outcome in neonatal surfactant-depleted lungs. The additional use of budesonide does not disturb the function of the exogenous surfactant. Intratracheal administration of a corticosteroid combined with surfactant may be an effective method for alleviating local pulmonary inflammation in severe RDS.

  12. Behavioral self-regulation for weight loss in young adults: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Wing Rena R

    2009-02-01

    Full Text Available Abstract Objective To determine the feasibility of recruiting and retaining young adults in a brief behavioral weight loss intervention tailored for this age group, and to assess the preliminary efficacy of an intervention that emphasizes daily self-weighing within the context of a self-regulation model. Methods Forty young adults (29.1 ± 3.9 years, range 21–35, average BMI of 33.36 ± 3.4 were randomized to one of two brief behavioral weight loss interventions: behavioral self-regulation (BSR or adapted standard behavioral treatment (SBT. Assessments were conducted at baseline, post-treatment (10 weeks, and follow-up (20 weeks. Intent to treat analyses were conducted using general linear modeling in SPSS version 14.0. Results Participants in both groups attended an average of 8.7 out of 10 group meetings, and retention rates were 93% and 88% for post-treatment and follow-up assessments, respectively. Both groups achieved significant weight losses at post-treatment (BSR = -6.4 kg (4.0; SBT = -6.2 kg (4.5 and follow-up (BSR = -6.6 kg (5.5; SBT = -5.8 kg (5.2, p p = .84. Across groups, there was a positive association between frequency of weighing at follow-up and overall weight change at follow-up (p = .01. Daily weighing was not associated with any adverse changes in psychological symptoms. Conclusion Young adults can be recruited and retained in a behavioral weight loss program tailored to their needs, and significant weight losses can be achieved and maintained through this brief intervention. Future research on the longer-term efficacy of a self-regulation approach using daily self-weighing for weight loss in this age group is warranted. Clinical Trials Registration # NCT00488228

  13. The relationship between weight loss and time and risk preference parameters: a randomized controlled trial.

    Science.gov (United States)

    Takada, Akemi; Nakamura, Ryota; Furukawa, Masakazu; Takahashi, Yoshimitsu; Nishimura, Shuzo; Kosugi, Shinji

    2011-07-01

    This study aimed to assess the effectiveness of intervention (specifically, intervention by telephone and mails, known as 'tele-care') relative to self-help as a weight-loss method. The question of whether there is a correlation between changes in two preference parameters--time discounting (i.e. impatience) and risk aversion--and the level of commitment was examined. The study, spanning a period of 24 weeks in 2006-2007, comprised 118 participants, each of whom was randomly assigned to either the tele-care or the self-help group. A public-health nurse provided support through telephone and mail communications to the tele-care group, aiming to reduce their calorie intake and increase exercise via this intervention. There was a significant decrease in the body weight of the participants of the tele-care group from the baseline; however, there were no significant differences in the weight loss, median time discounting or risk aversion between the two groups. The subsequent analysis for weight loss with changes in time and risk parameters revealed a significant difference in the weight loss in the time-discounting-loss and risk-aversion-gain groups. From the results of the multiple regression analysis, the time discounting was noted to be associated with age, initial BMI and marital status among men, and risk aversion was associated with age and job status among women. There is a possibility that a decrease in time discounting and increase in risk aversion might correlate with the weight loss or effectiveness of commitment in this trial. This study suggests that time discounting and risk aversion may be useful in anti-obesity efforts, since they are accurate criteria of behavioural patterns associated with weight problems. © Cambridge University Press, 2011

  14. Flexible Stock Allocation and Trim Loss Control for Cutting Problem in the Industrial-Use Paper Production

    Directory of Open Access Journals (Sweden)

    Fu-Kwun Wang

    2014-01-01

    Full Text Available We consider a one-dimensional cutting stock problem (CSP in which the stock widths are not used to fulfill the order but kept for use in the future for the industrial-use paper production. We present a new model based on the flexible stock allocation and trim loss control to determine the production quantity. We evaluate our approach using a real data and show that we are able to solve industrial-size problems, while also addressing common cutting considerations such as aggregation of orders, multiple stock widths, and cutting different patterns on the same machine. In addition, we compare our model with others, including trim loss minimization problem (TLMP and cutting stock problem (CSP. The results show that the proposed model outperforms the other two models regarding total flexibility and trim loss ratio.

  15. Use of therapeutic surfactant lavage in a preterm infant with massive pulmonary hemorrhage

    Directory of Open Access Journals (Sweden)

    Ino Kanavaki

    2012-08-01

    Full Text Available We report a case of a premature infant presenting with recurrent pulmonary hemorrhage in which we performed a therapeutic lavage with diluted surfactant after an acute episode of bleeding with severe intractable hypoxemia. Repeated small aliquots of diluted surfactant (10x2 mL allowed rapid improvement in oxygenation and reduction of required mean airway pressures during high frequency oscillatory ventilation. This observation may suggest that surfactant lavage could be beneficial in massive pulmonary hemorrhage in infants. A randomized controlled trial might be needed to clarify the potential benefit of this therapeutic intervention on outcome of infants suffering from this life-threatening complication.

  16. Control of recoil losses in nanomechanical SiN membrane resonators

    Science.gov (United States)

    Borrielli, A.; Marconi, L.; Marin, F.; Marino, F.; Morana, B.; Pandraud, G.; Pontin, A.; Prodi, G. A.; Sarro, P. M.; Serra, E.; Bonaldi, M.

    2016-09-01

    In the context of a recoil damping analysis, we have designed and produced a membrane resonator equipped with a specific on-chip structure working as a "loss shield" for a circular membrane. In this device the vibrations of the membrane, with a quality factor of 107, reach the limit set by the intrinsic dissipation in silicon nitride, for all the modes and regardless of the modal shape, also at low frequency. Guided by our theoretical model of the loss shield, we describe the design rationale of the device, which can be used as effective replacement of commercial membrane resonators in advanced optomechanical setups, also at cryogenic temperatures.

  17. [Control of Soil Nutrient Loss of Typical Reforestation Patterns Along the Three Gorges Reservoir Area].

    Science.gov (United States)

    Wu, Dong; Huang, Zhi-lin; Xiao, Wen-fa; Zeng, Li-xiong

    2015-10-01

    Annual soil nutrient loss characteristics on typical reforestation patterns in watershed along the Three Gorges Reservoir Area were studied based on runoff plot experiment. Runoff and sediment nutrition content from May to October 2014 of typical reforestation patterns including garden plot (tea garden), forest land (Chinese chestnut) and the original slope farmland were determined and then analyzed. The results showed that: (1) After the Returning Farmland to Forest Project the quantity of annual soil nutrient (nitrogen and phosphorus, the sum of them in sediment and runoff) loss decreased. The output of total nitrogen (TN) was in the order of slope farmland (2 444.27 g x hm(-2)) > tea garden (998.70 g x hm(-2)) > Chinese chestnut forest (532.61 g x hm(-2)), and for total phosphorus (TP) loss was slope farmland (1 690.48 g x hm(-2)) > tea garden (488.06 g x hm(-2)) > Chinese chestnut forest (129.00 g x hm(-2)) . Compared with slope farmland, the load of TN and TP output of reforestation patterns decreased 68.68% and 81.75%, respectively. (2) Compared with slope farmland, available nitrogen loss decreased in reforestation patterns. Total nitrate nitrogen (NO3(-)-N) loss ranked in the order of slope farmland (113.79 g x hm(-2)) > tea garden (73.75 g x hm(-2)) > Chinese chestnut forest (56.06 g x hm(-2)) The largest amount of ammonium nitrogen (NH4(+)-N) was found in tea garden (69.34 g x hm(-2)), then in farmland (52.45 g x hm(-2)), and the least in Chinese chestnut forest (47.23 g x hm(-2)). (3) The main route of NO3(-)-N and NH4(+)-N loss was both through runoff, the quantity of NO3(-)-N and NH4(+)-N output in which accounted for 91.4% and 92.2% of the total, respectively. The quantity of TN and TP in sediment accounted for 86.6% and 98.4% of the total. TN and TP loss showed an extremely significant correlation with sediments, which showed that sediment output was the main approach of TN and TP loss.

  18. Cationic versus anionic surfactant in tuning the structure and interaction of nanoparticle, protein, and surfactant complexes.

    Science.gov (United States)

    Mehan, Sumit; Aswal, Vinod K; Kohlbrecher, Joachim

    2014-08-26

    The structure and interaction in complexes of anionic Ludox HS40 silica nanoparticle, anionic bovine serum albumin (BSA) protein, and cationic dodecyl trimethylammonium bromide (DTAB) surfactant have been studied using small-angle neutron scattering (SANS). The results are compared with similar complexes having anionic sodium dodecyl sulfate (SDS) surfactant (Mehan, S; Chinchalikar, A. J.; Kumar, S.; Aswal, V. K.; Schweins, R. Langmuir 2013, 29, 11290). In both cases (DTAB and SDS), the structure in nanoparticle-protein-surfactant complexes is predominantly determined by the interactions of the individual two-component systems. The nanoparticle-surfactant (mediated through protein-surfactant complex) and protein-surfactant interactions for DTAB, but nanoparticle-protein (mediated through protein-surfactant complex) and protein-surfactant interactions for SDS, are found to be responsible for the resultant structure of nanoparticle-protein-surfactant complexes. Irrespective of the charge on the surfactant, the cooperative binding of surfactant with protein leads to micellelike clusters of surfactant formed along the unfolded protein chain. The adsorption of these protein-surfactant complexes for DTAB on oppositely charged nanoparticles gives rise to the protein-surfactant complex-mediated aggregation of nanoparticles (similar to that of DTAB surfactant). It is unlike that of depletion-induced aggregation of nanoparticles with nonadsorption of protein-surfactant complexes for SDS in similarly charged nanoparticle systems (similar to that of protein alone). The modifications in nanoparticle aggregation as well as unfolding of protein in these systems as compared to the corresponding two-component systems have also been examined by selectively contrast matching the constituents.

  19. Surfactant exfoliated 2D hexagonal Boron Nitride (2D-hBN) explored as a potential electrochemical sensor for dopamine: surfactants significantly influence sensor capabilities.

    Science.gov (United States)

    Khan, Aamar F; Brownson, Dale A C; Foster, Christopher W; Smith, Graham C; Banks, Craig E

    2017-05-21

    Surfactant exfoliated 2D hexagonal Boron Nitride (2D-hBN) nanosheets are explored as a potential electrochemical sensing platform and evaluated towards the electroanalytical sensing of dopamine (DA) in the presence of the common interferents, ascorbic acid (AA) and uric acid (UA). Surfactant exfoliated 2D-hBN nanosheets (2-4 layers) fabricated using sodium cholate in aqueous media are electrically wired via a drop-casting modification process onto disposable screen-printed graphite electrodes (SPEs). We critically evaluate the performance of these 2D-hBN modified SPEs and demonstrate the effect of 'mass coverage' towards the detection of DA, AA and UA. Previous studies utilising surfactant-free (pristine) 2D-hBN modified SPEs have shown a beneficial effect towards the detection of DA, AA and UA when compared to the underlying/unmodified graphite-based electrode. We show that the fabrication route utilised to prepare 2D-hBN is a vital experimental consideration, such that the beneficial effect previously reported is considerably reduced when surfactant exfoliated 2D-hBN is utilised. We demonstrate for the first time, through implementation of control experiments in the form of surfactant modified graphite electrodes, that sodium cholate is a major contributing factor to the aforementioned detrimental behaviour. The significance here is not in the material per se, but the fundamental knowledge of the surfactant and surface coverage changing the electrochemical properties of the material under investigation. Given the wide variety of ionic and non-ionic surfactants that are utilised in the manufacture of novel 2D materials, the control experiments reported herein need to be performed in order to de-convolute the electrochemical response and effectively evaluate the 'underlying surface/surfactant/2D materials' electrocatalytic contribution.

  20. Habitual physical activity and plasma metabolomic patterns distinguish individuals with low vs. high weight loss during controlled energy restriction.

    Science.gov (United States)

    Piccolo, Brian D; Keim, Nancy L; Fiehn, Oliver; Adams, Sean H; Van Loan, Marta D; Newman, John W

    2015-04-01

    Total weight loss induced by energy restriction is highly variable even under tightly controlled conditions. Identifying weight-loss discriminants would provide a valuable weight management tool and insights into body weight regulation. This study characterized responsiveness to energy restriction in adults from variables including the plasma metabolome, endocrine and inflammatory markers, clinical indices, body composition, diet, and physical activity. Data were derived from a controlled feeding trial investigating the effect of 3-4 dairy product servings in an energy-restricted diet (2092 kJ/d reduction) over 12 wk. Partial least squares regression was used to identify weight-loss discriminants in 67 overweight and obese adults. Linear mixed models were developed to identify discriminant variable differences in high- vs. low-weight-loss responders. Both pre- and postintervention variables (n = 127) were identified as weight-loss discriminants (root mean squared error of prediction = 1.85 kg; Q(2) = 0.43). Compared with low-responders (LR), high-responders (HR) had greater decreases in body weight (LR: 2.7 ± 1.6 kg; HR: 9.4 ± 1.8 kg, P physical activity (LR: 127 ± 52 min; HR: 167 ± 68 min, P = 0.02), sedentary activity (LR: 1090 ± 99 min; HR: 1017 ± 110 min, P = 0.02), and plasma stearate [LR: 102,000 ± 21,000 quantifier ion peak height (QIPH); HR: 116,000 ± 24,000 QIPH, P = 0.01]. Overweight and obese individuals highly responsive to energy restriction had accelerated reductions in adiposity, likely supported in part by higher lipid mobilization and combustion. A novel observation was that person-to-person differences in habitual physical activity and magnitude of weight loss were accompanied by unique blood metabolite signatures. This trial was registered at clinicaltrials.gov as NCT00858312. © 2015 American Society for Nutrition.

  1. Phase transitions in surfactant monolayers

    International Nuclear Information System (INIS)

    Casson, B.D.

    1998-01-01

    Two-dimensional phase transitions have been studied in surfactant monolayers at the air/water interface by sum-frequency spectroscopy and ellipsometry. In equilibrium monolayers of medium-chain alcohols C n H 2n+1 OH (n = 9-14) a transition from a two-dimensional crystalline phase to a liquid was observed at temperatures above the bulk melting point. The small population of gauche defects in the solid phase increased only slightly at the phase transition. A model of the hydrocarbon chains as freely rotating rigid rods allowed the area per molecule and chain tilt in the liquid phase to be determined. The area per molecule, chain tilt and density of the liquid phase all increased with increasing chain length, but for each chain length the density was higher than in a bulk liquid hydrocarbon. In a monolayer of decanol adsorbed at the air/water interface a transition from a two-dimensional liquid to a gas was observed. A clear discontinuity in the coefficient of ellipticity as a function of temperature showed that the transition is first-order. This result suggests that liquid-gas phase transitions in surfactant monolayers may be more widespread than once thought. A solid-liquid phase transition has also been studied in mixed monolayers of dodecanol with an anionic surfactant (sodium dodecyl sulphate) and with a homologous series of cationic surfactants (alkyltrimethylammonium bromides: C n TABs, n = 12, 14, 16). The composition and structure of the mixed monolayers was studied above and below the phase transition. At low temperatures the mixed monolayers were as densely packed as a monolayer of pure dodecanol in its solid phase. At a fixed temperature the monolayers under-went a first-order phase transition to form a phase that was less dense and more conformationally disordered. The proportion of ionic surfactant in the mixed monolayer was greatest in the high temperature phase. As the chain length of the C n TAB increased the number of conformational defects

  2. A randomized controlled trial of a commercially available weight loss program

    Science.gov (United States)

    The U.S. Preventive Services Task Force (USPSTF) recommends that clinicians refer obese adults for intensive, multi-component behavioral counseling, yet most obese Americans choose a self-help approach to lose weight. The current study examined weight loss between a community-based, intensive behavi...

  3. Control of Ore Loss and Dilution at AngloGold Ashanti, Iduapriem ...

    African Journals Online (AJOL)

    Blast Movement Monitoring (BMM) system is a new method of determining material movement during blasting in order to minimise ore loss, dilution and sometimes misclassification. The BMM system was introduced at AngloGold Ashanti Iduapriem (AAIL) Mine in the first quarter of 2013 as a result of reconciliation ...

  4. Surfactant nebulisation : lung function, surfactant distribution and pulmonary blood flow distribution in lung lavaged rabbits

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto

    1997-01-01

    Objective: Surfactant nebulisation is a promising alternative to surfactant instillation in newborns with the respiratory distress syndrome. Although less surfactant is deposited in the lung, it improves gas exchange, probably due to a superior distribution. We hypothesize that a more uniform

  5. Solubilization of Hydrophobic Dyes in Surfactant Solutions

    Directory of Open Access Journals (Sweden)

    Ali Reza Tehrani-Bagha

    2013-02-01

    Full Text Available In this paper, the use of surfactants for solubilization of hydrophobic organic dyes (mainly solvent and disperse dyes has been reviewed. The effect of parameters such as the chemical structures of the surfactant and the dye, addition of salt and of polyelectrolytes, pH, and temperature on dye solubilization has been discussed. Surfactant self-assemble into micelles in aqueous solution and below the concentration where this occurs—the critical micelle concentration (CMC—there is no solubilization. Above the CMC, the amount of solubilized dye increases linearly with the increase in surfactant concentration. It is demonstrated that different surfactants work best for different dyes. In general, nonionic surfactants have higher solubilization power than anionic and cationic surfactants. It is likely that the reason for the good performance of nonionic surfactants is that they allow dyes to be accommodated not only in the inner, hydrocarbon part of the micelle but also in the headgroup shell. It is demonstrated that the location of a dye in a surfactant micelle can be assessed from the absorption spectrum of the dye-containing micellar solution.

  6. Remediation using trace element humate surfactant

    Science.gov (United States)

    Riddle, Catherine Lynn; Taylor, Steven Cheney; Bruhn, Debra Fox

    2016-08-30

    A method of remediation at a remediation site having one or more undesirable conditions in which one or more soil characteristics, preferably soil pH and/or elemental concentrations, are measured at a remediation site. A trace element humate surfactant composition is prepared comprising a humate solution, element solution and at least one surfactant. The prepared trace element humate surfactant composition is then dispensed onto the remediation site whereby the trace element humate surfactant composition will reduce the amount of undesirable compounds by promoting growth of native species activity. By promoting native species activity, remediation occurs quickly and environmental impact is minimal.

  7. Do Individual Online Motivational Interviewing Chat Sessions Enhance Weight Loss in a Group Online Weight Control Program?

    Science.gov (United States)

    West, Delia Smith; Harvey, Jean R.; Krukowski, Rebecca A.; Prewitt, T. Elaine; Priest, Jeffrey; Ashikaga, Takamaru

    2016-01-01

    Objective To examine whether the addition of online MI chats to a web-based, group behavioral obesity treatment program augments weight loss outcomes relative to the web-based online weight control program alone. Methods Healthy individuals (N=398, 24% minority) with overweight/obesity were randomized to a 36-session group internet behavioral weight control treatment (BT) or the same group internet treatment plus 6 individual MI chat sessions (BT+MI). Both conditions received weekly synchronous online chat group sessions for 6 months followed by 12 monthly group chats. Participants in both groups received identical behavioral lessons and individualized therapist feedback on progress toward meeting exercise and calorie goals. BT+MI also received 6 individual MI sessions delivered by a separate MI counselor via web chat. Weight loss was measured at 6- and 18-months. Results There were no significant differences in weight loss between BT (−5.5±6.0 kg) and BT+MI (−5.1±6.3 kg) at 6-months or at 18-months (−3.3±7.1 kg vs −3.5±7.7 for BT and BT+MI, respectively). Attendance at group chats did not differ between groups, nor did self–monitoring patterns, suggesting comparable engagement in the weight control program in both conditions. Conclusions Online MI chat sessions are not a viable strategy to enhance web-based weight control treatment outcomes. PMID:27616628

  8. Estimated crop loss due to coconut mite and financial analysis of controlling the pest using the acaricide abamectin.

    Science.gov (United States)

    Rezende, Daniela; Melo, José W S; Oliveira, José E M; Gondim, Manoel G C

    2016-07-01

    Reducing the losses caused by Aceria guerreronis Keifer has been an arduous task for farmers. However, there are no detailed studies on losses that simultaneously analyse correlated parameters, and very few studies that address the economic viability of chemical control, the main strategy for managing this pest. In this study the objectives were (1) to estimate the crop loss due to coconut mite and (2) to perform a financial analysis of acaricide application to control the pest. For this, the following parameters were evaluated: number and weight of fruits, liquid albumen volume, and market destination of plants with and without monthly abamectin spraying (three harvests). The costs involved in the chemical control of A. guerreronis were also quantified. Higher A. guerreronis incidence on plants resulted in a 60 % decrease in the mean number of fruits harvested per bunch and a 28 % decrease in liquid albumen volume. Mean fruit weight remained unaffected. The market destination of the harvested fruit was also affected by higher A. guerreronis incidence. Untreated plants, with higher A. guerreronis infestation intensity, produced a lower proportion of fruit intended for fresh market and higher proportions of non-marketable fruit and fruit intended for industrial processing. Despite the costs involved in controlling A. guerreronis, the difference between the profit from the treated site and the untreated site was 18,123.50 Brazilian Real; this value represents 69.1 % higher profit at the treated site.

  9. Longitudinal associations between binge eating and overeating and adverse outcomes among adolescents and young adults: does loss of control matter?

    Science.gov (United States)

    Sonneville, Kendrin R; Horton, Nicholas J; Micali, Nadia; Crosby, Ross D; Swanson, Sonja A; Solmi, Francesca; Field, Alison E

    2013-02-01

    To investigate the association between overeating (without loss of control) and binge eating (overeating with loss of control) and adverse outcomes. Prospective cohort study. Adolescents and young adults living throughout the United States. Sixteen thousand eight hundred eighty-two males and females participating in the Growing Up Today Study who were 9 to 15 years old at enrollment in 1996. Overeating and binge eating assessed via questionnaire every 12 to 24 months between 1996 and 2005. Risk of becoming overweight or obese, starting to binge drink frequently, starting to use marijuana, starting to use other drugs, and developing high levels of depressive symptoms. Generalized estimating equations were used to estimate associations. All models controlled for age and sex; additional covariates varied by outcome. Among this large cohort of adolescents and young adults, binge eating was more common among females than males. In fully adjusted models, binge eating, but not overeating, was associated with incident overweight/obesity (odds ratio, 1.73; 95% CI, 1.11-2.69) and the onset of high depressive symptoms (odds ratio, 2.19; 95% CI, 1.40-3.45). Neither overeating nor binge eating was associated with starting to binge drink frequently, while both overeating and binge eating predicted starting to use marijuana and other drugs. Although any overeating, with or without loss of control, predicted the onset of marijuana and other drug use, we found that binge eating is uniquely predictive of incident overweight/obesity and the onset of high depressive symptoms. These findings suggest that loss of control is an important indicator of severity of overeating episodes.

  10. Studies of the ionizing radiation effects on the effluents acute toxicity due to anionic surfactants

    International Nuclear Information System (INIS)

    Moraes, Maria Cristina Franco de

    2004-01-01

    Several studies have shown the negative effects of surfactants, as detergents active substance, when discharged on biological sewage wastewater treatment plants. High toxicity may represent a lower efficiency for biological treatment. When surfactants are in aquatic environment they may induce a loss of grease revetment on birds (feather). Depending on the surfactant concentration, several damages to all biotic systems can happen. Looking for an alternative technology for wastewater treatment, efficient for surfactant removal, the present work applied ionizing radiation as an advanced oxidation process for affluents and effluents from Suzano Treatment Station. Such wastewater samples were submitted to radiation using an electron beam from a Dynamic Electron Beam Accelerator from Instituto de Pesquisas Energeticas e Nucleares. In order to assess this proposed treatment efficacy, it was performed acute toxicity evaluation with two test-organisms, the crustacean Daphnia similis and the luminescent bacteria Vibrio fischeri. The studied effluents were: one from a chemical industry (IND), three from sewage plant (affluents - GG, GM and Guaio) and the last biologically treated secondary effluent (EfF), discharged at Tiete river. The applied radiation doses varied from 3 kGy to 50 kGy, being 50 kGy enough for surfactant degradation contained at industrial effluent. For GG, GM and Guaio samples, doses of 6 kGy and 10 kGy were efficient for surfactant and toxicity reduction, representing an average removal that varied from 71.80% to 82.76% and toxicity from 30% to 91% for most the effluents. The final effluent was less toxic than the others and the radiation induced an average 11% removal for anionic surfactant. The industrial effluents were also submitted to an aeration process in order to quantify the contribution of surfactant to the whole sample toxicity, once it was partially removed as foam and several fractions were evaluated for toxicity. (author)

  11. Comparison of animal-derived surfactants for the prevention and treatment of respiratory distress syndrome in preterm infants.

    Science.gov (United States)

    Singh, Neetu; Halliday, Henry L; Stevens, Timothy P; Suresh, Gautham; Soll, Roger; Rojas-Reyes, Maria Ximena

    2015-12-21

    Animal-derived surfactants have been shown to have several advantages over the first generation synthetic surfactants and are the most commonly used surfactant preparations. The animal-derived surfactants in clinical use are minced or lavaged and modified or purified from bovine or porcine lungs. It is unclear whether significant differences in clinical outcome exist among the available bovine (modified minced or lavage) and porcine (minced or lavage) surfactant extracts. To compare the effect of administration of different animal-derived surfactant extracts on the risk of mortality, chronic lung disease, and other morbidities associated with prematurity in preterm infants at risk for or having respiratory distress syndrome (RDS). We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 7), MEDLINE via PubMed (1966 to July 31, 2015), EMBASE (1980 to July 31, 2015), and CINAHL (1982 to July 31, 2015). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials. Randomized or quasi-randomized controlled trials that compared the effect of animal-derived surfactant extract treatment administered to preterm infants at risk for or having RDS to prevent complications of prematurity and mortality. Data regarding clinical outcomes were excerpted from the reports of the clinical trials by the review authors. Subgroup analyses were performed based on gestational age, surfactant dosing and schedule, treatment severity and treatment strategy. Data analysis was performed in accordance with the standards of the Cochrane Neonatal Review Group. Sixteen randomized controlled trials were included in the analysis. Bovine lung lavage surfactant extract to modified bovine minced lung surfactant extract: Seven treatment studies and two prevention studies compared bovine lung

  12. Hemolysis by surfactants--A review.

    Science.gov (United States)

    Manaargadoo-Catin, Magalie; Ali-Cherif, Anaïs; Pougnas, Jean-Luc; Perrin, Catherine

    2016-02-01

    An overview of the use of surfactants for erythrocyte lysis and their cell membrane action mechanisms is given. Erythrocyte membrane characteristics and its association with the cell cytoskeleton are presented in order to complete understanding of the erythrocyte membrane distortion. Cell homeostasis disturbances caused by surfactants might induce changes starting from shape modification to cell lysis. Two main mechanisms are hypothesized in literature which are osmotic lysis and lysis by solubilization even if the boundary between them is not clearly defined. Another specific mechanism based on the formation of membrane pores is suggested in the particular case of saponins. The lytic potency of a surfactant is related to its affinity for the membrane and the modification of the lipid membrane curvature. This is to be related to the surfactant shape defined by its hydrophobic and hydrophilic moieties but also by experimental conditions. As a consequence, prediction of the hemolytic potency of a given surfactant is challenging. Several studies are focused on the relation between surfactant erythrolytic potency and their physico-chemical parameters such as the critical micellar concentration (CMC), the hydrophile-lipophile balance (HLB), the surfactant membrane/water partition coefficient (K) or the packing parameter (P). The CMC is one of the most important factors considered even if a lytic activity cut-off effect points out that the only consideration of CMC not enough predictive. The relation K.CMC must be considered in addition to the CMC to predict the surfactant lytic capacity within the same family of non ionic surfactant. Those surfactant structure/lytic activity studies demonstrate the requirement to take into account a combination of physico-chemical parameters to understand and foresee surfactant lytic potency. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Investigation of some locally water-soluble natural polymers as circulation loss control agents during oil fields drilling

    Directory of Open Access Journals (Sweden)

    A.M. Alsabagh

    2014-03-01

    Full Text Available Eliminating or controlling lost circulation during drilling process is costly and time-consuming. Polymers play an important role in mud loss control for their viscosity due to their high molecular weight. In this paper, three natural cellulosic polymers (carboxymethyl cellulose, guar gum and potato starch were investigated as lost circulation control material by measuring different filtration parameters such as; spurt loss, fluid loss and permeability plugging tester value according to the American Petroleum Institute (API standard. The experiments were conducted in a permeability plugging apparatus (PPA at a differential pressure of 100 and 300 psi, using 10, 60 and 90 ceramic discs. From the obtained data, it was found that the 0.1% from the carboxymethyl cellulose exhibited the best results in the filtration parameters among 0.3% guar gum and 0.6% potato starch. At the same time the carboxymethyl cellulose (CMC enhanced the rheological properties of the drilling mud better than the two other used natural polymers in the term of gel strength, thixotropy, plastic and apparent viscosity. These results were discussed in the light of the adsorption and micellar formation.

  14. Influence of surfactants on the morphology of SnO{sub 2} nanocrystals prepared via a hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Wang Mi [State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); Shanghai Institute of Ceramics (SIC), Chinese Academy of Sciences (CAS), 1295 Dingxi Road, Shanghai 200050 (China); Gao Yanfeng, E-mail: yfgao@mail.sic.ac.cn [Shanghai Institute of Ceramics (SIC), Chinese Academy of Sciences (CAS), 1295 Dingxi Road, Shanghai 200050 (China); Dai Lei; Cao Chuanxiang [Shanghai Institute of Ceramics (SIC), Chinese Academy of Sciences (CAS), 1295 Dingxi Road, Shanghai 200050 (China); Guo Xuhong, E-mail: guoxuhong@ecust.edu.cn [State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China)

    2012-05-15

    Nanoscaled SnO{sub 2} with different morphologies has been synthesized via a simple hydrothermal process at 180 Degree-Sign C using polyvinylpyrrolidone (PVP), sodium dodecyl sulfonate (SDS), cetyl trimethyl ammonium bromide (CTAB) or tetrapropyl ammonium bromide (TPAB) as surfactant. All the prepared SnO{sub 2} are of a tetragonal crystal structure. Nanocubes, nanorods, nanosheets, nanobelts and nanoparticles were prepared when changing the type and dosage of organic surfactants. It is shown that anionic surfactant (SDS) and cationic surfactant (CTAB or TPAB) at their suitable addition amounts can largely influence the morphologies of SnO{sub 2} nanocrystals. The effect is significantly dependent on the solvent types: water or ethanol. The non-ionic surfactant (PVP) can also change the morphologies like SDS but the impacts are less obvious. The effect of surfactants on the shape and size of SnO{sub 2} nanoparticles was discussed in detail. The particle growth mechanism is described based on the electrostatic interactions and Van der Waals' forces. - Graphical abstract: SnO{sub 2} nanocrystals with controllable morphologies were prepared via a hydrothermal method with surfactants. Highlights: Black-Right-Pointing-Pointer SnO{sub 2} nanocrystals were prepared via a hydrothermal method with surfactants. Black-Right-Pointing-Pointer SnO{sub 2} morphologies changed with the type and the dosage of surfactants. Black-Right-Pointing-Pointer The effect of surfactants on the growth of crystal planes was studied. Black-Right-Pointing-Pointer The controlling mechanisms of surfactants on SnO{sub 2} morphologies were discussed.

  15. Study of adjuvant effect of model surfactants from the groups of alkyl sulfates, alkylbenzene sulfonates, alcohol ethoxylates and soaps

    DEFF Research Database (Denmark)

    Clausen, S K; Sobhani, S; Poulsen, O M

    2000-01-01

    The sodium salts of representatives of anionic surfactants, dodecylbenzene sulfonate (SDBS), dodecyl sulfate (SDS) and coconut oil fatty acids, and a nonionic surfactant, dodecyl alcohol ethoxylate, were studied for adjuvant effect on the production of specific IgE antibodies in mice....... The surfactants were injected subcutaneously (sc) in concentrations of 1000, 100, 10 or 1 mg/l, respectively, together with 1 microg of ovalbumin (OVA). In addition, groups of mice received OVA in saline (control group) or in Al(OH)(3) (positive adjuvant control group). After the primary immunization the mice...... that a limited number of surfactants possess an adjuvant effect whereas all surfactants at certain levels can suppress specific IgE production....

  16. Momentary Affect Surrounding Loss of Control and Overeating in Obese Adults With and Without Binge Eating Disorder

    OpenAIRE

    Goldschmidt, Andrea B.; Engel, Scott G.; Wonderlich, Stephen A.; Crosby, Ross D.; Peterson, Carol B.; Le Grange, Daniel; Tanofsky-Kraff, Marian; Cao, Li; Mitchell, James E.

    2011-01-01

    Research suggests that loss of control (LOC) while eating (the sense that one cannot control what or how much one is eating) is a more salient feature of binge eating than the amount of food consumed. This study examined the unique contributions of LOC and episode size to negative affect surrounding eating episodes in binge eating disorder (BED) and obesity. Twenty-two obese adults with (n = 9) and without (n = 13) BED completed daily records of eating patterns and mood using ecological momen...

  17. Efficacy of a new technique - INtubate-RECruit-SURfactant-Extubate - "IN-REC-SUR-E" - in preterm neonates with respiratory distress syndrome: study protocol for a randomized controlled trial

    NARCIS (Netherlands)

    Vento, Giovanni; Pastorino, Roberta; Boni, Luca; Cota, Francesco; Carnielli, Virgilio; Cools, Filip; Dani, Carlo; Mosca, Fabio; Pillow, Jane; Polglase, Graeme; Tagliabue, Paolo; van Kaam, Anton H.; Ventura, Maria Luisa; Tana, Milena; Tirone, Chiara; Aurilia, Claudia; Lio, Alessandra; Ricci, Cinzia; Gambacorta, Alessandro; Consigli, Chiara; D'Onofrio, Danila; Gizzi, Camilla; Massenzi, Luca; Cardilli, Viviana; Casati, Alessandra; Bottino, Roberto; Pontiggia, Federica; Ciarmoli, Elena; Martinelli, Stefano; Ilardi, Laura; Colnaghi, Mariarosa; Matassa, Piero Giuseppe; Vendettuoli, Valentina; Villani, Paolo; Fusco, Francesca; Gazzolo, Diego; Ricotti, Alberto; Ferrero, Federica; Stasi, Ilaria; Magaldi, Rosario; Maffei, Gianfranco; Presta, Giuseppe; Perniola, Roberto; Messina, Francesco; Montesano, Giovanna; Poggi, Chiara; Giordano, Lucio; Roma, Enza; Grassia, Carolina; Ausanio, Gaetano; Sandri, Fabrizio; Mescoli, Giovanna; Giura, Francesco; Garani, Giampaolo; Solinas, Agostina; Lucente, Maria; Nigro, Gabriella; del Vecchio, Antonello; Petrillo, Flavia; Orfeo, Luigi; Grappone, Lidia; Quartulli, Lorenzo; Scorrano, Antonio; Messner, Hubert; Staffler, Alex; Gargano, Giancarlo; Balestri, Eleonora; Nobile, Stefano; Cacace, Caterina; Meli, Valerio; Dallaglio, Sara; Pasqua, Betta; Mattia, Loretta; Gitto, Eloisa; Vitaliti, Marcello; Re, Maria Paola; Vedovato, Stefania; Grison, Alessandra; Berardi, Alberto; Torcetta, Francesco; Guidotti, Isotta; di Fabio, Sandra; Maranella, Eugenia; Mondello, Isabella; Visentin, Stefano; Tormena, Francesca

    2016-01-01

    Although beneficial in clinical practice, the INtubate-SURfactant-Extubate (IN-SUR-E) method is not successful in all preterm neonates with respiratory distress syndrome, with a reported failure rate ranging from 19 to 69 %. One of the possible mechanisms responsible for the unsuccessful IN-SUR-E

  18. Increased meal frequency attenuates fat-free mass losses and some markers of health status with a portion-controlled weight loss diet.

    Science.gov (United States)

    Alencar, Michelle K; Beam, Jason R; McCormick, James J; White, Ailish C; Salgado, Roy M; Kravitz, Len R; Mermier, Christine M; Gibson, Ann L; Conn, Carole A; Kolkmeyer, Deborah; Ferraro, Robert T; Kerksick, Chad M

    2015-05-01

    Increased meal frequency (MF) may be associated with improvements in blood markers of health and body composition during weight loss; however, this claim has not been validated. The purpose of the study was to determine if either a 2-meal (2 MF) or 6-meal frequency (6 MF) regimen can improve body composition and blood-based markers of health while consuming a portion-controlled equihypocaloric diet. Eleven (N=11) obese women (52 ± 7 years, 101.7 ± 22.6 kg, 39.1 ± 7.6 kg/m(2)) were randomized into treatment condition (2 MF or 6 MF) for 2 weeks, completed a 2-week washout, and alternated treatment conditions. In pre/post fashion, changes in body composition, glucose, insulin, and lipid components were measured in response to a test meal. Body mass was successfully lost (P ≤ .05) under both feeding regimens (2 MF: -2.8 ± 1.5 vs 6 MF: -1.9 ± 1.5 kg). Altering MF did not impact glucose, insulin, total cholesterol, or low-density lipoprotein cholesterol (P>.05). On average, fat-free mass (FFM) decreased by -3.3% ± 2.6% following the 2 MF condition and, on average, increased by 1.2% ± 1.7% following the 6 MF condition (P ≤ .05). Fasting high-density lipoprotein cholesterol (HDL-C) percentage increased during the 2 MF condition; this was significantly greater than that in the 6 MF condition (1.3% ± 12.2% vs 0.12% ± 10.3%) (P ≤ .05). Overall, reductions in MF (2 MF) were associated with improved HDL-C levels; but the clinical significance is not clear. Alternatively, increased MF (6 MF) did appear to favorably preserve FFM during weight loss. In conclusion, caloric restriction was effective in reducing body mass and attenuating FFM changes in body composition; however, glucose, insulin, and lipid metabolism had no significant differences between MF. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Reducing losses inflicted by insect pests on cashew, using weaver ants as a biological control agent

    DEFF Research Database (Denmark)

    Anato, Florence; Wargui, Rosine; Sinzogan, Antonio

    2015-01-01

    BACKGROUND: Cashew (Anacardium occidentale Linnaeus) is the largest agricultural export product in Benin. However, yields and quality are lost due to inefficient pest control. Weaver ants (Oecophylla spp.) may control pests in this crop as they eat and deter pests. In Benin, cashew pest damages......, nut quality and yield were compared among: (i) trees with weaver ant (Oecophylla longinoda Latreille), (ii) trees where weaver ants were fed sugar, (iii) IPM trees with weaver ants combined with GF-120 (a natural insecticide), and (iv) control trees receiving no control measures. RESULTS: Thrips...... damages on nuts were higher than other damage symptoms and significantly lower on control trees compared to other treatments. Percentage of first quality nuts was higher in the control compared to ants treatments, but not different from the IPM-treatment. However, compared to the control treatment, ants...

  20. Surfactant treatment before first breath for respiratory distress syndrome in preterm lambs: comparison of a peptide-containing synthetic lung surfactant with porcine-derived surfactant

    Directory of Open Access Journals (Sweden)

    van Zyl JM

    2013-08-01

    Full Text Available Johann M van Zyl,1 Johan Smith2 1Division of Pharmacology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa; 2Department of Paediatrics and Child Health, Tygerberg Children's Hospital, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa Background: In a recent study utilizing a saline-lavaged adult rabbit model, we described a significant improvement in systemic oxygenation and pulmonary shunt after the instillation of a novel synthetic peptide-containing surfactant, Synsurf. Respiratory distress syndrome in the preterm lamb more closely resembles that of the human infant, as their blood gas, pH values, and lung mechanics deteriorate dramatically from birth despite ventilator support. Moreover, premature lambs have lungs which are mechanically unstable, with the advantage of being able to measure multiple variables over extended periods. Our objective in this study was to investigate if Synsurf leads to improved systemic oxygenation, lung mechanics, and histology in comparison to the commercially available porcine-derived lung surfactant Curosurf® when administered before first breath in a preterm lamb model. Materials and methods: A Cesarean section was performed under general anesthesia on 18 time-dated pregnant Dohne Merino ewes at 129–130 days gestation. The premature lambs were delivered and ventilated with an expiratory tidal volume of 6–8 mL/kg for the first 30 minutes and thereafter at 8–10 mL/kg. In a randomized controlled trial, the two surfactants tested were Synsurf and Curosurf®, both at a dose of 100 mg/kg phospholipids (1,2-dipalmitoyl-L-α-phosphatidylcholine; 90% in Synsurf, 40% in Curosurf®. A control group of animals was treated with normal saline. Measurements of physiological variables, blood gases, and lung mechanics were made before and after surfactant and saline replacement and at 15, 30, 45, 60, 90, 120, 180

  1. Supervised Physical Training Improves Weight Loss After Roux-en-Y Gastric Bypass Surgery: A Randomized Controlled Trial.

    Science.gov (United States)

    Mundbjerg, Lene Hymøller; Stolberg, Charlotte Røn; Cecere, Stefano; Bladbjerg, Else-Marie; Funch-Jensen, Peter; Gram, Bibi; Juhl, Claus Bogh

    2018-03-22

    Bariatric surgery results in significant weight loss and reduces cardiovascular morbidity. However, a large variation in postsurgery weight loss is seen. Physical activity promotes weight loss in nonsurgically treated subjects with obesity. The aim of this study was to investigate the effects of 6 months of supervised physical training following Roux-en-Y gastric bypass surgery (RYGB) on body weight and cardiovascular risk markers. Sixty participants eligible for RYGB were included. Six months post surgery, the participants were randomly assigned to either twice-weekly supervised physical training sessions in a fitness center (INT) or a control group (CON) for 26 weeks. Before surgery and 6, 12, and 24 months after surgery, the participants underwent an examination program that included anthropometric measurements, blood pressure, heart rate, blood samples, and an abdominal computed tomography scan. RYGB significantly reduced body weight and improved cardiovascular risk markers (all P physical training intervention resulted in a 4.2-kg (CI: -0.2 to -8.3 kg) lower body weight in INT compared with CON at the study end (P = 0.042). The high-density lipoprotein concentration was significantly higher in INT than in CON at the termination of the intervention, but this was not maintained at the 24-months examination. Physical training following RYGB improves weight loss and cardiovascular health. © 2018 The Obesity Society.

  2. Effectiveness of a tailored return to work program for cancer survivors with job loss: results of a randomized controlled trial.

    Science.gov (United States)

    van Egmond, M P; Duijts, S F A; Jonker, M A; van der Beek, A J; Anema, J R

    Up to 53% of cancer survivors (CSs) experiences job loss during or after treatment. To support CSs with job loss in the Netherlands, a tailored return to work (RTW) program was developed. The objective of this study was to assess the effectiveness of the program on duration until sustainable RTW in CSs with job loss. This study employed a two-armed (intervention/control) randomized controlled design with one-year follow-up. The primary outcome measure was duration until sustainable RTW. The secondary outcome measures were: rate of RTW, fatigue, quality of life, and participation in society. Descriptive analyses, Kaplan-Meier estimators and Cox regression analyses were conducted. Participants (N = 171) had a mean age of 48.4 years (SD = 8.6). The majority was female (69%) and breast cancer survivor (40%). The crude hazard ratio (HR) for duration until sustainable RTW was 0.86 (95% CI 0.46-1.62; p = 0.642). In the adjusted model, the intervention group had a slight, but statistically non-significant, improvement in duration until sustainable RTW compared to the control group (HR 1.16; 95% CI 0.59-2.31; p = 0.663). The program did not have any significant effects on secondary outcome measures. As the tailored RTW program did not demonstrate a statistically significant effect on duration until sustainable RTW in CSs with job loss, implementation of the program in its current form is not recommended.

  3. A theoretical study of bubble motion in surfactant solutions

    Science.gov (United States)

    Wang, Yanping

    1999-08-01

    We examine the effect of surfactants on a spherical gas bubble rising steadily in an infinite fluid at low and order one Reynolds number with order one and larger Peclet numbers. Our mathematical model is based on the Navier-Stokes equations coupled with a convection- diffusion equation together with appropriate interfacial conditions. The nonlinearity of the equations and boundary conditions, and the coupling between hydrodynamics and surfactant transport make the problem very challenging. When a bubble rises in a fluid containing surface-active agents, surfactant adsorbs onto the bubble surface at the leading edge, convects to the trailing edge by the surface flow and desorbs into the bulk along the interface. This adsorption develops a surface concentration gradient on the interface that makes the surface tension at the back end relatively lower than that at the front end, and thus retards the bubble velocity. Because of surfactant impurities unavoidably present in materials, this retardation can cause a problem in materials processing in space and glass processing when bubbles are created during chemical reactions. Thus the study of how to remobilize (remove the surfactant gradient on the surface) the bubble surface becomes necessary. Many studies have been done on this retarding effects of the surfactant on a moving bubble. However, most were focused on the retarding effect due to a trace amount of surfactant, in which case the bubble velocity monotonically decreases as the bulk concentration increases. The question of how to remobilize the bubble surface remains unanswered. In this work, we will show that the bubble velocity can be controlled by remobilizing the bubble interface using the surfactant concentration. This technique not only can be used to maximize the bubble velocity, but also can be used to maximize mass transfer on purifying materials and extracting materials from mixtures. In the first part of the work, we illustrate numerically that the

  4. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2003-07-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have conducted adsorption, phase behavior, interfacial tension (IFT) and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases IFT with a minimum at about 0.2 M. Addition of surfactant decreases IFT further. In the absence of surfactant the minerals are oil-wet after aging with crude oil. Addition of surfactant solution decreases the contact angle to intermediate-wet for many surfactants and water-wet for one surfactant. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Plans for the next quarter include conducting core adsorption, phase behavior, wettability and mobilization studies.

  5. of surfactant replacement therapy at Johannesburg Hospital ...

    African Journals Online (AJOL)

    Objective. To assess the impact of surfactant replacement therapy (SRl) on the outcome of hyaline membrane disease (HMD) and to assess the cost implications of a policy of selective administration of artificial surfactant. Design. The short-term outcome of 103 newborns ventilated for HMD (61 selected for SRT according to ...

  6. Surfactant protein D in newborn infants

    DEFF Research Database (Denmark)

    Dahl, Marianne; Juvonen, Pekka Olavi; Holmskov, Uffe

    2005-01-01

    Surfactant protein D (SP-D) is a collectin that plays an important role in the innate immune system. The role of SP-D in the metabolism of surfactant is as yet quite unclear. The aims of this study were to establish normal values of SP-D in the umbilical cord blood and capillary blood of mature...

  7. Surfactant effects on soil aggregate tensile strength

    Science.gov (United States)

    Little is known regarding a soil aggregate's tensile strength response to surfactants that may be applied to alleviate soil water repellency. Two laboratory investigations were performed to determine surfactant effects on the tensile strength of 1) Ap horizons of nine wettable, agricultural soils co...

  8. Measuring surfactant concentration in plating solutions

    Science.gov (United States)

    Bonivert, William D.; Farmer, Joseph C.; Hachman, John T.

    1989-01-01

    An arrangement for measuring the concentration of surfactants in a electrolyte containing metal ions includes applying a DC bias voltage and a modulated voltage to a counter electrode. The phase angle between the modulated voltage and the current response to the modulated voltage at a working electrode is correlated to the surfactant concentration.

  9. Surfactant Adsorption: A Revised Physical Chemistry Lab

    Science.gov (United States)

    Bresler, Marc R.; Hagen, John P.

    2008-01-01

    Many physical chemistry lab courses include an experiment in which students measure surface tension as a function of surfactant concentration. In the traditional experiment, the data are fit to the Gibbs isotherm to determine the molar area for the surfactant, and the critical micelle concentration is used to calculate the Gibbs energy of micelle…

  10. Surfactants and submicron sea spray generation

    NARCIS (Netherlands)

    Sellegri, K.; O'Dowd, C.D.; Yoon, Y.J.; Jennings, S.G.; Leeuw, G. de

    2006-01-01

    Laboratory experiments have been carried out to elucidate the role of surfactants on the primary marine aerosol production of submicron marine aerosols. A synthetic surfactant SDS was used in conjunction with artificially generated seawater, and the resultant bubble-mediated aerosol produced was

  11. Does the incorporation of portion-control strategies in a behavioral program improve weight loss in a 1-year randomized controlled trial?

    Science.gov (United States)

    Rolls, B J; Roe, L S; James, B L; Sanchez, C E

    2017-03-01

    Controlling food portion sizes can help reduce energy intake, but the effect of different portion-control methods on weight management is not known. In a 1-year randomized trial, we tested whether the efficacy of a behavioral weight-loss program was improved by incorporating either of the two portion-control strategies instead of standard advice about eating less. The Portion-Control Strategies Trial included 186 women with obesity (81%) or overweight (19%). Participants were randomly assigned to one of three equally intensive behavioral programs, consisting of 19 individual sessions over 12 months. The Standard Advice Group was instructed to eat less food while making healthy choices, the Portion Selection Group was instructed to choose portions based on the energy density using tools such as food scales and the Pre-portioned Foods Group was instructed to structure meals around pre-portioned foods such as single-serving main dishes, for which some vouchers were provided. In an intention-to-treat analysis, a mixed-effects model compared weight loss trajectories across 23 measurements; at month 12, weight was measured for 151 participants (81%). The trajectories showed that the Pre-portioned Foods Group initially lost weight at a greater rate than the other two groups (P=0.021), but subsequently regained weight at a greater rate (P=0.0005). As a result, weight loss did not differ significantly across groups at month 6 (mean±s.e. 5.2±0.4 kg) or month 12 (4.5±0.5 kg). After 1 year, measured weight loss averaged 6% of baseline weight. The frequency of using portion-control strategies initially differed across groups, then declined over time and converged at months 6 and 12. Incorporating instruction on portion-control strategies within a 1-year behavioral program did not lead to a greater weight loss than standard advice. Using pre-portioned foods enhanced early weight loss, but this was not sustained over time. Long-term maintenance of behavioral strategies to

  12. Selective labeling of pulmonary surfactant protein SP-C in organic solution

    DEFF Research Database (Denmark)

    Plasencia, I; Cruz, A; López-Lacomba, J L

    2001-01-01

    Pulmonary surfactant protein SP-C has been isolated from porcine lungs and treated with dansyl isothiocyanate in chloroform:methanol 2:1 (v/v) solutions,under conditions optimized to introduce a single dansyl group covalently attached to the N-terminalamine group of the protein without loss of its...

  13. Cerebral gray matter volume losses in essential tremor: A case-control study using high resolution tissue probability maps.

    Science.gov (United States)

    Cameron, Eric; Dyke, Jonathan P; Hernandez, Nora; Louis, Elan D; Dydak, Ulrike

    2018-03-10

    Essential tremor (ET) is increasingly recognized as a multi-dimensional disorder with both motor and non-motor features. For this reason, imaging studies are more broadly examining regions outside the cerebellar motor loop. Reliable detection of cerebral gray matter (GM) atrophy requires optimized processing, adapted to high-resolution magnetic resonance imaging (MRI). We investigated cerebral GM volume loss in ET cases using automated segmentation of MRI T1-weighted images. MRI was acquired on 47 ET cases and 36 controls. Automated segmentation and voxel-wise comparisons of volume were performed using Statistical Parametric Mapping (SPM) software. To improve upon standard protocols, the high-resolution International Consortium for Brain Mapping (ICBM) 2009a atlas and tissue probability maps were used to process each subject image. Group comparisons were performed: all ET vs. Controls, ET with head tremor (ETH) vs. Controls, and severe ET vs. An analysis of variance (ANOVA) was performed between ET with and without head tremor and controls. Age, sex, and Montreal Cognitive Assessment (MoCA) score were regressed out from each comparison. We were able to consistently identify regions of cerebral GM volume loss in ET and in ET subgroups in the posterior insula, superior temporal gyri, cingulate cortex, inferior frontal gyri and other occipital and parietal regions. There were no significant increases in GM volume in ET in any comparisons with controls. This study, which uses improved methodologies, provides evidence that GM volume loss in ET is present beyond the cerebellum, and in fact, is widespread throughout the cerebrum as well. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Reduction of coupling loss to photonic crystal fibers by controlled hole collapse: A numerical study

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Bjarklev, Anders Overgaard

    2004-01-01

    The mode profile evolution of small-core photonic crystal fibers (PCFs) during a gradual collapse of the cladding airholes is investigated. The mode overlap with standard step-index fibers having a small index contrast is calculated, and it is found that overlaps around 90% can be achieved in all...... cases studied, with the proper degree of hole collapse. Thus, hole collapse induced by, e.g. laser irradiation could prove an efficient and practical way of reducing splice losses when coupling small-core PCFs to other fiber types....

  15. Effects of soluble surfactants on the deformation and breakup of stretching liquid bridges.

    Science.gov (United States)

    Liao, Ying-Chih; Subramani, Hariprasad J; Franses, Elias I; Basaran, Osman A

    2004-11-09

    Surfactants are routinely used to control the breakup of drops and jets in many applications such as inkjet printing, crop spraying, and DNA or protein microarraying. The breakup of surfactant-free drops and jets has been extensively studied. By contrast, little is known about the closely related problem of interface rupture when surfactants are present. Solutions of a nonionic surfactant, pentaethylene glycol monododecyl ether, or C12E5, in water and in 90 wt % glycerol/water are used to show the effects of surfactant and viscosity on the deformation and breakup dynamics of stretching liquid bridges. Equilibrium surface tensions for both solutions can be fitted with the Langmuir-Szyskowski equation. All experiments have been done at 24 degrees C. The critical micelle concentrations for C12E5 are 0.04 and 0.4 mM in water and the glycerol/water solution, respectively. With high-speed imaging, the dynamic shapes of bridges held captive between two rods of 3.15 mm diameter are captured and analyzed with a time resolution of 0.1-1 ms. The bridge lengths are 3.15 mm initially and about 5-7 mm at pinch-off. Breakup occurs after stretching for about 0.2-0.3 s, depending on the solution viscosity and the surfactant concentration. When the liquid bridges break up, the volume of the sessile drop left on the bottom rod is about 3 times larger than that of the pendant drop left on the top rod. This asymmetry is due to gravity and is influenced by the equilibrium surface tensions. Surfactant-containing low-viscosity water bridges are shown to break up faster than surfactant-free ones because of the effect of gravity. With or without surfactant, water bridges form satellite drops. Surfactant-containing high-viscosity glycerol/water bridges break up more slowly than surfactant-free ones because of strong viscous effects. Moreover, the shapes of the sessile drops close to breakup exhibit a "pear-like" tip; whether a satellite forms depends on the surface age of the bridge before

  16. An arbitrary Lagrangian-Eulerian method for interfacial flows with insoluble surfactants

    Science.gov (United States)

    Yang, Xiaofeng

    results in the literature. The dynamics that guide the effect of surfactants on drop deformation are revealed by examining the variable surface tension, the Marangoni force, and the surfactant concentration profiles. This study will contribute to improved understanding and control of processes such as polymer blending, fuel spray formation, crude oil recovery, and so on.

  17. Effect of ionic surfactant on the self-assembly of triblock copolymer

    Science.gov (United States)

    Ray, D.; Kohlbrecher, J.; Aswal, V. K.

    2017-05-01

    The effect of anionic surfactant sodium dodecyl sulfate (SDS) on the self-assembly of PEO-PPO-PEO triblock copolymer in aqueous solution has been studied using small-angle neutron scattering (SANS). The measurements have been carried out for fixed concentrations (1 wt%) of block copolymer and surfactant, and at varying temperatures between 20 to 80°C. Micelles of pure ionic surfactants show little change in their sizes with increasing temperature, whereas structures of the non-ionic micelles increase significantly (sphere-to-rod transition for some block copolymers). Contrast variation SANS measurement suggests addition of SDS to aqueous copolymer solutions leads to the formation of mixed micelles. Interestingly, the self-assembly of block copolymer is found to get completely arrested by the ionic surfactant in the mixed micelles which gives a control over the block copolymer phase behavior.

  18. Rheologycal properties of sodium carboxymethylcellulose in the presence of electrolyte and mixed micelle of surfactants

    Directory of Open Access Journals (Sweden)

    Sovilj Verica J.

    2003-01-01

    Full Text Available One of the most significant aspects of polymer-surfactant interaction, from the practical point of view, is that of rheology control and viscosity enhancement. In the oppositely charged polyelectrolyte-surfactant system strong ionic interaction often leads to precipitation of the formed complex yielding serious problems. In this paper the interaction between anionic polyelectrolyte - sodium carboxymethylcellulose (NaCMC and cationic surfactant - cethyltrimethylammonium bromide (CTMAB has been investigated by rheological measurements. Addition of electrolyte NaBr and nonionic surfactant - Tween 80 reduced the binding strength, prevented the precipitation of the complex and increased the viscosity of the system. It was found that rheological properties are strong influenced by NaCMC-CTMAB interaction and the system exhibits either pseudoplastic or thixotropic or rheopectic behavior according to the intensity of interaction.

  19. Characteristic features of heterophase polymerisation of styrene with simultaneous formation of surfactants at the interface

    International Nuclear Information System (INIS)

    Prokopov, Nikolai I; Gritskova, Inessa A

    2001-01-01

    Data on the heterophase polymerisation of styrene under conditions of surfactant formation at the monomer-water interface are generalised. A new, in principle, approach is proposed the essence of which is to obtain a monomer emulsion simultaneously with the synthesis of an emulsifier at the monomer-water interface and with initiation of the polymerisation in the interfacial layer. The preparation of surfactants at the interface allows one to control efficiently the degree of dispersion and the stability of the emulsions formed. By varying the nature of the acid and the metal counter-ion used in the surfactant synthesis at the interface, it is possible to change the interfacial tension, to influence the microemulsification, disintegration of the monomer, and the formation of structure of interfacial adsorption layers. The mechanism of formation of polymer-monomeric particles as well as their diameter and size distribution depend substantially on the solubility of the resulting surfactants in water. The bibliography includes 47 references.

  20. Characteristic features of heterophase polymerisation of styrene with simultaneous formation of surfactants at the interface

    Energy Technology Data Exchange (ETDEWEB)

    Prokopov, Nikolai I; Gritskova, Inessa A [M.V. Lomonosov Moscow State Academy of Fine Chemical Technology, Moscow (Russian Federation)

    2001-09-30

    Data on the heterophase polymerisation of styrene under conditions of surfactant formation at the monomer-water interface are generalised. A new, in principle, approach is proposed the essence of which is to obtain a monomer emulsion simultaneously with the synthesis of an emulsifier at the monomer-water interface and with initiation of the polymerisation in the interfacial layer. The preparation of surfactants at the interface allows one to control efficiently the degree of dispersion and the stability of the emulsions formed. By varying the nature of the acid and the metal counter-ion used in the surfactant synthesis at the interface, it is possible to change the interfacial tension, to influence the microemulsification, disintegration of the monomer, and the formation of structure of interfacial adsorption layers. The mechanism of formation of polymer-monomeric particles as well as their diameter and size distribution depend substantially on the solubility of the resulting surfactants in water. The bibliography includes 47 references.

  1. Family involvement in weight control, weight maintenance and weight-loss interventions: a systematic review of randomised trials.

    Science.gov (United States)

    McLean, N; Griffin, S; Toney, K; Hardeman, W

    2003-09-01

    To conduct a descriptive systematic review into the nature and effectiveness of family involvement in weight control, weight maintenance and weight-loss interventions. We searched Medline and Psyclit for English language papers describing randomised trials with at least 1-y follow-up that evaluated interventions incorporating a family-based component. Studies involving people with eating disorders, learning disabilities and undernutrition or malnutrition were excluded. Data were extracted on characteristics of the participants, study design, target behaviours, nature of the intervention and study outcomes. A taxonomy was developed and used to classify family involvement in behaviour change interventions. Interventions were also classified according to an existing taxonomy that characterised the behaviour change techniques employed. A total of 21 papers describing 16 intervention studies were identified. Studies were small (mean sample size: 52), heterogeneous, poorly described but with few losses to follow-up (median 15%). The majority were North American and aimed at weight loss. Few studies described a theoretical underpinning to the behaviour change techniques employed. There was a suggestion that spouse involvement increased effectiveness but that adolescents achieved greater weight loss when treated alone. In studies including children, beneficial effects were seen when greater numbers of behaviour change techniques were taught to both parents and children. Relatively few intervention studies exist in this important area, particularly studies targeting adolescents, and they highlight continued uncertainty about how best to involve family members. The studies provide limited support for the involvement of spouses. They suggest that parental involvement is associated with weight loss in children, and that use of a greater range of behaviour change techniques improves weight outcomes for both parents and children. The development of future interventions and

  2. Sensorimotor posture control in the blind: superior ankle proprioceptive acuity does not compensate for vision loss.

    Science.gov (United States)

    Ozdemir, Recep A; Pourmoghaddam, Amir; Paloski, William H

    2013-09-01

    To better understand sensorimotor posture control differences between blind and sighted individuals, we examined the role of ankle joint proprioception and ankle muscle strength on postural control in healthy blind (n=13, 25-58 years) and age- and sex-matched sighted (n=15, 20-65 years) volunteers. We measured ankle joint proprioceptive acuity and isokinetic muscle strength in plantarflexion and dorsiflexion using an isokinetic dynamometer. We also assessed postural control performance during quiet bipedal stance with and without sudden postural perturbations, and during quiet unipedal stance. We found that while our blind subjects exhibited significantly better proprioceptive acuity than our sighted subjects their postural control performance was significantly poorer than that of the sighted group with eyes open, and no different from that of the sighted group with eyes closed suggesting that their superior proprioceptive acuity does not translate to improved balance control. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. An Erlang Loss Queue with Time-Phased Batch Arrivals as a Model for Traffic Control in Communication Networks

    Directory of Open Access Journals (Sweden)

    Moon Ho Lee

    2008-01-01

    Full Text Available A multiserver queueing model that does not have a buffer but has batch arrival of customers is considered. In contrast to the standard batch arrival, in which the entire batch arrives at the system during a single epoch, we assume that the customers of a batch (flow arrive individually in exponentially distributed times. The service time is exponentially distributed. Flows arrive according to a stationary Poisson arrival process. The flow size distribution is geometric. The number of flows that can be simultaneously admitted to the system is under control. The loss of any customer from an admitted flow, with a fixed probability, implies termination of the flow arrival. Analysis of the sojourn time and loss probability of an arbitrary flow is performed.

  4. Operation of wind power plants in high impedance grids. Loss of stability control for maximizing wind power vs. power quality

    Energy Technology Data Exchange (ETDEWEB)

    Diedrichs, Volker [Univ. of Applied Sciences Wilhelmshaven (Germany); Beekmann, Alfred; Busker, Kai; Nikolai, Swantje; Kentler, Florian [ENERCON GmbH, Aurich (Germany)

    2012-07-01

    Challenging wind power projects are often confronted with low short circuit ratio (SCR < 4) and sometimes even very low ratio (SCR < 2). Wind power plants (WPP) feeding in their power by means of voltage source converters (VSC) have the potential to be operated in those high impedance grids if they are appropriately controlled. When approaching the ultimate physical limits (well-known and referred to as voltage collapse and loss of angle stability, generic: loss of stability) the sensitivity of the voltage at the PCC of the WPP against changes of injected power increases exponentially. As consequence of wind fluctuations and therefore fluctuating active power of WPP, voltage fluctuates more intensively and higher flicker level can occur. Measurements taken from a 4 MW micro WPP demonstrate the conflict between maximizing wind power and power quality if approaching the LOS-limit. (orig.)

  5. Whey Protein Supplementation Enhances Body Fat and Weight Loss in Women Long After Bariatric Surgery: a Randomized Controlled Trial.

    Science.gov (United States)

    Lopes Gomes, Daniela; Moehlecke, Milene; Lopes da Silva, Fernanda Bassan; Dutra, Eliane Said; D'Agord Schaan, Beatriz; Baiocchi de Carvalho, Kenia Mara

    2017-02-01

    The ideal nutritional approach for weight regain after bariatric surgery remains unclear. The objective of this study is to assess the effect of whey protein supplementation on weight loss and body composition of women who regained weight 24 or more months after bariatric surgery. This is a 16-week open-label, parallel-group, randomized controlled trial of women who regained at least 5 % of their lowest postoperative weight after a Roux-en-Y gastric bypass (RYGB). A total of 34 participants were treated with hypocaloric diet and randomized (1:1) to receive or not supplementation with whey protein, 0.5 g/kg of the ideal body weight. The primary outcomes were changes in body weight, fat free mass (FFM), and fat mass (FM), evaluated by tetrapolar bioelectrical impedance analysis (BIA). Secondary outcomes included resting energy expenditure, blood glucose, lipids, adiponectin, interleukin 6 (IL-6), and cholecystokinin levels. Statistical analyses included generalized estimating equations adjusted for age and physical activity. Fifteen patients in each group were evaluated: mean age was 45 ± 11 years, body mass index (BMI) was 35.7 ± 5.2 kg/m 2 , and time since surgery was 69 ± 23 months. Protein intake during follow-up increased by approximately 75 % in the intervention group (p = 0.01). The intervention group presented more body weight loss (1.86 kg, p = 0.017), accounted for FM loss (2.78, p = 0.021) and no change in FFM, as compared to controls (gain of 0.42 kg of body weight and 0.6 kg of FM). No differences in secondary outcomes were observed between groups. Whey protein supplementation promoted body weight and FM loss in women with long-term weight regain following RYGB.

  6. Reason's Enemy Is Not Emotion: Engagement of Cognitive Control Networks Explains Biases in Gain/Loss Framing.

    Science.gov (United States)

    Li, Rosa; Smith, David V; Clithero, John A; Venkatraman, Vinod; Carter, R McKell; Huettel, Scott A

    2017-03-29

    In the classic gain/loss framing effect, describing a gamble as a potential gain or loss biases people to make risk-averse or risk-seeking decisions, respectively. The canonical explanation for this effect is that frames differentially modulate emotional processes, which in turn leads to irrational choice behavior. Here, we evaluate the source of framing biases by integrating functional magnetic resonance imaging data from 143 human participants performing a gain/loss framing task with meta-analytic data from >8000 neuroimaging studies. We found that activation during choices consistent with the framing effect were most correlated with activation associated with the resting or default brain, while activation during choices inconsistent with the framing effect was most correlated with the task-engaged brain. Our findings argue against the common interpretation of gain/loss framing as a competition between emotion and control. Instead, our study indicates that this effect results from differential cognitive engagement across decision frames. SIGNIFICANCE STATEMENT The biases frequently exhibited by human decision makers have often been attributed to the presence of emotion. Using a large fMRI sample and analysis of whole-brain networks defined with the meta-analytic tool Neurosynth, we find that neural activity during frame-biased decisions was more significantly associated with default behaviors (and the absence of executive control) than with emotion. These findings point to a role for neuroscience in shaping long-standing psychological theories in decision science. Copyright © 2017 the authors 0270-6474/17/373588-11$15.00/0.

  7. Changes in hydration of the stratum corneum are the most suitable indicator to evaluate the irritation of surfactants on the skin.

    Science.gov (United States)

    Fujimura, T; Shimotoyodome, Y; Nishijima, T; Sugata, K; Taguchi, H; Moriwaki, S

    2017-02-01

    Irritancy levels of surfactants on human skin have not been clarified completely. The relationships between skin damage and changes of skin properties caused by various surfactants were investigated using non-invasive measurements. Aqueous solutions of seven kinds of anionic, non-ionic, and amphoteric surfactants were exposed to the inside of forearm skin of 20 human subjects in two separate studies using the cup method. Hydration of the stratum corneum (SC), transepidermal water loss (TEWL), pH, skin surface roughness, and contents of the SC were measured before and after one exposure and after five and nine consecutive exposures to various surfactants. The discontinuation ratio of subjects for testing in each surfactant was determined by skin irritation symptoms and was defined as the degree of skin damage. Significant changes were observed only in hydration, TEWL, and natural moisturizing factors (NMF) content in the SC following surfactant exposure. A significant correlation was observed between the discontinuation ratio of each surfactant and the changes of hydration, TEWL, and NMF. Especially, the change of SC hydration showed an excellent correlation with the discontinuation ratio both for single (r = 0.942, P surfactants, and therefore is the most suitable indicator to evaluate the irritation of surfactants on the skin. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Habit-based interventions for weight loss maintenance in adults with overweight and obesity: a randomized controlled trial.

    Science.gov (United States)

    Cleo, Gina; Glasziou, Paul; Beller, Elaine; Isenring, Elisabeth; Thomas, Rae

    2018-04-23

    The objective of this study was to determine whether habit-based interventions are clinically beneficial in achieving long-term (12-month) weight loss maintenance and explore whether making new habits or breaking old habits is more effective. Volunteer community members aged 18-75 years who had overweight or obesity (BMI ≥ 25 kg/m 2 ) were randomized in a single-blind, three-arm, randomized controlled trial. Ten Top Tips (TTT), Do Something Different (DSD), and the attention-only waitlist (WL) control groups were conducted for 12 weeks from July to October 2015. Participants were followed up post-intervention (all groups) and at 6 and 12-month post-intervention (Ten Top Tips and Do Something Different only). The primary outcome was weight-loss maintenance at 12-month follow-up. Secondary outcomes included weight loss at all time points, fruit and vegetable consumption, exercise, wellbeing, depression, anxiety, habit strength, and openness to change. Of the 130 participants assessed for eligibility, 75 adults (mean BMI 34.5 kg/m 2 [SD 6.2]), with a mean age of 51 years were recruited. Assessments were completed post-intervention by 66/75 (88%) of participants and by 43/50 (86%) at 12 months. At post-intervention, participants in the Ten Top Tips (-3.3 kg; 95% CI -5.2, -1.4) and Do Something Different (-2.9 kg; 95% CI -4.3, -1.4) interventions lost significantly more weight (P = < .001) than those on the waitlist control (-0.4 kg; 95% CI -1.2, 0.3). Both intervention groups continued to lose further weight to the 12-month follow-up; TTT lost an additional -2.4 kg (95% CI -5.1, 0.4) and DSD lost -1.7 kg (95% CI -3.4, -0.1). At 12-month post-intervention, 28/43 (65%) of participants in both intervention groups had reduced their total body weight by ≥5%, a clinically important change. Habit-based weight-loss interventions-forming new habits (TTT) and breaking old habits (DSD), resulted in clinically important weight-loss maintenance at 12

  9. Loss of controller-pilot voice communications in domestic en route airspace

    Science.gov (United States)

    2017-02-10

    With the planned implementation of ControllerPilot Data Link Communications (CPDLC) in en route airspace, information on voice communication performance in this airspace can help to predict specific benefits associated with CPDLC, identify adjustm...

  10. Exogenous Pulmonary Surfactant as a Vehicle for Antimicrobials: Assessment of Surfactant-Antibacterial Interactions In Vitro

    Directory of Open Access Journals (Sweden)

    Alexei Birkun

    2014-01-01

    Full Text Available Owing to its unique surface-active properties, an exogenous pulmonary surfactant may become a promising drug delivery agent, in particular, acting as a vehicle for antibiotics in topical treatment of pneumonia. The purpose of this study was to assess a mutual influence of natural surfactant preparation and three antibiotics (amikacin, cefepime, and colistimethate sodium in vitro and to identify appropriate combination(s for subsequent in vivo investigations of experimental surfactant/antibiotic mixtures. Influence of antibiotics on surface-active properties of exogenous surfactant was assessed using the modified Pattle method. Effects of exogenous surfactant on antibacterial activity of antimicrobials against Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa were evaluated using conventional microbiologic procedures. Addition of amikacin or cefepime to surfactant had no significant influence on surface-active properties of the latter. Obvious reduction of surface-active properties was confirmed for surfactant/colistimethate composition. When suspended with antibiotics, surfactant either had no impact on their antimicrobial activity (amikacin or exerted mild to moderate influence (reduction of cefepime bactericidal activity and increase of colistimethate bacteriostatic activity against S. aureus and P. aeruginosa. Considering favorable compatibility profile, the surfactant/amikacin combination is advisable for subsequent investigation of joint surfactant/antibacterial therapy in animals with bacterial pneumonia.

  11. Exogenous Pulmonary Surfactant as a Vehicle for Antimicrobials: Assessment of Surfactant-Antibacterial Interactions In Vitro

    Science.gov (United States)

    2014-01-01

    Owing to its unique surface-active properties, an exogenous pulmonary surfactant may become a promising drug delivery agent, in particular, acting as a vehicle for antibiotics in topical treatment of pneumonia. The purpose of this study was to assess a mutual influence of natural surfactant preparation and three antibiotics (amikacin, cefepime, and colistimethate sodium) in vitro and to identify appropriate combination(s) for subsequent in vivo investigations of experimental surfactant/antibiotic mixtures. Influence of antibiotics on surface-active properties of exogenous surfactant was assessed using the modified Pattle method. Effects of exogenous surfactant on antibacterial activity of antimicrobials against Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa were evaluated using conventional microbiologic procedures. Addition of amikacin or cefepime to surfactant had no significant influence on surface-active properties of the latter. Obvious reduction of surface-active properties was confirmed for surfactant/colistimethate composition. When suspended with antibiotics, surfactant either had no impact on their antimicrobial activity (amikacin) or exerted mild to moderate influence (reduction of cefepime bactericidal activity and increase of colistimethate bacteriostatic activity against S. aureus and P. aeruginosa). Considering favorable compatibility profile, the surfactant/amikacin combination is advisable for subsequent investigation of joint surfactant/antibacterial therapy in animals with bacterial pneumonia. PMID:24876994

  12. Different effects of surfactant proteins B and C - implications for development of synthetic surfactants.

    Science.gov (United States)

    Curstedt, Tore; Johansson, Jan

    2010-06-01

    Treatment of premature newborn rabbits with synthetic surfactants containing a surfactant protein C analogue in a simple phospholipid mixture gives similar tidal volumes as treatment with poractant alfa (Curosurf(R)) but ventilation with a positive end-expiratory pressure (PEEP) is needed for this synthetic surfactant to stabilize the alveoli at end-expiration. The effect on lung gas volumes seems to depend on the structure of the peptide since treatment with a synthetic surfactant containing the 21-residue peptide (LysLeu(4))(4)Lys (KL(4)) gives low lung gas volumes in experiments also performed with PEEP. Surfactant preparations containing both surfactant proteins B and C or their analogues prevent alveolar collapse at end-expiration even if ventilated without PEEP. Treatment of premature newborn rabbits with different natural surfactants indicates that both the lipid composition and the proteins are important in order to stabilize the alveoli at end-expiration. Synthetic surfactants containing two peptides may be able to replace natural surfactants within the near future but more trials need to be performed before any conclusion can be drawn about the ideal composition of this new generation of synthetic surfactants. Copyright 2010 S. Karger AG, Basel.

  13. Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide gemini surfactants as novel corrosion inhibitors for mild steel in formic acid

    Directory of Open Access Journals (Sweden)

    Mohammad Mobin

    2012-12-01

    Full Text Available Gemini surfactants, butanediyl 1,4-bis(dimethyl cetylammonium bromide, pentanediyl 1,5 - bis (dimethyl cetylammonium bromide and hexanediyl 1,6 - bis (dimethyl cetylammonium bromide from Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide series were synthesized in laboratory and were characterized by using Nuclear Magnetic Resonance (NMR spectroscopy. The surfactants were tested as corrosion inhibitors for mild steel in 20% formic acid. The influence of surfactants on mild steel corrosion inhibition was investigated by measuring the corrosion rate of mild steel in their absence and presence by weight loss measurements, solvent analysis of iron ions into the test solution and potentiodynamic polarization measurements. The surface morphology of the corroded steel samples in presence and absence of surfactants was evaluated by using Scanning Electron Microscopy (SEM. The synthesized gemini surfactants performed as excellent corrosion inhibitor, the inhibition efficiency (IE being in the range of 76.66-97.41%. The IE of surfactants is slightly affected by the spacer length. The IE increased with increase in surfactant concentration and temperature. The adsorption of gemini surfactants on the steel surface was found to obey Langmuir adsorption isotherm. The results of the potentiodynamic polarization studies are consistent with the results of weight loss studies.

  14. A shorter set reduces the loss of cardiac autonomic and baroreflex control after resistance exercise.

    Science.gov (United States)

    Mayo, Xián; Iglesias-Soler, Eliseo; Carballeira-Fernández, Eduardo; Fernández-Del-Olmo, Miguel

    2016-11-01

    Set configuration may affect the recovery pattern of cardiac vagal autonomic and reflex modulation after a resistance exercise, since it is closely associated with intensity and volume and determines the metabolic involvement of the session. We tested the hypothesis that longer set configurations have a higher impact on cardiac autonomic control and baroreflex sensitivity compared with shorter set configurations. We studied the effects of three set configurations with the same components of work on the cardiac autonomic control and baroreflex sensitivity. Seventeen subjects performed one control session and three experimental sessions of a leg-press exercise with the same volume (40 repetitions), resting time (720 s) and intensity (10RM load): (a) 5 sets of 8 repetitions with 3 min of rest between sets (8S), (b) 10 sets of 4 repetitions with 80 s of rest between sets (4S) and (c) 40 sets of 1 repetition with 18.5 s of rest between each repetition (1S). Longer set configurations (8S and 4S) induced greater reductions of the vagal cardiac autonomic control and baroreflex sensitivity (p ≤ .001) compared with a shorter set configuration (1S). Also, 1S had non-significant reductions versus the control session (p > .05). These findings suggest that a shorter set configuration can reduce the impact of resistance exercise on the post-exercise cardiac vagal autonomic control and baroreflex sensitivity.

  15. Optimization of Surfactant Mixtures and Their Interfacial Behavior for Advanced Oil Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Somasundaran, Prof. P.

    2002-03-04

    The objective of this project was to develop a knowledge base that is helpful for the design of improved processes for mobilizing and producing oil left untapped using conventional techniques. The main goal was to develop and evaluate mixtures of new or modified surfactants for improved oil recovery. In this regard, interfacial properties of novel biodegradable n-alkyl pyrrolidones and sugar-based surfactants have been studied systematically. Emphasis was on designing cost-effective processes compatible with existing conditions and operations in addition to ensuring minimal reagent loss.

  16. Degradation of anionic surfactants using the reactor based on dielectric barrier discharge

    Directory of Open Access Journals (Sweden)

    Aonyas Munera Mustafa

    2016-01-01

    Full Text Available Two anionic surfactants (sodium lauryl sulfate - SDS and sodium dodecylbenzenesulfonate - SDBS were treated with dielectric barrier discharge. Loss of surfactant activity, decrease of chemical oxygen demand and total organic carbon as well as lower toxicity of degradation products were determined. Effects of catalysts - hydrogen peroxide and iron (II, on parameters mentioned above, were determined. Catalysts affect the degradation of SDBS and in the case of SDS catalysts have no effect on degradation. Both catalysts induce the decrease of COD and TOC values. Toxicity of solutions after the plasma treatment is lower in all the systems tested. [Projekat Ministarstva nauke Republike Srbije, br. OI 172030

  17. Surfactant administration without intubation in preterm infants with respiratory distress syndrome--our experiences.

    Science.gov (United States)

    Krajewski, Paweł; Chudzik, Anita; Strzałko-Głoskowska, Barbara; Górska, Monika; Kmiecik, Magdalena; Więckowska, Katarzyna; Mesjasz, Anna; Sieroszewski, Piotr

    2015-07-01

    Surfactant replacement therapy is crucial in the management of respiratory distress syndrome (RDS) in preterm infants. Classic strategies of surfactant administration required intubation. To reduce the need of intubation and mechanical ventilation (MV), we applied surfactant via a thin endotracheal catheter without intubation. We compared 26 preterm infants threatened by RDS treated with surfactant via a thin endotracheal catheter without intubation (studied group - SG) with a retrospective group of preterm infants managed on MV with early surfactant treatment using INtubation SURfactant Extubation (INSURE) method (control group - CG). Study had an approval from the ethics committee (RNN/6/14/KE). In the SG, 26 preterm infants were treated with one dose of surfactant (Curosurf®) administered via endotracheal catheter without intubation while receiving nasal continuous positive airway pressure (nCPAP)/SiPAP (Infant Flow). After surfactant administration, significantly less patients in SG required intubation and MV (19.2%) versus 65% necessity of second intubation in the CG. The median of time of MV in SG was 5 d versus 3.5 d in CG. Median time spent on nCPAP was 5.5 d versus 4.0 d in CG. The incidence of intraventricular hemorrhage (IVH) in the SG was 53.9%, including 50% with ≥ IVH II versus 36.7% (30% ≥ IVH II) in CG. The incidence of other complications of prematurity in the SG, such as necrotizing enterocolitis was 11.5% versus 23.3% in CG, the hemodynamically important patent ductus arteriosus was observed in 53.9% in SG versus 45% in CG. Bronchopulmonary dysplasia level in SG was significantly lower (15.4%) than in CG (40%), and the incidence of retinopathy of prematurity in SG was also lower (3.9%) versus 11.7% in MV group. Surfactant application via a thin endotracheal catheter without intubation seems to be a beneficial therapy for preterm infants with slight and mild degree of RDS. This new method of surfactant application was associated with a lower

  18. The effect of age on improvements in vestibulo-ocular reflexes and balance control after acute unilateral peripheral vestibular loss.

    Directory of Open Access Journals (Sweden)

    Alja eScheltinga

    2016-02-01

    Full Text Available Background: An acute unilateral peripheral vestibular loss (aUVL initially causes severe gaze and balance control problems. However, vestibulo-ocular reflexes (VOR and balance control are nearly normal 3 months later as a result of peripheral recovery and/or central compensation. As pre-existing vestibular sensory loss is assumed to be greater in the healthy elderly, this study investigated whether improvements in VOR and balance function over time after aUVL are different for the elderly than for the young. Methods: 30 aUVL patients divided into 3 age groups were studied (8 age range 23-35, 10 with range 43-58 and 12 with range 60-74 years. To measure VOR function, eye movements during caloric irrigation, rotating chair (ROT and head impulse tests were performed. Balance control during stance and gait was recorded as lower trunk angular velocity in the pitch and roll planes. Measurements were taken at deficit onset, and 3, 6, and 13 weeks later.Results: There was one difference in VOR improvements over time between the age groups: Low acceleration ROT responses were less at onset in the elderly group. Deficit side VOR responses and asymmetries in each group improved to within ranges of healthy controls at 13 weeks. Trunk sway of the elderly was greater for stance and gait at onset when compared to healthy age-matched controls and the young and greater than that of the young and controls during gait tasks at 13 weeks. The sway of the young was not different from controls at either time point. Balance control for the elderly improved slower than for the young. Conclusions: These results indicate that VOR improvement after an aUVL does not differ with age, except for low accelerations. Recovery rates are different between age groups for balance control tests. Balance control in the elderly is more abnormal at aUVL onset for stance and gait tasks with the gait abnormalities remaining after 13 weeks. Thus we conclude that balance control in the

  19. The Effect of Age on Improvements in Vestibulo-Ocular Reflexes and Balance Control after Acute Unilateral Peripheral Vestibular Loss.

    Science.gov (United States)

    Scheltinga, Alja; Honegger, Flurin; Timmermans, Dionne P H; Allum, John H J

    2016-01-01

    An acute unilateral peripheral vestibular loss (aUVL) initially causes severe gaze and balance control problems. However, vestibulo-ocular reflexes (VOR) and balance control are nearly normal 3 months later as a result of peripheral recovery and/or central compensation. As pre-existing vestibular sensory loss is assumed to be greater in the healthy elderly, this study investigated whether improvements in VOR and balance function over time after aUVL are different for the elderly than for the young. Thirty aUVL patients divided into three age-groups were studied (8 age range 23-35, 10 with range 43-58, and 12 with range 60-74 years). To measure VOR function eye movements were recorded during caloric irrigation, rotating chair (ROT), and head impulse tests. Balance control during stance and gait was recorded as lower trunk angular velocity in the pitch and roll planes. Measurements were taken at deficit onset, and 3, 6, and 13 weeks later. There was one difference in VOR improvements over time between the age-groups: Low acceleration ROT responses were less at onset in the elderly group. Deficit side VOR responses and asymmetries in each group improved to within ranges of healthy controls at 13 weeks. Trunk sway of the elderly was greater for stance and gait at onset when compared to healthy age-matched controls and the young and greater than that of the young and controls during gait tasks at 13 weeks. The sway of the young was not different from controls at either time point. Balance control for the elderly improved slower than for the young. These results indicate that VOR improvement after an aUVL does not differ with age, except for low accelerations. Recovery rates are different between age-groups for balance control tests. Balance control in the elderly is more abnormal at aUVL onset for stance and gait tasks with the gait abnormalities remaining after 13 weeks. Thus, we conclude that balance control in the elderly is more affected by the UVL than

  20. Spontaneous breathing or mechanical ventilation alters lung compliance and tissue association of exogenous surfactant in preterm newborn rabbits.

    Science.gov (United States)

    Bohlin, Kajsa; Bouhafs, Rabea K L; Jarstrand, Connie; Curstedt, Tore; Blennow, Mats; Robertson, Bengt

    2005-05-01

    In preterm infants with respiratory distress syndrome, surfactant administration followed by immediate extubation to spontaneous breathing with nasal continuous positive airway pressure reduces the need for mechanical ventilation. With this treatment approach, repeated doses of surfactant are rarely indicated. We used a rabbit model to test the hypothesis that exogenous surfactant therapy followed by spontaneous breathing results in a more sustained initial treatment response compared with treatment followed by mechanical ventilation. Preterm rabbits (gestational age 28.5 d) were treated with pharyngeal deposition of 200 mg/kg radiolabeled surfactant (14C-Curosurf) and randomized to 4 h of spontaneous breathing or mechanical ventilation or to a control group, killed immediately after surfactant administration. With pharyngeal deposition, 46 +/- 10% (mean +/- SEM) of the administered surfactant reached the lungs. The dynamic lung-thorax compliance was higher in spontaneously breathing compared with mechanically ventilated animals (median, 9.9 and 0.75 ml x cm H2O(-1) x kg(-1), respectively; p mechanically ventilated animals (p mechanically ventilated animals. We conclude that the initial lung tissue association of exogenous surfactant is impaired by mechanical ventilation. This is associated with a reduction of dynamic compliance and evidence of increased surfactant inactivation.

  1. The interrelationship of recruitment maneuver at birth, antenatal steroids, and exogenous surfactant on compliance and oxygenation in preterm lambs.

    Science.gov (United States)

    Tingay, David G; Rajapaksa, Anushi; McCall, Karen; Zonneveld, Cornelis E E; Black, Don; Perkins, Elizabeth; Sourial, Magdy; Lavizzari, Anna; Davis, Peter G

    2016-06-01

    To describe the interrelationship between antenatal steroids, exogenous surfactant, and two approaches to lung recruitment at birth on oxygenation and respiratory system compliance (Cdyn) in preterm lambs. Lambs (n = 63; gestational age 127 ± 1 d) received either surfactant at 10-min life (Surfactant), antenatal corticosteroids (Steroid), or neither (Control). Within each epoch lambs were randomly assigned to a 30-s 40 cmH2O sustained inflation (SI) or an initial stepwise positive end-expiratory pressure (PEEP) open lung ventilation (OLV) maneuver at birth. All lambs then received the same management for 60-min with alveolar-arterial oxygen difference (AaDO2) and Cdyn measured at regular time points. Overall, the OLV strategy improved Cdyn and AaDO2 (all epochs except Surfactant) compared to SI (all P < 0.05; two-way ANOVA). Irrespective of strategy, Cdyn was better in the Steroid group in the first 10 min (all P < 0.05). Thereafter, Cdyn was similar to Steroid epoch in the OLV + Surfactant, but not SI + Surfactant group. OLV influenced the effect of steroid and surfactant (P = 0.005) on AaDO2 more than SI (P = 0.235). The antenatal state of the lung influences the type and impact of a recruitment maneuver at birth. The effectiveness of surfactant maybe enhanced using PEEP-based time-dependent recruitment strategies rather than approaches solely aimed at initial lung liquid clearance.

  2. Risk factors associated with loss to follow-up from tuberculosis treatment in Tajikistan: a case-control study.

    Science.gov (United States)

    Wohlleben, Jessica; Makhmudova, Mavluda; Saidova, Firuza; Azamova, Shahnoza; Mergenthaler, Christina; Verver, Suzanne

    2017-08-04

    There are very few studies on reasons for loss to follow-up from TB treatment in Central Asia. This study assessed risk factors for LTFU and compared their occurrence with successfully treated (ST) patients in Tajikistan. This study took place in all TB facilities in the 19 districts with at least 5 TB patients registered as loss to follow-up (LTFU) from treatment. With a matched case control design we included all LTFU patients registered in the selected districts in 2011 and 2012 as cases, with ST patients from the same districts being controls. Data were copied from patient records and registers. Conditional logistic regressions were run to analyse associations between collected variables and LTFU as dependent variable. Three hundred cases were compared to 592 controls. Half of the cases had migrated or moved. In multivariate analysis, risk factors associated with increased LTFU were migration to another country (OR 10.6, 95% CI 6.12-18.4), moving within country (OR 11.0, 95% CI 3.50-34.9), having side effects of treatment (OR 3.67, 95% CI 1.68-8.00) and being previously treated for TB (OR 2.03, 95% CI 1.05-3.93). Medical staff also mentioned patient refusal, stigma and family problems as risk factors. LTFU of TB patients in Tajikistan is largely a result of migration, and to a lesser extent associated with side-effects and previous treatment. There is a need to strengthen referral between health facilities within Tajikistan and with neighbouring countries and support patients with side effects and/or previous TB to prevent loss to follow-up from treatment.

  3. Small angle neutron scattering study of doxorubicin–surfactant ...

    Indian Academy of Sciences (India)

    The binding affinity of doxorubicin within the micelle carrier is enhanced through complex formation of drug and anionic surfactant, aerosol OT (AOT). Electrostatic binding of doxorubicin with negatively charged surfactants leads to the formation of hydrophobic drug–surfactant complexes. Surfactant-induced partitioning of ...

  4. Characterizing adsorption of associating surfactants on carbonates surfaces.

    Science.gov (United States)

    Jian, Guoqing; Puerto, Maura; Wehowsky, Anna; Miller, Clarence; Hirasaki, George J; Biswal, Sibani L

    2018-03-01

    The adsorption of anionic surfactants onto positively charged carbonate minerals is typically high due to electrostatic interactions. By blending anionic surfactants with cationic or zwitterionic surfactants, which naturally form surfactant complexes, surfactant adsorption is expected to be influenced by a competition between surfactant complexes and surfactant-surface interactions. The adsorption behavior of surfactant blends known to form complexes was investigated. The surfactants probed include an anionic C 15-18 internal olefin sulfonate (IOS), a zwitterionic lauryl betaine (LB), and an anionic C 13 -alcohol polyethylene glycol ether carboxylic acid (L38). An analytical method based on high-performance liquid chromatography evaporative light scattering detector (HPLC-ELSD) was developed to measure three individual surfactant concentrations from a blended surfactant solution. The adsorption of the individual surfactants and surfactant blends were systematically investigated on different mineral surfaces using varying brine solutions. LB adsorption on calcite surfaces was found to be significantly increased when blended with IOS or L38 since it forms surfactant complexes that partition to the surface. However, the total adsorption of the LB-IOS-L38 solution on dolomite decreased from 3.09 mg/m 2 to 1.97 mg/m 2 when blended together compared to summing the adsorption values of individual surfactants, which highlights the importance of mixed surfactant association. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Synthesis of mesoporous zirconia using an amphoteric surfactant

    International Nuclear Information System (INIS)

    Kim, A.Y.; Bruinsma, P.J.; Chen, Y.L.; Liu, J.

    1996-01-01

    An amphoteric surfactant, cocamidopropyl betaine, was used for the synthesis of mesoporous zirconia. The carboxylate functionality of the surfactant permitted strong bonding with soluble zirconium species, while the quaternary ammonium group ensured large headgroup area and high solubility under acidic conditions. An amphoteric co-template [betaine, or (carboxymethyl)trimethylammonium hydroxide] improved uniformity of the hexagonal mesophase. Transmission electron microscopy (TEM) of the as-synthesized zirconium sulfate mesophase indicated hexagonal mesostructure, and low-angle X-ray diffraction (XRD) showed a 41 angstrom primary d-spacing and two higher order reflections of a hexagonal lattice. High surface area zirconia was produced by controlled base treatment of the hexagonal mesophase with sodium hydroxide, followed by calcination. TEM and XRD indicated that the mesostructure was stable to 350 C

  6. Surfactants tailored by the class Actinobacteria

    Directory of Open Access Journals (Sweden)

    Johannes H Kügler

    2015-03-01

    Full Text Available Gloablly, the drive towards the establishment of a bio-based economy has resulted in an increased need for bio-based applications. This, in turn, has served as a driving force for the discovery and application of novel biosurfactants. The class Actinobacteria represents a vast group of microorganisms with the ability to produce a diverse range of secondary metabolites, including surfactants. Understanding the extensive nature of the biosurfactants produced by actinobacterial strains can assist in finding novel biosurfactants with new potential applications. This review therefore presents a comprehensive overview of the knowledge available on actinobacterial surfactants, the chemical structures that have been completely or partly elucidated, as well as the identity of the biosurfactant-producing strains. Producer strains of not yet elucidated compounds are discussed, as well as the original habitats of all the producer strains, which seems to indicate that biosurfactant production is environmentally driven. Methodology applied in the isolation, purification and structural elucidation of the different types of surface active compounds, as well as surfactant activity tests, are also discussed. Overall, actinobacterial surfactants can be summarized to include the dominantly occurring trehalose-comprising surfactants, other non-trehalose containing glycolipids, lipopeptides and the more rare actinobacterial surfactants. The lack of structural information on a large proportion of actinobacterial surfactants should be considered as a driving force to further explore the abundance and diversity of these compounds. This would allow for a better understanding of actinobacterial surface active compounds and their potential for biotechnological application.

  7. Surfactants tailored by the class Actinobacteria

    Science.gov (United States)

    Kügler, Johannes H.; Le Roes-Hill, Marilize; Syldatk, Christoph; Hausmann, Rudolf

    2015-01-01

    Globally the change towards the establishment of a bio-based economy has resulted in an increased need for bio-based applications. This, in turn, has served as a driving force for the discovery and application of novel biosurfactants. The class Actinobacteria represents a vast group of microorganisms with the ability to produce a diverse range of secondary metabolites, including surfactants. Understanding the extensive nature of the biosurfactants produced by actinobacterial strains can assist in finding novel biosurfactants with new potential applications. This review therefore presents a comprehensive overview of the knowledge available on actinobacterial surfactants, the chemical structures that have been completely or partly elucidated, as well as the identity of the biosurfactant-producing strains. Producer strains of not yet elucidated compounds are discussed, as well as the original habitats of all the producer strains, which seems to indicate that biosurfactant production is environmentally driven. Methodology applied in the isolation, purification and structural elucidation of the different types of surface active compounds, as well as surfactant activity tests, are also discussed. Overall, actinobacterial surfactants can be summarized to include the dominantly occurring trehalose-comprising surfactants, other non-trehalose containing glycolipids, lipopeptides and the more rare actinobacterial surfactants. The lack of structural information on a large proportion of actinobacterial surfactants should be considered as a driving force to further explore the abundance and diversity of these compounds. This would allow for a better understanding of actinobacterial surface active compounds and their potential for biotechnological application. PMID:25852670

  8. Tunable, antibacterial activity of silicone polyether surfactants.

    Science.gov (United States)

    Khan, Madiha F; Zepeda-Velazquez, Laura; Brook, Michael A

    2015-08-01

    Silicone surfactants are used in a variety of applications, however, limited data is available on the relationship between surfactant structure and biological activity. A series of seven nonionic, silicone polyether surfactants with known structures was tested for in vitro antibacterial activity against Escherichia coli BL21. The compounds varied in their hydrophobic head, comprised of branched silicone structures with 3-10 siloxane linkages and, in two cases, phenyl substitution, and hydrophilic tail of 8-44 poly(ethylene glycol) units. The surfactants were tested at three concentrations: below, at, and above their Critical Micelle Concentrations (CMC) against 5 concentrations of E. coli BL21 in a three-step assay comprised of a 14-24h turbidometric screen, a live-dead stain and viable colony counts. The bacterial concentration had little effect on antibacterial activity. For most of the surfactants, antibacterial activity was higher at concentrations above the CMC. Surfactants with smaller silicone head groups had as much as 4 times the bioactivity of surfactants with larger groups, with the smallest hydrophobe exhibiting potency equivalent to sodium dodecyl sulfate (SDS). Smaller PEG chains were similarly associated with higher potency. These data link lower micelle stability and enhanced permeability of smaller silicone head groups to antibacterial activity. The results demonstrate that simple manipulation of nonionic silicone polyether structure leads to significant changes in antibacterial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Rhamnolipids--next generation surfactants?

    Science.gov (United States)

    Müller, Markus Michael; Kügler, Johannes H; Henkel, Marius; Gerlitzki, Melanie; Hörmann, Barbara; Pöhnlein, Martin; Syldatk, Christoph; Hausmann, Rudolf

    2012-12-31

    The demand for bio-based processes and materials in the petrochemical industry has significantly increased during the last decade because of the expected running out of petroleum. This trend can be ascribed to three main causes: (1) the increased use of renewable resources for chemical synthesis of already established product classes, (2) the replacement of chemical synthesis of already established product classes by new biotechnological processes based on renewable resources, and (3) the biotechnological production of new molecules with new features or better performances than already established comparable chemically synthesized products. All three approaches are currently being pursued for surfactant production. Biosurfactants are a very promising and interesting substance class because they are based on renewable resources, sustainable, and biologically degradable. Alkyl polyglycosides are chemically synthesized biosurfactants established on the surfactant market. The first microbiological biosurfactants on the market were sophorolipids. Of all currently known biosurfactants, rhamnolipids have the highest potential for becoming the next generation of biosurfactants introduced on the market. Although the metabolic pathways and genetic regulation of biosynthesis are known qualitatively, the quantitative understanding relevant for bioreactor cultivation is still missing. Additionally, high product titers have been exclusively described with vegetable oil as sole carbon source in combination with Pseudomonas aeruginosa strains. Competitive productivity is still out of reach for heterologous hosts or non-pathogenic natural producer strains. Thus, on the one hand there is a need to gain a deeper understanding of the regulation of rhamnolipid production on process and cellular level during bioreactor cultivations. On the other hand, there is a need for metabolizable renewable substrates, which do not compete with food and feed. A sustainable bioeconomy approach should

  10. Flexible Stock Allocation and Trim Loss Control for Cutting Problem in the Industrial-Use Paper Production

    OpenAIRE

    Wang, Fu-Kwun; Liu, Feng-Tai

    2014-01-01

    We consider a one-dimensional cutting stock problem (CSP) in which the stock widths are not used to fulfill the order but kept for use in the future for the industrial-use paper production. We present a new model based on the flexible stock allocation and trim loss control to determine the production quantity. We evaluate our approach using a real data and show that we are able to solve industrial-size problems, while also addressing common cutting considerations such as aggregation of orders...

  11. Weight loss as treatment for knee osteoarthritis symptoms in obese patients: 1-year results from a randomised controlled trial

    DEFF Research Database (Denmark)

    Bliddal, Henning; Leeds, Anthony R; Stigsgaard, Lise

    2011-01-01

    OBJECTIVE: To evaluate 1-year symptomatic improvement in obese patients with knee osteoarthritis (OA) on an intensive low-energy diet (LED) maintained by frequent consultations with a dietician compared to minimal attention. METHODS: The LED programme consisted of group therapy with dietary......) was assessed as the mean group difference during and after 1 year. RESULTS: The study population consisted of 89 patients, 89% women, average age 63 years. After 1 year, mean weight loss in the LED group was -10.9 kg (11%) versus -3.6 kg (4%) in the control group (p...

  12. Serum concentrations of Krebs von den Lungen-6, surfactant protein D, and matrix metalloproteinase-2 as diagnostic biomarkers in patients with asbestosis and silicosis: a case-control study.

    Science.gov (United States)

    Xue, Changjiang; Wu, Na; Li, Xue; Qiu, Meihua; Du, Xuqin; Ye, Qiao

    2017-11-17

    Asbestosis and silicosis are progressive pneumoconioses characterized by interstitial fibrosis following exposure to asbestos or silica dust. We evaluated the potential diagnostic biomarkers for these diseases. The serum concentrations of Krebs von den Lungen-6 (KL-6), surfactant protein D (SP-D), and matrix metalloproteinase-2 (MMP-2), MMP-7, and MMP-9 were measured in 43 patients with asbestosis, 45 patients with silicosis, 40 dust-exposed workers (DEWs) without pneumoconiosis, and 45 healthy controls (HCs). Chest high-resolution computed tomography (HRCT) images were reviewed by experts blinded to the clinical data. According to the receiver operating characteristic (ROC) curve, the ideal level of each biomarker and its diagnostic sensitivity were obtained. The serum KL-6 and MMP-2 concentrations were highest in patients with asbestosis, particularly in comparison with those in DEWs and HCs (P<0.05). The serum SP-D concentration was significantly higher in patients with asbestosis than in patients with silicosis, DEWs, and HCs (P<0.01), whereas no significant difference was noted among patients with silicosis, DEWs, and HCs. No significant difference in the serum MMP-7 or -9 concentration was found among patients with asbestosis, patients with silicosis, DEWs, or HCs. Among patients with asbestosis, the serum KL-6 concentration was significantly correlated with the lung fibrosis scores on HRCT and negatively correlated with the forced vital capacity (FVC) % predicted and diffusing capacity of the lung for carbon monoxide (DL CO ) % predicted. The serum SP-D and MMP-2 concentrations were negatively correlated with the DL CO % predicted (all P<0.05). The order of diagnostic accuracy according to the ROC curve was KL-6, SP-D, and MMP-2 in patients with asbestosis alone and in the combination of both patients with asbestosis and those with silicosis. The combination of all three biomarkers may increase the possibility of diagnosing asbestosis (sensitivity, 93

  13. Randomised, double-blinded, placebo-controlled, clinical trial of ozone therapy as treatment of sudden sensorineural hearing loss.

    Science.gov (United States)

    Ragab, A; Shreef, E; Behiry, E; Zalat, S; Noaman, M

    2009-01-01

    To investigate the safety and efficacy of ozone therapy in adult patients with sudden sensorineural hearing loss. Prospective, randomised, double-blinded, placebo-controlled, parallel group, clinical trial. Forty-five adult patients presented with sudden sensorineural hearing loss, and were randomly allocated to receive either placebo (15 patients) or ozone therapy (auto-haemotherapy; 30 patients). For the latter treatment, 100 ml of the patient's blood was treated immediately with a 1:1 volume, gaseous mixture of oxygen and ozone (from an ozone generator) and re-injected into the patient by intravenous infusion. Treatments were administered twice weekly for 10 sessions. The following data were recorded: pre- and post-treatment mean hearing gains; air and bone pure tone averages; speech reception thresholds; speech discrimination scores; and subjective recovery rates. Significant recovery was observed in 23 patients (77 per cent) receiving ozone treatment, compared with six (40 per cent) patients receiving placebo (p ozone-treated patients compared with placebo-treated patients (p Ozone therapy is a significant modality for treatment of sudden sensorineural hearing loss; no complications were observed.

  14. Impact of Neutral Point Current Control on Copper Loss Distribution of Five Phase PM Generators Used in Wind Power Plants

    Directory of Open Access Journals (Sweden)

    ARASHLOO, R. S.

    2014-05-01

    Full Text Available Efficiency improvement under faulty conditions is one of the main objectives of fault tolerant PM drives. This goal can be achieved by increasing the output power while reducing the losses. Stator copper loss not only directly affects the total efficiency, but also plays an important role in thermal stress generations of iron core. In this paper, the effect of having control on neutral point current is studied on the efficiency of five-phase permanent magnet machines. Open circuit fault is considered for both one and two phases, and the distribution of copper loss along the windings are evaluated in each case. It is shown that only by having access to neutral point, it is possible to generate less stator thermal stress and more mechanical power in five-phase permanent magnet generators. Wind power generation and their applications are kept in mind, and the results are verified via simulations and experimental tests on an outer-rotor type of five-phase PM machine.

  15. Binge eating, binge eating disorder and loss of control eating: effects on weight outcomes after bariatric surgery.

    Science.gov (United States)

    Meany, Gavin; Conceição, Eva; Mitchell, James E

    2014-03-01

    There is increasing evidence that patients who have problems with binge eating (BE) or BE disorder (BED) are quite common among the severely obese, including bariatric surgery candidates. The literature suggests that in many cases such eating behaviours improve after bariatric surgery, although this is not uniformly true. The current paper reviews the data on the development of BE, BED and loss of control (LOC) eating after bariatric surgery and the impact of these problems on long-term weight outcome. A search was made of various databases regarding evidence of BE, BED and LOC eating post-operatively in bariatric surgery patients. The data extracted from the literature suggests that 15 research studies have now examined this question. Fourteen of the available 15 studies suggest that the development of problems with BE, BED or LOC eating post-bariatric surgery is associated with less weight loss and/or more weight regain post-bariatric surgery. These data suggests that it is important to identify individuals at high risk for these problems, to follow them post-operatively, and, if appropriate interventions can be developed if such behaviours occur in order to maximize weight loss outcomes. Copyright © 2013 John Wiley & Sons, Ltd and Eating Disorders Association.

  16. A randomized controlled trial of behavioral weight loss treatment versus combined weight loss/depression treatment among women with comorbid obesity and depression.

    Science.gov (United States)

    Linde, Jennifer A; Simon, Gregory E; Ludman, Evette J; Ichikawa, Laura E; Operskalski, Belinda H; Arterburn, David; Rohde, Paul; Finch, Emily A; Jeffery, Robert W

    2011-02-01

    Obesity is associated with clinical depression among women. However, depressed women are often excluded from weight loss trials. This study examined treatment outcomes among women with comorbid obesity and depression. Two hundred three (203) women were randomized to behavioral weight loss (n = 102) or behavioral weight loss combined with cognitive-behavioral depression management (n = 101). Average participant age was 52 years; mean baseline body mass index was 39 kg/m(2). Mean Patient Health Questionnaire and Hopkins Symptom Checklist (SCL-20) scores indicated moderate to severe baseline depression. Weight loss and SCL-20 changes did not differ between groups at 6 or 12 months in intent-to-treat analyses (p = 0.26 and 0.55 for weight, p = 0.70 and 0.25 for depressive symptoms). Depressed obese women lost weight and demonstrated improved mood in both treatment programs. Future weight loss trials are encouraged to enroll depressed women.

  17. Efficacy of polyglucosamine for weight loss-confirmed in a randomized double-blind, placebo-controlled clinical investigation.

    Science.gov (United States)

    Pokhis, Karina; Bitterlich, Norman; Cornelli, Umberto; Cassano, Giuseppina

    2015-01-01

    The purpose of this clinical study was to ascertain whether low molecular weight chitosan polyglucosamine is able to produce significantly better weight loss than placebo. 115 participants were included in the study. We used a two-center randomized, double blind, placebo-controlled design. The participants followed a standard treatment (ST), which included the combination of a low-calorie diet achieved through creating a daily calorie deficit (500 cal) and an increased daily physical activity (7 MET-h/week). They were randomized to receive standard treatment plus placebo (ST + PL) or standard treatment plus polyglucosamine (ST + PG), respectively. Participants were instructed to take 2 × 2 tablets before the two meals containing the highest fat content for at least 24 weeks. Body weight, BMI, waist circumference and the time needed for a 5 % body weight reduction (5R) were taken as main variables. The average weight loss over a period of 25 weeks in the ITT population was 5.8 ± 4.09 kg in the ST + PG group versus 4.0 ± 2.94 kg in the ST + PL (pU = 0.023; pt = 0.010). After 25 weeks, 34 participants achieved 5R in the ST + PG group (64.1 %) compared to only 23 participants in the ST + PL group (42.6 %) (ITT) (p Fisher = 0.033). Weight loss through hypo-caloric diets have been found to be effective. The additional effect of PG in combination with standard treatment is able to produce significantly better weight loss than placebo. Participants treated with ST + PG showed a significant amount of weight loss, an additional 1.8 kg, compared to controls treated with ST + PL. Trial Registration at ClinicalTrials.gov: NCT02410785 Registered 07 April 2015.

  18. Controlled synthesis of La{sub 1−x}Sr{sub x}CrO{sub 3} nanoparticles by hydrothermal method with nonionic surfactant and their ORR activity in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Bo Hyun; Park, Shin-Ae [Energy System Major, School of Mechanical Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Park, Bong Kyu [GIFT Center, Pusan National University, Busan, 609-735 (Korea, Republic of); Chun, Ho Hwan, E-mail: chunahh@pusan.ac.kr [Global Core Research Center for Ships and Offshore Plants(GCRC-SOP), Pusan National University, Busan, 609-735 (Korea, Republic of); Kim, Yong-Tae, E-mail: yongtae@pusan.ac.kr [Energy System Major, School of Mechanical Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)

    2013-10-15

    Graphical abstract: We demonstrate that Sr-doped LaCrO{sub 3} nanoparticles were successfully prepared by the hydrothermal synthesis method using the nonionic surfactant Triton X-100 and the applicability of La{sub 1−x}Sr{sub x}CrO{sub 3} to oxygen reduction reaction (ORR) electrocatalysis in an alkaline medium. Compared with the nanoparticles synthesized by the coprecipitation method, they showed enhanced ORR activity. - Highlights: • Sr-doped LaCrO{sub 3} nanoparticles were successfully prepared by the hydrothermal method using the nonionic surfactant. • Homogeneously shaped and sized Sr-doped LaCrO{sub 3} nanoparticles were readily obtained. • Compared with the nanoparticles synthesized by the coprecipitation method, they showed an enhanced ORR activity. • The main origin was revealed to be the decreased particle size due to the nonionic surfactant. - Abstract: Sr-doped LaCrO{sub 3} nanoparticles were prepared by the hydrothermal method with the nonionic surfactant Triton X-100 followed by heat treatment at 1000 °C for 10 h. The obtained perovskite nanoparticles had smaller particle size (about 100 nm) and more uniform size distribution than those synthesized by the conventional coprecipitation method. On the other hand, it was identified with the material simulation that the electronic structure change by Sr doping was negligible, because the initially unfilled e{sub g}-band was not affected by the p-type doping. Finally, the perovskite nanoparticles synthesized by hydrothermal method showed much higher ORR activity by over 200% at 0.8 V vs. RHE than those by coprecipitation method.

  19. Cultural control measures to diminish sorghum yield loss and parasite success under Striga hermonthica infestation

    NARCIS (Netherlands)

    Ast, van A.; Bastiaans, L.; Katile, S.

    2005-01-01

    Prospects of reducing Striga hermonthica (Del.) Benth. parasitism by means of cultural control measures were assessed. In a pot experiment, deep planting, the use of transplants and shallow soil-tillage, strongly delayed and reduced Striga infection of a sensitive and a tolerant sorghum cultivar.

  20. Review of first trial responses in balance control: influence of vestibular loss and Parkinson's disease

    NARCIS (Netherlands)

    Allum, J.H.J.; Tang, K.S.; Carpenter, M.G.; Oude Nijhuis, L.B.; Bloem, B.R.

    2011-01-01

    The reaction to an unexpected balance disturbance is unpracticed, often startling and frequently associated with falls. This everyday situation can be reproduced in an experimental setting by exposing standing humans to sudden, unexpected and controlled movements of a support surface. In this

  1. 40 CFR 52.256 - Control of evaporative losses from the filling of vehicular tanks.

    Science.gov (United States)

    2010-07-01

    ... filling of vehicular tanks. 52.256 Section 52.256 Protection of Environment ENVIRONMENTAL PROTECTION... discharge of hydrocarbon vapors to the atmosphere from either the vehicle filler neck or dispensing nozzle... sign all necessary contracts for emission control systems, or issue orders for the purchase of...

  2. 9,10-Phenanthrenequinone promotes secretion of pulmonary aldo-keto reductases with surfactant.

    Science.gov (United States)

    Matsunaga, Toshiyuki; Haga, Mariko; Watanabe, Gou; Shinoda, Yuhki; Endo, Satoshi; Kajiwara, Yu; Tanaka, Hiroyuki; Inagaki, Naoki; El-Kabbani, Ossama; Hara, Akira

    2012-02-01

    9,10-Phenanthrenequinone (9,10-PQ), a major quinone in diesel exhaust particles, induces apoptosis via the generation of reactive oxygen species (ROS) because of 9,10-PQ redox cycling. We have found that intratracheal infusion of 9,10-PQ facilitates the secretion of surfactant into rat alveolus. In the cultured rat lung, treatment with 9,10-PQ results in an increase in a lower-density surfactant by ROS generation through redox cycling of the quinone. The surfactant contains aldo-keto reductase (AKR) 1C15, which reduces 9,10-PQ and the enzyme level in the surfactant increases on treatment with 9,10-PQ suggesting an involvement of AKR1C15 in the redox cycling of the quinone. In six human cell types (A549, MKN45, Caco2, Hela, Molt4 and U937) only type II epithelial A549 cells secrete three human AKR1C subfamily members (AKR1C1, AKR1C2 and AKR1C3) with the surfactant into the medium; this secretion is highly increased by 9,10-PQ treatment. Using in vitro enzyme inhibition analysis, we have identified AKR1C3 as the most abundantly secreted AKR1C member. The AKR1C enzymes in the medium efficiently reduce 9,10-PQ and initiate its redox cycling accompanied by ROS production. The exposure of A549 cells to 9,10-PQ provokes viability loss, which is significantly protected by the addition of the AKR1C3 inhibitor and antioxidant enzyme and by the removal of the surfactants from the culture medium. Thus, the AKR1C enzymes secreted in pulmonary surfactants probably participate in the toxic mechanism triggered by 9,10-PQ.

  3. Adherence and success in long-term weight loss diets: the dietary intervention randomized controlled trial (DIRECT).

    Science.gov (United States)

    Greenberg, Ilana; Stampfer, Meir J; Schwarzfuchs, Dan; Shai, Iris

    2009-04-01

    Data are limited as to whether participants in diet trials truly adhere to their assigned diet and the factors that affect their adherence. We evaluated success and adherence in a two-year dietary intervention randomized controlled trial (DIRECT) in which 322 moderately obese participants (mean age 52 yrs, mean body-mass-index (BMI) 31 kg/m(2), 86% men) were randomized to one of three groups: low-fat, Mediterranean, or low-carbohydrate diets. Overall compliance at month-24 was 85%, with 90% in low-fat, 85% in Mediterranean, and 78% in low-carbohydrate diet (p = .042 between groups). Attrition was higher in women (29% vs. 14% men, p = .001) and current smokers (25% vs. 14% among maintainers, p = 0.04). In a multivariate model, independent predictors of dropping-out were: higher baseline BMI (OR = 1.11; CI: 1.03-1.21) and less weight loss at month-6 (OR = 1.20; CI: 1.1-1.3). In a multivariate model, greater weight loss achieved at month-6 was the main predictor associated with success in weight loss (> 5%) over 2 years (OR = 1.5; CI: 1.35-1.67). Self-reported complete adherence score to diet was greater on low-carbohydrate diet (p low-fat) until month-6, but dropped overall from 81% at month-1 to 57% at month-24. Holidays were a trigger to a significant decrease in adherence followed by a partial rebound. Changes in diet composition from month-1 to month-12 were more pronounced in the multi-stage low-carbohydrate diet-group (p weight is the main predictor of both long-term retention and success in weight loss. Special attention is needed for women, current smokers, and during holidays. Physical activity is associated with subsequent reduction in energy intake.

  4. Can local application of Tranexamic acid reduce post-coronary bypass surgery blood loss? A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Latter David

    2009-06-01

    Full Text Available Abstract Background Diffuse microvascular bleeding remains a common problem after cardiac procedures. Systemic use of antifibrinolytic reduces the postoperative blood loss. The purpose of this study was to examine the effectiveness of local application of tranexamic acid to reduce blood loss after coronary artery bypass grafting (CABG. Methods Thirty eight patients scheduled for primary isolated coronary artery bypass grafting were included in this double blind, prospective, randomized, placebo controlled study. Tranexamic acid (TA group (19 patients received 1 gram of TA diluted in 100 ml normal saline. Placebo group (19 patients received 100 ml of normal saline only. The solution was purred in the pericardial and mediastinal cavities. Results Both groups were comparable in their baseline demographic and surgical characteristics. During the first 24 hours post-operatively, cumulative blood loss was significantly less in TA group (median of 626 ml compared to Placebo group (median of 1040 ml (P = 0.04. There was no significant difference in the post-op Packed RBCs transfusion between both groups (median of one unit in each (P = 0.82. Significant less platelets transfusion required in TA group (median zero unit than in placebo group (median 2 units (P = 0.03. Apart from re-exploration for excessive surgical bleeding in one patient in TA group, no difference was found in morbidity or mortality between both groups. Conclusion Topical application of tranexamic acid in patients undergoing primary coronary artery bypass grafting led to a significant reduction in postoperative blood loss without adding extra risk to the patient.

  5. Controlled exploration of the effects of conductive hearing loss on wideband acoustic immittance in human cadaveric preparations.

    Science.gov (United States)

    Merchant, Gabrielle R; Merchant, Saumil N; Rosowski, John J; Nakajima, Hideko Heidi

    2016-11-01

    Current clinical practice cannot distinguish, with any degree of certainty, the multiple pathologies that produce conductive hearing loss in patients with an intact tympanic membrane and a well-aerated middle ear without exploratory surgery. The lack of an effective non-surgical diagnostic procedure leads to unnecessary surgery and limits the accuracy of information available during pre-surgical consultations with the patient. A non-invasive measurement to determine the pathology responsible for a conductive hearing loss prior to surgery would be of great value. This work investigates the utility of wideband acoustic immittance (WAI), a non-invasive measure of middle-ear mobility, in the differential diagnosis of pathologies responsible for conductive hearing loss. We focus on determining whether power reflectance (PR), a derivative of WAI, is a possible solution to this problem. PR is a measure of the fraction of sound power reflected from the middle ear when a sound stimulus is presented to the ear canal. PR and other metrics of middle-ear performance (such as ossicular motion via laser Doppler vibrometry) were measured in well-controlled human temporal bone preparations with simulated pathologies. We report measurements before and after simulation of stapes fixation (n = 8), malleus fixation (n = 10), ossicular disarticulation (n = 10), and superior canal dehiscence (n = 8). Our results are consistent with the small set of previously published reflectance measurements made in temporal bones and patients. In this present study, these temporal bone experiments with different middle- and inner-ear pathologies were compared to the initial normal state by analyzing both WAI and ossicular motion, demonstrating that WAI can be a valuable tool in the diagnosis of conductive hearing loss. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Out of Control!? How Loss of Self-Control Influences Prosocial Behavior: The Role of Power and Moral Values

    Science.gov (United States)

    Joosten, Anne; van Dijke, Marius; Van Hiel, Alain; De Cremer, David

    2015-01-01

    Lack of self-control has been suggested to facilitate norm-transgressing behaviors because of the operation of automatic selfish impulses. Previous research, however, has shown that people having a high moral identity may not show such selfish impulses when their self-control resources are depleted. In the present research, we extended this effect to prosocial behavior. Moreover, we investigated the role of power in the interaction between moral identity and self-control depletion. More specifically, we expected that power facilitates the externalization of internal states, which implies that for people who feel powerful, rather than powerless, depletion decreases prosocial behavior especially for those low in moral identity. A laboratory experiment and a multisource field study supported our predictions. The present finding that the interaction between self-control depletion and moral identity is contingent upon people’s level of power suggests that power may enable people to refrain from helping behavior. Moreover, the findings suggest that if organizations want to improve prosocial behaviors, it may be effective to situationally induce moral values in their employees. PMID:26024380

  7. Gemini surfactants from natural amino acids.

    Science.gov (United States)

    Pérez, Lourdes; Pinazo, Aurora; Pons, Ramon; Infante, Mrosa

    2014-03-01

    In this review, we report the most important contributions in the structure, synthesis, physicochemical (surface adsorption, aggregation and phase behaviour) and biological properties (toxicity, antimicrobial activity and biodegradation) of Gemini natural amino acid-based surfactants, and some potential applications, with an emphasis on the use of these surfactants as non-viral delivery system agents. Gemini surfactants derived from basic (Arg, Lys), neutral (Ser, Ala, Sar), acid (Asp) and sulphur containing amino acids (Cys) as polar head groups, and Geminis with amino acids/peptides in the spacer chain are reviewed. © 2013.

  8. Mechanism of bacterial inactivation by cationic surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Pavlova, I.B.; Samoylenko, I.I.

    1985-03-01

    The mechanism of bacteriocidal action of the cationic surfactant dimethylbenzylammonium chloride was studied on exposure of Staphylococcus aureus, Streptococcus faecium, Bacillus subtilis and Escherichia coli to different concentrations of the agent and determinations of survival plots. The data showed that the surfactant was bacteriocidal for all the bacteria tested at a concentration of 0.0001%, but more efficient in the case of the gram positives. Electron microscopy showed considerable damage and dissarrangement of the cytoplasmic membrane, indicating that the killing mechanism involved this organelle. It appears that cationic surfactants may constitute effective disinfectant preparations. 9 references, 2 figures.

  9. Surfactant-Assisted Coal Liquefaction

    Science.gov (United States)

    Hickey, Gregory S.; Sharma, Pramod K.

    1993-01-01

    Obtaining liquid fuels from coal which are economically competitive with those obtained from petroleum based sources is a significant challenge for the researcher as well as the chemical industry. Presently, the economics of coal liquefaction are not favorable because of relatively intense processing conditions (temperatures of 430 degrees C and pressures of 2200 psig), use of a costly catalyst, and a low quality product slate of relatively high boiling fractions. The economics could be made more favorable by achieving adequate coal conversions at less intense processing conditions and improving the product slate. A study has been carried out to examine the effect of a surfactant in reducing particle agglomeration and improving hydrodynamics in the coal liquefaction reactor to increase coal conversions...

  10. Effect of weekly physical activity frequency on weight loss in healthy overweight and obese women attending a weight loss program: a randomized controlled trial.

    Science.gov (United States)

    Madjd, Ameneh; Taylor, Moira A; Shafiei Neek, Leila; Delavari, Alireza; Malekzadeh, Reza; Macdonald, Ian A; Farshchi, Hamid R

    2016-11-01

    The effect of intensity and duration of physical activity (PA) on weight loss has been well described. However, the effect of the frequency of weekly PA on weight loss is still unknown. The purpose of this study was to evaluate the effect of the frequency of weekly PA sessions while maintaining the same total activity time on weight loss during a 24-wk weight loss program. Overweight and obese women [n = 75; body mass index (BMI; in kg/m 2 ): 27-37; age: 18-40 y] who had a normally sedentary lifestyle were randomly allocated to 1 of 2 intervention groups: a high-frequency physical activity (HF) or a low-frequency physical activity (LF) group. The HF group included 50 min/d PA, 6 d/wk (300 min/wk). The LF group included 100 min/d PA, 3 d/wk (300 min/wk). Both groups were advised to follow the same dietary weight loss program. Both groups showed a significant decrease in anthropometric measurements and significant improvements in cardiometabolic disease risk characteristics over the 24 wk of the study. Compared with the HF group, the LF group had a greater decrease in weight (mean ± SD; LF: 9.58 ± 3.77 kg; HF: 7.78 ± 2.68 kg; P = 0.028), BMI (LF: 3.62 ± 1.56; HF: 2.97 ± 1.02; P = 0.029) and waist circumference (LF: 9.36 ± 4.02 cm; HF: 7.86 ± 2.41 cm; P = 0.031). However, there were no significant differences in carbohydrate metabolism characteristics or lipid profile after the 24 wk of intervention. Weekly PA undertaken over fewer sessions of longer duration during the week could be more effective for weight loss than when undertaken as more frequent shorter sessions in overweight and obese women on a weight loss program. This may be helpful for those who are neither willing nor able to schedule time for PA almost every day to achieve weight loss. This trial was registered at www.irct.ir as IRCT201402157754N4. © 2016 American Society for Nutrition.

  11. The influence of lung surfactant liquid crystalline nanostructures on respiratory drug delivery.

    Science.gov (United States)

    Das, Shyamal C; Stewart, Peter J

    2016-12-05

    The respiratory route increasingly has been used for both local and systemic drug delivery. Although drug is absorbed rapidly after respiratory delivery, the role of lung surfactant in drug delivery is not well understood. The human lung contains only around 15mL of surface lining fluid spread over ∼100m 2 surface. The fluid contains lung surfactant at a concentration of 8-24mg/kg/body weight; the lung surfactant which is lipo-protein in nature can form different liquid crystalline nanostructures. After a brief overview of the anatomy of respiratory system, the review has focused on the current understanding of lung surface lining fluid, lung surfactants and their composition and possible self-assembled nanostructures. The role of lung surfactant in drug delivery and drug dissolution has been briefly considered. Lung surfactant may form different liquid crystalline phases which can have an active role in drug delivery. The hypotheses developed in this review focuses on the potential roles of surface epithelial fluid containing liquid crystalline nanostructures in defining the dissolution mechanism and rate. The hypotheses also focus an understanding how liquid crystalline nanostructures can be used to control dissolution rate and how the nanostructures might be changed to influence delivery and induce toxicity. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Surfactant-Enhanced Desorption and Biodegradation of Polycyclic Aromatic Hydrocarbons in Contaminated Soil

    Science.gov (United States)

    Zhu, Hongbo; Aitken, Michael D.

    2010-01-01

    We evaluated two nonionic surfactants, one hydrophobic (Brij 30) and one hydrophilic (C12E8), for their ability to enhance the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil after it had been treated in an aerobic bioreactor. The effects of each surfactant were evaluated at doses corresponding to equilibrium aqueous-phase concentrations well above the surfactant’s critical micelle concentration (CMC), slightly above the CMC, and below the CMC. The concentrations of all 3- and 4-ring PAHs were significantly lower in the soil amended with Brij 30 at the two lower doses compared to controls, whereas removal of only the 3-ring PAHs was significantly enhanced at the highest Brij 30 dose. In contrast, C12E8 did not enhance PAH removal at any dose. In the absence of surfactant, surfactants on PAH biodegradation could be explained by their effects on PAH bioavailability. Overall, this study demonstrates that the properties of the surfactant and its dose relative to the corresponding aqueous-phase concentration are important factors in designing systems for surfactant-enhanced bioremediation of PAH-contaminated soils in which PAH bioavailability is limited. PMID:20586488

  13. Isolation of Surfactant-Resistant Bacteria from Natural, Surfactant-Rich Marine Habitats▿

    OpenAIRE

    Plante, Craig J.; Coe, Kieran M.; Plante, Rebecca G.

    2008-01-01

    Environmental remediation efforts often utilize either biodegradative microbes or surfactants, but not in combination. Coupling both strategies holds the potential to dramatically increase the rate and extent of remediation because surfactants can enhance the bioavailability of contaminants to microbes. However, many surfactants permeabilize bacterial cell membranes and are effective disinfectants. An important goal then is to find or genetically modify microorganisms that possess both desira...

  14. Pulmonary Surfactants for Acute and Chronic Lung Diseases (Part I

    Directory of Open Access Journals (Sweden)

    O. A. Rozenberg

    2014-01-01

    Full Text Available Part 1 of the review gives information on the composition and properties of a pulmonary surfactant and quantitative and qual itative impairments in the pulmonary surfactant system in different neonatal and adult abnormalities and describes the composition of commercial synthetic and natural surfactants. The results of surfactant therapy for respiratory distress syndrome and other lung diseases with secondary surfactant deficiency in the newborns are analyzed.

  15. LQ Optimal Sliding Mode Control of Periodic Review Perishable Inventories with Transportation Losses

    OpenAIRE

    Leśniewski, Piotr; Bartoszewicz, Andrzej

    2013-01-01

    In this work we apply the control-theoretic approach to design a new replenishment strategy for inventory systems with perishable stock. Such systems are supposed to effectively satisfy an unknown and permanently time-varying consumers’ demand. The main obstacle of achieving this goal is the need of obtaining supplies from a distant source. During the supply process goods are inevitably lost due to various causes. Furthermore, those goods which successfully arrive at the distribution center s...

  16. Psychobiology of cocaine addiction: Contribution of a multi-symptomatic animal model of loss of control.

    Science.gov (United States)

    Deroche-Gamonet, Véronique; Piazza, Pier Vincenzo

    2014-01-01

    Transition to addiction is the shift from controlled to uncontrolled drug use that occurs after prolonged drug intake in a limited number of drug users. A major challenge of addiction research in recent years has been to develop models for studying this pathological transition. Toward this goal, a DSM-IV/5-based multi-symptomatic model of cocaine addiction has been developed in the rat. It is based on an operational translation of the main features of the disease. 1. Addiction is not just taking drug; it is a non-adaptive drug use: The procedure models addiction in relation to its clinical definition. 2. All drug users do not face the same individual risk of developing addiction: The model includes an individual-based approach. 3. Addiction develops after protracted periods of controlled drug use: This procedure allows for the study of the long-term shift from controlled drug use to addiction. We describe this model in detail and show how it can contribute to our understanding of the pathophysiology of cocaine addiction. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'. Copyright © 2013. Published by Elsevier Ltd.

  17. LQ Optimal Sliding Mode Control of Periodic Review Perishable Inventories with Transportation Losses

    Directory of Open Access Journals (Sweden)

    Piotr Leśniewski

    2013-01-01

    Full Text Available In this work we apply the control-theoretic approach to design a new replenishment strategy for inventory systems with perishable stock. Such systems are supposed to effectively satisfy an unknown and permanently time-varying consumers’ demand. The main obstacle of achieving this goal is the need of obtaining supplies from a distant source. During the supply process goods are inevitably lost due to various causes. Furthermore, those goods which successfully arrive at the distribution center still deteriorate while stored in its warehouse. We explicitly take into account both of these factors in designing our control strategy. We propose a sliding mode strategy and choose its parameters to minimize a quadratic quality criterion. This approach allows us to ameliorate the bullwhip effect (the amplification of the demand variations when going up in the supply chain. The control strategy proposed in this work ensures bounded orders, guarantees full consumers’ demand satisfaction, and eliminates the risk of exceeding the warehouse capacity. These properties are stated in three theorems and proved in the paper.

  18. Emotion dysregulation across the spectrum of pathological eating: Comparisons among women with binge eating, overeating, and loss of control eating.

    Science.gov (United States)

    Racine, Sarah E; Horvath, Sarah A

    2018-01-01

    Emotion regulation difficulties influence the etiology and maintenance of binge eating and eating disorders, but differential associations between emotion dysregulation and objective binge eating (OBE) components have not been examined. We compared emotion dysregulation dimensions in women with OBEs (n = 27), overeating only (n = 25), loss of control (LOC) only (n = 32), or no pathological eating (n = 137). Women with OBEs had significantly more difficulty with overall emotion dysregulation, access to strategies, and impulse control when upset than other groups. Women with OBEs and women with overeating did not differ on poor emotional clarity, whereas women with OBEs and women with LOC did not differ on non-acceptance of emotions. The combination of overeating and LOC eating is associated with the greatest emotion dysregulation, but certain emotion regulation facets may differentially relate to overeating and LOC. Identifying emotion-related treatment targets for core eating disorder symptoms is important.

  19. BENCH-SCALE VISUALIZATION OF DNAPL REMEDIATION PROCESSES IN ANALOG HETEROGENEOUS AQUIFERS: SURFACTANT FLOODS, AND IN SITU OXIDATION USING PERMANGANATE

    Science.gov (United States)

    We have conducted well-controlled DNAPL remediation experiments using surfactants (Aerosol MA and Tween 80) to increase solubility and an oxidant (permanganate) to chemically degrade the DNAPL. Photographs and digital image analysis illustrate previously unobserved interactions b...

  20. Effects of medium-chain triglycerides on weight loss and body composition: a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Mumme, Karen; Stonehouse, Welma

    2015-02-01

    Medium-chain triglycerides (MCTs) may result in negative energy balance and weight loss through increased energy expenditure and lipid oxidation. However, results from human intervention studies investigating the weight reducing potential of MCTs, have been mixed. To conduct a systematic review and meta-analysis of randomized controlled trials comparing the effects of MCTs, specifically C8:0 and C10:0, to long-chain triglycerides (LCTs) on weight loss and body composition in adults. Changes in blood lipid levels were secondary outcomes. Randomized controlled trials >3 weeks' duration conducted in healthy adults were identified searching Web of Knowledge, Discover, PubMed, Scopus, New Zealand Science, and Cochrane CENTRAL until March 2014 with no language restriction. Identified trials were assessed for bias. Mean differences were pooled and analyzed using inverse variance models with fixed effects. Heterogeneity between studies was calculated using I(2) statistic. An I(2)>50% or Pweight (-0.51 kg [95% CI-0.80 to -0.23 kg]; Preductions in body weight and composition without adversely affecting lipid profiles. However, further research is required by independent research groups using large, well-designed studies to confirm the efficacy of MCT and to determine the dosage needed for the management of a healthy body weight and composition. Copyright © 2015 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  1. The Correlation of Surfactant Concentrations on the Properties of Mesoporous Bioactive Glass

    Directory of Open Access Journals (Sweden)

    Shao-Ju Shih

    2016-01-01

    Full Text Available Bioactive glass (BG, a potential biomaterial, has received increasing attention since the discovery of its superior bioactivity. One of the main research objectives is to improve the bioactive property of BGs; therefore, surfactant-derived mesoporous bioactive glasses (MBGs were developed to provide a high specific surface area for achieving higher bioactivity. In this study, various concentrations of typical triblock F127 surfactant were used to manipulate the morphology, specific surface area, and bioactivity of MBG particles. Two typical morphologies of smooth (Type I and wrinkled (Type II spheres were observed, and the population of Type II particles increased with an increase in the surfactant concentration. A direct correlation between specific surface area and bioactivity was observed by comparing the data obtained using the nitrogen adsorption-desorption method and in vitro bioactive tests. Furthermore, the optimal surfactant concentration corresponding to the highest bioactivity revealed that the surfactant aggregated to form Type II particles when the surface concentration was higher than the critical micelle concentration, and the h